diff options
Diffstat (limited to 'drivers/tty/hvc')
| -rw-r--r-- | drivers/tty/hvc/Makefile | 13 | ||||
| -rw-r--r-- | drivers/tty/hvc/hvc_beat.c | 134 | ||||
| -rw-r--r-- | drivers/tty/hvc/hvc_console.c | 914 | ||||
| -rw-r--r-- | drivers/tty/hvc/hvc_console.h | 119 | ||||
| -rw-r--r-- | drivers/tty/hvc/hvc_dcc.c | 133 | ||||
| -rw-r--r-- | drivers/tty/hvc/hvc_irq.c | 49 | ||||
| -rw-r--r-- | drivers/tty/hvc/hvc_iseries.c | 598 | ||||
| -rw-r--r-- | drivers/tty/hvc/hvc_iucv.c | 1337 | ||||
| -rw-r--r-- | drivers/tty/hvc/hvc_rtas.c | 133 | ||||
| -rw-r--r-- | drivers/tty/hvc/hvc_tile.c | 68 | ||||
| -rw-r--r-- | drivers/tty/hvc/hvc_udbg.c | 96 | ||||
| -rw-r--r-- | drivers/tty/hvc/hvc_vio.c | 173 | ||||
| -rw-r--r-- | drivers/tty/hvc/hvc_xen.c | 271 | ||||
| -rw-r--r-- | drivers/tty/hvc/hvcs.c | 1604 | ||||
| -rw-r--r-- | drivers/tty/hvc/hvsi.c | 1314 | ||||
| -rw-r--r-- | drivers/tty/hvc/virtio_console.c | 1838 |
16 files changed, 8794 insertions, 0 deletions
diff --git a/drivers/tty/hvc/Makefile b/drivers/tty/hvc/Makefile new file mode 100644 index 000000000000..e6bed5f177ff --- /dev/null +++ b/drivers/tty/hvc/Makefile @@ -0,0 +1,13 @@ +obj-$(CONFIG_HVC_CONSOLE) += hvc_vio.o hvsi.o +obj-$(CONFIG_HVC_ISERIES) += hvc_iseries.o +obj-$(CONFIG_HVC_RTAS) += hvc_rtas.o +obj-$(CONFIG_HVC_TILE) += hvc_tile.o +obj-$(CONFIG_HVC_DCC) += hvc_dcc.o +obj-$(CONFIG_HVC_BEAT) += hvc_beat.o +obj-$(CONFIG_HVC_DRIVER) += hvc_console.o +obj-$(CONFIG_HVC_IRQ) += hvc_irq.o +obj-$(CONFIG_HVC_XEN) += hvc_xen.o +obj-$(CONFIG_HVC_IUCV) += hvc_iucv.o +obj-$(CONFIG_HVC_UDBG) += hvc_udbg.o +obj-$(CONFIG_HVCS) += hvcs.o +obj-$(CONFIG_VIRTIO_CONSOLE) += virtio_console.o diff --git a/drivers/tty/hvc/hvc_beat.c b/drivers/tty/hvc/hvc_beat.c new file mode 100644 index 000000000000..5fe4631e2a61 --- /dev/null +++ b/drivers/tty/hvc/hvc_beat.c @@ -0,0 +1,134 @@ +/* + * Beat hypervisor console driver + * + * (C) Copyright 2006 TOSHIBA CORPORATION + * + * This code is based on drivers/char/hvc_rtas.c: + * (C) Copyright IBM Corporation 2001-2005 + * (C) Copyright Red Hat, Inc. 2005 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/err.h> +#include <linux/string.h> +#include <linux/console.h> +#include <asm/prom.h> +#include <asm/hvconsole.h> +#include <asm/firmware.h> + +#include "hvc_console.h" + +extern int64_t beat_get_term_char(uint64_t, uint64_t *, uint64_t *, uint64_t *); +extern int64_t beat_put_term_char(uint64_t, uint64_t, uint64_t, uint64_t); + +struct hvc_struct *hvc_beat_dev = NULL; + +/* bug: only one queue is available regardless of vtermno */ +static int hvc_beat_get_chars(uint32_t vtermno, char *buf, int cnt) +{ + static unsigned char q[sizeof(unsigned long) * 2] + __attribute__((aligned(sizeof(unsigned long)))); + static int qlen = 0; + u64 got; + +again: + if (qlen) { + if (qlen > cnt) { + memcpy(buf, q, cnt); + qlen -= cnt; + memmove(q + cnt, q, qlen); + return cnt; + } else { /* qlen <= cnt */ + int r; + + memcpy(buf, q, qlen); + r = qlen; + qlen = 0; + return r; + } + } + if (beat_get_term_char(vtermno, &got, + ((u64 *)q), ((u64 *)q) + 1) == 0) { + qlen = got; + goto again; + } + return 0; +} + +static int hvc_beat_put_chars(uint32_t vtermno, const char *buf, int cnt) +{ + unsigned long kb[2]; + int rest, nlen; + + for (rest = cnt; rest > 0; rest -= nlen) { + nlen = (rest > 16) ? 16 : rest; + memcpy(kb, buf, nlen); + beat_put_term_char(vtermno, nlen, kb[0], kb[1]); + buf += nlen; + } + return cnt; +} + +static const struct hv_ops hvc_beat_get_put_ops = { + .get_chars = hvc_beat_get_chars, + .put_chars = hvc_beat_put_chars, +}; + +static int hvc_beat_useit = 1; + +static int hvc_beat_config(char *p) +{ + hvc_beat_useit = simple_strtoul(p, NULL, 0); + return 0; +} + +static int __init hvc_beat_console_init(void) +{ + if (hvc_beat_useit && of_machine_is_compatible("Beat")) { + hvc_instantiate(0, 0, &hvc_beat_get_put_ops); + } + return 0; +} + +/* temp */ +static int __init hvc_beat_init(void) +{ + struct hvc_struct *hp; + + if (!firmware_has_feature(FW_FEATURE_BEAT)) + return -ENODEV; + + hp = hvc_alloc(0, NO_IRQ, &hvc_beat_get_put_ops, 16); + if (IS_ERR(hp)) + return PTR_ERR(hp); + hvc_beat_dev = hp; + return 0; +} + +static void __exit hvc_beat_exit(void) +{ + if (hvc_beat_dev) + hvc_remove(hvc_beat_dev); +} + +module_init(hvc_beat_init); +module_exit(hvc_beat_exit); + +__setup("hvc_beat=", hvc_beat_config); + +console_initcall(hvc_beat_console_init); diff --git a/drivers/tty/hvc/hvc_console.c b/drivers/tty/hvc/hvc_console.c new file mode 100644 index 000000000000..e9cba13ee800 --- /dev/null +++ b/drivers/tty/hvc/hvc_console.c @@ -0,0 +1,914 @@ +/* + * Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM + * Copyright (C) 2001 Paul Mackerras <paulus@au.ibm.com>, IBM + * Copyright (C) 2004 Benjamin Herrenschmidt <benh@kernel.crashing.org>, IBM Corp. + * Copyright (C) 2004 IBM Corporation + * + * Additional Author(s): + * Ryan S. Arnold <rsa@us.ibm.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include <linux/console.h> +#include <linux/cpumask.h> +#include <linux/init.h> +#include <linux/kbd_kern.h> +#include <linux/kernel.h> +#include <linux/kthread.h> +#include <linux/list.h> +#include <linux/module.h> +#include <linux/major.h> +#include <linux/sysrq.h> +#include <linux/tty.h> +#include <linux/tty_flip.h> +#include <linux/sched.h> +#include <linux/spinlock.h> +#include <linux/delay.h> +#include <linux/freezer.h> +#include <linux/slab.h> + +#include <asm/uaccess.h> + +#include "hvc_console.h" + +#define HVC_MAJOR 229 +#define HVC_MINOR 0 + +/* + * Wait this long per iteration while trying to push buffered data to the + * hypervisor before allowing the tty to complete a close operation. + */ +#define HVC_CLOSE_WAIT (HZ/100) /* 1/10 of a second */ + +/* + * These sizes are most efficient for vio, because they are the + * native transfer size. We could make them selectable in the + * future to better deal with backends that want other buffer sizes. + */ +#define N_OUTBUF 16 +#define N_INBUF 16 + +#define __ALIGNED__ __attribute__((__aligned__(sizeof(long)))) + +static struct tty_driver *hvc_driver; +static struct task_struct *hvc_task; + +/* Picks up late kicks after list walk but before schedule() */ +static int hvc_kicked; + +static int hvc_init(void); + +#ifdef CONFIG_MAGIC_SYSRQ +static int sysrq_pressed; +#endif + +/* dynamic list of hvc_struct instances */ +static LIST_HEAD(hvc_structs); + +/* + * Protect the list of hvc_struct instances from inserts and removals during + * list traversal. + */ +static DEFINE_SPINLOCK(hvc_structs_lock); + +/* + * This value is used to assign a tty->index value to a hvc_struct based + * upon order of exposure via hvc_probe(), when we can not match it to + * a console candidate registered with hvc_instantiate(). + */ +static int last_hvc = -1; + +/* + * Do not call this function with either the hvc_structs_lock or the hvc_struct + * lock held. If successful, this function increments the kref reference + * count against the target hvc_struct so it should be released when finished. + */ +static struct hvc_struct *hvc_get_by_index(int index) +{ + struct hvc_struct *hp; + unsigned long flags; + + spin_lock(&hvc_structs_lock); + + list_for_each_entry(hp, &hvc_structs, next) { + spin_lock_irqsave(&hp->lock, flags); + if (hp->index == index) { + kref_get(&hp->kref); + spin_unlock_irqrestore(&hp->lock, flags); + spin_unlock(&hvc_structs_lock); + return hp; + } + spin_unlock_irqrestore(&hp->lock, flags); + } + hp = NULL; + + spin_unlock(&hvc_structs_lock); + return hp; +} + + +/* + * Initial console vtermnos for console API usage prior to full console + * initialization. Any vty adapter outside this range will not have usable + * console interfaces but can still be used as a tty device. This has to be + * static because kmalloc will not work during early console init. + */ +static const struct hv_ops *cons_ops[MAX_NR_HVC_CONSOLES]; +static uint32_t vtermnos[MAX_NR_HVC_CONSOLES] = + {[0 ... MAX_NR_HVC_CONSOLES - 1] = -1}; + +/* + * Console APIs, NOT TTY. These APIs are available immediately when + * hvc_console_setup() finds adapters. + */ + +static void hvc_console_print(struct console *co, const char *b, + unsigned count) +{ + char c[N_OUTBUF] __ALIGNED__; + unsigned i = 0, n = 0; + int r, donecr = 0, index = co->index; + + /* Console access attempt outside of acceptable console range. */ + if (index >= MAX_NR_HVC_CONSOLES) + return; + + /* This console adapter was removed so it is not usable. */ + if (vtermnos[index] == -1) + return; + + while (count > 0 || i > 0) { + if (count > 0 && i < sizeof(c)) { + if (b[n] == '\n' && !donecr) { + c[i++] = '\r'; + donecr = 1; + } else { + c[i++] = b[n++]; + donecr = 0; + --count; + } + } else { + r = cons_ops[index]->put_chars(vtermnos[index], c, i); + if (r <= 0) { + /* throw away chars on error */ + i = 0; + } else if (r > 0) { + i -= r; + if (i > 0) + memmove(c, c+r, i); + } + } + } +} + +static struct tty_driver *hvc_console_device(struct console *c, int *index) +{ + if (vtermnos[c->index] == -1) + return NULL; + + *index = c->index; + return hvc_driver; +} + +static int __init hvc_console_setup(struct console *co, char *options) +{ + if (co->index < 0 || co->index >= MAX_NR_HVC_CONSOLES) + return -ENODEV; + + if (vtermnos[co->index] == -1) + return -ENODEV; + + return 0; +} + +static struct console hvc_console = { + .name = "hvc", + .write = hvc_console_print, + .device = hvc_console_device, + .setup = hvc_console_setup, + .flags = CON_PRINTBUFFER, + .index = -1, +}; + +/* + * Early console initialization. Precedes driver initialization. + * + * (1) we are first, and the user specified another driver + * -- index will remain -1 + * (2) we are first and the user specified no driver + * -- index will be set to 0, then we will fail setup. + * (3) we are first and the user specified our driver + * -- index will be set to user specified driver, and we will fail + * (4) we are after driver, and this initcall will register us + * -- if the user didn't specify a driver then the console will match + * + * Note that for cases 2 and 3, we will match later when the io driver + * calls hvc_instantiate() and call register again. + */ +static int __init hvc_console_init(void) +{ + register_console(&hvc_console); + return 0; +} +console_initcall(hvc_console_init); + +/* callback when the kboject ref count reaches zero. */ +static void destroy_hvc_struct(struct kref *kref) +{ + struct hvc_struct *hp = container_of(kref, struct hvc_struct, kref); + unsigned long flags; + + spin_lock(&hvc_structs_lock); + + spin_lock_irqsave(&hp->lock, flags); + list_del(&(hp->next)); + spin_unlock_irqrestore(&hp->lock, flags); + + spin_unlock(&hvc_structs_lock); + + kfree(hp); +} + +/* + * hvc_instantiate() is an early console discovery method which locates + * consoles * prior to the vio subsystem discovering them. Hotplugged + * vty adapters do NOT get an hvc_instantiate() callback since they + * appear after early console init. + */ +int hvc_instantiate(uint32_t vtermno, int index, const struct hv_ops *ops) +{ + struct hvc_struct *hp; + + if (index < 0 || index >= MAX_NR_HVC_CONSOLES) + return -1; + + if (vtermnos[index] != -1) + return -1; + + /* make sure no no tty has been registered in this index */ + hp = hvc_get_by_index(index); + if (hp) { + kref_put(&hp->kref, destroy_hvc_struct); + return -1; + } + + vtermnos[index] = vtermno; + cons_ops[index] = ops; + + /* reserve all indices up to and including this index */ + if (last_hvc < index) + last_hvc = index; + + /* if this index is what the user requested, then register + * now (setup won't fail at this point). It's ok to just + * call register again if previously .setup failed. + */ + if (index == hvc_console.index) + register_console(&hvc_console); + + return 0; +} +EXPORT_SYMBOL_GPL(hvc_instantiate); + +/* Wake the sleeping khvcd */ +void hvc_kick(void) +{ + hvc_kicked = 1; + wake_up_process(hvc_task); +} +EXPORT_SYMBOL_GPL(hvc_kick); + +static void hvc_unthrottle(struct tty_struct *tty) +{ + hvc_kick(); +} + +/* + * The TTY interface won't be used until after the vio layer has exposed the vty + * adapter to the kernel. + */ +static int hvc_open(struct tty_struct *tty, struct file * filp) +{ + struct hvc_struct *hp; + unsigned long flags; + int rc = 0; + + /* Auto increments kref reference if found. */ + if (!(hp = hvc_get_by_index(tty->index))) + return -ENODEV; + + spin_lock_irqsave(&hp->lock, flags); + /* Check and then increment for fast path open. */ + if (hp->count++ > 0) { + tty_kref_get(tty); + spin_unlock_irqrestore(&hp->lock, flags); + hvc_kick(); + return 0; + } /* else count == 0 */ + + tty->driver_data = hp; + + hp->tty = tty_kref_get(tty); + + spin_unlock_irqrestore(&hp->lock, flags); + + if (hp->ops->notifier_add) + rc = hp->ops->notifier_add(hp, hp->data); + + /* + * If the notifier fails we return an error. The tty layer + * will call hvc_close() after a failed open but we don't want to clean + * up there so we'll clean up here and clear out the previously set + * tty fields and return the kref reference. + */ + if (rc) { + spin_lock_irqsave(&hp->lock, flags); + hp->tty = NULL; + spin_unlock_irqrestore(&hp->lock, flags); + tty_kref_put(tty); + tty->driver_data = NULL; + kref_put(&hp->kref, destroy_hvc_struct); + printk(KERN_ERR "hvc_open: request_irq failed with rc %d.\n", rc); + } + /* Force wakeup of the polling thread */ + hvc_kick(); + + return rc; +} + +static void hvc_close(struct tty_struct *tty, struct file * filp) +{ + struct hvc_struct *hp; + unsigned long flags; + + if (tty_hung_up_p(filp)) + return; + + /* + * No driver_data means that this close was issued after a failed + * hvc_open by the tty layer's release_dev() function and we can just + * exit cleanly because the kref reference wasn't made. + */ + if (!tty->driver_data) + return; + + hp = tty->driver_data; + + spin_lock_irqsave(&hp->lock, flags); + + if (--hp->count == 0) { + /* We are done with the tty pointer now. */ + hp->tty = NULL; + spin_unlock_irqrestore(&hp->lock, flags); + + if (hp->ops->notifier_del) + hp->ops->notifier_del(hp, hp->data); + + /* cancel pending tty resize work */ + cancel_work_sync(&hp->tty_resize); + + /* + * Chain calls chars_in_buffer() and returns immediately if + * there is no buffered data otherwise sleeps on a wait queue + * waking periodically to check chars_in_buffer(). + */ + tty_wait_until_sent(tty, HVC_CLOSE_WAIT); + } else { + if (hp->count < 0) + printk(KERN_ERR "hvc_close %X: oops, count is %d\n", + hp->vtermno, hp->count); + spin_unlock_irqrestore(&hp->lock, flags); + } + + tty_kref_put(tty); + kref_put(&hp->kref, destroy_hvc_struct); +} + +static void hvc_hangup(struct tty_struct *tty) +{ + struct hvc_struct *hp = tty->driver_data; + unsigned long flags; + int temp_open_count; + + if (!hp) + return; + + /* cancel pending tty resize work */ + cancel_work_sync(&hp->tty_resize); + + spin_lock_irqsave(&hp->lock, flags); + + /* + * The N_TTY line discipline has problems such that in a close vs + * open->hangup case this can be called after the final close so prevent + * that from happening for now. + */ + if (hp->count <= 0) { + spin_unlock_irqrestore(&hp->lock, flags); + return; + } + + temp_open_count = hp->count; + hp->count = 0; + hp->n_outbuf = 0; + hp->tty = NULL; + + spin_unlock_irqrestore(&hp->lock, flags); + + if (hp->ops->notifier_hangup) + hp->ops->notifier_hangup(hp, hp->data); + + while(temp_open_count) { + --temp_open_count; + tty_kref_put(tty); + kref_put(&hp->kref, destroy_hvc_struct); + } +} + +/* + * Push buffered characters whether they were just recently buffered or waiting + * on a blocked hypervisor. Call this function with hp->lock held. + */ +static int hvc_push(struct hvc_struct *hp) +{ + int n; + + n = hp->ops->put_chars(hp->vtermno, hp->outbuf, hp->n_outbuf); + if (n <= 0) { + if (n == 0) { + hp->do_wakeup = 1; + return 0; + } + /* throw away output on error; this happens when + there is no session connected to the vterm. */ + hp->n_outbuf = 0; + } else + hp->n_outbuf -= n; + if (hp->n_outbuf > 0) + memmove(hp->outbuf, hp->outbuf + n, hp->n_outbuf); + else + hp->do_wakeup = 1; + + return n; +} + +static int hvc_write(struct tty_struct *tty, const unsigned char *buf, int count) +{ + struct hvc_struct *hp = tty->driver_data; + unsigned long flags; + int rsize, written = 0; + + /* This write was probably executed during a tty close. */ + if (!hp) + return -EPIPE; + + if (hp->count <= 0) + return -EIO; + + spin_lock_irqsave(&hp->lock, flags); + + /* Push pending writes */ + if (hp->n_outbuf > 0) + hvc_push(hp); + + while (count > 0 && (rsize = hp->outbuf_size - hp->n_outbuf) > 0) { + if (rsize > count) + rsize = count; + memcpy(hp->outbuf + hp->n_outbuf, buf, rsize); + count -= rsize; + buf += rsize; + hp->n_outbuf += rsize; + written += rsize; + hvc_push(hp); + } + spin_unlock_irqrestore(&hp->lock, flags); + + /* + * Racy, but harmless, kick thread if there is still pending data. + */ + if (hp->n_outbuf) + hvc_kick(); + + return written; +} + +/** + * hvc_set_winsz() - Resize the hvc tty terminal window. + * @work: work structure. + * + * The routine shall not be called within an atomic context because it + * might sleep. + * + * Locking: hp->lock + */ +static void hvc_set_winsz(struct work_struct *work) +{ + struct hvc_struct *hp; + unsigned long hvc_flags; + struct tty_struct *tty; + struct winsize ws; + + hp = container_of(work, struct hvc_struct, tty_resize); + + spin_lock_irqsave(&hp->lock, hvc_flags); + if (!hp->tty) { + spin_unlock_irqrestore(&hp->lock, hvc_flags); + return; + } + ws = hp->ws; + tty = tty_kref_get(hp->tty); + spin_unlock_irqrestore(&hp->lock, hvc_flags); + + tty_do_resize(tty, &ws); + tty_kref_put(tty); +} + +/* + * This is actually a contract between the driver and the tty layer outlining + * how much write room the driver can guarantee will be sent OR BUFFERED. This + * driver MUST honor the return value. + */ +static int hvc_write_room(struct tty_struct *tty) +{ + struct hvc_struct *hp = tty->driver_data; + + if (!hp) + return -1; + + return hp->outbuf_size - hp->n_outbuf; +} + +static int hvc_chars_in_buffer(struct tty_struct *tty) +{ + struct hvc_struct *hp = tty->driver_data; + + if (!hp) + return 0; + return hp->n_outbuf; +} + +/* + * timeout will vary between the MIN and MAX values defined here. By default + * and during console activity we will use a default MIN_TIMEOUT of 10. When + * the console is idle, we increase the timeout value on each pass through + * msleep until we reach the max. This may be noticeable as a brief (average + * one second) delay on the console before the console responds to input when + * there has been no input for some time. + */ +#define MIN_TIMEOUT (10) +#define MAX_TIMEOUT (2000) +static u32 timeout = MIN_TIMEOUT; + +#define HVC_POLL_READ 0x00000001 +#define HVC_POLL_WRITE 0x00000002 + +int hvc_poll(struct hvc_struct *hp) +{ + struct tty_struct *tty; + int i, n, poll_mask = 0; + char buf[N_INBUF] __ALIGNED__; + unsigned long flags; + int read_total = 0; + int written_total = 0; + + spin_lock_irqsave(&hp->lock, flags); + + /* Push pending writes */ + if (hp->n_outbuf > 0) + written_total = hvc_push(hp); + + /* Reschedule us if still some write pending */ + if (hp->n_outbuf > 0) { + poll_mask |= HVC_POLL_WRITE; + /* If hvc_push() was not able to write, sleep a few msecs */ + timeout = (written_total) ? 0 : MIN_TIMEOUT; + } + + /* No tty attached, just skip */ + tty = tty_kref_get(hp->tty); + if (tty == NULL) + goto bail; + + /* Now check if we can get data (are we throttled ?) */ + if (test_bit(TTY_THROTTLED, &tty->flags)) + goto throttled; + + /* If we aren't notifier driven and aren't throttled, we always + * request a reschedule + */ + if (!hp->irq_requested) + poll_mask |= HVC_POLL_READ; + + /* Read data if any */ + for (;;) { + int count = tty_buffer_request_room(tty, N_INBUF); + + /* If flip is full, just reschedule a later read */ + if (count == 0) { + poll_mask |= HVC_POLL_READ; + break; + } + + n = hp->ops->get_chars(hp->vtermno, buf, count); + if (n <= 0) { + /* Hangup the tty when disconnected from host */ + if (n == -EPIPE) { + spin_unlock_irqrestore(&hp->lock, flags); + tty_hangup(tty); + spin_lock_irqsave(&hp->lock, flags); + } else if ( n == -EAGAIN ) { + /* + * Some back-ends can only ensure a certain min + * num of bytes read, which may be > 'count'. + * Let the tty clear the flip buff to make room. + */ + poll_mask |= HVC_POLL_READ; + } + break; + } + for (i = 0; i < n; ++i) { +#ifdef CONFIG_MAGIC_SYSRQ + if (hp->index == hvc_console.index) { + /* Handle the SysRq Hack */ + /* XXX should support a sequence */ + if (buf[i] == '\x0f') { /* ^O */ + /* if ^O is pressed again, reset + * sysrq_pressed and flip ^O char */ + sysrq_pressed = !sysrq_pressed; + if (sysrq_pressed) + continue; + } else if (sysrq_pressed) { + handle_sysrq(buf[i]); + sysrq_pressed = 0; + continue; + } + } +#endif /* CONFIG_MAGIC_SYSRQ */ + tty_insert_flip_char(tty, buf[i], 0); + } + + read_total += n; + } + throttled: + /* Wakeup write queue if necessary */ + if (hp->do_wakeup) { + hp->do_wakeup = 0; + tty_wakeup(tty); + } + bail: + spin_unlock_irqrestore(&hp->lock, flags); + + if (read_total) { + /* Activity is occurring, so reset the polling backoff value to + a minimum for performance. */ + timeout = MIN_TIMEOUT; + + tty_flip_buffer_push(tty); + } + if (tty) + tty_kref_put(tty); + + return poll_mask; +} +EXPORT_SYMBOL_GPL(hvc_poll); + +/** + * __hvc_resize() - Update terminal window size information. + * @hp: HVC console pointer + * @ws: Terminal window size structure + * + * Stores the specified window size information in the hvc structure of @hp. + * The function schedule the tty resize update. + * + * Locking: Locking free; the function MUST be called holding hp->lock + */ +void __hvc_resize(struct hvc_struct *hp, struct winsize ws) +{ + hp->ws = ws; + schedule_work(&hp->tty_resize); +} +EXPORT_SYMBOL_GPL(__hvc_resize); + +/* + * This kthread is either polling or interrupt driven. This is determined by + * calling hvc_poll() who determines whether a console adapter support + * interrupts. + */ +static int khvcd(void *unused) +{ + int poll_mask; + struct hvc_struct *hp; + + set_freezable(); + do { + poll_mask = 0; + hvc_kicked = 0; + try_to_freeze(); + wmb(); + if (!cpus_are_in_xmon()) { + spin_lock(&hvc_structs_lock); + list_for_each_entry(hp, &hvc_structs, next) { + poll_mask |= hvc_poll(hp); + } + spin_unlock(&hvc_structs_lock); + } else + poll_mask |= HVC_POLL_READ; + if (hvc_kicked) + continue; + set_current_state(TASK_INTERRUPTIBLE); + if (!hvc_kicked) { + if (poll_mask == 0) + schedule(); + else { + if (timeout < MAX_TIMEOUT) + timeout += (timeout >> 6) + 1; + + msleep_interruptible(timeout); + } + } + __set_current_state(TASK_RUNNING); + } while (!kthread_should_stop()); + + return 0; +} + +static const struct tty_operations hvc_ops = { + .open = hvc_open, + .close = hvc_close, + .write = hvc_write, + .hangup = hvc_hangup, + .unthrottle = hvc_unthrottle, + .write_room = hvc_write_room, + .chars_in_buffer = hvc_chars_in_buffer, +}; + +struct hvc_struct *hvc_alloc(uint32_t vtermno, int data, + const struct hv_ops *ops, + int outbuf_size) +{ + struct hvc_struct *hp; + int i; + + /* We wait until a driver actually comes along */ + if (!hvc_driver) { + int err = hvc_init(); + if (err) + return ERR_PTR(err); + } + + hp = kzalloc(ALIGN(sizeof(*hp), sizeof(long)) + outbuf_size, + GFP_KERNEL); + if (!hp) + return ERR_PTR(-ENOMEM); + + hp->vtermno = vtermno; + hp->data = data; + hp->ops = ops; + hp->outbuf_size = outbuf_size; + hp->outbuf = &((char *)hp)[ALIGN(sizeof(*hp), sizeof(long))]; + + kref_init(&hp->kref); + + INIT_WORK(&hp->tty_resize, hvc_set_winsz); + spin_lock_init(&hp->lock); + spin_lock(&hvc_structs_lock); + + /* + * find index to use: + * see if this vterm id matches one registered for console. + */ + for (i=0; i < MAX_NR_HVC_CONSOLES; i++) + if (vtermnos[i] == hp->vtermno && + cons_ops[i] == hp->ops) + break; + + /* no matching slot, just use a counter */ + if (i >= MAX_NR_HVC_CONSOLES) + i = ++last_hvc; + + hp->index = i; + + list_add_tail(&(hp->next), &hvc_structs); + spin_unlock(&hvc_structs_lock); + + return hp; +} +EXPORT_SYMBOL_GPL(hvc_alloc); + +int hvc_remove(struct hvc_struct *hp) +{ + unsigned long flags; + struct tty_struct *tty; + + spin_lock_irqsave(&hp->lock, flags); + tty = tty_kref_get(hp->tty); + + if (hp->index < MAX_NR_HVC_CONSOLES) + vtermnos[hp->index] = -1; + + /* Don't whack hp->irq because tty_hangup() will need to free the irq. */ + + spin_unlock_irqrestore(&hp->lock, flags); + + /* + * We 'put' the instance that was grabbed when the kref instance + * was initialized using kref_init(). Let the last holder of this + * kref cause it to be removed, which will probably be the tty_vhangup + * below. + */ + kref_put(&hp->kref, destroy_hvc_struct); + + /* + * This function call will auto chain call hvc_hangup. + */ + if (tty) { + tty_vhangup(tty); + tty_kref_put(tty); + } + return 0; +} +EXPORT_SYMBOL_GPL(hvc_remove); + +/* Driver initialization: called as soon as someone uses hvc_alloc(). */ +static int hvc_init(void) +{ + struct tty_driver *drv; + int err; + + /* We need more than hvc_count adapters due to hotplug additions. */ + drv = alloc_tty_driver(HVC_ALLOC_TTY_ADAPTERS); + if (!drv) { + err = -ENOMEM; + goto out; + } + + drv->owner = THIS_MODULE; + drv->driver_name = "hvc"; + drv->name = "hvc"; + drv->major = HVC_MAJOR; + drv->minor_start = HVC_MINOR; + drv->type = TTY_DRIVER_TYPE_SYSTEM; + drv->init_termios = tty_std_termios; + drv->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_RESET_TERMIOS; + tty_set_operations(drv, &hvc_ops); + + /* Always start the kthread because there can be hotplug vty adapters + * added later. */ + hvc_task = kthread_run(khvcd, NULL, "khvcd"); + if (IS_ERR(hvc_task)) { + printk(KERN_ERR "Couldn't create kthread for console.\n"); + err = PTR_ERR(hvc_task); + goto put_tty; + } + + err = tty_register_driver(drv); + if (err) { + printk(KERN_ERR "Couldn't register hvc console driver\n"); + goto stop_thread; + } + + /* + * Make sure tty is fully registered before allowing it to be + * found by hvc_console_device. + */ + smp_mb(); + hvc_driver = drv; + return 0; + +stop_thread: + kthread_stop(hvc_task); + hvc_task = NULL; +put_tty: + put_tty_driver(drv); +out: + return err; +} + +/* This isn't particularly necessary due to this being a console driver + * but it is nice to be thorough. + */ +static void __exit hvc_exit(void) +{ + if (hvc_driver) { + kthread_stop(hvc_task); + + tty_unregister_driver(hvc_driver); + /* return tty_struct instances allocated in hvc_init(). */ + put_tty_driver(hvc_driver); + unregister_console(&hvc_console); + } +} +module_exit(hvc_exit); diff --git a/drivers/tty/hvc/hvc_console.h b/drivers/tty/hvc/hvc_console.h new file mode 100644 index 000000000000..54381eba4e4a --- /dev/null +++ b/drivers/tty/hvc/hvc_console.h @@ -0,0 +1,119 @@ +/* + * hvc_console.h + * Copyright (C) 2005 IBM Corporation + * + * Author(s): + * Ryan S. Arnold <rsa@us.ibm.com> + * + * hvc_console header information: + * moved here from arch/powerpc/include/asm/hvconsole.h + * and drivers/char/hvc_console.c + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#ifndef HVC_CONSOLE_H +#define HVC_CONSOLE_H +#include <linux/kref.h> +#include <linux/tty.h> +#include <linux/spinlock.h> + +/* + * This is the max number of console adapters that can/will be found as + * console devices on first stage console init. Any number beyond this range + * can't be used as a console device but is still a valid tty device. + */ +#define MAX_NR_HVC_CONSOLES 16 + +/* + * The Linux TTY code does not support dynamic addition of tty derived devices + * so we need to know how many tty devices we might need when space is allocated + * for the tty device. Since this driver supports hotplug of vty adapters we + * need to make sure we have enough allocated. + */ +#define HVC_ALLOC_TTY_ADAPTERS 8 + +struct hvc_struct { + spinlock_t lock; + int index; + struct tty_struct *tty; + int count; + int do_wakeup; + char *outbuf; + int outbuf_size; + int n_outbuf; + uint32_t vtermno; + const struct hv_ops *ops; + int irq_requested; + int data; + struct winsize ws; + struct work_struct tty_resize; + struct list_head next; + struct kref kref; /* ref count & hvc_struct lifetime */ +}; + +/* implemented by a low level driver */ +struct hv_ops { + int (*get_chars)(uint32_t vtermno, char *buf, int count); + int (*put_chars)(uint32_t vtermno, const char *buf, int count); + + /* Callbacks for notification. Called in open, close and hangup */ + int (*notifier_add)(struct hvc_struct *hp, int irq); + void (*notifier_del)(struct hvc_struct *hp, int irq); + void (*notifier_hangup)(struct hvc_struct *hp, int irq); +}; + +/* Register a vterm and a slot index for use as a console (console_init) */ +extern int hvc_instantiate(uint32_t vtermno, int index, + const struct hv_ops *ops); + +/* register a vterm for hvc tty operation (module_init or hotplug add) */ +extern struct hvc_struct * hvc_alloc(uint32_t vtermno, int data, + const struct hv_ops *ops, int outbuf_size); +/* remove a vterm from hvc tty operation (module_exit or hotplug remove) */ +extern int hvc_remove(struct hvc_struct *hp); + +/* data available */ +int hvc_poll(struct hvc_struct *hp); +void hvc_kick(void); + +/* Resize hvc tty terminal window */ +extern void __hvc_resize(struct hvc_struct *hp, struct winsize ws); + +static inline void hvc_resize(struct hvc_struct *hp, struct winsize ws) +{ + unsigned long flags; + + spin_lock_irqsave(&hp->lock, flags); + __hvc_resize(hp, ws); + spin_unlock_irqrestore(&hp->lock, flags); +} + +/* default notifier for irq based notification */ +extern int notifier_add_irq(struct hvc_struct *hp, int data); +extern void notifier_del_irq(struct hvc_struct *hp, int data); +extern void notifier_hangup_irq(struct hvc_struct *hp, int data); + + +#if defined(CONFIG_XMON) && defined(CONFIG_SMP) +#include <asm/xmon.h> +#else +static inline int cpus_are_in_xmon(void) +{ + return 0; +} +#endif + +#endif // HVC_CONSOLE_H diff --git a/drivers/tty/hvc/hvc_dcc.c b/drivers/tty/hvc/hvc_dcc.c new file mode 100644 index 000000000000..6470f63deb4b --- /dev/null +++ b/drivers/tty/hvc/hvc_dcc.c @@ -0,0 +1,133 @@ +/* Copyright (c) 2010, Code Aurora Forum. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 and + * only version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA. + */ + +#include <linux/console.h> +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/moduleparam.h> +#include <linux/types.h> + +#include <asm/processor.h> + +#include "hvc_console.h" + +/* DCC Status Bits */ +#define DCC_STATUS_RX (1 << 30) +#define DCC_STATUS_TX (1 << 29) + +static inline u32 __dcc_getstatus(void) +{ + u32 __ret; + + asm("mrc p14, 0, %0, c0, c1, 0 @ read comms ctrl reg" + : "=r" (__ret) : : "cc"); + + return __ret; +} + + +#if defined(CONFIG_CPU_V7) +static inline char __dcc_getchar(void) +{ + char __c; + + asm("get_wait: mrc p14, 0, pc, c0, c1, 0 \n\ + bne get_wait \n\ + mrc p14, 0, %0, c0, c5, 0 @ read comms data reg" + : "=r" (__c) : : "cc"); + + return __c; +} +#else +static inline char __dcc_getchar(void) +{ + char __c; + + asm("mrc p14, 0, %0, c0, c5, 0 @ read comms data reg" + : "=r" (__c)); + + return __c; +} +#endif + +#if defined(CONFIG_CPU_V7) +static inline void __dcc_putchar(char c) +{ + asm("put_wait: mrc p14, 0, pc, c0, c1, 0 \n\ + bcs put_wait \n\ + mcr p14, 0, %0, c0, c5, 0 " + : : "r" (c) : "cc"); +} +#else +static inline void __dcc_putchar(char c) +{ + asm("mcr p14, 0, %0, c0, c5, 0 @ write a char" + : /* no output register */ + : "r" (c)); +} +#endif + +static int hvc_dcc_put_chars(uint32_t vt, const char *buf, int count) +{ + int i; + + for (i = 0; i < count; i++) { + while (__dcc_getstatus() & DCC_STATUS_TX) + cpu_relax(); + + __dcc_putchar((char)(buf[i] & 0xFF)); + } + + return count; +} + +static int hvc_dcc_get_chars(uint32_t vt, char *buf, int count) +{ + int i; + + for (i = 0; i < count; ++i) { + int c = -1; + + if (__dcc_getstatus() & DCC_STATUS_RX) + c = __dcc_getchar(); + if (c < 0) + break; + buf[i] = c; + } + + return i; +} + +static const struct hv_ops hvc_dcc_get_put_ops = { + .get_chars = hvc_dcc_get_chars, + .put_chars = hvc_dcc_put_chars, +}; + +static int __init hvc_dcc_console_init(void) +{ + hvc_instantiate(0, 0, &hvc_dcc_get_put_ops); + return 0; +} +console_initcall(hvc_dcc_console_init); + +static int __init hvc_dcc_init(void) +{ + hvc_alloc(0, 0, &hvc_dcc_get_put_ops, 128); + return 0; +} +device_initcall(hvc_dcc_init); diff --git a/drivers/tty/hvc/hvc_irq.c b/drivers/tty/hvc/hvc_irq.c new file mode 100644 index 000000000000..2623e177e8d6 --- /dev/null +++ b/drivers/tty/hvc/hvc_irq.c @@ -0,0 +1,49 @@ +/* + * Copyright IBM Corp. 2001,2008 + * + * This file contains the IRQ specific code for hvc_console + * + */ + +#include <linux/interrupt.h> + +#include "hvc_console.h" + +static irqreturn_t hvc_handle_interrupt(int irq, void *dev_instance) +{ + /* if hvc_poll request a repoll, then kick the hvcd thread */ + if (hvc_poll(dev_instance)) + hvc_kick(); + return IRQ_HANDLED; +} + +/* + * For IRQ based systems these callbacks can be used + */ +int notifier_add_irq(struct hvc_struct *hp, int irq) +{ + int rc; + + if (!irq) { + hp->irq_requested = 0; + return 0; + } + rc = request_irq(irq, hvc_handle_interrupt, IRQF_DISABLED, + "hvc_console", hp); + if (!rc) + hp->irq_requested = 1; + return rc; +} + +void notifier_del_irq(struct hvc_struct *hp, int irq) +{ + if (!hp->irq_requested) + return; + free_irq(irq, hp); + hp->irq_requested = 0; +} + +void notifier_hangup_irq(struct hvc_struct *hp, int irq) +{ + notifier_del_irq(hp, irq); +} diff --git a/drivers/tty/hvc/hvc_iseries.c b/drivers/tty/hvc/hvc_iseries.c new file mode 100644 index 000000000000..21c54955084e --- /dev/null +++ b/drivers/tty/hvc/hvc_iseries.c @@ -0,0 +1,598 @@ +/* + * iSeries vio driver interface to hvc_console.c + * + * This code is based heavily on hvc_vio.c and viocons.c + * + * Copyright (C) 2006 Stephen Rothwell, IBM Corporation + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ +#include <stdarg.h> +#include <linux/types.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/spinlock.h> +#include <linux/console.h> + +#include <asm/hvconsole.h> +#include <asm/vio.h> +#include <asm/prom.h> +#include <asm/firmware.h> +#include <asm/iseries/vio.h> +#include <asm/iseries/hv_call.h> +#include <asm/iseries/hv_lp_config.h> +#include <asm/iseries/hv_lp_event.h> + +#include "hvc_console.h" + +#define VTTY_PORTS 10 + +static DEFINE_SPINLOCK(consolelock); +static DEFINE_SPINLOCK(consoleloglock); + +static const char hvc_driver_name[] = "hvc_console"; + +#define IN_BUF_SIZE 200 + +/* + * Our port information. + */ +static struct port_info { + HvLpIndex lp; + u64 seq; /* sequence number of last HV send */ + u64 ack; /* last ack from HV */ + struct hvc_struct *hp; + int in_start; + int in_end; + unsigned char in_buf[IN_BUF_SIZE]; +} port_info[VTTY_PORTS] = { + [ 0 ... VTTY_PORTS - 1 ] = { + .lp = HvLpIndexInvalid + } +}; + +#define viochar_is_console(pi) ((pi) == &port_info[0]) + +static struct vio_device_id hvc_driver_table[] __devinitdata = { + {"serial", "IBM,iSeries-vty"}, + { "", "" } +}; +MODULE_DEVICE_TABLE(vio, hvc_driver_table); + +static void hvlog(char *fmt, ...) +{ + int i; + unsigned long flags; + va_list args; + static char buf[256]; + + spin_lock_irqsave(&consoleloglock, flags); + va_start(args, fmt); + i = vscnprintf(buf, sizeof(buf) - 1, fmt, args); + va_end(args); + buf[i++] = '\r'; + HvCall_writeLogBuffer(buf, i); + spin_unlock_irqrestore(&consoleloglock, flags); +} + +/* + * Initialize the common fields in a charLpEvent + */ +static void init_data_event(struct viocharlpevent *viochar, HvLpIndex lp) +{ + struct HvLpEvent *hev = &viochar->event; + + memset(viochar, 0, sizeof(struct viocharlpevent)); + + hev->flags = HV_LP_EVENT_VALID | HV_LP_EVENT_DEFERRED_ACK | + HV_LP_EVENT_INT; + hev->xType = HvLpEvent_Type_VirtualIo; + hev->xSubtype = viomajorsubtype_chario | viochardata; + hev->xSourceLp = HvLpConfig_getLpIndex(); + hev->xTargetLp = lp; + hev->xSizeMinus1 = sizeof(struct viocharlpevent); + hev->xSourceInstanceId = viopath_sourceinst(lp); + hev->xTargetInstanceId = viopath_targetinst(lp); +} + +static int get_chars(uint32_t vtermno, char *buf, int count) +{ + struct port_info *pi; + int n = 0; + unsigned long flags; + + if (vtermno >= VTTY_PORTS) + return -EINVAL; + if (count == 0) + return 0; + + pi = &port_info[vtermno]; + spin_lock_irqsave(&consolelock, flags); + + if (pi->in_end == 0) + goto done; + + n = pi->in_end - pi->in_start; + if (n > count) + n = count; + memcpy(buf, &pi->in_buf[pi->in_start], n); + pi->in_start += n; + if (pi->in_start == pi->in_end) { + pi->in_start = 0; + pi->in_end = 0; + } +done: + spin_unlock_irqrestore(&consolelock, flags); + return n; +} + +static int put_chars(uint32_t vtermno, const char *buf, int count) +{ + struct viocharlpevent *viochar; + struct port_info *pi; + HvLpEvent_Rc hvrc; + unsigned long flags; + int sent = 0; + + if (vtermno >= VTTY_PORTS) + return -EINVAL; + + pi = &port_info[vtermno]; + + spin_lock_irqsave(&consolelock, flags); + + if (viochar_is_console(pi) && !viopath_isactive(pi->lp)) { + HvCall_writeLogBuffer(buf, count); + sent = count; + goto done; + } + + viochar = vio_get_event_buffer(viomajorsubtype_chario); + if (viochar == NULL) { + hvlog("\n\rviocons: Can't get viochar buffer."); + goto done; + } + + while ((count > 0) && ((pi->seq - pi->ack) < VIOCHAR_WINDOW)) { + int len; + + len = (count > VIOCHAR_MAX_DATA) ? VIOCHAR_MAX_DATA : count; + + if (viochar_is_console(pi)) + HvCall_writeLogBuffer(buf, len); + + init_data_event(viochar, pi->lp); + + viochar->len = len; + viochar->event.xCorrelationToken = pi->seq++; + viochar->event.xSizeMinus1 = + offsetof(struct viocharlpevent, data) + len; + + memcpy(viochar->data, buf, len); + + hvrc = HvCallEvent_signalLpEvent(&viochar->event); + if (hvrc) + hvlog("\n\rerror sending event! return code %d\n\r", + (int)hvrc); + sent += len; + count -= len; + buf += len; + } + + vio_free_event_buffer(viomajorsubtype_chario, viochar); +done: + spin_unlock_irqrestore(&consolelock, flags); + return sent; +} + +static const struct hv_ops hvc_get_put_ops = { + .get_chars = get_chars, + .put_chars = put_chars, + .notifier_add = notifier_add_irq, + .notifier_del = notifier_del_irq, + .notifier_hangup = notifier_hangup_irq, +}; + +static int __devinit hvc_vio_probe(struct vio_dev *vdev, + const struct vio_device_id *id) +{ + struct hvc_struct *hp; + struct port_info *pi; + + /* probed with invalid parameters. */ + if (!vdev || !id) + return -EPERM; + + if (vdev->unit_address >= VTTY_PORTS) + return -ENODEV; + + pi = &port_info[vdev->unit_address]; + + hp = hvc_alloc(vdev->unit_address, vdev->irq, &hvc_get_put_ops, + VIOCHAR_MAX_DATA); + if (IS_ERR(hp)) + return PTR_ERR(hp); + pi->hp = hp; + dev_set_drvdata(&vdev->dev, pi); + + return 0; +} + +static int __devexit hvc_vio_remove(struct vio_dev *vdev) +{ + struct port_info *pi = dev_get_drvdata(&vdev->dev); + struct hvc_struct *hp = pi->hp; + + return hvc_remove(hp); +} + +static struct vio_driver hvc_vio_driver = { + .id_table = hvc_driver_table, + .probe = hvc_vio_probe, + .remove = __devexit_p(hvc_vio_remove), + .driver = { + .name = hvc_driver_name, + .owner = THIS_MODULE, + } +}; + +static void hvc_open_event(struct HvLpEvent *event) +{ + unsigned long flags; + struct viocharlpevent *cevent = (struct viocharlpevent *)event; + u8 port = cevent->virtual_device; + struct port_info *pi; + int reject = 0; + + if (hvlpevent_is_ack(event)) { + if (port >= VTTY_PORTS) + return; + + spin_lock_irqsave(&consolelock, flags); + + pi = &port_info[port]; + if (event->xRc == HvLpEvent_Rc_Good) { + pi->seq = pi->ack = 0; + /* + * This line allows connections from the primary + * partition but once one is connected from the + * primary partition nothing short of a reboot + * of linux will allow access from the hosting + * partition again without a required iSeries fix. + */ + pi->lp = event->xTargetLp; + } + + spin_unlock_irqrestore(&consolelock, flags); + if (event->xRc != HvLpEvent_Rc_Good) + printk(KERN_WARNING + "hvc: handle_open_event: event->xRc == (%d).\n", + event->xRc); + + if (event->xCorrelationToken != 0) { + atomic_t *aptr= (atomic_t *)event->xCorrelationToken; + atomic_set(aptr, 1); + } else + printk(KERN_WARNING + "hvc: weird...got open ack without atomic\n"); + return; + } + + /* This had better require an ack, otherwise complain */ + if (!hvlpevent_need_ack(event)) { + printk(KERN_WARNING "hvc: viocharopen without ack bit!\n"); + return; + } + + spin_lock_irqsave(&consolelock, flags); + + /* Make sure this is a good virtual tty */ + if (port >= VTTY_PORTS) { + event->xRc = HvLpEvent_Rc_SubtypeError; + cevent->subtype_result_code = viorc_openRejected; + /* + * Flag state here since we can't printk while holding + * the consolelock spinlock. + */ + reject = 1; + } else { + pi = &port_info[port]; + if ((pi->lp != HvLpIndexInvalid) && + (pi->lp != event->xSourceLp)) { + /* + * If this is tty is already connected to a different + * partition, fail. + */ + event->xRc = HvLpEvent_Rc_SubtypeError; + cevent->subtype_result_code = viorc_openRejected; + reject = 2; + } else { + pi->lp = event->xSourceLp; + event->xRc = HvLpEvent_Rc_Good; + cevent->subtype_result_code = viorc_good; + pi->seq = pi->ack = 0; + } + } + + spin_unlock_irqrestore(&consolelock, flags); + + if (reject == 1) + printk(KERN_WARNING "hvc: open rejected: bad virtual tty.\n"); + else if (reject == 2) + printk(KERN_WARNING "hvc: open rejected: console in exclusive " + "use by another partition.\n"); + + /* Return the acknowledgement */ + HvCallEvent_ackLpEvent(event); +} + +/* + * Handle a close charLpEvent. This should ONLY be an Interrupt because the + * virtual console should never actually issue a close event to the hypervisor + * because the virtual console never goes away. A close event coming from the + * hypervisor simply means that there are no client consoles connected to the + * virtual console. + */ +static void hvc_close_event(struct HvLpEvent *event) +{ + unsigned long flags; + struct viocharlpevent *cevent = (struct viocharlpevent *)event; + u8 port = cevent->virtual_device; + + if (!hvlpevent_is_int(event)) { + printk(KERN_WARNING + "hvc: got unexpected close acknowledgement\n"); + return; + } + + if (port >= VTTY_PORTS) { + printk(KERN_WARNING + "hvc: close message from invalid virtual device.\n"); + return; + } + + /* For closes, just mark the console partition invalid */ + spin_lock_irqsave(&consolelock, flags); + + if (port_info[port].lp == event->xSourceLp) + port_info[port].lp = HvLpIndexInvalid; + + spin_unlock_irqrestore(&consolelock, flags); +} + +static void hvc_data_event(struct HvLpEvent *event) +{ + unsigned long flags; + struct viocharlpevent *cevent = (struct viocharlpevent *)event; + struct port_info *pi; + int n; + u8 port = cevent->virtual_device; + + if (port >= VTTY_PORTS) { + printk(KERN_WARNING "hvc: data on invalid virtual device %d\n", + port); + return; + } + if (cevent->len == 0) + return; + + /* + * Change 05/01/2003 - Ryan Arnold: If a partition other than + * the current exclusive partition tries to send us data + * events then just drop them on the floor because we don't + * want his stinking data. He isn't authorized to receive + * data because he wasn't the first one to get the console, + * therefore he shouldn't be allowed to send data either. + * This will work without an iSeries fix. + */ + pi = &port_info[port]; + if (pi->lp != event->xSourceLp) + return; + + spin_lock_irqsave(&consolelock, flags); + + n = IN_BUF_SIZE - pi->in_end; + if (n > cevent->len) + n = cevent->len; + if (n > 0) { + memcpy(&pi->in_buf[pi->in_end], cevent->data, n); + pi->in_end += n; + } + spin_unlock_irqrestore(&consolelock, flags); + if (n == 0) + printk(KERN_WARNING "hvc: input buffer overflow\n"); +} + +static void hvc_ack_event(struct HvLpEvent *event) +{ + struct viocharlpevent *cevent = (struct viocharlpevent *)event; + unsigned long flags; + u8 port = cevent->virtual_device; + + if (port >= VTTY_PORTS) { + printk(KERN_WARNING "hvc: data on invalid virtual device\n"); + return; + } + + spin_lock_irqsave(&consolelock, flags); + port_info[port].ack = event->xCorrelationToken; + spin_unlock_irqrestore(&consolelock, flags); +} + +static void hvc_config_event(struct HvLpEvent *event) +{ + struct viocharlpevent *cevent = (struct viocharlpevent *)event; + + if (cevent->data[0] == 0x01) + printk(KERN_INFO "hvc: window resized to %d: %d: %d: %d\n", + cevent->data[1], cevent->data[2], + cevent->data[3], cevent->data[4]); + else + printk(KERN_WARNING "hvc: unknown config event\n"); +} + +static void hvc_handle_event(struct HvLpEvent *event) +{ + int charminor; + + if (event == NULL) + return; + + charminor = event->xSubtype & VIOMINOR_SUBTYPE_MASK; + switch (charminor) { + case viocharopen: + hvc_open_event(event); + break; + case viocharclose: + hvc_close_event(event); + break; + case viochardata: + hvc_data_event(event); + break; + case viocharack: + hvc_ack_event(event); + break; + case viocharconfig: + hvc_config_event(event); + break; + default: + if (hvlpevent_is_int(event) && hvlpevent_need_ack(event)) { + event->xRc = HvLpEvent_Rc_InvalidSubtype; + HvCallEvent_ackLpEvent(event); + } + } +} + +static int __init send_open(HvLpIndex remoteLp, void *sem) +{ + return HvCallEvent_signalLpEventFast(remoteLp, + HvLpEvent_Type_VirtualIo, + viomajorsubtype_chario | viocharopen, + HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck, + viopath_sourceinst(remoteLp), + viopath_targetinst(remoteLp), + (u64)(unsigned long)sem, VIOVERSION << 16, + 0, 0, 0, 0); +} + +static int __init hvc_vio_init(void) +{ + atomic_t wait_flag; + int rc; + + if (!firmware_has_feature(FW_FEATURE_ISERIES)) + return -EIO; + + /* +2 for fudge */ + rc = viopath_open(HvLpConfig_getPrimaryLpIndex(), + viomajorsubtype_chario, VIOCHAR_WINDOW + 2); + if (rc) + printk(KERN_WARNING "hvc: error opening to primary %d\n", rc); + + if (viopath_hostLp == HvLpIndexInvalid) + vio_set_hostlp(); + + /* + * And if the primary is not the same as the hosting LP, open to the + * hosting lp + */ + if ((viopath_hostLp != HvLpIndexInvalid) && + (viopath_hostLp != HvLpConfig_getPrimaryLpIndex())) { + printk(KERN_INFO "hvc: open path to hosting (%d)\n", + viopath_hostLp); + rc = viopath_open(viopath_hostLp, viomajorsubtype_chario, + VIOCHAR_WINDOW + 2); /* +2 for fudge */ + if (rc) + printk(KERN_WARNING + "error opening to partition %d: %d\n", + viopath_hostLp, rc); + } + + if (vio_setHandler(viomajorsubtype_chario, hvc_handle_event) < 0) + printk(KERN_WARNING + "hvc: error seting handler for console events!\n"); + + /* + * First, try to open the console to the hosting lp. + * Wait on a semaphore for the response. + */ + atomic_set(&wait_flag, 0); + if ((viopath_isactive(viopath_hostLp)) && + (send_open(viopath_hostLp, &wait_flag) == 0)) { + printk(KERN_INFO "hvc: hosting partition %d\n", viopath_hostLp); + while (atomic_read(&wait_flag) == 0) + mb(); + atomic_set(&wait_flag, 0); + } + + /* + * If we don't have an active console, try the primary + */ + if ((!viopath_isactive(port_info[0].lp)) && + (viopath_isactive(HvLpConfig_getPrimaryLpIndex())) && + (send_open(HvLpConfig_getPrimaryLpIndex(), &wait_flag) == 0)) { + printk(KERN_INFO "hvc: opening console to primary partition\n"); + while (atomic_read(&wait_flag) == 0) + mb(); + } + + /* Register as a vio device to receive callbacks */ + rc = vio_register_driver(&hvc_vio_driver); + + return rc; +} +module_init(hvc_vio_init); /* after drivers/char/hvc_console.c */ + +static void __exit hvc_vio_exit(void) +{ + vio_unregister_driver(&hvc_vio_driver); +} +module_exit(hvc_vio_exit); + +/* the device tree order defines our numbering */ +static int __init hvc_find_vtys(void) +{ + struct device_node *vty; + int num_found = 0; + + for (vty = of_find_node_by_name(NULL, "vty"); vty != NULL; + vty = of_find_node_by_name(vty, "vty")) { + const uint32_t *vtermno; + + /* We have statically defined space for only a certain number + * of console adapters. + */ + if ((num_found >= MAX_NR_HVC_CONSOLES) || + (num_found >= VTTY_PORTS)) { + of_node_put(vty); + break; + } + + vtermno = of_get_property(vty, "reg", NULL); + if (!vtermno) + continue; + + if (!of_device_is_compatible(vty, "IBM,iSeries-vty")) + continue; + + if (num_found == 0) + add_preferred_console("hvc", 0, NULL); + hvc_instantiate(*vtermno, num_found, &hvc_get_put_ops); + ++num_found; + } + + return num_found; +} +console_initcall(hvc_find_vtys); diff --git a/drivers/tty/hvc/hvc_iucv.c b/drivers/tty/hvc/hvc_iucv.c new file mode 100644 index 000000000000..c3425bb3a1f6 --- /dev/null +++ b/drivers/tty/hvc/hvc_iucv.c @@ -0,0 +1,1337 @@ +/* + * hvc_iucv.c - z/VM IUCV hypervisor console (HVC) device driver + * + * This HVC device driver provides terminal access using + * z/VM IUCV communication paths. + * + * Copyright IBM Corp. 2008, 2009 + * + * Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com> + */ +#define KMSG_COMPONENT "hvc_iucv" +#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt + +#include <linux/types.h> +#include <linux/slab.h> +#include <asm/ebcdic.h> +#include <linux/ctype.h> +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/init.h> +#include <linux/mempool.h> +#include <linux/moduleparam.h> +#include <linux/tty.h> +#include <linux/wait.h> +#include <net/iucv/iucv.h> + +#include "hvc_console.h" + + +/* General device driver settings */ +#define HVC_IUCV_MAGIC 0xc9e4c3e5 +#define MAX_HVC_IUCV_LINES HVC_ALLOC_TTY_ADAPTERS +#define MEMPOOL_MIN_NR (PAGE_SIZE / sizeof(struct iucv_tty_buffer)/4) + +/* IUCV TTY message */ +#define MSG_VERSION 0x02 /* Message version */ +#define MSG_TYPE_ERROR 0x01 /* Error message */ +#define MSG_TYPE_TERMENV 0x02 /* Terminal environment variable */ +#define MSG_TYPE_TERMIOS 0x04 /* Terminal IO struct update */ +#define MSG_TYPE_WINSIZE 0x08 /* Terminal window size update */ +#define MSG_TYPE_DATA 0x10 /* Terminal data */ + +struct iucv_tty_msg { + u8 version; /* Message version */ + u8 type; /* Message type */ +#define MSG_MAX_DATALEN ((u16)(~0)) + u16 datalen; /* Payload length */ + u8 data[]; /* Payload buffer */ +} __attribute__((packed)); +#define MSG_SIZE(s) ((s) + offsetof(struct iucv_tty_msg, data)) + +enum iucv_state_t { + IUCV_DISCONN = 0, + IUCV_CONNECTED = 1, + IUCV_SEVERED = 2, +}; + +enum tty_state_t { + TTY_CLOSED = 0, + TTY_OPENED = 1, +}; + +struct hvc_iucv_private { + struct hvc_struct *hvc; /* HVC struct reference */ + u8 srv_name[8]; /* IUCV service name (ebcdic) */ + unsigned char is_console; /* Linux console usage flag */ + enum iucv_state_t iucv_state; /* IUCV connection status */ + enum tty_state_t tty_state; /* TTY status */ + struct iucv_path *path; /* IUCV path pointer */ + spinlock_t lock; /* hvc_iucv_private lock */ +#define SNDBUF_SIZE (PAGE_SIZE) /* must be < MSG_MAX_DATALEN */ + void *sndbuf; /* send buffer */ + size_t sndbuf_len; /* length of send buffer */ +#define QUEUE_SNDBUF_DELAY (HZ / 25) + struct delayed_work sndbuf_work; /* work: send iucv msg(s) */ + wait_queue_head_t sndbuf_waitq; /* wait for send completion */ + struct list_head tty_outqueue; /* outgoing IUCV messages */ + struct list_head tty_inqueue; /* incoming IUCV messages */ + struct device *dev; /* device structure */ +}; + +struct iucv_tty_buffer { + struct list_head list; /* list pointer */ + struct iucv_message msg; /* store an IUCV message */ + size_t offset; /* data buffer offset */ + struct iucv_tty_msg *mbuf; /* buffer to store input/output data */ +}; + +/* IUCV callback handler */ +static int hvc_iucv_path_pending(struct iucv_path *, u8[8], u8[16]); +static void hvc_iucv_path_severed(struct iucv_path *, u8[16]); +static void hvc_iucv_msg_pending(struct iucv_path *, struct iucv_message *); +static void hvc_iucv_msg_complete(struct iucv_path *, struct iucv_message *); + + +/* Kernel module parameter: use one terminal device as default */ +static unsigned long hvc_iucv_devices = 1; + +/* Array of allocated hvc iucv tty lines... */ +static struct hvc_iucv_private *hvc_iucv_table[MAX_HVC_IUCV_LINES]; +#define IUCV_HVC_CON_IDX (0) +/* List of z/VM user ID filter entries (struct iucv_vmid_filter) */ +#define MAX_VMID_FILTER (500) +static size_t hvc_iucv_filter_size; +static void *hvc_iucv_filter; +static const char *hvc_iucv_filter_string; +static DEFINE_RWLOCK(hvc_iucv_filter_lock); + +/* Kmem cache and mempool for iucv_tty_buffer elements */ +static struct kmem_cache *hvc_iucv_buffer_cache; +static mempool_t *hvc_iucv_mempool; + +/* IUCV handler callback functions */ +static struct iucv_handler hvc_iucv_handler = { + .path_pending = hvc_iucv_path_pending, + .path_severed = hvc_iucv_path_severed, + .message_complete = hvc_iucv_msg_complete, + .message_pending = hvc_iucv_msg_pending, +}; + + +/** + * hvc_iucv_get_private() - Return a struct hvc_iucv_private instance. + * @num: The HVC virtual terminal number (vtermno) + * + * This function returns the struct hvc_iucv_private instance that corresponds + * to the HVC virtual terminal number specified as parameter @num. + */ +struct hvc_iucv_private *hvc_iucv_get_private(uint32_t num) +{ + if ((num < HVC_IUCV_MAGIC) || (num - HVC_IUCV_MAGIC > hvc_iucv_devices)) + return NULL; + return hvc_iucv_table[num - HVC_IUCV_MAGIC]; +} + +/** + * alloc_tty_buffer() - Return a new struct iucv_tty_buffer element. + * @size: Size of the internal buffer used to store data. + * @flags: Memory allocation flags passed to mempool. + * + * This function allocates a new struct iucv_tty_buffer element and, optionally, + * allocates an internal data buffer with the specified size @size. + * The internal data buffer is always allocated with GFP_DMA which is + * required for receiving and sending data with IUCV. + * Note: The total message size arises from the internal buffer size and the + * members of the iucv_tty_msg structure. + * The function returns NULL if memory allocation has failed. + */ +static struct iucv_tty_buffer *alloc_tty_buffer(size_t size, gfp_t flags) +{ + struct iucv_tty_buffer *bufp; + + bufp = mempool_alloc(hvc_iucv_mempool, flags); + if (!bufp) + return NULL; + memset(bufp, 0, sizeof(*bufp)); + + if (size > 0) { + bufp->msg.length = MSG_SIZE(size); + bufp->mbuf = kmalloc(bufp->msg.length, flags | GFP_DMA); + if (!bufp->mbuf) { + mempool_free(bufp, hvc_iucv_mempool); + return NULL; + } + bufp->mbuf->version = MSG_VERSION; + bufp->mbuf->type = MSG_TYPE_DATA; + bufp->mbuf->datalen = (u16) size; + } + return bufp; +} + +/** + * destroy_tty_buffer() - destroy struct iucv_tty_buffer element. + * @bufp: Pointer to a struct iucv_tty_buffer element, SHALL NOT be NULL. + */ +static void destroy_tty_buffer(struct iucv_tty_buffer *bufp) +{ + kfree(bufp->mbuf); + mempool_free(bufp, hvc_iucv_mempool); +} + +/** + * destroy_tty_buffer_list() - call destroy_tty_buffer() for each list element. + * @list: List containing struct iucv_tty_buffer elements. + */ +static void destroy_tty_buffer_list(struct list_head *list) +{ + struct iucv_tty_buffer *ent, *next; + + list_for_each_entry_safe(ent, next, list, list) { + list_del(&ent->list); + destroy_tty_buffer(ent); + } +} + +/** + * hvc_iucv_write() - Receive IUCV message & write data to HVC buffer. + * @priv: Pointer to struct hvc_iucv_private + * @buf: HVC buffer for writing received terminal data. + * @count: HVC buffer size. + * @has_more_data: Pointer to an int variable. + * + * The function picks up pending messages from the input queue and receives + * the message data that is then written to the specified buffer @buf. + * If the buffer size @count is less than the data message size, the + * message is kept on the input queue and @has_more_data is set to 1. + * If all message data has been written, the message is removed from + * the input queue. + * + * The function returns the number of bytes written to the terminal, zero if + * there are no pending data messages available or if there is no established + * IUCV path. + * If the IUCV path has been severed, then -EPIPE is returned to cause a + * hang up (that is issued by the HVC layer). + */ +static int hvc_iucv_write(struct hvc_iucv_private *priv, + char *buf, int count, int *has_more_data) +{ + struct iucv_tty_buffer *rb; + int written; + int rc; + + /* immediately return if there is no IUCV connection */ + if (priv->iucv_state == IUCV_DISCONN) + return 0; + + /* if the IUCV path has been severed, return -EPIPE to inform the + * HVC layer to hang up the tty device. */ + if (priv->iucv_state == IUCV_SEVERED) + return -EPIPE; + + /* check if there are pending messages */ + if (list_empty(&priv->tty_inqueue)) + return 0; + + /* receive an iucv message and flip data to the tty (ldisc) */ + rb = list_first_entry(&priv->tty_inqueue, struct iucv_tty_buffer, list); + + written = 0; + if (!rb->mbuf) { /* message not yet received ... */ + /* allocate mem to store msg data; if no memory is available + * then leave the buffer on the list and re-try later */ + rb->mbuf = kmalloc(rb->msg.length, GFP_ATOMIC | GFP_DMA); + if (!rb->mbuf) + return -ENOMEM; + + rc = __iucv_message_receive(priv->path, &rb->msg, 0, + rb->mbuf, rb->msg.length, NULL); + switch (rc) { + case 0: /* Successful */ + break; + case 2: /* No message found */ + case 9: /* Message purged */ + break; + default: + written = -EIO; + } + /* remove buffer if an error has occured or received data + * is not correct */ + if (rc || (rb->mbuf->version != MSG_VERSION) || + (rb->msg.length != MSG_SIZE(rb->mbuf->datalen))) + goto out_remove_buffer; + } + + switch (rb->mbuf->type) { + case MSG_TYPE_DATA: + written = min_t(int, rb->mbuf->datalen - rb->offset, count); + memcpy(buf, rb->mbuf->data + rb->offset, written); + if (written < (rb->mbuf->datalen - rb->offset)) { + rb->offset += written; + *has_more_data = 1; + goto out_written; + } + break; + + case MSG_TYPE_WINSIZE: + if (rb->mbuf->datalen != sizeof(struct winsize)) + break; + /* The caller must ensure that the hvc is locked, which + * is the case when called from hvc_iucv_get_chars() */ + __hvc_resize(priv->hvc, *((struct winsize *) rb->mbuf->data)); + break; + + case MSG_TYPE_ERROR: /* ignored ... */ + case MSG_TYPE_TERMENV: /* ignored ... */ + case MSG_TYPE_TERMIOS: /* ignored ... */ + break; + } + +out_remove_buffer: + list_del(&rb->list); + destroy_tty_buffer(rb); + *has_more_data = !list_empty(&priv->tty_inqueue); + +out_written: + return written; +} + +/** + * hvc_iucv_get_chars() - HVC get_chars operation. + * @vtermno: HVC virtual terminal number. + * @buf: Pointer to a buffer to store data + * @count: Size of buffer available for writing + * + * The HVC thread calls this method to read characters from the back-end. + * If an IUCV communication path has been established, pending IUCV messages + * are received and data is copied into buffer @buf up to @count bytes. + * + * Locking: The routine gets called under an irqsave() spinlock; and + * the routine locks the struct hvc_iucv_private->lock to call + * helper functions. + */ +static int hvc_iucv_get_chars(uint32_t vtermno, char *buf, int count) +{ + struct hvc_iucv_private *priv = hvc_iucv_get_private(vtermno); + int written; + int has_more_data; + + if (count <= 0) + return 0; + + if (!priv) + return -ENODEV; + + spin_lock(&priv->lock); + has_more_data = 0; + written = hvc_iucv_write(priv, buf, count, &has_more_data); + spin_unlock(&priv->lock); + + /* if there are still messages on the queue... schedule another run */ + if (has_more_data) + hvc_kick(); + + return written; +} + +/** + * hvc_iucv_queue() - Buffer terminal data for sending. + * @priv: Pointer to struct hvc_iucv_private instance. + * @buf: Buffer containing data to send. + * @count: Size of buffer and amount of data to send. + * + * The function queues data for sending. To actually send the buffered data, + * a work queue function is scheduled (with QUEUE_SNDBUF_DELAY). + * The function returns the number of data bytes that has been buffered. + * + * If the device is not connected, data is ignored and the function returns + * @count. + * If the buffer is full, the function returns 0. + * If an existing IUCV communicaton path has been severed, -EPIPE is returned + * (that can be passed to HVC layer to cause a tty hangup). + */ +static int hvc_iucv_queue(struct hvc_iucv_private *priv, const char *buf, + int count) +{ + size_t len; + + if (priv->iucv_state == IUCV_DISCONN) + return count; /* ignore data */ + + if (priv->iucv_state == IUCV_SEVERED) + return -EPIPE; + + len = min_t(size_t, count, SNDBUF_SIZE - priv->sndbuf_len); + if (!len) + return 0; + + memcpy(priv->sndbuf + priv->sndbuf_len, buf, len); + priv->sndbuf_len += len; + + if (priv->iucv_state == IUCV_CONNECTED) + schedule_delayed_work(&priv->sndbuf_work, QUEUE_SNDBUF_DELAY); + + return len; +} + +/** + * hvc_iucv_send() - Send an IUCV message containing terminal data. + * @priv: Pointer to struct hvc_iucv_private instance. + * + * If an IUCV communication path has been established, the buffered output data + * is sent via an IUCV message and the number of bytes sent is returned. + * Returns 0 if there is no established IUCV communication path or + * -EPIPE if an existing IUCV communicaton path has been severed. + */ +static int hvc_iucv_send(struct hvc_iucv_private *priv) +{ + struct iucv_tty_buffer *sb; + int rc, len; + + if (priv->iucv_state == IUCV_SEVERED) + return -EPIPE; + + if (priv->iucv_state == IUCV_DISCONN) + return -EIO; + + if (!priv->sndbuf_len) + return 0; + + /* allocate internal buffer to store msg data and also compute total + * message length */ + sb = alloc_tty_buffer(priv->sndbuf_len, GFP_ATOMIC); + if (!sb) + return -ENOMEM; + + memcpy(sb->mbuf->data, priv->sndbuf, priv->sndbuf_len); + sb->mbuf->datalen = (u16) priv->sndbuf_len; + sb->msg.length = MSG_SIZE(sb->mbuf->datalen); + + list_add_tail(&sb->list, &priv->tty_outqueue); + + rc = __iucv_message_send(priv->path, &sb->msg, 0, 0, + (void *) sb->mbuf, sb->msg.length); + if (rc) { + /* drop the message here; however we might want to handle + * 0x03 (msg limit reached) by trying again... */ + list_del(&sb->list); + destroy_tty_buffer(sb); + } + len = priv->sndbuf_len; + priv->sndbuf_len = 0; + + return len; +} + +/** + * hvc_iucv_sndbuf_work() - Send buffered data over IUCV + * @work: Work structure. + * + * This work queue function sends buffered output data over IUCV and, + * if not all buffered data could be sent, reschedules itself. + */ +static void hvc_iucv_sndbuf_work(struct work_struct *work) +{ + struct hvc_iucv_private *priv; + + priv = container_of(work, struct hvc_iucv_private, sndbuf_work.work); + if (!priv) + return; + + spin_lock_bh(&priv->lock); + hvc_iucv_send(priv); + spin_unlock_bh(&priv->lock); +} + +/** + * hvc_iucv_put_chars() - HVC put_chars operation. + * @vtermno: HVC virtual terminal number. + * @buf: Pointer to an buffer to read data from + * @count: Size of buffer available for reading + * + * The HVC thread calls this method to write characters to the back-end. + * The function calls hvc_iucv_queue() to queue terminal data for sending. + * + * Locking: The method gets called under an irqsave() spinlock; and + * locks struct hvc_iucv_private->lock. + */ +static int hvc_iucv_put_chars(uint32_t vtermno, const char *buf, int count) +{ + struct hvc_iucv_private *priv = hvc_iucv_get_private(vtermno); + int queued; + + if (count <= 0) + return 0; + + if (!priv) + return -ENODEV; + + spin_lock(&priv->lock); + queued = hvc_iucv_queue(priv, buf, count); + spin_unlock(&priv->lock); + + return queued; +} + +/** + * hvc_iucv_notifier_add() - HVC notifier for opening a TTY for the first time. + * @hp: Pointer to the HVC device (struct hvc_struct) + * @id: Additional data (originally passed to hvc_alloc): the index of an struct + * hvc_iucv_private instance. + * + * The function sets the tty state to TTY_OPENED for the struct hvc_iucv_private + * instance that is derived from @id. Always returns 0. + * + * Locking: struct hvc_iucv_private->lock, spin_lock_bh + */ +static int hvc_iucv_notifier_add(struct hvc_struct *hp, int id) +{ + struct hvc_iucv_private *priv; + + priv = hvc_iucv_get_private(id); + if (!priv) + return 0; + + spin_lock_bh(&priv->lock); + priv->tty_state = TTY_OPENED; + spin_unlock_bh(&priv->lock); + + return 0; +} + +/** + * hvc_iucv_cleanup() - Clean up and reset a z/VM IUCV HVC instance. + * @priv: Pointer to the struct hvc_iucv_private instance. + */ +static void hvc_iucv_cleanup(struct hvc_iucv_private *priv) +{ + destroy_tty_buffer_list(&priv->tty_outqueue); + destroy_tty_buffer_list(&priv->tty_inqueue); + + priv->tty_state = TTY_CLOSED; + priv->iucv_state = IUCV_DISCONN; + + priv->sndbuf_len = 0; +} + +/** + * tty_outqueue_empty() - Test if the tty outq is empty + * @priv: Pointer to struct hvc_iucv_private instance. + */ +static inline int tty_outqueue_empty(struct hvc_iucv_private *priv) +{ + int rc; + + spin_lock_bh(&priv->lock); + rc = list_empty(&priv->tty_outqueue); + spin_unlock_bh(&priv->lock); + + return rc; +} + +/** + * flush_sndbuf_sync() - Flush send buffer and wait for completion + * @priv: Pointer to struct hvc_iucv_private instance. + * + * The routine cancels a pending sndbuf work, calls hvc_iucv_send() + * to flush any buffered terminal output data and waits for completion. + */ +static void flush_sndbuf_sync(struct hvc_iucv_private *priv) +{ + int sync_wait; + + cancel_delayed_work_sync(&priv->sndbuf_work); + + spin_lock_bh(&priv->lock); + hvc_iucv_send(priv); /* force sending buffered data */ + sync_wait = !list_empty(&priv->tty_outqueue); /* anything queued ? */ + spin_unlock_bh(&priv->lock); + + if (sync_wait) + wait_event_timeout(priv->sndbuf_waitq, + tty_outqueue_empty(priv), HZ/10); +} + +/** + * hvc_iucv_hangup() - Sever IUCV path and schedule hvc tty hang up + * @priv: Pointer to hvc_iucv_private structure + * + * This routine severs an existing IUCV communication path and hangs + * up the underlying HVC terminal device. + * The hang-up occurs only if an IUCV communication path is established; + * otherwise there is no need to hang up the terminal device. + * + * The IUCV HVC hang-up is separated into two steps: + * 1. After the IUCV path has been severed, the iucv_state is set to + * IUCV_SEVERED. + * 2. Later, when the HVC thread calls hvc_iucv_get_chars(), the + * IUCV_SEVERED state causes the tty hang-up in the HVC layer. + * + * If the tty has not yet been opened, clean up the hvc_iucv_private + * structure to allow re-connects. + * If the tty has been opened, let get_chars() return -EPIPE to signal + * the HVC layer to hang up the tty and, if so, wake up the HVC thread + * to call get_chars()... + * + * Special notes on hanging up a HVC terminal instantiated as console: + * Hang-up: 1. do_tty_hangup() replaces file ops (= hung_up_tty_fops) + * 2. do_tty_hangup() calls tty->ops->close() for console_filp + * => no hangup notifier is called by HVC (default) + * 2. hvc_close() returns because of tty_hung_up_p(filp) + * => no delete notifier is called! + * Finally, the back-end is not being notified, thus, the tty session is + * kept active (TTY_OPEN) to be ready for re-connects. + * + * Locking: spin_lock(&priv->lock) w/o disabling bh + */ +static void hvc_iucv_hangup(struct hvc_iucv_private *priv) +{ + struct iucv_path *path; + + path = NULL; + spin_lock(&priv->lock); + if (priv->iucv_state == IUCV_CONNECTED) { + path = priv->path; + priv->path = NULL; + priv->iucv_state = IUCV_SEVERED; + if (priv->tty_state == TTY_CLOSED) + hvc_iucv_cleanup(priv); + else + /* console is special (see above) */ + if (priv->is_console) { + hvc_iucv_cleanup(priv); + priv->tty_state = TTY_OPENED; + } else + hvc_kick(); + } + spin_unlock(&priv->lock); + + /* finally sever path (outside of priv->lock due to lock ordering) */ + if (path) { + iucv_path_sever(path, NULL); + iucv_path_free(path); + } +} + +/** + * hvc_iucv_notifier_hangup() - HVC notifier for TTY hangups. + * @hp: Pointer to the HVC device (struct hvc_struct) + * @id: Additional data (originally passed to hvc_alloc): + * the index of an struct hvc_iucv_private instance. + * + * This routine notifies the HVC back-end that a tty hangup (carrier loss, + * virtual or otherwise) has occured. + * The z/VM IUCV HVC device driver ignores virtual hangups (vhangup()) + * to keep an existing IUCV communication path established. + * (Background: vhangup() is called from user space (by getty or login) to + * disable writing to the tty by other applications). + * If the tty has been opened and an established IUCV path has been severed + * (we caused the tty hangup), the function calls hvc_iucv_cleanup(). + * + * Locking: struct hvc_iucv_private->lock + */ +static void hvc_iucv_notifier_hangup(struct hvc_struct *hp, int id) +{ + struct hvc_iucv_private *priv; + + priv = hvc_iucv_get_private(id); + if (!priv) + return; + + flush_sndbuf_sync(priv); + + spin_lock_bh(&priv->lock); + /* NOTE: If the hangup was scheduled by ourself (from the iucv + * path_servered callback [IUCV_SEVERED]), we have to clean up + * our structure and to set state to TTY_CLOSED. + * If the tty was hung up otherwise (e.g. vhangup()), then we + * ignore this hangup and keep an established IUCV path open... + * (...the reason is that we are not able to connect back to the + * client if we disconnect on hang up) */ + priv->tty_state = TTY_CLOSED; + + if (priv->iucv_state == IUCV_SEVERED) + hvc_iucv_cleanup(priv); + spin_unlock_bh(&priv->lock); +} + +/** + * hvc_iucv_notifier_del() - HVC notifier for closing a TTY for the last time. + * @hp: Pointer to the HVC device (struct hvc_struct) + * @id: Additional data (originally passed to hvc_alloc): + * the index of an struct hvc_iucv_private instance. + * + * This routine notifies the HVC back-end that the last tty device fd has been + * closed. The function calls hvc_iucv_cleanup() to clean up the struct + * hvc_iucv_private instance. + * + * Locking: struct hvc_iucv_private->lock + */ +static void hvc_iucv_notifier_del(struct hvc_struct *hp, int id) +{ + struct hvc_iucv_private *priv; + struct iucv_path *path; + + priv = hvc_iucv_get_private(id); + if (!priv) + return; + + flush_sndbuf_sync(priv); + + spin_lock_bh(&priv->lock); + path = priv->path; /* save reference to IUCV path */ + priv->path = NULL; + hvc_iucv_cleanup(priv); + spin_unlock_bh(&priv->lock); + + /* sever IUCV path outside of priv->lock due to lock ordering of: + * priv->lock <--> iucv_table_lock */ + if (path) { + iucv_path_sever(path, NULL); + iucv_path_free(path); + } +} + +/** + * hvc_iucv_filter_connreq() - Filter connection request based on z/VM user ID + * @ipvmid: Originating z/VM user ID (right padded with blanks) + * + * Returns 0 if the z/VM user ID @ipvmid is allowed to connection, otherwise + * non-zero. + */ +static int hvc_iucv_filter_connreq(u8 ipvmid[8]) +{ + size_t i; + + /* Note: default policy is ACCEPT if no filter is set */ + if (!hvc_iucv_filter_size) + return 0; + + for (i = 0; i < hvc_iucv_filter_size; i++) + if (0 == memcmp(ipvmid, hvc_iucv_filter + (8 * i), 8)) + return 0; + return 1; +} + +/** + * hvc_iucv_path_pending() - IUCV handler to process a connection request. + * @path: Pending path (struct iucv_path) + * @ipvmid: z/VM system identifier of originator + * @ipuser: User specified data for this path + * (AF_IUCV: port/service name and originator port) + * + * The function uses the @ipuser data to determine if the pending path belongs + * to a terminal managed by this device driver. + * If the path belongs to this driver, ensure that the terminal is not accessed + * multiple times (only one connection to a terminal is allowed). + * If the terminal is not yet connected, the pending path is accepted and is + * associated to the appropriate struct hvc_iucv_private instance. + * + * Returns 0 if @path belongs to a terminal managed by the this device driver; + * otherwise returns -ENODEV in order to dispatch this path to other handlers. + * + * Locking: struct hvc_iucv_private->lock + */ +static int hvc_iucv_path_pending(struct iucv_path *path, + u8 ipvmid[8], u8 ipuser[16]) +{ + struct hvc_iucv_private *priv; + u8 nuser_data[16]; + u8 vm_user_id[9]; + int i, rc; + + priv = NULL; + for (i = 0; i < hvc_iucv_devices; i++) + if (hvc_iucv_table[i] && + (0 == memcmp(hvc_iucv_table[i]->srv_name, ipuser, 8))) { + priv = hvc_iucv_table[i]; + break; + } + if (!priv) + return -ENODEV; + + /* Enforce that ipvmid is allowed to connect to us */ + read_lock(&hvc_iucv_filter_lock); + rc = hvc_iucv_filter_connreq(ipvmid); + read_unlock(&hvc_iucv_filter_lock); + if (rc) { + iucv_path_sever(path, ipuser); + iucv_path_free(path); + memcpy(vm_user_id, ipvmid, 8); + vm_user_id[8] = 0; + pr_info("A connection request from z/VM user ID %s " + "was refused\n", vm_user_id); + return 0; + } + + spin_lock(&priv->lock); + + /* If the terminal is already connected or being severed, then sever + * this path to enforce that there is only ONE established communication + * path per terminal. */ + if (priv->iucv_state != IUCV_DISCONN) { + iucv_path_sever(path, ipuser); + iucv_path_free(path); + goto out_path_handled; + } + + /* accept path */ + memcpy(nuser_data, ipuser + 8, 8); /* remote service (for af_iucv) */ + memcpy(nuser_data + 8, ipuser, 8); /* local service (for af_iucv) */ + path->msglim = 0xffff; /* IUCV MSGLIMIT */ + path->flags &= ~IUCV_IPRMDATA; /* TODO: use IUCV_IPRMDATA */ + rc = iucv_path_accept(path, &hvc_iucv_handler, nuser_data, priv); + if (rc) { + iucv_path_sever(path, ipuser); + iucv_path_free(path); + goto out_path_handled; + } + priv->path = path; + priv->iucv_state = IUCV_CONNECTED; + + /* flush buffered output data... */ + schedule_delayed_work(&priv->sndbuf_work, 5); + +out_path_handled: + spin_unlock(&priv->lock); + return 0; +} + +/** + * hvc_iucv_path_severed() - IUCV handler to process a path sever. + * @path: Pending path (struct iucv_path) + * @ipuser: User specified data for this path + * (AF_IUCV: port/service name and originator port) + * + * This function calls the hvc_iucv_hangup() function for the + * respective IUCV HVC terminal. + * + * Locking: struct hvc_iucv_private->lock + */ +static void hvc_iucv_path_severed(struct iucv_path *path, u8 ipuser[16]) +{ + struct hvc_iucv_private *priv = path->private; + + hvc_iucv_hangup(priv); +} + +/** + * hvc_iucv_msg_pending() - IUCV handler to process an incoming IUCV message. + * @path: Pending path (struct iucv_path) + * @msg: Pointer to the IUCV message + * + * The function puts an incoming message on the input queue for later + * processing (by hvc_iucv_get_chars() / hvc_iucv_write()). + * If the tty has not yet been opened, the message is rejected. + * + * Locking: struct hvc_iucv_private->lock + */ +static void hvc_iucv_msg_pending(struct iucv_path *path, + struct iucv_message *msg) +{ + struct hvc_iucv_private *priv = path->private; + struct iucv_tty_buffer *rb; + + /* reject messages that exceed max size of iucv_tty_msg->datalen */ + if (msg->length > MSG_SIZE(MSG_MAX_DATALEN)) { + iucv_message_reject(path, msg); + return; + } + + spin_lock(&priv->lock); + + /* reject messages if tty has not yet been opened */ + if (priv->tty_state == TTY_CLOSED) { + iucv_message_reject(path, msg); + goto unlock_return; + } + + /* allocate tty buffer to save iucv msg only */ + rb = alloc_tty_buffer(0, GFP_ATOMIC); + if (!rb) { + iucv_message_reject(path, msg); + goto unlock_return; /* -ENOMEM */ + } + rb->msg = *msg; + + list_add_tail(&rb->list, &priv->tty_inqueue); + + hvc_kick(); /* wake up hvc thread */ + +unlock_return: + spin_unlock(&priv->lock); +} + +/** + * hvc_iucv_msg_complete() - IUCV handler to process message completion + * @path: Pending path (struct iucv_path) + * @msg: Pointer to the IUCV message + * + * The function is called upon completion of message delivery to remove the + * message from the outqueue. Additional delivery information can be found + * msg->audit: rejected messages (0x040000 (IPADRJCT)), and + * purged messages (0x010000 (IPADPGNR)). + * + * Locking: struct hvc_iucv_private->lock + */ +static void hvc_iucv_msg_complete(struct iucv_path *path, + struct iucv_message *msg) +{ + struct hvc_iucv_private *priv = path->private; + struct iucv_tty_buffer *ent, *next; + LIST_HEAD(list_remove); + + spin_lock(&priv->lock); + list_for_each_entry_safe(ent, next, &priv->tty_outqueue, list) + if (ent->msg.id == msg->id) { + list_move(&ent->list, &list_remove); + break; + } + wake_up(&priv->sndbuf_waitq); + spin_unlock(&priv->lock); + destroy_tty_buffer_list(&list_remove); +} + +/** + * hvc_iucv_pm_freeze() - Freeze PM callback + * @dev: IUVC HVC terminal device + * + * Sever an established IUCV communication path and + * trigger a hang-up of the underlying HVC terminal. + */ +static int hvc_iucv_pm_freeze(struct device *dev) +{ + struct hvc_iucv_private *priv = dev_get_drvdata(dev); + + local_bh_disable(); + hvc_iucv_hangup(priv); + local_bh_enable(); + + return 0; +} + +/** + * hvc_iucv_pm_restore_thaw() - Thaw and restore PM callback + * @dev: IUVC HVC terminal device + * + * Wake up the HVC thread to trigger hang-up and respective + * HVC back-end notifier invocations. + */ +static int hvc_iucv_pm_restore_thaw(struct device *dev) +{ + hvc_kick(); + return 0; +} + + +/* HVC operations */ +static const struct hv_ops hvc_iucv_ops = { + .get_chars = hvc_iucv_get_chars, + .put_chars = hvc_iucv_put_chars, + .notifier_add = hvc_iucv_notifier_add, + .notifier_del = hvc_iucv_notifier_del, + .notifier_hangup = hvc_iucv_notifier_hangup, +}; + +/* Suspend / resume device operations */ +static const struct dev_pm_ops hvc_iucv_pm_ops = { + .freeze = hvc_iucv_pm_freeze, + .thaw = hvc_iucv_pm_restore_thaw, + .restore = hvc_iucv_pm_restore_thaw, +}; + +/* IUCV HVC device driver */ +static struct device_driver hvc_iucv_driver = { + .name = KMSG_COMPONENT, + .bus = &iucv_bus, + .pm = &hvc_iucv_pm_ops, +}; + +/** + * hvc_iucv_alloc() - Allocates a new struct hvc_iucv_private instance + * @id: hvc_iucv_table index + * @is_console: Flag if the instance is used as Linux console + * + * This function allocates a new hvc_iucv_private structure and stores + * the instance in hvc_iucv_table at index @id. + * Returns 0 on success; otherwise non-zero. + */ +static int __init hvc_iucv_alloc(int id, unsigned int is_console) +{ + struct hvc_iucv_private *priv; + char name[9]; + int rc; + + priv = kzalloc(sizeof(struct hvc_iucv_private), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + spin_lock_init(&priv->lock); + INIT_LIST_HEAD(&priv->tty_outqueue); + INIT_LIST_HEAD(&priv->tty_inqueue); + INIT_DELAYED_WORK(&priv->sndbuf_work, hvc_iucv_sndbuf_work); + init_waitqueue_head(&priv->sndbuf_waitq); + + priv->sndbuf = (void *) get_zeroed_page(GFP_KERNEL); + if (!priv->sndbuf) { + kfree(priv); + return -ENOMEM; + } + + /* set console flag */ + priv->is_console = is_console; + + /* allocate hvc device */ + priv->hvc = hvc_alloc(HVC_IUCV_MAGIC + id, /* PAGE_SIZE */ + HVC_IUCV_MAGIC + id, &hvc_iucv_ops, 256); + if (IS_ERR(priv->hvc)) { + rc = PTR_ERR(priv->hvc); + goto out_error_hvc; + } + + /* notify HVC thread instead of using polling */ + priv->hvc->irq_requested = 1; + + /* setup iucv related information */ + snprintf(name, 9, "lnxhvc%-2d", id); + memcpy(priv->srv_name, name, 8); + ASCEBC(priv->srv_name, 8); + + /* create and setup device */ + priv->dev = kzalloc(sizeof(*priv->dev), GFP_KERNEL); + if (!priv->dev) { + rc = -ENOMEM; + goto out_error_dev; + } + dev_set_name(priv->dev, "hvc_iucv%d", id); + dev_set_drvdata(priv->dev, priv); + priv->dev->bus = &iucv_bus; + priv->dev->parent = iucv_root; + priv->dev->driver = &hvc_iucv_driver; + priv->dev->release = (void (*)(struct device *)) kfree; + rc = device_register(priv->dev); + if (rc) { + put_device(priv->dev); + goto out_error_dev; + } + + hvc_iucv_table[id] = priv; + return 0; + +out_error_dev: + hvc_remove(priv->hvc); +out_error_hvc: + free_page((unsigned long) priv->sndbuf); + kfree(priv); + + return rc; +} + +/** + * hvc_iucv_destroy() - Destroy and free hvc_iucv_private instances + */ +static void __init hvc_iucv_destroy(struct hvc_iucv_private *priv) +{ + hvc_remove(priv->hvc); + device_unregister(priv->dev); + free_page((unsigned long) priv->sndbuf); + kfree(priv); +} + +/** + * hvc_iucv_parse_filter() - Parse filter for a single z/VM user ID + * @filter: String containing a comma-separated list of z/VM user IDs + */ +static const char *hvc_iucv_parse_filter(const char *filter, char *dest) +{ + const char *nextdelim, *residual; + size_t len; + + nextdelim = strchr(filter, ','); + if (nextdelim) { + len = nextdelim - filter; + residual = nextdelim + 1; + } else { + len = strlen(filter); + residual = filter + len; + } + + if (len == 0) + return ERR_PTR(-EINVAL); + + /* check for '\n' (if called from sysfs) */ + if (filter[len - 1] == '\n') + len--; + + if (len > 8) + return ERR_PTR(-EINVAL); + + /* pad with blanks and save upper case version of user ID */ + memset(dest, ' ', 8); + while (len--) + dest[len] = toupper(filter[len]); + return residual; +} + +/** + * hvc_iucv_setup_filter() - Set up z/VM user ID filter + * @filter: String consisting of a comma-separated list of z/VM user IDs + * + * The function parses the @filter string and creates an array containing + * the list of z/VM user ID filter entries. + * Return code 0 means success, -EINVAL if the filter is syntactically + * incorrect, -ENOMEM if there was not enough memory to allocate the + * filter list array, or -ENOSPC if too many z/VM user IDs have been specified. + */ +static int hvc_iucv_setup_filter(const char *val) +{ + const char *residual; + int err; + size_t size, count; + void *array, *old_filter; + + count = strlen(val); + if (count == 0 || (count == 1 && val[0] == '\n')) { + size = 0; + array = NULL; + goto out_replace_filter; /* clear filter */ + } + + /* count user IDs in order to allocate sufficient memory */ + size = 1; + residual = val; + while ((residual = strchr(residual, ',')) != NULL) { + residual++; + size++; + } + + /* check if the specified list exceeds the filter limit */ + if (size > MAX_VMID_FILTER) + return -ENOSPC; + + array = kzalloc(size * 8, GFP_KERNEL); + if (!array) + return -ENOMEM; + + count = size; + residual = val; + while (*residual && count) { + residual = hvc_iucv_parse_filter(residual, + array + ((size - count) * 8)); + if (IS_ERR(residual)) { + err = PTR_ERR(residual); + kfree(array); + goto out_err; + } + count--; + } + +out_replace_filter: + write_lock_bh(&hvc_iucv_filter_lock); + old_filter = hvc_iucv_filter; + hvc_iucv_filter_size = size; + hvc_iucv_filter = array; + write_unlock_bh(&hvc_iucv_filter_lock); + kfree(old_filter); + + err = 0; +out_err: + return err; +} + +/** + * param_set_vmidfilter() - Set z/VM user ID filter parameter + * @val: String consisting of a comma-separated list of z/VM user IDs + * @kp: Kernel parameter pointing to hvc_iucv_filter array + * + * The function sets up the z/VM user ID filter specified as comma-separated + * list of user IDs in @val. + * Note: If it is called early in the boot process, @val is stored and + * parsed later in hvc_iucv_init(). + */ +static int param_set_vmidfilter(const char *val, const struct kernel_param *kp) +{ + int rc; + + if (!MACHINE_IS_VM || !hvc_iucv_devices) + return -ENODEV; + + if (!val) + return -EINVAL; + + rc = 0; + if (slab_is_available()) + rc = hvc_iucv_setup_filter(val); + else + hvc_iucv_filter_string = val; /* defer... */ + return rc; +} + +/** + * param_get_vmidfilter() - Get z/VM user ID filter + * @buffer: Buffer to store z/VM user ID filter, + * (buffer size assumption PAGE_SIZE) + * @kp: Kernel parameter pointing to the hvc_iucv_filter array + * + * The function stores the filter as a comma-separated list of z/VM user IDs + * in @buffer. Typically, sysfs routines call this function for attr show. + */ +static int param_get_vmidfilter(char *buffer, const struct kernel_param *kp) +{ + int rc; + size_t index, len; + void *start, *end; + + if (!MACHINE_IS_VM || !hvc_iucv_devices) + return -ENODEV; + + rc = 0; + read_lock_bh(&hvc_iucv_filter_lock); + for (index = 0; index < hvc_iucv_filter_size; index++) { + start = hvc_iucv_filter + (8 * index); + end = memchr(start, ' ', 8); + len = (end) ? end - start : 8; + memcpy(buffer + rc, start, len); + rc += len; + buffer[rc++] = ','; + } + read_unlock_bh(&hvc_iucv_filter_lock); + if (rc) + buffer[--rc] = '\0'; /* replace last comma and update rc */ + return rc; +} + +#define param_check_vmidfilter(name, p) __param_check(name, p, void) + +static struct kernel_param_ops param_ops_vmidfilter = { + .set = param_set_vmidfilter, + .get = param_get_vmidfilter, +}; + +/** + * hvc_iucv_init() - z/VM IUCV HVC device driver initialization + */ +static int __init hvc_iucv_init(void) +{ + int rc; + unsigned int i; + + if (!hvc_iucv_devices) + return -ENODEV; + + if (!MACHINE_IS_VM) { + pr_notice("The z/VM IUCV HVC device driver cannot " + "be used without z/VM\n"); + rc = -ENODEV; + goto out_error; + } + + if (hvc_iucv_devices > MAX_HVC_IUCV_LINES) { + pr_err("%lu is not a valid value for the hvc_iucv= " + "kernel parameter\n", hvc_iucv_devices); + rc = -EINVAL; + goto out_error; + } + + /* register IUCV HVC device driver */ + rc = driver_register(&hvc_iucv_driver); + if (rc) + goto out_error; + + /* parse hvc_iucv_allow string and create z/VM user ID filter list */ + if (hvc_iucv_filter_string) { + rc = hvc_iucv_setup_filter(hvc_iucv_filter_string); + switch (rc) { + case 0: + break; + case -ENOMEM: + pr_err("Allocating memory failed with " + "reason code=%d\n", 3); + goto out_error; + case -EINVAL: + pr_err("hvc_iucv_allow= does not specify a valid " + "z/VM user ID list\n"); + goto out_error; + case -ENOSPC: + pr_err("hvc_iucv_allow= specifies too many " + "z/VM user IDs\n"); + goto out_error; + default: + goto out_error; + } + } + + hvc_iucv_buffer_cache = kmem_cache_create(KMSG_COMPONENT, + sizeof(struct iucv_tty_buffer), + 0, 0, NULL); + if (!hvc_iucv_buffer_cache) { + pr_err("Allocating memory failed with reason code=%d\n", 1); + rc = -ENOMEM; + goto out_error; + } + + hvc_iucv_mempool = mempool_create_slab_pool(MEMPOOL_MIN_NR, + hvc_iucv_buffer_cache); + if (!hvc_iucv_mempool) { + pr_err("Allocating memory failed with reason code=%d\n", 2); + kmem_cache_destroy(hvc_iucv_buffer_cache); + rc = -ENOMEM; + goto out_error; + } + + /* register the first terminal device as console + * (must be done before allocating hvc terminal devices) */ + rc = hvc_instantiate(HVC_IUCV_MAGIC, IUCV_HVC_CON_IDX, &hvc_iucv_ops); + if (rc) { + pr_err("Registering HVC terminal device as " + "Linux console failed\n"); + goto out_error_memory; + } + + /* allocate hvc_iucv_private structs */ + for (i = 0; i < hvc_iucv_devices; i++) { + rc = hvc_iucv_alloc(i, (i == IUCV_HVC_CON_IDX) ? 1 : 0); + if (rc) { + pr_err("Creating a new HVC terminal device " + "failed with error code=%d\n", rc); + goto out_error_hvc; + } + } + + /* register IUCV callback handler */ + rc = iucv_register(&hvc_iucv_handler, 0); + if (rc) { + pr_err("Registering IUCV handlers failed with error code=%d\n", + rc); + goto out_error_hvc; + } + + return 0; + +out_error_hvc: + for (i = 0; i < hvc_iucv_devices; i++) + if (hvc_iucv_table[i]) + hvc_iucv_destroy(hvc_iucv_table[i]); +out_error_memory: + mempool_destroy(hvc_iucv_mempool); + kmem_cache_destroy(hvc_iucv_buffer_cache); +out_error: + if (hvc_iucv_filter) + kfree(hvc_iucv_filter); + hvc_iucv_devices = 0; /* ensure that we do not provide any device */ + return rc; +} + +/** + * hvc_iucv_config() - Parsing of hvc_iucv= kernel command line parameter + * @val: Parameter value (numeric) + */ +static int __init hvc_iucv_config(char *val) +{ + return strict_strtoul(val, 10, &hvc_iucv_devices); +} + + +device_initcall(hvc_iucv_init); +__setup("hvc_iucv=", hvc_iucv_config); +core_param(hvc_iucv_allow, hvc_iucv_filter, vmidfilter, 0640); diff --git a/drivers/tty/hvc/hvc_rtas.c b/drivers/tty/hvc/hvc_rtas.c new file mode 100644 index 000000000000..61c4a61558d9 --- /dev/null +++ b/drivers/tty/hvc/hvc_rtas.c @@ -0,0 +1,133 @@ +/* + * IBM RTAS driver interface to hvc_console.c + * + * (C) Copyright IBM Corporation 2001-2005 + * (C) Copyright Red Hat, Inc. 2005 + * + * Author(s): Maximino Augilar <IBM STI Design Center> + * : Ryan S. Arnold <rsa@us.ibm.com> + * : Utz Bacher <utz.bacher@de.ibm.com> + * : David Woodhouse <dwmw2@infradead.org> + * + * inspired by drivers/char/hvc_console.c + * written by Anton Blanchard and Paul Mackerras + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include <linux/console.h> +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/moduleparam.h> +#include <linux/types.h> + +#include <asm/irq.h> +#include <asm/rtas.h> +#include "hvc_console.h" + +#define hvc_rtas_cookie 0x67781e15 +struct hvc_struct *hvc_rtas_dev; + +static int rtascons_put_char_token = RTAS_UNKNOWN_SERVICE; +static int rtascons_get_char_token = RTAS_UNKNOWN_SERVICE; + +static inline int hvc_rtas_write_console(uint32_t vtermno, const char *buf, + int count) +{ + int i; + + for (i = 0; i < count; i++) { + if (rtas_call(rtascons_put_char_token, 1, 1, NULL, buf[i])) + break; + } + + return i; +} + +static int hvc_rtas_read_console(uint32_t vtermno, char *buf, int count) +{ + int i, c; + + for (i = 0; i < count; i++) { + if (rtas_call(rtascons_get_char_token, 0, 2, &c)) + break; + + buf[i] = c; + } + + return i; +} + +static const struct hv_ops hvc_rtas_get_put_ops = { + .get_chars = hvc_rtas_read_console, + .put_chars = hvc_rtas_write_console, +}; + +static int __init hvc_rtas_init(void) +{ + struct hvc_struct *hp; + + if (rtascons_put_char_token == RTAS_UNKNOWN_SERVICE) + rtascons_put_char_token = rtas_token("put-term-char"); + if (rtascons_put_char_token == RTAS_UNKNOWN_SERVICE) + return -EIO; + + if (rtascons_get_char_token == RTAS_UNKNOWN_SERVICE) + rtascons_get_char_token = rtas_token("get-term-char"); + if (rtascons_get_char_token == RTAS_UNKNOWN_SERVICE) + return -EIO; + + BUG_ON(hvc_rtas_dev); + + /* Allocate an hvc_struct for the console device we instantiated + * earlier. Save off hp so that we can return it on exit */ + hp = hvc_alloc(hvc_rtas_cookie, NO_IRQ, &hvc_rtas_get_put_ops, 16); + if (IS_ERR(hp)) + return PTR_ERR(hp); + + hvc_rtas_dev = hp; + + return 0; +} +module_init(hvc_rtas_init); + +/* This will tear down the tty portion of the driver */ +static void __exit hvc_rtas_exit(void) +{ + /* Really the fun isn't over until the worker thread breaks down and + * the tty cleans up */ + if (hvc_rtas_dev) + hvc_remove(hvc_rtas_dev); +} +module_exit(hvc_rtas_exit); + +/* This will happen prior to module init. There is no tty at this time? */ +static int __init hvc_rtas_console_init(void) +{ + rtascons_put_char_token = rtas_token("put-term-char"); + if (rtascons_put_char_token == RTAS_UNKNOWN_SERVICE) + return -EIO; + + rtascons_get_char_token = rtas_token("get-term-char"); + if (rtascons_get_char_token == RTAS_UNKNOWN_SERVICE) + return -EIO; + + hvc_instantiate(hvc_rtas_cookie, 0, &hvc_rtas_get_put_ops); + add_preferred_console("hvc", 0, NULL); + + return 0; +} +console_initcall(hvc_rtas_console_init); diff --git a/drivers/tty/hvc/hvc_tile.c b/drivers/tty/hvc/hvc_tile.c new file mode 100644 index 000000000000..7a84a0595477 --- /dev/null +++ b/drivers/tty/hvc/hvc_tile.c @@ -0,0 +1,68 @@ +/* + * Copyright 2010 Tilera Corporation. All Rights Reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation, version 2. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or + * NON INFRINGEMENT. See the GNU General Public License for + * more details. + * + * Tilera TILE Processor hypervisor console + */ + +#include <linux/console.h> +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/moduleparam.h> +#include <linux/types.h> + +#include <hv/hypervisor.h> + +#include "hvc_console.h" + +static int hvc_tile_put_chars(uint32_t vt, const char *buf, int count) +{ + return hv_console_write((HV_VirtAddr)buf, count); +} + +static int hvc_tile_get_chars(uint32_t vt, char *buf, int count) +{ + int i, c; + + for (i = 0; i < count; ++i) { + c = hv_console_read_if_ready(); + if (c < 0) + break; + buf[i] = c; + } + + return i; +} + +static const struct hv_ops hvc_tile_get_put_ops = { + .get_chars = hvc_tile_get_chars, + .put_chars = hvc_tile_put_chars, +}; + +static int __init hvc_tile_console_init(void) +{ + extern void disable_early_printk(void); + hvc_instantiate(0, 0, &hvc_tile_get_put_ops); + add_preferred_console("hvc", 0, NULL); + disable_early_printk(); + return 0; +} +console_initcall(hvc_tile_console_init); + +static int __init hvc_tile_init(void) +{ + struct hvc_struct *s; + s = hvc_alloc(0, 0, &hvc_tile_get_put_ops, 128); + return IS_ERR(s) ? PTR_ERR(s) : 0; +} +device_initcall(hvc_tile_init); diff --git a/drivers/tty/hvc/hvc_udbg.c b/drivers/tty/hvc/hvc_udbg.c new file mode 100644 index 000000000000..b0957e61a7be --- /dev/null +++ b/drivers/tty/hvc/hvc_udbg.c @@ -0,0 +1,96 @@ +/* + * udbg interface to hvc_console.c + * + * (C) Copyright David Gibson, IBM Corporation 2008. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include <linux/console.h> +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/moduleparam.h> +#include <linux/types.h> +#include <linux/irq.h> + +#include <asm/udbg.h> + +#include "hvc_console.h" + +struct hvc_struct *hvc_udbg_dev; + +static int hvc_udbg_put(uint32_t vtermno, const char *buf, int count) +{ + int i; + + for (i = 0; i < count; i++) + udbg_putc(buf[i]); + + return i; +} + +static int hvc_udbg_get(uint32_t vtermno, char *buf, int count) +{ + int i, c; + + if (!udbg_getc_poll) + return 0; + + for (i = 0; i < count; i++) { + if ((c = udbg_getc_poll()) == -1) + break; + buf[i] = c; + } + + return i; +} + +static const struct hv_ops hvc_udbg_ops = { + .get_chars = hvc_udbg_get, + .put_chars = hvc_udbg_put, +}; + +static int __init hvc_udbg_init(void) +{ + struct hvc_struct *hp; + + BUG_ON(hvc_udbg_dev); + + hp = hvc_alloc(0, NO_IRQ, &hvc_udbg_ops, 16); + if (IS_ERR(hp)) + return PTR_ERR(hp); + + hvc_udbg_dev = hp; + + return 0; +} +module_init(hvc_udbg_init); + +static void __exit hvc_udbg_exit(void) +{ + if (hvc_udbg_dev) + hvc_remove(hvc_udbg_dev); +} +module_exit(hvc_udbg_exit); + +static int __init hvc_udbg_console_init(void) +{ + hvc_instantiate(0, 0, &hvc_udbg_ops); + add_preferred_console("hvc", 0, NULL); + + return 0; +} +console_initcall(hvc_udbg_console_init); diff --git a/drivers/tty/hvc/hvc_vio.c b/drivers/tty/hvc/hvc_vio.c new file mode 100644 index 000000000000..5e2f52b33327 --- /dev/null +++ b/drivers/tty/hvc/hvc_vio.c @@ -0,0 +1,173 @@ +/* + * vio driver interface to hvc_console.c + * + * This code was moved here to allow the remaing code to be reused as a + * generic polling mode with semi-reliable transport driver core to the + * console and tty subsystems. + * + * + * Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM + * Copyright (C) 2001 Paul Mackerras <paulus@au.ibm.com>, IBM + * Copyright (C) 2004 Benjamin Herrenschmidt <benh@kernel.crashing.org>, IBM Corp. + * Copyright (C) 2004 IBM Corporation + * + * Additional Author(s): + * Ryan S. Arnold <rsa@us.ibm.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include <linux/types.h> +#include <linux/init.h> + +#include <asm/hvconsole.h> +#include <asm/vio.h> +#include <asm/prom.h> +#include <asm/firmware.h> + +#include "hvc_console.h" + +static const char hvc_driver_name[] = "hvc_console"; + +static struct vio_device_id hvc_driver_table[] __devinitdata = { + {"serial", "hvterm1"}, + { "", "" } +}; +MODULE_DEVICE_TABLE(vio, hvc_driver_table); + +static int filtered_get_chars(uint32_t vtermno, char *buf, int count) +{ + unsigned long got; + int i; + + /* + * Vio firmware will read up to SIZE_VIO_GET_CHARS at its own discretion + * so we play safe and avoid the situation where got > count which could + * overload the flip buffer. + */ + if (count < SIZE_VIO_GET_CHARS) + return -EAGAIN; + + got = hvc_get_chars(vtermno, buf, count); + + /* + * Work around a HV bug where it gives us a null + * after every \r. -- paulus + */ + for (i = 1; i < got; ++i) { + if (buf[i] == 0 && buf[i-1] == '\r') { + --got; + if (i < got) + memmove(&buf[i], &buf[i+1], + got - i); + } + } + return got; +} + +static const struct hv_ops hvc_get_put_ops = { + .get_chars = filtered_get_chars, + .put_chars = hvc_put_chars, + .notifier_add = notifier_add_irq, + .notifier_del = notifier_del_irq, + .notifier_hangup = notifier_hangup_irq, +}; + +static int __devinit hvc_vio_probe(struct vio_dev *vdev, + const struct vio_device_id *id) +{ + struct hvc_struct *hp; + + /* probed with invalid parameters. */ + if (!vdev || !id) + return -EPERM; + + hp = hvc_alloc(vdev->unit_address, vdev->irq, &hvc_get_put_ops, + MAX_VIO_PUT_CHARS); + if (IS_ERR(hp)) + return PTR_ERR(hp); + dev_set_drvdata(&vdev->dev, hp); + + return 0; +} + +static int __devexit hvc_vio_remove(struct vio_dev *vdev) +{ + struct hvc_struct *hp = dev_get_drvdata(&vdev->dev); + + return hvc_remove(hp); +} + +static struct vio_driver hvc_vio_driver = { + .id_table = hvc_driver_table, + .probe = hvc_vio_probe, + .remove = __devexit_p(hvc_vio_remove), + .driver = { + .name = hvc_driver_name, + .owner = THIS_MODULE, + } +}; + +static int __init hvc_vio_init(void) +{ + int rc; + + if (firmware_has_feature(FW_FEATURE_ISERIES)) + return -EIO; + + /* Register as a vio device to receive callbacks */ + rc = vio_register_driver(&hvc_vio_driver); + + return rc; +} +module_init(hvc_vio_init); /* after drivers/char/hvc_console.c */ + +static void __exit hvc_vio_exit(void) +{ + vio_unregister_driver(&hvc_vio_driver); +} +module_exit(hvc_vio_exit); + +/* the device tree order defines our numbering */ +static int hvc_find_vtys(void) +{ + struct device_node *vty; + int num_found = 0; + + for (vty = of_find_node_by_name(NULL, "vty"); vty != NULL; + vty = of_find_node_by_name(vty, "vty")) { + const uint32_t *vtermno; + + /* We have statically defined space for only a certain number + * of console adapters. + */ + if (num_found >= MAX_NR_HVC_CONSOLES) { + of_node_put(vty); + break; + } + + vtermno = of_get_property(vty, "reg", NULL); + if (!vtermno) + continue; + + if (of_device_is_compatible(vty, "hvterm1")) { + hvc_instantiate(*vtermno, num_found, &hvc_get_put_ops); + ++num_found; + } + } + + return num_found; +} +console_initcall(hvc_find_vtys); diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c new file mode 100644 index 000000000000..3740e327f180 --- /dev/null +++ b/drivers/tty/hvc/hvc_xen.c @@ -0,0 +1,271 @@ +/* + * xen console driver interface to hvc_console.c + * + * (c) 2007 Gerd Hoffmann <kraxel@suse.de> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include <linux/console.h> +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/types.h> + +#include <asm/xen/hypervisor.h> + +#include <xen/xen.h> +#include <xen/page.h> +#include <xen/events.h> +#include <xen/interface/io/console.h> +#include <xen/hvc-console.h> + +#include "hvc_console.h" + +#define HVC_COOKIE 0x58656e /* "Xen" in hex */ + +static struct hvc_struct *hvc; +static int xencons_irq; + +/* ------------------------------------------------------------------ */ + +static unsigned long console_pfn = ~0ul; + +static inline struct xencons_interface *xencons_interface(void) +{ + if (console_pfn == ~0ul) + return mfn_to_virt(xen_start_info->console.domU.mfn); + else + return __va(console_pfn << PAGE_SHIFT); +} + +static inline void notify_daemon(void) +{ + /* Use evtchn: this is called early, before irq is set up. */ + notify_remote_via_evtchn(xen_start_info->console.domU.evtchn); +} + +static int __write_console(const char *data, int len) +{ + struct xencons_interface *intf = xencons_interface(); + XENCONS_RING_IDX cons, prod; + int sent = 0; + + cons = intf->out_cons; + prod = intf->out_prod; + mb(); /* update queue values before going on */ + BUG_ON((prod - cons) > sizeof(intf->out)); + + while ((sent < len) && ((prod - cons) < sizeof(intf->out))) + intf->out[MASK_XENCONS_IDX(prod++, intf->out)] = data[sent++]; + + wmb(); /* write ring before updating pointer */ + intf->out_prod = prod; + + if (sent) + notify_daemon(); + return sent; +} + +static int domU_write_console(uint32_t vtermno, const char *data, int len) +{ + int ret = len; + + /* + * Make sure the whole buffer is emitted, polling if + * necessary. We don't ever want to rely on the hvc daemon + * because the most interesting console output is when the + * kernel is crippled. + */ + while (len) { + int sent = __write_console(data, len); + + data += sent; + len -= sent; + + if (unlikely(len)) + HYPERVISOR_sched_op(SCHEDOP_yield, NULL); + } + + return ret; +} + +static int domU_read_console(uint32_t vtermno, char *buf, int len) +{ + struct xencons_interface *intf = xencons_interface(); + XENCONS_RING_IDX cons, prod; + int recv = 0; + + cons = intf->in_cons; + prod = intf->in_prod; + mb(); /* get pointers before reading ring */ + BUG_ON((prod - cons) > sizeof(intf->in)); + + while (cons != prod && recv < len) + buf[recv++] = intf->in[MASK_XENCONS_IDX(cons++, intf->in)]; + + mb(); /* read ring before consuming */ + intf->in_cons = cons; + + notify_daemon(); + return recv; +} + +static struct hv_ops domU_hvc_ops = { + .get_chars = domU_read_console, + .put_chars = domU_write_console, + .notifier_add = notifier_add_irq, + .notifier_del = notifier_del_irq, + .notifier_hangup = notifier_hangup_irq, +}; + +static int dom0_read_console(uint32_t vtermno, char *buf, int len) +{ + return HYPERVISOR_console_io(CONSOLEIO_read, len, buf); +} + +/* + * Either for a dom0 to write to the system console, or a domU with a + * debug version of Xen + */ +static int dom0_write_console(uint32_t vtermno, const char *str, int len) +{ + int rc = HYPERVISOR_console_io(CONSOLEIO_write, len, (char *)str); + if (rc < 0) + return 0; + + return len; +} + +static struct hv_ops dom0_hvc_ops = { + .get_chars = dom0_read_console, + .put_chars = dom0_write_console, + .notifier_add = notifier_add_irq, + .notifier_del = notifier_del_irq, + .notifier_hangup = notifier_hangup_irq, +}; + +static int __init xen_hvc_init(void) +{ + struct hvc_struct *hp; + struct hv_ops *ops; + + if (!xen_pv_domain()) + return -ENODEV; + + if (xen_initial_domain()) { + ops = &dom0_hvc_ops; + xencons_irq = bind_virq_to_irq(VIRQ_CONSOLE, 0); + } else { + if (!xen_start_info->console.domU.evtchn) + return -ENODEV; + + ops = &domU_hvc_ops; + xencons_irq = bind_evtchn_to_irq(xen_start_info->console.domU.evtchn); + } + if (xencons_irq < 0) + xencons_irq = 0; /* NO_IRQ */ + + hp = hvc_alloc(HVC_COOKIE, xencons_irq, ops, 256); + if (IS_ERR(hp)) + return PTR_ERR(hp); + + hvc = hp; + + console_pfn = mfn_to_pfn(xen_start_info->console.domU.mfn); + + return 0; +} + +void xen_console_resume(void) +{ + if (xencons_irq) + rebind_evtchn_irq(xen_start_info->console.domU.evtchn, xencons_irq); +} + +static void __exit xen_hvc_fini(void) +{ + if (hvc) + hvc_remove(hvc); +} + +static int xen_cons_init(void) +{ + struct hv_ops *ops; + + if (!xen_pv_domain()) + return 0; + + if (xen_initial_domain()) + ops = &dom0_hvc_ops; + else + ops = &domU_hvc_ops; + + hvc_instantiate(HVC_COOKIE, 0, ops); + return 0; +} + +module_init(xen_hvc_init); +module_exit(xen_hvc_fini); +console_initcall(xen_cons_init); + +#ifdef CONFIG_EARLY_PRINTK +static void xenboot_write_console(struct console *console, const char *string, + unsigned len) +{ + unsigned int linelen, off = 0; + const char *pos; + + dom0_write_console(0, string, len); + + if (xen_initial_domain()) + return; + + domU_write_console(0, "(early) ", 8); + while (off < len && NULL != (pos = strchr(string+off, '\n'))) { + linelen = pos-string+off; + if (off + linelen > len) + break; + domU_write_console(0, string+off, linelen); + domU_write_console(0, "\r\n", 2); + off += linelen + 1; + } + if (off < len) + domU_write_console(0, string+off, len-off); +} + +struct console xenboot_console = { + .name = "xenboot", + .write = xenboot_write_console, + .flags = CON_PRINTBUFFER | CON_BOOT | CON_ANYTIME, +}; +#endif /* CONFIG_EARLY_PRINTK */ + +void xen_raw_console_write(const char *str) +{ + dom0_write_console(0, str, strlen(str)); +} + +void xen_raw_printk(const char *fmt, ...) +{ + static char buf[512]; + va_list ap; + + va_start(ap, fmt); + vsnprintf(buf, sizeof(buf), fmt, ap); + va_end(ap); + + xen_raw_console_write(buf); +} diff --git a/drivers/tty/hvc/hvcs.c b/drivers/tty/hvc/hvcs.c new file mode 100644 index 000000000000..bedc6c1b6fa5 --- /dev/null +++ b/drivers/tty/hvc/hvcs.c @@ -0,0 +1,1604 @@ +/* + * IBM eServer Hypervisor Virtual Console Server Device Driver + * Copyright (C) 2003, 2004 IBM Corp. + * Ryan S. Arnold (rsa@us.ibm.com) + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Author(s) : Ryan S. Arnold <rsa@us.ibm.com> + * + * This is the device driver for the IBM Hypervisor Virtual Console Server, + * "hvcs". The IBM hvcs provides a tty driver interface to allow Linux + * user space applications access to the system consoles of logically + * partitioned operating systems, e.g. Linux, running on the same partitioned + * Power5 ppc64 system. Physical hardware consoles per partition are not + * practical on this hardware so system consoles are accessed by this driver + * using inter-partition firmware interfaces to virtual terminal devices. + * + * A vty is known to the HMC as a "virtual serial server adapter". It is a + * virtual terminal device that is created by firmware upon partition creation + * to act as a partitioned OS's console device. + * + * Firmware dynamically (via hotplug) exposes vty-servers to a running ppc64 + * Linux system upon their creation by the HMC or their exposure during boot. + * The non-user interactive backend of this driver is implemented as a vio + * device driver so that it can receive notification of vty-server lifetimes + * after it registers with the vio bus to handle vty-server probe and remove + * callbacks. + * + * Many vty-servers can be configured to connect to one vty, but a vty can + * only be actively connected to by a single vty-server, in any manner, at one + * time. If the HMC is currently hosting the console for a target Linux + * partition; attempts to open the tty device to the partition's console using + * the hvcs on any partition will return -EBUSY with every open attempt until + * the HMC frees the connection between its vty-server and the desired + * partition's vty device. Conversely, a vty-server may only be connected to + * a single vty at one time even though it may have several configured vty + * partner possibilities. + * + * Firmware does not provide notification of vty partner changes to this + * driver. This means that an HMC Super Admin may add or remove partner vtys + * from a vty-server's partner list but the changes will not be signaled to + * the vty-server. Firmware only notifies the driver when a vty-server is + * added or removed from the system. To compensate for this deficiency, this + * driver implements a sysfs update attribute which provides a method for + * rescanning partner information upon a user's request. + * + * Each vty-server, prior to being exposed to this driver is reference counted + * using the 2.6 Linux kernel kref construct. + * + * For direction on installation and usage of this driver please reference + * Documentation/powerpc/hvcs.txt. + */ + +#include <linux/device.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/kernel.h> +#include <linux/kref.h> +#include <linux/kthread.h> +#include <linux/list.h> +#include <linux/major.h> +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/stat.h> +#include <linux/tty.h> +#include <linux/tty_flip.h> +#include <asm/hvconsole.h> +#include <asm/hvcserver.h> +#include <asm/uaccess.h> +#include <asm/vio.h> + +/* + * 1.3.0 -> 1.3.1 In hvcs_open memset(..,0x00,..) instead of memset(..,0x3F,00). + * Removed braces around single statements following conditionals. Removed '= + * 0' after static int declarations since these default to zero. Removed + * list_for_each_safe() and replaced with list_for_each_entry() in + * hvcs_get_by_index(). The 'safe' version is un-needed now that the driver is + * using spinlocks. Changed spin_lock_irqsave() to spin_lock() when locking + * hvcs_structs_lock and hvcs_pi_lock since these are not touched in an int + * handler. Initialized hvcs_structs_lock and hvcs_pi_lock to + * SPIN_LOCK_UNLOCKED at declaration time rather than in hvcs_module_init(). + * Added spin_lock around list_del() in destroy_hvcs_struct() to protect the + * list traversals from a deletion. Removed '= NULL' from pointer declaration + * statements since they are initialized NULL by default. Removed wmb() + * instances from hvcs_try_write(). They probably aren't needed with locking in + * place. Added check and cleanup for hvcs_pi_buff = kmalloc() in + * hvcs_module_init(). Exposed hvcs_struct.index via a sysfs attribute so that + * the coupling between /dev/hvcs* and a vty-server can be automatically + * determined. Moved kobject_put() in hvcs_open outside of the + * spin_unlock_irqrestore(). + * + * 1.3.1 -> 1.3.2 Changed method for determining hvcs_struct->index and had it + * align with how the tty layer always assigns the lowest index available. This + * change resulted in a list of ints that denotes which indexes are available. + * Device additions and removals use the new hvcs_get_index() and + * hvcs_return_index() helper functions. The list is created with + * hvsc_alloc_index_list() and it is destroyed with hvcs_free_index_list(). + * Without these fixes hotplug vty-server adapter support goes crazy with this + * driver if the user removes a vty-server adapter. Moved free_irq() outside of + * the hvcs_final_close() function in order to get it out of the spinlock. + * Rearranged hvcs_close(). Cleaned up some printks and did some housekeeping + * on the changelog. Removed local CLC_LENGTH and used HVCS_CLC_LENGTH from + * arch/powerepc/include/asm/hvcserver.h + * + * 1.3.2 -> 1.3.3 Replaced yield() in hvcs_close() with tty_wait_until_sent() to + * prevent possible lockup with realtime scheduling as similarily pointed out by + * akpm in hvc_console. Changed resulted in the removal of hvcs_final_close() + * to reorder cleanup operations and prevent discarding of pending data during + * an hvcs_close(). Removed spinlock protection of hvcs_struct data members in + * hvcs_write_room() and hvcs_chars_in_buffer() because they aren't needed. + */ + +#define HVCS_DRIVER_VERSION "1.3.3" + +MODULE_AUTHOR("Ryan S. Arnold <rsa@us.ibm.com>"); +MODULE_DESCRIPTION("IBM hvcs (Hypervisor Virtual Console Server) Driver"); +MODULE_LICENSE("GPL"); +MODULE_VERSION(HVCS_DRIVER_VERSION); + +/* + * Wait this long per iteration while trying to push buffered data to the + * hypervisor before allowing the tty to complete a close operation. + */ +#define HVCS_CLOSE_WAIT (HZ/100) /* 1/10 of a second */ + +/* + * Since the Linux TTY code does not currently (2-04-2004) support dynamic + * addition of tty derived devices and we shouldn't allocate thousands of + * tty_device pointers when the number of vty-server & vty partner connections + * will most often be much lower than this, we'll arbitrarily allocate + * HVCS_DEFAULT_SERVER_ADAPTERS tty_structs and cdev's by default when we + * register the tty_driver. This can be overridden using an insmod parameter. + */ +#define HVCS_DEFAULT_SERVER_ADAPTERS 64 + +/* + * The user can't insmod with more than HVCS_MAX_SERVER_ADAPTERS hvcs device + * nodes as a sanity check. Theoretically there can be over 1 Billion + * vty-server & vty partner connections. + */ +#define HVCS_MAX_SERVER_ADAPTERS 1024 + +/* + * We let Linux assign us a major number and we start the minors at zero. There + * is no intuitive mapping between minor number and the target vty-server + * adapter except that each new vty-server adapter is always assigned to the + * smallest minor number available. + */ +#define HVCS_MINOR_START 0 + +/* + * The hcall interface involves putting 8 chars into each of two registers. + * We load up those 2 registers (in arch/powerpc/platforms/pseries/hvconsole.c) + * by casting char[16] to long[2]. It would work without __ALIGNED__, but a + * little (tiny) bit slower because an unaligned load is slower than aligned + * load. + */ +#define __ALIGNED__ __attribute__((__aligned__(8))) + +/* + * How much data can firmware send with each hvc_put_chars()? Maybe this + * should be moved into an architecture specific area. + */ +#define HVCS_BUFF_LEN 16 + +/* + * This is the maximum amount of data we'll let the user send us (hvcs_write) at + * once in a chunk as a sanity check. + */ +#define HVCS_MAX_FROM_USER 4096 + +/* + * Be careful when adding flags to this line discipline. Don't add anything + * that will cause echoing or we'll go into recursive loop echoing chars back + * and forth with the console drivers. + */ +static struct ktermios hvcs_tty_termios = { + .c_iflag = IGNBRK | IGNPAR, + .c_oflag = OPOST, + .c_cflag = B38400 | CS8 | CREAD | HUPCL, + .c_cc = INIT_C_CC, + .c_ispeed = 38400, + .c_ospeed = 38400 +}; + +/* + * This value is used to take the place of a command line parameter when the + * module is inserted. It starts as -1 and stays as such if the user doesn't + * specify a module insmod parameter. If they DO specify one then it is set to + * the value of the integer passed in. + */ +static int hvcs_parm_num_devs = -1; +module_param(hvcs_parm_num_devs, int, 0); + +static const char hvcs_driver_name[] = "hvcs"; +static const char hvcs_device_node[] = "hvcs"; +static const char hvcs_driver_string[] + = "IBM hvcs (Hypervisor Virtual Console Server) Driver"; + +/* Status of partner info rescan triggered via sysfs. */ +static int hvcs_rescan_status; + +static struct tty_driver *hvcs_tty_driver; + +/* + * In order to be somewhat sane this driver always associates the hvcs_struct + * index element with the numerically equal tty->index. This means that a + * hotplugged vty-server adapter will always map to the lowest index valued + * device node. If vty-servers were hotplug removed from the system and then + * new ones added the new vty-server may have the largest slot number of all + * the vty-server adapters in the partition but it may have the lowest dev node + * index of all the adapters due to the hole left by the hotplug removed + * adapter. There are a set of functions provided to get the lowest index for + * a new device as well as return the index to the list. This list is allocated + * with a number of elements equal to the number of device nodes requested when + * the module was inserted. + */ +static int *hvcs_index_list; + +/* + * How large is the list? This is kept for traversal since the list is + * dynamically created. + */ +static int hvcs_index_count; + +/* + * Used by the khvcsd to pick up I/O operations when the kernel_thread is + * already awake but potentially shifted to TASK_INTERRUPTIBLE state. + */ +static int hvcs_kicked; + +/* + * Use by the kthread construct for task operations like waking the sleeping + * thread and stopping the kthread. + */ +static struct task_struct *hvcs_task; + +/* + * We allocate this for the use of all of the hvcs_structs when they fetch + * partner info. + */ +static unsigned long *hvcs_pi_buff; + +/* Only allow one hvcs_struct to use the hvcs_pi_buff at a time. */ +static DEFINE_SPINLOCK(hvcs_pi_lock); + +/* One vty-server per hvcs_struct */ +struct hvcs_struct { + spinlock_t lock; + + /* + * This index identifies this hvcs device as the complement to a + * specific tty index. + */ + unsigned int index; + + struct tty_struct *tty; + int open_count; + + /* + * Used to tell the driver kernel_thread what operations need to take + * place upon this hvcs_struct instance. + */ + int todo_mask; + + /* + * This buffer is required so that when hvcs_write_room() reports that + * it can send HVCS_BUFF_LEN characters that it will buffer the full + * HVCS_BUFF_LEN characters if need be. This is essential for opost + * writes since they do not do high level buffering and expect to be + * able to send what the driver commits to sending buffering + * [e.g. tab to space conversions in n_tty.c opost()]. + */ + char buffer[HVCS_BUFF_LEN]; + int chars_in_buffer; + + /* + * Any variable below the kref is valid before a tty is connected and + * stays valid after the tty is disconnected. These shouldn't be + * whacked until the koject refcount reaches zero though some entries + * may be changed via sysfs initiatives. + */ + struct kref kref; /* ref count & hvcs_struct lifetime */ + int connected; /* is the vty-server currently connected to a vty? */ + uint32_t p_unit_address; /* partner unit address */ + uint32_t p_partition_ID; /* partner partition ID */ + char p_location_code[HVCS_CLC_LENGTH + 1]; /* CLC + Null Term */ + struct list_head next; /* list management */ + struct vio_dev *vdev; +}; + +/* Required to back map a kref to its containing object */ +#define from_kref(k) container_of(k, struct hvcs_struct, kref) + +static LIST_HEAD(hvcs_structs); +static DEFINE_SPINLOCK(hvcs_structs_lock); + +static void hvcs_unthrottle(struct tty_struct *tty); +static void hvcs_throttle(struct tty_struct *tty); +static irqreturn_t hvcs_handle_interrupt(int irq, void *dev_instance); + +static int hvcs_write(struct tty_struct *tty, + const unsigned char *buf, int count); +static int hvcs_write_room(struct tty_struct *tty); +static int hvcs_chars_in_buffer(struct tty_struct *tty); + +static int hvcs_has_pi(struct hvcs_struct *hvcsd); +static void hvcs_set_pi(struct hvcs_partner_info *pi, + struct hvcs_struct *hvcsd); +static int hvcs_get_pi(struct hvcs_struct *hvcsd); +static int hvcs_rescan_devices_list(void); + +static int hvcs_partner_connect(struct hvcs_struct *hvcsd); +static void hvcs_partner_free(struct hvcs_struct *hvcsd); + +static int hvcs_enable_device(struct hvcs_struct *hvcsd, + uint32_t unit_address, unsigned int irq, struct vio_dev *dev); + +static int hvcs_open(struct tty_struct *tty, struct file *filp); +static void hvcs_close(struct tty_struct *tty, struct file *filp); +static void hvcs_hangup(struct tty_struct * tty); + +static int __devinit hvcs_probe(struct vio_dev *dev, + const struct vio_device_id *id); +static int __devexit hvcs_remove(struct vio_dev *dev); +static int __init hvcs_module_init(void); +static void __exit hvcs_module_exit(void); + +#define HVCS_SCHED_READ 0x00000001 +#define HVCS_QUICK_READ 0x00000002 +#define HVCS_TRY_WRITE 0x00000004 +#define HVCS_READ_MASK (HVCS_SCHED_READ | HVCS_QUICK_READ) + +static inline struct hvcs_struct *from_vio_dev(struct vio_dev *viod) +{ + return dev_get_drvdata(&viod->dev); +} +/* The sysfs interface for the driver and devices */ + +static ssize_t hvcs_partner_vtys_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct vio_dev *viod = to_vio_dev(dev); + struct hvcs_struct *hvcsd = from_vio_dev(viod); + unsigned long flags; + int retval; + + spin_lock_irqsave(&hvcsd->lock, flags); + retval = sprintf(buf, "%X\n", hvcsd->p_unit_address); + spin_unlock_irqrestore(&hvcsd->lock, flags); + return retval; +} +static DEVICE_ATTR(partner_vtys, S_IRUGO, hvcs_partner_vtys_show, NULL); + +static ssize_t hvcs_partner_clcs_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct vio_dev *viod = to_vio_dev(dev); + struct hvcs_struct *hvcsd = from_vio_dev(viod); + unsigned long flags; + int retval; + + spin_lock_irqsave(&hvcsd->lock, flags); + retval = sprintf(buf, "%s\n", &hvcsd->p_location_code[0]); + spin_unlock_irqrestore(&hvcsd->lock, flags); + return retval; +} +static DEVICE_ATTR(partner_clcs, S_IRUGO, hvcs_partner_clcs_show, NULL); + +static ssize_t hvcs_current_vty_store(struct device *dev, struct device_attribute *attr, const char * buf, + size_t count) +{ + /* + * Don't need this feature at the present time because firmware doesn't + * yet support multiple partners. + */ + printk(KERN_INFO "HVCS: Denied current_vty change: -EPERM.\n"); + return -EPERM; +} + +static ssize_t hvcs_current_vty_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct vio_dev *viod = to_vio_dev(dev); + struct hvcs_struct *hvcsd = from_vio_dev(viod); + unsigned long flags; + int retval; + + spin_lock_irqsave(&hvcsd->lock, flags); + retval = sprintf(buf, "%s\n", &hvcsd->p_location_code[0]); + spin_unlock_irqrestore(&hvcsd->lock, flags); + return retval; +} + +static DEVICE_ATTR(current_vty, + S_IRUGO | S_IWUSR, hvcs_current_vty_show, hvcs_current_vty_store); + +static ssize_t hvcs_vterm_state_store(struct device *dev, struct device_attribute *attr, const char *buf, + size_t count) +{ + struct vio_dev *viod = to_vio_dev(dev); + struct hvcs_struct *hvcsd = from_vio_dev(viod); + unsigned long flags; + + /* writing a '0' to this sysfs entry will result in the disconnect. */ + if (simple_strtol(buf, NULL, 0) != 0) + return -EINVAL; + + spin_lock_irqsave(&hvcsd->lock, flags); + + if (hvcsd->open_count > 0) { + spin_unlock_irqrestore(&hvcsd->lock, flags); + printk(KERN_INFO "HVCS: vterm state unchanged. " + "The hvcs device node is still in use.\n"); + return -EPERM; + } + + if (hvcsd->connected == 0) { + spin_unlock_irqrestore(&hvcsd->lock, flags); + printk(KERN_INFO "HVCS: vterm state unchanged. The" + " vty-server is not connected to a vty.\n"); + return -EPERM; + } + + hvcs_partner_free(hvcsd); + printk(KERN_INFO "HVCS: Closed vty-server@%X and" + " partner vty@%X:%d connection.\n", + hvcsd->vdev->unit_address, + hvcsd->p_unit_address, + (uint32_t)hvcsd->p_partition_ID); + + spin_unlock_irqrestore(&hvcsd->lock, flags); + return count; +} + +static ssize_t hvcs_vterm_state_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct vio_dev *viod = to_vio_dev(dev); + struct hvcs_struct *hvcsd = from_vio_dev(viod); + unsigned long flags; + int retval; + + spin_lock_irqsave(&hvcsd->lock, flags); + retval = sprintf(buf, "%d\n", hvcsd->connected); + spin_unlock_irqrestore(&hvcsd->lock, flags); + return retval; +} +static DEVICE_ATTR(vterm_state, S_IRUGO | S_IWUSR, + hvcs_vterm_state_show, hvcs_vterm_state_store); + +static ssize_t hvcs_index_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct vio_dev *viod = to_vio_dev(dev); + struct hvcs_struct *hvcsd = from_vio_dev(viod); + unsigned long flags; + int retval; + + spin_lock_irqsave(&hvcsd->lock, flags); + retval = sprintf(buf, "%d\n", hvcsd->index); + spin_unlock_irqrestore(&hvcsd->lock, flags); + return retval; +} + +static DEVICE_ATTR(index, S_IRUGO, hvcs_index_show, NULL); + +static struct attribute *hvcs_attrs[] = { + &dev_attr_partner_vtys.attr, + &dev_attr_partner_clcs.attr, + &dev_attr_current_vty.attr, + &dev_attr_vterm_state.attr, + &dev_attr_index.attr, + NULL, +}; + +static struct attribute_group hvcs_attr_group = { + .attrs = hvcs_attrs, +}; + +static ssize_t hvcs_rescan_show(struct device_driver *ddp, char *buf) +{ + /* A 1 means it is updating, a 0 means it is done updating */ + return snprintf(buf, PAGE_SIZE, "%d\n", hvcs_rescan_status); +} + +static ssize_t hvcs_rescan_store(struct device_driver *ddp, const char * buf, + size_t count) +{ + if ((simple_strtol(buf, NULL, 0) != 1) + && (hvcs_rescan_status != 0)) + return -EINVAL; + + hvcs_rescan_status = 1; + printk(KERN_INFO "HVCS: rescanning partner info for all" + " vty-servers.\n"); + hvcs_rescan_devices_list(); + hvcs_rescan_status = 0; + return count; +} + +static DRIVER_ATTR(rescan, + S_IRUGO | S_IWUSR, hvcs_rescan_show, hvcs_rescan_store); + +static void hvcs_kick(void) +{ + hvcs_kicked = 1; + wmb(); + wake_up_process(hvcs_task); +} + +static void hvcs_unthrottle(struct tty_struct *tty) +{ + struct hvcs_struct *hvcsd = tty->driver_data; + unsigned long flags; + + spin_lock_irqsave(&hvcsd->lock, flags); + hvcsd->todo_mask |= HVCS_SCHED_READ; + spin_unlock_irqrestore(&hvcsd->lock, flags); + hvcs_kick(); +} + +static void hvcs_throttle(struct tty_struct *tty) +{ + struct hvcs_struct *hvcsd = tty->driver_data; + unsigned long flags; + + spin_lock_irqsave(&hvcsd->lock, flags); + vio_disable_interrupts(hvcsd->vdev); + spin_unlock_irqrestore(&hvcsd->lock, flags); +} + +/* + * If the device is being removed we don't have to worry about this interrupt + * handler taking any further interrupts because they are disabled which means + * the hvcs_struct will always be valid in this handler. + */ +static irqreturn_t hvcs_handle_interrupt(int irq, void *dev_instance) +{ + struct hvcs_struct *hvcsd = dev_instance; + + spin_lock(&hvcsd->lock); + vio_disable_interrupts(hvcsd->vdev); + hvcsd->todo_mask |= HVCS_SCHED_READ; + spin_unlock(&hvcsd->lock); + hvcs_kick(); + + return IRQ_HANDLED; +} + +/* This function must be called with the hvcsd->lock held */ +static void hvcs_try_write(struct hvcs_struct *hvcsd) +{ + uint32_t unit_address = hvcsd->vdev->unit_address; + struct tty_struct *tty = hvcsd->tty; + int sent; + + if (hvcsd->todo_mask & HVCS_TRY_WRITE) { + /* won't send partial writes */ + sent = hvc_put_chars(unit_address, + &hvcsd->buffer[0], + hvcsd->chars_in_buffer ); + if (sent > 0) { + hvcsd->chars_in_buffer = 0; + /* wmb(); */ + hvcsd->todo_mask &= ~(HVCS_TRY_WRITE); + /* wmb(); */ + + /* + * We are still obligated to deliver the data to the + * hypervisor even if the tty has been closed because + * we commited to delivering it. But don't try to wake + * a non-existent tty. + */ + if (tty) { + tty_wakeup(tty); + } + } + } +} + +static int hvcs_io(struct hvcs_struct *hvcsd) +{ + uint32_t unit_address; + struct tty_struct *tty; + char buf[HVCS_BUFF_LEN] __ALIGNED__; + unsigned long flags; + int got = 0; + + spin_lock_irqsave(&hvcsd->lock, flags); + + unit_address = hvcsd->vdev->unit_address; + tty = hvcsd->tty; + + hvcs_try_write(hvcsd); + + if (!tty || test_bit(TTY_THROTTLED, &tty->flags)) { + hvcsd->todo_mask &= ~(HVCS_READ_MASK); + goto bail; + } else if (!(hvcsd->todo_mask & (HVCS_READ_MASK))) + goto bail; + + /* remove the read masks */ + hvcsd->todo_mask &= ~(HVCS_READ_MASK); + + if (tty_buffer_request_room(tty, HVCS_BUFF_LEN) >= HVCS_BUFF_LEN) { + got = hvc_get_chars(unit_address, + &buf[0], + HVCS_BUFF_LEN); + tty_insert_flip_string(tty, buf, got); + } + + /* Give the TTY time to process the data we just sent. */ + if (got) + hvcsd->todo_mask |= HVCS_QUICK_READ; + + spin_unlock_irqrestore(&hvcsd->lock, flags); + /* This is synch because tty->low_latency == 1 */ + if(got) + tty_flip_buffer_push(tty); + + if (!got) { + /* Do this _after_ the flip_buffer_push */ + spin_lock_irqsave(&hvcsd->lock, flags); + vio_enable_interrupts(hvcsd->vdev); + spin_unlock_irqrestore(&hvcsd->lock, flags); + } + + return hvcsd->todo_mask; + + bail: + spin_unlock_irqrestore(&hvcsd->lock, flags); + return hvcsd->todo_mask; +} + +static int khvcsd(void *unused) +{ + struct hvcs_struct *hvcsd; + int hvcs_todo_mask; + + __set_current_state(TASK_RUNNING); + + do { + hvcs_todo_mask = 0; + hvcs_kicked = 0; + wmb(); + + spin_lock(&hvcs_structs_lock); + list_for_each_entry(hvcsd, &hvcs_structs, next) { + hvcs_todo_mask |= hvcs_io(hvcsd); + } + spin_unlock(&hvcs_structs_lock); + + /* + * If any of the hvcs adapters want to try a write or quick read + * don't schedule(), yield a smidgen then execute the hvcs_io + * thread again for those that want the write. + */ + if (hvcs_todo_mask & (HVCS_TRY_WRITE | HVCS_QUICK_READ)) { + yield(); + continue; + } + + set_current_state(TASK_INTERRUPTIBLE); + if (!hvcs_kicked) + schedule(); + __set_current_state(TASK_RUNNING); + } while (!kthread_should_stop()); + + return 0; +} + +static struct vio_device_id hvcs_driver_table[] __devinitdata= { + {"serial-server", "hvterm2"}, + { "", "" } +}; +MODULE_DEVICE_TABLE(vio, hvcs_driver_table); + +static void hvcs_return_index(int index) +{ + /* Paranoia check */ + if (!hvcs_index_list) + return; + if (index < 0 || index >= hvcs_index_count) + return; + if (hvcs_index_list[index] == -1) + return; + else + hvcs_index_list[index] = -1; +} + +/* callback when the kref ref count reaches zero */ +static void destroy_hvcs_struct(struct kref *kref) +{ + struct hvcs_struct *hvcsd = from_kref(kref); + struct vio_dev *vdev; + unsigned long flags; + + spin_lock(&hvcs_structs_lock); + spin_lock_irqsave(&hvcsd->lock, flags); + + /* the list_del poisons the pointers */ + list_del(&(hvcsd->next)); + + if (hvcsd->connected == 1) { + hvcs_partner_free(hvcsd); + printk(KERN_INFO "HVCS: Closed vty-server@%X and" + " partner vty@%X:%d connection.\n", + hvcsd->vdev->unit_address, + hvcsd->p_unit_address, + (uint32_t)hvcsd->p_partition_ID); + } + printk(KERN_INFO "HVCS: Destroyed hvcs_struct for vty-server@%X.\n", + hvcsd->vdev->unit_address); + + vdev = hvcsd->vdev; + hvcsd->vdev = NULL; + + hvcsd->p_unit_address = 0; + hvcsd->p_partition_ID = 0; + hvcs_return_index(hvcsd->index); + memset(&hvcsd->p_location_code[0], 0x00, HVCS_CLC_LENGTH + 1); + + spin_unlock_irqrestore(&hvcsd->lock, flags); + spin_unlock(&hvcs_structs_lock); + + sysfs_remove_group(&vdev->dev.kobj, &hvcs_attr_group); + + kfree(hvcsd); +} + +static int hvcs_get_index(void) +{ + int i; + /* Paranoia check */ + if (!hvcs_index_list) { + printk(KERN_ERR "HVCS: hvcs_index_list NOT valid!.\n"); + return -EFAULT; + } + /* Find the numerically lowest first free index. */ + for(i = 0; i < hvcs_index_count; i++) { + if (hvcs_index_list[i] == -1) { + hvcs_index_list[i] = 0; + return i; + } + } + return -1; +} + +static int __devinit hvcs_probe( + struct vio_dev *dev, + const struct vio_device_id *id) +{ + struct hvcs_struct *hvcsd; + int index; + int retval; + + if (!dev || !id) { + printk(KERN_ERR "HVCS: probed with invalid parameter.\n"); + return -EPERM; + } + + /* early to avoid cleanup on failure */ + index = hvcs_get_index(); + if (index < 0) { + return -EFAULT; + } + + hvcsd = kzalloc(sizeof(*hvcsd), GFP_KERNEL); + if (!hvcsd) + return -ENODEV; + + + spin_lock_init(&hvcsd->lock); + /* Automatically incs the refcount the first time */ + kref_init(&hvcsd->kref); + + hvcsd->vdev = dev; + dev_set_drvdata(&dev->dev, hvcsd); + + hvcsd->index = index; + + /* hvcsd->index = ++hvcs_struct_count; */ + hvcsd->chars_in_buffer = 0; + hvcsd->todo_mask = 0; + hvcsd->connected = 0; + + /* + * This will populate the hvcs_struct's partner info fields for the + * first time. + */ + if (hvcs_get_pi(hvcsd)) { + printk(KERN_ERR "HVCS: Failed to fetch partner" + " info for vty-server@%X on device probe.\n", + hvcsd->vdev->unit_address); + } + + /* + * If a user app opens a tty that corresponds to this vty-server before + * the hvcs_struct has been added to the devices list then the user app + * will get -ENODEV. + */ + spin_lock(&hvcs_structs_lock); + list_add_tail(&(hvcsd->next), &hvcs_structs); + spin_unlock(&hvcs_structs_lock); + + retval = sysfs_create_group(&dev->dev.kobj, &hvcs_attr_group); + if (retval) { + printk(KERN_ERR "HVCS: Can't create sysfs attrs for vty-server@%X\n", + hvcsd->vdev->unit_address); + return retval; + } + + printk(KERN_INFO "HVCS: vty-server@%X added to the vio bus.\n", dev->unit_address); + + /* + * DON'T enable interrupts here because there is no user to receive the + * data. + */ + return 0; +} + +static int __devexit hvcs_remove(struct vio_dev *dev) +{ + struct hvcs_struct *hvcsd = dev_get_drvdata(&dev->dev); + unsigned long flags; + struct tty_struct *tty; + + if (!hvcsd) + return -ENODEV; + + /* By this time the vty-server won't be getting any more interrupts */ + + spin_lock_irqsave(&hvcsd->lock, flags); + + tty = hvcsd->tty; + + spin_unlock_irqrestore(&hvcsd->lock, flags); + + /* + * Let the last holder of this object cause it to be removed, which + * would probably be tty_hangup below. + */ + kref_put(&hvcsd->kref, destroy_hvcs_struct); + + /* + * The hangup is a scheduled function which will auto chain call + * hvcs_hangup. The tty should always be valid at this time unless a + * simultaneous tty close already cleaned up the hvcs_struct. + */ + if (tty) + tty_hangup(tty); + + printk(KERN_INFO "HVCS: vty-server@%X removed from the" + " vio bus.\n", dev->unit_address); + return 0; +}; + +static struct vio_driver hvcs_vio_driver = { + .id_table = hvcs_driver_table, + .probe = hvcs_probe, + .remove = __devexit_p(hvcs_remove), + .driver = { + .name = hvcs_driver_name, + .owner = THIS_MODULE, + } +}; + +/* Only called from hvcs_get_pi please */ +static void hvcs_set_pi(struct hvcs_partner_info *pi, struct hvcs_struct *hvcsd) +{ + int clclength; + + hvcsd->p_unit_address = pi->unit_address; + hvcsd->p_partition_ID = pi->partition_ID; + clclength = strlen(&pi->location_code[0]); + if (clclength > HVCS_CLC_LENGTH) + clclength = HVCS_CLC_LENGTH; + + /* copy the null-term char too */ + strncpy(&hvcsd->p_location_code[0], + &pi->location_code[0], clclength + 1); +} + +/* + * Traverse the list and add the partner info that is found to the hvcs_struct + * struct entry. NOTE: At this time I know that partner info will return a + * single entry but in the future there may be multiple partner info entries per + * vty-server and you'll want to zero out that list and reset it. If for some + * reason you have an old version of this driver but there IS more than one + * partner info then hvcsd->p_* will hold the last partner info data from the + * firmware query. A good way to update this code would be to replace the three + * partner info fields in hvcs_struct with a list of hvcs_partner_info + * instances. + * + * This function must be called with the hvcsd->lock held. + */ +static int hvcs_get_pi(struct hvcs_struct *hvcsd) +{ + struct hvcs_partner_info *pi; + uint32_t unit_address = hvcsd->vdev->unit_address; + struct list_head head; + int retval; + + spin_lock(&hvcs_pi_lock); + if (!hvcs_pi_buff) { + spin_unlock(&hvcs_pi_lock); + return -EFAULT; + } + retval = hvcs_get_partner_info(unit_address, &head, hvcs_pi_buff); + spin_unlock(&hvcs_pi_lock); + if (retval) { + printk(KERN_ERR "HVCS: Failed to fetch partner" + " info for vty-server@%x.\n", unit_address); + return retval; + } + + /* nixes the values if the partner vty went away */ + hvcsd->p_unit_address = 0; + hvcsd->p_partition_ID = 0; + + list_for_each_entry(pi, &head, node) + hvcs_set_pi(pi, hvcsd); + + hvcs_free_partner_info(&head); + return 0; +} + +/* + * This function is executed by the driver "rescan" sysfs entry. It shouldn't + * be executed elsewhere, in order to prevent deadlock issues. + */ +static int hvcs_rescan_devices_list(void) +{ + struct hvcs_struct *hvcsd; + unsigned long flags; + + spin_lock(&hvcs_structs_lock); + + list_for_each_entry(hvcsd, &hvcs_structs, next) { + spin_lock_irqsave(&hvcsd->lock, flags); + hvcs_get_pi(hvcsd); + spin_unlock_irqrestore(&hvcsd->lock, flags); + } + + spin_unlock(&hvcs_structs_lock); + + return 0; +} + +/* + * Farm this off into its own function because it could be more complex once + * multiple partners support is added. This function should be called with + * the hvcsd->lock held. + */ +static int hvcs_has_pi(struct hvcs_struct *hvcsd) +{ + if ((!hvcsd->p_unit_address) || (!hvcsd->p_partition_ID)) + return 0; + return 1; +} + +/* + * NOTE: It is possible that the super admin removed a partner vty and then + * added a different vty as the new partner. + * + * This function must be called with the hvcsd->lock held. + */ +static int hvcs_partner_connect(struct hvcs_struct *hvcsd) +{ + int retval; + unsigned int unit_address = hvcsd->vdev->unit_address; + + /* + * If there wasn't any pi when the device was added it doesn't meant + * there isn't any now. This driver isn't notified when a new partner + * vty is added to a vty-server so we discover changes on our own. + * Please see comments in hvcs_register_connection() for justification + * of this bizarre code. + */ + retval = hvcs_register_connection(unit_address, + hvcsd->p_partition_ID, + hvcsd->p_unit_address); + if (!retval) { + hvcsd->connected = 1; + return 0; + } else if (retval != -EINVAL) + return retval; + + /* + * As per the spec re-get the pi and try again if -EINVAL after the + * first connection attempt. + */ + if (hvcs_get_pi(hvcsd)) + return -ENOMEM; + + if (!hvcs_has_pi(hvcsd)) + return -ENODEV; + + retval = hvcs_register_connection(unit_address, + hvcsd->p_partition_ID, + hvcsd->p_unit_address); + if (retval != -EINVAL) { + hvcsd->connected = 1; + return retval; + } + + /* + * EBUSY is the most likely scenario though the vty could have been + * removed or there really could be an hcall error due to the parameter + * data but thanks to ambiguous firmware return codes we can't really + * tell. + */ + printk(KERN_INFO "HVCS: vty-server or partner" + " vty is busy. Try again later.\n"); + return -EBUSY; +} + +/* This function must be called with the hvcsd->lock held */ +static void hvcs_partner_free(struct hvcs_struct *hvcsd) +{ + int retval; + do { + retval = hvcs_free_connection(hvcsd->vdev->unit_address); + } while (retval == -EBUSY); + hvcsd->connected = 0; +} + +/* This helper function must be called WITHOUT the hvcsd->lock held */ +static int hvcs_enable_device(struct hvcs_struct *hvcsd, uint32_t unit_address, + unsigned int irq, struct vio_dev *vdev) +{ + unsigned long flags; + int rc; + + /* + * It is possible that the vty-server was removed between the time that + * the conn was registered and now. + */ + if (!(rc = request_irq(irq, &hvcs_handle_interrupt, + IRQF_DISABLED, "ibmhvcs", hvcsd))) { + /* + * It is possible the vty-server was removed after the irq was + * requested but before we have time to enable interrupts. + */ + if (vio_enable_interrupts(vdev) == H_SUCCESS) + return 0; + else { + printk(KERN_ERR "HVCS: int enable failed for" + " vty-server@%X.\n", unit_address); + free_irq(irq, hvcsd); + } + } else + printk(KERN_ERR "HVCS: irq req failed for" + " vty-server@%X.\n", unit_address); + + spin_lock_irqsave(&hvcsd->lock, flags); + hvcs_partner_free(hvcsd); + spin_unlock_irqrestore(&hvcsd->lock, flags); + + return rc; + +} + +/* + * This always increments the kref ref count if the call is successful. + * Please remember to dec when you are done with the instance. + * + * NOTICE: Do NOT hold either the hvcs_struct.lock or hvcs_structs_lock when + * calling this function or you will get deadlock. + */ +static struct hvcs_struct *hvcs_get_by_index(int index) +{ + struct hvcs_struct *hvcsd = NULL; + unsigned long flags; + + spin_lock(&hvcs_structs_lock); + /* We can immediately discard OOB requests */ + if (index >= 0 && index < HVCS_MAX_SERVER_ADAPTERS) { + list_for_each_entry(hvcsd, &hvcs_structs, next) { + spin_lock_irqsave(&hvcsd->lock, flags); + if (hvcsd->index == index) { + kref_get(&hvcsd->kref); + spin_unlock_irqrestore(&hvcsd->lock, flags); + spin_unlock(&hvcs_structs_lock); + return hvcsd; + } + spin_unlock_irqrestore(&hvcsd->lock, flags); + } + hvcsd = NULL; + } + + spin_unlock(&hvcs_structs_lock); + return hvcsd; +} + +/* + * This is invoked via the tty_open interface when a user app connects to the + * /dev node. + */ +static int hvcs_open(struct tty_struct *tty, struct file *filp) +{ + struct hvcs_struct *hvcsd; + int rc, retval = 0; + unsigned long flags; + unsigned int irq; + struct vio_dev *vdev; + unsigned long unit_address; + + if (tty->driver_data) + goto fast_open; + + /* + * Is there a vty-server that shares the same index? + * This function increments the kref index. + */ + if (!(hvcsd = hvcs_get_by_index(tty->index))) { + printk(KERN_WARNING "HVCS: open failed, no device associated" + " with tty->index %d.\n", tty->index); + return -ENODEV; + } + + spin_lock_irqsave(&hvcsd->lock, flags); + + if (hvcsd->connected == 0) + if ((retval = hvcs_partner_connect(hvcsd))) + goto error_release; + + hvcsd->open_count = 1; + hvcsd->tty = tty; + tty->driver_data = hvcsd; + + memset(&hvcsd->buffer[0], 0x00, HVCS_BUFF_LEN); + + /* + * Save these in the spinlock for the enable operations that need them + * outside of the spinlock. + */ + irq = hvcsd->vdev->irq; + vdev = hvcsd->vdev; + unit_address = hvcsd->vdev->unit_address; + + hvcsd->todo_mask |= HVCS_SCHED_READ; + spin_unlock_irqrestore(&hvcsd->lock, flags); + + /* + * This must be done outside of the spinlock because it requests irqs + * and will grab the spinlock and free the connection if it fails. + */ + if (((rc = hvcs_enable_device(hvcsd, unit_address, irq, vdev)))) { + kref_put(&hvcsd->kref, destroy_hvcs_struct); + printk(KERN_WARNING "HVCS: enable device failed.\n"); + return rc; + } + + goto open_success; + +fast_open: + hvcsd = tty->driver_data; + + spin_lock_irqsave(&hvcsd->lock, flags); + kref_get(&hvcsd->kref); + hvcsd->open_count++; + hvcsd->todo_mask |= HVCS_SCHED_READ; + spin_unlock_irqrestore(&hvcsd->lock, flags); + +open_success: + hvcs_kick(); + + printk(KERN_INFO "HVCS: vty-server@%X connection opened.\n", + hvcsd->vdev->unit_address ); + + return 0; + +error_release: + spin_unlock_irqrestore(&hvcsd->lock, flags); + kref_put(&hvcsd->kref, destroy_hvcs_struct); + + printk(KERN_WARNING "HVCS: partner connect failed.\n"); + return retval; +} + +static void hvcs_close(struct tty_struct *tty, struct file *filp) +{ + struct hvcs_struct *hvcsd; + unsigned long flags; + int irq = NO_IRQ; + + /* + * Is someone trying to close the file associated with this device after + * we have hung up? If so tty->driver_data wouldn't be valid. + */ + if (tty_hung_up_p(filp)) + return; + + /* + * No driver_data means that this close was probably issued after a + * failed hvcs_open by the tty layer's release_dev() api and we can just + * exit cleanly. + */ + if (!tty->driver_data) + return; + + hvcsd = tty->driver_data; + + spin_lock_irqsave(&hvcsd->lock, flags); + if (--hvcsd->open_count == 0) { + + vio_disable_interrupts(hvcsd->vdev); + + /* + * NULL this early so that the kernel_thread doesn't try to + * execute any operations on the TTY even though it is obligated + * to deliver any pending I/O to the hypervisor. + */ + hvcsd->tty = NULL; + + irq = hvcsd->vdev->irq; + spin_unlock_irqrestore(&hvcsd->lock, flags); + + tty_wait_until_sent(tty, HVCS_CLOSE_WAIT); + + /* + * This line is important because it tells hvcs_open that this + * device needs to be re-configured the next time hvcs_open is + * called. + */ + tty->driver_data = NULL; + + free_irq(irq, hvcsd); + kref_put(&hvcsd->kref, destroy_hvcs_struct); + return; + } else if (hvcsd->open_count < 0) { + printk(KERN_ERR "HVCS: vty-server@%X open_count: %d" + " is missmanaged.\n", + hvcsd->vdev->unit_address, hvcsd->open_count); + } + + spin_unlock_irqrestore(&hvcsd->lock, flags); + kref_put(&hvcsd->kref, destroy_hvcs_struct); +} + +static void hvcs_hangup(struct tty_struct * tty) +{ + struct hvcs_struct *hvcsd = tty->driver_data; + unsigned long flags; + int temp_open_count; + int irq = NO_IRQ; + + spin_lock_irqsave(&hvcsd->lock, flags); + /* Preserve this so that we know how many kref refs to put */ + temp_open_count = hvcsd->open_count; + + /* + * Don't kref put inside the spinlock because the destruction + * callback may use the spinlock and it may get called before the + * spinlock has been released. + */ + vio_disable_interrupts(hvcsd->vdev); + + hvcsd->todo_mask = 0; + + /* I don't think the tty needs the hvcs_struct pointer after a hangup */ + hvcsd->tty->driver_data = NULL; + hvcsd->tty = NULL; + + hvcsd->open_count = 0; + + /* This will drop any buffered data on the floor which is OK in a hangup + * scenario. */ + memset(&hvcsd->buffer[0], 0x00, HVCS_BUFF_LEN); + hvcsd->chars_in_buffer = 0; + + irq = hvcsd->vdev->irq; + + spin_unlock_irqrestore(&hvcsd->lock, flags); + + free_irq(irq, hvcsd); + + /* + * We need to kref_put() for every open_count we have since the + * tty_hangup() function doesn't invoke a close per open connection on a + * non-console device. + */ + while(temp_open_count) { + --temp_open_count; + /* + * The final put will trigger destruction of the hvcs_struct. + * NOTE: If this hangup was signaled from user space then the + * final put will never happen. + */ + kref_put(&hvcsd->kref, destroy_hvcs_struct); + } +} + +/* + * NOTE: This is almost always from_user since user level apps interact with the + * /dev nodes. I'm trusting that if hvcs_write gets called and interrupted by + * hvcs_remove (which removes the target device and executes tty_hangup()) that + * tty_hangup will allow hvcs_write time to complete execution before it + * terminates our device. + */ +static int hvcs_write(struct tty_struct *tty, + const unsigned char *buf, int count) +{ + struct hvcs_struct *hvcsd = tty->driver_data; + unsigned int unit_address; + const unsigned char *charbuf; + unsigned long flags; + int total_sent = 0; + int tosend = 0; + int result = 0; + + /* + * If they don't check the return code off of their open they may + * attempt this even if there is no connected device. + */ + if (!hvcsd) + return -ENODEV; + + /* Reasonable size to prevent user level flooding */ + if (count > HVCS_MAX_FROM_USER) { + printk(KERN_WARNING "HVCS write: count being truncated to" + " HVCS_MAX_FROM_USER.\n"); + count = HVCS_MAX_FROM_USER; + } + + charbuf = buf; + + spin_lock_irqsave(&hvcsd->lock, flags); + + /* + * Somehow an open succedded but the device was removed or the + * connection terminated between the vty-server and partner vty during + * the middle of a write operation? This is a crummy place to do this + * but we want to keep it all in the spinlock. + */ + if (hvcsd->open_count <= 0) { + spin_unlock_irqrestore(&hvcsd->lock, flags); + return -ENODEV; + } + + unit_address = hvcsd->vdev->unit_address; + + while (count > 0) { + tosend = min(count, (HVCS_BUFF_LEN - hvcsd->chars_in_buffer)); + /* + * No more space, this probably means that the last call to + * hvcs_write() didn't succeed and the buffer was filled up. + */ + if (!tosend) + break; + + memcpy(&hvcsd->buffer[hvcsd->chars_in_buffer], + &charbuf[total_sent], + tosend); + + hvcsd->chars_in_buffer += tosend; + + result = 0; + + /* + * If this is true then we don't want to try writing to the + * hypervisor because that is the kernel_threads job now. We'll + * just add to the buffer. + */ + if (!(hvcsd->todo_mask & HVCS_TRY_WRITE)) + /* won't send partial writes */ + result = hvc_put_chars(unit_address, + &hvcsd->buffer[0], + hvcsd->chars_in_buffer); + + /* + * Since we know we have enough room in hvcsd->buffer for + * tosend we record that it was sent regardless of whether the + * hypervisor actually took it because we have it buffered. + */ + total_sent+=tosend; + count-=tosend; + if (result == 0) { + hvcsd->todo_mask |= HVCS_TRY_WRITE; + hvcs_kick(); + break; + } + + hvcsd->chars_in_buffer = 0; + /* + * Test after the chars_in_buffer reset otherwise this could + * deadlock our writes if hvc_put_chars fails. + */ + if (result < 0) + break; + } + + spin_unlock_irqrestore(&hvcsd->lock, flags); + + if (result == -1) + return -EIO; + else + return total_sent; +} + +/* + * This is really asking how much can we guarentee that we can send or that we + * absolutely WILL BUFFER if we can't send it. This driver MUST honor the + * return value, hence the reason for hvcs_struct buffering. + */ +static int hvcs_write_room(struct tty_struct *tty) +{ + struct hvcs_struct *hvcsd = tty->driver_data; + + if (!hvcsd || hvcsd->open_count <= 0) + return 0; + + return HVCS_BUFF_LEN - hvcsd->chars_in_buffer; +} + +static int hvcs_chars_in_buffer(struct tty_struct *tty) +{ + struct hvcs_struct *hvcsd = tty->driver_data; + + return hvcsd->chars_in_buffer; +} + +static const struct tty_operations hvcs_ops = { + .open = hvcs_open, + .close = hvcs_close, + .hangup = hvcs_hangup, + .write = hvcs_write, + .write_room = hvcs_write_room, + .chars_in_buffer = hvcs_chars_in_buffer, + .unthrottle = hvcs_unthrottle, + .throttle = hvcs_throttle, +}; + +static int hvcs_alloc_index_list(int n) +{ + int i; + + hvcs_index_list = kmalloc(n * sizeof(hvcs_index_count),GFP_KERNEL); + if (!hvcs_index_list) + return -ENOMEM; + hvcs_index_count = n; + for (i = 0; i < hvcs_index_count; i++) + hvcs_index_list[i] = -1; + return 0; +} + +static void hvcs_free_index_list(void) +{ + /* Paranoia check to be thorough. */ + kfree(hvcs_index_list); + hvcs_index_list = NULL; + hvcs_index_count = 0; +} + +static int __init hvcs_module_init(void) +{ + int rc; + int num_ttys_to_alloc; + + printk(KERN_INFO "Initializing %s\n", hvcs_driver_string); + + /* Has the user specified an overload with an insmod param? */ + if (hvcs_parm_num_devs <= 0 || + (hvcs_parm_num_devs > HVCS_MAX_SERVER_ADAPTERS)) { + num_ttys_to_alloc = HVCS_DEFAULT_SERVER_ADAPTERS; + } else + num_ttys_to_alloc = hvcs_parm_num_devs; + + hvcs_tty_driver = alloc_tty_driver(num_ttys_to_alloc); + if (!hvcs_tty_driver) + return -ENOMEM; + + if (hvcs_alloc_index_list(num_ttys_to_alloc)) { + rc = -ENOMEM; + goto index_fail; + } + + hvcs_tty_driver->owner = THIS_MODULE; + + hvcs_tty_driver->driver_name = hvcs_driver_name; + hvcs_tty_driver->name = hvcs_device_node; + + /* + * We'll let the system assign us a major number, indicated by leaving + * it blank. + */ + + hvcs_tty_driver->minor_start = HVCS_MINOR_START; + hvcs_tty_driver->type = TTY_DRIVER_TYPE_SYSTEM; + + /* + * We role our own so that we DONT ECHO. We can't echo because the + * device we are connecting to already echoes by default and this would + * throw us into a horrible recursive echo-echo-echo loop. + */ + hvcs_tty_driver->init_termios = hvcs_tty_termios; + hvcs_tty_driver->flags = TTY_DRIVER_REAL_RAW; + + tty_set_operations(hvcs_tty_driver, &hvcs_ops); + + /* + * The following call will result in sysfs entries that denote the + * dynamically assigned major and minor numbers for our devices. + */ + if (tty_register_driver(hvcs_tty_driver)) { + printk(KERN_ERR "HVCS: registration as a tty driver failed.\n"); + rc = -EIO; + goto register_fail; + } + + hvcs_pi_buff = kmalloc(PAGE_SIZE, GFP_KERNEL); + if (!hvcs_pi_buff) { + rc = -ENOMEM; + goto buff_alloc_fail; + } + + hvcs_task = kthread_run(khvcsd, NULL, "khvcsd"); + if (IS_ERR(hvcs_task)) { + printk(KERN_ERR "HVCS: khvcsd creation failed. Driver not loaded.\n"); + rc = -EIO; + goto kthread_fail; + } + + rc = vio_register_driver(&hvcs_vio_driver); + if (rc) { + printk(KERN_ERR "HVCS: can't register vio driver\n"); + goto vio_fail; + } + + /* + * This needs to be done AFTER the vio_register_driver() call or else + * the kobjects won't be initialized properly. + */ + rc = driver_create_file(&(hvcs_vio_driver.driver), &driver_attr_rescan); + if (rc) { + printk(KERN_ERR "HVCS: sysfs attr create failed\n"); + goto attr_fail; + } + + printk(KERN_INFO "HVCS: driver module inserted.\n"); + + return 0; + +attr_fail: + vio_unregister_driver(&hvcs_vio_driver); +vio_fail: + kthread_stop(hvcs_task); +kthread_fail: + kfree(hvcs_pi_buff); +buff_alloc_fail: + tty_unregister_driver(hvcs_tty_driver); +register_fail: + hvcs_free_index_list(); +index_fail: + put_tty_driver(hvcs_tty_driver); + hvcs_tty_driver = NULL; + return rc; +} + +static void __exit hvcs_module_exit(void) +{ + /* + * This driver receives hvcs_remove callbacks for each device upon + * module removal. + */ + + /* + * This synchronous operation will wake the khvcsd kthread if it is + * asleep and will return when khvcsd has terminated. + */ + kthread_stop(hvcs_task); + + spin_lock(&hvcs_pi_lock); + kfree(hvcs_pi_buff); + hvcs_pi_buff = NULL; + spin_unlock(&hvcs_pi_lock); + + driver_remove_file(&hvcs_vio_driver.driver, &driver_attr_rescan); + + vio_unregister_driver(&hvcs_vio_driver); + + tty_unregister_driver(hvcs_tty_driver); + + hvcs_free_index_list(); + + put_tty_driver(hvcs_tty_driver); + + printk(KERN_INFO "HVCS: driver module removed.\n"); +} + +module_init(hvcs_module_init); +module_exit(hvcs_module_exit); diff --git a/drivers/tty/hvc/hvsi.c b/drivers/tty/hvc/hvsi.c new file mode 100644 index 000000000000..67a75a502c01 --- /dev/null +++ b/drivers/tty/hvc/hvsi.c @@ -0,0 +1,1314 @@ +/* + * Copyright (C) 2004 Hollis Blanchard <hollisb@us.ibm.com>, IBM + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +/* Host Virtual Serial Interface (HVSI) is a protocol between the hosted OS + * and the service processor on IBM pSeries servers. On these servers, there + * are no serial ports under the OS's control, and sometimes there is no other + * console available either. However, the service processor has two standard + * serial ports, so this over-complicated protocol allows the OS to control + * those ports by proxy. + * + * Besides data, the procotol supports the reading/writing of the serial + * port's DTR line, and the reading of the CD line. This is to allow the OS to + * control a modem attached to the service processor's serial port. Note that + * the OS cannot change the speed of the port through this protocol. + */ + +#undef DEBUG + +#include <linux/console.h> +#include <linux/ctype.h> +#include <linux/delay.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/module.h> +#include <linux/major.h> +#include <linux/kernel.h> +#include <linux/spinlock.h> +#include <linux/sysrq.h> +#include <linux/tty.h> +#include <linux/tty_flip.h> +#include <asm/hvcall.h> +#include <asm/hvconsole.h> +#include <asm/prom.h> +#include <asm/uaccess.h> +#include <asm/vio.h> +#include <asm/param.h> + +#define HVSI_MAJOR 229 +#define HVSI_MINOR 128 +#define MAX_NR_HVSI_CONSOLES 4 + +#define HVSI_TIMEOUT (5*HZ) +#define HVSI_VERSION 1 +#define HVSI_MAX_PACKET 256 +#define HVSI_MAX_READ 16 +#define HVSI_MAX_OUTGOING_DATA 12 +#define N_OUTBUF 12 + +/* + * we pass data via two 8-byte registers, so we would like our char arrays + * properly aligned for those loads. + */ +#define __ALIGNED__ __attribute__((__aligned__(sizeof(long)))) + +struct hvsi_struct { + struct delayed_work writer; + struct work_struct handshaker; + wait_queue_head_t emptyq; /* woken when outbuf is emptied */ + wait_queue_head_t stateq; /* woken when HVSI state changes */ + spinlock_t lock; + int index; + struct tty_struct *tty; + int count; + uint8_t throttle_buf[128]; + uint8_t outbuf[N_OUTBUF]; /* to implement write_room and chars_in_buffer */ + /* inbuf is for packet reassembly. leave a little room for leftovers. */ + uint8_t inbuf[HVSI_MAX_PACKET + HVSI_MAX_READ]; + uint8_t *inbuf_end; + int n_throttle; + int n_outbuf; + uint32_t vtermno; + uint32_t virq; + atomic_t seqno; /* HVSI packet sequence number */ + uint16_t mctrl; + uint8_t state; /* HVSI protocol state */ + uint8_t flags; +#ifdef CONFIG_MAGIC_SYSRQ + uint8_t sysrq; +#endif /* CONFIG_MAGIC_SYSRQ */ +}; +static struct hvsi_struct hvsi_ports[MAX_NR_HVSI_CONSOLES]; + +static struct tty_driver *hvsi_driver; +static int hvsi_count; +static int (*hvsi_wait)(struct hvsi_struct *hp, int state); + +enum HVSI_PROTOCOL_STATE { + HVSI_CLOSED, + HVSI_WAIT_FOR_VER_RESPONSE, + HVSI_WAIT_FOR_VER_QUERY, + HVSI_OPEN, + HVSI_WAIT_FOR_MCTRL_RESPONSE, + HVSI_FSP_DIED, +}; +#define HVSI_CONSOLE 0x1 + +#define VS_DATA_PACKET_HEADER 0xff +#define VS_CONTROL_PACKET_HEADER 0xfe +#define VS_QUERY_PACKET_HEADER 0xfd +#define VS_QUERY_RESPONSE_PACKET_HEADER 0xfc + +/* control verbs */ +#define VSV_SET_MODEM_CTL 1 /* to service processor only */ +#define VSV_MODEM_CTL_UPDATE 2 /* from service processor only */ +#define VSV_CLOSE_PROTOCOL 3 + +/* query verbs */ +#define VSV_SEND_VERSION_NUMBER 1 +#define VSV_SEND_MODEM_CTL_STATUS 2 + +/* yes, these masks are not consecutive. */ +#define HVSI_TSDTR 0x01 +#define HVSI_TSCD 0x20 + +struct hvsi_header { + uint8_t type; + uint8_t len; + uint16_t seqno; +} __attribute__((packed)); + +struct hvsi_data { + uint8_t type; + uint8_t len; + uint16_t seqno; + uint8_t data[HVSI_MAX_OUTGOING_DATA]; +} __attribute__((packed)); + +struct hvsi_control { + uint8_t type; + uint8_t len; + uint16_t seqno; + uint16_t verb; + /* optional depending on verb: */ + uint32_t word; + uint32_t mask; +} __attribute__((packed)); + +struct hvsi_query { + uint8_t type; + uint8_t len; + uint16_t seqno; + uint16_t verb; +} __attribute__((packed)); + +struct hvsi_query_response { + uint8_t type; + uint8_t len; + uint16_t seqno; + uint16_t verb; + uint16_t query_seqno; + union { + uint8_t version; + uint32_t mctrl_word; + } u; +} __attribute__((packed)); + + + +static inline int is_console(struct hvsi_struct *hp) +{ + return hp->flags & HVSI_CONSOLE; +} + +static inline int is_open(struct hvsi_struct *hp) +{ + /* if we're waiting for an mctrl then we're already open */ + return (hp->state == HVSI_OPEN) + || (hp->state == HVSI_WAIT_FOR_MCTRL_RESPONSE); +} + +static inline void print_state(struct hvsi_struct *hp) +{ +#ifdef DEBUG + static const char *state_names[] = { + "HVSI_CLOSED", + "HVSI_WAIT_FOR_VER_RESPONSE", + "HVSI_WAIT_FOR_VER_QUERY", + "HVSI_OPEN", + "HVSI_WAIT_FOR_MCTRL_RESPONSE", + "HVSI_FSP_DIED", + }; + const char *name = (hp->state < ARRAY_SIZE(state_names)) + ? state_names[hp->state] : "UNKNOWN"; + + pr_debug("hvsi%i: state = %s\n", hp->index, name); +#endif /* DEBUG */ +} + +static inline void __set_state(struct hvsi_struct *hp, int state) +{ + hp->state = state; + print_state(hp); + wake_up_all(&hp->stateq); +} + +static inline void set_state(struct hvsi_struct *hp, int state) +{ + unsigned long flags; + + spin_lock_irqsave(&hp->lock, flags); + __set_state(hp, state); + spin_unlock_irqrestore(&hp->lock, flags); +} + +static inline int len_packet(const uint8_t *packet) +{ + return (int)((struct hvsi_header *)packet)->len; +} + +static inline int is_header(const uint8_t *packet) +{ + struct hvsi_header *header = (struct hvsi_header *)packet; + return header->type >= VS_QUERY_RESPONSE_PACKET_HEADER; +} + +static inline int got_packet(const struct hvsi_struct *hp, uint8_t *packet) +{ + if (hp->inbuf_end < packet + sizeof(struct hvsi_header)) + return 0; /* don't even have the packet header */ + + if (hp->inbuf_end < (packet + len_packet(packet))) + return 0; /* don't have the rest of the packet */ + + return 1; +} + +/* shift remaining bytes in packetbuf down */ +static void compact_inbuf(struct hvsi_struct *hp, uint8_t *read_to) +{ + int remaining = (int)(hp->inbuf_end - read_to); + + pr_debug("%s: %i chars remain\n", __func__, remaining); + + if (read_to != hp->inbuf) + memmove(hp->inbuf, read_to, remaining); + + hp->inbuf_end = hp->inbuf + remaining; +} + +#ifdef DEBUG +#define dbg_dump_packet(packet) dump_packet(packet) +#define dbg_dump_hex(data, len) dump_hex(data, len) +#else +#define dbg_dump_packet(packet) do { } while (0) +#define dbg_dump_hex(data, len) do { } while (0) +#endif + +static void dump_hex(const uint8_t *data, int len) +{ + int i; + + printk(" "); + for (i=0; i < len; i++) + printk("%.2x", data[i]); + + printk("\n "); + for (i=0; i < len; i++) { + if (isprint(data[i])) + printk("%c", data[i]); + else + printk("."); + } + printk("\n"); +} + +static void dump_packet(uint8_t *packet) +{ + struct hvsi_header *header = (struct hvsi_header *)packet; + + printk("type 0x%x, len %i, seqno %i:\n", header->type, header->len, + header->seqno); + + dump_hex(packet, header->len); +} + +static int hvsi_read(struct hvsi_struct *hp, char *buf, int count) +{ + unsigned long got; + + got = hvc_get_chars(hp->vtermno, buf, count); + + return got; +} + +static void hvsi_recv_control(struct hvsi_struct *hp, uint8_t *packet, + struct tty_struct **to_hangup, struct hvsi_struct **to_handshake) +{ + struct hvsi_control *header = (struct hvsi_control *)packet; + + switch (header->verb) { + case VSV_MODEM_CTL_UPDATE: + if ((header->word & HVSI_TSCD) == 0) { + /* CD went away; no more connection */ + pr_debug("hvsi%i: CD dropped\n", hp->index); + hp->mctrl &= TIOCM_CD; + /* If userland hasn't done an open(2) yet, hp->tty is NULL. */ + if (hp->tty && !(hp->tty->flags & CLOCAL)) + *to_hangup = hp->tty; + } + break; + case VSV_CLOSE_PROTOCOL: + pr_debug("hvsi%i: service processor came back\n", hp->index); + if (hp->state != HVSI_CLOSED) { + *to_handshake = hp; + } + break; + default: + printk(KERN_WARNING "hvsi%i: unknown HVSI control packet: ", + hp->index); + dump_packet(packet); + break; + } +} + +static void hvsi_recv_response(struct hvsi_struct *hp, uint8_t *packet) +{ + struct hvsi_query_response *resp = (struct hvsi_query_response *)packet; + + switch (hp->state) { + case HVSI_WAIT_FOR_VER_RESPONSE: + __set_state(hp, HVSI_WAIT_FOR_VER_QUERY); + break; + case HVSI_WAIT_FOR_MCTRL_RESPONSE: + hp->mctrl = 0; + if (resp->u.mctrl_word & HVSI_TSDTR) + hp->mctrl |= TIOCM_DTR; + if (resp->u.mctrl_word & HVSI_TSCD) + hp->mctrl |= TIOCM_CD; + __set_state(hp, HVSI_OPEN); + break; + default: + printk(KERN_ERR "hvsi%i: unexpected query response: ", hp->index); + dump_packet(packet); + break; + } +} + +/* respond to service processor's version query */ +static int hvsi_version_respond(struct hvsi_struct *hp, uint16_t query_seqno) +{ + struct hvsi_query_response packet __ALIGNED__; + int wrote; + + packet.type = VS_QUERY_RESPONSE_PACKET_HEADER; + packet.len = sizeof(struct hvsi_query_response); + packet.seqno = atomic_inc_return(&hp->seqno); + packet.verb = VSV_SEND_VERSION_NUMBER; + packet.u.version = HVSI_VERSION; + packet.query_seqno = query_seqno+1; + + pr_debug("%s: sending %i bytes\n", __func__, packet.len); + dbg_dump_hex((uint8_t*)&packet, packet.len); + + wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.len); + if (wrote != packet.len) { + printk(KERN_ERR "hvsi%i: couldn't send query response!\n", + hp->index); + return -EIO; + } + + return 0; +} + +static void hvsi_recv_query(struct hvsi_struct *hp, uint8_t *packet) +{ + struct hvsi_query *query = (struct hvsi_query *)packet; + + switch (hp->state) { + case HVSI_WAIT_FOR_VER_QUERY: + hvsi_version_respond(hp, query->seqno); + __set_state(hp, HVSI_OPEN); + break; + default: + printk(KERN_ERR "hvsi%i: unexpected query: ", hp->index); + dump_packet(packet); + break; + } +} + +static void hvsi_insert_chars(struct hvsi_struct *hp, const char *buf, int len) +{ + int i; + + for (i=0; i < len; i++) { + char c = buf[i]; +#ifdef CONFIG_MAGIC_SYSRQ + if (c == '\0') { + hp->sysrq = 1; + continue; + } else if (hp->sysrq) { + handle_sysrq(c); + hp->sysrq = 0; + continue; + } +#endif /* CONFIG_MAGIC_SYSRQ */ + tty_insert_flip_char(hp->tty, c, 0); + } +} + +/* + * We could get 252 bytes of data at once here. But the tty layer only + * throttles us at TTY_THRESHOLD_THROTTLE (128) bytes, so we could overflow + * it. Accordingly we won't send more than 128 bytes at a time to the flip + * buffer, which will give the tty buffer a chance to throttle us. Should the + * value of TTY_THRESHOLD_THROTTLE change in n_tty.c, this code should be + * revisited. + */ +#define TTY_THRESHOLD_THROTTLE 128 +static struct tty_struct *hvsi_recv_data(struct hvsi_struct *hp, + const uint8_t *packet) +{ + const struct hvsi_header *header = (const struct hvsi_header *)packet; + const uint8_t *data = packet + sizeof(struct hvsi_header); + int datalen = header->len - sizeof(struct hvsi_header); + int overflow = datalen - TTY_THRESHOLD_THROTTLE; + + pr_debug("queueing %i chars '%.*s'\n", datalen, datalen, data); + + if (datalen == 0) + return NULL; + + if (overflow > 0) { + pr_debug("%s: got >TTY_THRESHOLD_THROTTLE bytes\n", __func__); + datalen = TTY_THRESHOLD_THROTTLE; + } + + hvsi_insert_chars(hp, data, datalen); + + if (overflow > 0) { + /* + * we still have more data to deliver, so we need to save off the + * overflow and send it later + */ + pr_debug("%s: deferring overflow\n", __func__); + memcpy(hp->throttle_buf, data + TTY_THRESHOLD_THROTTLE, overflow); + hp->n_throttle = overflow; + } + + return hp->tty; +} + +/* + * Returns true/false indicating data successfully read from hypervisor. + * Used both to get packets for tty connections and to advance the state + * machine during console handshaking (in which case tty = NULL and we ignore + * incoming data). + */ +static int hvsi_load_chunk(struct hvsi_struct *hp, struct tty_struct **flip, + struct tty_struct **hangup, struct hvsi_struct **handshake) +{ + uint8_t *packet = hp->inbuf; + int chunklen; + + *flip = NULL; + *hangup = NULL; + *handshake = NULL; + + chunklen = hvsi_read(hp, hp->inbuf_end, HVSI_MAX_READ); + if (chunklen == 0) { + pr_debug("%s: 0-length read\n", __func__); + return 0; + } + + pr_debug("%s: got %i bytes\n", __func__, chunklen); + dbg_dump_hex(hp->inbuf_end, chunklen); + + hp->inbuf_end += chunklen; + + /* handle all completed packets */ + while ((packet < hp->inbuf_end) && got_packet(hp, packet)) { + struct hvsi_header *header = (struct hvsi_header *)packet; + + if (!is_header(packet)) { + printk(KERN_ERR "hvsi%i: got malformed packet\n", hp->index); + /* skip bytes until we find a header or run out of data */ + while ((packet < hp->inbuf_end) && (!is_header(packet))) + packet++; + continue; + } + + pr_debug("%s: handling %i-byte packet\n", __func__, + len_packet(packet)); + dbg_dump_packet(packet); + + switch (header->type) { + case VS_DATA_PACKET_HEADER: + if (!is_open(hp)) + break; + if (hp->tty == NULL) + break; /* no tty buffer to put data in */ + *flip = hvsi_recv_data(hp, packet); + break; + case VS_CONTROL_PACKET_HEADER: + hvsi_recv_control(hp, packet, hangup, handshake); + break; + case VS_QUERY_RESPONSE_PACKET_HEADER: + hvsi_recv_response(hp, packet); + break; + case VS_QUERY_PACKET_HEADER: + hvsi_recv_query(hp, packet); + break; + default: + printk(KERN_ERR "hvsi%i: unknown HVSI packet type 0x%x\n", + hp->index, header->type); + dump_packet(packet); + break; + } + + packet += len_packet(packet); + + if (*hangup || *handshake) { + pr_debug("%s: hangup or handshake\n", __func__); + /* + * we need to send the hangup now before receiving any more data. + * If we get "data, hangup, data", we can't deliver the second + * data before the hangup. + */ + break; + } + } + + compact_inbuf(hp, packet); + + return 1; +} + +static void hvsi_send_overflow(struct hvsi_struct *hp) +{ + pr_debug("%s: delivering %i bytes overflow\n", __func__, + hp->n_throttle); + + hvsi_insert_chars(hp, hp->throttle_buf, hp->n_throttle); + hp->n_throttle = 0; +} + +/* + * must get all pending data because we only get an irq on empty->non-empty + * transition + */ +static irqreturn_t hvsi_interrupt(int irq, void *arg) +{ + struct hvsi_struct *hp = (struct hvsi_struct *)arg; + struct tty_struct *flip; + struct tty_struct *hangup; + struct hvsi_struct *handshake; + unsigned long flags; + int again = 1; + + pr_debug("%s\n", __func__); + + while (again) { + spin_lock_irqsave(&hp->lock, flags); + again = hvsi_load_chunk(hp, &flip, &hangup, &handshake); + spin_unlock_irqrestore(&hp->lock, flags); + + /* + * we have to call tty_flip_buffer_push() and tty_hangup() outside our + * spinlock. But we also have to keep going until we've read all the + * available data. + */ + + if (flip) { + /* there was data put in the tty flip buffer */ + tty_flip_buffer_push(flip); + flip = NULL; + } + + if (hangup) { + tty_hangup(hangup); + } + + if (handshake) { + pr_debug("hvsi%i: attempting re-handshake\n", handshake->index); + schedule_work(&handshake->handshaker); + } + } + + spin_lock_irqsave(&hp->lock, flags); + if (hp->tty && hp->n_throttle + && (!test_bit(TTY_THROTTLED, &hp->tty->flags))) { + /* we weren't hung up and we weren't throttled, so we can deliver the + * rest now */ + flip = hp->tty; + hvsi_send_overflow(hp); + } + spin_unlock_irqrestore(&hp->lock, flags); + + if (flip) { + tty_flip_buffer_push(flip); + } + + return IRQ_HANDLED; +} + +/* for boot console, before the irq handler is running */ +static int __init poll_for_state(struct hvsi_struct *hp, int state) +{ + unsigned long end_jiffies = jiffies + HVSI_TIMEOUT; + + for (;;) { + hvsi_interrupt(hp->virq, (void *)hp); /* get pending data */ + + if (hp->state == state) + return 0; + + mdelay(5); + if (time_after(jiffies, end_jiffies)) + return -EIO; + } +} + +/* wait for irq handler to change our state */ +static int wait_for_state(struct hvsi_struct *hp, int state) +{ + int ret = 0; + + if (!wait_event_timeout(hp->stateq, (hp->state == state), HVSI_TIMEOUT)) + ret = -EIO; + + return ret; +} + +static int hvsi_query(struct hvsi_struct *hp, uint16_t verb) +{ + struct hvsi_query packet __ALIGNED__; + int wrote; + + packet.type = VS_QUERY_PACKET_HEADER; + packet.len = sizeof(struct hvsi_query); + packet.seqno = atomic_inc_return(&hp->seqno); + packet.verb = verb; + + pr_debug("%s: sending %i bytes\n", __func__, packet.len); + dbg_dump_hex((uint8_t*)&packet, packet.len); + + wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.len); + if (wrote != packet.len) { + printk(KERN_ERR "hvsi%i: couldn't send query (%i)!\n", hp->index, + wrote); + return -EIO; + } + + return 0; +} + +static int hvsi_get_mctrl(struct hvsi_struct *hp) +{ + int ret; + + set_state(hp, HVSI_WAIT_FOR_MCTRL_RESPONSE); + hvsi_query(hp, VSV_SEND_MODEM_CTL_STATUS); + + ret = hvsi_wait(hp, HVSI_OPEN); + if (ret < 0) { + printk(KERN_ERR "hvsi%i: didn't get modem flags\n", hp->index); + set_state(hp, HVSI_OPEN); + return ret; + } + + pr_debug("%s: mctrl 0x%x\n", __func__, hp->mctrl); + + return 0; +} + +/* note that we can only set DTR */ +static int hvsi_set_mctrl(struct hvsi_struct *hp, uint16_t mctrl) +{ + struct hvsi_control packet __ALIGNED__; + int wrote; + + packet.type = VS_CONTROL_PACKET_HEADER, + packet.seqno = atomic_inc_return(&hp->seqno); + packet.len = sizeof(struct hvsi_control); + packet.verb = VSV_SET_MODEM_CTL; + packet.mask = HVSI_TSDTR; + + if (mctrl & TIOCM_DTR) + packet.word = HVSI_TSDTR; + + pr_debug("%s: sending %i bytes\n", __func__, packet.len); + dbg_dump_hex((uint8_t*)&packet, packet.len); + + wrote = hvc_put_chars(hp->vtermno, (char *)&packet, packet.len); + if (wrote != packet.len) { + printk(KERN_ERR "hvsi%i: couldn't set DTR!\n", hp->index); + return -EIO; + } + + return 0; +} + +static void hvsi_drain_input(struct hvsi_struct *hp) +{ + uint8_t buf[HVSI_MAX_READ] __ALIGNED__; + unsigned long end_jiffies = jiffies + HVSI_TIMEOUT; + + while (time_before(end_jiffies, jiffies)) + if (0 == hvsi_read(hp, buf, HVSI_MAX_READ)) + break; +} + +static int hvsi_handshake(struct hvsi_struct *hp) +{ + int ret; + + /* + * We could have a CLOSE or other data waiting for us before we even try + * to open; try to throw it all away so we don't get confused. (CLOSE + * is the first message sent up the pipe when the FSP comes online. We + * need to distinguish between "it came up a while ago and we're the first + * user" and "it was just reset before it saw our handshake packet".) + */ + hvsi_drain_input(hp); + + set_state(hp, HVSI_WAIT_FOR_VER_RESPONSE); + ret = hvsi_query(hp, VSV_SEND_VERSION_NUMBER); + if (ret < 0) { + printk(KERN_ERR "hvsi%i: couldn't send version query\n", hp->index); + return ret; + } + + ret = hvsi_wait(hp, HVSI_OPEN); + if (ret < 0) + return ret; + + return 0; +} + +static void hvsi_handshaker(struct work_struct *work) +{ + struct hvsi_struct *hp = + container_of(work, struct hvsi_struct, handshaker); + + if (hvsi_handshake(hp) >= 0) + return; + + printk(KERN_ERR "hvsi%i: re-handshaking failed\n", hp->index); + if (is_console(hp)) { + /* + * ttys will re-attempt the handshake via hvsi_open, but + * the console will not. + */ + printk(KERN_ERR "hvsi%i: lost console!\n", hp->index); + } +} + +static int hvsi_put_chars(struct hvsi_struct *hp, const char *buf, int count) +{ + struct hvsi_data packet __ALIGNED__; + int ret; + + BUG_ON(count > HVSI_MAX_OUTGOING_DATA); + + packet.type = VS_DATA_PACKET_HEADER; + packet.seqno = atomic_inc_return(&hp->seqno); + packet.len = count + sizeof(struct hvsi_header); + memcpy(&packet.data, buf, count); + + ret = hvc_put_chars(hp->vtermno, (char *)&packet, packet.len); + if (ret == packet.len) { + /* return the number of chars written, not the packet length */ + return count; + } + return ret; /* return any errors */ +} + +static void hvsi_close_protocol(struct hvsi_struct *hp) +{ + struct hvsi_control packet __ALIGNED__; + + packet.type = VS_CONTROL_PACKET_HEADER; + packet.seqno = atomic_inc_return(&hp->seqno); + packet.len = 6; + packet.verb = VSV_CLOSE_PROTOCOL; + + pr_debug("%s: sending %i bytes\n", __func__, packet.len); + dbg_dump_hex((uint8_t*)&packet, packet.len); + + hvc_put_chars(hp->vtermno, (char *)&packet, packet.len); +} + +static int hvsi_open(struct tty_struct *tty, struct file *filp) +{ + struct hvsi_struct *hp; + unsigned long flags; + int line = tty->index; + int ret; + + pr_debug("%s\n", __func__); + + if (line < 0 || line >= hvsi_count) + return -ENODEV; + hp = &hvsi_ports[line]; + + tty->driver_data = hp; + + mb(); + if (hp->state == HVSI_FSP_DIED) + return -EIO; + + spin_lock_irqsave(&hp->lock, flags); + hp->tty = tty; + hp->count++; + atomic_set(&hp->seqno, 0); + h_vio_signal(hp->vtermno, VIO_IRQ_ENABLE); + spin_unlock_irqrestore(&hp->lock, flags); + + if (is_console(hp)) + return 0; /* this has already been handshaked as the console */ + + ret = hvsi_handshake(hp); + if (ret < 0) { + printk(KERN_ERR "%s: HVSI handshaking failed\n", tty->name); + return ret; + } + + ret = hvsi_get_mctrl(hp); + if (ret < 0) { + printk(KERN_ERR "%s: couldn't get initial modem flags\n", tty->name); + return ret; + } + + ret = hvsi_set_mctrl(hp, hp->mctrl | TIOCM_DTR); + if (ret < 0) { + printk(KERN_ERR "%s: couldn't set DTR\n", tty->name); + return ret; + } + + return 0; +} + +/* wait for hvsi_write_worker to empty hp->outbuf */ +static void hvsi_flush_output(struct hvsi_struct *hp) +{ + wait_event_timeout(hp->emptyq, (hp->n_outbuf <= 0), HVSI_TIMEOUT); + + /* 'writer' could still be pending if it didn't see n_outbuf = 0 yet */ + cancel_delayed_work_sync(&hp->writer); + flush_work_sync(&hp->handshaker); + + /* + * it's also possible that our timeout expired and hvsi_write_worker + * didn't manage to push outbuf. poof. + */ + hp->n_outbuf = 0; +} + +static void hvsi_close(struct tty_struct *tty, struct file *filp) +{ + struct hvsi_struct *hp = tty->driver_data; + unsigned long flags; + + pr_debug("%s\n", __func__); + + if (tty_hung_up_p(filp)) + return; + + spin_lock_irqsave(&hp->lock, flags); + + if (--hp->count == 0) { + hp->tty = NULL; + hp->inbuf_end = hp->inbuf; /* discard remaining partial packets */ + + /* only close down connection if it is not the console */ + if (!is_console(hp)) { + h_vio_signal(hp->vtermno, VIO_IRQ_DISABLE); /* no more irqs */ + __set_state(hp, HVSI_CLOSED); + /* + * any data delivered to the tty layer after this will be + * discarded (except for XON/XOFF) + */ + tty->closing = 1; + + spin_unlock_irqrestore(&hp->lock, flags); + + /* let any existing irq handlers finish. no more will start. */ + synchronize_irq(hp->virq); + + /* hvsi_write_worker will re-schedule until outbuf is empty. */ + hvsi_flush_output(hp); + + /* tell FSP to stop sending data */ + hvsi_close_protocol(hp); + + /* + * drain anything FSP is still in the middle of sending, and let + * hvsi_handshake drain the rest on the next open. + */ + hvsi_drain_input(hp); + + spin_lock_irqsave(&hp->lock, flags); + } + } else if (hp->count < 0) + printk(KERN_ERR "hvsi_close %lu: oops, count is %d\n", + hp - hvsi_ports, hp->count); + + spin_unlock_irqrestore(&hp->lock, flags); +} + +static void hvsi_hangup(struct tty_struct *tty) +{ + struct hvsi_struct *hp = tty->driver_data; + unsigned long flags; + + pr_debug("%s\n", __func__); + + spin_lock_irqsave(&hp->lock, flags); + + hp->count = 0; + hp->n_outbuf = 0; + hp->tty = NULL; + + spin_unlock_irqrestore(&hp->lock, flags); +} + +/* called with hp->lock held */ +static void hvsi_push(struct hvsi_struct *hp) +{ + int n; + + if (hp->n_outbuf <= 0) + return; + + n = hvsi_put_chars(hp, hp->outbuf, hp->n_outbuf); + if (n > 0) { + /* success */ + pr_debug("%s: wrote %i chars\n", __func__, n); + hp->n_outbuf = 0; + } else if (n == -EIO) { + __set_state(hp, HVSI_FSP_DIED); + printk(KERN_ERR "hvsi%i: service processor died\n", hp->index); + } +} + +/* hvsi_write_worker will keep rescheduling itself until outbuf is empty */ +static void hvsi_write_worker(struct work_struct *work) +{ + struct hvsi_struct *hp = + container_of(work, struct hvsi_struct, writer.work); + unsigned long flags; +#ifdef DEBUG + static long start_j = 0; + + if (start_j == 0) + start_j = jiffies; +#endif /* DEBUG */ + + spin_lock_irqsave(&hp->lock, flags); + + pr_debug("%s: %i chars in buffer\n", __func__, hp->n_outbuf); + + if (!is_open(hp)) { + /* + * We could have a non-open connection if the service processor died + * while we were busily scheduling ourselves. In that case, it could + * be minutes before the service processor comes back, so only try + * again once a second. + */ + schedule_delayed_work(&hp->writer, HZ); + goto out; + } + + hvsi_push(hp); + if (hp->n_outbuf > 0) + schedule_delayed_work(&hp->writer, 10); + else { +#ifdef DEBUG + pr_debug("%s: outbuf emptied after %li jiffies\n", __func__, + jiffies - start_j); + start_j = 0; +#endif /* DEBUG */ + wake_up_all(&hp->emptyq); + tty_wakeup(hp->tty); + } + +out: + spin_unlock_irqrestore(&hp->lock, flags); +} + +static int hvsi_write_room(struct tty_struct *tty) +{ + struct hvsi_struct *hp = tty->driver_data; + + return N_OUTBUF - hp->n_outbuf; +} + +static int hvsi_chars_in_buffer(struct tty_struct *tty) +{ + struct hvsi_struct *hp = tty->driver_data; + + return hp->n_outbuf; +} + +static int hvsi_write(struct tty_struct *tty, + const unsigned char *buf, int count) +{ + struct hvsi_struct *hp = tty->driver_data; + const char *source = buf; + unsigned long flags; + int total = 0; + int origcount = count; + + spin_lock_irqsave(&hp->lock, flags); + + pr_debug("%s: %i chars in buffer\n", __func__, hp->n_outbuf); + + if (!is_open(hp)) { + /* we're either closing or not yet open; don't accept data */ + pr_debug("%s: not open\n", __func__); + goto out; + } + + /* + * when the hypervisor buffer (16K) fills, data will stay in hp->outbuf + * and hvsi_write_worker will be scheduled. subsequent hvsi_write() calls + * will see there is no room in outbuf and return. + */ + while ((count > 0) && (hvsi_write_room(hp->tty) > 0)) { + int chunksize = min(count, hvsi_write_room(hp->tty)); + + BUG_ON(hp->n_outbuf < 0); + memcpy(hp->outbuf + hp->n_outbuf, source, chunksize); + hp->n_outbuf += chunksize; + + total += chunksize; + source += chunksize; + count -= chunksize; + hvsi_push(hp); + } + + if (hp->n_outbuf > 0) { + /* + * we weren't able to write it all to the hypervisor. + * schedule another push attempt. + */ + schedule_delayed_work(&hp->writer, 10); + } + +out: + spin_unlock_irqrestore(&hp->lock, flags); + + if (total != origcount) + pr_debug("%s: wanted %i, only wrote %i\n", __func__, origcount, + total); + + return total; +} + +/* + * I have never seen throttle or unthrottle called, so this little throttle + * buffering scheme may or may not work. + */ +static void hvsi_throttle(struct tty_struct *tty) +{ + struct hvsi_struct *hp = tty->driver_data; + + pr_debug("%s\n", __func__); + + h_vio_signal(hp->vtermno, VIO_IRQ_DISABLE); +} + +static void hvsi_unthrottle(struct tty_struct *tty) +{ + struct hvsi_struct *hp = tty->driver_data; + unsigned long flags; + int shouldflip = 0; + + pr_debug("%s\n", __func__); + + spin_lock_irqsave(&hp->lock, flags); + if (hp->n_throttle) { + hvsi_send_overflow(hp); + shouldflip = 1; + } + spin_unlock_irqrestore(&hp->lock, flags); + + if (shouldflip) + tty_flip_buffer_push(hp->tty); + + h_vio_signal(hp->vtermno, VIO_IRQ_ENABLE); +} + +static int hvsi_tiocmget(struct tty_struct *tty, struct file *file) +{ + struct hvsi_struct *hp = tty->driver_data; + + hvsi_get_mctrl(hp); + return hp->mctrl; +} + +static int hvsi_tiocmset(struct tty_struct *tty, struct file *file, + unsigned int set, unsigned int clear) +{ + struct hvsi_struct *hp = tty->driver_data; + unsigned long flags; + uint16_t new_mctrl; + + /* we can only alter DTR */ + clear &= TIOCM_DTR; + set &= TIOCM_DTR; + + spin_lock_irqsave(&hp->lock, flags); + + new_mctrl = (hp->mctrl & ~clear) | set; + + if (hp->mctrl != new_mctrl) { + hvsi_set_mctrl(hp, new_mctrl); + hp->mctrl = new_mctrl; + } + spin_unlock_irqrestore(&hp->lock, flags); + + return 0; +} + + +static const struct tty_operations hvsi_ops = { + .open = hvsi_open, + .close = hvsi_close, + .write = hvsi_write, + .hangup = hvsi_hangup, + .write_room = hvsi_write_room, + .chars_in_buffer = hvsi_chars_in_buffer, + .throttle = hvsi_throttle, + .unthrottle = hvsi_unthrottle, + .tiocmget = hvsi_tiocmget, + .tiocmset = hvsi_tiocmset, +}; + +static int __init hvsi_init(void) +{ + int i; + + hvsi_driver = alloc_tty_driver(hvsi_count); + if (!hvsi_driver) + return -ENOMEM; + + hvsi_driver->owner = THIS_MODULE; + hvsi_driver->driver_name = "hvsi"; + hvsi_driver->name = "hvsi"; + hvsi_driver->major = HVSI_MAJOR; + hvsi_driver->minor_start = HVSI_MINOR; + hvsi_driver->type = TTY_DRIVER_TYPE_SYSTEM; + hvsi_driver->init_termios = tty_std_termios; + hvsi_driver->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL; + hvsi_driver->init_termios.c_ispeed = 9600; + hvsi_driver->init_termios.c_ospeed = 9600; + hvsi_driver->flags = TTY_DRIVER_REAL_RAW; + tty_set_operations(hvsi_driver, &hvsi_ops); + + for (i=0; i < hvsi_count; i++) { + struct hvsi_struct *hp = &hvsi_ports[i]; + int ret = 1; + + ret = request_irq(hp->virq, hvsi_interrupt, IRQF_DISABLED, "hvsi", hp); + if (ret) + printk(KERN_ERR "HVSI: couldn't reserve irq 0x%x (error %i)\n", + hp->virq, ret); + } + hvsi_wait = wait_for_state; /* irqs active now */ + + if (tty_register_driver(hvsi_driver)) + panic("Couldn't register hvsi console driver\n"); + + printk(KERN_DEBUG "HVSI: registered %i devices\n", hvsi_count); + + return 0; +} +device_initcall(hvsi_init); + +/***** console (not tty) code: *****/ + +static void hvsi_console_print(struct console *console, const char *buf, + unsigned int count) +{ + struct hvsi_struct *hp = &hvsi_ports[console->index]; + char c[HVSI_MAX_OUTGOING_DATA] __ALIGNED__; + unsigned int i = 0, n = 0; + int ret, donecr = 0; + + mb(); + if (!is_open(hp)) + return; + + /* + * ugh, we have to translate LF -> CRLF ourselves, in place. + * copied from hvc_console.c: + */ + while (count > 0 || i > 0) { + if (count > 0 && i < sizeof(c)) { + if (buf[n] == '\n' && !donecr) { + c[i++] = '\r'; + donecr = 1; + } else { + c[i++] = buf[n++]; + donecr = 0; + --count; + } + } else { + ret = hvsi_put_chars(hp, c, i); + if (ret < 0) + i = 0; + i -= ret; + } + } +} + +static struct tty_driver *hvsi_console_device(struct console *console, + int *index) +{ + *index = console->index; + return hvsi_driver; +} + +static int __init hvsi_console_setup(struct console *console, char *options) +{ + struct hvsi_struct *hp; + int ret; + + if (console->index < 0 || console->index >= hvsi_count) + return -1; + hp = &hvsi_ports[console->index]; + + /* give the FSP a chance to change the baud rate when we re-open */ + hvsi_close_protocol(hp); + + ret = hvsi_handshake(hp); + if (ret < 0) + return ret; + + ret = hvsi_get_mctrl(hp); + if (ret < 0) + return ret; + + ret = hvsi_set_mctrl(hp, hp->mctrl | TIOCM_DTR); + if (ret < 0) + return ret; + + hp->flags |= HVSI_CONSOLE; + + return 0; +} + +static struct console hvsi_console = { + .name = "hvsi", + .write = hvsi_console_print, + .device = hvsi_console_device, + .setup = hvsi_console_setup, + .flags = CON_PRINTBUFFER, + .index = -1, +}; + +static int __init hvsi_console_init(void) +{ + struct device_node *vty; + + hvsi_wait = poll_for_state; /* no irqs yet; must poll */ + + /* search device tree for vty nodes */ + for (vty = of_find_compatible_node(NULL, "serial", "hvterm-protocol"); + vty != NULL; + vty = of_find_compatible_node(vty, "serial", "hvterm-protocol")) { + struct hvsi_struct *hp; + const uint32_t *vtermno, *irq; + + vtermno = of_get_property(vty, "reg", NULL); + irq = of_get_property(vty, "interrupts", NULL); + if (!vtermno || !irq) + continue; + + if (hvsi_count >= MAX_NR_HVSI_CONSOLES) { + of_node_put(vty); + break; + } + + hp = &hvsi_ports[hvsi_count]; + INIT_DELAYED_WORK(&hp->writer, hvsi_write_worker); + INIT_WORK(&hp->handshaker, hvsi_handshaker); + init_waitqueue_head(&hp->emptyq); + init_waitqueue_head(&hp->stateq); + spin_lock_init(&hp->lock); + hp->index = hvsi_count; + hp->inbuf_end = hp->inbuf; + hp->state = HVSI_CLOSED; + hp->vtermno = *vtermno; + hp->virq = irq_create_mapping(NULL, irq[0]); + if (hp->virq == NO_IRQ) { + printk(KERN_ERR "%s: couldn't create irq mapping for 0x%x\n", + __func__, irq[0]); + continue; + } + + hvsi_count++; + } + + if (hvsi_count) + register_console(&hvsi_console); + return 0; +} +console_initcall(hvsi_console_init); diff --git a/drivers/tty/hvc/virtio_console.c b/drivers/tty/hvc/virtio_console.c new file mode 100644 index 000000000000..896a2ced1d27 --- /dev/null +++ b/drivers/tty/hvc/virtio_console.c @@ -0,0 +1,1838 @@ +/* + * Copyright (C) 2006, 2007, 2009 Rusty Russell, IBM Corporation + * Copyright (C) 2009, 2010 Red Hat, Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ +#include <linux/cdev.h> +#include <linux/debugfs.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/fs.h> +#include <linux/init.h> +#include <linux/list.h> +#include <linux/poll.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/virtio.h> +#include <linux/virtio_console.h> +#include <linux/wait.h> +#include <linux/workqueue.h> +#include "hvc_console.h" + +/* + * This is a global struct for storing common data for all the devices + * this driver handles. + * + * Mainly, it has a linked list for all the consoles in one place so + * that callbacks from hvc for get_chars(), put_chars() work properly + * across multiple devices and multiple ports per device. + */ +struct ports_driver_data { + /* Used for registering chardevs */ + struct class *class; + + /* Used for exporting per-port information to debugfs */ + struct dentry *debugfs_dir; + + /* List of all the devices we're handling */ + struct list_head portdevs; + + /* Number of devices this driver is handling */ + unsigned int index; + + /* + * This is used to keep track of the number of hvc consoles + * spawned by this driver. This number is given as the first + * argument to hvc_alloc(). To correctly map an initial + * console spawned via hvc_instantiate to the console being + * hooked up via hvc_alloc, we need to pass the same vtermno. + * + * We also just assume the first console being initialised was + * the first one that got used as the initial console. + */ + unsigned int next_vtermno; + + /* All the console devices handled by this driver */ + struct list_head consoles; +}; +static struct ports_driver_data pdrvdata; + +DEFINE_SPINLOCK(pdrvdata_lock); + +/* This struct holds information that's relevant only for console ports */ +struct console { + /* We'll place all consoles in a list in the pdrvdata struct */ + struct list_head list; + + /* The hvc device associated with this console port */ + struct hvc_struct *hvc; + + /* The size of the console */ + struct winsize ws; + + /* + * This number identifies the number that we used to register + * with hvc in hvc_instantiate() and hvc_alloc(); this is the + * number passed on by the hvc callbacks to us to + * differentiate between the other console ports handled by + * this driver + */ + u32 vtermno; +}; + +struct port_buffer { + char *buf; + + /* size of the buffer in *buf above */ + size_t size; + + /* used length of the buffer */ + size_t len; + /* offset in the buf from which to consume data */ + size_t offset; +}; + +/* + * This is a per-device struct that stores data common to all the + * ports for that device (vdev->priv). + */ +struct ports_device { + /* Next portdev in the list, head is in the pdrvdata struct */ + struct list_head list; + + /* + * Workqueue handlers where we process deferred work after + * notification + */ + struct work_struct control_work; + + struct list_head ports; + + /* To protect the list of ports */ + spinlock_t ports_lock; + + /* To protect the vq operations for the control channel */ + spinlock_t cvq_lock; + + /* The current config space is stored here */ + struct virtio_console_config config; + + /* The virtio device we're associated with */ + struct virtio_device *vdev; + + /* + * A couple of virtqueues for the control channel: one for + * guest->host transfers, one for host->guest transfers + */ + struct virtqueue *c_ivq, *c_ovq; + + /* Array of per-port IO virtqueues */ + struct virtqueue **in_vqs, **out_vqs; + + /* Used for numbering devices for sysfs and debugfs */ + unsigned int drv_index; + + /* Major number for this device. Ports will be created as minors. */ + int chr_major; +}; + +/* This struct holds the per-port data */ +struct port { + /* Next port in the list, head is in the ports_device */ + struct list_head list; + + /* Pointer to the parent virtio_console device */ + struct ports_device *portdev; + + /* The current buffer from which data has to be fed to readers */ + struct port_buffer *inbuf; + + /* + * To protect the operations on the in_vq associated with this + * port. Has to be a spinlock because it can be called from + * interrupt context (get_char()). + */ + spinlock_t inbuf_lock; + + /* Protect the operations on the out_vq. */ + spinlock_t outvq_lock; + + /* The IO vqs for this port */ + struct virtqueue *in_vq, *out_vq; + + /* File in the debugfs directory that exposes this port's information */ + struct dentry *debugfs_file; + + /* + * The entries in this struct will be valid if this port is + * hooked up to an hvc console + */ + struct console cons; + + /* Each port associates with a separate char device */ + struct cdev *cdev; + struct device *dev; + + /* Reference-counting to handle port hot-unplugs and file operations */ + struct kref kref; + + /* A waitqueue for poll() or blocking read operations */ + wait_queue_head_t waitqueue; + + /* The 'name' of the port that we expose via sysfs properties */ + char *name; + + /* We can notify apps of host connect / disconnect events via SIGIO */ + struct fasync_struct *async_queue; + + /* The 'id' to identify the port with the Host */ + u32 id; + + bool outvq_full; + + /* Is the host device open */ + bool host_connected; + + /* We should allow only one process to open a port */ + bool guest_connected; +}; + +/* This is the very early arch-specified put chars function. */ +static int (*early_put_chars)(u32, const char *, int); + +static struct port *find_port_by_vtermno(u32 vtermno) +{ + struct port *port; + struct console *cons; + unsigned long flags; + + spin_lock_irqsave(&pdrvdata_lock, flags); + list_for_each_entry(cons, &pdrvdata.consoles, list) { + if (cons->vtermno == vtermno) { + port = container_of(cons, struct port, cons); + goto out; + } + } + port = NULL; +out: + spin_unlock_irqrestore(&pdrvdata_lock, flags); + return port; +} + +static struct port *find_port_by_devt_in_portdev(struct ports_device *portdev, + dev_t dev) +{ + struct port *port; + unsigned long flags; + + spin_lock_irqsave(&portdev->ports_lock, flags); + list_for_each_entry(port, &portdev->ports, list) + if (port->cdev->dev == dev) + goto out; + port = NULL; +out: + spin_unlock_irqrestore(&portdev->ports_lock, flags); + + return port; +} + +static struct port *find_port_by_devt(dev_t dev) +{ + struct ports_device *portdev; + struct port *port; + unsigned long flags; + + spin_lock_irqsave(&pdrvdata_lock, flags); + list_for_each_entry(portdev, &pdrvdata.portdevs, list) { + port = find_port_by_devt_in_portdev(portdev, dev); + if (port) + goto out; + } + port = NULL; +out: + spin_unlock_irqrestore(&pdrvdata_lock, flags); + return port; +} + +static struct port *find_port_by_id(struct ports_device *portdev, u32 id) +{ + struct port *port; + unsigned long flags; + + spin_lock_irqsave(&portdev->ports_lock, flags); + list_for_each_entry(port, &portdev->ports, list) + if (port->id == id) + goto out; + port = NULL; +out: + spin_unlock_irqrestore(&portdev->ports_lock, flags); + + return port; +} + +static struct port *find_port_by_vq(struct ports_device *portdev, + struct virtqueue *vq) +{ + struct port *port; + unsigned long flags; + + spin_lock_irqsave(&portdev->ports_lock, flags); + list_for_each_entry(port, &portdev->ports, list) + if (port->in_vq == vq || port->out_vq == vq) + goto out; + port = NULL; +out: + spin_unlock_irqrestore(&portdev->ports_lock, flags); + return port; +} + +static bool is_console_port(struct port *port) +{ + if (port->cons.hvc) + return true; + return false; +} + +static inline bool use_multiport(struct ports_device *portdev) +{ + /* + * This condition can be true when put_chars is called from + * early_init + */ + if (!portdev->vdev) + return 0; + return portdev->vdev->features[0] & (1 << VIRTIO_CONSOLE_F_MULTIPORT); +} + +static void free_buf(struct port_buffer *buf) +{ + kfree(buf->buf); + kfree(buf); +} + +static struct port_buffer *alloc_buf(size_t buf_size) +{ + struct port_buffer *buf; + + buf = kmalloc(sizeof(*buf), GFP_KERNEL); + if (!buf) + goto fail; + buf->buf = kzalloc(buf_size, GFP_KERNEL); + if (!buf->buf) + goto free_buf; + buf->len = 0; + buf->offset = 0; + buf->size = buf_size; + return buf; + +free_buf: + kfree(buf); +fail: + return NULL; +} + +/* Callers should take appropriate locks */ +static void *get_inbuf(struct port *port) +{ + struct port_buffer *buf; + struct virtqueue *vq; + unsigned int len; + + vq = port->in_vq; + buf = virtqueue_get_buf(vq, &len); + if (buf) { + buf->len = len; + buf->offset = 0; + } + return buf; +} + +/* + * Create a scatter-gather list representing our input buffer and put + * it in the queue. + * + * Callers should take appropriate locks. + */ +static int add_inbuf(struct virtqueue *vq, struct port_buffer *buf) +{ + struct scatterlist sg[1]; + int ret; + + sg_init_one(sg, buf->buf, buf->size); + + ret = virtqueue_add_buf(vq, sg, 0, 1, buf); + virtqueue_kick(vq); + return ret; +} + +/* Discard any unread data this port has. Callers lockers. */ +static void discard_port_data(struct port *port) +{ + struct port_buffer *buf; + struct virtqueue *vq; + unsigned int len; + int ret; + + vq = port->in_vq; + if (port->inbuf) + buf = port->inbuf; + else + buf = virtqueue_get_buf(vq, &len); + + ret = 0; + while (buf) { + if (add_inbuf(vq, buf) < 0) { + ret++; + free_buf(buf); + } + buf = virtqueue_get_buf(vq, &len); + } + port->inbuf = NULL; + if (ret) + dev_warn(port->dev, "Errors adding %d buffers back to vq\n", + ret); +} + +static bool port_has_data(struct port *port) +{ + unsigned long flags; + bool ret; + + spin_lock_irqsave(&port->inbuf_lock, flags); + if (port->inbuf) { + ret = true; + goto out; + } + port->inbuf = get_inbuf(port); + if (port->inbuf) { + ret = true; + goto out; + } + ret = false; +out: + spin_unlock_irqrestore(&port->inbuf_lock, flags); + return ret; +} + +static ssize_t __send_control_msg(struct ports_device *portdev, u32 port_id, + unsigned int event, unsigned int value) +{ + struct scatterlist sg[1]; + struct virtio_console_control cpkt; + struct virtqueue *vq; + unsigned int len; + + if (!use_multiport(portdev)) + return 0; + + cpkt.id = port_id; + cpkt.event = event; + cpkt.value = value; + + vq = portdev->c_ovq; + + sg_init_one(sg, &cpkt, sizeof(cpkt)); + if (virtqueue_add_buf(vq, sg, 1, 0, &cpkt) >= 0) { + virtqueue_kick(vq); + while (!virtqueue_get_buf(vq, &len)) + cpu_relax(); + } + return 0; +} + +static ssize_t send_control_msg(struct port *port, unsigned int event, + unsigned int value) +{ + /* Did the port get unplugged before userspace closed it? */ + if (port->portdev) + return __send_control_msg(port->portdev, port->id, event, value); + return 0; +} + +/* Callers must take the port->outvq_lock */ +static void reclaim_consumed_buffers(struct port *port) +{ + void *buf; + unsigned int len; + + while ((buf = virtqueue_get_buf(port->out_vq, &len))) { + kfree(buf); + port->outvq_full = false; + } +} + +static ssize_t send_buf(struct port *port, void *in_buf, size_t in_count, + bool nonblock) +{ + struct scatterlist sg[1]; + struct virtqueue *out_vq; + ssize_t ret; + unsigned long flags; + unsigned int len; + + out_vq = port->out_vq; + + spin_lock_irqsave(&port->outvq_lock, flags); + + reclaim_consumed_buffers(port); + + sg_init_one(sg, in_buf, in_count); + ret = virtqueue_add_buf(out_vq, sg, 1, 0, in_buf); + + /* Tell Host to go! */ + virtqueue_kick(out_vq); + + if (ret < 0) { + in_count = 0; + goto done; + } + + if (ret == 0) + port->outvq_full = true; + + if (nonblock) + goto done; + + /* + * Wait till the host acknowledges it pushed out the data we + * sent. This is done for data from the hvc_console; the tty + * operations are performed with spinlocks held so we can't + * sleep here. An alternative would be to copy the data to a + * buffer and relax the spinning requirement. The downside is + * we need to kmalloc a GFP_ATOMIC buffer each time the + * console driver writes something out. + */ + while (!virtqueue_get_buf(out_vq, &len)) + cpu_relax(); +done: + spin_unlock_irqrestore(&port->outvq_lock, flags); + /* + * We're expected to return the amount of data we wrote -- all + * of it + */ + return in_count; +} + +/* + * Give out the data that's requested from the buffer that we have + * queued up. + */ +static ssize_t fill_readbuf(struct port *port, char *out_buf, size_t out_count, + bool to_user) +{ + struct port_buffer *buf; + unsigned long flags; + + if (!out_count || !port_has_data(port)) + return 0; + + buf = port->inbuf; + out_count = min(out_count, buf->len - buf->offset); + + if (to_user) { + ssize_t ret; + + ret = copy_to_user(out_buf, buf->buf + buf->offset, out_count); + if (ret) + return -EFAULT; + } else { + memcpy(out_buf, buf->buf + buf->offset, out_count); + } + + buf->offset += out_count; + + if (buf->offset == buf->len) { + /* + * We're done using all the data in this buffer. + * Re-queue so that the Host can send us more data. + */ + spin_lock_irqsave(&port->inbuf_lock, flags); + port->inbuf = NULL; + + if (add_inbuf(port->in_vq, buf) < 0) + dev_warn(port->dev, "failed add_buf\n"); + + spin_unlock_irqrestore(&port->inbuf_lock, flags); + } + /* Return the number of bytes actually copied */ + return out_count; +} + +/* The condition that must be true for polling to end */ +static bool will_read_block(struct port *port) +{ + if (!port->guest_connected) { + /* Port got hot-unplugged. Let's exit. */ + return false; + } + return !port_has_data(port) && port->host_connected; +} + +static bool will_write_block(struct port *port) +{ + bool ret; + + if (!port->guest_connected) { + /* Port got hot-unplugged. Let's exit. */ + return false; + } + if (!port->host_connected) + return true; + + spin_lock_irq(&port->outvq_lock); + /* + * Check if the Host has consumed any buffers since we last + * sent data (this is only applicable for nonblocking ports). + */ + reclaim_consumed_buffers(port); + ret = port->outvq_full; + spin_unlock_irq(&port->outvq_lock); + + return ret; +} + +static ssize_t port_fops_read(struct file *filp, char __user *ubuf, + size_t count, loff_t *offp) +{ + struct port *port; + ssize_t ret; + + port = filp->private_data; + + if (!port_has_data(port)) { + /* + * If nothing's connected on the host just return 0 in + * case of list_empty; this tells the userspace app + * that there's no connection + */ + if (!port->host_connected) + return 0; + if (filp->f_flags & O_NONBLOCK) + return -EAGAIN; + + ret = wait_event_interruptible(port->waitqueue, + !will_read_block(port)); + if (ret < 0) + return ret; + } + /* Port got hot-unplugged. */ + if (!port->guest_connected) + return -ENODEV; + /* + * We could've received a disconnection message while we were + * waiting for more data. + * + * This check is not clubbed in the if() statement above as we + * might receive some data as well as the host could get + * disconnected after we got woken up from our wait. So we + * really want to give off whatever data we have and only then + * check for host_connected. + */ + if (!port_has_data(port) && !port->host_connected) + return 0; + + return fill_readbuf(port, ubuf, count, true); +} + +static ssize_t port_fops_write(struct file *filp, const char __user *ubuf, + size_t count, loff_t *offp) +{ + struct port *port; + char *buf; + ssize_t ret; + bool nonblock; + + /* Userspace could be out to fool us */ + if (!count) + return 0; + + port = filp->private_data; + + nonblock = filp->f_flags & O_NONBLOCK; + + if (will_write_block(port)) { + if (nonblock) + return -EAGAIN; + + ret = wait_event_interruptible(port->waitqueue, + !will_write_block(port)); + if (ret < 0) + return ret; + } + /* Port got hot-unplugged. */ + if (!port->guest_connected) + return -ENODEV; + + count = min((size_t)(32 * 1024), count); + + buf = kmalloc(count, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + ret = copy_from_user(buf, ubuf, count); + if (ret) { + ret = -EFAULT; + goto free_buf; + } + + /* + * We now ask send_buf() to not spin for generic ports -- we + * can re-use the same code path that non-blocking file + * descriptors take for blocking file descriptors since the + * wait is already done and we're certain the write will go + * through to the host. + */ + nonblock = true; + ret = send_buf(port, buf, count, nonblock); + + if (nonblock && ret > 0) + goto out; + +free_buf: + kfree(buf); +out: + return ret; +} + +static unsigned int port_fops_poll(struct file *filp, poll_table *wait) +{ + struct port *port; + unsigned int ret; + + port = filp->private_data; + poll_wait(filp, &port->waitqueue, wait); + + if (!port->guest_connected) { + /* Port got unplugged */ + return POLLHUP; + } + ret = 0; + if (!will_read_block(port)) + ret |= POLLIN | POLLRDNORM; + if (!will_write_block(port)) + ret |= POLLOUT; + if (!port->host_connected) + ret |= POLLHUP; + + return ret; +} + +static void remove_port(struct kref *kref); + +static int port_fops_release(struct inode *inode, struct file *filp) +{ + struct port *port; + + port = filp->private_data; + + /* Notify host of port being closed */ + send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0); + + spin_lock_irq(&port->inbuf_lock); + port->guest_connected = false; + + discard_port_data(port); + + spin_unlock_irq(&port->inbuf_lock); + + spin_lock_irq(&port->outvq_lock); + reclaim_consumed_buffers(port); + spin_unlock_irq(&port->outvq_lock); + + /* + * Locks aren't necessary here as a port can't be opened after + * unplug, and if a port isn't unplugged, a kref would already + * exist for the port. Plus, taking ports_lock here would + * create a dependency on other locks taken by functions + * inside remove_port if we're the last holder of the port, + * creating many problems. + */ + kref_put(&port->kref, remove_port); + + return 0; +} + +static int port_fops_open(struct inode *inode, struct file *filp) +{ + struct cdev *cdev = inode->i_cdev; + struct port *port; + int ret; + + port = find_port_by_devt(cdev->dev); + filp->private_data = port; + + /* Prevent against a port getting hot-unplugged at the same time */ + spin_lock_irq(&port->portdev->ports_lock); + kref_get(&port->kref); + spin_unlock_irq(&port->portdev->ports_lock); + + /* + * Don't allow opening of console port devices -- that's done + * via /dev/hvc + */ + if (is_console_port(port)) { + ret = -ENXIO; + goto out; + } + + /* Allow only one process to open a particular port at a time */ + spin_lock_irq(&port->inbuf_lock); + if (port->guest_connected) { + spin_unlock_irq(&port->inbuf_lock); + ret = -EMFILE; + goto out; + } + + port->guest_connected = true; + spin_unlock_irq(&port->inbuf_lock); + + spin_lock_irq(&port->outvq_lock); + /* + * There might be a chance that we missed reclaiming a few + * buffers in the window of the port getting previously closed + * and opening now. + */ + reclaim_consumed_buffers(port); + spin_unlock_irq(&port->outvq_lock); + + nonseekable_open(inode, filp); + + /* Notify host of port being opened */ + send_control_msg(filp->private_data, VIRTIO_CONSOLE_PORT_OPEN, 1); + + return 0; +out: + kref_put(&port->kref, remove_port); + return ret; +} + +static int port_fops_fasync(int fd, struct file *filp, int mode) +{ + struct port *port; + + port = filp->private_data; + return fasync_helper(fd, filp, mode, &port->async_queue); +} + +/* + * The file operations that we support: programs in the guest can open + * a console device, read from it, write to it, poll for data and + * close it. The devices are at + * /dev/vport<device number>p<port number> + */ +static const struct file_operations port_fops = { + .owner = THIS_MODULE, + .open = port_fops_open, + .read = port_fops_read, + .write = port_fops_write, + .poll = port_fops_poll, + .release = port_fops_release, + .fasync = port_fops_fasync, + .llseek = no_llseek, +}; + +/* + * The put_chars() callback is pretty straightforward. + * + * We turn the characters into a scatter-gather list, add it to the + * output queue and then kick the Host. Then we sit here waiting for + * it to finish: inefficient in theory, but in practice + * implementations will do it immediately (lguest's Launcher does). + */ +static int put_chars(u32 vtermno, const char *buf, int count) +{ + struct port *port; + + if (unlikely(early_put_chars)) + return early_put_chars(vtermno, buf, count); + + port = find_port_by_vtermno(vtermno); + if (!port) + return -EPIPE; + + return send_buf(port, (void *)buf, count, false); +} + +/* + * get_chars() is the callback from the hvc_console infrastructure + * when an interrupt is received. + * + * We call out to fill_readbuf that gets us the required data from the + * buffers that are queued up. + */ +static int get_chars(u32 vtermno, char *buf, int count) +{ + struct port *port; + + /* If we've not set up the port yet, we have no input to give. */ + if (unlikely(early_put_chars)) + return 0; + + port = find_port_by_vtermno(vtermno); + if (!port) + return -EPIPE; + + /* If we don't have an input queue yet, we can't get input. */ + BUG_ON(!port->in_vq); + + return fill_readbuf(port, buf, count, false); +} + +static void resize_console(struct port *port) +{ + struct virtio_device *vdev; + + /* The port could have been hot-unplugged */ + if (!port || !is_console_port(port)) + return; + + vdev = port->portdev->vdev; + if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE)) + hvc_resize(port->cons.hvc, port->cons.ws); +} + +/* We set the configuration at this point, since we now have a tty */ +static int notifier_add_vio(struct hvc_struct *hp, int data) +{ + struct port *port; + + port = find_port_by_vtermno(hp->vtermno); + if (!port) + return -EINVAL; + + hp->irq_requested = 1; + resize_console(port); + + return 0; +} + +static void notifier_del_vio(struct hvc_struct *hp, int data) +{ + hp->irq_requested = 0; +} + +/* The operations for console ports. */ +static const struct hv_ops hv_ops = { + .get_chars = get_chars, + .put_chars = put_chars, + .notifier_add = notifier_add_vio, + .notifier_del = notifier_del_vio, + .notifier_hangup = notifier_del_vio, +}; + +/* + * Console drivers are initialized very early so boot messages can go + * out, so we do things slightly differently from the generic virtio + * initialization of the net and block drivers. + * + * At this stage, the console is output-only. It's too early to set + * up a virtqueue, so we let the drivers do some boutique early-output + * thing. + */ +int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int)) +{ + early_put_chars = put_chars; + return hvc_instantiate(0, 0, &hv_ops); +} + +int init_port_console(struct port *port) +{ + int ret; + + /* + * The Host's telling us this port is a console port. Hook it + * up with an hvc console. + * + * To set up and manage our virtual console, we call + * hvc_alloc(). + * + * The first argument of hvc_alloc() is the virtual console + * number. The second argument is the parameter for the + * notification mechanism (like irq number). We currently + * leave this as zero, virtqueues have implicit notifications. + * + * The third argument is a "struct hv_ops" containing the + * put_chars() get_chars(), notifier_add() and notifier_del() + * pointers. The final argument is the output buffer size: we + * can do any size, so we put PAGE_SIZE here. + */ + port->cons.vtermno = pdrvdata.next_vtermno; + + port->cons.hvc = hvc_alloc(port->cons.vtermno, 0, &hv_ops, PAGE_SIZE); + if (IS_ERR(port->cons.hvc)) { + ret = PTR_ERR(port->cons.hvc); + dev_err(port->dev, + "error %d allocating hvc for port\n", ret); + port->cons.hvc = NULL; + return ret; + } + spin_lock_irq(&pdrvdata_lock); + pdrvdata.next_vtermno++; + list_add_tail(&port->cons.list, &pdrvdata.consoles); + spin_unlock_irq(&pdrvdata_lock); + port->guest_connected = true; + + /* + * Start using the new console output if this is the first + * console to come up. + */ + if (early_put_chars) + early_put_chars = NULL; + + /* Notify host of port being opened */ + send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1); + + return 0; +} + +static ssize_t show_port_name(struct device *dev, + struct device_attribute *attr, char *buffer) +{ + struct port *port; + + port = dev_get_drvdata(dev); + + return sprintf(buffer, "%s\n", port->name); +} + +static DEVICE_ATTR(name, S_IRUGO, show_port_name, NULL); + +static struct attribute *port_sysfs_entries[] = { + &dev_attr_name.attr, + NULL +}; + +static struct attribute_group port_attribute_group = { + .name = NULL, /* put in device directory */ + .attrs = port_sysfs_entries, +}; + +static int debugfs_open(struct inode *inode, struct file *filp) +{ + filp->private_data = inode->i_private; + return 0; +} + +static ssize_t debugfs_read(struct file *filp, char __user *ubuf, + size_t count, loff_t *offp) +{ + struct port *port; + char *buf; + ssize_t ret, out_offset, out_count; + + out_count = 1024; + buf = kmalloc(out_count, GFP_KERNEL); + if (!buf) + return -ENOMEM; + + port = filp->private_data; + out_offset = 0; + out_offset += snprintf(buf + out_offset, out_count, + "name: %s\n", port->name ? port->name : ""); + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "guest_connected: %d\n", port->guest_connected); + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "host_connected: %d\n", port->host_connected); + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "outvq_full: %d\n", port->outvq_full); + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "is_console: %s\n", + is_console_port(port) ? "yes" : "no"); + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "console_vtermno: %u\n", port->cons.vtermno); + + ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset); + kfree(buf); + return ret; +} + +static const struct file_operations port_debugfs_ops = { + .owner = THIS_MODULE, + .open = debugfs_open, + .read = debugfs_read, +}; + +static void set_console_size(struct port *port, u16 rows, u16 cols) +{ + if (!port || !is_console_port(port)) + return; + + port->cons.ws.ws_row = rows; + port->cons.ws.ws_col = cols; +} + +static unsigned int fill_queue(struct virtqueue *vq, spinlock_t *lock) +{ + struct port_buffer *buf; + unsigned int nr_added_bufs; + int ret; + + nr_added_bufs = 0; + do { + buf = alloc_buf(PAGE_SIZE); + if (!buf) + break; + + spin_lock_irq(lock); + ret = add_inbuf(vq, buf); + if (ret < 0) { + spin_unlock_irq(lock); + free_buf(buf); + break; + } + nr_added_bufs++; + spin_unlock_irq(lock); + } while (ret > 0); + + return nr_added_bufs; +} + +static void send_sigio_to_port(struct port *port) +{ + if (port->async_queue && port->guest_connected) + kill_fasync(&port->async_queue, SIGIO, POLL_OUT); +} + +static int add_port(struct ports_device *portdev, u32 id) +{ + char debugfs_name[16]; + struct port *port; + struct port_buffer *buf; + dev_t devt; + unsigned int nr_added_bufs; + int err; + + port = kmalloc(sizeof(*port), GFP_KERNEL); + if (!port) { + err = -ENOMEM; + goto fail; + } + kref_init(&port->kref); + + port->portdev = portdev; + port->id = id; + + port->name = NULL; + port->inbuf = NULL; + port->cons.hvc = NULL; + port->async_queue = NULL; + + port->cons.ws.ws_row = port->cons.ws.ws_col = 0; + + port->host_connected = port->guest_connected = false; + + port->outvq_full = false; + + port->in_vq = portdev->in_vqs[port->id]; + port->out_vq = portdev->out_vqs[port->id]; + + port->cdev = cdev_alloc(); + if (!port->cdev) { + dev_err(&port->portdev->vdev->dev, "Error allocating cdev\n"); + err = -ENOMEM; + goto free_port; + } + port->cdev->ops = &port_fops; + + devt = MKDEV(portdev->chr_major, id); + err = cdev_add(port->cdev, devt, 1); + if (err < 0) { + dev_err(&port->portdev->vdev->dev, + "Error %d adding cdev for port %u\n", err, id); + goto free_cdev; + } + port->dev = device_create(pdrvdata.class, &port->portdev->vdev->dev, + devt, port, "vport%up%u", + port->portdev->drv_index, id); + if (IS_ERR(port->dev)) { + err = PTR_ERR(port->dev); + dev_err(&port->portdev->vdev->dev, + "Error %d creating device for port %u\n", + err, id); + goto free_cdev; + } + + spin_lock_init(&port->inbuf_lock); + spin_lock_init(&port->outvq_lock); + init_waitqueue_head(&port->waitqueue); + + /* Fill the in_vq with buffers so the host can send us data. */ + nr_added_bufs = fill_queue(port->in_vq, &port->inbuf_lock); + if (!nr_added_bufs) { + dev_err(port->dev, "Error allocating inbufs\n"); + err = -ENOMEM; + goto free_device; + } + + /* + * If we're not using multiport support, this has to be a console port + */ + if (!use_multiport(port->portdev)) { + err = init_port_console(port); + if (err) + goto free_inbufs; + } + + spin_lock_irq(&portdev->ports_lock); + list_add_tail(&port->list, &port->portdev->ports); + spin_unlock_irq(&portdev->ports_lock); + + /* + * Tell the Host we're set so that it can send us various + * configuration parameters for this port (eg, port name, + * caching, whether this is a console port, etc.) + */ + send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1); + + if (pdrvdata.debugfs_dir) { + /* + * Finally, create the debugfs file that we can use to + * inspect a port's state at any time + */ + sprintf(debugfs_name, "vport%up%u", + port->portdev->drv_index, id); + port->debugfs_file = debugfs_create_file(debugfs_name, 0444, + pdrvdata.debugfs_dir, + port, + &port_debugfs_ops); + } + return 0; + +free_inbufs: + while ((buf = virtqueue_detach_unused_buf(port->in_vq))) + free_buf(buf); +free_device: + device_destroy(pdrvdata.class, port->dev->devt); +free_cdev: + cdev_del(port->cdev); +free_port: + kfree(port); +fail: + /* The host might want to notify management sw about port add failure */ + __send_control_msg(portdev, id, VIRTIO_CONSOLE_PORT_READY, 0); + return err; +} + +/* No users remain, remove all port-specific data. */ +static void remove_port(struct kref *kref) +{ + struct port *port; + + port = container_of(kref, struct port, kref); + + sysfs_remove_group(&port->dev->kobj, &port_attribute_group); + device_destroy(pdrvdata.class, port->dev->devt); + cdev_del(port->cdev); + + kfree(port->name); + + debugfs_remove(port->debugfs_file); + + kfree(port); +} + +/* + * Port got unplugged. Remove port from portdev's list and drop the + * kref reference. If no userspace has this port opened, it will + * result in immediate removal the port. + */ +static void unplug_port(struct port *port) +{ + struct port_buffer *buf; + + spin_lock_irq(&port->portdev->ports_lock); + list_del(&port->list); + spin_unlock_irq(&port->portdev->ports_lock); + + if (port->guest_connected) { + port->guest_connected = false; + port->host_connected = false; + wake_up_interruptible(&port->waitqueue); + + /* Let the app know the port is going down. */ + send_sigio_to_port(port); + } + + if (is_console_port(port)) { + spin_lock_irq(&pdrvdata_lock); + list_del(&port->cons.list); + spin_unlock_irq(&pdrvdata_lock); +#if 0 + /* + * hvc_remove() not called as removing one hvc port + * results in other hvc ports getting frozen. + * + * Once this is resolved in hvc, this functionality + * will be enabled. Till that is done, the -EPIPE + * return from get_chars() above will help + * hvc_console.c to clean up on ports we remove here. + */ + hvc_remove(port->cons.hvc); +#endif + } + + /* Remove unused data this port might have received. */ + discard_port_data(port); + + reclaim_consumed_buffers(port); + + /* Remove buffers we queued up for the Host to send us data in. */ + while ((buf = virtqueue_detach_unused_buf(port->in_vq))) + free_buf(buf); + + /* + * We should just assume the device itself has gone off -- + * else a close on an open port later will try to send out a + * control message. + */ + port->portdev = NULL; + + /* + * Locks around here are not necessary - a port can't be + * opened after we removed the port struct from ports_list + * above. + */ + kref_put(&port->kref, remove_port); +} + +/* Any private messages that the Host and Guest want to share */ +static void handle_control_message(struct ports_device *portdev, + struct port_buffer *buf) +{ + struct virtio_console_control *cpkt; + struct port *port; + size_t name_size; + int err; + + cpkt = (struct virtio_console_control *)(buf->buf + buf->offset); + + port = find_port_by_id(portdev, cpkt->id); + if (!port && cpkt->event != VIRTIO_CONSOLE_PORT_ADD) { + /* No valid header at start of buffer. Drop it. */ + dev_dbg(&portdev->vdev->dev, + "Invalid index %u in control packet\n", cpkt->id); + return; + } + + switch (cpkt->event) { + case VIRTIO_CONSOLE_PORT_ADD: + if (port) { + dev_dbg(&portdev->vdev->dev, + "Port %u already added\n", port->id); + send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1); + break; + } + if (cpkt->id >= portdev->config.max_nr_ports) { + dev_warn(&portdev->vdev->dev, + "Request for adding port with out-of-bound id %u, max. supported id: %u\n", + cpkt->id, portdev->config.max_nr_ports - 1); + break; + } + add_port(portdev, cpkt->id); + break; + case VIRTIO_CONSOLE_PORT_REMOVE: + unplug_port(port); + break; + case VIRTIO_CONSOLE_CONSOLE_PORT: + if (!cpkt->value) + break; + if (is_console_port(port)) + break; + + init_port_console(port); + /* + * Could remove the port here in case init fails - but + * have to notify the host first. + */ + break; + case VIRTIO_CONSOLE_RESIZE: { + struct { + __u16 rows; + __u16 cols; + } size; + + if (!is_console_port(port)) + break; + + memcpy(&size, buf->buf + buf->offset + sizeof(*cpkt), + sizeof(size)); + set_console_size(port, size.rows, size.cols); + + port->cons.hvc->irq_requested = 1; + resize_console(port); + break; + } + case VIRTIO_CONSOLE_PORT_OPEN: + port->host_connected = cpkt->value; + wake_up_interruptible(&port->waitqueue); + /* + * If the host port got closed and the host had any + * unconsumed buffers, we'll be able to reclaim them + * now. + */ + spin_lock_irq(&port->outvq_lock); + reclaim_consumed_buffers(port); + spin_unlock_irq(&port->outvq_lock); + + /* + * If the guest is connected, it'll be interested in + * knowing the host connection state changed. + */ + send_sigio_to_port(port); + break; + case VIRTIO_CONSOLE_PORT_NAME: + /* + * Skip the size of the header and the cpkt to get the size + * of the name that was sent + */ + name_size = buf->len - buf->offset - sizeof(*cpkt) + 1; + + port->name = kmalloc(name_size, GFP_KERNEL); + if (!port->name) { + dev_err(port->dev, + "Not enough space to store port name\n"); + break; + } + strncpy(port->name, buf->buf + buf->offset + sizeof(*cpkt), + name_size - 1); + port->name[name_size - 1] = 0; + + /* + * Since we only have one sysfs attribute, 'name', + * create it only if we have a name for the port. + */ + err = sysfs_create_group(&port->dev->kobj, + &port_attribute_group); + if (err) { + dev_err(port->dev, + "Error %d creating sysfs device attributes\n", + err); + } else { + /* + * Generate a udev event so that appropriate + * symlinks can be created based on udev + * rules. + */ + kobject_uevent(&port->dev->kobj, KOBJ_CHANGE); + } + break; + } +} + +static void control_work_handler(struct work_struct *work) +{ + struct ports_device *portdev; + struct virtqueue *vq; + struct port_buffer *buf; + unsigned int len; + + portdev = container_of(work, struct ports_device, control_work); + vq = portdev->c_ivq; + + spin_lock(&portdev->cvq_lock); + while ((buf = virtqueue_get_buf(vq, &len))) { + spin_unlock(&portdev->cvq_lock); + + buf->len = len; + buf->offset = 0; + + handle_control_message(portdev, buf); + + spin_lock(&portdev->cvq_lock); + if (add_inbuf(portdev->c_ivq, buf) < 0) { + dev_warn(&portdev->vdev->dev, + "Error adding buffer to queue\n"); + free_buf(buf); + } + } + spin_unlock(&portdev->cvq_lock); +} + +static void in_intr(struct virtqueue *vq) +{ + struct port *port; + unsigned long flags; + + port = find_port_by_vq(vq->vdev->priv, vq); + if (!port) + return; + + spin_lock_irqsave(&port->inbuf_lock, flags); + if (!port->inbuf) + port->inbuf = get_inbuf(port); + + /* + * Don't queue up data when port is closed. This condition + * can be reached when a console port is not yet connected (no + * tty is spawned) and the host sends out data to console + * ports. For generic serial ports, the host won't + * (shouldn't) send data till the guest is connected. + */ + if (!port->guest_connected) + discard_port_data(port); + + spin_unlock_irqrestore(&port->inbuf_lock, flags); + + wake_up_interruptible(&port->waitqueue); + + /* Send a SIGIO indicating new data in case the process asked for it */ + send_sigio_to_port(port); + + if (is_console_port(port) && hvc_poll(port->cons.hvc)) + hvc_kick(); +} + +static void control_intr(struct virtqueue *vq) +{ + struct ports_device *portdev; + + portdev = vq->vdev->priv; + schedule_work(&portdev->control_work); +} + +static void config_intr(struct virtio_device *vdev) +{ + struct ports_device *portdev; + + portdev = vdev->priv; + + if (!use_multiport(portdev)) { + struct port *port; + u16 rows, cols; + + vdev->config->get(vdev, + offsetof(struct virtio_console_config, cols), + &cols, sizeof(u16)); + vdev->config->get(vdev, + offsetof(struct virtio_console_config, rows), + &rows, sizeof(u16)); + + port = find_port_by_id(portdev, 0); + set_console_size(port, rows, cols); + + /* + * We'll use this way of resizing only for legacy + * support. For newer userspace + * (VIRTIO_CONSOLE_F_MULTPORT+), use control messages + * to indicate console size changes so that it can be + * done per-port. + */ + resize_console(port); + } +} + +static int init_vqs(struct ports_device *portdev) +{ + vq_callback_t **io_callbacks; + char **io_names; + struct virtqueue **vqs; + u32 i, j, nr_ports, nr_queues; + int err; + + nr_ports = portdev->config.max_nr_ports; + nr_queues = use_multiport(portdev) ? (nr_ports + 1) * 2 : 2; + + vqs = kmalloc(nr_queues * sizeof(struct virtqueue *), GFP_KERNEL); + io_callbacks = kmalloc(nr_queues * sizeof(vq_callback_t *), GFP_KERNEL); + io_names = kmalloc(nr_queues * sizeof(char *), GFP_KERNEL); + portdev->in_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *), + GFP_KERNEL); + portdev->out_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *), + GFP_KERNEL); + if (!vqs || !io_callbacks || !io_names || !portdev->in_vqs || + !portdev->out_vqs) { + err = -ENOMEM; + goto free; + } + + /* + * For backward compat (newer host but older guest), the host + * spawns a console port first and also inits the vqs for port + * 0 before others. + */ + j = 0; + io_callbacks[j] = in_intr; + io_callbacks[j + 1] = NULL; + io_names[j] = "input"; + io_names[j + 1] = "output"; + j += 2; + + if (use_multiport(portdev)) { + io_callbacks[j] = control_intr; + io_callbacks[j + 1] = NULL; + io_names[j] = "control-i"; + io_names[j + 1] = "control-o"; + + for (i = 1; i < nr_ports; i++) { + j += 2; + io_callbacks[j] = in_intr; + io_callbacks[j + 1] = NULL; + io_names[j] = "input"; + io_names[j + 1] = "output"; + } + } + /* Find the queues. */ + err = portdev->vdev->config->find_vqs(portdev->vdev, nr_queues, vqs, + io_callbacks, + (const char **)io_names); + if (err) + goto free; + + j = 0; + portdev->in_vqs[0] = vqs[0]; + portdev->out_vqs[0] = vqs[1]; + j += 2; + if (use_multiport(portdev)) { + portdev->c_ivq = vqs[j]; + portdev->c_ovq = vqs[j + 1]; + + for (i = 1; i < nr_ports; i++) { + j += 2; + portdev->in_vqs[i] = vqs[j]; + portdev->out_vqs[i] = vqs[j + 1]; + } + } + kfree(io_names); + kfree(io_callbacks); + kfree(vqs); + + return 0; + +free: + kfree(portdev->out_vqs); + kfree(portdev->in_vqs); + kfree(io_names); + kfree(io_callbacks); + kfree(vqs); + + return err; +} + +static const struct file_operations portdev_fops = { + .owner = THIS_MODULE, +}; + +/* + * Once we're further in boot, we get probed like any other virtio + * device. + * + * If the host also supports multiple console ports, we check the + * config space to see how many ports the host has spawned. We + * initialize each port found. + */ +static int __devinit virtcons_probe(struct virtio_device *vdev) +{ + struct ports_device *portdev; + int err; + bool multiport; + + portdev = kmalloc(sizeof(*portdev), GFP_KERNEL); + if (!portdev) { + err = -ENOMEM; + goto fail; + } + + /* Attach this portdev to this virtio_device, and vice-versa. */ + portdev->vdev = vdev; + vdev->priv = portdev; + + spin_lock_irq(&pdrvdata_lock); + portdev->drv_index = pdrvdata.index++; + spin_unlock_irq(&pdrvdata_lock); + + portdev->chr_major = register_chrdev(0, "virtio-portsdev", + &portdev_fops); + if (portdev->chr_major < 0) { + dev_err(&vdev->dev, + "Error %d registering chrdev for device %u\n", + portdev->chr_major, portdev->drv_index); + err = portdev->chr_major; + goto free; + } + + multiport = false; + portdev->config.max_nr_ports = 1; + if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT)) { + multiport = true; + vdev->features[0] |= 1 << VIRTIO_CONSOLE_F_MULTIPORT; + + vdev->config->get(vdev, offsetof(struct virtio_console_config, + max_nr_ports), + &portdev->config.max_nr_ports, + sizeof(portdev->config.max_nr_ports)); + } + + /* Let the Host know we support multiple ports.*/ + vdev->config->finalize_features(vdev); + + err = init_vqs(portdev); + if (err < 0) { + dev_err(&vdev->dev, "Error %d initializing vqs\n", err); + goto free_chrdev; + } + + spin_lock_init(&portdev->ports_lock); + INIT_LIST_HEAD(&portdev->ports); + + if (multiport) { + unsigned int nr_added_bufs; + + spin_lock_init(&portdev->cvq_lock); + INIT_WORK(&portdev->control_work, &control_work_handler); + + nr_added_bufs = fill_queue(portdev->c_ivq, &portdev->cvq_lock); + if (!nr_added_bufs) { + dev_err(&vdev->dev, + "Error allocating buffers for control queue\n"); + err = -ENOMEM; + goto free_vqs; + } + } else { + /* + * For backward compatibility: Create a console port + * if we're running on older host. + */ + add_port(portdev, 0); + } + + spin_lock_irq(&pdrvdata_lock); + list_add_tail(&portdev->list, &pdrvdata.portdevs); + spin_unlock_irq(&pdrvdata_lock); + + __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID, + VIRTIO_CONSOLE_DEVICE_READY, 1); + return 0; + +free_vqs: + /* The host might want to notify mgmt sw about device add failure */ + __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID, + VIRTIO_CONSOLE_DEVICE_READY, 0); + vdev->config->del_vqs(vdev); + kfree(portdev->in_vqs); + kfree(portdev->out_vqs); +free_chrdev: + unregister_chrdev(portdev->chr_major, "virtio-portsdev"); +free: + kfree(portdev); +fail: + return err; +} + +static void virtcons_remove(struct virtio_device *vdev) +{ + struct ports_device *portdev; + struct port *port, *port2; + + portdev = vdev->priv; + + spin_lock_irq(&pdrvdata_lock); + list_del(&portdev->list); + spin_unlock_irq(&pdrvdata_lock); + + /* Disable interrupts for vqs */ + vdev->config->reset(vdev); + /* Finish up work that's lined up */ + cancel_work_sync(&portdev->control_work); + + list_for_each_entry_safe(port, port2, &portdev->ports, list) + unplug_port(port); + + unregister_chrdev(portdev->chr_major, "virtio-portsdev"); + + /* + * When yanking out a device, we immediately lose the + * (device-side) queues. So there's no point in keeping the + * guest side around till we drop our final reference. This + * also means that any ports which are in an open state will + * have to just stop using the port, as the vqs are going + * away. + */ + if (use_multiport(portdev)) { + struct port_buffer *buf; + unsigned int len; + + while ((buf = virtqueue_get_buf(portdev->c_ivq, &len))) + free_buf(buf); + + while ((buf = virtqueue_detach_unused_buf(portdev->c_ivq))) + free_buf(buf); + } + + vdev->config->del_vqs(vdev); + kfree(portdev->in_vqs); + kfree(portdev->out_vqs); + + kfree(portdev); +} + +static struct virtio_device_id id_table[] = { + { VIRTIO_ID_CONSOLE, VIRTIO_DEV_ANY_ID }, + { 0 }, +}; + +static unsigned int features[] = { + VIRTIO_CONSOLE_F_SIZE, + VIRTIO_CONSOLE_F_MULTIPORT, +}; + +static struct virtio_driver virtio_console = { + .feature_table = features, + .feature_table_size = ARRAY_SIZE(features), + .driver.name = KBUILD_MODNAME, + .driver.owner = THIS_MODULE, + .id_table = id_table, + .probe = virtcons_probe, + .remove = virtcons_remove, + .config_changed = config_intr, +}; + +static int __init init(void) +{ + int err; + + pdrvdata.class = class_create(THIS_MODULE, "virtio-ports"); + if (IS_ERR(pdrvdata.class)) { + err = PTR_ERR(pdrvdata.class); + pr_err("Error %d creating virtio-ports class\n", err); + return err; + } + + pdrvdata.debugfs_dir = debugfs_create_dir("virtio-ports", NULL); + if (!pdrvdata.debugfs_dir) { + pr_warning("Error %ld creating debugfs dir for virtio-ports\n", + PTR_ERR(pdrvdata.debugfs_dir)); + } + INIT_LIST_HEAD(&pdrvdata.consoles); + INIT_LIST_HEAD(&pdrvdata.portdevs); + + return register_virtio_driver(&virtio_console); +} + +static void __exit fini(void) +{ + unregister_virtio_driver(&virtio_console); + + class_destroy(pdrvdata.class); + if (pdrvdata.debugfs_dir) + debugfs_remove_recursive(pdrvdata.debugfs_dir); +} +module_init(init); +module_exit(fini); + +MODULE_DEVICE_TABLE(virtio, id_table); +MODULE_DESCRIPTION("Virtio console driver"); +MODULE_LICENSE("GPL"); |