diff options
Diffstat (limited to 'drivers/pci/hotplug/acpiphp_ibm.c')
| -rw-r--r-- | drivers/pci/hotplug/acpiphp_ibm.c | 499 |
1 files changed, 499 insertions, 0 deletions
diff --git a/drivers/pci/hotplug/acpiphp_ibm.c b/drivers/pci/hotplug/acpiphp_ibm.c new file mode 100644 index 000000000000..7e7f913ba7b9 --- /dev/null +++ b/drivers/pci/hotplug/acpiphp_ibm.c @@ -0,0 +1,499 @@ +/* + * ACPI PCI Hot Plug IBM Extension + * + * Copyright (C) 2004 Vernon Mauery <vernux@us.ibm.com> + * Copyright (C) 2004 IBM Corp. + * + * 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; 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, GOOD TITLE or + * NON INFRINGEMENT. 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., 675 Mass Ave, Cambridge, MA 02139, USA. + * + * Send feedback to <vernux@us.ibm.com> + * + */ + +#include <linux/init.h> +#include <linux/module.h> +#include <linux/kernel.h> +#include <acpi/acpi_bus.h> +#include <linux/sysfs.h> +#include <linux/kobject.h> +#include <asm/uaccess.h> +#include <linux/moduleparam.h> + +#include "acpiphp.h" +#include "pci_hotplug.h" + +#define DRIVER_VERSION "1.0.1" +#define DRIVER_AUTHOR "Irene Zubarev <zubarev@us.ibm.com>, Vernon Mauery <vernux@us.ibm.com>" +#define DRIVER_DESC "ACPI Hot Plug PCI Controller Driver IBM extension" + +static int debug; + +MODULE_AUTHOR(DRIVER_AUTHOR); +MODULE_DESCRIPTION(DRIVER_DESC); +MODULE_LICENSE("GPL"); +MODULE_VERSION(DRIVER_VERSION); +module_param(debug, bool, 0644); +MODULE_PARM_DESC(debug, " Debugging mode enabled or not"); +#define MY_NAME "acpiphp_ibm" + +#undef dbg +#define dbg(format, arg...) \ +do { \ + if (debug) \ + printk(KERN_DEBUG "%s: " format, \ + MY_NAME , ## arg); \ +} while (0) + +#define FOUND_APCI 0x61504349 +/* these are the names for the IBM ACPI pseudo-device */ +#define IBM_HARDWARE_ID1 "IBM37D0" +#define IBM_HARDWARE_ID2 "IBM37D4" + +#define hpslot_to_sun(A) (((struct slot *)((A)->private))->acpi_slot->sun) + +/* union apci_descriptor - allows access to the + * various device descriptors that are embedded in the + * aPCI table + */ +union apci_descriptor { + struct { + char sig[4]; + u8 len; + } header; + struct { + u8 type; + u8 len; + u16 slot_id; + u8 bus_id; + u8 dev_num; + u8 slot_num; + u8 slot_attr[2]; + u8 attn; + u8 status[2]; + u8 sun; + u8 res[3]; + } slot; + struct { + u8 type; + u8 len; + } generic; +}; + +/* struct notification - keeps info about the device + * that cause the ACPI notification event + */ +struct notification { + struct acpi_device *device; + u8 event; +}; + +static int ibm_set_attention_status(struct hotplug_slot *slot, u8 status); +static int ibm_get_attention_status(struct hotplug_slot *slot, u8 *status); +static void ibm_handle_events(acpi_handle handle, u32 event, void *context); +static int ibm_get_table_from_acpi(char **bufp); +static ssize_t ibm_read_apci_table(struct kobject *kobj, + char *buffer, loff_t pos, size_t size); +static acpi_status __init ibm_find_acpi_device(acpi_handle handle, + u32 lvl, void *context, void **rv); +static int __init ibm_acpiphp_init(void); +static void __exit ibm_acpiphp_exit(void); + +static acpi_handle ibm_acpi_handle; +static struct notification ibm_note; +static struct bin_attribute ibm_apci_table_attr = { + .attr = { + .name = "apci_table", + .owner = THIS_MODULE, + .mode = S_IRUGO, + }, + .read = ibm_read_apci_table, + .write = NULL, +}; +static struct acpiphp_attention_info ibm_attention_info = +{ + .set_attn = ibm_set_attention_status, + .get_attn = ibm_get_attention_status, + .owner = THIS_MODULE, +}; + +/** + * ibm_slot_from_id - workaround for bad ibm hardware + * @id: the slot number that linux refers to the slot by + * + * Description: this method returns the aCPI slot descriptor + * corresponding to the Linux slot number. This descriptor + * has info about the aPCI slot id and attention status. + * This descriptor must be freed using kfree when done. + **/ +static union apci_descriptor *ibm_slot_from_id(int id) +{ + int ind = 0, size; + union apci_descriptor *ret = NULL, *des; + char *table; + + size = ibm_get_table_from_acpi(&table); + des = (union apci_descriptor *)table; + if (memcmp(des->header.sig, "aPCI", 4) != 0) + goto ibm_slot_done; + + des = (union apci_descriptor *)&table[ind += des->header.len]; + while (ind < size && (des->generic.type != 0x82 || + des->slot.slot_num != id)) { + des = (union apci_descriptor *)&table[ind += des->generic.len]; + } + + if (ind < size && des->slot.slot_num == id) + ret = des; + +ibm_slot_done: + if (ret) { + ret = kmalloc(sizeof(union apci_descriptor), GFP_KERNEL); + memcpy(ret, des, sizeof(union apci_descriptor)); + } + kfree(table); + return ret; +} + +/** + * ibm_set_attention_status - callback method to set the attention LED + * @slot: the hotplug_slot to work with + * @status: what to set the LED to (0 or 1) + * + * Description: this method is registered with the acpiphp module as a + * callback to do the device specific task of setting the LED status + **/ +static int ibm_set_attention_status(struct hotplug_slot *slot, u8 status) +{ + union acpi_object args[2]; + struct acpi_object_list params = { .pointer = args, .count = 2 }; + acpi_status stat; + unsigned long rc; + union apci_descriptor *ibm_slot; + + ibm_slot = ibm_slot_from_id(hpslot_to_sun(slot)); + + dbg("%s: set slot %d (%d) attention status to %d\n", __FUNCTION__, + ibm_slot->slot.slot_num, ibm_slot->slot.slot_id, + (status ? 1 : 0)); + + args[0].type = ACPI_TYPE_INTEGER; + args[0].integer.value = ibm_slot->slot.slot_id; + args[1].type = ACPI_TYPE_INTEGER; + args[1].integer.value = (status) ? 1 : 0; + + kfree(ibm_slot); + + stat = acpi_evaluate_integer(ibm_acpi_handle, "APLS", ¶ms, &rc); + if (ACPI_FAILURE(stat)) { + err("APLS evaluation failed: 0x%08x\n", stat); + return -ENODEV; + } else if (!rc) { + err("APLS method failed: 0x%08lx\n", rc); + return -ERANGE; + } + return 0; +} + +/** + * ibm_get_attention_status - callback method to get attention LED status + * @slot: the hotplug_slot to work with + * @status: returns what the LED is set to (0 or 1) + * + * Description: this method is registered with the acpiphp module as a + * callback to do the device specific task of getting the LED status + * + * Because there is no direct method of getting the LED status directly + * from an ACPI call, we read the aPCI table and parse out our + * slot descriptor to read the status from that. + **/ +static int ibm_get_attention_status(struct hotplug_slot *slot, u8 *status) +{ + union apci_descriptor *ibm_slot; + + ibm_slot = ibm_slot_from_id(hpslot_to_sun(slot)); + + if (ibm_slot->slot.attn & 0xa0 || ibm_slot->slot.status[1] & 0x08) + *status = 1; + else + *status = 0; + + dbg("%s: get slot %d (%d) attention status is %d\n", __FUNCTION__, + ibm_slot->slot.slot_num, ibm_slot->slot.slot_id, + *status); + + kfree(ibm_slot); + return 0; +} + +/** + * ibm_handle_events - listens for ACPI events for the IBM37D0 device + * @handle: an ACPI handle to the device that caused the event + * @event: the event info (device specific) + * @context: passed context (our notification struct) + * + * Description: this method is registered as a callback with the ACPI + * subsystem it is called when this device has an event to notify the OS of + * + * The events actually come from the device as two events that get + * synthesized into one event with data by this function. The event + * ID comes first and then the slot number that caused it. We report + * this as one event to the OS. + * + * From section 5.6.2.2 of the ACPI 2.0 spec, I understand that the OSPM will + * only re-enable the interrupt that causes this event AFTER this method + * has returned, thereby enforcing serial access for the notification struct. + **/ +static void ibm_handle_events(acpi_handle handle, u32 event, void *context) +{ + u8 detail = event & 0x0f; + u8 subevent = event & 0xf0; + struct notification *note = context; + + dbg("%s: Received notification %02x\n", __FUNCTION__, event); + + if (subevent == 0x80) { + dbg("%s: generationg bus event\n", __FUNCTION__); + acpi_bus_generate_event(note->device, note->event, detail); + } else + note->event = event; +} + +/** + * ibm_get_table_from_acpi - reads the APLS buffer from ACPI + * @bufp: address to pointer to allocate for the table + * + * Description: this method reads the APLS buffer in from ACPI and + * stores the "stripped" table into a single buffer + * it allocates and passes the address back in bufp + * + * If NULL is passed in as buffer, this method only calculates + * the size of the table and returns that without filling + * in the buffer + * + * returns < 0 on error or the size of the table on success + **/ +static int ibm_get_table_from_acpi(char **bufp) +{ + union acpi_object *package; + struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; + acpi_status status; + char *lbuf = NULL; + int i, size = -EIO; + + status = acpi_evaluate_object(ibm_acpi_handle, "APCI", NULL, &buffer); + if (ACPI_FAILURE(status)) { + err("%s: APCI evaluation failed\n", __FUNCTION__); + return -ENODEV; + } + + package = (union acpi_object *) buffer.pointer; + if(!(package) || + (package->type != ACPI_TYPE_PACKAGE) || + !(package->package.elements)) { + err("%s: Invalid APCI object\n", __FUNCTION__); + goto read_table_done; + } + + for(size = 0, i = 0; i < package->package.count; i++) { + if (package->package.elements[i].type != ACPI_TYPE_BUFFER) { + err("%s: Invalid APCI element %d\n", __FUNCTION__, i); + goto read_table_done; + } + size += package->package.elements[i].buffer.length; + } + + if (bufp == NULL) + goto read_table_done; + + lbuf = kmalloc(size, GFP_KERNEL); + dbg("%s: element count: %i, ASL table size: %i, &table = 0x%p\n", + __FUNCTION__, package->package.count, size, lbuf); + + if (lbuf) { + *bufp = lbuf; + memset(lbuf, 0, size); + } else { + size = -ENOMEM; + goto read_table_done; + } + + size = 0; + for (i=0; i<package->package.count; i++) { + memcpy(&lbuf[size], + package->package.elements[i].buffer.pointer, + package->package.elements[i].buffer.length); + size += package->package.elements[i].buffer.length; + } + +read_table_done: + kfree(buffer.pointer); + return size; +} + +/** + * ibm_read_apci_table - callback for the sysfs apci_table file + * @kobj: the kobject this binary attribute is a part of + * @buffer: the kernel space buffer to fill + * @pos: the offset into the file + * @size: the number of bytes requested + * + * Description: gets registered with sysfs as the reader callback + * to be executed when /sys/bus/pci/slots/apci_table gets read + * + * Since we don't get notified on open and close for this file, + * things get really tricky here... + * our solution is to only allow reading the table in all at once + **/ +static ssize_t ibm_read_apci_table(struct kobject *kobj, + char *buffer, loff_t pos, size_t size) +{ + int bytes_read = -EINVAL; + char *table = NULL; + + dbg("%s: pos = %d, size = %zd\n", __FUNCTION__, (int)pos, size); + + if (pos == 0) { + bytes_read = ibm_get_table_from_acpi(&table); + if (bytes_read > 0 && bytes_read <= size) + memcpy(buffer, table, bytes_read); + kfree(table); + } + return bytes_read; +} + +/** + * ibm_find_acpi_device - callback to find our ACPI device + * @handle: the ACPI handle of the device we are inspecting + * @lvl: depth into the namespace tree + * @context: a pointer to our handle to fill when we find the device + * @rv: a return value to fill if desired + * + * Description: used as a callback when calling acpi_walk_namespace + * to find our device. When this method returns non-zero + * acpi_walk_namespace quits its search and returns our value + **/ +static acpi_status __init ibm_find_acpi_device(acpi_handle handle, + u32 lvl, void *context, void **rv) +{ + acpi_handle *phandle = (acpi_handle *)context; + acpi_status status; + struct acpi_device_info info; + struct acpi_buffer info_buffer = { + .length = sizeof(struct acpi_device_info), + .pointer = &info, + }; + + status = acpi_get_object_info(handle, &info_buffer); + if (ACPI_FAILURE(status)) { + err("%s: Failed to get device information", __FUNCTION__); + return 0; + } + info.hardware_id.value[sizeof(info.hardware_id.value) - 1] = '\0'; + + if(info.current_status && (info.valid & ACPI_VALID_HID) && + (!strcmp(info.hardware_id.value, IBM_HARDWARE_ID1) || + !strcmp(info.hardware_id.value, IBM_HARDWARE_ID2))) { + dbg("found hardware: %s, handle: %p\n", info.hardware_id.value, + handle); + *phandle = handle; + /* returning non-zero causes the search to stop + * and returns this value to the caller of + * acpi_walk_namespace, but it also causes some warnings + * in the acpi debug code to print... + */ + return FOUND_APCI; + } + return 0; +} + +static int __init ibm_acpiphp_init(void) +{ + int retval = 0; + acpi_status status; + struct acpi_device *device; + struct kobject *sysdir = &pci_hotplug_slots_subsys.kset.kobj; + + dbg("%s\n", __FUNCTION__); + + if (acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, + ACPI_UINT32_MAX, ibm_find_acpi_device, + &ibm_acpi_handle, NULL) != FOUND_APCI) { + err("%s: acpi_walk_namespace failed\n", __FUNCTION__); + retval = -ENODEV; + goto init_return; + } + dbg("%s: found IBM aPCI device\n", __FUNCTION__); + if (acpi_bus_get_device(ibm_acpi_handle, &device)) { + err("%s: acpi_bus_get_device failed\n", __FUNCTION__); + retval = -ENODEV; + goto init_return; + } + if (acpiphp_register_attention(&ibm_attention_info)) { + retval = -ENODEV; + goto init_return; + } + + ibm_note.device = device; + status = acpi_install_notify_handler( + ibm_acpi_handle, + ACPI_DEVICE_NOTIFY, + ibm_handle_events, + &ibm_note); + if (ACPI_FAILURE(status)) { + err("%s: Failed to register notification handler\n", + __FUNCTION__); + retval = -EBUSY; + goto init_cleanup; + } + + ibm_apci_table_attr.size = ibm_get_table_from_acpi(NULL); + retval = sysfs_create_bin_file(sysdir, &ibm_apci_table_attr); + + return retval; + +init_cleanup: + acpiphp_unregister_attention(&ibm_attention_info); +init_return: + return retval; +} + +static void __exit ibm_acpiphp_exit(void) +{ + acpi_status status; + struct kobject *sysdir = &pci_hotplug_slots_subsys.kset.kobj; + + dbg("%s\n", __FUNCTION__); + + if (acpiphp_unregister_attention(&ibm_attention_info)) + err("%s: attention info deregistration failed", __FUNCTION__); + + status = acpi_remove_notify_handler( + ibm_acpi_handle, + ACPI_DEVICE_NOTIFY, + ibm_handle_events); + if (ACPI_FAILURE(status)) + err("%s: Notification handler removal failed\n", + __FUNCTION__); + // remove the /sys entries + if (sysfs_remove_bin_file(sysdir, &ibm_apci_table_attr)) + err("%s: removal of sysfs file apci_table failed\n", + __FUNCTION__); +} + +module_init(ibm_acpiphp_init); +module_exit(ibm_acpiphp_exit); |