diff options
Diffstat (limited to 'drivers/s390/cio/chp.c')
| -rw-r--r-- | drivers/s390/cio/chp.c | 250 |
1 files changed, 249 insertions, 1 deletions
diff --git a/drivers/s390/cio/chp.c b/drivers/s390/cio/chp.c index 8a5839147f8a..0e92c8c89860 100644 --- a/drivers/s390/cio/chp.c +++ b/drivers/s390/cio/chp.c @@ -10,9 +10,14 @@ #include <linux/bug.h> #include <linux/workqueue.h> #include <linux/spinlock.h> +#include <linux/init.h> +#include <linux/jiffies.h> +#include <linux/wait.h> +#include <linux/mutex.h> #include <asm/errno.h> +#include <asm/chpid.h> +#include <asm/sclp.h> -#include "chpid.h" #include "cio.h" #include "css.h" #include "ioasm.h" @@ -20,6 +25,32 @@ #include "chp.h" #define to_channelpath(device) container_of(device, struct channel_path, dev) +#define CHP_INFO_UPDATE_INTERVAL 1*HZ + +enum cfg_task_t { + cfg_none, + cfg_configure, + cfg_deconfigure +}; + +/* Map for pending configure tasks. */ +static enum cfg_task_t chp_cfg_task[__MAX_CSSID + 1][__MAX_CHPID + 1]; +static DEFINE_MUTEX(cfg_lock); +static int cfg_busy; + +/* Map for channel-path status. */ +static struct sclp_chp_info chp_info; +static DEFINE_MUTEX(info_lock); + +/* Time after which channel-path status may be outdated. */ +static unsigned long chp_info_expires; + +/* Workqueue to perform pending configure tasks. */ +static struct workqueue_struct *chp_wq; +static struct work_struct cfg_work; + +/* Wait queue for configure completion events. */ +static wait_queue_head_t cfg_wait_queue; /* Return channel_path struct for given chpid. */ static inline struct channel_path *chpid_to_chp(struct chp_id chpid) @@ -251,6 +282,43 @@ static ssize_t chp_status_write(struct device *dev, static DEVICE_ATTR(status, 0644, chp_status_show, chp_status_write); +static ssize_t chp_configure_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct channel_path *cp; + int status; + + cp = container_of(dev, struct channel_path, dev); + status = chp_info_get_status(cp->chpid); + if (status < 0) + return status; + + return snprintf(buf, PAGE_SIZE, "%d\n", status); +} + +static int cfg_wait_idle(void); + +static ssize_t chp_configure_write(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct channel_path *cp; + int val; + char delim; + + if (sscanf(buf, "%d %c", &val, &delim) != 1) + return -EINVAL; + if (val != 0 && val != 1) + return -EINVAL; + cp = container_of(dev, struct channel_path, dev); + chp_cfg_schedule(cp->chpid, val); + cfg_wait_idle(); + + return count; +} + +static DEVICE_ATTR(configure, 0644, chp_configure_show, chp_configure_write); + static ssize_t chp_type_show(struct device *dev, struct device_attribute *attr, char *buf) { @@ -293,6 +361,7 @@ static DEVICE_ATTR(shared, 0444, chp_shared_show, NULL); static struct attribute * chp_attrs[] = { &dev_attr_status.attr, + &dev_attr_configure.attr, &dev_attr_type.attr, &dev_attr_cmg.attr, &dev_attr_shared.attr, @@ -323,6 +392,8 @@ int chp_new(struct chp_id chpid) struct channel_path *chp; int ret; + if (chp_is_registered(chpid)) + return 0; chp = kzalloc(sizeof(struct channel_path), GFP_KERNEL); if (!chp) return -ENOMEM; @@ -435,3 +506,180 @@ int chp_process_crw(int id, int status) return 0; } } + +static inline int info_bit_num(struct chp_id id) +{ + return id.id + id.cssid * (__MAX_CHPID + 1); +} + +/* Force chp_info refresh on next call to info_validate(). */ +static void info_expire(void) +{ + mutex_lock(&info_lock); + chp_info_expires = jiffies - 1; + mutex_unlock(&info_lock); +} + +/* Ensure that chp_info is up-to-date. */ +static int info_update(void) +{ + int rc; + + mutex_lock(&info_lock); + rc = 0; + if (time_after(jiffies, chp_info_expires)) { + /* Data is too old, update. */ + rc = sclp_chp_read_info(&chp_info); + chp_info_expires = jiffies + CHP_INFO_UPDATE_INTERVAL ; + } + mutex_unlock(&info_lock); + + return rc; +} + +/** + * chp_info_get_status - retrieve configure status of a channel-path + * @chpid: channel-path ID + * + * On success, return 0 for standby, 1 for configured, 2 for reserved, + * 3 for not recognized. Return negative error code on error. + */ +int chp_info_get_status(struct chp_id chpid) +{ + int rc; + int bit; + + rc = info_update(); + if (rc) + return rc; + + bit = info_bit_num(chpid); + mutex_lock(&info_lock); + if (!chp_test_bit(chp_info.recognized, bit)) + rc = CHP_STATUS_NOT_RECOGNIZED; + else if (chp_test_bit(chp_info.configured, bit)) + rc = CHP_STATUS_CONFIGURED; + else if (chp_test_bit(chp_info.standby, bit)) + rc = CHP_STATUS_STANDBY; + else + rc = CHP_STATUS_RESERVED; + mutex_unlock(&info_lock); + + return rc; +} + +/* Return configure task for chpid. */ +static enum cfg_task_t cfg_get_task(struct chp_id chpid) +{ + return chp_cfg_task[chpid.cssid][chpid.id]; +} + +/* Set configure task for chpid. */ +static void cfg_set_task(struct chp_id chpid, enum cfg_task_t cfg) +{ + chp_cfg_task[chpid.cssid][chpid.id] = cfg; +} + +/* Perform one configure/deconfigure request. Reschedule work function until + * last request. */ +static void cfg_func(struct work_struct *work) +{ + struct chp_id chpid; + enum cfg_task_t t; + + mutex_lock(&cfg_lock); + t = cfg_none; + chp_id_for_each(&chpid) { + t = cfg_get_task(chpid); + if (t != cfg_none) { + cfg_set_task(chpid, cfg_none); + break; + } + } + mutex_unlock(&cfg_lock); + + switch (t) { + case cfg_configure: + sclp_chp_configure(chpid); + info_expire(); + chsc_chp_online(chpid); + break; + case cfg_deconfigure: + sclp_chp_deconfigure(chpid); + info_expire(); + chsc_chp_offline(chpid); + break; + case cfg_none: + /* Get updated information after last change. */ + info_update(); + mutex_lock(&cfg_lock); + cfg_busy = 0; + mutex_unlock(&cfg_lock); + wake_up_interruptible(&cfg_wait_queue); + return; + } + queue_work(chp_wq, &cfg_work); +} + +/** + * chp_cfg_schedule - schedule chpid configuration request + * @chpid - channel-path ID + * @configure - Non-zero for configure, zero for deconfigure + * + * Schedule a channel-path configuration/deconfiguration request. + */ +void chp_cfg_schedule(struct chp_id chpid, int configure) +{ + CIO_MSG_EVENT(2, "chp_cfg_sched%x.%02x=%d\n", chpid.cssid, chpid.id, + configure); + mutex_lock(&cfg_lock); + cfg_set_task(chpid, configure ? cfg_configure : cfg_deconfigure); + cfg_busy = 1; + mutex_unlock(&cfg_lock); + queue_work(chp_wq, &cfg_work); +} + +/** + * chp_cfg_cancel_deconfigure - cancel chpid deconfiguration request + * @chpid - channel-path ID + * + * Cancel an active channel-path deconfiguration request if it has not yet + * been performed. + */ +void chp_cfg_cancel_deconfigure(struct chp_id chpid) +{ + CIO_MSG_EVENT(2, "chp_cfg_cancel:%x.%02x\n", chpid.cssid, chpid.id); + mutex_lock(&cfg_lock); + if (cfg_get_task(chpid) == cfg_deconfigure) + cfg_set_task(chpid, cfg_none); + mutex_unlock(&cfg_lock); +} + +static int cfg_wait_idle(void) +{ + if (wait_event_interruptible(cfg_wait_queue, !cfg_busy)) + return -ERESTARTSYS; + return 0; +} + +static int __init chp_init(void) +{ + struct chp_id chpid; + + chp_wq = create_singlethread_workqueue("cio_chp"); + if (!chp_wq) + return -ENOMEM; + INIT_WORK(&cfg_work, cfg_func); + init_waitqueue_head(&cfg_wait_queue); + if (info_update()) + return 0; + /* Register available channel-paths. */ + chp_id_for_each(&chpid) { + if (chp_info_get_status(chpid) != CHP_STATUS_NOT_RECOGNIZED) + chp_new(chpid); + } + + return 0; +} + +subsys_initcall(chp_init); |