diff options
Diffstat (limited to 'drivers/s390/cio/chp.c')
| -rw-r--r-- | drivers/s390/cio/chp.c | 82 |
1 files changed, 48 insertions, 34 deletions
diff --git a/drivers/s390/cio/chp.c b/drivers/s390/cio/chp.c index 50597f9522fe..46be25c7461e 100644 --- a/drivers/s390/cio/chp.c +++ b/drivers/s390/cio/chp.c @@ -37,8 +37,7 @@ enum cfg_task_t { /* 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; +static DEFINE_SPINLOCK(cfg_lock); /* Map for channel-path status. */ static struct sclp_chp_info chp_info; @@ -47,8 +46,6 @@ static DEFINE_MUTEX(info_lock); /* Time after which channel-path status may be outdated.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. */ @@ -428,11 +425,14 @@ int chp_update_desc(struct channel_path *chp) if (rc) return rc; - rc = chsc_determine_fmt1_channel_path_desc(chp->chpid, &chp->desc_fmt1); - if (rc) - return rc; + /* + * Fetching the following data is optional. Not all machines or + * hypervisors implement the required chsc commands. + */ + chsc_determine_fmt1_channel_path_desc(chp->chpid, &chp->desc_fmt1); + chsc_get_channel_measurement_chars(chp); - return chsc_get_channel_measurement_chars(chp); + return 0; } /** @@ -665,6 +665,20 @@ static void cfg_set_task(struct chp_id chpid, enum cfg_task_t cfg) chp_cfg_task[chpid.cssid][chpid.id] = cfg; } +/* Fetch the first configure task. Set chpid accordingly. */ +static enum cfg_task_t chp_cfg_fetch_task(struct chp_id *chpid) +{ + enum cfg_task_t t = cfg_none; + + chp_id_for_each(chpid) { + t = cfg_get_task(*chpid); + if (t != cfg_none) + break; + } + + return t; +} + /* Perform one configure/deconfigure request. Reschedule work function until * last request. */ static void cfg_func(struct work_struct *work) @@ -673,16 +687,9 @@ static void cfg_func(struct work_struct *work) enum cfg_task_t t; int rc; - 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); + spin_lock(&cfg_lock); + t = chp_cfg_fetch_task(&chpid); + spin_unlock(&cfg_lock); switch (t) { case cfg_configure: @@ -708,13 +715,14 @@ static void cfg_func(struct work_struct *work) 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); + spin_lock(&cfg_lock); + if (t == cfg_get_task(chpid)) + cfg_set_task(chpid, cfg_none); + spin_unlock(&cfg_lock); + schedule_work(&cfg_work); } /** @@ -728,11 +736,10 @@ 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); + spin_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); + spin_unlock(&cfg_lock); + schedule_work(&cfg_work); } /** @@ -745,15 +752,27 @@ void chp_cfg_schedule(struct chp_id chpid, int configure) 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); + spin_lock(&cfg_lock); if (cfg_get_task(chpid) == cfg_deconfigure) cfg_set_task(chpid, cfg_none); - mutex_unlock(&cfg_lock); + spin_unlock(&cfg_lock); +} + +static bool cfg_idle(void) +{ + struct chp_id chpid; + enum cfg_task_t t; + + spin_lock(&cfg_lock); + t = chp_cfg_fetch_task(&chpid); + spin_unlock(&cfg_lock); + + return t == cfg_none; } static int cfg_wait_idle(void) { - if (wait_event_interruptible(cfg_wait_queue, !cfg_busy)) + if (wait_event_interruptible(cfg_wait_queue, cfg_idle())) return -ERESTARTSYS; return 0; } @@ -766,11 +785,6 @@ static int __init chp_init(void) ret = crw_register_handler(CRW_RSC_CPATH, chp_process_crw); if (ret) return ret; - chp_wq = create_singlethread_workqueue("cio_chp"); - if (!chp_wq) { - crw_unregister_handler(CRW_RSC_CPATH); - return -ENOMEM; - } INIT_WORK(&cfg_work, cfg_func); init_waitqueue_head(&cfg_wait_queue); if (info_update()) |