diff options
Diffstat (limited to 'drivers/s390/cio/css.c')
| -rw-r--r-- | drivers/s390/cio/css.c | 148 |
1 files changed, 47 insertions, 101 deletions
diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c index fe0ace7aece..fcc641e578f 100644 --- a/drivers/s390/cio/css.c +++ b/drivers/s390/cio/css.c @@ -20,8 +20,8 @@ #include "ioasm.h" #include "chsc.h" #include "device.h" +#include "idset.h" -int need_rescan = 0; int css_init_done = 0; static int need_reprobe = 0; static int max_ssid = 0; @@ -306,7 +306,7 @@ static int css_evaluate_new_subchannel(struct subchannel_id schid, int slow) return css_probe_device(schid); } -static int css_evaluate_subchannel(struct subchannel_id schid, int slow) +static void css_evaluate_subchannel(struct subchannel_id schid, int slow) { struct subchannel *sch; int ret; @@ -317,53 +317,66 @@ static int css_evaluate_subchannel(struct subchannel_id schid, int slow) put_device(&sch->dev); } else ret = css_evaluate_new_subchannel(schid, slow); - - return ret; + if (ret == -EAGAIN) + css_schedule_eval(schid); } -static int -css_rescan_devices(struct subchannel_id schid, void *data) +static struct idset *slow_subchannel_set; +static spinlock_t slow_subchannel_lock; + +static int __init slow_subchannel_init(void) { - return css_evaluate_subchannel(schid, 1); + spin_lock_init(&slow_subchannel_lock); + slow_subchannel_set = idset_sch_new(); + if (!slow_subchannel_set) { + printk(KERN_WARNING "cio: could not allocate slow subchannel " + "set\n"); + return -ENOMEM; + } + return 0; } -struct slow_subchannel { - struct list_head slow_list; - struct subchannel_id schid; -}; - -static LIST_HEAD(slow_subchannels_head); -static DEFINE_SPINLOCK(slow_subchannel_lock); +subsys_initcall(slow_subchannel_init); -static void -css_trigger_slow_path(struct work_struct *unused) +static void css_slow_path_func(struct work_struct *unused) { - CIO_TRACE_EVENT(4, "slowpath"); - - if (need_rescan) { - need_rescan = 0; - for_each_subchannel(css_rescan_devices, NULL); - return; - } + struct subchannel_id schid; + CIO_TRACE_EVENT(4, "slowpath"); spin_lock_irq(&slow_subchannel_lock); - while (!list_empty(&slow_subchannels_head)) { - struct slow_subchannel *slow_sch = - list_entry(slow_subchannels_head.next, - struct slow_subchannel, slow_list); - - list_del_init(slow_subchannels_head.next); + init_subchannel_id(&schid); + while (idset_sch_get_first(slow_subchannel_set, &schid)) { + idset_sch_del(slow_subchannel_set, schid); spin_unlock_irq(&slow_subchannel_lock); - css_evaluate_subchannel(slow_sch->schid, 1); + css_evaluate_subchannel(schid, 1); spin_lock_irq(&slow_subchannel_lock); - kfree(slow_sch); } spin_unlock_irq(&slow_subchannel_lock); } -DECLARE_WORK(slow_path_work, css_trigger_slow_path); +static DECLARE_WORK(slow_path_work, css_slow_path_func); struct workqueue_struct *slow_path_wq; +void css_schedule_eval(struct subchannel_id schid) +{ + unsigned long flags; + + spin_lock_irqsave(&slow_subchannel_lock, flags); + idset_sch_add(slow_subchannel_set, schid); + queue_work(slow_path_wq, &slow_path_work); + spin_unlock_irqrestore(&slow_subchannel_lock, flags); +} + +void css_schedule_eval_all(void) +{ + unsigned long flags; + + spin_lock_irqsave(&slow_subchannel_lock, flags); + idset_fill(slow_subchannel_set); + queue_work(slow_path_wq, &slow_path_work); + spin_unlock_irqrestore(&slow_subchannel_lock, flags); +} + /* Reprobe subchannel if unregistered. */ static int reprobe_subchannel(struct subchannel_id schid, void *data) { @@ -426,33 +439,14 @@ void css_schedule_reprobe(void) EXPORT_SYMBOL_GPL(css_schedule_reprobe); /* - * Rescan for new devices. FIXME: This is slow. - * This function is called when we have lost CRWs due to overflows and we have - * to do subchannel housekeeping. - */ -void -css_reiterate_subchannels(void) -{ - css_clear_subchannel_slow_list(); - need_rescan = 1; -} - -/* * Called from the machine check handler for subchannel report words. */ -int -css_process_crw(int rsid1, int rsid2) +void css_process_crw(int rsid1, int rsid2) { - int ret; struct subchannel_id mchk_schid; CIO_CRW_EVENT(2, "source is subchannel %04X, subsystem id %x\n", rsid1, rsid2); - - if (need_rescan) - /* We need to iterate all subchannels anyway. */ - return -EAGAIN; - init_subchannel_id(&mchk_schid); mchk_schid.sch_no = rsid1; if (rsid2 != 0) @@ -463,14 +457,7 @@ css_process_crw(int rsid1, int rsid2) * use stsch() to find out if the subchannel in question has come * or gone. */ - ret = css_evaluate_subchannel(mchk_schid, 0); - if (ret == -EAGAIN) { - if (css_enqueue_subchannel_slow(mchk_schid)) { - css_clear_subchannel_slow_list(); - need_rescan = 1; - } - } - return ret; + css_evaluate_subchannel(mchk_schid, 0); } static int __init @@ -745,47 +732,6 @@ struct bus_type css_bus_type = { subsys_initcall(init_channel_subsystem); -int -css_enqueue_subchannel_slow(struct subchannel_id schid) -{ - struct slow_subchannel *new_slow_sch; - unsigned long flags; - - new_slow_sch = kzalloc(sizeof(struct slow_subchannel), GFP_ATOMIC); - if (!new_slow_sch) - return -ENOMEM; - new_slow_sch->schid = schid; - spin_lock_irqsave(&slow_subchannel_lock, flags); - list_add_tail(&new_slow_sch->slow_list, &slow_subchannels_head); - spin_unlock_irqrestore(&slow_subchannel_lock, flags); - return 0; -} - -void -css_clear_subchannel_slow_list(void) -{ - unsigned long flags; - - spin_lock_irqsave(&slow_subchannel_lock, flags); - while (!list_empty(&slow_subchannels_head)) { - struct slow_subchannel *slow_sch = - list_entry(slow_subchannels_head.next, - struct slow_subchannel, slow_list); - - list_del_init(slow_subchannels_head.next); - kfree(slow_sch); - } - spin_unlock_irqrestore(&slow_subchannel_lock, flags); -} - - - -int -css_slow_subchannels_exist(void) -{ - return (!list_empty(&slow_subchannels_head)); -} - MODULE_LICENSE("GPL"); EXPORT_SYMBOL(css_bus_type); EXPORT_SYMBOL_GPL(css_characteristics_avail); |