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authorPeter Oberparleiter <peter.oberparleiter@de.ibm.com>2008-01-26 14:10:52 +0100
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2008-01-26 14:11:06 +0100
commit90ab133603d066e850fc9ed297b6eb52f888dd25 (patch)
treeab26ae8c0733a979c8c215fa1d491be3e500cf95 /drivers/s390
parent808e48882316dd4a325cd1cc382516945edad77d (diff)
[S390] cio: introduce timed recovery procedure
Add a timed recovery procedure to reactivate ccw devices in cases where HW/VM events are not sufficient to allow for proper recovery of reappearing channel paths. Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'drivers/s390')
-rw-r--r--drivers/s390/cio/device.c63
-rw-r--r--drivers/s390/cio/device.h2
-rw-r--r--drivers/s390/cio/device_fsm.c2
3 files changed, 67 insertions, 0 deletions
diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index f80d7f5418d..d35dc3f25d0 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -17,6 +17,7 @@
#include <linux/list.h>
#include <linux/device.h>
#include <linux/workqueue.h>
+#include <linux/timer.h>
#include <asm/ccwdev.h>
#include <asm/cio.h>
@@ -30,6 +31,11 @@
#include "ioasm.h"
#include "io_sch.h"
+static struct timer_list recovery_timer;
+static spinlock_t recovery_lock;
+static int recovery_phase;
+static const unsigned long recovery_delay[] = { 3, 30, 300 };
+
/******************* bus type handling ***********************/
/* The Linux driver model distinguishes between a bus type and
@@ -142,6 +148,8 @@ struct workqueue_struct *ccw_device_notify_work;
wait_queue_head_t ccw_device_init_wq;
atomic_t ccw_device_init_count;
+static void recovery_func(unsigned long data);
+
static int __init
init_ccw_bus_type (void)
{
@@ -149,6 +157,7 @@ init_ccw_bus_type (void)
init_waitqueue_head(&ccw_device_init_wq);
atomic_set(&ccw_device_init_count, 0);
+ setup_timer(&recovery_timer, recovery_func, 0);
ccw_device_work = create_singlethread_workqueue("cio");
if (!ccw_device_work)
@@ -1503,6 +1512,60 @@ ccw_device_get_subchannel_id(struct ccw_device *cdev)
return sch->schid;
}
+static int recovery_check(struct device *dev, void *data)
+{
+ struct ccw_device *cdev = to_ccwdev(dev);
+ int *redo = data;
+
+ spin_lock_irq(cdev->ccwlock);
+ switch (cdev->private->state) {
+ case DEV_STATE_DISCONNECTED:
+ CIO_MSG_EVENT(3, "recovery: trigger 0.%x.%04x\n",
+ cdev->private->dev_id.ssid,
+ cdev->private->dev_id.devno);
+ dev_fsm_event(cdev, DEV_EVENT_VERIFY);
+ *redo = 1;
+ break;
+ case DEV_STATE_DISCONNECTED_SENSE_ID:
+ *redo = 1;
+ break;
+ }
+ spin_unlock_irq(cdev->ccwlock);
+
+ return 0;
+}
+
+static void recovery_func(unsigned long data)
+{
+ int redo = 0;
+
+ bus_for_each_dev(&ccw_bus_type, NULL, &redo, recovery_check);
+ if (redo) {
+ spin_lock_irq(&recovery_lock);
+ if (!timer_pending(&recovery_timer)) {
+ if (recovery_phase < ARRAY_SIZE(recovery_delay) - 1)
+ recovery_phase++;
+ mod_timer(&recovery_timer, jiffies +
+ recovery_delay[recovery_phase] * HZ);
+ }
+ spin_unlock_irq(&recovery_lock);
+ } else
+ CIO_MSG_EVENT(2, "recovery: end\n");
+}
+
+void ccw_device_schedule_recovery(void)
+{
+ unsigned long flags;
+
+ CIO_MSG_EVENT(2, "recovery: schedule\n");
+ spin_lock_irqsave(&recovery_lock, flags);
+ if (!timer_pending(&recovery_timer) || (recovery_phase != 0)) {
+ recovery_phase = 0;
+ mod_timer(&recovery_timer, jiffies + recovery_delay[0] * HZ);
+ }
+ spin_unlock_irqrestore(&recovery_lock, flags);
+}
+
MODULE_LICENSE("GPL");
EXPORT_SYMBOL(ccw_device_set_online);
EXPORT_SYMBOL(ccw_device_set_offline);
diff --git a/drivers/s390/cio/device.h b/drivers/s390/cio/device.h
index 87576fe2c7c..d40a2ffaa00 100644
--- a/drivers/s390/cio/device.h
+++ b/drivers/s390/cio/device.h
@@ -88,6 +88,8 @@ int ccw_device_recognition(struct ccw_device *);
int ccw_device_online(struct ccw_device *);
int ccw_device_offline(struct ccw_device *);
+void ccw_device_schedule_recovery(void);
+
/* Function prototypes for device status and basic sense stuff. */
void ccw_device_accumulate_irb(struct ccw_device *, struct irb *);
void ccw_device_accumulate_basic_sense(struct ccw_device *, struct irb *);
diff --git a/drivers/s390/cio/device_fsm.c b/drivers/s390/cio/device_fsm.c
index 485741a1212..4b92c84fb43 100644
--- a/drivers/s390/cio/device_fsm.c
+++ b/drivers/s390/cio/device_fsm.c
@@ -61,6 +61,8 @@ device_set_disconnected(struct subchannel *sch)
ccw_device_set_timeout(cdev, 0);
cdev->private->flags.fake_irb = 0;
cdev->private->state = DEV_STATE_DISCONNECTED;
+ if (cdev->online)
+ ccw_device_schedule_recovery();
}
void device_set_intretry(struct subchannel *sch)