[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>
diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index f80d7f5..d35dc3f 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 @@
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_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 @@
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);