Commit 90ab1336 authored by Peter Oberparleiter's avatar Peter Oberparleiter Committed by Martin Schwidefsky
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[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: default avatarPeter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 808e4888
......@@ -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);
......
......@@ -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 *);
......
......@@ -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)
......
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