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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

drivers/s390/cio/device.c

+63 −0
Original line number Diff line number Diff line
@@ -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);

drivers/s390/cio/device.h

+2 −0
Original line number Diff line number Diff line
@@ -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 *);

drivers/s390/cio/device_fsm.c

+2 −0
Original line number Diff line number Diff line
@@ -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)