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[S390] cio: make steal lock procedure more robust

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An Unconditional Reserve + Release operation (steal lock) for a
boxed device may fail when encountering special error cases
(e.g. unit checks or path errors). Fix this by using the more
robust ccw_request infrastructure for performing the steal lock
CCW program.

Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Peter Oberparleiter
2009-12-07 12:51:32 +01:00
committed by Martin Schwidefsky
parent 52ef0608e3
commit d7d12ef2be
4 changed files with 134 additions and 89 deletions
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112
drivers/s390/cio/device_ops.c
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@@ -11,6 +11,7 @@
#include <linux/list.h>
#include <linux/device.h>
#include <linux/delay.h>
#include <linux/completion.h>
#include <asm/ccwdev.h>
#include <asm/idals.h>
@@ -504,74 +505,65 @@ __u8 ccw_device_get_path_mask(struct ccw_device *cdev)
return sch->lpm;
}
/*
* Try to break the lock on a boxed device.
*/
int
ccw_device_stlck(struct ccw_device *cdev)
struct stlck_data {
struct completion done;
int rc;
};
void ccw_device_stlck_done(struct ccw_device *cdev, void *data, int rc)
{
void *buf, *buf2;
unsigned long flags;
struct subchannel *sch;
int ret;
struct stlck_data *sdata = data;
if (!cdev)
return -ENODEV;
sdata->rc = rc;
complete(&sdata->done);
}
if (cdev->drv && !cdev->private->options.force)
return -EINVAL;
/*
* Perform unconditional reserve + release.
*/
int ccw_device_stlck(struct ccw_device *cdev)
{
struct subchannel *sch = to_subchannel(cdev->dev.parent);
struct stlck_data data;
u8 *buffer;
int rc;
sch = to_subchannel(cdev->dev.parent);
CIO_TRACE_EVENT(2, "stl lock");
CIO_TRACE_EVENT(2, dev_name(&cdev->dev));
buf = kmalloc(32*sizeof(char), GFP_DMA|GFP_KERNEL);
if (!buf)
return -ENOMEM;
buf2 = kmalloc(32*sizeof(char), GFP_DMA|GFP_KERNEL);
if (!buf2) {
kfree(buf);
return -ENOMEM;
/* Check if steal lock operation is valid for this device. */
if (cdev->drv) {
if (!cdev->private->options.force)
return -EINVAL;
}
spin_lock_irqsave(sch->lock, flags);
ret = cio_enable_subchannel(sch, (u32)(addr_t)sch);
if (ret)
goto out_unlock;
/*
* Setup ccw. We chain an unconditional reserve and a release so we
* only break the lock.
*/
cdev->private->iccws[0].cmd_code = CCW_CMD_STLCK;
cdev->private->iccws[0].cda = (__u32) __pa(buf);
cdev->private->iccws[0].count = 32;
cdev->private->iccws[0].flags = CCW_FLAG_CC;
cdev->private->iccws[1].cmd_code = CCW_CMD_RELEASE;
cdev->private->iccws[1].cda = (__u32) __pa(buf2);
cdev->private->iccws[1].count = 32;
cdev->private->iccws[1].flags = 0;
ret = cio_start(sch, cdev->private->iccws, 0);
if (ret) {
cio_disable_subchannel(sch); //FIXME: return code?
buffer = kzalloc(64, GFP_DMA | GFP_KERNEL);
if (!buffer)
return -ENOMEM;
init_completion(&data.done);
data.rc = -EIO;
spin_lock_irq(sch->lock);
rc = cio_enable_subchannel(sch, (u32) (addr_t) sch);
if (rc)
goto out_unlock;
/* Perform operation. */
cdev->private->state = DEV_STATE_STEAL_LOCK,
ccw_device_stlck_start(cdev, &data, &buffer[0], &buffer[32]);
spin_unlock_irq(sch->lock);
/* Wait for operation to finish. */
if (wait_for_completion_interruptible(&data.done)) {
/* Got a signal. */
spin_lock_irq(sch->lock);
ccw_request_cancel(cdev);
spin_unlock_irq(sch->lock);
wait_for_completion(&data.done);
}
cdev->private->irb.scsw.cmd.actl |= SCSW_ACTL_START_PEND;
spin_unlock_irqrestore(sch->lock, flags);
wait_event(cdev->private->wait_q,
cdev->private->irb.scsw.cmd.actl == 0);
spin_lock_irqsave(sch->lock, flags);
cio_disable_subchannel(sch); //FIXME: return code?
if ((cdev->private->irb.scsw.cmd.dstat !=
(DEV_STAT_CHN_END|DEV_STAT_DEV_END)) ||
(cdev->private->irb.scsw.cmd.cstat != 0))
ret = -EIO;
/* Clear irb. */
memset(&cdev->private->irb, 0, sizeof(struct irb));
rc = data.rc;
/* Check results. */
spin_lock_irq(sch->lock);
cio_disable_subchannel(sch);
cdev->private->state = DEV_STATE_BOXED;
out_unlock:
kfree(buf);
kfree(buf2);
spin_unlock_irqrestore(sch->lock, flags);
return ret;
spin_unlock_irq(sch->lock);
kfree(buffer);
return rc;
}
void *ccw_device_get_chp_desc(struct ccw_device *cdev, int chp_no)