[S390] cio: make steal lock procedure more robust
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>
diff --git a/drivers/s390/cio/device_ops.c b/drivers/s390/cio/device_ops.c
index d4be16a..6da8454 100644
--- a/drivers/s390/cio/device_ops.c
+++ b/drivers/s390/cio/device_ops.c
@@ -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 @@
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)
+ 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;
- /*
- * 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?
- 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)