diff options
author | Peter Oberparleiter <peter.oberparleiter@de.ibm.com> | 2009-12-07 14:51:32 +0300 |
---|---|---|
committer | Martin Schwidefsky <sky@mschwide.boeblingen.de.ibm.com> | 2009-12-07 14:51:32 +0300 |
commit | d7d12ef2befac4fed0dccaddff11338b654804df (patch) | |
tree | 1563b299e609024844affbc3ebba99c0718db238 /drivers/s390/cio/device_ops.c | |
parent | 52ef0608e3ee4a511725e443c4b572fece22b353 (diff) | |
download | linux-d7d12ef2befac4fed0dccaddff11338b654804df.tar.xz |
[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>
Diffstat (limited to 'drivers/s390/cio/device_ops.c')
-rw-r--r-- | drivers/s390/cio/device_ops.c | 112 |
1 files changed, 52 insertions, 60 deletions
diff --git a/drivers/s390/cio/device_ops.c b/drivers/s390/cio/device_ops.c index d4be16acebe4..6da84543dfe9 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 @@ __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) -{ - void *buf, *buf2; - unsigned long flags; - struct subchannel *sch; - int ret; +struct stlck_data { + struct completion done; + int rc; +}; - if (!cdev) - return -ENODEV; +void ccw_device_stlck_done(struct ccw_device *cdev, void *data, int rc) +{ + struct stlck_data *sdata = data; - if (cdev->drv && !cdev->private->options.force) - return -EINVAL; + sdata->rc = rc; + complete(&sdata->done); +} - sch = to_subchannel(cdev->dev.parent); - - CIO_TRACE_EVENT(2, "stl lock"); - CIO_TRACE_EVENT(2, dev_name(&cdev->dev)); +/* + * 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; - 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) |