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path: root/drivers/s390/cio/device_pgid.c
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Diffstat (limited to 'drivers/s390/cio/device_pgid.c')
-rw-r--r--drivers/s390/cio/device_pgid.c108
1 files changed, 63 insertions, 45 deletions
diff --git a/drivers/s390/cio/device_pgid.c b/drivers/s390/cio/device_pgid.c
index 32610fd8868e..8ca2d078848c 100644
--- a/drivers/s390/cio/device_pgid.c
+++ b/drivers/s390/cio/device_pgid.c
@@ -24,6 +24,21 @@
#include "ioasm.h"
/*
+ * Helper function called from interrupt context to decide whether an
+ * operation should be tried again.
+ */
+static int __ccw_device_should_retry(struct scsw *scsw)
+{
+ /* CC is only valid if start function bit is set. */
+ if ((scsw->fctl & SCSW_FCTL_START_FUNC) && scsw->cc == 1)
+ return 1;
+ /* No more activity. For sense and set PGID we stubbornly try again. */
+ if (!scsw->actl)
+ return 1;
+ return 0;
+}
+
+/*
* Start Sense Path Group ID helper function. Used in ccw_device_recog
* and ccw_device_sense_pgid.
*/
@@ -155,10 +170,10 @@ ccw_device_sense_pgid_irq(struct ccw_device *cdev, enum dev_event dev_event)
int ret;
irb = (struct irb *) __LC_IRB;
- /* Retry sense pgid for cc=1. */
+
if (irb->scsw.stctl ==
(SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
- if (irb->scsw.cc == 1) {
+ if (__ccw_device_should_retry(&irb->scsw)) {
ret = __ccw_device_sense_pgid_start(cdev);
if (ret && ret != -EBUSY)
ccw_device_sense_pgid_done(cdev, ret);
@@ -230,18 +245,17 @@ __ccw_device_do_pgid(struct ccw_device *cdev, __u8 func)
memset(&cdev->private->irb, 0, sizeof(struct irb));
/* Try multiple times. */
- ret = -ENODEV;
+ ret = -EACCES;
if (cdev->private->iretry > 0) {
cdev->private->iretry--;
ret = cio_start (sch, cdev->private->iccws,
cdev->private->imask);
- /* ret is 0, -EBUSY, -EACCES or -ENODEV */
- if ((ret != -EACCES) && (ret != -ENODEV))
+ /* We expect an interrupt in case of success or busy
+ * indication. */
+ if ((ret == 0) || (ret == -EBUSY))
return ret;
}
- /* PGID command failed on this path. Switch it off. */
- sch->lpm &= ~cdev->private->imask;
- sch->vpm &= ~cdev->private->imask;
+ /* PGID command failed on this path. */
CIO_MSG_EVENT(2, "SPID - Device %04x on Subchannel "
"0.%x.%04x, lpm %02X, became 'not operational'\n",
cdev->private->devno, sch->schid.ssid,
@@ -271,18 +285,17 @@ static int __ccw_device_do_nop(struct ccw_device *cdev)
memset(&cdev->private->irb, 0, sizeof(struct irb));
/* Try multiple times. */
- ret = -ENODEV;
+ ret = -EACCES;
if (cdev->private->iretry > 0) {
cdev->private->iretry--;
ret = cio_start (sch, cdev->private->iccws,
cdev->private->imask);
- /* ret is 0, -EBUSY, -EACCES or -ENODEV */
- if ((ret != -EACCES) && (ret != -ENODEV))
+ /* We expect an interrupt in case of success or busy
+ * indication. */
+ if ((ret == 0) || (ret == -EBUSY))
return ret;
}
- /* nop command failed on this path. Switch it off. */
- sch->lpm &= ~cdev->private->imask;
- sch->vpm &= ~cdev->private->imask;
+ /* nop command failed on this path. */
CIO_MSG_EVENT(2, "NOP - Device %04x on Subchannel "
"0.%x.%04x, lpm %02X, became 'not operational'\n",
cdev->private->devno, sch->schid.ssid,
@@ -357,27 +370,32 @@ static void
__ccw_device_verify_start(struct ccw_device *cdev)
{
struct subchannel *sch;
- __u8 imask, func;
+ __u8 func;
int ret;
sch = to_subchannel(cdev->dev.parent);
- while (sch->vpm != sch->lpm) {
- /* Find first unequal bit in vpm vs. lpm */
- for (imask = 0x80; imask != 0; imask >>= 1)
- if ((sch->vpm & imask) != (sch->lpm & imask))
- break;
- cdev->private->imask = imask;
+ /* Repeat for all paths. */
+ for (; cdev->private->imask; cdev->private->imask >>= 1,
+ cdev->private->iretry = 5) {
+ if ((cdev->private->imask & sch->schib.pmcw.pam) == 0)
+ /* Path not available, try next. */
+ continue;
if (cdev->private->options.pgroup) {
- func = (sch->vpm & imask) ?
- SPID_FUNC_RESIGN : SPID_FUNC_ESTABLISH;
+ if (sch->opm & cdev->private->imask)
+ func = SPID_FUNC_ESTABLISH;
+ else
+ func = SPID_FUNC_RESIGN;
ret = __ccw_device_do_pgid(cdev, func);
} else
ret = __ccw_device_do_nop(cdev);
+ /* We expect an interrupt in case of success or busy
+ * indication. */
if (ret == 0 || ret == -EBUSY)
return;
- cdev->private->iretry = 5;
+ /* Permanent path failure, try next. */
}
- ccw_device_verify_done(cdev, (sch->lpm != 0) ? 0 : -ENODEV);
+ /* Done with all paths. */
+ ccw_device_verify_done(cdev, (sch->vpm != 0) ? 0 : -ENODEV);
}
/*
@@ -391,10 +409,10 @@ ccw_device_verify_irq(struct ccw_device *cdev, enum dev_event dev_event)
int ret;
irb = (struct irb *) __LC_IRB;
- /* Retry set pgid for cc=1. */
+
if (irb->scsw.stctl ==
(SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
- if (irb->scsw.cc == 1)
+ if (__ccw_device_should_retry(&irb->scsw))
__ccw_device_verify_start(cdev);
return;
}
@@ -406,14 +424,14 @@ ccw_device_verify_irq(struct ccw_device *cdev, enum dev_event dev_event)
else
ret = __ccw_device_check_nop(cdev);
memset(&cdev->private->irb, 0, sizeof(struct irb));
+
switch (ret) {
/* 0, -ETIME, -EAGAIN, -EOPNOTSUPP or -EACCES */
case 0:
- /* Establish or Resign Path Group done. Update vpm. */
- if ((sch->lpm & cdev->private->imask) != 0)
- sch->vpm |= cdev->private->imask;
- else
- sch->vpm &= ~cdev->private->imask;
+ /* Path verification ccw finished successfully, update lpm. */
+ sch->vpm |= sch->opm & cdev->private->imask;
+ /* Go on with next path. */
+ cdev->private->imask >>= 1;
cdev->private->iretry = 5;
__ccw_device_verify_start(cdev);
break;
@@ -426,6 +444,10 @@ ccw_device_verify_irq(struct ccw_device *cdev, enum dev_event dev_event)
cdev->private->options.pgroup = 0;
else
cdev->private->flags.pgid_single = 1;
+ /* Retry */
+ sch->vpm = 0;
+ cdev->private->imask = 0x80;
+ cdev->private->iretry = 5;
/* fall through. */
case -EAGAIN: /* Try again. */
__ccw_device_verify_start(cdev);
@@ -434,8 +456,7 @@ ccw_device_verify_irq(struct ccw_device *cdev, enum dev_event dev_event)
ccw_device_verify_done(cdev, -ETIME);
break;
case -EACCES: /* channel is not operational. */
- sch->lpm &= ~cdev->private->imask;
- sch->vpm &= ~cdev->private->imask;
+ cdev->private->imask >>= 1;
cdev->private->iretry = 5;
__ccw_device_verify_start(cdev);
break;
@@ -448,19 +469,17 @@ ccw_device_verify_start(struct ccw_device *cdev)
struct subchannel *sch = to_subchannel(cdev->dev.parent);
cdev->private->flags.pgid_single = 0;
+ cdev->private->imask = 0x80;
cdev->private->iretry = 5;
- /*
- * Update sch->lpm with current values to catch paths becoming
- * available again.
- */
+
+ /* Start with empty vpm. */
+ sch->vpm = 0;
+
+ /* Get current pam. */
if (stsch(sch->schid, &sch->schib)) {
ccw_device_verify_done(cdev, -ENODEV);
return;
}
- sch->lpm = sch->schib.pmcw.pim &
- sch->schib.pmcw.pam &
- sch->schib.pmcw.pom &
- sch->opm;
__ccw_device_verify_start(cdev);
}
@@ -494,10 +513,10 @@ ccw_device_disband_irq(struct ccw_device *cdev, enum dev_event dev_event)
int ret;
irb = (struct irb *) __LC_IRB;
- /* Retry set pgid for cc=1. */
+
if (irb->scsw.stctl ==
(SCSW_STCTL_STATUS_PEND | SCSW_STCTL_ALERT_STATUS)) {
- if (irb->scsw.cc == 1)
+ if (__ccw_device_should_retry(&irb->scsw))
__ccw_device_disband_start(cdev);
return;
}
@@ -509,7 +528,6 @@ ccw_device_disband_irq(struct ccw_device *cdev, enum dev_event dev_event)
switch (ret) {
/* 0, -ETIME, -EAGAIN, -EOPNOTSUPP or -EACCES */
case 0: /* disband successful. */
- sch->vpm = 0;
ccw_device_disband_done(cdev, ret);
break;
case -EOPNOTSUPP:
generated by cgit v1.2.3 (git 2.39.0) at 2024-12-23 23:24:50 +0300