[S390] path grouping and path verifications fixes.
1. Multipath devices for which SetPGID is not supported are not handled well.
Use NOP ccws for path verification (sans path grouping) when SetPGID is not
supported.
2. Check for PGIDs already set with SensePGID on _all_ paths (not just the
first one) and try to find a common one. Moan if no common PGID can be
found (and use NOP verification). If no PGIDs have been set, use the css
global PGID (as before). (Rationale: SetPGID will get a command reject if
the PGID it tries to set does not match the already set PGID.)
3. Immediately before reboot, issue RESET CHANNEL PATH (rcp) on all chpids. This
will remove the old PGIDs. rcp will generate solicited CRWs which can be
savely ignored by the machine check handler (all other actions create
unsolicited CRWs).
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/cio/device_pgid.c b/drivers/s390/cio/device_pgid.c
index 54cb64e..32610fd 100644
--- a/drivers/s390/cio/device_pgid.c
+++ b/drivers/s390/cio/device_pgid.c
@@ -33,12 +33,17 @@
struct subchannel *sch;
struct ccw1 *ccw;
int ret;
+ int i;
sch = to_subchannel(cdev->dev.parent);
+ /* Return if we already checked on all paths. */
+ if (cdev->private->imask == 0)
+ return (sch->lpm == 0) ? -ENODEV : -EACCES;
+ i = 8 - ffs(cdev->private->imask);
+
/* Setup sense path group id channel program. */
ccw = cdev->private->iccws;
ccw->cmd_code = CCW_CMD_SENSE_PGID;
- ccw->cda = (__u32) __pa (&cdev->private->pgid);
ccw->count = sizeof (struct pgid);
ccw->flags = CCW_FLAG_SLI;
@@ -48,6 +53,7 @@
ret = -ENODEV;
while (cdev->private->imask != 0) {
/* Try every path multiple times. */
+ ccw->cda = (__u32) __pa (&cdev->private->pgid[i]);
if (cdev->private->iretry > 0) {
cdev->private->iretry--;
ret = cio_start (sch, cdev->private->iccws,
@@ -64,7 +70,9 @@
}
cdev->private->imask >>= 1;
cdev->private->iretry = 5;
+ i++;
}
+
return ret;
}
@@ -76,7 +84,7 @@
cdev->private->state = DEV_STATE_SENSE_PGID;
cdev->private->imask = 0x80;
cdev->private->iretry = 5;
- memset (&cdev->private->pgid, 0, sizeof (struct pgid));
+ memset (&cdev->private->pgid, 0, sizeof (cdev->private->pgid));
ret = __ccw_device_sense_pgid_start(cdev);
if (ret && ret != -EBUSY)
ccw_device_sense_pgid_done(cdev, ret);
@@ -91,6 +99,7 @@
{
struct subchannel *sch;
struct irb *irb;
+ int i;
sch = to_subchannel(cdev->dev.parent);
irb = &cdev->private->irb;
@@ -124,7 +133,8 @@
sch->schid.sch_no, sch->orb.lpm);
return -EACCES;
}
- if (cdev->private->pgid.inf.ps.state2 == SNID_STATE2_RESVD_ELSE) {
+ i = 8 - ffs(cdev->private->imask);
+ if (cdev->private->pgid[i].inf.ps.state2 == SNID_STATE2_RESVD_ELSE) {
CIO_MSG_EVENT(2, "SNID - Device %04x on Subchannel 0.%x.%04x "
"is reserved by someone else\n",
cdev->private->devno, sch->schid.ssid,
@@ -162,12 +172,6 @@
memset(&cdev->private->irb, 0, sizeof(struct irb));
switch (ret) {
/* 0, -ETIME, -EOPNOTSUPP, -EAGAIN, -EACCES or -EUSERS */
- case 0: /* Sense Path Group ID successful. */
- if (cdev->private->pgid.inf.ps.state1 == SNID_STATE1_RESET)
- memcpy(&cdev->private->pgid, &css[0]->global_pgid,
- sizeof(struct pgid));
- ccw_device_sense_pgid_done(cdev, 0);
- break;
case -EOPNOTSUPP: /* Sense Path Group ID not supported */
ccw_device_sense_pgid_done(cdev, -EOPNOTSUPP);
break;
@@ -176,13 +180,15 @@
break;
case -EACCES: /* channel is not operational. */
sch->lpm &= ~cdev->private->imask;
+ /* Fall through. */
+ case 0: /* Sense Path Group ID successful. */
cdev->private->imask >>= 1;
cdev->private->iretry = 5;
/* Fall through. */
case -EAGAIN: /* Try again. */
ret = __ccw_device_sense_pgid_start(cdev);
if (ret != 0 && ret != -EBUSY)
- ccw_device_sense_pgid_done(cdev, -ENODEV);
+ ccw_device_sense_pgid_done(cdev, ret);
break;
case -EUSERS: /* device is reserved for someone else. */
ccw_device_sense_pgid_done(cdev, -EUSERS);
@@ -203,20 +209,20 @@
sch = to_subchannel(cdev->dev.parent);
/* Setup sense path group id channel program. */
- cdev->private->pgid.inf.fc = func;
+ cdev->private->pgid[0].inf.fc = func;
ccw = cdev->private->iccws;
if (!cdev->private->flags.pgid_single) {
- cdev->private->pgid.inf.fc |= SPID_FUNC_MULTI_PATH;
+ cdev->private->pgid[0].inf.fc |= SPID_FUNC_MULTI_PATH;
ccw->cmd_code = CCW_CMD_SUSPEND_RECONN;
ccw->cda = 0;
ccw->count = 0;
ccw->flags = CCW_FLAG_SLI | CCW_FLAG_CC;
ccw++;
} else
- cdev->private->pgid.inf.fc |= SPID_FUNC_SINGLE_PATH;
+ cdev->private->pgid[0].inf.fc |= SPID_FUNC_SINGLE_PATH;
ccw->cmd_code = CCW_CMD_SET_PGID;
- ccw->cda = (__u32) __pa (&cdev->private->pgid);
+ ccw->cda = (__u32) __pa (&cdev->private->pgid[0]);
ccw->count = sizeof (struct pgid);
ccw->flags = CCW_FLAG_SLI;
@@ -244,6 +250,48 @@
}
/*
+ * Helper function to send a nop ccw down a path.
+ */
+static int __ccw_device_do_nop(struct ccw_device *cdev)
+{
+ struct subchannel *sch;
+ struct ccw1 *ccw;
+ int ret;
+
+ sch = to_subchannel(cdev->dev.parent);
+
+ /* Setup nop channel program. */
+ ccw = cdev->private->iccws;
+ ccw->cmd_code = CCW_CMD_NOOP;
+ ccw->cda = 0;
+ ccw->count = 0;
+ ccw->flags = CCW_FLAG_SLI;
+
+ /* Reset device status. */
+ memset(&cdev->private->irb, 0, sizeof(struct irb));
+
+ /* Try multiple times. */
+ ret = -ENODEV;
+ 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))
+ return ret;
+ }
+ /* nop command failed on this path. Switch it off. */
+ sch->lpm &= ~cdev->private->imask;
+ sch->vpm &= ~cdev->private->imask;
+ CIO_MSG_EVENT(2, "NOP - Device %04x on Subchannel "
+ "0.%x.%04x, lpm %02X, became 'not operational'\n",
+ cdev->private->devno, sch->schid.ssid,
+ sch->schid.sch_no, cdev->private->imask);
+ return ret;
+}
+
+
+/*
* Called from interrupt context to check if a valid answer
* to Set Path Group ID was received.
*/
@@ -282,6 +330,29 @@
return 0;
}
+/*
+ * Called from interrupt context to check the path status after a nop has
+ * been send.
+ */
+static int __ccw_device_check_nop(struct ccw_device *cdev)
+{
+ struct subchannel *sch;
+ struct irb *irb;
+
+ sch = to_subchannel(cdev->dev.parent);
+ irb = &cdev->private->irb;
+ if (irb->scsw.fctl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC))
+ return -ETIME;
+ if (irb->scsw.cc == 3) {
+ CIO_MSG_EVENT(2, "NOP - Device %04x on Subchannel 0.%x.%04x,"
+ " lpm %02X, became 'not operational'\n",
+ cdev->private->devno, sch->schid.ssid,
+ sch->schid.sch_no, cdev->private->imask);
+ return -EACCES;
+ }
+ return 0;
+}
+
static void
__ccw_device_verify_start(struct ccw_device *cdev)
{
@@ -296,9 +367,12 @@
if ((sch->vpm & imask) != (sch->lpm & imask))
break;
cdev->private->imask = imask;
- func = (sch->vpm & imask) ?
- SPID_FUNC_RESIGN : SPID_FUNC_ESTABLISH;
- ret = __ccw_device_do_pgid(cdev, func);
+ if (cdev->private->options.pgroup) {
+ func = (sch->vpm & imask) ?
+ SPID_FUNC_RESIGN : SPID_FUNC_ESTABLISH;
+ ret = __ccw_device_do_pgid(cdev, func);
+ } else
+ ret = __ccw_device_do_nop(cdev);
if (ret == 0 || ret == -EBUSY)
return;
cdev->private->iretry = 5;
@@ -327,7 +401,10 @@
if (ccw_device_accumulate_and_sense(cdev, irb) != 0)
return;
sch = to_subchannel(cdev->dev.parent);
- ret = __ccw_device_check_pgid(cdev);
+ if (cdev->private->options.pgroup)
+ ret = __ccw_device_check_pgid(cdev);
+ else
+ ret = __ccw_device_check_nop(cdev);
memset(&cdev->private->irb, 0, sizeof(struct irb));
switch (ret) {
/* 0, -ETIME, -EAGAIN, -EOPNOTSUPP or -EACCES */
@@ -345,11 +422,10 @@
* One of those strange devices which claim to be able
* to do multipathing but not for Set Path Group ID.
*/
- if (cdev->private->flags.pgid_single) {
- ccw_device_verify_done(cdev, -EOPNOTSUPP);
- break;
- }
- cdev->private->flags.pgid_single = 1;
+ if (cdev->private->flags.pgid_single)
+ cdev->private->options.pgroup = 0;
+ else
+ cdev->private->flags.pgid_single = 1;
/* fall through. */
case -EAGAIN: /* Try again. */
__ccw_device_verify_start(cdev);