[S390] cio: introduce cio_update_schib
There is the chance that we get condition code 0 for a stsch but
the resulting schib is not vaild. In the current code there are
2 cases:
* we do a check for validity of the schib after stsch, but at this
time we have already stored the invaild schib in the subchannel
structure. This may lead to problems.
* we don't do a check for validity, which is not that good either.
The patch addresses both issues by introducing the stsch wrapper
cio_update_schib which performs stsch on a local schib. This schib
is only written back to the subchannel if it's valid.
side note: For some functions (chp_events) the return codes are
different now (-ENXIO vs -ENODEV) but this shouldn't do harm
since the caller doesn't check for _specific_ errors.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/cio/chsc_sch.c b/drivers/s390/cio/chsc_sch.c
index f49f0e5..0a2f2ed 100644
--- a/drivers/s390/cio/chsc_sch.c
+++ b/drivers/s390/cio/chsc_sch.c
@@ -61,7 +61,7 @@
}
private->request = NULL;
memcpy(&request->irb, irb, sizeof(*irb));
- stsch(sch->schid, &sch->schib);
+ cio_update_schib(sch);
complete(&request->completion);
put_device(&sch->dev);
}
diff --git a/drivers/s390/cio/cio.c b/drivers/s390/cio/cio.c
index 8047800..9bdb463 100644
--- a/drivers/s390/cio/cio.c
+++ b/drivers/s390/cio/cio.c
@@ -114,11 +114,13 @@
else
sch->lpm = 0;
- stsch (sch->schid, &sch->schib);
-
CIO_MSG_EVENT(2, "cio_start: 'not oper' status for "
"subchannel 0.%x.%04x!\n", sch->schid.ssid,
sch->schid.sch_no);
+
+ if (cio_update_schib(sch))
+ return -ENODEV;
+
sprintf(dbf_text, "no%s", dev_name(&sch->dev));
CIO_TRACE_EVENT(0, dbf_text);
CIO_HEX_EVENT(0, &sch->schib, sizeof (struct schib));
@@ -316,7 +318,8 @@
switch (ccode) {
case 0: /* success */
/* Update information in scsw. */
- stsch (sch->schid, &sch->schib);
+ if (cio_update_schib(sch))
+ return -ENODEV;
return 0;
case 1: /* status pending */
return -EBUSY;
@@ -358,6 +361,23 @@
}
/**
+ * cio_update_schib - Perform stsch and update schib if subchannel is valid.
+ * @sch: subchannel on which to perform stsch
+ * Return zero on success, -ENODEV otherwise.
+ */
+int cio_update_schib(struct subchannel *sch)
+{
+ struct schib schib;
+
+ if (stsch(sch->schid, &schib) || !css_sch_is_valid(&schib))
+ return -ENODEV;
+
+ memcpy(&sch->schib, &schib, sizeof(schib));
+ return 0;
+}
+EXPORT_SYMBOL_GPL(cio_update_schib);
+
+/**
* cio_enable_subchannel - enable a subchannel.
* @sch: subchannel to be enabled
* @intparm: interruption parameter to set
@@ -365,7 +385,6 @@
int cio_enable_subchannel(struct subchannel *sch, u32 intparm)
{
char dbf_txt[15];
- int ccode;
int retry;
int ret;
@@ -374,8 +393,7 @@
if (sch_is_pseudo_sch(sch))
return -EINVAL;
- ccode = stsch (sch->schid, &sch->schib);
- if (ccode)
+ if (cio_update_schib(sch))
return -ENODEV;
for (retry = 5, ret = 0; retry > 0; retry--) {
@@ -392,7 +410,10 @@
*/
sch->schib.pmcw.csense = 0;
if (ret == 0) {
- stsch (sch->schid, &sch->schib);
+ if (cio_update_schib(sch)) {
+ ret = -ENODEV;
+ break;
+ }
if (sch->schib.pmcw.ena)
break;
}
@@ -415,7 +436,6 @@
int cio_disable_subchannel(struct subchannel *sch)
{
char dbf_txt[15];
- int ccode;
int retry;
int ret;
@@ -424,8 +444,7 @@
if (sch_is_pseudo_sch(sch))
return 0;
- ccode = stsch (sch->schid, &sch->schib);
- if (ccode == 3) /* Not operational. */
+ if (cio_update_schib(sch))
return -ENODEV;
if (scsw_actl(&sch->schib.scsw) != 0)
@@ -448,7 +467,10 @@
*/
break;
if (ret == 0) {
- stsch (sch->schid, &sch->schib);
+ if (cio_update_schib(sch)) {
+ ret = -ENODEV;
+ break;
+ }
if (!sch->schib.pmcw.ena)
break;
}
@@ -851,7 +873,8 @@
cc = msch(schid, schib);
if (cc)
return (cc==3?-ENODEV:-EBUSY);
- stsch(schid, schib);
+ if (stsch(schid, schib) || !css_sch_is_valid(schib))
+ return -ENODEV;
if (!schib->pmcw.ena)
return 0;
}
diff --git a/drivers/s390/cio/cio.h b/drivers/s390/cio/cio.h
index 5db887e..fb125ef 100644
--- a/drivers/s390/cio/cio.h
+++ b/drivers/s390/cio/cio.h
@@ -102,6 +102,7 @@
extern int cio_set_options (struct subchannel *, int);
extern int cio_get_options (struct subchannel *);
extern int cio_modify (struct subchannel *);
+extern int cio_update_schib(struct subchannel *sch);
int cio_tm_start_key(struct subchannel *sch, struct tcw *tcw, u8 lpm, u8 key);
int cio_tm_intrg(struct subchannel *sch);
diff --git a/drivers/s390/cio/cmf.c b/drivers/s390/cio/cmf.c
index a90b28c..288482b 100644
--- a/drivers/s390/cio/cmf.c
+++ b/drivers/s390/cio/cmf.c
@@ -195,7 +195,8 @@
/* msch can silently fail, so do it again if necessary */
for (retry = 0; retry < 3; retry++) {
/* prepare schib */
- stsch(sch->schid, schib);
+ if (cio_update_schib(sch))
+ return -ENODEV;
schib->pmcw.mme = mme;
schib->pmcw.mbfc = mbfc;
/* address can be either a block address or a block index */
@@ -219,7 +220,8 @@
ret = -EINVAL;
break;
}
- stsch(sch->schid, schib); /* restore the schib */
+ if (cio_update_schib(sch))
+ return -ENODEV;
if (ret)
break;
@@ -338,7 +340,7 @@
sch = to_subchannel(cdev->dev.parent);
- if (stsch(sch->schid, &sch->schib))
+ if (cio_update_schib(sch))
return -ENODEV;
if (scsw_fctl(&sch->schib.scsw) & SCSW_FCTL_START_FUNC) {
diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index 868aa19..51e9421 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -1350,10 +1350,7 @@
static int check_for_io_on_path(struct subchannel *sch, int mask)
{
- int cc;
-
- cc = stsch(sch->schid, &sch->schib);
- if (cc)
+ if (cio_update_schib(sch))
return 0;
if (scsw_actl(&sch->schib.scsw) && sch->schib.pmcw.lpum == mask)
return 1;
@@ -1422,15 +1419,13 @@
io_subchannel_verify(sch);
break;
case CHP_OFFLINE:
- if (stsch(sch->schid, &sch->schib))
- return -ENXIO;
- if (!css_sch_is_valid(&sch->schib))
+ if (cio_update_schib(sch))
return -ENODEV;
io_subchannel_terminate_path(sch, mask);
break;
case CHP_ONLINE:
- if (stsch(sch->schid, &sch->schib))
- return -ENXIO;
+ if (cio_update_schib(sch))
+ return -ENODEV;
sch->lpm |= mask & sch->opm;
io_subchannel_verify(sch);
break;
diff --git a/drivers/s390/cio/device_fsm.c b/drivers/s390/cio/device_fsm.c
index 01330cf..e1a3786 100644
--- a/drivers/s390/cio/device_fsm.c
+++ b/drivers/s390/cio/device_fsm.c
@@ -140,8 +140,7 @@
int ret;
sch = to_subchannel(cdev->dev.parent);
- ret = stsch(sch->schid, &sch->schib);
- if (ret || !sch->schib.pmcw.dnv)
+ if (cio_update_schib(sch))
return -ENODEV;
if (!sch->schib.pmcw.ena)
/* Not operational -> done. */
@@ -245,11 +244,13 @@
* through ssch() and the path information is up to date.
*/
old_lpm = sch->lpm;
- stsch(sch->schid, &sch->schib);
- sch->lpm = sch->schib.pmcw.pam & sch->opm;
+
/* Check since device may again have become not operational. */
- if (!sch->schib.pmcw.dnv)
+ if (cio_update_schib(sch))
state = DEV_STATE_NOT_OPER;
+ else
+ sch->lpm = sch->schib.pmcw.pam & sch->opm;
+
if (cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID)
/* Force reprobe on all chpids. */
old_lpm = 0;
@@ -549,7 +550,11 @@
sch = to_subchannel(cdev->dev.parent);
/* Update schib - pom may have changed. */
- stsch(sch->schid, &sch->schib);
+ if (cio_update_schib(sch)) {
+ cdev->private->flags.donotify = 0;
+ ccw_device_done(cdev, DEV_STATE_NOT_OPER);
+ return;
+ }
/* Update lpm with verified path mask. */
sch->lpm = sch->vpm;
/* Repeat path verification? */
@@ -667,7 +672,7 @@
return 0;
}
sch = to_subchannel(cdev->dev.parent);
- if (stsch(sch->schid, &sch->schib) || !sch->schib.pmcw.dnv)
+ if (cio_update_schib(sch))
return -ENODEV;
if (scsw_actl(&sch->schib.scsw) != 0)
return -EBUSY;
@@ -745,7 +750,10 @@
* Since we might not just be coming from an interrupt from the
* subchannel we have to update the schib.
*/
- stsch(sch->schid, &sch->schib);
+ if (cio_update_schib(sch)) {
+ ccw_device_verify_done(cdev, -ENODEV);
+ return;
+ }
if (scsw_actl(&sch->schib.scsw) != 0 ||
(scsw_stctl(&sch->schib.scsw) & SCSW_STCTL_STATUS_PEND) ||
@@ -1011,9 +1019,7 @@
sch = to_subchannel(cdev->dev.parent);
/* Update some values. */
- if (stsch(sch->schid, &sch->schib))
- return;
- if (!sch->schib.pmcw.dnv)
+ if (cio_update_schib(sch))
return;
/*
* The pim, pam, pom values may not be accurate, but they are the best
diff --git a/drivers/s390/cio/device_pgid.c b/drivers/s390/cio/device_pgid.c
index 86bc94e..fc5ca1d 100644
--- a/drivers/s390/cio/device_pgid.c
+++ b/drivers/s390/cio/device_pgid.c
@@ -504,7 +504,7 @@
sch->vpm = 0;
/* Get current pam. */
- if (stsch(sch->schid, &sch->schib)) {
+ if (cio_update_schib(sch)) {
ccw_device_verify_done(cdev, -ENODEV);
return;
}
diff --git a/drivers/s390/cio/device_status.c b/drivers/s390/cio/device_status.c
index 1b03c54..5814dbe 100644
--- a/drivers/s390/cio/device_status.c
+++ b/drivers/s390/cio/device_status.c
@@ -56,7 +56,8 @@
struct subchannel *sch;
sch = to_subchannel(cdev->dev.parent);
- stsch (sch->schid, &sch->schib);
+ if (cio_update_schib(sch))
+ goto doverify;
CIO_MSG_EVENT(0, "%s(0.%x.%04x) - path(s) %02x are "
"not operational \n", __func__,
@@ -64,6 +65,7 @@
sch->schib.pmcw.pnom);
sch->lpm &= ~sch->schib.pmcw.pnom;
+doverify:
cdev->private->flags.doverify = 1;
}