Commit cdb912a4 authored by Sebastian Ott's avatar Sebastian Ott Committed by Martin Schwidefsky
Browse files

[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: default avatarSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent d6a30761
......@@ -61,7 +61,7 @@ static void chsc_subchannel_irq(struct subchannel *sch)
}
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);
}
......
......@@ -114,11 +114,13 @@ cio_start_handle_notoper(struct subchannel *sch, __u8 lpm)
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 @@ cio_cancel (struct subchannel *sch)
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;
......@@ -357,6 +360,23 @@ cio_modify (struct subchannel *sch)
return ret;
}
/**
* 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
......@@ -365,7 +385,6 @@ cio_modify (struct subchannel *sch)
int cio_enable_subchannel(struct subchannel *sch, u32 intparm)
{
char dbf_txt[15];
int ccode;
int retry;
int ret;
......@@ -374,8 +393,7 @@ int cio_enable_subchannel(struct subchannel *sch, u32 intparm)
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 @@ int cio_enable_subchannel(struct subchannel *sch, u32 intparm)
*/
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 @@ EXPORT_SYMBOL_GPL(cio_enable_subchannel);
int cio_disable_subchannel(struct subchannel *sch)
{
char dbf_txt[15];
int ccode;
int retry;
int ret;
......@@ -424,8 +444,7 @@ int cio_disable_subchannel(struct subchannel *sch)
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 @@ int cio_disable_subchannel(struct subchannel *sch)
*/
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 @@ __disable_subchannel_easy(struct subchannel_id schid, struct schib *schib)
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;
}
......
......@@ -102,6 +102,7 @@ extern int cio_cancel (struct subchannel *);
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);
......
......@@ -195,7 +195,8 @@ static int set_schib(struct ccw_device *cdev, u32 mme, int mbfc,
/* 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 @@ static int set_schib(struct ccw_device *cdev, u32 mme, int mbfc,
ret = -EINVAL;
break;
}
stsch(sch->schid, schib); /* restore the schib */
if (cio_update_schib(sch))
return -ENODEV;
if (ret)
break;
......@@ -338,7 +340,7 @@ static int cmf_copy_block(struct ccw_device *cdev)
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) {
......
......@@ -1350,10 +1350,7 @@ static void io_subchannel_verify(struct subchannel *sch)
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 @@ static int io_subchannel_chp_event(struct subchannel *sch,
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;
......
......@@ -140,8 +140,7 @@ ccw_device_cancel_halt_clear(struct ccw_device *cdev)
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 @@ ccw_device_recog_done(struct ccw_device *cdev, int state)
* 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 @@ ccw_device_verify_done(struct ccw_device *cdev, int err)
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 @@ ccw_device_offline(struct ccw_device *cdev)
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 @@ ccw_device_online_verify(struct ccw_device *cdev, enum dev_event dev_event)
* 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 @@ void ccw_device_trigger_reprobe(struct ccw_device *cdev)
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
......
......@@ -504,7 +504,7 @@ ccw_device_verify_start(struct ccw_device *cdev)
sch->vpm = 0;
/* Get current pam. */
if (stsch(sch->schid, &sch->schib)) {
if (cio_update_schib(sch)) {
ccw_device_verify_done(cdev, -ENODEV);
return;
}
......
......@@ -56,7 +56,8 @@ ccw_device_path_notoper(struct ccw_device *cdev)
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 @@ ccw_device_path_notoper(struct ccw_device *cdev)
sch->schib.pmcw.pnom);
sch->lpm &= ~sch->schib.pmcw.pnom;
doverify:
cdev->private->flags.doverify = 1;
}
......
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