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[S390] cio: introduce cio_commit_config

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To change the configuration of a subchannel we alter the modifiable
bits of the subchannel's schib field and issue a modify subchannel.
There can be the case that not all changes were applied -or worse-
quietly overwritten by the hardware. With the next store subchannel
we obtain the current state of the hardware but lose our target
configuration.

With this patch we introduce a subchannel_config structure which
contains the target subchannel configuration. Additionally the msch
wrapper cio_modify is replaced with cio_commit_config which
copies the desired changes to a temporary schib. msch is then
called with the temporary schib. This schib is only written back
to the subchannel if all changes were applied.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Sebastian Ott
2008-12-25 13:39:13 +01:00
committed by Martin Schwidefsky
parent cdb912a40d
commit 13952ec12d
7 changed files with 126 additions and 137 deletions
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140
drivers/s390/cio/cio.c
View File

@@ -330,30 +330,70 @@ cio_cancel (struct subchannel *sch)
}
}
/*
* Function: cio_modify
* Issues a "Modify Subchannel" on the specified subchannel
*/
int
cio_modify (struct subchannel *sch)
{
int ccode, retry, ret;
ret = 0;
static void cio_apply_config(struct subchannel *sch, struct schib *schib)
{
schib->pmcw.intparm = sch->config.intparm;
schib->pmcw.mbi = sch->config.mbi;
schib->pmcw.isc = sch->config.isc;
schib->pmcw.ena = sch->config.ena;
schib->pmcw.mme = sch->config.mme;
schib->pmcw.mp = sch->config.mp;
schib->pmcw.csense = sch->config.csense;
schib->pmcw.mbfc = sch->config.mbfc;
if (sch->config.mbfc)
schib->mba = sch->config.mba;
}
static int cio_check_config(struct subchannel *sch, struct schib *schib)
{
return (schib->pmcw.intparm == sch->config.intparm) &&
(schib->pmcw.mbi == sch->config.mbi) &&
(schib->pmcw.isc == sch->config.isc) &&
(schib->pmcw.ena == sch->config.ena) &&
(schib->pmcw.mme == sch->config.mme) &&
(schib->pmcw.mp == sch->config.mp) &&
(schib->pmcw.csense == sch->config.csense) &&
(schib->pmcw.mbfc == sch->config.mbfc) &&
(!sch->config.mbfc || (schib->mba == sch->config.mba));
}
/*
* cio_commit_config - apply configuration to the subchannel
*/
int cio_commit_config(struct subchannel *sch)
{
struct schib schib;
int ccode, retry, ret = 0;
if (stsch(sch->schid, &schib) || !css_sch_is_valid(&schib))
return -ENODEV;
for (retry = 0; retry < 5; retry++) {
ccode = msch_err (sch->schid, &sch->schib);
if (ccode < 0) /* -EIO if msch gets a program check. */
/* copy desired changes to local schib */
cio_apply_config(sch, &schib);
ccode = msch_err(sch->schid, &schib);
if (ccode < 0) /* -EIO if msch gets a program check. */
return ccode;
switch (ccode) {
case 0: /* successfull */
return 0;
case 1: /* status pending */
if (stsch(sch->schid, &schib) ||
!css_sch_is_valid(&schib))
return -ENODEV;
if (cio_check_config(sch, &schib)) {
/* commit changes from local schib */
memcpy(&sch->schib, &schib, sizeof(schib));
return 0;
}
ret = -EAGAIN;
break;
case 1: /* status pending */
return -EBUSY;
case 2: /* busy */
udelay (100); /* allow for recovery */
case 2: /* busy */
udelay(100); /* allow for recovery */
ret = -EBUSY;
break;
case 3: /* not operational */
case 3: /* not operational */
return -ENODEV;
}
}
@@ -396,32 +436,24 @@ int cio_enable_subchannel(struct subchannel *sch, u32 intparm)
if (cio_update_schib(sch))
return -ENODEV;
for (retry = 5, ret = 0; retry > 0; retry--) {
sch->schib.pmcw.ena = 1;
sch->schib.pmcw.isc = sch->isc;
sch->schib.pmcw.intparm = intparm;
ret = cio_modify(sch);
if (ret == -ENODEV)
break;
if (ret == -EIO)
sch->config.ena = 1;
sch->config.isc = sch->isc;
sch->config.intparm = intparm;
for (retry = 0; retry < 3; retry++) {
ret = cio_commit_config(sch);
if (ret == -EIO) {
/*
* Got a program check in cio_modify. Try without
* Got a program check in msch. Try without
* the concurrent sense bit the next time.
*/
sch->schib.pmcw.csense = 0;
if (ret == 0) {
if (cio_update_schib(sch)) {
ret = -ENODEV;
break;
}
if (sch->schib.pmcw.ena)
break;
}
if (ret == -EBUSY) {
sch->config.csense = 0;
} else if (ret == -EBUSY) {
struct irb irb;
if (tsch(sch->schid, &irb) != 0)
break;
}
} else
break;
}
sprintf (dbf_txt, "ret:%d", ret);
CIO_TRACE_EVENT (2, dbf_txt);
@@ -436,7 +468,6 @@ EXPORT_SYMBOL_GPL(cio_enable_subchannel);
int cio_disable_subchannel(struct subchannel *sch)
{
char dbf_txt[15];
int retry;
int ret;
CIO_TRACE_EVENT (2, "dissch");
@@ -454,27 +485,9 @@ int cio_disable_subchannel(struct subchannel *sch)
*/
return -EBUSY;
for (retry = 5, ret = 0; retry > 0; retry--) {
sch->schib.pmcw.ena = 0;
ret = cio_modify(sch);
if (ret == -ENODEV)
break;
if (ret == -EBUSY)
/*
* The subchannel is busy or status pending.
* We'll disable when the next interrupt was delivered
* via the state machine.
*/
break;
if (ret == 0) {
if (cio_update_schib(sch)) {
ret = -ENODEV;
break;
}
if (!sch->schib.pmcw.ena)
break;
}
}
sch->config.ena = 0;
ret = cio_commit_config(sch);
sprintf (dbf_txt, "ret:%d", ret);
CIO_TRACE_EVENT (2, dbf_txt);
return ret;
@@ -817,10 +830,9 @@ cio_probe_console(void)
* enable console I/O-interrupt subclass
*/
isc_register(CONSOLE_ISC);
console_subchannel.schib.pmcw.isc = CONSOLE_ISC;
console_subchannel.schib.pmcw.intparm =
(u32)(addr_t)&console_subchannel;
ret = cio_modify(&console_subchannel);
console_subchannel.config.isc = CONSOLE_ISC;
console_subchannel.config.intparm = (u32)(addr_t)&console_subchannel;
ret = cio_commit_config(&console_subchannel);
if (ret) {
isc_unregister(CONSOLE_ISC);
console_subchannel_in_use = 0;
@@ -832,8 +844,8 @@ cio_probe_console(void)
void
cio_release_console(void)
{
console_subchannel.schib.pmcw.intparm = 0;
cio_modify(&console_subchannel);
console_subchannel.config.intparm = 0;
cio_commit_config(&console_subchannel);
isc_unregister(CONSOLE_ISC);
console_subchannel_in_use = 0;
}