[S390] cio: introduce cio_commit_config
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>
diff --git a/drivers/s390/cio/cmf.c b/drivers/s390/cio/cmf.c
index 288482b..6ddd023 100644
--- a/drivers/s390/cio/cmf.c
+++ b/drivers/s390/cio/cmf.c
@@ -185,58 +185,19 @@
static int set_schib(struct ccw_device *cdev, u32 mme, int mbfc,
unsigned long address)
{
- int ret;
- int retry;
struct subchannel *sch;
- struct schib *schib;
sch = to_subchannel(cdev->dev.parent);
- schib = &sch->schib;
- /* msch can silently fail, so do it again if necessary */
- for (retry = 0; retry < 3; retry++) {
- /* prepare 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 */
- if (mbfc)
- schib->mba = address;
- else
- schib->pmcw.mbi = address;
- /* try to submit it */
- switch(ret = msch_err(sch->schid, schib)) {
- case 0:
- break;
- case 1:
- case 2: /* in I/O or status pending */
- ret = -EBUSY;
- break;
- case 3: /* subchannel is no longer valid */
- ret = -ENODEV;
- break;
- default: /* msch caught an exception */
- ret = -EINVAL;
- break;
- }
- if (cio_update_schib(sch))
- return -ENODEV;
+ sch->config.mme = mme;
+ sch->config.mbfc = mbfc;
+ /* address can be either a block address or a block index */
+ if (mbfc)
+ sch->config.mba = address;
+ else
+ sch->config.mbi = address;
- if (ret)
- break;
-
- /* check if it worked */
- if (schib->pmcw.mme == mme &&
- schib->pmcw.mbfc == mbfc &&
- (mbfc ? (schib->mba == address)
- : (schib->pmcw.mbi == address)))
- return 0;
-
- ret = -EINVAL;
- }
-
- return ret;
+ return cio_commit_config(sch);
}
struct set_schib_struct {