[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/device.c b/drivers/s390/cio/device.c
index 51e9421..d312701 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -1020,8 +1020,8 @@
sch = to_subchannel(cdev->dev.parent);
css_sch_device_unregister(sch);
/* Reset intparm to zeroes. */
- sch->schib.pmcw.intparm = 0;
- cio_modify(sch);
+ sch->config.intparm = 0;
+ cio_commit_config(sch);
/* Release cdev reference for workqueue processing.*/
put_device(&cdev->dev);
/* Release subchannel reference for local processing. */
@@ -1148,8 +1148,8 @@
spin_unlock_irq(former_parent->lock);
css_sch_device_unregister(former_parent);
/* Reset intparm to zeroes. */
- former_parent->schib.pmcw.intparm = 0;
- cio_modify(former_parent);
+ former_parent->config.intparm = 0;
+ cio_commit_config(former_parent);
}
sch_attach_device(sch, cdev);
out:
@@ -1170,6 +1170,14 @@
dev_fsm_event(cdev, DEV_EVENT_INTERRUPT);
}
+void io_subchannel_init_config(struct subchannel *sch)
+{
+ memset(&sch->config, 0, sizeof(sch->config));
+ sch->config.csense = 1;
+ if ((sch->lpm & (sch->lpm - 1)) != 0)
+ sch->config.mp = 1;
+}
+
static void io_subchannel_init_fields(struct subchannel *sch)
{
if (cio_is_console(sch->schid))
@@ -1184,16 +1192,8 @@
sch->schib.pmcw.dev, sch->schid.ssid,
sch->schid.sch_no, sch->schib.pmcw.pim,
sch->schib.pmcw.pam, sch->schib.pmcw.pom);
- /* Initially set up some fields in the pmcw. */
- sch->schib.pmcw.ena = 0;
- sch->schib.pmcw.csense = 1; /* concurrent sense */
- if ((sch->lpm & (sch->lpm - 1)) != 0)
- sch->schib.pmcw.mp = 1; /* multipath mode */
- /* clean up possible residual cmf stuff */
- sch->schib.pmcw.mme = 0;
- sch->schib.pmcw.mbfc = 0;
- sch->schib.pmcw.mbi = 0;
- sch->schib.mba = 0;
+
+ io_subchannel_init_config(sch);
}
static void io_subchannel_do_unreg(struct work_struct *work)
@@ -1203,8 +1203,8 @@
sch = container_of(work, struct subchannel, work);
css_sch_device_unregister(sch);
/* Reset intparm to zeroes. */
- sch->schib.pmcw.intparm = 0;
- cio_modify(sch);
+ sch->config.intparm = 0;
+ cio_commit_config(sch);
put_device(&sch->dev);
}
@@ -1680,8 +1680,8 @@
spin_lock_irqsave(sch->lock, flags);
/* Reset intparm to zeroes. */
- sch->schib.pmcw.intparm = 0;
- cio_modify(sch);
+ sch->config.intparm = 0;
+ cio_commit_config(sch);
break;
case REPROBE:
ccw_device_trigger_reprobe(cdev);