[S390] cio: Rework css driver.
Rework the css driver methods to provide sane callbacks for
subchannels of all types.
As a bonus, this cleans up and simplyfies the machine check
handling for I/O subchannels a lot.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c
index 53e7496..0205665 100644
--- a/drivers/s390/cio/css.c
+++ b/drivers/s390/cio/css.c
@@ -283,7 +283,7 @@
return ret;
}
-static int css_probe_device(struct subchannel_id schid)
+int css_probe_device(struct subchannel_id schid)
{
int ret;
struct subchannel *sch;
@@ -330,112 +330,6 @@
}
EXPORT_SYMBOL_GPL(css_sch_is_valid);
-static int css_get_subchannel_status(struct subchannel *sch)
-{
- struct schib schib;
-
- if (stsch(sch->schid, &schib))
- return CIO_GONE;
- if (!css_sch_is_valid(&schib))
- return CIO_GONE;
- if (sch->schib.pmcw.dnv && (schib.pmcw.dev != sch->schib.pmcw.dev))
- return CIO_REVALIDATE;
- if (!sch->lpm)
- return CIO_NO_PATH;
- return CIO_OPER;
-}
-
-static int css_evaluate_known_subchannel(struct subchannel *sch, int slow)
-{
- int event, ret, disc;
- unsigned long flags;
- enum { NONE, UNREGISTER, UNREGISTER_PROBE, REPROBE } action;
-
- spin_lock_irqsave(sch->lock, flags);
- disc = device_is_disconnected(sch);
- if (disc && slow) {
- /* Disconnected devices are evaluated directly only.*/
- spin_unlock_irqrestore(sch->lock, flags);
- return 0;
- }
- /* No interrupt after machine check - kill pending timers. */
- device_kill_pending_timer(sch);
- if (!disc && !slow) {
- /* Non-disconnected devices are evaluated on the slow path. */
- spin_unlock_irqrestore(sch->lock, flags);
- return -EAGAIN;
- }
- event = css_get_subchannel_status(sch);
- CIO_MSG_EVENT(4, "Evaluating schid 0.%x.%04x, event %d, %s, %s path.\n",
- sch->schid.ssid, sch->schid.sch_no, event,
- disc ? "disconnected" : "normal",
- slow ? "slow" : "fast");
- /* Analyze subchannel status. */
- action = NONE;
- switch (event) {
- case CIO_NO_PATH:
- if (disc) {
- /* Check if paths have become available. */
- action = REPROBE;
- break;
- }
- /* fall through */
- case CIO_GONE:
- /* Prevent unwanted effects when opening lock. */
- cio_disable_subchannel(sch);
- device_set_disconnected(sch);
- /* Ask driver what to do with device. */
- action = UNREGISTER;
- if (sch->driver && sch->driver->notify) {
- spin_unlock_irqrestore(sch->lock, flags);
- ret = sch->driver->notify(sch, event);
- spin_lock_irqsave(sch->lock, flags);
- if (ret)
- action = NONE;
- }
- break;
- case CIO_REVALIDATE:
- /* Device will be removed, so no notify necessary. */
- if (disc)
- /* Reprobe because immediate unregister might block. */
- action = REPROBE;
- else
- action = UNREGISTER_PROBE;
- break;
- case CIO_OPER:
- if (disc)
- /* Get device operational again. */
- action = REPROBE;
- break;
- }
- /* Perform action. */
- ret = 0;
- switch (action) {
- case UNREGISTER:
- case UNREGISTER_PROBE:
- /* Unregister device (will use subchannel lock). */
- spin_unlock_irqrestore(sch->lock, flags);
- css_sch_device_unregister(sch);
- spin_lock_irqsave(sch->lock, flags);
-
- /* Reset intparm to zeroes. */
- sch->schib.pmcw.intparm = 0;
- cio_modify(sch);
- break;
- case REPROBE:
- device_trigger_reprobe(sch);
- break;
- default:
- break;
- }
- spin_unlock_irqrestore(sch->lock, flags);
- /* Probe if necessary. */
- if (action == UNREGISTER_PROBE)
- ret = css_probe_device(sch->schid);
-
- return ret;
-}
-
static int css_evaluate_new_subchannel(struct subchannel_id schid, int slow)
{
struct schib schib;
@@ -454,6 +348,21 @@
return css_probe_device(schid);
}
+static int css_evaluate_known_subchannel(struct subchannel *sch, int slow)
+{
+ int ret = 0;
+
+ if (sch->driver) {
+ if (sch->driver->sch_event)
+ ret = sch->driver->sch_event(sch, slow);
+ else
+ dev_dbg(&sch->dev,
+ "Got subchannel machine check but "
+ "no sch_event handler provided.\n");
+ }
+ return ret;
+}
+
static void css_evaluate_subchannel(struct subchannel_id schid, int slow)
{
struct subchannel *sch;