[S390] pm: chsc subchannel driver power management callbacks

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 31 insertions, 1 deletions

diff --git a/drivers/s390/cio/chsc_sch.c b/drivers/s390/cio/chsc_sch.c
index 93eca1731b81..cc5144b6f9d9 100644
--- a/drivers/s390/cio/chsc_sch.c
+++ b/drivers/s390/cio/chsc_sch.c
@@ -1,7 +1,8 @@
 /*
  * Driver for s390 chsc subchannels
  *
- * Copyright IBM Corp. 2008
+ * Copyright IBM Corp. 2008, 2009
+ *
  * Author(s): Cornelia Huck <cornelia.huck@de.ibm.com>
  *
  */
@@ -112,6 +113,31 @@ static void chsc_subchannel_shutdown(struct subchannel *sch)
         cio_disable_subchannel(sch);
 }
 
+static int chsc_subchannel_prepare(struct subchannel *sch)
+{
+        int cc;
+        struct schib schib;
+        /*
+         * Don't allow suspend while the subchannel is not idle
+         * since we don't have a way to clear the subchannel and
+         * cannot disable it with a request running.
+         */
+        cc = stsch(sch->schid, &schib);
+        if (!cc && scsw_stctl(&schib.scsw))
+                return -EAGAIN;
+        return 0;
+}
+
+static int chsc_subchannel_freeze(struct subchannel *sch)
+{
+        return cio_disable_subchannel(sch);
+}
+
+static int chsc_subchannel_restore(struct subchannel *sch)
+{
+        return cio_enable_subchannel(sch, (u32)(unsigned long)sch);
+}
+
 static struct css_device_id chsc_subchannel_ids[] = {
         { .match_flags = 0x1, .type =SUBCHANNEL_TYPE_CHSC, },
         { /* end of list */ },
@@ -125,6 +151,10 @@ static struct css_driver chsc_subchannel_driver = {
         .probe = chsc_subchannel_probe,
         .remove = chsc_subchannel_remove,
         .shutdown = chsc_subchannel_shutdown,
+        .prepare = chsc_subchannel_prepare,
+        .freeze = chsc_subchannel_freeze,
+        .thaw = chsc_subchannel_restore,
+        .restore = chsc_subchannel_restore,
         .name = "chsc_subchannel",
 };