[S390] cio: I/O subchannel specific fields.

Some fields may be !0 only for I/O subchannels. Add some checks
where required. Also adapt cio_enable_subchannel() to make the
caller specify the intparm, which makes it more generic.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 16 insertions, 2 deletions

diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c
index 2520a44fb93d..4d98a0fddedf 100644
--- a/drivers/s390/cio/css.c
+++ b/drivers/s390/cio/css.c
@@ -237,11 +237,25 @@ get_subchannel_by_schid(struct subchannel_id schid)
         return dev ? to_subchannel(dev) : NULL;
 }
 
+/**
+ * css_sch_is_valid() - check if a subchannel is valid
+ * @schib: subchannel information block for the subchannel
+ */
+int css_sch_is_valid(struct schib *schib)
+{
+        if ((schib->pmcw.st == SUBCHANNEL_TYPE_IO) && !schib->pmcw.dnv)
+                return 0;
+        return 1;
+}
+EXPORT_SYMBOL_GPL(css_sch_is_valid);
+
 static int css_get_subchannel_status(struct subchannel *sch)
 {
         struct schib schib;
 
-        if (stsch(sch->schid, &schib) || !schib.pmcw.dnv)
+        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;
@@ -349,7 +363,7 @@ static int css_evaluate_new_subchannel(struct subchannel_id schid, int slow)
                 /* Will be done on the slow path. */
                 return -EAGAIN;
         }
-        if (stsch_err(schid, &schib) || !schib.pmcw.dnv) {
+        if (stsch_err(schid, &schib) || !css_sch_is_valid(&schib)) {
                 /* Unusable - ignore. */
                 return 0;
         }