3 files changed, 27 insertions, 7 deletions

diff --git a/drivers/s390/cio/cio.c b/drivers/s390/cio/cio.c
index be53f0ee2b1c..0511fe31d049 100644
--- a/drivers/s390/cio/cio.c
+++ b/drivers/s390/cio/cio.c
@@ -498,13 +498,8 @@ int cio_create_sch_lock(struct subchannel *sch)
         return 0;
 }
 
-static int cio_validate_io_subchannel(struct subchannel *sch)
+static int cio_check_devno_blacklisted(struct subchannel *sch)
 {
-        /* Initialization for io subchannels. */
-        if (!css_sch_is_valid(&sch->schib))
-                return -ENODEV;
-
-        /* Devno is valid. */
         if (is_blacklisted(sch->schid.ssid, sch->schib.pmcw.dev)) {
                 /*
                  * This device must not be known to Linux. So we simply
@@ -518,6 +513,26 @@ static int cio_validate_io_subchannel(struct subchannel *sch)
         return 0;
 }
 
+static int cio_validate_io_subchannel(struct subchannel *sch)
+{
+        /* Initialization for io subchannels. */
+        if (!css_sch_is_valid(&sch->schib))
+                return -ENODEV;
+
+        /* Devno is valid. */
+        return cio_check_devno_blacklisted(sch);
+}
+
+static int cio_validate_msg_subchannel(struct subchannel *sch)
+{
+        /* Initialization for message subchannels. */
+        if (!css_sch_is_valid(&sch->schib))
+                return -ENODEV;
+
+        /* Devno is valid. */
+        return cio_check_devno_blacklisted(sch);
+}
+
 /**
  * cio_validate_subchannel - basic validation of subchannel
  * @sch: subchannel structure to be filled out
@@ -573,6 +588,9 @@ int cio_validate_subchannel(struct subchannel *sch, struct subchannel_id schid)
         case SUBCHANNEL_TYPE_IO:
                 err = cio_validate_io_subchannel(sch);
                 break;
+        case SUBCHANNEL_TYPE_MSG:
+                err = cio_validate_msg_subchannel(sch);
+                break;
         default:
                 err = 0;
         }
diff --git a/drivers/s390/cio/cio.h b/drivers/s390/cio/cio.h
index 4062748e8346..efdb9fd4a84a 100644
--- a/drivers/s390/cio/cio.h
+++ b/drivers/s390/cio/cio.h
@@ -14,7 +14,7 @@
 struct pmcw {
         u32 intparm;            /* interruption parameter */
         u32 qf   : 1;           /* qdio facility */
-        u32 res0 : 1;           /* reserved zeros */
+        u32 w    : 1;
         u32 isc  : 3;           /* interruption sublass */
         u32 res5 : 3;           /* reserved zeros */
         u32 ena  : 1;           /* enabled */
diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c
index bc3a8e4a49f7..062716cf0f0c 100644
--- a/drivers/s390/cio/css.c
+++ b/drivers/s390/cio/css.c
@@ -332,6 +332,8 @@ int css_sch_is_valid(struct schib *schib)
 {
         if ((schib->pmcw.st == SUBCHANNEL_TYPE_IO) && !schib->pmcw.dnv)
                 return 0;
+        if ((schib->pmcw.st == SUBCHANNEL_TYPE_MSG) && !schib->pmcw.w)
+                return 0;
         return 1;
 }
 EXPORT_SYMBOL_GPL(css_sch_is_valid);