s390/cio: ensure consistent measurement state

Make sure that in all cases where we could not obtain measurement
characteristics the associated fields are set to invalid values.

Note: without this change the "shared" capability of a channel path
for which we could not obtain the measurement characteristics was
incorrectly displayed as 0 (not shared). We will now correctly
report "unknown" in this case.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/drivers/s390/cio/chp.c b/drivers/s390/cio/chp.c
index 3d2b6c4..8504629 100644 (file)
--- a/drivers/s390/cio/chp.c
+++ b/drivers/s390/cio/chp.c
@@ -466,14 +466,11 @@ int chp_new(struct chp_id chpid)
                ret = -ENODEV;
                goto out_free;
        }
-       /* Get channel-measurement characteristics. */
-       if (css_chsc_characteristics.scmc && css_chsc_characteristics.secm) {
-               ret = chsc_get_channel_measurement_chars(chp);
-               if (ret)
-                       goto out_free;
-       } else {
-               chp->cmg = -1;
-       }
+
+       ret = chsc_get_channel_measurement_chars(chp);
+       if (ret)
+               goto out_free;
+
        dev_set_name(&chp->dev, "chp%x.%02x", chpid.cssid, chpid.id);
 
        /* make it known to the system */

diff --git a/drivers/s390/cio/chsc.c b/drivers/s390/cio/chsc.c
index 5df0efe..13747c5 100644 (file)
--- a/drivers/s390/cio/chsc.c
+++ b/drivers/s390/cio/chsc.c
@@ -1003,6 +1003,12 @@ int chsc_get_channel_measurement_chars(struct channel_path *chp)
                u32 data[NR_MEASUREMENT_CHARS];
        } __attribute__ ((packed)) *scmc_area;
 
+       chp->shared = -1;
+       chp->cmg = -1;
+
+       if (!css_chsc_characteristics.scmc || !css_chsc_characteristics.secm)
+               return 0;
+
        spin_lock_irq(&chsc_page_lock);
        memset(chsc_page, 0, PAGE_SIZE);
        scmc_area = chsc_page;
@@ -1023,11 +1029,9 @@ int chsc_get_channel_measurement_chars(struct channel_path *chp)
                              scmc_area->response.code);
                goto out;
        }
-       if (scmc_area->not_valid) {
-               chp->cmg = -1;
-               chp->shared = -1;
+       if (scmc_area->not_valid)
                goto out;
-       }
+
        chp->cmg = scmc_area->cmg;
        chp->shared = scmc_area->shared;
        if (chp->cmg != 2 && chp->cmg != 3) {