s390/cio: make use of newly added format 1 channel-path data

Make use of the stored copy of format 1 channel-path data instead
of querying the information every time the corresponding function
is called.

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

1 files changed, 14 insertions, 8 deletions

diff --git a/drivers/s390/cio/device_ops.c b/drivers/s390/cio/device_ops.c
index c77b6e06bf64..4845d64f2842 100644
--- a/drivers/s390/cio/device_ops.c
+++ b/drivers/s390/cio/device_ops.c
@@ -704,9 +704,9 @@ EXPORT_SYMBOL(ccw_device_tm_start_timeout);
 int ccw_device_get_mdc(struct ccw_device *cdev, u8 mask)
 {
         struct subchannel *sch = to_subchannel(cdev->dev.parent);
-        struct channel_path_desc_fmt1 desc;
+        struct channel_path *chp;
         struct chp_id chpid;
-        int mdc = 0, ret, i;
+        int mdc = 0, i;
 
         /* Adjust requested path mask to excluded varied off paths. */
         if (mask)
@@ -719,14 +719,20 @@ int ccw_device_get_mdc(struct ccw_device *cdev, u8 mask)
                 if (!(mask & (0x80 >> i)))
                         continue;
                 chpid.id = sch->schib.pmcw.chpid[i];
-                ret = chsc_determine_fmt1_channel_path_desc(chpid, &desc);
-                if (ret)
-                        return ret;
-                if (!desc.f)
+                chp = chpid_to_chp(chpid);
+                if (!chp)
+                        continue;
+
+                mutex_lock(&chp->lock);
+                if (!chp->desc_fmt1.f) {
+                        mutex_unlock(&chp->lock);
                         return 0;
-                if (!desc.r)
+                }
+                if (!chp->desc_fmt1.r)
                         mdc = 1;
-                mdc = mdc ? min(mdc, (int)desc.mdc) : desc.mdc;
+                mdc = mdc ? min_t(int, mdc, chp->desc_fmt1.mdc) :
+                            chp->desc_fmt1.mdc;
+                mutex_unlock(&chp->lock);
         }
 
         return mdc;