ses: add reliable slot attribute

The name provided by firmware is in a vendor specific format, publish
the slot number to have a reliable mechanism for identifying slots
across firmware implementations.  If the enclosure does not provide a
slot number fallback to the component number which is guaranteed unique,
and usually mirrors the slot number.

Cleaned up the unused ses_component.desc in the process.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Reviewed-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

1 files changed, 12 insertions, 5 deletions

diff --git a/drivers/scsi/ses.c b/drivers/scsi/ses.c
index 1041556cdbf3..433de8e6f538 100644
--- a/drivers/scsi/ses.c
+++ b/drivers/scsi/ses.c
@@ -47,7 +47,6 @@ struct ses_device {
 
 struct ses_component {
         u64 addr;
-        unsigned char *desc;
 };
 
 static int ses_probe(struct device *dev)
@@ -307,19 +306,26 @@ static void ses_process_descriptor(struct enclosure_component *ecomp,
         int invalid = desc[0] & 0x80;
         enum scsi_protocol proto = desc[0] & 0x0f;
         u64 addr = 0;
+        int slot = -1;
         struct ses_component *scomp = ecomp->scratch;
         unsigned char *d;
 
-        scomp->desc = desc;
-
         if (invalid)
                 return;
 
         switch (proto) {
+        case SCSI_PROTOCOL_FCP:
+                if (eip) {
+                        d = desc + 4;
+                        slot = d[3];
+                }
+                break;
         case SCSI_PROTOCOL_SAS:
-                if (eip)
+                if (eip) {
+                        d = desc + 4;
+                        slot = d[3];
                         d = desc + 8;
-                else
+                } else
                         d = desc + 4;
                 /* only take the phy0 addr */
                 addr = (u64)d[12] << 56 |
@@ -335,6 +341,7 @@ static void ses_process_descriptor(struct enclosure_component *ecomp,
                 /* FIXME: Need to add more protocols than just SAS */
                 break;
         }
+        ecomp->slot = slot;
         scomp->addr = addr;
 }