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 1041556..433de8e 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;
 }