firewire: sbp2: Take into account Unit_Unique_ID

If the target's unit directory contains a Unit_Unique_ID entry, we
should use that as the target's GUID for identification purposes. The
SBP-2 standards document says:

"Although the node unique ID (EUI-64) present in the bus information
block is sufficient to uniquely identify nodes attached to Serial Bus,
it is insufficient to identify a target when a vendor implements a
device with multiple Serial Bus node connections. In this case initiator
software requires information by which a particular target may be
uniquely identified, regardless of the Serial Bus access path used."

[ IEEE T10 P1155D Revision 4, Section 7.6 (page 51) ] and
[ IEEE T10 P1467D Revision 5, Section 7.9 (page 74) ]

Signed-off-by: Chris Boot <bootc@bootc.net>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

diff --git a/drivers/firewire/sbp2.c b/drivers/firewire/sbp2.c
index 481e1c8..4865d64 100644 (file)
--- a/drivers/firewire/sbp2.c
+++ b/drivers/firewire/sbp2.c
@@ -218,6 +218,7 @@ static const struct device *lu_dev(const struct sbp2_logical_unit *lu)
 #define SBP2_CSR_UNIT_CHARACTERISTICS  0x3a
 #define SBP2_CSR_FIRMWARE_REVISION     0x3c
 #define SBP2_CSR_LOGICAL_UNIT_NUMBER   0x14
+#define SBP2_CSR_UNIT_UNIQUE_ID                0x8d
 #define SBP2_CSR_LOGICAL_UNIT_DIRECTORY        0xd4
 
 /* Management orb opcodes */
@@ -1005,6 +1006,13 @@ static int sbp2_add_logical_unit(struct sbp2_target *tgt, int lun_entry)
        return 0;
 }
 
+static void sbp2_get_unit_unique_id(struct sbp2_target *tgt,
+                                   const u32 *leaf)
+{
+       if ((leaf[0] & 0xffff0000) == 0x00020000)
+               tgt->guid = (u64)leaf[1] << 32 | leaf[2];
+}
+
 static int sbp2_scan_logical_unit_dir(struct sbp2_target *tgt,
                                      const u32 *directory)
 {
@@ -1056,6 +1064,10 @@ static int sbp2_scan_unit_dir(struct sbp2_target *tgt, const u32 *directory,
                                return -ENOMEM;
                        break;
 
+               case SBP2_CSR_UNIT_UNIQUE_ID:
+                       sbp2_get_unit_unique_id(tgt, ci.p - 1 + value);
+                       break;
+
                case SBP2_CSR_LOGICAL_UNIT_DIRECTORY:
                        /* Adjust for the increment in the iterator */
                        if (sbp2_scan_logical_unit_dir(tgt, ci.p - 1 + value) < 0)