firewire: sbp2: omit Scsi_Host lock from queuecommand

firewire-sbp2 already takes care for internal serialization where
required (ORB list accesses), and it does not use cmd->serial_number
internally.  Hence it is safe to not grab the shost lock around
queuecommand.

While we are at housekeeping, drop a redundant struct member:
sbp2_command_orb.done is set once in a hot path and dereferenced once in
a hot path.  We can as well dereference sbp2_command_orb.cmd->scsi_done
instead.

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

1 files changed, 6 insertions, 14 deletions

diff --git a/drivers/firewire/sbp2.c b/drivers/firewire/sbp2.c
index 77ed589b360d..cc002e92275a 100644
--- a/drivers/firewire/sbp2.c
+++ b/drivers/firewire/sbp2.c
@@ -125,9 +125,6 @@ MODULE_PARM_DESC(workarounds, "Work around device bugs (default = 0"
         ", override internal blacklist = " __stringify(SBP2_WORKAROUND_OVERRIDE)
         ", or a combination)");
 
-/* I don't know why the SCSI stack doesn't define something like this... */
-typedef void (*scsi_done_fn_t)(struct scsi_cmnd *);
-
 static const char sbp2_driver_name[] = "sbp2";
 
 /*
@@ -314,7 +311,6 @@ struct sbp2_command_orb {
                 u8 command_block[SBP2_MAX_CDB_SIZE];
         } request;
         struct scsi_cmnd *cmd;
-        scsi_done_fn_t done;
         struct sbp2_logical_unit *lu;
 
         struct sbp2_pointer page_table[SG_ALL] __attribute__((aligned(8)));
@@ -1398,7 +1394,7 @@ static void complete_command_orb(struct sbp2_orb *base_orb,
         sbp2_unmap_scatterlist(device->card->device, orb);
 
         orb->cmd->result = result;
-        orb->done(orb->cmd);
+        orb->cmd->scsi_done(orb->cmd);
 }
 
 static int sbp2_map_scatterlist(struct sbp2_command_orb *orb,
@@ -1463,7 +1459,8 @@ static int sbp2_map_scatterlist(struct sbp2_command_orb *orb,
 
 /* SCSI stack integration */
 
-static int sbp2_scsi_queuecommand_lck(struct scsi_cmnd *cmd, scsi_done_fn_t done)
+static int sbp2_scsi_queuecommand(struct Scsi_Host *shost,
+                                  struct scsi_cmnd *cmd)
 {
         struct sbp2_logical_unit *lu = cmd->device->hostdata;
         struct fw_device *device = target_device(lu->tgt);
@@ -1477,7 +1474,7 @@ static int sbp2_scsi_queuecommand_lck(struct scsi_cmnd *cmd, scsi_done_fn_t done
         if (cmd->sc_data_direction == DMA_BIDIRECTIONAL) {
                 fw_error("Can't handle DMA_BIDIRECTIONAL, rejecting command\n");
                 cmd->result = DID_ERROR << 16;
-                done(cmd);
+                cmd->scsi_done(cmd);
                 return 0;
         }
 
@@ -1490,11 +1487,8 @@ static int sbp2_scsi_queuecommand_lck(struct scsi_cmnd *cmd, scsi_done_fn_t done
         /* Initialize rcode to something not RCODE_COMPLETE. */
         orb->base.rcode = -1;
         kref_init(&orb->base.kref);
-
-        orb->lu   = lu;
-        orb->done = done;
-        orb->cmd  = cmd;
-
+        orb->lu = lu;
+        orb->cmd = cmd;
         orb->request.next.high = cpu_to_be32(SBP2_ORB_NULL);
         orb->request.misc = cpu_to_be32(
                 COMMAND_ORB_MAX_PAYLOAD(lu->tgt->max_payload) |
@@ -1529,8 +1523,6 @@ static int sbp2_scsi_queuecommand_lck(struct scsi_cmnd *cmd, scsi_done_fn_t done
         return retval;
 }
 
-static DEF_SCSI_QCMD(sbp2_scsi_queuecommand)
-
 static int sbp2_scsi_slave_alloc(struct scsi_device *sdev)
 {
         struct sbp2_logical_unit *lu = sdev->hostdata;