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>

diff --git a/drivers/firewire/sbp2.c b/drivers/firewire/sbp2.c
index 77ed589b360d7dce2d7567685fa032f96f40ed54..cc002e92275a6895dc3b1d5bc76b995b2a563364 100644 (file)
--- 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;