SCSI host lock push-down

Move the mid-layer's ->queuecommand() invocation from being locked
with the host lock to being unlocked to facilitate speeding up the
critical path for drivers who don't need this lock taken anyway.

The patch below presents a simple SCSI host lock push-down as an
equivalent transformation.  No locking or other behavior should change
with this patch.  All existing bugs and locking orders are preserved.

Additionally, add one parameter to queuecommand,
	struct Scsi_Host *
and remove one parameter from queuecommand,
	void (*done)(struct scsi_cmnd *)

Scsi_Host* is a convenient pointer that most host drivers need anyway,
and 'done' is redundant to struct scsi_cmnd->scsi_done.

Minimal code disturbance was attempted with this change.  Most drivers
needed only two one-line modifications for their host lock push-down.

Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Acked-by: James Bottomley <James.Bottomley@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

95 files changed, 271 insertions, 167 deletions

diff --git a/drivers/scsi/3w-9xxx.c b/drivers/scsi/3w-9xxx.c
index fcf08b3f52c1..b7bd5b0cc7aa 100644
--- a/drivers/scsi/3w-9xxx.c
+++ b/drivers/scsi/3w-9xxx.c
@@ -1765,7 +1765,7 @@ out:
 } /* End twa_scsi_eh_reset() */
 
 /* This is the main scsi queue function to handle scsi opcodes */
-static int twa_scsi_queue(struct scsi_cmnd *SCpnt, void (*done)(struct scsi_cmnd *))
+static int twa_scsi_queue_lck(struct scsi_cmnd *SCpnt, void (*done)(struct scsi_cmnd *))
 {
 	int request_id, retval;
 	TW_Device_Extension *tw_dev = (TW_Device_Extension *)SCpnt->device->host->hostdata;
@@ -1812,6 +1812,8 @@ out:
 	return retval;
 } /* End twa_scsi_queue() */
 
+static DEF_SCSI_QCMD(twa_scsi_queue)
+
 /* This function hands scsi cdb's to the firmware */
 static int twa_scsiop_execute_scsi(TW_Device_Extension *tw_dev, int request_id, char *cdb, int use_sg, TW_SG_Entry *sglistarg)
 {
diff --git a/drivers/scsi/3w-sas.c b/drivers/scsi/3w-sas.c
index 6a95d111d207..13e39e1fdfe2 100644
--- a/drivers/scsi/3w-sas.c
+++ b/drivers/scsi/3w-sas.c
@@ -1501,7 +1501,7 @@ out:
 } /* End twl_scsi_eh_reset() */
 
 /* This is the main scsi queue function to handle scsi opcodes */
-static int twl_scsi_queue(struct scsi_cmnd *SCpnt, void (*done)(struct scsi_cmnd *))
+static int twl_scsi_queue_lck(struct scsi_cmnd *SCpnt, void (*done)(struct scsi_cmnd *))
 {
 	int request_id, retval;
 	TW_Device_Extension *tw_dev = (TW_Device_Extension *)SCpnt->device->host->hostdata;
@@ -1536,6 +1536,8 @@ out:
 	return retval;
 } /* End twl_scsi_queue() */
 
+static DEF_SCSI_QCMD(twl_scsi_queue)
+
 /* This function tells the controller to shut down */
 static void __twl_shutdown(TW_Device_Extension *tw_dev)
 {
diff --git a/drivers/scsi/3w-xxxx.c b/drivers/scsi/3w-xxxx.c
index b1125341f4c8..7fe96ff60c58 100644
--- a/drivers/scsi/3w-xxxx.c
+++ b/drivers/scsi/3w-xxxx.c
@@ -1947,7 +1947,7 @@ static int tw_scsiop_test_unit_ready_complete(TW_Device_Extension *tw_dev, int r
 } /* End tw_scsiop_test_unit_ready_complete() */
 
 /* This is the main scsi queue function to handle scsi opcodes */
-static int tw_scsi_queue(struct scsi_cmnd *SCpnt, void (*done)(struct scsi_cmnd *)) 
+static int tw_scsi_queue_lck(struct scsi_cmnd *SCpnt, void (*done)(struct scsi_cmnd *))
 {
 	unsigned char *command = SCpnt->cmnd;
 	int request_id = 0;
@@ -2023,6 +2023,8 @@ static int tw_scsi_queue(struct scsi_cmnd *SCpnt, void (*done)(struct scsi_cmnd
 	return retval;
 } /* End tw_scsi_queue() */
 
+static DEF_SCSI_QCMD(tw_scsi_queue)
+
 /* This function is the interrupt service routine */
 static irqreturn_t tw_interrupt(int irq, void *dev_instance) 
 {
diff --git a/drivers/scsi/53c700.c b/drivers/scsi/53c700.c
index 89fc1c8af86b..f672491774eb 100644
--- a/drivers/scsi/53c700.c
+++ b/drivers/scsi/53c700.c
@@ -167,7 +167,7 @@ MODULE_LICENSE("GPL");
 #include "53c700_d.h"
 
 
-STATIC int NCR_700_queuecommand(struct scsi_cmnd *, void (*done)(struct scsi_cmnd *));
+STATIC int NCR_700_queuecommand(struct Scsi_Host *h, struct scsi_cmnd *);
 STATIC int NCR_700_abort(struct scsi_cmnd * SCpnt);
 STATIC int NCR_700_bus_reset(struct scsi_cmnd * SCpnt);
 STATIC int NCR_700_host_reset(struct scsi_cmnd * SCpnt);
@@ -1749,8 +1749,8 @@ NCR_700_intr(int irq, void *dev_id)
 	return IRQ_RETVAL(handled);
 }
 
-STATIC int
-NCR_700_queuecommand(struct scsi_cmnd *SCp, void (*done)(struct scsi_cmnd *))
+static int
+NCR_700_queuecommand_lck(struct scsi_cmnd *SCp, void (*done)(struct scsi_cmnd *))
 {
 	struct NCR_700_Host_Parameters *hostdata = 
 		(struct NCR_700_Host_Parameters *)SCp->device->host->hostdata[0];
@@ -1904,6 +1904,8 @@ NCR_700_queuecommand(struct scsi_cmnd *SCp, void (*done)(struct scsi_cmnd *))
 	return 0;
 }
 
+STATIC DEF_SCSI_QCMD(NCR_700_queuecommand)
+
 STATIC int
 NCR_700_abort(struct scsi_cmnd * SCp)
 {
diff --git a/drivers/scsi/BusLogic.c b/drivers/scsi/BusLogic.c
index fc0b4b81d552..f66c33b9ab41 100644
--- a/drivers/scsi/BusLogic.c
+++ b/drivers/scsi/BusLogic.c
@@ -2807,7 +2807,7 @@ static int BusLogic_host_reset(struct scsi_cmnd * SCpnt)
   Outgoing Mailbox for execution by the associated Host Adapter.
 */
 
-static int BusLogic_QueueCommand(struct scsi_cmnd *Command, void (*CompletionRoutine) (struct scsi_cmnd *))
+static int BusLogic_QueueCommand_lck(struct scsi_cmnd *Command, void (*CompletionRoutine) (struct scsi_cmnd *))
 {
 	struct BusLogic_HostAdapter *HostAdapter = (struct BusLogic_HostAdapter *) Command->device->host->hostdata;
 	struct BusLogic_TargetFlags *TargetFlags = &HostAdapter->TargetFlags[Command->device->id];
@@ -2994,6 +2994,7 @@ static int BusLogic_QueueCommand(struct scsi_cmnd *Command, void (*CompletionRou
 	return 0;
 }
 
+static DEF_SCSI_QCMD(BusLogic_QueueCommand)
 
 #if 0
 /*
diff --git a/drivers/scsi/BusLogic.h b/drivers/scsi/BusLogic.h
index 73f237a1ed94..649fcb31f26d 100644
--- a/drivers/scsi/BusLogic.h
+++ b/drivers/scsi/BusLogic.h
@@ -1319,7 +1319,7 @@ static inline void BusLogic_IncrementSizeBucket(BusLogic_CommandSizeBuckets_T Co
 */
 
 static const char *BusLogic_DriverInfo(struct Scsi_Host *);
-static int BusLogic_QueueCommand(struct scsi_cmnd *, void (*CompletionRoutine) (struct scsi_cmnd *));
+static int BusLogic_QueueCommand(struct Scsi_Host *h, struct scsi_cmnd *);
 static int BusLogic_BIOSDiskParameters(struct scsi_device *, struct block_device *, sector_t, int *);
 static int BusLogic_ProcDirectoryInfo(struct Scsi_Host *, char *, char **, off_t, int, int);
 static int BusLogic_SlaveConfigure(struct scsi_device *);
diff --git a/drivers/scsi/NCR5380.c b/drivers/scsi/NCR5380.c
index 5d2f148889ad..9a5629f94f95 100644
--- a/drivers/scsi/NCR5380.c
+++ b/drivers/scsi/NCR5380.c
@@ -952,7 +952,7 @@ static void NCR5380_exit(struct Scsi_Host *instance)
  *	Locks: host lock taken by caller
  */
 
-static int NCR5380_queue_command(Scsi_Cmnd * cmd, void (*done) (Scsi_Cmnd *)) 
+static int NCR5380_queue_command_lck(Scsi_Cmnd * cmd, void (*done) (Scsi_Cmnd *))
 {
 	struct Scsi_Host *instance = cmd->device->host;
 	struct NCR5380_hostdata *hostdata = (struct NCR5380_hostdata *) instance->hostdata;
@@ -1021,6 +1021,7 @@ static int NCR5380_queue_command(Scsi_Cmnd * cmd, void (*done) (Scsi_Cmnd *))
 	return 0;
 }
 
+static DEF_SCSI_QCMD(NCR5380_queue_command)
 
 /**
  *	NCR5380_main	-	NCR state machines
diff --git a/drivers/scsi/NCR5380.h b/drivers/scsi/NCR5380.h
index bdc468c9e1d9..fd40a32b1f6f 100644
--- a/drivers/scsi/NCR5380.h
+++ b/drivers/scsi/NCR5380.h
@@ -313,7 +313,7 @@ static void NCR5380_print(struct Scsi_Host *instance);
 #endif
 static int NCR5380_abort(Scsi_Cmnd * cmd);
 static int NCR5380_bus_reset(Scsi_Cmnd * cmd);
-static int NCR5380_queue_command(Scsi_Cmnd * cmd, void (*done) (Scsi_Cmnd *));
+static int NCR5380_queue_command(struct Scsi_Host *, struct scsi_cmnd *);
 static int __maybe_unused NCR5380_proc_info(struct Scsi_Host *instance,
 	char *buffer, char **start, off_t offset, int length, int inout);
 
diff --git a/drivers/scsi/NCR53c406a.c b/drivers/scsi/NCR53c406a.c
index 6961f78742ae..c91888a0a23c 100644
--- a/drivers/scsi/NCR53c406a.c
+++ b/drivers/scsi/NCR53c406a.c
@@ -693,7 +693,7 @@ static void wait_intr(void)
 }
 #endif
 
-static int NCR53c406a_queue(Scsi_Cmnd * SCpnt, void (*done) (Scsi_Cmnd *))
+static int NCR53c406a_queue_lck(Scsi_Cmnd * SCpnt, void (*done) (Scsi_Cmnd *))
 {
 	int i;
 
@@ -726,6 +726,8 @@ static int NCR53c406a_queue(Scsi_Cmnd * SCpnt, void (*done) (Scsi_Cmnd *))
 	return 0;
 }
 
+static DEF_SCSI_QCMD(NCR53c406a_queue)
+
 static int NCR53c406a_host_reset(Scsi_Cmnd * SCpnt)
 {
 	DEB(printk("NCR53c406a_reset called\n"));
diff --git a/drivers/scsi/a100u2w.c b/drivers/scsi/a100u2w.c
index dbbc601948e5..dc5ac6e528c4 100644
--- a/drivers/scsi/a100u2w.c
+++ b/drivers/scsi/a100u2w.c
@@ -911,7 +911,7 @@ static int inia100_build_scb(struct orc_host * host, struct orc_scb * scb, struc
  *	queue the command down to the controller
  */
 
-static int inia100_queue(struct scsi_cmnd * cmd, void (*done) (struct scsi_cmnd *))
+static int inia100_queue_lck(struct scsi_cmnd * cmd, void (*done) (struct scsi_cmnd *))
 {
 	struct orc_scb *scb;
 	struct orc_host *host;		/* Point to Host adapter control block */
@@ -930,6 +930,8 @@ static int inia100_queue(struct scsi_cmnd * cmd, void (*done) (struct scsi_cmnd
 	return 0;
 }
 
+static DEF_SCSI_QCMD(inia100_queue)
+
 /*****************************************************************************
  Function name  : inia100_abort
  Description    : Abort a queued command.
diff --git a/drivers/scsi/aacraid/linit.c b/drivers/scsi/aacraid/linit.c
index 29c0ed1cf507..2c93d9496d62 100644
--- a/drivers/scsi/aacraid/linit.c
+++ b/drivers/scsi/aacraid/linit.c
@@ -248,7 +248,7 @@ static struct aac_driver_ident aac_drivers[] = {
  *	TODO: unify with aac_scsi_cmd().
  */
 
-static int aac_queuecommand(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
+static int aac_queuecommand_lck(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
 {
 	struct Scsi_Host *host = cmd->device->host;
 	struct aac_dev *dev = (struct aac_dev *)host->hostdata;
@@ -267,6 +267,8 @@ static int aac_queuecommand(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd
 	return (aac_scsi_cmd(cmd) ? FAILED : 0);
 }
 
+static DEF_SCSI_QCMD(aac_queuecommand)
+
 /**
  *	aac_info		-	Returns the host adapter name
  *	@shost:		Scsi host to report on
diff --git a/drivers/scsi/advansys.c b/drivers/scsi/advansys.c
index 0ec3da6f3e12..081c6de92bc5 100644
--- a/drivers/scsi/advansys.c
+++ b/drivers/scsi/advansys.c
@@ -9500,7 +9500,7 @@ static int asc_execute_scsi_cmnd(struct scsi_cmnd *scp)
  * in the 'scp' result field.
  */
 static int
-advansys_queuecommand(struct scsi_cmnd *scp, void (*done)(struct scsi_cmnd *))
+advansys_queuecommand_lck(struct scsi_cmnd *scp, void (*done)(struct scsi_cmnd *))
 {
 	struct Scsi_Host *shost = scp->device->host;
 	int asc_res, result = 0;
@@ -9525,6 +9525,8 @@ advansys_queuecommand(struct scsi_cmnd *scp, void (*done)(struct scsi_cmnd *))