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>

arch/ia64/hp/sim/simscsi.c

@@ -202,7 +202,7 @@ simscsi_readwrite10 (struct scsi_cmnd *sc, int mode)
 }
 
 static int
-simscsi_queuecommand (struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
+simscsi_queuecommand_lck (struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
 {
 	unsigned int target_id = sc->device->id;
 	char fname[MAX_ROOT_LEN+16];
@@ -326,6 +326,8 @@ simscsi_queuecommand (struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
 	return 0;
 }
 
+static DEF_SCSI_QCMD(simscsi_queuecommand)
+
 static int
 simscsi_host_reset (struct scsi_cmnd *sc)
 {

drivers/ata/libata-scsi.c

@@ -3183,7 +3183,7 @@ static inline int __ata_scsi_queuecmd(struct scsi_cmnd *scmd,
  *	Return value from __ata_scsi_queuecmd() if @cmd can be queued,
  *	0 otherwise.
  */
-int ata_scsi_queuecmd(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
+static int ata_scsi_queuecmd_lck(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
 {
 	struct ata_port *ap;
 	struct ata_device *dev;
@@ -3211,6 +3211,8 @@ int ata_scsi_queuecmd(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
 	return rc;
 }
 
+DEF_SCSI_QCMD(ata_scsi_queuecmd)
+
 /**
  *	ata_scsi_simulate - simulate SCSI command on ATA device
  *	@dev: the target device

drivers/block/cciss_scsi.c

@@ -62,8 +62,8 @@ static int cciss_scsi_proc_info(
 		int length, 	   /* length of data in buffer */
 		int func);	   /* 0 == read, 1 == write */
 
-static int cciss_scsi_queue_command (struct scsi_cmnd *cmd,
-		void (* done)(struct scsi_cmnd *));
+static int cciss_scsi_queue_command (struct Scsi_Host *h,
+				     struct scsi_cmnd *cmd);
 static int cciss_eh_device_reset_handler(struct scsi_cmnd *);
 static int cciss_eh_abort_handler(struct scsi_cmnd *);
 
@@ -1406,7 +1406,7 @@ static void cciss_scatter_gather(ctlr_info_t *h, CommandList_struct *c,
 
 
 static int
-cciss_scsi_queue_command (struct scsi_cmnd *cmd, void (* done)(struct scsi_cmnd *))
+cciss_scsi_queue_command_lck(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
 {
 	ctlr_info_t *h;
 	int rc;
@@ -1504,6 +1504,8 @@ cciss_scsi_queue_command (struct scsi_cmnd *cmd, void (* done)(struct scsi_cmnd
 	return 0;
 }
 
+static DEF_SCSI_QCMD(cciss_scsi_queue_command)
+
 static void cciss_unregister_scsi(ctlr_info_t *h)
 {
 	struct cciss_scsi_adapter_data_t *sa;

drivers/firewire/sbp2.c

@@ -1468,7 +1468,7 @@ static int sbp2_map_scatterlist(struct sbp2_command_orb *orb,
 
 /* SCSI stack integration */
 
-static int sbp2_scsi_queuecommand(struct scsi_cmnd *cmd, scsi_done_fn_t done)
+static int sbp2_scsi_queuecommand_lck(struct scsi_cmnd *cmd, scsi_done_fn_t done)
 {
 	struct sbp2_logical_unit *lu = cmd->device->hostdata;
 	struct fw_device *device = target_device(lu->tgt);
@@ -1534,6 +1534,8 @@ static int sbp2_scsi_queuecommand(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;

drivers/infiniband/ulp/srp/ib_srp.c

@@ -1123,7 +1123,7 @@ static void srp_send_completion(struct ib_cq *cq, void *target_ptr)
 	}
 }
 
-static int srp_queuecommand(struct scsi_cmnd *scmnd,
+static int srp_queuecommand_lck(struct scsi_cmnd *scmnd,
 			    void (*done)(struct scsi_cmnd *))
 {
 	struct srp_target_port *target = host_to_target(scmnd->device->host);
@@ -1196,6 +1196,8 @@ err:
 	return SCSI_MLQUEUE_HOST_BUSY;
 }
 
+static DEF_SCSI_QCMD(srp_queuecommand)
+
 static int srp_alloc_iu_bufs(struct srp_target_port *target)
 {
 	int i;

drivers/message/fusion/mptfc.c

@@ -97,8 +97,7 @@ static u8	mptfcInternalCtx = MPT_MAX_PROTOCOL_DRIVERS;
 
 static int mptfc_target_alloc(struct scsi_target *starget);
 static int mptfc_slave_alloc(struct scsi_device *sdev);
-static int mptfc_qcmd(struct scsi_cmnd *SCpnt,
-		      void (*done)(struct scsi_cmnd *));
+static int mptfc_qcmd(struct Scsi_Host *shost, struct scsi_cmnd *SCpnt);
 static void mptfc_target_destroy(struct scsi_target *starget);
 static void mptfc_set_rport_loss_tmo(struct fc_rport *rport, uint32_t timeout);
 static void __devexit mptfc_remove(struct pci_dev *pdev);
@@ -650,7 +649,7 @@ mptfc_slave_alloc(struct scsi_device *sdev)
 }
 
 static int
-mptfc_qcmd(struct scsi_cmnd *SCpnt, void (*done)(struct scsi_cmnd *))
+mptfc_qcmd_lck(struct scsi_cmnd *SCpnt, void (*done)(struct scsi_cmnd *))
 {
 	struct mptfc_rport_info	*ri;
 	struct fc_rport	*rport = starget_to_rport(scsi_target(SCpnt->device));
@@ -681,6 +680,8 @@ mptfc_qcmd(struct scsi_cmnd *SCpnt, void (*done)(struct scsi_cmnd *))
 	return mptscsih_qcmd(SCpnt,done);
 }
 
+static DEF_SCSI_QCMD(mptfc_qcmd)
+
 /*
  *	mptfc_display_port_link_speed - displaying link speed
  *	@ioc: Pointer to MPT_ADAPTER structure

drivers/message/fusion/mptsas.c

@@ -1889,7 +1889,7 @@ mptsas_slave_alloc(struct scsi_device *sdev)
 }
 
 static int
-mptsas_qcmd(struct scsi_cmnd *SCpnt, void (*done)(struct scsi_cmnd *))
+mptsas_qcmd_lck(struct scsi_cmnd *SCpnt, void (*done)(struct scsi_cmnd *))
 {
 	MPT_SCSI_HOST	*hd;
 	MPT_ADAPTER	*ioc;
@@ -1913,6 +1913,8 @@ mptsas_qcmd(struct scsi_cmnd *SCpnt, void (*done)(struct scsi_cmnd *))
 	return mptscsih_qcmd(SCpnt,done);
 }
 
+static DEF_SCSI_QCMD(mptsas_qcmd)
+
 /**
  *	mptsas_mptsas_eh_timed_out - resets the scsi_cmnd timeout
  *		if the device under question is currently in the

drivers/message/fusion/mptspi.c

@@ -780,7 +780,7 @@ static int mptspi_slave_configure(struct scsi_device *sdev)
 }
 
 static int
-mptspi_qcmd(struct scsi_cmnd *SCpnt, void (*done)(struct scsi_cmnd *))
+mptspi_qcmd_lck(struct scsi_cmnd *SCpnt, void (*done)(struct scsi_cmnd *))
 {
 	struct _MPT_SCSI_HOST *hd = shost_priv(SCpnt->device->host);
 	VirtDevice	*vdevice = SCpnt->device->hostdata;
@@ -805,6 +805,8 @@ mptspi_qcmd(struct scsi_cmnd *SCpnt, void (*done)(struct scsi_cmnd *))
 	return mptscsih_qcmd(SCpnt,done);
 }
 
+static DEF_SCSI_QCMD(mptspi_qcmd)
+
 static void mptspi_slave_destroy(struct scsi_device *sdev)
 {
 	struct scsi_target *starget = scsi_target(sdev);

drivers/message/i2o/i2o_scsi.c

@@ -506,7 +506,7 @@ static struct i2o_driver i2o_scsi_driver = {
  *	Locks: takes the controller lock on error path only
  */
 
-static int i2o_scsi_queuecommand(struct scsi_cmnd *SCpnt,
+static int i2o_scsi_queuecommand_lck(struct scsi_cmnd *SCpnt,
 				 void (*done) (struct scsi_cmnd *))
 {
 	struct i2o_controller *c;
@@ -688,7 +688,9 @@ static int i2o_scsi_queuecommand(struct scsi_cmnd *SCpnt,
 
       exit:
 	return rc;
-};
+}
+
+static DEF_SCSI_QCMD(i2o_scsi_queuecommand)
 
 /**
  *	i2o_scsi_abort - abort a running command

drivers/s390/scsi/zfcp_scsi.c

@@ -76,7 +76,7 @@ static void zfcp_scsi_command_fail(struct scsi_cmnd *scpnt, int result)
 	scpnt->scsi_done(scpnt);
 }
 
-static int zfcp_scsi_queuecommand(struct scsi_cmnd *scpnt,
+static int zfcp_scsi_queuecommand_lck(struct scsi_cmnd *scpnt,
 				  void (*done) (struct scsi_cmnd *))
 {
 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(scpnt->device);
@@ -127,6 +127,8 @@ static int zfcp_scsi_queuecommand(struct scsi_cmnd *scpnt,
 	return ret;
 }
 
+static DEF_SCSI_QCMD(zfcp_scsi_queuecommand)
+
 static int zfcp_scsi_slave_alloc(struct scsi_device *sdev)
 {
 	struct fc_rport *rport = starget_to_rport(scsi_target(sdev));

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)
 {

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)
 {

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) 
 {

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)
 {

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
 /*

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 *);

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

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);
 

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"));

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.