From f281233d3eba15fb225d21ae2e228fd4553d824a Mon Sep 17 00:00:00 2001 From: Jeff Garzik Date: Tue, 16 Nov 2010 02:10:29 -0500 Subject: 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 Acked-by: James Bottomley Signed-off-by: Linus Torvalds --- drivers/scsi/sym53c8xx_2/sym_glue.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'drivers/scsi/sym53c8xx_2') diff --git a/drivers/scsi/sym53c8xx_2/sym_glue.c b/drivers/scsi/sym53c8xx_2/sym_glue.c index 8b955b534a3..6b97ded9d45 100644 --- a/drivers/scsi/sym53c8xx_2/sym_glue.c +++ b/drivers/scsi/sym53c8xx_2/sym_glue.c @@ -505,7 +505,7 @@ void sym_log_bus_error(struct Scsi_Host *shost) * queuecommand method. Entered with the host adapter lock held and * interrupts disabled. */ -static int sym53c8xx_queue_command(struct scsi_cmnd *cmd, +static int sym53c8xx_queue_command_lck(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *)) { struct sym_hcb *np = SYM_SOFTC_PTR(cmd); @@ -536,6 +536,8 @@ static int sym53c8xx_queue_command(struct scsi_cmnd *cmd, return 0; } +static DEF_SCSI_QCMD(sym53c8xx_queue_command) + /* * Linux entry point of the interrupt handler. */ -- cgit v1.2.3-70-g09d2