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/initio.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'drivers/scsi/initio.c') diff --git a/drivers/scsi/initio.c b/drivers/scsi/initio.c index 108797761b9..9627d062e16 100644 --- a/drivers/scsi/initio.c +++ b/drivers/scsi/initio.c @@ -2639,7 +2639,7 @@ static void initio_build_scb(struct initio_host * host, struct scsi_ctrl_blk * c * will cause the mid layer to call us again later with the command) */ -static int i91u_queuecommand(struct scsi_cmnd *cmd, +static int i91u_queuecommand_lck(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *)) { struct initio_host *host = (struct initio_host *) cmd->device->host->hostdata; @@ -2656,6 +2656,8 @@ static int i91u_queuecommand(struct scsi_cmnd *cmd, return 0; } +static DEF_SCSI_QCMD(i91u_queuecommand) + /** * i91u_bus_reset - reset the SCSI bus * @cmnd: Command block we want to trigger the reset for -- cgit v1.2.3