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/eata.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'drivers/scsi/eata.c') diff --git a/drivers/scsi/eata.c b/drivers/scsi/eata.c index d1c3137..53925ac 100644 --- a/drivers/scsi/eata.c +++ b/drivers/scsi/eata.c @@ -505,8 +505,7 @@ static int eata2x_detect(struct scsi_host_template *); static int eata2x_release(struct Scsi_Host *); -static int eata2x_queuecommand(struct scsi_cmnd *, - void (*done) (struct scsi_cmnd *)); +static int eata2x_queuecommand(struct Scsi_Host *, struct scsi_cmnd *); static int eata2x_eh_abort(struct scsi_cmnd *); static int eata2x_eh_host_reset(struct scsi_cmnd *); static int eata2x_bios_param(struct scsi_device *, struct block_device *, @@ -1758,7 +1757,7 @@ static void scsi_to_dev_dir(unsigned int i, struct hostdata *ha) } -static int eata2x_queuecommand(struct scsi_cmnd *SCpnt, +static int eata2x_queuecommand_lck(struct scsi_cmnd *SCpnt, void (*done) (struct scsi_cmnd *)) { struct Scsi_Host *shost = SCpnt->device->host; @@ -1843,6 +1842,8 @@ static int eata2x_queuecommand(struct scsi_cmnd *SCpnt, return 0; } +static DEF_SCSI_QCMD(eata2x_queuecommand) + static int eata2x_eh_abort(struct scsi_cmnd *SCarg) { struct Scsi_Host *shost = SCarg->device->host; -- cgit v1.1