diff options
| author | Jeff Garzik <jeff@garzik.org> | 2010-11-16 07:10:29 (GMT) |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-11-16 21:33:23 (GMT) |
| commit | f281233d3eba15fb225d21ae2e228fd4553d824a (patch) | |
| tree | 51134454ba8acb558735f90be5540f7d756483e3 /drivers/staging | |
| parent | bdbd01ac444bffb3c9aefed3059d12554059b320 (diff) | |
| download | linux-fsl-qoriq-f281233d3eba15fb225d21ae2e228fd4553d824a.tar.xz | |
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>
Diffstat (limited to 'drivers/staging')
| -rw-r--r-- | drivers/staging/hv/storvsc_drv.c | 7 | ||||
| -rw-r--r-- | drivers/staging/keucr/scsiglue.c | 4 |
2 files changed, 7 insertions, 4 deletions
diff --git a/drivers/staging/hv/storvsc_drv.c b/drivers/staging/hv/storvsc_drv.c index 41d9acf..6f8d67d 100644 --- a/drivers/staging/hv/storvsc_drv.c +++ b/drivers/staging/hv/storvsc_drv.c @@ -72,8 +72,7 @@ struct storvsc_driver_context { /* Static decl */ static int storvsc_probe(struct device *dev); -static int storvsc_queuecommand(struct scsi_cmnd *scmnd, - void (*done)(struct scsi_cmnd *)); +static int storvsc_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *scmnd); static int storvsc_device_alloc(struct scsi_device *); static int storvsc_device_configure(struct scsi_device *); static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd); @@ -595,7 +594,7 @@ static unsigned int copy_from_bounce_buffer(struct scatterlist *orig_sgl, /* * storvsc_queuecommand - Initiate command processing */ -static int storvsc_queuecommand(struct scsi_cmnd *scmnd, +static int storvsc_queuecommand_lck(struct scsi_cmnd *scmnd, void (*done)(struct scsi_cmnd *)) { int ret; @@ -783,6 +782,8 @@ retry_request: return ret; } +static DEF_SCSI_QCMD(storvsc_queuecommand) + static int storvsc_merge_bvec(struct request_queue *q, struct bvec_merge_data *bmd, struct bio_vec *bvec) { diff --git a/drivers/staging/keucr/scsiglue.c b/drivers/staging/keucr/scsiglue.c index a267140..da4f42a 100644 --- a/drivers/staging/keucr/scsiglue.c +++ b/drivers/staging/keucr/scsiglue.c @@ -87,7 +87,7 @@ static int slave_configure(struct scsi_device *sdev) /* This is always called with scsi_lock(host) held */ //----- queuecommand() --------------------- -static int queuecommand(struct scsi_cmnd *srb, void (*done)(struct scsi_cmnd *)) +static int queuecommand_lck(struct scsi_cmnd *srb, void (*done)(struct scsi_cmnd *)) { struct us_data *us = host_to_us(srb->device->host); @@ -117,6 +117,8 @@ static int queuecommand(struct scsi_cmnd *srb, void (*done)(struct scsi_cmnd *)) return 0; } +static DEF_SCSI_QCMD(queuecommand) + /*********************************************************************** * Error handling functions ***********************************************************************/ |