Commit 3cd6d3d9 authored by Long Li's avatar Long Li Committed by Martin K. Petersen

scsi: storvsc: use tagged SRB requests if supported by the device

Properly set SRB flags when hosting device supports tagged queuing.
This patch improves the performance on Fiber Channel disks.
Signed-off-by: default avatarLong Li <longli@microsoft.com>
Reviewed-by: default avatarK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: default avatarK. Y. Srinivasan <kys@microsoft.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent d86adf48
...@@ -136,6 +136,8 @@ struct hv_fc_wwn_packet { ...@@ -136,6 +136,8 @@ struct hv_fc_wwn_packet {
#define SRB_FLAGS_PORT_DRIVER_RESERVED 0x0F000000 #define SRB_FLAGS_PORT_DRIVER_RESERVED 0x0F000000
#define SRB_FLAGS_CLASS_DRIVER_RESERVED 0xF0000000 #define SRB_FLAGS_CLASS_DRIVER_RESERVED 0xF0000000
#define SP_UNTAGGED ((unsigned char) ~0)
#define SRB_SIMPLE_TAG_REQUEST 0x20
/* /*
* Platform neutral description of a scsi request - * Platform neutral description of a scsi request -
...@@ -1549,6 +1551,13 @@ static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd) ...@@ -1549,6 +1551,13 @@ static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
vm_srb->win8_extension.srb_flags |= vm_srb->win8_extension.srb_flags |=
SRB_FLAGS_DISABLE_SYNCH_TRANSFER; SRB_FLAGS_DISABLE_SYNCH_TRANSFER;
if (scmnd->device->tagged_supported) {
vm_srb->win8_extension.srb_flags |=
(SRB_FLAGS_QUEUE_ACTION_ENABLE | SRB_FLAGS_NO_QUEUE_FREEZE);
vm_srb->win8_extension.queue_tag = SP_UNTAGGED;
vm_srb->win8_extension.queue_action = SRB_SIMPLE_TAG_REQUEST;
}
/* Build the SRB */ /* Build the SRB */
switch (scmnd->sc_data_direction) { switch (scmnd->sc_data_direction) {
case DMA_TO_DEVICE: case DMA_TO_DEVICE:
......
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