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authorLong Li <longli@microsoft.com>2016-12-14 18:46:01 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-03-12 06:37:26 +0100
commit5cdc8193ac38cc5094918cd0095bf76cb1c4181a (patch)
tree8ae014c7f0eba3854ebe01a0dcea8e2c9ce760ec /drivers
parent6a284310d5dd7faa9c185863583f55ab1b6679ce (diff)
scsi: storvsc: use tagged SRB requests if supported by the device
commit 3cd6d3d9b1abab8dcdf0800224ce26daac24eea2 upstream. Properly set SRB flags when hosting device supports tagged queuing. This patch improves the performance on Fiber Channel disks. Signed-off-by: Long Li <longli@microsoft.com> Reviewed-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/scsi/storvsc_drv.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
index 0f636cc4c809..4ccbcadb5713 100644
--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c
@@ -135,6 +135,8 @@ struct hv_fc_wwn_packet {
#define SRB_FLAGS_PORT_DRIVER_RESERVED 0x0F000000
#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 -
@@ -1409,6 +1411,13 @@ static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
vm_srb->win8_extension.srb_flags |=
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 */
switch (scmnd->sc_data_direction) {
case DMA_TO_DEVICE: