From 3cd6d3d9b1abab8dcdf0800224ce26daac24eea2 Mon Sep 17 00:00:00 2001 From: Long Li Date: Wed, 14 Dec 2016 18:46:01 -0800 Subject: [PATCH] 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: Long Li Reviewed-by: K. Y. Srinivasan Signed-off-by: K. Y. Srinivasan Cc: Signed-off-by: Martin K. Petersen --- drivers/scsi/storvsc_drv.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c index 63f6b1ad57c5..320938720544 100644 --- a/drivers/scsi/storvsc_drv.c +++ b/drivers/scsi/storvsc_drv.c @@ -136,6 +136,8 @@ 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 - @@ -1549,6 +1551,13 @@ 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: