From 27f5ef378d2d56dad3c1a4c93c27fc5ce7c6eda0 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 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 Reviewed-by: K. Y. Srinivasan Signed-off-by: K. Y. Srinivasan Signed-off-by: Martin K. Petersen Signed-off-by: Greg Kroah-Hartman --- 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 8ccfc9ea874b..c193629ac060 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 - @@ -1451,6 +1453,13 @@ 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: -- 2.17.1