From 71444b97816ae08a1cc435f044f9f1f4cbd51e6a Mon Sep 17 00:00:00 2001 From: Jack Wang Date: Thu, 7 Nov 2013 11:37:37 +0100 Subject: [PATCH] IB/srp: Add change_queue_depth and change_queue_type support Currently, it's not possible to change queue depth for a device behind SRP host. Sometimes, we need to adjust queue_depth for performance reason (eg storage busy, we need lower queue_depth to avoid running into SCSI error handler), so this patch add support for SRP driver. Signed-off-by: Jack Wang Tested-by: Bart Van Assche Acked-by: David Dillow Signed-off-by: Roland Dreier --- drivers/infiniband/ulp/srp/ib_srp.c | 54 +++++++++++++++++++++++++++++ 1 file changed, 54 insertions(+) diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c index 6aa660d188a3..a8f8d0b8a777 100644 --- a/drivers/infiniband/ulp/srp/ib_srp.c +++ b/drivers/infiniband/ulp/srp/ib_srp.c @@ -46,6 +46,7 @@ #include #include #include +#include #include #include @@ -1882,6 +1883,57 @@ static int srp_cm_handler(struct ib_cm_id *cm_id, struct ib_cm_event *event) return 0; } +/** + * srp_change_queue_type - changing device queue tag type + * @sdev: scsi device struct + * @tag_type: requested tag type + * + * Returns queue tag type. + */ +static int +srp_change_queue_type(struct scsi_device *sdev, int tag_type) +{ + if (sdev->tagged_supported) { + scsi_set_tag_type(sdev, tag_type); + if (tag_type) + scsi_activate_tcq(sdev, sdev->queue_depth); + else + scsi_deactivate_tcq(sdev, sdev->queue_depth); + } else + tag_type = 0; + + return tag_type; +} + +/** + * srp_change_queue_depth - setting device queue depth + * @sdev: scsi device struct + * @qdepth: requested queue depth + * @reason: SCSI_QDEPTH_DEFAULT/SCSI_QDEPTH_QFULL/SCSI_QDEPTH_RAMP_UP + * (see include/scsi/scsi_host.h for definition) + * + * Returns queue depth. + */ +static int +srp_change_queue_depth(struct scsi_device *sdev, int qdepth, int reason) +{ + struct Scsi_Host *shost = sdev->host; + int max_depth; + if (reason == SCSI_QDEPTH_DEFAULT || reason == SCSI_QDEPTH_RAMP_UP) { + max_depth = shost->can_queue; + if (!sdev->tagged_supported) + max_depth = 1; + if (qdepth > max_depth) + qdepth = max_depth; + scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), qdepth); + } else if (reason == SCSI_QDEPTH_QFULL) + scsi_track_queue_full(sdev, qdepth); + else + return -EOPNOTSUPP; + + return sdev->queue_depth; +} + static int srp_send_tsk_mgmt(struct srp_target_port *target, u64 req_tag, unsigned int lun, u8 func) { @@ -2173,6 +2225,8 @@ static struct scsi_host_template srp_template = { .slave_configure = srp_slave_configure, .info = srp_target_info, .queuecommand = srp_queuecommand, + .change_queue_depth = srp_change_queue_depth, + .change_queue_type = srp_change_queue_type, .eh_abort_handler = srp_abort, .eh_device_reset_handler = srp_reset_device, .eh_host_reset_handler = srp_reset_host,