[SCSI] qla2xxx: Add CPU affinity support.

Set the module parameter ql2xmultique_tag to 1 to enable this
feature. In this mode, the total number of response queues
created is equal to the number of online cpus. Turning the block
layer's rq_affinity mode on enables requests to be routed to the
proper cpu and at the same time it enables completion of the IO
in a response queue that is affined to the cpu in the request
path.

Signed-off-by: Anirban Chakraborty <anirban.chakraborty@qlogic.com>
Signed-off-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/scsi/qla2xxx/qla_mid.c b/drivers/scsi/qla2xxx/qla_mid.c
index 9c08479c3e1b..650bcef08f2a 100644
--- a/drivers/scsi/qla2xxx/qla_mid.c
+++ b/drivers/scsi/qla2xxx/qla_mid.c
@@ -633,6 +633,15 @@ que_failed:
         return 0;
 }
 
+static void qla_do_work(struct work_struct *work)
+{
+        struct rsp_que *rsp = container_of(work, struct rsp_que, q_work);
+        struct scsi_qla_host *vha;
+
+        vha = qla25xx_get_host(rsp);
+        qla24xx_process_response_queue(vha, rsp);
+}
+
 /* create response queue */
 int
 qla25xx_create_rsp_que(struct qla_hw_data *ha, uint16_t options,
@@ -711,6 +720,8 @@ qla25xx_create_rsp_que(struct qla_hw_data *ha, uint16_t options,
                 rsp->req = NULL;
 
         qla2x00_init_response_q_entries(rsp);
+        if (rsp->hw->wq)
+                INIT_WORK(&rsp->q_work, qla_do_work);
         return rsp->id;
 
 que_failed: