[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, 21 insertions, 1 deletions

diff --git a/drivers/scsi/qla2xxx/qla_isr.c b/drivers/scsi/qla2xxx/qla_isr.c
index c8e906c702a1..41e50c2bec0f 100644
--- a/drivers/scsi/qla2xxx/qla_isr.c
+++ b/drivers/scsi/qla2xxx/qla_isr.c
@@ -1718,6 +1718,25 @@ qla24xx_msix_rsp_q(int irq, void *dev_id)
 }
 
 static irqreturn_t
+qla25xx_msix_rsp_q(int irq, void *dev_id)
+{
+        struct qla_hw_data *ha;
+        struct rsp_que *rsp;
+
+        rsp = (struct rsp_que *) dev_id;
+        if (!rsp) {
+                printk(KERN_INFO
+                        "%s(): NULL response queue pointer\n", __func__);
+                return IRQ_NONE;
+        }
+        ha = rsp->hw;
+
+        queue_work_on((int) (rsp->id - 1), ha->wq, &rsp->q_work);
+
+        return IRQ_HANDLED;
+}
+
+static irqreturn_t
 qla24xx_msix_default(int irq, void *dev_id)
 {
         scsi_qla_host_t *vha;
@@ -1806,9 +1825,10 @@ struct qla_init_msix_entry {
         irq_handler_t handler;
 };
 
-static struct qla_init_msix_entry msix_entries[2] = {
+static struct qla_init_msix_entry msix_entries[3] = {
         { "qla2xxx (default)", qla24xx_msix_default },
         { "qla2xxx (rsp_q)", qla24xx_msix_rsp_q },
+        { "qla2xxx (multiq)", qla25xx_msix_rsp_q },
 };
 
 static void