[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>

7 files changed, 140 insertions, 9 deletions

diff --git a/drivers/scsi/qla2xxx/qla_attr.c b/drivers/scsi/qla2xxx/qla_attr.c
index bda6658d4fbf..f3536e56dce4 100644
--- a/drivers/scsi/qla2xxx/qla_attr.c
+++ b/drivers/scsi/qla2xxx/qla_attr.c
@@ -1531,7 +1531,7 @@ qla24xx_vport_create(struct fc_vport *fc_vport, bool disable)
         qla24xx_vport_disable(fc_vport, disable);
 
         ret = 0;
-        if (ha->cur_vport_count <= ha->flex_port_count
+        if (ha->cur_vport_count <= ha->flex_port_count || ql2xmultique_tag
                 || ha->max_req_queues == 1 || !ha->npiv_info)
                 goto vport_queue;
         /* Create a request queue in QoS mode for the vport */
@@ -1599,7 +1599,7 @@ qla24xx_vport_delete(struct fc_vport *fc_vport)
                     vha->host_no, vha->vp_idx, vha));
         }
 
-        if (vha->req->id) {
+        if (vha->req->id && !ql2xmultique_tag) {
                 if (qla25xx_delete_req_que(vha, vha->req) != QLA_SUCCESS)
                         qla_printk(KERN_WARNING, ha,
                                 "Queue delete failed.\n");
diff --git a/drivers/scsi/qla2xxx/qla_def.h b/drivers/scsi/qla2xxx/qla_def.h
index 57d659cf99ee..09190ba411fd 100644
--- a/drivers/scsi/qla2xxx/qla_def.h
+++ b/drivers/scsi/qla2xxx/qla_def.h
@@ -2171,6 +2171,7 @@ struct rsp_que {
         struct qla_msix_entry *msix;
         struct req_que *req;
         srb_t *status_srb; /* status continuation entry */
+        struct work_struct q_work;
 };
 
 /* Request queue data structure */
@@ -2539,6 +2540,7 @@ struct qla_hw_data {
         struct qla_chip_state_84xx *cs84xx;
         struct qla_statistics qla_stats;
         struct isp_operations *isp_ops;
+        struct workqueue_struct *wq;
 };
 
 /*
diff --git a/drivers/scsi/qla2xxx/qla_iocb.c b/drivers/scsi/qla2xxx/qla_iocb.c
index 94b69d86482d..7b15ded991cb 100644
--- a/drivers/scsi/qla2xxx/qla_iocb.c
+++ b/drivers/scsi/qla2xxx/qla_iocb.c
@@ -15,6 +15,7 @@ static request_t *qla2x00_req_pkt(struct scsi_qla_host *, struct req_que *,
                                                         struct rsp_que *rsp);
 static void qla2x00_isp_cmd(struct scsi_qla_host *, struct req_que *);
 
+static void qla25xx_set_que(srb_t *, struct req_que **, struct rsp_que **);
 /**
  * qla2x00_get_cmd_direction() - Determine control_flag data direction.
  * @cmd: SCSI command
@@ -726,8 +727,7 @@ qla24xx_start_scsi(srb_t *sp)
         /* Setup device pointers. */
         ret = 0;
 
-        req = vha->req;
-        rsp = ha->rsp_q_map[0];
+        qla25xx_set_que(sp, &req, &rsp);
         sp->que = req;
 
         /* So we know we haven't pci_map'ed anything yet */
@@ -850,3 +850,21 @@ queuing_error:
 
         return QLA_FUNCTION_FAILED;
 }
+
+static void qla25xx_set_que(srb_t *sp, struct req_que **req,
+        struct rsp_que **rsp)
+{
+        struct scsi_cmnd *cmd = sp->cmd;
+        struct scsi_qla_host *vha = sp->fcport->vha;
+        struct qla_hw_data *ha = sp->fcport->vha->hw;
+        int affinity = cmd->request->cpu;
+
+        if (ql2xmultique_tag && affinity >= 0 &&
+                affinity < ha->max_rsp_queues - 1) {
+                *rsp = ha->rsp_q_map[affinity + 1];
+                *req = ha->req_q_map[1];
+        } else {
+                *req = vha->req;
+                *rsp = ha->rsp_q_map[0];
+        }
+}
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
diff --git a/drivers/scsi/qla2xxx/qla_mbx.c b/drivers/scsi/qla2xxx/qla_mbx.c
index bfdc89f8569b..366522e8a766 100644
--- a/drivers/scsi/qla2xxx/qla_mbx.c
+++ b/drivers/scsi/qla2xxx/qla_mbx.c
@@ -1497,7 +1497,10 @@ qla24xx_login_fabric(scsi_qla_host_t *vha, uint16_t loop_id, uint8_t domain,
 
         DEBUG11(printk("%s(%ld): entered.\n", __func__, vha->host_no));
 
-        req = vha->req;
+        if (ql2xmultique_tag)
+                req = ha->req_q_map[0];
+        else
+                req = vha->req;
         rsp = req->rsp;
 
         lg = dma_pool_alloc(ha->s_dma_pool, GFP_KERNEL, &lg_dma);
@@ -2311,7 +2314,10 @@ __qla24xx_issue_tmf(char *name, uint32_t type, struct fc_port *fcport,
         vha = fcport->vha;
         ha = vha->hw;
         req = vha->req;
-        rsp = req->rsp;
+        if (ql2xmultique_tag)
+                rsp = ha->rsp_q_map[tag + 1];
+        else
+                rsp = req->rsp;
         tsk = dma_pool_alloc(ha->s_dma_pool, GFP_KERNEL, &tsk_dma);
         if (tsk == NULL) {
                 DEBUG2_3(printk("%s(%ld): failed to allocate Task Management "
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:
diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c
index e2647e02dac9..d6817df95e30 100644
--- a/drivers/scsi/qla2xxx/qla_os.c
+++ b/drivers/scsi/qla2xxx/qla_os.c
@@ -96,6 +96,13 @@ MODULE_PARM_DESC(ql2xmaxqueues,
                 "Enables MQ settings "
                 "Default is 1 for single queue. Set it to number \
                         of queues in MQ mode.");
+
+int ql2xmultique_tag;
+module_param(ql2xmultique_tag, int, S_IRUGO|S_IRUSR);
+MODULE_PARM_DESC(ql2xmultique_tag,
+                "Enables CPU affinity settings for the driver "
+                "Default is 0 for no affinity of request and response IO. "
+                "Set it to 1 to turn on the cpu affinity.");
 /*
  * SCSI host template entry points
  */
@@ -256,6 +263,47 @@ static void qla2x00_free_queues(struct qla_hw_data *ha)
         ha->rsp_q_map = NULL;
 }
 
+static int qla25xx_setup_mode(struct scsi_qla_host *vha)
+{
+        uint16_t options = 0;
+        int ques, req, ret;
+        struct qla_hw_data *ha = vha->hw;
+
+        if (ql2xmultique_tag) {
+                /* CPU affinity mode */
+                ha->wq = create_workqueue("qla2xxx_wq");
+                /* create a request queue for IO */
+                options |= BIT_7;
+                req = qla25xx_create_req_que(ha, options, 0, 0, -1,
+                        QLA_DEFAULT_QUE_QOS);
+                if (!req) {
+                        qla_printk(KERN_WARNING, ha,
+                                "Can't create request queue\n");
+                        goto fail;
+                }
+                vha->req = ha->req_q_map[req];
+                options |= BIT_1;
+                for (ques = 1; ques < ha->max_rsp_queues; ques++) {
+                        ret = qla25xx_create_rsp_que(ha, options, 0, 0, req);
+                        if (!ret) {
+                                qla_printk(KERN_WARNING, ha,
+                                        "Response Queue create failed\n");
+                                goto fail2;
+                        }
+                }
+                DEBUG2(qla_printk(KERN_INFO, ha,
+                        "CPU affinity mode enabled, no. of response"
+                        " queues:%d, no. of request queues:%d\n",
+                        ha->max_rsp_queues, ha->max_req_queues));
+        }
+        return 0;
+fail2:
+        qla25xx_delete_queues(vha);
+fail:
+        ha->mqenable = 0;
+        return 1;
+}
+
 static char *
 qla2x00_pci_info_str(struct scsi_qla_host *vha, char *str)
 {
@@ -998,6 +1046,9 @@ qla2xxx_eh_host_reset(struct scsi_cmnd *cmd)
                 if (qla2x00_vp_abort_isp(vha))
                         goto eh_host_reset_lock;
         } else {
+                if (ha->wq)
+                        flush_workqueue(ha->wq);
+
                 set_bit(ABORT_ISP_ACTIVE, &base_vha->dpc_flags);
                 if (qla2x00_abort_isp(base_vha)) {
                         clear_bit(ABORT_ISP_ACTIVE, &base_vha->dpc_flags);
@@ -1521,6 +1572,7 @@ qla2x00_iospace_config(struct qla_hw_data *ha)
 {
         resource_size_t pio;
         uint16_t msix;
+        int cpus;
 
         if (pci_request_selected_regions(ha->pdev, ha->bars,
             QLA2XXX_DRIVER_NAME)) {
@@ -1575,7 +1627,7 @@ skip_pio:
 
         /* Determine queue resources */
         ha->max_req_queues = ha->max_rsp_queues = 1;
-        if (ql2xmaxqueues <= 1  &&
+        if ((ql2xmaxqueues <= 1 || ql2xmultique_tag < 1) &&
                 (!IS_QLA25XX(ha) && !IS_QLA81XX(ha)))
                 goto mqiobase_exit;
         ha->mqiobase = ioremap(pci_resource_start(ha->pdev, 3),
@@ -1584,12 +1636,21 @@ skip_pio:
                 /* Read MSIX vector size of the board */
                 pci_read_config_word(ha->pdev, QLA_PCI_MSIX_CONTROL, &msix);
                 ha->msix_count = msix;
-                if (ql2xmaxqueues > 1) {
+                /* Max queues are bounded by available msix vectors */
+                /* queue 0 uses two msix vectors */
+                if (ql2xmultique_tag) {
+                        cpus = num_online_cpus();
+                        ha->max_rsp_queues = (ha->msix_count - 1 - cpus) ?
+                                (cpus + 1) : (ha->msix_count - 1);
+                        ha->max_req_queues = 2;
+                } else if (ql2xmaxqueues > 1) {
                         ha->max_req_queues = ql2xmaxqueues > QLA_MQ_SIZE ?
                                                 QLA_MQ_SIZE : ql2xmaxqueues;
                         DEBUG2(qla_printk(KERN_INFO, ha, "QoS mode set, max no"
                         " of request queues:%d\n", ha->max_req_queues));
                 }
+                qla_printk(KERN_INFO, ha,
+                        "MSI-X vector count: %d\n", msix);
         } else
                 qla_printk(KERN_INFO, ha, "BAR 3 not enabled\n");
 
@@ -1871,6 +1932,12 @@ qla2x00_probe_one(struct pci_dev *pdev, const struct pci_device_id *id)
                 goto probe_failed;
         }
 
+        if (ha->mqenable)
+                if (qla25xx_setup_mode(base_vha))
+                        qla_printk(KERN_WARNING, ha,
+                                "Can't create queues, falling back to single"
+                                " queue mode\n");
+
         /*
          * Startup the kernel thread for this host adapter
          */
@@ -1982,6 +2049,13 @@ qla2x00_remove_one(struct pci_dev *pdev)
 
         base_vha->flags.online = 0;
 
+        /* Flush the work queue and remove it */
+        if (ha->wq) {
+                flush_workqueue(ha->wq);
+                destroy_workqueue(ha->wq);
+                ha->wq = NULL;
+        }
+
         /* Kill the kernel thread for this host */
         if (ha->dpc_thread) {
                 struct task_struct *t = ha->dpc_thread;