RDMA/ocrdma: Add support for interrupt moderation

Add support for interrupt moderation for ocrdma device.  Thresholds
for high interrupt rates are static values derived based on experimental
results.

Signed-off-by: Mitesh Ahuja <mitesh.ahuja@emulex.com>
Signed-off-by: Devesh Sharma <devesh.sharma@emulex.com>
Signed-off-by: Selvin Xavier <selvin.xavier@emulex.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

4 files changed, 119 insertions, 0 deletions

diff --git a/drivers/infiniband/hw/ocrdma/ocrdma.h b/drivers/infiniband/hw/ocrdma/ocrdma.h
index 933b38af13f0..b9fee0ed32d2 100644
--- a/drivers/infiniband/hw/ocrdma/ocrdma.h
+++ b/drivers/infiniband/hw/ocrdma/ocrdma.h
@@ -55,6 +55,12 @@
 #define OCRDMA_UVERBS(CMD_NAME) (1ull << IB_USER_VERBS_CMD_##CMD_NAME)
 
 #define convert_to_64bit(lo, hi) ((u64)hi << 32 | (u64)lo)
+#define EQ_INTR_PER_SEC_THRSH_HI 150000
+#define EQ_INTR_PER_SEC_THRSH_LOW 100000
+#define EQ_AIC_MAX_EQD 20
+#define EQ_AIC_MIN_EQD 0
+
+void ocrdma_eqd_set_task(struct work_struct *work);
 
 struct ocrdma_dev_attr {
         u8 fw_ver[32];
@@ -117,12 +123,19 @@ struct ocrdma_queue_info {
         bool created;
 };
 
+struct ocrdma_aic_obj {         /* Adaptive interrupt coalescing (AIC) info */
+        u32 prev_eqd;
+        u64 eq_intr_cnt;
+        u64 prev_eq_intr_cnt;
+};
+
 struct ocrdma_eq {
         struct ocrdma_queue_info q;
         u32 vector;
         int cq_cnt;
         struct ocrdma_dev *dev;
         char irq_name[32];
+        struct ocrdma_aic_obj aic_obj;
 };
 
 struct ocrdma_mq {
@@ -214,6 +227,7 @@ struct ocrdma_dev {
 
         struct ocrdma_eq *eq_tbl;
         int eq_cnt;
+        struct delayed_work eqd_work;
         u16 base_eqid;
         u16 max_eq;
 
diff --git a/drivers/infiniband/hw/ocrdma/ocrdma_hw.c b/drivers/infiniband/hw/ocrdma/ocrdma_hw.c
index 6e9680d18934..189ebc7c20af 100644
--- a/drivers/infiniband/hw/ocrdma/ocrdma_hw.c
+++ b/drivers/infiniband/hw/ocrdma/ocrdma_hw.c
@@ -960,6 +960,7 @@ static irqreturn_t ocrdma_irq_handler(int irq, void *handle)
 
         } while (budget);
 
+        eq->aic_obj.eq_intr_cnt++;
         ocrdma_ring_eq_db(dev, eq->q.id, true, true, 0);
         return IRQ_HANDLED;
 }
@@ -3016,6 +3017,82 @@ done:
         return status;
 }
 
+static int ocrdma_mbx_modify_eqd(struct ocrdma_dev *dev, struct ocrdma_eq *eq,
+                                 int num)
+{
+        int i, status = -ENOMEM;
+        struct ocrdma_modify_eqd_req *cmd;
+
+        cmd = ocrdma_init_emb_mqe(OCRDMA_CMD_MODIFY_EQ_DELAY, sizeof(*cmd));
+        if (!cmd)
+                return status;
+
+        ocrdma_init_mch(&cmd->cmd.req, OCRDMA_CMD_MODIFY_EQ_DELAY,
+                        OCRDMA_SUBSYS_COMMON, sizeof(*cmd));
+
+        cmd->cmd.num_eq = num;
+        for (i = 0; i < num; i++) {
+                cmd->cmd.set_eqd[i].eq_id = eq[i].q.id;
+                cmd->cmd.set_eqd[i].phase = 0;
+                cmd->cmd.set_eqd[i].delay_multiplier =
+                                (eq[i].aic_obj.prev_eqd * 65)/100;
+        }
+        status = ocrdma_mbx_cmd(dev, (struct ocrdma_mqe *)cmd);
+        if (status)
+                goto mbx_err;
+mbx_err:
+        kfree(cmd);
+        return status;
+}
+
+static int ocrdma_modify_eqd(struct ocrdma_dev *dev, struct ocrdma_eq *eq,
+                             int num)
+{
+        int num_eqs, i = 0;
+        if (num > 8) {
+                while (num) {
+                        num_eqs = min(num, 8);
+                        ocrdma_mbx_modify_eqd(dev, &eq[i], num_eqs);
+                        i += num_eqs;
+                        num -= num_eqs;
+                }
+        } else {
+                ocrdma_mbx_modify_eqd(dev, eq, num);
+        }
+        return 0;
+}
+
+void ocrdma_eqd_set_task(struct work_struct *work)
+{
+        struct ocrdma_dev *dev =
+                container_of(work, struct ocrdma_dev, eqd_work.work);
+        struct ocrdma_eq *eq = 0;
+        int i, num = 0, status = -EINVAL;
+        u64 eq_intr;
+
+        for (i = 0; i < dev->eq_cnt; i++) {
+                eq = &dev->eq_tbl[i];
+                if (eq->aic_obj.eq_intr_cnt > eq->aic_obj.prev_eq_intr_cnt) {
+                        eq_intr = eq->aic_obj.eq_intr_cnt -
+                                  eq->aic_obj.prev_eq_intr_cnt;
+                        if ((eq_intr > EQ_INTR_PER_SEC_THRSH_HI) &&
+                            (eq->aic_obj.prev_eqd == EQ_AIC_MIN_EQD)) {
+                                eq->aic_obj.prev_eqd = EQ_AIC_MAX_EQD;
+                                num++;
+                        } else if ((eq_intr < EQ_INTR_PER_SEC_THRSH_LOW) &&
+                                   (eq->aic_obj.prev_eqd == EQ_AIC_MAX_EQD)) {
+                                eq->aic_obj.prev_eqd = EQ_AIC_MIN_EQD;
+                                num++;
+                        }
+                }
+                eq->aic_obj.prev_eq_intr_cnt = eq->aic_obj.eq_intr_cnt;
+        }
+
+        if (num)
+                status = ocrdma_modify_eqd(dev, &dev->eq_tbl[0], num);
+        schedule_delayed_work(&dev->eqd_work, msecs_to_jiffies(1000));
+}
+
 int ocrdma_init_hw(struct ocrdma_dev *dev)
 {
         int status;
diff --git a/drivers/infiniband/hw/ocrdma/ocrdma_main.c b/drivers/infiniband/hw/ocrdma/ocrdma_main.c
index 0083360d918e..7a2b59aca004 100644
--- a/drivers/infiniband/hw/ocrdma/ocrdma_main.c
+++ b/drivers/infiniband/hw/ocrdma/ocrdma_main.c
@@ -493,6 +493,9 @@ static struct ocrdma_dev *ocrdma_add(struct be_dev_info *dev_info)
         spin_unlock(&ocrdma_devlist_lock);
         /* Init stats */
         ocrdma_add_port_stats(dev);
+        /* Interrupt Moderation */
+        INIT_DELAYED_WORK(&dev->eqd_work, ocrdma_eqd_set_task);
+        schedule_delayed_work(&dev->eqd_work, msecs_to_jiffies(1000));
 
         pr_info("%s %s: %s \"%s\" port %d\n",
                 dev_name(&dev->nic_info.pdev->dev), hca_name(dev),
@@ -530,6 +533,7 @@ static void ocrdma_remove(struct ocrdma_dev *dev)
         /* first unregister with stack to stop all the active traffic
          * of the registered clients.
          */
+        cancel_delayed_work_sync(&dev->eqd_work);
         ocrdma_remove_sysfiles(dev);
         ib_unregister_device(&dev->ibdev);
 
diff --git a/drivers/infiniband/hw/ocrdma/ocrdma_sli.h b/drivers/infiniband/hw/ocrdma/ocrdma_sli.h
index 6ba9939868a3..801883aa4145 100644
--- a/drivers/infiniband/hw/ocrdma/ocrdma_sli.h
+++ b/drivers/infiniband/hw/ocrdma/ocrdma_sli.h
@@ -89,6 +89,7 @@ enum {
         OCRDMA_CMD_CREATE_MQ            = 21,
         OCRDMA_CMD_GET_CTRL_ATTRIBUTES  = 32,
         OCRDMA_CMD_GET_FW_VER           = 35,
+        OCRDMA_CMD_MODIFY_EQ_DELAY      = 41,
         OCRDMA_CMD_DELETE_MQ            = 53,
         OCRDMA_CMD_DELETE_CQ            = 54,
         OCRDMA_CMD_DELETE_EQ            = 55,
@@ -316,6 +317,29 @@ struct ocrdma_create_eq_rsp {
 
 #define OCRDMA_EQ_MINOR_OTHER   0x1
 
+struct ocrmda_set_eqd {
+        u32 eq_id;
+        u32 phase;
+        u32 delay_multiplier;
+};
+
+struct ocrdma_modify_eqd_cmd {
+        struct ocrdma_mbx_hdr req;
+        u32 num_eq;
+        struct ocrmda_set_eqd set_eqd[8];
+} __packed;
+
+struct ocrdma_modify_eqd_req {
+        struct ocrdma_mqe_hdr hdr;
+        struct ocrdma_modify_eqd_cmd cmd;
+};
+
+
+struct ocrdma_modify_eq_delay_rsp {
+        struct ocrdma_mbx_rsp hdr;
+        u32 rsvd0;
+} __packed;
+
 enum {
         OCRDMA_MCQE_STATUS_SHIFT        = 0,
         OCRDMA_MCQE_STATUS_MASK         = 0xFFFF,