IB/iser: Centralize iser completion contexts

Introduce iser_comp which centralizes all iser completion related
items and is referenced by iser_device and each ib_conn.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

2 files changed, 84 insertions, 87 deletions

diff --git a/drivers/infiniband/ulp/iser/iscsi_iser.h b/drivers/infiniband/ulp/iser/iscsi_iser.h
index 95c484d0f881..2bc34aa50705 100644
--- a/drivers/infiniband/ulp/iser/iscsi_iser.h
+++ b/drivers/infiniband/ulp/iser/iscsi_iser.h
@@ -213,7 +213,6 @@ struct iser_data_buf {
 
 /* fwd declarations */
 struct iser_device;
-struct iser_cq_desc;
 struct iscsi_iser_task;
 struct iscsi_endpoint;
 
@@ -268,20 +267,34 @@ struct iser_conn;
 struct ib_conn;
 struct iscsi_iser_task;
 
+/**
+ * struct iser_comp - iSER completion context
+ *
+ * @device:     pointer to device handle
+ * @rx_cq:      RX completion queue
+ * @tx_cq:      TX completion queue
+ * @tasklet:    Tasklet handle
+ * @active_qps: Number of active QPs attached
+ *              to completion context
+ */
+struct iser_comp {
+        struct iser_device      *device;
+        struct ib_cq            *rx_cq;
+        struct ib_cq            *tx_cq;
+        struct tasklet_struct    tasklet;
+        int                      active_qps;
+};
+
 struct iser_device {
         struct ib_device             *ib_device;
         struct ib_pd                 *pd;
         struct ib_device_attr        dev_attr;
-        struct ib_cq                 *rx_cq[ISER_MAX_CQ];
-        struct ib_cq                 *tx_cq[ISER_MAX_CQ];
         struct ib_mr                 *mr;
-        struct tasklet_struct        cq_tasklet[ISER_MAX_CQ];
         struct ib_event_handler      event_handler;
         struct list_head             ig_list; /* entry in ig devices list */
         int                          refcount;
-        int                          cq_active_qps[ISER_MAX_CQ];
-        int                          cqs_used;
-        struct iser_cq_desc          *cq_desc;
+        int                          comps_used;
+        struct iser_comp             comps[ISER_MAX_CQ];
         int                          (*iser_alloc_rdma_reg_res)(struct ib_conn *ib_conn,
                                                                 unsigned cmds_max);
         void                         (*iser_free_rdma_reg_res)(struct ib_conn *ib_conn);
@@ -327,6 +340,7 @@ struct fast_reg_descriptor {
  * @post_send_buf_count: post send counter
  * @rx_wr:               receive work request for batch posts
  * @device:              reference to iser device
+ * @comp:                iser completion context
  * @pi_support:          Indicate device T10-PI support
  * @lock:                protects fmr/fastreg pool
  * @union.fmr:
@@ -345,7 +359,7 @@ struct ib_conn {
         atomic_t                     post_send_buf_count;
         struct ib_recv_wr            rx_wr[ISER_MIN_POSTED_RX];
         struct iser_device          *device;
-        int                          cq_index;
+        struct iser_comp            *comp;
         bool                         pi_support;
         spinlock_t                   lock;
         union {
@@ -404,11 +418,6 @@ struct iser_page_vec {
         int data_size;
 };
 
-struct iser_cq_desc {
-        struct iser_device           *device;
-        int                          cq_index;
-};
-
 struct iser_global {
         struct mutex      device_list_mutex;/*                   */
         struct list_head  device_list;       /* all iSER devices */
diff --git a/drivers/infiniband/ulp/iser/iser_verbs.c b/drivers/infiniband/ulp/iser/iser_verbs.c
index 57b20c691367..94d1b46b467a 100644
--- a/drivers/infiniband/ulp/iser/iser_verbs.c
+++ b/drivers/infiniband/ulp/iser/iser_verbs.c
@@ -44,7 +44,7 @@
 
 static void iser_cq_tasklet_fn(unsigned long data);
 static void iser_cq_callback(struct ib_cq *cq, void *cq_context);
-static int iser_drain_tx_cq(struct iser_device  *device, int cq_index);
+static int iser_drain_tx_cq(struct iser_comp *comp);
 
 static void iser_cq_event_callback(struct ib_event *cause, void *context)
 {
@@ -72,7 +72,6 @@ static void iser_event_handler(struct ib_event_handler *handler,
  */
 static int iser_create_device_ib_res(struct iser_device *device)
 {
-        struct iser_cq_desc *cq_desc;
         struct ib_device_attr *dev_attr = &device->dev_attr;
         int ret, i;
 
@@ -102,51 +101,44 @@ static int iser_create_device_ib_res(struct iser_device *device)
                 return -1;
         }
 
-        device->cqs_used = min(ISER_MAX_CQ, device->ib_device->num_comp_vectors);
+        device->comps_used = min(ISER_MAX_CQ,
+                                 device->ib_device->num_comp_vectors);
         iser_info("using %d CQs, device %s supports %d vectors\n",
-                  device->cqs_used, device->ib_device->name,
+                  device->comps_used, device->ib_device->name,
                   device->ib_device->num_comp_vectors);
 
-        device->cq_desc = kmalloc(sizeof(struct iser_cq_desc) * device->cqs_used,
-                                  GFP_KERNEL);
-        if (device->cq_desc == NULL)
-                goto cq_desc_err;
-        cq_desc = device->cq_desc;
-
         device->pd = ib_alloc_pd(device->ib_device);
         if (IS_ERR(device->pd))
                 goto pd_err;
 
-        for (i = 0; i < device->cqs_used; i++) {
-                cq_desc[i].device   = device;
-                cq_desc[i].cq_index = i;
-
-                device->rx_cq[i] = ib_create_cq(device->ib_device,
-                                          iser_cq_callback,
-                                          iser_cq_event_callback,
-                                          (void *)&cq_desc[i],
-                                          ISER_MAX_RX_CQ_LEN, i);
-                if (IS_ERR(device->rx_cq[i])) {
-                        device->rx_cq[i] = NULL;
+        for (i = 0; i < device->comps_used; i++) {
+                struct iser_comp *comp = &device->comps[i];
+
+                comp->device = device;
+                comp->rx_cq = ib_create_cq(device->ib_device,
+                                           iser_cq_callback,
+                                           iser_cq_event_callback,
+                                           (void *)comp,
+                                           ISER_MAX_RX_CQ_LEN, i);
+                if (IS_ERR(comp->rx_cq)) {
+                        comp->rx_cq = NULL;
                         goto cq_err;
                 }
 
-                device->tx_cq[i] = ib_create_cq(device->ib_device,
-                                          NULL, iser_cq_event_callback,
-                                          (void *)&cq_desc[i],
-                                          ISER_MAX_TX_CQ_LEN, i);
-
-                if (IS_ERR(device->tx_cq[i])) {
-                        device->tx_cq[i] = NULL;
+                comp->tx_cq = ib_create_cq(device->ib_device, NULL,
+                                           iser_cq_event_callback,
+                                           (void *)comp,
+                                           ISER_MAX_TX_CQ_LEN, i);
+                if (IS_ERR(comp->tx_cq)) {
+                        comp->tx_cq = NULL;
                         goto cq_err;
                 }
 
-                if (ib_req_notify_cq(device->rx_cq[i], IB_CQ_NEXT_COMP))
+                if (ib_req_notify_cq(comp->rx_cq, IB_CQ_NEXT_COMP))
                         goto cq_err;
 
-                tasklet_init(&device->cq_tasklet[i],
-                             iser_cq_tasklet_fn,
-                        (unsigned long)&cq_desc[i]);
+                tasklet_init(&comp->tasklet, iser_cq_tasklet_fn,
+                             (unsigned long)comp);
         }
 
         device->mr = ib_get_dma_mr(device->pd, IB_ACCESS_LOCAL_WRITE |
@@ -165,19 +157,19 @@ static int iser_create_device_ib_res(struct iser_device *device)
 handler_err:
         ib_dereg_mr(device->mr);
 dma_mr_err:
-        for (i = 0; i < device->cqs_used; i++)
-                tasklet_kill(&device->cq_tasklet[i]);
+        for (i = 0; i < device->comps_used; i++)
+                tasklet_kill(&device->comps[i].tasklet);
 cq_err:
-        for (i = 0; i < device->cqs_used; i++) {
-                if (device->tx_cq[i])
-                        ib_destroy_cq(device->tx_cq[i]);
-                if (device->rx_cq[i])
-                        ib_destroy_cq(device->rx_cq[i]);
+        for (i = 0; i < device->comps_used; i++) {
+                struct iser_comp *comp = &device->comps[i];
+
+                if (comp->tx_cq)
+                        ib_destroy_cq(comp->tx_cq);
+                if (comp->rx_cq)
+                        ib_destroy_cq(comp->rx_cq);
         }
         ib_dealloc_pd(device->pd);
 pd_err:
-        kfree(device->cq_desc);
-cq_desc_err:
         iser_err("failed to allocate an IB resource\n");
         return -1;
 }
@@ -191,20 +183,20 @@ static void iser_free_device_ib_res(struct iser_device *device)
         int i;
         BUG_ON(device->mr == NULL);
 
-        for (i = 0; i < device->cqs_used; i++) {
-                tasklet_kill(&device->cq_tasklet[i]);
-                (void)ib_destroy_cq(device->tx_cq[i]);
-                (void)ib_destroy_cq(device->rx_cq[i]);
-                device->tx_cq[i] = NULL;
-                device->rx_cq[i] = NULL;
+        for (i = 0; i < device->comps_used; i++) {
+                struct iser_comp *comp = &device->comps[i];
+
+                tasklet_kill(&comp->tasklet);
+                ib_destroy_cq(comp->tx_cq);
+                ib_destroy_cq(comp->rx_cq);
+                comp->tx_cq = NULL;
+                comp->rx_cq = NULL;
         }
 
         (void)ib_unregister_event_handler(&device->event_handler);
         (void)ib_dereg_mr(device->mr);
         (void)ib_dealloc_pd(device->pd);
 
-        kfree(device->cq_desc);
-
         device->mr = NULL;
         device->pd = NULL;
 }
@@ -456,19 +448,20 @@ static int iser_create_ib_conn_res(struct ib_conn *ib_conn)
 
         mutex_lock(&ig.connlist_mutex);
         /* select the CQ with the minimal number of usages */
-        for (index = 0; index < device->cqs_used; index++)
-                if (device->cq_active_qps[index] <
-                    device->cq_active_qps[min_index])
+        for (index = 0; index < device->comps_used; index++) {
+                if (device->comps[index].active_qps <
+                    device->comps[min_index].active_qps)
                         min_index = index;
-        device->cq_active_qps[min_index]++;
-        ib_conn->cq_index = min_index;
+        }
+        ib_conn->comp = &device->comps[min_index];
+        ib_conn->comp->active_qps++;
         mutex_unlock(&ig.connlist_mutex);
         iser_info("cq index %d used for ib_conn %p\n", min_index, ib_conn);
 
         init_attr.event_handler = iser_qp_event_callback;
         init_attr.qp_context    = (void *)ib_conn;
-        init_attr.send_cq       = device->tx_cq[min_index];
-        init_attr.recv_cq       = device->rx_cq[min_index];
+        init_attr.send_cq       = ib_conn->comp->tx_cq;
+        init_attr.recv_cq       = ib_conn->comp->rx_cq;
         init_attr.cap.max_recv_wr  = ISER_QP_MAX_RECV_DTOS;
         init_attr.cap.max_send_sge = 2;
         init_attr.cap.max_recv_sge = 1;
@@ -604,7 +597,7 @@ static void iser_free_ib_conn_res(struct iser_conn *iser_conn,
         iser_free_rx_descriptors(iser_conn);
 
         if (ib_conn->qp != NULL) {
-                ib_conn->device->cq_active_qps[ib_conn->cq_index]--;
+                ib_conn->comp->active_qps--;
                 rdma_destroy_qp(ib_conn->cma_id);
                 ib_conn->qp = NULL;
         }
@@ -655,14 +648,13 @@ void iser_conn_release(struct iser_conn *iser_conn)
  */
 static void iser_poll_for_flush_errors(struct ib_conn *ib_conn)
 {
-        struct iser_device *device = ib_conn->device;
         int count = 0;
 
         while (ib_conn->post_recv_buf_count > 0 ||
                atomic_read(&ib_conn->post_send_buf_count) > 0) {
                 msleep(100);
                 if (atomic_read(&ib_conn->post_send_buf_count) > 0)
-                        iser_drain_tx_cq(device, ib_conn->cq_index);
+                        iser_drain_tx_cq(ib_conn->comp);
 
                 count++;
                 /* Don't flood with prints */
@@ -1189,9 +1181,9 @@ iser_handle_comp_error(struct iser_tx_desc *desc,
                 kmem_cache_free(ig.desc_cache, desc);
 }
 
-static int iser_drain_tx_cq(struct iser_device  *device, int cq_index)
+static int iser_drain_tx_cq(struct iser_comp *comp)
 {
-        struct ib_cq  *cq = device->tx_cq[cq_index];
+        struct ib_cq *cq = comp->tx_cq;
         struct ib_wc  wc;
         struct iser_tx_desc *tx_desc;
         struct ib_conn *ib_conn;
@@ -1222,20 +1214,18 @@ static int iser_drain_tx_cq(struct iser_device  *device, int cq_index)
 
 static void iser_cq_tasklet_fn(unsigned long data)
 {
-        struct iser_cq_desc *cq_desc = (struct iser_cq_desc *)data;
-        struct iser_device  *device = cq_desc->device;
-        int cq_index = cq_desc->cq_index;
-        struct ib_cq         *cq = device->rx_cq[cq_index];
-         struct ib_wc        wc;
-         struct iser_rx_desc *desc;
-         unsigned long       xfer_len;
+        struct iser_comp *comp = (struct iser_comp *)data;
+        struct ib_cq *cq = comp->rx_cq;
+        struct ib_wc wc;
+        struct iser_rx_desc *desc;
+        unsigned long xfer_len;
         struct ib_conn *ib_conn;
         int completed_tx, completed_rx = 0;
 
         /* First do tx drain, so in a case where we have rx flushes and a successful
          * tx completion we will still go through completion error handling.
          */
-        completed_tx = iser_drain_tx_cq(device, cq_index);
+        completed_tx = iser_drain_tx_cq(comp);
 
         while (ib_poll_cq(cq, 1, &wc) == 1) {
                 desc     = (struct iser_rx_desc *) (unsigned long) wc.wr_id;
@@ -1257,7 +1247,7 @@ static void iser_cq_tasklet_fn(unsigned long data)
                 }
                 completed_rx++;
                 if (!(completed_rx & 63))
-                        completed_tx += iser_drain_tx_cq(device, cq_index);
+                        completed_tx += iser_drain_tx_cq(comp);
         }
         /* #warning "it is assumed here that arming CQ only once its empty" *
          * " would not cause interrupts to be missed"                       */
@@ -1268,11 +1258,9 @@ static void iser_cq_tasklet_fn(unsigned long data)
 
 static void iser_cq_callback(struct ib_cq *cq, void *cq_context)
 {
-        struct iser_cq_desc *cq_desc = (struct iser_cq_desc *)cq_context;
-        struct iser_device  *device = cq_desc->device;
-        int cq_index = cq_desc->cq_index;
+        struct iser_comp *comp = cq_context;
 
-        tasklet_schedule(&device->cq_tasklet[cq_index]);
+        tasklet_schedule(&comp->tasklet);
 }
 
 u8 iser_check_task_pi_status(struct iscsi_iser_task *iser_task,