iser-target: Use a single DMA MR and PD per device

This is to favor the HCA cache hit rate using less MRs
and PDs. This commit partially reverts commit:
"eb6ab13 IB/isert: separate connection protection domains and dma MRs"

At the time I thought this would be needed.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

2 files changed, 55 insertions, 48 deletions

diff --git a/drivers/infiniband/ulp/isert/ib_isert.c b/drivers/infiniband/ulp/isert/ib_isert.c
index 147029adb885..506c2eb60808 100644
--- a/drivers/infiniband/ulp/isert/ib_isert.c
+++ b/drivers/infiniband/ulp/isert/ib_isert.c
@@ -149,7 +149,7 @@ isert_conn_setup_qp(struct isert_conn *isert_conn, struct rdma_cm_id *cma_id)
         if (device->pi_capable)
                 attr.create_flags |= IB_QP_CREATE_SIGNATURE_EN;
 
-        ret = rdma_create_qp(cma_id, isert_conn->conn_pd, &attr);
+        ret = rdma_create_qp(cma_id, device->pd, &attr);
         if (ret) {
                 isert_err("rdma_create_qp failed for cma_id %d\n", ret);
                 goto err;
@@ -174,7 +174,8 @@ isert_cq_event_callback(struct ib_event *e, void *context)
 static int
 isert_alloc_rx_descriptors(struct isert_conn *isert_conn)
 {
-        struct ib_device *ib_dev = isert_conn->conn_cm_id->device;
+        struct isert_device *device = isert_conn->conn_device;
+        struct ib_device *ib_dev = device->ib_device;
         struct iser_rx_desc *rx_desc;
         struct ib_sge *rx_sg;
         u64 dma_addr;
@@ -198,7 +199,7 @@ isert_alloc_rx_descriptors(struct isert_conn *isert_conn)
                 rx_sg = &rx_desc->rx_sg;
                 rx_sg->addr = rx_desc->dma_addr;
                 rx_sg->length = ISER_RX_PAYLOAD_SIZE;
-                rx_sg->lkey = isert_conn->conn_mr->lkey;
+                rx_sg->lkey = device->mr->lkey;
         }
 
         isert_conn->conn_rx_desc_head = 0;
@@ -309,8 +310,27 @@ isert_create_device_ib_res(struct isert_device *device)
                         goto out_cq;
         }
 
+        device->pd = ib_alloc_pd(device->ib_device);
+        if (IS_ERR(device->pd)) {
+                ret = PTR_ERR(device->pd);
+                isert_err("failed to allocate pd, device %p, ret=%d\n",
+                          device, ret);
+                goto out_cq;
+        }
+
+        device->mr = ib_get_dma_mr(device->pd, IB_ACCESS_LOCAL_WRITE);
+        if (IS_ERR(device->mr)) {
+                ret = PTR_ERR(device->mr);
+                isert_err("failed to create dma mr, device %p, ret=%d\n",
+                          device, ret);
+                goto out_mr;
+        }
+
+
         return 0;
 
+out_mr:
+        ib_dealloc_pd(device->pd);
 out_cq:
         for (i = 0; i < device->comps_used; i++) {
                 struct isert_comp *comp = &device->comps[i];
@@ -332,6 +352,8 @@ isert_free_device_ib_res(struct isert_device *device)
 
         isert_info("device %p\n", device);
 
+        ib_dereg_mr(device->mr);
+        ib_dealloc_pd(device->pd);
         for (i = 0; i < device->comps_used; i++) {
                 struct isert_comp *comp = &device->comps[i];
 
@@ -547,7 +569,7 @@ isert_conn_create_fastreg_pool(struct isert_conn *isert_conn)
                 }
 
                 ret = isert_create_fr_desc(device->ib_device,
-                                           isert_conn->conn_pd, fr_desc);
+                                           device->pd, fr_desc);
                 if (ret) {
                         isert_err("Failed to create fastreg descriptor err=%d\n",
                                ret);
@@ -659,22 +681,6 @@ isert_connect_request(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
         isert_dbg("Using initiator_depth: %u\n", isert_conn->initiator_depth);
 
         isert_conn->conn_device = device;
-        isert_conn->conn_pd = ib_alloc_pd(isert_conn->conn_device->ib_device);
-        if (IS_ERR(isert_conn->conn_pd)) {
-                ret = PTR_ERR(isert_conn->conn_pd);
-                isert_err("ib_alloc_pd failed for conn %p: ret=%d\n",
-                       isert_conn, ret);
-                goto out_pd;
-        }
-
-        isert_conn->conn_mr = ib_get_dma_mr(isert_conn->conn_pd,
-                                           IB_ACCESS_LOCAL_WRITE);
-        if (IS_ERR(isert_conn->conn_mr)) {
-                ret = PTR_ERR(isert_conn->conn_mr);
-                isert_err("ib_get_dma_mr failed for conn %p: ret=%d\n",
-                       isert_conn, ret);
-                goto out_mr;
-        }
 
         ret = isert_conn_setup_qp(isert_conn, cma_id);
         if (ret)
@@ -697,10 +703,6 @@ isert_connect_request(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
         return 0;
 
 out_conn_dev:
-        ib_dereg_mr(isert_conn->conn_mr);
-out_mr:
-        ib_dealloc_pd(isert_conn->conn_pd);
-out_pd:
         isert_device_try_release(device);
 out_rsp_dma_map:
         ib_dma_unmap_single(ib_dev, isert_conn->login_rsp_dma,
@@ -742,9 +744,6 @@ isert_connect_release(struct isert_conn *isert_conn)
                 ib_destroy_qp(isert_conn->conn_qp);
         }
 
-        ib_dereg_mr(isert_conn->conn_mr);
-        ib_dealloc_pd(isert_conn->conn_pd);
-
         if (isert_conn->login_buf) {
                 ib_dma_unmap_single(ib_dev, isert_conn->login_rsp_dma,
                                     ISER_RX_LOGIN_SIZE, DMA_TO_DEVICE);
@@ -988,7 +987,8 @@ isert_create_send_desc(struct isert_conn *isert_conn,
                        struct isert_cmd *isert_cmd,
                        struct iser_tx_desc *tx_desc)
 {
-        struct ib_device *ib_dev = isert_conn->conn_cm_id->device;
+        struct isert_device *device = isert_conn->conn_device;
+        struct ib_device *ib_dev = device->ib_device;
 
         ib_dma_sync_single_for_cpu(ib_dev, tx_desc->dma_addr,
                                    ISER_HEADERS_LEN, DMA_TO_DEVICE);
@@ -999,8 +999,8 @@ isert_create_send_desc(struct isert_conn *isert_conn,
         tx_desc->num_sge = 1;
         tx_desc->isert_cmd = isert_cmd;
 
-        if (tx_desc->tx_sg[0].lkey != isert_conn->conn_mr->lkey) {
-                tx_desc->tx_sg[0].lkey = isert_conn->conn_mr->lkey;
+        if (tx_desc->tx_sg[0].lkey != device->mr->lkey) {
+                tx_desc->tx_sg[0].lkey = device->mr->lkey;
                 isert_dbg("tx_desc %p lkey mismatch, fixing\n", tx_desc);
         }
 }
@@ -1009,7 +1009,8 @@ static int
 isert_init_tx_hdrs(struct isert_conn *isert_conn,
                    struct iser_tx_desc *tx_desc)
 {
-        struct ib_device *ib_dev = isert_conn->conn_cm_id->device;
+        struct isert_device *device = isert_conn->conn_device;
+        struct ib_device *ib_dev = device->ib_device;
         u64 dma_addr;
 
         dma_addr = ib_dma_map_single(ib_dev, (void *)tx_desc,
@@ -1022,7 +1023,7 @@ isert_init_tx_hdrs(struct isert_conn *isert_conn,
         tx_desc->dma_addr = dma_addr;
         tx_desc->tx_sg[0].addr  = tx_desc->dma_addr;
         tx_desc->tx_sg[0].length = ISER_HEADERS_LEN;
-        tx_desc->tx_sg[0].lkey = isert_conn->conn_mr->lkey;
+        tx_desc->tx_sg[0].lkey = device->mr->lkey;
 
         isert_dbg("Setup tx_sg[0].addr: 0x%llx length: %u lkey: 0x%x\n",
                   tx_desc->tx_sg[0].addr, tx_desc->tx_sg[0].length,
@@ -1055,7 +1056,7 @@ isert_rdma_post_recvl(struct isert_conn *isert_conn)
         memset(&sge, 0, sizeof(struct ib_sge));
         sge.addr = isert_conn->login_req_dma;
         sge.length = ISER_RX_LOGIN_SIZE;
-        sge.lkey = isert_conn->conn_mr->lkey;
+        sge.lkey = isert_conn->conn_device->mr->lkey;
 
         isert_dbg("Setup sge: addr: %llx length: %d 0x%08x\n",
                 sge.addr, sge.length, sge.lkey);
@@ -1080,7 +1081,8 @@ isert_put_login_tx(struct iscsi_conn *conn, struct iscsi_login *login,
                    u32 length)
 {
         struct isert_conn *isert_conn = conn->context;
-        struct ib_device *ib_dev = isert_conn->conn_cm_id->device;
+        struct isert_device *device = isert_conn->conn_device;
+        struct ib_device *ib_dev = device->ib_device;
         struct iser_tx_desc *tx_desc = &isert_conn->conn_login_tx_desc;
         int ret;
 
@@ -1104,7 +1106,7 @@ isert_put_login_tx(struct iscsi_conn *conn, struct iscsi_login *login,
 
                 tx_dsg->addr    = isert_conn->login_rsp_dma;
                 tx_dsg->length  = length;
-                tx_dsg->lkey    = isert_conn->conn_mr->lkey;
+                tx_dsg->lkey    = isert_conn->conn_device->mr->lkey;
                 tx_desc->num_sge = 2;
         }
         if (!login->login_failed) {
@@ -2103,7 +2105,8 @@ isert_put_response(struct iscsi_conn *conn, struct iscsi_cmd *cmd)
         if (cmd->se_cmd.sense_buffer &&
             ((cmd->se_cmd.se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
             (cmd->se_cmd.se_cmd_flags & SCF_EMULATED_TASK_SENSE))) {
-                struct ib_device *ib_dev = isert_conn->conn_cm_id->device;
+                struct isert_device *device = isert_conn->conn_device;
+                struct ib_device *ib_dev = device->ib_device;
                 struct ib_sge *tx_dsg = &isert_cmd->tx_desc.tx_sg[1];
                 u32 padding, pdu_len;
 
@@ -2122,7 +2125,7 @@ isert_put_response(struct iscsi_conn *conn, struct iscsi_cmd *cmd)
                 isert_cmd->pdu_buf_len = pdu_len;
                 tx_dsg->addr    = isert_cmd->pdu_buf_dma;
                 tx_dsg->length  = pdu_len;
-                tx_dsg->lkey    = isert_conn->conn_mr->lkey;
+                tx_dsg->lkey    = device->mr->lkey;
                 isert_cmd->tx_desc.num_sge = 2;
         }
 
@@ -2233,7 +2236,8 @@ isert_put_reject(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
         struct isert_cmd *isert_cmd = iscsit_priv_cmd(cmd);
         struct isert_conn *isert_conn = (struct isert_conn *)conn->context;
         struct ib_send_wr *send_wr = &isert_cmd->tx_desc.send_wr;
-        struct ib_device *ib_dev = isert_conn->conn_cm_id->device;
+        struct isert_device *device = isert_conn->conn_device;
+        struct ib_device *ib_dev = device->ib_device;
         struct ib_sge *tx_dsg = &isert_cmd->tx_desc.tx_sg[1];
         struct iscsi_reject *hdr =
                 (struct iscsi_reject *)&isert_cmd->tx_desc.iscsi_header;
@@ -2249,7 +2253,7 @@ isert_put_reject(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
         isert_cmd->pdu_buf_len = ISCSI_HDR_LEN;
         tx_dsg->addr    = isert_cmd->pdu_buf_dma;
         tx_dsg->length  = ISCSI_HDR_LEN;
-        tx_dsg->lkey    = isert_conn->conn_mr->lkey;
+        tx_dsg->lkey    = device->mr->lkey;
         isert_cmd->tx_desc.num_sge = 2;
 
         isert_init_send_wr(isert_conn, isert_cmd, send_wr);
@@ -2279,7 +2283,8 @@ isert_put_text_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
         isert_init_tx_hdrs(isert_conn, &isert_cmd->tx_desc);
 
         if (txt_rsp_len) {
-                struct ib_device *ib_dev = isert_conn->conn_cm_id->device;
+                struct isert_device *device = isert_conn->conn_device;
+                struct ib_device *ib_dev = device->ib_device;
                 struct ib_sge *tx_dsg = &isert_cmd->tx_desc.tx_sg[1];
                 void *txt_rsp_buf = cmd->buf_ptr;
 
@@ -2289,7 +2294,7 @@ isert_put_text_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
                 isert_cmd->pdu_buf_len = txt_rsp_len;
                 tx_dsg->addr    = isert_cmd->pdu_buf_dma;
                 tx_dsg->length  = txt_rsp_len;
-                tx_dsg->lkey    = isert_conn->conn_mr->lkey;
+                tx_dsg->lkey    = device->mr->lkey;
                 isert_cmd->tx_desc.num_sge = 2;
         }
         isert_init_send_wr(isert_conn, isert_cmd, send_wr);
@@ -2306,7 +2311,8 @@ isert_build_rdma_wr(struct isert_conn *isert_conn, struct isert_cmd *isert_cmd,
 {
         struct iscsi_cmd *cmd = isert_cmd->iscsi_cmd;
         struct scatterlist *sg_start, *tmp_sg;
-        struct ib_device *ib_dev = isert_conn->conn_cm_id->device;
+        struct isert_device *device = isert_conn->conn_device;
+        struct ib_device *ib_dev = device->ib_device;
         u32 sg_off, page_off;
         int i = 0, sg_nents;
 
@@ -2330,7 +2336,7 @@ isert_build_rdma_wr(struct isert_conn *isert_conn, struct isert_cmd *isert_cmd,
                 ib_sge->addr = ib_sg_dma_address(ib_dev, tmp_sg) + page_off;
                 ib_sge->length = min_t(u32, data_left,
                                 ib_sg_dma_len(ib_dev, tmp_sg) - page_off);
-                ib_sge->lkey = isert_conn->conn_mr->lkey;
+                ib_sge->lkey = device->mr->lkey;
 
                 isert_dbg("RDMA ib_sge: addr: 0x%llx  length: %u lkey: %x\n",
                           ib_sge->addr, ib_sge->length, ib_sge->lkey);
@@ -2491,7 +2497,8 @@ isert_fast_reg_mr(struct isert_conn *isert_conn,
                   enum isert_indicator ind,
                   struct ib_sge *sge)
 {
-        struct ib_device *ib_dev = isert_conn->conn_cm_id->device;
+        struct isert_device *device = isert_conn->conn_device;
+        struct ib_device *ib_dev = device->ib_device;
         struct ib_mr *mr;
         struct ib_fast_reg_page_list *frpl;
         struct ib_send_wr fr_wr, inv_wr;
@@ -2500,7 +2507,7 @@ isert_fast_reg_mr(struct isert_conn *isert_conn,
         u32 page_off;
 
         if (mem->dma_nents == 1) {
-                sge->lkey = isert_conn->conn_mr->lkey;
+                sge->lkey = device->mr->lkey;
                 sge->addr = ib_sg_dma_address(ib_dev, &mem->sg[0]);
                 sge->length = ib_sg_dma_len(ib_dev, &mem->sg[0]);
                 isert_dbg("sge: addr: 0x%llx  length: %u lkey: %x\n",
@@ -2698,7 +2705,7 @@ isert_handle_prot_cmd(struct isert_conn *isert_conn,
         if (!wr->fr_desc->pi_ctx) {
                 ret = isert_create_pi_ctx(wr->fr_desc,
                                           device->ib_device,
-                                          isert_conn->conn_pd);
+                                          device->pd);
                 if (ret) {
                         isert_err("conn %p failed to allocate pi_ctx\n",
                                   isert_conn);
diff --git a/drivers/infiniband/ulp/isert/ib_isert.h b/drivers/infiniband/ulp/isert/ib_isert.h
index 8dc8415d152d..e386092a3274 100644
--- a/drivers/infiniband/ulp/isert/ib_isert.h
+++ b/drivers/infiniband/ulp/isert/ib_isert.h
@@ -169,8 +169,6 @@ struct isert_conn {
         struct completion       login_req_comp;
         struct iser_tx_desc     conn_login_tx_desc;
         struct rdma_cm_id       *conn_cm_id;
-        struct ib_pd            *conn_pd;
-        struct ib_mr            *conn_mr;
         struct ib_qp            *conn_qp;
         struct isert_device     *conn_device;
         struct mutex            conn_mutex;
@@ -211,6 +209,8 @@ struct isert_device {
         bool                    pi_capable;
         int                     refcount;
         struct ib_device        *ib_device;
+        struct ib_pd            *pd;
+        struct ib_mr            *mr;
         struct isert_comp       *comps;
         int                     comps_used;
         struct list_head        dev_node;