IB/mlx4: Don't allocate RQ doorbell if using SRQ

If a QP is attached to a shared receive queue (SRQ), then it doesn't
have a receive queue (RQ).  So don't allocate an RQ doorbell (or map a
doorbell from userspace for userspace QPs) for that QP.

Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 22 insertions, 15 deletions

diff --git a/drivers/infiniband/hw/mlx4/qp.c b/drivers/infiniband/hw/mlx4/qp.c
index a824bc5f79fd..88a994d8a133 100644
--- a/drivers/infiniband/hw/mlx4/qp.c
+++ b/drivers/infiniband/hw/mlx4/qp.c
@@ -319,20 +319,24 @@ static int create_qp_common(struct mlx4_ib_dev *dev, struct ib_pd *pd,
                 if (err)
                         goto err_mtt;
 
-                err = mlx4_ib_db_map_user(to_mucontext(pd->uobject->context),
-                                          ucmd.db_addr, &qp->db);
-                if (err)
-                        goto err_mtt;
+                if (!init_attr->srq) {
+                        err = mlx4_ib_db_map_user(to_mucontext(pd->uobject->context),
+                                                  ucmd.db_addr, &qp->db);
+                        if (err)
+                                goto err_mtt;
+                }
         } else {
                 err = set_kernel_sq_size(dev, &init_attr->cap, init_attr->qp_type, qp);
                 if (err)
                         goto err;
 
-                err = mlx4_ib_db_alloc(dev, &qp->db, 0);
-                if (err)
-                        goto err;
+                if (!init_attr->srq) {
+                        err = mlx4_ib_db_alloc(dev, &qp->db, 0);
+                        if (err)
+                                goto err;
 
-                *qp->db.db = 0;
+                        *qp->db.db = 0;
+                }
 
                 if (mlx4_buf_alloc(dev->dev, qp->buf_size, PAGE_SIZE * 2, &qp->buf)) {
                         err = -ENOMEM;
@@ -386,7 +390,7 @@ static int create_qp_common(struct mlx4_ib_dev *dev, struct ib_pd *pd,
         return 0;
 
 err_wrid:
-        if (pd->uobject)
+        if (pd->uobject && !init_attr->srq)
                 mlx4_ib_db_unmap_user(to_mucontext(pd->uobject->context), &qp->db);
         else {
                 kfree(qp->sq.wrid);
@@ -403,7 +407,7 @@ err_buf:
                 mlx4_buf_free(dev->dev, qp->buf_size, &qp->buf);
 
 err_db:
-        if (!pd->uobject)
+        if (!pd->uobject && !init_attr->srq)
                 mlx4_ib_db_free(dev, &qp->db);
 
 err:
@@ -481,14 +485,16 @@ static void destroy_qp_common(struct mlx4_ib_dev *dev, struct mlx4_ib_qp *qp,
         mlx4_mtt_cleanup(dev->dev, &qp->mtt);
 
         if (is_user) {
-                mlx4_ib_db_unmap_user(to_mucontext(qp->ibqp.uobject->context),
-                                      &qp->db);
+                if (!qp->ibqp.srq)
+                        mlx4_ib_db_unmap_user(to_mucontext(qp->ibqp.uobject->context),
+                                              &qp->db);
                 ib_umem_release(qp->umem);
         } else {
                 kfree(qp->sq.wrid);
                 kfree(qp->rq.wrid);
                 mlx4_buf_free(dev->dev, qp->buf_size, &qp->buf);
-                mlx4_ib_db_free(dev, &qp->db);
+                if (!qp->ibqp.srq)
+                        mlx4_ib_db_free(dev, &qp->db);
         }
 }
 
@@ -852,7 +858,7 @@ static int __mlx4_ib_modify_qp(struct ib_qp *ibqp,
         if (ibqp->srq)
                 context->srqn = cpu_to_be32(1 << 24 | to_msrq(ibqp->srq)->msrq.srqn);
 
-        if (cur_state == IB_QPS_RESET && new_state == IB_QPS_INIT)
+        if (!ibqp->srq && cur_state == IB_QPS_RESET && new_state == IB_QPS_INIT)
                 context->db_rec_addr = cpu_to_be64(qp->db.dma);
 
         if (cur_state == IB_QPS_INIT &&
@@ -919,7 +925,8 @@ static int __mlx4_ib_modify_qp(struct ib_qp *ibqp,
                 qp->rq.tail = 0;
                 qp->sq.head = 0;
                 qp->sq.tail = 0;
-                *qp->db.db  = 0;
+                if (!ibqp->srq)
+                        *qp->db.db  = 0;
         }
 
 out: