IB/mlx5: Refactor UMR to have its own context struct

Instead of having the UMR context part of each memory region, allocate
a struct on the stack.  This allows queuing multiple UMRs that access
the same memory region.

Signed-off-by: Shachar Raindel <raindel@mellanox.com>
Signed-off-by: Haggai Eran <haggaie@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

2 files changed, 31 insertions, 22 deletions

diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h
index 50541586e0a6..f2ccf1a5a291 100644
--- a/drivers/infiniband/hw/mlx5/mlx5_ib.h
+++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h
@@ -264,8 +264,6 @@ struct mlx5_ib_mr {
         __be64                  *pas;
         dma_addr_t              dma;
         int                     npages;
-        struct completion       done;
-        enum ib_wc_status       status;
         struct mlx5_ib_dev     *dev;
         struct mlx5_create_mkey_mbox_out out;
         struct mlx5_core_sig_ctx    *sig;
@@ -277,6 +275,17 @@ struct mlx5_ib_fast_reg_page_list {
         dma_addr_t                      map;
 };
 
+struct mlx5_ib_umr_context {
+        enum ib_wc_status       status;
+        struct completion       done;
+};
+
+static inline void mlx5_ib_init_umr_context(struct mlx5_ib_umr_context *context)
+{
+        context->status = -1;
+        init_completion(&context->done);
+}
+
 struct umr_common {
         struct ib_pd    *pd;
         struct ib_cq    *cq;
diff --git a/drivers/infiniband/hw/mlx5/mr.c b/drivers/infiniband/hw/mlx5/mr.c
index f472ab246d94..14ee4fdcf172 100644
--- a/drivers/infiniband/hw/mlx5/mr.c
+++ b/drivers/infiniband/hw/mlx5/mr.c
@@ -708,7 +708,7 @@ static void prep_umr_unreg_wqe(struct mlx5_ib_dev *dev,
 
 void mlx5_umr_cq_handler(struct ib_cq *cq, void *cq_context)
 {
-        struct mlx5_ib_mr *mr;
+        struct mlx5_ib_umr_context *context;
         struct ib_wc wc;
         int err;
 
@@ -721,9 +721,9 @@ void mlx5_umr_cq_handler(struct ib_cq *cq, void *cq_context)
                 if (err == 0)
                         break;
 
-                mr = (struct mlx5_ib_mr *)(unsigned long)wc.wr_id;
-                mr->status = wc.status;
-                complete(&mr->done);
+                context = (struct mlx5_ib_umr_context *)wc.wr_id;
+                context->status = wc.status;
+                complete(&context->done);
         }
         ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
 }
@@ -735,6 +735,7 @@ static struct mlx5_ib_mr *reg_umr(struct ib_pd *pd, struct ib_umem *umem,
         struct mlx5_ib_dev *dev = to_mdev(pd->device);
         struct device *ddev = dev->ib_dev.dma_device;
         struct umr_common *umrc = &dev->umrc;
+        struct mlx5_ib_umr_context umr_context;
         struct ib_send_wr wr, *bad;
         struct mlx5_ib_mr *mr;
         struct ib_sge sg;
@@ -774,24 +775,21 @@ static struct mlx5_ib_mr *reg_umr(struct ib_pd *pd, struct ib_umem *umem,
         }
 
         memset(&wr, 0, sizeof(wr));
-        wr.wr_id = (u64)(unsigned long)mr;
+        wr.wr_id = (u64)(unsigned long)&umr_context;
         prep_umr_reg_wqe(pd, &wr, &sg, mr->dma, npages, mr->mmr.key, page_shift, virt_addr, len, access_flags);
 
-        /* We serialize polls so one process does not kidnap another's
-         * completion. This is not a problem since wr is completed in
-         * around 1 usec
-         */
+        mlx5_ib_init_umr_context(&umr_context);
         down(&umrc->sem);
-        init_completion(&mr->done);
         err = ib_post_send(umrc->qp, &wr, &bad);
         if (err) {
                 mlx5_ib_warn(dev, "post send failed, err %d\n", err);
                 goto unmap_dma;
-        }
-        wait_for_completion(&mr->done);
-        if (mr->status != IB_WC_SUCCESS) {
-                mlx5_ib_warn(dev, "reg umr failed\n");
-                err = -EFAULT;
+        } else {
+                wait_for_completion(&umr_context.done);
+                if (umr_context.status != IB_WC_SUCCESS) {
+                        mlx5_ib_warn(dev, "reg umr failed\n");
+                        err = -EFAULT;
+                }
         }
 
         mr->mmr.iova = virt_addr;
@@ -940,24 +938,26 @@ error:
 static int unreg_umr(struct mlx5_ib_dev *dev, struct mlx5_ib_mr *mr)
 {
         struct umr_common *umrc = &dev->umrc;
+        struct mlx5_ib_umr_context umr_context;
         struct ib_send_wr wr, *bad;
         int err;
 
         memset(&wr, 0, sizeof(wr));
-        wr.wr_id = (u64)(unsigned long)mr;
+        wr.wr_id = (u64)(unsigned long)&umr_context;
         prep_umr_unreg_wqe(dev, &wr, mr->mmr.key);
 
+        mlx5_ib_init_umr_context(&umr_context);
         down(&umrc->sem);
-        init_completion(&mr->done);
         err = ib_post_send(umrc->qp, &wr, &bad);
         if (err) {
                 up(&umrc->sem);
                 mlx5_ib_dbg(dev, "err %d\n", err);
                 goto error;
+        } else {
+                wait_for_completion(&umr_context.done);
+                up(&umrc->sem);
         }
-        wait_for_completion(&mr->done);
-        up(&umrc->sem);
-        if (mr->status != IB_WC_SUCCESS) {
+        if (umr_context.status != IB_WC_SUCCESS) {
                 mlx5_ib_warn(dev, "unreg umr failed\n");
                 err = -EFAULT;
                 goto error;