xprtrdma: Remove last ib_reg_phys_mr() call site

All HCA providers have an ib_get_dma_mr() verb. Thus
rpcrdma_ia_open() will either grab the device's local_dma_key if one
is available, or it will call ib_get_dma_mr(). If ib_get_dma_mr()
fails, rpcrdma_ia_open() fails and no transport is created.

Therefore execution never reaches the ib_reg_phys_mr() call site in
rpcrdma_register_internal(), so it can be removed.

The remaining logic in rpcrdma_{de}register_internal() is folded
into rpcrdma_{alloc,free}_regbuf().

This is clean up only. No behavior change is expected.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Devesh Sharma <devesh.sharma@avagotech.com>
Reviewed-By: Sagi Grimberg <sagig@mellanox.com>
Tested-by: Devesh Sharma <devesh.sharma@avagotech.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

2 files changed, 21 insertions, 82 deletions

diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index 1065808d25b4..da184f98fdf9 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -1229,75 +1229,6 @@ rpcrdma_mapping_error(struct rpcrdma_mr_seg *seg)
                 (unsigned long long)seg->mr_dma, seg->mr_dmalen);
 }
 
-static int
-rpcrdma_register_internal(struct rpcrdma_ia *ia, void *va, int len,
-                                struct ib_mr **mrp, struct ib_sge *iov)
-{
-        struct ib_phys_buf ipb;
-        struct ib_mr *mr;
-        int rc;
-
-        /*
-         * All memory passed here was kmalloc'ed, therefore phys-contiguous.
-         */
-        iov->addr = ib_dma_map_single(ia->ri_device,
-                        va, len, DMA_BIDIRECTIONAL);
-        if (ib_dma_mapping_error(ia->ri_device, iov->addr))
-                return -ENOMEM;
-
-        iov->length = len;
-
-        if (ia->ri_have_dma_lkey) {
-                *mrp = NULL;
-                iov->lkey = ia->ri_dma_lkey;
-                return 0;
-        } else if (ia->ri_bind_mem != NULL) {
-                *mrp = NULL;
-                iov->lkey = ia->ri_bind_mem->lkey;
-                return 0;
-        }
-
-        ipb.addr = iov->addr;
-        ipb.size = iov->length;
-        mr = ib_reg_phys_mr(ia->ri_pd, &ipb, 1,
-                        IB_ACCESS_LOCAL_WRITE, &iov->addr);
-
-        dprintk("RPC:       %s: phys convert: 0x%llx "
-                        "registered 0x%llx length %d\n",
-                        __func__, (unsigned long long)ipb.addr,
-                        (unsigned long long)iov->addr, len);
-
-        if (IS_ERR(mr)) {
-                *mrp = NULL;
-                rc = PTR_ERR(mr);
-                dprintk("RPC:       %s: failed with %i\n", __func__, rc);
-        } else {
-                *mrp = mr;
-                iov->lkey = mr->lkey;
-                rc = 0;
-        }
-
-        return rc;
-}
-
-static int
-rpcrdma_deregister_internal(struct rpcrdma_ia *ia,
-                                struct ib_mr *mr, struct ib_sge *iov)
-{
-        int rc;
-
-        ib_dma_unmap_single(ia->ri_device,
-                            iov->addr, iov->length, DMA_BIDIRECTIONAL);
-
-        if (NULL == mr)
-                return 0;
-
-        rc = ib_dereg_mr(mr);
-        if (rc)
-                dprintk("RPC:       %s: ib_dereg_mr failed %i\n", __func__, rc);
-        return rc;
-}
-
 /**
  * rpcrdma_alloc_regbuf - kmalloc and register memory for SEND/RECV buffers
  * @ia: controlling rpcrdma_ia
@@ -1317,26 +1248,30 @@ struct rpcrdma_regbuf *
 rpcrdma_alloc_regbuf(struct rpcrdma_ia *ia, size_t size, gfp_t flags)
 {
         struct rpcrdma_regbuf *rb;
-        int rc;
+        struct ib_sge *iov;
 
-        rc = -ENOMEM;
         rb = kmalloc(sizeof(*rb) + size, flags);
         if (rb == NULL)
                 goto out;
 
-        rb->rg_size = size;
-        rb->rg_owner = NULL;
-        rc = rpcrdma_register_internal(ia, rb->rg_base, size,
-                                       &rb->rg_mr, &rb->rg_iov);
-        if (rc)
+        iov = &rb->rg_iov;
+        iov->addr = ib_dma_map_single(ia->ri_device,
+                                      (void *)rb->rg_base, size,
+                                      DMA_BIDIRECTIONAL);
+        if (ib_dma_mapping_error(ia->ri_device, iov->addr))
                 goto out_free;
 
+        iov->length = size;
+        iov->lkey = ia->ri_have_dma_lkey ?
+                                ia->ri_dma_lkey : ia->ri_bind_mem->lkey;
+        rb->rg_size = size;
+        rb->rg_owner = NULL;
         return rb;
 
 out_free:
         kfree(rb);
 out:
-        return ERR_PTR(rc);
+        return ERR_PTR(-ENOMEM);
 }
 
 /**
@@ -1347,10 +1282,15 @@ out:
 void
 rpcrdma_free_regbuf(struct rpcrdma_ia *ia, struct rpcrdma_regbuf *rb)
 {
-        if (rb) {
-                rpcrdma_deregister_internal(ia, rb->rg_mr, &rb->rg_iov);
-                kfree(rb);
-        }
+        struct ib_sge *iov;
+
+        if (!rb)
+                return;
+
+        iov = &rb->rg_iov;
+        ib_dma_unmap_single(ia->ri_device,
+                            iov->addr, iov->length, DMA_BIDIRECTIONAL);
+        kfree(rb);
 }
 
 /*
diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h
index abee4728f885..ce4e79e4cf1d 100644
--- a/net/sunrpc/xprtrdma/xprt_rdma.h
+++ b/net/sunrpc/xprtrdma/xprt_rdma.h
@@ -119,7 +119,6 @@ struct rpcrdma_ep {
 struct rpcrdma_regbuf {
         size_t                  rg_size;
         struct rpcrdma_req      *rg_owner;
-        struct ib_mr            *rg_mr;
         struct ib_sge           rg_iov;
         __be32                  rg_base[0] __attribute__ ((aligned(256)));
 };