xprtrdma: Replace global lkey with lkey local to PD

The core API has changed so that devices that do not have a global
DMA lkey automatically create an mr, per-PD, and make that lkey
available. The global DMA lkey interface is going away in favor of
the per-PD DMA lkey.

The per-PD DMA lkey is always available. Convert xprtrdma to use the
device's per-PD DMA lkey for regbufs, no matter which memory
registration scheme is in use.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Cc: linux-nfs <linux-nfs@vger.kernel.org>
Acked-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

net/sunrpc/xprtrdma/fmr_ops.c

@@ -39,25 +39,6 @@ static int
 fmr_op_open(struct rpcrdma_ia *ia, struct rpcrdma_ep *ep,
 	    struct rpcrdma_create_data_internal *cdata)
 {
-	struct ib_device_attr *devattr = &ia->ri_devattr;
-	struct ib_mr *mr;
-
-	/* Obtain an lkey to use for the regbufs, which are
-	 * protected from remote access.
-	 */
-	if (devattr->device_cap_flags & IB_DEVICE_LOCAL_DMA_LKEY) {
-		ia->ri_dma_lkey = ia->ri_device->local_dma_lkey;
-	} else {
-		mr = ib_get_dma_mr(ia->ri_pd, IB_ACCESS_LOCAL_WRITE);
-		if (IS_ERR(mr)) {
-			pr_err("%s: ib_get_dma_mr for failed with %lX\n",
-			       __func__, PTR_ERR(mr));
-			return -ENOMEM;
-		}
-		ia->ri_dma_lkey = ia->ri_dma_mr->lkey;
-		ia->ri_dma_mr = mr;
-	}
-
 	return 0;
 }
 

net/sunrpc/xprtrdma/frwr_ops.c

@@ -189,11 +189,6 @@ frwr_op_open(struct rpcrdma_ia *ia, struct rpcrdma_ep *ep,
 	struct ib_device_attr *devattr = &ia->ri_devattr;
 	int depth, delta;
 
-	/* Obtain an lkey to use for the regbufs, which are
-	 * protected from remote access.
-	 */
-	ia->ri_dma_lkey = ia->ri_device->local_dma_lkey;
-
 	ia->ri_max_frmr_depth =
 			min_t(unsigned int, RPCRDMA_MAX_DATA_SEGS,
 			      devattr->max_fast_reg_page_list_len);

net/sunrpc/xprtrdma/physical_ops.c

@@ -23,7 +23,6 @@ static int
 physical_op_open(struct rpcrdma_ia *ia, struct rpcrdma_ep *ep,
 		 struct rpcrdma_create_data_internal *cdata)
 {
-	struct ib_device_attr *devattr = &ia->ri_devattr;
 	struct ib_mr *mr;
 
 	/* Obtain an rkey to use for RPC data payloads.
@@ -37,15 +36,8 @@ physical_op_open(struct rpcrdma_ia *ia, struct rpcrdma_ep *ep,
 		       __func__, PTR_ERR(mr));
 		return -ENOMEM;
 	}
+
 	ia->ri_dma_mr = mr;
-
-	/* Obtain an lkey to use for regbufs.
-	 */
-	if (devattr->device_cap_flags & IB_DEVICE_LOCAL_DMA_LKEY)
-		ia->ri_dma_lkey = ia->ri_device->local_dma_lkey;
-	else
-		ia->ri_dma_lkey = ia->ri_dma_mr->lkey;
-
 	return 0;
 }
 

net/sunrpc/xprtrdma/verbs.c

@@ -1252,7 +1252,7 @@ rpcrdma_alloc_regbuf(struct rpcrdma_ia *ia, size_t size, gfp_t flags)
 		goto out_free;
 
 	iov->length = size;
-	iov->lkey = ia->ri_dma_lkey;
+	iov->lkey = ia->ri_pd->local_dma_lkey;
 	rb->rg_size = size;
 	rb->rg_owner = NULL;
 	return rb;

net/sunrpc/xprtrdma/xprt_rdma.h

@@ -65,7 +65,6 @@ struct rpcrdma_ia {
 	struct rdma_cm_id 	*ri_id;
 	struct ib_pd		*ri_pd;
 	struct ib_mr		*ri_dma_mr;
-	u32			ri_dma_lkey;
 	struct completion	ri_done;
 	int			ri_async_rc;
 	unsigned int		ri_max_frmr_depth;