svcrdma: Clean up use of rdma->sc_pd->device in Receive paths

I can't think of a reason why svcrdma is using the PD's device. Most
other consumers of the IB DMA API use the ib_device pointer from the
connection's rdma_cm_id.

I don't believe there's any functional difference between the two,
but it is a little confusing to see some uses of rdma_cm_id->device
and some of ib_pd->device.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Author: chucklever

net/sunrpc/xprtrdma/svc_rdma_recvfrom.c

@@ -118,7 +118,8 @@ svc_rdma_next_recv_ctxt(struct list_head *list)
 static struct svc_rdma_recv_ctxt *
 svc_rdma_recv_ctxt_alloc(struct svcxprt_rdma *rdma)
 {
-	int node = ibdev_to_node(rdma->sc_cm_id->device);
+	struct ib_device *device = rdma->sc_cm_id->device;
+	int node = ibdev_to_node(device);
 	struct svc_rdma_recv_ctxt *ctxt;
 	unsigned long pages;
 	dma_addr_t addr;
@@ -133,9 +134,9 @@ svc_rdma_recv_ctxt_alloc(struct svcxprt_rdma *rdma)
 	buffer = kmalloc_node(rdma->sc_max_req_size, GFP_KERNEL, node);
 	if (!buffer)
 		goto fail1;
-	addr = ib_dma_map_single(rdma->sc_pd->device, buffer,
-				 rdma->sc_max_req_size, DMA_FROM_DEVICE);
-	if (ib_dma_mapping_error(rdma->sc_pd->device, addr))
+	addr = ib_dma_map_single(device, buffer, rdma->sc_max_req_size,
+				 DMA_FROM_DEVICE);
+	if (ib_dma_mapping_error(device, addr))
 		goto fail2;
 
 	svc_rdma_recv_cid_init(rdma, &ctxt->rc_cid);
@@ -167,7 +168,7 @@ svc_rdma_recv_ctxt_alloc(struct svcxprt_rdma *rdma)
 static void svc_rdma_recv_ctxt_destroy(struct svcxprt_rdma *rdma,
 				       struct svc_rdma_recv_ctxt *ctxt)
 {
-	ib_dma_unmap_single(rdma->sc_pd->device, ctxt->rc_recv_sge.addr,
+	ib_dma_unmap_single(rdma->sc_cm_id->device, ctxt->rc_recv_sge.addr,
 			    ctxt->rc_recv_sge.length, DMA_FROM_DEVICE);
 	kfree(ctxt->rc_recv_buf);
 	kfree(ctxt);
@@ -955,7 +956,7 @@ int svc_rdma_recvfrom(struct svc_rqst *rqstp)
 		return 0;
 
 	percpu_counter_inc(&svcrdma_stat_recv);
-	ib_dma_sync_single_for_cpu(rdma_xprt->sc_pd->device,
+	ib_dma_sync_single_for_cpu(rdma_xprt->sc_cm_id->device,
 				   ctxt->rc_recv_sge.addr, ctxt->rc_byte_len,
 				   DMA_FROM_DEVICE);
 	svc_rdma_build_arg_xdr(rqstp, ctxt);