svcrdma: Clean up use of rdma->sc_pd->device

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 think there's any functional difference between the two, but
it is a little confusing to see some uses of rdma_cm_id and some of
ib_pd.

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

Author: chucklever

net/sunrpc/xprtrdma/svc_rdma_sendto.c

@@ -116,7 +116,8 @@ static void svc_rdma_wc_send(struct ib_cq *cq, struct ib_wc *wc);
 static struct svc_rdma_send_ctxt *
 svc_rdma_send_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_send_ctxt *ctxt;
 	unsigned long pages;
 	dma_addr_t addr;
@@ -136,9 +137,9 @@ svc_rdma_send_ctxt_alloc(struct svcxprt_rdma *rdma)
 	buffer = kmalloc_node(rdma->sc_max_req_size, GFP_KERNEL, node);
 	if (!buffer)
 		goto fail2;
-	addr = ib_dma_map_single(rdma->sc_pd->device, buffer,
-				 rdma->sc_max_req_size, DMA_TO_DEVICE);
-	if (ib_dma_mapping_error(rdma->sc_pd->device, addr))
+	addr = ib_dma_map_single(device, buffer, rdma->sc_max_req_size,
+				 DMA_TO_DEVICE);
+	if (ib_dma_mapping_error(device, addr))
 		goto fail3;
 
 	svc_rdma_send_cid_init(rdma, &ctxt->sc_cid);
@@ -175,15 +176,14 @@ svc_rdma_send_ctxt_alloc(struct svcxprt_rdma *rdma)
  */
 void svc_rdma_send_ctxts_destroy(struct svcxprt_rdma *rdma)
 {
+	struct ib_device *device = rdma->sc_cm_id->device;
 	struct svc_rdma_send_ctxt *ctxt;
 	struct llist_node *node;
 
 	while ((node = llist_del_first(&rdma->sc_send_ctxts)) != NULL) {
 		ctxt = llist_entry(node, struct svc_rdma_send_ctxt, sc_node);
-		ib_dma_unmap_single(rdma->sc_pd->device,
-				    ctxt->sc_sges[0].addr,
-				    rdma->sc_max_req_size,
-				    DMA_TO_DEVICE);
+		ib_dma_unmap_single(device, ctxt->sc_sges[0].addr,
+				    rdma->sc_max_req_size, DMA_TO_DEVICE);
 		kfree(ctxt->sc_xprt_buf);
 		kfree(ctxt->sc_pages);
 		kfree(ctxt);
@@ -463,7 +463,7 @@ int svc_rdma_post_send(struct svcxprt_rdma *rdma,
 	might_sleep();
 
 	/* Sync the transport header buffer */
-	ib_dma_sync_single_for_device(rdma->sc_pd->device,
+	ib_dma_sync_single_for_device(rdma->sc_cm_id->device,
 				      send_wr->sg_list[0].addr,
 				      send_wr->sg_list[0].length,
 				      DMA_TO_DEVICE);