Introduce a helper to DMA-map a reply's transport header before
sending it. This will in part replace the map vector cache.
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
include/linux/sunrpc/svc_rdma.h | 3 +
net/sunrpc/xprtrdma/svc_rdma_backchannel.c | 38 +++++------------
net/sunrpc/xprtrdma/svc_rdma_sendto.c | 61 ++++++++++++++++++++++------
3 files changed, 62 insertions(+), 40 deletions(-)
diff --git a/include/linux/sunrpc/svc_rdma.h b/include/linux/sunrpc/svc_rdma.h
index fa3ef11..ac05495 100644
--- a/include/linux/sunrpc/svc_rdma.h
+++ b/include/linux/sunrpc/svc_rdma.h
@@ -228,6 +228,9 @@ extern int rdma_read_chunk_frmr(struct svcxprt_rdma *, struct svc_rqst *,
/* svc_rdma_sendto.c */
extern int svc_rdma_map_xdr(struct svcxprt_rdma *, struct xdr_buf *,
struct svc_rdma_req_map *, bool);
+extern int svc_rdma_map_reply_hdr(struct svcxprt_rdma *rdma,
+ struct svc_rdma_op_ctxt *ctxt,
+ __be32 *rdma_resp, unsigned int len);
extern void svc_rdma_build_send_wr(struct svc_rdma_op_ctxt *ctxt,
int num_sge);
extern int svc_rdma_sendto(struct svc_rqst *);
diff --git a/net/sunrpc/xprtrdma/svc_rdma_backchannel.c b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c
index 6741ed0..71ad9cd 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_backchannel.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_backchannel.c
@@ -101,52 +101,36 @@ int svc_rdma_handle_bc_reply(struct rpc_xprt *xprt, struct rpcrdma_msg *rmsgp,
static int svc_rdma_bc_sendto(struct svcxprt_rdma *rdma,
struct rpc_rqst *rqst)
{
- struct xdr_buf *sndbuf = &rqst->rq_snd_buf;
struct svc_rdma_op_ctxt *ctxt;
- struct svc_rdma_req_map *vec;
int ret;
- vec = svc_rdma_get_req_map(rdma);
- ret = svc_rdma_map_xdr(rdma, sndbuf, vec, false);
- if (ret)
+ ctxt = svc_rdma_get_context(rdma);
+
+ /* rpcrdma_bc_send_request builds the transport header and
+ * the backchannel RPC message in the same buffer. Thus only
+ * one SGE is needed to send both.
+ */
+ ret = svc_rdma_map_reply_hdr(rdma, ctxt, rqst->rq_buffer,
+ rqst->rq_snd_buf.len);
+ if (ret < 0)
goto out_err;
ret = svc_rdma_repost_recv(rdma, GFP_NOIO);
if (ret)
goto out_err;
- ctxt = svc_rdma_get_context(rdma);
- ctxt->pages[0] = virt_to_page(rqst->rq_buffer);
- ctxt->count = 1;
-
- ctxt->direction = DMA_TO_DEVICE;
- ctxt->sge[0].lkey = rdma->sc_pd->local_dma_lkey;
- ctxt->sge[0].length = sndbuf->len;
- ctxt->sge[0].addr =
- ib_dma_map_page(rdma->sc_cm_id->device, ctxt->pages[0], 0,
- sndbuf->len, DMA_TO_DEVICE);
- if (ib_dma_mapping_error(rdma->sc_cm_id->device, ctxt->sge[0].addr)) {
- ret = -EIO;
- goto out_unmap;
- }
- svc_rdma_count_mappings(rdma, ctxt);
-
svc_rdma_build_send_wr(ctxt, 1);
ret = svc_rdma_send(rdma, &ctxt->send_wr);
if (ret) {
+ svc_rdma_unmap_dma(ctxt);
+ svc_rdma_put_context(ctxt, 1);
ret = -EIO;
- goto out_unmap;
}
out_err:
- svc_rdma_put_req_map(rdma, vec);
dprintk("svcrdma: %s returns %d\n", __func__, ret);
return ret;
-out_unmap:
- svc_rdma_unmap_dma(ctxt);
- svc_rdma_put_context(ctxt, 1);
- goto out_err;
}
/* Server-side transport endpoint wants a whole page for its send
diff --git a/net/sunrpc/xprtrdma/svc_rdma_sendto.c b/net/sunrpc/xprtrdma/svc_rdma_sendto.c
index fdf8e3d..0e55b34 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_sendto.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_sendto.c
@@ -217,6 +217,49 @@ static u32 svc_rdma_get_inv_rkey(struct rpcrdma_msg *rdma_argp,
return 0;
}
+static int svc_rdma_dma_map_page(struct svcxprt_rdma *rdma,
+ struct svc_rdma_op_ctxt *ctxt,
+ unsigned int sge_no,
+ struct page *page,
+ unsigned int offset,
+ unsigned int len)
+{
+ struct ib_device *dev = rdma->sc_cm_id->device;
+ dma_addr_t dma_addr;
+
+ dma_addr = ib_dma_map_page(dev, page, offset, len, DMA_TO_DEVICE);
+ if (ib_dma_mapping_error(dev, dma_addr))
+ return -EIO;
+
+ ctxt->sge[sge_no].addr = dma_addr;
+ ctxt->sge[sge_no].length = len;
+ ctxt->sge[sge_no].lkey = rdma->sc_pd->local_dma_lkey;
+ svc_rdma_count_mappings(rdma, ctxt);
+ return 0;
+}
+
+/**
+ * svc_rdma_map_reply_hdr - DMA map the transport header buffer
+ * @rdma: controlling transport
+ * @ctxt: op_ctxt for the Send WR
+ * @rdma_resp: buffer containing transport header
+ * @len: length of transport header
+ *
+ * Returns:
+ * %0 if the header is DMA mapped,
+ * %-EIO if DMA mapping failed.
+ */
+int svc_rdma_map_reply_hdr(struct svcxprt_rdma *rdma,
+ struct svc_rdma_op_ctxt *ctxt,
+ __be32 *rdma_resp,
+ unsigned int len)
+{
+ ctxt->direction = DMA_TO_DEVICE;
+ ctxt->pages[0] = virt_to_page(rdma_resp);
+ ctxt->count = 1;
+ return svc_rdma_dma_map_page(rdma, ctxt, 0, ctxt->pages[0], 0, len);
+}
+
/* Assumptions:
* - The specified write_len can be represented in sc_max_sge * PAGE_SIZE
*/
@@ -691,22 +734,14 @@ void svc_rdma_send_error(struct svcxprt_rdma *xprt, struct rpcrdma_msg *rmsgp,
err = ERR_VERS;
length = svc_rdma_xdr_encode_error(xprt, rmsgp, err, va);
+ /* Map transport header; no RPC message payload */
ctxt = svc_rdma_get_context(xprt);
- ctxt->direction = DMA_TO_DEVICE;
- ctxt->count = 1;
- ctxt->pages[0] = p;
-
- /* Prepare SGE for local address */
- ctxt->sge[0].lkey = xprt->sc_pd->local_dma_lkey;
- ctxt->sge[0].length = length;
- ctxt->sge[0].addr = ib_dma_map_page(xprt->sc_cm_id->device,
- p, 0, length, DMA_TO_DEVICE);
- if (ib_dma_mapping_error(xprt->sc_cm_id->device, ctxt->sge[0].addr)) {
- dprintk("svcrdma: Error mapping buffer for protocol error\n");
- svc_rdma_put_context(ctxt, 1);
+ ret = svc_rdma_map_reply_hdr(xprt, ctxt, &rmsgp->rm_xid, length);
+ if (ret) {
+ dprintk("svcrdma: Error %d mapping send for protocol error\n",
+ ret);
return;
}
- svc_rdma_count_mappings(xprt, ctxt);
svc_rdma_build_send_wr(ctxt, 1);
ret = svc_rdma_send(xprt, &ctxt->send_wr);
--
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