1 files changed, 560 insertions, 0 deletions

diff --git a/kernel/net/sunrpc/xprtrdma/svc_rdma_sendto.c b/kernel/net/sunrpc/xprtrdma/svc_rdma_sendto.c
new file mode 100644
index 000000000..7de33d1af
--- /dev/null
+++ b/kernel/net/sunrpc/xprtrdma/svc_rdma_sendto.c
@@ -0,0 +1,560 @@
+/*
+ * Copyright (c) 2014 Open Grid Computing, Inc. All rights reserved.
+ * Copyright (c) 2005-2006 Network Appliance, Inc. All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses.  You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the BSD-type
+ * license below:
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *      Redistributions of source code must retain the above copyright
+ *      notice, this list of conditions and the following disclaimer.
+ *
+ *      Redistributions in binary form must reproduce the above
+ *      copyright notice, this list of conditions and the following
+ *      disclaimer in the documentation and/or other materials provided
+ *      with the distribution.
+ *
+ *      Neither the name of the Network Appliance, Inc. nor the names of
+ *      its contributors may be used to endorse or promote products
+ *      derived from this software without specific prior written
+ *      permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Author: Tom Tucker <tom@opengridcomputing.com>
+ */
+
+#include <linux/sunrpc/debug.h>
+#include <linux/sunrpc/rpc_rdma.h>
+#include <linux/spinlock.h>
+#include <asm/unaligned.h>
+#include <rdma/ib_verbs.h>
+#include <rdma/rdma_cm.h>
+#include <linux/sunrpc/svc_rdma.h>
+
+#define RPCDBG_FACILITY	RPCDBG_SVCXPRT
+
+static int map_xdr(struct svcxprt_rdma *xprt,
+		   struct xdr_buf *xdr,
+		   struct svc_rdma_req_map *vec)
+{
+	int sge_no;
+	u32 sge_bytes;
+	u32 page_bytes;
+	u32 page_off;
+	int page_no;
+
+	if (xdr->len !=
+	    (xdr->head[0].iov_len + xdr->page_len + xdr->tail[0].iov_len)) {
+		pr_err("svcrdma: map_xdr: XDR buffer length error\n");
+		return -EIO;
+	}
+
+	/* Skip the first sge, this is for the RPCRDMA header */
+	sge_no = 1;
+
+	/* Head SGE */
+	vec->sge[sge_no].iov_base = xdr->head[0].iov_base;
+	vec->sge[sge_no].iov_len = xdr->head[0].iov_len;
+	sge_no++;
+
+	/* pages SGE */
+	page_no = 0;
+	page_bytes = xdr->page_len;
+	page_off = xdr->page_base;
+	while (page_bytes) {
+		vec->sge[sge_no].iov_base =
+			page_address(xdr->pages[page_no]) + page_off;
+		sge_bytes = min_t(u32, page_bytes, (PAGE_SIZE - page_off));
+		page_bytes -= sge_bytes;
+		vec->sge[sge_no].iov_len = sge_bytes;
+
+		sge_no++;
+		page_no++;
+		page_off = 0; /* reset for next time through loop */
+	}
+
+	/* Tail SGE */
+	if (xdr->tail[0].iov_len) {
+		vec->sge[sge_no].iov_base = xdr->tail[0].iov_base;
+		vec->sge[sge_no].iov_len = xdr->tail[0].iov_len;
+		sge_no++;
+	}
+
+	dprintk("svcrdma: map_xdr: sge_no %d page_no %d "
+		"page_base %u page_len %u head_len %zu tail_len %zu\n",
+		sge_no, page_no, xdr->page_base, xdr->page_len,
+		xdr->head[0].iov_len, xdr->tail[0].iov_len);
+
+	vec->count = sge_no;
+	return 0;
+}
+
+static dma_addr_t dma_map_xdr(struct svcxprt_rdma *xprt,
+			      struct xdr_buf *xdr,
+			      u32 xdr_off, size_t len, int dir)
+{
+	struct page *page;
+	dma_addr_t dma_addr;
+	if (xdr_off < xdr->head[0].iov_len) {
+		/* This offset is in the head */
+		xdr_off += (unsigned long)xdr->head[0].iov_base & ~PAGE_MASK;
+		page = virt_to_page(xdr->head[0].iov_base);
+	} else {
+		xdr_off -= xdr->head[0].iov_len;
+		if (xdr_off < xdr->page_len) {
+			/* This offset is in the page list */
+			xdr_off += xdr->page_base;
+			page = xdr->pages[xdr_off >> PAGE_SHIFT];
+			xdr_off &= ~PAGE_MASK;
+		} else {
+			/* This offset is in the tail */
+			xdr_off -= xdr->page_len;
+			xdr_off += (unsigned long)
+				xdr->tail[0].iov_base & ~PAGE_MASK;
+			page = virt_to_page(xdr->tail[0].iov_base);
+		}
+	}
+	dma_addr = ib_dma_map_page(xprt->sc_cm_id->device, page, xdr_off,
+				   min_t(size_t, PAGE_SIZE, len), dir);
+	return dma_addr;
+}
+
+/* Assumptions:
+ * - The specified write_len can be represented in sc_max_sge * PAGE_SIZE
+ */
+static int send_write(struct svcxprt_rdma *xprt, struct svc_rqst *rqstp,
+		      u32 rmr, u64 to,
+		      u32 xdr_off, int write_len,
+		      struct svc_rdma_req_map *vec)
+{
+	struct ib_send_wr write_wr;
+	struct ib_sge *sge;
+	int xdr_sge_no;
+	int sge_no;
+	int sge_bytes;
+	int sge_off;
+	int bc;
+	struct svc_rdma_op_ctxt *ctxt;
+
+	if (vec->count > RPCSVC_MAXPAGES) {
+		pr_err("svcrdma: Too many pages (%lu)\n", vec->count);
+		return -EIO;
+	}
+
+	dprintk("svcrdma: RDMA_WRITE rmr=%x, to=%llx, xdr_off=%d, "
+		"write_len=%d, vec->sge=%p, vec->count=%lu\n",
+		rmr, (unsigned long long)to, xdr_off,
+		write_len, vec->sge, vec->count);
+
+	ctxt = svc_rdma_get_context(xprt);
+	ctxt->direction = DMA_TO_DEVICE;
+	sge = ctxt->sge;
+
+	/* Find the SGE associated with xdr_off */
+	for (bc = xdr_off, xdr_sge_no = 1; bc && xdr_sge_no < vec->count;
+	     xdr_sge_no++) {
+		if (vec->sge[xdr_sge_no].iov_len > bc)
+			break;
+		bc -= vec->sge[xdr_sge_no].iov_len;
+	}
+
+	sge_off = bc;
+	bc = write_len;
+	sge_no = 0;
+
+	/* Copy the remaining SGE */
+	while (bc != 0) {
+		sge_bytes = min_t(size_t,
+			  bc, vec->sge[xdr_sge_no].iov_len-sge_off);
+		sge[sge_no].length = sge_bytes;
+		sge[sge_no].addr =
+			dma_map_xdr(xprt, &rqstp->rq_res, xdr_off,
+				    sge_bytes, DMA_TO_DEVICE);
+		xdr_off += sge_bytes;
+		if (ib_dma_mapping_error(xprt->sc_cm_id->device,
+					 sge[sge_no].addr))
+			goto err;
+		atomic_inc(&xprt->sc_dma_used);
+		sge[sge_no].lkey = xprt->sc_dma_lkey;
+		ctxt->count++;
+		sge_off = 0;
+		sge_no++;
+		xdr_sge_no++;
+		if (xdr_sge_no > vec->count) {
+			pr_err("svcrdma: Too many sges (%d)\n", xdr_sge_no);
+			goto err;
+		}
+		bc -= sge_bytes;
+		if (sge_no == xprt->sc_max_sge)
+			break;
+	}
+
+	/* Prepare WRITE WR */
+	memset(&write_wr, 0, sizeof write_wr);
+	ctxt->wr_op = IB_WR_RDMA_WRITE;
+	write_wr.wr_id = (unsigned long)ctxt;
+	write_wr.sg_list = &sge[0];
+	write_wr.num_sge = sge_no;
+	write_wr.opcode = IB_WR_RDMA_WRITE;
+	write_wr.send_flags = IB_SEND_SIGNALED;
+	write_wr.wr.rdma.rkey = rmr;
+	write_wr.wr.rdma.remote_addr = to;
+
+	/* Post It */
+	atomic_inc(&rdma_stat_write);
+	if (svc_rdma_send(xprt, &write_wr))
+		goto err;
+	return write_len - bc;
+ err:
+	svc_rdma_unmap_dma(ctxt);
+	svc_rdma_put_context(ctxt, 0);
+	/* Fatal error, close transport */
+	return -EIO;
+}
+
+static int send_write_chunks(struct svcxprt_rdma *xprt,
+			     struct rpcrdma_msg *rdma_argp,
+			     struct rpcrdma_msg *rdma_resp,
+			     struct svc_rqst *rqstp,
+			     struct svc_rdma_req_map *vec)
+{
+	u32 xfer_len = rqstp->rq_res.page_len + rqstp->rq_res.tail[0].iov_len;
+	int write_len;
+	u32 xdr_off;
+	int chunk_off;
+	int chunk_no;
+	struct rpcrdma_write_array *arg_ary;
+	struct rpcrdma_write_array *res_ary;
+	int ret;
+
+	arg_ary = svc_rdma_get_write_array(rdma_argp);
+	if (!arg_ary)
+		return 0;
+	res_ary = (struct rpcrdma_write_array *)
+		&rdma_resp->rm_body.rm_chunks[1];
+
+	/* Write chunks start at the pagelist */
+	for (xdr_off = rqstp->rq_res.head[0].iov_len, chunk_no = 0;
+	     xfer_len && chunk_no < arg_ary->wc_nchunks;
+	     chunk_no++) {
+		struct rpcrdma_segment *arg_ch;
+		u64 rs_offset;
+
+		arg_ch = &arg_ary->wc_array[chunk_no].wc_target;
+		write_len = min(xfer_len, ntohl(arg_ch->rs_length));
+
+		/* Prepare the response chunk given the length actually
+		 * written */
+		xdr_decode_hyper((__be32 *)&arg_ch->rs_offset, &rs_offset);
+		svc_rdma_xdr_encode_array_chunk(res_ary, chunk_no,
+						arg_ch->rs_handle,
+						arg_ch->rs_offset,
+						write_len);
+		chunk_off = 0;
+		while (write_len) {
+			ret = send_write(xprt, rqstp,
+					 ntohl(arg_ch->rs_handle),
+					 rs_offset + chunk_off,
+					 xdr_off,
+					 write_len,
+					 vec);
+			if (ret <= 0) {
+				dprintk("svcrdma: RDMA_WRITE failed, ret=%d\n",
+					ret);
+				return -EIO;
+			}
+			chunk_off += ret;
+			xdr_off += ret;
+			xfer_len -= ret;
+			write_len -= ret;
+		}
+	}
+	/* Update the req with the number of chunks actually used */
+	svc_rdma_xdr_encode_write_list(rdma_resp, chunk_no);
+
+	return rqstp->rq_res.page_len + rqstp->rq_res.tail[0].iov_len;
+}
+
+static int send_reply_chunks(struct svcxprt_rdma *xprt,
+			     struct rpcrdma_msg *rdma_argp,
+			     struct rpcrdma_msg *rdma_resp,
+			     struct svc_rqst *rqstp,
+			     struct svc_rdma_req_map *vec)
+{
+	u32 xfer_len = rqstp->rq_res.len;
+	int write_len;
+	u32 xdr_off;
+	int chunk_no;
+	int chunk_off;
+	int nchunks;
+	struct rpcrdma_segment *ch;
+	struct rpcrdma_write_array *arg_ary;
+	struct rpcrdma_write_array *res_ary;
+	int ret;
+
+	arg_ary = svc_rdma_get_reply_array(rdma_argp);
+	if (!arg_ary)
+		return 0;
+	/* XXX: need to fix when reply lists occur with read-list and or
+	 * write-list */
+	res_ary = (struct rpcrdma_write_array *)
+		&rdma_resp->rm_body.rm_chunks[2];
+
+	/* xdr offset starts at RPC message */
+	nchunks = ntohl(arg_ary->wc_nchunks);
+	for (xdr_off = 0, chunk_no = 0;
+	     xfer_len && chunk_no < nchunks;
+	     chunk_no++) {
+		u64 rs_offset;
+		ch = &arg_ary->wc_array[chunk_no].wc_target;
+		write_len = min(xfer_len, htonl(ch->rs_length));
+
+		/* Prepare the reply chunk given the length actually
+		 * written */
+		xdr_decode_hyper((__be32 *)&ch->rs_offset, &rs_offset);
+		svc_rdma_xdr_encode_array_chunk(res_ary, chunk_no,
+						ch->rs_handle, ch->rs_offset,
+						write_len);
+		chunk_off = 0;
+		while (write_len) {
+			ret = send_write(xprt, rqstp,
+					 ntohl(ch->rs_handle),
+					 rs_offset + chunk_off,
+					 xdr_off,
+					 write_len,
+					 vec);
+			if (ret <= 0) {
+				dprintk("svcrdma: RDMA_WRITE failed, ret=%d\n",
+					ret);
+				return -EIO;
+			}
+			chunk_off += ret;
+			xdr_off += ret;
+			xfer_len -= ret;
+			write_len -= ret;
+		}
+	}
+	/* Update the req with the number of chunks actually used */
+	svc_rdma_xdr_encode_reply_array(res_ary, chunk_no);
+
+	return rqstp->rq_res.len;
+}
+
+/* This function prepares the portion of the RPCRDMA message to be
+ * sent in the RDMA_SEND. This function is called after data sent via
+ * RDMA has already been transmitted. There are three cases:
+ * - The RPCRDMA header, RPC header, and payload are all sent in a
+ *   single RDMA_SEND. This is the "inline" case.
+ * - The RPCRDMA header and some portion of the RPC header and data
+ *   are sent via this RDMA_SEND and another portion of the data is
+ *   sent via RDMA.
+ * - The RPCRDMA header [NOMSG] is sent in this RDMA_SEND and the RPC
+ *   header and data are all transmitted via RDMA.
+ * In all three cases, this function prepares the RPCRDMA header in
+ * sge[0], the 'type' parameter indicates the type to place in the
+ * RPCRDMA header, and the 'byte_count' field indicates how much of
+ * the XDR to include in this RDMA_SEND. NB: The offset of the payload
+ * to send is zero in the XDR.
+ */
+static int send_reply(struct svcxprt_rdma *rdma,
+		      struct svc_rqst *rqstp,
+		      struct page *page,
+		      struct rpcrdma_msg *rdma_resp,
+		      struct svc_rdma_op_ctxt *ctxt,
+		      struct svc_rdma_req_map *vec,
+		      int byte_count)
+{
+	struct ib_send_wr send_wr;
+	int sge_no;
+	int sge_bytes;
+	int page_no;
+	int pages;
+	int ret;
+
+	/* Post a recv buffer to handle another request. */
+	ret = svc_rdma_post_recv(rdma);
+	if (ret) {
+		printk(KERN_INFO
+		       "svcrdma: could not post a receive buffer, err=%d."
+		       "Closing transport %p.\n", ret, rdma);
+		set_bit(XPT_CLOSE, &rdma->sc_xprt.xpt_flags);
+		svc_rdma_put_context(ctxt, 0);
+		return -ENOTCONN;
+	}
+
+	/* Prepare the context */
+	ctxt->pages[0] = page;
+	ctxt->count = 1;
+
+	/* Prepare the SGE for the RPCRDMA Header */
+	ctxt->sge[0].lkey = rdma->sc_dma_lkey;
+	ctxt->sge[0].length = svc_rdma_xdr_get_reply_hdr_len(rdma_resp);
+	ctxt->sge[0].addr =
+	    ib_dma_map_page(rdma->sc_cm_id->device, page, 0,
+			    ctxt->sge[0].length, DMA_TO_DEVICE);
+	if (ib_dma_mapping_error(rdma->sc_cm_id->device, ctxt->sge[0].addr))
+		goto err;
+	atomic_inc(&rdma->sc_dma_used);
+
+	ctxt->direction = DMA_TO_DEVICE;
+
+	/* Map the payload indicated by 'byte_count' */
+	for (sge_no = 1; byte_count && sge_no < vec->count; sge_no++) {
+		int xdr_off = 0;
+		sge_bytes = min_t(size_t, vec->sge[sge_no].iov_len, byte_count);
+		byte_count -= sge_bytes;
+		ctxt->sge[sge_no].addr =
+			dma_map_xdr(rdma, &rqstp->rq_res, xdr_off,
+				    sge_bytes, DMA_TO_DEVICE);
+		xdr_off += sge_bytes;
+		if (ib_dma_mapping_error(rdma->sc_cm_id->device,
+					 ctxt->sge[sge_no].addr))
+			goto err;
+		atomic_inc(&rdma->sc_dma_used);
+		ctxt->sge[sge_no].lkey = rdma->sc_dma_lkey;
+		ctxt->sge[sge_no].length = sge_bytes;
+	}
+	if (byte_count != 0) {
+		pr_err("svcrdma: Could not map %d bytes\n", byte_count);
+		goto err;
+	}
+
+	/* Save all respages in the ctxt and remove them from the
+	 * respages array. They are our pages until the I/O
+	 * completes.
+	 */
+	pages = rqstp->rq_next_page - rqstp->rq_respages;
+	for (page_no = 0; page_no < pages; page_no++) {
+		ctxt->pages[page_no+1] = rqstp->rq_respages[page_no];
+		ctxt->count++;
+		rqstp->rq_respages[page_no] = NULL;
+		/*
+		 * If there are more pages than SGE, terminate SGE
+		 * list so that svc_rdma_unmap_dma doesn't attempt to
+		 * unmap garbage.
+		 */
+		if (page_no+1 >= sge_no)
+			ctxt->sge[page_no+1].length = 0;
+	}
+	rqstp->rq_next_page = rqstp->rq_respages + 1;
+
+	if (sge_no > rdma->sc_max_sge) {
+		pr_err("svcrdma: Too many sges (%d)\n", sge_no);
+		goto err;
+	}
+	memset(&send_wr, 0, sizeof send_wr);
+	ctxt->wr_op = IB_WR_SEND;
+	send_wr.wr_id = (unsigned long)ctxt;
+	send_wr.sg_list = ctxt->sge;
+	send_wr.num_sge = sge_no;
+	send_wr.opcode = IB_WR_SEND;
+	send_wr.send_flags =  IB_SEND_SIGNALED;
+
+	ret = svc_rdma_send(rdma, &send_wr);
+	if (ret)
+		goto err;
+
+	return 0;
+
+ err:
+	svc_rdma_unmap_dma(ctxt);
+	svc_rdma_put_context(ctxt, 1);
+	return -EIO;
+}
+
+void svc_rdma_prep_reply_hdr(struct svc_rqst *rqstp)
+{
+}
+
+int svc_rdma_sendto(struct svc_rqst *rqstp)
+{
+	struct svc_xprt *xprt = rqstp->rq_xprt;
+	struct svcxprt_rdma *rdma =
+		container_of(xprt, struct svcxprt_rdma, sc_xprt);
+	struct rpcrdma_msg *rdma_argp;
+	struct rpcrdma_msg *rdma_resp;
+	struct rpcrdma_write_array *reply_ary;
+	enum rpcrdma_proc reply_type;
+	int ret;
+	int inline_bytes;
+	struct page *res_page;
+	struct svc_rdma_op_ctxt *ctxt;
+	struct svc_rdma_req_map *vec;
+
+	dprintk("svcrdma: sending response for rqstp=%p\n", rqstp);
+
+	/* Get the RDMA request header. The receive logic always
+	 * places this at the start of page 0.
+	 */
+	rdma_argp = page_address(rqstp->rq_pages[0]);
+
+	/* Build an req vec for the XDR */
+	ctxt = svc_rdma_get_context(rdma);
+	ctxt->direction = DMA_TO_DEVICE;
+	vec = svc_rdma_get_req_map();
+	ret = map_xdr(rdma, &rqstp->rq_res, vec);
+	if (ret)
+		goto err0;
+	inline_bytes = rqstp->rq_res.len;
+
+	/* Create the RDMA response header */
+	res_page = svc_rdma_get_page();
+	rdma_resp = page_address(res_page);
+	reply_ary = svc_rdma_get_reply_array(rdma_argp);
+	if (reply_ary)
+		reply_type = RDMA_NOMSG;
+	else
+		reply_type = RDMA_MSG;
+	svc_rdma_xdr_encode_reply_header(rdma, rdma_argp,
+					 rdma_resp, reply_type);
+
+	/* Send any write-chunk data and build resp write-list */
+	ret = send_write_chunks(rdma, rdma_argp, rdma_resp,
+				rqstp, vec);
+	if (ret < 0) {
+		printk(KERN_ERR "svcrdma: failed to send write chunks, rc=%d\n",
+		       ret);
+		goto err1;
+	}
+	inline_bytes -= ret;
+
+	/* Send any reply-list data and update resp reply-list */
+	ret = send_reply_chunks(rdma, rdma_argp, rdma_resp,
+				rqstp, vec);
+	if (ret < 0) {
+		printk(KERN_ERR "svcrdma: failed to send reply chunks, rc=%d\n",
+		       ret);
+		goto err1;
+	}
+	inline_bytes -= ret;
+
+	ret = send_reply(rdma, rqstp, res_page, rdma_resp, ctxt, vec,
+			 inline_bytes);
+	svc_rdma_put_req_map(vec);
+	dprintk("svcrdma: send_reply returns %d\n", ret);
+	return ret;
+
+ err1:
+	put_page(res_page);
+ err0:
+	svc_rdma_put_req_map(vec);
+	svc_rdma_put_context(ctxt, 0);
+	return ret;
+}