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-rw-r--r--net/sunrpc/xprtrdma/svc_rdma_sendto.c520
1 files changed, 520 insertions, 0 deletions
diff --git a/net/sunrpc/xprtrdma/svc_rdma_sendto.c b/net/sunrpc/xprtrdma/svc_rdma_sendto.c
new file mode 100644
index 00000000000..3e321949e1d
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+++ b/net/sunrpc/xprtrdma/svc_rdma_sendto.c
@@ -0,0 +1,520 @@
+/*
+ * 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
+
+/* Encode an XDR as an array of IB SGE
+ *
+ * Assumptions:
+ * - head[0] is physically contiguous.
+ * - tail[0] is physically contiguous.
+ * - pages[] is not physically or virtually contigous and consists of
+ * PAGE_SIZE elements.
+ *
+ * Output:
+ * SGE[0] reserved for RCPRDMA header
+ * SGE[1] data from xdr->head[]
+ * SGE[2..sge_count-2] data from xdr->pages[]
+ * SGE[sge_count-1] data from xdr->tail.
+ *
+ */
+static struct ib_sge *xdr_to_sge(struct svcxprt_rdma *xprt,
+ struct xdr_buf *xdr,
+ struct ib_sge *sge,
+ int *sge_count)
+{
+ /* Max we need is the length of the XDR / pagesize + one for
+ * head + one for tail + one for RPCRDMA header
+ */
+ int sge_max = (xdr->len+PAGE_SIZE-1) / PAGE_SIZE + 3;
+ int sge_no;
+ u32 byte_count = xdr->len;
+ u32 sge_bytes;
+ u32 page_bytes;
+ int page_off;
+ int page_no;
+
+ /* Skip the first sge, this is for the RPCRDMA header */
+ sge_no = 1;
+
+ /* Head SGE */
+ sge[sge_no].addr = ib_dma_map_single(xprt->sc_cm_id->device,
+ xdr->head[0].iov_base,
+ xdr->head[0].iov_len,
+ DMA_TO_DEVICE);
+ sge_bytes = min_t(u32, byte_count, xdr->head[0].iov_len);
+ byte_count -= sge_bytes;
+ sge[sge_no].length = sge_bytes;
+ sge[sge_no].lkey = xprt->sc_phys_mr->lkey;
+ sge_no++;
+
+ /* pages SGE */
+ page_no = 0;
+ page_bytes = xdr->page_len;
+ page_off = xdr->page_base;
+ while (byte_count && page_bytes) {
+ sge_bytes = min_t(u32, byte_count, (PAGE_SIZE-page_off));
+ sge[sge_no].addr =
+ ib_dma_map_page(xprt->sc_cm_id->device,
+ xdr->pages[page_no], page_off,
+ sge_bytes, DMA_TO_DEVICE);
+ sge_bytes = min(sge_bytes, page_bytes);
+ byte_count -= sge_bytes;
+ page_bytes -= sge_bytes;
+ sge[sge_no].length = sge_bytes;
+ sge[sge_no].lkey = xprt->sc_phys_mr->lkey;
+
+ sge_no++;
+ page_no++;
+ page_off = 0; /* reset for next time through loop */
+ }
+
+ /* Tail SGE */
+ if (byte_count && xdr->tail[0].iov_len) {
+ sge[sge_no].addr =
+ ib_dma_map_single(xprt->sc_cm_id->device,
+ xdr->tail[0].iov_base,
+ xdr->tail[0].iov_len,
+ DMA_TO_DEVICE);
+ sge_bytes = min_t(u32, byte_count, xdr->tail[0].iov_len);
+ byte_count -= sge_bytes;
+ sge[sge_no].length = sge_bytes;
+ sge[sge_no].lkey = xprt->sc_phys_mr->lkey;
+ sge_no++;
+ }
+
+ BUG_ON(sge_no > sge_max);
+ BUG_ON(byte_count != 0);
+
+ *sge_count = sge_no;
+ return sge;
+}
+
+
+/* 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 ib_sge *xdr_sge, int sge_count)
+{
+ struct svc_rdma_op_ctxt *tmp_sge_ctxt;
+ 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;
+ int ret = 0;
+
+ BUG_ON(sge_count >= 32);
+ dprintk("svcrdma: RDMA_WRITE rmr=%x, to=%llx, xdr_off=%d, "
+ "write_len=%d, xdr_sge=%p, sge_count=%d\n",
+ rmr, to, xdr_off, write_len, xdr_sge, sge_count);
+
+ ctxt = svc_rdma_get_context(xprt);
+ ctxt->count = 0;
+ tmp_sge_ctxt = svc_rdma_get_context(xprt);
+ sge = tmp_sge_ctxt->sge;
+
+ /* Find the SGE associated with xdr_off */
+ for (bc = xdr_off, xdr_sge_no = 1; bc && xdr_sge_no < sge_count;
+ xdr_sge_no++) {
+ if (xdr_sge[xdr_sge_no].length > bc)
+ break;
+ bc -= xdr_sge[xdr_sge_no].length;
+ }
+
+ sge_off = bc;
+ bc = write_len;
+ sge_no = 0;
+
+ /* Copy the remaining SGE */
+ while (bc != 0 && xdr_sge_no < sge_count) {
+ sge[sge_no].addr = xdr_sge[xdr_sge_no].addr + sge_off;
+ sge[sge_no].lkey = xdr_sge[xdr_sge_no].lkey;
+ sge_bytes = min((size_t)bc,
+ (size_t)(xdr_sge[xdr_sge_no].length-sge_off));
+ sge[sge_no].length = sge_bytes;
+
+ sge_off = 0;
+ sge_no++;
+ xdr_sge_no++;
+ bc -= sge_bytes;
+ }
+
+ BUG_ON(bc != 0);
+ BUG_ON(xdr_sge_no > sge_count);
+
+ /* 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)) {
+ svc_rdma_put_context(ctxt, 1);
+ /* Fatal error, close transport */
+ ret = -EIO;
+ }
+ svc_rdma_put_context(tmp_sge_ctxt, 0);
+ return ret;
+}
+
+static int send_write_chunks(struct svcxprt_rdma *xprt,
+ struct rpcrdma_msg *rdma_argp,
+ struct rpcrdma_msg *rdma_resp,
+ struct svc_rqst *rqstp,
+ struct ib_sge *sge,
+ int sge_count)
+{
+ u32 xfer_len = rqstp->rq_res.page_len + rqstp->rq_res.tail[0].iov_len;
+ int write_len;
+ int max_write;
+ 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];
+
+ max_write = xprt->sc_max_sge * PAGE_SIZE;
+
+ /* 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, arg_ch->rs_length);
+
+ /* Prepare the response chunk given the length actually
+ * written */
+ rs_offset = get_unaligned(&(arg_ch->rs_offset));
+ svc_rdma_xdr_encode_array_chunk(res_ary, chunk_no,
+ arg_ch->rs_handle,
+ rs_offset,
+ write_len);
+ chunk_off = 0;
+ while (write_len) {
+ int this_write;
+ this_write = min(write_len, max_write);
+ ret = send_write(xprt, rqstp,
+ arg_ch->rs_handle,
+ rs_offset + chunk_off,
+ xdr_off,
+ this_write,
+ sge,
+ sge_count);
+ if (ret) {
+ dprintk("svcrdma: RDMA_WRITE failed, ret=%d\n",
+ ret);
+ return -EIO;
+ }
+ chunk_off += this_write;
+ xdr_off += this_write;
+ xfer_len -= this_write;
+ write_len -= this_write;
+ }
+ }
+ /* 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 ib_sge *sge,
+ int sge_count)
+{
+ u32 xfer_len = rqstp->rq_res.len;
+ int write_len;
+ int max_write;
+ u32 xdr_off;
+ int chunk_no;
+ int chunk_off;
+ 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];
+
+ max_write = xprt->sc_max_sge * PAGE_SIZE;
+
+ /* xdr offset starts at RPC message */
+ for (xdr_off = 0, chunk_no = 0;
+ xfer_len && chunk_no < arg_ary->wc_nchunks;
+ chunk_no++) {
+ u64 rs_offset;
+ ch = &arg_ary->wc_array[chunk_no].wc_target;
+ write_len = min(xfer_len, ch->rs_length);
+
+
+ /* Prepare the reply chunk given the length actually
+ * written */
+ rs_offset = get_unaligned(&(ch->rs_offset));
+ svc_rdma_xdr_encode_array_chunk(res_ary, chunk_no,
+ ch->rs_handle, rs_offset,
+ write_len);
+ chunk_off = 0;
+ while (write_len) {
+ int this_write;
+
+ this_write = min(write_len, max_write);
+ ret = send_write(xprt, rqstp,
+ ch->rs_handle,
+ rs_offset + chunk_off,
+ xdr_off,
+ this_write,
+ sge,
+ sge_count);
+ if (ret) {
+ dprintk("svcrdma: RDMA_WRITE failed, ret=%d\n",
+ ret);
+ return -EIO;
+ }
+ chunk_off += this_write;
+ xdr_off += this_write;
+ xfer_len -= this_write;
+ write_len -= this_write;
+ }
+ }
+ /* 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.
+ */
+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,
+ int sge_count,
+ int byte_count)
+{
+ struct ib_send_wr send_wr;
+ int sge_no;
+ int sge_bytes;
+ int page_no;
+ int ret;
+
+ /* Prepare the context */
+ ctxt->pages[0] = page;
+ ctxt->count = 1;
+
+ /* Prepare the SGE for the RPCRDMA Header */
+ ctxt->sge[0].addr =
+ ib_dma_map_page(rdma->sc_cm_id->device,
+ page, 0, PAGE_SIZE, DMA_TO_DEVICE);
+ ctxt->direction = DMA_TO_DEVICE;
+ ctxt->sge[0].length = svc_rdma_xdr_get_reply_hdr_len(rdma_resp);
+ ctxt->sge[0].lkey = rdma->sc_phys_mr->lkey;
+
+ /* Determine how many of our SGE are to be transmitted */
+ for (sge_no = 1; byte_count && sge_no < sge_count; sge_no++) {
+ sge_bytes = min((size_t)ctxt->sge[sge_no].length,
+ (size_t)byte_count);
+ byte_count -= sge_bytes;
+ }
+ BUG_ON(byte_count != 0);
+
+ /* Save all respages in the ctxt and remove them from the
+ * respages array. They are our pages until the I/O
+ * completes.
+ */
+ for (page_no = 0; page_no < rqstp->rq_resused; page_no++) {
+ ctxt->pages[page_no+1] = rqstp->rq_respages[page_no];
+ ctxt->count++;
+ rqstp->rq_respages[page_no] = NULL;
+ }
+
+ BUG_ON(sge_no > rdma->sc_max_sge);
+ 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)
+ svc_rdma_put_context(ctxt, 1);
+
+ return ret;
+}
+
+void svc_rdma_prep_reply_hdr(struct svc_rqst *rqstp)
+{
+}
+
+/*
+ * Return the start of an xdr buffer.
+ */
+static void *xdr_start(struct xdr_buf *xdr)
+{
+ return xdr->head[0].iov_base -
+ (xdr->len -
+ xdr->page_len -
+ xdr->tail[0].iov_len -
+ xdr->head[0].iov_len);
+}
+
+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 ib_sge *sge;
+ int sge_count = 0;
+ struct page *res_page;
+ struct svc_rdma_op_ctxt *ctxt;
+
+ dprintk("svcrdma: sending response for rqstp=%p\n", rqstp);
+
+ /* Get the RDMA request header. */
+ rdma_argp = xdr_start(&rqstp->rq_arg);
+
+ /* Build an SGE for the XDR */
+ ctxt = svc_rdma_get_context(rdma);
+ ctxt->direction = DMA_TO_DEVICE;
+ sge = xdr_to_sge(rdma, &rqstp->rq_res, ctxt->sge, &sge_count);
+
+ 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, sge, sge_count);
+ if (ret < 0) {
+ printk(KERN_ERR "svcrdma: failed to send write chunks, rc=%d\n",
+ ret);
+ goto error;
+ }
+ inline_bytes -= ret;
+
+ /* Send any reply-list data and update resp reply-list */
+ ret = send_reply_chunks(rdma, rdma_argp, rdma_resp,
+ rqstp, sge, sge_count);
+ if (ret < 0) {
+ printk(KERN_ERR "svcrdma: failed to send reply chunks, rc=%d\n",
+ ret);
+ goto error;
+ }
+ inline_bytes -= ret;
+
+ ret = send_reply(rdma, rqstp, res_page, rdma_resp, ctxt, sge_count,
+ inline_bytes);
+ dprintk("svcrdma: send_reply returns %d\n", ret);
+ return ret;
+ error:
+ svc_rdma_put_context(ctxt, 0);
+ put_page(res_page);
+ return ret;
+}
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