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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 000000000000..3e321949e1dc
--- /dev/null
+++ b/net/sunrpc/xprtrdma/svc_rdma_sendto.c
@@ -0,0 +1,520 @@
1/*
2 * Copyright (c) 2005-2006 Network Appliance, Inc. All rights reserved.
3 *
4 * This software is available to you under a choice of one of two
5 * licenses. You may choose to be licensed under the terms of the GNU
6 * General Public License (GPL) Version 2, available from the file
7 * COPYING in the main directory of this source tree, or the BSD-type
8 * license below:
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 *
14 * Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 *
17 * Redistributions in binary form must reproduce the above
18 * copyright notice, this list of conditions and the following
19 * disclaimer in the documentation and/or other materials provided
20 * with the distribution.
21 *
22 * Neither the name of the Network Appliance, Inc. nor the names of
23 * its contributors may be used to endorse or promote products
24 * derived from this software without specific prior written
25 * permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
28 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
29 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
30 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
31 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
32 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
33 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
37 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
38 *
39 * Author: Tom Tucker <tom@opengridcomputing.com>
40 */
41
42#include <linux/sunrpc/debug.h>
43#include <linux/sunrpc/rpc_rdma.h>
44#include <linux/spinlock.h>
45#include <asm/unaligned.h>
46#include <rdma/ib_verbs.h>
47#include <rdma/rdma_cm.h>
48#include <linux/sunrpc/svc_rdma.h>
49
50#define RPCDBG_FACILITY RPCDBG_SVCXPRT
51
52/* Encode an XDR as an array of IB SGE
53 *
54 * Assumptions:
55 * - head[0] is physically contiguous.
56 * - tail[0] is physically contiguous.
57 * - pages[] is not physically or virtually contigous and consists of
58 * PAGE_SIZE elements.
59 *
60 * Output:
61 * SGE[0] reserved for RCPRDMA header
62 * SGE[1] data from xdr->head[]
63 * SGE[2..sge_count-2] data from xdr->pages[]
64 * SGE[sge_count-1] data from xdr->tail.
65 *
66 */
67static struct ib_sge *xdr_to_sge(struct svcxprt_rdma *xprt,
68 struct xdr_buf *xdr,
69 struct ib_sge *sge,
70 int *sge_count)
71{
72 /* Max we need is the length of the XDR / pagesize + one for
73 * head + one for tail + one for RPCRDMA header
74 */
75 int sge_max = (xdr->len+PAGE_SIZE-1) / PAGE_SIZE + 3;
76 int sge_no;
77 u32 byte_count = xdr->len;
78 u32 sge_bytes;
79 u32 page_bytes;
80 int page_off;
81 int page_no;
82
83 /* Skip the first sge, this is for the RPCRDMA header */
84 sge_no = 1;
85
86 /* Head SGE */
87 sge[sge_no].addr = ib_dma_map_single(xprt->sc_cm_id->device,
88 xdr->head[0].iov_base,
89 xdr->head[0].iov_len,
90 DMA_TO_DEVICE);
91 sge_bytes = min_t(u32, byte_count, xdr->head[0].iov_len);
92 byte_count -= sge_bytes;
93 sge[sge_no].length = sge_bytes;
94 sge[sge_no].lkey = xprt->sc_phys_mr->lkey;
95 sge_no++;
96
97 /* pages SGE */
98 page_no = 0;
99 page_bytes = xdr->page_len;
100 page_off = xdr->page_base;
101 while (byte_count && page_bytes) {
102 sge_bytes = min_t(u32, byte_count, (PAGE_SIZE-page_off));
103 sge[sge_no].addr =
104 ib_dma_map_page(xprt->sc_cm_id->device,
105 xdr->pages[page_no], page_off,
106 sge_bytes, DMA_TO_DEVICE);
107 sge_bytes = min(sge_bytes, page_bytes);
108 byte_count -= sge_bytes;
109 page_bytes -= sge_bytes;
110 sge[sge_no].length = sge_bytes;
111 sge[sge_no].lkey = xprt->sc_phys_mr->lkey;
112
113 sge_no++;
114 page_no++;
115 page_off = 0; /* reset for next time through loop */
116 }
117
118 /* Tail SGE */
119 if (byte_count && xdr->tail[0].iov_len) {
120 sge[sge_no].addr =
121 ib_dma_map_single(xprt->sc_cm_id->device,
122 xdr->tail[0].iov_base,
123 xdr->tail[0].iov_len,
124 DMA_TO_DEVICE);
125 sge_bytes = min_t(u32, byte_count, xdr->tail[0].iov_len);
126 byte_count -= sge_bytes;
127 sge[sge_no].length = sge_bytes;
128 sge[sge_no].lkey = xprt->sc_phys_mr->lkey;
129 sge_no++;
130 }
131
132 BUG_ON(sge_no > sge_max);
133 BUG_ON(byte_count != 0);
134
135 *sge_count = sge_no;
136 return sge;
137}
138
139
140/* Assumptions:
141 * - The specified write_len can be represented in sc_max_sge * PAGE_SIZE
142 */
143static int send_write(struct svcxprt_rdma *xprt, struct svc_rqst *rqstp,
144 u32 rmr, u64 to,
145 u32 xdr_off, int write_len,
146 struct ib_sge *xdr_sge, int sge_count)
147{
148 struct svc_rdma_op_ctxt *tmp_sge_ctxt;
149 struct ib_send_wr write_wr;
150 struct ib_sge *sge;
151 int xdr_sge_no;
152 int sge_no;
153 int sge_bytes;
154 int sge_off;
155 int bc;
156 struct svc_rdma_op_ctxt *ctxt;
157 int ret = 0;
158
159 BUG_ON(sge_count >= 32);
160 dprintk("svcrdma: RDMA_WRITE rmr=%x, to=%llx, xdr_off=%d, "
161 "write_len=%d, xdr_sge=%p, sge_count=%d\n",
162 rmr, to, xdr_off, write_len, xdr_sge, sge_count);
163
164 ctxt = svc_rdma_get_context(xprt);
165 ctxt->count = 0;
166 tmp_sge_ctxt = svc_rdma_get_context(xprt);
167 sge = tmp_sge_ctxt->sge;
168
169 /* Find the SGE associated with xdr_off */
170 for (bc = xdr_off, xdr_sge_no = 1; bc && xdr_sge_no < sge_count;
171 xdr_sge_no++) {
172 if (xdr_sge[xdr_sge_no].length > bc)
173 break;
174 bc -= xdr_sge[xdr_sge_no].length;
175 }
176
177 sge_off = bc;
178 bc = write_len;
179 sge_no = 0;
180
181 /* Copy the remaining SGE */
182 while (bc != 0 && xdr_sge_no < sge_count) {
183 sge[sge_no].addr = xdr_sge[xdr_sge_no].addr + sge_off;
184 sge[sge_no].lkey = xdr_sge[xdr_sge_no].lkey;
185 sge_bytes = min((size_t)bc,
186 (size_t)(xdr_sge[xdr_sge_no].length-sge_off));
187 sge[sge_no].length = sge_bytes;
188
189 sge_off = 0;
190 sge_no++;
191 xdr_sge_no++;
192 bc -= sge_bytes;
193 }
194
195 BUG_ON(bc != 0);
196 BUG_ON(xdr_sge_no > sge_count);
197
198 /* Prepare WRITE WR */
199 memset(&write_wr, 0, sizeof write_wr);
200 ctxt->wr_op = IB_WR_RDMA_WRITE;
201 write_wr.wr_id = (unsigned long)ctxt;
202 write_wr.sg_list = &sge[0];
203 write_wr.num_sge = sge_no;
204 write_wr.opcode = IB_WR_RDMA_WRITE;
205 write_wr.send_flags = IB_SEND_SIGNALED;
206 write_wr.wr.rdma.rkey = rmr;
207 write_wr.wr.rdma.remote_addr = to;
208
209 /* Post It */
210 atomic_inc(&rdma_stat_write);
211 if (svc_rdma_send(xprt, &write_wr)) {
212 svc_rdma_put_context(ctxt, 1);
213 /* Fatal error, close transport */
214 ret = -EIO;
215 }
216 svc_rdma_put_context(tmp_sge_ctxt, 0);
217 return ret;
218}
219
220static int send_write_chunks(struct svcxprt_rdma *xprt,
221 struct rpcrdma_msg *rdma_argp,
222 struct rpcrdma_msg *rdma_resp,
223 struct svc_rqst *rqstp,
224 struct ib_sge *sge,
225 int sge_count)
226{
227 u32 xfer_len = rqstp->rq_res.page_len + rqstp->rq_res.tail[0].iov_len;
228 int write_len;
229 int max_write;
230 u32 xdr_off;
231 int chunk_off;
232 int chunk_no;
233 struct rpcrdma_write_array *arg_ary;
234 struct rpcrdma_write_array *res_ary;
235 int ret;
236
237 arg_ary = svc_rdma_get_write_array(rdma_argp);
238 if (!arg_ary)
239 return 0;
240 res_ary = (struct rpcrdma_write_array *)
241 &rdma_resp->rm_body.rm_chunks[1];
242
243 max_write = xprt->sc_max_sge * PAGE_SIZE;
244
245 /* Write chunks start at the pagelist */
246 for (xdr_off = rqstp->rq_res.head[0].iov_len, chunk_no = 0;
247 xfer_len && chunk_no < arg_ary->wc_nchunks;
248 chunk_no++) {
249 struct rpcrdma_segment *arg_ch;
250 u64 rs_offset;
251
252 arg_ch = &arg_ary->wc_array[chunk_no].wc_target;
253 write_len = min(xfer_len, arg_ch->rs_length);
254
255 /* Prepare the response chunk given the length actually
256 * written */
257 rs_offset = get_unaligned(&(arg_ch->rs_offset));
258 svc_rdma_xdr_encode_array_chunk(res_ary, chunk_no,
259 arg_ch->rs_handle,
260 rs_offset,
261 write_len);
262 chunk_off = 0;
263 while (write_len) {
264 int this_write;
265 this_write = min(write_len, max_write);
266 ret = send_write(xprt, rqstp,
267 arg_ch->rs_handle,
268 rs_offset + chunk_off,
269 xdr_off,
270 this_write,
271 sge,
272 sge_count);
273 if (ret) {
274 dprintk("svcrdma: RDMA_WRITE failed, ret=%d\n",
275 ret);
276 return -EIO;
277 }
278 chunk_off += this_write;
279 xdr_off += this_write;
280 xfer_len -= this_write;
281 write_len -= this_write;
282 }
283 }
284 /* Update the req with the number of chunks actually used */
285 svc_rdma_xdr_encode_write_list(rdma_resp, chunk_no);
286
287 return rqstp->rq_res.page_len + rqstp->rq_res.tail[0].iov_len;
288}
289
290static int send_reply_chunks(struct svcxprt_rdma *xprt,
291 struct rpcrdma_msg *rdma_argp,
292 struct rpcrdma_msg *rdma_resp,
293 struct svc_rqst *rqstp,
294 struct ib_sge *sge,
295 int sge_count)
296{
297 u32 xfer_len = rqstp->rq_res.len;
298 int write_len;
299 int max_write;
300 u32 xdr_off;
301 int chunk_no;
302 int chunk_off;
303 struct rpcrdma_segment *ch;
304 struct rpcrdma_write_array *arg_ary;
305 struct rpcrdma_write_array *res_ary;
306 int ret;
307
308 arg_ary = svc_rdma_get_reply_array(rdma_argp);
309 if (!arg_ary)
310 return 0;
311 /* XXX: need to fix when reply lists occur with read-list and or
312 * write-list */
313 res_ary = (struct rpcrdma_write_array *)
314 &rdma_resp->rm_body.rm_chunks[2];
315
316 max_write = xprt->sc_max_sge * PAGE_SIZE;
317
318 /* xdr offset starts at RPC message */
319 for (xdr_off = 0, chunk_no = 0;
320 xfer_len && chunk_no < arg_ary->wc_nchunks;
321 chunk_no++) {
322 u64 rs_offset;
323 ch = &arg_ary->wc_array[chunk_no].wc_target;
324 write_len = min(xfer_len, ch->rs_length);
325
326
327 /* Prepare the reply chunk given the length actually
328 * written */
329 rs_offset = get_unaligned(&(ch->rs_offset));
330 svc_rdma_xdr_encode_array_chunk(res_ary, chunk_no,
331 ch->rs_handle, rs_offset,
332 write_len);
333 chunk_off = 0;
334 while (write_len) {
335 int this_write;
336
337 this_write = min(write_len, max_write);
338 ret = send_write(xprt, rqstp,
339 ch->rs_handle,
340 rs_offset + chunk_off,
341 xdr_off,
342 this_write,
343 sge,
344 sge_count);
345 if (ret) {
346 dprintk("svcrdma: RDMA_WRITE failed, ret=%d\n",
347 ret);
348 return -EIO;
349 }
350 chunk_off += this_write;
351 xdr_off += this_write;
352 xfer_len -= this_write;
353 write_len -= this_write;
354 }
355 }
356 /* Update the req with the number of chunks actually used */
357 svc_rdma_xdr_encode_reply_array(res_ary, chunk_no);
358
359 return rqstp->rq_res.len;
360}
361
362/* This function prepares the portion of the RPCRDMA message to be
363 * sent in the RDMA_SEND. This function is called after data sent via
364 * RDMA has already been transmitted. There are three cases:
365 * - The RPCRDMA header, RPC header, and payload are all sent in a
366 * single RDMA_SEND. This is the "inline" case.
367 * - The RPCRDMA header and some portion of the RPC header and data
368 * are sent via this RDMA_SEND and another portion of the data is
369 * sent via RDMA.
370 * - The RPCRDMA header [NOMSG] is sent in this RDMA_SEND and the RPC
371 * header and data are all transmitted via RDMA.
372 * In all three cases, this function prepares the RPCRDMA header in
373 * sge[0], the 'type' parameter indicates the type to place in the
374 * RPCRDMA header, and the 'byte_count' field indicates how much of
375 * the XDR to include in this RDMA_SEND.
376 */
377static int send_reply(struct svcxprt_rdma *rdma,
378 struct svc_rqst *rqstp,
379 struct page *page,
380 struct rpcrdma_msg *rdma_resp,
381 struct svc_rdma_op_ctxt *ctxt,
382 int sge_count,
383 int byte_count)
384{
385 struct ib_send_wr send_wr;
386 int sge_no;
387 int sge_bytes;
388 int page_no;
389 int ret;
390
391 /* Prepare the context */
392 ctxt->pages[0] = page;
393 ctxt->count = 1;
394
395 /* Prepare the SGE for the RPCRDMA Header */
396 ctxt->sge[0].addr =
397 ib_dma_map_page(rdma->sc_cm_id->device,
398 page, 0, PAGE_SIZE, DMA_TO_DEVICE);
399 ctxt->direction = DMA_TO_DEVICE;
400 ctxt->sge[0].length = svc_rdma_xdr_get_reply_hdr_len(rdma_resp);
401 ctxt->sge[0].lkey = rdma->sc_phys_mr->lkey;
402
403 /* Determine how many of our SGE are to be transmitted */
404 for (sge_no = 1; byte_count && sge_no < sge_count; sge_no++) {
405 sge_bytes = min((size_t)ctxt->sge[sge_no].length,
406 (size_t)byte_count);
407 byte_count -= sge_bytes;
408 }
409 BUG_ON(byte_count != 0);
410
411 /* Save all respages in the ctxt and remove them from the
412 * respages array. They are our pages until the I/O
413 * completes.
414 */
415 for (page_no = 0; page_no < rqstp->rq_resused; page_no++) {
416 ctxt->pages[page_no+1] = rqstp->rq_respages[page_no];
417 ctxt->count++;
418 rqstp->rq_respages[page_no] = NULL;
419 }
420
421 BUG_ON(sge_no > rdma->sc_max_sge);
422 memset(&send_wr, 0, sizeof send_wr);
423 ctxt->wr_op = IB_WR_SEND;
424 send_wr.wr_id = (unsigned long)ctxt;
425 send_wr.sg_list = ctxt->sge;
426 send_wr.num_sge = sge_no;
427 send_wr.opcode = IB_WR_SEND;
428 send_wr.send_flags = IB_SEND_SIGNALED;
429
430 ret = svc_rdma_send(rdma, &send_wr);
431 if (ret)
432 svc_rdma_put_context(ctxt, 1);
433
434 return ret;
435}
436
437void svc_rdma_prep_reply_hdr(struct svc_rqst *rqstp)
438{
439}
440
441/*
442 * Return the start of an xdr buffer.
443 */
444static void *xdr_start(struct xdr_buf *xdr)
445{
446 return xdr->head[0].iov_base -
447 (xdr->len -
448 xdr->page_len -
449 xdr->tail[0].iov_len -
450 xdr->head[0].iov_len);
451}
452
453int svc_rdma_sendto(struct svc_rqst *rqstp)
454{
455 struct svc_xprt *xprt = rqstp->rq_xprt;
456 struct svcxprt_rdma *rdma =
457 container_of(xprt, struct svcxprt_rdma, sc_xprt);
458 struct rpcrdma_msg *rdma_argp;
459 struct rpcrdma_msg *rdma_resp;
460 struct rpcrdma_write_array *reply_ary;
461 enum rpcrdma_proc reply_type;
462 int ret;
463 int inline_bytes;
464 struct ib_sge *sge;
465 int sge_count = 0;
466 struct page *res_page;
467 struct svc_rdma_op_ctxt *ctxt;
468
469 dprintk("svcrdma: sending response for rqstp=%p\n", rqstp);
470
471 /* Get the RDMA request header. */
472 rdma_argp = xdr_start(&rqstp->rq_arg);
473
474 /* Build an SGE for the XDR */
475 ctxt = svc_rdma_get_context(rdma);
476 ctxt->direction = DMA_TO_DEVICE;
477 sge = xdr_to_sge(rdma, &rqstp->rq_res, ctxt->sge, &sge_count);
478
479 inline_bytes = rqstp->rq_res.len;
480
481 /* Create the RDMA response header */
482 res_page = svc_rdma_get_page();
483 rdma_resp = page_address(res_page);
484 reply_ary = svc_rdma_get_reply_array(rdma_argp);
485 if (reply_ary)
486 reply_type = RDMA_NOMSG;
487 else
488 reply_type = RDMA_MSG;
489 svc_rdma_xdr_encode_reply_header(rdma, rdma_argp,
490 rdma_resp, reply_type);
491
492 /* Send any write-chunk data and build resp write-list */
493 ret = send_write_chunks(rdma, rdma_argp, rdma_resp,
494 rqstp, sge, sge_count);
495 if (ret < 0) {
496 printk(KERN_ERR "svcrdma: failed to send write chunks, rc=%d\n",
497 ret);
498 goto error;
499 }
500 inline_bytes -= ret;
501
502 /* Send any reply-list data and update resp reply-list */
503 ret = send_reply_chunks(rdma, rdma_argp, rdma_resp,
504 rqstp, sge, sge_count);
505 if (ret < 0) {
506 printk(KERN_ERR "svcrdma: failed to send reply chunks, rc=%d\n",
507 ret);
508 goto error;
509 }
510 inline_bytes -= ret;
511
512 ret = send_reply(rdma, rqstp, res_page, rdma_resp, ctxt, sge_count,
513 inline_bytes);
514 dprintk("svcrdma: send_reply returns %d\n", ret);
515 return ret;
516 error:
517 svc_rdma_put_context(ctxt, 0);
518 put_page(res_page);
519 return ret;
520}
generated by cgit v1.2.2 (git 2.25.0) at 2025-11-24 12:01:00 -0500