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 contiguous 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 * The max SGE we need is the length of the XDR / pagesize + one for
67 * head + one for tail + one for RPCRDMA header. Since RPCSVC_MAXPAGES
68 * reserves a page for both the request and the reply header, and this
69 * array is only concerned with the reply we are assured that we have
70 * on extra page for the RPCRMDA header.
71 */
fast_reg_xdr(struct svcxprt_rdma * xprt,struct xdr_buf * xdr,struct svc_rdma_req_map * vec)72 static int fast_reg_xdr(struct svcxprt_rdma *xprt,
73 struct xdr_buf *xdr,
74 struct svc_rdma_req_map *vec)
75 {
76 int sge_no;
77 u32 sge_bytes;
78 u32 page_bytes;
79 u32 page_off;
80 int page_no = 0;
81 u8 *frva;
82 struct svc_rdma_fastreg_mr *frmr;
83
84 frmr = svc_rdma_get_frmr(xprt);
85 if (IS_ERR(frmr))
86 return -ENOMEM;
87 vec->frmr = frmr;
88
89 /* Skip the RPCRDMA header */
90 sge_no = 1;
91
92 /* Map the head. */
93 frva = (void *)((unsigned long)(xdr->head[0].iov_base) & PAGE_MASK);
94 vec->sge[sge_no].iov_base = xdr->head[0].iov_base;
95 vec->sge[sge_no].iov_len = xdr->head[0].iov_len;
96 vec->count = 2;
97 sge_no++;
98
99 /* Map the XDR head */
100 frmr->kva = frva;
101 frmr->direction = DMA_TO_DEVICE;
102 frmr->access_flags = 0;
103 frmr->map_len = PAGE_SIZE;
104 frmr->page_list_len = 1;
105 page_off = (unsigned long)xdr->head[0].iov_base & ~PAGE_MASK;
106 frmr->page_list->page_list[page_no] =
107 ib_dma_map_page(xprt->sc_cm_id->device,
108 virt_to_page(xdr->head[0].iov_base),
109 page_off,
110 PAGE_SIZE - page_off,
111 DMA_TO_DEVICE);
112 if (ib_dma_mapping_error(xprt->sc_cm_id->device,
113 frmr->page_list->page_list[page_no]))
114 goto fatal_err;
115 atomic_inc(&xprt->sc_dma_used);
116
117 /* Map the XDR page list */
118 page_off = xdr->page_base;
119 page_bytes = xdr->page_len + page_off;
120 if (!page_bytes)
121 goto encode_tail;
122
123 /* Map the pages */
124 vec->sge[sge_no].iov_base = frva + frmr->map_len + page_off;
125 vec->sge[sge_no].iov_len = page_bytes;
126 sge_no++;
127 while (page_bytes) {
128 struct page *page;
129
130 page = xdr->pages[page_no++];
131 sge_bytes = min_t(u32, page_bytes, (PAGE_SIZE - page_off));
132 page_bytes -= sge_bytes;
133
134 frmr->page_list->page_list[page_no] =
135 ib_dma_map_page(xprt->sc_cm_id->device,
136 page, page_off,
137 sge_bytes, DMA_TO_DEVICE);
138 if (ib_dma_mapping_error(xprt->sc_cm_id->device,
139 frmr->page_list->page_list[page_no]))
140 goto fatal_err;
141
142 atomic_inc(&xprt->sc_dma_used);
143 page_off = 0; /* reset for next time through loop */
144 frmr->map_len += PAGE_SIZE;
145 frmr->page_list_len++;
146 }
147 vec->count++;
148
149 encode_tail:
150 /* Map tail */
151 if (0 == xdr->tail[0].iov_len)
152 goto done;
153
154 vec->count++;
155 vec->sge[sge_no].iov_len = xdr->tail[0].iov_len;
156
157 if (((unsigned long)xdr->tail[0].iov_base & PAGE_MASK) ==
158 ((unsigned long)xdr->head[0].iov_base & PAGE_MASK)) {
159 /*
160 * If head and tail use the same page, we don't need
161 * to map it again.
162 */
163 vec->sge[sge_no].iov_base = xdr->tail[0].iov_base;
164 } else {
165 void *va;
166
167 /* Map another page for the tail */
168 page_off = (unsigned long)xdr->tail[0].iov_base & ~PAGE_MASK;
169 va = (void *)((unsigned long)xdr->tail[0].iov_base & PAGE_MASK);
170 vec->sge[sge_no].iov_base = frva + frmr->map_len + page_off;
171
172 frmr->page_list->page_list[page_no] =
173 ib_dma_map_page(xprt->sc_cm_id->device, virt_to_page(va),
174 page_off,
175 PAGE_SIZE,
176 DMA_TO_DEVICE);
177 if (ib_dma_mapping_error(xprt->sc_cm_id->device,
178 frmr->page_list->page_list[page_no]))
179 goto fatal_err;
180 atomic_inc(&xprt->sc_dma_used);
181 frmr->map_len += PAGE_SIZE;
182 frmr->page_list_len++;
183 }
184
185 done:
186 if (svc_rdma_fastreg(xprt, frmr))
187 goto fatal_err;
188
189 return 0;
190
191 fatal_err:
192 printk("svcrdma: Error fast registering memory for xprt %p\n", xprt);
193 vec->frmr = NULL;
194 svc_rdma_put_frmr(xprt, frmr);
195 return -EIO;
196 }
197
map_xdr(struct svcxprt_rdma * xprt,struct xdr_buf * xdr,struct svc_rdma_req_map * vec)198 static int map_xdr(struct svcxprt_rdma *xprt,
199 struct xdr_buf *xdr,
200 struct svc_rdma_req_map *vec)
201 {
202 int sge_no;
203 u32 sge_bytes;
204 u32 page_bytes;
205 u32 page_off;
206 int page_no;
207
208 BUG_ON(xdr->len !=
209 (xdr->head[0].iov_len + xdr->page_len + xdr->tail[0].iov_len));
210
211 if (xprt->sc_frmr_pg_list_len)
212 return fast_reg_xdr(xprt, xdr, vec);
213
214 /* Skip the first sge, this is for the RPCRDMA header */
215 sge_no = 1;
216
217 /* Head SGE */
218 vec->sge[sge_no].iov_base = xdr->head[0].iov_base;
219 vec->sge[sge_no].iov_len = xdr->head[0].iov_len;
220 sge_no++;
221
222 /* pages SGE */
223 page_no = 0;
224 page_bytes = xdr->page_len;
225 page_off = xdr->page_base;
226 while (page_bytes) {
227 vec->sge[sge_no].iov_base =
228 page_address(xdr->pages[page_no]) + page_off;
229 sge_bytes = min_t(u32, page_bytes, (PAGE_SIZE - page_off));
230 page_bytes -= sge_bytes;
231 vec->sge[sge_no].iov_len = sge_bytes;
232
233 sge_no++;
234 page_no++;
235 page_off = 0; /* reset for next time through loop */
236 }
237
238 /* Tail SGE */
239 if (xdr->tail[0].iov_len) {
240 vec->sge[sge_no].iov_base = xdr->tail[0].iov_base;
241 vec->sge[sge_no].iov_len = xdr->tail[0].iov_len;
242 sge_no++;
243 }
244
245 dprintk("svcrdma: map_xdr: sge_no %d page_no %d "
246 "page_base %u page_len %u head_len %zu tail_len %zu\n",
247 sge_no, page_no, xdr->page_base, xdr->page_len,
248 xdr->head[0].iov_len, xdr->tail[0].iov_len);
249
250 vec->count = sge_no;
251 return 0;
252 }
253
dma_map_xdr(struct svcxprt_rdma * xprt,struct xdr_buf * xdr,u32 xdr_off,size_t len,int dir)254 static dma_addr_t dma_map_xdr(struct svcxprt_rdma *xprt,
255 struct xdr_buf *xdr,
256 u32 xdr_off, size_t len, int dir)
257 {
258 struct page *page;
259 dma_addr_t dma_addr;
260 if (xdr_off < xdr->head[0].iov_len) {
261 /* This offset is in the head */
262 xdr_off += (unsigned long)xdr->head[0].iov_base & ~PAGE_MASK;
263 page = virt_to_page(xdr->head[0].iov_base);
264 } else {
265 xdr_off -= xdr->head[0].iov_len;
266 if (xdr_off < xdr->page_len) {
267 /* This offset is in the page list */
268 page = xdr->pages[xdr_off >> PAGE_SHIFT];
269 xdr_off &= ~PAGE_MASK;
270 } else {
271 /* This offset is in the tail */
272 xdr_off -= xdr->page_len;
273 xdr_off += (unsigned long)
274 xdr->tail[0].iov_base & ~PAGE_MASK;
275 page = virt_to_page(xdr->tail[0].iov_base);
276 }
277 }
278 dma_addr = ib_dma_map_page(xprt->sc_cm_id->device, page, xdr_off,
279 min_t(size_t, PAGE_SIZE, len), dir);
280 return dma_addr;
281 }
282
283 /* Assumptions:
284 * - We are using FRMR
285 * - or -
286 * - The specified write_len can be represented in sc_max_sge * PAGE_SIZE
287 */
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)288 static int send_write(struct svcxprt_rdma *xprt, struct svc_rqst *rqstp,
289 u32 rmr, u64 to,
290 u32 xdr_off, int write_len,
291 struct svc_rdma_req_map *vec)
292 {
293 struct ib_send_wr write_wr;
294 struct ib_sge *sge;
295 int xdr_sge_no;
296 int sge_no;
297 int sge_bytes;
298 int sge_off;
299 int bc;
300 struct svc_rdma_op_ctxt *ctxt;
301
302 BUG_ON(vec->count > RPCSVC_MAXPAGES);
303 dprintk("svcrdma: RDMA_WRITE rmr=%x, to=%llx, xdr_off=%d, "
304 "write_len=%d, vec->sge=%p, vec->count=%lu\n",
305 rmr, (unsigned long long)to, xdr_off,
306 write_len, vec->sge, vec->count);
307
308 ctxt = svc_rdma_get_context(xprt);
309 ctxt->direction = DMA_TO_DEVICE;
310 sge = ctxt->sge;
311
312 /* Find the SGE associated with xdr_off */
313 for (bc = xdr_off, xdr_sge_no = 1; bc && xdr_sge_no < vec->count;
314 xdr_sge_no++) {
315 if (vec->sge[xdr_sge_no].iov_len > bc)
316 break;
317 bc -= vec->sge[xdr_sge_no].iov_len;
318 }
319
320 sge_off = bc;
321 bc = write_len;
322 sge_no = 0;
323
324 /* Copy the remaining SGE */
325 while (bc != 0) {
326 sge_bytes = min_t(size_t,
327 bc, vec->sge[xdr_sge_no].iov_len-sge_off);
328 sge[sge_no].length = sge_bytes;
329 if (!vec->frmr) {
330 sge[sge_no].addr =
331 dma_map_xdr(xprt, &rqstp->rq_res, xdr_off,
332 sge_bytes, DMA_TO_DEVICE);
333 xdr_off += sge_bytes;
334 if (ib_dma_mapping_error(xprt->sc_cm_id->device,
335 sge[sge_no].addr))
336 goto err;
337 atomic_inc(&xprt->sc_dma_used);
338 sge[sge_no].lkey = xprt->sc_dma_lkey;
339 } else {
340 sge[sge_no].addr = (unsigned long)
341 vec->sge[xdr_sge_no].iov_base + sge_off;
342 sge[sge_no].lkey = vec->frmr->mr->lkey;
343 }
344 ctxt->count++;
345 ctxt->frmr = vec->frmr;
346 sge_off = 0;
347 sge_no++;
348 xdr_sge_no++;
349 BUG_ON(xdr_sge_no > vec->count);
350 bc -= sge_bytes;
351 }
352
353 /* Prepare WRITE WR */
354 memset(&write_wr, 0, sizeof write_wr);
355 ctxt->wr_op = IB_WR_RDMA_WRITE;
356 write_wr.wr_id = (unsigned long)ctxt;
357 write_wr.sg_list = &sge[0];
358 write_wr.num_sge = sge_no;
359 write_wr.opcode = IB_WR_RDMA_WRITE;
360 write_wr.send_flags = IB_SEND_SIGNALED;
361 write_wr.wr.rdma.rkey = rmr;
362 write_wr.wr.rdma.remote_addr = to;
363
364 /* Post It */
365 atomic_inc(&rdma_stat_write);
366 if (svc_rdma_send(xprt, &write_wr))
367 goto err;
368 return 0;
369 err:
370 svc_rdma_unmap_dma(ctxt);
371 svc_rdma_put_frmr(xprt, vec->frmr);
372 svc_rdma_put_context(ctxt, 0);
373 /* Fatal error, close transport */
374 return -EIO;
375 }
376
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)377 static int send_write_chunks(struct svcxprt_rdma *xprt,
378 struct rpcrdma_msg *rdma_argp,
379 struct rpcrdma_msg *rdma_resp,
380 struct svc_rqst *rqstp,
381 struct svc_rdma_req_map *vec)
382 {
383 u32 xfer_len = rqstp->rq_res.page_len + rqstp->rq_res.tail[0].iov_len;
384 int write_len;
385 int max_write;
386 u32 xdr_off;
387 int chunk_off;
388 int chunk_no;
389 struct rpcrdma_write_array *arg_ary;
390 struct rpcrdma_write_array *res_ary;
391 int ret;
392
393 arg_ary = svc_rdma_get_write_array(rdma_argp);
394 if (!arg_ary)
395 return 0;
396 res_ary = (struct rpcrdma_write_array *)
397 &rdma_resp->rm_body.rm_chunks[1];
398
399 if (vec->frmr)
400 max_write = vec->frmr->map_len;
401 else
402 max_write = xprt->sc_max_sge * PAGE_SIZE;
403
404 /* Write chunks start at the pagelist */
405 for (xdr_off = rqstp->rq_res.head[0].iov_len, chunk_no = 0;
406 xfer_len && chunk_no < arg_ary->wc_nchunks;
407 chunk_no++) {
408 struct rpcrdma_segment *arg_ch;
409 u64 rs_offset;
410
411 arg_ch = &arg_ary->wc_array[chunk_no].wc_target;
412 write_len = min(xfer_len, ntohl(arg_ch->rs_length));
413
414 /* Prepare the response chunk given the length actually
415 * written */
416 xdr_decode_hyper((__be32 *)&arg_ch->rs_offset, &rs_offset);
417 svc_rdma_xdr_encode_array_chunk(res_ary, chunk_no,
418 arg_ch->rs_handle,
419 arg_ch->rs_offset,
420 write_len);
421 chunk_off = 0;
422 while (write_len) {
423 int this_write;
424 this_write = min(write_len, max_write);
425 ret = send_write(xprt, rqstp,
426 ntohl(arg_ch->rs_handle),
427 rs_offset + chunk_off,
428 xdr_off,
429 this_write,
430 vec);
431 if (ret) {
432 dprintk("svcrdma: RDMA_WRITE failed, ret=%d\n",
433 ret);
434 return -EIO;
435 }
436 chunk_off += this_write;
437 xdr_off += this_write;
438 xfer_len -= this_write;
439 write_len -= this_write;
440 }
441 }
442 /* Update the req with the number of chunks actually used */
443 svc_rdma_xdr_encode_write_list(rdma_resp, chunk_no);
444
445 return rqstp->rq_res.page_len + rqstp->rq_res.tail[0].iov_len;
446 }
447
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)448 static int send_reply_chunks(struct svcxprt_rdma *xprt,
449 struct rpcrdma_msg *rdma_argp,
450 struct rpcrdma_msg *rdma_resp,
451 struct svc_rqst *rqstp,
452 struct svc_rdma_req_map *vec)
453 {
454 u32 xfer_len = rqstp->rq_res.len;
455 int write_len;
456 int max_write;
457 u32 xdr_off;
458 int chunk_no;
459 int chunk_off;
460 int nchunks;
461 struct rpcrdma_segment *ch;
462 struct rpcrdma_write_array *arg_ary;
463 struct rpcrdma_write_array *res_ary;
464 int ret;
465
466 arg_ary = svc_rdma_get_reply_array(rdma_argp);
467 if (!arg_ary)
468 return 0;
469 /* XXX: need to fix when reply lists occur with read-list and or
470 * write-list */
471 res_ary = (struct rpcrdma_write_array *)
472 &rdma_resp->rm_body.rm_chunks[2];
473
474 if (vec->frmr)
475 max_write = vec->frmr->map_len;
476 else
477 max_write = xprt->sc_max_sge * PAGE_SIZE;
478
479 /* xdr offset starts at RPC message */
480 nchunks = ntohl(arg_ary->wc_nchunks);
481 for (xdr_off = 0, chunk_no = 0;
482 xfer_len && chunk_no < nchunks;
483 chunk_no++) {
484 u64 rs_offset;
485 ch = &arg_ary->wc_array[chunk_no].wc_target;
486 write_len = min(xfer_len, htonl(ch->rs_length));
487
488 /* Prepare the reply chunk given the length actually
489 * written */
490 xdr_decode_hyper((__be32 *)&ch->rs_offset, &rs_offset);
491 svc_rdma_xdr_encode_array_chunk(res_ary, chunk_no,
492 ch->rs_handle, ch->rs_offset,
493 write_len);
494 chunk_off = 0;
495 while (write_len) {
496 int this_write;
497
498 this_write = min(write_len, max_write);
499 ret = send_write(xprt, rqstp,
500 ntohl(ch->rs_handle),
501 rs_offset + chunk_off,
502 xdr_off,
503 this_write,
504 vec);
505 if (ret) {
506 dprintk("svcrdma: RDMA_WRITE failed, ret=%d\n",
507 ret);
508 return -EIO;
509 }
510 chunk_off += this_write;
511 xdr_off += this_write;
512 xfer_len -= this_write;
513 write_len -= this_write;
514 }
515 }
516 /* Update the req with the number of chunks actually used */
517 svc_rdma_xdr_encode_reply_array(res_ary, chunk_no);
518
519 return rqstp->rq_res.len;
520 }
521
522 /* This function prepares the portion of the RPCRDMA message to be
523 * sent in the RDMA_SEND. This function is called after data sent via
524 * RDMA has already been transmitted. There are three cases:
525 * - The RPCRDMA header, RPC header, and payload are all sent in a
526 * single RDMA_SEND. This is the "inline" case.
527 * - The RPCRDMA header and some portion of the RPC header and data
528 * are sent via this RDMA_SEND and another portion of the data is
529 * sent via RDMA.
530 * - The RPCRDMA header [NOMSG] is sent in this RDMA_SEND and the RPC
531 * header and data are all transmitted via RDMA.
532 * In all three cases, this function prepares the RPCRDMA header in
533 * sge[0], the 'type' parameter indicates the type to place in the
534 * RPCRDMA header, and the 'byte_count' field indicates how much of
535 * the XDR to include in this RDMA_SEND. NB: The offset of the payload
536 * to send is zero in the XDR.
537 */
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)538 static int send_reply(struct svcxprt_rdma *rdma,
539 struct svc_rqst *rqstp,
540 struct page *page,
541 struct rpcrdma_msg *rdma_resp,
542 struct svc_rdma_op_ctxt *ctxt,
543 struct svc_rdma_req_map *vec,
544 int byte_count)
545 {
546 struct ib_send_wr send_wr;
547 struct ib_send_wr inv_wr;
548 int sge_no;
549 int sge_bytes;
550 int page_no;
551 int ret;
552
553 /* Post a recv buffer to handle another request. */
554 ret = svc_rdma_post_recv(rdma);
555 if (ret) {
556 printk(KERN_INFO
557 "svcrdma: could not post a receive buffer, err=%d."
558 "Closing transport %p.\n", ret, rdma);
559 set_bit(XPT_CLOSE, &rdma->sc_xprt.xpt_flags);
560 svc_rdma_put_frmr(rdma, vec->frmr);
561 svc_rdma_put_context(ctxt, 0);
562 return -ENOTCONN;
563 }
564
565 /* Prepare the context */
566 ctxt->pages[0] = page;
567 ctxt->count = 1;
568 ctxt->frmr = vec->frmr;
569 if (vec->frmr)
570 set_bit(RDMACTXT_F_FAST_UNREG, &ctxt->flags);
571 else
572 clear_bit(RDMACTXT_F_FAST_UNREG, &ctxt->flags);
573
574 /* Prepare the SGE for the RPCRDMA Header */
575 ctxt->sge[0].lkey = rdma->sc_dma_lkey;
576 ctxt->sge[0].length = svc_rdma_xdr_get_reply_hdr_len(rdma_resp);
577 ctxt->sge[0].addr =
578 ib_dma_map_page(rdma->sc_cm_id->device, page, 0,
579 ctxt->sge[0].length, DMA_TO_DEVICE);
580 if (ib_dma_mapping_error(rdma->sc_cm_id->device, ctxt->sge[0].addr))
581 goto err;
582 atomic_inc(&rdma->sc_dma_used);
583
584 ctxt->direction = DMA_TO_DEVICE;
585
586 /* Map the payload indicated by 'byte_count' */
587 for (sge_no = 1; byte_count && sge_no < vec->count; sge_no++) {
588 int xdr_off = 0;
589 sge_bytes = min_t(size_t, vec->sge[sge_no].iov_len, byte_count);
590 byte_count -= sge_bytes;
591 if (!vec->frmr) {
592 ctxt->sge[sge_no].addr =
593 dma_map_xdr(rdma, &rqstp->rq_res, xdr_off,
594 sge_bytes, DMA_TO_DEVICE);
595 xdr_off += sge_bytes;
596 if (ib_dma_mapping_error(rdma->sc_cm_id->device,
597 ctxt->sge[sge_no].addr))
598 goto err;
599 atomic_inc(&rdma->sc_dma_used);
600 ctxt->sge[sge_no].lkey = rdma->sc_dma_lkey;
601 } else {
602 ctxt->sge[sge_no].addr = (unsigned long)
603 vec->sge[sge_no].iov_base;
604 ctxt->sge[sge_no].lkey = vec->frmr->mr->lkey;
605 }
606 ctxt->sge[sge_no].length = sge_bytes;
607 }
608 BUG_ON(byte_count != 0);
609
610 /* Save all respages in the ctxt and remove them from the
611 * respages array. They are our pages until the I/O
612 * completes.
613 */
614 for (page_no = 0; page_no < rqstp->rq_resused; page_no++) {
615 ctxt->pages[page_no+1] = rqstp->rq_respages[page_no];
616 ctxt->count++;
617 rqstp->rq_respages[page_no] = NULL;
618 /*
619 * If there are more pages than SGE, terminate SGE
620 * list so that svc_rdma_unmap_dma doesn't attempt to
621 * unmap garbage.
622 */
623 if (page_no+1 >= sge_no)
624 ctxt->sge[page_no+1].length = 0;
625 }
626 BUG_ON(sge_no > rdma->sc_max_sge);
627 memset(&send_wr, 0, sizeof send_wr);
628 ctxt->wr_op = IB_WR_SEND;
629 send_wr.wr_id = (unsigned long)ctxt;
630 send_wr.sg_list = ctxt->sge;
631 send_wr.num_sge = sge_no;
632 send_wr.opcode = IB_WR_SEND;
633 send_wr.send_flags = IB_SEND_SIGNALED;
634 if (vec->frmr) {
635 /* Prepare INVALIDATE WR */
636 memset(&inv_wr, 0, sizeof inv_wr);
637 inv_wr.opcode = IB_WR_LOCAL_INV;
638 inv_wr.send_flags = IB_SEND_SIGNALED;
639 inv_wr.ex.invalidate_rkey =
640 vec->frmr->mr->lkey;
641 send_wr.next = &inv_wr;
642 }
643
644 ret = svc_rdma_send(rdma, &send_wr);
645 if (ret)
646 goto err;
647
648 return 0;
649
650 err:
651 svc_rdma_unmap_dma(ctxt);
652 svc_rdma_put_frmr(rdma, vec->frmr);
653 svc_rdma_put_context(ctxt, 1);
654 return -EIO;
655 }
656
svc_rdma_prep_reply_hdr(struct svc_rqst * rqstp)657 void svc_rdma_prep_reply_hdr(struct svc_rqst *rqstp)
658 {
659 }
660
661 /*
662 * Return the start of an xdr buffer.
663 */
xdr_start(struct xdr_buf * xdr)664 static void *xdr_start(struct xdr_buf *xdr)
665 {
666 return xdr->head[0].iov_base -
667 (xdr->len -
668 xdr->page_len -
669 xdr->tail[0].iov_len -
670 xdr->head[0].iov_len);
671 }
672
svc_rdma_sendto(struct svc_rqst * rqstp)673 int svc_rdma_sendto(struct svc_rqst *rqstp)
674 {
675 struct svc_xprt *xprt = rqstp->rq_xprt;
676 struct svcxprt_rdma *rdma =
677 container_of(xprt, struct svcxprt_rdma, sc_xprt);
678 struct rpcrdma_msg *rdma_argp;
679 struct rpcrdma_msg *rdma_resp;
680 struct rpcrdma_write_array *reply_ary;
681 enum rpcrdma_proc reply_type;
682 int ret;
683 int inline_bytes;
684 struct page *res_page;
685 struct svc_rdma_op_ctxt *ctxt;
686 struct svc_rdma_req_map *vec;
687
688 dprintk("svcrdma: sending response for rqstp=%p\n", rqstp);
689
690 /* Get the RDMA request header. */
691 rdma_argp = xdr_start(&rqstp->rq_arg);
692
693 /* Build an req vec for the XDR */
694 ctxt = svc_rdma_get_context(rdma);
695 ctxt->direction = DMA_TO_DEVICE;
696 vec = svc_rdma_get_req_map();
697 ret = map_xdr(rdma, &rqstp->rq_res, vec);
698 if (ret)
699 goto err0;
700 inline_bytes = rqstp->rq_res.len;
701
702 /* Create the RDMA response header */
703 res_page = svc_rdma_get_page();
704 rdma_resp = page_address(res_page);
705 reply_ary = svc_rdma_get_reply_array(rdma_argp);
706 if (reply_ary)
707 reply_type = RDMA_NOMSG;
708 else
709 reply_type = RDMA_MSG;
710 svc_rdma_xdr_encode_reply_header(rdma, rdma_argp,
711 rdma_resp, reply_type);
712
713 /* Send any write-chunk data and build resp write-list */
714 ret = send_write_chunks(rdma, rdma_argp, rdma_resp,
715 rqstp, vec);
716 if (ret < 0) {
717 printk(KERN_ERR "svcrdma: failed to send write chunks, rc=%d\n",
718 ret);
719 goto err1;
720 }
721 inline_bytes -= ret;
722
723 /* Send any reply-list data and update resp reply-list */
724 ret = send_reply_chunks(rdma, rdma_argp, rdma_resp,
725 rqstp, vec);
726 if (ret < 0) {
727 printk(KERN_ERR "svcrdma: failed to send reply chunks, rc=%d\n",
728 ret);
729 goto err1;
730 }
731 inline_bytes -= ret;
732
733 ret = send_reply(rdma, rqstp, res_page, rdma_resp, ctxt, vec,
734 inline_bytes);
735 svc_rdma_put_req_map(vec);
736 dprintk("svcrdma: send_reply returns %d\n", ret);
737 return ret;
738
739 err1:
740 put_page(res_page);
741 err0:
742 svc_rdma_put_req_map(vec);
743 svc_rdma_put_context(ctxt, 0);
744 return ret;
745 }
746