~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/net/sunrpc/xprtrdma/svc_rdma_sendto.c

Version: ~ [ linux-5.6-rc7 ] ~ [ linux-5.5.11 ] ~ [ linux-5.4.27 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.112 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.174 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.217 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.217 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.82 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  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  */
 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 
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 
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  */
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 
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 
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  */
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 
657 void svc_rdma_prep_reply_hdr(struct svc_rqst *rqstp)
658 {
659 }
660 
661 /*
662  * Return the start of an xdr buffer.
663  */
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 
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 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp