1 /* 2 * Copyright (c) 2014 Open Grid Computing, Inc. All rights reserved. 3 * Copyright (c) 2005-2006 Network Appliance, Inc. All rights reserved. 4 * 5 * This software is available to you under a choice of one of two 6 * licenses. You may choose to be licensed under the terms of the GNU 7 * General Public License (GPL) Version 2, available from the file 8 * COPYING in the main directory of this source tree, or the BSD-type 9 * license below: 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 15 * Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 18 * Redistributions in binary form must reproduce the above 19 * copyright notice, this list of conditions and the following 20 * disclaimer in the documentation and/or other materials provided 21 * with the distribution. 22 * 23 * Neither the name of the Network Appliance, Inc. nor the names of 24 * its contributors may be used to endorse or promote products 25 * derived from this software without specific prior written 26 * permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 29 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 30 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 31 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 32 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 33 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 34 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 35 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 36 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 37 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 38 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 39 * 40 * Author: Tom Tucker <tom@opengridcomputing.com> 41 */ 42 43 #include <linux/sunrpc/debug.h> 44 #include <linux/sunrpc/rpc_rdma.h> 45 #include <linux/spinlock.h> 46 #include <asm/unaligned.h> 47 #include <rdma/ib_verbs.h> 48 #include <rdma/rdma_cm.h> 49 #include <linux/sunrpc/svc_rdma.h> 50 51 #define RPCDBG_FACILITY RPCDBG_SVCXPRT 52 53 static u32 xdr_padsize(u32 len) 54 { 55 return (len & 3) ? (4 - (len & 3)) : 0; 56 } 57 58 int svc_rdma_map_xdr(struct svcxprt_rdma *xprt, 59 struct xdr_buf *xdr, 60 struct svc_rdma_req_map *vec, 61 bool write_chunk_present) 62 { 63 int sge_no; 64 u32 sge_bytes; 65 u32 page_bytes; 66 u32 page_off; 67 int page_no; 68 69 if (xdr->len != 70 (xdr->head[0].iov_len + xdr->page_len + xdr->tail[0].iov_len)) { 71 pr_err("svcrdma: %s: XDR buffer length error\n", __func__); 72 return -EIO; 73 } 74 75 /* Skip the first sge, this is for the RPCRDMA header */ 76 sge_no = 1; 77 78 /* Head SGE */ 79 vec->sge[sge_no].iov_base = xdr->head[0].iov_base; 80 vec->sge[sge_no].iov_len = xdr->head[0].iov_len; 81 sge_no++; 82 83 /* pages SGE */ 84 page_no = 0; 85 page_bytes = xdr->page_len; 86 page_off = xdr->page_base; 87 while (page_bytes) { 88 vec->sge[sge_no].iov_base = 89 page_address(xdr->pages[page_no]) + page_off; 90 sge_bytes = min_t(u32, page_bytes, (PAGE_SIZE - page_off)); 91 page_bytes -= sge_bytes; 92 vec->sge[sge_no].iov_len = sge_bytes; 93 94 sge_no++; 95 page_no++; 96 page_off = 0; /* reset for next time through loop */ 97 } 98 99 /* Tail SGE */ 100 if (xdr->tail[0].iov_len) { 101 unsigned char *base = xdr->tail[0].iov_base; 102 size_t len = xdr->tail[0].iov_len; 103 u32 xdr_pad = xdr_padsize(xdr->page_len); 104 105 if (write_chunk_present && xdr_pad) { 106 base += xdr_pad; 107 len -= xdr_pad; 108 } 109 110 if (len) { 111 vec->sge[sge_no].iov_base = base; 112 vec->sge[sge_no].iov_len = len; 113 sge_no++; 114 } 115 } 116 117 dprintk("svcrdma: %s: sge_no %d page_no %d " 118 "page_base %u page_len %u head_len %zu tail_len %zu\n", 119 __func__, sge_no, page_no, xdr->page_base, xdr->page_len, 120 xdr->head[0].iov_len, xdr->tail[0].iov_len); 121 122 vec->count = sge_no; 123 return 0; 124 } 125 126 static dma_addr_t dma_map_xdr(struct svcxprt_rdma *xprt, 127 struct xdr_buf *xdr, 128 u32 xdr_off, size_t len, int dir) 129 { 130 struct page *page; 131 dma_addr_t dma_addr; 132 if (xdr_off < xdr->head[0].iov_len) { 133 /* This offset is in the head */ 134 xdr_off += (unsigned long)xdr->head[0].iov_base & ~PAGE_MASK; 135 page = virt_to_page(xdr->head[0].iov_base); 136 } else { 137 xdr_off -= xdr->head[0].iov_len; 138 if (xdr_off < xdr->page_len) { 139 /* This offset is in the page list */ 140 xdr_off += xdr->page_base; 141 page = xdr->pages[xdr_off >> PAGE_SHIFT]; 142 xdr_off &= ~PAGE_MASK; 143 } else { 144 /* This offset is in the tail */ 145 xdr_off -= xdr->page_len; 146 xdr_off += (unsigned long) 147 xdr->tail[0].iov_base & ~PAGE_MASK; 148 page = virt_to_page(xdr->tail[0].iov_base); 149 } 150 } 151 dma_addr = ib_dma_map_page(xprt->sc_cm_id->device, page, xdr_off, 152 min_t(size_t, PAGE_SIZE, len), dir); 153 return dma_addr; 154 } 155 156 /* Returns the address of the first read chunk or <nul> if no read chunk 157 * is present 158 */ 159 struct rpcrdma_read_chunk * 160 svc_rdma_get_read_chunk(struct rpcrdma_msg *rmsgp) 161 { 162 struct rpcrdma_read_chunk *ch = 163 (struct rpcrdma_read_chunk *)&rmsgp->rm_body.rm_chunks[0]; 164 165 if (ch->rc_discrim == xdr_zero) 166 return NULL; 167 return ch; 168 } 169 170 /* Returns the address of the first read write array element or <nul> 171 * if no write array list is present 172 */ 173 static struct rpcrdma_write_array * 174 svc_rdma_get_write_array(struct rpcrdma_msg *rmsgp) 175 { 176 if (rmsgp->rm_body.rm_chunks[0] != xdr_zero || 177 rmsgp->rm_body.rm_chunks[1] == xdr_zero) 178 return NULL; 179 return (struct rpcrdma_write_array *)&rmsgp->rm_body.rm_chunks[1]; 180 } 181 182 /* Returns the address of the first reply array element or <nul> if no 183 * reply array is present 184 */ 185 static struct rpcrdma_write_array * 186 svc_rdma_get_reply_array(struct rpcrdma_msg *rmsgp, 187 struct rpcrdma_write_array *wr_ary) 188 { 189 struct rpcrdma_read_chunk *rch; 190 struct rpcrdma_write_array *rp_ary; 191 192 /* XXX: Need to fix when reply chunk may occur with read list 193 * and/or write list. 194 */ 195 if (rmsgp->rm_body.rm_chunks[0] != xdr_zero || 196 rmsgp->rm_body.rm_chunks[1] != xdr_zero) 197 return NULL; 198 199 rch = svc_rdma_get_read_chunk(rmsgp); 200 if (rch) { 201 while (rch->rc_discrim != xdr_zero) 202 rch++; 203 204 /* The reply chunk follows an empty write array located 205 * at 'rc_position' here. The reply array is at rc_target. 206 */ 207 rp_ary = (struct rpcrdma_write_array *)&rch->rc_target; 208 goto found_it; 209 } 210 211 if (wr_ary) { 212 int chunk = be32_to_cpu(wr_ary->wc_nchunks); 213 214 rp_ary = (struct rpcrdma_write_array *) 215 &wr_ary->wc_array[chunk].wc_target.rs_length; 216 goto found_it; 217 } 218 219 /* No read list, no write list */ 220 rp_ary = (struct rpcrdma_write_array *)&rmsgp->rm_body.rm_chunks[2]; 221 222 found_it: 223 if (rp_ary->wc_discrim == xdr_zero) 224 return NULL; 225 return rp_ary; 226 } 227 228 /* Assumptions: 229 * - The specified write_len can be represented in sc_max_sge * PAGE_SIZE 230 */ 231 static int send_write(struct svcxprt_rdma *xprt, struct svc_rqst *rqstp, 232 u32 rmr, u64 to, 233 u32 xdr_off, int write_len, 234 struct svc_rdma_req_map *vec) 235 { 236 struct ib_rdma_wr write_wr; 237 struct ib_sge *sge; 238 int xdr_sge_no; 239 int sge_no; 240 int sge_bytes; 241 int sge_off; 242 int bc; 243 struct svc_rdma_op_ctxt *ctxt; 244 245 if (vec->count > RPCSVC_MAXPAGES) { 246 pr_err("svcrdma: Too many pages (%lu)\n", vec->count); 247 return -EIO; 248 } 249 250 dprintk("svcrdma: RDMA_WRITE rmr=%x, to=%llx, xdr_off=%d, " 251 "write_len=%d, vec->sge=%p, vec->count=%lu\n", 252 rmr, (unsigned long long)to, xdr_off, 253 write_len, vec->sge, vec->count); 254 255 ctxt = svc_rdma_get_context(xprt); 256 ctxt->direction = DMA_TO_DEVICE; 257 sge = ctxt->sge; 258 259 /* Find the SGE associated with xdr_off */ 260 for (bc = xdr_off, xdr_sge_no = 1; bc && xdr_sge_no < vec->count; 261 xdr_sge_no++) { 262 if (vec->sge[xdr_sge_no].iov_len > bc) 263 break; 264 bc -= vec->sge[xdr_sge_no].iov_len; 265 } 266 267 sge_off = bc; 268 bc = write_len; 269 sge_no = 0; 270 271 /* Copy the remaining SGE */ 272 while (bc != 0) { 273 sge_bytes = min_t(size_t, 274 bc, vec->sge[xdr_sge_no].iov_len-sge_off); 275 sge[sge_no].length = sge_bytes; 276 sge[sge_no].addr = 277 dma_map_xdr(xprt, &rqstp->rq_res, xdr_off, 278 sge_bytes, DMA_TO_DEVICE); 279 xdr_off += sge_bytes; 280 if (ib_dma_mapping_error(xprt->sc_cm_id->device, 281 sge[sge_no].addr)) 282 goto err; 283 atomic_inc(&xprt->sc_dma_used); 284 sge[sge_no].lkey = xprt->sc_pd->local_dma_lkey; 285 ctxt->count++; 286 sge_off = 0; 287 sge_no++; 288 xdr_sge_no++; 289 if (xdr_sge_no > vec->count) { 290 pr_err("svcrdma: Too many sges (%d)\n", xdr_sge_no); 291 goto err; 292 } 293 bc -= sge_bytes; 294 if (sge_no == xprt->sc_max_sge) 295 break; 296 } 297 298 /* Prepare WRITE WR */ 299 memset(&write_wr, 0, sizeof write_wr); 300 ctxt->cqe.done = svc_rdma_wc_write; 301 write_wr.wr.wr_cqe = &ctxt->cqe; 302 write_wr.wr.sg_list = &sge[0]; 303 write_wr.wr.num_sge = sge_no; 304 write_wr.wr.opcode = IB_WR_RDMA_WRITE; 305 write_wr.wr.send_flags = IB_SEND_SIGNALED; 306 write_wr.rkey = rmr; 307 write_wr.remote_addr = to; 308 309 /* Post It */ 310 atomic_inc(&rdma_stat_write); 311 if (svc_rdma_send(xprt, &write_wr.wr)) 312 goto err; 313 return write_len - bc; 314 err: 315 svc_rdma_unmap_dma(ctxt); 316 svc_rdma_put_context(ctxt, 0); 317 return -EIO; 318 } 319 320 noinline 321 static int send_write_chunks(struct svcxprt_rdma *xprt, 322 struct rpcrdma_write_array *wr_ary, 323 struct rpcrdma_msg *rdma_resp, 324 struct svc_rqst *rqstp, 325 struct svc_rdma_req_map *vec) 326 { 327 u32 xfer_len = rqstp->rq_res.page_len; 328 int write_len; 329 u32 xdr_off; 330 int chunk_off; 331 int chunk_no; 332 int nchunks; 333 struct rpcrdma_write_array *res_ary; 334 int ret; 335 336 res_ary = (struct rpcrdma_write_array *) 337 &rdma_resp->rm_body.rm_chunks[1]; 338 339 /* Write chunks start at the pagelist */ 340 nchunks = be32_to_cpu(wr_ary->wc_nchunks); 341 for (xdr_off = rqstp->rq_res.head[0].iov_len, chunk_no = 0; 342 xfer_len && chunk_no < nchunks; 343 chunk_no++) { 344 struct rpcrdma_segment *arg_ch; 345 u64 rs_offset; 346 347 arg_ch = &wr_ary->wc_array[chunk_no].wc_target; 348 write_len = min(xfer_len, be32_to_cpu(arg_ch->rs_length)); 349 350 /* Prepare the response chunk given the length actually 351 * written */ 352 xdr_decode_hyper((__be32 *)&arg_ch->rs_offset, &rs_offset); 353 svc_rdma_xdr_encode_array_chunk(res_ary, chunk_no, 354 arg_ch->rs_handle, 355 arg_ch->rs_offset, 356 write_len); 357 chunk_off = 0; 358 while (write_len) { 359 ret = send_write(xprt, rqstp, 360 be32_to_cpu(arg_ch->rs_handle), 361 rs_offset + chunk_off, 362 xdr_off, 363 write_len, 364 vec); 365 if (ret <= 0) 366 goto out_err; 367 chunk_off += ret; 368 xdr_off += ret; 369 xfer_len -= ret; 370 write_len -= ret; 371 } 372 } 373 /* Update the req with the number of chunks actually used */ 374 svc_rdma_xdr_encode_write_list(rdma_resp, chunk_no); 375 376 return rqstp->rq_res.page_len; 377 378 out_err: 379 pr_err("svcrdma: failed to send write chunks, rc=%d\n", ret); 380 return -EIO; 381 } 382 383 noinline 384 static int send_reply_chunks(struct svcxprt_rdma *xprt, 385 struct rpcrdma_write_array *rp_ary, 386 struct rpcrdma_msg *rdma_resp, 387 struct svc_rqst *rqstp, 388 struct svc_rdma_req_map *vec) 389 { 390 u32 xfer_len = rqstp->rq_res.len; 391 int write_len; 392 u32 xdr_off; 393 int chunk_no; 394 int chunk_off; 395 int nchunks; 396 struct rpcrdma_segment *ch; 397 struct rpcrdma_write_array *res_ary; 398 int ret; 399 400 /* XXX: need to fix when reply lists occur with read-list and or 401 * write-list */ 402 res_ary = (struct rpcrdma_write_array *) 403 &rdma_resp->rm_body.rm_chunks[2]; 404 405 /* xdr offset starts at RPC message */ 406 nchunks = be32_to_cpu(rp_ary->wc_nchunks); 407 for (xdr_off = 0, chunk_no = 0; 408 xfer_len && chunk_no < nchunks; 409 chunk_no++) { 410 u64 rs_offset; 411 ch = &rp_ary->wc_array[chunk_no].wc_target; 412 write_len = min(xfer_len, be32_to_cpu(ch->rs_length)); 413 414 /* Prepare the reply chunk given the length actually 415 * written */ 416 xdr_decode_hyper((__be32 *)&ch->rs_offset, &rs_offset); 417 svc_rdma_xdr_encode_array_chunk(res_ary, chunk_no, 418 ch->rs_handle, ch->rs_offset, 419 write_len); 420 chunk_off = 0; 421 while (write_len) { 422 ret = send_write(xprt, rqstp, 423 be32_to_cpu(ch->rs_handle), 424 rs_offset + chunk_off, 425 xdr_off, 426 write_len, 427 vec); 428 if (ret <= 0) 429 goto out_err; 430 chunk_off += ret; 431 xdr_off += ret; 432 xfer_len -= ret; 433 write_len -= ret; 434 } 435 } 436 /* Update the req with the number of chunks actually used */ 437 svc_rdma_xdr_encode_reply_array(res_ary, chunk_no); 438 439 return rqstp->rq_res.len; 440 441 out_err: 442 pr_err("svcrdma: failed to send reply chunks, rc=%d\n", ret); 443 return -EIO; 444 } 445 446 /* This function prepares the portion of the RPCRDMA message to be 447 * sent in the RDMA_SEND. This function is called after data sent via 448 * RDMA has already been transmitted. There are three cases: 449 * - The RPCRDMA header, RPC header, and payload are all sent in a 450 * single RDMA_SEND. This is the "inline" case. 451 * - The RPCRDMA header and some portion of the RPC header and data 452 * are sent via this RDMA_SEND and another portion of the data is 453 * sent via RDMA. 454 * - The RPCRDMA header [NOMSG] is sent in this RDMA_SEND and the RPC 455 * header and data are all transmitted via RDMA. 456 * In all three cases, this function prepares the RPCRDMA header in 457 * sge[0], the 'type' parameter indicates the type to place in the 458 * RPCRDMA header, and the 'byte_count' field indicates how much of 459 * the XDR to include in this RDMA_SEND. NB: The offset of the payload 460 * to send is zero in the XDR. 461 */ 462 static int send_reply(struct svcxprt_rdma *rdma, 463 struct svc_rqst *rqstp, 464 struct page *page, 465 struct rpcrdma_msg *rdma_resp, 466 struct svc_rdma_req_map *vec, 467 int byte_count) 468 { 469 struct svc_rdma_op_ctxt *ctxt; 470 struct ib_send_wr send_wr; 471 u32 xdr_off; 472 int sge_no; 473 int sge_bytes; 474 int page_no; 475 int pages; 476 int ret = -EIO; 477 478 /* Prepare the context */ 479 ctxt = svc_rdma_get_context(rdma); 480 ctxt->direction = DMA_TO_DEVICE; 481 ctxt->pages[0] = page; 482 ctxt->count = 1; 483 484 /* Prepare the SGE for the RPCRDMA Header */ 485 ctxt->sge[0].lkey = rdma->sc_pd->local_dma_lkey; 486 ctxt->sge[0].length = svc_rdma_xdr_get_reply_hdr_len(rdma_resp); 487 ctxt->sge[0].addr = 488 ib_dma_map_page(rdma->sc_cm_id->device, page, 0, 489 ctxt->sge[0].length, DMA_TO_DEVICE); 490 if (ib_dma_mapping_error(rdma->sc_cm_id->device, ctxt->sge[0].addr)) 491 goto err; 492 atomic_inc(&rdma->sc_dma_used); 493 494 ctxt->direction = DMA_TO_DEVICE; 495 496 /* Map the payload indicated by 'byte_count' */ 497 xdr_off = 0; 498 for (sge_no = 1; byte_count && sge_no < vec->count; sge_no++) { 499 sge_bytes = min_t(size_t, vec->sge[sge_no].iov_len, byte_count); 500 byte_count -= sge_bytes; 501 ctxt->sge[sge_no].addr = 502 dma_map_xdr(rdma, &rqstp->rq_res, xdr_off, 503 sge_bytes, DMA_TO_DEVICE); 504 xdr_off += sge_bytes; 505 if (ib_dma_mapping_error(rdma->sc_cm_id->device, 506 ctxt->sge[sge_no].addr)) 507 goto err; 508 atomic_inc(&rdma->sc_dma_used); 509 ctxt->sge[sge_no].lkey = rdma->sc_pd->local_dma_lkey; 510 ctxt->sge[sge_no].length = sge_bytes; 511 } 512 if (byte_count != 0) { 513 pr_err("svcrdma: Could not map %d bytes\n", byte_count); 514 goto err; 515 } 516 517 /* Save all respages in the ctxt and remove them from the 518 * respages array. They are our pages until the I/O 519 * completes. 520 */ 521 pages = rqstp->rq_next_page - rqstp->rq_respages; 522 for (page_no = 0; page_no < pages; page_no++) { 523 ctxt->pages[page_no+1] = rqstp->rq_respages[page_no]; 524 ctxt->count++; 525 rqstp->rq_respages[page_no] = NULL; 526 /* 527 * If there are more pages than SGE, terminate SGE 528 * list so that svc_rdma_unmap_dma doesn't attempt to 529 * unmap garbage. 530 */ 531 if (page_no+1 >= sge_no) 532 ctxt->sge[page_no+1].length = 0; 533 } 534 rqstp->rq_next_page = rqstp->rq_respages + 1; 535 536 /* The loop above bumps sc_dma_used for each sge. The 537 * xdr_buf.tail gets a separate sge, but resides in the 538 * same page as xdr_buf.head. Don't count it twice. 539 */ 540 if (sge_no > ctxt->count) 541 atomic_dec(&rdma->sc_dma_used); 542 543 if (sge_no > rdma->sc_max_sge) { 544 pr_err("svcrdma: Too many sges (%d)\n", sge_no); 545 goto err; 546 } 547 memset(&send_wr, 0, sizeof send_wr); 548 ctxt->cqe.done = svc_rdma_wc_send; 549 send_wr.wr_cqe = &ctxt->cqe; 550 send_wr.sg_list = ctxt->sge; 551 send_wr.num_sge = sge_no; 552 send_wr.opcode = IB_WR_SEND; 553 send_wr.send_flags = IB_SEND_SIGNALED; 554 555 ret = svc_rdma_send(rdma, &send_wr); 556 if (ret) 557 goto err; 558 559 return 0; 560 561 err: 562 svc_rdma_unmap_dma(ctxt); 563 svc_rdma_put_context(ctxt, 1); 564 return ret; 565 } 566 567 void svc_rdma_prep_reply_hdr(struct svc_rqst *rqstp) 568 { 569 } 570 571 int svc_rdma_sendto(struct svc_rqst *rqstp) 572 { 573 struct svc_xprt *xprt = rqstp->rq_xprt; 574 struct svcxprt_rdma *rdma = 575 container_of(xprt, struct svcxprt_rdma, sc_xprt); 576 struct rpcrdma_msg *rdma_argp; 577 struct rpcrdma_msg *rdma_resp; 578 struct rpcrdma_write_array *wr_ary, *rp_ary; 579 enum rpcrdma_proc reply_type; 580 int ret; 581 int inline_bytes; 582 struct page *res_page; 583 struct svc_rdma_req_map *vec; 584 585 dprintk("svcrdma: sending response for rqstp=%p\n", rqstp); 586 587 /* Get the RDMA request header. The receive logic always 588 * places this at the start of page 0. 589 */ 590 rdma_argp = page_address(rqstp->rq_pages[0]); 591 wr_ary = svc_rdma_get_write_array(rdma_argp); 592 rp_ary = svc_rdma_get_reply_array(rdma_argp, wr_ary); 593 594 /* Build an req vec for the XDR */ 595 vec = svc_rdma_get_req_map(rdma); 596 ret = svc_rdma_map_xdr(rdma, &rqstp->rq_res, vec, wr_ary != NULL); 597 if (ret) 598 goto err0; 599 inline_bytes = rqstp->rq_res.len; 600 601 /* Create the RDMA response header */ 602 ret = -ENOMEM; 603 res_page = alloc_page(GFP_KERNEL); 604 if (!res_page) 605 goto err0; 606 rdma_resp = page_address(res_page); 607 if (rp_ary) 608 reply_type = RDMA_NOMSG; 609 else 610 reply_type = RDMA_MSG; 611 svc_rdma_xdr_encode_reply_header(rdma, rdma_argp, 612 rdma_resp, reply_type); 613 614 /* Send any write-chunk data and build resp write-list */ 615 if (wr_ary) { 616 ret = send_write_chunks(rdma, wr_ary, rdma_resp, rqstp, vec); 617 if (ret < 0) 618 goto err1; 619 inline_bytes -= ret + xdr_padsize(ret); 620 } 621 622 /* Send any reply-list data and update resp reply-list */ 623 if (rp_ary) { 624 ret = send_reply_chunks(rdma, rp_ary, rdma_resp, rqstp, vec); 625 if (ret < 0) 626 goto err1; 627 inline_bytes -= ret; 628 } 629 630 /* Post a fresh Receive buffer _before_ sending the reply */ 631 ret = svc_rdma_post_recv(rdma, GFP_KERNEL); 632 if (ret) 633 goto err1; 634 635 ret = send_reply(rdma, rqstp, res_page, rdma_resp, vec, 636 inline_bytes); 637 if (ret < 0) 638 goto err1; 639 640 svc_rdma_put_req_map(rdma, vec); 641 dprintk("svcrdma: send_reply returns %d\n", ret); 642 return ret; 643 644 err1: 645 put_page(res_page); 646 err0: 647 svc_rdma_put_req_map(rdma, vec); 648 pr_err("svcrdma: Could not send reply, err=%d. Closing transport.\n", 649 ret); 650 set_bit(XPT_CLOSE, &rdma->sc_xprt.xpt_flags); 651 return -ENOTCONN; 652 } 653 654 void svc_rdma_send_error(struct svcxprt_rdma *xprt, struct rpcrdma_msg *rmsgp, 655 int status) 656 { 657 struct ib_send_wr err_wr; 658 struct page *p; 659 struct svc_rdma_op_ctxt *ctxt; 660 enum rpcrdma_errcode err; 661 __be32 *va; 662 int length; 663 int ret; 664 665 ret = svc_rdma_repost_recv(xprt, GFP_KERNEL); 666 if (ret) 667 return; 668 669 p = alloc_page(GFP_KERNEL); 670 if (!p) 671 return; 672 va = page_address(p); 673 674 /* XDR encode an error reply */ 675 err = ERR_CHUNK; 676 if (status == -EPROTONOSUPPORT) 677 err = ERR_VERS; 678 length = svc_rdma_xdr_encode_error(xprt, rmsgp, err, va); 679 680 ctxt = svc_rdma_get_context(xprt); 681 ctxt->direction = DMA_TO_DEVICE; 682 ctxt->count = 1; 683 ctxt->pages[0] = p; 684 685 /* Prepare SGE for local address */ 686 ctxt->sge[0].lkey = xprt->sc_pd->local_dma_lkey; 687 ctxt->sge[0].length = length; 688 ctxt->sge[0].addr = ib_dma_map_page(xprt->sc_cm_id->device, 689 p, 0, length, DMA_TO_DEVICE); 690 if (ib_dma_mapping_error(xprt->sc_cm_id->device, ctxt->sge[0].addr)) { 691 dprintk("svcrdma: Error mapping buffer for protocol error\n"); 692 svc_rdma_put_context(ctxt, 1); 693 return; 694 } 695 atomic_inc(&xprt->sc_dma_used); 696 697 /* Prepare SEND WR */ 698 memset(&err_wr, 0, sizeof(err_wr)); 699 ctxt->cqe.done = svc_rdma_wc_send; 700 err_wr.wr_cqe = &ctxt->cqe; 701 err_wr.sg_list = ctxt->sge; 702 err_wr.num_sge = 1; 703 err_wr.opcode = IB_WR_SEND; 704 err_wr.send_flags = IB_SEND_SIGNALED; 705 706 /* Post It */ 707 ret = svc_rdma_send(xprt, &err_wr); 708 if (ret) { 709 dprintk("svcrdma: Error %d posting send for protocol error\n", 710 ret); 711 svc_rdma_unmap_dma(ctxt); 712 svc_rdma_put_context(ctxt, 1); 713 } 714 } 715