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 int map_xdr(struct svcxprt_rdma *xprt, 54 struct xdr_buf *xdr, 55 struct svc_rdma_req_map *vec) 56 { 57 int sge_no; 58 u32 sge_bytes; 59 u32 page_bytes; 60 u32 page_off; 61 int page_no; 62 63 BUG_ON(xdr->len != 64 (xdr->head[0].iov_len + xdr->page_len + xdr->tail[0].iov_len)); 65 66 /* Skip the first sge, this is for the RPCRDMA header */ 67 sge_no = 1; 68 69 /* Head SGE */ 70 vec->sge[sge_no].iov_base = xdr->head[0].iov_base; 71 vec->sge[sge_no].iov_len = xdr->head[0].iov_len; 72 sge_no++; 73 74 /* pages SGE */ 75 page_no = 0; 76 page_bytes = xdr->page_len; 77 page_off = xdr->page_base; 78 while (page_bytes) { 79 vec->sge[sge_no].iov_base = 80 page_address(xdr->pages[page_no]) + page_off; 81 sge_bytes = min_t(u32, page_bytes, (PAGE_SIZE - page_off)); 82 page_bytes -= sge_bytes; 83 vec->sge[sge_no].iov_len = sge_bytes; 84 85 sge_no++; 86 page_no++; 87 page_off = 0; /* reset for next time through loop */ 88 } 89 90 /* Tail SGE */ 91 if (xdr->tail[0].iov_len) { 92 vec->sge[sge_no].iov_base = xdr->tail[0].iov_base; 93 vec->sge[sge_no].iov_len = xdr->tail[0].iov_len; 94 sge_no++; 95 } 96 97 dprintk("svcrdma: map_xdr: sge_no %d page_no %d " 98 "page_base %u page_len %u head_len %zu tail_len %zu\n", 99 sge_no, page_no, xdr->page_base, xdr->page_len, 100 xdr->head[0].iov_len, xdr->tail[0].iov_len); 101 102 vec->count = sge_no; 103 return 0; 104 } 105 106 static dma_addr_t dma_map_xdr(struct svcxprt_rdma *xprt, 107 struct xdr_buf *xdr, 108 u32 xdr_off, size_t len, int dir) 109 { 110 struct page *page; 111 dma_addr_t dma_addr; 112 if (xdr_off < xdr->head[0].iov_len) { 113 /* This offset is in the head */ 114 xdr_off += (unsigned long)xdr->head[0].iov_base & ~PAGE_MASK; 115 page = virt_to_page(xdr->head[0].iov_base); 116 } else { 117 xdr_off -= xdr->head[0].iov_len; 118 if (xdr_off < xdr->page_len) { 119 /* This offset is in the page list */ 120 xdr_off += xdr->page_base; 121 page = xdr->pages[xdr_off >> PAGE_SHIFT]; 122 xdr_off &= ~PAGE_MASK; 123 } else { 124 /* This offset is in the tail */ 125 xdr_off -= xdr->page_len; 126 xdr_off += (unsigned long) 127 xdr->tail[0].iov_base & ~PAGE_MASK; 128 page = virt_to_page(xdr->tail[0].iov_base); 129 } 130 } 131 dma_addr = ib_dma_map_page(xprt->sc_cm_id->device, page, xdr_off, 132 min_t(size_t, PAGE_SIZE, len), dir); 133 return dma_addr; 134 } 135 136 /* Assumptions: 137 * - The specified write_len can be represented in sc_max_sge * PAGE_SIZE 138 */ 139 static int send_write(struct svcxprt_rdma *xprt, struct svc_rqst *rqstp, 140 u32 rmr, u64 to, 141 u32 xdr_off, int write_len, 142 struct svc_rdma_req_map *vec) 143 { 144 struct ib_send_wr write_wr; 145 struct ib_sge *sge; 146 int xdr_sge_no; 147 int sge_no; 148 int sge_bytes; 149 int sge_off; 150 int bc; 151 struct svc_rdma_op_ctxt *ctxt; 152 153 BUG_ON(vec->count > RPCSVC_MAXPAGES); 154 dprintk("svcrdma: RDMA_WRITE rmr=%x, to=%llx, xdr_off=%d, " 155 "write_len=%d, vec->sge=%p, vec->count=%lu\n", 156 rmr, (unsigned long long)to, xdr_off, 157 write_len, vec->sge, vec->count); 158 159 ctxt = svc_rdma_get_context(xprt); 160 ctxt->direction = DMA_TO_DEVICE; 161 sge = ctxt->sge; 162 163 /* Find the SGE associated with xdr_off */ 164 for (bc = xdr_off, xdr_sge_no = 1; bc && xdr_sge_no < vec->count; 165 xdr_sge_no++) { 166 if (vec->sge[xdr_sge_no].iov_len > bc) 167 break; 168 bc -= vec->sge[xdr_sge_no].iov_len; 169 } 170 171 sge_off = bc; 172 bc = write_len; 173 sge_no = 0; 174 175 /* Copy the remaining SGE */ 176 while (bc != 0) { 177 sge_bytes = min_t(size_t, 178 bc, vec->sge[xdr_sge_no].iov_len-sge_off); 179 sge[sge_no].length = sge_bytes; 180 sge[sge_no].addr = 181 dma_map_xdr(xprt, &rqstp->rq_res, xdr_off, 182 sge_bytes, DMA_TO_DEVICE); 183 xdr_off += sge_bytes; 184 if (ib_dma_mapping_error(xprt->sc_cm_id->device, 185 sge[sge_no].addr)) 186 goto err; 187 atomic_inc(&xprt->sc_dma_used); 188 sge[sge_no].lkey = xprt->sc_dma_lkey; 189 ctxt->count++; 190 sge_off = 0; 191 sge_no++; 192 xdr_sge_no++; 193 BUG_ON(xdr_sge_no > vec->count); 194 bc -= sge_bytes; 195 } 196 197 /* Prepare WRITE WR */ 198 memset(&write_wr, 0, sizeof write_wr); 199 ctxt->wr_op = IB_WR_RDMA_WRITE; 200 write_wr.wr_id = (unsigned long)ctxt; 201 write_wr.sg_list = &sge[0]; 202 write_wr.num_sge = sge_no; 203 write_wr.opcode = IB_WR_RDMA_WRITE; 204 write_wr.send_flags = IB_SEND_SIGNALED; 205 write_wr.wr.rdma.rkey = rmr; 206 write_wr.wr.rdma.remote_addr = to; 207 208 /* Post It */ 209 atomic_inc(&rdma_stat_write); 210 if (svc_rdma_send(xprt, &write_wr)) 211 goto err; 212 return 0; 213 err: 214 svc_rdma_unmap_dma(ctxt); 215 svc_rdma_put_context(ctxt, 0); 216 /* Fatal error, close transport */ 217 return -EIO; 218 } 219 220 static 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 svc_rdma_req_map *vec) 225 { 226 u32 xfer_len = rqstp->rq_res.page_len + rqstp->rq_res.tail[0].iov_len; 227 int write_len; 228 int max_write; 229 u32 xdr_off; 230 int chunk_off; 231 int chunk_no; 232 struct rpcrdma_write_array *arg_ary; 233 struct rpcrdma_write_array *res_ary; 234 int ret; 235 236 arg_ary = svc_rdma_get_write_array(rdma_argp); 237 if (!arg_ary) 238 return 0; 239 res_ary = (struct rpcrdma_write_array *) 240 &rdma_resp->rm_body.rm_chunks[1]; 241 242 max_write = xprt->sc_max_sge * PAGE_SIZE; 243 244 /* Write chunks start at the pagelist */ 245 for (xdr_off = rqstp->rq_res.head[0].iov_len, chunk_no = 0; 246 xfer_len && chunk_no < arg_ary->wc_nchunks; 247 chunk_no++) { 248 struct rpcrdma_segment *arg_ch; 249 u64 rs_offset; 250 251 arg_ch = &arg_ary->wc_array[chunk_no].wc_target; 252 write_len = min(xfer_len, ntohl(arg_ch->rs_length)); 253 254 /* Prepare the response chunk given the length actually 255 * written */ 256 xdr_decode_hyper((__be32 *)&arg_ch->rs_offset, &rs_offset); 257 svc_rdma_xdr_encode_array_chunk(res_ary, chunk_no, 258 arg_ch->rs_handle, 259 arg_ch->rs_offset, 260 write_len); 261 chunk_off = 0; 262 while (write_len) { 263 int this_write; 264 this_write = min(write_len, max_write); 265 ret = send_write(xprt, rqstp, 266 ntohl(arg_ch->rs_handle), 267 rs_offset + chunk_off, 268 xdr_off, 269 this_write, 270 vec); 271 if (ret) { 272 dprintk("svcrdma: RDMA_WRITE failed, ret=%d\n", 273 ret); 274 return -EIO; 275 } 276 chunk_off += this_write; 277 xdr_off += this_write; 278 xfer_len -= this_write; 279 write_len -= this_write; 280 } 281 } 282 /* Update the req with the number of chunks actually used */ 283 svc_rdma_xdr_encode_write_list(rdma_resp, chunk_no); 284 285 return rqstp->rq_res.page_len + rqstp->rq_res.tail[0].iov_len; 286 } 287 288 static int send_reply_chunks(struct svcxprt_rdma *xprt, 289 struct rpcrdma_msg *rdma_argp, 290 struct rpcrdma_msg *rdma_resp, 291 struct svc_rqst *rqstp, 292 struct svc_rdma_req_map *vec) 293 { 294 u32 xfer_len = rqstp->rq_res.len; 295 int write_len; 296 int max_write; 297 u32 xdr_off; 298 int chunk_no; 299 int chunk_off; 300 int nchunks; 301 struct rpcrdma_segment *ch; 302 struct rpcrdma_write_array *arg_ary; 303 struct rpcrdma_write_array *res_ary; 304 int ret; 305 306 arg_ary = svc_rdma_get_reply_array(rdma_argp); 307 if (!arg_ary) 308 return 0; 309 /* XXX: need to fix when reply lists occur with read-list and or 310 * write-list */ 311 res_ary = (struct rpcrdma_write_array *) 312 &rdma_resp->rm_body.rm_chunks[2]; 313 314 max_write = xprt->sc_max_sge * PAGE_SIZE; 315 316 /* xdr offset starts at RPC message */ 317 nchunks = ntohl(arg_ary->wc_nchunks); 318 for (xdr_off = 0, chunk_no = 0; 319 xfer_len && chunk_no < nchunks; 320 chunk_no++) { 321 u64 rs_offset; 322 ch = &arg_ary->wc_array[chunk_no].wc_target; 323 write_len = min(xfer_len, htonl(ch->rs_length)); 324 325 /* Prepare the reply chunk given the length actually 326 * written */ 327 xdr_decode_hyper((__be32 *)&ch->rs_offset, &rs_offset); 328 svc_rdma_xdr_encode_array_chunk(res_ary, chunk_no, 329 ch->rs_handle, ch->rs_offset, 330 write_len); 331 chunk_off = 0; 332 while (write_len) { 333 int this_write; 334 335 this_write = min(write_len, max_write); 336 ret = send_write(xprt, rqstp, 337 ntohl(ch->rs_handle), 338 rs_offset + chunk_off, 339 xdr_off, 340 this_write, 341 vec); 342 if (ret) { 343 dprintk("svcrdma: RDMA_WRITE failed, ret=%d\n", 344 ret); 345 return -EIO; 346 } 347 chunk_off += this_write; 348 xdr_off += this_write; 349 xfer_len -= this_write; 350 write_len -= this_write; 351 } 352 } 353 /* Update the req with the number of chunks actually used */ 354 svc_rdma_xdr_encode_reply_array(res_ary, chunk_no); 355 356 return rqstp->rq_res.len; 357 } 358 359 /* This function prepares the portion of the RPCRDMA message to be 360 * sent in the RDMA_SEND. This function is called after data sent via 361 * RDMA has already been transmitted. There are three cases: 362 * - The RPCRDMA header, RPC header, and payload are all sent in a 363 * single RDMA_SEND. This is the "inline" case. 364 * - The RPCRDMA header and some portion of the RPC header and data 365 * are sent via this RDMA_SEND and another portion of the data is 366 * sent via RDMA. 367 * - The RPCRDMA header [NOMSG] is sent in this RDMA_SEND and the RPC 368 * header and data are all transmitted via RDMA. 369 * In all three cases, this function prepares the RPCRDMA header in 370 * sge[0], the 'type' parameter indicates the type to place in the 371 * RPCRDMA header, and the 'byte_count' field indicates how much of 372 * the XDR to include in this RDMA_SEND. NB: The offset of the payload 373 * to send is zero in the XDR. 374 */ 375 static int send_reply(struct svcxprt_rdma *rdma, 376 struct svc_rqst *rqstp, 377 struct page *page, 378 struct rpcrdma_msg *rdma_resp, 379 struct svc_rdma_op_ctxt *ctxt, 380 struct svc_rdma_req_map *vec, 381 int byte_count) 382 { 383 struct ib_send_wr send_wr; 384 int sge_no; 385 int sge_bytes; 386 int page_no; 387 int pages; 388 int ret; 389 390 /* Post a recv buffer to handle another request. */ 391 ret = svc_rdma_post_recv(rdma); 392 if (ret) { 393 printk(KERN_INFO 394 "svcrdma: could not post a receive buffer, err=%d." 395 "Closing transport %p.\n", ret, rdma); 396 set_bit(XPT_CLOSE, &rdma->sc_xprt.xpt_flags); 397 svc_rdma_put_context(ctxt, 0); 398 return -ENOTCONN; 399 } 400 401 /* Prepare the context */ 402 ctxt->pages[0] = page; 403 ctxt->count = 1; 404 405 /* Prepare the SGE for the RPCRDMA Header */ 406 ctxt->sge[0].lkey = rdma->sc_dma_lkey; 407 ctxt->sge[0].length = svc_rdma_xdr_get_reply_hdr_len(rdma_resp); 408 ctxt->sge[0].addr = 409 ib_dma_map_page(rdma->sc_cm_id->device, page, 0, 410 ctxt->sge[0].length, DMA_TO_DEVICE); 411 if (ib_dma_mapping_error(rdma->sc_cm_id->device, ctxt->sge[0].addr)) 412 goto err; 413 atomic_inc(&rdma->sc_dma_used); 414 415 ctxt->direction = DMA_TO_DEVICE; 416 417 /* Map the payload indicated by 'byte_count' */ 418 for (sge_no = 1; byte_count && sge_no < vec->count; sge_no++) { 419 int xdr_off = 0; 420 sge_bytes = min_t(size_t, vec->sge[sge_no].iov_len, byte_count); 421 byte_count -= sge_bytes; 422 ctxt->sge[sge_no].addr = 423 dma_map_xdr(rdma, &rqstp->rq_res, xdr_off, 424 sge_bytes, DMA_TO_DEVICE); 425 xdr_off += sge_bytes; 426 if (ib_dma_mapping_error(rdma->sc_cm_id->device, 427 ctxt->sge[sge_no].addr)) 428 goto err; 429 atomic_inc(&rdma->sc_dma_used); 430 ctxt->sge[sge_no].lkey = rdma->sc_dma_lkey; 431 ctxt->sge[sge_no].length = sge_bytes; 432 } 433 BUG_ON(byte_count != 0); 434 435 /* Save all respages in the ctxt and remove them from the 436 * respages array. They are our pages until the I/O 437 * completes. 438 */ 439 pages = rqstp->rq_next_page - rqstp->rq_respages; 440 for (page_no = 0; page_no < pages; page_no++) { 441 ctxt->pages[page_no+1] = rqstp->rq_respages[page_no]; 442 ctxt->count++; 443 rqstp->rq_respages[page_no] = NULL; 444 /* 445 * If there are more pages than SGE, terminate SGE 446 * list so that svc_rdma_unmap_dma doesn't attempt to 447 * unmap garbage. 448 */ 449 if (page_no+1 >= sge_no) 450 ctxt->sge[page_no+1].length = 0; 451 } 452 rqstp->rq_next_page = rqstp->rq_respages + 1; 453 454 BUG_ON(sge_no > rdma->sc_max_sge); 455 memset(&send_wr, 0, sizeof send_wr); 456 ctxt->wr_op = IB_WR_SEND; 457 send_wr.wr_id = (unsigned long)ctxt; 458 send_wr.sg_list = ctxt->sge; 459 send_wr.num_sge = sge_no; 460 send_wr.opcode = IB_WR_SEND; 461 send_wr.send_flags = IB_SEND_SIGNALED; 462 463 ret = svc_rdma_send(rdma, &send_wr); 464 if (ret) 465 goto err; 466 467 return 0; 468 469 err: 470 svc_rdma_unmap_dma(ctxt); 471 svc_rdma_put_context(ctxt, 1); 472 return -EIO; 473 } 474 475 void svc_rdma_prep_reply_hdr(struct svc_rqst *rqstp) 476 { 477 } 478 479 /* 480 * Return the start of an xdr buffer. 481 */ 482 static void *xdr_start(struct xdr_buf *xdr) 483 { 484 return xdr->head[0].iov_base - 485 (xdr->len - 486 xdr->page_len - 487 xdr->tail[0].iov_len - 488 xdr->head[0].iov_len); 489 } 490 491 int svc_rdma_sendto(struct svc_rqst *rqstp) 492 { 493 struct svc_xprt *xprt = rqstp->rq_xprt; 494 struct svcxprt_rdma *rdma = 495 container_of(xprt, struct svcxprt_rdma, sc_xprt); 496 struct rpcrdma_msg *rdma_argp; 497 struct rpcrdma_msg *rdma_resp; 498 struct rpcrdma_write_array *reply_ary; 499 enum rpcrdma_proc reply_type; 500 int ret; 501 int inline_bytes; 502 struct page *res_page; 503 struct svc_rdma_op_ctxt *ctxt; 504 struct svc_rdma_req_map *vec; 505 506 dprintk("svcrdma: sending response for rqstp=%p\n", rqstp); 507 508 /* Get the RDMA request header. */ 509 rdma_argp = xdr_start(&rqstp->rq_arg); 510 511 /* Build an req vec for the XDR */ 512 ctxt = svc_rdma_get_context(rdma); 513 ctxt->direction = DMA_TO_DEVICE; 514 vec = svc_rdma_get_req_map(); 515 ret = map_xdr(rdma, &rqstp->rq_res, vec); 516 if (ret) 517 goto err0; 518 inline_bytes = rqstp->rq_res.len; 519 520 /* Create the RDMA response header */ 521 res_page = svc_rdma_get_page(); 522 rdma_resp = page_address(res_page); 523 reply_ary = svc_rdma_get_reply_array(rdma_argp); 524 if (reply_ary) 525 reply_type = RDMA_NOMSG; 526 else 527 reply_type = RDMA_MSG; 528 svc_rdma_xdr_encode_reply_header(rdma, rdma_argp, 529 rdma_resp, reply_type); 530 531 /* Send any write-chunk data and build resp write-list */ 532 ret = send_write_chunks(rdma, rdma_argp, rdma_resp, 533 rqstp, vec); 534 if (ret < 0) { 535 printk(KERN_ERR "svcrdma: failed to send write chunks, rc=%d\n", 536 ret); 537 goto err1; 538 } 539 inline_bytes -= ret; 540 541 /* Send any reply-list data and update resp reply-list */ 542 ret = send_reply_chunks(rdma, rdma_argp, rdma_resp, 543 rqstp, vec); 544 if (ret < 0) { 545 printk(KERN_ERR "svcrdma: failed to send reply chunks, rc=%d\n", 546 ret); 547 goto err1; 548 } 549 inline_bytes -= ret; 550 551 ret = send_reply(rdma, rqstp, res_page, rdma_resp, ctxt, vec, 552 inline_bytes); 553 svc_rdma_put_req_map(vec); 554 dprintk("svcrdma: send_reply returns %d\n", ret); 555 return ret; 556 557 err1: 558 put_page(res_page); 559 err0: 560 svc_rdma_put_req_map(vec); 561 svc_rdma_put_context(ctxt, 0); 562 return ret; 563 } 564