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 /* 53 * Replace the pages in the rq_argpages array with the pages from the SGE in 54 * the RDMA_RECV completion. The SGL should contain full pages up until the 55 * last one. 56 */ 57 static void rdma_build_arg_xdr(struct svc_rqst *rqstp, 58 struct svc_rdma_op_ctxt *ctxt, 59 u32 byte_count) 60 { 61 struct page *page; 62 u32 bc; 63 int sge_no; 64 65 /* Swap the page in the SGE with the page in argpages */ 66 page = ctxt->pages[0]; 67 put_page(rqstp->rq_pages[0]); 68 rqstp->rq_pages[0] = page; 69 70 /* Set up the XDR head */ 71 rqstp->rq_arg.head[0].iov_base = page_address(page); 72 rqstp->rq_arg.head[0].iov_len = min(byte_count, ctxt->sge[0].length); 73 rqstp->rq_arg.len = byte_count; 74 rqstp->rq_arg.buflen = byte_count; 75 76 /* Compute bytes past head in the SGL */ 77 bc = byte_count - rqstp->rq_arg.head[0].iov_len; 78 79 /* If data remains, store it in the pagelist */ 80 rqstp->rq_arg.page_len = bc; 81 rqstp->rq_arg.page_base = 0; 82 rqstp->rq_arg.pages = &rqstp->rq_pages[1]; 83 sge_no = 1; 84 while (bc && sge_no < ctxt->count) { 85 page = ctxt->pages[sge_no]; 86 put_page(rqstp->rq_pages[sge_no]); 87 rqstp->rq_pages[sge_no] = page; 88 bc -= min(bc, ctxt->sge[sge_no].length); 89 rqstp->rq_arg.buflen += ctxt->sge[sge_no].length; 90 sge_no++; 91 } 92 rqstp->rq_respages = &rqstp->rq_pages[sge_no]; 93 94 /* We should never run out of SGE because the limit is defined to 95 * support the max allowed RPC data length 96 */ 97 BUG_ON(bc && (sge_no == ctxt->count)); 98 BUG_ON((rqstp->rq_arg.head[0].iov_len + rqstp->rq_arg.page_len) 99 != byte_count); 100 BUG_ON(rqstp->rq_arg.len != byte_count); 101 102 /* If not all pages were used from the SGL, free the remaining ones */ 103 bc = sge_no; 104 while (sge_no < ctxt->count) { 105 page = ctxt->pages[sge_no++]; 106 put_page(page); 107 } 108 ctxt->count = bc; 109 110 /* Set up tail */ 111 rqstp->rq_arg.tail[0].iov_base = NULL; 112 rqstp->rq_arg.tail[0].iov_len = 0; 113 } 114 115 /* Encode a read-chunk-list as an array of IB SGE 116 * 117 * Assumptions: 118 * - chunk[0]->position points to pages[0] at an offset of 0 119 * - pages[] is not physically or virtually contigous and consists of 120 * PAGE_SIZE elements. 121 * 122 * Output: 123 * - sge array pointing into pages[] array. 124 * - chunk_sge array specifying sge index and count for each 125 * chunk in the read list 126 * 127 */ 128 static int rdma_rcl_to_sge(struct svcxprt_rdma *xprt, 129 struct svc_rqst *rqstp, 130 struct svc_rdma_op_ctxt *head, 131 struct rpcrdma_msg *rmsgp, 132 struct svc_rdma_req_map *rpl_map, 133 struct svc_rdma_req_map *chl_map, 134 int ch_count, 135 int byte_count) 136 { 137 int sge_no; 138 int sge_bytes; 139 int page_off; 140 int page_no; 141 int ch_bytes; 142 int ch_no; 143 struct rpcrdma_read_chunk *ch; 144 145 sge_no = 0; 146 page_no = 0; 147 page_off = 0; 148 ch = (struct rpcrdma_read_chunk *)&rmsgp->rm_body.rm_chunks[0]; 149 ch_no = 0; 150 ch_bytes = ch->rc_target.rs_length; 151 head->arg.head[0] = rqstp->rq_arg.head[0]; 152 head->arg.tail[0] = rqstp->rq_arg.tail[0]; 153 head->arg.pages = &head->pages[head->count]; 154 head->hdr_count = head->count; /* save count of hdr pages */ 155 head->arg.page_base = 0; 156 head->arg.page_len = ch_bytes; 157 head->arg.len = rqstp->rq_arg.len + ch_bytes; 158 head->arg.buflen = rqstp->rq_arg.buflen + ch_bytes; 159 head->count++; 160 chl_map->ch[0].start = 0; 161 while (byte_count) { 162 rpl_map->sge[sge_no].iov_base = 163 page_address(rqstp->rq_arg.pages[page_no]) + page_off; 164 sge_bytes = min_t(int, PAGE_SIZE-page_off, ch_bytes); 165 rpl_map->sge[sge_no].iov_len = sge_bytes; 166 /* 167 * Don't bump head->count here because the same page 168 * may be used by multiple SGE. 169 */ 170 head->arg.pages[page_no] = rqstp->rq_arg.pages[page_no]; 171 rqstp->rq_respages = &rqstp->rq_arg.pages[page_no+1]; 172 173 byte_count -= sge_bytes; 174 ch_bytes -= sge_bytes; 175 sge_no++; 176 /* 177 * If all bytes for this chunk have been mapped to an 178 * SGE, move to the next SGE 179 */ 180 if (ch_bytes == 0) { 181 chl_map->ch[ch_no].count = 182 sge_no - chl_map->ch[ch_no].start; 183 ch_no++; 184 ch++; 185 chl_map->ch[ch_no].start = sge_no; 186 ch_bytes = ch->rc_target.rs_length; 187 /* If bytes remaining account for next chunk */ 188 if (byte_count) { 189 head->arg.page_len += ch_bytes; 190 head->arg.len += ch_bytes; 191 head->arg.buflen += ch_bytes; 192 } 193 } 194 /* 195 * If this SGE consumed all of the page, move to the 196 * next page 197 */ 198 if ((sge_bytes + page_off) == PAGE_SIZE) { 199 page_no++; 200 page_off = 0; 201 /* 202 * If there are still bytes left to map, bump 203 * the page count 204 */ 205 if (byte_count) 206 head->count++; 207 } else 208 page_off += sge_bytes; 209 } 210 BUG_ON(byte_count != 0); 211 return sge_no; 212 } 213 214 static void rdma_set_ctxt_sge(struct svcxprt_rdma *xprt, 215 struct svc_rdma_op_ctxt *ctxt, 216 struct kvec *vec, 217 u64 *sgl_offset, 218 int count) 219 { 220 int i; 221 222 ctxt->count = count; 223 ctxt->direction = DMA_FROM_DEVICE; 224 for (i = 0; i < count; i++) { 225 atomic_inc(&xprt->sc_dma_used); 226 ctxt->sge[i].addr = 227 ib_dma_map_single(xprt->sc_cm_id->device, 228 vec[i].iov_base, vec[i].iov_len, 229 DMA_FROM_DEVICE); 230 ctxt->sge[i].length = vec[i].iov_len; 231 ctxt->sge[i].lkey = xprt->sc_phys_mr->lkey; 232 *sgl_offset = *sgl_offset + vec[i].iov_len; 233 } 234 } 235 236 static int rdma_read_max_sge(struct svcxprt_rdma *xprt, int sge_count) 237 { 238 if ((RDMA_TRANSPORT_IWARP == 239 rdma_node_get_transport(xprt->sc_cm_id-> 240 device->node_type)) 241 && sge_count > 1) 242 return 1; 243 else 244 return min_t(int, sge_count, xprt->sc_max_sge); 245 } 246 247 /* 248 * Use RDMA_READ to read data from the advertised client buffer into the 249 * XDR stream starting at rq_arg.head[0].iov_base. 250 * Each chunk in the array 251 * contains the following fields: 252 * discrim - '1', This isn't used for data placement 253 * position - The xdr stream offset (the same for every chunk) 254 * handle - RMR for client memory region 255 * length - data transfer length 256 * offset - 64 bit tagged offset in remote memory region 257 * 258 * On our side, we need to read into a pagelist. The first page immediately 259 * follows the RPC header. 260 * 261 * This function returns: 262 * 0 - No error and no read-list found. 263 * 264 * 1 - Successful read-list processing. The data is not yet in 265 * the pagelist and therefore the RPC request must be deferred. The 266 * I/O completion will enqueue the transport again and 267 * svc_rdma_recvfrom will complete the request. 268 * 269 * <0 - Error processing/posting read-list. 270 * 271 * NOTE: The ctxt must not be touched after the last WR has been posted 272 * because the I/O completion processing may occur on another 273 * processor and free / modify the context. Ne touche pas! 274 */ 275 static int rdma_read_xdr(struct svcxprt_rdma *xprt, 276 struct rpcrdma_msg *rmsgp, 277 struct svc_rqst *rqstp, 278 struct svc_rdma_op_ctxt *hdr_ctxt) 279 { 280 struct ib_send_wr read_wr; 281 int err = 0; 282 int ch_no; 283 int ch_count; 284 int byte_count; 285 int sge_count; 286 u64 sgl_offset; 287 struct rpcrdma_read_chunk *ch; 288 struct svc_rdma_op_ctxt *ctxt = NULL; 289 struct svc_rdma_req_map *rpl_map; 290 struct svc_rdma_req_map *chl_map; 291 292 /* If no read list is present, return 0 */ 293 ch = svc_rdma_get_read_chunk(rmsgp); 294 if (!ch) 295 return 0; 296 297 /* Allocate temporary reply and chunk maps */ 298 rpl_map = svc_rdma_get_req_map(); 299 chl_map = svc_rdma_get_req_map(); 300 301 svc_rdma_rcl_chunk_counts(ch, &ch_count, &byte_count); 302 if (ch_count > RPCSVC_MAXPAGES) 303 return -EINVAL; 304 sge_count = rdma_rcl_to_sge(xprt, rqstp, hdr_ctxt, rmsgp, 305 rpl_map, chl_map, 306 ch_count, byte_count); 307 sgl_offset = 0; 308 ch_no = 0; 309 310 for (ch = (struct rpcrdma_read_chunk *)&rmsgp->rm_body.rm_chunks[0]; 311 ch->rc_discrim != 0; ch++, ch_no++) { 312 next_sge: 313 ctxt = svc_rdma_get_context(xprt); 314 ctxt->direction = DMA_FROM_DEVICE; 315 clear_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags); 316 317 /* Prepare READ WR */ 318 memset(&read_wr, 0, sizeof read_wr); 319 ctxt->wr_op = IB_WR_RDMA_READ; 320 read_wr.wr_id = (unsigned long)ctxt; 321 read_wr.opcode = IB_WR_RDMA_READ; 322 read_wr.send_flags = IB_SEND_SIGNALED; 323 read_wr.wr.rdma.rkey = ch->rc_target.rs_handle; 324 read_wr.wr.rdma.remote_addr = 325 get_unaligned(&(ch->rc_target.rs_offset)) + 326 sgl_offset; 327 read_wr.sg_list = ctxt->sge; 328 read_wr.num_sge = 329 rdma_read_max_sge(xprt, chl_map->ch[ch_no].count); 330 rdma_set_ctxt_sge(xprt, ctxt, 331 &rpl_map->sge[chl_map->ch[ch_no].start], 332 &sgl_offset, 333 read_wr.num_sge); 334 if (((ch+1)->rc_discrim == 0) && 335 (read_wr.num_sge == chl_map->ch[ch_no].count)) { 336 /* 337 * Mark the last RDMA_READ with a bit to 338 * indicate all RPC data has been fetched from 339 * the client and the RPC needs to be enqueued. 340 */ 341 set_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags); 342 ctxt->read_hdr = hdr_ctxt; 343 } 344 /* Post the read */ 345 err = svc_rdma_send(xprt, &read_wr); 346 if (err) { 347 printk(KERN_ERR "svcrdma: Error %d posting RDMA_READ\n", 348 err); 349 set_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags); 350 svc_rdma_put_context(ctxt, 0); 351 goto out; 352 } 353 atomic_inc(&rdma_stat_read); 354 355 if (read_wr.num_sge < chl_map->ch[ch_no].count) { 356 chl_map->ch[ch_no].count -= read_wr.num_sge; 357 chl_map->ch[ch_no].start += read_wr.num_sge; 358 goto next_sge; 359 } 360 sgl_offset = 0; 361 err = 1; 362 } 363 364 out: 365 svc_rdma_put_req_map(rpl_map); 366 svc_rdma_put_req_map(chl_map); 367 368 /* Detach arg pages. svc_recv will replenish them */ 369 for (ch_no = 0; &rqstp->rq_pages[ch_no] < rqstp->rq_respages; ch_no++) 370 rqstp->rq_pages[ch_no] = NULL; 371 372 /* 373 * Detach res pages. svc_release must see a resused count of 374 * zero or it will attempt to put them. 375 */ 376 while (rqstp->rq_resused) 377 rqstp->rq_respages[--rqstp->rq_resused] = NULL; 378 379 return err; 380 } 381 382 static int rdma_read_complete(struct svc_rqst *rqstp, 383 struct svc_rdma_op_ctxt *head) 384 { 385 int page_no; 386 int ret; 387 388 BUG_ON(!head); 389 390 /* Copy RPC pages */ 391 for (page_no = 0; page_no < head->count; page_no++) { 392 put_page(rqstp->rq_pages[page_no]); 393 rqstp->rq_pages[page_no] = head->pages[page_no]; 394 } 395 /* Point rq_arg.pages past header */ 396 rqstp->rq_arg.pages = &rqstp->rq_pages[head->hdr_count]; 397 rqstp->rq_arg.page_len = head->arg.page_len; 398 rqstp->rq_arg.page_base = head->arg.page_base; 399 400 /* rq_respages starts after the last arg page */ 401 rqstp->rq_respages = &rqstp->rq_arg.pages[page_no]; 402 rqstp->rq_resused = 0; 403 404 /* Rebuild rq_arg head and tail. */ 405 rqstp->rq_arg.head[0] = head->arg.head[0]; 406 rqstp->rq_arg.tail[0] = head->arg.tail[0]; 407 rqstp->rq_arg.len = head->arg.len; 408 rqstp->rq_arg.buflen = head->arg.buflen; 409 410 /* Free the context */ 411 svc_rdma_put_context(head, 0); 412 413 /* XXX: What should this be? */ 414 rqstp->rq_prot = IPPROTO_MAX; 415 svc_xprt_copy_addrs(rqstp, rqstp->rq_xprt); 416 417 ret = rqstp->rq_arg.head[0].iov_len 418 + rqstp->rq_arg.page_len 419 + rqstp->rq_arg.tail[0].iov_len; 420 dprintk("svcrdma: deferred read ret=%d, rq_arg.len =%d, " 421 "rq_arg.head[0].iov_base=%p, rq_arg.head[0].iov_len = %zd\n", 422 ret, rqstp->rq_arg.len, rqstp->rq_arg.head[0].iov_base, 423 rqstp->rq_arg.head[0].iov_len); 424 425 svc_xprt_received(rqstp->rq_xprt); 426 return ret; 427 } 428 429 /* 430 * Set up the rqstp thread context to point to the RQ buffer. If 431 * necessary, pull additional data from the client with an RDMA_READ 432 * request. 433 */ 434 int svc_rdma_recvfrom(struct svc_rqst *rqstp) 435 { 436 struct svc_xprt *xprt = rqstp->rq_xprt; 437 struct svcxprt_rdma *rdma_xprt = 438 container_of(xprt, struct svcxprt_rdma, sc_xprt); 439 struct svc_rdma_op_ctxt *ctxt = NULL; 440 struct rpcrdma_msg *rmsgp; 441 int ret = 0; 442 int len; 443 444 dprintk("svcrdma: rqstp=%p\n", rqstp); 445 446 spin_lock_bh(&rdma_xprt->sc_read_complete_lock); 447 if (!list_empty(&rdma_xprt->sc_read_complete_q)) { 448 ctxt = list_entry(rdma_xprt->sc_read_complete_q.next, 449 struct svc_rdma_op_ctxt, 450 dto_q); 451 list_del_init(&ctxt->dto_q); 452 } 453 spin_unlock_bh(&rdma_xprt->sc_read_complete_lock); 454 if (ctxt) 455 return rdma_read_complete(rqstp, ctxt); 456 457 spin_lock_bh(&rdma_xprt->sc_rq_dto_lock); 458 if (!list_empty(&rdma_xprt->sc_rq_dto_q)) { 459 ctxt = list_entry(rdma_xprt->sc_rq_dto_q.next, 460 struct svc_rdma_op_ctxt, 461 dto_q); 462 list_del_init(&ctxt->dto_q); 463 } else { 464 atomic_inc(&rdma_stat_rq_starve); 465 clear_bit(XPT_DATA, &xprt->xpt_flags); 466 ctxt = NULL; 467 } 468 spin_unlock_bh(&rdma_xprt->sc_rq_dto_lock); 469 if (!ctxt) { 470 /* This is the EAGAIN path. The svc_recv routine will 471 * return -EAGAIN, the nfsd thread will go to call into 472 * svc_recv again and we shouldn't be on the active 473 * transport list 474 */ 475 if (test_bit(XPT_CLOSE, &xprt->xpt_flags)) 476 goto close_out; 477 478 BUG_ON(ret); 479 goto out; 480 } 481 dprintk("svcrdma: processing ctxt=%p on xprt=%p, rqstp=%p, status=%d\n", 482 ctxt, rdma_xprt, rqstp, ctxt->wc_status); 483 BUG_ON(ctxt->wc_status != IB_WC_SUCCESS); 484 atomic_inc(&rdma_stat_recv); 485 486 /* Build up the XDR from the receive buffers. */ 487 rdma_build_arg_xdr(rqstp, ctxt, ctxt->byte_len); 488 489 /* Decode the RDMA header. */ 490 len = svc_rdma_xdr_decode_req(&rmsgp, rqstp); 491 rqstp->rq_xprt_hlen = len; 492 493 /* If the request is invalid, reply with an error */ 494 if (len < 0) { 495 if (len == -ENOSYS) 496 svc_rdma_send_error(rdma_xprt, rmsgp, ERR_VERS); 497 goto close_out; 498 } 499 500 /* Read read-list data. */ 501 ret = rdma_read_xdr(rdma_xprt, rmsgp, rqstp, ctxt); 502 if (ret > 0) { 503 /* read-list posted, defer until data received from client. */ 504 svc_xprt_received(xprt); 505 return 0; 506 } 507 if (ret < 0) { 508 /* Post of read-list failed, free context. */ 509 svc_rdma_put_context(ctxt, 1); 510 return 0; 511 } 512 513 ret = rqstp->rq_arg.head[0].iov_len 514 + rqstp->rq_arg.page_len 515 + rqstp->rq_arg.tail[0].iov_len; 516 svc_rdma_put_context(ctxt, 0); 517 out: 518 dprintk("svcrdma: ret = %d, rq_arg.len =%d, " 519 "rq_arg.head[0].iov_base=%p, rq_arg.head[0].iov_len = %zd\n", 520 ret, rqstp->rq_arg.len, 521 rqstp->rq_arg.head[0].iov_base, 522 rqstp->rq_arg.head[0].iov_len); 523 rqstp->rq_prot = IPPROTO_MAX; 524 svc_xprt_copy_addrs(rqstp, xprt); 525 svc_xprt_received(xprt); 526 return ret; 527 528 close_out: 529 if (ctxt) 530 svc_rdma_put_context(ctxt, 1); 531 dprintk("svcrdma: transport %p is closing\n", xprt); 532 /* 533 * Set the close bit and enqueue it. svc_recv will see the 534 * close bit and call svc_xprt_delete 535 */ 536 set_bit(XPT_CLOSE, &xprt->xpt_flags); 537 svc_xprt_received(xprt); 538 return 0; 539 } 540