1 /* 2 * Copyright (c) 2005-2007 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/svc_xprt.h> 43 #include <linux/sunrpc/debug.h> 44 #include <linux/sunrpc/rpc_rdma.h> 45 #include <linux/spinlock.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 static struct svc_xprt *svc_rdma_create(struct svc_serv *serv, 53 struct sockaddr *sa, int salen, 54 int flags); 55 static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt); 56 static void svc_rdma_release_rqst(struct svc_rqst *); 57 static void dto_tasklet_func(unsigned long data); 58 static void svc_rdma_detach(struct svc_xprt *xprt); 59 static void svc_rdma_free(struct svc_xprt *xprt); 60 static int svc_rdma_has_wspace(struct svc_xprt *xprt); 61 static void rq_cq_reap(struct svcxprt_rdma *xprt); 62 static void sq_cq_reap(struct svcxprt_rdma *xprt); 63 64 DECLARE_TASKLET(dto_tasklet, dto_tasklet_func, 0UL); 65 static DEFINE_SPINLOCK(dto_lock); 66 static LIST_HEAD(dto_xprt_q); 67 68 static struct svc_xprt_ops svc_rdma_ops = { 69 .xpo_create = svc_rdma_create, 70 .xpo_recvfrom = svc_rdma_recvfrom, 71 .xpo_sendto = svc_rdma_sendto, 72 .xpo_release_rqst = svc_rdma_release_rqst, 73 .xpo_detach = svc_rdma_detach, 74 .xpo_free = svc_rdma_free, 75 .xpo_prep_reply_hdr = svc_rdma_prep_reply_hdr, 76 .xpo_has_wspace = svc_rdma_has_wspace, 77 .xpo_accept = svc_rdma_accept, 78 }; 79 80 struct svc_xprt_class svc_rdma_class = { 81 .xcl_name = "rdma", 82 .xcl_owner = THIS_MODULE, 83 .xcl_ops = &svc_rdma_ops, 84 .xcl_max_payload = RPCSVC_MAXPAYLOAD_TCP, 85 }; 86 87 /* WR context cache. Created in svc_rdma.c */ 88 extern struct kmem_cache *svc_rdma_ctxt_cachep; 89 90 struct svc_rdma_op_ctxt *svc_rdma_get_context(struct svcxprt_rdma *xprt) 91 { 92 struct svc_rdma_op_ctxt *ctxt; 93 94 while (1) { 95 ctxt = kmem_cache_alloc(svc_rdma_ctxt_cachep, GFP_KERNEL); 96 if (ctxt) 97 break; 98 schedule_timeout_uninterruptible(msecs_to_jiffies(500)); 99 } 100 ctxt->xprt = xprt; 101 INIT_LIST_HEAD(&ctxt->dto_q); 102 ctxt->count = 0; 103 atomic_inc(&xprt->sc_ctxt_used); 104 return ctxt; 105 } 106 107 static void svc_rdma_unmap_dma(struct svc_rdma_op_ctxt *ctxt) 108 { 109 struct svcxprt_rdma *xprt = ctxt->xprt; 110 int i; 111 for (i = 0; i < ctxt->count && ctxt->sge[i].length; i++) { 112 atomic_dec(&xprt->sc_dma_used); 113 ib_dma_unmap_single(xprt->sc_cm_id->device, 114 ctxt->sge[i].addr, 115 ctxt->sge[i].length, 116 ctxt->direction); 117 } 118 } 119 120 void svc_rdma_put_context(struct svc_rdma_op_ctxt *ctxt, int free_pages) 121 { 122 struct svcxprt_rdma *xprt; 123 int i; 124 125 BUG_ON(!ctxt); 126 xprt = ctxt->xprt; 127 if (free_pages) 128 for (i = 0; i < ctxt->count; i++) 129 put_page(ctxt->pages[i]); 130 131 kmem_cache_free(svc_rdma_ctxt_cachep, ctxt); 132 atomic_dec(&xprt->sc_ctxt_used); 133 } 134 135 /* Temporary NFS request map cache. Created in svc_rdma.c */ 136 extern struct kmem_cache *svc_rdma_map_cachep; 137 138 /* 139 * Temporary NFS req mappings are shared across all transport 140 * instances. These are short lived and should be bounded by the number 141 * of concurrent server threads * depth of the SQ. 142 */ 143 struct svc_rdma_req_map *svc_rdma_get_req_map(void) 144 { 145 struct svc_rdma_req_map *map; 146 while (1) { 147 map = kmem_cache_alloc(svc_rdma_map_cachep, GFP_KERNEL); 148 if (map) 149 break; 150 schedule_timeout_uninterruptible(msecs_to_jiffies(500)); 151 } 152 map->count = 0; 153 return map; 154 } 155 156 void svc_rdma_put_req_map(struct svc_rdma_req_map *map) 157 { 158 kmem_cache_free(svc_rdma_map_cachep, map); 159 } 160 161 /* ib_cq event handler */ 162 static void cq_event_handler(struct ib_event *event, void *context) 163 { 164 struct svc_xprt *xprt = context; 165 dprintk("svcrdma: received CQ event id=%d, context=%p\n", 166 event->event, context); 167 set_bit(XPT_CLOSE, &xprt->xpt_flags); 168 } 169 170 /* QP event handler */ 171 static void qp_event_handler(struct ib_event *event, void *context) 172 { 173 struct svc_xprt *xprt = context; 174 175 switch (event->event) { 176 /* These are considered benign events */ 177 case IB_EVENT_PATH_MIG: 178 case IB_EVENT_COMM_EST: 179 case IB_EVENT_SQ_DRAINED: 180 case IB_EVENT_QP_LAST_WQE_REACHED: 181 dprintk("svcrdma: QP event %d received for QP=%p\n", 182 event->event, event->element.qp); 183 break; 184 /* These are considered fatal events */ 185 case IB_EVENT_PATH_MIG_ERR: 186 case IB_EVENT_QP_FATAL: 187 case IB_EVENT_QP_REQ_ERR: 188 case IB_EVENT_QP_ACCESS_ERR: 189 case IB_EVENT_DEVICE_FATAL: 190 default: 191 dprintk("svcrdma: QP ERROR event %d received for QP=%p, " 192 "closing transport\n", 193 event->event, event->element.qp); 194 set_bit(XPT_CLOSE, &xprt->xpt_flags); 195 break; 196 } 197 } 198 199 /* 200 * Data Transfer Operation Tasklet 201 * 202 * Walks a list of transports with I/O pending, removing entries as 203 * they are added to the server's I/O pending list. Two bits indicate 204 * if SQ, RQ, or both have I/O pending. The dto_lock is an irqsave 205 * spinlock that serializes access to the transport list with the RQ 206 * and SQ interrupt handlers. 207 */ 208 static void dto_tasklet_func(unsigned long data) 209 { 210 struct svcxprt_rdma *xprt; 211 unsigned long flags; 212 213 spin_lock_irqsave(&dto_lock, flags); 214 while (!list_empty(&dto_xprt_q)) { 215 xprt = list_entry(dto_xprt_q.next, 216 struct svcxprt_rdma, sc_dto_q); 217 list_del_init(&xprt->sc_dto_q); 218 spin_unlock_irqrestore(&dto_lock, flags); 219 220 rq_cq_reap(xprt); 221 sq_cq_reap(xprt); 222 223 svc_xprt_put(&xprt->sc_xprt); 224 spin_lock_irqsave(&dto_lock, flags); 225 } 226 spin_unlock_irqrestore(&dto_lock, flags); 227 } 228 229 /* 230 * Receive Queue Completion Handler 231 * 232 * Since an RQ completion handler is called on interrupt context, we 233 * need to defer the handling of the I/O to a tasklet 234 */ 235 static void rq_comp_handler(struct ib_cq *cq, void *cq_context) 236 { 237 struct svcxprt_rdma *xprt = cq_context; 238 unsigned long flags; 239 240 /* Guard against unconditional flush call for destroyed QP */ 241 if (atomic_read(&xprt->sc_xprt.xpt_ref.refcount)==0) 242 return; 243 244 /* 245 * Set the bit regardless of whether or not it's on the list 246 * because it may be on the list already due to an SQ 247 * completion. 248 */ 249 set_bit(RDMAXPRT_RQ_PENDING, &xprt->sc_flags); 250 251 /* 252 * If this transport is not already on the DTO transport queue, 253 * add it 254 */ 255 spin_lock_irqsave(&dto_lock, flags); 256 if (list_empty(&xprt->sc_dto_q)) { 257 svc_xprt_get(&xprt->sc_xprt); 258 list_add_tail(&xprt->sc_dto_q, &dto_xprt_q); 259 } 260 spin_unlock_irqrestore(&dto_lock, flags); 261 262 /* Tasklet does all the work to avoid irqsave locks. */ 263 tasklet_schedule(&dto_tasklet); 264 } 265 266 /* 267 * rq_cq_reap - Process the RQ CQ. 268 * 269 * Take all completing WC off the CQE and enqueue the associated DTO 270 * context on the dto_q for the transport. 271 * 272 * Note that caller must hold a transport reference. 273 */ 274 static void rq_cq_reap(struct svcxprt_rdma *xprt) 275 { 276 int ret; 277 struct ib_wc wc; 278 struct svc_rdma_op_ctxt *ctxt = NULL; 279 280 if (!test_and_clear_bit(RDMAXPRT_RQ_PENDING, &xprt->sc_flags)) 281 return; 282 283 ib_req_notify_cq(xprt->sc_rq_cq, IB_CQ_NEXT_COMP); 284 atomic_inc(&rdma_stat_rq_poll); 285 286 while ((ret = ib_poll_cq(xprt->sc_rq_cq, 1, &wc)) > 0) { 287 ctxt = (struct svc_rdma_op_ctxt *)(unsigned long)wc.wr_id; 288 ctxt->wc_status = wc.status; 289 ctxt->byte_len = wc.byte_len; 290 svc_rdma_unmap_dma(ctxt); 291 if (wc.status != IB_WC_SUCCESS) { 292 /* Close the transport */ 293 dprintk("svcrdma: transport closing putting ctxt %p\n", ctxt); 294 set_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags); 295 svc_rdma_put_context(ctxt, 1); 296 svc_xprt_put(&xprt->sc_xprt); 297 continue; 298 } 299 spin_lock_bh(&xprt->sc_rq_dto_lock); 300 list_add_tail(&ctxt->dto_q, &xprt->sc_rq_dto_q); 301 spin_unlock_bh(&xprt->sc_rq_dto_lock); 302 svc_xprt_put(&xprt->sc_xprt); 303 } 304 305 if (ctxt) 306 atomic_inc(&rdma_stat_rq_prod); 307 308 set_bit(XPT_DATA, &xprt->sc_xprt.xpt_flags); 309 /* 310 * If data arrived before established event, 311 * don't enqueue. This defers RPC I/O until the 312 * RDMA connection is complete. 313 */ 314 if (!test_bit(RDMAXPRT_CONN_PENDING, &xprt->sc_flags)) 315 svc_xprt_enqueue(&xprt->sc_xprt); 316 } 317 318 /* 319 * Send Queue Completion Handler - potentially called on interrupt context. 320 * 321 * Note that caller must hold a transport reference. 322 */ 323 static void sq_cq_reap(struct svcxprt_rdma *xprt) 324 { 325 struct svc_rdma_op_ctxt *ctxt = NULL; 326 struct ib_wc wc; 327 struct ib_cq *cq = xprt->sc_sq_cq; 328 int ret; 329 330 331 if (!test_and_clear_bit(RDMAXPRT_SQ_PENDING, &xprt->sc_flags)) 332 return; 333 334 ib_req_notify_cq(xprt->sc_sq_cq, IB_CQ_NEXT_COMP); 335 atomic_inc(&rdma_stat_sq_poll); 336 while ((ret = ib_poll_cq(cq, 1, &wc)) > 0) { 337 ctxt = (struct svc_rdma_op_ctxt *)(unsigned long)wc.wr_id; 338 xprt = ctxt->xprt; 339 340 svc_rdma_unmap_dma(ctxt); 341 if (wc.status != IB_WC_SUCCESS) 342 /* Close the transport */ 343 set_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags); 344 345 /* Decrement used SQ WR count */ 346 atomic_dec(&xprt->sc_sq_count); 347 wake_up(&xprt->sc_send_wait); 348 349 switch (ctxt->wr_op) { 350 case IB_WR_SEND: 351 svc_rdma_put_context(ctxt, 1); 352 break; 353 354 case IB_WR_RDMA_WRITE: 355 svc_rdma_put_context(ctxt, 0); 356 break; 357 358 case IB_WR_RDMA_READ: 359 if (test_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags)) { 360 struct svc_rdma_op_ctxt *read_hdr = ctxt->read_hdr; 361 BUG_ON(!read_hdr); 362 set_bit(XPT_DATA, &xprt->sc_xprt.xpt_flags); 363 spin_lock_bh(&xprt->sc_read_complete_lock); 364 list_add_tail(&read_hdr->dto_q, 365 &xprt->sc_read_complete_q); 366 spin_unlock_bh(&xprt->sc_read_complete_lock); 367 svc_xprt_enqueue(&xprt->sc_xprt); 368 } 369 svc_rdma_put_context(ctxt, 0); 370 break; 371 372 default: 373 printk(KERN_ERR "svcrdma: unexpected completion type, " 374 "opcode=%d, status=%d\n", 375 wc.opcode, wc.status); 376 break; 377 } 378 svc_xprt_put(&xprt->sc_xprt); 379 } 380 381 if (ctxt) 382 atomic_inc(&rdma_stat_sq_prod); 383 } 384 385 static void sq_comp_handler(struct ib_cq *cq, void *cq_context) 386 { 387 struct svcxprt_rdma *xprt = cq_context; 388 unsigned long flags; 389 390 /* Guard against unconditional flush call for destroyed QP */ 391 if (atomic_read(&xprt->sc_xprt.xpt_ref.refcount)==0) 392 return; 393 394 /* 395 * Set the bit regardless of whether or not it's on the list 396 * because it may be on the list already due to an RQ 397 * completion. 398 */ 399 set_bit(RDMAXPRT_SQ_PENDING, &xprt->sc_flags); 400 401 /* 402 * If this transport is not already on the DTO transport queue, 403 * add it 404 */ 405 spin_lock_irqsave(&dto_lock, flags); 406 if (list_empty(&xprt->sc_dto_q)) { 407 svc_xprt_get(&xprt->sc_xprt); 408 list_add_tail(&xprt->sc_dto_q, &dto_xprt_q); 409 } 410 spin_unlock_irqrestore(&dto_lock, flags); 411 412 /* Tasklet does all the work to avoid irqsave locks. */ 413 tasklet_schedule(&dto_tasklet); 414 } 415 416 static struct svcxprt_rdma *rdma_create_xprt(struct svc_serv *serv, 417 int listener) 418 { 419 struct svcxprt_rdma *cma_xprt = kzalloc(sizeof *cma_xprt, GFP_KERNEL); 420 421 if (!cma_xprt) 422 return NULL; 423 svc_xprt_init(&svc_rdma_class, &cma_xprt->sc_xprt, serv); 424 INIT_LIST_HEAD(&cma_xprt->sc_accept_q); 425 INIT_LIST_HEAD(&cma_xprt->sc_dto_q); 426 INIT_LIST_HEAD(&cma_xprt->sc_rq_dto_q); 427 INIT_LIST_HEAD(&cma_xprt->sc_read_complete_q); 428 init_waitqueue_head(&cma_xprt->sc_send_wait); 429 430 spin_lock_init(&cma_xprt->sc_lock); 431 spin_lock_init(&cma_xprt->sc_read_complete_lock); 432 spin_lock_init(&cma_xprt->sc_rq_dto_lock); 433 434 cma_xprt->sc_ord = svcrdma_ord; 435 436 cma_xprt->sc_max_req_size = svcrdma_max_req_size; 437 cma_xprt->sc_max_requests = svcrdma_max_requests; 438 cma_xprt->sc_sq_depth = svcrdma_max_requests * RPCRDMA_SQ_DEPTH_MULT; 439 atomic_set(&cma_xprt->sc_sq_count, 0); 440 atomic_set(&cma_xprt->sc_ctxt_used, 0); 441 442 if (listener) 443 set_bit(XPT_LISTENER, &cma_xprt->sc_xprt.xpt_flags); 444 445 return cma_xprt; 446 } 447 448 struct page *svc_rdma_get_page(void) 449 { 450 struct page *page; 451 452 while ((page = alloc_page(GFP_KERNEL)) == NULL) { 453 /* If we can't get memory, wait a bit and try again */ 454 printk(KERN_INFO "svcrdma: out of memory...retrying in 1000 " 455 "jiffies.\n"); 456 schedule_timeout_uninterruptible(msecs_to_jiffies(1000)); 457 } 458 return page; 459 } 460 461 int svc_rdma_post_recv(struct svcxprt_rdma *xprt) 462 { 463 struct ib_recv_wr recv_wr, *bad_recv_wr; 464 struct svc_rdma_op_ctxt *ctxt; 465 struct page *page; 466 unsigned long pa; 467 int sge_no; 468 int buflen; 469 int ret; 470 471 ctxt = svc_rdma_get_context(xprt); 472 buflen = 0; 473 ctxt->direction = DMA_FROM_DEVICE; 474 for (sge_no = 0; buflen < xprt->sc_max_req_size; sge_no++) { 475 BUG_ON(sge_no >= xprt->sc_max_sge); 476 page = svc_rdma_get_page(); 477 ctxt->pages[sge_no] = page; 478 atomic_inc(&xprt->sc_dma_used); 479 pa = ib_dma_map_page(xprt->sc_cm_id->device, 480 page, 0, PAGE_SIZE, 481 DMA_FROM_DEVICE); 482 ctxt->sge[sge_no].addr = pa; 483 ctxt->sge[sge_no].length = PAGE_SIZE; 484 ctxt->sge[sge_no].lkey = xprt->sc_phys_mr->lkey; 485 buflen += PAGE_SIZE; 486 } 487 ctxt->count = sge_no; 488 recv_wr.next = NULL; 489 recv_wr.sg_list = &ctxt->sge[0]; 490 recv_wr.num_sge = ctxt->count; 491 recv_wr.wr_id = (u64)(unsigned long)ctxt; 492 493 svc_xprt_get(&xprt->sc_xprt); 494 ret = ib_post_recv(xprt->sc_qp, &recv_wr, &bad_recv_wr); 495 if (ret) { 496 svc_xprt_put(&xprt->sc_xprt); 497 svc_rdma_put_context(ctxt, 1); 498 } 499 return ret; 500 } 501 502 /* 503 * This function handles the CONNECT_REQUEST event on a listening 504 * endpoint. It is passed the cma_id for the _new_ connection. The context in 505 * this cma_id is inherited from the listening cma_id and is the svc_xprt 506 * structure for the listening endpoint. 507 * 508 * This function creates a new xprt for the new connection and enqueues it on 509 * the accept queue for the listent xprt. When the listen thread is kicked, it 510 * will call the recvfrom method on the listen xprt which will accept the new 511 * connection. 512 */ 513 static void handle_connect_req(struct rdma_cm_id *new_cma_id, size_t client_ird) 514 { 515 struct svcxprt_rdma *listen_xprt = new_cma_id->context; 516 struct svcxprt_rdma *newxprt; 517 struct sockaddr *sa; 518 519 /* Create a new transport */ 520 newxprt = rdma_create_xprt(listen_xprt->sc_xprt.xpt_server, 0); 521 if (!newxprt) { 522 dprintk("svcrdma: failed to create new transport\n"); 523 return; 524 } 525 newxprt->sc_cm_id = new_cma_id; 526 new_cma_id->context = newxprt; 527 dprintk("svcrdma: Creating newxprt=%p, cm_id=%p, listenxprt=%p\n", 528 newxprt, newxprt->sc_cm_id, listen_xprt); 529 530 /* Save client advertised inbound read limit for use later in accept. */ 531 newxprt->sc_ord = client_ird; 532 533 /* Set the local and remote addresses in the transport */ 534 sa = (struct sockaddr *)&newxprt->sc_cm_id->route.addr.dst_addr; 535 svc_xprt_set_remote(&newxprt->sc_xprt, sa, svc_addr_len(sa)); 536 sa = (struct sockaddr *)&newxprt->sc_cm_id->route.addr.src_addr; 537 svc_xprt_set_local(&newxprt->sc_xprt, sa, svc_addr_len(sa)); 538 539 /* 540 * Enqueue the new transport on the accept queue of the listening 541 * transport 542 */ 543 spin_lock_bh(&listen_xprt->sc_lock); 544 list_add_tail(&newxprt->sc_accept_q, &listen_xprt->sc_accept_q); 545 spin_unlock_bh(&listen_xprt->sc_lock); 546 547 /* 548 * Can't use svc_xprt_received here because we are not on a 549 * rqstp thread 550 */ 551 set_bit(XPT_CONN, &listen_xprt->sc_xprt.xpt_flags); 552 svc_xprt_enqueue(&listen_xprt->sc_xprt); 553 } 554 555 /* 556 * Handles events generated on the listening endpoint. These events will be 557 * either be incoming connect requests or adapter removal events. 558 */ 559 static int rdma_listen_handler(struct rdma_cm_id *cma_id, 560 struct rdma_cm_event *event) 561 { 562 struct svcxprt_rdma *xprt = cma_id->context; 563 int ret = 0; 564 565 switch (event->event) { 566 case RDMA_CM_EVENT_CONNECT_REQUEST: 567 dprintk("svcrdma: Connect request on cma_id=%p, xprt = %p, " 568 "event=%d\n", cma_id, cma_id->context, event->event); 569 handle_connect_req(cma_id, 570 event->param.conn.responder_resources); 571 break; 572 573 case RDMA_CM_EVENT_ESTABLISHED: 574 /* Accept complete */ 575 dprintk("svcrdma: Connection completed on LISTEN xprt=%p, " 576 "cm_id=%p\n", xprt, cma_id); 577 break; 578 579 case RDMA_CM_EVENT_DEVICE_REMOVAL: 580 dprintk("svcrdma: Device removal xprt=%p, cm_id=%p\n", 581 xprt, cma_id); 582 if (xprt) 583 set_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags); 584 break; 585 586 default: 587 dprintk("svcrdma: Unexpected event on listening endpoint %p, " 588 "event=%d\n", cma_id, event->event); 589 break; 590 } 591 592 return ret; 593 } 594 595 static int rdma_cma_handler(struct rdma_cm_id *cma_id, 596 struct rdma_cm_event *event) 597 { 598 struct svc_xprt *xprt = cma_id->context; 599 struct svcxprt_rdma *rdma = 600 container_of(xprt, struct svcxprt_rdma, sc_xprt); 601 switch (event->event) { 602 case RDMA_CM_EVENT_ESTABLISHED: 603 /* Accept complete */ 604 svc_xprt_get(xprt); 605 dprintk("svcrdma: Connection completed on DTO xprt=%p, " 606 "cm_id=%p\n", xprt, cma_id); 607 clear_bit(RDMAXPRT_CONN_PENDING, &rdma->sc_flags); 608 svc_xprt_enqueue(xprt); 609 break; 610 case RDMA_CM_EVENT_DISCONNECTED: 611 dprintk("svcrdma: Disconnect on DTO xprt=%p, cm_id=%p\n", 612 xprt, cma_id); 613 if (xprt) { 614 set_bit(XPT_CLOSE, &xprt->xpt_flags); 615 svc_xprt_enqueue(xprt); 616 svc_xprt_put(xprt); 617 } 618 break; 619 case RDMA_CM_EVENT_DEVICE_REMOVAL: 620 dprintk("svcrdma: Device removal cma_id=%p, xprt = %p, " 621 "event=%d\n", cma_id, xprt, event->event); 622 if (xprt) { 623 set_bit(XPT_CLOSE, &xprt->xpt_flags); 624 svc_xprt_enqueue(xprt); 625 } 626 break; 627 default: 628 dprintk("svcrdma: Unexpected event on DTO endpoint %p, " 629 "event=%d\n", cma_id, event->event); 630 break; 631 } 632 return 0; 633 } 634 635 /* 636 * Create a listening RDMA service endpoint. 637 */ 638 static struct svc_xprt *svc_rdma_create(struct svc_serv *serv, 639 struct sockaddr *sa, int salen, 640 int flags) 641 { 642 struct rdma_cm_id *listen_id; 643 struct svcxprt_rdma *cma_xprt; 644 struct svc_xprt *xprt; 645 int ret; 646 647 dprintk("svcrdma: Creating RDMA socket\n"); 648 649 cma_xprt = rdma_create_xprt(serv, 1); 650 if (!cma_xprt) 651 return ERR_PTR(-ENOMEM); 652 xprt = &cma_xprt->sc_xprt; 653 654 listen_id = rdma_create_id(rdma_listen_handler, cma_xprt, RDMA_PS_TCP); 655 if (IS_ERR(listen_id)) { 656 ret = PTR_ERR(listen_id); 657 dprintk("svcrdma: rdma_create_id failed = %d\n", ret); 658 goto err0; 659 } 660 661 ret = rdma_bind_addr(listen_id, sa); 662 if (ret) { 663 dprintk("svcrdma: rdma_bind_addr failed = %d\n", ret); 664 goto err1; 665 } 666 cma_xprt->sc_cm_id = listen_id; 667 668 ret = rdma_listen(listen_id, RPCRDMA_LISTEN_BACKLOG); 669 if (ret) { 670 dprintk("svcrdma: rdma_listen failed = %d\n", ret); 671 goto err1; 672 } 673 674 /* 675 * We need to use the address from the cm_id in case the 676 * caller specified 0 for the port number. 677 */ 678 sa = (struct sockaddr *)&cma_xprt->sc_cm_id->route.addr.src_addr; 679 svc_xprt_set_local(&cma_xprt->sc_xprt, sa, salen); 680 681 return &cma_xprt->sc_xprt; 682 683 err1: 684 rdma_destroy_id(listen_id); 685 err0: 686 kfree(cma_xprt); 687 return ERR_PTR(ret); 688 } 689 690 /* 691 * This is the xpo_recvfrom function for listening endpoints. Its 692 * purpose is to accept incoming connections. The CMA callback handler 693 * has already created a new transport and attached it to the new CMA 694 * ID. 695 * 696 * There is a queue of pending connections hung on the listening 697 * transport. This queue contains the new svc_xprt structure. This 698 * function takes svc_xprt structures off the accept_q and completes 699 * the connection. 700 */ 701 static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt) 702 { 703 struct svcxprt_rdma *listen_rdma; 704 struct svcxprt_rdma *newxprt = NULL; 705 struct rdma_conn_param conn_param; 706 struct ib_qp_init_attr qp_attr; 707 struct ib_device_attr devattr; 708 int ret; 709 int i; 710 711 listen_rdma = container_of(xprt, struct svcxprt_rdma, sc_xprt); 712 clear_bit(XPT_CONN, &xprt->xpt_flags); 713 /* Get the next entry off the accept list */ 714 spin_lock_bh(&listen_rdma->sc_lock); 715 if (!list_empty(&listen_rdma->sc_accept_q)) { 716 newxprt = list_entry(listen_rdma->sc_accept_q.next, 717 struct svcxprt_rdma, sc_accept_q); 718 list_del_init(&newxprt->sc_accept_q); 719 } 720 if (!list_empty(&listen_rdma->sc_accept_q)) 721 set_bit(XPT_CONN, &listen_rdma->sc_xprt.xpt_flags); 722 spin_unlock_bh(&listen_rdma->sc_lock); 723 if (!newxprt) 724 return NULL; 725 726 dprintk("svcrdma: newxprt from accept queue = %p, cm_id=%p\n", 727 newxprt, newxprt->sc_cm_id); 728 729 ret = ib_query_device(newxprt->sc_cm_id->device, &devattr); 730 if (ret) { 731 dprintk("svcrdma: could not query device attributes on " 732 "device %p, rc=%d\n", newxprt->sc_cm_id->device, ret); 733 goto errout; 734 } 735 736 /* Qualify the transport resource defaults with the 737 * capabilities of this particular device */ 738 newxprt->sc_max_sge = min((size_t)devattr.max_sge, 739 (size_t)RPCSVC_MAXPAGES); 740 newxprt->sc_max_requests = min((size_t)devattr.max_qp_wr, 741 (size_t)svcrdma_max_requests); 742 newxprt->sc_sq_depth = RPCRDMA_SQ_DEPTH_MULT * newxprt->sc_max_requests; 743 744 /* 745 * Limit ORD based on client limit, local device limit, and 746 * configured svcrdma limit. 747 */ 748 newxprt->sc_ord = min_t(size_t, devattr.max_qp_rd_atom, newxprt->sc_ord); 749 newxprt->sc_ord = min_t(size_t, svcrdma_ord, newxprt->sc_ord); 750 751 newxprt->sc_pd = ib_alloc_pd(newxprt->sc_cm_id->device); 752 if (IS_ERR(newxprt->sc_pd)) { 753 dprintk("svcrdma: error creating PD for connect request\n"); 754 goto errout; 755 } 756 newxprt->sc_sq_cq = ib_create_cq(newxprt->sc_cm_id->device, 757 sq_comp_handler, 758 cq_event_handler, 759 newxprt, 760 newxprt->sc_sq_depth, 761 0); 762 if (IS_ERR(newxprt->sc_sq_cq)) { 763 dprintk("svcrdma: error creating SQ CQ for connect request\n"); 764 goto errout; 765 } 766 newxprt->sc_rq_cq = ib_create_cq(newxprt->sc_cm_id->device, 767 rq_comp_handler, 768 cq_event_handler, 769 newxprt, 770 newxprt->sc_max_requests, 771 0); 772 if (IS_ERR(newxprt->sc_rq_cq)) { 773 dprintk("svcrdma: error creating RQ CQ for connect request\n"); 774 goto errout; 775 } 776 777 memset(&qp_attr, 0, sizeof qp_attr); 778 qp_attr.event_handler = qp_event_handler; 779 qp_attr.qp_context = &newxprt->sc_xprt; 780 qp_attr.cap.max_send_wr = newxprt->sc_sq_depth; 781 qp_attr.cap.max_recv_wr = newxprt->sc_max_requests; 782 qp_attr.cap.max_send_sge = newxprt->sc_max_sge; 783 qp_attr.cap.max_recv_sge = newxprt->sc_max_sge; 784 qp_attr.sq_sig_type = IB_SIGNAL_REQ_WR; 785 qp_attr.qp_type = IB_QPT_RC; 786 qp_attr.send_cq = newxprt->sc_sq_cq; 787 qp_attr.recv_cq = newxprt->sc_rq_cq; 788 dprintk("svcrdma: newxprt->sc_cm_id=%p, newxprt->sc_pd=%p\n" 789 " cm_id->device=%p, sc_pd->device=%p\n" 790 " cap.max_send_wr = %d\n" 791 " cap.max_recv_wr = %d\n" 792 " cap.max_send_sge = %d\n" 793 " cap.max_recv_sge = %d\n", 794 newxprt->sc_cm_id, newxprt->sc_pd, 795 newxprt->sc_cm_id->device, newxprt->sc_pd->device, 796 qp_attr.cap.max_send_wr, 797 qp_attr.cap.max_recv_wr, 798 qp_attr.cap.max_send_sge, 799 qp_attr.cap.max_recv_sge); 800 801 ret = rdma_create_qp(newxprt->sc_cm_id, newxprt->sc_pd, &qp_attr); 802 if (ret) { 803 /* 804 * XXX: This is a hack. We need a xx_request_qp interface 805 * that will adjust the qp_attr's with a best-effort 806 * number 807 */ 808 qp_attr.cap.max_send_sge -= 2; 809 qp_attr.cap.max_recv_sge -= 2; 810 ret = rdma_create_qp(newxprt->sc_cm_id, newxprt->sc_pd, 811 &qp_attr); 812 if (ret) { 813 dprintk("svcrdma: failed to create QP, ret=%d\n", ret); 814 goto errout; 815 } 816 newxprt->sc_max_sge = qp_attr.cap.max_send_sge; 817 newxprt->sc_max_sge = qp_attr.cap.max_recv_sge; 818 newxprt->sc_sq_depth = qp_attr.cap.max_send_wr; 819 newxprt->sc_max_requests = qp_attr.cap.max_recv_wr; 820 } 821 newxprt->sc_qp = newxprt->sc_cm_id->qp; 822 823 /* Register all of physical memory */ 824 newxprt->sc_phys_mr = ib_get_dma_mr(newxprt->sc_pd, 825 IB_ACCESS_LOCAL_WRITE | 826 IB_ACCESS_REMOTE_WRITE); 827 if (IS_ERR(newxprt->sc_phys_mr)) { 828 dprintk("svcrdma: Failed to create DMA MR ret=%d\n", ret); 829 goto errout; 830 } 831 832 /* Post receive buffers */ 833 for (i = 0; i < newxprt->sc_max_requests; i++) { 834 ret = svc_rdma_post_recv(newxprt); 835 if (ret) { 836 dprintk("svcrdma: failure posting receive buffers\n"); 837 goto errout; 838 } 839 } 840 841 /* Swap out the handler */ 842 newxprt->sc_cm_id->event_handler = rdma_cma_handler; 843 844 /* 845 * Arm the CQs for the SQ and RQ before accepting so we can't 846 * miss the first message 847 */ 848 ib_req_notify_cq(newxprt->sc_sq_cq, IB_CQ_NEXT_COMP); 849 ib_req_notify_cq(newxprt->sc_rq_cq, IB_CQ_NEXT_COMP); 850 851 /* Accept Connection */ 852 set_bit(RDMAXPRT_CONN_PENDING, &newxprt->sc_flags); 853 memset(&conn_param, 0, sizeof conn_param); 854 conn_param.responder_resources = 0; 855 conn_param.initiator_depth = newxprt->sc_ord; 856 ret = rdma_accept(newxprt->sc_cm_id, &conn_param); 857 if (ret) { 858 dprintk("svcrdma: failed to accept new connection, ret=%d\n", 859 ret); 860 goto errout; 861 } 862 863 dprintk("svcrdma: new connection %p accepted with the following " 864 "attributes:\n" 865 " local_ip : %d.%d.%d.%d\n" 866 " local_port : %d\n" 867 " remote_ip : %d.%d.%d.%d\n" 868 " remote_port : %d\n" 869 " max_sge : %d\n" 870 " sq_depth : %d\n" 871 " max_requests : %d\n" 872 " ord : %d\n", 873 newxprt, 874 NIPQUAD(((struct sockaddr_in *)&newxprt->sc_cm_id-> 875 route.addr.src_addr)->sin_addr.s_addr), 876 ntohs(((struct sockaddr_in *)&newxprt->sc_cm_id-> 877 route.addr.src_addr)->sin_port), 878 NIPQUAD(((struct sockaddr_in *)&newxprt->sc_cm_id-> 879 route.addr.dst_addr)->sin_addr.s_addr), 880 ntohs(((struct sockaddr_in *)&newxprt->sc_cm_id-> 881 route.addr.dst_addr)->sin_port), 882 newxprt->sc_max_sge, 883 newxprt->sc_sq_depth, 884 newxprt->sc_max_requests, 885 newxprt->sc_ord); 886 887 return &newxprt->sc_xprt; 888 889 errout: 890 dprintk("svcrdma: failure accepting new connection rc=%d.\n", ret); 891 /* Take a reference in case the DTO handler runs */ 892 svc_xprt_get(&newxprt->sc_xprt); 893 if (newxprt->sc_qp && !IS_ERR(newxprt->sc_qp)) 894 ib_destroy_qp(newxprt->sc_qp); 895 rdma_destroy_id(newxprt->sc_cm_id); 896 /* This call to put will destroy the transport */ 897 svc_xprt_put(&newxprt->sc_xprt); 898 return NULL; 899 } 900 901 static void svc_rdma_release_rqst(struct svc_rqst *rqstp) 902 { 903 } 904 905 /* 906 * When connected, an svc_xprt has at least two references: 907 * 908 * - A reference held by the cm_id between the ESTABLISHED and 909 * DISCONNECTED events. If the remote peer disconnected first, this 910 * reference could be gone. 911 * 912 * - A reference held by the svc_recv code that called this function 913 * as part of close processing. 914 * 915 * At a minimum one references should still be held. 916 */ 917 static void svc_rdma_detach(struct svc_xprt *xprt) 918 { 919 struct svcxprt_rdma *rdma = 920 container_of(xprt, struct svcxprt_rdma, sc_xprt); 921 dprintk("svc: svc_rdma_detach(%p)\n", xprt); 922 923 /* Disconnect and flush posted WQE */ 924 rdma_disconnect(rdma->sc_cm_id); 925 } 926 927 static void __svc_rdma_free(struct work_struct *work) 928 { 929 struct svcxprt_rdma *rdma = 930 container_of(work, struct svcxprt_rdma, sc_work); 931 dprintk("svcrdma: svc_rdma_free(%p)\n", rdma); 932 933 /* We should only be called from kref_put */ 934 BUG_ON(atomic_read(&rdma->sc_xprt.xpt_ref.refcount) != 0); 935 936 /* 937 * Destroy queued, but not processed read completions. Note 938 * that this cleanup has to be done before destroying the 939 * cm_id because the device ptr is needed to unmap the dma in 940 * svc_rdma_put_context. 941 */ 942 while (!list_empty(&rdma->sc_read_complete_q)) { 943 struct svc_rdma_op_ctxt *ctxt; 944 ctxt = list_entry(rdma->sc_read_complete_q.next, 945 struct svc_rdma_op_ctxt, 946 dto_q); 947 list_del_init(&ctxt->dto_q); 948 svc_rdma_put_context(ctxt, 1); 949 } 950 951 /* Destroy queued, but not processed recv completions */ 952 while (!list_empty(&rdma->sc_rq_dto_q)) { 953 struct svc_rdma_op_ctxt *ctxt; 954 ctxt = list_entry(rdma->sc_rq_dto_q.next, 955 struct svc_rdma_op_ctxt, 956 dto_q); 957 list_del_init(&ctxt->dto_q); 958 svc_rdma_put_context(ctxt, 1); 959 } 960 961 /* Warn if we leaked a resource or under-referenced */ 962 WARN_ON(atomic_read(&rdma->sc_ctxt_used) != 0); 963 WARN_ON(atomic_read(&rdma->sc_dma_used) != 0); 964 965 /* Destroy the QP if present (not a listener) */ 966 if (rdma->sc_qp && !IS_ERR(rdma->sc_qp)) 967 ib_destroy_qp(rdma->sc_qp); 968 969 if (rdma->sc_sq_cq && !IS_ERR(rdma->sc_sq_cq)) 970 ib_destroy_cq(rdma->sc_sq_cq); 971 972 if (rdma->sc_rq_cq && !IS_ERR(rdma->sc_rq_cq)) 973 ib_destroy_cq(rdma->sc_rq_cq); 974 975 if (rdma->sc_phys_mr && !IS_ERR(rdma->sc_phys_mr)) 976 ib_dereg_mr(rdma->sc_phys_mr); 977 978 if (rdma->sc_pd && !IS_ERR(rdma->sc_pd)) 979 ib_dealloc_pd(rdma->sc_pd); 980 981 /* Destroy the CM ID */ 982 rdma_destroy_id(rdma->sc_cm_id); 983 984 kfree(rdma); 985 } 986 987 static void svc_rdma_free(struct svc_xprt *xprt) 988 { 989 struct svcxprt_rdma *rdma = 990 container_of(xprt, struct svcxprt_rdma, sc_xprt); 991 INIT_WORK(&rdma->sc_work, __svc_rdma_free); 992 schedule_work(&rdma->sc_work); 993 } 994 995 static int svc_rdma_has_wspace(struct svc_xprt *xprt) 996 { 997 struct svcxprt_rdma *rdma = 998 container_of(xprt, struct svcxprt_rdma, sc_xprt); 999 1000 /* 1001 * If there are fewer SQ WR available than required to send a 1002 * simple response, return false. 1003 */ 1004 if ((rdma->sc_sq_depth - atomic_read(&rdma->sc_sq_count) < 3)) 1005 return 0; 1006 1007 /* 1008 * ...or there are already waiters on the SQ, 1009 * return false. 1010 */ 1011 if (waitqueue_active(&rdma->sc_send_wait)) 1012 return 0; 1013 1014 /* Otherwise return true. */ 1015 return 1; 1016 } 1017 1018 int svc_rdma_send(struct svcxprt_rdma *xprt, struct ib_send_wr *wr) 1019 { 1020 struct ib_send_wr *bad_wr; 1021 int ret; 1022 1023 if (test_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags)) 1024 return -ENOTCONN; 1025 1026 BUG_ON(wr->send_flags != IB_SEND_SIGNALED); 1027 BUG_ON(((struct svc_rdma_op_ctxt *)(unsigned long)wr->wr_id)->wr_op != 1028 wr->opcode); 1029 /* If the SQ is full, wait until an SQ entry is available */ 1030 while (1) { 1031 spin_lock_bh(&xprt->sc_lock); 1032 if (xprt->sc_sq_depth == atomic_read(&xprt->sc_sq_count)) { 1033 spin_unlock_bh(&xprt->sc_lock); 1034 atomic_inc(&rdma_stat_sq_starve); 1035 1036 /* See if we can opportunistically reap SQ WR to make room */ 1037 sq_cq_reap(xprt); 1038 1039 /* Wait until SQ WR available if SQ still full */ 1040 wait_event(xprt->sc_send_wait, 1041 atomic_read(&xprt->sc_sq_count) < 1042 xprt->sc_sq_depth); 1043 if (test_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags)) 1044 return 0; 1045 continue; 1046 } 1047 /* Bumped used SQ WR count and post */ 1048 svc_xprt_get(&xprt->sc_xprt); 1049 ret = ib_post_send(xprt->sc_qp, wr, &bad_wr); 1050 if (!ret) 1051 atomic_inc(&xprt->sc_sq_count); 1052 else { 1053 svc_xprt_put(&xprt->sc_xprt); 1054 dprintk("svcrdma: failed to post SQ WR rc=%d, " 1055 "sc_sq_count=%d, sc_sq_depth=%d\n", 1056 ret, atomic_read(&xprt->sc_sq_count), 1057 xprt->sc_sq_depth); 1058 } 1059 spin_unlock_bh(&xprt->sc_lock); 1060 break; 1061 } 1062 return ret; 1063 } 1064 1065 void svc_rdma_send_error(struct svcxprt_rdma *xprt, struct rpcrdma_msg *rmsgp, 1066 enum rpcrdma_errcode err) 1067 { 1068 struct ib_send_wr err_wr; 1069 struct ib_sge sge; 1070 struct page *p; 1071 struct svc_rdma_op_ctxt *ctxt; 1072 u32 *va; 1073 int length; 1074 int ret; 1075 1076 p = svc_rdma_get_page(); 1077 va = page_address(p); 1078 1079 /* XDR encode error */ 1080 length = svc_rdma_xdr_encode_error(xprt, rmsgp, err, va); 1081 1082 /* Prepare SGE for local address */ 1083 atomic_inc(&xprt->sc_dma_used); 1084 sge.addr = ib_dma_map_page(xprt->sc_cm_id->device, 1085 p, 0, PAGE_SIZE, DMA_FROM_DEVICE); 1086 sge.lkey = xprt->sc_phys_mr->lkey; 1087 sge.length = length; 1088 1089 ctxt = svc_rdma_get_context(xprt); 1090 ctxt->count = 1; 1091 ctxt->pages[0] = p; 1092 1093 /* Prepare SEND WR */ 1094 memset(&err_wr, 0, sizeof err_wr); 1095 ctxt->wr_op = IB_WR_SEND; 1096 err_wr.wr_id = (unsigned long)ctxt; 1097 err_wr.sg_list = &sge; 1098 err_wr.num_sge = 1; 1099 err_wr.opcode = IB_WR_SEND; 1100 err_wr.send_flags = IB_SEND_SIGNALED; 1101 1102 /* Post It */ 1103 ret = svc_rdma_send(xprt, &err_wr); 1104 if (ret) { 1105 dprintk("svcrdma: Error %d posting send for protocol error\n", 1106 ret); 1107 svc_rdma_put_context(ctxt, 1); 1108 } 1109 } 1110