1// SPDX-License-Identifier: GPL-2.0 2/* 3 * Copyright (c) 2015, 2017 Oracle. All rights reserved. 4 * Copyright (c) 2003-2007 Network Appliance, Inc. All rights reserved. 5 */ 6 7/* Lightweight memory registration using Fast Registration Work 8 * Requests (FRWR). 9 * 10 * FRWR features ordered asynchronous registration and invalidation 11 * of arbitrarily-sized memory regions. This is the fastest and safest 12 * but most complex memory registration mode. 13 */ 14 15/* Normal operation 16 * 17 * A Memory Region is prepared for RDMA Read or Write using a FAST_REG 18 * Work Request (frwr_map). When the RDMA operation is finished, this 19 * Memory Region is invalidated using a LOCAL_INV Work Request 20 * (frwr_unmap_async and frwr_unmap_sync). 21 * 22 * Typically FAST_REG Work Requests are not signaled, and neither are 23 * RDMA Send Work Requests (with the exception of signaling occasionally 24 * to prevent provider work queue overflows). This greatly reduces HCA 25 * interrupt workload. 26 */ 27 28/* Transport recovery 29 * 30 * frwr_map and frwr_unmap_* cannot run at the same time the transport 31 * connect worker is running. The connect worker holds the transport 32 * send lock, just as ->send_request does. This prevents frwr_map and 33 * the connect worker from running concurrently. When a connection is 34 * closed, the Receive completion queue is drained before the allowing 35 * the connect worker to get control. This prevents frwr_unmap and the 36 * connect worker from running concurrently. 37 * 38 * When the underlying transport disconnects, MRs that are in flight 39 * are flushed and are likely unusable. Thus all MRs are destroyed. 40 * New MRs are created on demand. 41 */ 42 43#include <linux/sunrpc/svc_rdma.h> 44 45#include "xprt_rdma.h" 46#include <trace/events/rpcrdma.h> 47 48static void frwr_cid_init(struct rpcrdma_ep *ep, 49 struct rpcrdma_mr *mr) 50{ 51 struct rpc_rdma_cid *cid = &mr->mr_cid; 52 53 cid->ci_queue_id = ep->re_attr.send_cq->res.id; 54 cid->ci_completion_id = mr->mr_ibmr->res.id; 55} 56 57static void frwr_mr_unmap(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr *mr) 58{ 59 if (mr->mr_device) { 60 trace_xprtrdma_mr_unmap(mr); 61 ib_dma_unmap_sg(mr->mr_device, mr->mr_sg, mr->mr_nents, 62 mr->mr_dir); 63 mr->mr_device = NULL; 64 } 65} 66 67/** 68 * frwr_mr_release - Destroy one MR 69 * @mr: MR allocated by frwr_mr_init 70 * 71 */ 72void frwr_mr_release(struct rpcrdma_mr *mr) 73{ 74 int rc; 75 76 frwr_mr_unmap(mr->mr_xprt, mr); 77 78 rc = ib_dereg_mr(mr->mr_ibmr); 79 if (rc) 80 trace_xprtrdma_frwr_dereg(mr, rc); 81 kfree(mr->mr_sg); 82 kfree(mr); 83} 84 85static void frwr_mr_put(struct rpcrdma_mr *mr) 86{ 87 frwr_mr_unmap(mr->mr_xprt, mr); 88 89 /* The MR is returned to the req's MR free list instead 90 * of to the xprt's MR free list. No spinlock is needed. 91 */ 92 rpcrdma_mr_push(mr, &mr->mr_req->rl_free_mrs); 93} 94 95/* frwr_reset - Place MRs back on the free list 96 * @req: request to reset 97 * 98 * Used after a failed marshal. For FRWR, this means the MRs 99 * don't have to be fully released and recreated. 100 * 101 * NB: This is safe only as long as none of @req's MRs are 102 * involved with an ongoing asynchronous FAST_REG or LOCAL_INV 103 * Work Request. 104 */ 105void frwr_reset(struct rpcrdma_req *req) 106{ 107 struct rpcrdma_mr *mr; 108 109 while ((mr = rpcrdma_mr_pop(&req->rl_registered))) 110 frwr_mr_put(mr); 111} 112 113/** 114 * frwr_mr_init - Initialize one MR 115 * @r_xprt: controlling transport instance 116 * @mr: generic MR to prepare for FRWR 117 * 118 * Returns zero if successful. Otherwise a negative errno 119 * is returned. 120 */ 121int frwr_mr_init(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr *mr) 122{ 123 struct rpcrdma_ep *ep = r_xprt->rx_ep; 124 unsigned int depth = ep->re_max_fr_depth; 125 struct scatterlist *sg; 126 struct ib_mr *frmr; 127 128 sg = kcalloc_node(depth, sizeof(*sg), XPRTRDMA_GFP_FLAGS, 129 ibdev_to_node(ep->re_id->device)); 130 if (!sg) 131 return -ENOMEM; 132 133 frmr = ib_alloc_mr(ep->re_pd, ep->re_mrtype, depth); 134 if (IS_ERR(frmr)) 135 goto out_mr_err; 136 137 mr->mr_xprt = r_xprt; 138 mr->mr_ibmr = frmr; 139 mr->mr_device = NULL; 140 INIT_LIST_HEAD(&mr->mr_list); 141 init_completion(&mr->mr_linv_done); 142 frwr_cid_init(ep, mr); 143 144 sg_init_table(sg, depth); 145 mr->mr_sg = sg; 146 return 0; 147 148out_mr_err: 149 kfree(sg); 150 trace_xprtrdma_frwr_alloc(mr, PTR_ERR(frmr)); 151 return PTR_ERR(frmr); 152} 153 154/** 155 * frwr_query_device - Prepare a transport for use with FRWR 156 * @ep: endpoint to fill in 157 * @device: RDMA device to query 158 * 159 * On success, sets: 160 * ep->re_attr 161 * ep->re_max_requests 162 * ep->re_max_rdma_segs 163 * ep->re_max_fr_depth 164 * ep->re_mrtype 165 * 166 * Return values: 167 * On success, returns zero. 168 * %-EINVAL - the device does not support FRWR memory registration 169 * %-ENOMEM - the device is not sufficiently capable for NFS/RDMA 170 */ 171int frwr_query_device(struct rpcrdma_ep *ep, const struct ib_device *device) 172{ 173 const struct ib_device_attr *attrs = &device->attrs; 174 int max_qp_wr, depth, delta; 175 unsigned int max_sge; 176 177 if (!(attrs->device_cap_flags & IB_DEVICE_MEM_MGT_EXTENSIONS) || 178 attrs->max_fast_reg_page_list_len == 0) { 179 pr_err("rpcrdma: 'frwr' mode is not supported by device %s\n", 180 device->name); 181 return -EINVAL; 182 } 183 184 max_sge = min_t(unsigned int, attrs->max_send_sge, 185 RPCRDMA_MAX_SEND_SGES); 186 if (max_sge < RPCRDMA_MIN_SEND_SGES) { 187 pr_err("rpcrdma: HCA provides only %u send SGEs\n", max_sge); 188 return -ENOMEM; 189 } 190 ep->re_attr.cap.max_send_sge = max_sge; 191 ep->re_attr.cap.max_recv_sge = 1; 192 193 ep->re_mrtype = IB_MR_TYPE_MEM_REG; 194 if (attrs->kernel_cap_flags & IBK_SG_GAPS_REG) 195 ep->re_mrtype = IB_MR_TYPE_SG_GAPS; 196 197 /* Quirk: Some devices advertise a large max_fast_reg_page_list_len 198 * capability, but perform optimally when the MRs are not larger 199 * than a page. 200 */ 201 if (attrs->max_sge_rd > RPCRDMA_MAX_HDR_SEGS) 202 ep->re_max_fr_depth = attrs->max_sge_rd; 203 else 204 ep->re_max_fr_depth = attrs->max_fast_reg_page_list_len; 205 if (ep->re_max_fr_depth > RPCRDMA_MAX_DATA_SEGS) 206 ep->re_max_fr_depth = RPCRDMA_MAX_DATA_SEGS; 207 208 /* Add room for frwr register and invalidate WRs. 209 * 1. FRWR reg WR for head 210 * 2. FRWR invalidate WR for head 211 * 3. N FRWR reg WRs for pagelist 212 * 4. N FRWR invalidate WRs for pagelist 213 * 5. FRWR reg WR for tail 214 * 6. FRWR invalidate WR for tail 215 * 7. The RDMA_SEND WR 216 */ 217 depth = 7; 218 219 /* Calculate N if the device max FRWR depth is smaller than 220 * RPCRDMA_MAX_DATA_SEGS. 221 */ 222 if (ep->re_max_fr_depth < RPCRDMA_MAX_DATA_SEGS) { 223 delta = RPCRDMA_MAX_DATA_SEGS - ep->re_max_fr_depth; 224 do { 225 depth += 2; /* FRWR reg + invalidate */ 226 delta -= ep->re_max_fr_depth; 227 } while (delta > 0); 228 } 229 230 max_qp_wr = attrs->max_qp_wr; 231 max_qp_wr -= RPCRDMA_BACKWARD_WRS; 232 max_qp_wr -= 1; 233 if (max_qp_wr < RPCRDMA_MIN_SLOT_TABLE) 234 return -ENOMEM; 235 if (ep->re_max_requests > max_qp_wr) 236 ep->re_max_requests = max_qp_wr; 237 ep->re_attr.cap.max_send_wr = ep->re_max_requests * depth; 238 if (ep->re_attr.cap.max_send_wr > max_qp_wr) { 239 ep->re_max_requests = max_qp_wr / depth; 240 if (!ep->re_max_requests) 241 return -ENOMEM; 242 ep->re_attr.cap.max_send_wr = ep->re_max_requests * depth; 243 } 244 ep->re_attr.cap.max_send_wr += RPCRDMA_BACKWARD_WRS; 245 ep->re_attr.cap.max_send_wr += 1; /* for ib_drain_sq */ 246 ep->re_attr.cap.max_recv_wr = ep->re_max_requests; 247 ep->re_attr.cap.max_recv_wr += RPCRDMA_BACKWARD_WRS; 248 ep->re_attr.cap.max_recv_wr += RPCRDMA_MAX_RECV_BATCH; 249 ep->re_attr.cap.max_recv_wr += 1; /* for ib_drain_rq */ 250 251 ep->re_max_rdma_segs = 252 DIV_ROUND_UP(RPCRDMA_MAX_DATA_SEGS, ep->re_max_fr_depth); 253 /* Reply chunks require segments for head and tail buffers */ 254 ep->re_max_rdma_segs += 2; 255 if (ep->re_max_rdma_segs > RPCRDMA_MAX_HDR_SEGS) 256 ep->re_max_rdma_segs = RPCRDMA_MAX_HDR_SEGS; 257 258 /* Ensure the underlying device is capable of conveying the 259 * largest r/wsize NFS will ask for. This guarantees that 260 * failing over from one RDMA device to another will not 261 * break NFS I/O. 262 */ 263 if ((ep->re_max_rdma_segs * ep->re_max_fr_depth) < RPCRDMA_MAX_SEGS) 264 return -ENOMEM; 265 266 return 0; 267} 268 269/** 270 * frwr_map - Register a memory region 271 * @r_xprt: controlling transport 272 * @seg: memory region co-ordinates 273 * @nsegs: number of segments remaining 274 * @writing: true when RDMA Write will be used 275 * @xid: XID of RPC using the registered memory 276 * @mr: MR to fill in 277 * 278 * Prepare a REG_MR Work Request to register a memory region 279 * for remote access via RDMA READ or RDMA WRITE. 280 * 281 * Returns the next segment or a negative errno pointer. 282 * On success, @mr is filled in. 283 */ 284struct rpcrdma_mr_seg *frwr_map(struct rpcrdma_xprt *r_xprt, 285 struct rpcrdma_mr_seg *seg, 286 int nsegs, bool writing, __be32 xid, 287 struct rpcrdma_mr *mr) 288{ 289 struct rpcrdma_ep *ep = r_xprt->rx_ep; 290 struct ib_reg_wr *reg_wr; 291 int i, n, dma_nents; 292 struct ib_mr *ibmr; 293 u8 key; 294 295 if (nsegs > ep->re_max_fr_depth) 296 nsegs = ep->re_max_fr_depth; 297 for (i = 0; i < nsegs;) { 298 sg_set_page(&mr->mr_sg[i], seg->mr_page, 299 seg->mr_len, seg->mr_offset); 300 301 ++seg; 302 ++i; 303 if (ep->re_mrtype == IB_MR_TYPE_SG_GAPS) 304 continue; 305 if ((i < nsegs && seg->mr_offset) || 306 offset_in_page((seg-1)->mr_offset + (seg-1)->mr_len)) 307 break; 308 } 309 mr->mr_dir = rpcrdma_data_dir(writing); 310 mr->mr_nents = i; 311 312 dma_nents = ib_dma_map_sg(ep->re_id->device, mr->mr_sg, mr->mr_nents, 313 mr->mr_dir); 314 if (!dma_nents) 315 goto out_dmamap_err; 316 mr->mr_device = ep->re_id->device; 317 318 ibmr = mr->mr_ibmr; 319 n = ib_map_mr_sg(ibmr, mr->mr_sg, dma_nents, NULL, PAGE_SIZE); 320 if (n != dma_nents) 321 goto out_mapmr_err; 322 323 ibmr->iova &= 0x00000000ffffffff; 324 ibmr->iova |= ((u64)be32_to_cpu(xid)) << 32; 325 key = (u8)(ibmr->rkey & 0x000000FF); 326 ib_update_fast_reg_key(ibmr, ++key); 327 328 reg_wr = &mr->mr_regwr; 329 reg_wr->mr = ibmr; 330 reg_wr->key = ibmr->rkey; 331 reg_wr->access = writing ? 332 IB_ACCESS_REMOTE_WRITE | IB_ACCESS_LOCAL_WRITE : 333 IB_ACCESS_REMOTE_READ; 334 335 mr->mr_handle = ibmr->rkey; 336 mr->mr_length = ibmr->length; 337 mr->mr_offset = ibmr->iova; 338 trace_xprtrdma_mr_map(mr); 339 340 return seg; 341 342out_dmamap_err: 343 trace_xprtrdma_frwr_sgerr(mr, i); 344 return ERR_PTR(-EIO); 345 346out_mapmr_err: 347 trace_xprtrdma_frwr_maperr(mr, n); 348 return ERR_PTR(-EIO); 349} 350 351/** 352 * frwr_wc_fastreg - Invoked by RDMA provider for a flushed FastReg WC 353 * @cq: completion queue 354 * @wc: WCE for a completed FastReg WR 355 * 356 * Each flushed MR gets destroyed after the QP has drained. 357 */ 358static void frwr_wc_fastreg(struct ib_cq *cq, struct ib_wc *wc) 359{ 360 struct ib_cqe *cqe = wc->wr_cqe; 361 struct rpcrdma_mr *mr = container_of(cqe, struct rpcrdma_mr, mr_cqe); 362 363 /* WARNING: Only wr_cqe and status are reliable at this point */ 364 trace_xprtrdma_wc_fastreg(wc, &mr->mr_cid); 365 366 rpcrdma_flush_disconnect(cq->cq_context, wc); 367} 368 369/** 370 * frwr_send - post Send WRs containing the RPC Call message 371 * @r_xprt: controlling transport instance 372 * @req: prepared RPC Call 373 * 374 * For FRWR, chain any FastReg WRs to the Send WR. Only a 375 * single ib_post_send call is needed to register memory 376 * and then post the Send WR. 377 * 378 * Returns the return code from ib_post_send. 379 * 380 * Caller must hold the transport send lock to ensure that the 381 * pointers to the transport's rdma_cm_id and QP are stable. 382 */ 383int frwr_send(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req) 384{ 385 struct ib_send_wr *post_wr, *send_wr = &req->rl_wr; 386 struct rpcrdma_ep *ep = r_xprt->rx_ep; 387 struct rpcrdma_mr *mr; 388 unsigned int num_wrs; 389 int ret; 390 391 num_wrs = 1; 392 post_wr = send_wr; 393 list_for_each_entry(mr, &req->rl_registered, mr_list) { 394 trace_xprtrdma_mr_fastreg(mr); 395 396 mr->mr_cqe.done = frwr_wc_fastreg; 397 mr->mr_regwr.wr.next = post_wr; 398 mr->mr_regwr.wr.wr_cqe = &mr->mr_cqe; 399 mr->mr_regwr.wr.num_sge = 0; 400 mr->mr_regwr.wr.opcode = IB_WR_REG_MR; 401 mr->mr_regwr.wr.send_flags = 0; 402 post_wr = &mr->mr_regwr.wr; 403 ++num_wrs; 404 } 405 406 if ((kref_read(&req->rl_kref) > 1) || num_wrs > ep->re_send_count) { 407 send_wr->send_flags |= IB_SEND_SIGNALED; 408 ep->re_send_count = min_t(unsigned int, ep->re_send_batch, 409 num_wrs - ep->re_send_count); 410 } else { 411 send_wr->send_flags &= ~IB_SEND_SIGNALED; 412 ep->re_send_count -= num_wrs; 413 } 414 415 trace_xprtrdma_post_send(req); 416 ret = ib_post_send(ep->re_id->qp, post_wr, NULL); 417 if (ret) 418 trace_xprtrdma_post_send_err(r_xprt, req, ret); 419 return ret; 420} 421 422/** 423 * frwr_reminv - handle a remotely invalidated mr on the @mrs list 424 * @rep: Received reply 425 * @mrs: list of MRs to check 426 * 427 */ 428void frwr_reminv(struct rpcrdma_rep *rep, struct list_head *mrs) 429{ 430 struct rpcrdma_mr *mr; 431 432 list_for_each_entry(mr, mrs, mr_list) 433 if (mr->mr_handle == rep->rr_inv_rkey) { 434 list_del_init(&mr->mr_list); 435 trace_xprtrdma_mr_reminv(mr); 436 frwr_mr_put(mr); 437 break; /* only one invalidated MR per RPC */ 438 } 439} 440 441static void frwr_mr_done(struct ib_wc *wc, struct rpcrdma_mr *mr) 442{ 443 if (likely(wc->status == IB_WC_SUCCESS)) 444 frwr_mr_put(mr); 445} 446 447/** 448 * frwr_wc_localinv - Invoked by RDMA provider for a LOCAL_INV WC 449 * @cq: completion queue 450 * @wc: WCE for a completed LocalInv WR 451 * 452 */ 453static void frwr_wc_localinv(struct ib_cq *cq, struct ib_wc *wc) 454{ 455 struct ib_cqe *cqe = wc->wr_cqe; 456 struct rpcrdma_mr *mr = container_of(cqe, struct rpcrdma_mr, mr_cqe); 457 458 /* WARNING: Only wr_cqe and status are reliable at this point */ 459 trace_xprtrdma_wc_li(wc, &mr->mr_cid); 460 frwr_mr_done(wc, mr); 461 462 rpcrdma_flush_disconnect(cq->cq_context, wc); 463} 464 465/** 466 * frwr_wc_localinv_wake - Invoked by RDMA provider for a LOCAL_INV WC 467 * @cq: completion queue 468 * @wc: WCE for a completed LocalInv WR 469 * 470 * Awaken anyone waiting for an MR to finish being fenced. 471 */ 472static void frwr_wc_localinv_wake(struct ib_cq *cq, struct ib_wc *wc) 473{ 474 struct ib_cqe *cqe = wc->wr_cqe; 475 struct rpcrdma_mr *mr = container_of(cqe, struct rpcrdma_mr, mr_cqe); 476 477 /* WARNING: Only wr_cqe and status are reliable at this point */ 478 trace_xprtrdma_wc_li_wake(wc, &mr->mr_cid); 479 frwr_mr_done(wc, mr); 480 complete(&mr->mr_linv_done); 481 482 rpcrdma_flush_disconnect(cq->cq_context, wc); 483} 484 485/** 486 * frwr_unmap_sync - invalidate memory regions that were registered for @req 487 * @r_xprt: controlling transport instance 488 * @req: rpcrdma_req with a non-empty list of MRs to process 489 * 490 * Sleeps until it is safe for the host CPU to access the previously mapped 491 * memory regions. This guarantees that registered MRs are properly fenced 492 * from the server before the RPC consumer accesses the data in them. It 493 * also ensures proper Send flow control: waking the next RPC waits until 494 * this RPC has relinquished all its Send Queue entries. 495 */ 496void frwr_unmap_sync(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req) 497{ 498 struct ib_send_wr *first, **prev, *last; 499 struct rpcrdma_ep *ep = r_xprt->rx_ep; 500 const struct ib_send_wr *bad_wr; 501 struct rpcrdma_mr *mr; 502 int rc; 503 504 /* ORDER: Invalidate all of the MRs first 505 * 506 * Chain the LOCAL_INV Work Requests and post them with 507 * a single ib_post_send() call. 508 */ 509 prev = &first; 510 mr = rpcrdma_mr_pop(&req->rl_registered); 511 do { 512 trace_xprtrdma_mr_localinv(mr); 513 r_xprt->rx_stats.local_inv_needed++; 514 515 last = &mr->mr_invwr; 516 last->next = NULL; 517 last->wr_cqe = &mr->mr_cqe; 518 last->sg_list = NULL; 519 last->num_sge = 0; 520 last->opcode = IB_WR_LOCAL_INV; 521 last->send_flags = IB_SEND_SIGNALED; 522 last->ex.invalidate_rkey = mr->mr_handle; 523 524 last->wr_cqe->done = frwr_wc_localinv; 525 526 *prev = last; 527 prev = &last->next; 528 } while ((mr = rpcrdma_mr_pop(&req->rl_registered))); 529 530 mr = container_of(last, struct rpcrdma_mr, mr_invwr); 531 532 /* Strong send queue ordering guarantees that when the 533 * last WR in the chain completes, all WRs in the chain 534 * are complete. 535 */ 536 last->wr_cqe->done = frwr_wc_localinv_wake; 537 reinit_completion(&mr->mr_linv_done); 538 539 /* Transport disconnect drains the receive CQ before it 540 * replaces the QP. The RPC reply handler won't call us 541 * unless re_id->qp is a valid pointer. 542 */ 543 bad_wr = NULL; 544 rc = ib_post_send(ep->re_id->qp, first, &bad_wr); 545 546 /* The final LOCAL_INV WR in the chain is supposed to 547 * do the wake. If it was never posted, the wake will 548 * not happen, so don't wait in that case. 549 */ 550 if (bad_wr != first) 551 wait_for_completion(&mr->mr_linv_done); 552 if (!rc) 553 return; 554 555 /* On error, the MRs get destroyed once the QP has drained. */ 556 trace_xprtrdma_post_linv_err(req, rc); 557 558 /* Force a connection loss to ensure complete recovery. 559 */ 560 rpcrdma_force_disconnect(ep); 561} 562 563/** 564 * frwr_wc_localinv_done - Invoked by RDMA provider for a signaled LOCAL_INV WC 565 * @cq: completion queue 566 * @wc: WCE for a completed LocalInv WR 567 * 568 */ 569static void frwr_wc_localinv_done(struct ib_cq *cq, struct ib_wc *wc) 570{ 571 struct ib_cqe *cqe = wc->wr_cqe; 572 struct rpcrdma_mr *mr = container_of(cqe, struct rpcrdma_mr, mr_cqe); 573 struct rpcrdma_rep *rep; 574 575 /* WARNING: Only wr_cqe and status are reliable at this point */ 576 trace_xprtrdma_wc_li_done(wc, &mr->mr_cid); 577 578 /* Ensure that @rep is generated before the MR is released */ 579 rep = mr->mr_req->rl_reply; 580 smp_rmb(); 581 582 if (wc->status != IB_WC_SUCCESS) { 583 if (rep) 584 rpcrdma_unpin_rqst(rep); 585 rpcrdma_flush_disconnect(cq->cq_context, wc); 586 return; 587 } 588 frwr_mr_put(mr); 589 rpcrdma_complete_rqst(rep); 590} 591 592/** 593 * frwr_unmap_async - invalidate memory regions that were registered for @req 594 * @r_xprt: controlling transport instance 595 * @req: rpcrdma_req with a non-empty list of MRs to process 596 * 597 * This guarantees that registered MRs are properly fenced from the 598 * server before the RPC consumer accesses the data in them. It also 599 * ensures proper Send flow control: waking the next RPC waits until 600 * this RPC has relinquished all its Send Queue entries. 601 */ 602void frwr_unmap_async(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req) 603{ 604 struct ib_send_wr *first, *last, **prev; 605 struct rpcrdma_ep *ep = r_xprt->rx_ep; 606 struct rpcrdma_mr *mr; 607 int rc; 608 609 /* Chain the LOCAL_INV Work Requests and post them with 610 * a single ib_post_send() call. 611 */ 612 prev = &first; 613 mr = rpcrdma_mr_pop(&req->rl_registered); 614 do { 615 trace_xprtrdma_mr_localinv(mr); 616 r_xprt->rx_stats.local_inv_needed++; 617 618 last = &mr->mr_invwr; 619 last->next = NULL; 620 last->wr_cqe = &mr->mr_cqe; 621 last->sg_list = NULL; 622 last->num_sge = 0; 623 last->opcode = IB_WR_LOCAL_INV; 624 last->send_flags = IB_SEND_SIGNALED; 625 last->ex.invalidate_rkey = mr->mr_handle; 626 627 last->wr_cqe->done = frwr_wc_localinv; 628 629 *prev = last; 630 prev = &last->next; 631 } while ((mr = rpcrdma_mr_pop(&req->rl_registered))); 632 633 /* Strong send queue ordering guarantees that when the 634 * last WR in the chain completes, all WRs in the chain 635 * are complete. The last completion will wake up the 636 * RPC waiter. 637 */ 638 last->wr_cqe->done = frwr_wc_localinv_done; 639 640 /* Transport disconnect drains the receive CQ before it 641 * replaces the QP. The RPC reply handler won't call us 642 * unless re_id->qp is a valid pointer. 643 */ 644 rc = ib_post_send(ep->re_id->qp, first, NULL); 645 if (!rc) 646 return; 647 648 /* On error, the MRs get destroyed once the QP has drained. */ 649 trace_xprtrdma_post_linv_err(req, rc); 650 651 /* The final LOCAL_INV WR in the chain is supposed to 652 * do the wake. If it was never posted, the wake does 653 * not happen. Unpin the rqst in preparation for its 654 * retransmission. 655 */ 656 rpcrdma_unpin_rqst(req->rl_reply); 657 658 /* Force a connection loss to ensure complete recovery. 659 */ 660 rpcrdma_force_disconnect(ep); 661} 662 663/** 664 * frwr_wp_create - Create an MR for padding Write chunks 665 * @r_xprt: transport resources to use 666 * 667 * Return 0 on success, negative errno on failure. 668 */ 669int frwr_wp_create(struct rpcrdma_xprt *r_xprt) 670{ 671 struct rpcrdma_ep *ep = r_xprt->rx_ep; 672 struct rpcrdma_mr_seg seg; 673 struct rpcrdma_mr *mr; 674 675 mr = rpcrdma_mr_get(r_xprt); 676 if (!mr) 677 return -EAGAIN; 678 mr->mr_req = NULL; 679 ep->re_write_pad_mr = mr; 680 681 seg.mr_len = XDR_UNIT; 682 seg.mr_page = virt_to_page(ep->re_write_pad); 683 seg.mr_offset = offset_in_page(ep->re_write_pad); 684 if (IS_ERR(frwr_map(r_xprt, &seg, 1, true, xdr_zero, mr))) 685 return -EIO; 686 trace_xprtrdma_mr_fastreg(mr); 687 688 mr->mr_cqe.done = frwr_wc_fastreg; 689 mr->mr_regwr.wr.next = NULL; 690 mr->mr_regwr.wr.wr_cqe = &mr->mr_cqe; 691 mr->mr_regwr.wr.num_sge = 0; 692 mr->mr_regwr.wr.opcode = IB_WR_REG_MR; 693 mr->mr_regwr.wr.send_flags = 0; 694 695 return ib_post_send(ep->re_id->qp, &mr->mr_regwr.wr, NULL); 696} 697