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xprtrdma: Explicitly resetting MRs is no longer necessary
[linux-2.6-block.git] / net / sunrpc / xprtrdma / verbs.c
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1// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
2/*
3 * Copyright (c) 2014-2017 Oracle. All rights reserved.
4 * Copyright (c) 2003-2007 Network Appliance, Inc. All rights reserved.
5 *
6 * This software is available to you under a choice of one of two
7 * licenses. You may choose to be licensed under the terms of the GNU
8 * General Public License (GPL) Version 2, available from the file
9 * COPYING in the main directory of this source tree, or the BSD-type
10 * license below:
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 *
16 * Redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer.
18 *
19 * Redistributions in binary form must reproduce the above
20 * copyright notice, this list of conditions and the following
21 * disclaimer in the documentation and/or other materials provided
22 * with the distribution.
23 *
24 * Neither the name of the Network Appliance, Inc. nor the names of
25 * its contributors may be used to endorse or promote products
26 * derived from this software without specific prior written
27 * permission.
28 *
29 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
30 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
31 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
32 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
33 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
34 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
35 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
36 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
37 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
38 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
39 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
40 */
41
42/*
43 * verbs.c
44 *
45 * Encapsulates the major functions managing:
46 * o adapters
47 * o endpoints
48 * o connections
49 * o buffer memory
50 */
51
52#include <linux/interrupt.h>
53#include <linux/slab.h>
54#include <linux/sunrpc/addr.h>
55#include <linux/sunrpc/svc_rdma.h>
56
57#include <asm-generic/barrier.h>
58#include <asm/bitops.h>
59
60#include <rdma/ib_cm.h>
61
62#include "xprt_rdma.h"
63#include <trace/events/rpcrdma.h>
64
65/*
66 * Globals/Macros
67 */
68
69#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
70# define RPCDBG_FACILITY RPCDBG_TRANS
71#endif
72
73/*
74 * internal functions
75 */
76static void rpcrdma_sendctx_put_locked(struct rpcrdma_sendctx *sc);
77static void rpcrdma_mrs_create(struct rpcrdma_xprt *r_xprt);
78static void rpcrdma_mrs_destroy(struct rpcrdma_buffer *buf);
79static int rpcrdma_create_rep(struct rpcrdma_xprt *r_xprt, bool temp);
80static void rpcrdma_dma_unmap_regbuf(struct rpcrdma_regbuf *rb);
81
82struct workqueue_struct *rpcrdma_receive_wq __read_mostly;
83
84int
85rpcrdma_alloc_wq(void)
86{
87 struct workqueue_struct *recv_wq;
88
89 recv_wq = alloc_workqueue("xprtrdma_receive",
90 WQ_MEM_RECLAIM | WQ_HIGHPRI,
91 0);
92 if (!recv_wq)
93 return -ENOMEM;
94
95 rpcrdma_receive_wq = recv_wq;
96 return 0;
97}
98
99void
100rpcrdma_destroy_wq(void)
101{
102 struct workqueue_struct *wq;
103
104 if (rpcrdma_receive_wq) {
105 wq = rpcrdma_receive_wq;
106 rpcrdma_receive_wq = NULL;
107 destroy_workqueue(wq);
108 }
109}
110
111static void
112rpcrdma_qp_async_error_upcall(struct ib_event *event, void *context)
113{
114 struct rpcrdma_ep *ep = context;
115 struct rpcrdma_xprt *r_xprt = container_of(ep, struct rpcrdma_xprt,
116 rx_ep);
117
118 trace_xprtrdma_qp_error(r_xprt, event);
119 pr_err("rpcrdma: %s on device %s ep %p\n",
120 ib_event_msg(event->event), event->device->name, context);
121
122 if (ep->rep_connected == 1) {
123 ep->rep_connected = -EIO;
124 rpcrdma_conn_func(ep);
125 wake_up_all(&ep->rep_connect_wait);
126 }
127}
128
129/**
130 * rpcrdma_wc_send - Invoked by RDMA provider for each polled Send WC
131 * @cq: completion queue (ignored)
132 * @wc: completed WR
133 *
134 */
135static void
136rpcrdma_wc_send(struct ib_cq *cq, struct ib_wc *wc)
137{
138 struct ib_cqe *cqe = wc->wr_cqe;
139 struct rpcrdma_sendctx *sc =
140 container_of(cqe, struct rpcrdma_sendctx, sc_cqe);
141
142 /* WARNING: Only wr_cqe and status are reliable at this point */
143 trace_xprtrdma_wc_send(sc, wc);
144 if (wc->status != IB_WC_SUCCESS && wc->status != IB_WC_WR_FLUSH_ERR)
145 pr_err("rpcrdma: Send: %s (%u/0x%x)\n",
146 ib_wc_status_msg(wc->status),
147 wc->status, wc->vendor_err);
148
149 rpcrdma_sendctx_put_locked(sc);
150}
151
152/**
153 * rpcrdma_wc_receive - Invoked by RDMA provider for each polled Receive WC
154 * @cq: completion queue (ignored)
155 * @wc: completed WR
156 *
157 */
158static void
159rpcrdma_wc_receive(struct ib_cq *cq, struct ib_wc *wc)
160{
161 struct ib_cqe *cqe = wc->wr_cqe;
162 struct rpcrdma_rep *rep = container_of(cqe, struct rpcrdma_rep,
163 rr_cqe);
164
165 /* WARNING: Only wr_id and status are reliable at this point */
166 trace_xprtrdma_wc_receive(wc);
167 if (wc->status != IB_WC_SUCCESS)
168 goto out_fail;
169
170 /* status == SUCCESS means all fields in wc are trustworthy */
171 rpcrdma_set_xdrlen(&rep->rr_hdrbuf, wc->byte_len);
172 rep->rr_wc_flags = wc->wc_flags;
173 rep->rr_inv_rkey = wc->ex.invalidate_rkey;
174
175 ib_dma_sync_single_for_cpu(rdmab_device(rep->rr_rdmabuf),
176 rdmab_addr(rep->rr_rdmabuf),
177 wc->byte_len, DMA_FROM_DEVICE);
178
179out_schedule:
180 rpcrdma_reply_handler(rep);
181 return;
182
183out_fail:
184 if (wc->status != IB_WC_WR_FLUSH_ERR)
185 pr_err("rpcrdma: Recv: %s (%u/0x%x)\n",
186 ib_wc_status_msg(wc->status),
187 wc->status, wc->vendor_err);
188 rpcrdma_set_xdrlen(&rep->rr_hdrbuf, 0);
189 goto out_schedule;
190}
191
192static void
193rpcrdma_update_connect_private(struct rpcrdma_xprt *r_xprt,
194 struct rdma_conn_param *param)
195{
196 struct rpcrdma_create_data_internal *cdata = &r_xprt->rx_data;
197 const struct rpcrdma_connect_private *pmsg = param->private_data;
198 unsigned int rsize, wsize;
199
200 /* Default settings for RPC-over-RDMA Version One */
201 r_xprt->rx_ia.ri_implicit_roundup = xprt_rdma_pad_optimize;
202 rsize = RPCRDMA_V1_DEF_INLINE_SIZE;
203 wsize = RPCRDMA_V1_DEF_INLINE_SIZE;
204
205 if (pmsg &&
206 pmsg->cp_magic == rpcrdma_cmp_magic &&
207 pmsg->cp_version == RPCRDMA_CMP_VERSION) {
208 r_xprt->rx_ia.ri_implicit_roundup = true;
209 rsize = rpcrdma_decode_buffer_size(pmsg->cp_send_size);
210 wsize = rpcrdma_decode_buffer_size(pmsg->cp_recv_size);
211 }
212
213 if (rsize < cdata->inline_rsize)
214 cdata->inline_rsize = rsize;
215 if (wsize < cdata->inline_wsize)
216 cdata->inline_wsize = wsize;
217 dprintk("RPC: %s: max send %u, max recv %u\n",
218 __func__, cdata->inline_wsize, cdata->inline_rsize);
219 rpcrdma_set_max_header_sizes(r_xprt);
220}
221
222static int
223rpcrdma_conn_upcall(struct rdma_cm_id *id, struct rdma_cm_event *event)
224{
225 struct rpcrdma_xprt *xprt = id->context;
226 struct rpcrdma_ia *ia = &xprt->rx_ia;
227 struct rpcrdma_ep *ep = &xprt->rx_ep;
228 int connstate = 0;
229
230 trace_xprtrdma_conn_upcall(xprt, event);
231 switch (event->event) {
232 case RDMA_CM_EVENT_ADDR_RESOLVED:
233 case RDMA_CM_EVENT_ROUTE_RESOLVED:
234 ia->ri_async_rc = 0;
235 complete(&ia->ri_done);
236 break;
237 case RDMA_CM_EVENT_ADDR_ERROR:
238 ia->ri_async_rc = -EPROTO;
239 complete(&ia->ri_done);
240 break;
241 case RDMA_CM_EVENT_ROUTE_ERROR:
242 ia->ri_async_rc = -ENETUNREACH;
243 complete(&ia->ri_done);
244 break;
245 case RDMA_CM_EVENT_DEVICE_REMOVAL:
246#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
247 pr_info("rpcrdma: removing device %s for %s:%s\n",
248 ia->ri_device->name,
249 rpcrdma_addrstr(xprt), rpcrdma_portstr(xprt));
250#endif
251 set_bit(RPCRDMA_IAF_REMOVING, &ia->ri_flags);
252 ep->rep_connected = -ENODEV;
253 xprt_force_disconnect(&xprt->rx_xprt);
254 wait_for_completion(&ia->ri_remove_done);
255
256 ia->ri_id = NULL;
257 ia->ri_device = NULL;
258 /* Return 1 to ensure the core destroys the id. */
259 return 1;
260 case RDMA_CM_EVENT_ESTABLISHED:
261 ++xprt->rx_xprt.connect_cookie;
262 connstate = 1;
263 rpcrdma_update_connect_private(xprt, &event->param.conn);
264 goto connected;
265 case RDMA_CM_EVENT_CONNECT_ERROR:
266 connstate = -ENOTCONN;
267 goto connected;
268 case RDMA_CM_EVENT_UNREACHABLE:
269 connstate = -ENETUNREACH;
270 goto connected;
271 case RDMA_CM_EVENT_REJECTED:
272 dprintk("rpcrdma: connection to %s:%s rejected: %s\n",
273 rpcrdma_addrstr(xprt), rpcrdma_portstr(xprt),
274 rdma_reject_msg(id, event->status));
275 connstate = -ECONNREFUSED;
276 if (event->status == IB_CM_REJ_STALE_CONN)
277 connstate = -EAGAIN;
278 goto connected;
279 case RDMA_CM_EVENT_DISCONNECTED:
280 ++xprt->rx_xprt.connect_cookie;
281 connstate = -ECONNABORTED;
282connected:
283 ep->rep_connected = connstate;
284 rpcrdma_conn_func(ep);
285 wake_up_all(&ep->rep_connect_wait);
286 /*FALLTHROUGH*/
287 default:
288 dprintk("RPC: %s: %s:%s on %s/%s (ep 0x%p): %s\n",
289 __func__,
290 rpcrdma_addrstr(xprt), rpcrdma_portstr(xprt),
291 ia->ri_device->name, ia->ri_ops->ro_displayname,
292 ep, rdma_event_msg(event->event));
293 break;
294 }
295
296 return 0;
297}
298
299static struct rdma_cm_id *
300rpcrdma_create_id(struct rpcrdma_xprt *xprt, struct rpcrdma_ia *ia)
301{
302 unsigned long wtimeout = msecs_to_jiffies(RDMA_RESOLVE_TIMEOUT) + 1;
303 struct rdma_cm_id *id;
304 int rc;
305
306 trace_xprtrdma_conn_start(xprt);
307
308 init_completion(&ia->ri_done);
309 init_completion(&ia->ri_remove_done);
310
311 id = rdma_create_id(xprt->rx_xprt.xprt_net, rpcrdma_conn_upcall,
312 xprt, RDMA_PS_TCP, IB_QPT_RC);
313 if (IS_ERR(id)) {
314 rc = PTR_ERR(id);
315 dprintk("RPC: %s: rdma_create_id() failed %i\n",
316 __func__, rc);
317 return id;
318 }
319
320 ia->ri_async_rc = -ETIMEDOUT;
321 rc = rdma_resolve_addr(id, NULL,
322 (struct sockaddr *)&xprt->rx_xprt.addr,
323 RDMA_RESOLVE_TIMEOUT);
324 if (rc) {
325 dprintk("RPC: %s: rdma_resolve_addr() failed %i\n",
326 __func__, rc);
327 goto out;
328 }
329 rc = wait_for_completion_interruptible_timeout(&ia->ri_done, wtimeout);
330 if (rc < 0) {
331 trace_xprtrdma_conn_tout(xprt);
332 goto out;
333 }
334
335 rc = ia->ri_async_rc;
336 if (rc)
337 goto out;
338
339 ia->ri_async_rc = -ETIMEDOUT;
340 rc = rdma_resolve_route(id, RDMA_RESOLVE_TIMEOUT);
341 if (rc) {
342 dprintk("RPC: %s: rdma_resolve_route() failed %i\n",
343 __func__, rc);
344 goto out;
345 }
346 rc = wait_for_completion_interruptible_timeout(&ia->ri_done, wtimeout);
347 if (rc < 0) {
348 trace_xprtrdma_conn_tout(xprt);
349 goto out;
350 }
351 rc = ia->ri_async_rc;
352 if (rc)
353 goto out;
354
355 return id;
356
357out:
358 rdma_destroy_id(id);
359 return ERR_PTR(rc);
360}
361
362/*
363 * Exported functions.
364 */
365
366/**
367 * rpcrdma_ia_open - Open and initialize an Interface Adapter.
368 * @xprt: transport with IA to (re)initialize
369 *
370 * Returns 0 on success, negative errno if an appropriate
371 * Interface Adapter could not be found and opened.
372 */
373int
374rpcrdma_ia_open(struct rpcrdma_xprt *xprt)
375{
376 struct rpcrdma_ia *ia = &xprt->rx_ia;
377 int rc;
378
379 ia->ri_id = rpcrdma_create_id(xprt, ia);
380 if (IS_ERR(ia->ri_id)) {
381 rc = PTR_ERR(ia->ri_id);
382 goto out_err;
383 }
384 ia->ri_device = ia->ri_id->device;
385
386 ia->ri_pd = ib_alloc_pd(ia->ri_device, 0);
387 if (IS_ERR(ia->ri_pd)) {
388 rc = PTR_ERR(ia->ri_pd);
389 pr_err("rpcrdma: ib_alloc_pd() returned %d\n", rc);
390 goto out_err;
391 }
392
393 switch (xprt_rdma_memreg_strategy) {
394 case RPCRDMA_FRWR:
395 if (frwr_is_supported(ia)) {
396 ia->ri_ops = &rpcrdma_frwr_memreg_ops;
397 break;
398 }
399 /*FALLTHROUGH*/
400 case RPCRDMA_MTHCAFMR:
401 if (fmr_is_supported(ia)) {
402 ia->ri_ops = &rpcrdma_fmr_memreg_ops;
403 break;
404 }
405 /*FALLTHROUGH*/
406 default:
407 pr_err("rpcrdma: Device %s does not support memreg mode %d\n",
408 ia->ri_device->name, xprt_rdma_memreg_strategy);
409 rc = -EINVAL;
410 goto out_err;
411 }
412
413 return 0;
414
415out_err:
416 rpcrdma_ia_close(ia);
417 return rc;
418}
419
420/**
421 * rpcrdma_ia_remove - Handle device driver unload
422 * @ia: interface adapter being removed
423 *
424 * Divest transport H/W resources associated with this adapter,
425 * but allow it to be restored later.
426 */
427void
428rpcrdma_ia_remove(struct rpcrdma_ia *ia)
429{
430 struct rpcrdma_xprt *r_xprt = container_of(ia, struct rpcrdma_xprt,
431 rx_ia);
432 struct rpcrdma_ep *ep = &r_xprt->rx_ep;
433 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
434 struct rpcrdma_req *req;
435 struct rpcrdma_rep *rep;
436
437 cancel_delayed_work_sync(&buf->rb_refresh_worker);
438
439 /* This is similar to rpcrdma_ep_destroy, but:
440 * - Don't cancel the connect worker.
441 * - Don't call rpcrdma_ep_disconnect, which waits
442 * for another conn upcall, which will deadlock.
443 * - rdma_disconnect is unneeded, the underlying
444 * connection is already gone.
445 */
446 if (ia->ri_id->qp) {
447 ib_drain_qp(ia->ri_id->qp);
448 rdma_destroy_qp(ia->ri_id);
449 ia->ri_id->qp = NULL;
450 }
451 ib_free_cq(ep->rep_attr.recv_cq);
452 ep->rep_attr.recv_cq = NULL;
453 ib_free_cq(ep->rep_attr.send_cq);
454 ep->rep_attr.send_cq = NULL;
455
456 /* The ULP is responsible for ensuring all DMA
457 * mappings and MRs are gone.
458 */
459 list_for_each_entry(rep, &buf->rb_recv_bufs, rr_list)
460 rpcrdma_dma_unmap_regbuf(rep->rr_rdmabuf);
461 list_for_each_entry(req, &buf->rb_allreqs, rl_all) {
462 rpcrdma_dma_unmap_regbuf(req->rl_rdmabuf);
463 rpcrdma_dma_unmap_regbuf(req->rl_sendbuf);
464 rpcrdma_dma_unmap_regbuf(req->rl_recvbuf);
465 }
466 rpcrdma_mrs_destroy(buf);
467 ib_dealloc_pd(ia->ri_pd);
468 ia->ri_pd = NULL;
469
470 /* Allow waiters to continue */
471 complete(&ia->ri_remove_done);
472
473 trace_xprtrdma_remove(r_xprt);
474}
475
476/**
477 * rpcrdma_ia_close - Clean up/close an IA.
478 * @ia: interface adapter to close
479 *
480 */
481void
482rpcrdma_ia_close(struct rpcrdma_ia *ia)
483{
484 if (ia->ri_id != NULL && !IS_ERR(ia->ri_id)) {
485 if (ia->ri_id->qp)
486 rdma_destroy_qp(ia->ri_id);
487 rdma_destroy_id(ia->ri_id);
488 }
489 ia->ri_id = NULL;
490 ia->ri_device = NULL;
491
492 /* If the pd is still busy, xprtrdma missed freeing a resource */
493 if (ia->ri_pd && !IS_ERR(ia->ri_pd))
494 ib_dealloc_pd(ia->ri_pd);
495 ia->ri_pd = NULL;
496}
497
498/*
499 * Create unconnected endpoint.
500 */
501int
502rpcrdma_ep_create(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia,
503 struct rpcrdma_create_data_internal *cdata)
504{
505 struct rpcrdma_connect_private *pmsg = &ep->rep_cm_private;
506 struct ib_cq *sendcq, *recvcq;
507 unsigned int max_sge;
508 int rc;
509
510 max_sge = min_t(unsigned int, ia->ri_device->attrs.max_send_sge,
511 RPCRDMA_MAX_SEND_SGES);
512 if (max_sge < RPCRDMA_MIN_SEND_SGES) {
513 pr_warn("rpcrdma: HCA provides only %d send SGEs\n", max_sge);
514 return -ENOMEM;
515 }
516 ia->ri_max_send_sges = max_sge;
517
518 rc = ia->ri_ops->ro_open(ia, ep, cdata);
519 if (rc)
520 return rc;
521
522 ep->rep_attr.event_handler = rpcrdma_qp_async_error_upcall;
523 ep->rep_attr.qp_context = ep;
524 ep->rep_attr.srq = NULL;
525 ep->rep_attr.cap.max_send_sge = max_sge;
526 ep->rep_attr.cap.max_recv_sge = 1;
527 ep->rep_attr.cap.max_inline_data = 0;
528 ep->rep_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
529 ep->rep_attr.qp_type = IB_QPT_RC;
530 ep->rep_attr.port_num = ~0;
531
532 dprintk("RPC: %s: requested max: dtos: send %d recv %d; "
533 "iovs: send %d recv %d\n",
534 __func__,
535 ep->rep_attr.cap.max_send_wr,
536 ep->rep_attr.cap.max_recv_wr,
537 ep->rep_attr.cap.max_send_sge,
538 ep->rep_attr.cap.max_recv_sge);
539
540 /* set trigger for requesting send completion */
541 ep->rep_send_batch = min_t(unsigned int, RPCRDMA_MAX_SEND_BATCH,
542 cdata->max_requests >> 2);
543 ep->rep_send_count = ep->rep_send_batch;
544 init_waitqueue_head(&ep->rep_connect_wait);
545 INIT_DELAYED_WORK(&ep->rep_connect_worker, rpcrdma_connect_worker);
546
547 sendcq = ib_alloc_cq(ia->ri_device, NULL,
548 ep->rep_attr.cap.max_send_wr + 1,
549 1, IB_POLL_WORKQUEUE);
550 if (IS_ERR(sendcq)) {
551 rc = PTR_ERR(sendcq);
552 dprintk("RPC: %s: failed to create send CQ: %i\n",
553 __func__, rc);
554 goto out1;
555 }
556
557 recvcq = ib_alloc_cq(ia->ri_device, NULL,
558 ep->rep_attr.cap.max_recv_wr + 1,
559 0, IB_POLL_WORKQUEUE);
560 if (IS_ERR(recvcq)) {
561 rc = PTR_ERR(recvcq);
562 dprintk("RPC: %s: failed to create recv CQ: %i\n",
563 __func__, rc);
564 goto out2;
565 }
566
567 ep->rep_attr.send_cq = sendcq;
568 ep->rep_attr.recv_cq = recvcq;
569
570 /* Initialize cma parameters */
571 memset(&ep->rep_remote_cma, 0, sizeof(ep->rep_remote_cma));
572
573 /* Prepare RDMA-CM private message */
574 pmsg->cp_magic = rpcrdma_cmp_magic;
575 pmsg->cp_version = RPCRDMA_CMP_VERSION;
576 pmsg->cp_flags |= ia->ri_ops->ro_send_w_inv_ok;
577 pmsg->cp_send_size = rpcrdma_encode_buffer_size(cdata->inline_wsize);
578 pmsg->cp_recv_size = rpcrdma_encode_buffer_size(cdata->inline_rsize);
579 ep->rep_remote_cma.private_data = pmsg;
580 ep->rep_remote_cma.private_data_len = sizeof(*pmsg);
581
582 /* Client offers RDMA Read but does not initiate */
583 ep->rep_remote_cma.initiator_depth = 0;
584 ep->rep_remote_cma.responder_resources =
585 min_t(int, U8_MAX, ia->ri_device->attrs.max_qp_rd_atom);
586
587 /* Limit transport retries so client can detect server
588 * GID changes quickly. RPC layer handles re-establishing
589 * transport connection and retransmission.
590 */
591 ep->rep_remote_cma.retry_count = 6;
592
593 /* RPC-over-RDMA handles its own flow control. In addition,
594 * make all RNR NAKs visible so we know that RPC-over-RDMA
595 * flow control is working correctly (no NAKs should be seen).
596 */
597 ep->rep_remote_cma.flow_control = 0;
598 ep->rep_remote_cma.rnr_retry_count = 0;
599
600 return 0;
601
602out2:
603 ib_free_cq(sendcq);
604out1:
605 return rc;
606}
607
608/*
609 * rpcrdma_ep_destroy
610 *
611 * Disconnect and destroy endpoint. After this, the only
612 * valid operations on the ep are to free it (if dynamically
613 * allocated) or re-create it.
614 */
615void
616rpcrdma_ep_destroy(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
617{
618 cancel_delayed_work_sync(&ep->rep_connect_worker);
619
620 if (ia->ri_id && ia->ri_id->qp) {
621 rpcrdma_ep_disconnect(ep, ia);
622 rdma_destroy_qp(ia->ri_id);
623 ia->ri_id->qp = NULL;
624 }
625
626 if (ep->rep_attr.recv_cq)
627 ib_free_cq(ep->rep_attr.recv_cq);
628 if (ep->rep_attr.send_cq)
629 ib_free_cq(ep->rep_attr.send_cq);
630}
631
632/* Re-establish a connection after a device removal event.
633 * Unlike a normal reconnection, a fresh PD and a new set
634 * of MRs and buffers is needed.
635 */
636static int
637rpcrdma_ep_recreate_xprt(struct rpcrdma_xprt *r_xprt,
638 struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
639{
640 int rc, err;
641
642 trace_xprtrdma_reinsert(r_xprt);
643
644 rc = -EHOSTUNREACH;
645 if (rpcrdma_ia_open(r_xprt))
646 goto out1;
647
648 rc = -ENOMEM;
649 err = rpcrdma_ep_create(ep, ia, &r_xprt->rx_data);
650 if (err) {
651 pr_err("rpcrdma: rpcrdma_ep_create returned %d\n", err);
652 goto out2;
653 }
654
655 rc = -ENETUNREACH;
656 err = rdma_create_qp(ia->ri_id, ia->ri_pd, &ep->rep_attr);
657 if (err) {
658 pr_err("rpcrdma: rdma_create_qp returned %d\n", err);
659 goto out3;
660 }
661
662 rpcrdma_mrs_create(r_xprt);
663 return 0;
664
665out3:
666 rpcrdma_ep_destroy(ep, ia);
667out2:
668 rpcrdma_ia_close(ia);
669out1:
670 return rc;
671}
672
673static int
674rpcrdma_ep_reconnect(struct rpcrdma_xprt *r_xprt, struct rpcrdma_ep *ep,
675 struct rpcrdma_ia *ia)
676{
677 struct rdma_cm_id *id, *old;
678 int err, rc;
679
680 trace_xprtrdma_reconnect(r_xprt);
681
682 rpcrdma_ep_disconnect(ep, ia);
683
684 rc = -EHOSTUNREACH;
685 id = rpcrdma_create_id(r_xprt, ia);
686 if (IS_ERR(id))
687 goto out;
688
689 /* As long as the new ID points to the same device as the
690 * old ID, we can reuse the transport's existing PD and all
691 * previously allocated MRs. Also, the same device means
692 * the transport's previous DMA mappings are still valid.
693 *
694 * This is a sanity check only. There should be no way these
695 * point to two different devices here.
696 */
697 old = id;
698 rc = -ENETUNREACH;
699 if (ia->ri_device != id->device) {
700 pr_err("rpcrdma: can't reconnect on different device!\n");
701 goto out_destroy;
702 }
703
704 err = rdma_create_qp(id, ia->ri_pd, &ep->rep_attr);
705 if (err) {
706 dprintk("RPC: %s: rdma_create_qp returned %d\n",
707 __func__, err);
708 goto out_destroy;
709 }
710
711 /* Atomically replace the transport's ID and QP. */
712 rc = 0;
713 old = ia->ri_id;
714 ia->ri_id = id;
715 rdma_destroy_qp(old);
716
717out_destroy:
718 rdma_destroy_id(old);
719out:
720 return rc;
721}
722
723/*
724 * Connect unconnected endpoint.
725 */
726int
727rpcrdma_ep_connect(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
728{
729 struct rpcrdma_xprt *r_xprt = container_of(ia, struct rpcrdma_xprt,
730 rx_ia);
731 int rc;
732
733retry:
734 switch (ep->rep_connected) {
735 case 0:
736 dprintk("RPC: %s: connecting...\n", __func__);
737 rc = rdma_create_qp(ia->ri_id, ia->ri_pd, &ep->rep_attr);
738 if (rc) {
739 dprintk("RPC: %s: rdma_create_qp failed %i\n",
740 __func__, rc);
741 rc = -ENETUNREACH;
742 goto out_noupdate;
743 }
744 break;
745 case -ENODEV:
746 rc = rpcrdma_ep_recreate_xprt(r_xprt, ep, ia);
747 if (rc)
748 goto out_noupdate;
749 break;
750 default:
751 rc = rpcrdma_ep_reconnect(r_xprt, ep, ia);
752 if (rc)
753 goto out;
754 }
755
756 ep->rep_connected = 0;
757 rpcrdma_post_recvs(r_xprt, true);
758
759 rc = rdma_connect(ia->ri_id, &ep->rep_remote_cma);
760 if (rc) {
761 dprintk("RPC: %s: rdma_connect() failed with %i\n",
762 __func__, rc);
763 goto out;
764 }
765
766 wait_event_interruptible(ep->rep_connect_wait, ep->rep_connected != 0);
767 if (ep->rep_connected <= 0) {
768 if (ep->rep_connected == -EAGAIN)
769 goto retry;
770 rc = ep->rep_connected;
771 goto out;
772 }
773
774 dprintk("RPC: %s: connected\n", __func__);
775
776out:
777 if (rc)
778 ep->rep_connected = rc;
779
780out_noupdate:
781 return rc;
782}
783
784/*
785 * rpcrdma_ep_disconnect
786 *
787 * This is separate from destroy to facilitate the ability
788 * to reconnect without recreating the endpoint.
789 *
790 * This call is not reentrant, and must not be made in parallel
791 * on the same endpoint.
792 */
793void
794rpcrdma_ep_disconnect(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
795{
796 int rc;
797
798 rc = rdma_disconnect(ia->ri_id);
799 if (!rc)
800 /* returns without wait if not connected */
801 wait_event_interruptible(ep->rep_connect_wait,
802 ep->rep_connected != 1);
803 else
804 ep->rep_connected = rc;
805 trace_xprtrdma_disconnect(container_of(ep, struct rpcrdma_xprt,
806 rx_ep), rc);
807
808 ib_drain_qp(ia->ri_id->qp);
809}
810
811/* Fixed-size circular FIFO queue. This implementation is wait-free and
812 * lock-free.
813 *
814 * Consumer is the code path that posts Sends. This path dequeues a
815 * sendctx for use by a Send operation. Multiple consumer threads
816 * are serialized by the RPC transport lock, which allows only one
817 * ->send_request call at a time.
818 *
819 * Producer is the code path that handles Send completions. This path
820 * enqueues a sendctx that has been completed. Multiple producer
821 * threads are serialized by the ib_poll_cq() function.
822 */
823
824/* rpcrdma_sendctxs_destroy() assumes caller has already quiesced
825 * queue activity, and ib_drain_qp has flushed all remaining Send
826 * requests.
827 */
828static void rpcrdma_sendctxs_destroy(struct rpcrdma_buffer *buf)
829{
830 unsigned long i;
831
832 for (i = 0; i <= buf->rb_sc_last; i++)
833 kfree(buf->rb_sc_ctxs[i]);
834 kfree(buf->rb_sc_ctxs);
835}
836
837static struct rpcrdma_sendctx *rpcrdma_sendctx_create(struct rpcrdma_ia *ia)
838{
839 struct rpcrdma_sendctx *sc;
840
841 sc = kzalloc(sizeof(*sc) +
842 ia->ri_max_send_sges * sizeof(struct ib_sge),
843 GFP_KERNEL);
844 if (!sc)
845 return NULL;
846
847 sc->sc_wr.wr_cqe = &sc->sc_cqe;
848 sc->sc_wr.sg_list = sc->sc_sges;
849 sc->sc_wr.opcode = IB_WR_SEND;
850 sc->sc_cqe.done = rpcrdma_wc_send;
851 return sc;
852}
853
854static int rpcrdma_sendctxs_create(struct rpcrdma_xprt *r_xprt)
855{
856 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
857 struct rpcrdma_sendctx *sc;
858 unsigned long i;
859
860 /* Maximum number of concurrent outstanding Send WRs. Capping
861 * the circular queue size stops Send Queue overflow by causing
862 * the ->send_request call to fail temporarily before too many
863 * Sends are posted.
864 */
865 i = buf->rb_max_requests + RPCRDMA_MAX_BC_REQUESTS;
866 dprintk("RPC: %s: allocating %lu send_ctxs\n", __func__, i);
867 buf->rb_sc_ctxs = kcalloc(i, sizeof(sc), GFP_KERNEL);
868 if (!buf->rb_sc_ctxs)
869 return -ENOMEM;
870
871 buf->rb_sc_last = i - 1;
872 for (i = 0; i <= buf->rb_sc_last; i++) {
873 sc = rpcrdma_sendctx_create(&r_xprt->rx_ia);
874 if (!sc)
875 goto out_destroy;
876
877 sc->sc_xprt = r_xprt;
878 buf->rb_sc_ctxs[i] = sc;
879 }
880 buf->rb_flags = 0;
881
882 return 0;
883
884out_destroy:
885 rpcrdma_sendctxs_destroy(buf);
886 return -ENOMEM;
887}
888
889/* The sendctx queue is not guaranteed to have a size that is a
890 * power of two, thus the helpers in circ_buf.h cannot be used.
891 * The other option is to use modulus (%), which can be expensive.
892 */
893static unsigned long rpcrdma_sendctx_next(struct rpcrdma_buffer *buf,
894 unsigned long item)
895{
896 return likely(item < buf->rb_sc_last) ? item + 1 : 0;
897}
898
899/**
900 * rpcrdma_sendctx_get_locked - Acquire a send context
901 * @buf: transport buffers from which to acquire an unused context
902 *
903 * Returns pointer to a free send completion context; or NULL if
904 * the queue is empty.
905 *
906 * Usage: Called to acquire an SGE array before preparing a Send WR.
907 *
908 * The caller serializes calls to this function (per rpcrdma_buffer),
909 * and provides an effective memory barrier that flushes the new value
910 * of rb_sc_head.
911 */
912struct rpcrdma_sendctx *rpcrdma_sendctx_get_locked(struct rpcrdma_buffer *buf)
913{
914 struct rpcrdma_xprt *r_xprt;
915 struct rpcrdma_sendctx *sc;
916 unsigned long next_head;
917
918 next_head = rpcrdma_sendctx_next(buf, buf->rb_sc_head);
919
920 if (next_head == READ_ONCE(buf->rb_sc_tail))
921 goto out_emptyq;
922
923 /* ORDER: item must be accessed _before_ head is updated */
924 sc = buf->rb_sc_ctxs[next_head];
925
926 /* Releasing the lock in the caller acts as a memory
927 * barrier that flushes rb_sc_head.
928 */
929 buf->rb_sc_head = next_head;
930
931 return sc;
932
933out_emptyq:
934 /* The queue is "empty" if there have not been enough Send
935 * completions recently. This is a sign the Send Queue is
936 * backing up. Cause the caller to pause and try again.
937 */
938 set_bit(RPCRDMA_BUF_F_EMPTY_SCQ, &buf->rb_flags);
939 r_xprt = container_of(buf, struct rpcrdma_xprt, rx_buf);
940 r_xprt->rx_stats.empty_sendctx_q++;
941 return NULL;
942}
943
944/**
945 * rpcrdma_sendctx_put_locked - Release a send context
946 * @sc: send context to release
947 *
948 * Usage: Called from Send completion to return a sendctxt
949 * to the queue.
950 *
951 * The caller serializes calls to this function (per rpcrdma_buffer).
952 */
953static void
954rpcrdma_sendctx_put_locked(struct rpcrdma_sendctx *sc)
955{
956 struct rpcrdma_buffer *buf = &sc->sc_xprt->rx_buf;
957 unsigned long next_tail;
958
959 /* Unmap SGEs of previously completed by unsignaled
960 * Sends by walking up the queue until @sc is found.
961 */
962 next_tail = buf->rb_sc_tail;
963 do {
964 next_tail = rpcrdma_sendctx_next(buf, next_tail);
965
966 /* ORDER: item must be accessed _before_ tail is updated */
967 rpcrdma_unmap_sendctx(buf->rb_sc_ctxs[next_tail]);
968
969 } while (buf->rb_sc_ctxs[next_tail] != sc);
970
971 /* Paired with READ_ONCE */
972 smp_store_release(&buf->rb_sc_tail, next_tail);
973
974 if (test_and_clear_bit(RPCRDMA_BUF_F_EMPTY_SCQ, &buf->rb_flags)) {
975 smp_mb__after_atomic();
976 xprt_write_space(&sc->sc_xprt->rx_xprt);
977 }
978}
979
980static void
981rpcrdma_mrs_create(struct rpcrdma_xprt *r_xprt)
982{
983 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
984 struct rpcrdma_ia *ia = &r_xprt->rx_ia;
985 unsigned int count;
986 LIST_HEAD(free);
987 LIST_HEAD(all);
988
989 for (count = 0; count < ia->ri_max_segs; count++) {
990 struct rpcrdma_mr *mr;
991 int rc;
992
993 mr = kzalloc(sizeof(*mr), GFP_KERNEL);
994 if (!mr)
995 break;
996
997 rc = ia->ri_ops->ro_init_mr(ia, mr);
998 if (rc) {
999 kfree(mr);
1000 break;
1001 }
1002
1003 mr->mr_xprt = r_xprt;
1004
1005 list_add(&mr->mr_list, &free);
1006 list_add(&mr->mr_all, &all);
1007 }
1008
1009 spin_lock(&buf->rb_mrlock);
1010 list_splice(&free, &buf->rb_mrs);
1011 list_splice(&all, &buf->rb_all);
1012 r_xprt->rx_stats.mrs_allocated += count;
1013 spin_unlock(&buf->rb_mrlock);
1014 trace_xprtrdma_createmrs(r_xprt, count);
1015
1016 xprt_write_space(&r_xprt->rx_xprt);
1017}
1018
1019static void
1020rpcrdma_mr_refresh_worker(struct work_struct *work)
1021{
1022 struct rpcrdma_buffer *buf = container_of(work, struct rpcrdma_buffer,
1023 rb_refresh_worker.work);
1024 struct rpcrdma_xprt *r_xprt = container_of(buf, struct rpcrdma_xprt,
1025 rx_buf);
1026
1027 rpcrdma_mrs_create(r_xprt);
1028}
1029
1030struct rpcrdma_req *
1031rpcrdma_create_req(struct rpcrdma_xprt *r_xprt)
1032{
1033 struct rpcrdma_buffer *buffer = &r_xprt->rx_buf;
1034 struct rpcrdma_regbuf *rb;
1035 struct rpcrdma_req *req;
1036
1037 req = kzalloc(sizeof(*req), GFP_KERNEL);
1038 if (req == NULL)
1039 return ERR_PTR(-ENOMEM);
1040
1041 rb = rpcrdma_alloc_regbuf(RPCRDMA_HDRBUF_SIZE,
1042 DMA_TO_DEVICE, GFP_KERNEL);
1043 if (IS_ERR(rb)) {
1044 kfree(req);
1045 return ERR_PTR(-ENOMEM);
1046 }
1047 req->rl_rdmabuf = rb;
1048 xdr_buf_init(&req->rl_hdrbuf, rb->rg_base, rdmab_length(rb));
1049 req->rl_buffer = buffer;
1050 INIT_LIST_HEAD(&req->rl_registered);
1051
1052 spin_lock(&buffer->rb_reqslock);
1053 list_add(&req->rl_all, &buffer->rb_allreqs);
1054 spin_unlock(&buffer->rb_reqslock);
1055 return req;
1056}
1057
1058static int
1059rpcrdma_create_rep(struct rpcrdma_xprt *r_xprt, bool temp)
1060{
1061 struct rpcrdma_create_data_internal *cdata = &r_xprt->rx_data;
1062 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
1063 struct rpcrdma_rep *rep;
1064 int rc;
1065
1066 rc = -ENOMEM;
1067 rep = kzalloc(sizeof(*rep), GFP_KERNEL);
1068 if (rep == NULL)
1069 goto out;
1070
1071 rep->rr_rdmabuf = rpcrdma_alloc_regbuf(cdata->inline_rsize,
1072 DMA_FROM_DEVICE, GFP_KERNEL);
1073 if (IS_ERR(rep->rr_rdmabuf)) {
1074 rc = PTR_ERR(rep->rr_rdmabuf);
1075 goto out_free;
1076 }
1077 xdr_buf_init(&rep->rr_hdrbuf, rep->rr_rdmabuf->rg_base,
1078 rdmab_length(rep->rr_rdmabuf));
1079
1080 rep->rr_cqe.done = rpcrdma_wc_receive;
1081 rep->rr_rxprt = r_xprt;
1082 INIT_WORK(&rep->rr_work, rpcrdma_deferred_completion);
1083 rep->rr_recv_wr.next = NULL;
1084 rep->rr_recv_wr.wr_cqe = &rep->rr_cqe;
1085 rep->rr_recv_wr.sg_list = &rep->rr_rdmabuf->rg_iov;
1086 rep->rr_recv_wr.num_sge = 1;
1087 rep->rr_temp = temp;
1088
1089 spin_lock(&buf->rb_lock);
1090 list_add(&rep->rr_list, &buf->rb_recv_bufs);
1091 spin_unlock(&buf->rb_lock);
1092 return 0;
1093
1094out_free:
1095 kfree(rep);
1096out:
1097 dprintk("RPC: %s: reply buffer %d alloc failed\n",
1098 __func__, rc);
1099 return rc;
1100}
1101
1102int
1103rpcrdma_buffer_create(struct rpcrdma_xprt *r_xprt)
1104{
1105 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
1106 int i, rc;
1107
1108 buf->rb_max_requests = r_xprt->rx_data.max_requests;
1109 buf->rb_bc_srv_max_requests = 0;
1110 spin_lock_init(&buf->rb_mrlock);
1111 spin_lock_init(&buf->rb_lock);
1112 INIT_LIST_HEAD(&buf->rb_mrs);
1113 INIT_LIST_HEAD(&buf->rb_all);
1114 INIT_DELAYED_WORK(&buf->rb_refresh_worker,
1115 rpcrdma_mr_refresh_worker);
1116
1117 rpcrdma_mrs_create(r_xprt);
1118
1119 INIT_LIST_HEAD(&buf->rb_send_bufs);
1120 INIT_LIST_HEAD(&buf->rb_allreqs);
1121 spin_lock_init(&buf->rb_reqslock);
1122 for (i = 0; i < buf->rb_max_requests; i++) {
1123 struct rpcrdma_req *req;
1124
1125 req = rpcrdma_create_req(r_xprt);
1126 if (IS_ERR(req)) {
1127 dprintk("RPC: %s: request buffer %d alloc"
1128 " failed\n", __func__, i);
1129 rc = PTR_ERR(req);
1130 goto out;
1131 }
1132 list_add(&req->rl_list, &buf->rb_send_bufs);
1133 }
1134
1135 buf->rb_credits = 1;
1136 buf->rb_posted_receives = 0;
1137 INIT_LIST_HEAD(&buf->rb_recv_bufs);
1138
1139 rc = rpcrdma_sendctxs_create(r_xprt);
1140 if (rc)
1141 goto out;
1142
1143 return 0;
1144out:
1145 rpcrdma_buffer_destroy(buf);
1146 return rc;
1147}
1148
1149static void
1150rpcrdma_destroy_rep(struct rpcrdma_rep *rep)
1151{
1152 rpcrdma_free_regbuf(rep->rr_rdmabuf);
1153 kfree(rep);
1154}
1155
1156void
1157rpcrdma_destroy_req(struct rpcrdma_req *req)
1158{
1159 rpcrdma_free_regbuf(req->rl_recvbuf);
1160 rpcrdma_free_regbuf(req->rl_sendbuf);
1161 rpcrdma_free_regbuf(req->rl_rdmabuf);
1162 kfree(req);
1163}
1164
1165static void
1166rpcrdma_mrs_destroy(struct rpcrdma_buffer *buf)
1167{
1168 struct rpcrdma_xprt *r_xprt = container_of(buf, struct rpcrdma_xprt,
1169 rx_buf);
1170 struct rpcrdma_ia *ia = rdmab_to_ia(buf);
1171 struct rpcrdma_mr *mr;
1172 unsigned int count;
1173
1174 count = 0;
1175 spin_lock(&buf->rb_mrlock);
1176 while (!list_empty(&buf->rb_all)) {
1177 mr = list_entry(buf->rb_all.next, struct rpcrdma_mr, mr_all);
1178 list_del(&mr->mr_all);
1179
1180 spin_unlock(&buf->rb_mrlock);
1181
1182 /* Ensure MW is not on any rl_registered list */
1183 if (!list_empty(&mr->mr_list))
1184 list_del(&mr->mr_list);
1185
1186 ia->ri_ops->ro_release_mr(mr);
1187 count++;
1188 spin_lock(&buf->rb_mrlock);
1189 }
1190 spin_unlock(&buf->rb_mrlock);
1191 r_xprt->rx_stats.mrs_allocated = 0;
1192
1193 dprintk("RPC: %s: released %u MRs\n", __func__, count);
1194}
1195
1196void
1197rpcrdma_buffer_destroy(struct rpcrdma_buffer *buf)
1198{
1199 cancel_delayed_work_sync(&buf->rb_refresh_worker);
1200
1201 rpcrdma_sendctxs_destroy(buf);
1202
1203 while (!list_empty(&buf->rb_recv_bufs)) {
1204 struct rpcrdma_rep *rep;
1205
1206 rep = list_first_entry(&buf->rb_recv_bufs,
1207 struct rpcrdma_rep, rr_list);
1208 list_del(&rep->rr_list);
1209 rpcrdma_destroy_rep(rep);
1210 }
1211
1212 spin_lock(&buf->rb_reqslock);
1213 while (!list_empty(&buf->rb_allreqs)) {
1214 struct rpcrdma_req *req;
1215
1216 req = list_first_entry(&buf->rb_allreqs,
1217 struct rpcrdma_req, rl_all);
1218 list_del(&req->rl_all);
1219
1220 spin_unlock(&buf->rb_reqslock);
1221 rpcrdma_destroy_req(req);
1222 spin_lock(&buf->rb_reqslock);
1223 }
1224 spin_unlock(&buf->rb_reqslock);
1225
1226 rpcrdma_mrs_destroy(buf);
1227}
1228
1229/**
1230 * rpcrdma_mr_get - Allocate an rpcrdma_mr object
1231 * @r_xprt: controlling transport
1232 *
1233 * Returns an initialized rpcrdma_mr or NULL if no free
1234 * rpcrdma_mr objects are available.
1235 */
1236struct rpcrdma_mr *
1237rpcrdma_mr_get(struct rpcrdma_xprt *r_xprt)
1238{
1239 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
1240 struct rpcrdma_mr *mr = NULL;
1241
1242 spin_lock(&buf->rb_mrlock);
1243 if (!list_empty(&buf->rb_mrs))
1244 mr = rpcrdma_mr_pop(&buf->rb_mrs);
1245 spin_unlock(&buf->rb_mrlock);
1246
1247 if (!mr)
1248 goto out_nomrs;
1249 return mr;
1250
1251out_nomrs:
1252 trace_xprtrdma_nomrs(r_xprt);
1253 if (r_xprt->rx_ep.rep_connected != -ENODEV)
1254 schedule_delayed_work(&buf->rb_refresh_worker, 0);
1255
1256 /* Allow the reply handler and refresh worker to run */
1257 cond_resched();
1258
1259 return NULL;
1260}
1261
1262static void
1263__rpcrdma_mr_put(struct rpcrdma_buffer *buf, struct rpcrdma_mr *mr)
1264{
1265 spin_lock(&buf->rb_mrlock);
1266 rpcrdma_mr_push(mr, &buf->rb_mrs);
1267 spin_unlock(&buf->rb_mrlock);
1268}
1269
1270/**
1271 * rpcrdma_mr_put - Release an rpcrdma_mr object
1272 * @mr: object to release
1273 *
1274 */
1275void
1276rpcrdma_mr_put(struct rpcrdma_mr *mr)
1277{
1278 __rpcrdma_mr_put(&mr->mr_xprt->rx_buf, mr);
1279}
1280
1281/**
1282 * rpcrdma_mr_unmap_and_put - DMA unmap an MR and release it
1283 * @mr: object to release
1284 *
1285 */
1286void
1287rpcrdma_mr_unmap_and_put(struct rpcrdma_mr *mr)
1288{
1289 struct rpcrdma_xprt *r_xprt = mr->mr_xprt;
1290
1291 trace_xprtrdma_dma_unmap(mr);
1292 ib_dma_unmap_sg(r_xprt->rx_ia.ri_device,
1293 mr->mr_sg, mr->mr_nents, mr->mr_dir);
1294 __rpcrdma_mr_put(&r_xprt->rx_buf, mr);
1295}
1296
1297/**
1298 * rpcrdma_buffer_get - Get a request buffer
1299 * @buffers: Buffer pool from which to obtain a buffer
1300 *
1301 * Returns a fresh rpcrdma_req, or NULL if none are available.
1302 */
1303struct rpcrdma_req *
1304rpcrdma_buffer_get(struct rpcrdma_buffer *buffers)
1305{
1306 struct rpcrdma_req *req;
1307
1308 spin_lock(&buffers->rb_lock);
1309 req = list_first_entry_or_null(&buffers->rb_send_bufs,
1310 struct rpcrdma_req, rl_list);
1311 if (req)
1312 list_del_init(&req->rl_list);
1313 spin_unlock(&buffers->rb_lock);
1314 return req;
1315}
1316
1317/**
1318 * rpcrdma_buffer_put - Put request/reply buffers back into pool
1319 * @req: object to return
1320 *
1321 */
1322void
1323rpcrdma_buffer_put(struct rpcrdma_req *req)
1324{
1325 struct rpcrdma_buffer *buffers = req->rl_buffer;
1326 struct rpcrdma_rep *rep = req->rl_reply;
1327
1328 req->rl_reply = NULL;
1329
1330 spin_lock(&buffers->rb_lock);
1331 list_add(&req->rl_list, &buffers->rb_send_bufs);
1332 if (rep) {
1333 if (!rep->rr_temp) {
1334 list_add(&rep->rr_list, &buffers->rb_recv_bufs);
1335 rep = NULL;
1336 }
1337 }
1338 spin_unlock(&buffers->rb_lock);
1339 if (rep)
1340 rpcrdma_destroy_rep(rep);
1341}
1342
1343/*
1344 * Put reply buffers back into pool when not attached to
1345 * request. This happens in error conditions.
1346 */
1347void
1348rpcrdma_recv_buffer_put(struct rpcrdma_rep *rep)
1349{
1350 struct rpcrdma_buffer *buffers = &rep->rr_rxprt->rx_buf;
1351
1352 if (!rep->rr_temp) {
1353 spin_lock(&buffers->rb_lock);
1354 list_add(&rep->rr_list, &buffers->rb_recv_bufs);
1355 spin_unlock(&buffers->rb_lock);
1356 } else {
1357 rpcrdma_destroy_rep(rep);
1358 }
1359}
1360
1361/**
1362 * rpcrdma_alloc_regbuf - allocate and DMA-map memory for SEND/RECV buffers
1363 * @size: size of buffer to be allocated, in bytes
1364 * @direction: direction of data movement
1365 * @flags: GFP flags
1366 *
1367 * Returns an ERR_PTR, or a pointer to a regbuf, a buffer that
1368 * can be persistently DMA-mapped for I/O.
1369 *
1370 * xprtrdma uses a regbuf for posting an outgoing RDMA SEND, or for
1371 * receiving the payload of RDMA RECV operations. During Long Calls
1372 * or Replies they may be registered externally via ro_map.
1373 */
1374struct rpcrdma_regbuf *
1375rpcrdma_alloc_regbuf(size_t size, enum dma_data_direction direction,
1376 gfp_t flags)
1377{
1378 struct rpcrdma_regbuf *rb;
1379
1380 rb = kmalloc(sizeof(*rb) + size, flags);
1381 if (rb == NULL)
1382 return ERR_PTR(-ENOMEM);
1383
1384 rb->rg_device = NULL;
1385 rb->rg_direction = direction;
1386 rb->rg_iov.length = size;
1387
1388 return rb;
1389}
1390
1391/**
1392 * __rpcrdma_map_regbuf - DMA-map a regbuf
1393 * @ia: controlling rpcrdma_ia
1394 * @rb: regbuf to be mapped
1395 */
1396bool
1397__rpcrdma_dma_map_regbuf(struct rpcrdma_ia *ia, struct rpcrdma_regbuf *rb)
1398{
1399 struct ib_device *device = ia->ri_device;
1400
1401 if (rb->rg_direction == DMA_NONE)
1402 return false;
1403
1404 rb->rg_iov.addr = ib_dma_map_single(device,
1405 (void *)rb->rg_base,
1406 rdmab_length(rb),
1407 rb->rg_direction);
1408 if (ib_dma_mapping_error(device, rdmab_addr(rb)))
1409 return false;
1410
1411 rb->rg_device = device;
1412 rb->rg_iov.lkey = ia->ri_pd->local_dma_lkey;
1413 return true;
1414}
1415
1416static void
1417rpcrdma_dma_unmap_regbuf(struct rpcrdma_regbuf *rb)
1418{
1419 if (!rb)
1420 return;
1421
1422 if (!rpcrdma_regbuf_is_mapped(rb))
1423 return;
1424
1425 ib_dma_unmap_single(rb->rg_device, rdmab_addr(rb),
1426 rdmab_length(rb), rb->rg_direction);
1427 rb->rg_device = NULL;
1428}
1429
1430/**
1431 * rpcrdma_free_regbuf - deregister and free registered buffer
1432 * @rb: regbuf to be deregistered and freed
1433 */
1434void
1435rpcrdma_free_regbuf(struct rpcrdma_regbuf *rb)
1436{
1437 rpcrdma_dma_unmap_regbuf(rb);
1438 kfree(rb);
1439}
1440
1441/*
1442 * Prepost any receive buffer, then post send.
1443 *
1444 * Receive buffer is donated to hardware, reclaimed upon recv completion.
1445 */
1446int
1447rpcrdma_ep_post(struct rpcrdma_ia *ia,
1448 struct rpcrdma_ep *ep,
1449 struct rpcrdma_req *req)
1450{
1451 struct ib_send_wr *send_wr = &req->rl_sendctx->sc_wr;
1452 int rc;
1453
1454 if (!ep->rep_send_count ||
1455 test_bit(RPCRDMA_REQ_F_TX_RESOURCES, &req->rl_flags)) {
1456 send_wr->send_flags |= IB_SEND_SIGNALED;
1457 ep->rep_send_count = ep->rep_send_batch;
1458 } else {
1459 send_wr->send_flags &= ~IB_SEND_SIGNALED;
1460 --ep->rep_send_count;
1461 }
1462
1463 rc = ia->ri_ops->ro_send(ia, req);
1464 trace_xprtrdma_post_send(req, rc);
1465 if (rc)
1466 return -ENOTCONN;
1467 return 0;
1468}
1469
1470/**
1471 * rpcrdma_post_recvs - Maybe post some Receive buffers
1472 * @r_xprt: controlling transport
1473 * @temp: when true, allocate temp rpcrdma_rep objects
1474 *
1475 */
1476void
1477rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, bool temp)
1478{
1479 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
1480 struct ib_recv_wr *wr, *bad_wr;
1481 int needed, count, rc;
1482
1483 needed = buf->rb_credits + (buf->rb_bc_srv_max_requests << 1);
1484 if (buf->rb_posted_receives > needed)
1485 return;
1486 needed -= buf->rb_posted_receives;
1487
1488 count = 0;
1489 wr = NULL;
1490 while (needed) {
1491 struct rpcrdma_regbuf *rb;
1492 struct rpcrdma_rep *rep;
1493
1494 spin_lock(&buf->rb_lock);
1495 rep = list_first_entry_or_null(&buf->rb_recv_bufs,
1496 struct rpcrdma_rep, rr_list);
1497 if (likely(rep))
1498 list_del(&rep->rr_list);
1499 spin_unlock(&buf->rb_lock);
1500 if (!rep) {
1501 if (rpcrdma_create_rep(r_xprt, temp))
1502 break;
1503 continue;
1504 }
1505
1506 rb = rep->rr_rdmabuf;
1507 if (!rpcrdma_regbuf_is_mapped(rb)) {
1508 if (!__rpcrdma_dma_map_regbuf(&r_xprt->rx_ia, rb)) {
1509 rpcrdma_recv_buffer_put(rep);
1510 break;
1511 }
1512 }
1513
1514 trace_xprtrdma_post_recv(rep->rr_recv_wr.wr_cqe);
1515 rep->rr_recv_wr.next = wr;
1516 wr = &rep->rr_recv_wr;
1517 ++count;
1518 --needed;
1519 }
1520 if (!count)
1521 return;
1522
1523 rc = ib_post_recv(r_xprt->rx_ia.ri_id->qp, wr,
1524 (const struct ib_recv_wr **)&bad_wr);
1525 if (rc) {
1526 for (wr = bad_wr; wr; wr = wr->next) {
1527 struct rpcrdma_rep *rep;
1528
1529 rep = container_of(wr, struct rpcrdma_rep, rr_recv_wr);
1530 rpcrdma_recv_buffer_put(rep);
1531 --count;
1532 }
1533 }
1534 buf->rb_posted_receives += count;
1535 trace_xprtrdma_post_recvs(r_xprt, count, rc);
1536}
Linux 6.x block layer and io_uring tree(s)