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#include <linux/log2.h>
57
58#include <asm-generic/barrier.h>
59#include <asm/bitops.h>
60
61#include <rdma/ib_cm.h>
62
63#include "xprt_rdma.h"
64#include <trace/events/rpcrdma.h>
65
66static int rpcrdma_sendctxs_create(struct rpcrdma_xprt *r_xprt);
67static void rpcrdma_sendctxs_destroy(struct rpcrdma_xprt *r_xprt);
68static void rpcrdma_sendctx_put_locked(struct rpcrdma_xprt *r_xprt,
69 struct rpcrdma_sendctx *sc);
70static int rpcrdma_reqs_setup(struct rpcrdma_xprt *r_xprt);
71static void rpcrdma_reqs_reset(struct rpcrdma_xprt *r_xprt);
72static void rpcrdma_rep_destroy(struct rpcrdma_rep *rep);
73static void rpcrdma_reps_unmap(struct rpcrdma_xprt *r_xprt);
74static void rpcrdma_mrs_create(struct rpcrdma_xprt *r_xprt);
75static void rpcrdma_mrs_destroy(struct rpcrdma_xprt *r_xprt);
76static void rpcrdma_ep_get(struct rpcrdma_ep *ep);
77static int rpcrdma_ep_put(struct rpcrdma_ep *ep);
78static struct rpcrdma_regbuf *
79rpcrdma_regbuf_alloc(size_t size, enum dma_data_direction direction);
80static void rpcrdma_regbuf_dma_unmap(struct rpcrdma_regbuf *rb);
81static void rpcrdma_regbuf_free(struct rpcrdma_regbuf *rb);
82
83/* Wait for outstanding transport work to finish. ib_drain_qp
84 * handles the drains in the wrong order for us, so open code
85 * them here.
86 */
87static void rpcrdma_xprt_drain(struct rpcrdma_xprt *r_xprt)
88{
89 struct rpcrdma_ep *ep = r_xprt->rx_ep;
90 struct rdma_cm_id *id = ep->re_id;
91
92 /* Wait for rpcrdma_post_recvs() to leave its critical
93 * section.
94 */
95 if (atomic_inc_return(v: &ep->re_receiving) > 1)
96 wait_for_completion(&ep->re_done);
97
98 /* Flush Receives, then wait for deferred Reply work
99 * to complete.
100 */
101 ib_drain_rq(qp: id->qp);
102
103 /* Deferred Reply processing might have scheduled
104 * local invalidations.
105 */
106 ib_drain_sq(qp: id->qp);
107
108 rpcrdma_ep_put(ep);
109}
110
111/* Ensure xprt_force_disconnect() is invoked exactly once when a
112 * connection is closed or lost. (The important thing is it needs
113 * to be invoked "at least" once).
114 */
115void rpcrdma_force_disconnect(struct rpcrdma_ep *ep)
116{
117 if (atomic_add_unless(v: &ep->re_force_disconnect, a: 1, u: 1))
118 xprt_force_disconnect(xprt: ep->re_xprt);
119}
120
121/**
122 * rpcrdma_flush_disconnect - Disconnect on flushed completion
123 * @r_xprt: transport to disconnect
124 * @wc: work completion entry
125 *
126 * Must be called in process context.
127 */
128void rpcrdma_flush_disconnect(struct rpcrdma_xprt *r_xprt, struct ib_wc *wc)
129{
130 if (wc->status != IB_WC_SUCCESS)
131 rpcrdma_force_disconnect(ep: r_xprt->rx_ep);
132}
133
134/**
135 * rpcrdma_wc_send - Invoked by RDMA provider for each polled Send WC
136 * @cq: completion queue
137 * @wc: WCE for a completed Send WR
138 *
139 */
140static void rpcrdma_wc_send(struct ib_cq *cq, struct ib_wc *wc)
141{
142 struct ib_cqe *cqe = wc->wr_cqe;
143 struct rpcrdma_sendctx *sc =
144 container_of(cqe, struct rpcrdma_sendctx, sc_cqe);
145 struct rpcrdma_xprt *r_xprt = cq->cq_context;
146
147 /* WARNING: Only wr_cqe and status are reliable at this point */
148 trace_xprtrdma_wc_send(wc, cid: &sc->sc_cid);
149 rpcrdma_sendctx_put_locked(r_xprt, sc);
150 rpcrdma_flush_disconnect(r_xprt, wc);
151}
152
153/**
154 * rpcrdma_wc_receive - Invoked by RDMA provider for each polled Receive WC
155 * @cq: completion queue
156 * @wc: WCE for a completed Receive WR
157 *
158 */
159static void rpcrdma_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 struct rpcrdma_xprt *r_xprt = cq->cq_context;
165
166 /* WARNING: Only wr_cqe and status are reliable at this point */
167 trace_xprtrdma_wc_receive(wc, cid: &rep->rr_cid);
168 --r_xprt->rx_ep->re_receive_count;
169 if (wc->status != IB_WC_SUCCESS)
170 goto out_flushed;
171
172 /* status == SUCCESS means all fields in wc are trustworthy */
173 rpcrdma_set_xdrlen(xdr: &rep->rr_hdrbuf, len: wc->byte_len);
174 rep->rr_wc_flags = wc->wc_flags;
175 rep->rr_inv_rkey = wc->ex.invalidate_rkey;
176
177 ib_dma_sync_single_for_cpu(dev: rdmab_device(rb: rep->rr_rdmabuf),
178 addr: rdmab_addr(rb: rep->rr_rdmabuf),
179 size: wc->byte_len, dir: DMA_FROM_DEVICE);
180
181 rpcrdma_reply_handler(rep);
182 return;
183
184out_flushed:
185 rpcrdma_flush_disconnect(r_xprt, wc);
186 rpcrdma_rep_put(buf: &r_xprt->rx_buf, rep);
187}
188
189static void rpcrdma_update_cm_private(struct rpcrdma_ep *ep,
190 struct rdma_conn_param *param)
191{
192 const struct rpcrdma_connect_private *pmsg = param->private_data;
193 unsigned int rsize, wsize;
194
195 /* Default settings for RPC-over-RDMA Version One */
196 rsize = RPCRDMA_V1_DEF_INLINE_SIZE;
197 wsize = RPCRDMA_V1_DEF_INLINE_SIZE;
198
199 if (pmsg &&
200 pmsg->cp_magic == rpcrdma_cmp_magic &&
201 pmsg->cp_version == RPCRDMA_CMP_VERSION) {
202 rsize = rpcrdma_decode_buffer_size(val: pmsg->cp_send_size);
203 wsize = rpcrdma_decode_buffer_size(val: pmsg->cp_recv_size);
204 }
205
206 if (rsize < ep->re_inline_recv)
207 ep->re_inline_recv = rsize;
208 if (wsize < ep->re_inline_send)
209 ep->re_inline_send = wsize;
210
211 rpcrdma_set_max_header_sizes(ep);
212}
213
214/**
215 * rpcrdma_cm_event_handler - Handle RDMA CM events
216 * @id: rdma_cm_id on which an event has occurred
217 * @event: details of the event
218 *
219 * Called with @id's mutex held. Returns 1 if caller should
220 * destroy @id, otherwise 0.
221 */
222static int
223rpcrdma_cm_event_handler(struct rdma_cm_id *id, struct rdma_cm_event *event)
224{
225 struct sockaddr *sap = (struct sockaddr *)&id->route.addr.dst_addr;
226 struct rpcrdma_ep *ep = id->context;
227
228 might_sleep();
229
230 switch (event->event) {
231 case RDMA_CM_EVENT_ADDR_RESOLVED:
232 case RDMA_CM_EVENT_ROUTE_RESOLVED:
233 ep->re_async_rc = 0;
234 complete(&ep->re_done);
235 return 0;
236 case RDMA_CM_EVENT_ADDR_ERROR:
237 ep->re_async_rc = -EPROTO;
238 complete(&ep->re_done);
239 return 0;
240 case RDMA_CM_EVENT_ROUTE_ERROR:
241 ep->re_async_rc = -ENETUNREACH;
242 complete(&ep->re_done);
243 return 0;
244 case RDMA_CM_EVENT_DEVICE_REMOVAL:
245 pr_info("rpcrdma: removing device %s for %pISpc\n",
246 ep->re_id->device->name, sap);
247 fallthrough;
248 case RDMA_CM_EVENT_ADDR_CHANGE:
249 ep->re_connect_status = -ENODEV;
250 goto disconnected;
251 case RDMA_CM_EVENT_ESTABLISHED:
252 rpcrdma_ep_get(ep);
253 ep->re_connect_status = 1;
254 rpcrdma_update_cm_private(ep, param: &event->param.conn);
255 trace_xprtrdma_inline_thresh(ep);
256 wake_up_all(&ep->re_connect_wait);
257 break;
258 case RDMA_CM_EVENT_CONNECT_ERROR:
259 ep->re_connect_status = -ENOTCONN;
260 goto wake_connect_worker;
261 case RDMA_CM_EVENT_UNREACHABLE:
262 ep->re_connect_status = -ENETUNREACH;
263 goto wake_connect_worker;
264 case RDMA_CM_EVENT_REJECTED:
265 ep->re_connect_status = -ECONNREFUSED;
266 if (event->status == IB_CM_REJ_STALE_CONN)
267 ep->re_connect_status = -ENOTCONN;
268wake_connect_worker:
269 wake_up_all(&ep->re_connect_wait);
270 return 0;
271 case RDMA_CM_EVENT_DISCONNECTED:
272 ep->re_connect_status = -ECONNABORTED;
273disconnected:
274 rpcrdma_force_disconnect(ep);
275 return rpcrdma_ep_put(ep);
276 default:
277 break;
278 }
279
280 return 0;
281}
282
283static struct rdma_cm_id *rpcrdma_create_id(struct rpcrdma_xprt *r_xprt,
284 struct rpcrdma_ep *ep)
285{
286 unsigned long wtimeout = msecs_to_jiffies(RDMA_RESOLVE_TIMEOUT) + 1;
287 struct rpc_xprt *xprt = &r_xprt->rx_xprt;
288 struct rdma_cm_id *id;
289 int rc;
290
291 init_completion(x: &ep->re_done);
292
293 id = rdma_create_id(xprt->xprt_net, rpcrdma_cm_event_handler, ep,
294 RDMA_PS_TCP, IB_QPT_RC);
295 if (IS_ERR(ptr: id))
296 return id;
297
298 ep->re_async_rc = -ETIMEDOUT;
299 rc = rdma_resolve_addr(id, NULL, dst_addr: (struct sockaddr *)&xprt->addr,
300 RDMA_RESOLVE_TIMEOUT);
301 if (rc)
302 goto out;
303 rc = wait_for_completion_interruptible_timeout(x: &ep->re_done, timeout: wtimeout);
304 if (rc < 0)
305 goto out;
306
307 rc = ep->re_async_rc;
308 if (rc)
309 goto out;
310
311 ep->re_async_rc = -ETIMEDOUT;
312 rc = rdma_resolve_route(id, RDMA_RESOLVE_TIMEOUT);
313 if (rc)
314 goto out;
315 rc = wait_for_completion_interruptible_timeout(x: &ep->re_done, timeout: wtimeout);
316 if (rc < 0)
317 goto out;
318 rc = ep->re_async_rc;
319 if (rc)
320 goto out;
321
322 return id;
323
324out:
325 rdma_destroy_id(id);
326 return ERR_PTR(error: rc);
327}
328
329static void rpcrdma_ep_destroy(struct kref *kref)
330{
331 struct rpcrdma_ep *ep = container_of(kref, struct rpcrdma_ep, re_kref);
332
333 if (ep->re_id->qp) {
334 rdma_destroy_qp(id: ep->re_id);
335 ep->re_id->qp = NULL;
336 }
337
338 if (ep->re_attr.recv_cq)
339 ib_free_cq(cq: ep->re_attr.recv_cq);
340 ep->re_attr.recv_cq = NULL;
341 if (ep->re_attr.send_cq)
342 ib_free_cq(cq: ep->re_attr.send_cq);
343 ep->re_attr.send_cq = NULL;
344
345 if (ep->re_pd)
346 ib_dealloc_pd(pd: ep->re_pd);
347 ep->re_pd = NULL;
348
349 kfree(objp: ep);
350 module_put(THIS_MODULE);
351}
352
353static noinline void rpcrdma_ep_get(struct rpcrdma_ep *ep)
354{
355 kref_get(kref: &ep->re_kref);
356}
357
358/* Returns:
359 * %0 if @ep still has a positive kref count, or
360 * %1 if @ep was destroyed successfully.
361 */
362static noinline int rpcrdma_ep_put(struct rpcrdma_ep *ep)
363{
364 return kref_put(kref: &ep->re_kref, release: rpcrdma_ep_destroy);
365}
366
367static int rpcrdma_ep_create(struct rpcrdma_xprt *r_xprt)
368{
369 struct rpcrdma_connect_private *pmsg;
370 struct ib_device *device;
371 struct rdma_cm_id *id;
372 struct rpcrdma_ep *ep;
373 int rc;
374
375 ep = kzalloc(size: sizeof(*ep), XPRTRDMA_GFP_FLAGS);
376 if (!ep)
377 return -ENOTCONN;
378 ep->re_xprt = &r_xprt->rx_xprt;
379 kref_init(kref: &ep->re_kref);
380
381 id = rpcrdma_create_id(r_xprt, ep);
382 if (IS_ERR(ptr: id)) {
383 kfree(objp: ep);
384 return PTR_ERR(ptr: id);
385 }
386 __module_get(THIS_MODULE);
387 device = id->device;
388 ep->re_id = id;
389 reinit_completion(x: &ep->re_done);
390
391 ep->re_max_requests = r_xprt->rx_xprt.max_reqs;
392 ep->re_inline_send = xprt_rdma_max_inline_write;
393 ep->re_inline_recv = xprt_rdma_max_inline_read;
394 rc = frwr_query_device(ep, device);
395 if (rc)
396 goto out_destroy;
397
398 r_xprt->rx_buf.rb_max_requests = cpu_to_be32(ep->re_max_requests);
399
400 ep->re_attr.srq = NULL;
401 ep->re_attr.cap.max_inline_data = 0;
402 ep->re_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
403 ep->re_attr.qp_type = IB_QPT_RC;
404 ep->re_attr.port_num = ~0;
405
406 ep->re_send_batch = ep->re_max_requests >> 3;
407 ep->re_send_count = ep->re_send_batch;
408 init_waitqueue_head(&ep->re_connect_wait);
409
410 ep->re_attr.send_cq = ib_alloc_cq_any(dev: device, private: r_xprt,
411 nr_cqe: ep->re_attr.cap.max_send_wr,
412 poll_ctx: IB_POLL_WORKQUEUE);
413 if (IS_ERR(ptr: ep->re_attr.send_cq)) {
414 rc = PTR_ERR(ptr: ep->re_attr.send_cq);
415 ep->re_attr.send_cq = NULL;
416 goto out_destroy;
417 }
418
419 ep->re_attr.recv_cq = ib_alloc_cq_any(dev: device, private: r_xprt,
420 nr_cqe: ep->re_attr.cap.max_recv_wr,
421 poll_ctx: IB_POLL_WORKQUEUE);
422 if (IS_ERR(ptr: ep->re_attr.recv_cq)) {
423 rc = PTR_ERR(ptr: ep->re_attr.recv_cq);
424 ep->re_attr.recv_cq = NULL;
425 goto out_destroy;
426 }
427 ep->re_receive_count = 0;
428
429 /* Initialize cma parameters */
430 memset(&ep->re_remote_cma, 0, sizeof(ep->re_remote_cma));
431
432 /* Prepare RDMA-CM private message */
433 pmsg = &ep->re_cm_private;
434 pmsg->cp_magic = rpcrdma_cmp_magic;
435 pmsg->cp_version = RPCRDMA_CMP_VERSION;
436 pmsg->cp_flags |= RPCRDMA_CMP_F_SND_W_INV_OK;
437 pmsg->cp_send_size = rpcrdma_encode_buffer_size(size: ep->re_inline_send);
438 pmsg->cp_recv_size = rpcrdma_encode_buffer_size(size: ep->re_inline_recv);
439 ep->re_remote_cma.private_data = pmsg;
440 ep->re_remote_cma.private_data_len = sizeof(*pmsg);
441
442 /* Client offers RDMA Read but does not initiate */
443 ep->re_remote_cma.initiator_depth = 0;
444 ep->re_remote_cma.responder_resources =
445 min_t(int, U8_MAX, device->attrs.max_qp_rd_atom);
446
447 /* Limit transport retries so client can detect server
448 * GID changes quickly. RPC layer handles re-establishing
449 * transport connection and retransmission.
450 */
451 ep->re_remote_cma.retry_count = 6;
452
453 /* RPC-over-RDMA handles its own flow control. In addition,
454 * make all RNR NAKs visible so we know that RPC-over-RDMA
455 * flow control is working correctly (no NAKs should be seen).
456 */
457 ep->re_remote_cma.flow_control = 0;
458 ep->re_remote_cma.rnr_retry_count = 0;
459
460 ep->re_pd = ib_alloc_pd(device, 0);
461 if (IS_ERR(ptr: ep->re_pd)) {
462 rc = PTR_ERR(ptr: ep->re_pd);
463 ep->re_pd = NULL;
464 goto out_destroy;
465 }
466
467 rc = rdma_create_qp(id, pd: ep->re_pd, qp_init_attr: &ep->re_attr);
468 if (rc)
469 goto out_destroy;
470
471 r_xprt->rx_ep = ep;
472 return 0;
473
474out_destroy:
475 rpcrdma_ep_put(ep);
476 rdma_destroy_id(id);
477 return rc;
478}
479
480/**
481 * rpcrdma_xprt_connect - Connect an unconnected transport
482 * @r_xprt: controlling transport instance
483 *
484 * Returns 0 on success or a negative errno.
485 */
486int rpcrdma_xprt_connect(struct rpcrdma_xprt *r_xprt)
487{
488 struct rpc_xprt *xprt = &r_xprt->rx_xprt;
489 struct rpcrdma_ep *ep;
490 int rc;
491
492 rc = rpcrdma_ep_create(r_xprt);
493 if (rc)
494 return rc;
495 ep = r_xprt->rx_ep;
496
497 xprt_clear_connected(xprt);
498 rpcrdma_reset_cwnd(r_xprt);
499
500 /* Bump the ep's reference count while there are
501 * outstanding Receives.
502 */
503 rpcrdma_ep_get(ep);
504 rpcrdma_post_recvs(r_xprt, needed: 1, temp: true);
505
506 rc = rdma_connect(id: ep->re_id, conn_param: &ep->re_remote_cma);
507 if (rc)
508 goto out;
509
510 if (xprt->reestablish_timeout < RPCRDMA_INIT_REEST_TO)
511 xprt->reestablish_timeout = RPCRDMA_INIT_REEST_TO;
512 wait_event_interruptible(ep->re_connect_wait,
513 ep->re_connect_status != 0);
514 if (ep->re_connect_status <= 0) {
515 rc = ep->re_connect_status;
516 goto out;
517 }
518
519 rc = rpcrdma_sendctxs_create(r_xprt);
520 if (rc) {
521 rc = -ENOTCONN;
522 goto out;
523 }
524
525 rc = rpcrdma_reqs_setup(r_xprt);
526 if (rc) {
527 rc = -ENOTCONN;
528 goto out;
529 }
530 rpcrdma_mrs_create(r_xprt);
531 frwr_wp_create(r_xprt);
532
533out:
534 trace_xprtrdma_connect(r_xprt, rc);
535 return rc;
536}
537
538/**
539 * rpcrdma_xprt_disconnect - Disconnect underlying transport
540 * @r_xprt: controlling transport instance
541 *
542 * Caller serializes. Either the transport send lock is held,
543 * or we're being called to destroy the transport.
544 *
545 * On return, @r_xprt is completely divested of all hardware
546 * resources and prepared for the next ->connect operation.
547 */
548void rpcrdma_xprt_disconnect(struct rpcrdma_xprt *r_xprt)
549{
550 struct rpcrdma_ep *ep = r_xprt->rx_ep;
551 struct rdma_cm_id *id;
552 int rc;
553
554 if (!ep)
555 return;
556
557 id = ep->re_id;
558 rc = rdma_disconnect(id);
559 trace_xprtrdma_disconnect(r_xprt, rc);
560
561 rpcrdma_xprt_drain(r_xprt);
562 rpcrdma_reps_unmap(r_xprt);
563 rpcrdma_reqs_reset(r_xprt);
564 rpcrdma_mrs_destroy(r_xprt);
565 rpcrdma_sendctxs_destroy(r_xprt);
566
567 if (rpcrdma_ep_put(ep))
568 rdma_destroy_id(id);
569
570 r_xprt->rx_ep = NULL;
571}
572
573/* Fixed-size circular FIFO queue. This implementation is wait-free and
574 * lock-free.
575 *
576 * Consumer is the code path that posts Sends. This path dequeues a
577 * sendctx for use by a Send operation. Multiple consumer threads
578 * are serialized by the RPC transport lock, which allows only one
579 * ->send_request call at a time.
580 *
581 * Producer is the code path that handles Send completions. This path
582 * enqueues a sendctx that has been completed. Multiple producer
583 * threads are serialized by the ib_poll_cq() function.
584 */
585
586/* rpcrdma_sendctxs_destroy() assumes caller has already quiesced
587 * queue activity, and rpcrdma_xprt_drain has flushed all remaining
588 * Send requests.
589 */
590static void rpcrdma_sendctxs_destroy(struct rpcrdma_xprt *r_xprt)
591{
592 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
593 unsigned long i;
594
595 if (!buf->rb_sc_ctxs)
596 return;
597 for (i = 0; i <= buf->rb_sc_last; i++)
598 kfree(objp: buf->rb_sc_ctxs[i]);
599 kfree(objp: buf->rb_sc_ctxs);
600 buf->rb_sc_ctxs = NULL;
601}
602
603static struct rpcrdma_sendctx *rpcrdma_sendctx_create(struct rpcrdma_ep *ep)
604{
605 struct rpcrdma_sendctx *sc;
606
607 sc = kzalloc(struct_size(sc, sc_sges, ep->re_attr.cap.max_send_sge),
608 XPRTRDMA_GFP_FLAGS);
609 if (!sc)
610 return NULL;
611
612 sc->sc_cqe.done = rpcrdma_wc_send;
613 sc->sc_cid.ci_queue_id = ep->re_attr.send_cq->res.id;
614 sc->sc_cid.ci_completion_id =
615 atomic_inc_return(v: &ep->re_completion_ids);
616 return sc;
617}
618
619static int rpcrdma_sendctxs_create(struct rpcrdma_xprt *r_xprt)
620{
621 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
622 struct rpcrdma_sendctx *sc;
623 unsigned long i;
624
625 /* Maximum number of concurrent outstanding Send WRs. Capping
626 * the circular queue size stops Send Queue overflow by causing
627 * the ->send_request call to fail temporarily before too many
628 * Sends are posted.
629 */
630 i = r_xprt->rx_ep->re_max_requests + RPCRDMA_MAX_BC_REQUESTS;
631 buf->rb_sc_ctxs = kcalloc(n: i, size: sizeof(sc), XPRTRDMA_GFP_FLAGS);
632 if (!buf->rb_sc_ctxs)
633 return -ENOMEM;
634
635 buf->rb_sc_last = i - 1;
636 for (i = 0; i <= buf->rb_sc_last; i++) {
637 sc = rpcrdma_sendctx_create(ep: r_xprt->rx_ep);
638 if (!sc)
639 return -ENOMEM;
640
641 buf->rb_sc_ctxs[i] = sc;
642 }
643
644 buf->rb_sc_head = 0;
645 buf->rb_sc_tail = 0;
646 return 0;
647}
648
649/* The sendctx queue is not guaranteed to have a size that is a
650 * power of two, thus the helpers in circ_buf.h cannot be used.
651 * The other option is to use modulus (%), which can be expensive.
652 */
653static unsigned long rpcrdma_sendctx_next(struct rpcrdma_buffer *buf,
654 unsigned long item)
655{
656 return likely(item < buf->rb_sc_last) ? item + 1 : 0;
657}
658
659/**
660 * rpcrdma_sendctx_get_locked - Acquire a send context
661 * @r_xprt: controlling transport instance
662 *
663 * Returns pointer to a free send completion context; or NULL if
664 * the queue is empty.
665 *
666 * Usage: Called to acquire an SGE array before preparing a Send WR.
667 *
668 * The caller serializes calls to this function (per transport), and
669 * provides an effective memory barrier that flushes the new value
670 * of rb_sc_head.
671 */
672struct rpcrdma_sendctx *rpcrdma_sendctx_get_locked(struct rpcrdma_xprt *r_xprt)
673{
674 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
675 struct rpcrdma_sendctx *sc;
676 unsigned long next_head;
677
678 next_head = rpcrdma_sendctx_next(buf, item: buf->rb_sc_head);
679
680 if (next_head == READ_ONCE(buf->rb_sc_tail))
681 goto out_emptyq;
682
683 /* ORDER: item must be accessed _before_ head is updated */
684 sc = buf->rb_sc_ctxs[next_head];
685
686 /* Releasing the lock in the caller acts as a memory
687 * barrier that flushes rb_sc_head.
688 */
689 buf->rb_sc_head = next_head;
690
691 return sc;
692
693out_emptyq:
694 /* The queue is "empty" if there have not been enough Send
695 * completions recently. This is a sign the Send Queue is
696 * backing up. Cause the caller to pause and try again.
697 */
698 xprt_wait_for_buffer_space(xprt: &r_xprt->rx_xprt);
699 r_xprt->rx_stats.empty_sendctx_q++;
700 return NULL;
701}
702
703/**
704 * rpcrdma_sendctx_put_locked - Release a send context
705 * @r_xprt: controlling transport instance
706 * @sc: send context to release
707 *
708 * Usage: Called from Send completion to return a sendctxt
709 * to the queue.
710 *
711 * The caller serializes calls to this function (per transport).
712 */
713static void rpcrdma_sendctx_put_locked(struct rpcrdma_xprt *r_xprt,
714 struct rpcrdma_sendctx *sc)
715{
716 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
717 unsigned long next_tail;
718
719 /* Unmap SGEs of previously completed but unsignaled
720 * Sends by walking up the queue until @sc is found.
721 */
722 next_tail = buf->rb_sc_tail;
723 do {
724 next_tail = rpcrdma_sendctx_next(buf, item: next_tail);
725
726 /* ORDER: item must be accessed _before_ tail is updated */
727 rpcrdma_sendctx_unmap(sc: buf->rb_sc_ctxs[next_tail]);
728
729 } while (buf->rb_sc_ctxs[next_tail] != sc);
730
731 /* Paired with READ_ONCE */
732 smp_store_release(&buf->rb_sc_tail, next_tail);
733
734 xprt_write_space(xprt: &r_xprt->rx_xprt);
735}
736
737static void
738rpcrdma_mrs_create(struct rpcrdma_xprt *r_xprt)
739{
740 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
741 struct rpcrdma_ep *ep = r_xprt->rx_ep;
742 struct ib_device *device = ep->re_id->device;
743 unsigned int count;
744
745 /* Try to allocate enough to perform one full-sized I/O */
746 for (count = 0; count < ep->re_max_rdma_segs; count++) {
747 struct rpcrdma_mr *mr;
748 int rc;
749
750 mr = kzalloc_node(size: sizeof(*mr), XPRTRDMA_GFP_FLAGS,
751 node: ibdev_to_node(ibdev: device));
752 if (!mr)
753 break;
754
755 rc = frwr_mr_init(r_xprt, mr);
756 if (rc) {
757 kfree(objp: mr);
758 break;
759 }
760
761 spin_lock(lock: &buf->rb_lock);
762 rpcrdma_mr_push(mr, list: &buf->rb_mrs);
763 list_add(new: &mr->mr_all, head: &buf->rb_all_mrs);
764 spin_unlock(lock: &buf->rb_lock);
765 }
766
767 r_xprt->rx_stats.mrs_allocated += count;
768 trace_xprtrdma_createmrs(r_xprt, count);
769}
770
771static void
772rpcrdma_mr_refresh_worker(struct work_struct *work)
773{
774 struct rpcrdma_buffer *buf = container_of(work, struct rpcrdma_buffer,
775 rb_refresh_worker);
776 struct rpcrdma_xprt *r_xprt = container_of(buf, struct rpcrdma_xprt,
777 rx_buf);
778
779 rpcrdma_mrs_create(r_xprt);
780 xprt_write_space(xprt: &r_xprt->rx_xprt);
781}
782
783/**
784 * rpcrdma_mrs_refresh - Wake the MR refresh worker
785 * @r_xprt: controlling transport instance
786 *
787 */
788void rpcrdma_mrs_refresh(struct rpcrdma_xprt *r_xprt)
789{
790 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
791 struct rpcrdma_ep *ep = r_xprt->rx_ep;
792
793 /* If there is no underlying connection, it's no use
794 * to wake the refresh worker.
795 */
796 if (ep->re_connect_status != 1)
797 return;
798 queue_work(wq: system_highpri_wq, work: &buf->rb_refresh_worker);
799}
800
801/**
802 * rpcrdma_req_create - Allocate an rpcrdma_req object
803 * @r_xprt: controlling r_xprt
804 * @size: initial size, in bytes, of send and receive buffers
805 *
806 * Returns an allocated and fully initialized rpcrdma_req or NULL.
807 */
808struct rpcrdma_req *rpcrdma_req_create(struct rpcrdma_xprt *r_xprt,
809 size_t size)
810{
811 struct rpcrdma_buffer *buffer = &r_xprt->rx_buf;
812 struct rpcrdma_req *req;
813
814 req = kzalloc(size: sizeof(*req), XPRTRDMA_GFP_FLAGS);
815 if (req == NULL)
816 goto out1;
817
818 req->rl_sendbuf = rpcrdma_regbuf_alloc(size, direction: DMA_TO_DEVICE);
819 if (!req->rl_sendbuf)
820 goto out2;
821
822 req->rl_recvbuf = rpcrdma_regbuf_alloc(size, direction: DMA_NONE);
823 if (!req->rl_recvbuf)
824 goto out3;
825
826 INIT_LIST_HEAD(list: &req->rl_free_mrs);
827 INIT_LIST_HEAD(list: &req->rl_registered);
828 spin_lock(lock: &buffer->rb_lock);
829 list_add(new: &req->rl_all, head: &buffer->rb_allreqs);
830 spin_unlock(lock: &buffer->rb_lock);
831 return req;
832
833out3:
834 rpcrdma_regbuf_free(rb: req->rl_sendbuf);
835out2:
836 kfree(objp: req);
837out1:
838 return NULL;
839}
840
841/**
842 * rpcrdma_req_setup - Per-connection instance setup of an rpcrdma_req object
843 * @r_xprt: controlling transport instance
844 * @req: rpcrdma_req object to set up
845 *
846 * Returns zero on success, and a negative errno on failure.
847 */
848int rpcrdma_req_setup(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req)
849{
850 struct rpcrdma_regbuf *rb;
851 size_t maxhdrsize;
852
853 /* Compute maximum header buffer size in bytes */
854 maxhdrsize = rpcrdma_fixed_maxsz + 3 +
855 r_xprt->rx_ep->re_max_rdma_segs * rpcrdma_readchunk_maxsz;
856 maxhdrsize *= sizeof(__be32);
857 rb = rpcrdma_regbuf_alloc(size: __roundup_pow_of_two(n: maxhdrsize),
858 direction: DMA_TO_DEVICE);
859 if (!rb)
860 goto out;
861
862 if (!__rpcrdma_regbuf_dma_map(r_xprt, rb))
863 goto out_free;
864
865 req->rl_rdmabuf = rb;
866 xdr_buf_init(buf: &req->rl_hdrbuf, start: rdmab_data(rb), len: rdmab_length(rb));
867 return 0;
868
869out_free:
870 rpcrdma_regbuf_free(rb);
871out:
872 return -ENOMEM;
873}
874
875/* ASSUMPTION: the rb_allreqs list is stable for the duration,
876 * and thus can be walked without holding rb_lock. Eg. the
877 * caller is holding the transport send lock to exclude
878 * device removal or disconnection.
879 */
880static int rpcrdma_reqs_setup(struct rpcrdma_xprt *r_xprt)
881{
882 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
883 struct rpcrdma_req *req;
884 int rc;
885
886 list_for_each_entry(req, &buf->rb_allreqs, rl_all) {
887 rc = rpcrdma_req_setup(r_xprt, req);
888 if (rc)
889 return rc;
890 }
891 return 0;
892}
893
894static void rpcrdma_req_reset(struct rpcrdma_req *req)
895{
896 /* Credits are valid for only one connection */
897 req->rl_slot.rq_cong = 0;
898
899 rpcrdma_regbuf_free(rb: req->rl_rdmabuf);
900 req->rl_rdmabuf = NULL;
901
902 rpcrdma_regbuf_dma_unmap(rb: req->rl_sendbuf);
903 rpcrdma_regbuf_dma_unmap(rb: req->rl_recvbuf);
904
905 frwr_reset(req);
906}
907
908/* ASSUMPTION: the rb_allreqs list is stable for the duration,
909 * and thus can be walked without holding rb_lock. Eg. the
910 * caller is holding the transport send lock to exclude
911 * device removal or disconnection.
912 */
913static void rpcrdma_reqs_reset(struct rpcrdma_xprt *r_xprt)
914{
915 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
916 struct rpcrdma_req *req;
917
918 list_for_each_entry(req, &buf->rb_allreqs, rl_all)
919 rpcrdma_req_reset(req);
920}
921
922static noinline
923struct rpcrdma_rep *rpcrdma_rep_create(struct rpcrdma_xprt *r_xprt,
924 bool temp)
925{
926 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
927 struct rpcrdma_rep *rep;
928
929 rep = kzalloc(size: sizeof(*rep), XPRTRDMA_GFP_FLAGS);
930 if (rep == NULL)
931 goto out;
932
933 rep->rr_rdmabuf = rpcrdma_regbuf_alloc(size: r_xprt->rx_ep->re_inline_recv,
934 direction: DMA_FROM_DEVICE);
935 if (!rep->rr_rdmabuf)
936 goto out_free;
937
938 rep->rr_cid.ci_completion_id =
939 atomic_inc_return(v: &r_xprt->rx_ep->re_completion_ids);
940
941 xdr_buf_init(buf: &rep->rr_hdrbuf, start: rdmab_data(rb: rep->rr_rdmabuf),
942 len: rdmab_length(rb: rep->rr_rdmabuf));
943 rep->rr_cqe.done = rpcrdma_wc_receive;
944 rep->rr_rxprt = r_xprt;
945 rep->rr_recv_wr.next = NULL;
946 rep->rr_recv_wr.wr_cqe = &rep->rr_cqe;
947 rep->rr_recv_wr.sg_list = &rep->rr_rdmabuf->rg_iov;
948 rep->rr_recv_wr.num_sge = 1;
949 rep->rr_temp = temp;
950
951 spin_lock(lock: &buf->rb_lock);
952 list_add(new: &rep->rr_all, head: &buf->rb_all_reps);
953 spin_unlock(lock: &buf->rb_lock);
954 return rep;
955
956out_free:
957 kfree(objp: rep);
958out:
959 return NULL;
960}
961
962static void rpcrdma_rep_free(struct rpcrdma_rep *rep)
963{
964 rpcrdma_regbuf_free(rb: rep->rr_rdmabuf);
965 kfree(objp: rep);
966}
967
968static void rpcrdma_rep_destroy(struct rpcrdma_rep *rep)
969{
970 struct rpcrdma_buffer *buf = &rep->rr_rxprt->rx_buf;
971
972 spin_lock(lock: &buf->rb_lock);
973 list_del(entry: &rep->rr_all);
974 spin_unlock(lock: &buf->rb_lock);
975
976 rpcrdma_rep_free(rep);
977}
978
979static struct rpcrdma_rep *rpcrdma_rep_get_locked(struct rpcrdma_buffer *buf)
980{
981 struct llist_node *node;
982
983 /* Calls to llist_del_first are required to be serialized */
984 node = llist_del_first(head: &buf->rb_free_reps);
985 if (!node)
986 return NULL;
987 return llist_entry(node, struct rpcrdma_rep, rr_node);
988}
989
990/**
991 * rpcrdma_rep_put - Release rpcrdma_rep back to free list
992 * @buf: buffer pool
993 * @rep: rep to release
994 *
995 */
996void rpcrdma_rep_put(struct rpcrdma_buffer *buf, struct rpcrdma_rep *rep)
997{
998 llist_add(new: &rep->rr_node, head: &buf->rb_free_reps);
999}
1000
1001/* Caller must ensure the QP is quiescent (RQ is drained) before
1002 * invoking this function, to guarantee rb_all_reps is not
1003 * changing.
1004 */
1005static void rpcrdma_reps_unmap(struct rpcrdma_xprt *r_xprt)
1006{
1007 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
1008 struct rpcrdma_rep *rep;
1009
1010 list_for_each_entry(rep, &buf->rb_all_reps, rr_all) {
1011 rpcrdma_regbuf_dma_unmap(rb: rep->rr_rdmabuf);
1012 rep->rr_temp = true; /* Mark this rep for destruction */
1013 }
1014}
1015
1016static void rpcrdma_reps_destroy(struct rpcrdma_buffer *buf)
1017{
1018 struct rpcrdma_rep *rep;
1019
1020 spin_lock(lock: &buf->rb_lock);
1021 while ((rep = list_first_entry_or_null(&buf->rb_all_reps,
1022 struct rpcrdma_rep,
1023 rr_all)) != NULL) {
1024 list_del(entry: &rep->rr_all);
1025 spin_unlock(lock: &buf->rb_lock);
1026
1027 rpcrdma_rep_free(rep);
1028
1029 spin_lock(lock: &buf->rb_lock);
1030 }
1031 spin_unlock(lock: &buf->rb_lock);
1032}
1033
1034/**
1035 * rpcrdma_buffer_create - Create initial set of req/rep objects
1036 * @r_xprt: transport instance to (re)initialize
1037 *
1038 * Returns zero on success, otherwise a negative errno.
1039 */
1040int rpcrdma_buffer_create(struct rpcrdma_xprt *r_xprt)
1041{
1042 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
1043 int i, rc;
1044
1045 buf->rb_bc_srv_max_requests = 0;
1046 spin_lock_init(&buf->rb_lock);
1047 INIT_LIST_HEAD(list: &buf->rb_mrs);
1048 INIT_LIST_HEAD(list: &buf->rb_all_mrs);
1049 INIT_WORK(&buf->rb_refresh_worker, rpcrdma_mr_refresh_worker);
1050
1051 INIT_LIST_HEAD(list: &buf->rb_send_bufs);
1052 INIT_LIST_HEAD(list: &buf->rb_allreqs);
1053 INIT_LIST_HEAD(list: &buf->rb_all_reps);
1054
1055 rc = -ENOMEM;
1056 for (i = 0; i < r_xprt->rx_xprt.max_reqs; i++) {
1057 struct rpcrdma_req *req;
1058
1059 req = rpcrdma_req_create(r_xprt,
1060 size: RPCRDMA_V1_DEF_INLINE_SIZE * 2);
1061 if (!req)
1062 goto out;
1063 list_add(new: &req->rl_list, head: &buf->rb_send_bufs);
1064 }
1065
1066 init_llist_head(list: &buf->rb_free_reps);
1067
1068 return 0;
1069out:
1070 rpcrdma_buffer_destroy(buf);
1071 return rc;
1072}
1073
1074/**
1075 * rpcrdma_req_destroy - Destroy an rpcrdma_req object
1076 * @req: unused object to be destroyed
1077 *
1078 * Relies on caller holding the transport send lock to protect
1079 * removing req->rl_all from buf->rb_all_reqs safely.
1080 */
1081void rpcrdma_req_destroy(struct rpcrdma_req *req)
1082{
1083 struct rpcrdma_mr *mr;
1084
1085 list_del(entry: &req->rl_all);
1086
1087 while ((mr = rpcrdma_mr_pop(list: &req->rl_free_mrs))) {
1088 struct rpcrdma_buffer *buf = &mr->mr_xprt->rx_buf;
1089
1090 spin_lock(lock: &buf->rb_lock);
1091 list_del(entry: &mr->mr_all);
1092 spin_unlock(lock: &buf->rb_lock);
1093
1094 frwr_mr_release(mr);
1095 }
1096
1097 rpcrdma_regbuf_free(rb: req->rl_recvbuf);
1098 rpcrdma_regbuf_free(rb: req->rl_sendbuf);
1099 rpcrdma_regbuf_free(rb: req->rl_rdmabuf);
1100 kfree(objp: req);
1101}
1102
1103/**
1104 * rpcrdma_mrs_destroy - Release all of a transport's MRs
1105 * @r_xprt: controlling transport instance
1106 *
1107 * Relies on caller holding the transport send lock to protect
1108 * removing mr->mr_list from req->rl_free_mrs safely.
1109 */
1110static void rpcrdma_mrs_destroy(struct rpcrdma_xprt *r_xprt)
1111{
1112 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
1113 struct rpcrdma_mr *mr;
1114
1115 cancel_work_sync(work: &buf->rb_refresh_worker);
1116
1117 spin_lock(lock: &buf->rb_lock);
1118 while ((mr = list_first_entry_or_null(&buf->rb_all_mrs,
1119 struct rpcrdma_mr,
1120 mr_all)) != NULL) {
1121 list_del(entry: &mr->mr_list);
1122 list_del(entry: &mr->mr_all);
1123 spin_unlock(lock: &buf->rb_lock);
1124
1125 frwr_mr_release(mr);
1126
1127 spin_lock(lock: &buf->rb_lock);
1128 }
1129 spin_unlock(lock: &buf->rb_lock);
1130}
1131
1132/**
1133 * rpcrdma_buffer_destroy - Release all hw resources
1134 * @buf: root control block for resources
1135 *
1136 * ORDERING: relies on a prior rpcrdma_xprt_drain :
1137 * - No more Send or Receive completions can occur
1138 * - All MRs, reps, and reqs are returned to their free lists
1139 */
1140void
1141rpcrdma_buffer_destroy(struct rpcrdma_buffer *buf)
1142{
1143 rpcrdma_reps_destroy(buf);
1144
1145 while (!list_empty(head: &buf->rb_send_bufs)) {
1146 struct rpcrdma_req *req;
1147
1148 req = list_first_entry(&buf->rb_send_bufs,
1149 struct rpcrdma_req, rl_list);
1150 list_del(entry: &req->rl_list);
1151 rpcrdma_req_destroy(req);
1152 }
1153}
1154
1155/**
1156 * rpcrdma_mr_get - Allocate an rpcrdma_mr object
1157 * @r_xprt: controlling transport
1158 *
1159 * Returns an initialized rpcrdma_mr or NULL if no free
1160 * rpcrdma_mr objects are available.
1161 */
1162struct rpcrdma_mr *
1163rpcrdma_mr_get(struct rpcrdma_xprt *r_xprt)
1164{
1165 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
1166 struct rpcrdma_mr *mr;
1167
1168 spin_lock(lock: &buf->rb_lock);
1169 mr = rpcrdma_mr_pop(list: &buf->rb_mrs);
1170 spin_unlock(lock: &buf->rb_lock);
1171 return mr;
1172}
1173
1174/**
1175 * rpcrdma_reply_put - Put reply buffers back into pool
1176 * @buffers: buffer pool
1177 * @req: object to return
1178 *
1179 */
1180void rpcrdma_reply_put(struct rpcrdma_buffer *buffers, struct rpcrdma_req *req)
1181{
1182 if (req->rl_reply) {
1183 rpcrdma_rep_put(buf: buffers, rep: req->rl_reply);
1184 req->rl_reply = NULL;
1185 }
1186}
1187
1188/**
1189 * rpcrdma_buffer_get - Get a request buffer
1190 * @buffers: Buffer pool from which to obtain a buffer
1191 *
1192 * Returns a fresh rpcrdma_req, or NULL if none are available.
1193 */
1194struct rpcrdma_req *
1195rpcrdma_buffer_get(struct rpcrdma_buffer *buffers)
1196{
1197 struct rpcrdma_req *req;
1198
1199 spin_lock(lock: &buffers->rb_lock);
1200 req = list_first_entry_or_null(&buffers->rb_send_bufs,
1201 struct rpcrdma_req, rl_list);
1202 if (req)
1203 list_del_init(entry: &req->rl_list);
1204 spin_unlock(lock: &buffers->rb_lock);
1205 return req;
1206}
1207
1208/**
1209 * rpcrdma_buffer_put - Put request/reply buffers back into pool
1210 * @buffers: buffer pool
1211 * @req: object to return
1212 *
1213 */
1214void rpcrdma_buffer_put(struct rpcrdma_buffer *buffers, struct rpcrdma_req *req)
1215{
1216 rpcrdma_reply_put(buffers, req);
1217
1218 spin_lock(lock: &buffers->rb_lock);
1219 list_add(new: &req->rl_list, head: &buffers->rb_send_bufs);
1220 spin_unlock(lock: &buffers->rb_lock);
1221}
1222
1223/* Returns a pointer to a rpcrdma_regbuf object, or NULL.
1224 *
1225 * xprtrdma uses a regbuf for posting an outgoing RDMA SEND, or for
1226 * receiving the payload of RDMA RECV operations. During Long Calls
1227 * or Replies they may be registered externally via frwr_map.
1228 */
1229static struct rpcrdma_regbuf *
1230rpcrdma_regbuf_alloc(size_t size, enum dma_data_direction direction)
1231{
1232 struct rpcrdma_regbuf *rb;
1233
1234 rb = kmalloc(size: sizeof(*rb), XPRTRDMA_GFP_FLAGS);
1235 if (!rb)
1236 return NULL;
1237 rb->rg_data = kmalloc(size, XPRTRDMA_GFP_FLAGS);
1238 if (!rb->rg_data) {
1239 kfree(objp: rb);
1240 return NULL;
1241 }
1242
1243 rb->rg_device = NULL;
1244 rb->rg_direction = direction;
1245 rb->rg_iov.length = size;
1246 return rb;
1247}
1248
1249/**
1250 * rpcrdma_regbuf_realloc - re-allocate a SEND/RECV buffer
1251 * @rb: regbuf to reallocate
1252 * @size: size of buffer to be allocated, in bytes
1253 * @flags: GFP flags
1254 *
1255 * Returns true if reallocation was successful. If false is
1256 * returned, @rb is left untouched.
1257 */
1258bool rpcrdma_regbuf_realloc(struct rpcrdma_regbuf *rb, size_t size, gfp_t flags)
1259{
1260 void *buf;
1261
1262 buf = kmalloc(size, flags);
1263 if (!buf)
1264 return false;
1265
1266 rpcrdma_regbuf_dma_unmap(rb);
1267 kfree(objp: rb->rg_data);
1268
1269 rb->rg_data = buf;
1270 rb->rg_iov.length = size;
1271 return true;
1272}
1273
1274/**
1275 * __rpcrdma_regbuf_dma_map - DMA-map a regbuf
1276 * @r_xprt: controlling transport instance
1277 * @rb: regbuf to be mapped
1278 *
1279 * Returns true if the buffer is now DMA mapped to @r_xprt's device
1280 */
1281bool __rpcrdma_regbuf_dma_map(struct rpcrdma_xprt *r_xprt,
1282 struct rpcrdma_regbuf *rb)
1283{
1284 struct ib_device *device = r_xprt->rx_ep->re_id->device;
1285
1286 if (rb->rg_direction == DMA_NONE)
1287 return false;
1288
1289 rb->rg_iov.addr = ib_dma_map_single(dev: device, cpu_addr: rdmab_data(rb),
1290 size: rdmab_length(rb), direction: rb->rg_direction);
1291 if (ib_dma_mapping_error(dev: device, dma_addr: rdmab_addr(rb))) {
1292 trace_xprtrdma_dma_maperr(addr: rdmab_addr(rb));
1293 return false;
1294 }
1295
1296 rb->rg_device = device;
1297 rb->rg_iov.lkey = r_xprt->rx_ep->re_pd->local_dma_lkey;
1298 return true;
1299}
1300
1301static void rpcrdma_regbuf_dma_unmap(struct rpcrdma_regbuf *rb)
1302{
1303 if (!rb)
1304 return;
1305
1306 if (!rpcrdma_regbuf_is_mapped(rb))
1307 return;
1308
1309 ib_dma_unmap_single(dev: rb->rg_device, addr: rdmab_addr(rb), size: rdmab_length(rb),
1310 direction: rb->rg_direction);
1311 rb->rg_device = NULL;
1312}
1313
1314static void rpcrdma_regbuf_free(struct rpcrdma_regbuf *rb)
1315{
1316 rpcrdma_regbuf_dma_unmap(rb);
1317 if (rb)
1318 kfree(objp: rb->rg_data);
1319 kfree(objp: rb);
1320}
1321
1322/**
1323 * rpcrdma_post_recvs - Refill the Receive Queue
1324 * @r_xprt: controlling transport instance
1325 * @needed: current credit grant
1326 * @temp: mark Receive buffers to be deleted after one use
1327 *
1328 */
1329void rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, int needed, bool temp)
1330{
1331 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
1332 struct rpcrdma_ep *ep = r_xprt->rx_ep;
1333 struct ib_recv_wr *wr, *bad_wr;
1334 struct rpcrdma_rep *rep;
1335 int count, rc;
1336
1337 rc = 0;
1338 count = 0;
1339
1340 if (likely(ep->re_receive_count > needed))
1341 goto out;
1342 needed -= ep->re_receive_count;
1343 if (!temp)
1344 needed += RPCRDMA_MAX_RECV_BATCH;
1345
1346 if (atomic_inc_return(v: &ep->re_receiving) > 1)
1347 goto out;
1348
1349 /* fast path: all needed reps can be found on the free list */
1350 wr = NULL;
1351 while (needed) {
1352 rep = rpcrdma_rep_get_locked(buf);
1353 if (rep && rep->rr_temp) {
1354 rpcrdma_rep_destroy(rep);
1355 continue;
1356 }
1357 if (!rep)
1358 rep = rpcrdma_rep_create(r_xprt, temp);
1359 if (!rep)
1360 break;
1361 if (!rpcrdma_regbuf_dma_map(r_xprt, rb: rep->rr_rdmabuf)) {
1362 rpcrdma_rep_put(buf, rep);
1363 break;
1364 }
1365
1366 rep->rr_cid.ci_queue_id = ep->re_attr.recv_cq->res.id;
1367 trace_xprtrdma_post_recv(cid: &rep->rr_cid);
1368 rep->rr_recv_wr.next = wr;
1369 wr = &rep->rr_recv_wr;
1370 --needed;
1371 ++count;
1372 }
1373 if (!wr)
1374 goto out;
1375
1376 rc = ib_post_recv(qp: ep->re_id->qp, recv_wr: wr,
1377 bad_recv_wr: (const struct ib_recv_wr **)&bad_wr);
1378 if (rc) {
1379 trace_xprtrdma_post_recvs_err(r_xprt, status: rc);
1380 for (wr = bad_wr; wr;) {
1381 struct rpcrdma_rep *rep;
1382
1383 rep = container_of(wr, struct rpcrdma_rep, rr_recv_wr);
1384 wr = wr->next;
1385 rpcrdma_rep_put(buf, rep);
1386 --count;
1387 }
1388 }
1389 if (atomic_dec_return(v: &ep->re_receiving) > 0)
1390 complete(&ep->re_done);
1391
1392out:
1393 trace_xprtrdma_post_recvs(r_xprt, count);
1394 ep->re_receive_count += count;
1395 return;
1396}
1397

source code of linux/net/sunrpc/xprtrdma/verbs.c