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1/*
2 * Copyright (c) 2003-2007 Network Appliance, Inc. All rights reserved.
3 *
4 * This software is available to you under a choice of one of two
5 * licenses. You may choose to be licensed under the terms of the GNU
6 * General Public License (GPL) Version 2, available from the file
7 * COPYING in the main directory of this source tree, or the BSD-type
8 * license below:
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 *
14 * Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 *
17 * Redistributions in binary form must reproduce the above
18 * copyright notice, this list of conditions and the following
19 * disclaimer in the documentation and/or other materials provided
20 * with the distribution.
21 *
22 * Neither the name of the Network Appliance, Inc. nor the names of
23 * its contributors may be used to endorse or promote products
24 * derived from this software without specific prior written
25 * permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
28 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
29 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
30 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
31 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
32 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
33 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
37 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
38 */
39
40/*
41 * verbs.c
42 *
43 * Encapsulates the major functions managing:
44 * o adapters
45 * o endpoints
46 * o connections
47 * o buffer memory
48 */
49
50#include <linux/interrupt.h>
51#include <linux/slab.h>
52#include <linux/prefetch.h>
53#include <linux/sunrpc/addr.h>
54#include <asm/bitops.h>
55#include <linux/module.h> /* try_module_get()/module_put() */
56
57#include "xprt_rdma.h"
58
59/*
60 * Globals/Macros
61 */
62
63#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
64# define RPCDBG_FACILITY RPCDBG_TRANS
65#endif
66
67/*
68 * internal functions
69 */
70
71static struct workqueue_struct *rpcrdma_receive_wq;
72
73int
74rpcrdma_alloc_wq(void)
75{
76 struct workqueue_struct *recv_wq;
77
78 recv_wq = alloc_workqueue("xprtrdma_receive",
79 WQ_MEM_RECLAIM | WQ_UNBOUND | WQ_HIGHPRI,
80 0);
81 if (!recv_wq)
82 return -ENOMEM;
83
84 rpcrdma_receive_wq = recv_wq;
85 return 0;
86}
87
88void
89rpcrdma_destroy_wq(void)
90{
91 struct workqueue_struct *wq;
92
93 if (rpcrdma_receive_wq) {
94 wq = rpcrdma_receive_wq;
95 rpcrdma_receive_wq = NULL;
96 destroy_workqueue(wq);
97 }
98}
99
100static void
101rpcrdma_qp_async_error_upcall(struct ib_event *event, void *context)
102{
103 struct rpcrdma_ep *ep = context;
104
105 pr_err("RPC: %s: %s on device %s ep %p\n",
106 __func__, ib_event_msg(event->event),
107 event->device->name, context);
108 if (ep->rep_connected == 1) {
109 ep->rep_connected = -EIO;
110 rpcrdma_conn_func(ep);
111 wake_up_all(&ep->rep_connect_wait);
112 }
113}
114
115/**
116 * rpcrdma_wc_send - Invoked by RDMA provider for each polled Send WC
117 * @cq: completion queue (ignored)
118 * @wc: completed WR
119 *
120 */
121static void
122rpcrdma_wc_send(struct ib_cq *cq, struct ib_wc *wc)
123{
124 /* WARNING: Only wr_cqe and status are reliable at this point */
125 if (wc->status != IB_WC_SUCCESS && wc->status != IB_WC_WR_FLUSH_ERR)
126 pr_err("rpcrdma: Send: %s (%u/0x%x)\n",
127 ib_wc_status_msg(wc->status),
128 wc->status, wc->vendor_err);
129}
130
131static void
132rpcrdma_receive_worker(struct work_struct *work)
133{
134 struct rpcrdma_rep *rep =
135 container_of(work, struct rpcrdma_rep, rr_work);
136
137 rpcrdma_reply_handler(rep);
138}
139
140/* Perform basic sanity checking to avoid using garbage
141 * to update the credit grant value.
142 */
143static void
144rpcrdma_update_granted_credits(struct rpcrdma_rep *rep)
145{
146 struct rpcrdma_msg *rmsgp = rdmab_to_msg(rep->rr_rdmabuf);
147 struct rpcrdma_buffer *buffer = &rep->rr_rxprt->rx_buf;
148 u32 credits;
149
150 if (rep->rr_len < RPCRDMA_HDRLEN_ERR)
151 return;
152
153 credits = be32_to_cpu(rmsgp->rm_credit);
154 if (credits == 0)
155 credits = 1; /* don't deadlock */
156 else if (credits > buffer->rb_max_requests)
157 credits = buffer->rb_max_requests;
158
159 atomic_set(&buffer->rb_credits, credits);
160}
161
162/**
163 * rpcrdma_receive_wc - Invoked by RDMA provider for each polled Receive WC
164 * @cq: completion queue (ignored)
165 * @wc: completed WR
166 *
167 */
168static void
169rpcrdma_receive_wc(struct ib_cq *cq, struct ib_wc *wc)
170{
171 struct ib_cqe *cqe = wc->wr_cqe;
172 struct rpcrdma_rep *rep = container_of(cqe, struct rpcrdma_rep,
173 rr_cqe);
174
175 /* WARNING: Only wr_id and status are reliable at this point */
176 if (wc->status != IB_WC_SUCCESS)
177 goto out_fail;
178
179 /* status == SUCCESS means all fields in wc are trustworthy */
180 if (wc->opcode != IB_WC_RECV)
181 return;
182
183 dprintk("RPC: %s: rep %p opcode 'recv', length %u: success\n",
184 __func__, rep, wc->byte_len);
185
186 rep->rr_len = wc->byte_len;
187 ib_dma_sync_single_for_cpu(rep->rr_device,
188 rdmab_addr(rep->rr_rdmabuf),
189 rep->rr_len, DMA_FROM_DEVICE);
190
191 rpcrdma_update_granted_credits(rep);
192
193out_schedule:
194 queue_work(rpcrdma_receive_wq, &rep->rr_work);
195 return;
196
197out_fail:
198 if (wc->status != IB_WC_WR_FLUSH_ERR)
199 pr_err("rpcrdma: Recv: %s (%u/0x%x)\n",
200 ib_wc_status_msg(wc->status),
201 wc->status, wc->vendor_err);
202 rep->rr_len = RPCRDMA_BAD_LEN;
203 goto out_schedule;
204}
205
206static void
207rpcrdma_flush_cqs(struct rpcrdma_ep *ep)
208{
209 struct ib_wc wc;
210
211 while (ib_poll_cq(ep->rep_attr.recv_cq, 1, &wc) > 0)
212 rpcrdma_receive_wc(NULL, &wc);
213}
214
215static int
216rpcrdma_conn_upcall(struct rdma_cm_id *id, struct rdma_cm_event *event)
217{
218 struct rpcrdma_xprt *xprt = id->context;
219 struct rpcrdma_ia *ia = &xprt->rx_ia;
220 struct rpcrdma_ep *ep = &xprt->rx_ep;
221#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
222 struct sockaddr *sap = (struct sockaddr *)&ep->rep_remote_addr;
223#endif
224 struct ib_qp_attr *attr = &ia->ri_qp_attr;
225 struct ib_qp_init_attr *iattr = &ia->ri_qp_init_attr;
226 int connstate = 0;
227
228 switch (event->event) {
229 case RDMA_CM_EVENT_ADDR_RESOLVED:
230 case RDMA_CM_EVENT_ROUTE_RESOLVED:
231 ia->ri_async_rc = 0;
232 complete(&ia->ri_done);
233 break;
234 case RDMA_CM_EVENT_ADDR_ERROR:
235 ia->ri_async_rc = -EHOSTUNREACH;
236 dprintk("RPC: %s: CM address resolution error, ep 0x%p\n",
237 __func__, ep);
238 complete(&ia->ri_done);
239 break;
240 case RDMA_CM_EVENT_ROUTE_ERROR:
241 ia->ri_async_rc = -ENETUNREACH;
242 dprintk("RPC: %s: CM route resolution error, ep 0x%p\n",
243 __func__, ep);
244 complete(&ia->ri_done);
245 break;
246 case RDMA_CM_EVENT_ESTABLISHED:
247 connstate = 1;
248 ib_query_qp(ia->ri_id->qp, attr,
249 IB_QP_MAX_QP_RD_ATOMIC | IB_QP_MAX_DEST_RD_ATOMIC,
250 iattr);
251 dprintk("RPC: %s: %d responder resources"
252 " (%d initiator)\n",
253 __func__, attr->max_dest_rd_atomic,
254 attr->max_rd_atomic);
255 goto connected;
256 case RDMA_CM_EVENT_CONNECT_ERROR:
257 connstate = -ENOTCONN;
258 goto connected;
259 case RDMA_CM_EVENT_UNREACHABLE:
260 connstate = -ENETDOWN;
261 goto connected;
262 case RDMA_CM_EVENT_REJECTED:
263 connstate = -ECONNREFUSED;
264 goto connected;
265 case RDMA_CM_EVENT_DISCONNECTED:
266 connstate = -ECONNABORTED;
267 goto connected;
268 case RDMA_CM_EVENT_DEVICE_REMOVAL:
269 connstate = -ENODEV;
270connected:
271 dprintk("RPC: %s: %sconnected\n",
272 __func__, connstate > 0 ? "" : "dis");
273 atomic_set(&xprt->rx_buf.rb_credits, 1);
274 ep->rep_connected = connstate;
275 rpcrdma_conn_func(ep);
276 wake_up_all(&ep->rep_connect_wait);
277 /*FALLTHROUGH*/
278 default:
279 dprintk("RPC: %s: %pIS:%u (ep 0x%p): %s\n",
280 __func__, sap, rpc_get_port(sap), ep,
281 rdma_event_msg(event->event));
282 break;
283 }
284
285#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
286 if (connstate == 1) {
287 int ird = attr->max_dest_rd_atomic;
288 int tird = ep->rep_remote_cma.responder_resources;
289
290 pr_info("rpcrdma: connection to %pIS:%u on %s, memreg '%s', %d credits, %d responders%s\n",
291 sap, rpc_get_port(sap),
292 ia->ri_device->name,
293 ia->ri_ops->ro_displayname,
294 xprt->rx_buf.rb_max_requests,
295 ird, ird < 4 && ird < tird / 2 ? " (low!)" : "");
296 } else if (connstate < 0) {
297 pr_info("rpcrdma: connection to %pIS:%u closed (%d)\n",
298 sap, rpc_get_port(sap), connstate);
299 }
300#endif
301
302 return 0;
303}
304
305static void rpcrdma_destroy_id(struct rdma_cm_id *id)
306{
307 if (id) {
308 module_put(id->device->owner);
309 rdma_destroy_id(id);
310 }
311}
312
313static struct rdma_cm_id *
314rpcrdma_create_id(struct rpcrdma_xprt *xprt,
315 struct rpcrdma_ia *ia, struct sockaddr *addr)
316{
317 struct rdma_cm_id *id;
318 int rc;
319
320 init_completion(&ia->ri_done);
321
322 id = rdma_create_id(&init_net, rpcrdma_conn_upcall, xprt, RDMA_PS_TCP,
323 IB_QPT_RC);
324 if (IS_ERR(id)) {
325 rc = PTR_ERR(id);
326 dprintk("RPC: %s: rdma_create_id() failed %i\n",
327 __func__, rc);
328 return id;
329 }
330
331 ia->ri_async_rc = -ETIMEDOUT;
332 rc = rdma_resolve_addr(id, NULL, addr, RDMA_RESOLVE_TIMEOUT);
333 if (rc) {
334 dprintk("RPC: %s: rdma_resolve_addr() failed %i\n",
335 __func__, rc);
336 goto out;
337 }
338 wait_for_completion_interruptible_timeout(&ia->ri_done,
339 msecs_to_jiffies(RDMA_RESOLVE_TIMEOUT) + 1);
340
341 /* FIXME:
342 * Until xprtrdma supports DEVICE_REMOVAL, the provider must
343 * be pinned while there are active NFS/RDMA mounts to prevent
344 * hangs and crashes at umount time.
345 */
346 if (!ia->ri_async_rc && !try_module_get(id->device->owner)) {
347 dprintk("RPC: %s: Failed to get device module\n",
348 __func__);
349 ia->ri_async_rc = -ENODEV;
350 }
351 rc = ia->ri_async_rc;
352 if (rc)
353 goto out;
354
355 ia->ri_async_rc = -ETIMEDOUT;
356 rc = rdma_resolve_route(id, RDMA_RESOLVE_TIMEOUT);
357 if (rc) {
358 dprintk("RPC: %s: rdma_resolve_route() failed %i\n",
359 __func__, rc);
360 goto put;
361 }
362 wait_for_completion_interruptible_timeout(&ia->ri_done,
363 msecs_to_jiffies(RDMA_RESOLVE_TIMEOUT) + 1);
364 rc = ia->ri_async_rc;
365 if (rc)
366 goto put;
367
368 return id;
369put:
370 module_put(id->device->owner);
371out:
372 rdma_destroy_id(id);
373 return ERR_PTR(rc);
374}
375
376/*
377 * Drain any cq, prior to teardown.
378 */
379static void
380rpcrdma_clean_cq(struct ib_cq *cq)
381{
382 struct ib_wc wc;
383 int count = 0;
384
385 while (1 == ib_poll_cq(cq, 1, &wc))
386 ++count;
387
388 if (count)
389 dprintk("RPC: %s: flushed %d events (last 0x%x)\n",
390 __func__, count, wc.opcode);
391}
392
393/*
394 * Exported functions.
395 */
396
397/*
398 * Open and initialize an Interface Adapter.
399 * o initializes fields of struct rpcrdma_ia, including
400 * interface and provider attributes and protection zone.
401 */
402int
403rpcrdma_ia_open(struct rpcrdma_xprt *xprt, struct sockaddr *addr, int memreg)
404{
405 struct rpcrdma_ia *ia = &xprt->rx_ia;
406 int rc;
407
408 ia->ri_dma_mr = NULL;
409
410 ia->ri_id = rpcrdma_create_id(xprt, ia, addr);
411 if (IS_ERR(ia->ri_id)) {
412 rc = PTR_ERR(ia->ri_id);
413 goto out1;
414 }
415 ia->ri_device = ia->ri_id->device;
416
417 ia->ri_pd = ib_alloc_pd(ia->ri_device);
418 if (IS_ERR(ia->ri_pd)) {
419 rc = PTR_ERR(ia->ri_pd);
420 dprintk("RPC: %s: ib_alloc_pd() failed %i\n",
421 __func__, rc);
422 goto out2;
423 }
424
425 if (memreg == RPCRDMA_FRMR) {
426 if (!(ia->ri_device->attrs.device_cap_flags &
427 IB_DEVICE_MEM_MGT_EXTENSIONS) ||
428 (ia->ri_device->attrs.max_fast_reg_page_list_len == 0)) {
429 dprintk("RPC: %s: FRMR registration "
430 "not supported by HCA\n", __func__);
431 memreg = RPCRDMA_MTHCAFMR;
432 }
433 }
434 if (memreg == RPCRDMA_MTHCAFMR) {
435 if (!ia->ri_device->alloc_fmr) {
436 dprintk("RPC: %s: MTHCAFMR registration "
437 "not supported by HCA\n", __func__);
438 rc = -EINVAL;
439 goto out3;
440 }
441 }
442
443 switch (memreg) {
444 case RPCRDMA_FRMR:
445 ia->ri_ops = &rpcrdma_frwr_memreg_ops;
446 break;
447 case RPCRDMA_ALLPHYSICAL:
448 ia->ri_ops = &rpcrdma_physical_memreg_ops;
449 break;
450 case RPCRDMA_MTHCAFMR:
451 ia->ri_ops = &rpcrdma_fmr_memreg_ops;
452 break;
453 default:
454 printk(KERN_ERR "RPC: Unsupported memory "
455 "registration mode: %d\n", memreg);
456 rc = -ENOMEM;
457 goto out3;
458 }
459 dprintk("RPC: %s: memory registration strategy is '%s'\n",
460 __func__, ia->ri_ops->ro_displayname);
461
462 rwlock_init(&ia->ri_qplock);
463 return 0;
464
465out3:
466 ib_dealloc_pd(ia->ri_pd);
467 ia->ri_pd = NULL;
468out2:
469 rpcrdma_destroy_id(ia->ri_id);
470 ia->ri_id = NULL;
471out1:
472 return rc;
473}
474
475/*
476 * Clean up/close an IA.
477 * o if event handles and PD have been initialized, free them.
478 * o close the IA
479 */
480void
481rpcrdma_ia_close(struct rpcrdma_ia *ia)
482{
483 dprintk("RPC: %s: entering\n", __func__);
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 rpcrdma_destroy_id(ia->ri_id);
488 ia->ri_id = NULL;
489 }
490
491 /* If the pd is still busy, xprtrdma missed freeing a resource */
492 if (ia->ri_pd && !IS_ERR(ia->ri_pd))
493 ib_dealloc_pd(ia->ri_pd);
494}
495
496/*
497 * Create unconnected endpoint.
498 */
499int
500rpcrdma_ep_create(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia,
501 struct rpcrdma_create_data_internal *cdata)
502{
503 struct ib_cq *sendcq, *recvcq;
504 unsigned int max_qp_wr;
505 int rc;
506
507 if (ia->ri_device->attrs.max_sge < RPCRDMA_MAX_IOVS) {
508 dprintk("RPC: %s: insufficient sge's available\n",
509 __func__);
510 return -ENOMEM;
511 }
512
513 if (ia->ri_device->attrs.max_qp_wr <= RPCRDMA_BACKWARD_WRS) {
514 dprintk("RPC: %s: insufficient wqe's available\n",
515 __func__);
516 return -ENOMEM;
517 }
518 max_qp_wr = ia->ri_device->attrs.max_qp_wr - RPCRDMA_BACKWARD_WRS;
519
520 /* check provider's send/recv wr limits */
521 if (cdata->max_requests > max_qp_wr)
522 cdata->max_requests = max_qp_wr;
523
524 ep->rep_attr.event_handler = rpcrdma_qp_async_error_upcall;
525 ep->rep_attr.qp_context = ep;
526 ep->rep_attr.srq = NULL;
527 ep->rep_attr.cap.max_send_wr = cdata->max_requests;
528 ep->rep_attr.cap.max_send_wr += RPCRDMA_BACKWARD_WRS;
529 rc = ia->ri_ops->ro_open(ia, ep, cdata);
530 if (rc)
531 return rc;
532 ep->rep_attr.cap.max_recv_wr = cdata->max_requests;
533 ep->rep_attr.cap.max_recv_wr += RPCRDMA_BACKWARD_WRS;
534 ep->rep_attr.cap.max_send_sge = RPCRDMA_MAX_IOVS;
535 ep->rep_attr.cap.max_recv_sge = 1;
536 ep->rep_attr.cap.max_inline_data = 0;
537 ep->rep_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
538 ep->rep_attr.qp_type = IB_QPT_RC;
539 ep->rep_attr.port_num = ~0;
540
541 dprintk("RPC: %s: requested max: dtos: send %d recv %d; "
542 "iovs: send %d recv %d\n",
543 __func__,
544 ep->rep_attr.cap.max_send_wr,
545 ep->rep_attr.cap.max_recv_wr,
546 ep->rep_attr.cap.max_send_sge,
547 ep->rep_attr.cap.max_recv_sge);
548
549 /* set trigger for requesting send completion */
550 ep->rep_cqinit = ep->rep_attr.cap.max_send_wr/2 - 1;
551 if (ep->rep_cqinit <= 2)
552 ep->rep_cqinit = 0; /* always signal? */
553 INIT_CQCOUNT(ep);
554 init_waitqueue_head(&ep->rep_connect_wait);
555 INIT_DELAYED_WORK(&ep->rep_connect_worker, rpcrdma_connect_worker);
556
557 sendcq = ib_alloc_cq(ia->ri_device, NULL,
558 ep->rep_attr.cap.max_send_wr + 1,
559 0, IB_POLL_SOFTIRQ);
560 if (IS_ERR(sendcq)) {
561 rc = PTR_ERR(sendcq);
562 dprintk("RPC: %s: failed to create send CQ: %i\n",
563 __func__, rc);
564 goto out1;
565 }
566
567 recvcq = ib_alloc_cq(ia->ri_device, NULL,
568 ep->rep_attr.cap.max_recv_wr + 1,
569 0, IB_POLL_SOFTIRQ);
570 if (IS_ERR(recvcq)) {
571 rc = PTR_ERR(recvcq);
572 dprintk("RPC: %s: failed to create recv CQ: %i\n",
573 __func__, rc);
574 goto out2;
575 }
576
577 ep->rep_attr.send_cq = sendcq;
578 ep->rep_attr.recv_cq = recvcq;
579
580 /* Initialize cma parameters */
581
582 /* RPC/RDMA does not use private data */
583 ep->rep_remote_cma.private_data = NULL;
584 ep->rep_remote_cma.private_data_len = 0;
585
586 /* Client offers RDMA Read but does not initiate */
587 ep->rep_remote_cma.initiator_depth = 0;
588 if (ia->ri_device->attrs.max_qp_rd_atom > 32) /* arbitrary but <= 255 */
589 ep->rep_remote_cma.responder_resources = 32;
590 else
591 ep->rep_remote_cma.responder_resources =
592 ia->ri_device->attrs.max_qp_rd_atom;
593
594 ep->rep_remote_cma.retry_count = 7;
595 ep->rep_remote_cma.flow_control = 0;
596 ep->rep_remote_cma.rnr_retry_count = 0;
597
598 return 0;
599
600out2:
601 ib_free_cq(sendcq);
602out1:
603 if (ia->ri_dma_mr)
604 ib_dereg_mr(ia->ri_dma_mr);
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 int rc;
619
620 dprintk("RPC: %s: entering, connected is %d\n",
621 __func__, ep->rep_connected);
622
623 cancel_delayed_work_sync(&ep->rep_connect_worker);
624
625 if (ia->ri_id->qp)
626 rpcrdma_ep_disconnect(ep, ia);
627
628 rpcrdma_clean_cq(ep->rep_attr.recv_cq);
629 rpcrdma_clean_cq(ep->rep_attr.send_cq);
630
631 if (ia->ri_id->qp) {
632 rdma_destroy_qp(ia->ri_id);
633 ia->ri_id->qp = NULL;
634 }
635
636 ib_free_cq(ep->rep_attr.recv_cq);
637 ib_free_cq(ep->rep_attr.send_cq);
638
639 if (ia->ri_dma_mr) {
640 rc = ib_dereg_mr(ia->ri_dma_mr);
641 dprintk("RPC: %s: ib_dereg_mr returned %i\n",
642 __func__, rc);
643 }
644}
645
646/*
647 * Connect unconnected endpoint.
648 */
649int
650rpcrdma_ep_connect(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
651{
652 struct rdma_cm_id *id, *old;
653 int rc = 0;
654 int retry_count = 0;
655
656 if (ep->rep_connected != 0) {
657 struct rpcrdma_xprt *xprt;
658retry:
659 dprintk("RPC: %s: reconnecting...\n", __func__);
660
661 rpcrdma_ep_disconnect(ep, ia);
662 rpcrdma_flush_cqs(ep);
663
664 xprt = container_of(ia, struct rpcrdma_xprt, rx_ia);
665 id = rpcrdma_create_id(xprt, ia,
666 (struct sockaddr *)&xprt->rx_data.addr);
667 if (IS_ERR(id)) {
668 rc = -EHOSTUNREACH;
669 goto out;
670 }
671 /* TEMP TEMP TEMP - fail if new device:
672 * Deregister/remarshal *all* requests!
673 * Close and recreate adapter, pd, etc!
674 * Re-determine all attributes still sane!
675 * More stuff I haven't thought of!
676 * Rrrgh!
677 */
678 if (ia->ri_device != id->device) {
679 printk("RPC: %s: can't reconnect on "
680 "different device!\n", __func__);
681 rpcrdma_destroy_id(id);
682 rc = -ENETUNREACH;
683 goto out;
684 }
685 /* END TEMP */
686 rc = rdma_create_qp(id, ia->ri_pd, &ep->rep_attr);
687 if (rc) {
688 dprintk("RPC: %s: rdma_create_qp failed %i\n",
689 __func__, rc);
690 rpcrdma_destroy_id(id);
691 rc = -ENETUNREACH;
692 goto out;
693 }
694
695 write_lock(&ia->ri_qplock);
696 old = ia->ri_id;
697 ia->ri_id = id;
698 write_unlock(&ia->ri_qplock);
699
700 rdma_destroy_qp(old);
701 rpcrdma_destroy_id(old);
702 } else {
703 dprintk("RPC: %s: connecting...\n", __func__);
704 rc = rdma_create_qp(ia->ri_id, ia->ri_pd, &ep->rep_attr);
705 if (rc) {
706 dprintk("RPC: %s: rdma_create_qp failed %i\n",
707 __func__, rc);
708 /* do not update ep->rep_connected */
709 return -ENETUNREACH;
710 }
711 }
712
713 ep->rep_connected = 0;
714
715 rc = rdma_connect(ia->ri_id, &ep->rep_remote_cma);
716 if (rc) {
717 dprintk("RPC: %s: rdma_connect() failed with %i\n",
718 __func__, rc);
719 goto out;
720 }
721
722 wait_event_interruptible(ep->rep_connect_wait, ep->rep_connected != 0);
723
724 /*
725 * Check state. A non-peer reject indicates no listener
726 * (ECONNREFUSED), which may be a transient state. All
727 * others indicate a transport condition which has already
728 * undergone a best-effort.
729 */
730 if (ep->rep_connected == -ECONNREFUSED &&
731 ++retry_count <= RDMA_CONNECT_RETRY_MAX) {
732 dprintk("RPC: %s: non-peer_reject, retry\n", __func__);
733 goto retry;
734 }
735 if (ep->rep_connected <= 0) {
736 /* Sometimes, the only way to reliably connect to remote
737 * CMs is to use same nonzero values for ORD and IRD. */
738 if (retry_count++ <= RDMA_CONNECT_RETRY_MAX + 1 &&
739 (ep->rep_remote_cma.responder_resources == 0 ||
740 ep->rep_remote_cma.initiator_depth !=
741 ep->rep_remote_cma.responder_resources)) {
742 if (ep->rep_remote_cma.responder_resources == 0)
743 ep->rep_remote_cma.responder_resources = 1;
744 ep->rep_remote_cma.initiator_depth =
745 ep->rep_remote_cma.responder_resources;
746 goto retry;
747 }
748 rc = ep->rep_connected;
749 } else {
750 struct rpcrdma_xprt *r_xprt;
751 unsigned int extras;
752
753 dprintk("RPC: %s: connected\n", __func__);
754
755 r_xprt = container_of(ia, struct rpcrdma_xprt, rx_ia);
756 extras = r_xprt->rx_buf.rb_bc_srv_max_requests;
757
758 if (extras) {
759 rc = rpcrdma_ep_post_extra_recv(r_xprt, extras);
760 if (rc) {
761 pr_warn("%s: rpcrdma_ep_post_extra_recv: %i\n",
762 __func__, rc);
763 rc = 0;
764 }
765 }
766 }
767
768out:
769 if (rc)
770 ep->rep_connected = rc;
771 return rc;
772}
773
774/*
775 * rpcrdma_ep_disconnect
776 *
777 * This is separate from destroy to facilitate the ability
778 * to reconnect without recreating the endpoint.
779 *
780 * This call is not reentrant, and must not be made in parallel
781 * on the same endpoint.
782 */
783void
784rpcrdma_ep_disconnect(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
785{
786 int rc;
787
788 rpcrdma_flush_cqs(ep);
789 rc = rdma_disconnect(ia->ri_id);
790 if (!rc) {
791 /* returns without wait if not connected */
792 wait_event_interruptible(ep->rep_connect_wait,
793 ep->rep_connected != 1);
794 dprintk("RPC: %s: after wait, %sconnected\n", __func__,
795 (ep->rep_connected == 1) ? "still " : "dis");
796 } else {
797 dprintk("RPC: %s: rdma_disconnect %i\n", __func__, rc);
798 ep->rep_connected = rc;
799 }
800}
801
802struct rpcrdma_req *
803rpcrdma_create_req(struct rpcrdma_xprt *r_xprt)
804{
805 struct rpcrdma_buffer *buffer = &r_xprt->rx_buf;
806 struct rpcrdma_req *req;
807
808 req = kzalloc(sizeof(*req), GFP_KERNEL);
809 if (req == NULL)
810 return ERR_PTR(-ENOMEM);
811
812 INIT_LIST_HEAD(&req->rl_free);
813 spin_lock(&buffer->rb_reqslock);
814 list_add(&req->rl_all, &buffer->rb_allreqs);
815 spin_unlock(&buffer->rb_reqslock);
816 req->rl_cqe.done = rpcrdma_wc_send;
817 req->rl_buffer = &r_xprt->rx_buf;
818 return req;
819}
820
821struct rpcrdma_rep *
822rpcrdma_create_rep(struct rpcrdma_xprt *r_xprt)
823{
824 struct rpcrdma_create_data_internal *cdata = &r_xprt->rx_data;
825 struct rpcrdma_ia *ia = &r_xprt->rx_ia;
826 struct rpcrdma_rep *rep;
827 int rc;
828
829 rc = -ENOMEM;
830 rep = kzalloc(sizeof(*rep), GFP_KERNEL);
831 if (rep == NULL)
832 goto out;
833
834 rep->rr_rdmabuf = rpcrdma_alloc_regbuf(ia, cdata->inline_rsize,
835 GFP_KERNEL);
836 if (IS_ERR(rep->rr_rdmabuf)) {
837 rc = PTR_ERR(rep->rr_rdmabuf);
838 goto out_free;
839 }
840
841 rep->rr_device = ia->ri_device;
842 rep->rr_cqe.done = rpcrdma_receive_wc;
843 rep->rr_rxprt = r_xprt;
844 INIT_WORK(&rep->rr_work, rpcrdma_receive_worker);
845 return rep;
846
847out_free:
848 kfree(rep);
849out:
850 return ERR_PTR(rc);
851}
852
853int
854rpcrdma_buffer_create(struct rpcrdma_xprt *r_xprt)
855{
856 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
857 struct rpcrdma_ia *ia = &r_xprt->rx_ia;
858 int i, rc;
859
860 buf->rb_max_requests = r_xprt->rx_data.max_requests;
861 buf->rb_bc_srv_max_requests = 0;
862 spin_lock_init(&buf->rb_lock);
863 atomic_set(&buf->rb_credits, 1);
864
865 rc = ia->ri_ops->ro_init(r_xprt);
866 if (rc)
867 goto out;
868
869 INIT_LIST_HEAD(&buf->rb_send_bufs);
870 INIT_LIST_HEAD(&buf->rb_allreqs);
871 spin_lock_init(&buf->rb_reqslock);
872 for (i = 0; i < buf->rb_max_requests; i++) {
873 struct rpcrdma_req *req;
874
875 req = rpcrdma_create_req(r_xprt);
876 if (IS_ERR(req)) {
877 dprintk("RPC: %s: request buffer %d alloc"
878 " failed\n", __func__, i);
879 rc = PTR_ERR(req);
880 goto out;
881 }
882 req->rl_backchannel = false;
883 list_add(&req->rl_free, &buf->rb_send_bufs);
884 }
885
886 INIT_LIST_HEAD(&buf->rb_recv_bufs);
887 for (i = 0; i < buf->rb_max_requests + 2; i++) {
888 struct rpcrdma_rep *rep;
889
890 rep = rpcrdma_create_rep(r_xprt);
891 if (IS_ERR(rep)) {
892 dprintk("RPC: %s: reply buffer %d alloc failed\n",
893 __func__, i);
894 rc = PTR_ERR(rep);
895 goto out;
896 }
897 list_add(&rep->rr_list, &buf->rb_recv_bufs);
898 }
899
900 return 0;
901out:
902 rpcrdma_buffer_destroy(buf);
903 return rc;
904}
905
906static struct rpcrdma_req *
907rpcrdma_buffer_get_req_locked(struct rpcrdma_buffer *buf)
908{
909 struct rpcrdma_req *req;
910
911 req = list_first_entry(&buf->rb_send_bufs,
912 struct rpcrdma_req, rl_free);
913 list_del(&req->rl_free);
914 return req;
915}
916
917static struct rpcrdma_rep *
918rpcrdma_buffer_get_rep_locked(struct rpcrdma_buffer *buf)
919{
920 struct rpcrdma_rep *rep;
921
922 rep = list_first_entry(&buf->rb_recv_bufs,
923 struct rpcrdma_rep, rr_list);
924 list_del(&rep->rr_list);
925 return rep;
926}
927
928static void
929rpcrdma_destroy_rep(struct rpcrdma_ia *ia, struct rpcrdma_rep *rep)
930{
931 rpcrdma_free_regbuf(ia, rep->rr_rdmabuf);
932 kfree(rep);
933}
934
935void
936rpcrdma_destroy_req(struct rpcrdma_ia *ia, struct rpcrdma_req *req)
937{
938 rpcrdma_free_regbuf(ia, req->rl_sendbuf);
939 rpcrdma_free_regbuf(ia, req->rl_rdmabuf);
940 kfree(req);
941}
942
943void
944rpcrdma_buffer_destroy(struct rpcrdma_buffer *buf)
945{
946 struct rpcrdma_ia *ia = rdmab_to_ia(buf);
947
948 while (!list_empty(&buf->rb_recv_bufs)) {
949 struct rpcrdma_rep *rep;
950
951 rep = rpcrdma_buffer_get_rep_locked(buf);
952 rpcrdma_destroy_rep(ia, rep);
953 }
954
955 spin_lock(&buf->rb_reqslock);
956 while (!list_empty(&buf->rb_allreqs)) {
957 struct rpcrdma_req *req;
958
959 req = list_first_entry(&buf->rb_allreqs,
960 struct rpcrdma_req, rl_all);
961 list_del(&req->rl_all);
962
963 spin_unlock(&buf->rb_reqslock);
964 rpcrdma_destroy_req(ia, req);
965 spin_lock(&buf->rb_reqslock);
966 }
967 spin_unlock(&buf->rb_reqslock);
968
969 ia->ri_ops->ro_destroy(buf);
970}
971
972struct rpcrdma_mw *
973rpcrdma_get_mw(struct rpcrdma_xprt *r_xprt)
974{
975 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
976 struct rpcrdma_mw *mw = NULL;
977
978 spin_lock(&buf->rb_mwlock);
979 if (!list_empty(&buf->rb_mws)) {
980 mw = list_first_entry(&buf->rb_mws,
981 struct rpcrdma_mw, mw_list);
982 list_del_init(&mw->mw_list);
983 }
984 spin_unlock(&buf->rb_mwlock);
985
986 if (!mw)
987 pr_err("RPC: %s: no MWs available\n", __func__);
988 return mw;
989}
990
991void
992rpcrdma_put_mw(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mw *mw)
993{
994 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
995
996 spin_lock(&buf->rb_mwlock);
997 list_add_tail(&mw->mw_list, &buf->rb_mws);
998 spin_unlock(&buf->rb_mwlock);
999}
1000
1001/*
1002 * Get a set of request/reply buffers.
1003 *
1004 * Reply buffer (if available) is attached to send buffer upon return.
1005 */
1006struct rpcrdma_req *
1007rpcrdma_buffer_get(struct rpcrdma_buffer *buffers)
1008{
1009 struct rpcrdma_req *req;
1010
1011 spin_lock(&buffers->rb_lock);
1012 if (list_empty(&buffers->rb_send_bufs))
1013 goto out_reqbuf;
1014 req = rpcrdma_buffer_get_req_locked(buffers);
1015 if (list_empty(&buffers->rb_recv_bufs))
1016 goto out_repbuf;
1017 req->rl_reply = rpcrdma_buffer_get_rep_locked(buffers);
1018 spin_unlock(&buffers->rb_lock);
1019 return req;
1020
1021out_reqbuf:
1022 spin_unlock(&buffers->rb_lock);
1023 pr_warn("RPC: %s: out of request buffers\n", __func__);
1024 return NULL;
1025out_repbuf:
1026 spin_unlock(&buffers->rb_lock);
1027 pr_warn("RPC: %s: out of reply buffers\n", __func__);
1028 req->rl_reply = NULL;
1029 return req;
1030}
1031
1032/*
1033 * Put request/reply buffers back into pool.
1034 * Pre-decrement counter/array index.
1035 */
1036void
1037rpcrdma_buffer_put(struct rpcrdma_req *req)
1038{
1039 struct rpcrdma_buffer *buffers = req->rl_buffer;
1040 struct rpcrdma_rep *rep = req->rl_reply;
1041
1042 req->rl_niovs = 0;
1043 req->rl_reply = NULL;
1044
1045 spin_lock(&buffers->rb_lock);
1046 list_add_tail(&req->rl_free, &buffers->rb_send_bufs);
1047 if (rep)
1048 list_add_tail(&rep->rr_list, &buffers->rb_recv_bufs);
1049 spin_unlock(&buffers->rb_lock);
1050}
1051
1052/*
1053 * Recover reply buffers from pool.
1054 * This happens when recovering from disconnect.
1055 */
1056void
1057rpcrdma_recv_buffer_get(struct rpcrdma_req *req)
1058{
1059 struct rpcrdma_buffer *buffers = req->rl_buffer;
1060
1061 spin_lock(&buffers->rb_lock);
1062 if (!list_empty(&buffers->rb_recv_bufs))
1063 req->rl_reply = rpcrdma_buffer_get_rep_locked(buffers);
1064 spin_unlock(&buffers->rb_lock);
1065}
1066
1067/*
1068 * Put reply buffers back into pool when not attached to
1069 * request. This happens in error conditions.
1070 */
1071void
1072rpcrdma_recv_buffer_put(struct rpcrdma_rep *rep)
1073{
1074 struct rpcrdma_buffer *buffers = &rep->rr_rxprt->rx_buf;
1075
1076 spin_lock(&buffers->rb_lock);
1077 list_add_tail(&rep->rr_list, &buffers->rb_recv_bufs);
1078 spin_unlock(&buffers->rb_lock);
1079}
1080
1081/*
1082 * Wrappers for internal-use kmalloc memory registration, used by buffer code.
1083 */
1084
1085void
1086rpcrdma_mapping_error(struct rpcrdma_mr_seg *seg)
1087{
1088 dprintk("RPC: map_one: offset %p iova %llx len %zu\n",
1089 seg->mr_offset,
1090 (unsigned long long)seg->mr_dma, seg->mr_dmalen);
1091}
1092
1093/**
1094 * rpcrdma_alloc_regbuf - kmalloc and register memory for SEND/RECV buffers
1095 * @ia: controlling rpcrdma_ia
1096 * @size: size of buffer to be allocated, in bytes
1097 * @flags: GFP flags
1098 *
1099 * Returns pointer to private header of an area of internally
1100 * registered memory, or an ERR_PTR. The registered buffer follows
1101 * the end of the private header.
1102 *
1103 * xprtrdma uses a regbuf for posting an outgoing RDMA SEND, or for
1104 * receiving the payload of RDMA RECV operations. regbufs are not
1105 * used for RDMA READ/WRITE operations, thus are registered only for
1106 * LOCAL access.
1107 */
1108struct rpcrdma_regbuf *
1109rpcrdma_alloc_regbuf(struct rpcrdma_ia *ia, size_t size, gfp_t flags)
1110{
1111 struct rpcrdma_regbuf *rb;
1112 struct ib_sge *iov;
1113
1114 rb = kmalloc(sizeof(*rb) + size, flags);
1115 if (rb == NULL)
1116 goto out;
1117
1118 iov = &rb->rg_iov;
1119 iov->addr = ib_dma_map_single(ia->ri_device,
1120 (void *)rb->rg_base, size,
1121 DMA_BIDIRECTIONAL);
1122 if (ib_dma_mapping_error(ia->ri_device, iov->addr))
1123 goto out_free;
1124
1125 iov->length = size;
1126 iov->lkey = ia->ri_pd->local_dma_lkey;
1127 rb->rg_size = size;
1128 rb->rg_owner = NULL;
1129 return rb;
1130
1131out_free:
1132 kfree(rb);
1133out:
1134 return ERR_PTR(-ENOMEM);
1135}
1136
1137/**
1138 * rpcrdma_free_regbuf - deregister and free registered buffer
1139 * @ia: controlling rpcrdma_ia
1140 * @rb: regbuf to be deregistered and freed
1141 */
1142void
1143rpcrdma_free_regbuf(struct rpcrdma_ia *ia, struct rpcrdma_regbuf *rb)
1144{
1145 struct ib_sge *iov;
1146
1147 if (!rb)
1148 return;
1149
1150 iov = &rb->rg_iov;
1151 ib_dma_unmap_single(ia->ri_device,
1152 iov->addr, iov->length, DMA_BIDIRECTIONAL);
1153 kfree(rb);
1154}
1155
1156/*
1157 * Prepost any receive buffer, then post send.
1158 *
1159 * Receive buffer is donated to hardware, reclaimed upon recv completion.
1160 */
1161int
1162rpcrdma_ep_post(struct rpcrdma_ia *ia,
1163 struct rpcrdma_ep *ep,
1164 struct rpcrdma_req *req)
1165{
1166 struct ib_device *device = ia->ri_device;
1167 struct ib_send_wr send_wr, *send_wr_fail;
1168 struct rpcrdma_rep *rep = req->rl_reply;
1169 struct ib_sge *iov = req->rl_send_iov;
1170 int i, rc;
1171
1172 if (rep) {
1173 rc = rpcrdma_ep_post_recv(ia, ep, rep);
1174 if (rc)
1175 goto out;
1176 req->rl_reply = NULL;
1177 }
1178
1179 send_wr.next = NULL;
1180 send_wr.wr_cqe = &req->rl_cqe;
1181 send_wr.sg_list = iov;
1182 send_wr.num_sge = req->rl_niovs;
1183 send_wr.opcode = IB_WR_SEND;
1184
1185 for (i = 0; i < send_wr.num_sge; i++)
1186 ib_dma_sync_single_for_device(device, iov[i].addr,
1187 iov[i].length, DMA_TO_DEVICE);
1188 dprintk("RPC: %s: posting %d s/g entries\n",
1189 __func__, send_wr.num_sge);
1190
1191 if (DECR_CQCOUNT(ep) > 0)
1192 send_wr.send_flags = 0;
1193 else { /* Provider must take a send completion every now and then */
1194 INIT_CQCOUNT(ep);
1195 send_wr.send_flags = IB_SEND_SIGNALED;
1196 }
1197
1198 rc = ib_post_send(ia->ri_id->qp, &send_wr, &send_wr_fail);
1199 if (rc)
1200 dprintk("RPC: %s: ib_post_send returned %i\n", __func__,
1201 rc);
1202out:
1203 return rc;
1204}
1205
1206/*
1207 * (Re)post a receive buffer.
1208 */
1209int
1210rpcrdma_ep_post_recv(struct rpcrdma_ia *ia,
1211 struct rpcrdma_ep *ep,
1212 struct rpcrdma_rep *rep)
1213{
1214 struct ib_recv_wr recv_wr, *recv_wr_fail;
1215 int rc;
1216
1217 recv_wr.next = NULL;
1218 recv_wr.wr_cqe = &rep->rr_cqe;
1219 recv_wr.sg_list = &rep->rr_rdmabuf->rg_iov;
1220 recv_wr.num_sge = 1;
1221
1222 ib_dma_sync_single_for_cpu(ia->ri_device,
1223 rdmab_addr(rep->rr_rdmabuf),
1224 rdmab_length(rep->rr_rdmabuf),
1225 DMA_BIDIRECTIONAL);
1226
1227 rc = ib_post_recv(ia->ri_id->qp, &recv_wr, &recv_wr_fail);
1228
1229 if (rc)
1230 dprintk("RPC: %s: ib_post_recv returned %i\n", __func__,
1231 rc);
1232 return rc;
1233}
1234
1235/**
1236 * rpcrdma_ep_post_extra_recv - Post buffers for incoming backchannel requests
1237 * @r_xprt: transport associated with these backchannel resources
1238 * @min_reqs: minimum number of incoming requests expected
1239 *
1240 * Returns zero if all requested buffers were posted, or a negative errno.
1241 */
1242int
1243rpcrdma_ep_post_extra_recv(struct rpcrdma_xprt *r_xprt, unsigned int count)
1244{
1245 struct rpcrdma_buffer *buffers = &r_xprt->rx_buf;
1246 struct rpcrdma_ia *ia = &r_xprt->rx_ia;
1247 struct rpcrdma_ep *ep = &r_xprt->rx_ep;
1248 struct rpcrdma_rep *rep;
1249 int rc;
1250
1251 while (count--) {
1252 spin_lock(&buffers->rb_lock);
1253 if (list_empty(&buffers->rb_recv_bufs))
1254 goto out_reqbuf;
1255 rep = rpcrdma_buffer_get_rep_locked(buffers);
1256 spin_unlock(&buffers->rb_lock);
1257
1258 rc = rpcrdma_ep_post_recv(ia, ep, rep);
1259 if (rc)
1260 goto out_rc;
1261 }
1262
1263 return 0;
1264
1265out_reqbuf:
1266 spin_unlock(&buffers->rb_lock);
1267 pr_warn("%s: no extra receive buffers\n", __func__);
1268 return -ENOMEM;
1269
1270out_rc:
1271 rpcrdma_recv_buffer_put(rep);
1272 return rc;
1273}
1274
1275/* How many chunk list items fit within our inline buffers?
1276 */
1277unsigned int
1278rpcrdma_max_segments(struct rpcrdma_xprt *r_xprt)
1279{
1280 struct rpcrdma_create_data_internal *cdata = &r_xprt->rx_data;
1281 int bytes, segments;
1282
1283 bytes = min_t(unsigned int, cdata->inline_wsize, cdata->inline_rsize);
1284 bytes -= RPCRDMA_HDRLEN_MIN;
1285 if (bytes < sizeof(struct rpcrdma_segment) * 2) {
1286 pr_warn("RPC: %s: inline threshold too small\n",
1287 __func__);
1288 return 0;
1289 }
1290
1291 segments = 1 << (fls(bytes / sizeof(struct rpcrdma_segment)) - 1);
1292 dprintk("RPC: %s: max chunk list size = %d segments\n",
1293 __func__, segments);
1294 return segments;
1295}
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(&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(id->qp);
102
103 /* Deferred Reply processing might have scheduled
104 * local invalidations.
105 */
106 ib_drain_sq(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(&ep->re_force_disconnect, 1, 1))
118 xprt_force_disconnect(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(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, &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, &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(&rep->rr_hdrbuf, 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(rdmab_device(rep->rr_rdmabuf),
178 rdmab_addr(rep->rr_rdmabuf),
179 wc->byte_len, 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(&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(pmsg->cp_send_size);
203 wsize = rpcrdma_decode_buffer_size(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, &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(&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(id))
296 return id;
297
298 ep->re_async_rc = -ETIMEDOUT;
299 rc = rdma_resolve_addr(id, NULL, (struct sockaddr *)&xprt->addr,
300 RDMA_RESOLVE_TIMEOUT);
301 if (rc)
302 goto out;
303 rc = wait_for_completion_interruptible_timeout(&ep->re_done, 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(&ep->re_done, 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(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(ep->re_id);
335 ep->re_id->qp = NULL;
336 }
337
338 if (ep->re_attr.recv_cq)
339 ib_free_cq(ep->re_attr.recv_cq);
340 ep->re_attr.recv_cq = NULL;
341 if (ep->re_attr.send_cq)
342 ib_free_cq(ep->re_attr.send_cq);
343 ep->re_attr.send_cq = NULL;
344
345 if (ep->re_pd)
346 ib_dealloc_pd(ep->re_pd);
347 ep->re_pd = NULL;
348
349 kfree(ep);
350 module_put(THIS_MODULE);
351}
352
353static noinline void rpcrdma_ep_get(struct rpcrdma_ep *ep)
354{
355 kref_get(&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(&ep->re_kref, 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(sizeof(*ep), XPRTRDMA_GFP_FLAGS);
376 if (!ep)
377 return -ENOTCONN;
378 ep->re_xprt = &r_xprt->rx_xprt;
379 kref_init(&ep->re_kref);
380
381 id = rpcrdma_create_id(r_xprt, ep);
382 if (IS_ERR(id)) {
383 kfree(ep);
384 return PTR_ERR(id);
385 }
386 __module_get(THIS_MODULE);
387 device = id->device;
388 ep->re_id = id;
389 reinit_completion(&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(device, r_xprt,
411 ep->re_attr.cap.max_send_wr,
412 IB_POLL_WORKQUEUE);
413 if (IS_ERR(ep->re_attr.send_cq)) {
414 rc = PTR_ERR(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(device, r_xprt,
420 ep->re_attr.cap.max_recv_wr,
421 IB_POLL_WORKQUEUE);
422 if (IS_ERR(ep->re_attr.recv_cq)) {
423 rc = PTR_ERR(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(ep->re_inline_send);
438 pmsg->cp_recv_size = rpcrdma_encode_buffer_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(ep->re_pd)) {
462 rc = PTR_ERR(ep->re_pd);
463 ep->re_pd = NULL;
464 goto out_destroy;
465 }
466
467 rc = rdma_create_qp(id, ep->re_pd, &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, 1, true);
505
506 rc = rdma_connect(ep->re_id, &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(buf->rb_sc_ctxs[i]);
599 kfree(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(&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(i, 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(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, 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(&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, next_tail);
725
726 /* ORDER: item must be accessed _before_ tail is updated */
727 rpcrdma_sendctx_unmap(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(&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(sizeof(*mr), XPRTRDMA_GFP_FLAGS,
751 ibdev_to_node(device));
752 if (!mr)
753 break;
754
755 rc = frwr_mr_init(r_xprt, mr);
756 if (rc) {
757 kfree(mr);
758 break;
759 }
760
761 spin_lock(&buf->rb_lock);
762 rpcrdma_mr_push(mr, &buf->rb_mrs);
763 list_add(&mr->mr_all, &buf->rb_all_mrs);
764 spin_unlock(&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(&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(system_highpri_wq, &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(sizeof(*req), XPRTRDMA_GFP_FLAGS);
815 if (req == NULL)
816 goto out1;
817
818 req->rl_sendbuf = rpcrdma_regbuf_alloc(size, DMA_TO_DEVICE);
819 if (!req->rl_sendbuf)
820 goto out2;
821
822 req->rl_recvbuf = rpcrdma_regbuf_alloc(size, DMA_NONE);
823 if (!req->rl_recvbuf)
824 goto out3;
825
826 INIT_LIST_HEAD(&req->rl_free_mrs);
827 INIT_LIST_HEAD(&req->rl_registered);
828 spin_lock(&buffer->rb_lock);
829 list_add(&req->rl_all, &buffer->rb_allreqs);
830 spin_unlock(&buffer->rb_lock);
831 return req;
832
833out3:
834 rpcrdma_regbuf_free(req->rl_sendbuf);
835out2:
836 kfree(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(__roundup_pow_of_two(maxhdrsize),
858 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(&req->rl_hdrbuf, rdmab_data(rb), 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(req->rl_rdmabuf);
900 req->rl_rdmabuf = NULL;
901
902 rpcrdma_regbuf_dma_unmap(req->rl_sendbuf);
903 rpcrdma_regbuf_dma_unmap(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(sizeof(*rep), XPRTRDMA_GFP_FLAGS);
930 if (rep == NULL)
931 goto out;
932
933 rep->rr_rdmabuf = rpcrdma_regbuf_alloc(r_xprt->rx_ep->re_inline_recv,
934 DMA_FROM_DEVICE);
935 if (!rep->rr_rdmabuf)
936 goto out_free;
937
938 if (!rpcrdma_regbuf_dma_map(r_xprt, rep->rr_rdmabuf))
939 goto out_free_regbuf;
940
941 rep->rr_cid.ci_completion_id =
942 atomic_inc_return(&r_xprt->rx_ep->re_completion_ids);
943
944 xdr_buf_init(&rep->rr_hdrbuf, rdmab_data(rep->rr_rdmabuf),
945 rdmab_length(rep->rr_rdmabuf));
946 rep->rr_cqe.done = rpcrdma_wc_receive;
947 rep->rr_rxprt = r_xprt;
948 rep->rr_recv_wr.next = NULL;
949 rep->rr_recv_wr.wr_cqe = &rep->rr_cqe;
950 rep->rr_recv_wr.sg_list = &rep->rr_rdmabuf->rg_iov;
951 rep->rr_recv_wr.num_sge = 1;
952 rep->rr_temp = temp;
953
954 spin_lock(&buf->rb_lock);
955 list_add(&rep->rr_all, &buf->rb_all_reps);
956 spin_unlock(&buf->rb_lock);
957 return rep;
958
959out_free_regbuf:
960 rpcrdma_regbuf_free(rep->rr_rdmabuf);
961out_free:
962 kfree(rep);
963out:
964 return NULL;
965}
966
967static void rpcrdma_rep_free(struct rpcrdma_rep *rep)
968{
969 rpcrdma_regbuf_free(rep->rr_rdmabuf);
970 kfree(rep);
971}
972
973static void rpcrdma_rep_destroy(struct rpcrdma_rep *rep)
974{
975 struct rpcrdma_buffer *buf = &rep->rr_rxprt->rx_buf;
976
977 spin_lock(&buf->rb_lock);
978 list_del(&rep->rr_all);
979 spin_unlock(&buf->rb_lock);
980
981 rpcrdma_rep_free(rep);
982}
983
984static struct rpcrdma_rep *rpcrdma_rep_get_locked(struct rpcrdma_buffer *buf)
985{
986 struct llist_node *node;
987
988 /* Calls to llist_del_first are required to be serialized */
989 node = llist_del_first(&buf->rb_free_reps);
990 if (!node)
991 return NULL;
992 return llist_entry(node, struct rpcrdma_rep, rr_node);
993}
994
995/**
996 * rpcrdma_rep_put - Release rpcrdma_rep back to free list
997 * @buf: buffer pool
998 * @rep: rep to release
999 *
1000 */
1001void rpcrdma_rep_put(struct rpcrdma_buffer *buf, struct rpcrdma_rep *rep)
1002{
1003 llist_add(&rep->rr_node, &buf->rb_free_reps);
1004}
1005
1006/* Caller must ensure the QP is quiescent (RQ is drained) before
1007 * invoking this function, to guarantee rb_all_reps is not
1008 * changing.
1009 */
1010static void rpcrdma_reps_unmap(struct rpcrdma_xprt *r_xprt)
1011{
1012 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
1013 struct rpcrdma_rep *rep;
1014
1015 list_for_each_entry(rep, &buf->rb_all_reps, rr_all) {
1016 rpcrdma_regbuf_dma_unmap(rep->rr_rdmabuf);
1017 rep->rr_temp = true; /* Mark this rep for destruction */
1018 }
1019}
1020
1021static void rpcrdma_reps_destroy(struct rpcrdma_buffer *buf)
1022{
1023 struct rpcrdma_rep *rep;
1024
1025 spin_lock(&buf->rb_lock);
1026 while ((rep = list_first_entry_or_null(&buf->rb_all_reps,
1027 struct rpcrdma_rep,
1028 rr_all)) != NULL) {
1029 list_del(&rep->rr_all);
1030 spin_unlock(&buf->rb_lock);
1031
1032 rpcrdma_rep_free(rep);
1033
1034 spin_lock(&buf->rb_lock);
1035 }
1036 spin_unlock(&buf->rb_lock);
1037}
1038
1039/**
1040 * rpcrdma_buffer_create - Create initial set of req/rep objects
1041 * @r_xprt: transport instance to (re)initialize
1042 *
1043 * Returns zero on success, otherwise a negative errno.
1044 */
1045int rpcrdma_buffer_create(struct rpcrdma_xprt *r_xprt)
1046{
1047 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
1048 int i, rc;
1049
1050 buf->rb_bc_srv_max_requests = 0;
1051 spin_lock_init(&buf->rb_lock);
1052 INIT_LIST_HEAD(&buf->rb_mrs);
1053 INIT_LIST_HEAD(&buf->rb_all_mrs);
1054 INIT_WORK(&buf->rb_refresh_worker, rpcrdma_mr_refresh_worker);
1055
1056 INIT_LIST_HEAD(&buf->rb_send_bufs);
1057 INIT_LIST_HEAD(&buf->rb_allreqs);
1058 INIT_LIST_HEAD(&buf->rb_all_reps);
1059
1060 rc = -ENOMEM;
1061 for (i = 0; i < r_xprt->rx_xprt.max_reqs; i++) {
1062 struct rpcrdma_req *req;
1063
1064 req = rpcrdma_req_create(r_xprt,
1065 RPCRDMA_V1_DEF_INLINE_SIZE * 2);
1066 if (!req)
1067 goto out;
1068 list_add(&req->rl_list, &buf->rb_send_bufs);
1069 }
1070
1071 init_llist_head(&buf->rb_free_reps);
1072
1073 return 0;
1074out:
1075 rpcrdma_buffer_destroy(buf);
1076 return rc;
1077}
1078
1079/**
1080 * rpcrdma_req_destroy - Destroy an rpcrdma_req object
1081 * @req: unused object to be destroyed
1082 *
1083 * Relies on caller holding the transport send lock to protect
1084 * removing req->rl_all from buf->rb_all_reqs safely.
1085 */
1086void rpcrdma_req_destroy(struct rpcrdma_req *req)
1087{
1088 struct rpcrdma_mr *mr;
1089
1090 list_del(&req->rl_all);
1091
1092 while ((mr = rpcrdma_mr_pop(&req->rl_free_mrs))) {
1093 struct rpcrdma_buffer *buf = &mr->mr_xprt->rx_buf;
1094
1095 spin_lock(&buf->rb_lock);
1096 list_del(&mr->mr_all);
1097 spin_unlock(&buf->rb_lock);
1098
1099 frwr_mr_release(mr);
1100 }
1101
1102 rpcrdma_regbuf_free(req->rl_recvbuf);
1103 rpcrdma_regbuf_free(req->rl_sendbuf);
1104 rpcrdma_regbuf_free(req->rl_rdmabuf);
1105 kfree(req);
1106}
1107
1108/**
1109 * rpcrdma_mrs_destroy - Release all of a transport's MRs
1110 * @r_xprt: controlling transport instance
1111 *
1112 * Relies on caller holding the transport send lock to protect
1113 * removing mr->mr_list from req->rl_free_mrs safely.
1114 */
1115static void rpcrdma_mrs_destroy(struct rpcrdma_xprt *r_xprt)
1116{
1117 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
1118 struct rpcrdma_mr *mr;
1119
1120 cancel_work_sync(&buf->rb_refresh_worker);
1121
1122 spin_lock(&buf->rb_lock);
1123 while ((mr = list_first_entry_or_null(&buf->rb_all_mrs,
1124 struct rpcrdma_mr,
1125 mr_all)) != NULL) {
1126 list_del(&mr->mr_list);
1127 list_del(&mr->mr_all);
1128 spin_unlock(&buf->rb_lock);
1129
1130 frwr_mr_release(mr);
1131
1132 spin_lock(&buf->rb_lock);
1133 }
1134 spin_unlock(&buf->rb_lock);
1135}
1136
1137/**
1138 * rpcrdma_buffer_destroy - Release all hw resources
1139 * @buf: root control block for resources
1140 *
1141 * ORDERING: relies on a prior rpcrdma_xprt_drain :
1142 * - No more Send or Receive completions can occur
1143 * - All MRs, reps, and reqs are returned to their free lists
1144 */
1145void
1146rpcrdma_buffer_destroy(struct rpcrdma_buffer *buf)
1147{
1148 rpcrdma_reps_destroy(buf);
1149
1150 while (!list_empty(&buf->rb_send_bufs)) {
1151 struct rpcrdma_req *req;
1152
1153 req = list_first_entry(&buf->rb_send_bufs,
1154 struct rpcrdma_req, rl_list);
1155 list_del(&req->rl_list);
1156 rpcrdma_req_destroy(req);
1157 }
1158}
1159
1160/**
1161 * rpcrdma_mr_get - Allocate an rpcrdma_mr object
1162 * @r_xprt: controlling transport
1163 *
1164 * Returns an initialized rpcrdma_mr or NULL if no free
1165 * rpcrdma_mr objects are available.
1166 */
1167struct rpcrdma_mr *
1168rpcrdma_mr_get(struct rpcrdma_xprt *r_xprt)
1169{
1170 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
1171 struct rpcrdma_mr *mr;
1172
1173 spin_lock(&buf->rb_lock);
1174 mr = rpcrdma_mr_pop(&buf->rb_mrs);
1175 spin_unlock(&buf->rb_lock);
1176 return mr;
1177}
1178
1179/**
1180 * rpcrdma_reply_put - Put reply buffers back into pool
1181 * @buffers: buffer pool
1182 * @req: object to return
1183 *
1184 */
1185void rpcrdma_reply_put(struct rpcrdma_buffer *buffers, struct rpcrdma_req *req)
1186{
1187 if (req->rl_reply) {
1188 rpcrdma_rep_put(buffers, req->rl_reply);
1189 req->rl_reply = NULL;
1190 }
1191}
1192
1193/**
1194 * rpcrdma_buffer_get - Get a request buffer
1195 * @buffers: Buffer pool from which to obtain a buffer
1196 *
1197 * Returns a fresh rpcrdma_req, or NULL if none are available.
1198 */
1199struct rpcrdma_req *
1200rpcrdma_buffer_get(struct rpcrdma_buffer *buffers)
1201{
1202 struct rpcrdma_req *req;
1203
1204 spin_lock(&buffers->rb_lock);
1205 req = list_first_entry_or_null(&buffers->rb_send_bufs,
1206 struct rpcrdma_req, rl_list);
1207 if (req)
1208 list_del_init(&req->rl_list);
1209 spin_unlock(&buffers->rb_lock);
1210 return req;
1211}
1212
1213/**
1214 * rpcrdma_buffer_put - Put request/reply buffers back into pool
1215 * @buffers: buffer pool
1216 * @req: object to return
1217 *
1218 */
1219void rpcrdma_buffer_put(struct rpcrdma_buffer *buffers, struct rpcrdma_req *req)
1220{
1221 rpcrdma_reply_put(buffers, req);
1222
1223 spin_lock(&buffers->rb_lock);
1224 list_add(&req->rl_list, &buffers->rb_send_bufs);
1225 spin_unlock(&buffers->rb_lock);
1226}
1227
1228/* Returns a pointer to a rpcrdma_regbuf object, or NULL.
1229 *
1230 * xprtrdma uses a regbuf for posting an outgoing RDMA SEND, or for
1231 * receiving the payload of RDMA RECV operations. During Long Calls
1232 * or Replies they may be registered externally via frwr_map.
1233 */
1234static struct rpcrdma_regbuf *
1235rpcrdma_regbuf_alloc(size_t size, enum dma_data_direction direction)
1236{
1237 struct rpcrdma_regbuf *rb;
1238
1239 rb = kmalloc(sizeof(*rb), XPRTRDMA_GFP_FLAGS);
1240 if (!rb)
1241 return NULL;
1242 rb->rg_data = kmalloc(size, XPRTRDMA_GFP_FLAGS);
1243 if (!rb->rg_data) {
1244 kfree(rb);
1245 return NULL;
1246 }
1247
1248 rb->rg_device = NULL;
1249 rb->rg_direction = direction;
1250 rb->rg_iov.length = size;
1251 return rb;
1252}
1253
1254/**
1255 * rpcrdma_regbuf_realloc - re-allocate a SEND/RECV buffer
1256 * @rb: regbuf to reallocate
1257 * @size: size of buffer to be allocated, in bytes
1258 * @flags: GFP flags
1259 *
1260 * Returns true if reallocation was successful. If false is
1261 * returned, @rb is left untouched.
1262 */
1263bool rpcrdma_regbuf_realloc(struct rpcrdma_regbuf *rb, size_t size, gfp_t flags)
1264{
1265 void *buf;
1266
1267 buf = kmalloc(size, flags);
1268 if (!buf)
1269 return false;
1270
1271 rpcrdma_regbuf_dma_unmap(rb);
1272 kfree(rb->rg_data);
1273
1274 rb->rg_data = buf;
1275 rb->rg_iov.length = size;
1276 return true;
1277}
1278
1279/**
1280 * __rpcrdma_regbuf_dma_map - DMA-map a regbuf
1281 * @r_xprt: controlling transport instance
1282 * @rb: regbuf to be mapped
1283 *
1284 * Returns true if the buffer is now DMA mapped to @r_xprt's device
1285 */
1286bool __rpcrdma_regbuf_dma_map(struct rpcrdma_xprt *r_xprt,
1287 struct rpcrdma_regbuf *rb)
1288{
1289 struct ib_device *device = r_xprt->rx_ep->re_id->device;
1290
1291 if (rb->rg_direction == DMA_NONE)
1292 return false;
1293
1294 rb->rg_iov.addr = ib_dma_map_single(device, rdmab_data(rb),
1295 rdmab_length(rb), rb->rg_direction);
1296 if (ib_dma_mapping_error(device, rdmab_addr(rb))) {
1297 trace_xprtrdma_dma_maperr(rdmab_addr(rb));
1298 return false;
1299 }
1300
1301 rb->rg_device = device;
1302 rb->rg_iov.lkey = r_xprt->rx_ep->re_pd->local_dma_lkey;
1303 return true;
1304}
1305
1306static void rpcrdma_regbuf_dma_unmap(struct rpcrdma_regbuf *rb)
1307{
1308 if (!rb)
1309 return;
1310
1311 if (!rpcrdma_regbuf_is_mapped(rb))
1312 return;
1313
1314 ib_dma_unmap_single(rb->rg_device, rdmab_addr(rb), rdmab_length(rb),
1315 rb->rg_direction);
1316 rb->rg_device = NULL;
1317}
1318
1319static void rpcrdma_regbuf_free(struct rpcrdma_regbuf *rb)
1320{
1321 rpcrdma_regbuf_dma_unmap(rb);
1322 if (rb)
1323 kfree(rb->rg_data);
1324 kfree(rb);
1325}
1326
1327/**
1328 * rpcrdma_post_recvs - Refill the Receive Queue
1329 * @r_xprt: controlling transport instance
1330 * @needed: current credit grant
1331 * @temp: mark Receive buffers to be deleted after one use
1332 *
1333 */
1334void rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, int needed, bool temp)
1335{
1336 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
1337 struct rpcrdma_ep *ep = r_xprt->rx_ep;
1338 struct ib_recv_wr *wr, *bad_wr;
1339 struct rpcrdma_rep *rep;
1340 int count, rc;
1341
1342 rc = 0;
1343 count = 0;
1344
1345 if (likely(ep->re_receive_count > needed))
1346 goto out;
1347 needed -= ep->re_receive_count;
1348 if (!temp)
1349 needed += RPCRDMA_MAX_RECV_BATCH;
1350
1351 if (atomic_inc_return(&ep->re_receiving) > 1)
1352 goto out;
1353
1354 /* fast path: all needed reps can be found on the free list */
1355 wr = NULL;
1356 while (needed) {
1357 rep = rpcrdma_rep_get_locked(buf);
1358 if (rep && rep->rr_temp) {
1359 rpcrdma_rep_destroy(rep);
1360 continue;
1361 }
1362 if (!rep)
1363 rep = rpcrdma_rep_create(r_xprt, temp);
1364 if (!rep)
1365 break;
1366
1367 rep->rr_cid.ci_queue_id = ep->re_attr.recv_cq->res.id;
1368 trace_xprtrdma_post_recv(rep);
1369 rep->rr_recv_wr.next = wr;
1370 wr = &rep->rr_recv_wr;
1371 --needed;
1372 ++count;
1373 }
1374 if (!wr)
1375 goto out;
1376
1377 rc = ib_post_recv(ep->re_id->qp, wr,
1378 (const struct ib_recv_wr **)&bad_wr);
1379 if (rc) {
1380 trace_xprtrdma_post_recvs_err(r_xprt, rc);
1381 for (wr = bad_wr; wr;) {
1382 struct rpcrdma_rep *rep;
1383
1384 rep = container_of(wr, struct rpcrdma_rep, rr_recv_wr);
1385 wr = wr->next;
1386 rpcrdma_rep_put(buf, rep);
1387 --count;
1388 }
1389 }
1390 if (atomic_dec_return(&ep->re_receiving) > 0)
1391 complete(&ep->re_done);
1392
1393out:
1394 trace_xprtrdma_post_recvs(r_xprt, count);
1395 ep->re_receive_count += count;
1396 return;
1397}