Loading...
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
66/*
67 * Globals/Macros
68 */
69
70#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
71# define RPCDBG_FACILITY RPCDBG_TRANS
72#endif
73
74/*
75 * internal functions
76 */
77static void rpcrdma_sendctx_put_locked(struct rpcrdma_sendctx *sc);
78static void rpcrdma_reps_destroy(struct rpcrdma_buffer *buf);
79static void rpcrdma_mrs_create(struct rpcrdma_xprt *r_xprt);
80static void rpcrdma_mrs_destroy(struct rpcrdma_buffer *buf);
81static void rpcrdma_mr_free(struct rpcrdma_mr *mr);
82static struct rpcrdma_regbuf *
83rpcrdma_regbuf_alloc(size_t size, enum dma_data_direction direction,
84 gfp_t flags);
85static void rpcrdma_regbuf_dma_unmap(struct rpcrdma_regbuf *rb);
86static void rpcrdma_regbuf_free(struct rpcrdma_regbuf *rb);
87static void rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, bool temp);
88
89/* Wait for outstanding transport work to finish. ib_drain_qp
90 * handles the drains in the wrong order for us, so open code
91 * them here.
92 */
93static void rpcrdma_xprt_drain(struct rpcrdma_xprt *r_xprt)
94{
95 struct rpcrdma_ia *ia = &r_xprt->rx_ia;
96
97 /* Flush Receives, then wait for deferred Reply work
98 * to complete.
99 */
100 ib_drain_rq(ia->ri_id->qp);
101
102 /* Deferred Reply processing might have scheduled
103 * local invalidations.
104 */
105 ib_drain_sq(ia->ri_id->qp);
106}
107
108/**
109 * rpcrdma_qp_event_handler - Handle one QP event (error notification)
110 * @event: details of the event
111 * @context: ep that owns QP where event occurred
112 *
113 * Called from the RDMA provider (device driver) possibly in an interrupt
114 * context.
115 */
116static void
117rpcrdma_qp_event_handler(struct ib_event *event, void *context)
118{
119 struct rpcrdma_ep *ep = context;
120 struct rpcrdma_xprt *r_xprt = container_of(ep, struct rpcrdma_xprt,
121 rx_ep);
122
123 trace_xprtrdma_qp_event(r_xprt, event);
124}
125
126/**
127 * rpcrdma_wc_send - Invoked by RDMA provider for each polled Send WC
128 * @cq: completion queue (ignored)
129 * @wc: completed WR
130 *
131 */
132static void
133rpcrdma_wc_send(struct ib_cq *cq, struct ib_wc *wc)
134{
135 struct ib_cqe *cqe = wc->wr_cqe;
136 struct rpcrdma_sendctx *sc =
137 container_of(cqe, struct rpcrdma_sendctx, sc_cqe);
138
139 /* WARNING: Only wr_cqe and status are reliable at this point */
140 trace_xprtrdma_wc_send(sc, wc);
141 rpcrdma_sendctx_put_locked(sc);
142}
143
144/**
145 * rpcrdma_wc_receive - Invoked by RDMA provider for each polled Receive WC
146 * @cq: completion queue (ignored)
147 * @wc: completed WR
148 *
149 */
150static void
151rpcrdma_wc_receive(struct ib_cq *cq, struct ib_wc *wc)
152{
153 struct ib_cqe *cqe = wc->wr_cqe;
154 struct rpcrdma_rep *rep = container_of(cqe, struct rpcrdma_rep,
155 rr_cqe);
156 struct rpcrdma_xprt *r_xprt = rep->rr_rxprt;
157
158 /* WARNING: Only wr_cqe and status are reliable at this point */
159 trace_xprtrdma_wc_receive(wc);
160 --r_xprt->rx_ep.rep_receive_count;
161 if (wc->status != IB_WC_SUCCESS)
162 goto out_flushed;
163
164 /* status == SUCCESS means all fields in wc are trustworthy */
165 rpcrdma_set_xdrlen(&rep->rr_hdrbuf, wc->byte_len);
166 rep->rr_wc_flags = wc->wc_flags;
167 rep->rr_inv_rkey = wc->ex.invalidate_rkey;
168
169 ib_dma_sync_single_for_cpu(rdmab_device(rep->rr_rdmabuf),
170 rdmab_addr(rep->rr_rdmabuf),
171 wc->byte_len, DMA_FROM_DEVICE);
172
173 rpcrdma_post_recvs(r_xprt, false);
174 rpcrdma_reply_handler(rep);
175 return;
176
177out_flushed:
178 rpcrdma_recv_buffer_put(rep);
179}
180
181static void
182rpcrdma_update_connect_private(struct rpcrdma_xprt *r_xprt,
183 struct rdma_conn_param *param)
184{
185 const struct rpcrdma_connect_private *pmsg = param->private_data;
186 unsigned int rsize, wsize;
187
188 /* Default settings for RPC-over-RDMA Version One */
189 r_xprt->rx_ia.ri_implicit_roundup = xprt_rdma_pad_optimize;
190 rsize = RPCRDMA_V1_DEF_INLINE_SIZE;
191 wsize = RPCRDMA_V1_DEF_INLINE_SIZE;
192
193 if (pmsg &&
194 pmsg->cp_magic == rpcrdma_cmp_magic &&
195 pmsg->cp_version == RPCRDMA_CMP_VERSION) {
196 r_xprt->rx_ia.ri_implicit_roundup = true;
197 rsize = rpcrdma_decode_buffer_size(pmsg->cp_send_size);
198 wsize = rpcrdma_decode_buffer_size(pmsg->cp_recv_size);
199 }
200
201 if (rsize < r_xprt->rx_ep.rep_inline_recv)
202 r_xprt->rx_ep.rep_inline_recv = rsize;
203 if (wsize < r_xprt->rx_ep.rep_inline_send)
204 r_xprt->rx_ep.rep_inline_send = wsize;
205 dprintk("RPC: %s: max send %u, max recv %u\n", __func__,
206 r_xprt->rx_ep.rep_inline_send,
207 r_xprt->rx_ep.rep_inline_recv);
208 rpcrdma_set_max_header_sizes(r_xprt);
209}
210
211/**
212 * rpcrdma_cm_event_handler - Handle RDMA CM events
213 * @id: rdma_cm_id on which an event has occurred
214 * @event: details of the event
215 *
216 * Called with @id's mutex held. Returns 1 if caller should
217 * destroy @id, otherwise 0.
218 */
219static int
220rpcrdma_cm_event_handler(struct rdma_cm_id *id, struct rdma_cm_event *event)
221{
222 struct rpcrdma_xprt *r_xprt = id->context;
223 struct rpcrdma_ia *ia = &r_xprt->rx_ia;
224 struct rpcrdma_ep *ep = &r_xprt->rx_ep;
225 struct rpc_xprt *xprt = &r_xprt->rx_xprt;
226
227 might_sleep();
228
229 trace_xprtrdma_cm_event(r_xprt, event);
230 switch (event->event) {
231 case RDMA_CM_EVENT_ADDR_RESOLVED:
232 case RDMA_CM_EVENT_ROUTE_RESOLVED:
233 ia->ri_async_rc = 0;
234 complete(&ia->ri_done);
235 return 0;
236 case RDMA_CM_EVENT_ADDR_ERROR:
237 ia->ri_async_rc = -EPROTO;
238 complete(&ia->ri_done);
239 return 0;
240 case RDMA_CM_EVENT_ROUTE_ERROR:
241 ia->ri_async_rc = -ENETUNREACH;
242 complete(&ia->ri_done);
243 return 0;
244 case RDMA_CM_EVENT_DEVICE_REMOVAL:
245#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
246 pr_info("rpcrdma: removing device %s for %s:%s\n",
247 ia->ri_id->device->name,
248 rpcrdma_addrstr(r_xprt), rpcrdma_portstr(r_xprt));
249#endif
250 set_bit(RPCRDMA_IAF_REMOVING, &ia->ri_flags);
251 ep->rep_connected = -ENODEV;
252 xprt_force_disconnect(xprt);
253 wait_for_completion(&ia->ri_remove_done);
254
255 ia->ri_id = NULL;
256 /* Return 1 to ensure the core destroys the id. */
257 return 1;
258 case RDMA_CM_EVENT_ESTABLISHED:
259 ++xprt->connect_cookie;
260 ep->rep_connected = 1;
261 rpcrdma_update_connect_private(r_xprt, &event->param.conn);
262 wake_up_all(&ep->rep_connect_wait);
263 break;
264 case RDMA_CM_EVENT_CONNECT_ERROR:
265 ep->rep_connected = -ENOTCONN;
266 goto disconnected;
267 case RDMA_CM_EVENT_UNREACHABLE:
268 ep->rep_connected = -ENETUNREACH;
269 goto disconnected;
270 case RDMA_CM_EVENT_REJECTED:
271 dprintk("rpcrdma: connection to %s:%s rejected: %s\n",
272 rpcrdma_addrstr(r_xprt), rpcrdma_portstr(r_xprt),
273 rdma_reject_msg(id, event->status));
274 ep->rep_connected = -ECONNREFUSED;
275 if (event->status == IB_CM_REJ_STALE_CONN)
276 ep->rep_connected = -EAGAIN;
277 goto disconnected;
278 case RDMA_CM_EVENT_DISCONNECTED:
279 ep->rep_connected = -ECONNABORTED;
280disconnected:
281 xprt_force_disconnect(xprt);
282 wake_up_all(&ep->rep_connect_wait);
283 break;
284 default:
285 break;
286 }
287
288 dprintk("RPC: %s: %s:%s on %s/frwr: %s\n", __func__,
289 rpcrdma_addrstr(r_xprt), rpcrdma_portstr(r_xprt),
290 ia->ri_id->device->name, rdma_event_msg(event->event));
291 return 0;
292}
293
294static struct rdma_cm_id *
295rpcrdma_create_id(struct rpcrdma_xprt *xprt, struct rpcrdma_ia *ia)
296{
297 unsigned long wtimeout = msecs_to_jiffies(RDMA_RESOLVE_TIMEOUT) + 1;
298 struct rdma_cm_id *id;
299 int rc;
300
301 trace_xprtrdma_conn_start(xprt);
302
303 init_completion(&ia->ri_done);
304 init_completion(&ia->ri_remove_done);
305
306 id = rdma_create_id(xprt->rx_xprt.xprt_net, rpcrdma_cm_event_handler,
307 xprt, RDMA_PS_TCP, IB_QPT_RC);
308 if (IS_ERR(id))
309 return id;
310
311 ia->ri_async_rc = -ETIMEDOUT;
312 rc = rdma_resolve_addr(id, NULL,
313 (struct sockaddr *)&xprt->rx_xprt.addr,
314 RDMA_RESOLVE_TIMEOUT);
315 if (rc)
316 goto out;
317 rc = wait_for_completion_interruptible_timeout(&ia->ri_done, wtimeout);
318 if (rc < 0) {
319 trace_xprtrdma_conn_tout(xprt);
320 goto out;
321 }
322
323 rc = ia->ri_async_rc;
324 if (rc)
325 goto out;
326
327 ia->ri_async_rc = -ETIMEDOUT;
328 rc = rdma_resolve_route(id, RDMA_RESOLVE_TIMEOUT);
329 if (rc)
330 goto out;
331 rc = wait_for_completion_interruptible_timeout(&ia->ri_done, wtimeout);
332 if (rc < 0) {
333 trace_xprtrdma_conn_tout(xprt);
334 goto out;
335 }
336 rc = ia->ri_async_rc;
337 if (rc)
338 goto out;
339
340 return id;
341
342out:
343 rdma_destroy_id(id);
344 return ERR_PTR(rc);
345}
346
347/*
348 * Exported functions.
349 */
350
351/**
352 * rpcrdma_ia_open - Open and initialize an Interface Adapter.
353 * @xprt: transport with IA to (re)initialize
354 *
355 * Returns 0 on success, negative errno if an appropriate
356 * Interface Adapter could not be found and opened.
357 */
358int
359rpcrdma_ia_open(struct rpcrdma_xprt *xprt)
360{
361 struct rpcrdma_ia *ia = &xprt->rx_ia;
362 int rc;
363
364 ia->ri_id = rpcrdma_create_id(xprt, ia);
365 if (IS_ERR(ia->ri_id)) {
366 rc = PTR_ERR(ia->ri_id);
367 goto out_err;
368 }
369
370 ia->ri_pd = ib_alloc_pd(ia->ri_id->device, 0);
371 if (IS_ERR(ia->ri_pd)) {
372 rc = PTR_ERR(ia->ri_pd);
373 pr_err("rpcrdma: ib_alloc_pd() returned %d\n", rc);
374 goto out_err;
375 }
376
377 switch (xprt_rdma_memreg_strategy) {
378 case RPCRDMA_FRWR:
379 if (frwr_is_supported(ia->ri_id->device))
380 break;
381 /*FALLTHROUGH*/
382 default:
383 pr_err("rpcrdma: Device %s does not support memreg mode %d\n",
384 ia->ri_id->device->name, xprt_rdma_memreg_strategy);
385 rc = -EINVAL;
386 goto out_err;
387 }
388
389 return 0;
390
391out_err:
392 rpcrdma_ia_close(ia);
393 return rc;
394}
395
396/**
397 * rpcrdma_ia_remove - Handle device driver unload
398 * @ia: interface adapter being removed
399 *
400 * Divest transport H/W resources associated with this adapter,
401 * but allow it to be restored later.
402 */
403void
404rpcrdma_ia_remove(struct rpcrdma_ia *ia)
405{
406 struct rpcrdma_xprt *r_xprt = container_of(ia, struct rpcrdma_xprt,
407 rx_ia);
408 struct rpcrdma_ep *ep = &r_xprt->rx_ep;
409 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
410 struct rpcrdma_req *req;
411
412 cancel_work_sync(&buf->rb_refresh_worker);
413
414 /* This is similar to rpcrdma_ep_destroy, but:
415 * - Don't cancel the connect worker.
416 * - Don't call rpcrdma_ep_disconnect, which waits
417 * for another conn upcall, which will deadlock.
418 * - rdma_disconnect is unneeded, the underlying
419 * connection is already gone.
420 */
421 if (ia->ri_id->qp) {
422 rpcrdma_xprt_drain(r_xprt);
423 rdma_destroy_qp(ia->ri_id);
424 ia->ri_id->qp = NULL;
425 }
426 ib_free_cq(ep->rep_attr.recv_cq);
427 ep->rep_attr.recv_cq = NULL;
428 ib_free_cq(ep->rep_attr.send_cq);
429 ep->rep_attr.send_cq = NULL;
430
431 /* The ULP is responsible for ensuring all DMA
432 * mappings and MRs are gone.
433 */
434 rpcrdma_reps_destroy(buf);
435 list_for_each_entry(req, &buf->rb_allreqs, rl_all) {
436 rpcrdma_regbuf_dma_unmap(req->rl_rdmabuf);
437 rpcrdma_regbuf_dma_unmap(req->rl_sendbuf);
438 rpcrdma_regbuf_dma_unmap(req->rl_recvbuf);
439 }
440 rpcrdma_mrs_destroy(buf);
441 ib_dealloc_pd(ia->ri_pd);
442 ia->ri_pd = NULL;
443
444 /* Allow waiters to continue */
445 complete(&ia->ri_remove_done);
446
447 trace_xprtrdma_remove(r_xprt);
448}
449
450/**
451 * rpcrdma_ia_close - Clean up/close an IA.
452 * @ia: interface adapter to close
453 *
454 */
455void
456rpcrdma_ia_close(struct rpcrdma_ia *ia)
457{
458 if (ia->ri_id != NULL && !IS_ERR(ia->ri_id)) {
459 if (ia->ri_id->qp)
460 rdma_destroy_qp(ia->ri_id);
461 rdma_destroy_id(ia->ri_id);
462 }
463 ia->ri_id = NULL;
464
465 /* If the pd is still busy, xprtrdma missed freeing a resource */
466 if (ia->ri_pd && !IS_ERR(ia->ri_pd))
467 ib_dealloc_pd(ia->ri_pd);
468 ia->ri_pd = NULL;
469}
470
471/**
472 * rpcrdma_ep_create - Create unconnected endpoint
473 * @r_xprt: transport to instantiate
474 *
475 * Returns zero on success, or a negative errno.
476 */
477int rpcrdma_ep_create(struct rpcrdma_xprt *r_xprt)
478{
479 struct rpcrdma_ep *ep = &r_xprt->rx_ep;
480 struct rpcrdma_ia *ia = &r_xprt->rx_ia;
481 struct rpcrdma_connect_private *pmsg = &ep->rep_cm_private;
482 struct ib_cq *sendcq, *recvcq;
483 unsigned int max_sge;
484 int rc;
485
486 ep->rep_max_requests = xprt_rdma_slot_table_entries;
487 ep->rep_inline_send = xprt_rdma_max_inline_write;
488 ep->rep_inline_recv = xprt_rdma_max_inline_read;
489
490 max_sge = min_t(unsigned int, ia->ri_id->device->attrs.max_send_sge,
491 RPCRDMA_MAX_SEND_SGES);
492 if (max_sge < RPCRDMA_MIN_SEND_SGES) {
493 pr_warn("rpcrdma: HCA provides only %d send SGEs\n", max_sge);
494 return -ENOMEM;
495 }
496 ia->ri_max_send_sges = max_sge;
497
498 rc = frwr_open(ia, ep);
499 if (rc)
500 return rc;
501
502 ep->rep_attr.event_handler = rpcrdma_qp_event_handler;
503 ep->rep_attr.qp_context = ep;
504 ep->rep_attr.srq = NULL;
505 ep->rep_attr.cap.max_send_sge = max_sge;
506 ep->rep_attr.cap.max_recv_sge = 1;
507 ep->rep_attr.cap.max_inline_data = 0;
508 ep->rep_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
509 ep->rep_attr.qp_type = IB_QPT_RC;
510 ep->rep_attr.port_num = ~0;
511
512 dprintk("RPC: %s: requested max: dtos: send %d recv %d; "
513 "iovs: send %d recv %d\n",
514 __func__,
515 ep->rep_attr.cap.max_send_wr,
516 ep->rep_attr.cap.max_recv_wr,
517 ep->rep_attr.cap.max_send_sge,
518 ep->rep_attr.cap.max_recv_sge);
519
520 ep->rep_send_batch = ep->rep_max_requests >> 3;
521 ep->rep_send_count = ep->rep_send_batch;
522 init_waitqueue_head(&ep->rep_connect_wait);
523 ep->rep_receive_count = 0;
524
525 sendcq = ib_alloc_cq_any(ia->ri_id->device, NULL,
526 ep->rep_attr.cap.max_send_wr + 1,
527 IB_POLL_WORKQUEUE);
528 if (IS_ERR(sendcq)) {
529 rc = PTR_ERR(sendcq);
530 goto out1;
531 }
532
533 recvcq = ib_alloc_cq_any(ia->ri_id->device, NULL,
534 ep->rep_attr.cap.max_recv_wr + 1,
535 IB_POLL_WORKQUEUE);
536 if (IS_ERR(recvcq)) {
537 rc = PTR_ERR(recvcq);
538 goto out2;
539 }
540
541 ep->rep_attr.send_cq = sendcq;
542 ep->rep_attr.recv_cq = recvcq;
543
544 /* Initialize cma parameters */
545 memset(&ep->rep_remote_cma, 0, sizeof(ep->rep_remote_cma));
546
547 /* Prepare RDMA-CM private message */
548 pmsg->cp_magic = rpcrdma_cmp_magic;
549 pmsg->cp_version = RPCRDMA_CMP_VERSION;
550 pmsg->cp_flags |= RPCRDMA_CMP_F_SND_W_INV_OK;
551 pmsg->cp_send_size = rpcrdma_encode_buffer_size(ep->rep_inline_send);
552 pmsg->cp_recv_size = rpcrdma_encode_buffer_size(ep->rep_inline_recv);
553 ep->rep_remote_cma.private_data = pmsg;
554 ep->rep_remote_cma.private_data_len = sizeof(*pmsg);
555
556 /* Client offers RDMA Read but does not initiate */
557 ep->rep_remote_cma.initiator_depth = 0;
558 ep->rep_remote_cma.responder_resources =
559 min_t(int, U8_MAX, ia->ri_id->device->attrs.max_qp_rd_atom);
560
561 /* Limit transport retries so client can detect server
562 * GID changes quickly. RPC layer handles re-establishing
563 * transport connection and retransmission.
564 */
565 ep->rep_remote_cma.retry_count = 6;
566
567 /* RPC-over-RDMA handles its own flow control. In addition,
568 * make all RNR NAKs visible so we know that RPC-over-RDMA
569 * flow control is working correctly (no NAKs should be seen).
570 */
571 ep->rep_remote_cma.flow_control = 0;
572 ep->rep_remote_cma.rnr_retry_count = 0;
573
574 return 0;
575
576out2:
577 ib_free_cq(sendcq);
578out1:
579 return rc;
580}
581
582/**
583 * rpcrdma_ep_destroy - Disconnect and destroy endpoint.
584 * @r_xprt: transport instance to shut down
585 *
586 */
587void rpcrdma_ep_destroy(struct rpcrdma_xprt *r_xprt)
588{
589 struct rpcrdma_ep *ep = &r_xprt->rx_ep;
590 struct rpcrdma_ia *ia = &r_xprt->rx_ia;
591
592 if (ia->ri_id && ia->ri_id->qp) {
593 rpcrdma_ep_disconnect(ep, ia);
594 rdma_destroy_qp(ia->ri_id);
595 ia->ri_id->qp = NULL;
596 }
597
598 if (ep->rep_attr.recv_cq)
599 ib_free_cq(ep->rep_attr.recv_cq);
600 if (ep->rep_attr.send_cq)
601 ib_free_cq(ep->rep_attr.send_cq);
602}
603
604/* Re-establish a connection after a device removal event.
605 * Unlike a normal reconnection, a fresh PD and a new set
606 * of MRs and buffers is needed.
607 */
608static int rpcrdma_ep_recreate_xprt(struct rpcrdma_xprt *r_xprt,
609 struct ib_qp_init_attr *qp_init_attr)
610{
611 struct rpcrdma_ia *ia = &r_xprt->rx_ia;
612 int rc, err;
613
614 trace_xprtrdma_reinsert(r_xprt);
615
616 rc = -EHOSTUNREACH;
617 if (rpcrdma_ia_open(r_xprt))
618 goto out1;
619
620 rc = -ENOMEM;
621 err = rpcrdma_ep_create(r_xprt);
622 if (err) {
623 pr_err("rpcrdma: rpcrdma_ep_create returned %d\n", err);
624 goto out2;
625 }
626
627 rc = -ENETUNREACH;
628 err = rdma_create_qp(ia->ri_id, ia->ri_pd, qp_init_attr);
629 if (err) {
630 pr_err("rpcrdma: rdma_create_qp returned %d\n", err);
631 goto out3;
632 }
633
634 rpcrdma_mrs_create(r_xprt);
635 return 0;
636
637out3:
638 rpcrdma_ep_destroy(r_xprt);
639out2:
640 rpcrdma_ia_close(ia);
641out1:
642 return rc;
643}
644
645static int rpcrdma_ep_reconnect(struct rpcrdma_xprt *r_xprt,
646 struct ib_qp_init_attr *qp_init_attr)
647{
648 struct rpcrdma_ia *ia = &r_xprt->rx_ia;
649 struct rdma_cm_id *id, *old;
650 int err, rc;
651
652 trace_xprtrdma_reconnect(r_xprt);
653
654 rpcrdma_ep_disconnect(&r_xprt->rx_ep, ia);
655
656 rc = -EHOSTUNREACH;
657 id = rpcrdma_create_id(r_xprt, ia);
658 if (IS_ERR(id))
659 goto out;
660
661 /* As long as the new ID points to the same device as the
662 * old ID, we can reuse the transport's existing PD and all
663 * previously allocated MRs. Also, the same device means
664 * the transport's previous DMA mappings are still valid.
665 *
666 * This is a sanity check only. There should be no way these
667 * point to two different devices here.
668 */
669 old = id;
670 rc = -ENETUNREACH;
671 if (ia->ri_id->device != id->device) {
672 pr_err("rpcrdma: can't reconnect on different device!\n");
673 goto out_destroy;
674 }
675
676 err = rdma_create_qp(id, ia->ri_pd, qp_init_attr);
677 if (err)
678 goto out_destroy;
679
680 /* Atomically replace the transport's ID and QP. */
681 rc = 0;
682 old = ia->ri_id;
683 ia->ri_id = id;
684 rdma_destroy_qp(old);
685
686out_destroy:
687 rdma_destroy_id(old);
688out:
689 return rc;
690}
691
692/*
693 * Connect unconnected endpoint.
694 */
695int
696rpcrdma_ep_connect(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
697{
698 struct rpcrdma_xprt *r_xprt = container_of(ia, struct rpcrdma_xprt,
699 rx_ia);
700 struct rpc_xprt *xprt = &r_xprt->rx_xprt;
701 struct ib_qp_init_attr qp_init_attr;
702 int rc;
703
704retry:
705 memcpy(&qp_init_attr, &ep->rep_attr, sizeof(qp_init_attr));
706 switch (ep->rep_connected) {
707 case 0:
708 dprintk("RPC: %s: connecting...\n", __func__);
709 rc = rdma_create_qp(ia->ri_id, ia->ri_pd, &qp_init_attr);
710 if (rc) {
711 rc = -ENETUNREACH;
712 goto out_noupdate;
713 }
714 break;
715 case -ENODEV:
716 rc = rpcrdma_ep_recreate_xprt(r_xprt, &qp_init_attr);
717 if (rc)
718 goto out_noupdate;
719 break;
720 default:
721 rc = rpcrdma_ep_reconnect(r_xprt, &qp_init_attr);
722 if (rc)
723 goto out;
724 }
725
726 ep->rep_connected = 0;
727 xprt_clear_connected(xprt);
728
729 rpcrdma_post_recvs(r_xprt, true);
730
731 rc = rdma_connect(ia->ri_id, &ep->rep_remote_cma);
732 if (rc)
733 goto out;
734
735 if (xprt->reestablish_timeout < RPCRDMA_INIT_REEST_TO)
736 xprt->reestablish_timeout = RPCRDMA_INIT_REEST_TO;
737 wait_event_interruptible(ep->rep_connect_wait, ep->rep_connected != 0);
738 if (ep->rep_connected <= 0) {
739 if (ep->rep_connected == -EAGAIN)
740 goto retry;
741 rc = ep->rep_connected;
742 goto out;
743 }
744
745 dprintk("RPC: %s: connected\n", __func__);
746
747out:
748 if (rc)
749 ep->rep_connected = rc;
750
751out_noupdate:
752 return rc;
753}
754
755/**
756 * rpcrdma_ep_disconnect - Disconnect underlying transport
757 * @ep: endpoint to disconnect
758 * @ia: associated interface adapter
759 *
760 * This is separate from destroy to facilitate the ability
761 * to reconnect without recreating the endpoint.
762 *
763 * This call is not reentrant, and must not be made in parallel
764 * on the same endpoint.
765 */
766void
767rpcrdma_ep_disconnect(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
768{
769 struct rpcrdma_xprt *r_xprt = container_of(ep, struct rpcrdma_xprt,
770 rx_ep);
771 int rc;
772
773 /* returns without wait if ID is not connected */
774 rc = rdma_disconnect(ia->ri_id);
775 if (!rc)
776 wait_event_interruptible(ep->rep_connect_wait,
777 ep->rep_connected != 1);
778 else
779 ep->rep_connected = rc;
780 trace_xprtrdma_disconnect(r_xprt, rc);
781
782 rpcrdma_xprt_drain(r_xprt);
783}
784
785/* Fixed-size circular FIFO queue. This implementation is wait-free and
786 * lock-free.
787 *
788 * Consumer is the code path that posts Sends. This path dequeues a
789 * sendctx for use by a Send operation. Multiple consumer threads
790 * are serialized by the RPC transport lock, which allows only one
791 * ->send_request call at a time.
792 *
793 * Producer is the code path that handles Send completions. This path
794 * enqueues a sendctx that has been completed. Multiple producer
795 * threads are serialized by the ib_poll_cq() function.
796 */
797
798/* rpcrdma_sendctxs_destroy() assumes caller has already quiesced
799 * queue activity, and rpcrdma_xprt_drain has flushed all remaining
800 * Send requests.
801 */
802static void rpcrdma_sendctxs_destroy(struct rpcrdma_buffer *buf)
803{
804 unsigned long i;
805
806 for (i = 0; i <= buf->rb_sc_last; i++)
807 kfree(buf->rb_sc_ctxs[i]);
808 kfree(buf->rb_sc_ctxs);
809}
810
811static struct rpcrdma_sendctx *rpcrdma_sendctx_create(struct rpcrdma_ia *ia)
812{
813 struct rpcrdma_sendctx *sc;
814
815 sc = kzalloc(struct_size(sc, sc_sges, ia->ri_max_send_sges),
816 GFP_KERNEL);
817 if (!sc)
818 return NULL;
819
820 sc->sc_wr.wr_cqe = &sc->sc_cqe;
821 sc->sc_wr.sg_list = sc->sc_sges;
822 sc->sc_wr.opcode = IB_WR_SEND;
823 sc->sc_cqe.done = rpcrdma_wc_send;
824 return sc;
825}
826
827static int rpcrdma_sendctxs_create(struct rpcrdma_xprt *r_xprt)
828{
829 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
830 struct rpcrdma_sendctx *sc;
831 unsigned long i;
832
833 /* Maximum number of concurrent outstanding Send WRs. Capping
834 * the circular queue size stops Send Queue overflow by causing
835 * the ->send_request call to fail temporarily before too many
836 * Sends are posted.
837 */
838 i = buf->rb_max_requests + RPCRDMA_MAX_BC_REQUESTS;
839 dprintk("RPC: %s: allocating %lu send_ctxs\n", __func__, i);
840 buf->rb_sc_ctxs = kcalloc(i, sizeof(sc), GFP_KERNEL);
841 if (!buf->rb_sc_ctxs)
842 return -ENOMEM;
843
844 buf->rb_sc_last = i - 1;
845 for (i = 0; i <= buf->rb_sc_last; i++) {
846 sc = rpcrdma_sendctx_create(&r_xprt->rx_ia);
847 if (!sc)
848 return -ENOMEM;
849
850 sc->sc_xprt = r_xprt;
851 buf->rb_sc_ctxs[i] = sc;
852 }
853
854 return 0;
855}
856
857/* The sendctx queue is not guaranteed to have a size that is a
858 * power of two, thus the helpers in circ_buf.h cannot be used.
859 * The other option is to use modulus (%), which can be expensive.
860 */
861static unsigned long rpcrdma_sendctx_next(struct rpcrdma_buffer *buf,
862 unsigned long item)
863{
864 return likely(item < buf->rb_sc_last) ? item + 1 : 0;
865}
866
867/**
868 * rpcrdma_sendctx_get_locked - Acquire a send context
869 * @r_xprt: controlling transport instance
870 *
871 * Returns pointer to a free send completion context; or NULL if
872 * the queue is empty.
873 *
874 * Usage: Called to acquire an SGE array before preparing a Send WR.
875 *
876 * The caller serializes calls to this function (per transport), and
877 * provides an effective memory barrier that flushes the new value
878 * of rb_sc_head.
879 */
880struct rpcrdma_sendctx *rpcrdma_sendctx_get_locked(struct rpcrdma_xprt *r_xprt)
881{
882 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
883 struct rpcrdma_sendctx *sc;
884 unsigned long next_head;
885
886 next_head = rpcrdma_sendctx_next(buf, buf->rb_sc_head);
887
888 if (next_head == READ_ONCE(buf->rb_sc_tail))
889 goto out_emptyq;
890
891 /* ORDER: item must be accessed _before_ head is updated */
892 sc = buf->rb_sc_ctxs[next_head];
893
894 /* Releasing the lock in the caller acts as a memory
895 * barrier that flushes rb_sc_head.
896 */
897 buf->rb_sc_head = next_head;
898
899 return sc;
900
901out_emptyq:
902 /* The queue is "empty" if there have not been enough Send
903 * completions recently. This is a sign the Send Queue is
904 * backing up. Cause the caller to pause and try again.
905 */
906 xprt_wait_for_buffer_space(&r_xprt->rx_xprt);
907 r_xprt->rx_stats.empty_sendctx_q++;
908 return NULL;
909}
910
911/**
912 * rpcrdma_sendctx_put_locked - Release a send context
913 * @sc: send context to release
914 *
915 * Usage: Called from Send completion to return a sendctxt
916 * to the queue.
917 *
918 * The caller serializes calls to this function (per transport).
919 */
920static void
921rpcrdma_sendctx_put_locked(struct rpcrdma_sendctx *sc)
922{
923 struct rpcrdma_buffer *buf = &sc->sc_xprt->rx_buf;
924 unsigned long next_tail;
925
926 /* Unmap SGEs of previously completed but unsignaled
927 * Sends by walking up the queue until @sc is found.
928 */
929 next_tail = buf->rb_sc_tail;
930 do {
931 next_tail = rpcrdma_sendctx_next(buf, next_tail);
932
933 /* ORDER: item must be accessed _before_ tail is updated */
934 rpcrdma_sendctx_unmap(buf->rb_sc_ctxs[next_tail]);
935
936 } while (buf->rb_sc_ctxs[next_tail] != sc);
937
938 /* Paired with READ_ONCE */
939 smp_store_release(&buf->rb_sc_tail, next_tail);
940
941 xprt_write_space(&sc->sc_xprt->rx_xprt);
942}
943
944static void
945rpcrdma_mrs_create(struct rpcrdma_xprt *r_xprt)
946{
947 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
948 struct rpcrdma_ia *ia = &r_xprt->rx_ia;
949 unsigned int count;
950
951 for (count = 0; count < ia->ri_max_segs; count++) {
952 struct rpcrdma_mr *mr;
953 int rc;
954
955 mr = kzalloc(sizeof(*mr), GFP_NOFS);
956 if (!mr)
957 break;
958
959 rc = frwr_init_mr(ia, mr);
960 if (rc) {
961 kfree(mr);
962 break;
963 }
964
965 mr->mr_xprt = r_xprt;
966
967 spin_lock(&buf->rb_lock);
968 list_add(&mr->mr_list, &buf->rb_mrs);
969 list_add(&mr->mr_all, &buf->rb_all_mrs);
970 spin_unlock(&buf->rb_lock);
971 }
972
973 r_xprt->rx_stats.mrs_allocated += count;
974 trace_xprtrdma_createmrs(r_xprt, count);
975}
976
977static void
978rpcrdma_mr_refresh_worker(struct work_struct *work)
979{
980 struct rpcrdma_buffer *buf = container_of(work, struct rpcrdma_buffer,
981 rb_refresh_worker);
982 struct rpcrdma_xprt *r_xprt = container_of(buf, struct rpcrdma_xprt,
983 rx_buf);
984
985 rpcrdma_mrs_create(r_xprt);
986 xprt_write_space(&r_xprt->rx_xprt);
987}
988
989/**
990 * rpcrdma_req_create - Allocate an rpcrdma_req object
991 * @r_xprt: controlling r_xprt
992 * @size: initial size, in bytes, of send and receive buffers
993 * @flags: GFP flags passed to memory allocators
994 *
995 * Returns an allocated and fully initialized rpcrdma_req or NULL.
996 */
997struct rpcrdma_req *rpcrdma_req_create(struct rpcrdma_xprt *r_xprt, size_t size,
998 gfp_t flags)
999{
1000 struct rpcrdma_buffer *buffer = &r_xprt->rx_buf;
1001 struct rpcrdma_regbuf *rb;
1002 struct rpcrdma_req *req;
1003 size_t maxhdrsize;
1004
1005 req = kzalloc(sizeof(*req), flags);
1006 if (req == NULL)
1007 goto out1;
1008
1009 /* Compute maximum header buffer size in bytes */
1010 maxhdrsize = rpcrdma_fixed_maxsz + 3 +
1011 r_xprt->rx_ia.ri_max_segs * rpcrdma_readchunk_maxsz;
1012 maxhdrsize *= sizeof(__be32);
1013 rb = rpcrdma_regbuf_alloc(__roundup_pow_of_two(maxhdrsize),
1014 DMA_TO_DEVICE, flags);
1015 if (!rb)
1016 goto out2;
1017 req->rl_rdmabuf = rb;
1018 xdr_buf_init(&req->rl_hdrbuf, rdmab_data(rb), rdmab_length(rb));
1019
1020 req->rl_sendbuf = rpcrdma_regbuf_alloc(size, DMA_TO_DEVICE, flags);
1021 if (!req->rl_sendbuf)
1022 goto out3;
1023
1024 req->rl_recvbuf = rpcrdma_regbuf_alloc(size, DMA_NONE, flags);
1025 if (!req->rl_recvbuf)
1026 goto out4;
1027
1028 INIT_LIST_HEAD(&req->rl_free_mrs);
1029 INIT_LIST_HEAD(&req->rl_registered);
1030 spin_lock(&buffer->rb_lock);
1031 list_add(&req->rl_all, &buffer->rb_allreqs);
1032 spin_unlock(&buffer->rb_lock);
1033 return req;
1034
1035out4:
1036 kfree(req->rl_sendbuf);
1037out3:
1038 kfree(req->rl_rdmabuf);
1039out2:
1040 kfree(req);
1041out1:
1042 return NULL;
1043}
1044
1045static struct rpcrdma_rep *rpcrdma_rep_create(struct rpcrdma_xprt *r_xprt,
1046 bool temp)
1047{
1048 struct rpcrdma_rep *rep;
1049
1050 rep = kzalloc(sizeof(*rep), GFP_KERNEL);
1051 if (rep == NULL)
1052 goto out;
1053
1054 rep->rr_rdmabuf = rpcrdma_regbuf_alloc(r_xprt->rx_ep.rep_inline_recv,
1055 DMA_FROM_DEVICE, GFP_KERNEL);
1056 if (!rep->rr_rdmabuf)
1057 goto out_free;
1058
1059 xdr_buf_init(&rep->rr_hdrbuf, rdmab_data(rep->rr_rdmabuf),
1060 rdmab_length(rep->rr_rdmabuf));
1061 rep->rr_cqe.done = rpcrdma_wc_receive;
1062 rep->rr_rxprt = r_xprt;
1063 rep->rr_recv_wr.next = NULL;
1064 rep->rr_recv_wr.wr_cqe = &rep->rr_cqe;
1065 rep->rr_recv_wr.sg_list = &rep->rr_rdmabuf->rg_iov;
1066 rep->rr_recv_wr.num_sge = 1;
1067 rep->rr_temp = temp;
1068 return rep;
1069
1070out_free:
1071 kfree(rep);
1072out:
1073 return NULL;
1074}
1075
1076static void rpcrdma_rep_destroy(struct rpcrdma_rep *rep)
1077{
1078 rpcrdma_regbuf_free(rep->rr_rdmabuf);
1079 kfree(rep);
1080}
1081
1082static struct rpcrdma_rep *rpcrdma_rep_get_locked(struct rpcrdma_buffer *buf)
1083{
1084 struct llist_node *node;
1085
1086 /* Calls to llist_del_first are required to be serialized */
1087 node = llist_del_first(&buf->rb_free_reps);
1088 if (!node)
1089 return NULL;
1090 return llist_entry(node, struct rpcrdma_rep, rr_node);
1091}
1092
1093static void rpcrdma_rep_put(struct rpcrdma_buffer *buf,
1094 struct rpcrdma_rep *rep)
1095{
1096 if (!rep->rr_temp)
1097 llist_add(&rep->rr_node, &buf->rb_free_reps);
1098 else
1099 rpcrdma_rep_destroy(rep);
1100}
1101
1102static void rpcrdma_reps_destroy(struct rpcrdma_buffer *buf)
1103{
1104 struct rpcrdma_rep *rep;
1105
1106 while ((rep = rpcrdma_rep_get_locked(buf)) != NULL)
1107 rpcrdma_rep_destroy(rep);
1108}
1109
1110/**
1111 * rpcrdma_buffer_create - Create initial set of req/rep objects
1112 * @r_xprt: transport instance to (re)initialize
1113 *
1114 * Returns zero on success, otherwise a negative errno.
1115 */
1116int rpcrdma_buffer_create(struct rpcrdma_xprt *r_xprt)
1117{
1118 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
1119 int i, rc;
1120
1121 buf->rb_max_requests = r_xprt->rx_ep.rep_max_requests;
1122 buf->rb_bc_srv_max_requests = 0;
1123 spin_lock_init(&buf->rb_lock);
1124 INIT_LIST_HEAD(&buf->rb_mrs);
1125 INIT_LIST_HEAD(&buf->rb_all_mrs);
1126 INIT_WORK(&buf->rb_refresh_worker, rpcrdma_mr_refresh_worker);
1127
1128 rpcrdma_mrs_create(r_xprt);
1129
1130 INIT_LIST_HEAD(&buf->rb_send_bufs);
1131 INIT_LIST_HEAD(&buf->rb_allreqs);
1132
1133 rc = -ENOMEM;
1134 for (i = 0; i < buf->rb_max_requests; i++) {
1135 struct rpcrdma_req *req;
1136
1137 req = rpcrdma_req_create(r_xprt, RPCRDMA_V1_DEF_INLINE_SIZE,
1138 GFP_KERNEL);
1139 if (!req)
1140 goto out;
1141 list_add(&req->rl_list, &buf->rb_send_bufs);
1142 }
1143
1144 buf->rb_credits = 1;
1145 init_llist_head(&buf->rb_free_reps);
1146
1147 rc = rpcrdma_sendctxs_create(r_xprt);
1148 if (rc)
1149 goto out;
1150
1151 return 0;
1152out:
1153 rpcrdma_buffer_destroy(buf);
1154 return rc;
1155}
1156
1157/**
1158 * rpcrdma_req_destroy - Destroy an rpcrdma_req object
1159 * @req: unused object to be destroyed
1160 *
1161 * This function assumes that the caller prevents concurrent device
1162 * unload and transport tear-down.
1163 */
1164void rpcrdma_req_destroy(struct rpcrdma_req *req)
1165{
1166 list_del(&req->rl_all);
1167
1168 while (!list_empty(&req->rl_free_mrs))
1169 rpcrdma_mr_free(rpcrdma_mr_pop(&req->rl_free_mrs));
1170
1171 rpcrdma_regbuf_free(req->rl_recvbuf);
1172 rpcrdma_regbuf_free(req->rl_sendbuf);
1173 rpcrdma_regbuf_free(req->rl_rdmabuf);
1174 kfree(req);
1175}
1176
1177static void
1178rpcrdma_mrs_destroy(struct rpcrdma_buffer *buf)
1179{
1180 struct rpcrdma_xprt *r_xprt = container_of(buf, struct rpcrdma_xprt,
1181 rx_buf);
1182 struct rpcrdma_mr *mr;
1183 unsigned int count;
1184
1185 count = 0;
1186 spin_lock(&buf->rb_lock);
1187 while ((mr = list_first_entry_or_null(&buf->rb_all_mrs,
1188 struct rpcrdma_mr,
1189 mr_all)) != NULL) {
1190 list_del(&mr->mr_all);
1191 spin_unlock(&buf->rb_lock);
1192
1193 frwr_release_mr(mr);
1194 count++;
1195 spin_lock(&buf->rb_lock);
1196 }
1197 spin_unlock(&buf->rb_lock);
1198 r_xprt->rx_stats.mrs_allocated = 0;
1199}
1200
1201/**
1202 * rpcrdma_buffer_destroy - Release all hw resources
1203 * @buf: root control block for resources
1204 *
1205 * ORDERING: relies on a prior rpcrdma_xprt_drain :
1206 * - No more Send or Receive completions can occur
1207 * - All MRs, reps, and reqs are returned to their free lists
1208 */
1209void
1210rpcrdma_buffer_destroy(struct rpcrdma_buffer *buf)
1211{
1212 cancel_work_sync(&buf->rb_refresh_worker);
1213
1214 rpcrdma_sendctxs_destroy(buf);
1215 rpcrdma_reps_destroy(buf);
1216
1217 while (!list_empty(&buf->rb_send_bufs)) {
1218 struct rpcrdma_req *req;
1219
1220 req = list_first_entry(&buf->rb_send_bufs,
1221 struct rpcrdma_req, rl_list);
1222 list_del(&req->rl_list);
1223 rpcrdma_req_destroy(req);
1224 }
1225
1226 rpcrdma_mrs_destroy(buf);
1227}
1228
1229/**
1230 * rpcrdma_mr_get - Allocate an rpcrdma_mr object
1231 * @r_xprt: controlling transport
1232 *
1233 * Returns an initialized rpcrdma_mr or NULL if no free
1234 * rpcrdma_mr objects are available.
1235 */
1236struct rpcrdma_mr *
1237rpcrdma_mr_get(struct rpcrdma_xprt *r_xprt)
1238{
1239 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
1240 struct rpcrdma_mr *mr;
1241
1242 spin_lock(&buf->rb_lock);
1243 mr = rpcrdma_mr_pop(&buf->rb_mrs);
1244 spin_unlock(&buf->rb_lock);
1245 return mr;
1246}
1247
1248/**
1249 * rpcrdma_mr_put - DMA unmap an MR and release it
1250 * @mr: MR to release
1251 *
1252 */
1253void rpcrdma_mr_put(struct rpcrdma_mr *mr)
1254{
1255 struct rpcrdma_xprt *r_xprt = mr->mr_xprt;
1256
1257 if (mr->mr_dir != DMA_NONE) {
1258 trace_xprtrdma_mr_unmap(mr);
1259 ib_dma_unmap_sg(r_xprt->rx_ia.ri_id->device,
1260 mr->mr_sg, mr->mr_nents, mr->mr_dir);
1261 mr->mr_dir = DMA_NONE;
1262 }
1263
1264 rpcrdma_mr_push(mr, &mr->mr_req->rl_free_mrs);
1265}
1266
1267static void rpcrdma_mr_free(struct rpcrdma_mr *mr)
1268{
1269 struct rpcrdma_xprt *r_xprt = mr->mr_xprt;
1270 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
1271
1272 mr->mr_req = NULL;
1273 spin_lock(&buf->rb_lock);
1274 rpcrdma_mr_push(mr, &buf->rb_mrs);
1275 spin_unlock(&buf->rb_lock);
1276}
1277
1278/**
1279 * rpcrdma_buffer_get - Get a request buffer
1280 * @buffers: Buffer pool from which to obtain a buffer
1281 *
1282 * Returns a fresh rpcrdma_req, or NULL if none are available.
1283 */
1284struct rpcrdma_req *
1285rpcrdma_buffer_get(struct rpcrdma_buffer *buffers)
1286{
1287 struct rpcrdma_req *req;
1288
1289 spin_lock(&buffers->rb_lock);
1290 req = list_first_entry_or_null(&buffers->rb_send_bufs,
1291 struct rpcrdma_req, rl_list);
1292 if (req)
1293 list_del_init(&req->rl_list);
1294 spin_unlock(&buffers->rb_lock);
1295 return req;
1296}
1297
1298/**
1299 * rpcrdma_buffer_put - Put request/reply buffers back into pool
1300 * @buffers: buffer pool
1301 * @req: object to return
1302 *
1303 */
1304void rpcrdma_buffer_put(struct rpcrdma_buffer *buffers, struct rpcrdma_req *req)
1305{
1306 if (req->rl_reply)
1307 rpcrdma_rep_put(buffers, req->rl_reply);
1308 req->rl_reply = NULL;
1309
1310 spin_lock(&buffers->rb_lock);
1311 list_add(&req->rl_list, &buffers->rb_send_bufs);
1312 spin_unlock(&buffers->rb_lock);
1313}
1314
1315/**
1316 * rpcrdma_recv_buffer_put - Release rpcrdma_rep back to free list
1317 * @rep: rep to release
1318 *
1319 * Used after error conditions.
1320 */
1321void rpcrdma_recv_buffer_put(struct rpcrdma_rep *rep)
1322{
1323 rpcrdma_rep_put(&rep->rr_rxprt->rx_buf, rep);
1324}
1325
1326/* Returns a pointer to a rpcrdma_regbuf object, or NULL.
1327 *
1328 * xprtrdma uses a regbuf for posting an outgoing RDMA SEND, or for
1329 * receiving the payload of RDMA RECV operations. During Long Calls
1330 * or Replies they may be registered externally via frwr_map.
1331 */
1332static struct rpcrdma_regbuf *
1333rpcrdma_regbuf_alloc(size_t size, enum dma_data_direction direction,
1334 gfp_t flags)
1335{
1336 struct rpcrdma_regbuf *rb;
1337
1338 rb = kmalloc(sizeof(*rb), flags);
1339 if (!rb)
1340 return NULL;
1341 rb->rg_data = kmalloc(size, flags);
1342 if (!rb->rg_data) {
1343 kfree(rb);
1344 return NULL;
1345 }
1346
1347 rb->rg_device = NULL;
1348 rb->rg_direction = direction;
1349 rb->rg_iov.length = size;
1350 return rb;
1351}
1352
1353/**
1354 * rpcrdma_regbuf_realloc - re-allocate a SEND/RECV buffer
1355 * @rb: regbuf to reallocate
1356 * @size: size of buffer to be allocated, in bytes
1357 * @flags: GFP flags
1358 *
1359 * Returns true if reallocation was successful. If false is
1360 * returned, @rb is left untouched.
1361 */
1362bool rpcrdma_regbuf_realloc(struct rpcrdma_regbuf *rb, size_t size, gfp_t flags)
1363{
1364 void *buf;
1365
1366 buf = kmalloc(size, flags);
1367 if (!buf)
1368 return false;
1369
1370 rpcrdma_regbuf_dma_unmap(rb);
1371 kfree(rb->rg_data);
1372
1373 rb->rg_data = buf;
1374 rb->rg_iov.length = size;
1375 return true;
1376}
1377
1378/**
1379 * __rpcrdma_regbuf_dma_map - DMA-map a regbuf
1380 * @r_xprt: controlling transport instance
1381 * @rb: regbuf to be mapped
1382 *
1383 * Returns true if the buffer is now DMA mapped to @r_xprt's device
1384 */
1385bool __rpcrdma_regbuf_dma_map(struct rpcrdma_xprt *r_xprt,
1386 struct rpcrdma_regbuf *rb)
1387{
1388 struct ib_device *device = r_xprt->rx_ia.ri_id->device;
1389
1390 if (rb->rg_direction == DMA_NONE)
1391 return false;
1392
1393 rb->rg_iov.addr = ib_dma_map_single(device, rdmab_data(rb),
1394 rdmab_length(rb), rb->rg_direction);
1395 if (ib_dma_mapping_error(device, rdmab_addr(rb))) {
1396 trace_xprtrdma_dma_maperr(rdmab_addr(rb));
1397 return false;
1398 }
1399
1400 rb->rg_device = device;
1401 rb->rg_iov.lkey = r_xprt->rx_ia.ri_pd->local_dma_lkey;
1402 return true;
1403}
1404
1405static void rpcrdma_regbuf_dma_unmap(struct rpcrdma_regbuf *rb)
1406{
1407 if (!rb)
1408 return;
1409
1410 if (!rpcrdma_regbuf_is_mapped(rb))
1411 return;
1412
1413 ib_dma_unmap_single(rb->rg_device, rdmab_addr(rb), rdmab_length(rb),
1414 rb->rg_direction);
1415 rb->rg_device = NULL;
1416}
1417
1418static void rpcrdma_regbuf_free(struct rpcrdma_regbuf *rb)
1419{
1420 rpcrdma_regbuf_dma_unmap(rb);
1421 if (rb)
1422 kfree(rb->rg_data);
1423 kfree(rb);
1424}
1425
1426/**
1427 * rpcrdma_ep_post - Post WRs to a transport's Send Queue
1428 * @ia: transport's device information
1429 * @ep: transport's RDMA endpoint information
1430 * @req: rpcrdma_req containing the Send WR to post
1431 *
1432 * Returns 0 if the post was successful, otherwise -ENOTCONN
1433 * is returned.
1434 */
1435int
1436rpcrdma_ep_post(struct rpcrdma_ia *ia,
1437 struct rpcrdma_ep *ep,
1438 struct rpcrdma_req *req)
1439{
1440 struct ib_send_wr *send_wr = &req->rl_sendctx->sc_wr;
1441 int rc;
1442
1443 if (!ep->rep_send_count || kref_read(&req->rl_kref) > 1) {
1444 send_wr->send_flags |= IB_SEND_SIGNALED;
1445 ep->rep_send_count = ep->rep_send_batch;
1446 } else {
1447 send_wr->send_flags &= ~IB_SEND_SIGNALED;
1448 --ep->rep_send_count;
1449 }
1450
1451 rc = frwr_send(ia, req);
1452 trace_xprtrdma_post_send(req, rc);
1453 if (rc)
1454 return -ENOTCONN;
1455 return 0;
1456}
1457
1458static void
1459rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, bool temp)
1460{
1461 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
1462 struct rpcrdma_ep *ep = &r_xprt->rx_ep;
1463 struct ib_recv_wr *i, *wr, *bad_wr;
1464 struct rpcrdma_rep *rep;
1465 int needed, count, rc;
1466
1467 rc = 0;
1468 count = 0;
1469
1470 needed = buf->rb_credits + (buf->rb_bc_srv_max_requests << 1);
1471 if (likely(ep->rep_receive_count > needed))
1472 goto out;
1473 needed -= ep->rep_receive_count;
1474 if (!temp)
1475 needed += RPCRDMA_MAX_RECV_BATCH;
1476
1477 /* fast path: all needed reps can be found on the free list */
1478 wr = NULL;
1479 while (needed) {
1480 rep = rpcrdma_rep_get_locked(buf);
1481 if (!rep)
1482 rep = rpcrdma_rep_create(r_xprt, temp);
1483 if (!rep)
1484 break;
1485
1486 rep->rr_recv_wr.next = wr;
1487 wr = &rep->rr_recv_wr;
1488 --needed;
1489 }
1490 if (!wr)
1491 goto out;
1492
1493 for (i = wr; i; i = i->next) {
1494 rep = container_of(i, struct rpcrdma_rep, rr_recv_wr);
1495
1496 if (!rpcrdma_regbuf_dma_map(r_xprt, rep->rr_rdmabuf))
1497 goto release_wrs;
1498
1499 trace_xprtrdma_post_recv(rep);
1500 ++count;
1501 }
1502
1503 rc = ib_post_recv(r_xprt->rx_ia.ri_id->qp, wr,
1504 (const struct ib_recv_wr **)&bad_wr);
1505out:
1506 trace_xprtrdma_post_recvs(r_xprt, count, rc);
1507 if (rc) {
1508 for (wr = bad_wr; wr;) {
1509 struct rpcrdma_rep *rep;
1510
1511 rep = container_of(wr, struct rpcrdma_rep, rr_recv_wr);
1512 wr = wr->next;
1513 rpcrdma_recv_buffer_put(rep);
1514 --count;
1515 }
1516 }
1517 ep->rep_receive_count += count;
1518 return;
1519
1520release_wrs:
1521 for (i = wr; i;) {
1522 rep = container_of(i, struct rpcrdma_rep, rr_recv_wr);
1523 i = i->next;
1524 rpcrdma_recv_buffer_put(rep);
1525 }
1526}