2 * Copyright (c) 2014-2017 Oracle. All rights reserved.
3 * Copyright (c) 2003-2007 Network Appliance, Inc. All rights reserved.
5 * This software is available to you under a choice of one of two
6 * licenses. You may choose to be licensed under the terms of the GNU
7 * General Public License (GPL) Version 2, available from the file
8 * COPYING in the main directory of this source tree, or the BSD-type
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
15 * Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
18 * Redistributions in binary form must reproduce the above
19 * copyright notice, this list of conditions and the following
20 * disclaimer in the documentation and/or other materials provided
21 * with the distribution.
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24 * its contributors may be used to endorse or promote products
25 * derived from this software without specific prior written
28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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30 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
31 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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33 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
34 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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38 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
44 * Encapsulates the major functions managing:
51 #include <linux/interrupt.h>
52 #include <linux/slab.h>
53 #include <linux/sunrpc/addr.h>
54 #include <linux/sunrpc/svc_rdma.h>
56 #include <asm-generic/barrier.h>
57 #include <asm/bitops.h>
59 #include <rdma/ib_cm.h>
61 #include "xprt_rdma.h"
67 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
68 # define RPCDBG_FACILITY RPCDBG_TRANS
74 static void rpcrdma_mrs_create(struct rpcrdma_xprt *r_xprt);
75 static void rpcrdma_mrs_destroy(struct rpcrdma_buffer *buf);
76 static void rpcrdma_dma_unmap_regbuf(struct rpcrdma_regbuf *rb);
78 struct workqueue_struct *rpcrdma_receive_wq __read_mostly;
81 rpcrdma_alloc_wq(void)
83 struct workqueue_struct *recv_wq;
85 recv_wq = alloc_workqueue("xprtrdma_receive",
86 WQ_MEM_RECLAIM | WQ_HIGHPRI,
91 rpcrdma_receive_wq = recv_wq;
96 rpcrdma_destroy_wq(void)
98 struct workqueue_struct *wq;
100 if (rpcrdma_receive_wq) {
101 wq = rpcrdma_receive_wq;
102 rpcrdma_receive_wq = NULL;
103 destroy_workqueue(wq);
108 rpcrdma_qp_async_error_upcall(struct ib_event *event, void *context)
110 struct rpcrdma_ep *ep = context;
111 struct rpcrdma_xprt *r_xprt = container_of(ep, struct rpcrdma_xprt,
114 trace_xprtrdma_qp_error(r_xprt, event);
115 pr_err("rpcrdma: %s on device %s ep %p\n",
116 ib_event_msg(event->event), event->device->name, context);
118 if (ep->rep_connected == 1) {
119 ep->rep_connected = -EIO;
120 rpcrdma_conn_func(ep);
121 wake_up_all(&ep->rep_connect_wait);
126 * rpcrdma_wc_send - Invoked by RDMA provider for each polled Send WC
127 * @cq: completion queue (ignored)
132 rpcrdma_wc_send(struct ib_cq *cq, struct ib_wc *wc)
134 struct ib_cqe *cqe = wc->wr_cqe;
135 struct rpcrdma_sendctx *sc =
136 container_of(cqe, struct rpcrdma_sendctx, sc_cqe);
138 /* WARNING: Only wr_cqe and status are reliable at this point */
139 trace_xprtrdma_wc_send(sc, wc);
140 if (wc->status != IB_WC_SUCCESS && wc->status != IB_WC_WR_FLUSH_ERR)
141 pr_err("rpcrdma: Send: %s (%u/0x%x)\n",
142 ib_wc_status_msg(wc->status),
143 wc->status, wc->vendor_err);
145 rpcrdma_sendctx_put_locked(sc);
149 * rpcrdma_wc_receive - Invoked by RDMA provider for each polled Receive WC
150 * @cq: completion queue (ignored)
155 rpcrdma_wc_receive(struct ib_cq *cq, struct ib_wc *wc)
157 struct ib_cqe *cqe = wc->wr_cqe;
158 struct rpcrdma_rep *rep = container_of(cqe, struct rpcrdma_rep,
161 /* WARNING: Only wr_id and status are reliable at this point */
162 trace_xprtrdma_wc_receive(rep, wc);
163 if (wc->status != IB_WC_SUCCESS)
166 /* status == SUCCESS means all fields in wc are trustworthy */
167 rpcrdma_set_xdrlen(&rep->rr_hdrbuf, wc->byte_len);
168 rep->rr_wc_flags = wc->wc_flags;
169 rep->rr_inv_rkey = wc->ex.invalidate_rkey;
171 ib_dma_sync_single_for_cpu(rdmab_device(rep->rr_rdmabuf),
172 rdmab_addr(rep->rr_rdmabuf),
173 wc->byte_len, DMA_FROM_DEVICE);
176 rpcrdma_reply_handler(rep);
180 if (wc->status != IB_WC_WR_FLUSH_ERR)
181 pr_err("rpcrdma: Recv: %s (%u/0x%x)\n",
182 ib_wc_status_msg(wc->status),
183 wc->status, wc->vendor_err);
184 rpcrdma_set_xdrlen(&rep->rr_hdrbuf, 0);
189 rpcrdma_update_connect_private(struct rpcrdma_xprt *r_xprt,
190 struct rdma_conn_param *param)
192 struct rpcrdma_create_data_internal *cdata = &r_xprt->rx_data;
193 const struct rpcrdma_connect_private *pmsg = param->private_data;
194 unsigned int rsize, wsize;
196 /* Default settings for RPC-over-RDMA Version One */
197 r_xprt->rx_ia.ri_implicit_roundup = xprt_rdma_pad_optimize;
198 rsize = RPCRDMA_V1_DEF_INLINE_SIZE;
199 wsize = RPCRDMA_V1_DEF_INLINE_SIZE;
202 pmsg->cp_magic == rpcrdma_cmp_magic &&
203 pmsg->cp_version == RPCRDMA_CMP_VERSION) {
204 r_xprt->rx_ia.ri_implicit_roundup = true;
205 rsize = rpcrdma_decode_buffer_size(pmsg->cp_send_size);
206 wsize = rpcrdma_decode_buffer_size(pmsg->cp_recv_size);
209 if (rsize < cdata->inline_rsize)
210 cdata->inline_rsize = rsize;
211 if (wsize < cdata->inline_wsize)
212 cdata->inline_wsize = wsize;
213 dprintk("RPC: %s: max send %u, max recv %u\n",
214 __func__, cdata->inline_wsize, cdata->inline_rsize);
215 rpcrdma_set_max_header_sizes(r_xprt);
219 rpcrdma_conn_upcall(struct rdma_cm_id *id, struct rdma_cm_event *event)
221 struct rpcrdma_xprt *xprt = id->context;
222 struct rpcrdma_ia *ia = &xprt->rx_ia;
223 struct rpcrdma_ep *ep = &xprt->rx_ep;
226 trace_xprtrdma_conn_upcall(xprt, event);
227 switch (event->event) {
228 case RDMA_CM_EVENT_ADDR_RESOLVED:
229 case RDMA_CM_EVENT_ROUTE_RESOLVED:
231 complete(&ia->ri_done);
233 case RDMA_CM_EVENT_ADDR_ERROR:
234 ia->ri_async_rc = -EHOSTUNREACH;
235 complete(&ia->ri_done);
237 case RDMA_CM_EVENT_ROUTE_ERROR:
238 ia->ri_async_rc = -ENETUNREACH;
239 complete(&ia->ri_done);
241 case RDMA_CM_EVENT_DEVICE_REMOVAL:
242 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
243 pr_info("rpcrdma: removing device %s for %s:%s\n",
245 rpcrdma_addrstr(xprt), rpcrdma_portstr(xprt));
247 set_bit(RPCRDMA_IAF_REMOVING, &ia->ri_flags);
248 ep->rep_connected = -ENODEV;
249 xprt_force_disconnect(&xprt->rx_xprt);
250 wait_for_completion(&ia->ri_remove_done);
253 ia->ri_device = NULL;
254 /* Return 1 to ensure the core destroys the id. */
256 case RDMA_CM_EVENT_ESTABLISHED:
257 ++xprt->rx_xprt.connect_cookie;
259 rpcrdma_update_connect_private(xprt, &event->param.conn);
261 case RDMA_CM_EVENT_CONNECT_ERROR:
262 connstate = -ENOTCONN;
264 case RDMA_CM_EVENT_UNREACHABLE:
265 connstate = -ENETDOWN;
267 case RDMA_CM_EVENT_REJECTED:
268 dprintk("rpcrdma: connection to %s:%s rejected: %s\n",
269 rpcrdma_addrstr(xprt), rpcrdma_portstr(xprt),
270 rdma_reject_msg(id, event->status));
271 connstate = -ECONNREFUSED;
272 if (event->status == IB_CM_REJ_STALE_CONN)
275 case RDMA_CM_EVENT_DISCONNECTED:
276 ++xprt->rx_xprt.connect_cookie;
277 connstate = -ECONNABORTED;
279 xprt->rx_buf.rb_credits = 1;
280 ep->rep_connected = connstate;
281 rpcrdma_conn_func(ep);
282 wake_up_all(&ep->rep_connect_wait);
285 dprintk("RPC: %s: %s:%s on %s/%s (ep 0x%p): %s\n",
287 rpcrdma_addrstr(xprt), rpcrdma_portstr(xprt),
288 ia->ri_device->name, ia->ri_ops->ro_displayname,
289 ep, rdma_event_msg(event->event));
296 static struct rdma_cm_id *
297 rpcrdma_create_id(struct rpcrdma_xprt *xprt, struct rpcrdma_ia *ia)
299 unsigned long wtimeout = msecs_to_jiffies(RDMA_RESOLVE_TIMEOUT) + 1;
300 struct rdma_cm_id *id;
303 trace_xprtrdma_conn_start(xprt);
305 init_completion(&ia->ri_done);
306 init_completion(&ia->ri_remove_done);
308 id = rdma_create_id(&init_net, rpcrdma_conn_upcall, xprt, RDMA_PS_TCP,
312 dprintk("RPC: %s: rdma_create_id() failed %i\n",
317 ia->ri_async_rc = -ETIMEDOUT;
318 rc = rdma_resolve_addr(id, NULL,
319 (struct sockaddr *)&xprt->rx_xprt.addr,
320 RDMA_RESOLVE_TIMEOUT);
322 dprintk("RPC: %s: rdma_resolve_addr() failed %i\n",
326 rc = wait_for_completion_interruptible_timeout(&ia->ri_done, wtimeout);
328 trace_xprtrdma_conn_tout(xprt);
332 rc = ia->ri_async_rc;
336 ia->ri_async_rc = -ETIMEDOUT;
337 rc = rdma_resolve_route(id, RDMA_RESOLVE_TIMEOUT);
339 dprintk("RPC: %s: rdma_resolve_route() failed %i\n",
343 rc = wait_for_completion_interruptible_timeout(&ia->ri_done, wtimeout);
345 trace_xprtrdma_conn_tout(xprt);
348 rc = ia->ri_async_rc;
360 * Exported functions.
364 * rpcrdma_ia_open - Open and initialize an Interface Adapter.
365 * @xprt: transport with IA to (re)initialize
367 * Returns 0 on success, negative errno if an appropriate
368 * Interface Adapter could not be found and opened.
371 rpcrdma_ia_open(struct rpcrdma_xprt *xprt)
373 struct rpcrdma_ia *ia = &xprt->rx_ia;
376 ia->ri_id = rpcrdma_create_id(xprt, ia);
377 if (IS_ERR(ia->ri_id)) {
378 rc = PTR_ERR(ia->ri_id);
381 ia->ri_device = ia->ri_id->device;
383 ia->ri_pd = ib_alloc_pd(ia->ri_device, 0);
384 if (IS_ERR(ia->ri_pd)) {
385 rc = PTR_ERR(ia->ri_pd);
386 pr_err("rpcrdma: ib_alloc_pd() returned %d\n", rc);
390 switch (xprt_rdma_memreg_strategy) {
392 if (frwr_is_supported(ia)) {
393 ia->ri_ops = &rpcrdma_frwr_memreg_ops;
397 case RPCRDMA_MTHCAFMR:
398 if (fmr_is_supported(ia)) {
399 ia->ri_ops = &rpcrdma_fmr_memreg_ops;
404 pr_err("rpcrdma: Device %s does not support memreg mode %d\n",
405 ia->ri_device->name, xprt_rdma_memreg_strategy);
413 rpcrdma_ia_close(ia);
418 * rpcrdma_ia_remove - Handle device driver unload
419 * @ia: interface adapter being removed
421 * Divest transport H/W resources associated with this adapter,
422 * but allow it to be restored later.
425 rpcrdma_ia_remove(struct rpcrdma_ia *ia)
427 struct rpcrdma_xprt *r_xprt = container_of(ia, struct rpcrdma_xprt,
429 struct rpcrdma_ep *ep = &r_xprt->rx_ep;
430 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
431 struct rpcrdma_req *req;
432 struct rpcrdma_rep *rep;
434 cancel_delayed_work_sync(&buf->rb_refresh_worker);
436 /* This is similar to rpcrdma_ep_destroy, but:
437 * - Don't cancel the connect worker.
438 * - Don't call rpcrdma_ep_disconnect, which waits
439 * for another conn upcall, which will deadlock.
440 * - rdma_disconnect is unneeded, the underlying
441 * connection is already gone.
444 ib_drain_qp(ia->ri_id->qp);
445 rdma_destroy_qp(ia->ri_id);
446 ia->ri_id->qp = NULL;
448 ib_free_cq(ep->rep_attr.recv_cq);
449 ep->rep_attr.recv_cq = NULL;
450 ib_free_cq(ep->rep_attr.send_cq);
451 ep->rep_attr.send_cq = NULL;
453 /* The ULP is responsible for ensuring all DMA
454 * mappings and MRs are gone.
456 list_for_each_entry(rep, &buf->rb_recv_bufs, rr_list)
457 rpcrdma_dma_unmap_regbuf(rep->rr_rdmabuf);
458 list_for_each_entry(req, &buf->rb_allreqs, rl_all) {
459 rpcrdma_dma_unmap_regbuf(req->rl_rdmabuf);
460 rpcrdma_dma_unmap_regbuf(req->rl_sendbuf);
461 rpcrdma_dma_unmap_regbuf(req->rl_recvbuf);
463 rpcrdma_mrs_destroy(buf);
464 ib_dealloc_pd(ia->ri_pd);
467 /* Allow waiters to continue */
468 complete(&ia->ri_remove_done);
470 trace_xprtrdma_remove(r_xprt);
474 * rpcrdma_ia_close - Clean up/close an IA.
475 * @ia: interface adapter to close
479 rpcrdma_ia_close(struct rpcrdma_ia *ia)
481 if (ia->ri_id != NULL && !IS_ERR(ia->ri_id)) {
483 rdma_destroy_qp(ia->ri_id);
484 rdma_destroy_id(ia->ri_id);
487 ia->ri_device = NULL;
489 /* If the pd is still busy, xprtrdma missed freeing a resource */
490 if (ia->ri_pd && !IS_ERR(ia->ri_pd))
491 ib_dealloc_pd(ia->ri_pd);
496 * Create unconnected endpoint.
499 rpcrdma_ep_create(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia,
500 struct rpcrdma_create_data_internal *cdata)
502 struct rpcrdma_connect_private *pmsg = &ep->rep_cm_private;
503 unsigned int max_qp_wr, max_sge;
504 struct ib_cq *sendcq, *recvcq;
507 max_sge = min_t(unsigned int, ia->ri_device->attrs.max_sge,
508 RPCRDMA_MAX_SEND_SGES);
509 if (max_sge < RPCRDMA_MIN_SEND_SGES) {
510 pr_warn("rpcrdma: HCA provides only %d send SGEs\n", max_sge);
513 ia->ri_max_send_sges = max_sge;
515 if (ia->ri_device->attrs.max_qp_wr <= RPCRDMA_BACKWARD_WRS) {
516 dprintk("RPC: %s: insufficient wqe's available\n",
520 max_qp_wr = ia->ri_device->attrs.max_qp_wr - RPCRDMA_BACKWARD_WRS - 1;
522 /* check provider's send/recv wr limits */
523 if (cdata->max_requests > max_qp_wr)
524 cdata->max_requests = max_qp_wr;
526 ep->rep_attr.event_handler = rpcrdma_qp_async_error_upcall;
527 ep->rep_attr.qp_context = ep;
528 ep->rep_attr.srq = NULL;
529 ep->rep_attr.cap.max_send_wr = cdata->max_requests;
530 ep->rep_attr.cap.max_send_wr += RPCRDMA_BACKWARD_WRS;
531 ep->rep_attr.cap.max_send_wr += 1; /* drain cqe */
532 rc = ia->ri_ops->ro_open(ia, ep, cdata);
535 ep->rep_attr.cap.max_recv_wr = cdata->max_requests;
536 ep->rep_attr.cap.max_recv_wr += RPCRDMA_BACKWARD_WRS;
537 ep->rep_attr.cap.max_recv_wr += 1; /* drain cqe */
538 ep->rep_attr.cap.max_send_sge = max_sge;
539 ep->rep_attr.cap.max_recv_sge = 1;
540 ep->rep_attr.cap.max_inline_data = 0;
541 ep->rep_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
542 ep->rep_attr.qp_type = IB_QPT_RC;
543 ep->rep_attr.port_num = ~0;
545 dprintk("RPC: %s: requested max: dtos: send %d recv %d; "
546 "iovs: send %d recv %d\n",
548 ep->rep_attr.cap.max_send_wr,
549 ep->rep_attr.cap.max_recv_wr,
550 ep->rep_attr.cap.max_send_sge,
551 ep->rep_attr.cap.max_recv_sge);
553 /* set trigger for requesting send completion */
554 ep->rep_send_batch = min_t(unsigned int, RPCRDMA_MAX_SEND_BATCH,
555 cdata->max_requests >> 2);
556 ep->rep_send_count = ep->rep_send_batch;
557 init_waitqueue_head(&ep->rep_connect_wait);
558 INIT_DELAYED_WORK(&ep->rep_connect_worker, rpcrdma_connect_worker);
560 sendcq = ib_alloc_cq(ia->ri_device, NULL,
561 ep->rep_attr.cap.max_send_wr + 1,
562 1, IB_POLL_WORKQUEUE);
563 if (IS_ERR(sendcq)) {
564 rc = PTR_ERR(sendcq);
565 dprintk("RPC: %s: failed to create send CQ: %i\n",
570 recvcq = ib_alloc_cq(ia->ri_device, NULL,
571 ep->rep_attr.cap.max_recv_wr + 1,
572 0, IB_POLL_WORKQUEUE);
573 if (IS_ERR(recvcq)) {
574 rc = PTR_ERR(recvcq);
575 dprintk("RPC: %s: failed to create recv CQ: %i\n",
580 ep->rep_attr.send_cq = sendcq;
581 ep->rep_attr.recv_cq = recvcq;
583 /* Initialize cma parameters */
584 memset(&ep->rep_remote_cma, 0, sizeof(ep->rep_remote_cma));
586 /* Prepare RDMA-CM private message */
587 pmsg->cp_magic = rpcrdma_cmp_magic;
588 pmsg->cp_version = RPCRDMA_CMP_VERSION;
589 pmsg->cp_flags |= ia->ri_ops->ro_send_w_inv_ok;
590 pmsg->cp_send_size = rpcrdma_encode_buffer_size(cdata->inline_wsize);
591 pmsg->cp_recv_size = rpcrdma_encode_buffer_size(cdata->inline_rsize);
592 ep->rep_remote_cma.private_data = pmsg;
593 ep->rep_remote_cma.private_data_len = sizeof(*pmsg);
595 /* Client offers RDMA Read but does not initiate */
596 ep->rep_remote_cma.initiator_depth = 0;
597 ep->rep_remote_cma.responder_resources =
598 min_t(int, U8_MAX, ia->ri_device->attrs.max_qp_rd_atom);
600 /* Limit transport retries so client can detect server
601 * GID changes quickly. RPC layer handles re-establishing
602 * transport connection and retransmission.
604 ep->rep_remote_cma.retry_count = 6;
606 /* RPC-over-RDMA handles its own flow control. In addition,
607 * make all RNR NAKs visible so we know that RPC-over-RDMA
608 * flow control is working correctly (no NAKs should be seen).
610 ep->rep_remote_cma.flow_control = 0;
611 ep->rep_remote_cma.rnr_retry_count = 0;
624 * Disconnect and destroy endpoint. After this, the only
625 * valid operations on the ep are to free it (if dynamically
626 * allocated) or re-create it.
629 rpcrdma_ep_destroy(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
631 cancel_delayed_work_sync(&ep->rep_connect_worker);
633 if (ia->ri_id && ia->ri_id->qp) {
634 rpcrdma_ep_disconnect(ep, ia);
635 rdma_destroy_qp(ia->ri_id);
636 ia->ri_id->qp = NULL;
639 if (ep->rep_attr.recv_cq)
640 ib_free_cq(ep->rep_attr.recv_cq);
641 if (ep->rep_attr.send_cq)
642 ib_free_cq(ep->rep_attr.send_cq);
645 /* Re-establish a connection after a device removal event.
646 * Unlike a normal reconnection, a fresh PD and a new set
647 * of MRs and buffers is needed.
650 rpcrdma_ep_recreate_xprt(struct rpcrdma_xprt *r_xprt,
651 struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
655 trace_xprtrdma_reinsert(r_xprt);
658 if (rpcrdma_ia_open(r_xprt))
662 err = rpcrdma_ep_create(ep, ia, &r_xprt->rx_data);
664 pr_err("rpcrdma: rpcrdma_ep_create returned %d\n", err);
669 err = rdma_create_qp(ia->ri_id, ia->ri_pd, &ep->rep_attr);
671 pr_err("rpcrdma: rdma_create_qp returned %d\n", err);
675 rpcrdma_mrs_create(r_xprt);
679 rpcrdma_ep_destroy(ep, ia);
681 rpcrdma_ia_close(ia);
687 rpcrdma_ep_reconnect(struct rpcrdma_xprt *r_xprt, struct rpcrdma_ep *ep,
688 struct rpcrdma_ia *ia)
690 struct rdma_cm_id *id, *old;
693 trace_xprtrdma_reconnect(r_xprt);
695 rpcrdma_ep_disconnect(ep, ia);
698 id = rpcrdma_create_id(r_xprt, ia);
702 /* As long as the new ID points to the same device as the
703 * old ID, we can reuse the transport's existing PD and all
704 * previously allocated MRs. Also, the same device means
705 * the transport's previous DMA mappings are still valid.
707 * This is a sanity check only. There should be no way these
708 * point to two different devices here.
712 if (ia->ri_device != id->device) {
713 pr_err("rpcrdma: can't reconnect on different device!\n");
717 err = rdma_create_qp(id, ia->ri_pd, &ep->rep_attr);
719 dprintk("RPC: %s: rdma_create_qp returned %d\n",
724 /* Atomically replace the transport's ID and QP. */
728 rdma_destroy_qp(old);
731 rdma_destroy_id(old);
737 * Connect unconnected endpoint.
740 rpcrdma_ep_connect(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
742 struct rpcrdma_xprt *r_xprt = container_of(ia, struct rpcrdma_xprt,
748 switch (ep->rep_connected) {
750 dprintk("RPC: %s: connecting...\n", __func__);
751 rc = rdma_create_qp(ia->ri_id, ia->ri_pd, &ep->rep_attr);
753 dprintk("RPC: %s: rdma_create_qp failed %i\n",
760 rc = rpcrdma_ep_recreate_xprt(r_xprt, ep, ia);
765 rc = rpcrdma_ep_reconnect(r_xprt, ep, ia);
770 ep->rep_connected = 0;
772 rc = rdma_connect(ia->ri_id, &ep->rep_remote_cma);
774 dprintk("RPC: %s: rdma_connect() failed with %i\n",
779 wait_event_interruptible(ep->rep_connect_wait, ep->rep_connected != 0);
780 if (ep->rep_connected <= 0) {
781 if (ep->rep_connected == -EAGAIN)
783 rc = ep->rep_connected;
787 dprintk("RPC: %s: connected\n", __func__);
788 extras = r_xprt->rx_buf.rb_bc_srv_max_requests;
790 rpcrdma_ep_post_extra_recv(r_xprt, extras);
794 ep->rep_connected = rc;
801 * rpcrdma_ep_disconnect
803 * This is separate from destroy to facilitate the ability
804 * to reconnect without recreating the endpoint.
806 * This call is not reentrant, and must not be made in parallel
807 * on the same endpoint.
810 rpcrdma_ep_disconnect(struct rpcrdma_ep *ep, struct rpcrdma_ia *ia)
814 rc = rdma_disconnect(ia->ri_id);
816 /* returns without wait if not connected */
817 wait_event_interruptible(ep->rep_connect_wait,
818 ep->rep_connected != 1);
820 ep->rep_connected = rc;
821 trace_xprtrdma_disconnect(container_of(ep, struct rpcrdma_xprt,
824 ib_drain_qp(ia->ri_id->qp);
827 /* Fixed-size circular FIFO queue. This implementation is wait-free and
830 * Consumer is the code path that posts Sends. This path dequeues a
831 * sendctx for use by a Send operation. Multiple consumer threads
832 * are serialized by the RPC transport lock, which allows only one
833 * ->send_request call at a time.
835 * Producer is the code path that handles Send completions. This path
836 * enqueues a sendctx that has been completed. Multiple producer
837 * threads are serialized by the ib_poll_cq() function.
840 /* rpcrdma_sendctxs_destroy() assumes caller has already quiesced
841 * queue activity, and ib_drain_qp has flushed all remaining Send
844 static void rpcrdma_sendctxs_destroy(struct rpcrdma_buffer *buf)
848 for (i = 0; i <= buf->rb_sc_last; i++)
849 kfree(buf->rb_sc_ctxs[i]);
850 kfree(buf->rb_sc_ctxs);
853 static struct rpcrdma_sendctx *rpcrdma_sendctx_create(struct rpcrdma_ia *ia)
855 struct rpcrdma_sendctx *sc;
857 sc = kzalloc(sizeof(*sc) +
858 ia->ri_max_send_sges * sizeof(struct ib_sge),
863 sc->sc_wr.wr_cqe = &sc->sc_cqe;
864 sc->sc_wr.sg_list = sc->sc_sges;
865 sc->sc_wr.opcode = IB_WR_SEND;
866 sc->sc_cqe.done = rpcrdma_wc_send;
870 static int rpcrdma_sendctxs_create(struct rpcrdma_xprt *r_xprt)
872 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
873 struct rpcrdma_sendctx *sc;
876 /* Maximum number of concurrent outstanding Send WRs. Capping
877 * the circular queue size stops Send Queue overflow by causing
878 * the ->send_request call to fail temporarily before too many
881 i = buf->rb_max_requests + RPCRDMA_MAX_BC_REQUESTS;
882 dprintk("RPC: %s: allocating %lu send_ctxs\n", __func__, i);
883 buf->rb_sc_ctxs = kcalloc(i, sizeof(sc), GFP_KERNEL);
884 if (!buf->rb_sc_ctxs)
887 buf->rb_sc_last = i - 1;
888 for (i = 0; i <= buf->rb_sc_last; i++) {
889 sc = rpcrdma_sendctx_create(&r_xprt->rx_ia);
893 sc->sc_xprt = r_xprt;
894 buf->rb_sc_ctxs[i] = sc;
900 rpcrdma_sendctxs_destroy(buf);
904 /* The sendctx queue is not guaranteed to have a size that is a
905 * power of two, thus the helpers in circ_buf.h cannot be used.
906 * The other option is to use modulus (%), which can be expensive.
908 static unsigned long rpcrdma_sendctx_next(struct rpcrdma_buffer *buf,
911 return likely(item < buf->rb_sc_last) ? item + 1 : 0;
915 * rpcrdma_sendctx_get_locked - Acquire a send context
916 * @buf: transport buffers from which to acquire an unused context
918 * Returns pointer to a free send completion context; or NULL if
919 * the queue is empty.
921 * Usage: Called to acquire an SGE array before preparing a Send WR.
923 * The caller serializes calls to this function (per rpcrdma_buffer),
924 * and provides an effective memory barrier that flushes the new value
927 struct rpcrdma_sendctx *rpcrdma_sendctx_get_locked(struct rpcrdma_buffer *buf)
929 struct rpcrdma_xprt *r_xprt;
930 struct rpcrdma_sendctx *sc;
931 unsigned long next_head;
933 next_head = rpcrdma_sendctx_next(buf, buf->rb_sc_head);
935 if (next_head == READ_ONCE(buf->rb_sc_tail))
938 /* ORDER: item must be accessed _before_ head is updated */
939 sc = buf->rb_sc_ctxs[next_head];
941 /* Releasing the lock in the caller acts as a memory
942 * barrier that flushes rb_sc_head.
944 buf->rb_sc_head = next_head;
949 /* The queue is "empty" if there have not been enough Send
950 * completions recently. This is a sign the Send Queue is
951 * backing up. Cause the caller to pause and try again.
953 dprintk("RPC: %s: empty sendctx queue\n", __func__);
954 r_xprt = container_of(buf, struct rpcrdma_xprt, rx_buf);
955 r_xprt->rx_stats.empty_sendctx_q++;
960 * rpcrdma_sendctx_put_locked - Release a send context
961 * @sc: send context to release
963 * Usage: Called from Send completion to return a sendctxt
966 * The caller serializes calls to this function (per rpcrdma_buffer).
968 void rpcrdma_sendctx_put_locked(struct rpcrdma_sendctx *sc)
970 struct rpcrdma_buffer *buf = &sc->sc_xprt->rx_buf;
971 unsigned long next_tail;
973 /* Unmap SGEs of previously completed by unsignaled
974 * Sends by walking up the queue until @sc is found.
976 next_tail = buf->rb_sc_tail;
978 next_tail = rpcrdma_sendctx_next(buf, next_tail);
980 /* ORDER: item must be accessed _before_ tail is updated */
981 rpcrdma_unmap_sendctx(buf->rb_sc_ctxs[next_tail]);
983 } while (buf->rb_sc_ctxs[next_tail] != sc);
985 /* Paired with READ_ONCE */
986 smp_store_release(&buf->rb_sc_tail, next_tail);
990 rpcrdma_mr_recovery_worker(struct work_struct *work)
992 struct rpcrdma_buffer *buf = container_of(work, struct rpcrdma_buffer,
993 rb_recovery_worker.work);
994 struct rpcrdma_mr *mr;
996 spin_lock(&buf->rb_recovery_lock);
997 while (!list_empty(&buf->rb_stale_mrs)) {
998 mr = rpcrdma_mr_pop(&buf->rb_stale_mrs);
999 spin_unlock(&buf->rb_recovery_lock);
1001 trace_xprtrdma_recover_mr(mr);
1002 mr->mr_xprt->rx_ia.ri_ops->ro_recover_mr(mr);
1004 spin_lock(&buf->rb_recovery_lock);
1006 spin_unlock(&buf->rb_recovery_lock);
1010 rpcrdma_mr_defer_recovery(struct rpcrdma_mr *mr)
1012 struct rpcrdma_xprt *r_xprt = mr->mr_xprt;
1013 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
1015 spin_lock(&buf->rb_recovery_lock);
1016 rpcrdma_mr_push(mr, &buf->rb_stale_mrs);
1017 spin_unlock(&buf->rb_recovery_lock);
1019 schedule_delayed_work(&buf->rb_recovery_worker, 0);
1023 rpcrdma_mrs_create(struct rpcrdma_xprt *r_xprt)
1025 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
1026 struct rpcrdma_ia *ia = &r_xprt->rx_ia;
1031 for (count = 0; count < 3; count++) {
1032 struct rpcrdma_mr *mr;
1035 mr = kzalloc(sizeof(*mr), GFP_KERNEL);
1039 rc = ia->ri_ops->ro_init_mr(ia, mr);
1045 mr->mr_xprt = r_xprt;
1047 list_add(&mr->mr_list, &free);
1048 list_add(&mr->mr_all, &all);
1051 spin_lock(&buf->rb_mrlock);
1052 list_splice(&free, &buf->rb_mrs);
1053 list_splice(&all, &buf->rb_all);
1054 r_xprt->rx_stats.mrs_allocated += count;
1055 spin_unlock(&buf->rb_mrlock);
1056 trace_xprtrdma_createmrs(r_xprt, count);
1058 xprt_write_space(&r_xprt->rx_xprt);
1062 rpcrdma_mr_refresh_worker(struct work_struct *work)
1064 struct rpcrdma_buffer *buf = container_of(work, struct rpcrdma_buffer,
1065 rb_refresh_worker.work);
1066 struct rpcrdma_xprt *r_xprt = container_of(buf, struct rpcrdma_xprt,
1069 rpcrdma_mrs_create(r_xprt);
1072 struct rpcrdma_req *
1073 rpcrdma_create_req(struct rpcrdma_xprt *r_xprt)
1075 struct rpcrdma_buffer *buffer = &r_xprt->rx_buf;
1076 struct rpcrdma_regbuf *rb;
1077 struct rpcrdma_req *req;
1079 req = kzalloc(sizeof(*req), GFP_KERNEL);
1081 return ERR_PTR(-ENOMEM);
1083 rb = rpcrdma_alloc_regbuf(RPCRDMA_HDRBUF_SIZE,
1084 DMA_TO_DEVICE, GFP_KERNEL);
1087 return ERR_PTR(-ENOMEM);
1089 req->rl_rdmabuf = rb;
1090 xdr_buf_init(&req->rl_hdrbuf, rb->rg_base, rdmab_length(rb));
1091 req->rl_buffer = buffer;
1092 INIT_LIST_HEAD(&req->rl_registered);
1094 spin_lock(&buffer->rb_reqslock);
1095 list_add(&req->rl_all, &buffer->rb_allreqs);
1096 spin_unlock(&buffer->rb_reqslock);
1101 * rpcrdma_create_rep - Allocate an rpcrdma_rep object
1102 * @r_xprt: controlling transport
1104 * Returns 0 on success or a negative errno on failure.
1107 rpcrdma_create_rep(struct rpcrdma_xprt *r_xprt)
1109 struct rpcrdma_create_data_internal *cdata = &r_xprt->rx_data;
1110 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
1111 struct rpcrdma_rep *rep;
1115 rep = kzalloc(sizeof(*rep), GFP_KERNEL);
1119 rep->rr_rdmabuf = rpcrdma_alloc_regbuf(cdata->inline_rsize,
1120 DMA_FROM_DEVICE, GFP_KERNEL);
1121 if (IS_ERR(rep->rr_rdmabuf)) {
1122 rc = PTR_ERR(rep->rr_rdmabuf);
1125 xdr_buf_init(&rep->rr_hdrbuf, rep->rr_rdmabuf->rg_base,
1126 rdmab_length(rep->rr_rdmabuf));
1128 rep->rr_cqe.done = rpcrdma_wc_receive;
1129 rep->rr_rxprt = r_xprt;
1130 INIT_WORK(&rep->rr_work, rpcrdma_deferred_completion);
1131 rep->rr_recv_wr.next = NULL;
1132 rep->rr_recv_wr.wr_cqe = &rep->rr_cqe;
1133 rep->rr_recv_wr.sg_list = &rep->rr_rdmabuf->rg_iov;
1134 rep->rr_recv_wr.num_sge = 1;
1136 spin_lock(&buf->rb_lock);
1137 list_add(&rep->rr_list, &buf->rb_recv_bufs);
1138 spin_unlock(&buf->rb_lock);
1144 dprintk("RPC: %s: reply buffer %d alloc failed\n",
1150 rpcrdma_buffer_create(struct rpcrdma_xprt *r_xprt)
1152 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
1155 buf->rb_max_requests = r_xprt->rx_data.max_requests;
1156 buf->rb_bc_srv_max_requests = 0;
1157 spin_lock_init(&buf->rb_mrlock);
1158 spin_lock_init(&buf->rb_lock);
1159 spin_lock_init(&buf->rb_recovery_lock);
1160 INIT_LIST_HEAD(&buf->rb_mrs);
1161 INIT_LIST_HEAD(&buf->rb_all);
1162 INIT_LIST_HEAD(&buf->rb_stale_mrs);
1163 INIT_DELAYED_WORK(&buf->rb_refresh_worker,
1164 rpcrdma_mr_refresh_worker);
1165 INIT_DELAYED_WORK(&buf->rb_recovery_worker,
1166 rpcrdma_mr_recovery_worker);
1168 rpcrdma_mrs_create(r_xprt);
1170 INIT_LIST_HEAD(&buf->rb_send_bufs);
1171 INIT_LIST_HEAD(&buf->rb_allreqs);
1172 spin_lock_init(&buf->rb_reqslock);
1173 for (i = 0; i < buf->rb_max_requests; i++) {
1174 struct rpcrdma_req *req;
1176 req = rpcrdma_create_req(r_xprt);
1178 dprintk("RPC: %s: request buffer %d alloc"
1179 " failed\n", __func__, i);
1183 list_add(&req->rl_list, &buf->rb_send_bufs);
1186 INIT_LIST_HEAD(&buf->rb_recv_bufs);
1187 for (i = 0; i <= buf->rb_max_requests; i++) {
1188 rc = rpcrdma_create_rep(r_xprt);
1193 rc = rpcrdma_sendctxs_create(r_xprt);
1199 rpcrdma_buffer_destroy(buf);
1203 static struct rpcrdma_req *
1204 rpcrdma_buffer_get_req_locked(struct rpcrdma_buffer *buf)
1206 struct rpcrdma_req *req;
1208 req = list_first_entry(&buf->rb_send_bufs,
1209 struct rpcrdma_req, rl_list);
1210 list_del_init(&req->rl_list);
1214 static struct rpcrdma_rep *
1215 rpcrdma_buffer_get_rep_locked(struct rpcrdma_buffer *buf)
1217 struct rpcrdma_rep *rep;
1219 rep = list_first_entry(&buf->rb_recv_bufs,
1220 struct rpcrdma_rep, rr_list);
1221 list_del(&rep->rr_list);
1226 rpcrdma_destroy_rep(struct rpcrdma_rep *rep)
1228 rpcrdma_free_regbuf(rep->rr_rdmabuf);
1233 rpcrdma_destroy_req(struct rpcrdma_req *req)
1235 rpcrdma_free_regbuf(req->rl_recvbuf);
1236 rpcrdma_free_regbuf(req->rl_sendbuf);
1237 rpcrdma_free_regbuf(req->rl_rdmabuf);
1242 rpcrdma_mrs_destroy(struct rpcrdma_buffer *buf)
1244 struct rpcrdma_xprt *r_xprt = container_of(buf, struct rpcrdma_xprt,
1246 struct rpcrdma_ia *ia = rdmab_to_ia(buf);
1247 struct rpcrdma_mr *mr;
1251 spin_lock(&buf->rb_mrlock);
1252 while (!list_empty(&buf->rb_all)) {
1253 mr = list_entry(buf->rb_all.next, struct rpcrdma_mr, mr_all);
1254 list_del(&mr->mr_all);
1256 spin_unlock(&buf->rb_mrlock);
1257 ia->ri_ops->ro_release_mr(mr);
1259 spin_lock(&buf->rb_mrlock);
1261 spin_unlock(&buf->rb_mrlock);
1262 r_xprt->rx_stats.mrs_allocated = 0;
1264 dprintk("RPC: %s: released %u MRs\n", __func__, count);
1268 rpcrdma_buffer_destroy(struct rpcrdma_buffer *buf)
1270 cancel_delayed_work_sync(&buf->rb_recovery_worker);
1271 cancel_delayed_work_sync(&buf->rb_refresh_worker);
1273 rpcrdma_sendctxs_destroy(buf);
1275 while (!list_empty(&buf->rb_recv_bufs)) {
1276 struct rpcrdma_rep *rep;
1278 rep = rpcrdma_buffer_get_rep_locked(buf);
1279 rpcrdma_destroy_rep(rep);
1281 buf->rb_send_count = 0;
1283 spin_lock(&buf->rb_reqslock);
1284 while (!list_empty(&buf->rb_allreqs)) {
1285 struct rpcrdma_req *req;
1287 req = list_first_entry(&buf->rb_allreqs,
1288 struct rpcrdma_req, rl_all);
1289 list_del(&req->rl_all);
1291 spin_unlock(&buf->rb_reqslock);
1292 rpcrdma_destroy_req(req);
1293 spin_lock(&buf->rb_reqslock);
1295 spin_unlock(&buf->rb_reqslock);
1296 buf->rb_recv_count = 0;
1298 rpcrdma_mrs_destroy(buf);
1302 * rpcrdma_mr_get - Allocate an rpcrdma_mr object
1303 * @r_xprt: controlling transport
1305 * Returns an initialized rpcrdma_mr or NULL if no free
1306 * rpcrdma_mr objects are available.
1309 rpcrdma_mr_get(struct rpcrdma_xprt *r_xprt)
1311 struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
1312 struct rpcrdma_mr *mr = NULL;
1314 spin_lock(&buf->rb_mrlock);
1315 if (!list_empty(&buf->rb_mrs))
1316 mr = rpcrdma_mr_pop(&buf->rb_mrs);
1317 spin_unlock(&buf->rb_mrlock);
1324 trace_xprtrdma_nomrs(r_xprt);
1325 if (r_xprt->rx_ep.rep_connected != -ENODEV)
1326 schedule_delayed_work(&buf->rb_refresh_worker, 0);
1328 /* Allow the reply handler and refresh worker to run */
1335 __rpcrdma_mr_put(struct rpcrdma_buffer *buf, struct rpcrdma_mr *mr)
1337 spin_lock(&buf->rb_mrlock);
1338 rpcrdma_mr_push(mr, &buf->rb_mrs);
1339 spin_unlock(&buf->rb_mrlock);
1343 * rpcrdma_mr_put - Release an rpcrdma_mr object
1344 * @mr: object to release
1348 rpcrdma_mr_put(struct rpcrdma_mr *mr)
1350 __rpcrdma_mr_put(&mr->mr_xprt->rx_buf, mr);
1354 * rpcrdma_mr_unmap_and_put - DMA unmap an MR and release it
1355 * @mr: object to release
1359 rpcrdma_mr_unmap_and_put(struct rpcrdma_mr *mr)
1361 struct rpcrdma_xprt *r_xprt = mr->mr_xprt;
1363 trace_xprtrdma_dma_unmap(mr);
1364 ib_dma_unmap_sg(r_xprt->rx_ia.ri_device,
1365 mr->mr_sg, mr->mr_nents, mr->mr_dir);
1366 __rpcrdma_mr_put(&r_xprt->rx_buf, mr);
1369 static struct rpcrdma_rep *
1370 rpcrdma_buffer_get_rep(struct rpcrdma_buffer *buffers)
1372 /* If an RPC previously completed without a reply (say, a
1373 * credential problem or a soft timeout occurs) then hold off
1374 * on supplying more Receive buffers until the number of new
1375 * pending RPCs catches up to the number of posted Receives.
1377 if (unlikely(buffers->rb_send_count < buffers->rb_recv_count))
1380 if (unlikely(list_empty(&buffers->rb_recv_bufs)))
1382 buffers->rb_recv_count++;
1383 return rpcrdma_buffer_get_rep_locked(buffers);
1387 * Get a set of request/reply buffers.
1389 * Reply buffer (if available) is attached to send buffer upon return.
1391 struct rpcrdma_req *
1392 rpcrdma_buffer_get(struct rpcrdma_buffer *buffers)
1394 struct rpcrdma_req *req;
1396 spin_lock(&buffers->rb_lock);
1397 if (list_empty(&buffers->rb_send_bufs))
1399 buffers->rb_send_count++;
1400 req = rpcrdma_buffer_get_req_locked(buffers);
1401 req->rl_reply = rpcrdma_buffer_get_rep(buffers);
1402 spin_unlock(&buffers->rb_lock);
1407 spin_unlock(&buffers->rb_lock);
1412 * Put request/reply buffers back into pool.
1413 * Pre-decrement counter/array index.
1416 rpcrdma_buffer_put(struct rpcrdma_req *req)
1418 struct rpcrdma_buffer *buffers = req->rl_buffer;
1419 struct rpcrdma_rep *rep = req->rl_reply;
1421 req->rl_reply = NULL;
1423 spin_lock(&buffers->rb_lock);
1424 buffers->rb_send_count--;
1425 list_add_tail(&req->rl_list, &buffers->rb_send_bufs);
1427 buffers->rb_recv_count--;
1428 list_add_tail(&rep->rr_list, &buffers->rb_recv_bufs);
1430 spin_unlock(&buffers->rb_lock);
1434 * Recover reply buffers from pool.
1435 * This happens when recovering from disconnect.
1438 rpcrdma_recv_buffer_get(struct rpcrdma_req *req)
1440 struct rpcrdma_buffer *buffers = req->rl_buffer;
1442 spin_lock(&buffers->rb_lock);
1443 req->rl_reply = rpcrdma_buffer_get_rep(buffers);
1444 spin_unlock(&buffers->rb_lock);
1448 * Put reply buffers back into pool when not attached to
1449 * request. This happens in error conditions.
1452 rpcrdma_recv_buffer_put(struct rpcrdma_rep *rep)
1454 struct rpcrdma_buffer *buffers = &rep->rr_rxprt->rx_buf;
1456 spin_lock(&buffers->rb_lock);
1457 buffers->rb_recv_count--;
1458 list_add_tail(&rep->rr_list, &buffers->rb_recv_bufs);
1459 spin_unlock(&buffers->rb_lock);
1463 * rpcrdma_alloc_regbuf - allocate and DMA-map memory for SEND/RECV buffers
1464 * @size: size of buffer to be allocated, in bytes
1465 * @direction: direction of data movement
1468 * Returns an ERR_PTR, or a pointer to a regbuf, a buffer that
1469 * can be persistently DMA-mapped for I/O.
1471 * xprtrdma uses a regbuf for posting an outgoing RDMA SEND, or for
1472 * receiving the payload of RDMA RECV operations. During Long Calls
1473 * or Replies they may be registered externally via ro_map.
1475 struct rpcrdma_regbuf *
1476 rpcrdma_alloc_regbuf(size_t size, enum dma_data_direction direction,
1479 struct rpcrdma_regbuf *rb;
1481 rb = kmalloc(sizeof(*rb) + size, flags);
1483 return ERR_PTR(-ENOMEM);
1485 rb->rg_device = NULL;
1486 rb->rg_direction = direction;
1487 rb->rg_iov.length = size;
1493 * __rpcrdma_map_regbuf - DMA-map a regbuf
1494 * @ia: controlling rpcrdma_ia
1495 * @rb: regbuf to be mapped
1498 __rpcrdma_dma_map_regbuf(struct rpcrdma_ia *ia, struct rpcrdma_regbuf *rb)
1500 struct ib_device *device = ia->ri_device;
1502 if (rb->rg_direction == DMA_NONE)
1505 rb->rg_iov.addr = ib_dma_map_single(device,
1506 (void *)rb->rg_base,
1509 if (ib_dma_mapping_error(device, rdmab_addr(rb)))
1512 rb->rg_device = device;
1513 rb->rg_iov.lkey = ia->ri_pd->local_dma_lkey;
1518 rpcrdma_dma_unmap_regbuf(struct rpcrdma_regbuf *rb)
1523 if (!rpcrdma_regbuf_is_mapped(rb))
1526 ib_dma_unmap_single(rb->rg_device, rdmab_addr(rb),
1527 rdmab_length(rb), rb->rg_direction);
1528 rb->rg_device = NULL;
1532 * rpcrdma_free_regbuf - deregister and free registered buffer
1533 * @rb: regbuf to be deregistered and freed
1536 rpcrdma_free_regbuf(struct rpcrdma_regbuf *rb)
1538 rpcrdma_dma_unmap_regbuf(rb);
1543 * Prepost any receive buffer, then post send.
1545 * Receive buffer is donated to hardware, reclaimed upon recv completion.
1548 rpcrdma_ep_post(struct rpcrdma_ia *ia,
1549 struct rpcrdma_ep *ep,
1550 struct rpcrdma_req *req)
1552 struct ib_send_wr *send_wr = &req->rl_sendctx->sc_wr;
1555 if (req->rl_reply) {
1556 rc = rpcrdma_ep_post_recv(ia, req->rl_reply);
1559 req->rl_reply = NULL;
1562 if (!ep->rep_send_count ||
1563 test_bit(RPCRDMA_REQ_F_TX_RESOURCES, &req->rl_flags)) {
1564 send_wr->send_flags |= IB_SEND_SIGNALED;
1565 ep->rep_send_count = ep->rep_send_batch;
1567 send_wr->send_flags &= ~IB_SEND_SIGNALED;
1568 --ep->rep_send_count;
1571 rc = ia->ri_ops->ro_send(ia, req);
1572 trace_xprtrdma_post_send(req, rc);
1579 rpcrdma_ep_post_recv(struct rpcrdma_ia *ia,
1580 struct rpcrdma_rep *rep)
1582 struct ib_recv_wr *recv_wr_fail;
1585 if (!rpcrdma_dma_map_regbuf(ia, rep->rr_rdmabuf))
1587 rc = ib_post_recv(ia->ri_id->qp, &rep->rr_recv_wr, &recv_wr_fail);
1588 trace_xprtrdma_post_recv(rep, rc);
1594 pr_err("rpcrdma: failed to DMA map the Receive buffer\n");
1599 * rpcrdma_ep_post_extra_recv - Post buffers for incoming backchannel requests
1600 * @r_xprt: transport associated with these backchannel resources
1601 * @count: minimum number of incoming requests expected
1603 * Returns zero if all requested buffers were posted, or a negative errno.
1606 rpcrdma_ep_post_extra_recv(struct rpcrdma_xprt *r_xprt, unsigned int count)
1608 struct rpcrdma_buffer *buffers = &r_xprt->rx_buf;
1609 struct rpcrdma_ia *ia = &r_xprt->rx_ia;
1610 struct rpcrdma_rep *rep;
1614 spin_lock(&buffers->rb_lock);
1615 if (list_empty(&buffers->rb_recv_bufs))
1617 rep = rpcrdma_buffer_get_rep_locked(buffers);
1618 spin_unlock(&buffers->rb_lock);
1620 rc = rpcrdma_ep_post_recv(ia, rep);
1628 spin_unlock(&buffers->rb_lock);
1629 trace_xprtrdma_noreps(r_xprt);
1633 rpcrdma_recv_buffer_put(rep);