xref: /linux/net/sunrpc/xprtrdma/svc_rdma_transport.c (revision 221013afb459e5deb8bd08e29b37050af5586d1c)
1 // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
2 /*
3  * Copyright (c) 2015-2018 Oracle. All rights reserved.
4  * Copyright (c) 2014 Open Grid Computing, Inc. All rights reserved.
5  * Copyright (c) 2005-2007 Network Appliance, Inc. All rights reserved.
6  *
7  * This software is available to you under a choice of one of two
8  * licenses.  You may choose to be licensed under the terms of the GNU
9  * General Public License (GPL) Version 2, available from the file
10  * COPYING in the main directory of this source tree, or the BSD-type
11  * license below:
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  *
17  *      Redistributions of source code must retain the above copyright
18  *      notice, this list of conditions and the following disclaimer.
19  *
20  *      Redistributions in binary form must reproduce the above
21  *      copyright notice, this list of conditions and the following
22  *      disclaimer in the documentation and/or other materials provided
23  *      with the distribution.
24  *
25  *      Neither the name of the Network Appliance, Inc. nor the names of
26  *      its contributors may be used to endorse or promote products
27  *      derived from this software without specific prior written
28  *      permission.
29  *
30  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
31  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
32  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
33  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
34  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
35  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
36  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
37  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
38  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
39  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
40  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
41  *
42  * Author: Tom Tucker <tom@opengridcomputing.com>
43  */
44 
45 #include <linux/interrupt.h>
46 #include <linux/sched.h>
47 #include <linux/slab.h>
48 #include <linux/spinlock.h>
49 #include <linux/workqueue.h>
50 #include <linux/export.h>
51 
52 #include <rdma/ib_verbs.h>
53 #include <rdma/rdma_cm.h>
54 #include <rdma/rw.h>
55 
56 #include <linux/sunrpc/addr.h>
57 #include <linux/sunrpc/debug.h>
58 #include <linux/sunrpc/svc_xprt.h>
59 #include <linux/sunrpc/svc_rdma.h>
60 
61 #include "xprt_rdma.h"
62 #include <trace/events/rpcrdma.h>
63 
64 #define RPCDBG_FACILITY	RPCDBG_SVCXPRT
65 
66 static struct svcxprt_rdma *svc_rdma_create_xprt(struct svc_serv *serv,
67 						 struct net *net, int node);
68 static int svc_rdma_listen_handler(struct rdma_cm_id *cma_id,
69 				   struct rdma_cm_event *event);
70 static struct svc_xprt *svc_rdma_create(struct svc_serv *serv,
71 					struct net *net,
72 					struct sockaddr *sa, int salen,
73 					int flags);
74 static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt);
75 static void svc_rdma_detach(struct svc_xprt *xprt);
76 static void svc_rdma_free(struct svc_xprt *xprt);
77 static int svc_rdma_has_wspace(struct svc_xprt *xprt);
78 static void svc_rdma_kill_temp_xprt(struct svc_xprt *);
79 
80 static const struct svc_xprt_ops svc_rdma_ops = {
81 	.xpo_create = svc_rdma_create,
82 	.xpo_recvfrom = svc_rdma_recvfrom,
83 	.xpo_sendto = svc_rdma_sendto,
84 	.xpo_result_payload = svc_rdma_result_payload,
85 	.xpo_release_ctxt = svc_rdma_release_ctxt,
86 	.xpo_detach = svc_rdma_detach,
87 	.xpo_free = svc_rdma_free,
88 	.xpo_has_wspace = svc_rdma_has_wspace,
89 	.xpo_accept = svc_rdma_accept,
90 	.xpo_kill_temp_xprt = svc_rdma_kill_temp_xprt,
91 };
92 
93 struct svc_xprt_class svc_rdma_class = {
94 	.xcl_name = "rdma",
95 	.xcl_owner = THIS_MODULE,
96 	.xcl_ops = &svc_rdma_ops,
97 	.xcl_max_payload = RPCSVC_MAXPAYLOAD_RDMA,
98 	.xcl_ident = XPRT_TRANSPORT_RDMA,
99 };
100 
101 /* QP event handler */
102 static void qp_event_handler(struct ib_event *event, void *context)
103 {
104 	struct svc_xprt *xprt = context;
105 
106 	trace_svcrdma_qp_error(event, (struct sockaddr *)&xprt->xpt_remote);
107 	switch (event->event) {
108 	/* These are considered benign events */
109 	case IB_EVENT_PATH_MIG:
110 	case IB_EVENT_COMM_EST:
111 	case IB_EVENT_SQ_DRAINED:
112 	case IB_EVENT_QP_LAST_WQE_REACHED:
113 		break;
114 
115 	/* These are considered fatal events */
116 	case IB_EVENT_PATH_MIG_ERR:
117 	case IB_EVENT_QP_FATAL:
118 	case IB_EVENT_QP_REQ_ERR:
119 	case IB_EVENT_QP_ACCESS_ERR:
120 	case IB_EVENT_DEVICE_FATAL:
121 	default:
122 		svc_xprt_deferred_close(xprt);
123 		break;
124 	}
125 }
126 
127 static struct rdma_cm_id *
128 svc_rdma_create_listen_id(struct net *net, struct sockaddr *sap,
129 			  void *context)
130 {
131 	struct rdma_cm_id *listen_id;
132 	int ret;
133 
134 	listen_id = rdma_create_id(net, svc_rdma_listen_handler, context,
135 				   RDMA_PS_TCP, IB_QPT_RC);
136 	if (IS_ERR(listen_id))
137 		return listen_id;
138 
139 	/* Allow both IPv4 and IPv6 sockets to bind a single port
140 	 * at the same time.
141 	 */
142 #if IS_ENABLED(CONFIG_IPV6)
143 	ret = rdma_set_afonly(listen_id, 1);
144 	if (ret)
145 		goto out_destroy;
146 #endif
147 	ret = rdma_bind_addr(listen_id, sap);
148 	if (ret)
149 		goto out_destroy;
150 
151 	ret = rdma_listen(listen_id, RPCRDMA_LISTEN_BACKLOG);
152 	if (ret)
153 		goto out_destroy;
154 
155 	return listen_id;
156 
157 out_destroy:
158 	rdma_destroy_id(listen_id);
159 	return ERR_PTR(ret);
160 }
161 
162 static struct svcxprt_rdma *svc_rdma_create_xprt(struct svc_serv *serv,
163 						 struct net *net, int node)
164 {
165 	static struct lock_class_key svcrdma_rwctx_lock;
166 	static struct lock_class_key svcrdma_sctx_lock;
167 	static struct lock_class_key svcrdma_dto_lock;
168 	struct svcxprt_rdma *cma_xprt;
169 
170 	cma_xprt = kzalloc_node(sizeof(*cma_xprt), GFP_KERNEL, node);
171 	if (!cma_xprt)
172 		return NULL;
173 
174 	svc_xprt_init(net, &svc_rdma_class, &cma_xprt->sc_xprt, serv);
175 	INIT_LIST_HEAD(&cma_xprt->sc_accept_q);
176 	INIT_LIST_HEAD(&cma_xprt->sc_rq_dto_q);
177 	INIT_LIST_HEAD(&cma_xprt->sc_read_complete_q);
178 	init_llist_head(&cma_xprt->sc_send_ctxts);
179 	init_llist_head(&cma_xprt->sc_recv_ctxts);
180 	init_llist_head(&cma_xprt->sc_rw_ctxts);
181 	init_waitqueue_head(&cma_xprt->sc_send_wait);
182 
183 	spin_lock_init(&cma_xprt->sc_lock);
184 	spin_lock_init(&cma_xprt->sc_rq_dto_lock);
185 	lockdep_set_class(&cma_xprt->sc_rq_dto_lock, &svcrdma_dto_lock);
186 	spin_lock_init(&cma_xprt->sc_send_lock);
187 	lockdep_set_class(&cma_xprt->sc_send_lock, &svcrdma_sctx_lock);
188 	spin_lock_init(&cma_xprt->sc_rw_ctxt_lock);
189 	lockdep_set_class(&cma_xprt->sc_rw_ctxt_lock, &svcrdma_rwctx_lock);
190 
191 	/*
192 	 * Note that this implies that the underlying transport support
193 	 * has some form of congestion control (see RFC 7530 section 3.1
194 	 * paragraph 2). For now, we assume that all supported RDMA
195 	 * transports are suitable here.
196 	 */
197 	set_bit(XPT_CONG_CTRL, &cma_xprt->sc_xprt.xpt_flags);
198 
199 	return cma_xprt;
200 }
201 
202 static void
203 svc_rdma_parse_connect_private(struct svcxprt_rdma *newxprt,
204 			       struct rdma_conn_param *param)
205 {
206 	const struct rpcrdma_connect_private *pmsg = param->private_data;
207 
208 	if (pmsg &&
209 	    pmsg->cp_magic == rpcrdma_cmp_magic &&
210 	    pmsg->cp_version == RPCRDMA_CMP_VERSION) {
211 		newxprt->sc_snd_w_inv = pmsg->cp_flags &
212 					RPCRDMA_CMP_F_SND_W_INV_OK;
213 
214 		dprintk("svcrdma: client send_size %u, recv_size %u "
215 			"remote inv %ssupported\n",
216 			rpcrdma_decode_buffer_size(pmsg->cp_send_size),
217 			rpcrdma_decode_buffer_size(pmsg->cp_recv_size),
218 			newxprt->sc_snd_w_inv ? "" : "un");
219 	}
220 }
221 
222 /*
223  * This function handles the CONNECT_REQUEST event on a listening
224  * endpoint. It is passed the cma_id for the _new_ connection. The context in
225  * this cma_id is inherited from the listening cma_id and is the svc_xprt
226  * structure for the listening endpoint.
227  *
228  * This function creates a new xprt for the new connection and enqueues it on
229  * the accept queue for the listent xprt. When the listen thread is kicked, it
230  * will call the recvfrom method on the listen xprt which will accept the new
231  * connection.
232  */
233 static void handle_connect_req(struct rdma_cm_id *new_cma_id,
234 			       struct rdma_conn_param *param)
235 {
236 	struct svcxprt_rdma *listen_xprt = new_cma_id->context;
237 	struct svcxprt_rdma *newxprt;
238 	struct sockaddr *sa;
239 
240 	newxprt = svc_rdma_create_xprt(listen_xprt->sc_xprt.xpt_server,
241 				       listen_xprt->sc_xprt.xpt_net,
242 				       ibdev_to_node(new_cma_id->device));
243 	if (!newxprt)
244 		return;
245 	newxprt->sc_cm_id = new_cma_id;
246 	new_cma_id->context = newxprt;
247 	svc_rdma_parse_connect_private(newxprt, param);
248 
249 	/* Save client advertised inbound read limit for use later in accept. */
250 	newxprt->sc_ord = param->initiator_depth;
251 
252 	sa = (struct sockaddr *)&newxprt->sc_cm_id->route.addr.dst_addr;
253 	newxprt->sc_xprt.xpt_remotelen = svc_addr_len(sa);
254 	memcpy(&newxprt->sc_xprt.xpt_remote, sa,
255 	       newxprt->sc_xprt.xpt_remotelen);
256 	snprintf(newxprt->sc_xprt.xpt_remotebuf,
257 		 sizeof(newxprt->sc_xprt.xpt_remotebuf) - 1, "%pISc", sa);
258 
259 	/* The remote port is arbitrary and not under the control of the
260 	 * client ULP. Set it to a fixed value so that the DRC continues
261 	 * to be effective after a reconnect.
262 	 */
263 	rpc_set_port((struct sockaddr *)&newxprt->sc_xprt.xpt_remote, 0);
264 
265 	sa = (struct sockaddr *)&newxprt->sc_cm_id->route.addr.src_addr;
266 	svc_xprt_set_local(&newxprt->sc_xprt, sa, svc_addr_len(sa));
267 
268 	/*
269 	 * Enqueue the new transport on the accept queue of the listening
270 	 * transport
271 	 */
272 	spin_lock(&listen_xprt->sc_lock);
273 	list_add_tail(&newxprt->sc_accept_q, &listen_xprt->sc_accept_q);
274 	spin_unlock(&listen_xprt->sc_lock);
275 
276 	set_bit(XPT_CONN, &listen_xprt->sc_xprt.xpt_flags);
277 	svc_xprt_enqueue(&listen_xprt->sc_xprt);
278 }
279 
280 /**
281  * svc_rdma_listen_handler - Handle CM events generated on a listening endpoint
282  * @cma_id: the server's listener rdma_cm_id
283  * @event: details of the event
284  *
285  * Return values:
286  *     %0: Do not destroy @cma_id
287  *     %1: Destroy @cma_id
288  *
289  * NB: There is never a DEVICE_REMOVAL event for INADDR_ANY listeners.
290  */
291 static int svc_rdma_listen_handler(struct rdma_cm_id *cma_id,
292 				   struct rdma_cm_event *event)
293 {
294 	struct sockaddr *sap = (struct sockaddr *)&cma_id->route.addr.src_addr;
295 	struct svcxprt_rdma *cma_xprt = cma_id->context;
296 	struct svc_xprt *cma_rdma = &cma_xprt->sc_xprt;
297 	struct rdma_cm_id *listen_id;
298 
299 	switch (event->event) {
300 	case RDMA_CM_EVENT_CONNECT_REQUEST:
301 		handle_connect_req(cma_id, &event->param.conn);
302 		break;
303 	case RDMA_CM_EVENT_ADDR_CHANGE:
304 		listen_id = svc_rdma_create_listen_id(cma_rdma->xpt_net,
305 						      sap, cma_xprt);
306 		if (IS_ERR(listen_id)) {
307 			pr_err("Listener dead, address change failed for device %s\n",
308 				cma_id->device->name);
309 		} else
310 			cma_xprt->sc_cm_id = listen_id;
311 		return 1;
312 	default:
313 		break;
314 	}
315 	return 0;
316 }
317 
318 /**
319  * svc_rdma_cma_handler - Handle CM events on client connections
320  * @cma_id: the server's listener rdma_cm_id
321  * @event: details of the event
322  *
323  * Return values:
324  *     %0: Do not destroy @cma_id
325  *     %1: Destroy @cma_id (never returned here)
326  */
327 static int svc_rdma_cma_handler(struct rdma_cm_id *cma_id,
328 				struct rdma_cm_event *event)
329 {
330 	struct svcxprt_rdma *rdma = cma_id->context;
331 	struct svc_xprt *xprt = &rdma->sc_xprt;
332 
333 	switch (event->event) {
334 	case RDMA_CM_EVENT_ESTABLISHED:
335 		clear_bit(RDMAXPRT_CONN_PENDING, &rdma->sc_flags);
336 
337 		/* Handle any requests that were received while
338 		 * CONN_PENDING was set. */
339 		svc_xprt_enqueue(xprt);
340 		break;
341 	case RDMA_CM_EVENT_DISCONNECTED:
342 	case RDMA_CM_EVENT_DEVICE_REMOVAL:
343 		svc_xprt_deferred_close(xprt);
344 		break;
345 	default:
346 		break;
347 	}
348 	return 0;
349 }
350 
351 /*
352  * Create a listening RDMA service endpoint.
353  */
354 static struct svc_xprt *svc_rdma_create(struct svc_serv *serv,
355 					struct net *net,
356 					struct sockaddr *sa, int salen,
357 					int flags)
358 {
359 	struct rdma_cm_id *listen_id;
360 	struct svcxprt_rdma *cma_xprt;
361 
362 	if (sa->sa_family != AF_INET && sa->sa_family != AF_INET6)
363 		return ERR_PTR(-EAFNOSUPPORT);
364 	cma_xprt = svc_rdma_create_xprt(serv, net, NUMA_NO_NODE);
365 	if (!cma_xprt)
366 		return ERR_PTR(-ENOMEM);
367 	set_bit(XPT_LISTENER, &cma_xprt->sc_xprt.xpt_flags);
368 	strcpy(cma_xprt->sc_xprt.xpt_remotebuf, "listener");
369 
370 	listen_id = svc_rdma_create_listen_id(net, sa, cma_xprt);
371 	if (IS_ERR(listen_id)) {
372 		kfree(cma_xprt);
373 		return (struct svc_xprt *)listen_id;
374 	}
375 	cma_xprt->sc_cm_id = listen_id;
376 
377 	/*
378 	 * We need to use the address from the cm_id in case the
379 	 * caller specified 0 for the port number.
380 	 */
381 	sa = (struct sockaddr *)&cma_xprt->sc_cm_id->route.addr.src_addr;
382 	svc_xprt_set_local(&cma_xprt->sc_xprt, sa, salen);
383 
384 	return &cma_xprt->sc_xprt;
385 }
386 
387 /*
388  * This is the xpo_recvfrom function for listening endpoints. Its
389  * purpose is to accept incoming connections. The CMA callback handler
390  * has already created a new transport and attached it to the new CMA
391  * ID.
392  *
393  * There is a queue of pending connections hung on the listening
394  * transport. This queue contains the new svc_xprt structure. This
395  * function takes svc_xprt structures off the accept_q and completes
396  * the connection.
397  */
398 static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt)
399 {
400 	struct svcxprt_rdma *listen_rdma;
401 	struct svcxprt_rdma *newxprt = NULL;
402 	struct rdma_conn_param conn_param;
403 	struct rpcrdma_connect_private pmsg;
404 	struct ib_qp_init_attr qp_attr;
405 	unsigned int ctxts, rq_depth;
406 	struct ib_device *dev;
407 	int ret = 0;
408 	RPC_IFDEBUG(struct sockaddr *sap);
409 
410 	listen_rdma = container_of(xprt, struct svcxprt_rdma, sc_xprt);
411 	clear_bit(XPT_CONN, &xprt->xpt_flags);
412 	/* Get the next entry off the accept list */
413 	spin_lock(&listen_rdma->sc_lock);
414 	if (!list_empty(&listen_rdma->sc_accept_q)) {
415 		newxprt = list_entry(listen_rdma->sc_accept_q.next,
416 				     struct svcxprt_rdma, sc_accept_q);
417 		list_del_init(&newxprt->sc_accept_q);
418 	}
419 	if (!list_empty(&listen_rdma->sc_accept_q))
420 		set_bit(XPT_CONN, &listen_rdma->sc_xprt.xpt_flags);
421 	spin_unlock(&listen_rdma->sc_lock);
422 	if (!newxprt)
423 		return NULL;
424 
425 	dev = newxprt->sc_cm_id->device;
426 	newxprt->sc_port_num = newxprt->sc_cm_id->port_num;
427 
428 	newxprt->sc_max_req_size = svcrdma_max_req_size;
429 	newxprt->sc_max_requests = svcrdma_max_requests;
430 	newxprt->sc_max_bc_requests = svcrdma_max_bc_requests;
431 	newxprt->sc_recv_batch = RPCRDMA_MAX_RECV_BATCH;
432 	newxprt->sc_fc_credits = cpu_to_be32(newxprt->sc_max_requests);
433 
434 	/* Qualify the transport's resource defaults with the
435 	 * capabilities of this particular device.
436 	 */
437 
438 	/* Transport header, head iovec, tail iovec */
439 	newxprt->sc_max_send_sges = 3;
440 	/* Add one SGE per page list entry */
441 	newxprt->sc_max_send_sges += (svcrdma_max_req_size / PAGE_SIZE) + 1;
442 	if (newxprt->sc_max_send_sges > dev->attrs.max_send_sge)
443 		newxprt->sc_max_send_sges = dev->attrs.max_send_sge;
444 	rq_depth = newxprt->sc_max_requests + newxprt->sc_max_bc_requests +
445 		   newxprt->sc_recv_batch + 1 /* drain */;
446 	if (rq_depth > dev->attrs.max_qp_wr) {
447 		rq_depth = dev->attrs.max_qp_wr;
448 		newxprt->sc_recv_batch = 1;
449 		newxprt->sc_max_requests = rq_depth - 2;
450 		newxprt->sc_max_bc_requests = 2;
451 	}
452 
453 	/* Arbitrarily estimate the number of rw_ctxs needed for
454 	 * this transport. This is enough rw_ctxs to make forward
455 	 * progress even if the client is using one rkey per page
456 	 * in each Read chunk.
457 	 */
458 	ctxts = 3 * RPCSVC_MAXPAGES;
459 	newxprt->sc_sq_depth = rq_depth + ctxts;
460 	if (newxprt->sc_sq_depth > dev->attrs.max_qp_wr)
461 		newxprt->sc_sq_depth = dev->attrs.max_qp_wr;
462 	atomic_set(&newxprt->sc_sq_avail, newxprt->sc_sq_depth);
463 
464 	newxprt->sc_pd = ib_alloc_pd(dev, 0);
465 	if (IS_ERR(newxprt->sc_pd)) {
466 		trace_svcrdma_pd_err(newxprt, PTR_ERR(newxprt->sc_pd));
467 		goto errout;
468 	}
469 	newxprt->sc_sq_cq = ib_alloc_cq_any(dev, newxprt, newxprt->sc_sq_depth,
470 					    IB_POLL_WORKQUEUE);
471 	if (IS_ERR(newxprt->sc_sq_cq))
472 		goto errout;
473 	newxprt->sc_rq_cq =
474 		ib_alloc_cq_any(dev, newxprt, rq_depth, IB_POLL_WORKQUEUE);
475 	if (IS_ERR(newxprt->sc_rq_cq))
476 		goto errout;
477 
478 	memset(&qp_attr, 0, sizeof qp_attr);
479 	qp_attr.event_handler = qp_event_handler;
480 	qp_attr.qp_context = &newxprt->sc_xprt;
481 	qp_attr.port_num = newxprt->sc_port_num;
482 	qp_attr.cap.max_rdma_ctxs = ctxts;
483 	qp_attr.cap.max_send_wr = newxprt->sc_sq_depth - ctxts;
484 	qp_attr.cap.max_recv_wr = rq_depth;
485 	qp_attr.cap.max_send_sge = newxprt->sc_max_send_sges;
486 	qp_attr.cap.max_recv_sge = 1;
487 	qp_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
488 	qp_attr.qp_type = IB_QPT_RC;
489 	qp_attr.send_cq = newxprt->sc_sq_cq;
490 	qp_attr.recv_cq = newxprt->sc_rq_cq;
491 	dprintk("    cap.max_send_wr = %d, cap.max_recv_wr = %d\n",
492 		qp_attr.cap.max_send_wr, qp_attr.cap.max_recv_wr);
493 	dprintk("    cap.max_send_sge = %d, cap.max_recv_sge = %d\n",
494 		qp_attr.cap.max_send_sge, qp_attr.cap.max_recv_sge);
495 	dprintk("    send CQ depth = %u, recv CQ depth = %u\n",
496 		newxprt->sc_sq_depth, rq_depth);
497 	ret = rdma_create_qp(newxprt->sc_cm_id, newxprt->sc_pd, &qp_attr);
498 	if (ret) {
499 		trace_svcrdma_qp_err(newxprt, ret);
500 		goto errout;
501 	}
502 	newxprt->sc_max_send_sges = qp_attr.cap.max_send_sge;
503 	newxprt->sc_qp = newxprt->sc_cm_id->qp;
504 
505 	if (!(dev->attrs.device_cap_flags & IB_DEVICE_MEM_MGT_EXTENSIONS))
506 		newxprt->sc_snd_w_inv = false;
507 	if (!rdma_protocol_iwarp(dev, newxprt->sc_port_num) &&
508 	    !rdma_ib_or_roce(dev, newxprt->sc_port_num)) {
509 		trace_svcrdma_fabric_err(newxprt, -EINVAL);
510 		goto errout;
511 	}
512 
513 	if (!svc_rdma_post_recvs(newxprt))
514 		goto errout;
515 
516 	/* Construct RDMA-CM private message */
517 	pmsg.cp_magic = rpcrdma_cmp_magic;
518 	pmsg.cp_version = RPCRDMA_CMP_VERSION;
519 	pmsg.cp_flags = 0;
520 	pmsg.cp_send_size = pmsg.cp_recv_size =
521 		rpcrdma_encode_buffer_size(newxprt->sc_max_req_size);
522 
523 	/* Accept Connection */
524 	set_bit(RDMAXPRT_CONN_PENDING, &newxprt->sc_flags);
525 	memset(&conn_param, 0, sizeof conn_param);
526 	conn_param.responder_resources = 0;
527 	conn_param.initiator_depth = min_t(int, newxprt->sc_ord,
528 					   dev->attrs.max_qp_init_rd_atom);
529 	if (!conn_param.initiator_depth) {
530 		ret = -EINVAL;
531 		trace_svcrdma_initdepth_err(newxprt, ret);
532 		goto errout;
533 	}
534 	conn_param.private_data = &pmsg;
535 	conn_param.private_data_len = sizeof(pmsg);
536 	rdma_lock_handler(newxprt->sc_cm_id);
537 	newxprt->sc_cm_id->event_handler = svc_rdma_cma_handler;
538 	ret = rdma_accept(newxprt->sc_cm_id, &conn_param);
539 	rdma_unlock_handler(newxprt->sc_cm_id);
540 	if (ret) {
541 		trace_svcrdma_accept_err(newxprt, ret);
542 		goto errout;
543 	}
544 
545 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
546 	dprintk("svcrdma: new connection accepted on device %s:\n", dev->name);
547 	sap = (struct sockaddr *)&newxprt->sc_cm_id->route.addr.src_addr;
548 	dprintk("    local address   : %pIS:%u\n", sap, rpc_get_port(sap));
549 	sap = (struct sockaddr *)&newxprt->sc_cm_id->route.addr.dst_addr;
550 	dprintk("    remote address  : %pIS:%u\n", sap, rpc_get_port(sap));
551 	dprintk("    max_sge         : %d\n", newxprt->sc_max_send_sges);
552 	dprintk("    sq_depth        : %d\n", newxprt->sc_sq_depth);
553 	dprintk("    rdma_rw_ctxs    : %d\n", ctxts);
554 	dprintk("    max_requests    : %d\n", newxprt->sc_max_requests);
555 	dprintk("    ord             : %d\n", conn_param.initiator_depth);
556 #endif
557 
558 	return &newxprt->sc_xprt;
559 
560  errout:
561 	/* Take a reference in case the DTO handler runs */
562 	svc_xprt_get(&newxprt->sc_xprt);
563 	if (newxprt->sc_qp && !IS_ERR(newxprt->sc_qp))
564 		ib_destroy_qp(newxprt->sc_qp);
565 	rdma_destroy_id(newxprt->sc_cm_id);
566 	/* This call to put will destroy the transport */
567 	svc_xprt_put(&newxprt->sc_xprt);
568 	return NULL;
569 }
570 
571 static void svc_rdma_detach(struct svc_xprt *xprt)
572 {
573 	struct svcxprt_rdma *rdma =
574 		container_of(xprt, struct svcxprt_rdma, sc_xprt);
575 
576 	rdma_disconnect(rdma->sc_cm_id);
577 }
578 
579 static void __svc_rdma_free(struct work_struct *work)
580 {
581 	struct svcxprt_rdma *rdma =
582 		container_of(work, struct svcxprt_rdma, sc_work);
583 
584 	/* This blocks until the Completion Queues are empty */
585 	if (rdma->sc_qp && !IS_ERR(rdma->sc_qp))
586 		ib_drain_qp(rdma->sc_qp);
587 	flush_workqueue(svcrdma_wq);
588 
589 	svc_rdma_flush_recv_queues(rdma);
590 
591 	svc_rdma_destroy_rw_ctxts(rdma);
592 	svc_rdma_send_ctxts_destroy(rdma);
593 	svc_rdma_recv_ctxts_destroy(rdma);
594 
595 	/* Destroy the QP if present (not a listener) */
596 	if (rdma->sc_qp && !IS_ERR(rdma->sc_qp))
597 		ib_destroy_qp(rdma->sc_qp);
598 
599 	if (rdma->sc_sq_cq && !IS_ERR(rdma->sc_sq_cq))
600 		ib_free_cq(rdma->sc_sq_cq);
601 
602 	if (rdma->sc_rq_cq && !IS_ERR(rdma->sc_rq_cq))
603 		ib_free_cq(rdma->sc_rq_cq);
604 
605 	if (rdma->sc_pd && !IS_ERR(rdma->sc_pd))
606 		ib_dealloc_pd(rdma->sc_pd);
607 
608 	/* Destroy the CM ID */
609 	rdma_destroy_id(rdma->sc_cm_id);
610 
611 	kfree(rdma);
612 }
613 
614 static void svc_rdma_free(struct svc_xprt *xprt)
615 {
616 	struct svcxprt_rdma *rdma =
617 		container_of(xprt, struct svcxprt_rdma, sc_xprt);
618 
619 	INIT_WORK(&rdma->sc_work, __svc_rdma_free);
620 	schedule_work(&rdma->sc_work);
621 }
622 
623 static int svc_rdma_has_wspace(struct svc_xprt *xprt)
624 {
625 	struct svcxprt_rdma *rdma =
626 		container_of(xprt, struct svcxprt_rdma, sc_xprt);
627 
628 	/*
629 	 * If there are already waiters on the SQ,
630 	 * return false.
631 	 */
632 	if (waitqueue_active(&rdma->sc_send_wait))
633 		return 0;
634 
635 	/* Otherwise return true. */
636 	return 1;
637 }
638 
639 static void svc_rdma_kill_temp_xprt(struct svc_xprt *xprt)
640 {
641 }
642