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);
68 static struct svc_xprt *svc_rdma_create(struct svc_serv *serv,
69 					struct net *net,
70 					struct sockaddr *sa, int salen,
71 					int flags);
72 static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt);
73 static void svc_rdma_detach(struct svc_xprt *xprt);
74 static void svc_rdma_free(struct svc_xprt *xprt);
75 static int svc_rdma_has_wspace(struct svc_xprt *xprt);
76 static void svc_rdma_secure_port(struct svc_rqst *);
77 static void svc_rdma_kill_temp_xprt(struct svc_xprt *);
78 
79 static const struct svc_xprt_ops svc_rdma_ops = {
80 	.xpo_create = svc_rdma_create,
81 	.xpo_recvfrom = svc_rdma_recvfrom,
82 	.xpo_sendto = svc_rdma_sendto,
83 	.xpo_result_payload = svc_rdma_result_payload,
84 	.xpo_release_rqst = svc_rdma_release_rqst,
85 	.xpo_detach = svc_rdma_detach,
86 	.xpo_free = svc_rdma_free,
87 	.xpo_has_wspace = svc_rdma_has_wspace,
88 	.xpo_accept = svc_rdma_accept,
89 	.xpo_secure_port = svc_rdma_secure_port,
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 svcxprt_rdma *svc_rdma_create_xprt(struct svc_serv *serv,
128 						 struct net *net)
129 {
130 	struct svcxprt_rdma *cma_xprt = kzalloc(sizeof *cma_xprt, GFP_KERNEL);
131 
132 	if (!cma_xprt) {
133 		dprintk("svcrdma: failed to create new transport\n");
134 		return NULL;
135 	}
136 	svc_xprt_init(net, &svc_rdma_class, &cma_xprt->sc_xprt, serv);
137 	INIT_LIST_HEAD(&cma_xprt->sc_accept_q);
138 	INIT_LIST_HEAD(&cma_xprt->sc_rq_dto_q);
139 	INIT_LIST_HEAD(&cma_xprt->sc_send_ctxts);
140 	init_llist_head(&cma_xprt->sc_recv_ctxts);
141 	INIT_LIST_HEAD(&cma_xprt->sc_rw_ctxts);
142 	init_waitqueue_head(&cma_xprt->sc_send_wait);
143 
144 	spin_lock_init(&cma_xprt->sc_lock);
145 	spin_lock_init(&cma_xprt->sc_rq_dto_lock);
146 	spin_lock_init(&cma_xprt->sc_send_lock);
147 	spin_lock_init(&cma_xprt->sc_rw_ctxt_lock);
148 
149 	/*
150 	 * Note that this implies that the underlying transport support
151 	 * has some form of congestion control (see RFC 7530 section 3.1
152 	 * paragraph 2). For now, we assume that all supported RDMA
153 	 * transports are suitable here.
154 	 */
155 	set_bit(XPT_CONG_CTRL, &cma_xprt->sc_xprt.xpt_flags);
156 
157 	return cma_xprt;
158 }
159 
160 static void
161 svc_rdma_parse_connect_private(struct svcxprt_rdma *newxprt,
162 			       struct rdma_conn_param *param)
163 {
164 	const struct rpcrdma_connect_private *pmsg = param->private_data;
165 
166 	if (pmsg &&
167 	    pmsg->cp_magic == rpcrdma_cmp_magic &&
168 	    pmsg->cp_version == RPCRDMA_CMP_VERSION) {
169 		newxprt->sc_snd_w_inv = pmsg->cp_flags &
170 					RPCRDMA_CMP_F_SND_W_INV_OK;
171 
172 		dprintk("svcrdma: client send_size %u, recv_size %u "
173 			"remote inv %ssupported\n",
174 			rpcrdma_decode_buffer_size(pmsg->cp_send_size),
175 			rpcrdma_decode_buffer_size(pmsg->cp_recv_size),
176 			newxprt->sc_snd_w_inv ? "" : "un");
177 	}
178 }
179 
180 /*
181  * This function handles the CONNECT_REQUEST event on a listening
182  * endpoint. It is passed the cma_id for the _new_ connection. The context in
183  * this cma_id is inherited from the listening cma_id and is the svc_xprt
184  * structure for the listening endpoint.
185  *
186  * This function creates a new xprt for the new connection and enqueues it on
187  * the accept queue for the listent xprt. When the listen thread is kicked, it
188  * will call the recvfrom method on the listen xprt which will accept the new
189  * connection.
190  */
191 static void handle_connect_req(struct rdma_cm_id *new_cma_id,
192 			       struct rdma_conn_param *param)
193 {
194 	struct svcxprt_rdma *listen_xprt = new_cma_id->context;
195 	struct svcxprt_rdma *newxprt;
196 	struct sockaddr *sa;
197 
198 	/* Create a new transport */
199 	newxprt = svc_rdma_create_xprt(listen_xprt->sc_xprt.xpt_server,
200 				       listen_xprt->sc_xprt.xpt_net);
201 	if (!newxprt)
202 		return;
203 	newxprt->sc_cm_id = new_cma_id;
204 	new_cma_id->context = newxprt;
205 	svc_rdma_parse_connect_private(newxprt, param);
206 
207 	/* Save client advertised inbound read limit for use later in accept. */
208 	newxprt->sc_ord = param->initiator_depth;
209 
210 	sa = (struct sockaddr *)&newxprt->sc_cm_id->route.addr.dst_addr;
211 	newxprt->sc_xprt.xpt_remotelen = svc_addr_len(sa);
212 	memcpy(&newxprt->sc_xprt.xpt_remote, sa,
213 	       newxprt->sc_xprt.xpt_remotelen);
214 	snprintf(newxprt->sc_xprt.xpt_remotebuf,
215 		 sizeof(newxprt->sc_xprt.xpt_remotebuf) - 1, "%pISc", sa);
216 
217 	/* The remote port is arbitrary and not under the control of the
218 	 * client ULP. Set it to a fixed value so that the DRC continues
219 	 * to be effective after a reconnect.
220 	 */
221 	rpc_set_port((struct sockaddr *)&newxprt->sc_xprt.xpt_remote, 0);
222 
223 	sa = (struct sockaddr *)&newxprt->sc_cm_id->route.addr.src_addr;
224 	svc_xprt_set_local(&newxprt->sc_xprt, sa, svc_addr_len(sa));
225 
226 	/*
227 	 * Enqueue the new transport on the accept queue of the listening
228 	 * transport
229 	 */
230 	spin_lock(&listen_xprt->sc_lock);
231 	list_add_tail(&newxprt->sc_accept_q, &listen_xprt->sc_accept_q);
232 	spin_unlock(&listen_xprt->sc_lock);
233 
234 	set_bit(XPT_CONN, &listen_xprt->sc_xprt.xpt_flags);
235 	svc_xprt_enqueue(&listen_xprt->sc_xprt);
236 }
237 
238 /**
239  * svc_rdma_listen_handler - Handle CM events generated on a listening endpoint
240  * @cma_id: the server's listener rdma_cm_id
241  * @event: details of the event
242  *
243  * Return values:
244  *     %0: Do not destroy @cma_id
245  *     %1: Destroy @cma_id (never returned here)
246  *
247  * NB: There is never a DEVICE_REMOVAL event for INADDR_ANY listeners.
248  */
249 static int svc_rdma_listen_handler(struct rdma_cm_id *cma_id,
250 				   struct rdma_cm_event *event)
251 {
252 	switch (event->event) {
253 	case RDMA_CM_EVENT_CONNECT_REQUEST:
254 		handle_connect_req(cma_id, &event->param.conn);
255 		break;
256 	default:
257 		break;
258 	}
259 	return 0;
260 }
261 
262 /**
263  * svc_rdma_cma_handler - Handle CM events on client connections
264  * @cma_id: the server's listener rdma_cm_id
265  * @event: details of the event
266  *
267  * Return values:
268  *     %0: Do not destroy @cma_id
269  *     %1: Destroy @cma_id (never returned here)
270  */
271 static int svc_rdma_cma_handler(struct rdma_cm_id *cma_id,
272 				struct rdma_cm_event *event)
273 {
274 	struct svcxprt_rdma *rdma = cma_id->context;
275 	struct svc_xprt *xprt = &rdma->sc_xprt;
276 
277 	switch (event->event) {
278 	case RDMA_CM_EVENT_ESTABLISHED:
279 		clear_bit(RDMAXPRT_CONN_PENDING, &rdma->sc_flags);
280 
281 		/* Handle any requests that were received while
282 		 * CONN_PENDING was set. */
283 		svc_xprt_enqueue(xprt);
284 		break;
285 	case RDMA_CM_EVENT_DISCONNECTED:
286 	case RDMA_CM_EVENT_DEVICE_REMOVAL:
287 		svc_xprt_deferred_close(xprt);
288 		break;
289 	default:
290 		break;
291 	}
292 	return 0;
293 }
294 
295 /*
296  * Create a listening RDMA service endpoint.
297  */
298 static struct svc_xprt *svc_rdma_create(struct svc_serv *serv,
299 					struct net *net,
300 					struct sockaddr *sa, int salen,
301 					int flags)
302 {
303 	struct rdma_cm_id *listen_id;
304 	struct svcxprt_rdma *cma_xprt;
305 	int ret;
306 
307 	if (sa->sa_family != AF_INET && sa->sa_family != AF_INET6)
308 		return ERR_PTR(-EAFNOSUPPORT);
309 	cma_xprt = svc_rdma_create_xprt(serv, net);
310 	if (!cma_xprt)
311 		return ERR_PTR(-ENOMEM);
312 	set_bit(XPT_LISTENER, &cma_xprt->sc_xprt.xpt_flags);
313 	strcpy(cma_xprt->sc_xprt.xpt_remotebuf, "listener");
314 
315 	listen_id = rdma_create_id(net, svc_rdma_listen_handler, cma_xprt,
316 				   RDMA_PS_TCP, IB_QPT_RC);
317 	if (IS_ERR(listen_id)) {
318 		ret = PTR_ERR(listen_id);
319 		goto err0;
320 	}
321 
322 	/* Allow both IPv4 and IPv6 sockets to bind a single port
323 	 * at the same time.
324 	 */
325 #if IS_ENABLED(CONFIG_IPV6)
326 	ret = rdma_set_afonly(listen_id, 1);
327 	if (ret)
328 		goto err1;
329 #endif
330 	ret = rdma_bind_addr(listen_id, sa);
331 	if (ret)
332 		goto err1;
333 	cma_xprt->sc_cm_id = listen_id;
334 
335 	ret = rdma_listen(listen_id, RPCRDMA_LISTEN_BACKLOG);
336 	if (ret)
337 		goto err1;
338 
339 	/*
340 	 * We need to use the address from the cm_id in case the
341 	 * caller specified 0 for the port number.
342 	 */
343 	sa = (struct sockaddr *)&cma_xprt->sc_cm_id->route.addr.src_addr;
344 	svc_xprt_set_local(&cma_xprt->sc_xprt, sa, salen);
345 
346 	return &cma_xprt->sc_xprt;
347 
348  err1:
349 	rdma_destroy_id(listen_id);
350  err0:
351 	kfree(cma_xprt);
352 	return ERR_PTR(ret);
353 }
354 
355 /*
356  * This is the xpo_recvfrom function for listening endpoints. Its
357  * purpose is to accept incoming connections. The CMA callback handler
358  * has already created a new transport and attached it to the new CMA
359  * ID.
360  *
361  * There is a queue of pending connections hung on the listening
362  * transport. This queue contains the new svc_xprt structure. This
363  * function takes svc_xprt structures off the accept_q and completes
364  * the connection.
365  */
366 static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt)
367 {
368 	struct svcxprt_rdma *listen_rdma;
369 	struct svcxprt_rdma *newxprt = NULL;
370 	struct rdma_conn_param conn_param;
371 	struct rpcrdma_connect_private pmsg;
372 	struct ib_qp_init_attr qp_attr;
373 	unsigned int ctxts, rq_depth;
374 	struct ib_device *dev;
375 	int ret = 0;
376 	RPC_IFDEBUG(struct sockaddr *sap);
377 
378 	listen_rdma = container_of(xprt, struct svcxprt_rdma, sc_xprt);
379 	clear_bit(XPT_CONN, &xprt->xpt_flags);
380 	/* Get the next entry off the accept list */
381 	spin_lock(&listen_rdma->sc_lock);
382 	if (!list_empty(&listen_rdma->sc_accept_q)) {
383 		newxprt = list_entry(listen_rdma->sc_accept_q.next,
384 				     struct svcxprt_rdma, sc_accept_q);
385 		list_del_init(&newxprt->sc_accept_q);
386 	}
387 	if (!list_empty(&listen_rdma->sc_accept_q))
388 		set_bit(XPT_CONN, &listen_rdma->sc_xprt.xpt_flags);
389 	spin_unlock(&listen_rdma->sc_lock);
390 	if (!newxprt)
391 		return NULL;
392 
393 	dev = newxprt->sc_cm_id->device;
394 	newxprt->sc_port_num = newxprt->sc_cm_id->port_num;
395 
396 	/* Qualify the transport resource defaults with the
397 	 * capabilities of this particular device */
398 	/* Transport header, head iovec, tail iovec */
399 	newxprt->sc_max_send_sges = 3;
400 	/* Add one SGE per page list entry */
401 	newxprt->sc_max_send_sges += (svcrdma_max_req_size / PAGE_SIZE) + 1;
402 	if (newxprt->sc_max_send_sges > dev->attrs.max_send_sge)
403 		newxprt->sc_max_send_sges = dev->attrs.max_send_sge;
404 	newxprt->sc_max_req_size = svcrdma_max_req_size;
405 	newxprt->sc_max_requests = svcrdma_max_requests;
406 	newxprt->sc_max_bc_requests = svcrdma_max_bc_requests;
407 	newxprt->sc_recv_batch = RPCRDMA_MAX_RECV_BATCH;
408 	rq_depth = newxprt->sc_max_requests + newxprt->sc_max_bc_requests +
409 		   newxprt->sc_recv_batch;
410 	if (rq_depth > dev->attrs.max_qp_wr) {
411 		pr_warn("svcrdma: reducing receive depth to %d\n",
412 			dev->attrs.max_qp_wr);
413 		rq_depth = dev->attrs.max_qp_wr;
414 		newxprt->sc_recv_batch = 1;
415 		newxprt->sc_max_requests = rq_depth - 2;
416 		newxprt->sc_max_bc_requests = 2;
417 	}
418 	newxprt->sc_fc_credits = cpu_to_be32(newxprt->sc_max_requests);
419 	ctxts = rdma_rw_mr_factor(dev, newxprt->sc_port_num, RPCSVC_MAXPAGES);
420 	ctxts *= newxprt->sc_max_requests;
421 	newxprt->sc_sq_depth = rq_depth + ctxts;
422 	if (newxprt->sc_sq_depth > dev->attrs.max_qp_wr) {
423 		pr_warn("svcrdma: reducing send depth to %d\n",
424 			dev->attrs.max_qp_wr);
425 		newxprt->sc_sq_depth = dev->attrs.max_qp_wr;
426 	}
427 	atomic_set(&newxprt->sc_sq_avail, newxprt->sc_sq_depth);
428 
429 	newxprt->sc_pd = ib_alloc_pd(dev, 0);
430 	if (IS_ERR(newxprt->sc_pd)) {
431 		trace_svcrdma_pd_err(newxprt, PTR_ERR(newxprt->sc_pd));
432 		goto errout;
433 	}
434 	newxprt->sc_sq_cq = ib_alloc_cq_any(dev, newxprt, newxprt->sc_sq_depth,
435 					    IB_POLL_WORKQUEUE);
436 	if (IS_ERR(newxprt->sc_sq_cq))
437 		goto errout;
438 	newxprt->sc_rq_cq =
439 		ib_alloc_cq_any(dev, newxprt, rq_depth, IB_POLL_WORKQUEUE);
440 	if (IS_ERR(newxprt->sc_rq_cq))
441 		goto errout;
442 
443 	memset(&qp_attr, 0, sizeof qp_attr);
444 	qp_attr.event_handler = qp_event_handler;
445 	qp_attr.qp_context = &newxprt->sc_xprt;
446 	qp_attr.port_num = newxprt->sc_port_num;
447 	qp_attr.cap.max_rdma_ctxs = ctxts;
448 	qp_attr.cap.max_send_wr = newxprt->sc_sq_depth - ctxts;
449 	qp_attr.cap.max_recv_wr = rq_depth;
450 	qp_attr.cap.max_send_sge = newxprt->sc_max_send_sges;
451 	qp_attr.cap.max_recv_sge = 1;
452 	qp_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
453 	qp_attr.qp_type = IB_QPT_RC;
454 	qp_attr.send_cq = newxprt->sc_sq_cq;
455 	qp_attr.recv_cq = newxprt->sc_rq_cq;
456 	dprintk("svcrdma: newxprt->sc_cm_id=%p, newxprt->sc_pd=%p\n",
457 		newxprt->sc_cm_id, newxprt->sc_pd);
458 	dprintk("    cap.max_send_wr = %d, cap.max_recv_wr = %d\n",
459 		qp_attr.cap.max_send_wr, qp_attr.cap.max_recv_wr);
460 	dprintk("    cap.max_send_sge = %d, cap.max_recv_sge = %d\n",
461 		qp_attr.cap.max_send_sge, qp_attr.cap.max_recv_sge);
462 
463 	ret = rdma_create_qp(newxprt->sc_cm_id, newxprt->sc_pd, &qp_attr);
464 	if (ret) {
465 		trace_svcrdma_qp_err(newxprt, ret);
466 		goto errout;
467 	}
468 	newxprt->sc_qp = newxprt->sc_cm_id->qp;
469 
470 	if (!(dev->attrs.device_cap_flags & IB_DEVICE_MEM_MGT_EXTENSIONS))
471 		newxprt->sc_snd_w_inv = false;
472 	if (!rdma_protocol_iwarp(dev, newxprt->sc_port_num) &&
473 	    !rdma_ib_or_roce(dev, newxprt->sc_port_num)) {
474 		trace_svcrdma_fabric_err(newxprt, -EINVAL);
475 		goto errout;
476 	}
477 
478 	if (!svc_rdma_post_recvs(newxprt))
479 		goto errout;
480 
481 	/* Construct RDMA-CM private message */
482 	pmsg.cp_magic = rpcrdma_cmp_magic;
483 	pmsg.cp_version = RPCRDMA_CMP_VERSION;
484 	pmsg.cp_flags = 0;
485 	pmsg.cp_send_size = pmsg.cp_recv_size =
486 		rpcrdma_encode_buffer_size(newxprt->sc_max_req_size);
487 
488 	/* Accept Connection */
489 	set_bit(RDMAXPRT_CONN_PENDING, &newxprt->sc_flags);
490 	memset(&conn_param, 0, sizeof conn_param);
491 	conn_param.responder_resources = 0;
492 	conn_param.initiator_depth = min_t(int, newxprt->sc_ord,
493 					   dev->attrs.max_qp_init_rd_atom);
494 	if (!conn_param.initiator_depth) {
495 		ret = -EINVAL;
496 		trace_svcrdma_initdepth_err(newxprt, ret);
497 		goto errout;
498 	}
499 	conn_param.private_data = &pmsg;
500 	conn_param.private_data_len = sizeof(pmsg);
501 	rdma_lock_handler(newxprt->sc_cm_id);
502 	newxprt->sc_cm_id->event_handler = svc_rdma_cma_handler;
503 	ret = rdma_accept(newxprt->sc_cm_id, &conn_param);
504 	rdma_unlock_handler(newxprt->sc_cm_id);
505 	if (ret) {
506 		trace_svcrdma_accept_err(newxprt, ret);
507 		goto errout;
508 	}
509 
510 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
511 	dprintk("svcrdma: new connection %p accepted:\n", newxprt);
512 	sap = (struct sockaddr *)&newxprt->sc_cm_id->route.addr.src_addr;
513 	dprintk("    local address   : %pIS:%u\n", sap, rpc_get_port(sap));
514 	sap = (struct sockaddr *)&newxprt->sc_cm_id->route.addr.dst_addr;
515 	dprintk("    remote address  : %pIS:%u\n", sap, rpc_get_port(sap));
516 	dprintk("    max_sge         : %d\n", newxprt->sc_max_send_sges);
517 	dprintk("    sq_depth        : %d\n", newxprt->sc_sq_depth);
518 	dprintk("    rdma_rw_ctxs    : %d\n", ctxts);
519 	dprintk("    max_requests    : %d\n", newxprt->sc_max_requests);
520 	dprintk("    ord             : %d\n", conn_param.initiator_depth);
521 #endif
522 
523 	return &newxprt->sc_xprt;
524 
525  errout:
526 	/* Take a reference in case the DTO handler runs */
527 	svc_xprt_get(&newxprt->sc_xprt);
528 	if (newxprt->sc_qp && !IS_ERR(newxprt->sc_qp))
529 		ib_destroy_qp(newxprt->sc_qp);
530 	rdma_destroy_id(newxprt->sc_cm_id);
531 	/* This call to put will destroy the transport */
532 	svc_xprt_put(&newxprt->sc_xprt);
533 	return NULL;
534 }
535 
536 static void svc_rdma_detach(struct svc_xprt *xprt)
537 {
538 	struct svcxprt_rdma *rdma =
539 		container_of(xprt, struct svcxprt_rdma, sc_xprt);
540 
541 	rdma_disconnect(rdma->sc_cm_id);
542 }
543 
544 static void __svc_rdma_free(struct work_struct *work)
545 {
546 	struct svcxprt_rdma *rdma =
547 		container_of(work, struct svcxprt_rdma, sc_work);
548 	struct svc_xprt *xprt = &rdma->sc_xprt;
549 
550 	/* This blocks until the Completion Queues are empty */
551 	if (rdma->sc_qp && !IS_ERR(rdma->sc_qp))
552 		ib_drain_qp(rdma->sc_qp);
553 
554 	svc_rdma_flush_recv_queues(rdma);
555 
556 	/* Final put of backchannel client transport */
557 	if (xprt->xpt_bc_xprt) {
558 		xprt_put(xprt->xpt_bc_xprt);
559 		xprt->xpt_bc_xprt = NULL;
560 	}
561 
562 	svc_rdma_destroy_rw_ctxts(rdma);
563 	svc_rdma_send_ctxts_destroy(rdma);
564 	svc_rdma_recv_ctxts_destroy(rdma);
565 
566 	/* Destroy the QP if present (not a listener) */
567 	if (rdma->sc_qp && !IS_ERR(rdma->sc_qp))
568 		ib_destroy_qp(rdma->sc_qp);
569 
570 	if (rdma->sc_sq_cq && !IS_ERR(rdma->sc_sq_cq))
571 		ib_free_cq(rdma->sc_sq_cq);
572 
573 	if (rdma->sc_rq_cq && !IS_ERR(rdma->sc_rq_cq))
574 		ib_free_cq(rdma->sc_rq_cq);
575 
576 	if (rdma->sc_pd && !IS_ERR(rdma->sc_pd))
577 		ib_dealloc_pd(rdma->sc_pd);
578 
579 	/* Destroy the CM ID */
580 	rdma_destroy_id(rdma->sc_cm_id);
581 
582 	kfree(rdma);
583 }
584 
585 static void svc_rdma_free(struct svc_xprt *xprt)
586 {
587 	struct svcxprt_rdma *rdma =
588 		container_of(xprt, struct svcxprt_rdma, sc_xprt);
589 
590 	INIT_WORK(&rdma->sc_work, __svc_rdma_free);
591 	schedule_work(&rdma->sc_work);
592 }
593 
594 static int svc_rdma_has_wspace(struct svc_xprt *xprt)
595 {
596 	struct svcxprt_rdma *rdma =
597 		container_of(xprt, struct svcxprt_rdma, sc_xprt);
598 
599 	/*
600 	 * If there are already waiters on the SQ,
601 	 * return false.
602 	 */
603 	if (waitqueue_active(&rdma->sc_send_wait))
604 		return 0;
605 
606 	/* Otherwise return true. */
607 	return 1;
608 }
609 
610 static void svc_rdma_secure_port(struct svc_rqst *rqstp)
611 {
612 	set_bit(RQ_SECURE, &rqstp->rq_flags);
613 }
614 
615 static void svc_rdma_kill_temp_xprt(struct svc_xprt *xprt)
616 {
617 }
618