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_kill_temp_xprt(struct svc_xprt *);
77 
78 static const struct svc_xprt_ops svc_rdma_ops = {
79 	.xpo_create = svc_rdma_create,
80 	.xpo_recvfrom = svc_rdma_recvfrom,
81 	.xpo_sendto = svc_rdma_sendto,
82 	.xpo_result_payload = svc_rdma_result_payload,
83 	.xpo_release_rqst = svc_rdma_release_rqst,
84 	.xpo_detach = svc_rdma_detach,
85 	.xpo_free = svc_rdma_free,
86 	.xpo_has_wspace = svc_rdma_has_wspace,
87 	.xpo_accept = svc_rdma_accept,
88 	.xpo_kill_temp_xprt = svc_rdma_kill_temp_xprt,
89 };
90 
91 struct svc_xprt_class svc_rdma_class = {
92 	.xcl_name = "rdma",
93 	.xcl_owner = THIS_MODULE,
94 	.xcl_ops = &svc_rdma_ops,
95 	.xcl_max_payload = RPCSVC_MAXPAYLOAD_RDMA,
96 	.xcl_ident = XPRT_TRANSPORT_RDMA,
97 };
98 
99 /* QP event handler */
100 static void qp_event_handler(struct ib_event *event, void *context)
101 {
102 	struct svc_xprt *xprt = context;
103 
104 	trace_svcrdma_qp_error(event, (struct sockaddr *)&xprt->xpt_remote);
105 	switch (event->event) {
106 	/* These are considered benign events */
107 	case IB_EVENT_PATH_MIG:
108 	case IB_EVENT_COMM_EST:
109 	case IB_EVENT_SQ_DRAINED:
110 	case IB_EVENT_QP_LAST_WQE_REACHED:
111 		break;
112 
113 	/* These are considered fatal events */
114 	case IB_EVENT_PATH_MIG_ERR:
115 	case IB_EVENT_QP_FATAL:
116 	case IB_EVENT_QP_REQ_ERR:
117 	case IB_EVENT_QP_ACCESS_ERR:
118 	case IB_EVENT_DEVICE_FATAL:
119 	default:
120 		svc_xprt_deferred_close(xprt);
121 		break;
122 	}
123 }
124 
125 static struct svcxprt_rdma *svc_rdma_create_xprt(struct svc_serv *serv,
126 						 struct net *net)
127 {
128 	struct svcxprt_rdma *cma_xprt = kzalloc(sizeof *cma_xprt, GFP_KERNEL);
129 
130 	if (!cma_xprt) {
131 		dprintk("svcrdma: failed to create new transport\n");
132 		return NULL;
133 	}
134 	svc_xprt_init(net, &svc_rdma_class, &cma_xprt->sc_xprt, serv);
135 	INIT_LIST_HEAD(&cma_xprt->sc_accept_q);
136 	INIT_LIST_HEAD(&cma_xprt->sc_rq_dto_q);
137 	init_llist_head(&cma_xprt->sc_send_ctxts);
138 	init_llist_head(&cma_xprt->sc_recv_ctxts);
139 	init_llist_head(&cma_xprt->sc_rw_ctxts);
140 	init_waitqueue_head(&cma_xprt->sc_send_wait);
141 
142 	spin_lock_init(&cma_xprt->sc_lock);
143 	spin_lock_init(&cma_xprt->sc_rq_dto_lock);
144 	spin_lock_init(&cma_xprt->sc_send_lock);
145 	spin_lock_init(&cma_xprt->sc_rw_ctxt_lock);
146 
147 	/*
148 	 * Note that this implies that the underlying transport support
149 	 * has some form of congestion control (see RFC 7530 section 3.1
150 	 * paragraph 2). For now, we assume that all supported RDMA
151 	 * transports are suitable here.
152 	 */
153 	set_bit(XPT_CONG_CTRL, &cma_xprt->sc_xprt.xpt_flags);
154 
155 	return cma_xprt;
156 }
157 
158 static void
159 svc_rdma_parse_connect_private(struct svcxprt_rdma *newxprt,
160 			       struct rdma_conn_param *param)
161 {
162 	const struct rpcrdma_connect_private *pmsg = param->private_data;
163 
164 	if (pmsg &&
165 	    pmsg->cp_magic == rpcrdma_cmp_magic &&
166 	    pmsg->cp_version == RPCRDMA_CMP_VERSION) {
167 		newxprt->sc_snd_w_inv = pmsg->cp_flags &
168 					RPCRDMA_CMP_F_SND_W_INV_OK;
169 
170 		dprintk("svcrdma: client send_size %u, recv_size %u "
171 			"remote inv %ssupported\n",
172 			rpcrdma_decode_buffer_size(pmsg->cp_send_size),
173 			rpcrdma_decode_buffer_size(pmsg->cp_recv_size),
174 			newxprt->sc_snd_w_inv ? "" : "un");
175 	}
176 }
177 
178 /*
179  * This function handles the CONNECT_REQUEST event on a listening
180  * endpoint. It is passed the cma_id for the _new_ connection. The context in
181  * this cma_id is inherited from the listening cma_id and is the svc_xprt
182  * structure for the listening endpoint.
183  *
184  * This function creates a new xprt for the new connection and enqueues it on
185  * the accept queue for the listent xprt. When the listen thread is kicked, it
186  * will call the recvfrom method on the listen xprt which will accept the new
187  * connection.
188  */
189 static void handle_connect_req(struct rdma_cm_id *new_cma_id,
190 			       struct rdma_conn_param *param)
191 {
192 	struct svcxprt_rdma *listen_xprt = new_cma_id->context;
193 	struct svcxprt_rdma *newxprt;
194 	struct sockaddr *sa;
195 
196 	/* Create a new transport */
197 	newxprt = svc_rdma_create_xprt(listen_xprt->sc_xprt.xpt_server,
198 				       listen_xprt->sc_xprt.xpt_net);
199 	if (!newxprt)
200 		return;
201 	newxprt->sc_cm_id = new_cma_id;
202 	new_cma_id->context = newxprt;
203 	svc_rdma_parse_connect_private(newxprt, param);
204 
205 	/* Save client advertised inbound read limit for use later in accept. */
206 	newxprt->sc_ord = param->initiator_depth;
207 
208 	sa = (struct sockaddr *)&newxprt->sc_cm_id->route.addr.dst_addr;
209 	newxprt->sc_xprt.xpt_remotelen = svc_addr_len(sa);
210 	memcpy(&newxprt->sc_xprt.xpt_remote, sa,
211 	       newxprt->sc_xprt.xpt_remotelen);
212 	snprintf(newxprt->sc_xprt.xpt_remotebuf,
213 		 sizeof(newxprt->sc_xprt.xpt_remotebuf) - 1, "%pISc", sa);
214 
215 	/* The remote port is arbitrary and not under the control of the
216 	 * client ULP. Set it to a fixed value so that the DRC continues
217 	 * to be effective after a reconnect.
218 	 */
219 	rpc_set_port((struct sockaddr *)&newxprt->sc_xprt.xpt_remote, 0);
220 
221 	sa = (struct sockaddr *)&newxprt->sc_cm_id->route.addr.src_addr;
222 	svc_xprt_set_local(&newxprt->sc_xprt, sa, svc_addr_len(sa));
223 
224 	/*
225 	 * Enqueue the new transport on the accept queue of the listening
226 	 * transport
227 	 */
228 	spin_lock(&listen_xprt->sc_lock);
229 	list_add_tail(&newxprt->sc_accept_q, &listen_xprt->sc_accept_q);
230 	spin_unlock(&listen_xprt->sc_lock);
231 
232 	set_bit(XPT_CONN, &listen_xprt->sc_xprt.xpt_flags);
233 	svc_xprt_enqueue(&listen_xprt->sc_xprt);
234 }
235 
236 /**
237  * svc_rdma_listen_handler - Handle CM events generated on a listening endpoint
238  * @cma_id: the server's listener rdma_cm_id
239  * @event: details of the event
240  *
241  * Return values:
242  *     %0: Do not destroy @cma_id
243  *     %1: Destroy @cma_id (never returned here)
244  *
245  * NB: There is never a DEVICE_REMOVAL event for INADDR_ANY listeners.
246  */
247 static int svc_rdma_listen_handler(struct rdma_cm_id *cma_id,
248 				   struct rdma_cm_event *event)
249 {
250 	switch (event->event) {
251 	case RDMA_CM_EVENT_CONNECT_REQUEST:
252 		handle_connect_req(cma_id, &event->param.conn);
253 		break;
254 	default:
255 		break;
256 	}
257 	return 0;
258 }
259 
260 /**
261  * svc_rdma_cma_handler - Handle CM events on client connections
262  * @cma_id: the server's listener rdma_cm_id
263  * @event: details of the event
264  *
265  * Return values:
266  *     %0: Do not destroy @cma_id
267  *     %1: Destroy @cma_id (never returned here)
268  */
269 static int svc_rdma_cma_handler(struct rdma_cm_id *cma_id,
270 				struct rdma_cm_event *event)
271 {
272 	struct svcxprt_rdma *rdma = cma_id->context;
273 	struct svc_xprt *xprt = &rdma->sc_xprt;
274 
275 	switch (event->event) {
276 	case RDMA_CM_EVENT_ESTABLISHED:
277 		clear_bit(RDMAXPRT_CONN_PENDING, &rdma->sc_flags);
278 
279 		/* Handle any requests that were received while
280 		 * CONN_PENDING was set. */
281 		svc_xprt_enqueue(xprt);
282 		break;
283 	case RDMA_CM_EVENT_DISCONNECTED:
284 	case RDMA_CM_EVENT_DEVICE_REMOVAL:
285 		svc_xprt_deferred_close(xprt);
286 		break;
287 	default:
288 		break;
289 	}
290 	return 0;
291 }
292 
293 /*
294  * Create a listening RDMA service endpoint.
295  */
296 static struct svc_xprt *svc_rdma_create(struct svc_serv *serv,
297 					struct net *net,
298 					struct sockaddr *sa, int salen,
299 					int flags)
300 {
301 	struct rdma_cm_id *listen_id;
302 	struct svcxprt_rdma *cma_xprt;
303 	int ret;
304 
305 	if (sa->sa_family != AF_INET && sa->sa_family != AF_INET6)
306 		return ERR_PTR(-EAFNOSUPPORT);
307 	cma_xprt = svc_rdma_create_xprt(serv, net);
308 	if (!cma_xprt)
309 		return ERR_PTR(-ENOMEM);
310 	set_bit(XPT_LISTENER, &cma_xprt->sc_xprt.xpt_flags);
311 	strcpy(cma_xprt->sc_xprt.xpt_remotebuf, "listener");
312 
313 	listen_id = rdma_create_id(net, svc_rdma_listen_handler, cma_xprt,
314 				   RDMA_PS_TCP, IB_QPT_RC);
315 	if (IS_ERR(listen_id)) {
316 		ret = PTR_ERR(listen_id);
317 		goto err0;
318 	}
319 
320 	/* Allow both IPv4 and IPv6 sockets to bind a single port
321 	 * at the same time.
322 	 */
323 #if IS_ENABLED(CONFIG_IPV6)
324 	ret = rdma_set_afonly(listen_id, 1);
325 	if (ret)
326 		goto err1;
327 #endif
328 	ret = rdma_bind_addr(listen_id, sa);
329 	if (ret)
330 		goto err1;
331 	cma_xprt->sc_cm_id = listen_id;
332 
333 	ret = rdma_listen(listen_id, RPCRDMA_LISTEN_BACKLOG);
334 	if (ret)
335 		goto err1;
336 
337 	/*
338 	 * We need to use the address from the cm_id in case the
339 	 * caller specified 0 for the port number.
340 	 */
341 	sa = (struct sockaddr *)&cma_xprt->sc_cm_id->route.addr.src_addr;
342 	svc_xprt_set_local(&cma_xprt->sc_xprt, sa, salen);
343 
344 	return &cma_xprt->sc_xprt;
345 
346  err1:
347 	rdma_destroy_id(listen_id);
348  err0:
349 	kfree(cma_xprt);
350 	return ERR_PTR(ret);
351 }
352 
353 /*
354  * This is the xpo_recvfrom function for listening endpoints. Its
355  * purpose is to accept incoming connections. The CMA callback handler
356  * has already created a new transport and attached it to the new CMA
357  * ID.
358  *
359  * There is a queue of pending connections hung on the listening
360  * transport. This queue contains the new svc_xprt structure. This
361  * function takes svc_xprt structures off the accept_q and completes
362  * the connection.
363  */
364 static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt)
365 {
366 	struct svcxprt_rdma *listen_rdma;
367 	struct svcxprt_rdma *newxprt = NULL;
368 	struct rdma_conn_param conn_param;
369 	struct rpcrdma_connect_private pmsg;
370 	struct ib_qp_init_attr qp_attr;
371 	unsigned int ctxts, rq_depth;
372 	struct ib_device *dev;
373 	int ret = 0;
374 	RPC_IFDEBUG(struct sockaddr *sap);
375 
376 	listen_rdma = container_of(xprt, struct svcxprt_rdma, sc_xprt);
377 	clear_bit(XPT_CONN, &xprt->xpt_flags);
378 	/* Get the next entry off the accept list */
379 	spin_lock(&listen_rdma->sc_lock);
380 	if (!list_empty(&listen_rdma->sc_accept_q)) {
381 		newxprt = list_entry(listen_rdma->sc_accept_q.next,
382 				     struct svcxprt_rdma, sc_accept_q);
383 		list_del_init(&newxprt->sc_accept_q);
384 	}
385 	if (!list_empty(&listen_rdma->sc_accept_q))
386 		set_bit(XPT_CONN, &listen_rdma->sc_xprt.xpt_flags);
387 	spin_unlock(&listen_rdma->sc_lock);
388 	if (!newxprt)
389 		return NULL;
390 
391 	dev = newxprt->sc_cm_id->device;
392 	newxprt->sc_port_num = newxprt->sc_cm_id->port_num;
393 
394 	/* Qualify the transport resource defaults with the
395 	 * capabilities of this particular device */
396 	/* Transport header, head iovec, tail iovec */
397 	newxprt->sc_max_send_sges = 3;
398 	/* Add one SGE per page list entry */
399 	newxprt->sc_max_send_sges += (svcrdma_max_req_size / PAGE_SIZE) + 1;
400 	if (newxprt->sc_max_send_sges > dev->attrs.max_send_sge)
401 		newxprt->sc_max_send_sges = dev->attrs.max_send_sge;
402 	newxprt->sc_max_req_size = svcrdma_max_req_size;
403 	newxprt->sc_max_requests = svcrdma_max_requests;
404 	newxprt->sc_max_bc_requests = svcrdma_max_bc_requests;
405 	newxprt->sc_recv_batch = RPCRDMA_MAX_RECV_BATCH;
406 	rq_depth = newxprt->sc_max_requests + newxprt->sc_max_bc_requests +
407 		   newxprt->sc_recv_batch;
408 	if (rq_depth > dev->attrs.max_qp_wr) {
409 		pr_warn("svcrdma: reducing receive depth to %d\n",
410 			dev->attrs.max_qp_wr);
411 		rq_depth = dev->attrs.max_qp_wr;
412 		newxprt->sc_recv_batch = 1;
413 		newxprt->sc_max_requests = rq_depth - 2;
414 		newxprt->sc_max_bc_requests = 2;
415 	}
416 	newxprt->sc_fc_credits = cpu_to_be32(newxprt->sc_max_requests);
417 	ctxts = rdma_rw_mr_factor(dev, newxprt->sc_port_num, RPCSVC_MAXPAGES);
418 	ctxts *= newxprt->sc_max_requests;
419 	newxprt->sc_sq_depth = rq_depth + ctxts;
420 	if (newxprt->sc_sq_depth > dev->attrs.max_qp_wr) {
421 		pr_warn("svcrdma: reducing send depth to %d\n",
422 			dev->attrs.max_qp_wr);
423 		newxprt->sc_sq_depth = dev->attrs.max_qp_wr;
424 	}
425 	atomic_set(&newxprt->sc_sq_avail, newxprt->sc_sq_depth);
426 
427 	newxprt->sc_pd = ib_alloc_pd(dev, 0);
428 	if (IS_ERR(newxprt->sc_pd)) {
429 		trace_svcrdma_pd_err(newxprt, PTR_ERR(newxprt->sc_pd));
430 		goto errout;
431 	}
432 	newxprt->sc_sq_cq = ib_alloc_cq_any(dev, newxprt, newxprt->sc_sq_depth,
433 					    IB_POLL_WORKQUEUE);
434 	if (IS_ERR(newxprt->sc_sq_cq))
435 		goto errout;
436 	newxprt->sc_rq_cq =
437 		ib_alloc_cq_any(dev, newxprt, rq_depth, IB_POLL_WORKQUEUE);
438 	if (IS_ERR(newxprt->sc_rq_cq))
439 		goto errout;
440 
441 	memset(&qp_attr, 0, sizeof qp_attr);
442 	qp_attr.event_handler = qp_event_handler;
443 	qp_attr.qp_context = &newxprt->sc_xprt;
444 	qp_attr.port_num = newxprt->sc_port_num;
445 	qp_attr.cap.max_rdma_ctxs = ctxts;
446 	qp_attr.cap.max_send_wr = newxprt->sc_sq_depth - ctxts;
447 	qp_attr.cap.max_recv_wr = rq_depth;
448 	qp_attr.cap.max_send_sge = newxprt->sc_max_send_sges;
449 	qp_attr.cap.max_recv_sge = 1;
450 	qp_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
451 	qp_attr.qp_type = IB_QPT_RC;
452 	qp_attr.send_cq = newxprt->sc_sq_cq;
453 	qp_attr.recv_cq = newxprt->sc_rq_cq;
454 	dprintk("svcrdma: newxprt->sc_cm_id=%p, newxprt->sc_pd=%p\n",
455 		newxprt->sc_cm_id, newxprt->sc_pd);
456 	dprintk("    cap.max_send_wr = %d, cap.max_recv_wr = %d\n",
457 		qp_attr.cap.max_send_wr, qp_attr.cap.max_recv_wr);
458 	dprintk("    cap.max_send_sge = %d, cap.max_recv_sge = %d\n",
459 		qp_attr.cap.max_send_sge, qp_attr.cap.max_recv_sge);
460 
461 	ret = rdma_create_qp(newxprt->sc_cm_id, newxprt->sc_pd, &qp_attr);
462 	if (ret) {
463 		trace_svcrdma_qp_err(newxprt, ret);
464 		goto errout;
465 	}
466 	newxprt->sc_qp = newxprt->sc_cm_id->qp;
467 
468 	if (!(dev->attrs.device_cap_flags & IB_DEVICE_MEM_MGT_EXTENSIONS))
469 		newxprt->sc_snd_w_inv = false;
470 	if (!rdma_protocol_iwarp(dev, newxprt->sc_port_num) &&
471 	    !rdma_ib_or_roce(dev, newxprt->sc_port_num)) {
472 		trace_svcrdma_fabric_err(newxprt, -EINVAL);
473 		goto errout;
474 	}
475 
476 	if (!svc_rdma_post_recvs(newxprt))
477 		goto errout;
478 
479 	/* Construct RDMA-CM private message */
480 	pmsg.cp_magic = rpcrdma_cmp_magic;
481 	pmsg.cp_version = RPCRDMA_CMP_VERSION;
482 	pmsg.cp_flags = 0;
483 	pmsg.cp_send_size = pmsg.cp_recv_size =
484 		rpcrdma_encode_buffer_size(newxprt->sc_max_req_size);
485 
486 	/* Accept Connection */
487 	set_bit(RDMAXPRT_CONN_PENDING, &newxprt->sc_flags);
488 	memset(&conn_param, 0, sizeof conn_param);
489 	conn_param.responder_resources = 0;
490 	conn_param.initiator_depth = min_t(int, newxprt->sc_ord,
491 					   dev->attrs.max_qp_init_rd_atom);
492 	if (!conn_param.initiator_depth) {
493 		ret = -EINVAL;
494 		trace_svcrdma_initdepth_err(newxprt, ret);
495 		goto errout;
496 	}
497 	conn_param.private_data = &pmsg;
498 	conn_param.private_data_len = sizeof(pmsg);
499 	rdma_lock_handler(newxprt->sc_cm_id);
500 	newxprt->sc_cm_id->event_handler = svc_rdma_cma_handler;
501 	ret = rdma_accept(newxprt->sc_cm_id, &conn_param);
502 	rdma_unlock_handler(newxprt->sc_cm_id);
503 	if (ret) {
504 		trace_svcrdma_accept_err(newxprt, ret);
505 		goto errout;
506 	}
507 
508 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
509 	dprintk("svcrdma: new connection %p accepted:\n", newxprt);
510 	sap = (struct sockaddr *)&newxprt->sc_cm_id->route.addr.src_addr;
511 	dprintk("    local address   : %pIS:%u\n", sap, rpc_get_port(sap));
512 	sap = (struct sockaddr *)&newxprt->sc_cm_id->route.addr.dst_addr;
513 	dprintk("    remote address  : %pIS:%u\n", sap, rpc_get_port(sap));
514 	dprintk("    max_sge         : %d\n", newxprt->sc_max_send_sges);
515 	dprintk("    sq_depth        : %d\n", newxprt->sc_sq_depth);
516 	dprintk("    rdma_rw_ctxs    : %d\n", ctxts);
517 	dprintk("    max_requests    : %d\n", newxprt->sc_max_requests);
518 	dprintk("    ord             : %d\n", conn_param.initiator_depth);
519 #endif
520 
521 	return &newxprt->sc_xprt;
522 
523  errout:
524 	/* Take a reference in case the DTO handler runs */
525 	svc_xprt_get(&newxprt->sc_xprt);
526 	if (newxprt->sc_qp && !IS_ERR(newxprt->sc_qp))
527 		ib_destroy_qp(newxprt->sc_qp);
528 	rdma_destroy_id(newxprt->sc_cm_id);
529 	/* This call to put will destroy the transport */
530 	svc_xprt_put(&newxprt->sc_xprt);
531 	return NULL;
532 }
533 
534 static void svc_rdma_detach(struct svc_xprt *xprt)
535 {
536 	struct svcxprt_rdma *rdma =
537 		container_of(xprt, struct svcxprt_rdma, sc_xprt);
538 
539 	rdma_disconnect(rdma->sc_cm_id);
540 }
541 
542 static void __svc_rdma_free(struct work_struct *work)
543 {
544 	struct svcxprt_rdma *rdma =
545 		container_of(work, struct svcxprt_rdma, sc_work);
546 
547 	/* This blocks until the Completion Queues are empty */
548 	if (rdma->sc_qp && !IS_ERR(rdma->sc_qp))
549 		ib_drain_qp(rdma->sc_qp);
550 
551 	svc_rdma_flush_recv_queues(rdma);
552 
553 	svc_rdma_destroy_rw_ctxts(rdma);
554 	svc_rdma_send_ctxts_destroy(rdma);
555 	svc_rdma_recv_ctxts_destroy(rdma);
556 
557 	/* Destroy the QP if present (not a listener) */
558 	if (rdma->sc_qp && !IS_ERR(rdma->sc_qp))
559 		ib_destroy_qp(rdma->sc_qp);
560 
561 	if (rdma->sc_sq_cq && !IS_ERR(rdma->sc_sq_cq))
562 		ib_free_cq(rdma->sc_sq_cq);
563 
564 	if (rdma->sc_rq_cq && !IS_ERR(rdma->sc_rq_cq))
565 		ib_free_cq(rdma->sc_rq_cq);
566 
567 	if (rdma->sc_pd && !IS_ERR(rdma->sc_pd))
568 		ib_dealloc_pd(rdma->sc_pd);
569 
570 	/* Destroy the CM ID */
571 	rdma_destroy_id(rdma->sc_cm_id);
572 
573 	kfree(rdma);
574 }
575 
576 static void svc_rdma_free(struct svc_xprt *xprt)
577 {
578 	struct svcxprt_rdma *rdma =
579 		container_of(xprt, struct svcxprt_rdma, sc_xprt);
580 
581 	INIT_WORK(&rdma->sc_work, __svc_rdma_free);
582 	schedule_work(&rdma->sc_work);
583 }
584 
585 static int svc_rdma_has_wspace(struct svc_xprt *xprt)
586 {
587 	struct svcxprt_rdma *rdma =
588 		container_of(xprt, struct svcxprt_rdma, sc_xprt);
589 
590 	/*
591 	 * If there are already waiters on the SQ,
592 	 * return false.
593 	 */
594 	if (waitqueue_active(&rdma->sc_send_wait))
595 		return 0;
596 
597 	/* Otherwise return true. */
598 	return 1;
599 }
600 
601 static void svc_rdma_kill_temp_xprt(struct svc_xprt *xprt)
602 {
603 }
604