1/*
2 * Copyright (c) 2006 Oracle.  All rights reserved.
3 *
4 * This software is available to you under a choice of one of two
5 * licenses.  You may choose to be licensed under the terms of the GNU
6 * General Public License (GPL) Version 2, available from the file
7 * COPYING in the main directory of this source tree, or the
8 * OpenIB.org BSD license below:
9 *
10 *     Redistribution and use in source and binary forms, with or
11 *     without modification, are permitted provided that the following
12 *     conditions are met:
13 *
14 *      - Redistributions of source code must retain the above
15 *        copyright notice, this list of conditions and the following
16 *        disclaimer.
17 *
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
21 *        provided with the distribution.
22 *
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30 * SOFTWARE.
31 *
32 */
33#include <linux/kernel.h>
34#include <linux/in.h>
35#include <linux/slab.h>
36#include <linux/vmalloc.h>
37#include <linux/ratelimit.h>
38
39#include "rds.h"
40#include "ib.h"
41
42static char *rds_ib_event_type_strings[] = {
43#define RDS_IB_EVENT_STRING(foo) \
44		[IB_EVENT_##foo] = __stringify(IB_EVENT_##foo)
45	RDS_IB_EVENT_STRING(CQ_ERR),
46	RDS_IB_EVENT_STRING(QP_FATAL),
47	RDS_IB_EVENT_STRING(QP_REQ_ERR),
48	RDS_IB_EVENT_STRING(QP_ACCESS_ERR),
49	RDS_IB_EVENT_STRING(COMM_EST),
50	RDS_IB_EVENT_STRING(SQ_DRAINED),
51	RDS_IB_EVENT_STRING(PATH_MIG),
52	RDS_IB_EVENT_STRING(PATH_MIG_ERR),
53	RDS_IB_EVENT_STRING(DEVICE_FATAL),
54	RDS_IB_EVENT_STRING(PORT_ACTIVE),
55	RDS_IB_EVENT_STRING(PORT_ERR),
56	RDS_IB_EVENT_STRING(LID_CHANGE),
57	RDS_IB_EVENT_STRING(PKEY_CHANGE),
58	RDS_IB_EVENT_STRING(SM_CHANGE),
59	RDS_IB_EVENT_STRING(SRQ_ERR),
60	RDS_IB_EVENT_STRING(SRQ_LIMIT_REACHED),
61	RDS_IB_EVENT_STRING(QP_LAST_WQE_REACHED),
62	RDS_IB_EVENT_STRING(CLIENT_REREGISTER),
63#undef RDS_IB_EVENT_STRING
64};
65
66static char *rds_ib_event_str(enum ib_event_type type)
67{
68	return rds_str_array(rds_ib_event_type_strings,
69			     ARRAY_SIZE(rds_ib_event_type_strings), type);
70};
71
72/*
73 * Set the selected protocol version
74 */
75static void rds_ib_set_protocol(struct rds_connection *conn, unsigned int version)
76{
77	conn->c_version = version;
78}
79
80/*
81 * Set up flow control
82 */
83static void rds_ib_set_flow_control(struct rds_connection *conn, u32 credits)
84{
85	struct rds_ib_connection *ic = conn->c_transport_data;
86
87	if (rds_ib_sysctl_flow_control && credits != 0) {
88		/* We're doing flow control */
89		ic->i_flowctl = 1;
90		rds_ib_send_add_credits(conn, credits);
91	} else {
92		ic->i_flowctl = 0;
93	}
94}
95
96/*
97 * Tune RNR behavior. Without flow control, we use a rather
98 * low timeout, but not the absolute minimum - this should
99 * be tunable.
100 *
101 * We already set the RNR retry count to 7 (which is the
102 * smallest infinite number :-) above.
103 * If flow control is off, we want to change this back to 0
104 * so that we learn quickly when our credit accounting is
105 * buggy.
106 *
107 * Caller passes in a qp_attr pointer - don't waste stack spacv
108 * by allocation this twice.
109 */
110static void
111rds_ib_tune_rnr(struct rds_ib_connection *ic, struct ib_qp_attr *attr)
112{
113	int ret;
114
115	attr->min_rnr_timer = IB_RNR_TIMER_000_32;
116	ret = ib_modify_qp(ic->i_cm_id->qp, attr, IB_QP_MIN_RNR_TIMER);
117	if (ret)
118		printk(KERN_NOTICE "ib_modify_qp(IB_QP_MIN_RNR_TIMER): err=%d\n", -ret);
119}
120
121/*
122 * Connection established.
123 * We get here for both outgoing and incoming connection.
124 */
125void rds_ib_cm_connect_complete(struct rds_connection *conn, struct rdma_cm_event *event)
126{
127	const struct rds_ib_connect_private *dp = NULL;
128	struct rds_ib_connection *ic = conn->c_transport_data;
129	struct ib_qp_attr qp_attr;
130	int err;
131
132	if (event->param.conn.private_data_len >= sizeof(*dp)) {
133		dp = event->param.conn.private_data;
134
135		/* make sure it isn't empty data */
136		if (dp->dp_protocol_major) {
137			rds_ib_set_protocol(conn,
138				RDS_PROTOCOL(dp->dp_protocol_major,
139				dp->dp_protocol_minor));
140			rds_ib_set_flow_control(conn, be32_to_cpu(dp->dp_credit));
141		}
142	}
143
144	if (conn->c_version < RDS_PROTOCOL(3,1)) {
145		printk(KERN_NOTICE "RDS/IB: Connection to %pI4 version %u.%u failed,"
146		       " no longer supported\n",
147		       &conn->c_faddr,
148		       RDS_PROTOCOL_MAJOR(conn->c_version),
149		       RDS_PROTOCOL_MINOR(conn->c_version));
150		rds_conn_destroy(conn);
151		return;
152	} else {
153		printk(KERN_NOTICE "RDS/IB: connected to %pI4 version %u.%u%s\n",
154		       &conn->c_faddr,
155		       RDS_PROTOCOL_MAJOR(conn->c_version),
156		       RDS_PROTOCOL_MINOR(conn->c_version),
157		       ic->i_flowctl ? ", flow control" : "");
158	}
159
160	/*
161	 * Init rings and fill recv. this needs to wait until protocol negotiation
162	 * is complete, since ring layout is different from 3.0 to 3.1.
163	 */
164	rds_ib_send_init_ring(ic);
165	rds_ib_recv_init_ring(ic);
166	/* Post receive buffers - as a side effect, this will update
167	 * the posted credit count. */
168	rds_ib_recv_refill(conn, 1);
169
170	/* Tune RNR behavior */
171	rds_ib_tune_rnr(ic, &qp_attr);
172
173	qp_attr.qp_state = IB_QPS_RTS;
174	err = ib_modify_qp(ic->i_cm_id->qp, &qp_attr, IB_QP_STATE);
175	if (err)
176		printk(KERN_NOTICE "ib_modify_qp(IB_QP_STATE, RTS): err=%d\n", err);
177
178	/* update ib_device with this local ipaddr */
179	err = rds_ib_update_ipaddr(ic->rds_ibdev, conn->c_laddr);
180	if (err)
181		printk(KERN_ERR "rds_ib_update_ipaddr failed (%d)\n",
182			err);
183
184	/* If the peer gave us the last packet it saw, process this as if
185	 * we had received a regular ACK. */
186	if (dp) {
187		/* dp structure start is not guaranteed to be 8 bytes aligned.
188		 * Since dp_ack_seq is 64-bit extended load operations can be
189		 * used so go through get_unaligned to avoid unaligned errors.
190		 */
191		__be64 dp_ack_seq = get_unaligned(&dp->dp_ack_seq);
192
193		if (dp_ack_seq)
194			rds_send_drop_acked(conn, be64_to_cpu(dp_ack_seq),
195					    NULL);
196	}
197
198	rds_connect_complete(conn);
199}
200
201static void rds_ib_cm_fill_conn_param(struct rds_connection *conn,
202			struct rdma_conn_param *conn_param,
203			struct rds_ib_connect_private *dp,
204			u32 protocol_version,
205			u32 max_responder_resources,
206			u32 max_initiator_depth)
207{
208	struct rds_ib_connection *ic = conn->c_transport_data;
209	struct rds_ib_device *rds_ibdev = ic->rds_ibdev;
210
211	memset(conn_param, 0, sizeof(struct rdma_conn_param));
212
213	conn_param->responder_resources =
214		min_t(u32, rds_ibdev->max_responder_resources, max_responder_resources);
215	conn_param->initiator_depth =
216		min_t(u32, rds_ibdev->max_initiator_depth, max_initiator_depth);
217	conn_param->retry_count = min_t(unsigned int, rds_ib_retry_count, 7);
218	conn_param->rnr_retry_count = 7;
219
220	if (dp) {
221		memset(dp, 0, sizeof(*dp));
222		dp->dp_saddr = conn->c_laddr;
223		dp->dp_daddr = conn->c_faddr;
224		dp->dp_protocol_major = RDS_PROTOCOL_MAJOR(protocol_version);
225		dp->dp_protocol_minor = RDS_PROTOCOL_MINOR(protocol_version);
226		dp->dp_protocol_minor_mask = cpu_to_be16(RDS_IB_SUPPORTED_PROTOCOLS);
227		dp->dp_ack_seq = rds_ib_piggyb_ack(ic);
228
229		/* Advertise flow control */
230		if (ic->i_flowctl) {
231			unsigned int credits;
232
233			credits = IB_GET_POST_CREDITS(atomic_read(&ic->i_credits));
234			dp->dp_credit = cpu_to_be32(credits);
235			atomic_sub(IB_SET_POST_CREDITS(credits), &ic->i_credits);
236		}
237
238		conn_param->private_data = dp;
239		conn_param->private_data_len = sizeof(*dp);
240	}
241}
242
243static void rds_ib_cq_event_handler(struct ib_event *event, void *data)
244{
245	rdsdebug("event %u (%s) data %p\n",
246		 event->event, rds_ib_event_str(event->event), data);
247}
248
249static void rds_ib_qp_event_handler(struct ib_event *event, void *data)
250{
251	struct rds_connection *conn = data;
252	struct rds_ib_connection *ic = conn->c_transport_data;
253
254	rdsdebug("conn %p ic %p event %u (%s)\n", conn, ic, event->event,
255		 rds_ib_event_str(event->event));
256
257	switch (event->event) {
258	case IB_EVENT_COMM_EST:
259		rdma_notify(ic->i_cm_id, IB_EVENT_COMM_EST);
260		break;
261	default:
262		rdsdebug("Fatal QP Event %u (%s) "
263			"- connection %pI4->%pI4, reconnecting\n",
264			event->event, rds_ib_event_str(event->event),
265			&conn->c_laddr, &conn->c_faddr);
266		rds_conn_drop(conn);
267		break;
268	}
269}
270
271/*
272 * This needs to be very careful to not leave IS_ERR pointers around for
273 * cleanup to trip over.
274 */
275static int rds_ib_setup_qp(struct rds_connection *conn)
276{
277	struct rds_ib_connection *ic = conn->c_transport_data;
278	struct ib_device *dev = ic->i_cm_id->device;
279	struct ib_qp_init_attr attr;
280	struct rds_ib_device *rds_ibdev;
281	int ret;
282
283	/*
284	 * It's normal to see a null device if an incoming connection races
285	 * with device removal, so we don't print a warning.
286	 */
287	rds_ibdev = rds_ib_get_client_data(dev);
288	if (!rds_ibdev)
289		return -EOPNOTSUPP;
290
291	/* add the conn now so that connection establishment has the dev */
292	rds_ib_add_conn(rds_ibdev, conn);
293
294	if (rds_ibdev->max_wrs < ic->i_send_ring.w_nr + 1)
295		rds_ib_ring_resize(&ic->i_send_ring, rds_ibdev->max_wrs - 1);
296	if (rds_ibdev->max_wrs < ic->i_recv_ring.w_nr + 1)
297		rds_ib_ring_resize(&ic->i_recv_ring, rds_ibdev->max_wrs - 1);
298
299	/* Protection domain and memory range */
300	ic->i_pd = rds_ibdev->pd;
301	ic->i_mr = rds_ibdev->mr;
302
303	ic->i_send_cq = ib_create_cq(dev, rds_ib_send_cq_comp_handler,
304				     rds_ib_cq_event_handler, conn,
305				     ic->i_send_ring.w_nr + 1, 0);
306	if (IS_ERR(ic->i_send_cq)) {
307		ret = PTR_ERR(ic->i_send_cq);
308		ic->i_send_cq = NULL;
309		rdsdebug("ib_create_cq send failed: %d\n", ret);
310		goto out;
311	}
312
313	ic->i_recv_cq = ib_create_cq(dev, rds_ib_recv_cq_comp_handler,
314				     rds_ib_cq_event_handler, conn,
315				     ic->i_recv_ring.w_nr, 0);
316	if (IS_ERR(ic->i_recv_cq)) {
317		ret = PTR_ERR(ic->i_recv_cq);
318		ic->i_recv_cq = NULL;
319		rdsdebug("ib_create_cq recv failed: %d\n", ret);
320		goto out;
321	}
322
323	ret = ib_req_notify_cq(ic->i_send_cq, IB_CQ_NEXT_COMP);
324	if (ret) {
325		rdsdebug("ib_req_notify_cq send failed: %d\n", ret);
326		goto out;
327	}
328
329	ret = ib_req_notify_cq(ic->i_recv_cq, IB_CQ_SOLICITED);
330	if (ret) {
331		rdsdebug("ib_req_notify_cq recv failed: %d\n", ret);
332		goto out;
333	}
334
335	/* XXX negotiate max send/recv with remote? */
336	memset(&attr, 0, sizeof(attr));
337	attr.event_handler = rds_ib_qp_event_handler;
338	attr.qp_context = conn;
339	/* + 1 to allow for the single ack message */
340	attr.cap.max_send_wr = ic->i_send_ring.w_nr + 1;
341	attr.cap.max_recv_wr = ic->i_recv_ring.w_nr + 1;
342	attr.cap.max_send_sge = rds_ibdev->max_sge;
343	attr.cap.max_recv_sge = RDS_IB_RECV_SGE;
344	attr.sq_sig_type = IB_SIGNAL_REQ_WR;
345	attr.qp_type = IB_QPT_RC;
346	attr.send_cq = ic->i_send_cq;
347	attr.recv_cq = ic->i_recv_cq;
348
349	/*
350	 * XXX this can fail if max_*_wr is too large?  Are we supposed
351	 * to back off until we get a value that the hardware can support?
352	 */
353	ret = rdma_create_qp(ic->i_cm_id, ic->i_pd, &attr);
354	if (ret) {
355		rdsdebug("rdma_create_qp failed: %d\n", ret);
356		goto out;
357	}
358
359	ic->i_send_hdrs = ib_dma_alloc_coherent(dev,
360					   ic->i_send_ring.w_nr *
361						sizeof(struct rds_header),
362					   &ic->i_send_hdrs_dma, GFP_KERNEL);
363	if (!ic->i_send_hdrs) {
364		ret = -ENOMEM;
365		rdsdebug("ib_dma_alloc_coherent send failed\n");
366		goto out;
367	}
368
369	ic->i_recv_hdrs = ib_dma_alloc_coherent(dev,
370					   ic->i_recv_ring.w_nr *
371						sizeof(struct rds_header),
372					   &ic->i_recv_hdrs_dma, GFP_KERNEL);
373	if (!ic->i_recv_hdrs) {
374		ret = -ENOMEM;
375		rdsdebug("ib_dma_alloc_coherent recv failed\n");
376		goto out;
377	}
378
379	ic->i_ack = ib_dma_alloc_coherent(dev, sizeof(struct rds_header),
380				       &ic->i_ack_dma, GFP_KERNEL);
381	if (!ic->i_ack) {
382		ret = -ENOMEM;
383		rdsdebug("ib_dma_alloc_coherent ack failed\n");
384		goto out;
385	}
386
387	ic->i_sends = vzalloc_node(ic->i_send_ring.w_nr * sizeof(struct rds_ib_send_work),
388				   ibdev_to_node(dev));
389	if (!ic->i_sends) {
390		ret = -ENOMEM;
391		rdsdebug("send allocation failed\n");
392		goto out;
393	}
394
395	ic->i_recvs = vzalloc_node(ic->i_recv_ring.w_nr * sizeof(struct rds_ib_recv_work),
396				   ibdev_to_node(dev));
397	if (!ic->i_recvs) {
398		ret = -ENOMEM;
399		rdsdebug("recv allocation failed\n");
400		goto out;
401	}
402
403	rds_ib_recv_init_ack(ic);
404
405	rdsdebug("conn %p pd %p mr %p cq %p %p\n", conn, ic->i_pd, ic->i_mr,
406		 ic->i_send_cq, ic->i_recv_cq);
407
408out:
409	rds_ib_dev_put(rds_ibdev);
410	return ret;
411}
412
413static u32 rds_ib_protocol_compatible(struct rdma_cm_event *event)
414{
415	const struct rds_ib_connect_private *dp = event->param.conn.private_data;
416	u16 common;
417	u32 version = 0;
418
419	/*
420	 * rdma_cm private data is odd - when there is any private data in the
421	 * request, we will be given a pretty large buffer without telling us the
422	 * original size. The only way to tell the difference is by looking at
423	 * the contents, which are initialized to zero.
424	 * If the protocol version fields aren't set, this is a connection attempt
425	 * from an older version. This could could be 3.0 or 2.0 - we can't tell.
426	 * We really should have changed this for OFED 1.3 :-(
427	 */
428
429	/* Be paranoid. RDS always has privdata */
430	if (!event->param.conn.private_data_len) {
431		printk(KERN_NOTICE "RDS incoming connection has no private data, "
432			"rejecting\n");
433		return 0;
434	}
435
436	/* Even if len is crap *now* I still want to check it. -ASG */
437	if (event->param.conn.private_data_len < sizeof (*dp) ||
438	    dp->dp_protocol_major == 0)
439		return RDS_PROTOCOL_3_0;
440
441	common = be16_to_cpu(dp->dp_protocol_minor_mask) & RDS_IB_SUPPORTED_PROTOCOLS;
442	if (dp->dp_protocol_major == 3 && common) {
443		version = RDS_PROTOCOL_3_0;
444		while ((common >>= 1) != 0)
445			version++;
446	} else
447		printk_ratelimited(KERN_NOTICE "RDS: Connection from %pI4 using incompatible protocol version %u.%u\n",
448				&dp->dp_saddr,
449				dp->dp_protocol_major,
450				dp->dp_protocol_minor);
451	return version;
452}
453
454int rds_ib_cm_handle_connect(struct rdma_cm_id *cm_id,
455				    struct rdma_cm_event *event)
456{
457	__be64 lguid = cm_id->route.path_rec->sgid.global.interface_id;
458	__be64 fguid = cm_id->route.path_rec->dgid.global.interface_id;
459	const struct rds_ib_connect_private *dp = event->param.conn.private_data;
460	struct rds_ib_connect_private dp_rep;
461	struct rds_connection *conn = NULL;
462	struct rds_ib_connection *ic = NULL;
463	struct rdma_conn_param conn_param;
464	u32 version;
465	int err = 1, destroy = 1;
466
467	/* Check whether the remote protocol version matches ours. */
468	version = rds_ib_protocol_compatible(event);
469	if (!version)
470		goto out;
471
472	rdsdebug("saddr %pI4 daddr %pI4 RDSv%u.%u lguid 0x%llx fguid "
473		 "0x%llx\n", &dp->dp_saddr, &dp->dp_daddr,
474		 RDS_PROTOCOL_MAJOR(version), RDS_PROTOCOL_MINOR(version),
475		 (unsigned long long)be64_to_cpu(lguid),
476		 (unsigned long long)be64_to_cpu(fguid));
477
478	conn = rds_conn_create(dp->dp_daddr, dp->dp_saddr, &rds_ib_transport,
479			       GFP_KERNEL);
480	if (IS_ERR(conn)) {
481		rdsdebug("rds_conn_create failed (%ld)\n", PTR_ERR(conn));
482		conn = NULL;
483		goto out;
484	}
485
486	/*
487	 * The connection request may occur while the
488	 * previous connection exist, e.g. in case of failover.
489	 * But as connections may be initiated simultaneously
490	 * by both hosts, we have a random backoff mechanism -
491	 * see the comment above rds_queue_reconnect()
492	 */
493	mutex_lock(&conn->c_cm_lock);
494	if (!rds_conn_transition(conn, RDS_CONN_DOWN, RDS_CONN_CONNECTING)) {
495		if (rds_conn_state(conn) == RDS_CONN_UP) {
496			rdsdebug("incoming connect while connecting\n");
497			rds_conn_drop(conn);
498			rds_ib_stats_inc(s_ib_listen_closed_stale);
499		} else
500		if (rds_conn_state(conn) == RDS_CONN_CONNECTING) {
501			/* Wait and see - our connect may still be succeeding */
502			rds_ib_stats_inc(s_ib_connect_raced);
503		}
504		goto out;
505	}
506
507	ic = conn->c_transport_data;
508
509	rds_ib_set_protocol(conn, version);
510	rds_ib_set_flow_control(conn, be32_to_cpu(dp->dp_credit));
511
512	/* If the peer gave us the last packet it saw, process this as if
513	 * we had received a regular ACK. */
514	if (dp->dp_ack_seq)
515		rds_send_drop_acked(conn, be64_to_cpu(dp->dp_ack_seq), NULL);
516
517	BUG_ON(cm_id->context);
518	BUG_ON(ic->i_cm_id);
519
520	ic->i_cm_id = cm_id;
521	cm_id->context = conn;
522
523	/* We got halfway through setting up the ib_connection, if we
524	 * fail now, we have to take the long route out of this mess. */
525	destroy = 0;
526
527	err = rds_ib_setup_qp(conn);
528	if (err) {
529		rds_ib_conn_error(conn, "rds_ib_setup_qp failed (%d)\n", err);
530		goto out;
531	}
532
533	rds_ib_cm_fill_conn_param(conn, &conn_param, &dp_rep, version,
534		event->param.conn.responder_resources,
535		event->param.conn.initiator_depth);
536
537	/* rdma_accept() calls rdma_reject() internally if it fails */
538	err = rdma_accept(cm_id, &conn_param);
539	if (err)
540		rds_ib_conn_error(conn, "rdma_accept failed (%d)\n", err);
541
542out:
543	if (conn)
544		mutex_unlock(&conn->c_cm_lock);
545	if (err)
546		rdma_reject(cm_id, NULL, 0);
547	return destroy;
548}
549
550
551int rds_ib_cm_initiate_connect(struct rdma_cm_id *cm_id)
552{
553	struct rds_connection *conn = cm_id->context;
554	struct rds_ib_connection *ic = conn->c_transport_data;
555	struct rdma_conn_param conn_param;
556	struct rds_ib_connect_private dp;
557	int ret;
558
559	/* If the peer doesn't do protocol negotiation, we must
560	 * default to RDSv3.0 */
561	rds_ib_set_protocol(conn, RDS_PROTOCOL_3_0);
562	ic->i_flowctl = rds_ib_sysctl_flow_control;	/* advertise flow control */
563
564	ret = rds_ib_setup_qp(conn);
565	if (ret) {
566		rds_ib_conn_error(conn, "rds_ib_setup_qp failed (%d)\n", ret);
567		goto out;
568	}
569
570	rds_ib_cm_fill_conn_param(conn, &conn_param, &dp, RDS_PROTOCOL_VERSION,
571		UINT_MAX, UINT_MAX);
572	ret = rdma_connect(cm_id, &conn_param);
573	if (ret)
574		rds_ib_conn_error(conn, "rdma_connect failed (%d)\n", ret);
575
576out:
577	/* Beware - returning non-zero tells the rdma_cm to destroy
578	 * the cm_id. We should certainly not do it as long as we still
579	 * "own" the cm_id. */
580	if (ret) {
581		if (ic->i_cm_id == cm_id)
582			ret = 0;
583	}
584	return ret;
585}
586
587int rds_ib_conn_connect(struct rds_connection *conn)
588{
589	struct rds_ib_connection *ic = conn->c_transport_data;
590	struct sockaddr_in src, dest;
591	int ret;
592
593	/* XXX I wonder what affect the port space has */
594	/* delegate cm event handler to rdma_transport */
595	ic->i_cm_id = rdma_create_id(rds_rdma_cm_event_handler, conn,
596				     RDMA_PS_TCP, IB_QPT_RC);
597	if (IS_ERR(ic->i_cm_id)) {
598		ret = PTR_ERR(ic->i_cm_id);
599		ic->i_cm_id = NULL;
600		rdsdebug("rdma_create_id() failed: %d\n", ret);
601		goto out;
602	}
603
604	rdsdebug("created cm id %p for conn %p\n", ic->i_cm_id, conn);
605
606	src.sin_family = AF_INET;
607	src.sin_addr.s_addr = (__force u32)conn->c_laddr;
608	src.sin_port = (__force u16)htons(0);
609
610	dest.sin_family = AF_INET;
611	dest.sin_addr.s_addr = (__force u32)conn->c_faddr;
612	dest.sin_port = (__force u16)htons(RDS_PORT);
613
614	ret = rdma_resolve_addr(ic->i_cm_id, (struct sockaddr *)&src,
615				(struct sockaddr *)&dest,
616				RDS_RDMA_RESOLVE_TIMEOUT_MS);
617	if (ret) {
618		rdsdebug("addr resolve failed for cm id %p: %d\n", ic->i_cm_id,
619			 ret);
620		rdma_destroy_id(ic->i_cm_id);
621		ic->i_cm_id = NULL;
622	}
623
624out:
625	return ret;
626}
627
628/*
629 * This is so careful about only cleaning up resources that were built up
630 * so that it can be called at any point during startup.  In fact it
631 * can be called multiple times for a given connection.
632 */
633void rds_ib_conn_shutdown(struct rds_connection *conn)
634{
635	struct rds_ib_connection *ic = conn->c_transport_data;
636	int err = 0;
637
638	rdsdebug("cm %p pd %p cq %p %p qp %p\n", ic->i_cm_id,
639		 ic->i_pd, ic->i_send_cq, ic->i_recv_cq,
640		 ic->i_cm_id ? ic->i_cm_id->qp : NULL);
641
642	if (ic->i_cm_id) {
643		struct ib_device *dev = ic->i_cm_id->device;
644
645		rdsdebug("disconnecting cm %p\n", ic->i_cm_id);
646		err = rdma_disconnect(ic->i_cm_id);
647		if (err) {
648			/* Actually this may happen quite frequently, when
649			 * an outgoing connect raced with an incoming connect.
650			 */
651			rdsdebug("failed to disconnect, cm: %p err %d\n",
652				ic->i_cm_id, err);
653		}
654
655		/*
656		 * We want to wait for tx and rx completion to finish
657		 * before we tear down the connection, but we have to be
658		 * careful not to get stuck waiting on a send ring that
659		 * only has unsignaled sends in it.  We've shutdown new
660		 * sends before getting here so by waiting for signaled
661		 * sends to complete we're ensured that there will be no
662		 * more tx processing.
663		 */
664		wait_event(rds_ib_ring_empty_wait,
665			   rds_ib_ring_empty(&ic->i_recv_ring) &&
666			   (atomic_read(&ic->i_signaled_sends) == 0));
667		tasklet_kill(&ic->i_recv_tasklet);
668
669		if (ic->i_send_hdrs)
670			ib_dma_free_coherent(dev,
671					   ic->i_send_ring.w_nr *
672						sizeof(struct rds_header),
673					   ic->i_send_hdrs,
674					   ic->i_send_hdrs_dma);
675
676		if (ic->i_recv_hdrs)
677			ib_dma_free_coherent(dev,
678					   ic->i_recv_ring.w_nr *
679						sizeof(struct rds_header),
680					   ic->i_recv_hdrs,
681					   ic->i_recv_hdrs_dma);
682
683		if (ic->i_ack)
684			ib_dma_free_coherent(dev, sizeof(struct rds_header),
685					     ic->i_ack, ic->i_ack_dma);
686
687		if (ic->i_sends)
688			rds_ib_send_clear_ring(ic);
689		if (ic->i_recvs)
690			rds_ib_recv_clear_ring(ic);
691
692		if (ic->i_cm_id->qp)
693			rdma_destroy_qp(ic->i_cm_id);
694		if (ic->i_send_cq)
695			ib_destroy_cq(ic->i_send_cq);
696		if (ic->i_recv_cq)
697			ib_destroy_cq(ic->i_recv_cq);
698		rdma_destroy_id(ic->i_cm_id);
699
700		/*
701		 * Move connection back to the nodev list.
702		 */
703		if (ic->rds_ibdev)
704			rds_ib_remove_conn(ic->rds_ibdev, conn);
705
706		ic->i_cm_id = NULL;
707		ic->i_pd = NULL;
708		ic->i_mr = NULL;
709		ic->i_send_cq = NULL;
710		ic->i_recv_cq = NULL;
711		ic->i_send_hdrs = NULL;
712		ic->i_recv_hdrs = NULL;
713		ic->i_ack = NULL;
714	}
715	BUG_ON(ic->rds_ibdev);
716
717	/* Clear pending transmit */
718	if (ic->i_data_op) {
719		struct rds_message *rm;
720
721		rm = container_of(ic->i_data_op, struct rds_message, data);
722		rds_message_put(rm);
723		ic->i_data_op = NULL;
724	}
725
726	/* Clear the ACK state */
727	clear_bit(IB_ACK_IN_FLIGHT, &ic->i_ack_flags);
728#ifdef KERNEL_HAS_ATOMIC64
729	atomic64_set(&ic->i_ack_next, 0);
730#else
731	ic->i_ack_next = 0;
732#endif
733	ic->i_ack_recv = 0;
734
735	/* Clear flow control state */
736	ic->i_flowctl = 0;
737	atomic_set(&ic->i_credits, 0);
738
739	rds_ib_ring_init(&ic->i_send_ring, rds_ib_sysctl_max_send_wr);
740	rds_ib_ring_init(&ic->i_recv_ring, rds_ib_sysctl_max_recv_wr);
741
742	if (ic->i_ibinc) {
743		rds_inc_put(&ic->i_ibinc->ii_inc);
744		ic->i_ibinc = NULL;
745	}
746
747	vfree(ic->i_sends);
748	ic->i_sends = NULL;
749	vfree(ic->i_recvs);
750	ic->i_recvs = NULL;
751}
752
753int rds_ib_conn_alloc(struct rds_connection *conn, gfp_t gfp)
754{
755	struct rds_ib_connection *ic;
756	unsigned long flags;
757	int ret;
758
759	/* XXX too lazy? */
760	ic = kzalloc(sizeof(struct rds_ib_connection), gfp);
761	if (!ic)
762		return -ENOMEM;
763
764	ret = rds_ib_recv_alloc_caches(ic);
765	if (ret) {
766		kfree(ic);
767		return ret;
768	}
769
770	INIT_LIST_HEAD(&ic->ib_node);
771	tasklet_init(&ic->i_recv_tasklet, rds_ib_recv_tasklet_fn,
772		     (unsigned long) ic);
773	mutex_init(&ic->i_recv_mutex);
774#ifndef KERNEL_HAS_ATOMIC64
775	spin_lock_init(&ic->i_ack_lock);
776#endif
777	atomic_set(&ic->i_signaled_sends, 0);
778
779	/*
780	 * rds_ib_conn_shutdown() waits for these to be emptied so they
781	 * must be initialized before it can be called.
782	 */
783	rds_ib_ring_init(&ic->i_send_ring, rds_ib_sysctl_max_send_wr);
784	rds_ib_ring_init(&ic->i_recv_ring, rds_ib_sysctl_max_recv_wr);
785
786	ic->conn = conn;
787	conn->c_transport_data = ic;
788
789	spin_lock_irqsave(&ib_nodev_conns_lock, flags);
790	list_add_tail(&ic->ib_node, &ib_nodev_conns);
791	spin_unlock_irqrestore(&ib_nodev_conns_lock, flags);
792
793
794	rdsdebug("conn %p conn ic %p\n", conn, conn->c_transport_data);
795	return 0;
796}
797
798/*
799 * Free a connection. Connection must be shut down and not set for reconnect.
800 */
801void rds_ib_conn_free(void *arg)
802{
803	struct rds_ib_connection *ic = arg;
804	spinlock_t	*lock_ptr;
805
806	rdsdebug("ic %p\n", ic);
807
808	/*
809	 * Conn is either on a dev's list or on the nodev list.
810	 * A race with shutdown() or connect() would cause problems
811	 * (since rds_ibdev would change) but that should never happen.
812	 */
813	lock_ptr = ic->rds_ibdev ? &ic->rds_ibdev->spinlock : &ib_nodev_conns_lock;
814
815	spin_lock_irq(lock_ptr);
816	list_del(&ic->ib_node);
817	spin_unlock_irq(lock_ptr);
818
819	rds_ib_recv_free_caches(ic);
820
821	kfree(ic);
822}
823
824
825/*
826 * An error occurred on the connection
827 */
828void
829__rds_ib_conn_error(struct rds_connection *conn, const char *fmt, ...)
830{
831	va_list ap;
832
833	rds_conn_drop(conn);
834
835	va_start(ap, fmt);
836	vprintk(fmt, ap);
837	va_end(ap);
838}
839