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  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 && dp->dp_ack_seq)
187		rds_send_drop_acked(conn, be64_to_cpu(dp->dp_ack_seq), NULL);
 
 
 
 
 
 
 
 
 
188
189	rds_connect_complete(conn);
190}
191
192static void rds_ib_cm_fill_conn_param(struct rds_connection *conn,
193			struct rdma_conn_param *conn_param,
194			struct rds_ib_connect_private *dp,
195			u32 protocol_version,
196			u32 max_responder_resources,
197			u32 max_initiator_depth)
198{
199	struct rds_ib_connection *ic = conn->c_transport_data;
200	struct rds_ib_device *rds_ibdev = ic->rds_ibdev;
201
202	memset(conn_param, 0, sizeof(struct rdma_conn_param));
203
204	conn_param->responder_resources =
205		min_t(u32, rds_ibdev->max_responder_resources, max_responder_resources);
206	conn_param->initiator_depth =
207		min_t(u32, rds_ibdev->max_initiator_depth, max_initiator_depth);
208	conn_param->retry_count = min_t(unsigned int, rds_ib_retry_count, 7);
209	conn_param->rnr_retry_count = 7;
210
211	if (dp) {
212		memset(dp, 0, sizeof(*dp));
213		dp->dp_saddr = conn->c_laddr;
214		dp->dp_daddr = conn->c_faddr;
215		dp->dp_protocol_major = RDS_PROTOCOL_MAJOR(protocol_version);
216		dp->dp_protocol_minor = RDS_PROTOCOL_MINOR(protocol_version);
217		dp->dp_protocol_minor_mask = cpu_to_be16(RDS_IB_SUPPORTED_PROTOCOLS);
218		dp->dp_ack_seq = rds_ib_piggyb_ack(ic);
219
220		/* Advertise flow control */
221		if (ic->i_flowctl) {
222			unsigned int credits;
223
224			credits = IB_GET_POST_CREDITS(atomic_read(&ic->i_credits));
225			dp->dp_credit = cpu_to_be32(credits);
226			atomic_sub(IB_SET_POST_CREDITS(credits), &ic->i_credits);
227		}
228
229		conn_param->private_data = dp;
230		conn_param->private_data_len = sizeof(*dp);
231	}
232}
233
234static void rds_ib_cq_event_handler(struct ib_event *event, void *data)
235{
236	rdsdebug("event %u (%s) data %p\n",
237		 event->event, rds_ib_event_str(event->event), data);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
238}
239
240static void rds_ib_qp_event_handler(struct ib_event *event, void *data)
241{
242	struct rds_connection *conn = data;
243	struct rds_ib_connection *ic = conn->c_transport_data;
244
245	rdsdebug("conn %p ic %p event %u (%s)\n", conn, ic, event->event,
246		 rds_ib_event_str(event->event));
247
248	switch (event->event) {
249	case IB_EVENT_COMM_EST:
250		rdma_notify(ic->i_cm_id, IB_EVENT_COMM_EST);
251		break;
252	default:
253		rdsdebug("Fatal QP Event %u (%s) "
254			"- connection %pI4->%pI4, reconnecting\n",
255			event->event, rds_ib_event_str(event->event),
256			&conn->c_laddr, &conn->c_faddr);
257		rds_conn_drop(conn);
258		break;
259	}
260}
261
 
 
 
 
 
 
 
 
 
 
 
 
262/*
263 * This needs to be very careful to not leave IS_ERR pointers around for
264 * cleanup to trip over.
265 */
266static int rds_ib_setup_qp(struct rds_connection *conn)
267{
268	struct rds_ib_connection *ic = conn->c_transport_data;
269	struct ib_device *dev = ic->i_cm_id->device;
270	struct ib_qp_init_attr attr;
 
271	struct rds_ib_device *rds_ibdev;
272	int ret;
273
274	/*
275	 * It's normal to see a null device if an incoming connection races
276	 * with device removal, so we don't print a warning.
277	 */
278	rds_ibdev = rds_ib_get_client_data(dev);
279	if (!rds_ibdev)
280		return -EOPNOTSUPP;
281
 
 
 
 
 
 
282	/* add the conn now so that connection establishment has the dev */
283	rds_ib_add_conn(rds_ibdev, conn);
284
285	if (rds_ibdev->max_wrs < ic->i_send_ring.w_nr + 1)
286		rds_ib_ring_resize(&ic->i_send_ring, rds_ibdev->max_wrs - 1);
287	if (rds_ibdev->max_wrs < ic->i_recv_ring.w_nr + 1)
288		rds_ib_ring_resize(&ic->i_recv_ring, rds_ibdev->max_wrs - 1);
289
290	/* Protection domain and memory range */
291	ic->i_pd = rds_ibdev->pd;
292	ic->i_mr = rds_ibdev->mr;
293
294	ic->i_send_cq = ib_create_cq(dev, rds_ib_send_cq_comp_handler,
 
 
295				     rds_ib_cq_event_handler, conn,
296				     ic->i_send_ring.w_nr + 1, 0);
297	if (IS_ERR(ic->i_send_cq)) {
298		ret = PTR_ERR(ic->i_send_cq);
299		ic->i_send_cq = NULL;
300		rdsdebug("ib_create_cq send failed: %d\n", ret);
301		goto out;
302	}
303
304	ic->i_recv_cq = ib_create_cq(dev, rds_ib_recv_cq_comp_handler,
 
305				     rds_ib_cq_event_handler, conn,
306				     ic->i_recv_ring.w_nr, 0);
307	if (IS_ERR(ic->i_recv_cq)) {
308		ret = PTR_ERR(ic->i_recv_cq);
309		ic->i_recv_cq = NULL;
310		rdsdebug("ib_create_cq recv failed: %d\n", ret);
311		goto out;
312	}
313
314	ret = ib_req_notify_cq(ic->i_send_cq, IB_CQ_NEXT_COMP);
315	if (ret) {
316		rdsdebug("ib_req_notify_cq send failed: %d\n", ret);
317		goto out;
318	}
319
320	ret = ib_req_notify_cq(ic->i_recv_cq, IB_CQ_SOLICITED);
321	if (ret) {
322		rdsdebug("ib_req_notify_cq recv failed: %d\n", ret);
323		goto out;
324	}
325
326	/* XXX negotiate max send/recv with remote? */
327	memset(&attr, 0, sizeof(attr));
328	attr.event_handler = rds_ib_qp_event_handler;
329	attr.qp_context = conn;
330	/* + 1 to allow for the single ack message */
331	attr.cap.max_send_wr = ic->i_send_ring.w_nr + 1;
332	attr.cap.max_recv_wr = ic->i_recv_ring.w_nr + 1;
333	attr.cap.max_send_sge = rds_ibdev->max_sge;
334	attr.cap.max_recv_sge = RDS_IB_RECV_SGE;
335	attr.sq_sig_type = IB_SIGNAL_REQ_WR;
336	attr.qp_type = IB_QPT_RC;
337	attr.send_cq = ic->i_send_cq;
338	attr.recv_cq = ic->i_recv_cq;
 
339
340	/*
341	 * XXX this can fail if max_*_wr is too large?  Are we supposed
342	 * to back off until we get a value that the hardware can support?
343	 */
344	ret = rdma_create_qp(ic->i_cm_id, ic->i_pd, &attr);
345	if (ret) {
346		rdsdebug("rdma_create_qp failed: %d\n", ret);
347		goto out;
348	}
349
350	ic->i_send_hdrs = ib_dma_alloc_coherent(dev,
351					   ic->i_send_ring.w_nr *
352						sizeof(struct rds_header),
353					   &ic->i_send_hdrs_dma, GFP_KERNEL);
354	if (!ic->i_send_hdrs) {
355		ret = -ENOMEM;
356		rdsdebug("ib_dma_alloc_coherent send failed\n");
357		goto out;
358	}
359
360	ic->i_recv_hdrs = ib_dma_alloc_coherent(dev,
361					   ic->i_recv_ring.w_nr *
362						sizeof(struct rds_header),
363					   &ic->i_recv_hdrs_dma, GFP_KERNEL);
364	if (!ic->i_recv_hdrs) {
365		ret = -ENOMEM;
366		rdsdebug("ib_dma_alloc_coherent recv failed\n");
367		goto out;
368	}
369
370	ic->i_ack = ib_dma_alloc_coherent(dev, sizeof(struct rds_header),
371				       &ic->i_ack_dma, GFP_KERNEL);
372	if (!ic->i_ack) {
373		ret = -ENOMEM;
374		rdsdebug("ib_dma_alloc_coherent ack failed\n");
375		goto out;
376	}
377
378	ic->i_sends = vmalloc_node(ic->i_send_ring.w_nr * sizeof(struct rds_ib_send_work),
379				   ibdev_to_node(dev));
380	if (!ic->i_sends) {
381		ret = -ENOMEM;
382		rdsdebug("send allocation failed\n");
383		goto out;
384	}
385	memset(ic->i_sends, 0, ic->i_send_ring.w_nr * sizeof(struct rds_ib_send_work));
386
387	ic->i_recvs = vmalloc_node(ic->i_recv_ring.w_nr * sizeof(struct rds_ib_recv_work),
388				   ibdev_to_node(dev));
389	if (!ic->i_recvs) {
390		ret = -ENOMEM;
391		rdsdebug("recv allocation failed\n");
392		goto out;
393	}
394	memset(ic->i_recvs, 0, ic->i_recv_ring.w_nr * sizeof(struct rds_ib_recv_work));
395
396	rds_ib_recv_init_ack(ic);
397
398	rdsdebug("conn %p pd %p mr %p cq %p %p\n", conn, ic->i_pd, ic->i_mr,
399		 ic->i_send_cq, ic->i_recv_cq);
400
401out:
402	rds_ib_dev_put(rds_ibdev);
403	return ret;
404}
405
406static u32 rds_ib_protocol_compatible(struct rdma_cm_event *event)
407{
408	const struct rds_ib_connect_private *dp = event->param.conn.private_data;
409	u16 common;
410	u32 version = 0;
411
412	/*
413	 * rdma_cm private data is odd - when there is any private data in the
414	 * request, we will be given a pretty large buffer without telling us the
415	 * original size. The only way to tell the difference is by looking at
416	 * the contents, which are initialized to zero.
417	 * If the protocol version fields aren't set, this is a connection attempt
418	 * from an older version. This could could be 3.0 or 2.0 - we can't tell.
419	 * We really should have changed this for OFED 1.3 :-(
420	 */
421
422	/* Be paranoid. RDS always has privdata */
423	if (!event->param.conn.private_data_len) {
424		printk(KERN_NOTICE "RDS incoming connection has no private data, "
425			"rejecting\n");
426		return 0;
427	}
428
429	/* Even if len is crap *now* I still want to check it. -ASG */
430	if (event->param.conn.private_data_len < sizeof (*dp) ||
431	    dp->dp_protocol_major == 0)
432		return RDS_PROTOCOL_3_0;
433
434	common = be16_to_cpu(dp->dp_protocol_minor_mask) & RDS_IB_SUPPORTED_PROTOCOLS;
435	if (dp->dp_protocol_major == 3 && common) {
436		version = RDS_PROTOCOL_3_0;
437		while ((common >>= 1) != 0)
438			version++;
439	}
440	printk_ratelimited(KERN_NOTICE "RDS: Connection from %pI4 using "
441			"incompatible protocol version %u.%u\n",
442			&dp->dp_saddr,
443			dp->dp_protocol_major,
444			dp->dp_protocol_minor);
445	return version;
446}
447
448int rds_ib_cm_handle_connect(struct rdma_cm_id *cm_id,
449				    struct rdma_cm_event *event)
450{
451	__be64 lguid = cm_id->route.path_rec->sgid.global.interface_id;
452	__be64 fguid = cm_id->route.path_rec->dgid.global.interface_id;
453	const struct rds_ib_connect_private *dp = event->param.conn.private_data;
454	struct rds_ib_connect_private dp_rep;
455	struct rds_connection *conn = NULL;
456	struct rds_ib_connection *ic = NULL;
457	struct rdma_conn_param conn_param;
458	u32 version;
459	int err = 1, destroy = 1;
460
461	/* Check whether the remote protocol version matches ours. */
462	version = rds_ib_protocol_compatible(event);
463	if (!version)
464		goto out;
465
466	rdsdebug("saddr %pI4 daddr %pI4 RDSv%u.%u lguid 0x%llx fguid "
467		 "0x%llx\n", &dp->dp_saddr, &dp->dp_daddr,
468		 RDS_PROTOCOL_MAJOR(version), RDS_PROTOCOL_MINOR(version),
469		 (unsigned long long)be64_to_cpu(lguid),
470		 (unsigned long long)be64_to_cpu(fguid));
471
472	conn = rds_conn_create(dp->dp_daddr, dp->dp_saddr, &rds_ib_transport,
473			       GFP_KERNEL);
 
474	if (IS_ERR(conn)) {
475		rdsdebug("rds_conn_create failed (%ld)\n", PTR_ERR(conn));
476		conn = NULL;
477		goto out;
478	}
479
480	/*
481	 * The connection request may occur while the
482	 * previous connection exist, e.g. in case of failover.
483	 * But as connections may be initiated simultaneously
484	 * by both hosts, we have a random backoff mechanism -
485	 * see the comment above rds_queue_reconnect()
486	 */
487	mutex_lock(&conn->c_cm_lock);
488	if (!rds_conn_transition(conn, RDS_CONN_DOWN, RDS_CONN_CONNECTING)) {
489		if (rds_conn_state(conn) == RDS_CONN_UP) {
490			rdsdebug("incoming connect while connecting\n");
491			rds_conn_drop(conn);
492			rds_ib_stats_inc(s_ib_listen_closed_stale);
493		} else
494		if (rds_conn_state(conn) == RDS_CONN_CONNECTING) {
495			/* Wait and see - our connect may still be succeeding */
496			rds_ib_stats_inc(s_ib_connect_raced);
497		}
498		goto out;
499	}
500
501	ic = conn->c_transport_data;
502
503	rds_ib_set_protocol(conn, version);
504	rds_ib_set_flow_control(conn, be32_to_cpu(dp->dp_credit));
505
506	/* If the peer gave us the last packet it saw, process this as if
507	 * we had received a regular ACK. */
508	if (dp->dp_ack_seq)
509		rds_send_drop_acked(conn, be64_to_cpu(dp->dp_ack_seq), NULL);
510
511	BUG_ON(cm_id->context);
512	BUG_ON(ic->i_cm_id);
513
514	ic->i_cm_id = cm_id;
515	cm_id->context = conn;
516
517	/* We got halfway through setting up the ib_connection, if we
518	 * fail now, we have to take the long route out of this mess. */
519	destroy = 0;
520
521	err = rds_ib_setup_qp(conn);
522	if (err) {
523		rds_ib_conn_error(conn, "rds_ib_setup_qp failed (%d)\n", err);
524		goto out;
525	}
526
527	rds_ib_cm_fill_conn_param(conn, &conn_param, &dp_rep, version,
528		event->param.conn.responder_resources,
529		event->param.conn.initiator_depth);
530
531	/* rdma_accept() calls rdma_reject() internally if it fails */
532	err = rdma_accept(cm_id, &conn_param);
533	if (err)
534		rds_ib_conn_error(conn, "rdma_accept failed (%d)\n", err);
535
536out:
537	if (conn)
538		mutex_unlock(&conn->c_cm_lock);
539	if (err)
540		rdma_reject(cm_id, NULL, 0);
541	return destroy;
542}
543
544
545int rds_ib_cm_initiate_connect(struct rdma_cm_id *cm_id)
546{
547	struct rds_connection *conn = cm_id->context;
548	struct rds_ib_connection *ic = conn->c_transport_data;
549	struct rdma_conn_param conn_param;
550	struct rds_ib_connect_private dp;
551	int ret;
552
553	/* If the peer doesn't do protocol negotiation, we must
554	 * default to RDSv3.0 */
555	rds_ib_set_protocol(conn, RDS_PROTOCOL_3_0);
556	ic->i_flowctl = rds_ib_sysctl_flow_control;	/* advertise flow control */
557
558	ret = rds_ib_setup_qp(conn);
559	if (ret) {
560		rds_ib_conn_error(conn, "rds_ib_setup_qp failed (%d)\n", ret);
561		goto out;
562	}
563
564	rds_ib_cm_fill_conn_param(conn, &conn_param, &dp, RDS_PROTOCOL_VERSION,
565		UINT_MAX, UINT_MAX);
566	ret = rdma_connect(cm_id, &conn_param);
567	if (ret)
568		rds_ib_conn_error(conn, "rdma_connect failed (%d)\n", ret);
569
570out:
571	/* Beware - returning non-zero tells the rdma_cm to destroy
572	 * the cm_id. We should certainly not do it as long as we still
573	 * "own" the cm_id. */
574	if (ret) {
575		if (ic->i_cm_id == cm_id)
576			ret = 0;
577	}
578	return ret;
579}
580
581int rds_ib_conn_connect(struct rds_connection *conn)
582{
583	struct rds_ib_connection *ic = conn->c_transport_data;
584	struct sockaddr_in src, dest;
585	int ret;
586
587	/* XXX I wonder what affect the port space has */
588	/* delegate cm event handler to rdma_transport */
589	ic->i_cm_id = rdma_create_id(rds_rdma_cm_event_handler, conn,
590				     RDMA_PS_TCP, IB_QPT_RC);
591	if (IS_ERR(ic->i_cm_id)) {
592		ret = PTR_ERR(ic->i_cm_id);
593		ic->i_cm_id = NULL;
594		rdsdebug("rdma_create_id() failed: %d\n", ret);
595		goto out;
596	}
597
598	rdsdebug("created cm id %p for conn %p\n", ic->i_cm_id, conn);
599
600	src.sin_family = AF_INET;
601	src.sin_addr.s_addr = (__force u32)conn->c_laddr;
602	src.sin_port = (__force u16)htons(0);
603
604	dest.sin_family = AF_INET;
605	dest.sin_addr.s_addr = (__force u32)conn->c_faddr;
606	dest.sin_port = (__force u16)htons(RDS_PORT);
607
608	ret = rdma_resolve_addr(ic->i_cm_id, (struct sockaddr *)&src,
609				(struct sockaddr *)&dest,
610				RDS_RDMA_RESOLVE_TIMEOUT_MS);
611	if (ret) {
612		rdsdebug("addr resolve failed for cm id %p: %d\n", ic->i_cm_id,
613			 ret);
614		rdma_destroy_id(ic->i_cm_id);
615		ic->i_cm_id = NULL;
616	}
617
618out:
619	return ret;
620}
621
622/*
623 * This is so careful about only cleaning up resources that were built up
624 * so that it can be called at any point during startup.  In fact it
625 * can be called multiple times for a given connection.
626 */
627void rds_ib_conn_shutdown(struct rds_connection *conn)
628{
629	struct rds_ib_connection *ic = conn->c_transport_data;
630	int err = 0;
631
632	rdsdebug("cm %p pd %p cq %p %p qp %p\n", ic->i_cm_id,
633		 ic->i_pd, ic->i_send_cq, ic->i_recv_cq,
634		 ic->i_cm_id ? ic->i_cm_id->qp : NULL);
635
636	if (ic->i_cm_id) {
637		struct ib_device *dev = ic->i_cm_id->device;
638
639		rdsdebug("disconnecting cm %p\n", ic->i_cm_id);
640		err = rdma_disconnect(ic->i_cm_id);
641		if (err) {
642			/* Actually this may happen quite frequently, when
643			 * an outgoing connect raced with an incoming connect.
644			 */
645			rdsdebug("failed to disconnect, cm: %p err %d\n",
646				ic->i_cm_id, err);
647		}
648
649		/*
650		 * We want to wait for tx and rx completion to finish
651		 * before we tear down the connection, but we have to be
652		 * careful not to get stuck waiting on a send ring that
653		 * only has unsignaled sends in it.  We've shutdown new
654		 * sends before getting here so by waiting for signaled
655		 * sends to complete we're ensured that there will be no
656		 * more tx processing.
657		 */
658		wait_event(rds_ib_ring_empty_wait,
659			   rds_ib_ring_empty(&ic->i_recv_ring) &&
660			   (atomic_read(&ic->i_signaled_sends) == 0));
 
 
661		tasklet_kill(&ic->i_recv_tasklet);
662
 
 
 
 
 
 
 
 
 
663		if (ic->i_send_hdrs)
664			ib_dma_free_coherent(dev,
665					   ic->i_send_ring.w_nr *
666						sizeof(struct rds_header),
667					   ic->i_send_hdrs,
668					   ic->i_send_hdrs_dma);
669
670		if (ic->i_recv_hdrs)
671			ib_dma_free_coherent(dev,
672					   ic->i_recv_ring.w_nr *
673						sizeof(struct rds_header),
674					   ic->i_recv_hdrs,
675					   ic->i_recv_hdrs_dma);
676
677		if (ic->i_ack)
678			ib_dma_free_coherent(dev, sizeof(struct rds_header),
679					     ic->i_ack, ic->i_ack_dma);
680
681		if (ic->i_sends)
682			rds_ib_send_clear_ring(ic);
683		if (ic->i_recvs)
684			rds_ib_recv_clear_ring(ic);
685
686		if (ic->i_cm_id->qp)
687			rdma_destroy_qp(ic->i_cm_id);
688		if (ic->i_send_cq)
689			ib_destroy_cq(ic->i_send_cq);
690		if (ic->i_recv_cq)
691			ib_destroy_cq(ic->i_recv_cq);
692		rdma_destroy_id(ic->i_cm_id);
693
694		/*
695		 * Move connection back to the nodev list.
696		 */
697		if (ic->rds_ibdev)
698			rds_ib_remove_conn(ic->rds_ibdev, conn);
699
700		ic->i_cm_id = NULL;
701		ic->i_pd = NULL;
702		ic->i_mr = NULL;
703		ic->i_send_cq = NULL;
704		ic->i_recv_cq = NULL;
705		ic->i_send_hdrs = NULL;
706		ic->i_recv_hdrs = NULL;
707		ic->i_ack = NULL;
708	}
709	BUG_ON(ic->rds_ibdev);
710
711	/* Clear pending transmit */
712	if (ic->i_data_op) {
713		struct rds_message *rm;
714
715		rm = container_of(ic->i_data_op, struct rds_message, data);
716		rds_message_put(rm);
717		ic->i_data_op = NULL;
718	}
719
720	/* Clear the ACK state */
721	clear_bit(IB_ACK_IN_FLIGHT, &ic->i_ack_flags);
722#ifdef KERNEL_HAS_ATOMIC64
723	atomic64_set(&ic->i_ack_next, 0);
724#else
725	ic->i_ack_next = 0;
726#endif
727	ic->i_ack_recv = 0;
728
729	/* Clear flow control state */
730	ic->i_flowctl = 0;
731	atomic_set(&ic->i_credits, 0);
732
733	rds_ib_ring_init(&ic->i_send_ring, rds_ib_sysctl_max_send_wr);
734	rds_ib_ring_init(&ic->i_recv_ring, rds_ib_sysctl_max_recv_wr);
735
736	if (ic->i_ibinc) {
737		rds_inc_put(&ic->i_ibinc->ii_inc);
738		ic->i_ibinc = NULL;
739	}
740
741	vfree(ic->i_sends);
742	ic->i_sends = NULL;
743	vfree(ic->i_recvs);
744	ic->i_recvs = NULL;
745}
746
747int rds_ib_conn_alloc(struct rds_connection *conn, gfp_t gfp)
748{
749	struct rds_ib_connection *ic;
750	unsigned long flags;
751	int ret;
752
753	/* XXX too lazy? */
754	ic = kzalloc(sizeof(struct rds_ib_connection), GFP_KERNEL);
755	if (!ic)
756		return -ENOMEM;
757
758	ret = rds_ib_recv_alloc_caches(ic);
759	if (ret) {
760		kfree(ic);
761		return ret;
762	}
763
764	INIT_LIST_HEAD(&ic->ib_node);
765	tasklet_init(&ic->i_recv_tasklet, rds_ib_recv_tasklet_fn,
766		     (unsigned long) ic);
 
 
767	mutex_init(&ic->i_recv_mutex);
768#ifndef KERNEL_HAS_ATOMIC64
769	spin_lock_init(&ic->i_ack_lock);
770#endif
771	atomic_set(&ic->i_signaled_sends, 0);
772
773	/*
774	 * rds_ib_conn_shutdown() waits for these to be emptied so they
775	 * must be initialized before it can be called.
776	 */
777	rds_ib_ring_init(&ic->i_send_ring, rds_ib_sysctl_max_send_wr);
778	rds_ib_ring_init(&ic->i_recv_ring, rds_ib_sysctl_max_recv_wr);
779
780	ic->conn = conn;
781	conn->c_transport_data = ic;
782
783	spin_lock_irqsave(&ib_nodev_conns_lock, flags);
784	list_add_tail(&ic->ib_node, &ib_nodev_conns);
785	spin_unlock_irqrestore(&ib_nodev_conns_lock, flags);
786
787
788	rdsdebug("conn %p conn ic %p\n", conn, conn->c_transport_data);
789	return 0;
790}
791
792/*
793 * Free a connection. Connection must be shut down and not set for reconnect.
794 */
795void rds_ib_conn_free(void *arg)
796{
797	struct rds_ib_connection *ic = arg;
798	spinlock_t	*lock_ptr;
799
800	rdsdebug("ic %p\n", ic);
801
802	/*
803	 * Conn is either on a dev's list or on the nodev list.
804	 * A race with shutdown() or connect() would cause problems
805	 * (since rds_ibdev would change) but that should never happen.
806	 */
807	lock_ptr = ic->rds_ibdev ? &ic->rds_ibdev->spinlock : &ib_nodev_conns_lock;
808
809	spin_lock_irq(lock_ptr);
810	list_del(&ic->ib_node);
811	spin_unlock_irq(lock_ptr);
812
813	rds_ib_recv_free_caches(ic);
814
815	kfree(ic);
816}
817
818
819/*
820 * An error occurred on the connection
821 */
822void
823__rds_ib_conn_error(struct rds_connection *conn, const char *fmt, ...)
824{
825	va_list ap;
826
827	rds_conn_drop(conn);
828
829	va_start(ap, fmt);
830	vprintk(fmt, ap);
831	va_end(ap);
832}
  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
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 42/*
 43 * Set the selected protocol version
 44 */
 45static void rds_ib_set_protocol(struct rds_connection *conn, unsigned int version)
 46{
 47	conn->c_version = version;
 48}
 49
 50/*
 51 * Set up flow control
 52 */
 53static void rds_ib_set_flow_control(struct rds_connection *conn, u32 credits)
 54{
 55	struct rds_ib_connection *ic = conn->c_transport_data;
 56
 57	if (rds_ib_sysctl_flow_control && credits != 0) {
 58		/* We're doing flow control */
 59		ic->i_flowctl = 1;
 60		rds_ib_send_add_credits(conn, credits);
 61	} else {
 62		ic->i_flowctl = 0;
 63	}
 64}
 65
 66/*
 67 * Tune RNR behavior. Without flow control, we use a rather
 68 * low timeout, but not the absolute minimum - this should
 69 * be tunable.
 70 *
 71 * We already set the RNR retry count to 7 (which is the
 72 * smallest infinite number :-) above.
 73 * If flow control is off, we want to change this back to 0
 74 * so that we learn quickly when our credit accounting is
 75 * buggy.
 76 *
 77 * Caller passes in a qp_attr pointer - don't waste stack spacv
 78 * by allocation this twice.
 79 */
 80static void
 81rds_ib_tune_rnr(struct rds_ib_connection *ic, struct ib_qp_attr *attr)
 82{
 83	int ret;
 84
 85	attr->min_rnr_timer = IB_RNR_TIMER_000_32;
 86	ret = ib_modify_qp(ic->i_cm_id->qp, attr, IB_QP_MIN_RNR_TIMER);
 87	if (ret)
 88		printk(KERN_NOTICE "ib_modify_qp(IB_QP_MIN_RNR_TIMER): err=%d\n", -ret);
 89}
 90
 91/*
 92 * Connection established.
 93 * We get here for both outgoing and incoming connection.
 94 */
 95void rds_ib_cm_connect_complete(struct rds_connection *conn, struct rdma_cm_event *event)
 96{
 97	const struct rds_ib_connect_private *dp = NULL;
 98	struct rds_ib_connection *ic = conn->c_transport_data;
 99	struct ib_qp_attr qp_attr;
100	int err;
101
102	if (event->param.conn.private_data_len >= sizeof(*dp)) {
103		dp = event->param.conn.private_data;
104
105		/* make sure it isn't empty data */
106		if (dp->dp_protocol_major) {
107			rds_ib_set_protocol(conn,
108				RDS_PROTOCOL(dp->dp_protocol_major,
109				dp->dp_protocol_minor));
110			rds_ib_set_flow_control(conn, be32_to_cpu(dp->dp_credit));
111		}
112	}
113
114	if (conn->c_version < RDS_PROTOCOL(3,1)) {
115		printk(KERN_NOTICE "RDS/IB: Connection to %pI4 version %u.%u failed,"
116		       " no longer supported\n",
117		       &conn->c_faddr,
118		       RDS_PROTOCOL_MAJOR(conn->c_version),
119		       RDS_PROTOCOL_MINOR(conn->c_version));
120		rds_conn_destroy(conn);
121		return;
122	} else {
123		printk(KERN_NOTICE "RDS/IB: connected to %pI4 version %u.%u%s\n",
124		       &conn->c_faddr,
125		       RDS_PROTOCOL_MAJOR(conn->c_version),
126		       RDS_PROTOCOL_MINOR(conn->c_version),
127		       ic->i_flowctl ? ", flow control" : "");
128	}
129
130	/*
131	 * Init rings and fill recv. this needs to wait until protocol negotiation
132	 * is complete, since ring layout is different from 3.0 to 3.1.
133	 */
134	rds_ib_send_init_ring(ic);
135	rds_ib_recv_init_ring(ic);
136	/* Post receive buffers - as a side effect, this will update
137	 * the posted credit count. */
138	rds_ib_recv_refill(conn, 1, GFP_KERNEL);
139
140	/* Tune RNR behavior */
141	rds_ib_tune_rnr(ic, &qp_attr);
142
143	qp_attr.qp_state = IB_QPS_RTS;
144	err = ib_modify_qp(ic->i_cm_id->qp, &qp_attr, IB_QP_STATE);
145	if (err)
146		printk(KERN_NOTICE "ib_modify_qp(IB_QP_STATE, RTS): err=%d\n", err);
147
148	/* update ib_device with this local ipaddr */
149	err = rds_ib_update_ipaddr(ic->rds_ibdev, conn->c_laddr);
150	if (err)
151		printk(KERN_ERR "rds_ib_update_ipaddr failed (%d)\n",
152			err);
153
154	/* If the peer gave us the last packet it saw, process this as if
155	 * we had received a regular ACK. */
156	if (dp) {
157		/* dp structure start is not guaranteed to be 8 bytes aligned.
158		 * Since dp_ack_seq is 64-bit extended load operations can be
159		 * used so go through get_unaligned to avoid unaligned errors.
160		 */
161		__be64 dp_ack_seq = get_unaligned(&dp->dp_ack_seq);
162
163		if (dp_ack_seq)
164			rds_send_drop_acked(conn, be64_to_cpu(dp_ack_seq),
165					    NULL);
166	}
167
168	rds_connect_complete(conn);
169}
170
171static void rds_ib_cm_fill_conn_param(struct rds_connection *conn,
172			struct rdma_conn_param *conn_param,
173			struct rds_ib_connect_private *dp,
174			u32 protocol_version,
175			u32 max_responder_resources,
176			u32 max_initiator_depth)
177{
178	struct rds_ib_connection *ic = conn->c_transport_data;
179	struct rds_ib_device *rds_ibdev = ic->rds_ibdev;
180
181	memset(conn_param, 0, sizeof(struct rdma_conn_param));
182
183	conn_param->responder_resources =
184		min_t(u32, rds_ibdev->max_responder_resources, max_responder_resources);
185	conn_param->initiator_depth =
186		min_t(u32, rds_ibdev->max_initiator_depth, max_initiator_depth);
187	conn_param->retry_count = min_t(unsigned int, rds_ib_retry_count, 7);
188	conn_param->rnr_retry_count = 7;
189
190	if (dp) {
191		memset(dp, 0, sizeof(*dp));
192		dp->dp_saddr = conn->c_laddr;
193		dp->dp_daddr = conn->c_faddr;
194		dp->dp_protocol_major = RDS_PROTOCOL_MAJOR(protocol_version);
195		dp->dp_protocol_minor = RDS_PROTOCOL_MINOR(protocol_version);
196		dp->dp_protocol_minor_mask = cpu_to_be16(RDS_IB_SUPPORTED_PROTOCOLS);
197		dp->dp_ack_seq = cpu_to_be64(rds_ib_piggyb_ack(ic));
198
199		/* Advertise flow control */
200		if (ic->i_flowctl) {
201			unsigned int credits;
202
203			credits = IB_GET_POST_CREDITS(atomic_read(&ic->i_credits));
204			dp->dp_credit = cpu_to_be32(credits);
205			atomic_sub(IB_SET_POST_CREDITS(credits), &ic->i_credits);
206		}
207
208		conn_param->private_data = dp;
209		conn_param->private_data_len = sizeof(*dp);
210	}
211}
212
213static void rds_ib_cq_event_handler(struct ib_event *event, void *data)
214{
215	rdsdebug("event %u (%s) data %p\n",
216		 event->event, ib_event_msg(event->event), data);
217}
218
219/* Plucking the oldest entry from the ring can be done concurrently with
220 * the thread refilling the ring.  Each ring operation is protected by
221 * spinlocks and the transient state of refilling doesn't change the
222 * recording of which entry is oldest.
223 *
224 * This relies on IB only calling one cq comp_handler for each cq so that
225 * there will only be one caller of rds_recv_incoming() per RDS connection.
226 */
227static void rds_ib_cq_comp_handler_recv(struct ib_cq *cq, void *context)
228{
229	struct rds_connection *conn = context;
230	struct rds_ib_connection *ic = conn->c_transport_data;
231
232	rdsdebug("conn %p cq %p\n", conn, cq);
233
234	rds_ib_stats_inc(s_ib_evt_handler_call);
235
236	tasklet_schedule(&ic->i_recv_tasklet);
237}
238
239static void poll_scq(struct rds_ib_connection *ic, struct ib_cq *cq,
240		     struct ib_wc *wcs)
241{
242	int nr, i;
243	struct ib_wc *wc;
244
245	while ((nr = ib_poll_cq(cq, RDS_IB_WC_MAX, wcs)) > 0) {
246		for (i = 0; i < nr; i++) {
247			wc = wcs + i;
248			rdsdebug("wc wr_id 0x%llx status %u byte_len %u imm_data %u\n",
249				 (unsigned long long)wc->wr_id, wc->status,
250				 wc->byte_len, be32_to_cpu(wc->ex.imm_data));
251
252			if (wc->wr_id <= ic->i_send_ring.w_nr ||
253			    wc->wr_id == RDS_IB_ACK_WR_ID)
254				rds_ib_send_cqe_handler(ic, wc);
255			else
256				rds_ib_mr_cqe_handler(ic, wc);
257
258		}
259	}
260}
261
262static void rds_ib_tasklet_fn_send(unsigned long data)
263{
264	struct rds_ib_connection *ic = (struct rds_ib_connection *)data;
265	struct rds_connection *conn = ic->conn;
266
267	rds_ib_stats_inc(s_ib_tasklet_call);
268
269	poll_scq(ic, ic->i_send_cq, ic->i_send_wc);
270	ib_req_notify_cq(ic->i_send_cq, IB_CQ_NEXT_COMP);
271	poll_scq(ic, ic->i_send_cq, ic->i_send_wc);
272
273	if (rds_conn_up(conn) &&
274	    (!test_bit(RDS_LL_SEND_FULL, &conn->c_flags) ||
275	    test_bit(0, &conn->c_map_queued)))
276		rds_send_xmit(ic->conn);
277}
278
279static void poll_rcq(struct rds_ib_connection *ic, struct ib_cq *cq,
280		     struct ib_wc *wcs,
281		     struct rds_ib_ack_state *ack_state)
282{
283	int nr, i;
284	struct ib_wc *wc;
285
286	while ((nr = ib_poll_cq(cq, RDS_IB_WC_MAX, wcs)) > 0) {
287		for (i = 0; i < nr; i++) {
288			wc = wcs + i;
289			rdsdebug("wc wr_id 0x%llx status %u byte_len %u imm_data %u\n",
290				 (unsigned long long)wc->wr_id, wc->status,
291				 wc->byte_len, be32_to_cpu(wc->ex.imm_data));
292
293			rds_ib_recv_cqe_handler(ic, wc, ack_state);
294		}
295	}
296}
297
298static void rds_ib_tasklet_fn_recv(unsigned long data)
299{
300	struct rds_ib_connection *ic = (struct rds_ib_connection *)data;
301	struct rds_connection *conn = ic->conn;
302	struct rds_ib_device *rds_ibdev = ic->rds_ibdev;
303	struct rds_ib_ack_state state;
304
305	if (!rds_ibdev)
306		rds_conn_drop(conn);
307
308	rds_ib_stats_inc(s_ib_tasklet_call);
309
310	memset(&state, 0, sizeof(state));
311	poll_rcq(ic, ic->i_recv_cq, ic->i_recv_wc, &state);
312	ib_req_notify_cq(ic->i_recv_cq, IB_CQ_SOLICITED);
313	poll_rcq(ic, ic->i_recv_cq, ic->i_recv_wc, &state);
314
315	if (state.ack_next_valid)
316		rds_ib_set_ack(ic, state.ack_next, state.ack_required);
317	if (state.ack_recv_valid && state.ack_recv > ic->i_ack_recv) {
318		rds_send_drop_acked(conn, state.ack_recv, NULL);
319		ic->i_ack_recv = state.ack_recv;
320	}
321
322	if (rds_conn_up(conn))
323		rds_ib_attempt_ack(ic);
324}
325
326static void rds_ib_qp_event_handler(struct ib_event *event, void *data)
327{
328	struct rds_connection *conn = data;
329	struct rds_ib_connection *ic = conn->c_transport_data;
330
331	rdsdebug("conn %p ic %p event %u (%s)\n", conn, ic, event->event,
332		 ib_event_msg(event->event));
333
334	switch (event->event) {
335	case IB_EVENT_COMM_EST:
336		rdma_notify(ic->i_cm_id, IB_EVENT_COMM_EST);
337		break;
338	default:
339		rdsdebug("Fatal QP Event %u (%s) "
340			"- connection %pI4->%pI4, reconnecting\n",
341			event->event, ib_event_msg(event->event),
342			&conn->c_laddr, &conn->c_faddr);
343		rds_conn_drop(conn);
344		break;
345	}
346}
347
348static void rds_ib_cq_comp_handler_send(struct ib_cq *cq, void *context)
349{
350	struct rds_connection *conn = context;
351	struct rds_ib_connection *ic = conn->c_transport_data;
352
353	rdsdebug("conn %p cq %p\n", conn, cq);
354
355	rds_ib_stats_inc(s_ib_evt_handler_call);
356
357	tasklet_schedule(&ic->i_send_tasklet);
358}
359
360/*
361 * This needs to be very careful to not leave IS_ERR pointers around for
362 * cleanup to trip over.
363 */
364static int rds_ib_setup_qp(struct rds_connection *conn)
365{
366	struct rds_ib_connection *ic = conn->c_transport_data;
367	struct ib_device *dev = ic->i_cm_id->device;
368	struct ib_qp_init_attr attr;
369	struct ib_cq_init_attr cq_attr = {};
370	struct rds_ib_device *rds_ibdev;
371	int ret, fr_queue_space;
372
373	/*
374	 * It's normal to see a null device if an incoming connection races
375	 * with device removal, so we don't print a warning.
376	 */
377	rds_ibdev = rds_ib_get_client_data(dev);
378	if (!rds_ibdev)
379		return -EOPNOTSUPP;
380
381	/* The fr_queue_space is currently set to 512, to add extra space on
382	 * completion queue and send queue. This extra space is used for FRMR
383	 * registration and invalidation work requests
384	 */
385	fr_queue_space = (rds_ibdev->use_fastreg ? RDS_IB_DEFAULT_FR_WR : 0);
386
387	/* add the conn now so that connection establishment has the dev */
388	rds_ib_add_conn(rds_ibdev, conn);
389
390	if (rds_ibdev->max_wrs < ic->i_send_ring.w_nr + 1)
391		rds_ib_ring_resize(&ic->i_send_ring, rds_ibdev->max_wrs - 1);
392	if (rds_ibdev->max_wrs < ic->i_recv_ring.w_nr + 1)
393		rds_ib_ring_resize(&ic->i_recv_ring, rds_ibdev->max_wrs - 1);
394
395	/* Protection domain and memory range */
396	ic->i_pd = rds_ibdev->pd;
 
397
398	cq_attr.cqe = ic->i_send_ring.w_nr + fr_queue_space + 1;
399
400	ic->i_send_cq = ib_create_cq(dev, rds_ib_cq_comp_handler_send,
401				     rds_ib_cq_event_handler, conn,
402				     &cq_attr);
403	if (IS_ERR(ic->i_send_cq)) {
404		ret = PTR_ERR(ic->i_send_cq);
405		ic->i_send_cq = NULL;
406		rdsdebug("ib_create_cq send failed: %d\n", ret);
407		goto out;
408	}
409
410	cq_attr.cqe = ic->i_recv_ring.w_nr;
411	ic->i_recv_cq = ib_create_cq(dev, rds_ib_cq_comp_handler_recv,
412				     rds_ib_cq_event_handler, conn,
413				     &cq_attr);
414	if (IS_ERR(ic->i_recv_cq)) {
415		ret = PTR_ERR(ic->i_recv_cq);
416		ic->i_recv_cq = NULL;
417		rdsdebug("ib_create_cq recv failed: %d\n", ret);
418		goto out;
419	}
420
421	ret = ib_req_notify_cq(ic->i_send_cq, IB_CQ_NEXT_COMP);
422	if (ret) {
423		rdsdebug("ib_req_notify_cq send failed: %d\n", ret);
424		goto out;
425	}
426
427	ret = ib_req_notify_cq(ic->i_recv_cq, IB_CQ_SOLICITED);
428	if (ret) {
429		rdsdebug("ib_req_notify_cq recv failed: %d\n", ret);
430		goto out;
431	}
432
433	/* XXX negotiate max send/recv with remote? */
434	memset(&attr, 0, sizeof(attr));
435	attr.event_handler = rds_ib_qp_event_handler;
436	attr.qp_context = conn;
437	/* + 1 to allow for the single ack message */
438	attr.cap.max_send_wr = ic->i_send_ring.w_nr + fr_queue_space + 1;
439	attr.cap.max_recv_wr = ic->i_recv_ring.w_nr + 1;
440	attr.cap.max_send_sge = rds_ibdev->max_sge;
441	attr.cap.max_recv_sge = RDS_IB_RECV_SGE;
442	attr.sq_sig_type = IB_SIGNAL_REQ_WR;
443	attr.qp_type = IB_QPT_RC;
444	attr.send_cq = ic->i_send_cq;
445	attr.recv_cq = ic->i_recv_cq;
446	atomic_set(&ic->i_fastreg_wrs, RDS_IB_DEFAULT_FR_WR);
447
448	/*
449	 * XXX this can fail if max_*_wr is too large?  Are we supposed
450	 * to back off until we get a value that the hardware can support?
451	 */
452	ret = rdma_create_qp(ic->i_cm_id, ic->i_pd, &attr);
453	if (ret) {
454		rdsdebug("rdma_create_qp failed: %d\n", ret);
455		goto out;
456	}
457
458	ic->i_send_hdrs = ib_dma_alloc_coherent(dev,
459					   ic->i_send_ring.w_nr *
460						sizeof(struct rds_header),
461					   &ic->i_send_hdrs_dma, GFP_KERNEL);
462	if (!ic->i_send_hdrs) {
463		ret = -ENOMEM;
464		rdsdebug("ib_dma_alloc_coherent send failed\n");
465		goto out;
466	}
467
468	ic->i_recv_hdrs = ib_dma_alloc_coherent(dev,
469					   ic->i_recv_ring.w_nr *
470						sizeof(struct rds_header),
471					   &ic->i_recv_hdrs_dma, GFP_KERNEL);
472	if (!ic->i_recv_hdrs) {
473		ret = -ENOMEM;
474		rdsdebug("ib_dma_alloc_coherent recv failed\n");
475		goto out;
476	}
477
478	ic->i_ack = ib_dma_alloc_coherent(dev, sizeof(struct rds_header),
479				       &ic->i_ack_dma, GFP_KERNEL);
480	if (!ic->i_ack) {
481		ret = -ENOMEM;
482		rdsdebug("ib_dma_alloc_coherent ack failed\n");
483		goto out;
484	}
485
486	ic->i_sends = vzalloc_node(ic->i_send_ring.w_nr * sizeof(struct rds_ib_send_work),
487				   ibdev_to_node(dev));
488	if (!ic->i_sends) {
489		ret = -ENOMEM;
490		rdsdebug("send allocation failed\n");
491		goto out;
492	}
 
493
494	ic->i_recvs = vzalloc_node(ic->i_recv_ring.w_nr * sizeof(struct rds_ib_recv_work),
495				   ibdev_to_node(dev));
496	if (!ic->i_recvs) {
497		ret = -ENOMEM;
498		rdsdebug("recv allocation failed\n");
499		goto out;
500	}
 
501
502	rds_ib_recv_init_ack(ic);
503
504	rdsdebug("conn %p pd %p cq %p %p\n", conn, ic->i_pd,
505		 ic->i_send_cq, ic->i_recv_cq);
506
507out:
508	rds_ib_dev_put(rds_ibdev);
509	return ret;
510}
511
512static u32 rds_ib_protocol_compatible(struct rdma_cm_event *event)
513{
514	const struct rds_ib_connect_private *dp = event->param.conn.private_data;
515	u16 common;
516	u32 version = 0;
517
518	/*
519	 * rdma_cm private data is odd - when there is any private data in the
520	 * request, we will be given a pretty large buffer without telling us the
521	 * original size. The only way to tell the difference is by looking at
522	 * the contents, which are initialized to zero.
523	 * If the protocol version fields aren't set, this is a connection attempt
524	 * from an older version. This could could be 3.0 or 2.0 - we can't tell.
525	 * We really should have changed this for OFED 1.3 :-(
526	 */
527
528	/* Be paranoid. RDS always has privdata */
529	if (!event->param.conn.private_data_len) {
530		printk(KERN_NOTICE "RDS incoming connection has no private data, "
531			"rejecting\n");
532		return 0;
533	}
534
535	/* Even if len is crap *now* I still want to check it. -ASG */
536	if (event->param.conn.private_data_len < sizeof (*dp) ||
537	    dp->dp_protocol_major == 0)
538		return RDS_PROTOCOL_3_0;
539
540	common = be16_to_cpu(dp->dp_protocol_minor_mask) & RDS_IB_SUPPORTED_PROTOCOLS;
541	if (dp->dp_protocol_major == 3 && common) {
542		version = RDS_PROTOCOL_3_0;
543		while ((common >>= 1) != 0)
544			version++;
545	} else
546		printk_ratelimited(KERN_NOTICE "RDS: Connection from %pI4 using incompatible protocol version %u.%u\n",
547				&dp->dp_saddr,
548				dp->dp_protocol_major,
549				dp->dp_protocol_minor);
 
550	return version;
551}
552
553int rds_ib_cm_handle_connect(struct rdma_cm_id *cm_id,
554				    struct rdma_cm_event *event)
555{
556	__be64 lguid = cm_id->route.path_rec->sgid.global.interface_id;
557	__be64 fguid = cm_id->route.path_rec->dgid.global.interface_id;
558	const struct rds_ib_connect_private *dp = event->param.conn.private_data;
559	struct rds_ib_connect_private dp_rep;
560	struct rds_connection *conn = NULL;
561	struct rds_ib_connection *ic = NULL;
562	struct rdma_conn_param conn_param;
563	u32 version;
564	int err = 1, destroy = 1;
565
566	/* Check whether the remote protocol version matches ours. */
567	version = rds_ib_protocol_compatible(event);
568	if (!version)
569		goto out;
570
571	rdsdebug("saddr %pI4 daddr %pI4 RDSv%u.%u lguid 0x%llx fguid "
572		 "0x%llx\n", &dp->dp_saddr, &dp->dp_daddr,
573		 RDS_PROTOCOL_MAJOR(version), RDS_PROTOCOL_MINOR(version),
574		 (unsigned long long)be64_to_cpu(lguid),
575		 (unsigned long long)be64_to_cpu(fguid));
576
577	/* RDS/IB is not currently netns aware, thus init_net */
578	conn = rds_conn_create(&init_net, dp->dp_daddr, dp->dp_saddr,
579			       &rds_ib_transport, GFP_KERNEL);
580	if (IS_ERR(conn)) {
581		rdsdebug("rds_conn_create failed (%ld)\n", PTR_ERR(conn));
582		conn = NULL;
583		goto out;
584	}
585
586	/*
587	 * The connection request may occur while the
588	 * previous connection exist, e.g. in case of failover.
589	 * But as connections may be initiated simultaneously
590	 * by both hosts, we have a random backoff mechanism -
591	 * see the comment above rds_queue_reconnect()
592	 */
593	mutex_lock(&conn->c_cm_lock);
594	if (!rds_conn_transition(conn, RDS_CONN_DOWN, RDS_CONN_CONNECTING)) {
595		if (rds_conn_state(conn) == RDS_CONN_UP) {
596			rdsdebug("incoming connect while connecting\n");
597			rds_conn_drop(conn);
598			rds_ib_stats_inc(s_ib_listen_closed_stale);
599		} else
600		if (rds_conn_state(conn) == RDS_CONN_CONNECTING) {
601			/* Wait and see - our connect may still be succeeding */
602			rds_ib_stats_inc(s_ib_connect_raced);
603		}
604		goto out;
605	}
606
607	ic = conn->c_transport_data;
608
609	rds_ib_set_protocol(conn, version);
610	rds_ib_set_flow_control(conn, be32_to_cpu(dp->dp_credit));
611
612	/* If the peer gave us the last packet it saw, process this as if
613	 * we had received a regular ACK. */
614	if (dp->dp_ack_seq)
615		rds_send_drop_acked(conn, be64_to_cpu(dp->dp_ack_seq), NULL);
616
617	BUG_ON(cm_id->context);
618	BUG_ON(ic->i_cm_id);
619
620	ic->i_cm_id = cm_id;
621	cm_id->context = conn;
622
623	/* We got halfway through setting up the ib_connection, if we
624	 * fail now, we have to take the long route out of this mess. */
625	destroy = 0;
626
627	err = rds_ib_setup_qp(conn);
628	if (err) {
629		rds_ib_conn_error(conn, "rds_ib_setup_qp failed (%d)\n", err);
630		goto out;
631	}
632
633	rds_ib_cm_fill_conn_param(conn, &conn_param, &dp_rep, version,
634		event->param.conn.responder_resources,
635		event->param.conn.initiator_depth);
636
637	/* rdma_accept() calls rdma_reject() internally if it fails */
638	err = rdma_accept(cm_id, &conn_param);
639	if (err)
640		rds_ib_conn_error(conn, "rdma_accept failed (%d)\n", err);
641
642out:
643	if (conn)
644		mutex_unlock(&conn->c_cm_lock);
645	if (err)
646		rdma_reject(cm_id, NULL, 0);
647	return destroy;
648}
649
650
651int rds_ib_cm_initiate_connect(struct rdma_cm_id *cm_id)
652{
653	struct rds_connection *conn = cm_id->context;
654	struct rds_ib_connection *ic = conn->c_transport_data;
655	struct rdma_conn_param conn_param;
656	struct rds_ib_connect_private dp;
657	int ret;
658
659	/* If the peer doesn't do protocol negotiation, we must
660	 * default to RDSv3.0 */
661	rds_ib_set_protocol(conn, RDS_PROTOCOL_3_0);
662	ic->i_flowctl = rds_ib_sysctl_flow_control;	/* advertise flow control */
663
664	ret = rds_ib_setup_qp(conn);
665	if (ret) {
666		rds_ib_conn_error(conn, "rds_ib_setup_qp failed (%d)\n", ret);
667		goto out;
668	}
669
670	rds_ib_cm_fill_conn_param(conn, &conn_param, &dp, RDS_PROTOCOL_VERSION,
671		UINT_MAX, UINT_MAX);
672	ret = rdma_connect(cm_id, &conn_param);
673	if (ret)
674		rds_ib_conn_error(conn, "rdma_connect failed (%d)\n", ret);
675
676out:
677	/* Beware - returning non-zero tells the rdma_cm to destroy
678	 * the cm_id. We should certainly not do it as long as we still
679	 * "own" the cm_id. */
680	if (ret) {
681		if (ic->i_cm_id == cm_id)
682			ret = 0;
683	}
684	return ret;
685}
686
687int rds_ib_conn_connect(struct rds_connection *conn)
688{
689	struct rds_ib_connection *ic = conn->c_transport_data;
690	struct sockaddr_in src, dest;
691	int ret;
692
693	/* XXX I wonder what affect the port space has */
694	/* delegate cm event handler to rdma_transport */
695	ic->i_cm_id = rdma_create_id(&init_net, rds_rdma_cm_event_handler, conn,
696				     RDMA_PS_TCP, IB_QPT_RC);
697	if (IS_ERR(ic->i_cm_id)) {
698		ret = PTR_ERR(ic->i_cm_id);
699		ic->i_cm_id = NULL;
700		rdsdebug("rdma_create_id() failed: %d\n", ret);
701		goto out;
702	}
703
704	rdsdebug("created cm id %p for conn %p\n", ic->i_cm_id, conn);
705
706	src.sin_family = AF_INET;
707	src.sin_addr.s_addr = (__force u32)conn->c_laddr;
708	src.sin_port = (__force u16)htons(0);
709
710	dest.sin_family = AF_INET;
711	dest.sin_addr.s_addr = (__force u32)conn->c_faddr;
712	dest.sin_port = (__force u16)htons(RDS_PORT);
713
714	ret = rdma_resolve_addr(ic->i_cm_id, (struct sockaddr *)&src,
715				(struct sockaddr *)&dest,
716				RDS_RDMA_RESOLVE_TIMEOUT_MS);
717	if (ret) {
718		rdsdebug("addr resolve failed for cm id %p: %d\n", ic->i_cm_id,
719			 ret);
720		rdma_destroy_id(ic->i_cm_id);
721		ic->i_cm_id = NULL;
722	}
723
724out:
725	return ret;
726}
727
728/*
729 * This is so careful about only cleaning up resources that were built up
730 * so that it can be called at any point during startup.  In fact it
731 * can be called multiple times for a given connection.
732 */
733void rds_ib_conn_shutdown(struct rds_connection *conn)
734{
735	struct rds_ib_connection *ic = conn->c_transport_data;
736	int err = 0;
737
738	rdsdebug("cm %p pd %p cq %p %p qp %p\n", ic->i_cm_id,
739		 ic->i_pd, ic->i_send_cq, ic->i_recv_cq,
740		 ic->i_cm_id ? ic->i_cm_id->qp : NULL);
741
742	if (ic->i_cm_id) {
743		struct ib_device *dev = ic->i_cm_id->device;
744
745		rdsdebug("disconnecting cm %p\n", ic->i_cm_id);
746		err = rdma_disconnect(ic->i_cm_id);
747		if (err) {
748			/* Actually this may happen quite frequently, when
749			 * an outgoing connect raced with an incoming connect.
750			 */
751			rdsdebug("failed to disconnect, cm: %p err %d\n",
752				ic->i_cm_id, err);
753		}
754
755		/*
756		 * We want to wait for tx and rx completion to finish
757		 * before we tear down the connection, but we have to be
758		 * careful not to get stuck waiting on a send ring that
759		 * only has unsignaled sends in it.  We've shutdown new
760		 * sends before getting here so by waiting for signaled
761		 * sends to complete we're ensured that there will be no
762		 * more tx processing.
763		 */
764		wait_event(rds_ib_ring_empty_wait,
765			   rds_ib_ring_empty(&ic->i_recv_ring) &&
766			   (atomic_read(&ic->i_signaled_sends) == 0) &&
767			   (atomic_read(&ic->i_fastreg_wrs) == RDS_IB_DEFAULT_FR_WR));
768		tasklet_kill(&ic->i_send_tasklet);
769		tasklet_kill(&ic->i_recv_tasklet);
770
771		/* first destroy the ib state that generates callbacks */
772		if (ic->i_cm_id->qp)
773			rdma_destroy_qp(ic->i_cm_id);
774		if (ic->i_send_cq)
775			ib_destroy_cq(ic->i_send_cq);
776		if (ic->i_recv_cq)
777			ib_destroy_cq(ic->i_recv_cq);
778
779		/* then free the resources that ib callbacks use */
780		if (ic->i_send_hdrs)
781			ib_dma_free_coherent(dev,
782					   ic->i_send_ring.w_nr *
783						sizeof(struct rds_header),
784					   ic->i_send_hdrs,
785					   ic->i_send_hdrs_dma);
786
787		if (ic->i_recv_hdrs)
788			ib_dma_free_coherent(dev,
789					   ic->i_recv_ring.w_nr *
790						sizeof(struct rds_header),
791					   ic->i_recv_hdrs,
792					   ic->i_recv_hdrs_dma);
793
794		if (ic->i_ack)
795			ib_dma_free_coherent(dev, sizeof(struct rds_header),
796					     ic->i_ack, ic->i_ack_dma);
797
798		if (ic->i_sends)
799			rds_ib_send_clear_ring(ic);
800		if (ic->i_recvs)
801			rds_ib_recv_clear_ring(ic);
802
 
 
 
 
 
 
803		rdma_destroy_id(ic->i_cm_id);
804
805		/*
806		 * Move connection back to the nodev list.
807		 */
808		if (ic->rds_ibdev)
809			rds_ib_remove_conn(ic->rds_ibdev, conn);
810
811		ic->i_cm_id = NULL;
812		ic->i_pd = NULL;
 
813		ic->i_send_cq = NULL;
814		ic->i_recv_cq = NULL;
815		ic->i_send_hdrs = NULL;
816		ic->i_recv_hdrs = NULL;
817		ic->i_ack = NULL;
818	}
819	BUG_ON(ic->rds_ibdev);
820
821	/* Clear pending transmit */
822	if (ic->i_data_op) {
823		struct rds_message *rm;
824
825		rm = container_of(ic->i_data_op, struct rds_message, data);
826		rds_message_put(rm);
827		ic->i_data_op = NULL;
828	}
829
830	/* Clear the ACK state */
831	clear_bit(IB_ACK_IN_FLIGHT, &ic->i_ack_flags);
832#ifdef KERNEL_HAS_ATOMIC64
833	atomic64_set(&ic->i_ack_next, 0);
834#else
835	ic->i_ack_next = 0;
836#endif
837	ic->i_ack_recv = 0;
838
839	/* Clear flow control state */
840	ic->i_flowctl = 0;
841	atomic_set(&ic->i_credits, 0);
842
843	rds_ib_ring_init(&ic->i_send_ring, rds_ib_sysctl_max_send_wr);
844	rds_ib_ring_init(&ic->i_recv_ring, rds_ib_sysctl_max_recv_wr);
845
846	if (ic->i_ibinc) {
847		rds_inc_put(&ic->i_ibinc->ii_inc);
848		ic->i_ibinc = NULL;
849	}
850
851	vfree(ic->i_sends);
852	ic->i_sends = NULL;
853	vfree(ic->i_recvs);
854	ic->i_recvs = NULL;
855}
856
857int rds_ib_conn_alloc(struct rds_connection *conn, gfp_t gfp)
858{
859	struct rds_ib_connection *ic;
860	unsigned long flags;
861	int ret;
862
863	/* XXX too lazy? */
864	ic = kzalloc(sizeof(struct rds_ib_connection), gfp);
865	if (!ic)
866		return -ENOMEM;
867
868	ret = rds_ib_recv_alloc_caches(ic);
869	if (ret) {
870		kfree(ic);
871		return ret;
872	}
873
874	INIT_LIST_HEAD(&ic->ib_node);
875	tasklet_init(&ic->i_send_tasklet, rds_ib_tasklet_fn_send,
876		     (unsigned long)ic);
877	tasklet_init(&ic->i_recv_tasklet, rds_ib_tasklet_fn_recv,
878		     (unsigned long)ic);
879	mutex_init(&ic->i_recv_mutex);
880#ifndef KERNEL_HAS_ATOMIC64
881	spin_lock_init(&ic->i_ack_lock);
882#endif
883	atomic_set(&ic->i_signaled_sends, 0);
884
885	/*
886	 * rds_ib_conn_shutdown() waits for these to be emptied so they
887	 * must be initialized before it can be called.
888	 */
889	rds_ib_ring_init(&ic->i_send_ring, rds_ib_sysctl_max_send_wr);
890	rds_ib_ring_init(&ic->i_recv_ring, rds_ib_sysctl_max_recv_wr);
891
892	ic->conn = conn;
893	conn->c_transport_data = ic;
894
895	spin_lock_irqsave(&ib_nodev_conns_lock, flags);
896	list_add_tail(&ic->ib_node, &ib_nodev_conns);
897	spin_unlock_irqrestore(&ib_nodev_conns_lock, flags);
898
899
900	rdsdebug("conn %p conn ic %p\n", conn, conn->c_transport_data);
901	return 0;
902}
903
904/*
905 * Free a connection. Connection must be shut down and not set for reconnect.
906 */
907void rds_ib_conn_free(void *arg)
908{
909	struct rds_ib_connection *ic = arg;
910	spinlock_t	*lock_ptr;
911
912	rdsdebug("ic %p\n", ic);
913
914	/*
915	 * Conn is either on a dev's list or on the nodev list.
916	 * A race with shutdown() or connect() would cause problems
917	 * (since rds_ibdev would change) but that should never happen.
918	 */
919	lock_ptr = ic->rds_ibdev ? &ic->rds_ibdev->spinlock : &ib_nodev_conns_lock;
920
921	spin_lock_irq(lock_ptr);
922	list_del(&ic->ib_node);
923	spin_unlock_irq(lock_ptr);
924
925	rds_ib_recv_free_caches(ic);
926
927	kfree(ic);
928}
929
930
931/*
932 * An error occurred on the connection
933 */
934void
935__rds_ib_conn_error(struct rds_connection *conn, const char *fmt, ...)
936{
937	va_list ap;
938
939	rds_conn_drop(conn);
940
941	va_start(ap, fmt);
942	vprintk(fmt, ap);
943	va_end(ap);
944}