perf probe: Add missing variable initialization
[linux-2.6.git] / net / rds / ib_cm.c
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/vmalloc.h>
36
37 #include "rds.h"
38 #include "ib.h"
39
40 /*
41  * Set the selected protocol version
42  */
43 static void rds_ib_set_protocol(struct rds_connection *conn, unsigned int version)
44 {
45         conn->c_version = version;
46 }
47
48 /*
49  * Set up flow control
50  */
51 static void rds_ib_set_flow_control(struct rds_connection *conn, u32 credits)
52 {
53         struct rds_ib_connection *ic = conn->c_transport_data;
54
55         if (rds_ib_sysctl_flow_control && credits != 0) {
56                 /* We're doing flow control */
57                 ic->i_flowctl = 1;
58                 rds_ib_send_add_credits(conn, credits);
59         } else {
60                 ic->i_flowctl = 0;
61         }
62 }
63
64 /*
65  * Tune RNR behavior. Without flow control, we use a rather
66  * low timeout, but not the absolute minimum - this should
67  * be tunable.
68  *
69  * We already set the RNR retry count to 7 (which is the
70  * smallest infinite number :-) above.
71  * If flow control is off, we want to change this back to 0
72  * so that we learn quickly when our credit accounting is
73  * buggy.
74  *
75  * Caller passes in a qp_attr pointer - don't waste stack spacv
76  * by allocation this twice.
77  */
78 static void
79 rds_ib_tune_rnr(struct rds_ib_connection *ic, struct ib_qp_attr *attr)
80 {
81         int ret;
82
83         attr->min_rnr_timer = IB_RNR_TIMER_000_32;
84         ret = ib_modify_qp(ic->i_cm_id->qp, attr, IB_QP_MIN_RNR_TIMER);
85         if (ret)
86                 printk(KERN_NOTICE "ib_modify_qp(IB_QP_MIN_RNR_TIMER): err=%d\n", -ret);
87 }
88
89 /*
90  * Connection established.
91  * We get here for both outgoing and incoming connection.
92  */
93 void rds_ib_cm_connect_complete(struct rds_connection *conn, struct rdma_cm_event *event)
94 {
95         const struct rds_ib_connect_private *dp = NULL;
96         struct rds_ib_connection *ic = conn->c_transport_data;
97         struct rds_ib_device *rds_ibdev;
98         struct ib_qp_attr qp_attr;
99         int err;
100
101         if (event->param.conn.private_data_len >= sizeof(*dp)) {
102                 dp = event->param.conn.private_data;
103
104                 /* make sure it isn't empty data */
105                 if (dp->dp_protocol_major) {
106                         rds_ib_set_protocol(conn,
107                                 RDS_PROTOCOL(dp->dp_protocol_major,
108                                 dp->dp_protocol_minor));
109                         rds_ib_set_flow_control(conn, be32_to_cpu(dp->dp_credit));
110                 }
111         }
112
113         printk(KERN_NOTICE "RDS/IB: connected to %pI4 version %u.%u%s\n",
114                         &conn->c_faddr,
115                         RDS_PROTOCOL_MAJOR(conn->c_version),
116                         RDS_PROTOCOL_MINOR(conn->c_version),
117                         ic->i_flowctl ? ", flow control" : "");
118
119         /*
120          * Init rings and fill recv. this needs to wait until protocol negotiation
121          * is complete, since ring layout is different from 3.0 to 3.1.
122          */
123         rds_ib_send_init_ring(ic);
124         rds_ib_recv_init_ring(ic);
125         /* Post receive buffers - as a side effect, this will update
126          * the posted credit count. */
127         rds_ib_recv_refill(conn, GFP_KERNEL, GFP_HIGHUSER, 1);
128
129         /* Tune RNR behavior */
130         rds_ib_tune_rnr(ic, &qp_attr);
131
132         qp_attr.qp_state = IB_QPS_RTS;
133         err = ib_modify_qp(ic->i_cm_id->qp, &qp_attr, IB_QP_STATE);
134         if (err)
135                 printk(KERN_NOTICE "ib_modify_qp(IB_QP_STATE, RTS): err=%d\n", err);
136
137         /* update ib_device with this local ipaddr & conn */
138         rds_ibdev = ib_get_client_data(ic->i_cm_id->device, &rds_ib_client);
139         err = rds_ib_update_ipaddr(rds_ibdev, conn->c_laddr);
140         if (err)
141                 printk(KERN_ERR "rds_ib_update_ipaddr failed (%d)\n", err);
142         rds_ib_add_conn(rds_ibdev, conn);
143
144         /* If the peer gave us the last packet it saw, process this as if
145          * we had received a regular ACK. */
146         if (dp && dp->dp_ack_seq)
147                 rds_send_drop_acked(conn, be64_to_cpu(dp->dp_ack_seq), NULL);
148
149         rds_connect_complete(conn);
150 }
151
152 static void rds_ib_cm_fill_conn_param(struct rds_connection *conn,
153                         struct rdma_conn_param *conn_param,
154                         struct rds_ib_connect_private *dp,
155                         u32 protocol_version)
156 {
157         memset(conn_param, 0, sizeof(struct rdma_conn_param));
158         /* XXX tune these? */
159         conn_param->responder_resources = 1;
160         conn_param->initiator_depth = 1;
161         conn_param->retry_count = min_t(unsigned int, rds_ib_retry_count, 7);
162         conn_param->rnr_retry_count = 7;
163
164         if (dp) {
165                 struct rds_ib_connection *ic = conn->c_transport_data;
166
167                 memset(dp, 0, sizeof(*dp));
168                 dp->dp_saddr = conn->c_laddr;
169                 dp->dp_daddr = conn->c_faddr;
170                 dp->dp_protocol_major = RDS_PROTOCOL_MAJOR(protocol_version);
171                 dp->dp_protocol_minor = RDS_PROTOCOL_MINOR(protocol_version);
172                 dp->dp_protocol_minor_mask = cpu_to_be16(RDS_IB_SUPPORTED_PROTOCOLS);
173                 dp->dp_ack_seq = rds_ib_piggyb_ack(ic);
174
175                 /* Advertise flow control */
176                 if (ic->i_flowctl) {
177                         unsigned int credits;
178
179                         credits = IB_GET_POST_CREDITS(atomic_read(&ic->i_credits));
180                         dp->dp_credit = cpu_to_be32(credits);
181                         atomic_sub(IB_SET_POST_CREDITS(credits), &ic->i_credits);
182                 }
183
184                 conn_param->private_data = dp;
185                 conn_param->private_data_len = sizeof(*dp);
186         }
187 }
188
189 static void rds_ib_cq_event_handler(struct ib_event *event, void *data)
190 {
191         rdsdebug("event %u data %p\n", event->event, data);
192 }
193
194 static void rds_ib_qp_event_handler(struct ib_event *event, void *data)
195 {
196         struct rds_connection *conn = data;
197         struct rds_ib_connection *ic = conn->c_transport_data;
198
199         rdsdebug("conn %p ic %p event %u\n", conn, ic, event->event);
200
201         switch (event->event) {
202         case IB_EVENT_COMM_EST:
203                 rdma_notify(ic->i_cm_id, IB_EVENT_COMM_EST);
204                 break;
205         default:
206                 rds_ib_conn_error(conn, "RDS/IB: Fatal QP Event %u "
207                         "- connection %pI4->%pI4, reconnecting\n",
208                         event->event, &conn->c_laddr, &conn->c_faddr);
209                 break;
210         }
211 }
212
213 /*
214  * This needs to be very careful to not leave IS_ERR pointers around for
215  * cleanup to trip over.
216  */
217 static int rds_ib_setup_qp(struct rds_connection *conn)
218 {
219         struct rds_ib_connection *ic = conn->c_transport_data;
220         struct ib_device *dev = ic->i_cm_id->device;
221         struct ib_qp_init_attr attr;
222         struct rds_ib_device *rds_ibdev;
223         int ret;
224
225         /* rds_ib_add_one creates a rds_ib_device object per IB device,
226          * and allocates a protection domain, memory range and FMR pool
227          * for each.  If that fails for any reason, it will not register
228          * the rds_ibdev at all.
229          */
230         rds_ibdev = ib_get_client_data(dev, &rds_ib_client);
231         if (rds_ibdev == NULL) {
232                 if (printk_ratelimit())
233                         printk(KERN_NOTICE "RDS/IB: No client_data for device %s\n",
234                                         dev->name);
235                 return -EOPNOTSUPP;
236         }
237
238         if (rds_ibdev->max_wrs < ic->i_send_ring.w_nr + 1)
239                 rds_ib_ring_resize(&ic->i_send_ring, rds_ibdev->max_wrs - 1);
240         if (rds_ibdev->max_wrs < ic->i_recv_ring.w_nr + 1)
241                 rds_ib_ring_resize(&ic->i_recv_ring, rds_ibdev->max_wrs - 1);
242
243         /* Protection domain and memory range */
244         ic->i_pd = rds_ibdev->pd;
245         ic->i_mr = rds_ibdev->mr;
246
247         ic->i_send_cq = ib_create_cq(dev, rds_ib_send_cq_comp_handler,
248                                      rds_ib_cq_event_handler, conn,
249                                      ic->i_send_ring.w_nr + 1, 0);
250         if (IS_ERR(ic->i_send_cq)) {
251                 ret = PTR_ERR(ic->i_send_cq);
252                 ic->i_send_cq = NULL;
253                 rdsdebug("ib_create_cq send failed: %d\n", ret);
254                 goto out;
255         }
256
257         ic->i_recv_cq = ib_create_cq(dev, rds_ib_recv_cq_comp_handler,
258                                      rds_ib_cq_event_handler, conn,
259                                      ic->i_recv_ring.w_nr, 0);
260         if (IS_ERR(ic->i_recv_cq)) {
261                 ret = PTR_ERR(ic->i_recv_cq);
262                 ic->i_recv_cq = NULL;
263                 rdsdebug("ib_create_cq recv failed: %d\n", ret);
264                 goto out;
265         }
266
267         ret = ib_req_notify_cq(ic->i_send_cq, IB_CQ_NEXT_COMP);
268         if (ret) {
269                 rdsdebug("ib_req_notify_cq send failed: %d\n", ret);
270                 goto out;
271         }
272
273         ret = ib_req_notify_cq(ic->i_recv_cq, IB_CQ_SOLICITED);
274         if (ret) {
275                 rdsdebug("ib_req_notify_cq recv failed: %d\n", ret);
276                 goto out;
277         }
278
279         /* XXX negotiate max send/recv with remote? */
280         memset(&attr, 0, sizeof(attr));
281         attr.event_handler = rds_ib_qp_event_handler;
282         attr.qp_context = conn;
283         /* + 1 to allow for the single ack message */
284         attr.cap.max_send_wr = ic->i_send_ring.w_nr + 1;
285         attr.cap.max_recv_wr = ic->i_recv_ring.w_nr + 1;
286         attr.cap.max_send_sge = rds_ibdev->max_sge;
287         attr.cap.max_recv_sge = RDS_IB_RECV_SGE;
288         attr.sq_sig_type = IB_SIGNAL_REQ_WR;
289         attr.qp_type = IB_QPT_RC;
290         attr.send_cq = ic->i_send_cq;
291         attr.recv_cq = ic->i_recv_cq;
292
293         /*
294          * XXX this can fail if max_*_wr is too large?  Are we supposed
295          * to back off until we get a value that the hardware can support?
296          */
297         ret = rdma_create_qp(ic->i_cm_id, ic->i_pd, &attr);
298         if (ret) {
299                 rdsdebug("rdma_create_qp failed: %d\n", ret);
300                 goto out;
301         }
302
303         ic->i_send_hdrs = ib_dma_alloc_coherent(dev,
304                                            ic->i_send_ring.w_nr *
305                                                 sizeof(struct rds_header),
306                                            &ic->i_send_hdrs_dma, GFP_KERNEL);
307         if (ic->i_send_hdrs == NULL) {
308                 ret = -ENOMEM;
309                 rdsdebug("ib_dma_alloc_coherent send failed\n");
310                 goto out;
311         }
312
313         ic->i_recv_hdrs = ib_dma_alloc_coherent(dev,
314                                            ic->i_recv_ring.w_nr *
315                                                 sizeof(struct rds_header),
316                                            &ic->i_recv_hdrs_dma, GFP_KERNEL);
317         if (ic->i_recv_hdrs == NULL) {
318                 ret = -ENOMEM;
319                 rdsdebug("ib_dma_alloc_coherent recv failed\n");
320                 goto out;
321         }
322
323         ic->i_ack = ib_dma_alloc_coherent(dev, sizeof(struct rds_header),
324                                        &ic->i_ack_dma, GFP_KERNEL);
325         if (ic->i_ack == NULL) {
326                 ret = -ENOMEM;
327                 rdsdebug("ib_dma_alloc_coherent ack failed\n");
328                 goto out;
329         }
330
331         ic->i_sends = vmalloc(ic->i_send_ring.w_nr * sizeof(struct rds_ib_send_work));
332         if (ic->i_sends == NULL) {
333                 ret = -ENOMEM;
334                 rdsdebug("send allocation failed\n");
335                 goto out;
336         }
337         memset(ic->i_sends, 0, ic->i_send_ring.w_nr * sizeof(struct rds_ib_send_work));
338
339         ic->i_recvs = vmalloc(ic->i_recv_ring.w_nr * sizeof(struct rds_ib_recv_work));
340         if (ic->i_recvs == NULL) {
341                 ret = -ENOMEM;
342                 rdsdebug("recv allocation failed\n");
343                 goto out;
344         }
345         memset(ic->i_recvs, 0, ic->i_recv_ring.w_nr * sizeof(struct rds_ib_recv_work));
346
347         rds_ib_recv_init_ack(ic);
348
349         rdsdebug("conn %p pd %p mr %p cq %p %p\n", conn, ic->i_pd, ic->i_mr,
350                  ic->i_send_cq, ic->i_recv_cq);
351
352 out:
353         return ret;
354 }
355
356 static u32 rds_ib_protocol_compatible(struct rdma_cm_event *event)
357 {
358         const struct rds_ib_connect_private *dp = event->param.conn.private_data;
359         u16 common;
360         u32 version = 0;
361
362         /*
363          * rdma_cm private data is odd - when there is any private data in the
364          * request, we will be given a pretty large buffer without telling us the
365          * original size. The only way to tell the difference is by looking at
366          * the contents, which are initialized to zero.
367          * If the protocol version fields aren't set, this is a connection attempt
368          * from an older version. This could could be 3.0 or 2.0 - we can't tell.
369          * We really should have changed this for OFED 1.3 :-(
370          */
371
372         /* Be paranoid. RDS always has privdata */
373         if (!event->param.conn.private_data_len) {
374                 printk(KERN_NOTICE "RDS incoming connection has no private data, "
375                         "rejecting\n");
376                 return 0;
377         }
378
379         /* Even if len is crap *now* I still want to check it. -ASG */
380         if (event->param.conn.private_data_len < sizeof (*dp) ||
381             dp->dp_protocol_major == 0)
382                 return RDS_PROTOCOL_3_0;
383
384         common = be16_to_cpu(dp->dp_protocol_minor_mask) & RDS_IB_SUPPORTED_PROTOCOLS;
385         if (dp->dp_protocol_major == 3 && common) {
386                 version = RDS_PROTOCOL_3_0;
387                 while ((common >>= 1) != 0)
388                         version++;
389         } else if (printk_ratelimit()) {
390                 printk(KERN_NOTICE "RDS: Connection from %pI4 using "
391                         "incompatible protocol version %u.%u\n",
392                         &dp->dp_saddr,
393                         dp->dp_protocol_major,
394                         dp->dp_protocol_minor);
395         }
396         return version;
397 }
398
399 int rds_ib_cm_handle_connect(struct rdma_cm_id *cm_id,
400                                     struct rdma_cm_event *event)
401 {
402         __be64 lguid = cm_id->route.path_rec->sgid.global.interface_id;
403         __be64 fguid = cm_id->route.path_rec->dgid.global.interface_id;
404         const struct rds_ib_connect_private *dp = event->param.conn.private_data;
405         struct rds_ib_connect_private dp_rep;
406         struct rds_connection *conn = NULL;
407         struct rds_ib_connection *ic = NULL;
408         struct rdma_conn_param conn_param;
409         u32 version;
410         int err, destroy = 1;
411
412         /* Check whether the remote protocol version matches ours. */
413         version = rds_ib_protocol_compatible(event);
414         if (!version)
415                 goto out;
416
417         rdsdebug("saddr %pI4 daddr %pI4 RDSv%u.%u lguid 0x%llx fguid "
418                  "0x%llx\n", &dp->dp_saddr, &dp->dp_daddr,
419                  RDS_PROTOCOL_MAJOR(version), RDS_PROTOCOL_MINOR(version),
420                  (unsigned long long)be64_to_cpu(lguid),
421                  (unsigned long long)be64_to_cpu(fguid));
422
423         conn = rds_conn_create(dp->dp_daddr, dp->dp_saddr, &rds_ib_transport,
424                                GFP_KERNEL);
425         if (IS_ERR(conn)) {
426                 rdsdebug("rds_conn_create failed (%ld)\n", PTR_ERR(conn));
427                 conn = NULL;
428                 goto out;
429         }
430
431         /*
432          * The connection request may occur while the
433          * previous connection exist, e.g. in case of failover.
434          * But as connections may be initiated simultaneously
435          * by both hosts, we have a random backoff mechanism -
436          * see the comment above rds_queue_reconnect()
437          */
438         mutex_lock(&conn->c_cm_lock);
439         if (!rds_conn_transition(conn, RDS_CONN_DOWN, RDS_CONN_CONNECTING)) {
440                 if (rds_conn_state(conn) == RDS_CONN_UP) {
441                         rdsdebug("incoming connect while connecting\n");
442                         rds_conn_drop(conn);
443                         rds_ib_stats_inc(s_ib_listen_closed_stale);
444                 } else
445                 if (rds_conn_state(conn) == RDS_CONN_CONNECTING) {
446                         /* Wait and see - our connect may still be succeeding */
447                         rds_ib_stats_inc(s_ib_connect_raced);
448                 }
449                 mutex_unlock(&conn->c_cm_lock);
450                 goto out;
451         }
452
453         ic = conn->c_transport_data;
454
455         rds_ib_set_protocol(conn, version);
456         rds_ib_set_flow_control(conn, be32_to_cpu(dp->dp_credit));
457
458         /* If the peer gave us the last packet it saw, process this as if
459          * we had received a regular ACK. */
460         if (dp->dp_ack_seq)
461                 rds_send_drop_acked(conn, be64_to_cpu(dp->dp_ack_seq), NULL);
462
463         BUG_ON(cm_id->context);
464         BUG_ON(ic->i_cm_id);
465
466         ic->i_cm_id = cm_id;
467         cm_id->context = conn;
468
469         /* We got halfway through setting up the ib_connection, if we
470          * fail now, we have to take the long route out of this mess. */
471         destroy = 0;
472
473         err = rds_ib_setup_qp(conn);
474         if (err) {
475                 rds_ib_conn_error(conn, "rds_ib_setup_qp failed (%d)\n", err);
476                 goto out;
477         }
478
479         rds_ib_cm_fill_conn_param(conn, &conn_param, &dp_rep, version);
480
481         /* rdma_accept() calls rdma_reject() internally if it fails */
482         err = rdma_accept(cm_id, &conn_param);
483         mutex_unlock(&conn->c_cm_lock);
484         if (err) {
485                 rds_ib_conn_error(conn, "rdma_accept failed (%d)\n", err);
486                 goto out;
487         }
488
489         return 0;
490
491 out:
492         rdma_reject(cm_id, NULL, 0);
493         return destroy;
494 }
495
496
497 int rds_ib_cm_initiate_connect(struct rdma_cm_id *cm_id)
498 {
499         struct rds_connection *conn = cm_id->context;
500         struct rds_ib_connection *ic = conn->c_transport_data;
501         struct rdma_conn_param conn_param;
502         struct rds_ib_connect_private dp;
503         int ret;
504
505         /* If the peer doesn't do protocol negotiation, we must
506          * default to RDSv3.0 */
507         rds_ib_set_protocol(conn, RDS_PROTOCOL_3_0);
508         ic->i_flowctl = rds_ib_sysctl_flow_control;     /* advertise flow control */
509
510         ret = rds_ib_setup_qp(conn);
511         if (ret) {
512                 rds_ib_conn_error(conn, "rds_ib_setup_qp failed (%d)\n", ret);
513                 goto out;
514         }
515
516         rds_ib_cm_fill_conn_param(conn, &conn_param, &dp, RDS_PROTOCOL_VERSION);
517
518         ret = rdma_connect(cm_id, &conn_param);
519         if (ret)
520                 rds_ib_conn_error(conn, "rdma_connect failed (%d)\n", ret);
521
522 out:
523         /* Beware - returning non-zero tells the rdma_cm to destroy
524          * the cm_id. We should certainly not do it as long as we still
525          * "own" the cm_id. */
526         if (ret) {
527                 if (ic->i_cm_id == cm_id)
528                         ret = 0;
529         }
530         return ret;
531 }
532
533 int rds_ib_conn_connect(struct rds_connection *conn)
534 {
535         struct rds_ib_connection *ic = conn->c_transport_data;
536         struct sockaddr_in src, dest;
537         int ret;
538
539         /* XXX I wonder what affect the port space has */
540         /* delegate cm event handler to rdma_transport */
541         ic->i_cm_id = rdma_create_id(rds_rdma_cm_event_handler, conn,
542                                      RDMA_PS_TCP);
543         if (IS_ERR(ic->i_cm_id)) {
544                 ret = PTR_ERR(ic->i_cm_id);
545                 ic->i_cm_id = NULL;
546                 rdsdebug("rdma_create_id() failed: %d\n", ret);
547                 goto out;
548         }
549
550         rdsdebug("created cm id %p for conn %p\n", ic->i_cm_id, conn);
551
552         src.sin_family = AF_INET;
553         src.sin_addr.s_addr = (__force u32)conn->c_laddr;
554         src.sin_port = (__force u16)htons(0);
555
556         dest.sin_family = AF_INET;
557         dest.sin_addr.s_addr = (__force u32)conn->c_faddr;
558         dest.sin_port = (__force u16)htons(RDS_PORT);
559
560         ret = rdma_resolve_addr(ic->i_cm_id, (struct sockaddr *)&src,
561                                 (struct sockaddr *)&dest,
562                                 RDS_RDMA_RESOLVE_TIMEOUT_MS);
563         if (ret) {
564                 rdsdebug("addr resolve failed for cm id %p: %d\n", ic->i_cm_id,
565                          ret);
566                 rdma_destroy_id(ic->i_cm_id);
567                 ic->i_cm_id = NULL;
568         }
569
570 out:
571         return ret;
572 }
573
574 /*
575  * This is so careful about only cleaning up resources that were built up
576  * so that it can be called at any point during startup.  In fact it
577  * can be called multiple times for a given connection.
578  */
579 void rds_ib_conn_shutdown(struct rds_connection *conn)
580 {
581         struct rds_ib_connection *ic = conn->c_transport_data;
582         int err = 0;
583
584         rdsdebug("cm %p pd %p cq %p %p qp %p\n", ic->i_cm_id,
585                  ic->i_pd, ic->i_send_cq, ic->i_recv_cq,
586                  ic->i_cm_id ? ic->i_cm_id->qp : NULL);
587
588         if (ic->i_cm_id) {
589                 struct ib_device *dev = ic->i_cm_id->device;
590
591                 rdsdebug("disconnecting cm %p\n", ic->i_cm_id);
592                 err = rdma_disconnect(ic->i_cm_id);
593                 if (err) {
594                         /* Actually this may happen quite frequently, when
595                          * an outgoing connect raced with an incoming connect.
596                          */
597                         rdsdebug("failed to disconnect, cm: %p err %d\n",
598                                 ic->i_cm_id, err);
599                 }
600
601                 wait_event(rds_ib_ring_empty_wait,
602                         rds_ib_ring_empty(&ic->i_send_ring) &&
603                         rds_ib_ring_empty(&ic->i_recv_ring));
604
605                 if (ic->i_send_hdrs)
606                         ib_dma_free_coherent(dev,
607                                            ic->i_send_ring.w_nr *
608                                                 sizeof(struct rds_header),
609                                            ic->i_send_hdrs,
610                                            ic->i_send_hdrs_dma);
611
612                 if (ic->i_recv_hdrs)
613                         ib_dma_free_coherent(dev,
614                                            ic->i_recv_ring.w_nr *
615                                                 sizeof(struct rds_header),
616                                            ic->i_recv_hdrs,
617                                            ic->i_recv_hdrs_dma);
618
619                 if (ic->i_ack)
620                         ib_dma_free_coherent(dev, sizeof(struct rds_header),
621                                              ic->i_ack, ic->i_ack_dma);
622
623                 if (ic->i_sends)
624                         rds_ib_send_clear_ring(ic);
625                 if (ic->i_recvs)
626                         rds_ib_recv_clear_ring(ic);
627
628                 if (ic->i_cm_id->qp)
629                         rdma_destroy_qp(ic->i_cm_id);
630                 if (ic->i_send_cq)
631                         ib_destroy_cq(ic->i_send_cq);
632                 if (ic->i_recv_cq)
633                         ib_destroy_cq(ic->i_recv_cq);
634                 rdma_destroy_id(ic->i_cm_id);
635
636                 /*
637                  * Move connection back to the nodev list.
638                  */
639                 if (ic->rds_ibdev)
640                         rds_ib_remove_conn(ic->rds_ibdev, conn);
641
642                 ic->i_cm_id = NULL;
643                 ic->i_pd = NULL;
644                 ic->i_mr = NULL;
645                 ic->i_send_cq = NULL;
646                 ic->i_recv_cq = NULL;
647                 ic->i_send_hdrs = NULL;
648                 ic->i_recv_hdrs = NULL;
649                 ic->i_ack = NULL;
650         }
651         BUG_ON(ic->rds_ibdev);
652
653         /* Clear pending transmit */
654         if (ic->i_rm) {
655                 rds_message_put(ic->i_rm);
656                 ic->i_rm = NULL;
657         }
658
659         /* Clear the ACK state */
660         clear_bit(IB_ACK_IN_FLIGHT, &ic->i_ack_flags);
661 #ifdef KERNEL_HAS_ATOMIC64
662         atomic64_set(&ic->i_ack_next, 0);
663 #else
664         ic->i_ack_next = 0;
665 #endif
666         ic->i_ack_recv = 0;
667
668         /* Clear flow control state */
669         ic->i_flowctl = 0;
670         atomic_set(&ic->i_credits, 0);
671
672         rds_ib_ring_init(&ic->i_send_ring, rds_ib_sysctl_max_send_wr);
673         rds_ib_ring_init(&ic->i_recv_ring, rds_ib_sysctl_max_recv_wr);
674
675         if (ic->i_ibinc) {
676                 rds_inc_put(&ic->i_ibinc->ii_inc);
677                 ic->i_ibinc = NULL;
678         }
679
680         vfree(ic->i_sends);
681         ic->i_sends = NULL;
682         vfree(ic->i_recvs);
683         ic->i_recvs = NULL;
684 }
685
686 int rds_ib_conn_alloc(struct rds_connection *conn, gfp_t gfp)
687 {
688         struct rds_ib_connection *ic;
689         unsigned long flags;
690
691         /* XXX too lazy? */
692         ic = kzalloc(sizeof(struct rds_ib_connection), GFP_KERNEL);
693         if (ic == NULL)
694                 return -ENOMEM;
695
696         INIT_LIST_HEAD(&ic->ib_node);
697         tasklet_init(&ic->i_recv_tasklet, rds_ib_recv_tasklet_fn,
698                      (unsigned long) ic);
699         mutex_init(&ic->i_recv_mutex);
700 #ifndef KERNEL_HAS_ATOMIC64
701         spin_lock_init(&ic->i_ack_lock);
702 #endif
703
704         /*
705          * rds_ib_conn_shutdown() waits for these to be emptied so they
706          * must be initialized before it can be called.
707          */
708         rds_ib_ring_init(&ic->i_send_ring, rds_ib_sysctl_max_send_wr);
709         rds_ib_ring_init(&ic->i_recv_ring, rds_ib_sysctl_max_recv_wr);
710
711         ic->conn = conn;
712         conn->c_transport_data = ic;
713
714         spin_lock_irqsave(&ib_nodev_conns_lock, flags);
715         list_add_tail(&ic->ib_node, &ib_nodev_conns);
716         spin_unlock_irqrestore(&ib_nodev_conns_lock, flags);
717
718
719         rdsdebug("conn %p conn ic %p\n", conn, conn->c_transport_data);
720         return 0;
721 }
722
723 /*
724  * Free a connection. Connection must be shut down and not set for reconnect.
725  */
726 void rds_ib_conn_free(void *arg)
727 {
728         struct rds_ib_connection *ic = arg;
729         spinlock_t      *lock_ptr;
730
731         rdsdebug("ic %p\n", ic);
732
733         /*
734          * Conn is either on a dev's list or on the nodev list.
735          * A race with shutdown() or connect() would cause problems
736          * (since rds_ibdev would change) but that should never happen.
737          */
738         lock_ptr = ic->rds_ibdev ? &ic->rds_ibdev->spinlock : &ib_nodev_conns_lock;
739
740         spin_lock_irq(lock_ptr);
741         list_del(&ic->ib_node);
742         spin_unlock_irq(lock_ptr);
743
744         kfree(ic);
745 }
746
747
748 /*
749  * An error occurred on the connection
750  */
751 void
752 __rds_ib_conn_error(struct rds_connection *conn, const char *fmt, ...)
753 {
754         va_list ap;
755
756         rds_conn_drop(conn);
757
758         va_start(ap, fmt);
759         vprintk(fmt, ap);
760         va_end(ap);
761 }