Merge branch 'pm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael...
[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/slab.h>
36 #include <linux/vmalloc.h>
37 #include <linux/ratelimit.h>
38
39 #include "rds.h"
40 #include "ib.h"
41
42 static 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
66 static 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  */
75 static 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  */
83 static 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  */
110 static void
111 rds_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  */
125 void 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
192 static 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
234 static 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
240 static 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  */
266 static 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 = vzalloc_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
386         ic->i_recvs = vzalloc_node(ic->i_recv_ring.w_nr * sizeof(struct rds_ib_recv_work),
387                                    ibdev_to_node(dev));
388         if (!ic->i_recvs) {
389                 ret = -ENOMEM;
390                 rdsdebug("recv allocation failed\n");
391                 goto out;
392         }
393
394         rds_ib_recv_init_ack(ic);
395
396         rdsdebug("conn %p pd %p mr %p cq %p %p\n", conn, ic->i_pd, ic->i_mr,
397                  ic->i_send_cq, ic->i_recv_cq);
398
399 out:
400         rds_ib_dev_put(rds_ibdev);
401         return ret;
402 }
403
404 static u32 rds_ib_protocol_compatible(struct rdma_cm_event *event)
405 {
406         const struct rds_ib_connect_private *dp = event->param.conn.private_data;
407         u16 common;
408         u32 version = 0;
409
410         /*
411          * rdma_cm private data is odd - when there is any private data in the
412          * request, we will be given a pretty large buffer without telling us the
413          * original size. The only way to tell the difference is by looking at
414          * the contents, which are initialized to zero.
415          * If the protocol version fields aren't set, this is a connection attempt
416          * from an older version. This could could be 3.0 or 2.0 - we can't tell.
417          * We really should have changed this for OFED 1.3 :-(
418          */
419
420         /* Be paranoid. RDS always has privdata */
421         if (!event->param.conn.private_data_len) {
422                 printk(KERN_NOTICE "RDS incoming connection has no private data, "
423                         "rejecting\n");
424                 return 0;
425         }
426
427         /* Even if len is crap *now* I still want to check it. -ASG */
428         if (event->param.conn.private_data_len < sizeof (*dp) ||
429             dp->dp_protocol_major == 0)
430                 return RDS_PROTOCOL_3_0;
431
432         common = be16_to_cpu(dp->dp_protocol_minor_mask) & RDS_IB_SUPPORTED_PROTOCOLS;
433         if (dp->dp_protocol_major == 3 && common) {
434                 version = RDS_PROTOCOL_3_0;
435                 while ((common >>= 1) != 0)
436                         version++;
437         }
438         printk_ratelimited(KERN_NOTICE "RDS: Connection from %pI4 using "
439                         "incompatible protocol version %u.%u\n",
440                         &dp->dp_saddr,
441                         dp->dp_protocol_major,
442                         dp->dp_protocol_minor);
443         return version;
444 }
445
446 int rds_ib_cm_handle_connect(struct rdma_cm_id *cm_id,
447                                     struct rdma_cm_event *event)
448 {
449         __be64 lguid = cm_id->route.path_rec->sgid.global.interface_id;
450         __be64 fguid = cm_id->route.path_rec->dgid.global.interface_id;
451         const struct rds_ib_connect_private *dp = event->param.conn.private_data;
452         struct rds_ib_connect_private dp_rep;
453         struct rds_connection *conn = NULL;
454         struct rds_ib_connection *ic = NULL;
455         struct rdma_conn_param conn_param;
456         u32 version;
457         int err = 1, destroy = 1;
458
459         /* Check whether the remote protocol version matches ours. */
460         version = rds_ib_protocol_compatible(event);
461         if (!version)
462                 goto out;
463
464         rdsdebug("saddr %pI4 daddr %pI4 RDSv%u.%u lguid 0x%llx fguid "
465                  "0x%llx\n", &dp->dp_saddr, &dp->dp_daddr,
466                  RDS_PROTOCOL_MAJOR(version), RDS_PROTOCOL_MINOR(version),
467                  (unsigned long long)be64_to_cpu(lguid),
468                  (unsigned long long)be64_to_cpu(fguid));
469
470         conn = rds_conn_create(dp->dp_daddr, dp->dp_saddr, &rds_ib_transport,
471                                GFP_KERNEL);
472         if (IS_ERR(conn)) {
473                 rdsdebug("rds_conn_create failed (%ld)\n", PTR_ERR(conn));
474                 conn = NULL;
475                 goto out;
476         }
477
478         /*
479          * The connection request may occur while the
480          * previous connection exist, e.g. in case of failover.
481          * But as connections may be initiated simultaneously
482          * by both hosts, we have a random backoff mechanism -
483          * see the comment above rds_queue_reconnect()
484          */
485         mutex_lock(&conn->c_cm_lock);
486         if (!rds_conn_transition(conn, RDS_CONN_DOWN, RDS_CONN_CONNECTING)) {
487                 if (rds_conn_state(conn) == RDS_CONN_UP) {
488                         rdsdebug("incoming connect while connecting\n");
489                         rds_conn_drop(conn);
490                         rds_ib_stats_inc(s_ib_listen_closed_stale);
491                 } else
492                 if (rds_conn_state(conn) == RDS_CONN_CONNECTING) {
493                         /* Wait and see - our connect may still be succeeding */
494                         rds_ib_stats_inc(s_ib_connect_raced);
495                 }
496                 goto out;
497         }
498
499         ic = conn->c_transport_data;
500
501         rds_ib_set_protocol(conn, version);
502         rds_ib_set_flow_control(conn, be32_to_cpu(dp->dp_credit));
503
504         /* If the peer gave us the last packet it saw, process this as if
505          * we had received a regular ACK. */
506         if (dp->dp_ack_seq)
507                 rds_send_drop_acked(conn, be64_to_cpu(dp->dp_ack_seq), NULL);
508
509         BUG_ON(cm_id->context);
510         BUG_ON(ic->i_cm_id);
511
512         ic->i_cm_id = cm_id;
513         cm_id->context = conn;
514
515         /* We got halfway through setting up the ib_connection, if we
516          * fail now, we have to take the long route out of this mess. */
517         destroy = 0;
518
519         err = rds_ib_setup_qp(conn);
520         if (err) {
521                 rds_ib_conn_error(conn, "rds_ib_setup_qp failed (%d)\n", err);
522                 goto out;
523         }
524
525         rds_ib_cm_fill_conn_param(conn, &conn_param, &dp_rep, version,
526                 event->param.conn.responder_resources,
527                 event->param.conn.initiator_depth);
528
529         /* rdma_accept() calls rdma_reject() internally if it fails */
530         err = rdma_accept(cm_id, &conn_param);
531         if (err)
532                 rds_ib_conn_error(conn, "rdma_accept failed (%d)\n", err);
533
534 out:
535         if (conn)
536                 mutex_unlock(&conn->c_cm_lock);
537         if (err)
538                 rdma_reject(cm_id, NULL, 0);
539         return destroy;
540 }
541
542
543 int rds_ib_cm_initiate_connect(struct rdma_cm_id *cm_id)
544 {
545         struct rds_connection *conn = cm_id->context;
546         struct rds_ib_connection *ic = conn->c_transport_data;
547         struct rdma_conn_param conn_param;
548         struct rds_ib_connect_private dp;
549         int ret;
550
551         /* If the peer doesn't do protocol negotiation, we must
552          * default to RDSv3.0 */
553         rds_ib_set_protocol(conn, RDS_PROTOCOL_3_0);
554         ic->i_flowctl = rds_ib_sysctl_flow_control;     /* advertise flow control */
555
556         ret = rds_ib_setup_qp(conn);
557         if (ret) {
558                 rds_ib_conn_error(conn, "rds_ib_setup_qp failed (%d)\n", ret);
559                 goto out;
560         }
561
562         rds_ib_cm_fill_conn_param(conn, &conn_param, &dp, RDS_PROTOCOL_VERSION,
563                 UINT_MAX, UINT_MAX);
564         ret = rdma_connect(cm_id, &conn_param);
565         if (ret)
566                 rds_ib_conn_error(conn, "rdma_connect failed (%d)\n", ret);
567
568 out:
569         /* Beware - returning non-zero tells the rdma_cm to destroy
570          * the cm_id. We should certainly not do it as long as we still
571          * "own" the cm_id. */
572         if (ret) {
573                 if (ic->i_cm_id == cm_id)
574                         ret = 0;
575         }
576         return ret;
577 }
578
579 int rds_ib_conn_connect(struct rds_connection *conn)
580 {
581         struct rds_ib_connection *ic = conn->c_transport_data;
582         struct sockaddr_in src, dest;
583         int ret;
584
585         /* XXX I wonder what affect the port space has */
586         /* delegate cm event handler to rdma_transport */
587         ic->i_cm_id = rdma_create_id(rds_rdma_cm_event_handler, conn,
588                                      RDMA_PS_TCP, IB_QPT_RC);
589         if (IS_ERR(ic->i_cm_id)) {
590                 ret = PTR_ERR(ic->i_cm_id);
591                 ic->i_cm_id = NULL;
592                 rdsdebug("rdma_create_id() failed: %d\n", ret);
593                 goto out;
594         }
595
596         rdsdebug("created cm id %p for conn %p\n", ic->i_cm_id, conn);
597
598         src.sin_family = AF_INET;
599         src.sin_addr.s_addr = (__force u32)conn->c_laddr;
600         src.sin_port = (__force u16)htons(0);
601
602         dest.sin_family = AF_INET;
603         dest.sin_addr.s_addr = (__force u32)conn->c_faddr;
604         dest.sin_port = (__force u16)htons(RDS_PORT);
605
606         ret = rdma_resolve_addr(ic->i_cm_id, (struct sockaddr *)&src,
607                                 (struct sockaddr *)&dest,
608                                 RDS_RDMA_RESOLVE_TIMEOUT_MS);
609         if (ret) {
610                 rdsdebug("addr resolve failed for cm id %p: %d\n", ic->i_cm_id,
611                          ret);
612                 rdma_destroy_id(ic->i_cm_id);
613                 ic->i_cm_id = NULL;
614         }
615
616 out:
617         return ret;
618 }
619
620 /*
621  * This is so careful about only cleaning up resources that were built up
622  * so that it can be called at any point during startup.  In fact it
623  * can be called multiple times for a given connection.
624  */
625 void rds_ib_conn_shutdown(struct rds_connection *conn)
626 {
627         struct rds_ib_connection *ic = conn->c_transport_data;
628         int err = 0;
629
630         rdsdebug("cm %p pd %p cq %p %p qp %p\n", ic->i_cm_id,
631                  ic->i_pd, ic->i_send_cq, ic->i_recv_cq,
632                  ic->i_cm_id ? ic->i_cm_id->qp : NULL);
633
634         if (ic->i_cm_id) {
635                 struct ib_device *dev = ic->i_cm_id->device;
636
637                 rdsdebug("disconnecting cm %p\n", ic->i_cm_id);
638                 err = rdma_disconnect(ic->i_cm_id);
639                 if (err) {
640                         /* Actually this may happen quite frequently, when
641                          * an outgoing connect raced with an incoming connect.
642                          */
643                         rdsdebug("failed to disconnect, cm: %p err %d\n",
644                                 ic->i_cm_id, err);
645                 }
646
647                 /*
648                  * We want to wait for tx and rx completion to finish
649                  * before we tear down the connection, but we have to be
650                  * careful not to get stuck waiting on a send ring that
651                  * only has unsignaled sends in it.  We've shutdown new
652                  * sends before getting here so by waiting for signaled
653                  * sends to complete we're ensured that there will be no
654                  * more tx processing.
655                  */
656                 wait_event(rds_ib_ring_empty_wait,
657                            rds_ib_ring_empty(&ic->i_recv_ring) &&
658                            (atomic_read(&ic->i_signaled_sends) == 0));
659                 tasklet_kill(&ic->i_recv_tasklet);
660
661                 if (ic->i_send_hdrs)
662                         ib_dma_free_coherent(dev,
663                                            ic->i_send_ring.w_nr *
664                                                 sizeof(struct rds_header),
665                                            ic->i_send_hdrs,
666                                            ic->i_send_hdrs_dma);
667
668                 if (ic->i_recv_hdrs)
669                         ib_dma_free_coherent(dev,
670                                            ic->i_recv_ring.w_nr *
671                                                 sizeof(struct rds_header),
672                                            ic->i_recv_hdrs,
673                                            ic->i_recv_hdrs_dma);
674
675                 if (ic->i_ack)
676                         ib_dma_free_coherent(dev, sizeof(struct rds_header),
677                                              ic->i_ack, ic->i_ack_dma);
678
679                 if (ic->i_sends)
680                         rds_ib_send_clear_ring(ic);
681                 if (ic->i_recvs)
682                         rds_ib_recv_clear_ring(ic);
683
684                 if (ic->i_cm_id->qp)
685                         rdma_destroy_qp(ic->i_cm_id);
686                 if (ic->i_send_cq)
687                         ib_destroy_cq(ic->i_send_cq);
688                 if (ic->i_recv_cq)
689                         ib_destroy_cq(ic->i_recv_cq);
690                 rdma_destroy_id(ic->i_cm_id);
691
692                 /*
693                  * Move connection back to the nodev list.
694                  */
695                 if (ic->rds_ibdev)
696                         rds_ib_remove_conn(ic->rds_ibdev, conn);
697
698                 ic->i_cm_id = NULL;
699                 ic->i_pd = NULL;
700                 ic->i_mr = NULL;
701                 ic->i_send_cq = NULL;
702                 ic->i_recv_cq = NULL;
703                 ic->i_send_hdrs = NULL;
704                 ic->i_recv_hdrs = NULL;
705                 ic->i_ack = NULL;
706         }
707         BUG_ON(ic->rds_ibdev);
708
709         /* Clear pending transmit */
710         if (ic->i_data_op) {
711                 struct rds_message *rm;
712
713                 rm = container_of(ic->i_data_op, struct rds_message, data);
714                 rds_message_put(rm);
715                 ic->i_data_op = NULL;
716         }
717
718         /* Clear the ACK state */
719         clear_bit(IB_ACK_IN_FLIGHT, &ic->i_ack_flags);
720 #ifdef KERNEL_HAS_ATOMIC64
721         atomic64_set(&ic->i_ack_next, 0);
722 #else
723         ic->i_ack_next = 0;
724 #endif
725         ic->i_ack_recv = 0;
726
727         /* Clear flow control state */
728         ic->i_flowctl = 0;
729         atomic_set(&ic->i_credits, 0);
730
731         rds_ib_ring_init(&ic->i_send_ring, rds_ib_sysctl_max_send_wr);
732         rds_ib_ring_init(&ic->i_recv_ring, rds_ib_sysctl_max_recv_wr);
733
734         if (ic->i_ibinc) {
735                 rds_inc_put(&ic->i_ibinc->ii_inc);
736                 ic->i_ibinc = NULL;
737         }
738
739         vfree(ic->i_sends);
740         ic->i_sends = NULL;
741         vfree(ic->i_recvs);
742         ic->i_recvs = NULL;
743 }
744
745 int rds_ib_conn_alloc(struct rds_connection *conn, gfp_t gfp)
746 {
747         struct rds_ib_connection *ic;
748         unsigned long flags;
749         int ret;
750
751         /* XXX too lazy? */
752         ic = kzalloc(sizeof(struct rds_ib_connection), GFP_KERNEL);
753         if (!ic)
754                 return -ENOMEM;
755
756         ret = rds_ib_recv_alloc_caches(ic);
757         if (ret) {
758                 kfree(ic);
759                 return ret;
760         }
761
762         INIT_LIST_HEAD(&ic->ib_node);
763         tasklet_init(&ic->i_recv_tasklet, rds_ib_recv_tasklet_fn,
764                      (unsigned long) ic);
765         mutex_init(&ic->i_recv_mutex);
766 #ifndef KERNEL_HAS_ATOMIC64
767         spin_lock_init(&ic->i_ack_lock);
768 #endif
769         atomic_set(&ic->i_signaled_sends, 0);
770
771         /*
772          * rds_ib_conn_shutdown() waits for these to be emptied so they
773          * must be initialized before it can be called.
774          */
775         rds_ib_ring_init(&ic->i_send_ring, rds_ib_sysctl_max_send_wr);
776         rds_ib_ring_init(&ic->i_recv_ring, rds_ib_sysctl_max_recv_wr);
777
778         ic->conn = conn;
779         conn->c_transport_data = ic;
780
781         spin_lock_irqsave(&ib_nodev_conns_lock, flags);
782         list_add_tail(&ic->ib_node, &ib_nodev_conns);
783         spin_unlock_irqrestore(&ib_nodev_conns_lock, flags);
784
785
786         rdsdebug("conn %p conn ic %p\n", conn, conn->c_transport_data);
787         return 0;
788 }
789
790 /*
791  * Free a connection. Connection must be shut down and not set for reconnect.
792  */
793 void rds_ib_conn_free(void *arg)
794 {
795         struct rds_ib_connection *ic = arg;
796         spinlock_t      *lock_ptr;
797
798         rdsdebug("ic %p\n", ic);
799
800         /*
801          * Conn is either on a dev's list or on the nodev list.
802          * A race with shutdown() or connect() would cause problems
803          * (since rds_ibdev would change) but that should never happen.
804          */
805         lock_ptr = ic->rds_ibdev ? &ic->rds_ibdev->spinlock : &ib_nodev_conns_lock;
806
807         spin_lock_irq(lock_ptr);
808         list_del(&ic->ib_node);
809         spin_unlock_irq(lock_ptr);
810
811         rds_ib_recv_free_caches(ic);
812
813         kfree(ic);
814 }
815
816
817 /*
818  * An error occurred on the connection
819  */
820 void
821 __rds_ib_conn_error(struct rds_connection *conn, const char *fmt, ...)
822 {
823         va_list ap;
824
825         rds_conn_drop(conn);
826
827         va_start(ap, fmt);
828         vprintk(fmt, ap);
829         va_end(ap);
830 }