]> git.karo-electronics.de Git - karo-tx-linux.git/blob - drivers/infiniband/core/iwcm.c
Merge remote-tracking branches 'spi/topic/devprop', 'spi/topic/fsl', 'spi/topic/fsl...
[karo-tx-linux.git] / drivers / infiniband / core / iwcm.c
1 /*
2  * Copyright (c) 2004, 2005 Intel Corporation.  All rights reserved.
3  * Copyright (c) 2004 Topspin Corporation.  All rights reserved.
4  * Copyright (c) 2004, 2005 Voltaire Corporation.  All rights reserved.
5  * Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
6  * Copyright (c) 2005 Open Grid Computing, Inc. All rights reserved.
7  * Copyright (c) 2005 Network Appliance, Inc. All rights reserved.
8  *
9  * This software is available to you under a choice of one of two
10  * licenses.  You may choose to be licensed under the terms of the GNU
11  * General Public License (GPL) Version 2, available from the file
12  * COPYING in the main directory of this source tree, or the
13  * OpenIB.org BSD license below:
14  *
15  *     Redistribution and use in source and binary forms, with or
16  *     without modification, are permitted provided that the following
17  *     conditions are met:
18  *
19  *      - Redistributions of source code must retain the above
20  *        copyright notice, this list of conditions and the following
21  *        disclaimer.
22  *
23  *      - Redistributions in binary form must reproduce the above
24  *        copyright notice, this list of conditions and the following
25  *        disclaimer in the documentation and/or other materials
26  *        provided with the distribution.
27  *
28  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
29  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
30  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
31  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
32  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
33  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
34  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
35  * SOFTWARE.
36  *
37  */
38 #include <linux/dma-mapping.h>
39 #include <linux/err.h>
40 #include <linux/idr.h>
41 #include <linux/interrupt.h>
42 #include <linux/rbtree.h>
43 #include <linux/sched.h>
44 #include <linux/spinlock.h>
45 #include <linux/workqueue.h>
46 #include <linux/completion.h>
47 #include <linux/slab.h>
48 #include <linux/module.h>
49 #include <linux/sysctl.h>
50
51 #include <rdma/iw_cm.h>
52 #include <rdma/ib_addr.h>
53 #include <rdma/iw_portmap.h>
54 #include <rdma/rdma_netlink.h>
55
56 #include "iwcm.h"
57
58 MODULE_AUTHOR("Tom Tucker");
59 MODULE_DESCRIPTION("iWARP CM");
60 MODULE_LICENSE("Dual BSD/GPL");
61
62 static const char * const iwcm_rej_reason_strs[] = {
63         [ECONNRESET]                    = "reset by remote host",
64         [ECONNREFUSED]                  = "refused by remote application",
65         [ETIMEDOUT]                     = "setup timeout",
66 };
67
68 const char *__attribute_const__ iwcm_reject_msg(int reason)
69 {
70         size_t index;
71
72         /* iWARP uses negative errnos */
73         index = -reason;
74
75         if (index < ARRAY_SIZE(iwcm_rej_reason_strs) &&
76             iwcm_rej_reason_strs[index])
77                 return iwcm_rej_reason_strs[index];
78         else
79                 return "unrecognized reason";
80 }
81 EXPORT_SYMBOL(iwcm_reject_msg);
82
83 static struct ibnl_client_cbs iwcm_nl_cb_table[] = {
84         [RDMA_NL_IWPM_REG_PID] = {.dump = iwpm_register_pid_cb},
85         [RDMA_NL_IWPM_ADD_MAPPING] = {.dump = iwpm_add_mapping_cb},
86         [RDMA_NL_IWPM_QUERY_MAPPING] = {.dump = iwpm_add_and_query_mapping_cb},
87         [RDMA_NL_IWPM_REMOTE_INFO] = {.dump = iwpm_remote_info_cb},
88         [RDMA_NL_IWPM_HANDLE_ERR] = {.dump = iwpm_mapping_error_cb},
89         [RDMA_NL_IWPM_MAPINFO] = {.dump = iwpm_mapping_info_cb},
90         [RDMA_NL_IWPM_MAPINFO_NUM] = {.dump = iwpm_ack_mapping_info_cb}
91 };
92
93 static struct workqueue_struct *iwcm_wq;
94 struct iwcm_work {
95         struct work_struct work;
96         struct iwcm_id_private *cm_id;
97         struct list_head list;
98         struct iw_cm_event event;
99         struct list_head free_list;
100 };
101
102 static unsigned int default_backlog = 256;
103
104 static struct ctl_table_header *iwcm_ctl_table_hdr;
105 static struct ctl_table iwcm_ctl_table[] = {
106         {
107                 .procname       = "default_backlog",
108                 .data           = &default_backlog,
109                 .maxlen         = sizeof(default_backlog),
110                 .mode           = 0644,
111                 .proc_handler   = proc_dointvec,
112         },
113         { }
114 };
115
116 /*
117  * The following services provide a mechanism for pre-allocating iwcm_work
118  * elements.  The design pre-allocates them  based on the cm_id type:
119  *      LISTENING IDS:  Get enough elements preallocated to handle the
120  *                      listen backlog.
121  *      ACTIVE IDS:     4: CONNECT_REPLY, ESTABLISHED, DISCONNECT, CLOSE
122  *      PASSIVE IDS:    3: ESTABLISHED, DISCONNECT, CLOSE
123  *
124  * Allocating them in connect and listen avoids having to deal
125  * with allocation failures on the event upcall from the provider (which
126  * is called in the interrupt context).
127  *
128  * One exception is when creating the cm_id for incoming connection requests.
129  * There are two cases:
130  * 1) in the event upcall, cm_event_handler(), for a listening cm_id.  If
131  *    the backlog is exceeded, then no more connection request events will
132  *    be processed.  cm_event_handler() returns -ENOMEM in this case.  Its up
133  *    to the provider to reject the connection request.
134  * 2) in the connection request workqueue handler, cm_conn_req_handler().
135  *    If work elements cannot be allocated for the new connect request cm_id,
136  *    then IWCM will call the provider reject method.  This is ok since
137  *    cm_conn_req_handler() runs in the workqueue thread context.
138  */
139
140 static struct iwcm_work *get_work(struct iwcm_id_private *cm_id_priv)
141 {
142         struct iwcm_work *work;
143
144         if (list_empty(&cm_id_priv->work_free_list))
145                 return NULL;
146         work = list_entry(cm_id_priv->work_free_list.next, struct iwcm_work,
147                           free_list);
148         list_del_init(&work->free_list);
149         return work;
150 }
151
152 static void put_work(struct iwcm_work *work)
153 {
154         list_add(&work->free_list, &work->cm_id->work_free_list);
155 }
156
157 static void dealloc_work_entries(struct iwcm_id_private *cm_id_priv)
158 {
159         struct list_head *e, *tmp;
160
161         list_for_each_safe(e, tmp, &cm_id_priv->work_free_list)
162                 kfree(list_entry(e, struct iwcm_work, free_list));
163 }
164
165 static int alloc_work_entries(struct iwcm_id_private *cm_id_priv, int count)
166 {
167         struct iwcm_work *work;
168
169         BUG_ON(!list_empty(&cm_id_priv->work_free_list));
170         while (count--) {
171                 work = kmalloc(sizeof(struct iwcm_work), GFP_KERNEL);
172                 if (!work) {
173                         dealloc_work_entries(cm_id_priv);
174                         return -ENOMEM;
175                 }
176                 work->cm_id = cm_id_priv;
177                 INIT_LIST_HEAD(&work->list);
178                 put_work(work);
179         }
180         return 0;
181 }
182
183 /*
184  * Save private data from incoming connection requests to
185  * iw_cm_event, so the low level driver doesn't have to. Adjust
186  * the event ptr to point to the local copy.
187  */
188 static int copy_private_data(struct iw_cm_event *event)
189 {
190         void *p;
191
192         p = kmemdup(event->private_data, event->private_data_len, GFP_ATOMIC);
193         if (!p)
194                 return -ENOMEM;
195         event->private_data = p;
196         return 0;
197 }
198
199 static void free_cm_id(struct iwcm_id_private *cm_id_priv)
200 {
201         dealloc_work_entries(cm_id_priv);
202         kfree(cm_id_priv);
203 }
204
205 /*
206  * Release a reference on cm_id. If the last reference is being
207  * released, free the cm_id and return 1.
208  */
209 static int iwcm_deref_id(struct iwcm_id_private *cm_id_priv)
210 {
211         BUG_ON(atomic_read(&cm_id_priv->refcount)==0);
212         if (atomic_dec_and_test(&cm_id_priv->refcount)) {
213                 BUG_ON(!list_empty(&cm_id_priv->work_list));
214                 free_cm_id(cm_id_priv);
215                 return 1;
216         }
217
218         return 0;
219 }
220
221 static void add_ref(struct iw_cm_id *cm_id)
222 {
223         struct iwcm_id_private *cm_id_priv;
224         cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
225         atomic_inc(&cm_id_priv->refcount);
226 }
227
228 static void rem_ref(struct iw_cm_id *cm_id)
229 {
230         struct iwcm_id_private *cm_id_priv;
231
232         cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
233
234         (void)iwcm_deref_id(cm_id_priv);
235 }
236
237 static int cm_event_handler(struct iw_cm_id *cm_id, struct iw_cm_event *event);
238
239 struct iw_cm_id *iw_create_cm_id(struct ib_device *device,
240                                  iw_cm_handler cm_handler,
241                                  void *context)
242 {
243         struct iwcm_id_private *cm_id_priv;
244
245         cm_id_priv = kzalloc(sizeof(*cm_id_priv), GFP_KERNEL);
246         if (!cm_id_priv)
247                 return ERR_PTR(-ENOMEM);
248
249         cm_id_priv->state = IW_CM_STATE_IDLE;
250         cm_id_priv->id.device = device;
251         cm_id_priv->id.cm_handler = cm_handler;
252         cm_id_priv->id.context = context;
253         cm_id_priv->id.event_handler = cm_event_handler;
254         cm_id_priv->id.add_ref = add_ref;
255         cm_id_priv->id.rem_ref = rem_ref;
256         spin_lock_init(&cm_id_priv->lock);
257         atomic_set(&cm_id_priv->refcount, 1);
258         init_waitqueue_head(&cm_id_priv->connect_wait);
259         init_completion(&cm_id_priv->destroy_comp);
260         INIT_LIST_HEAD(&cm_id_priv->work_list);
261         INIT_LIST_HEAD(&cm_id_priv->work_free_list);
262
263         return &cm_id_priv->id;
264 }
265 EXPORT_SYMBOL(iw_create_cm_id);
266
267
268 static int iwcm_modify_qp_err(struct ib_qp *qp)
269 {
270         struct ib_qp_attr qp_attr;
271
272         if (!qp)
273                 return -EINVAL;
274
275         qp_attr.qp_state = IB_QPS_ERR;
276         return ib_modify_qp(qp, &qp_attr, IB_QP_STATE);
277 }
278
279 /*
280  * This is really the RDMAC CLOSING state. It is most similar to the
281  * IB SQD QP state.
282  */
283 static int iwcm_modify_qp_sqd(struct ib_qp *qp)
284 {
285         struct ib_qp_attr qp_attr;
286
287         BUG_ON(qp == NULL);
288         qp_attr.qp_state = IB_QPS_SQD;
289         return ib_modify_qp(qp, &qp_attr, IB_QP_STATE);
290 }
291
292 /*
293  * CM_ID <-- CLOSING
294  *
295  * Block if a passive or active connection is currently being processed. Then
296  * process the event as follows:
297  * - If we are ESTABLISHED, move to CLOSING and modify the QP state
298  *   based on the abrupt flag
299  * - If the connection is already in the CLOSING or IDLE state, the peer is
300  *   disconnecting concurrently with us and we've already seen the
301  *   DISCONNECT event -- ignore the request and return 0
302  * - Disconnect on a listening endpoint returns -EINVAL
303  */
304 int iw_cm_disconnect(struct iw_cm_id *cm_id, int abrupt)
305 {
306         struct iwcm_id_private *cm_id_priv;
307         unsigned long flags;
308         int ret = 0;
309         struct ib_qp *qp = NULL;
310
311         cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
312         /* Wait if we're currently in a connect or accept downcall */
313         wait_event(cm_id_priv->connect_wait,
314                    !test_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags));
315
316         spin_lock_irqsave(&cm_id_priv->lock, flags);
317         switch (cm_id_priv->state) {
318         case IW_CM_STATE_ESTABLISHED:
319                 cm_id_priv->state = IW_CM_STATE_CLOSING;
320
321                 /* QP could be <nul> for user-mode client */
322                 if (cm_id_priv->qp)
323                         qp = cm_id_priv->qp;
324                 else
325                         ret = -EINVAL;
326                 break;
327         case IW_CM_STATE_LISTEN:
328                 ret = -EINVAL;
329                 break;
330         case IW_CM_STATE_CLOSING:
331                 /* remote peer closed first */
332         case IW_CM_STATE_IDLE:
333                 /* accept or connect returned !0 */
334                 break;
335         case IW_CM_STATE_CONN_RECV:
336                 /*
337                  * App called disconnect before/without calling accept after
338                  * connect_request event delivered.
339                  */
340                 break;
341         case IW_CM_STATE_CONN_SENT:
342                 /* Can only get here if wait above fails */
343         default:
344                 BUG();
345         }
346         spin_unlock_irqrestore(&cm_id_priv->lock, flags);
347
348         if (qp) {
349                 if (abrupt)
350                         ret = iwcm_modify_qp_err(qp);
351                 else
352                         ret = iwcm_modify_qp_sqd(qp);
353
354                 /*
355                  * If both sides are disconnecting the QP could
356                  * already be in ERR or SQD states
357                  */
358                 ret = 0;
359         }
360
361         return ret;
362 }
363 EXPORT_SYMBOL(iw_cm_disconnect);
364
365 /*
366  * CM_ID <-- DESTROYING
367  *
368  * Clean up all resources associated with the connection and release
369  * the initial reference taken by iw_create_cm_id.
370  */
371 static void destroy_cm_id(struct iw_cm_id *cm_id)
372 {
373         struct iwcm_id_private *cm_id_priv;
374         unsigned long flags;
375
376         cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
377         /*
378          * Wait if we're currently in a connect or accept downcall. A
379          * listening endpoint should never block here.
380          */
381         wait_event(cm_id_priv->connect_wait,
382                    !test_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags));
383
384         /*
385          * Since we're deleting the cm_id, drop any events that
386          * might arrive before the last dereference.
387          */
388         set_bit(IWCM_F_DROP_EVENTS, &cm_id_priv->flags);
389
390         spin_lock_irqsave(&cm_id_priv->lock, flags);
391         switch (cm_id_priv->state) {
392         case IW_CM_STATE_LISTEN:
393                 cm_id_priv->state = IW_CM_STATE_DESTROYING;
394                 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
395                 /* destroy the listening endpoint */
396                 cm_id->device->iwcm->destroy_listen(cm_id);
397                 spin_lock_irqsave(&cm_id_priv->lock, flags);
398                 break;
399         case IW_CM_STATE_ESTABLISHED:
400                 cm_id_priv->state = IW_CM_STATE_DESTROYING;
401                 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
402                 /* Abrupt close of the connection */
403                 (void)iwcm_modify_qp_err(cm_id_priv->qp);
404                 spin_lock_irqsave(&cm_id_priv->lock, flags);
405                 break;
406         case IW_CM_STATE_IDLE:
407         case IW_CM_STATE_CLOSING:
408                 cm_id_priv->state = IW_CM_STATE_DESTROYING;
409                 break;
410         case IW_CM_STATE_CONN_RECV:
411                 /*
412                  * App called destroy before/without calling accept after
413                  * receiving connection request event notification or
414                  * returned non zero from the event callback function.
415                  * In either case, must tell the provider to reject.
416                  */
417                 cm_id_priv->state = IW_CM_STATE_DESTROYING;
418                 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
419                 cm_id->device->iwcm->reject(cm_id, NULL, 0);
420                 spin_lock_irqsave(&cm_id_priv->lock, flags);
421                 break;
422         case IW_CM_STATE_CONN_SENT:
423         case IW_CM_STATE_DESTROYING:
424         default:
425                 BUG();
426                 break;
427         }
428         if (cm_id_priv->qp) {
429                 cm_id_priv->id.device->iwcm->rem_ref(cm_id_priv->qp);
430                 cm_id_priv->qp = NULL;
431         }
432         spin_unlock_irqrestore(&cm_id_priv->lock, flags);
433
434         if (cm_id->mapped) {
435                 iwpm_remove_mapinfo(&cm_id->local_addr, &cm_id->m_local_addr);
436                 iwpm_remove_mapping(&cm_id->local_addr, RDMA_NL_IWCM);
437         }
438
439         (void)iwcm_deref_id(cm_id_priv);
440 }
441
442 /*
443  * This function is only called by the application thread and cannot
444  * be called by the event thread. The function will wait for all
445  * references to be released on the cm_id and then kfree the cm_id
446  * object.
447  */
448 void iw_destroy_cm_id(struct iw_cm_id *cm_id)
449 {
450         struct iwcm_id_private *cm_id_priv;
451
452         cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
453         destroy_cm_id(cm_id);
454 }
455 EXPORT_SYMBOL(iw_destroy_cm_id);
456
457 /**
458  * iw_cm_check_wildcard - If IP address is 0 then use original
459  * @pm_addr: sockaddr containing the ip to check for wildcard
460  * @cm_addr: sockaddr containing the actual IP address
461  * @cm_outaddr: sockaddr to set IP addr which leaving port
462  *
463  *  Checks the pm_addr for wildcard and then sets cm_outaddr's
464  *  IP to the actual (cm_addr).
465  */
466 static void iw_cm_check_wildcard(struct sockaddr_storage *pm_addr,
467                                  struct sockaddr_storage *cm_addr,
468                                  struct sockaddr_storage *cm_outaddr)
469 {
470         if (pm_addr->ss_family == AF_INET) {
471                 struct sockaddr_in *pm4_addr = (struct sockaddr_in *)pm_addr;
472
473                 if (pm4_addr->sin_addr.s_addr == htonl(INADDR_ANY)) {
474                         struct sockaddr_in *cm4_addr =
475                                 (struct sockaddr_in *)cm_addr;
476                         struct sockaddr_in *cm4_outaddr =
477                                 (struct sockaddr_in *)cm_outaddr;
478
479                         cm4_outaddr->sin_addr = cm4_addr->sin_addr;
480                 }
481         } else {
482                 struct sockaddr_in6 *pm6_addr = (struct sockaddr_in6 *)pm_addr;
483
484                 if (ipv6_addr_type(&pm6_addr->sin6_addr) == IPV6_ADDR_ANY) {
485                         struct sockaddr_in6 *cm6_addr =
486                                 (struct sockaddr_in6 *)cm_addr;
487                         struct sockaddr_in6 *cm6_outaddr =
488                                 (struct sockaddr_in6 *)cm_outaddr;
489
490                         cm6_outaddr->sin6_addr = cm6_addr->sin6_addr;
491                 }
492         }
493 }
494
495 /**
496  * iw_cm_map - Use portmapper to map the ports
497  * @cm_id: connection manager pointer
498  * @active: Indicates the active side when true
499  * returns nonzero for error only if iwpm_create_mapinfo() fails
500  *
501  * Tries to add a mapping for a port using the Portmapper. If
502  * successful in mapping the IP/Port it will check the remote
503  * mapped IP address for a wildcard IP address and replace the
504  * zero IP address with the remote_addr.
505  */
506 static int iw_cm_map(struct iw_cm_id *cm_id, bool active)
507 {
508         struct iwpm_dev_data pm_reg_msg;
509         struct iwpm_sa_data pm_msg;
510         int status;
511
512         cm_id->m_local_addr = cm_id->local_addr;
513         cm_id->m_remote_addr = cm_id->remote_addr;
514
515         memcpy(pm_reg_msg.dev_name, cm_id->device->name,
516                sizeof(pm_reg_msg.dev_name));
517         memcpy(pm_reg_msg.if_name, cm_id->device->iwcm->ifname,
518                sizeof(pm_reg_msg.if_name));
519
520         if (iwpm_register_pid(&pm_reg_msg, RDMA_NL_IWCM) ||
521             !iwpm_valid_pid())
522                 return 0;
523
524         cm_id->mapped = true;
525         pm_msg.loc_addr = cm_id->local_addr;
526         pm_msg.rem_addr = cm_id->remote_addr;
527         if (active)
528                 status = iwpm_add_and_query_mapping(&pm_msg,
529                                                     RDMA_NL_IWCM);
530         else
531                 status = iwpm_add_mapping(&pm_msg, RDMA_NL_IWCM);
532
533         if (!status) {
534                 cm_id->m_local_addr = pm_msg.mapped_loc_addr;
535                 if (active) {
536                         cm_id->m_remote_addr = pm_msg.mapped_rem_addr;
537                         iw_cm_check_wildcard(&pm_msg.mapped_rem_addr,
538                                              &cm_id->remote_addr,
539                                              &cm_id->m_remote_addr);
540                 }
541         }
542
543         return iwpm_create_mapinfo(&cm_id->local_addr,
544                                    &cm_id->m_local_addr,
545                                    RDMA_NL_IWCM);
546 }
547
548 /*
549  * CM_ID <-- LISTEN
550  *
551  * Start listening for connect requests. Generates one CONNECT_REQUEST
552  * event for each inbound connect request.
553  */
554 int iw_cm_listen(struct iw_cm_id *cm_id, int backlog)
555 {
556         struct iwcm_id_private *cm_id_priv;
557         unsigned long flags;
558         int ret;
559
560         cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
561
562         if (!backlog)
563                 backlog = default_backlog;
564
565         ret = alloc_work_entries(cm_id_priv, backlog);
566         if (ret)
567                 return ret;
568
569         spin_lock_irqsave(&cm_id_priv->lock, flags);
570         switch (cm_id_priv->state) {
571         case IW_CM_STATE_IDLE:
572                 cm_id_priv->state = IW_CM_STATE_LISTEN;
573                 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
574                 ret = iw_cm_map(cm_id, false);
575                 if (!ret)
576                         ret = cm_id->device->iwcm->create_listen(cm_id, backlog);
577                 if (ret)
578                         cm_id_priv->state = IW_CM_STATE_IDLE;
579                 spin_lock_irqsave(&cm_id_priv->lock, flags);
580                 break;
581         default:
582                 ret = -EINVAL;
583         }
584         spin_unlock_irqrestore(&cm_id_priv->lock, flags);
585
586         return ret;
587 }
588 EXPORT_SYMBOL(iw_cm_listen);
589
590 /*
591  * CM_ID <-- IDLE
592  *
593  * Rejects an inbound connection request. No events are generated.
594  */
595 int iw_cm_reject(struct iw_cm_id *cm_id,
596                  const void *private_data,
597                  u8 private_data_len)
598 {
599         struct iwcm_id_private *cm_id_priv;
600         unsigned long flags;
601         int ret;
602
603         cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
604         set_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
605
606         spin_lock_irqsave(&cm_id_priv->lock, flags);
607         if (cm_id_priv->state != IW_CM_STATE_CONN_RECV) {
608                 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
609                 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
610                 wake_up_all(&cm_id_priv->connect_wait);
611                 return -EINVAL;
612         }
613         cm_id_priv->state = IW_CM_STATE_IDLE;
614         spin_unlock_irqrestore(&cm_id_priv->lock, flags);
615
616         ret = cm_id->device->iwcm->reject(cm_id, private_data,
617                                           private_data_len);
618
619         clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
620         wake_up_all(&cm_id_priv->connect_wait);
621
622         return ret;
623 }
624 EXPORT_SYMBOL(iw_cm_reject);
625
626 /*
627  * CM_ID <-- ESTABLISHED
628  *
629  * Accepts an inbound connection request and generates an ESTABLISHED
630  * event. Callers of iw_cm_disconnect and iw_destroy_cm_id will block
631  * until the ESTABLISHED event is received from the provider.
632  */
633 int iw_cm_accept(struct iw_cm_id *cm_id,
634                  struct iw_cm_conn_param *iw_param)
635 {
636         struct iwcm_id_private *cm_id_priv;
637         struct ib_qp *qp;
638         unsigned long flags;
639         int ret;
640
641         cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
642         set_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
643
644         spin_lock_irqsave(&cm_id_priv->lock, flags);
645         if (cm_id_priv->state != IW_CM_STATE_CONN_RECV) {
646                 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
647                 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
648                 wake_up_all(&cm_id_priv->connect_wait);
649                 return -EINVAL;
650         }
651         /* Get the ib_qp given the QPN */
652         qp = cm_id->device->iwcm->get_qp(cm_id->device, iw_param->qpn);
653         if (!qp) {
654                 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
655                 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
656                 wake_up_all(&cm_id_priv->connect_wait);
657                 return -EINVAL;
658         }
659         cm_id->device->iwcm->add_ref(qp);
660         cm_id_priv->qp = qp;
661         spin_unlock_irqrestore(&cm_id_priv->lock, flags);
662
663         ret = cm_id->device->iwcm->accept(cm_id, iw_param);
664         if (ret) {
665                 /* An error on accept precludes provider events */
666                 BUG_ON(cm_id_priv->state != IW_CM_STATE_CONN_RECV);
667                 cm_id_priv->state = IW_CM_STATE_IDLE;
668                 spin_lock_irqsave(&cm_id_priv->lock, flags);
669                 if (cm_id_priv->qp) {
670                         cm_id->device->iwcm->rem_ref(qp);
671                         cm_id_priv->qp = NULL;
672                 }
673                 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
674                 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
675                 wake_up_all(&cm_id_priv->connect_wait);
676         }
677
678         return ret;
679 }
680 EXPORT_SYMBOL(iw_cm_accept);
681
682 /*
683  * Active Side: CM_ID <-- CONN_SENT
684  *
685  * If successful, results in the generation of a CONNECT_REPLY
686  * event. iw_cm_disconnect and iw_cm_destroy will block until the
687  * CONNECT_REPLY event is received from the provider.
688  */
689 int iw_cm_connect(struct iw_cm_id *cm_id, struct iw_cm_conn_param *iw_param)
690 {
691         struct iwcm_id_private *cm_id_priv;
692         int ret;
693         unsigned long flags;
694         struct ib_qp *qp;
695
696         cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
697
698         ret = alloc_work_entries(cm_id_priv, 4);
699         if (ret)
700                 return ret;
701
702         set_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
703         spin_lock_irqsave(&cm_id_priv->lock, flags);
704
705         if (cm_id_priv->state != IW_CM_STATE_IDLE) {
706                 ret = -EINVAL;
707                 goto err;
708         }
709
710         /* Get the ib_qp given the QPN */
711         qp = cm_id->device->iwcm->get_qp(cm_id->device, iw_param->qpn);
712         if (!qp) {
713                 ret = -EINVAL;
714                 goto err;
715         }
716         cm_id->device->iwcm->add_ref(qp);
717         cm_id_priv->qp = qp;
718         cm_id_priv->state = IW_CM_STATE_CONN_SENT;
719         spin_unlock_irqrestore(&cm_id_priv->lock, flags);
720
721         ret = iw_cm_map(cm_id, true);
722         if (!ret)
723                 ret = cm_id->device->iwcm->connect(cm_id, iw_param);
724         if (!ret)
725                 return 0;       /* success */
726
727         spin_lock_irqsave(&cm_id_priv->lock, flags);
728         if (cm_id_priv->qp) {
729                 cm_id->device->iwcm->rem_ref(qp);
730                 cm_id_priv->qp = NULL;
731         }
732         cm_id_priv->state = IW_CM_STATE_IDLE;
733 err:
734         spin_unlock_irqrestore(&cm_id_priv->lock, flags);
735         clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
736         wake_up_all(&cm_id_priv->connect_wait);
737         return ret;
738 }
739 EXPORT_SYMBOL(iw_cm_connect);
740
741 /*
742  * Passive Side: new CM_ID <-- CONN_RECV
743  *
744  * Handles an inbound connect request. The function creates a new
745  * iw_cm_id to represent the new connection and inherits the client
746  * callback function and other attributes from the listening parent.
747  *
748  * The work item contains a pointer to the listen_cm_id and the event. The
749  * listen_cm_id contains the client cm_handler, context and
750  * device. These are copied when the device is cloned. The event
751  * contains the new four tuple.
752  *
753  * An error on the child should not affect the parent, so this
754  * function does not return a value.
755  */
756 static void cm_conn_req_handler(struct iwcm_id_private *listen_id_priv,
757                                 struct iw_cm_event *iw_event)
758 {
759         unsigned long flags;
760         struct iw_cm_id *cm_id;
761         struct iwcm_id_private *cm_id_priv;
762         int ret;
763
764         /*
765          * The provider should never generate a connection request
766          * event with a bad status.
767          */
768         BUG_ON(iw_event->status);
769
770         cm_id = iw_create_cm_id(listen_id_priv->id.device,
771                                 listen_id_priv->id.cm_handler,
772                                 listen_id_priv->id.context);
773         /* If the cm_id could not be created, ignore the request */
774         if (IS_ERR(cm_id))
775                 goto out;
776
777         cm_id->provider_data = iw_event->provider_data;
778         cm_id->m_local_addr = iw_event->local_addr;
779         cm_id->m_remote_addr = iw_event->remote_addr;
780         cm_id->local_addr = listen_id_priv->id.local_addr;
781
782         ret = iwpm_get_remote_info(&listen_id_priv->id.m_local_addr,
783                                    &iw_event->remote_addr,
784                                    &cm_id->remote_addr,
785                                    RDMA_NL_IWCM);
786         if (ret) {
787                 cm_id->remote_addr = iw_event->remote_addr;
788         } else {
789                 iw_cm_check_wildcard(&listen_id_priv->id.m_local_addr,
790                                      &iw_event->local_addr,
791                                      &cm_id->local_addr);
792                 iw_event->local_addr = cm_id->local_addr;
793                 iw_event->remote_addr = cm_id->remote_addr;
794         }
795
796         cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
797         cm_id_priv->state = IW_CM_STATE_CONN_RECV;
798
799         /*
800          * We could be destroying the listening id. If so, ignore this
801          * upcall.
802          */
803         spin_lock_irqsave(&listen_id_priv->lock, flags);
804         if (listen_id_priv->state != IW_CM_STATE_LISTEN) {
805                 spin_unlock_irqrestore(&listen_id_priv->lock, flags);
806                 iw_cm_reject(cm_id, NULL, 0);
807                 iw_destroy_cm_id(cm_id);
808                 goto out;
809         }
810         spin_unlock_irqrestore(&listen_id_priv->lock, flags);
811
812         ret = alloc_work_entries(cm_id_priv, 3);
813         if (ret) {
814                 iw_cm_reject(cm_id, NULL, 0);
815                 iw_destroy_cm_id(cm_id);
816                 goto out;
817         }
818
819         /* Call the client CM handler */
820         ret = cm_id->cm_handler(cm_id, iw_event);
821         if (ret) {
822                 iw_cm_reject(cm_id, NULL, 0);
823                 iw_destroy_cm_id(cm_id);
824         }
825
826 out:
827         if (iw_event->private_data_len)
828                 kfree(iw_event->private_data);
829 }
830
831 /*
832  * Passive Side: CM_ID <-- ESTABLISHED
833  *
834  * The provider generated an ESTABLISHED event which means that
835  * the MPA negotion has completed successfully and we are now in MPA
836  * FPDU mode.
837  *
838  * This event can only be received in the CONN_RECV state. If the
839  * remote peer closed, the ESTABLISHED event would be received followed
840  * by the CLOSE event. If the app closes, it will block until we wake
841  * it up after processing this event.
842  */
843 static int cm_conn_est_handler(struct iwcm_id_private *cm_id_priv,
844                                struct iw_cm_event *iw_event)
845 {
846         unsigned long flags;
847         int ret;
848
849         spin_lock_irqsave(&cm_id_priv->lock, flags);
850
851         /*
852          * We clear the CONNECT_WAIT bit here to allow the callback
853          * function to call iw_cm_disconnect. Calling iw_destroy_cm_id
854          * from a callback handler is not allowed.
855          */
856         clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
857         BUG_ON(cm_id_priv->state != IW_CM_STATE_CONN_RECV);
858         cm_id_priv->state = IW_CM_STATE_ESTABLISHED;
859         spin_unlock_irqrestore(&cm_id_priv->lock, flags);
860         ret = cm_id_priv->id.cm_handler(&cm_id_priv->id, iw_event);
861         wake_up_all(&cm_id_priv->connect_wait);
862
863         return ret;
864 }
865
866 /*
867  * Active Side: CM_ID <-- ESTABLISHED
868  *
869  * The app has called connect and is waiting for the established event to
870  * post it's requests to the server. This event will wake up anyone
871  * blocked in iw_cm_disconnect or iw_destroy_id.
872  */
873 static int cm_conn_rep_handler(struct iwcm_id_private *cm_id_priv,
874                                struct iw_cm_event *iw_event)
875 {
876         unsigned long flags;
877         int ret;
878
879         spin_lock_irqsave(&cm_id_priv->lock, flags);
880         /*
881          * Clear the connect wait bit so a callback function calling
882          * iw_cm_disconnect will not wait and deadlock this thread
883          */
884         clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
885         BUG_ON(cm_id_priv->state != IW_CM_STATE_CONN_SENT);
886         if (iw_event->status == 0) {
887                 cm_id_priv->id.m_local_addr = iw_event->local_addr;
888                 cm_id_priv->id.m_remote_addr = iw_event->remote_addr;
889                 iw_event->local_addr = cm_id_priv->id.local_addr;
890                 iw_event->remote_addr = cm_id_priv->id.remote_addr;
891                 cm_id_priv->state = IW_CM_STATE_ESTABLISHED;
892         } else {
893                 /* REJECTED or RESET */
894                 cm_id_priv->id.device->iwcm->rem_ref(cm_id_priv->qp);
895                 cm_id_priv->qp = NULL;
896                 cm_id_priv->state = IW_CM_STATE_IDLE;
897         }
898         spin_unlock_irqrestore(&cm_id_priv->lock, flags);
899         ret = cm_id_priv->id.cm_handler(&cm_id_priv->id, iw_event);
900
901         if (iw_event->private_data_len)
902                 kfree(iw_event->private_data);
903
904         /* Wake up waiters on connect complete */
905         wake_up_all(&cm_id_priv->connect_wait);
906
907         return ret;
908 }
909
910 /*
911  * CM_ID <-- CLOSING
912  *
913  * If in the ESTABLISHED state, move to CLOSING.
914  */
915 static void cm_disconnect_handler(struct iwcm_id_private *cm_id_priv,
916                                   struct iw_cm_event *iw_event)
917 {
918         unsigned long flags;
919
920         spin_lock_irqsave(&cm_id_priv->lock, flags);
921         if (cm_id_priv->state == IW_CM_STATE_ESTABLISHED)
922                 cm_id_priv->state = IW_CM_STATE_CLOSING;
923         spin_unlock_irqrestore(&cm_id_priv->lock, flags);
924 }
925
926 /*
927  * CM_ID <-- IDLE
928  *
929  * If in the ESTBLISHED or CLOSING states, the QP will have have been
930  * moved by the provider to the ERR state. Disassociate the CM_ID from
931  * the QP,  move to IDLE, and remove the 'connected' reference.
932  *
933  * If in some other state, the cm_id was destroyed asynchronously.
934  * This is the last reference that will result in waking up
935  * the app thread blocked in iw_destroy_cm_id.
936  */
937 static int cm_close_handler(struct iwcm_id_private *cm_id_priv,
938                                   struct iw_cm_event *iw_event)
939 {
940         unsigned long flags;
941         int ret = 0;
942         spin_lock_irqsave(&cm_id_priv->lock, flags);
943
944         if (cm_id_priv->qp) {
945                 cm_id_priv->id.device->iwcm->rem_ref(cm_id_priv->qp);
946                 cm_id_priv->qp = NULL;
947         }
948         switch (cm_id_priv->state) {
949         case IW_CM_STATE_ESTABLISHED:
950         case IW_CM_STATE_CLOSING:
951                 cm_id_priv->state = IW_CM_STATE_IDLE;
952                 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
953                 ret = cm_id_priv->id.cm_handler(&cm_id_priv->id, iw_event);
954                 spin_lock_irqsave(&cm_id_priv->lock, flags);
955                 break;
956         case IW_CM_STATE_DESTROYING:
957                 break;
958         default:
959                 BUG();
960         }
961         spin_unlock_irqrestore(&cm_id_priv->lock, flags);
962
963         return ret;
964 }
965
966 static int process_event(struct iwcm_id_private *cm_id_priv,
967                          struct iw_cm_event *iw_event)
968 {
969         int ret = 0;
970
971         switch (iw_event->event) {
972         case IW_CM_EVENT_CONNECT_REQUEST:
973                 cm_conn_req_handler(cm_id_priv, iw_event);
974                 break;
975         case IW_CM_EVENT_CONNECT_REPLY:
976                 ret = cm_conn_rep_handler(cm_id_priv, iw_event);
977                 break;
978         case IW_CM_EVENT_ESTABLISHED:
979                 ret = cm_conn_est_handler(cm_id_priv, iw_event);
980                 break;
981         case IW_CM_EVENT_DISCONNECT:
982                 cm_disconnect_handler(cm_id_priv, iw_event);
983                 break;
984         case IW_CM_EVENT_CLOSE:
985                 ret = cm_close_handler(cm_id_priv, iw_event);
986                 break;
987         default:
988                 BUG();
989         }
990
991         return ret;
992 }
993
994 /*
995  * Process events on the work_list for the cm_id. If the callback
996  * function requests that the cm_id be deleted, a flag is set in the
997  * cm_id flags to indicate that when the last reference is
998  * removed, the cm_id is to be destroyed. This is necessary to
999  * distinguish between an object that will be destroyed by the app
1000  * thread asleep on the destroy_comp list vs. an object destroyed
1001  * here synchronously when the last reference is removed.
1002  */
1003 static void cm_work_handler(struct work_struct *_work)
1004 {
1005         struct iwcm_work *work = container_of(_work, struct iwcm_work, work);
1006         struct iw_cm_event levent;
1007         struct iwcm_id_private *cm_id_priv = work->cm_id;
1008         unsigned long flags;
1009         int empty;
1010         int ret = 0;
1011
1012         spin_lock_irqsave(&cm_id_priv->lock, flags);
1013         empty = list_empty(&cm_id_priv->work_list);
1014         while (!empty) {
1015                 work = list_entry(cm_id_priv->work_list.next,
1016                                   struct iwcm_work, list);
1017                 list_del_init(&work->list);
1018                 empty = list_empty(&cm_id_priv->work_list);
1019                 levent = work->event;
1020                 put_work(work);
1021                 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
1022
1023                 if (!test_bit(IWCM_F_DROP_EVENTS, &cm_id_priv->flags)) {
1024                         ret = process_event(cm_id_priv, &levent);
1025                         if (ret)
1026                                 destroy_cm_id(&cm_id_priv->id);
1027                 } else
1028                         pr_debug("dropping event %d\n", levent.event);
1029                 if (iwcm_deref_id(cm_id_priv))
1030                         return;
1031                 if (empty)
1032                         return;
1033                 spin_lock_irqsave(&cm_id_priv->lock, flags);
1034         }
1035         spin_unlock_irqrestore(&cm_id_priv->lock, flags);
1036 }
1037
1038 /*
1039  * This function is called on interrupt context. Schedule events on
1040  * the iwcm_wq thread to allow callback functions to downcall into
1041  * the CM and/or block.  Events are queued to a per-CM_ID
1042  * work_list. If this is the first event on the work_list, the work
1043  * element is also queued on the iwcm_wq thread.
1044  *
1045  * Each event holds a reference on the cm_id. Until the last posted
1046  * event has been delivered and processed, the cm_id cannot be
1047  * deleted.
1048  *
1049  * Returns:
1050  *            0 - the event was handled.
1051  *      -ENOMEM - the event was not handled due to lack of resources.
1052  */
1053 static int cm_event_handler(struct iw_cm_id *cm_id,
1054                              struct iw_cm_event *iw_event)
1055 {
1056         struct iwcm_work *work;
1057         struct iwcm_id_private *cm_id_priv;
1058         unsigned long flags;
1059         int ret = 0;
1060
1061         cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
1062
1063         spin_lock_irqsave(&cm_id_priv->lock, flags);
1064         work = get_work(cm_id_priv);
1065         if (!work) {
1066                 ret = -ENOMEM;
1067                 goto out;
1068         }
1069
1070         INIT_WORK(&work->work, cm_work_handler);
1071         work->cm_id = cm_id_priv;
1072         work->event = *iw_event;
1073
1074         if ((work->event.event == IW_CM_EVENT_CONNECT_REQUEST ||
1075              work->event.event == IW_CM_EVENT_CONNECT_REPLY) &&
1076             work->event.private_data_len) {
1077                 ret = copy_private_data(&work->event);
1078                 if (ret) {
1079                         put_work(work);
1080                         goto out;
1081                 }
1082         }
1083
1084         atomic_inc(&cm_id_priv->refcount);
1085         if (list_empty(&cm_id_priv->work_list)) {
1086                 list_add_tail(&work->list, &cm_id_priv->work_list);
1087                 queue_work(iwcm_wq, &work->work);
1088         } else
1089                 list_add_tail(&work->list, &cm_id_priv->work_list);
1090 out:
1091         spin_unlock_irqrestore(&cm_id_priv->lock, flags);
1092         return ret;
1093 }
1094
1095 static int iwcm_init_qp_init_attr(struct iwcm_id_private *cm_id_priv,
1096                                   struct ib_qp_attr *qp_attr,
1097                                   int *qp_attr_mask)
1098 {
1099         unsigned long flags;
1100         int ret;
1101
1102         spin_lock_irqsave(&cm_id_priv->lock, flags);
1103         switch (cm_id_priv->state) {
1104         case IW_CM_STATE_IDLE:
1105         case IW_CM_STATE_CONN_SENT:
1106         case IW_CM_STATE_CONN_RECV:
1107         case IW_CM_STATE_ESTABLISHED:
1108                 *qp_attr_mask = IB_QP_STATE | IB_QP_ACCESS_FLAGS;
1109                 qp_attr->qp_access_flags = IB_ACCESS_REMOTE_WRITE|
1110                                            IB_ACCESS_REMOTE_READ;
1111                 ret = 0;
1112                 break;
1113         default:
1114                 ret = -EINVAL;
1115                 break;
1116         }
1117         spin_unlock_irqrestore(&cm_id_priv->lock, flags);
1118         return ret;
1119 }
1120
1121 static int iwcm_init_qp_rts_attr(struct iwcm_id_private *cm_id_priv,
1122                                   struct ib_qp_attr *qp_attr,
1123                                   int *qp_attr_mask)
1124 {
1125         unsigned long flags;
1126         int ret;
1127
1128         spin_lock_irqsave(&cm_id_priv->lock, flags);
1129         switch (cm_id_priv->state) {
1130         case IW_CM_STATE_IDLE:
1131         case IW_CM_STATE_CONN_SENT:
1132         case IW_CM_STATE_CONN_RECV:
1133         case IW_CM_STATE_ESTABLISHED:
1134                 *qp_attr_mask = 0;
1135                 ret = 0;
1136                 break;
1137         default:
1138                 ret = -EINVAL;
1139                 break;
1140         }
1141         spin_unlock_irqrestore(&cm_id_priv->lock, flags);
1142         return ret;
1143 }
1144
1145 int iw_cm_init_qp_attr(struct iw_cm_id *cm_id,
1146                        struct ib_qp_attr *qp_attr,
1147                        int *qp_attr_mask)
1148 {
1149         struct iwcm_id_private *cm_id_priv;
1150         int ret;
1151
1152         cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
1153         switch (qp_attr->qp_state) {
1154         case IB_QPS_INIT:
1155         case IB_QPS_RTR:
1156                 ret = iwcm_init_qp_init_attr(cm_id_priv,
1157                                              qp_attr, qp_attr_mask);
1158                 break;
1159         case IB_QPS_RTS:
1160                 ret = iwcm_init_qp_rts_attr(cm_id_priv,
1161                                             qp_attr, qp_attr_mask);
1162                 break;
1163         default:
1164                 ret = -EINVAL;
1165                 break;
1166         }
1167         return ret;
1168 }
1169 EXPORT_SYMBOL(iw_cm_init_qp_attr);
1170
1171 static int __init iw_cm_init(void)
1172 {
1173         int ret;
1174
1175         ret = iwpm_init(RDMA_NL_IWCM);
1176         if (ret)
1177                 pr_err("iw_cm: couldn't init iwpm\n");
1178
1179         ret = ibnl_add_client(RDMA_NL_IWCM, ARRAY_SIZE(iwcm_nl_cb_table),
1180                               iwcm_nl_cb_table);
1181         if (ret)
1182                 pr_err("iw_cm: couldn't register netlink callbacks\n");
1183
1184         iwcm_wq = alloc_ordered_workqueue("iw_cm_wq", WQ_MEM_RECLAIM);
1185         if (!iwcm_wq)
1186                 return -ENOMEM;
1187
1188         iwcm_ctl_table_hdr = register_net_sysctl(&init_net, "net/iw_cm",
1189                                                  iwcm_ctl_table);
1190         if (!iwcm_ctl_table_hdr) {
1191                 pr_err("iw_cm: couldn't register sysctl paths\n");
1192                 destroy_workqueue(iwcm_wq);
1193                 return -ENOMEM;
1194         }
1195
1196         return 0;
1197 }
1198
1199 static void __exit iw_cm_cleanup(void)
1200 {
1201         unregister_net_sysctl_table(iwcm_ctl_table_hdr);
1202         destroy_workqueue(iwcm_wq);
1203         ibnl_remove_client(RDMA_NL_IWCM);
1204         iwpm_exit(RDMA_NL_IWCM);
1205 }
1206
1207 module_init(iw_cm_init);
1208 module_exit(iw_cm_cleanup);