blob: 8f9509e1ebf76494217b7d48f6b7bdef307ac3b4 [file] [log] [blame]
Tom Tucker922a8e92006-08-03 16:02:40 -05001/*
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>
Tom Tucker922a8e92006-08-03 16:02:40 -050042#include <linux/rbtree.h>
43#include <linux/spinlock.h>
44#include <linux/workqueue.h>
45#include <linux/completion.h>
46
47#include <rdma/iw_cm.h>
48#include <rdma/ib_addr.h>
49
50#include "iwcm.h"
51
52MODULE_AUTHOR("Tom Tucker");
53MODULE_DESCRIPTION("iWARP CM");
54MODULE_LICENSE("Dual BSD/GPL");
55
56static struct workqueue_struct *iwcm_wq;
57struct iwcm_work {
58 struct work_struct work;
59 struct iwcm_id_private *cm_id;
60 struct list_head list;
61 struct iw_cm_event event;
62 struct list_head free_list;
63};
64
65/*
66 * The following services provide a mechanism for pre-allocating iwcm_work
67 * elements. The design pre-allocates them based on the cm_id type:
68 * LISTENING IDS: Get enough elements preallocated to handle the
69 * listen backlog.
70 * ACTIVE IDS: 4: CONNECT_REPLY, ESTABLISHED, DISCONNECT, CLOSE
71 * PASSIVE IDS: 3: ESTABLISHED, DISCONNECT, CLOSE
72 *
73 * Allocating them in connect and listen avoids having to deal
74 * with allocation failures on the event upcall from the provider (which
75 * is called in the interrupt context).
76 *
77 * One exception is when creating the cm_id for incoming connection requests.
78 * There are two cases:
79 * 1) in the event upcall, cm_event_handler(), for a listening cm_id. If
80 * the backlog is exceeded, then no more connection request events will
81 * be processed. cm_event_handler() returns -ENOMEM in this case. Its up
Krishna Kumar715a5882006-11-09 09:30:45 +053082 * to the provider to reject the connection request.
Tom Tucker922a8e92006-08-03 16:02:40 -050083 * 2) in the connection request workqueue handler, cm_conn_req_handler().
84 * If work elements cannot be allocated for the new connect request cm_id,
85 * then IWCM will call the provider reject method. This is ok since
86 * cm_conn_req_handler() runs in the workqueue thread context.
87 */
88
89static struct iwcm_work *get_work(struct iwcm_id_private *cm_id_priv)
90{
91 struct iwcm_work *work;
92
93 if (list_empty(&cm_id_priv->work_free_list))
94 return NULL;
95 work = list_entry(cm_id_priv->work_free_list.next, struct iwcm_work,
96 free_list);
97 list_del_init(&work->free_list);
98 return work;
99}
100
101static void put_work(struct iwcm_work *work)
102{
103 list_add(&work->free_list, &work->cm_id->work_free_list);
104}
105
106static void dealloc_work_entries(struct iwcm_id_private *cm_id_priv)
107{
108 struct list_head *e, *tmp;
109
110 list_for_each_safe(e, tmp, &cm_id_priv->work_free_list)
111 kfree(list_entry(e, struct iwcm_work, free_list));
112}
113
114static int alloc_work_entries(struct iwcm_id_private *cm_id_priv, int count)
115{
116 struct iwcm_work *work;
117
118 BUG_ON(!list_empty(&cm_id_priv->work_free_list));
119 while (count--) {
120 work = kmalloc(sizeof(struct iwcm_work), GFP_KERNEL);
121 if (!work) {
122 dealloc_work_entries(cm_id_priv);
123 return -ENOMEM;
124 }
125 work->cm_id = cm_id_priv;
126 INIT_LIST_HEAD(&work->list);
127 put_work(work);
128 }
129 return 0;
130}
131
132/*
Krishna Kumar715a5882006-11-09 09:30:45 +0530133 * Save private data from incoming connection requests to
134 * iw_cm_event, so the low level driver doesn't have to. Adjust
Tom Tucker922a8e92006-08-03 16:02:40 -0500135 * the event ptr to point to the local copy.
136 */
Krishna Kumar715a5882006-11-09 09:30:45 +0530137static int copy_private_data(struct iw_cm_event *event)
Tom Tucker922a8e92006-08-03 16:02:40 -0500138{
139 void *p;
140
Eric Sesterhennbed8bdf2006-10-23 22:17:21 +0200141 p = kmemdup(event->private_data, event->private_data_len, GFP_ATOMIC);
Tom Tucker922a8e92006-08-03 16:02:40 -0500142 if (!p)
143 return -ENOMEM;
Tom Tucker922a8e92006-08-03 16:02:40 -0500144 event->private_data = p;
145 return 0;
146}
147
Steve Wiseebb90982007-02-15 08:09:36 -0600148static void free_cm_id(struct iwcm_id_private *cm_id_priv)
149{
150 dealloc_work_entries(cm_id_priv);
151 kfree(cm_id_priv);
152}
153
Tom Tucker922a8e92006-08-03 16:02:40 -0500154/*
Krishna Kumar9ab1ffa2006-11-09 09:30:48 +0530155 * Release a reference on cm_id. If the last reference is being
156 * released, enable the waiting thread (in iw_destroy_cm_id) to
157 * get woken up, and return 1 if a thread is already waiting.
Tom Tucker922a8e92006-08-03 16:02:40 -0500158 */
159static int iwcm_deref_id(struct iwcm_id_private *cm_id_priv)
160{
Tom Tucker922a8e92006-08-03 16:02:40 -0500161 BUG_ON(atomic_read(&cm_id_priv->refcount)==0);
162 if (atomic_dec_and_test(&cm_id_priv->refcount)) {
163 BUG_ON(!list_empty(&cm_id_priv->work_list));
Tom Tucker922a8e92006-08-03 16:02:40 -0500164 complete(&cm_id_priv->destroy_comp);
Steve Wiseebb90982007-02-15 08:09:36 -0600165 return 1;
Tom Tucker922a8e92006-08-03 16:02:40 -0500166 }
167
Steve Wiseebb90982007-02-15 08:09:36 -0600168 return 0;
Tom Tucker922a8e92006-08-03 16:02:40 -0500169}
170
171static void add_ref(struct iw_cm_id *cm_id)
172{
173 struct iwcm_id_private *cm_id_priv;
174 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
175 atomic_inc(&cm_id_priv->refcount);
176}
177
178static void rem_ref(struct iw_cm_id *cm_id)
179{
180 struct iwcm_id_private *cm_id_priv;
181 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
Steve Wiseebb90982007-02-15 08:09:36 -0600182 if (iwcm_deref_id(cm_id_priv) &&
183 test_bit(IWCM_F_CALLBACK_DESTROY, &cm_id_priv->flags)) {
184 BUG_ON(!list_empty(&cm_id_priv->work_list));
185 free_cm_id(cm_id_priv);
186 }
Tom Tucker922a8e92006-08-03 16:02:40 -0500187}
188
189static int cm_event_handler(struct iw_cm_id *cm_id, struct iw_cm_event *event);
190
191struct iw_cm_id *iw_create_cm_id(struct ib_device *device,
192 iw_cm_handler cm_handler,
193 void *context)
194{
195 struct iwcm_id_private *cm_id_priv;
196
197 cm_id_priv = kzalloc(sizeof(*cm_id_priv), GFP_KERNEL);
198 if (!cm_id_priv)
199 return ERR_PTR(-ENOMEM);
200
201 cm_id_priv->state = IW_CM_STATE_IDLE;
202 cm_id_priv->id.device = device;
203 cm_id_priv->id.cm_handler = cm_handler;
204 cm_id_priv->id.context = context;
205 cm_id_priv->id.event_handler = cm_event_handler;
206 cm_id_priv->id.add_ref = add_ref;
207 cm_id_priv->id.rem_ref = rem_ref;
208 spin_lock_init(&cm_id_priv->lock);
209 atomic_set(&cm_id_priv->refcount, 1);
210 init_waitqueue_head(&cm_id_priv->connect_wait);
211 init_completion(&cm_id_priv->destroy_comp);
212 INIT_LIST_HEAD(&cm_id_priv->work_list);
213 INIT_LIST_HEAD(&cm_id_priv->work_free_list);
214
215 return &cm_id_priv->id;
216}
217EXPORT_SYMBOL(iw_create_cm_id);
218
219
220static int iwcm_modify_qp_err(struct ib_qp *qp)
221{
222 struct ib_qp_attr qp_attr;
223
224 if (!qp)
225 return -EINVAL;
226
227 qp_attr.qp_state = IB_QPS_ERR;
228 return ib_modify_qp(qp, &qp_attr, IB_QP_STATE);
229}
230
231/*
232 * This is really the RDMAC CLOSING state. It is most similar to the
233 * IB SQD QP state.
234 */
235static int iwcm_modify_qp_sqd(struct ib_qp *qp)
236{
237 struct ib_qp_attr qp_attr;
238
239 BUG_ON(qp == NULL);
240 qp_attr.qp_state = IB_QPS_SQD;
241 return ib_modify_qp(qp, &qp_attr, IB_QP_STATE);
242}
243
244/*
245 * CM_ID <-- CLOSING
246 *
Krishna Kumar715a5882006-11-09 09:30:45 +0530247 * Block if a passive or active connection is currently being processed. Then
Tom Tucker922a8e92006-08-03 16:02:40 -0500248 * process the event as follows:
249 * - If we are ESTABLISHED, move to CLOSING and modify the QP state
250 * based on the abrupt flag
251 * - If the connection is already in the CLOSING or IDLE state, the peer is
252 * disconnecting concurrently with us and we've already seen the
253 * DISCONNECT event -- ignore the request and return 0
254 * - Disconnect on a listening endpoint returns -EINVAL
255 */
256int iw_cm_disconnect(struct iw_cm_id *cm_id, int abrupt)
257{
258 struct iwcm_id_private *cm_id_priv;
259 unsigned long flags;
260 int ret = 0;
261 struct ib_qp *qp = NULL;
262
263 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
264 /* Wait if we're currently in a connect or accept downcall */
265 wait_event(cm_id_priv->connect_wait,
266 !test_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags));
267
268 spin_lock_irqsave(&cm_id_priv->lock, flags);
269 switch (cm_id_priv->state) {
270 case IW_CM_STATE_ESTABLISHED:
271 cm_id_priv->state = IW_CM_STATE_CLOSING;
272
273 /* QP could be <nul> for user-mode client */
274 if (cm_id_priv->qp)
275 qp = cm_id_priv->qp;
276 else
277 ret = -EINVAL;
278 break;
279 case IW_CM_STATE_LISTEN:
280 ret = -EINVAL;
281 break;
282 case IW_CM_STATE_CLOSING:
283 /* remote peer closed first */
284 case IW_CM_STATE_IDLE:
285 /* accept or connect returned !0 */
286 break;
287 case IW_CM_STATE_CONN_RECV:
288 /*
289 * App called disconnect before/without calling accept after
290 * connect_request event delivered.
291 */
292 break;
293 case IW_CM_STATE_CONN_SENT:
294 /* Can only get here if wait above fails */
295 default:
296 BUG();
297 }
298 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
299
300 if (qp) {
301 if (abrupt)
302 ret = iwcm_modify_qp_err(qp);
303 else
304 ret = iwcm_modify_qp_sqd(qp);
305
306 /*
307 * If both sides are disconnecting the QP could
308 * already be in ERR or SQD states
309 */
310 ret = 0;
311 }
312
313 return ret;
314}
315EXPORT_SYMBOL(iw_cm_disconnect);
316
317/*
318 * CM_ID <-- DESTROYING
319 *
320 * Clean up all resources associated with the connection and release
321 * the initial reference taken by iw_create_cm_id.
322 */
323static void destroy_cm_id(struct iw_cm_id *cm_id)
324{
325 struct iwcm_id_private *cm_id_priv;
326 unsigned long flags;
327 int ret;
328
329 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
330 /*
331 * Wait if we're currently in a connect or accept downcall. A
332 * listening endpoint should never block here.
333 */
334 wait_event(cm_id_priv->connect_wait,
335 !test_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags));
336
337 spin_lock_irqsave(&cm_id_priv->lock, flags);
338 switch (cm_id_priv->state) {
339 case IW_CM_STATE_LISTEN:
340 cm_id_priv->state = IW_CM_STATE_DESTROYING;
341 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
342 /* destroy the listening endpoint */
343 ret = cm_id->device->iwcm->destroy_listen(cm_id);
344 spin_lock_irqsave(&cm_id_priv->lock, flags);
345 break;
346 case IW_CM_STATE_ESTABLISHED:
347 cm_id_priv->state = IW_CM_STATE_DESTROYING;
348 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
349 /* Abrupt close of the connection */
350 (void)iwcm_modify_qp_err(cm_id_priv->qp);
351 spin_lock_irqsave(&cm_id_priv->lock, flags);
352 break;
353 case IW_CM_STATE_IDLE:
354 case IW_CM_STATE_CLOSING:
355 cm_id_priv->state = IW_CM_STATE_DESTROYING;
356 break;
357 case IW_CM_STATE_CONN_RECV:
358 /*
359 * App called destroy before/without calling accept after
Steve Wiseebb90982007-02-15 08:09:36 -0600360 * receiving connection request event notification or
361 * returned non zero from the event callback function.
362 * In either case, must tell the provider to reject.
Tom Tucker922a8e92006-08-03 16:02:40 -0500363 */
364 cm_id_priv->state = IW_CM_STATE_DESTROYING;
365 break;
366 case IW_CM_STATE_CONN_SENT:
367 case IW_CM_STATE_DESTROYING:
368 default:
369 BUG();
370 break;
371 }
372 if (cm_id_priv->qp) {
373 cm_id_priv->id.device->iwcm->rem_ref(cm_id_priv->qp);
374 cm_id_priv->qp = NULL;
375 }
376 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
377
378 (void)iwcm_deref_id(cm_id_priv);
379}
380
381/*
382 * This function is only called by the application thread and cannot
383 * be called by the event thread. The function will wait for all
384 * references to be released on the cm_id and then kfree the cm_id
385 * object.
386 */
387void iw_destroy_cm_id(struct iw_cm_id *cm_id)
388{
389 struct iwcm_id_private *cm_id_priv;
390
391 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
392 BUG_ON(test_bit(IWCM_F_CALLBACK_DESTROY, &cm_id_priv->flags));
393
394 destroy_cm_id(cm_id);
395
396 wait_for_completion(&cm_id_priv->destroy_comp);
397
Steve Wiseebb90982007-02-15 08:09:36 -0600398 free_cm_id(cm_id_priv);
Tom Tucker922a8e92006-08-03 16:02:40 -0500399}
400EXPORT_SYMBOL(iw_destroy_cm_id);
401
402/*
403 * CM_ID <-- LISTEN
404 *
405 * Start listening for connect requests. Generates one CONNECT_REQUEST
406 * event for each inbound connect request.
407 */
408int iw_cm_listen(struct iw_cm_id *cm_id, int backlog)
409{
410 struct iwcm_id_private *cm_id_priv;
411 unsigned long flags;
Krishna Kumar13fccdb2006-11-09 09:30:43 +0530412 int ret;
Tom Tucker922a8e92006-08-03 16:02:40 -0500413
414 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
415
416 ret = alloc_work_entries(cm_id_priv, backlog);
417 if (ret)
418 return ret;
419
420 spin_lock_irqsave(&cm_id_priv->lock, flags);
421 switch (cm_id_priv->state) {
422 case IW_CM_STATE_IDLE:
423 cm_id_priv->state = IW_CM_STATE_LISTEN;
424 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
425 ret = cm_id->device->iwcm->create_listen(cm_id, backlog);
426 if (ret)
427 cm_id_priv->state = IW_CM_STATE_IDLE;
428 spin_lock_irqsave(&cm_id_priv->lock, flags);
429 break;
430 default:
431 ret = -EINVAL;
432 }
433 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
434
435 return ret;
436}
437EXPORT_SYMBOL(iw_cm_listen);
438
439/*
440 * CM_ID <-- IDLE
441 *
442 * Rejects an inbound connection request. No events are generated.
443 */
444int iw_cm_reject(struct iw_cm_id *cm_id,
445 const void *private_data,
446 u8 private_data_len)
447{
448 struct iwcm_id_private *cm_id_priv;
449 unsigned long flags;
450 int ret;
451
452 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
453 set_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
454
455 spin_lock_irqsave(&cm_id_priv->lock, flags);
456 if (cm_id_priv->state != IW_CM_STATE_CONN_RECV) {
457 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
458 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
459 wake_up_all(&cm_id_priv->connect_wait);
460 return -EINVAL;
461 }
462 cm_id_priv->state = IW_CM_STATE_IDLE;
463 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
464
465 ret = cm_id->device->iwcm->reject(cm_id, private_data,
466 private_data_len);
467
468 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
469 wake_up_all(&cm_id_priv->connect_wait);
470
471 return ret;
472}
473EXPORT_SYMBOL(iw_cm_reject);
474
475/*
476 * CM_ID <-- ESTABLISHED
477 *
478 * Accepts an inbound connection request and generates an ESTABLISHED
479 * event. Callers of iw_cm_disconnect and iw_destroy_cm_id will block
480 * until the ESTABLISHED event is received from the provider.
481 */
482int iw_cm_accept(struct iw_cm_id *cm_id,
483 struct iw_cm_conn_param *iw_param)
484{
485 struct iwcm_id_private *cm_id_priv;
486 struct ib_qp *qp;
487 unsigned long flags;
488 int ret;
489
490 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
491 set_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
492
493 spin_lock_irqsave(&cm_id_priv->lock, flags);
494 if (cm_id_priv->state != IW_CM_STATE_CONN_RECV) {
495 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
496 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
497 wake_up_all(&cm_id_priv->connect_wait);
498 return -EINVAL;
499 }
500 /* Get the ib_qp given the QPN */
501 qp = cm_id->device->iwcm->get_qp(cm_id->device, iw_param->qpn);
502 if (!qp) {
503 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
504 return -EINVAL;
505 }
506 cm_id->device->iwcm->add_ref(qp);
507 cm_id_priv->qp = qp;
508 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
509
510 ret = cm_id->device->iwcm->accept(cm_id, iw_param);
511 if (ret) {
512 /* An error on accept precludes provider events */
513 BUG_ON(cm_id_priv->state != IW_CM_STATE_CONN_RECV);
514 cm_id_priv->state = IW_CM_STATE_IDLE;
515 spin_lock_irqsave(&cm_id_priv->lock, flags);
516 if (cm_id_priv->qp) {
517 cm_id->device->iwcm->rem_ref(qp);
518 cm_id_priv->qp = NULL;
519 }
520 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
521 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
522 wake_up_all(&cm_id_priv->connect_wait);
523 }
524
525 return ret;
526}
527EXPORT_SYMBOL(iw_cm_accept);
528
529/*
530 * Active Side: CM_ID <-- CONN_SENT
531 *
532 * If successful, results in the generation of a CONNECT_REPLY
533 * event. iw_cm_disconnect and iw_cm_destroy will block until the
534 * CONNECT_REPLY event is received from the provider.
535 */
536int iw_cm_connect(struct iw_cm_id *cm_id, struct iw_cm_conn_param *iw_param)
537{
538 struct iwcm_id_private *cm_id_priv;
Krishna Kumar13fccdb2006-11-09 09:30:43 +0530539 int ret;
Tom Tucker922a8e92006-08-03 16:02:40 -0500540 unsigned long flags;
541 struct ib_qp *qp;
542
543 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
544
545 ret = alloc_work_entries(cm_id_priv, 4);
546 if (ret)
547 return ret;
548
549 set_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
550 spin_lock_irqsave(&cm_id_priv->lock, flags);
551
552 if (cm_id_priv->state != IW_CM_STATE_IDLE) {
553 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
554 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
555 wake_up_all(&cm_id_priv->connect_wait);
556 return -EINVAL;
557 }
558
559 /* Get the ib_qp given the QPN */
560 qp = cm_id->device->iwcm->get_qp(cm_id->device, iw_param->qpn);
561 if (!qp) {
562 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
563 return -EINVAL;
564 }
565 cm_id->device->iwcm->add_ref(qp);
566 cm_id_priv->qp = qp;
567 cm_id_priv->state = IW_CM_STATE_CONN_SENT;
568 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
569
570 ret = cm_id->device->iwcm->connect(cm_id, iw_param);
571 if (ret) {
572 spin_lock_irqsave(&cm_id_priv->lock, flags);
573 if (cm_id_priv->qp) {
574 cm_id->device->iwcm->rem_ref(qp);
575 cm_id_priv->qp = NULL;
576 }
577 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
578 BUG_ON(cm_id_priv->state != IW_CM_STATE_CONN_SENT);
579 cm_id_priv->state = IW_CM_STATE_IDLE;
580 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
581 wake_up_all(&cm_id_priv->connect_wait);
582 }
583
584 return ret;
585}
586EXPORT_SYMBOL(iw_cm_connect);
587
588/*
589 * Passive Side: new CM_ID <-- CONN_RECV
590 *
591 * Handles an inbound connect request. The function creates a new
592 * iw_cm_id to represent the new connection and inherits the client
593 * callback function and other attributes from the listening parent.
594 *
595 * The work item contains a pointer to the listen_cm_id and the event. The
596 * listen_cm_id contains the client cm_handler, context and
597 * device. These are copied when the device is cloned. The event
598 * contains the new four tuple.
599 *
600 * An error on the child should not affect the parent, so this
601 * function does not return a value.
602 */
603static void cm_conn_req_handler(struct iwcm_id_private *listen_id_priv,
604 struct iw_cm_event *iw_event)
605{
606 unsigned long flags;
607 struct iw_cm_id *cm_id;
608 struct iwcm_id_private *cm_id_priv;
609 int ret;
610
611 /*
612 * The provider should never generate a connection request
613 * event with a bad status.
614 */
615 BUG_ON(iw_event->status);
616
617 /*
618 * We could be destroying the listening id. If so, ignore this
619 * upcall.
620 */
621 spin_lock_irqsave(&listen_id_priv->lock, flags);
622 if (listen_id_priv->state != IW_CM_STATE_LISTEN) {
623 spin_unlock_irqrestore(&listen_id_priv->lock, flags);
Krishna Kumar83b96582006-11-09 09:30:41 +0530624 goto out;
Tom Tucker922a8e92006-08-03 16:02:40 -0500625 }
626 spin_unlock_irqrestore(&listen_id_priv->lock, flags);
627
628 cm_id = iw_create_cm_id(listen_id_priv->id.device,
629 listen_id_priv->id.cm_handler,
630 listen_id_priv->id.context);
631 /* If the cm_id could not be created, ignore the request */
632 if (IS_ERR(cm_id))
Krishna Kumar83b96582006-11-09 09:30:41 +0530633 goto out;
Tom Tucker922a8e92006-08-03 16:02:40 -0500634
635 cm_id->provider_data = iw_event->provider_data;
636 cm_id->local_addr = iw_event->local_addr;
637 cm_id->remote_addr = iw_event->remote_addr;
638
639 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
640 cm_id_priv->state = IW_CM_STATE_CONN_RECV;
641
642 ret = alloc_work_entries(cm_id_priv, 3);
643 if (ret) {
644 iw_cm_reject(cm_id, NULL, 0);
645 iw_destroy_cm_id(cm_id);
Krishna Kumar83b96582006-11-09 09:30:41 +0530646 goto out;
Tom Tucker922a8e92006-08-03 16:02:40 -0500647 }
648
649 /* Call the client CM handler */
650 ret = cm_id->cm_handler(cm_id, iw_event);
651 if (ret) {
Steve Wiseebb90982007-02-15 08:09:36 -0600652 iw_cm_reject(cm_id, NULL, 0);
Tom Tucker922a8e92006-08-03 16:02:40 -0500653 set_bit(IWCM_F_CALLBACK_DESTROY, &cm_id_priv->flags);
654 destroy_cm_id(cm_id);
655 if (atomic_read(&cm_id_priv->refcount)==0)
Steve Wiseebb90982007-02-15 08:09:36 -0600656 free_cm_id(cm_id_priv);
Tom Tucker922a8e92006-08-03 16:02:40 -0500657 }
658
Krishna Kumar83b96582006-11-09 09:30:41 +0530659out:
Tom Tucker922a8e92006-08-03 16:02:40 -0500660 if (iw_event->private_data_len)
661 kfree(iw_event->private_data);
662}
663
664/*
665 * Passive Side: CM_ID <-- ESTABLISHED
666 *
667 * The provider generated an ESTABLISHED event which means that
668 * the MPA negotion has completed successfully and we are now in MPA
669 * FPDU mode.
670 *
671 * This event can only be received in the CONN_RECV state. If the
672 * remote peer closed, the ESTABLISHED event would be received followed
673 * by the CLOSE event. If the app closes, it will block until we wake
674 * it up after processing this event.
675 */
676static int cm_conn_est_handler(struct iwcm_id_private *cm_id_priv,
677 struct iw_cm_event *iw_event)
678{
679 unsigned long flags;
Krishna Kumar13fccdb2006-11-09 09:30:43 +0530680 int ret;
Tom Tucker922a8e92006-08-03 16:02:40 -0500681
682 spin_lock_irqsave(&cm_id_priv->lock, flags);
683
684 /*
685 * We clear the CONNECT_WAIT bit here to allow the callback
686 * function to call iw_cm_disconnect. Calling iw_destroy_cm_id
687 * from a callback handler is not allowed.
688 */
689 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
690 BUG_ON(cm_id_priv->state != IW_CM_STATE_CONN_RECV);
691 cm_id_priv->state = IW_CM_STATE_ESTABLISHED;
692 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
693 ret = cm_id_priv->id.cm_handler(&cm_id_priv->id, iw_event);
694 wake_up_all(&cm_id_priv->connect_wait);
695
696 return ret;
697}
698
699/*
700 * Active Side: CM_ID <-- ESTABLISHED
701 *
702 * The app has called connect and is waiting for the established event to
703 * post it's requests to the server. This event will wake up anyone
704 * blocked in iw_cm_disconnect or iw_destroy_id.
705 */
706static int cm_conn_rep_handler(struct iwcm_id_private *cm_id_priv,
707 struct iw_cm_event *iw_event)
708{
709 unsigned long flags;
Krishna Kumar13fccdb2006-11-09 09:30:43 +0530710 int ret;
Tom Tucker922a8e92006-08-03 16:02:40 -0500711
712 spin_lock_irqsave(&cm_id_priv->lock, flags);
713 /*
714 * Clear the connect wait bit so a callback function calling
715 * iw_cm_disconnect will not wait and deadlock this thread
716 */
717 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
718 BUG_ON(cm_id_priv->state != IW_CM_STATE_CONN_SENT);
719 if (iw_event->status == IW_CM_EVENT_STATUS_ACCEPTED) {
720 cm_id_priv->id.local_addr = iw_event->local_addr;
721 cm_id_priv->id.remote_addr = iw_event->remote_addr;
722 cm_id_priv->state = IW_CM_STATE_ESTABLISHED;
723 } else {
724 /* REJECTED or RESET */
725 cm_id_priv->id.device->iwcm->rem_ref(cm_id_priv->qp);
726 cm_id_priv->qp = NULL;
727 cm_id_priv->state = IW_CM_STATE_IDLE;
728 }
729 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
730 ret = cm_id_priv->id.cm_handler(&cm_id_priv->id, iw_event);
731
732 if (iw_event->private_data_len)
733 kfree(iw_event->private_data);
734
735 /* Wake up waiters on connect complete */
736 wake_up_all(&cm_id_priv->connect_wait);
737
738 return ret;
739}
740
741/*
742 * CM_ID <-- CLOSING
743 *
744 * If in the ESTABLISHED state, move to CLOSING.
745 */
746static void cm_disconnect_handler(struct iwcm_id_private *cm_id_priv,
747 struct iw_cm_event *iw_event)
748{
749 unsigned long flags;
750
751 spin_lock_irqsave(&cm_id_priv->lock, flags);
752 if (cm_id_priv->state == IW_CM_STATE_ESTABLISHED)
753 cm_id_priv->state = IW_CM_STATE_CLOSING;
754 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
755}
756
757/*
758 * CM_ID <-- IDLE
759 *
760 * If in the ESTBLISHED or CLOSING states, the QP will have have been
761 * moved by the provider to the ERR state. Disassociate the CM_ID from
762 * the QP, move to IDLE, and remove the 'connected' reference.
763 *
764 * If in some other state, the cm_id was destroyed asynchronously.
765 * This is the last reference that will result in waking up
766 * the app thread blocked in iw_destroy_cm_id.
767 */
768static int cm_close_handler(struct iwcm_id_private *cm_id_priv,
769 struct iw_cm_event *iw_event)
770{
771 unsigned long flags;
772 int ret = 0;
773 spin_lock_irqsave(&cm_id_priv->lock, flags);
774
775 if (cm_id_priv->qp) {
776 cm_id_priv->id.device->iwcm->rem_ref(cm_id_priv->qp);
777 cm_id_priv->qp = NULL;
778 }
779 switch (cm_id_priv->state) {
780 case IW_CM_STATE_ESTABLISHED:
781 case IW_CM_STATE_CLOSING:
782 cm_id_priv->state = IW_CM_STATE_IDLE;
783 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
784 ret = cm_id_priv->id.cm_handler(&cm_id_priv->id, iw_event);
785 spin_lock_irqsave(&cm_id_priv->lock, flags);
786 break;
787 case IW_CM_STATE_DESTROYING:
788 break;
789 default:
790 BUG();
791 }
792 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
793
794 return ret;
795}
796
797static int process_event(struct iwcm_id_private *cm_id_priv,
798 struct iw_cm_event *iw_event)
799{
800 int ret = 0;
801
802 switch (iw_event->event) {
803 case IW_CM_EVENT_CONNECT_REQUEST:
804 cm_conn_req_handler(cm_id_priv, iw_event);
805 break;
806 case IW_CM_EVENT_CONNECT_REPLY:
807 ret = cm_conn_rep_handler(cm_id_priv, iw_event);
808 break;
809 case IW_CM_EVENT_ESTABLISHED:
810 ret = cm_conn_est_handler(cm_id_priv, iw_event);
811 break;
812 case IW_CM_EVENT_DISCONNECT:
813 cm_disconnect_handler(cm_id_priv, iw_event);
814 break;
815 case IW_CM_EVENT_CLOSE:
816 ret = cm_close_handler(cm_id_priv, iw_event);
817 break;
818 default:
819 BUG();
820 }
821
822 return ret;
823}
824
825/*
826 * Process events on the work_list for the cm_id. If the callback
827 * function requests that the cm_id be deleted, a flag is set in the
828 * cm_id flags to indicate that when the last reference is
829 * removed, the cm_id is to be destroyed. This is necessary to
830 * distinguish between an object that will be destroyed by the app
831 * thread asleep on the destroy_comp list vs. an object destroyed
832 * here synchronously when the last reference is removed.
833 */
David Howellsc4028952006-11-22 14:57:56 +0000834static void cm_work_handler(struct work_struct *_work)
Tom Tucker922a8e92006-08-03 16:02:40 -0500835{
David Howells4c1ac1b2006-12-05 14:37:56 +0000836 struct iwcm_work *work = container_of(_work, struct iwcm_work, work);
Krishna Kumar33ba0fa2006-11-09 09:30:34 +0530837 struct iw_cm_event levent;
Tom Tucker922a8e92006-08-03 16:02:40 -0500838 struct iwcm_id_private *cm_id_priv = work->cm_id;
839 unsigned long flags;
840 int empty;
841 int ret = 0;
Steve Wised7c1fbd2008-03-04 16:44:52 -0600842 int destroy_id;
Tom Tucker922a8e92006-08-03 16:02:40 -0500843
844 spin_lock_irqsave(&cm_id_priv->lock, flags);
845 empty = list_empty(&cm_id_priv->work_list);
846 while (!empty) {
847 work = list_entry(cm_id_priv->work_list.next,
848 struct iwcm_work, list);
849 list_del_init(&work->list);
850 empty = list_empty(&cm_id_priv->work_list);
Krishna Kumar33ba0fa2006-11-09 09:30:34 +0530851 levent = work->event;
Tom Tucker922a8e92006-08-03 16:02:40 -0500852 put_work(work);
853 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
854
Krishna Kumar33ba0fa2006-11-09 09:30:34 +0530855 ret = process_event(cm_id_priv, &levent);
Tom Tucker922a8e92006-08-03 16:02:40 -0500856 if (ret) {
857 set_bit(IWCM_F_CALLBACK_DESTROY, &cm_id_priv->flags);
858 destroy_cm_id(&cm_id_priv->id);
859 }
860 BUG_ON(atomic_read(&cm_id_priv->refcount)==0);
Steve Wised7c1fbd2008-03-04 16:44:52 -0600861 destroy_id = test_bit(IWCM_F_CALLBACK_DESTROY, &cm_id_priv->flags);
Steve Wiseebb90982007-02-15 08:09:36 -0600862 if (iwcm_deref_id(cm_id_priv)) {
Steve Wised7c1fbd2008-03-04 16:44:52 -0600863 if (destroy_id) {
Steve Wiseebb90982007-02-15 08:09:36 -0600864 BUG_ON(!list_empty(&cm_id_priv->work_list));
865 free_cm_id(cm_id_priv);
866 }
Tom Tucker922a8e92006-08-03 16:02:40 -0500867 return;
868 }
869 spin_lock_irqsave(&cm_id_priv->lock, flags);
870 }
871 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
872}
873
874/*
875 * This function is called on interrupt context. Schedule events on
876 * the iwcm_wq thread to allow callback functions to downcall into
877 * the CM and/or block. Events are queued to a per-CM_ID
878 * work_list. If this is the first event on the work_list, the work
879 * element is also queued on the iwcm_wq thread.
880 *
881 * Each event holds a reference on the cm_id. Until the last posted
882 * event has been delivered and processed, the cm_id cannot be
883 * deleted.
884 *
885 * Returns:
886 * 0 - the event was handled.
887 * -ENOMEM - the event was not handled due to lack of resources.
888 */
889static int cm_event_handler(struct iw_cm_id *cm_id,
890 struct iw_cm_event *iw_event)
891{
892 struct iwcm_work *work;
893 struct iwcm_id_private *cm_id_priv;
894 unsigned long flags;
895 int ret = 0;
896
897 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
898
899 spin_lock_irqsave(&cm_id_priv->lock, flags);
900 work = get_work(cm_id_priv);
901 if (!work) {
902 ret = -ENOMEM;
903 goto out;
904 }
905
David Howellsc4028952006-11-22 14:57:56 +0000906 INIT_WORK(&work->work, cm_work_handler);
Tom Tucker922a8e92006-08-03 16:02:40 -0500907 work->cm_id = cm_id_priv;
908 work->event = *iw_event;
909
910 if ((work->event.event == IW_CM_EVENT_CONNECT_REQUEST ||
911 work->event.event == IW_CM_EVENT_CONNECT_REPLY) &&
912 work->event.private_data_len) {
Krishna Kumar715a5882006-11-09 09:30:45 +0530913 ret = copy_private_data(&work->event);
Tom Tucker922a8e92006-08-03 16:02:40 -0500914 if (ret) {
915 put_work(work);
916 goto out;
917 }
918 }
919
920 atomic_inc(&cm_id_priv->refcount);
921 if (list_empty(&cm_id_priv->work_list)) {
922 list_add_tail(&work->list, &cm_id_priv->work_list);
923 queue_work(iwcm_wq, &work->work);
924 } else
925 list_add_tail(&work->list, &cm_id_priv->work_list);
926out:
927 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
928 return ret;
929}
930
931static int iwcm_init_qp_init_attr(struct iwcm_id_private *cm_id_priv,
932 struct ib_qp_attr *qp_attr,
933 int *qp_attr_mask)
934{
935 unsigned long flags;
936 int ret;
937
938 spin_lock_irqsave(&cm_id_priv->lock, flags);
939 switch (cm_id_priv->state) {
940 case IW_CM_STATE_IDLE:
941 case IW_CM_STATE_CONN_SENT:
942 case IW_CM_STATE_CONN_RECV:
943 case IW_CM_STATE_ESTABLISHED:
944 *qp_attr_mask = IB_QP_STATE | IB_QP_ACCESS_FLAGS;
Dotan Barak1ca8d152008-07-22 14:18:34 -0700945 qp_attr->qp_access_flags = IB_ACCESS_REMOTE_WRITE|
Tom Tucker922a8e92006-08-03 16:02:40 -0500946 IB_ACCESS_REMOTE_READ;
947 ret = 0;
948 break;
949 default:
950 ret = -EINVAL;
951 break;
952 }
953 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
954 return ret;
955}
956
957static int iwcm_init_qp_rts_attr(struct iwcm_id_private *cm_id_priv,
958 struct ib_qp_attr *qp_attr,
959 int *qp_attr_mask)
960{
961 unsigned long flags;
962 int ret;
963
964 spin_lock_irqsave(&cm_id_priv->lock, flags);
965 switch (cm_id_priv->state) {
966 case IW_CM_STATE_IDLE:
967 case IW_CM_STATE_CONN_SENT:
968 case IW_CM_STATE_CONN_RECV:
969 case IW_CM_STATE_ESTABLISHED:
970 *qp_attr_mask = 0;
971 ret = 0;
972 break;
973 default:
974 ret = -EINVAL;
975 break;
976 }
977 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
978 return ret;
979}
980
981int iw_cm_init_qp_attr(struct iw_cm_id *cm_id,
982 struct ib_qp_attr *qp_attr,
983 int *qp_attr_mask)
984{
985 struct iwcm_id_private *cm_id_priv;
986 int ret;
987
988 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
989 switch (qp_attr->qp_state) {
990 case IB_QPS_INIT:
991 case IB_QPS_RTR:
992 ret = iwcm_init_qp_init_attr(cm_id_priv,
993 qp_attr, qp_attr_mask);
994 break;
995 case IB_QPS_RTS:
996 ret = iwcm_init_qp_rts_attr(cm_id_priv,
997 qp_attr, qp_attr_mask);
998 break;
999 default:
1000 ret = -EINVAL;
1001 break;
1002 }
1003 return ret;
1004}
1005EXPORT_SYMBOL(iw_cm_init_qp_attr);
1006
1007static int __init iw_cm_init(void)
1008{
1009 iwcm_wq = create_singlethread_workqueue("iw_cm_wq");
1010 if (!iwcm_wq)
1011 return -ENOMEM;
1012
1013 return 0;
1014}
1015
1016static void __exit iw_cm_cleanup(void)
1017{
1018 destroy_workqueue(iwcm_wq);
1019}
1020
1021module_init(iw_cm_init);
1022module_exit(iw_cm_cleanup);