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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
49#include <rdma/iw_cm.h>
50#include <rdma/ib_addr.h>
51
52#include "iwcm.h"
53
54MODULE_AUTHOR("Tom Tucker");
55MODULE_DESCRIPTION("iWARP CM");
56MODULE_LICENSE("Dual BSD/GPL");
57
58static struct workqueue_struct *iwcm_wq;
59struct iwcm_work {
60 struct work_struct work;
61 struct iwcm_id_private *cm_id;
62 struct list_head list;
63 struct iw_cm_event event;
64 struct list_head free_list;
65};
66
67/*
68 * The following services provide a mechanism for pre-allocating iwcm_work
69 * elements. The design pre-allocates them based on the cm_id type:
70 * LISTENING IDS: Get enough elements preallocated to handle the
71 * listen backlog.
72 * ACTIVE IDS: 4: CONNECT_REPLY, ESTABLISHED, DISCONNECT, CLOSE
73 * PASSIVE IDS: 3: ESTABLISHED, DISCONNECT, CLOSE
74 *
75 * Allocating them in connect and listen avoids having to deal
76 * with allocation failures on the event upcall from the provider (which
77 * is called in the interrupt context).
78 *
79 * One exception is when creating the cm_id for incoming connection requests.
80 * There are two cases:
81 * 1) in the event upcall, cm_event_handler(), for a listening cm_id. If
82 * the backlog is exceeded, then no more connection request events will
83 * be processed. cm_event_handler() returns -ENOMEM in this case. Its up
84 * to the provider to reject the connection request.
85 * 2) in the connection request workqueue handler, cm_conn_req_handler().
86 * If work elements cannot be allocated for the new connect request cm_id,
87 * then IWCM will call the provider reject method. This is ok since
88 * cm_conn_req_handler() runs in the workqueue thread context.
89 */
90
91static struct iwcm_work *get_work(struct iwcm_id_private *cm_id_priv)
92{
93 struct iwcm_work *work;
94
95 if (list_empty(&cm_id_priv->work_free_list))
96 return NULL;
97 work = list_entry(cm_id_priv->work_free_list.next, struct iwcm_work,
98 free_list);
99 list_del_init(&work->free_list);
100 return work;
101}
102
103static void put_work(struct iwcm_work *work)
104{
105 list_add(&work->free_list, &work->cm_id->work_free_list);
106}
107
108static void dealloc_work_entries(struct iwcm_id_private *cm_id_priv)
109{
110 struct list_head *e, *tmp;
111
112 list_for_each_safe(e, tmp, &cm_id_priv->work_free_list)
113 kfree(list_entry(e, struct iwcm_work, free_list));
114}
115
116static int alloc_work_entries(struct iwcm_id_private *cm_id_priv, int count)
117{
118 struct iwcm_work *work;
119
120 BUG_ON(!list_empty(&cm_id_priv->work_free_list));
121 while (count--) {
122 work = kmalloc(sizeof(struct iwcm_work), GFP_KERNEL);
123 if (!work) {
124 dealloc_work_entries(cm_id_priv);
125 return -ENOMEM;
126 }
127 work->cm_id = cm_id_priv;
128 INIT_LIST_HEAD(&work->list);
129 put_work(work);
130 }
131 return 0;
132}
133
134/*
135 * Save private data from incoming connection requests to
136 * iw_cm_event, so the low level driver doesn't have to. Adjust
137 * the event ptr to point to the local copy.
138 */
139static int copy_private_data(struct iw_cm_event *event)
140{
141 void *p;
142
143 p = kmemdup(event->private_data, event->private_data_len, GFP_ATOMIC);
144 if (!p)
145 return -ENOMEM;
146 event->private_data = p;
147 return 0;
148}
149
150static void free_cm_id(struct iwcm_id_private *cm_id_priv)
151{
152 dealloc_work_entries(cm_id_priv);
153 kfree(cm_id_priv);
154}
155
156/*
157 * Release a reference on cm_id. If the last reference is being
158 * released, enable the waiting thread (in iw_destroy_cm_id) to
159 * get woken up, and return 1 if a thread is already waiting.
160 */
161static int iwcm_deref_id(struct iwcm_id_private *cm_id_priv)
162{
163 BUG_ON(atomic_read(&cm_id_priv->refcount)==0);
164 if (atomic_dec_and_test(&cm_id_priv->refcount)) {
165 BUG_ON(!list_empty(&cm_id_priv->work_list));
166 complete(&cm_id_priv->destroy_comp);
167 return 1;
168 }
169
170 return 0;
171}
172
173static void add_ref(struct iw_cm_id *cm_id)
174{
175 struct iwcm_id_private *cm_id_priv;
176 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
177 atomic_inc(&cm_id_priv->refcount);
178}
179
180static void rem_ref(struct iw_cm_id *cm_id)
181{
182 struct iwcm_id_private *cm_id_priv;
183 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
184 if (iwcm_deref_id(cm_id_priv) &&
185 test_bit(IWCM_F_CALLBACK_DESTROY, &cm_id_priv->flags)) {
186 BUG_ON(!list_empty(&cm_id_priv->work_list));
187 free_cm_id(cm_id_priv);
188 }
189}
190
191static int cm_event_handler(struct iw_cm_id *cm_id, struct iw_cm_event *event);
192
193struct iw_cm_id *iw_create_cm_id(struct ib_device *device,
194 iw_cm_handler cm_handler,
195 void *context)
196{
197 struct iwcm_id_private *cm_id_priv;
198
199 cm_id_priv = kzalloc(sizeof(*cm_id_priv), GFP_KERNEL);
200 if (!cm_id_priv)
201 return ERR_PTR(-ENOMEM);
202
203 cm_id_priv->state = IW_CM_STATE_IDLE;
204 cm_id_priv->id.device = device;
205 cm_id_priv->id.cm_handler = cm_handler;
206 cm_id_priv->id.context = context;
207 cm_id_priv->id.event_handler = cm_event_handler;
208 cm_id_priv->id.add_ref = add_ref;
209 cm_id_priv->id.rem_ref = rem_ref;
210 spin_lock_init(&cm_id_priv->lock);
211 atomic_set(&cm_id_priv->refcount, 1);
212 init_waitqueue_head(&cm_id_priv->connect_wait);
213 init_completion(&cm_id_priv->destroy_comp);
214 INIT_LIST_HEAD(&cm_id_priv->work_list);
215 INIT_LIST_HEAD(&cm_id_priv->work_free_list);
216
217 return &cm_id_priv->id;
218}
219EXPORT_SYMBOL(iw_create_cm_id);
220
221
222static int iwcm_modify_qp_err(struct ib_qp *qp)
223{
224 struct ib_qp_attr qp_attr;
225
226 if (!qp)
227 return -EINVAL;
228
229 qp_attr.qp_state = IB_QPS_ERR;
230 return ib_modify_qp(qp, &qp_attr, IB_QP_STATE);
231}
232
233/*
234 * This is really the RDMAC CLOSING state. It is most similar to the
235 * IB SQD QP state.
236 */
237static int iwcm_modify_qp_sqd(struct ib_qp *qp)
238{
239 struct ib_qp_attr qp_attr;
240
241 BUG_ON(qp == NULL);
242 qp_attr.qp_state = IB_QPS_SQD;
243 return ib_modify_qp(qp, &qp_attr, IB_QP_STATE);
244}
245
246/*
247 * CM_ID <-- CLOSING
248 *
249 * Block if a passive or active connection is currently being processed. Then
250 * process the event as follows:
251 * - If we are ESTABLISHED, move to CLOSING and modify the QP state
252 * based on the abrupt flag
253 * - If the connection is already in the CLOSING or IDLE state, the peer is
254 * disconnecting concurrently with us and we've already seen the
255 * DISCONNECT event -- ignore the request and return 0
256 * - Disconnect on a listening endpoint returns -EINVAL
257 */
258int iw_cm_disconnect(struct iw_cm_id *cm_id, int abrupt)
259{
260 struct iwcm_id_private *cm_id_priv;
261 unsigned long flags;
262 int ret = 0;
263 struct ib_qp *qp = NULL;
264
265 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
266 /* Wait if we're currently in a connect or accept downcall */
267 wait_event(cm_id_priv->connect_wait,
268 !test_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags));
269
270 spin_lock_irqsave(&cm_id_priv->lock, flags);
271 switch (cm_id_priv->state) {
272 case IW_CM_STATE_ESTABLISHED:
273 cm_id_priv->state = IW_CM_STATE_CLOSING;
274
275 /* QP could be <nul> for user-mode client */
276 if (cm_id_priv->qp)
277 qp = cm_id_priv->qp;
278 else
279 ret = -EINVAL;
280 break;
281 case IW_CM_STATE_LISTEN:
282 ret = -EINVAL;
283 break;
284 case IW_CM_STATE_CLOSING:
285 /* remote peer closed first */
286 case IW_CM_STATE_IDLE:
287 /* accept or connect returned !0 */
288 break;
289 case IW_CM_STATE_CONN_RECV:
290 /*
291 * App called disconnect before/without calling accept after
292 * connect_request event delivered.
293 */
294 break;
295 case IW_CM_STATE_CONN_SENT:
296 /* Can only get here if wait above fails */
297 default:
298 BUG();
299 }
300 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
301
302 if (qp) {
303 if (abrupt)
304 ret = iwcm_modify_qp_err(qp);
305 else
306 ret = iwcm_modify_qp_sqd(qp);
307
308 /*
309 * If both sides are disconnecting the QP could
310 * already be in ERR or SQD states
311 */
312 ret = 0;
313 }
314
315 return ret;
316}
317EXPORT_SYMBOL(iw_cm_disconnect);
318
319/*
320 * CM_ID <-- DESTROYING
321 *
322 * Clean up all resources associated with the connection and release
323 * the initial reference taken by iw_create_cm_id.
324 */
325static void destroy_cm_id(struct iw_cm_id *cm_id)
326{
327 struct iwcm_id_private *cm_id_priv;
328 unsigned long flags;
329 int ret;
330
331 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
332 /*
333 * Wait if we're currently in a connect or accept downcall. A
334 * listening endpoint should never block here.
335 */
336 wait_event(cm_id_priv->connect_wait,
337 !test_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags));
338
339 spin_lock_irqsave(&cm_id_priv->lock, flags);
340 switch (cm_id_priv->state) {
341 case IW_CM_STATE_LISTEN:
342 cm_id_priv->state = IW_CM_STATE_DESTROYING;
343 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
344 /* destroy the listening endpoint */
345 ret = cm_id->device->iwcm->destroy_listen(cm_id);
346 spin_lock_irqsave(&cm_id_priv->lock, flags);
347 break;
348 case IW_CM_STATE_ESTABLISHED:
349 cm_id_priv->state = IW_CM_STATE_DESTROYING;
350 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
351 /* Abrupt close of the connection */
352 (void)iwcm_modify_qp_err(cm_id_priv->qp);
353 spin_lock_irqsave(&cm_id_priv->lock, flags);
354 break;
355 case IW_CM_STATE_IDLE:
356 case IW_CM_STATE_CLOSING:
357 cm_id_priv->state = IW_CM_STATE_DESTROYING;
358 break;
359 case IW_CM_STATE_CONN_RECV:
360 /*
361 * App called destroy before/without calling accept after
362 * receiving connection request event notification or
363 * returned non zero from the event callback function.
364 * In either case, must tell the provider to reject.
365 */
366 cm_id_priv->state = IW_CM_STATE_DESTROYING;
367 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
368 cm_id->device->iwcm->reject(cm_id, NULL, 0);
369 spin_lock_irqsave(&cm_id_priv->lock, flags);
370 break;
371 case IW_CM_STATE_CONN_SENT:
372 case IW_CM_STATE_DESTROYING:
373 default:
374 BUG();
375 break;
376 }
377 if (cm_id_priv->qp) {
378 cm_id_priv->id.device->iwcm->rem_ref(cm_id_priv->qp);
379 cm_id_priv->qp = NULL;
380 }
381 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
382
383 (void)iwcm_deref_id(cm_id_priv);
384}
385
386/*
387 * This function is only called by the application thread and cannot
388 * be called by the event thread. The function will wait for all
389 * references to be released on the cm_id and then kfree the cm_id
390 * object.
391 */
392void iw_destroy_cm_id(struct iw_cm_id *cm_id)
393{
394 struct iwcm_id_private *cm_id_priv;
395
396 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
397 BUG_ON(test_bit(IWCM_F_CALLBACK_DESTROY, &cm_id_priv->flags));
398
399 destroy_cm_id(cm_id);
400
401 wait_for_completion(&cm_id_priv->destroy_comp);
402
403 free_cm_id(cm_id_priv);
404}
405EXPORT_SYMBOL(iw_destroy_cm_id);
406
407/*
408 * CM_ID <-- LISTEN
409 *
410 * Start listening for connect requests. Generates one CONNECT_REQUEST
411 * event for each inbound connect request.
412 */
413int iw_cm_listen(struct iw_cm_id *cm_id, int backlog)
414{
415 struct iwcm_id_private *cm_id_priv;
416 unsigned long flags;
417 int ret;
418
419 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
420
421 ret = alloc_work_entries(cm_id_priv, backlog);
422 if (ret)
423 return ret;
424
425 spin_lock_irqsave(&cm_id_priv->lock, flags);
426 switch (cm_id_priv->state) {
427 case IW_CM_STATE_IDLE:
428 cm_id_priv->state = IW_CM_STATE_LISTEN;
429 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
430 ret = cm_id->device->iwcm->create_listen(cm_id, backlog);
431 if (ret)
432 cm_id_priv->state = IW_CM_STATE_IDLE;
433 spin_lock_irqsave(&cm_id_priv->lock, flags);
434 break;
435 default:
436 ret = -EINVAL;
437 }
438 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
439
440 return ret;
441}
442EXPORT_SYMBOL(iw_cm_listen);
443
444/*
445 * CM_ID <-- IDLE
446 *
447 * Rejects an inbound connection request. No events are generated.
448 */
449int iw_cm_reject(struct iw_cm_id *cm_id,
450 const void *private_data,
451 u8 private_data_len)
452{
453 struct iwcm_id_private *cm_id_priv;
454 unsigned long flags;
455 int ret;
456
457 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
458 set_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
459
460 spin_lock_irqsave(&cm_id_priv->lock, flags);
461 if (cm_id_priv->state != IW_CM_STATE_CONN_RECV) {
462 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
463 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
464 wake_up_all(&cm_id_priv->connect_wait);
465 return -EINVAL;
466 }
467 cm_id_priv->state = IW_CM_STATE_IDLE;
468 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
469
470 ret = cm_id->device->iwcm->reject(cm_id, private_data,
471 private_data_len);
472
473 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
474 wake_up_all(&cm_id_priv->connect_wait);
475
476 return ret;
477}
478EXPORT_SYMBOL(iw_cm_reject);
479
480/*
481 * CM_ID <-- ESTABLISHED
482 *
483 * Accepts an inbound connection request and generates an ESTABLISHED
484 * event. Callers of iw_cm_disconnect and iw_destroy_cm_id will block
485 * until the ESTABLISHED event is received from the provider.
486 */
487int iw_cm_accept(struct iw_cm_id *cm_id,
488 struct iw_cm_conn_param *iw_param)
489{
490 struct iwcm_id_private *cm_id_priv;
491 struct ib_qp *qp;
492 unsigned long flags;
493 int ret;
494
495 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
496 set_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
497
498 spin_lock_irqsave(&cm_id_priv->lock, flags);
499 if (cm_id_priv->state != IW_CM_STATE_CONN_RECV) {
500 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
501 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
502 wake_up_all(&cm_id_priv->connect_wait);
503 return -EINVAL;
504 }
505 /* Get the ib_qp given the QPN */
506 qp = cm_id->device->iwcm->get_qp(cm_id->device, iw_param->qpn);
507 if (!qp) {
508 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
509 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
510 wake_up_all(&cm_id_priv->connect_wait);
511 return -EINVAL;
512 }
513 cm_id->device->iwcm->add_ref(qp);
514 cm_id_priv->qp = qp;
515 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
516
517 ret = cm_id->device->iwcm->accept(cm_id, iw_param);
518 if (ret) {
519 /* An error on accept precludes provider events */
520 BUG_ON(cm_id_priv->state != IW_CM_STATE_CONN_RECV);
521 cm_id_priv->state = IW_CM_STATE_IDLE;
522 spin_lock_irqsave(&cm_id_priv->lock, flags);
523 if (cm_id_priv->qp) {
524 cm_id->device->iwcm->rem_ref(qp);
525 cm_id_priv->qp = NULL;
526 }
527 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
528 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
529 wake_up_all(&cm_id_priv->connect_wait);
530 }
531
532 return ret;
533}
534EXPORT_SYMBOL(iw_cm_accept);
535
536/*
537 * Active Side: CM_ID <-- CONN_SENT
538 *
539 * If successful, results in the generation of a CONNECT_REPLY
540 * event. iw_cm_disconnect and iw_cm_destroy will block until the
541 * CONNECT_REPLY event is received from the provider.
542 */
543int iw_cm_connect(struct iw_cm_id *cm_id, struct iw_cm_conn_param *iw_param)
544{
545 struct iwcm_id_private *cm_id_priv;
546 int ret;
547 unsigned long flags;
548 struct ib_qp *qp;
549
550 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
551
552 ret = alloc_work_entries(cm_id_priv, 4);
553 if (ret)
554 return ret;
555
556 set_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
557 spin_lock_irqsave(&cm_id_priv->lock, flags);
558
559 if (cm_id_priv->state != IW_CM_STATE_IDLE) {
560 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
561 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
562 wake_up_all(&cm_id_priv->connect_wait);
563 return -EINVAL;
564 }
565
566 /* Get the ib_qp given the QPN */
567 qp = cm_id->device->iwcm->get_qp(cm_id->device, iw_param->qpn);
568 if (!qp) {
569 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
570 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
571 wake_up_all(&cm_id_priv->connect_wait);
572 return -EINVAL;
573 }
574 cm_id->device->iwcm->add_ref(qp);
575 cm_id_priv->qp = qp;
576 cm_id_priv->state = IW_CM_STATE_CONN_SENT;
577 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
578
579 ret = cm_id->device->iwcm->connect(cm_id, iw_param);
580 if (ret) {
581 spin_lock_irqsave(&cm_id_priv->lock, flags);
582 if (cm_id_priv->qp) {
583 cm_id->device->iwcm->rem_ref(qp);
584 cm_id_priv->qp = NULL;
585 }
586 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
587 BUG_ON(cm_id_priv->state != IW_CM_STATE_CONN_SENT);
588 cm_id_priv->state = IW_CM_STATE_IDLE;
589 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
590 wake_up_all(&cm_id_priv->connect_wait);
591 }
592
593 return ret;
594}
595EXPORT_SYMBOL(iw_cm_connect);
596
597/*
598 * Passive Side: new CM_ID <-- CONN_RECV
599 *
600 * Handles an inbound connect request. The function creates a new
601 * iw_cm_id to represent the new connection and inherits the client
602 * callback function and other attributes from the listening parent.
603 *
604 * The work item contains a pointer to the listen_cm_id and the event. The
605 * listen_cm_id contains the client cm_handler, context and
606 * device. These are copied when the device is cloned. The event
607 * contains the new four tuple.
608 *
609 * An error on the child should not affect the parent, so this
610 * function does not return a value.
611 */
612static void cm_conn_req_handler(struct iwcm_id_private *listen_id_priv,
613 struct iw_cm_event *iw_event)
614{
615 unsigned long flags;
616 struct iw_cm_id *cm_id;
617 struct iwcm_id_private *cm_id_priv;
618 int ret;
619
620 /*
621 * The provider should never generate a connection request
622 * event with a bad status.
623 */
624 BUG_ON(iw_event->status);
625
626 /*
627 * We could be destroying the listening id. If so, ignore this
628 * upcall.
629 */
630 spin_lock_irqsave(&listen_id_priv->lock, flags);
631 if (listen_id_priv->state != IW_CM_STATE_LISTEN) {
632 spin_unlock_irqrestore(&listen_id_priv->lock, flags);
633 goto out;
634 }
635 spin_unlock_irqrestore(&listen_id_priv->lock, flags);
636
637 cm_id = iw_create_cm_id(listen_id_priv->id.device,
638 listen_id_priv->id.cm_handler,
639 listen_id_priv->id.context);
640 /* If the cm_id could not be created, ignore the request */
641 if (IS_ERR(cm_id))
642 goto out;
643
644 cm_id->provider_data = iw_event->provider_data;
645 cm_id->local_addr = iw_event->local_addr;
646 cm_id->remote_addr = iw_event->remote_addr;
647
648 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
649 cm_id_priv->state = IW_CM_STATE_CONN_RECV;
650
651 ret = alloc_work_entries(cm_id_priv, 3);
652 if (ret) {
653 iw_cm_reject(cm_id, NULL, 0);
654 iw_destroy_cm_id(cm_id);
655 goto out;
656 }
657
658 /* Call the client CM handler */
659 ret = cm_id->cm_handler(cm_id, iw_event);
660 if (ret) {
661 iw_cm_reject(cm_id, NULL, 0);
662 set_bit(IWCM_F_CALLBACK_DESTROY, &cm_id_priv->flags);
663 destroy_cm_id(cm_id);
664 if (atomic_read(&cm_id_priv->refcount)==0)
665 free_cm_id(cm_id_priv);
666 }
667
668out:
669 if (iw_event->private_data_len)
670 kfree(iw_event->private_data);
671}
672
673/*
674 * Passive Side: CM_ID <-- ESTABLISHED
675 *
676 * The provider generated an ESTABLISHED event which means that
677 * the MPA negotion has completed successfully and we are now in MPA
678 * FPDU mode.
679 *
680 * This event can only be received in the CONN_RECV state. If the
681 * remote peer closed, the ESTABLISHED event would be received followed
682 * by the CLOSE event. If the app closes, it will block until we wake
683 * it up after processing this event.
684 */
685static int cm_conn_est_handler(struct iwcm_id_private *cm_id_priv,
686 struct iw_cm_event *iw_event)
687{
688 unsigned long flags;
689 int ret;
690
691 spin_lock_irqsave(&cm_id_priv->lock, flags);
692
693 /*
694 * We clear the CONNECT_WAIT bit here to allow the callback
695 * function to call iw_cm_disconnect. Calling iw_destroy_cm_id
696 * from a callback handler is not allowed.
697 */
698 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
699 BUG_ON(cm_id_priv->state != IW_CM_STATE_CONN_RECV);
700 cm_id_priv->state = IW_CM_STATE_ESTABLISHED;
701 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
702 ret = cm_id_priv->id.cm_handler(&cm_id_priv->id, iw_event);
703 wake_up_all(&cm_id_priv->connect_wait);
704
705 return ret;
706}
707
708/*
709 * Active Side: CM_ID <-- ESTABLISHED
710 *
711 * The app has called connect and is waiting for the established event to
712 * post it's requests to the server. This event will wake up anyone
713 * blocked in iw_cm_disconnect or iw_destroy_id.
714 */
715static int cm_conn_rep_handler(struct iwcm_id_private *cm_id_priv,
716 struct iw_cm_event *iw_event)
717{
718 unsigned long flags;
719 int ret;
720
721 spin_lock_irqsave(&cm_id_priv->lock, flags);
722 /*
723 * Clear the connect wait bit so a callback function calling
724 * iw_cm_disconnect will not wait and deadlock this thread
725 */
726 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
727 BUG_ON(cm_id_priv->state != IW_CM_STATE_CONN_SENT);
728 if (iw_event->status == 0) {
729 cm_id_priv->id.local_addr = iw_event->local_addr;
730 cm_id_priv->id.remote_addr = iw_event->remote_addr;
731 cm_id_priv->state = IW_CM_STATE_ESTABLISHED;
732 } else {
733 /* REJECTED or RESET */
734 cm_id_priv->id.device->iwcm->rem_ref(cm_id_priv->qp);
735 cm_id_priv->qp = NULL;
736 cm_id_priv->state = IW_CM_STATE_IDLE;
737 }
738 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
739 ret = cm_id_priv->id.cm_handler(&cm_id_priv->id, iw_event);
740
741 if (iw_event->private_data_len)
742 kfree(iw_event->private_data);
743
744 /* Wake up waiters on connect complete */
745 wake_up_all(&cm_id_priv->connect_wait);
746
747 return ret;
748}
749
750/*
751 * CM_ID <-- CLOSING
752 *
753 * If in the ESTABLISHED state, move to CLOSING.
754 */
755static void cm_disconnect_handler(struct iwcm_id_private *cm_id_priv,
756 struct iw_cm_event *iw_event)
757{
758 unsigned long flags;
759
760 spin_lock_irqsave(&cm_id_priv->lock, flags);
761 if (cm_id_priv->state == IW_CM_STATE_ESTABLISHED)
762 cm_id_priv->state = IW_CM_STATE_CLOSING;
763 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
764}
765
766/*
767 * CM_ID <-- IDLE
768 *
769 * If in the ESTBLISHED or CLOSING states, the QP will have have been
770 * moved by the provider to the ERR state. Disassociate the CM_ID from
771 * the QP, move to IDLE, and remove the 'connected' reference.
772 *
773 * If in some other state, the cm_id was destroyed asynchronously.
774 * This is the last reference that will result in waking up
775 * the app thread blocked in iw_destroy_cm_id.
776 */
777static int cm_close_handler(struct iwcm_id_private *cm_id_priv,
778 struct iw_cm_event *iw_event)
779{
780 unsigned long flags;
781 int ret = 0;
782 spin_lock_irqsave(&cm_id_priv->lock, flags);
783
784 if (cm_id_priv->qp) {
785 cm_id_priv->id.device->iwcm->rem_ref(cm_id_priv->qp);
786 cm_id_priv->qp = NULL;
787 }
788 switch (cm_id_priv->state) {
789 case IW_CM_STATE_ESTABLISHED:
790 case IW_CM_STATE_CLOSING:
791 cm_id_priv->state = IW_CM_STATE_IDLE;
792 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
793 ret = cm_id_priv->id.cm_handler(&cm_id_priv->id, iw_event);
794 spin_lock_irqsave(&cm_id_priv->lock, flags);
795 break;
796 case IW_CM_STATE_DESTROYING:
797 break;
798 default:
799 BUG();
800 }
801 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
802
803 return ret;
804}
805
806static int process_event(struct iwcm_id_private *cm_id_priv,
807 struct iw_cm_event *iw_event)
808{
809 int ret = 0;
810
811 switch (iw_event->event) {
812 case IW_CM_EVENT_CONNECT_REQUEST:
813 cm_conn_req_handler(cm_id_priv, iw_event);
814 break;
815 case IW_CM_EVENT_CONNECT_REPLY:
816 ret = cm_conn_rep_handler(cm_id_priv, iw_event);
817 break;
818 case IW_CM_EVENT_ESTABLISHED:
819 ret = cm_conn_est_handler(cm_id_priv, iw_event);
820 break;
821 case IW_CM_EVENT_DISCONNECT:
822 cm_disconnect_handler(cm_id_priv, iw_event);
823 break;
824 case IW_CM_EVENT_CLOSE:
825 ret = cm_close_handler(cm_id_priv, iw_event);
826 break;
827 default:
828 BUG();
829 }
830
831 return ret;
832}
833
834/*
835 * Process events on the work_list for the cm_id. If the callback
836 * function requests that the cm_id be deleted, a flag is set in the
837 * cm_id flags to indicate that when the last reference is
838 * removed, the cm_id is to be destroyed. This is necessary to
839 * distinguish between an object that will be destroyed by the app
840 * thread asleep on the destroy_comp list vs. an object destroyed
841 * here synchronously when the last reference is removed.
842 */
843static void cm_work_handler(struct work_struct *_work)
844{
845 struct iwcm_work *work = container_of(_work, struct iwcm_work, work);
846 struct iw_cm_event levent;
847 struct iwcm_id_private *cm_id_priv = work->cm_id;
848 unsigned long flags;
849 int empty;
850 int ret = 0;
851 int destroy_id;
852
853 spin_lock_irqsave(&cm_id_priv->lock, flags);
854 empty = list_empty(&cm_id_priv->work_list);
855 while (!empty) {
856 work = list_entry(cm_id_priv->work_list.next,
857 struct iwcm_work, list);
858 list_del_init(&work->list);
859 empty = list_empty(&cm_id_priv->work_list);
860 levent = work->event;
861 put_work(work);
862 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
863
864 ret = process_event(cm_id_priv, &levent);
865 if (ret) {
866 set_bit(IWCM_F_CALLBACK_DESTROY, &cm_id_priv->flags);
867 destroy_cm_id(&cm_id_priv->id);
868 }
869 BUG_ON(atomic_read(&cm_id_priv->refcount)==0);
870 destroy_id = test_bit(IWCM_F_CALLBACK_DESTROY, &cm_id_priv->flags);
871 if (iwcm_deref_id(cm_id_priv)) {
872 if (destroy_id) {
873 BUG_ON(!list_empty(&cm_id_priv->work_list));
874 free_cm_id(cm_id_priv);
875 }
876 return;
877 }
878 spin_lock_irqsave(&cm_id_priv->lock, flags);
879 }
880 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
881}
882
883/*
884 * This function is called on interrupt context. Schedule events on
885 * the iwcm_wq thread to allow callback functions to downcall into
886 * the CM and/or block. Events are queued to a per-CM_ID
887 * work_list. If this is the first event on the work_list, the work
888 * element is also queued on the iwcm_wq thread.
889 *
890 * Each event holds a reference on the cm_id. Until the last posted
891 * event has been delivered and processed, the cm_id cannot be
892 * deleted.
893 *
894 * Returns:
895 * 0 - the event was handled.
896 * -ENOMEM - the event was not handled due to lack of resources.
897 */
898static int cm_event_handler(struct iw_cm_id *cm_id,
899 struct iw_cm_event *iw_event)
900{
901 struct iwcm_work *work;
902 struct iwcm_id_private *cm_id_priv;
903 unsigned long flags;
904 int ret = 0;
905
906 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
907
908 spin_lock_irqsave(&cm_id_priv->lock, flags);
909 work = get_work(cm_id_priv);
910 if (!work) {
911 ret = -ENOMEM;
912 goto out;
913 }
914
915 INIT_WORK(&work->work, cm_work_handler);
916 work->cm_id = cm_id_priv;
917 work->event = *iw_event;
918
919 if ((work->event.event == IW_CM_EVENT_CONNECT_REQUEST ||
920 work->event.event == IW_CM_EVENT_CONNECT_REPLY) &&
921 work->event.private_data_len) {
922 ret = copy_private_data(&work->event);
923 if (ret) {
924 put_work(work);
925 goto out;
926 }
927 }
928
929 atomic_inc(&cm_id_priv->refcount);
930 if (list_empty(&cm_id_priv->work_list)) {
931 list_add_tail(&work->list, &cm_id_priv->work_list);
932 queue_work(iwcm_wq, &work->work);
933 } else
934 list_add_tail(&work->list, &cm_id_priv->work_list);
935out:
936 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
937 return ret;
938}
939
940static int iwcm_init_qp_init_attr(struct iwcm_id_private *cm_id_priv,
941 struct ib_qp_attr *qp_attr,
942 int *qp_attr_mask)
943{
944 unsigned long flags;
945 int ret;
946
947 spin_lock_irqsave(&cm_id_priv->lock, flags);
948 switch (cm_id_priv->state) {
949 case IW_CM_STATE_IDLE:
950 case IW_CM_STATE_CONN_SENT:
951 case IW_CM_STATE_CONN_RECV:
952 case IW_CM_STATE_ESTABLISHED:
953 *qp_attr_mask = IB_QP_STATE | IB_QP_ACCESS_FLAGS;
954 qp_attr->qp_access_flags = IB_ACCESS_REMOTE_WRITE|
955 IB_ACCESS_REMOTE_READ;
956 ret = 0;
957 break;
958 default:
959 ret = -EINVAL;
960 break;
961 }
962 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
963 return ret;
964}
965
966static int iwcm_init_qp_rts_attr(struct iwcm_id_private *cm_id_priv,
967 struct ib_qp_attr *qp_attr,
968 int *qp_attr_mask)
969{
970 unsigned long flags;
971 int ret;
972
973 spin_lock_irqsave(&cm_id_priv->lock, flags);
974 switch (cm_id_priv->state) {
975 case IW_CM_STATE_IDLE:
976 case IW_CM_STATE_CONN_SENT:
977 case IW_CM_STATE_CONN_RECV:
978 case IW_CM_STATE_ESTABLISHED:
979 *qp_attr_mask = 0;
980 ret = 0;
981 break;
982 default:
983 ret = -EINVAL;
984 break;
985 }
986 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
987 return ret;
988}
989
990int iw_cm_init_qp_attr(struct iw_cm_id *cm_id,
991 struct ib_qp_attr *qp_attr,
992 int *qp_attr_mask)
993{
994 struct iwcm_id_private *cm_id_priv;
995 int ret;
996
997 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
998 switch (qp_attr->qp_state) {
999 case IB_QPS_INIT:
1000 case IB_QPS_RTR:
1001 ret = iwcm_init_qp_init_attr(cm_id_priv,
1002 qp_attr, qp_attr_mask);
1003 break;
1004 case IB_QPS_RTS:
1005 ret = iwcm_init_qp_rts_attr(cm_id_priv,
1006 qp_attr, qp_attr_mask);
1007 break;
1008 default:
1009 ret = -EINVAL;
1010 break;
1011 }
1012 return ret;
1013}
1014EXPORT_SYMBOL(iw_cm_init_qp_attr);
1015
1016static int __init iw_cm_init(void)
1017{
1018 iwcm_wq = create_singlethread_workqueue("iw_cm_wq");
1019 if (!iwcm_wq)
1020 return -ENOMEM;
1021
1022 return 0;
1023}
1024
1025static void __exit iw_cm_cleanup(void)
1026{
1027 destroy_workqueue(iwcm_wq);
1028}
1029
1030module_init(iw_cm_init);
1031module_exit(iw_cm_cleanup);
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
50#include <rdma/iw_cm.h>
51#include <rdma/ib_addr.h>
52
53#include "iwcm.h"
54
55MODULE_AUTHOR("Tom Tucker");
56MODULE_DESCRIPTION("iWARP CM");
57MODULE_LICENSE("Dual BSD/GPL");
58
59static struct workqueue_struct *iwcm_wq;
60struct iwcm_work {
61 struct work_struct work;
62 struct iwcm_id_private *cm_id;
63 struct list_head list;
64 struct iw_cm_event event;
65 struct list_head free_list;
66};
67
68/*
69 * The following services provide a mechanism for pre-allocating iwcm_work
70 * elements. The design pre-allocates them based on the cm_id type:
71 * LISTENING IDS: Get enough elements preallocated to handle the
72 * listen backlog.
73 * ACTIVE IDS: 4: CONNECT_REPLY, ESTABLISHED, DISCONNECT, CLOSE
74 * PASSIVE IDS: 3: ESTABLISHED, DISCONNECT, CLOSE
75 *
76 * Allocating them in connect and listen avoids having to deal
77 * with allocation failures on the event upcall from the provider (which
78 * is called in the interrupt context).
79 *
80 * One exception is when creating the cm_id for incoming connection requests.
81 * There are two cases:
82 * 1) in the event upcall, cm_event_handler(), for a listening cm_id. If
83 * the backlog is exceeded, then no more connection request events will
84 * be processed. cm_event_handler() returns -ENOMEM in this case. Its up
85 * to the provider to reject the connection request.
86 * 2) in the connection request workqueue handler, cm_conn_req_handler().
87 * If work elements cannot be allocated for the new connect request cm_id,
88 * then IWCM will call the provider reject method. This is ok since
89 * cm_conn_req_handler() runs in the workqueue thread context.
90 */
91
92static struct iwcm_work *get_work(struct iwcm_id_private *cm_id_priv)
93{
94 struct iwcm_work *work;
95
96 if (list_empty(&cm_id_priv->work_free_list))
97 return NULL;
98 work = list_entry(cm_id_priv->work_free_list.next, struct iwcm_work,
99 free_list);
100 list_del_init(&work->free_list);
101 return work;
102}
103
104static void put_work(struct iwcm_work *work)
105{
106 list_add(&work->free_list, &work->cm_id->work_free_list);
107}
108
109static void dealloc_work_entries(struct iwcm_id_private *cm_id_priv)
110{
111 struct list_head *e, *tmp;
112
113 list_for_each_safe(e, tmp, &cm_id_priv->work_free_list)
114 kfree(list_entry(e, struct iwcm_work, free_list));
115}
116
117static int alloc_work_entries(struct iwcm_id_private *cm_id_priv, int count)
118{
119 struct iwcm_work *work;
120
121 BUG_ON(!list_empty(&cm_id_priv->work_free_list));
122 while (count--) {
123 work = kmalloc(sizeof(struct iwcm_work), GFP_KERNEL);
124 if (!work) {
125 dealloc_work_entries(cm_id_priv);
126 return -ENOMEM;
127 }
128 work->cm_id = cm_id_priv;
129 INIT_LIST_HEAD(&work->list);
130 put_work(work);
131 }
132 return 0;
133}
134
135/*
136 * Save private data from incoming connection requests to
137 * iw_cm_event, so the low level driver doesn't have to. Adjust
138 * the event ptr to point to the local copy.
139 */
140static int copy_private_data(struct iw_cm_event *event)
141{
142 void *p;
143
144 p = kmemdup(event->private_data, event->private_data_len, GFP_ATOMIC);
145 if (!p)
146 return -ENOMEM;
147 event->private_data = p;
148 return 0;
149}
150
151static void free_cm_id(struct iwcm_id_private *cm_id_priv)
152{
153 dealloc_work_entries(cm_id_priv);
154 kfree(cm_id_priv);
155}
156
157/*
158 * Release a reference on cm_id. If the last reference is being
159 * released, enable the waiting thread (in iw_destroy_cm_id) to
160 * get woken up, and return 1 if a thread is already waiting.
161 */
162static int iwcm_deref_id(struct iwcm_id_private *cm_id_priv)
163{
164 BUG_ON(atomic_read(&cm_id_priv->refcount)==0);
165 if (atomic_dec_and_test(&cm_id_priv->refcount)) {
166 BUG_ON(!list_empty(&cm_id_priv->work_list));
167 complete(&cm_id_priv->destroy_comp);
168 return 1;
169 }
170
171 return 0;
172}
173
174static void add_ref(struct iw_cm_id *cm_id)
175{
176 struct iwcm_id_private *cm_id_priv;
177 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
178 atomic_inc(&cm_id_priv->refcount);
179}
180
181static void rem_ref(struct iw_cm_id *cm_id)
182{
183 struct iwcm_id_private *cm_id_priv;
184 int cb_destroy;
185
186 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
187
188 /*
189 * Test bit before deref in case the cm_id gets freed on another
190 * thread.
191 */
192 cb_destroy = test_bit(IWCM_F_CALLBACK_DESTROY, &cm_id_priv->flags);
193 if (iwcm_deref_id(cm_id_priv) && cb_destroy) {
194 BUG_ON(!list_empty(&cm_id_priv->work_list));
195 free_cm_id(cm_id_priv);
196 }
197}
198
199static int cm_event_handler(struct iw_cm_id *cm_id, struct iw_cm_event *event);
200
201struct iw_cm_id *iw_create_cm_id(struct ib_device *device,
202 iw_cm_handler cm_handler,
203 void *context)
204{
205 struct iwcm_id_private *cm_id_priv;
206
207 cm_id_priv = kzalloc(sizeof(*cm_id_priv), GFP_KERNEL);
208 if (!cm_id_priv)
209 return ERR_PTR(-ENOMEM);
210
211 cm_id_priv->state = IW_CM_STATE_IDLE;
212 cm_id_priv->id.device = device;
213 cm_id_priv->id.cm_handler = cm_handler;
214 cm_id_priv->id.context = context;
215 cm_id_priv->id.event_handler = cm_event_handler;
216 cm_id_priv->id.add_ref = add_ref;
217 cm_id_priv->id.rem_ref = rem_ref;
218 spin_lock_init(&cm_id_priv->lock);
219 atomic_set(&cm_id_priv->refcount, 1);
220 init_waitqueue_head(&cm_id_priv->connect_wait);
221 init_completion(&cm_id_priv->destroy_comp);
222 INIT_LIST_HEAD(&cm_id_priv->work_list);
223 INIT_LIST_HEAD(&cm_id_priv->work_free_list);
224
225 return &cm_id_priv->id;
226}
227EXPORT_SYMBOL(iw_create_cm_id);
228
229
230static int iwcm_modify_qp_err(struct ib_qp *qp)
231{
232 struct ib_qp_attr qp_attr;
233
234 if (!qp)
235 return -EINVAL;
236
237 qp_attr.qp_state = IB_QPS_ERR;
238 return ib_modify_qp(qp, &qp_attr, IB_QP_STATE);
239}
240
241/*
242 * This is really the RDMAC CLOSING state. It is most similar to the
243 * IB SQD QP state.
244 */
245static int iwcm_modify_qp_sqd(struct ib_qp *qp)
246{
247 struct ib_qp_attr qp_attr;
248
249 BUG_ON(qp == NULL);
250 qp_attr.qp_state = IB_QPS_SQD;
251 return ib_modify_qp(qp, &qp_attr, IB_QP_STATE);
252}
253
254/*
255 * CM_ID <-- CLOSING
256 *
257 * Block if a passive or active connection is currently being processed. Then
258 * process the event as follows:
259 * - If we are ESTABLISHED, move to CLOSING and modify the QP state
260 * based on the abrupt flag
261 * - If the connection is already in the CLOSING or IDLE state, the peer is
262 * disconnecting concurrently with us and we've already seen the
263 * DISCONNECT event -- ignore the request and return 0
264 * - Disconnect on a listening endpoint returns -EINVAL
265 */
266int iw_cm_disconnect(struct iw_cm_id *cm_id, int abrupt)
267{
268 struct iwcm_id_private *cm_id_priv;
269 unsigned long flags;
270 int ret = 0;
271 struct ib_qp *qp = NULL;
272
273 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
274 /* Wait if we're currently in a connect or accept downcall */
275 wait_event(cm_id_priv->connect_wait,
276 !test_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags));
277
278 spin_lock_irqsave(&cm_id_priv->lock, flags);
279 switch (cm_id_priv->state) {
280 case IW_CM_STATE_ESTABLISHED:
281 cm_id_priv->state = IW_CM_STATE_CLOSING;
282
283 /* QP could be <nul> for user-mode client */
284 if (cm_id_priv->qp)
285 qp = cm_id_priv->qp;
286 else
287 ret = -EINVAL;
288 break;
289 case IW_CM_STATE_LISTEN:
290 ret = -EINVAL;
291 break;
292 case IW_CM_STATE_CLOSING:
293 /* remote peer closed first */
294 case IW_CM_STATE_IDLE:
295 /* accept or connect returned !0 */
296 break;
297 case IW_CM_STATE_CONN_RECV:
298 /*
299 * App called disconnect before/without calling accept after
300 * connect_request event delivered.
301 */
302 break;
303 case IW_CM_STATE_CONN_SENT:
304 /* Can only get here if wait above fails */
305 default:
306 BUG();
307 }
308 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
309
310 if (qp) {
311 if (abrupt)
312 ret = iwcm_modify_qp_err(qp);
313 else
314 ret = iwcm_modify_qp_sqd(qp);
315
316 /*
317 * If both sides are disconnecting the QP could
318 * already be in ERR or SQD states
319 */
320 ret = 0;
321 }
322
323 return ret;
324}
325EXPORT_SYMBOL(iw_cm_disconnect);
326
327/*
328 * CM_ID <-- DESTROYING
329 *
330 * Clean up all resources associated with the connection and release
331 * the initial reference taken by iw_create_cm_id.
332 */
333static void destroy_cm_id(struct iw_cm_id *cm_id)
334{
335 struct iwcm_id_private *cm_id_priv;
336 unsigned long flags;
337
338 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
339 /*
340 * Wait if we're currently in a connect or accept downcall. A
341 * listening endpoint should never block here.
342 */
343 wait_event(cm_id_priv->connect_wait,
344 !test_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags));
345
346 spin_lock_irqsave(&cm_id_priv->lock, flags);
347 switch (cm_id_priv->state) {
348 case IW_CM_STATE_LISTEN:
349 cm_id_priv->state = IW_CM_STATE_DESTROYING;
350 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
351 /* destroy the listening endpoint */
352 cm_id->device->iwcm->destroy_listen(cm_id);
353 spin_lock_irqsave(&cm_id_priv->lock, flags);
354 break;
355 case IW_CM_STATE_ESTABLISHED:
356 cm_id_priv->state = IW_CM_STATE_DESTROYING;
357 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
358 /* Abrupt close of the connection */
359 (void)iwcm_modify_qp_err(cm_id_priv->qp);
360 spin_lock_irqsave(&cm_id_priv->lock, flags);
361 break;
362 case IW_CM_STATE_IDLE:
363 case IW_CM_STATE_CLOSING:
364 cm_id_priv->state = IW_CM_STATE_DESTROYING;
365 break;
366 case IW_CM_STATE_CONN_RECV:
367 /*
368 * App called destroy before/without calling accept after
369 * receiving connection request event notification or
370 * returned non zero from the event callback function.
371 * In either case, must tell the provider to reject.
372 */
373 cm_id_priv->state = IW_CM_STATE_DESTROYING;
374 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
375 cm_id->device->iwcm->reject(cm_id, NULL, 0);
376 spin_lock_irqsave(&cm_id_priv->lock, flags);
377 break;
378 case IW_CM_STATE_CONN_SENT:
379 case IW_CM_STATE_DESTROYING:
380 default:
381 BUG();
382 break;
383 }
384 if (cm_id_priv->qp) {
385 cm_id_priv->id.device->iwcm->rem_ref(cm_id_priv->qp);
386 cm_id_priv->qp = NULL;
387 }
388 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
389
390 (void)iwcm_deref_id(cm_id_priv);
391}
392
393/*
394 * This function is only called by the application thread and cannot
395 * be called by the event thread. The function will wait for all
396 * references to be released on the cm_id and then kfree the cm_id
397 * object.
398 */
399void iw_destroy_cm_id(struct iw_cm_id *cm_id)
400{
401 struct iwcm_id_private *cm_id_priv;
402
403 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
404 BUG_ON(test_bit(IWCM_F_CALLBACK_DESTROY, &cm_id_priv->flags));
405
406 destroy_cm_id(cm_id);
407
408 wait_for_completion(&cm_id_priv->destroy_comp);
409
410 free_cm_id(cm_id_priv);
411}
412EXPORT_SYMBOL(iw_destroy_cm_id);
413
414/*
415 * CM_ID <-- LISTEN
416 *
417 * Start listening for connect requests. Generates one CONNECT_REQUEST
418 * event for each inbound connect request.
419 */
420int iw_cm_listen(struct iw_cm_id *cm_id, int backlog)
421{
422 struct iwcm_id_private *cm_id_priv;
423 unsigned long flags;
424 int ret;
425
426 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
427
428 ret = alloc_work_entries(cm_id_priv, backlog);
429 if (ret)
430 return ret;
431
432 spin_lock_irqsave(&cm_id_priv->lock, flags);
433 switch (cm_id_priv->state) {
434 case IW_CM_STATE_IDLE:
435 cm_id_priv->state = IW_CM_STATE_LISTEN;
436 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
437 ret = cm_id->device->iwcm->create_listen(cm_id, backlog);
438 if (ret)
439 cm_id_priv->state = IW_CM_STATE_IDLE;
440 spin_lock_irqsave(&cm_id_priv->lock, flags);
441 break;
442 default:
443 ret = -EINVAL;
444 }
445 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
446
447 return ret;
448}
449EXPORT_SYMBOL(iw_cm_listen);
450
451/*
452 * CM_ID <-- IDLE
453 *
454 * Rejects an inbound connection request. No events are generated.
455 */
456int iw_cm_reject(struct iw_cm_id *cm_id,
457 const void *private_data,
458 u8 private_data_len)
459{
460 struct iwcm_id_private *cm_id_priv;
461 unsigned long flags;
462 int ret;
463
464 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
465 set_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
466
467 spin_lock_irqsave(&cm_id_priv->lock, flags);
468 if (cm_id_priv->state != IW_CM_STATE_CONN_RECV) {
469 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
470 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
471 wake_up_all(&cm_id_priv->connect_wait);
472 return -EINVAL;
473 }
474 cm_id_priv->state = IW_CM_STATE_IDLE;
475 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
476
477 ret = cm_id->device->iwcm->reject(cm_id, private_data,
478 private_data_len);
479
480 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
481 wake_up_all(&cm_id_priv->connect_wait);
482
483 return ret;
484}
485EXPORT_SYMBOL(iw_cm_reject);
486
487/*
488 * CM_ID <-- ESTABLISHED
489 *
490 * Accepts an inbound connection request and generates an ESTABLISHED
491 * event. Callers of iw_cm_disconnect and iw_destroy_cm_id will block
492 * until the ESTABLISHED event is received from the provider.
493 */
494int iw_cm_accept(struct iw_cm_id *cm_id,
495 struct iw_cm_conn_param *iw_param)
496{
497 struct iwcm_id_private *cm_id_priv;
498 struct ib_qp *qp;
499 unsigned long flags;
500 int ret;
501
502 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
503 set_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
504
505 spin_lock_irqsave(&cm_id_priv->lock, flags);
506 if (cm_id_priv->state != IW_CM_STATE_CONN_RECV) {
507 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
508 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
509 wake_up_all(&cm_id_priv->connect_wait);
510 return -EINVAL;
511 }
512 /* Get the ib_qp given the QPN */
513 qp = cm_id->device->iwcm->get_qp(cm_id->device, iw_param->qpn);
514 if (!qp) {
515 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
516 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
517 wake_up_all(&cm_id_priv->connect_wait);
518 return -EINVAL;
519 }
520 cm_id->device->iwcm->add_ref(qp);
521 cm_id_priv->qp = qp;
522 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
523
524 ret = cm_id->device->iwcm->accept(cm_id, iw_param);
525 if (ret) {
526 /* An error on accept precludes provider events */
527 BUG_ON(cm_id_priv->state != IW_CM_STATE_CONN_RECV);
528 cm_id_priv->state = IW_CM_STATE_IDLE;
529 spin_lock_irqsave(&cm_id_priv->lock, flags);
530 if (cm_id_priv->qp) {
531 cm_id->device->iwcm->rem_ref(qp);
532 cm_id_priv->qp = NULL;
533 }
534 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
535 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
536 wake_up_all(&cm_id_priv->connect_wait);
537 }
538
539 return ret;
540}
541EXPORT_SYMBOL(iw_cm_accept);
542
543/*
544 * Active Side: CM_ID <-- CONN_SENT
545 *
546 * If successful, results in the generation of a CONNECT_REPLY
547 * event. iw_cm_disconnect and iw_cm_destroy will block until the
548 * CONNECT_REPLY event is received from the provider.
549 */
550int iw_cm_connect(struct iw_cm_id *cm_id, struct iw_cm_conn_param *iw_param)
551{
552 struct iwcm_id_private *cm_id_priv;
553 int ret;
554 unsigned long flags;
555 struct ib_qp *qp;
556
557 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
558
559 ret = alloc_work_entries(cm_id_priv, 4);
560 if (ret)
561 return ret;
562
563 set_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
564 spin_lock_irqsave(&cm_id_priv->lock, flags);
565
566 if (cm_id_priv->state != IW_CM_STATE_IDLE) {
567 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
568 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
569 wake_up_all(&cm_id_priv->connect_wait);
570 return -EINVAL;
571 }
572
573 /* Get the ib_qp given the QPN */
574 qp = cm_id->device->iwcm->get_qp(cm_id->device, iw_param->qpn);
575 if (!qp) {
576 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
577 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
578 wake_up_all(&cm_id_priv->connect_wait);
579 return -EINVAL;
580 }
581 cm_id->device->iwcm->add_ref(qp);
582 cm_id_priv->qp = qp;
583 cm_id_priv->state = IW_CM_STATE_CONN_SENT;
584 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
585
586 ret = cm_id->device->iwcm->connect(cm_id, iw_param);
587 if (ret) {
588 spin_lock_irqsave(&cm_id_priv->lock, flags);
589 if (cm_id_priv->qp) {
590 cm_id->device->iwcm->rem_ref(qp);
591 cm_id_priv->qp = NULL;
592 }
593 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
594 BUG_ON(cm_id_priv->state != IW_CM_STATE_CONN_SENT);
595 cm_id_priv->state = IW_CM_STATE_IDLE;
596 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
597 wake_up_all(&cm_id_priv->connect_wait);
598 }
599
600 return ret;
601}
602EXPORT_SYMBOL(iw_cm_connect);
603
604/*
605 * Passive Side: new CM_ID <-- CONN_RECV
606 *
607 * Handles an inbound connect request. The function creates a new
608 * iw_cm_id to represent the new connection and inherits the client
609 * callback function and other attributes from the listening parent.
610 *
611 * The work item contains a pointer to the listen_cm_id and the event. The
612 * listen_cm_id contains the client cm_handler, context and
613 * device. These are copied when the device is cloned. The event
614 * contains the new four tuple.
615 *
616 * An error on the child should not affect the parent, so this
617 * function does not return a value.
618 */
619static void cm_conn_req_handler(struct iwcm_id_private *listen_id_priv,
620 struct iw_cm_event *iw_event)
621{
622 unsigned long flags;
623 struct iw_cm_id *cm_id;
624 struct iwcm_id_private *cm_id_priv;
625 int ret;
626
627 /*
628 * The provider should never generate a connection request
629 * event with a bad status.
630 */
631 BUG_ON(iw_event->status);
632
633 cm_id = iw_create_cm_id(listen_id_priv->id.device,
634 listen_id_priv->id.cm_handler,
635 listen_id_priv->id.context);
636 /* If the cm_id could not be created, ignore the request */
637 if (IS_ERR(cm_id))
638 goto out;
639
640 cm_id->provider_data = iw_event->provider_data;
641 cm_id->local_addr = iw_event->local_addr;
642 cm_id->remote_addr = iw_event->remote_addr;
643
644 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
645 cm_id_priv->state = IW_CM_STATE_CONN_RECV;
646
647 /*
648 * We could be destroying the listening id. If so, ignore this
649 * upcall.
650 */
651 spin_lock_irqsave(&listen_id_priv->lock, flags);
652 if (listen_id_priv->state != IW_CM_STATE_LISTEN) {
653 spin_unlock_irqrestore(&listen_id_priv->lock, flags);
654 iw_cm_reject(cm_id, NULL, 0);
655 iw_destroy_cm_id(cm_id);
656 goto out;
657 }
658 spin_unlock_irqrestore(&listen_id_priv->lock, flags);
659
660 ret = alloc_work_entries(cm_id_priv, 3);
661 if (ret) {
662 iw_cm_reject(cm_id, NULL, 0);
663 iw_destroy_cm_id(cm_id);
664 goto out;
665 }
666
667 /* Call the client CM handler */
668 ret = cm_id->cm_handler(cm_id, iw_event);
669 if (ret) {
670 iw_cm_reject(cm_id, NULL, 0);
671 set_bit(IWCM_F_CALLBACK_DESTROY, &cm_id_priv->flags);
672 destroy_cm_id(cm_id);
673 if (atomic_read(&cm_id_priv->refcount)==0)
674 free_cm_id(cm_id_priv);
675 }
676
677out:
678 if (iw_event->private_data_len)
679 kfree(iw_event->private_data);
680}
681
682/*
683 * Passive Side: CM_ID <-- ESTABLISHED
684 *
685 * The provider generated an ESTABLISHED event which means that
686 * the MPA negotion has completed successfully and we are now in MPA
687 * FPDU mode.
688 *
689 * This event can only be received in the CONN_RECV state. If the
690 * remote peer closed, the ESTABLISHED event would be received followed
691 * by the CLOSE event. If the app closes, it will block until we wake
692 * it up after processing this event.
693 */
694static int cm_conn_est_handler(struct iwcm_id_private *cm_id_priv,
695 struct iw_cm_event *iw_event)
696{
697 unsigned long flags;
698 int ret;
699
700 spin_lock_irqsave(&cm_id_priv->lock, flags);
701
702 /*
703 * We clear the CONNECT_WAIT bit here to allow the callback
704 * function to call iw_cm_disconnect. Calling iw_destroy_cm_id
705 * from a callback handler is not allowed.
706 */
707 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
708 BUG_ON(cm_id_priv->state != IW_CM_STATE_CONN_RECV);
709 cm_id_priv->state = IW_CM_STATE_ESTABLISHED;
710 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
711 ret = cm_id_priv->id.cm_handler(&cm_id_priv->id, iw_event);
712 wake_up_all(&cm_id_priv->connect_wait);
713
714 return ret;
715}
716
717/*
718 * Active Side: CM_ID <-- ESTABLISHED
719 *
720 * The app has called connect and is waiting for the established event to
721 * post it's requests to the server. This event will wake up anyone
722 * blocked in iw_cm_disconnect or iw_destroy_id.
723 */
724static int cm_conn_rep_handler(struct iwcm_id_private *cm_id_priv,
725 struct iw_cm_event *iw_event)
726{
727 unsigned long flags;
728 int ret;
729
730 spin_lock_irqsave(&cm_id_priv->lock, flags);
731 /*
732 * Clear the connect wait bit so a callback function calling
733 * iw_cm_disconnect will not wait and deadlock this thread
734 */
735 clear_bit(IWCM_F_CONNECT_WAIT, &cm_id_priv->flags);
736 BUG_ON(cm_id_priv->state != IW_CM_STATE_CONN_SENT);
737 if (iw_event->status == 0) {
738 cm_id_priv->id.local_addr = iw_event->local_addr;
739 cm_id_priv->id.remote_addr = iw_event->remote_addr;
740 cm_id_priv->state = IW_CM_STATE_ESTABLISHED;
741 } else {
742 /* REJECTED or RESET */
743 cm_id_priv->id.device->iwcm->rem_ref(cm_id_priv->qp);
744 cm_id_priv->qp = NULL;
745 cm_id_priv->state = IW_CM_STATE_IDLE;
746 }
747 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
748 ret = cm_id_priv->id.cm_handler(&cm_id_priv->id, iw_event);
749
750 if (iw_event->private_data_len)
751 kfree(iw_event->private_data);
752
753 /* Wake up waiters on connect complete */
754 wake_up_all(&cm_id_priv->connect_wait);
755
756 return ret;
757}
758
759/*
760 * CM_ID <-- CLOSING
761 *
762 * If in the ESTABLISHED state, move to CLOSING.
763 */
764static void cm_disconnect_handler(struct iwcm_id_private *cm_id_priv,
765 struct iw_cm_event *iw_event)
766{
767 unsigned long flags;
768
769 spin_lock_irqsave(&cm_id_priv->lock, flags);
770 if (cm_id_priv->state == IW_CM_STATE_ESTABLISHED)
771 cm_id_priv->state = IW_CM_STATE_CLOSING;
772 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
773}
774
775/*
776 * CM_ID <-- IDLE
777 *
778 * If in the ESTBLISHED or CLOSING states, the QP will have have been
779 * moved by the provider to the ERR state. Disassociate the CM_ID from
780 * the QP, move to IDLE, and remove the 'connected' reference.
781 *
782 * If in some other state, the cm_id was destroyed asynchronously.
783 * This is the last reference that will result in waking up
784 * the app thread blocked in iw_destroy_cm_id.
785 */
786static int cm_close_handler(struct iwcm_id_private *cm_id_priv,
787 struct iw_cm_event *iw_event)
788{
789 unsigned long flags;
790 int ret = 0;
791 spin_lock_irqsave(&cm_id_priv->lock, flags);
792
793 if (cm_id_priv->qp) {
794 cm_id_priv->id.device->iwcm->rem_ref(cm_id_priv->qp);
795 cm_id_priv->qp = NULL;
796 }
797 switch (cm_id_priv->state) {
798 case IW_CM_STATE_ESTABLISHED:
799 case IW_CM_STATE_CLOSING:
800 cm_id_priv->state = IW_CM_STATE_IDLE;
801 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
802 ret = cm_id_priv->id.cm_handler(&cm_id_priv->id, iw_event);
803 spin_lock_irqsave(&cm_id_priv->lock, flags);
804 break;
805 case IW_CM_STATE_DESTROYING:
806 break;
807 default:
808 BUG();
809 }
810 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
811
812 return ret;
813}
814
815static int process_event(struct iwcm_id_private *cm_id_priv,
816 struct iw_cm_event *iw_event)
817{
818 int ret = 0;
819
820 switch (iw_event->event) {
821 case IW_CM_EVENT_CONNECT_REQUEST:
822 cm_conn_req_handler(cm_id_priv, iw_event);
823 break;
824 case IW_CM_EVENT_CONNECT_REPLY:
825 ret = cm_conn_rep_handler(cm_id_priv, iw_event);
826 break;
827 case IW_CM_EVENT_ESTABLISHED:
828 ret = cm_conn_est_handler(cm_id_priv, iw_event);
829 break;
830 case IW_CM_EVENT_DISCONNECT:
831 cm_disconnect_handler(cm_id_priv, iw_event);
832 break;
833 case IW_CM_EVENT_CLOSE:
834 ret = cm_close_handler(cm_id_priv, iw_event);
835 break;
836 default:
837 BUG();
838 }
839
840 return ret;
841}
842
843/*
844 * Process events on the work_list for the cm_id. If the callback
845 * function requests that the cm_id be deleted, a flag is set in the
846 * cm_id flags to indicate that when the last reference is
847 * removed, the cm_id is to be destroyed. This is necessary to
848 * distinguish between an object that will be destroyed by the app
849 * thread asleep on the destroy_comp list vs. an object destroyed
850 * here synchronously when the last reference is removed.
851 */
852static void cm_work_handler(struct work_struct *_work)
853{
854 struct iwcm_work *work = container_of(_work, struct iwcm_work, work);
855 struct iw_cm_event levent;
856 struct iwcm_id_private *cm_id_priv = work->cm_id;
857 unsigned long flags;
858 int empty;
859 int ret = 0;
860 int destroy_id;
861
862 spin_lock_irqsave(&cm_id_priv->lock, flags);
863 empty = list_empty(&cm_id_priv->work_list);
864 while (!empty) {
865 work = list_entry(cm_id_priv->work_list.next,
866 struct iwcm_work, list);
867 list_del_init(&work->list);
868 empty = list_empty(&cm_id_priv->work_list);
869 levent = work->event;
870 put_work(work);
871 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
872
873 ret = process_event(cm_id_priv, &levent);
874 if (ret) {
875 set_bit(IWCM_F_CALLBACK_DESTROY, &cm_id_priv->flags);
876 destroy_cm_id(&cm_id_priv->id);
877 }
878 BUG_ON(atomic_read(&cm_id_priv->refcount)==0);
879 destroy_id = test_bit(IWCM_F_CALLBACK_DESTROY, &cm_id_priv->flags);
880 if (iwcm_deref_id(cm_id_priv)) {
881 if (destroy_id) {
882 BUG_ON(!list_empty(&cm_id_priv->work_list));
883 free_cm_id(cm_id_priv);
884 }
885 return;
886 }
887 if (empty)
888 return;
889 spin_lock_irqsave(&cm_id_priv->lock, flags);
890 }
891 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
892}
893
894/*
895 * This function is called on interrupt context. Schedule events on
896 * the iwcm_wq thread to allow callback functions to downcall into
897 * the CM and/or block. Events are queued to a per-CM_ID
898 * work_list. If this is the first event on the work_list, the work
899 * element is also queued on the iwcm_wq thread.
900 *
901 * Each event holds a reference on the cm_id. Until the last posted
902 * event has been delivered and processed, the cm_id cannot be
903 * deleted.
904 *
905 * Returns:
906 * 0 - the event was handled.
907 * -ENOMEM - the event was not handled due to lack of resources.
908 */
909static int cm_event_handler(struct iw_cm_id *cm_id,
910 struct iw_cm_event *iw_event)
911{
912 struct iwcm_work *work;
913 struct iwcm_id_private *cm_id_priv;
914 unsigned long flags;
915 int ret = 0;
916
917 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
918
919 spin_lock_irqsave(&cm_id_priv->lock, flags);
920 work = get_work(cm_id_priv);
921 if (!work) {
922 ret = -ENOMEM;
923 goto out;
924 }
925
926 INIT_WORK(&work->work, cm_work_handler);
927 work->cm_id = cm_id_priv;
928 work->event = *iw_event;
929
930 if ((work->event.event == IW_CM_EVENT_CONNECT_REQUEST ||
931 work->event.event == IW_CM_EVENT_CONNECT_REPLY) &&
932 work->event.private_data_len) {
933 ret = copy_private_data(&work->event);
934 if (ret) {
935 put_work(work);
936 goto out;
937 }
938 }
939
940 atomic_inc(&cm_id_priv->refcount);
941 if (list_empty(&cm_id_priv->work_list)) {
942 list_add_tail(&work->list, &cm_id_priv->work_list);
943 queue_work(iwcm_wq, &work->work);
944 } else
945 list_add_tail(&work->list, &cm_id_priv->work_list);
946out:
947 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
948 return ret;
949}
950
951static int iwcm_init_qp_init_attr(struct iwcm_id_private *cm_id_priv,
952 struct ib_qp_attr *qp_attr,
953 int *qp_attr_mask)
954{
955 unsigned long flags;
956 int ret;
957
958 spin_lock_irqsave(&cm_id_priv->lock, flags);
959 switch (cm_id_priv->state) {
960 case IW_CM_STATE_IDLE:
961 case IW_CM_STATE_CONN_SENT:
962 case IW_CM_STATE_CONN_RECV:
963 case IW_CM_STATE_ESTABLISHED:
964 *qp_attr_mask = IB_QP_STATE | IB_QP_ACCESS_FLAGS;
965 qp_attr->qp_access_flags = IB_ACCESS_REMOTE_WRITE|
966 IB_ACCESS_REMOTE_READ;
967 ret = 0;
968 break;
969 default:
970 ret = -EINVAL;
971 break;
972 }
973 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
974 return ret;
975}
976
977static int iwcm_init_qp_rts_attr(struct iwcm_id_private *cm_id_priv,
978 struct ib_qp_attr *qp_attr,
979 int *qp_attr_mask)
980{
981 unsigned long flags;
982 int ret;
983
984 spin_lock_irqsave(&cm_id_priv->lock, flags);
985 switch (cm_id_priv->state) {
986 case IW_CM_STATE_IDLE:
987 case IW_CM_STATE_CONN_SENT:
988 case IW_CM_STATE_CONN_RECV:
989 case IW_CM_STATE_ESTABLISHED:
990 *qp_attr_mask = 0;
991 ret = 0;
992 break;
993 default:
994 ret = -EINVAL;
995 break;
996 }
997 spin_unlock_irqrestore(&cm_id_priv->lock, flags);
998 return ret;
999}
1000
1001int iw_cm_init_qp_attr(struct iw_cm_id *cm_id,
1002 struct ib_qp_attr *qp_attr,
1003 int *qp_attr_mask)
1004{
1005 struct iwcm_id_private *cm_id_priv;
1006 int ret;
1007
1008 cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
1009 switch (qp_attr->qp_state) {
1010 case IB_QPS_INIT:
1011 case IB_QPS_RTR:
1012 ret = iwcm_init_qp_init_attr(cm_id_priv,
1013 qp_attr, qp_attr_mask);
1014 break;
1015 case IB_QPS_RTS:
1016 ret = iwcm_init_qp_rts_attr(cm_id_priv,
1017 qp_attr, qp_attr_mask);
1018 break;
1019 default:
1020 ret = -EINVAL;
1021 break;
1022 }
1023 return ret;
1024}
1025EXPORT_SYMBOL(iw_cm_init_qp_attr);
1026
1027static int __init iw_cm_init(void)
1028{
1029 iwcm_wq = create_singlethread_workqueue("iw_cm_wq");
1030 if (!iwcm_wq)
1031 return -ENOMEM;
1032
1033 return 0;
1034}
1035
1036static void __exit iw_cm_cleanup(void)
1037{
1038 destroy_workqueue(iwcm_wq);
1039}
1040
1041module_init(iw_cm_init);
1042module_exit(iw_cm_cleanup);