xref: /freebsd/sys/contrib/vchiq/interface/vchiq_arm/vchiq_arm.c (revision 09a53ad8f1318c5daae6cfb19d97f4f6459f0013)
1 /**
2  * Copyright (c) 2014 Raspberry Pi (Trading) Ltd. All rights reserved.
3  * Copyright (c) 2010-2012 Broadcom. All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions, and the following disclaimer,
10  *    without modification.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. The names of the above-listed copyright holders may not be used
15  *    to endorse or promote products derived from this software without
16  *    specific prior written permission.
17  *
18  * ALTERNATIVELY, this software may be distributed under the terms of the
19  * GNU General Public License ("GPL") version 2, as published by the Free
20  * Software Foundation.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
23  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
24  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
25  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
26  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
27  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
28  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
29  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
30  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
31  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
32  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33  */
34 
35 
36 #include "vchiq_core.h"
37 #include "vchiq_ioctl.h"
38 #include "vchiq_arm.h"
39 
40 #define DEVICE_NAME "vchiq"
41 
42 /* Override the default prefix, which would be vchiq_arm (from the filename) */
43 #undef MODULE_PARAM_PREFIX
44 #define MODULE_PARAM_PREFIX DEVICE_NAME "."
45 
46 #define VCHIQ_MINOR 0
47 
48 /* Some per-instance constants */
49 #define MAX_COMPLETIONS 128
50 #define MAX_SERVICES 64
51 #define MAX_ELEMENTS 8
52 #define MSG_QUEUE_SIZE 128
53 
54 #define KEEPALIVE_VER 1
55 #define KEEPALIVE_VER_MIN KEEPALIVE_VER
56 
57 /* Run time control of log level, based on KERN_XXX level. */
58 int vchiq_arm_log_level = VCHIQ_LOG_DEFAULT;
59 int vchiq_susp_log_level = VCHIQ_LOG_ERROR;
60 
61 #define SUSPEND_TIMER_TIMEOUT_MS 100
62 #define SUSPEND_RETRY_TIMER_TIMEOUT_MS 1000
63 
64 #define VC_SUSPEND_NUM_OFFSET 3 /* number of values before idle which are -ve */
65 static const char *const suspend_state_names[] = {
66 	"VC_SUSPEND_FORCE_CANCELED",
67 	"VC_SUSPEND_REJECTED",
68 	"VC_SUSPEND_FAILED",
69 	"VC_SUSPEND_IDLE",
70 	"VC_SUSPEND_REQUESTED",
71 	"VC_SUSPEND_IN_PROGRESS",
72 	"VC_SUSPEND_SUSPENDED"
73 };
74 #define VC_RESUME_NUM_OFFSET 1 /* number of values before idle which are -ve */
75 static const char *const resume_state_names[] = {
76 	"VC_RESUME_FAILED",
77 	"VC_RESUME_IDLE",
78 	"VC_RESUME_REQUESTED",
79 	"VC_RESUME_IN_PROGRESS",
80 	"VC_RESUME_RESUMED"
81 };
82 /* The number of times we allow force suspend to timeout before actually
83 ** _forcing_ suspend.  This is to cater for SW which fails to release vchiq
84 ** correctly - we don't want to prevent ARM suspend indefinitely in this case.
85 */
86 #define FORCE_SUSPEND_FAIL_MAX 8
87 
88 /* The time in ms allowed for videocore to go idle when force suspend has been
89  * requested */
90 #define FORCE_SUSPEND_TIMEOUT_MS 200
91 
92 
93 static void suspend_timer_callback(unsigned long context);
94 #ifdef notyet
95 static int vchiq_proc_add_instance(VCHIQ_INSTANCE_T instance);
96 static void vchiq_proc_remove_instance(VCHIQ_INSTANCE_T instance);
97 #endif
98 
99 
100 typedef struct user_service_struct {
101 	VCHIQ_SERVICE_T *service;
102 	void *userdata;
103 	VCHIQ_INSTANCE_T instance;
104 	char is_vchi;
105 	char dequeue_pending;
106 	char close_pending;
107 	int message_available_pos;
108 	int msg_insert;
109 	int msg_remove;
110 	struct semaphore insert_event;
111 	struct semaphore remove_event;
112 	struct semaphore close_event;
113 	VCHIQ_HEADER_T * msg_queue[MSG_QUEUE_SIZE];
114 } USER_SERVICE_T;
115 
116 struct bulk_waiter_node {
117 	struct bulk_waiter bulk_waiter;
118 	int pid;
119 	struct list_head list;
120 };
121 
122 struct vchiq_instance_struct {
123 	VCHIQ_STATE_T *state;
124 	VCHIQ_COMPLETION_DATA_T completions[MAX_COMPLETIONS];
125 	int completion_insert;
126 	int completion_remove;
127 	struct semaphore insert_event;
128 	struct semaphore remove_event;
129 	struct mutex completion_mutex;
130 
131 	int connected;
132 	int closing;
133 	int pid;
134 	int mark;
135 	int use_close_delivered;
136 	int trace;
137 
138 	struct list_head bulk_waiter_list;
139 	struct mutex bulk_waiter_list_mutex;
140 
141 #ifdef notyet
142 	VCHIQ_DEBUGFS_NODE_T proc_entry;
143 #endif
144 };
145 
146 typedef struct dump_context_struct {
147 	char __user *buf;
148 	size_t actual;
149 	size_t space;
150 	loff_t offset;
151 } DUMP_CONTEXT_T;
152 
153 static struct cdev *  vchiq_cdev;
154 VCHIQ_STATE_T g_state;
155 static DEFINE_SPINLOCK(msg_queue_spinlock);
156 
157 static const char *const ioctl_names[] = {
158 	"CONNECT",
159 	"SHUTDOWN",
160 	"CREATE_SERVICE",
161 	"REMOVE_SERVICE",
162 	"QUEUE_MESSAGE",
163 	"QUEUE_BULK_TRANSMIT",
164 	"QUEUE_BULK_RECEIVE",
165 	"AWAIT_COMPLETION",
166 	"DEQUEUE_MESSAGE",
167 	"GET_CLIENT_ID",
168 	"GET_CONFIG",
169 	"CLOSE_SERVICE",
170 	"USE_SERVICE",
171 	"RELEASE_SERVICE",
172 	"SET_SERVICE_OPTION",
173 	"DUMP_PHYS_MEM",
174 	"LIB_VERSION",
175 	"CLOSE_DELIVERED"
176 };
177 
178 vchiq_static_assert((sizeof(ioctl_names)/sizeof(ioctl_names[0])) ==
179 	(VCHIQ_IOC_MAX + 1));
180 
181 static eventhandler_tag vchiq_ehtag = NULL;
182 static d_open_t		vchiq_open;
183 static d_close_t	vchiq_close;
184 static d_ioctl_t	vchiq_ioctl;
185 
186 static struct cdevsw vchiq_cdevsw = {
187 	.d_version	= D_VERSION,
188 	.d_ioctl	= vchiq_ioctl,
189 	.d_open		= vchiq_open,
190 	.d_close	= vchiq_close,
191 	.d_name		= DEVICE_NAME,
192 };
193 
194 #if 0
195 static void
196 dump_phys_mem(void *virt_addr, uint32_t num_bytes);
197 #endif
198 
199 /****************************************************************************
200 *
201 *   add_completion
202 *
203 ***************************************************************************/
204 
205 static VCHIQ_STATUS_T
206 add_completion(VCHIQ_INSTANCE_T instance, VCHIQ_REASON_T reason,
207 	VCHIQ_HEADER_T *header, USER_SERVICE_T *user_service,
208 	void *bulk_userdata)
209 {
210 	VCHIQ_COMPLETION_DATA_T *completion;
211 	int insert;
212 	DEBUG_INITIALISE(g_state.local)
213 
214 	insert = instance->completion_insert;
215 	while ((insert - instance->completion_remove) >= MAX_COMPLETIONS) {
216 		/* Out of space - wait for the client */
217 		DEBUG_TRACE(SERVICE_CALLBACK_LINE);
218 		vchiq_log_trace(vchiq_arm_log_level,
219 			"add_completion - completion queue full");
220 		DEBUG_COUNT(COMPLETION_QUEUE_FULL_COUNT);
221 
222 		if (down_interruptible(&instance->remove_event) != 0) {
223 			vchiq_log_info(vchiq_arm_log_level,
224 				"service_callback interrupted");
225 			return VCHIQ_RETRY;
226 		}
227 
228 		if (instance->closing) {
229 			vchiq_log_info(vchiq_arm_log_level,
230 				"service_callback closing");
231 			return VCHIQ_SUCCESS;
232 		}
233 		DEBUG_TRACE(SERVICE_CALLBACK_LINE);
234 	}
235 
236 	completion = &instance->completions[insert & (MAX_COMPLETIONS - 1)];
237 
238 	completion->header = header;
239 	completion->reason = reason;
240 	/* N.B. service_userdata is updated while processing AWAIT_COMPLETION */
241 	completion->service_userdata = user_service->service;
242 	completion->bulk_userdata = bulk_userdata;
243 
244 	if (reason == VCHIQ_SERVICE_CLOSED) {
245 		/* Take an extra reference, to be held until
246 		   this CLOSED notification is delivered. */
247 		lock_service(user_service->service);
248 		if (instance->use_close_delivered)
249 			user_service->close_pending = 1;
250 	}
251 
252 	/* A write barrier is needed here to ensure that the entire completion
253 		record is written out before the insert point. */
254 	wmb();
255 
256 	if (reason == VCHIQ_MESSAGE_AVAILABLE)
257 		user_service->message_available_pos = insert;
258 
259 	instance->completion_insert = ++insert;
260 
261 	up(&instance->insert_event);
262 
263 	return VCHIQ_SUCCESS;
264 }
265 
266 /****************************************************************************
267 *
268 *   service_callback
269 *
270 ***************************************************************************/
271 
272 static VCHIQ_STATUS_T
273 service_callback(VCHIQ_REASON_T reason, VCHIQ_HEADER_T *header,
274 	VCHIQ_SERVICE_HANDLE_T handle, void *bulk_userdata)
275 {
276 	/* How do we ensure the callback goes to the right client?
277 	** The service_user data points to a USER_SERVICE_T record containing
278 	** the original callback and the user state structure, which contains a
279 	** circular buffer for completion records.
280 	*/
281 	USER_SERVICE_T *user_service;
282 	VCHIQ_SERVICE_T *service;
283 	VCHIQ_INSTANCE_T instance;
284 	int skip_completion = 0;
285 	DEBUG_INITIALISE(g_state.local)
286 
287 	DEBUG_TRACE(SERVICE_CALLBACK_LINE);
288 
289 	service = handle_to_service(handle);
290 	BUG_ON(!service);
291 	user_service = (USER_SERVICE_T *)service->base.userdata;
292 	instance = user_service->instance;
293 
294 	if (!instance || instance->closing)
295 		return VCHIQ_SUCCESS;
296 
297 	vchiq_log_trace(vchiq_arm_log_level,
298 		"service_callback - service %lx(%d,%p), reason %d, header %lx, "
299 		"instance %lx, bulk_userdata %lx",
300 		(unsigned long)user_service,
301 		service->localport, user_service->userdata,
302 		reason, (unsigned long)header,
303 		(unsigned long)instance, (unsigned long)bulk_userdata);
304 
305 	if (header && user_service->is_vchi) {
306 		spin_lock(&msg_queue_spinlock);
307 		while (user_service->msg_insert ==
308 			(user_service->msg_remove + MSG_QUEUE_SIZE)) {
309 			spin_unlock(&msg_queue_spinlock);
310 			DEBUG_TRACE(SERVICE_CALLBACK_LINE);
311 			DEBUG_COUNT(MSG_QUEUE_FULL_COUNT);
312 			vchiq_log_trace(vchiq_arm_log_level,
313 				"service_callback - msg queue full");
314 			/* If there is no MESSAGE_AVAILABLE in the completion
315 			** queue, add one
316 			*/
317 			if ((user_service->message_available_pos -
318 				instance->completion_remove) < 0) {
319 				VCHIQ_STATUS_T status;
320 				vchiq_log_info(vchiq_arm_log_level,
321 					"Inserting extra MESSAGE_AVAILABLE");
322 				DEBUG_TRACE(SERVICE_CALLBACK_LINE);
323 				status = add_completion(instance, reason,
324 					NULL, user_service, bulk_userdata);
325 				if (status != VCHIQ_SUCCESS) {
326 					DEBUG_TRACE(SERVICE_CALLBACK_LINE);
327 					return status;
328 				}
329 			}
330 
331 			DEBUG_TRACE(SERVICE_CALLBACK_LINE);
332 			if (down_interruptible(&user_service->remove_event)
333 				!= 0) {
334 				vchiq_log_info(vchiq_arm_log_level,
335 					"service_callback interrupted");
336 				DEBUG_TRACE(SERVICE_CALLBACK_LINE);
337 				return VCHIQ_RETRY;
338 			} else if (instance->closing) {
339 				vchiq_log_info(vchiq_arm_log_level,
340 					"service_callback closing");
341 				DEBUG_TRACE(SERVICE_CALLBACK_LINE);
342 				return VCHIQ_ERROR;
343 			}
344 			DEBUG_TRACE(SERVICE_CALLBACK_LINE);
345 			spin_lock(&msg_queue_spinlock);
346 		}
347 
348 		user_service->msg_queue[user_service->msg_insert &
349 			(MSG_QUEUE_SIZE - 1)] = header;
350 		user_service->msg_insert++;
351 
352 		/* If there is a thread waiting in DEQUEUE_MESSAGE, or if
353 		** there is a MESSAGE_AVAILABLE in the completion queue then
354 		** bypass the completion queue.
355 		*/
356 		if (((user_service->message_available_pos -
357 			instance->completion_remove) >= 0) ||
358 			user_service->dequeue_pending) {
359 			user_service->dequeue_pending = 0;
360 			skip_completion = 1;
361 		}
362 
363 		spin_unlock(&msg_queue_spinlock);
364 
365 		up(&user_service->insert_event);
366 
367 		header = NULL;
368 	}
369 
370 	if (skip_completion) {
371 		DEBUG_TRACE(SERVICE_CALLBACK_LINE);
372 		return VCHIQ_SUCCESS;
373 	}
374 
375 	DEBUG_TRACE(SERVICE_CALLBACK_LINE);
376 
377 	return add_completion(instance, reason, header, user_service,
378 		bulk_userdata);
379 }
380 
381 /****************************************************************************
382 *
383 *   user_service_free
384 *
385 ***************************************************************************/
386 static void
387 user_service_free(void *userdata)
388 {
389 	USER_SERVICE_T *user_service = userdata;
390 
391 	_sema_destroy(&user_service->insert_event);
392 	_sema_destroy(&user_service->remove_event);
393 
394 	kfree(user_service);
395 }
396 
397 /****************************************************************************
398 *
399 *   close_delivered
400 *
401 ***************************************************************************/
402 static void close_delivered(USER_SERVICE_T *user_service)
403 {
404 	vchiq_log_info(vchiq_arm_log_level,
405 		"close_delivered(handle=%x)",
406 		user_service->service->handle);
407 
408 	if (user_service->close_pending) {
409 		/* Allow the underlying service to be culled */
410 		unlock_service(user_service->service);
411 
412 		/* Wake the user-thread blocked in close_ or remove_service */
413 		up(&user_service->close_event);
414 
415 		user_service->close_pending = 0;
416 	}
417 }
418 
419 /****************************************************************************
420 *
421 *   vchiq_ioctl
422 *
423 ***************************************************************************/
424 
425 static int
426 vchiq_ioctl(struct cdev *cdev, u_long cmd, caddr_t arg, int fflag,
427    struct thread *td)
428 {
429 	VCHIQ_INSTANCE_T instance;
430 	VCHIQ_STATUS_T status = VCHIQ_SUCCESS;
431 	VCHIQ_SERVICE_T *service = NULL;
432 	int ret = 0;
433 	int i, rc;
434 	DEBUG_INITIALISE(g_state.local)
435 
436 	if ((ret = devfs_get_cdevpriv((void**)&instance))) {
437 		printf("vchiq_ioctl: devfs_get_cdevpriv failed: error %d\n", ret);
438 		return (ret);
439 	}
440 
441 /* XXXBSD: HACK! */
442 #define _IOC_NR(x) ((x) & 0xff)
443 #define	_IOC_TYPE(x)	IOCGROUP(x)
444 
445 	vchiq_log_trace(vchiq_arm_log_level,
446 		 "vchiq_ioctl - instance %x, cmd %s, arg %p",
447 		(unsigned int)instance,
448 		((_IOC_TYPE(cmd) == VCHIQ_IOC_MAGIC) &&
449 		(_IOC_NR(cmd) <= VCHIQ_IOC_MAX)) ?
450 		ioctl_names[_IOC_NR(cmd)] : "<invalid>", arg);
451 
452 	switch (cmd) {
453 	case VCHIQ_IOC_SHUTDOWN:
454 		if (!instance->connected)
455 			break;
456 
457 		/* Remove all services */
458 		i = 0;
459 		while ((service = next_service_by_instance(instance->state,
460 			instance, &i)) != NULL) {
461 			status = vchiq_remove_service(service->handle);
462 			unlock_service(service);
463 			if (status != VCHIQ_SUCCESS)
464 				break;
465 		}
466 		service = NULL;
467 
468 		if (status == VCHIQ_SUCCESS) {
469 			/* Wake the completion thread and ask it to exit */
470 			instance->closing = 1;
471 			up(&instance->insert_event);
472 		}
473 
474 		break;
475 
476 	case VCHIQ_IOC_CONNECT:
477 		if (instance->connected) {
478 			ret = -EINVAL;
479 			break;
480 		}
481 		rc = lmutex_lock_interruptible(&instance->state->mutex);
482 		if (rc != 0) {
483 			vchiq_log_error(vchiq_arm_log_level,
484 				"vchiq: connect: could not lock mutex for "
485 				"state %d: %d",
486 				instance->state->id, rc);
487 			ret = -EINTR;
488 			break;
489 		}
490 		status = vchiq_connect_internal(instance->state, instance);
491 		lmutex_unlock(&instance->state->mutex);
492 
493 		if (status == VCHIQ_SUCCESS)
494 			instance->connected = 1;
495 		else
496 			vchiq_log_error(vchiq_arm_log_level,
497 				"vchiq: could not connect: %d", status);
498 		break;
499 
500 	case VCHIQ_IOC_CREATE_SERVICE: {
501 		VCHIQ_CREATE_SERVICE_T args;
502 		USER_SERVICE_T *user_service = NULL;
503 		void *userdata;
504 		int srvstate;
505 
506 		memcpy(&args, (const void*)arg, sizeof(args));
507 
508 		user_service = kmalloc(sizeof(USER_SERVICE_T), GFP_KERNEL);
509 		if (!user_service) {
510 			ret = -ENOMEM;
511 			break;
512 		}
513 
514 		if (args.is_open) {
515 			if (!instance->connected) {
516 				ret = -ENOTCONN;
517 				kfree(user_service);
518 				break;
519 			}
520 			srvstate = VCHIQ_SRVSTATE_OPENING;
521 		} else {
522 			srvstate =
523 				 instance->connected ?
524 				 VCHIQ_SRVSTATE_LISTENING :
525 				 VCHIQ_SRVSTATE_HIDDEN;
526 		}
527 
528 		userdata = args.params.userdata;
529 		args.params.callback = service_callback;
530 		args.params.userdata = user_service;
531 		service = vchiq_add_service_internal(
532 				instance->state,
533 				&args.params, srvstate,
534 				instance, user_service_free);
535 
536 		if (service != NULL) {
537 			user_service->service = service;
538 			user_service->userdata = userdata;
539 			user_service->instance = instance;
540 			user_service->is_vchi = (args.is_vchi != 0);
541 			user_service->dequeue_pending = 0;
542 			user_service->close_pending = 0;
543 			user_service->message_available_pos =
544 				instance->completion_remove - 1;
545 			user_service->msg_insert = 0;
546 			user_service->msg_remove = 0;
547 			_sema_init(&user_service->insert_event, 0);
548 			_sema_init(&user_service->remove_event, 0);
549 			_sema_init(&user_service->close_event, 0);
550 
551 			if (args.is_open) {
552 				status = vchiq_open_service_internal
553 					(service, instance->pid);
554 				if (status != VCHIQ_SUCCESS) {
555 					vchiq_remove_service(service->handle);
556 					service = NULL;
557 					ret = (status == VCHIQ_RETRY) ?
558 						-EINTR : -EIO;
559 					break;
560 				}
561 			}
562 
563 #ifdef VCHIQ_IOCTL_DEBUG
564 			printf("%s: [CREATE SERVICE] handle = %08x\n", __func__, service->handle);
565 #endif
566 			memcpy((void *)
567 				&(((VCHIQ_CREATE_SERVICE_T*)
568 					arg)->handle),
569 				(const void *)&service->handle,
570 				sizeof(service->handle));
571 
572 			service = NULL;
573 		} else {
574 			ret = -EEXIST;
575 			kfree(user_service);
576 		}
577 	} break;
578 
579 	case VCHIQ_IOC_CLOSE_SERVICE: {
580 		VCHIQ_SERVICE_HANDLE_T handle;
581 
582 		memcpy(&handle, (const void*)arg, sizeof(handle));
583 
584 #ifdef VCHIQ_IOCTL_DEBUG
585 		printf("%s: [CLOSE SERVICE] handle = %08x\n", __func__, handle);
586 #endif
587 
588 		service = find_service_for_instance(instance, handle);
589 		if (service != NULL) {
590 			USER_SERVICE_T *user_service =
591 				(USER_SERVICE_T *)service->base.userdata;
592 			/* close_pending is false on first entry, and when the
593                            wait in vchiq_close_service has been interrupted. */
594 			if (!user_service->close_pending) {
595 				status = vchiq_close_service(service->handle);
596 				if (status != VCHIQ_SUCCESS)
597 					break;
598 			}
599 
600 			/* close_pending is true once the underlying service
601 			   has been closed until the client library calls the
602 			   CLOSE_DELIVERED ioctl, signalling close_event. */
603 			if (user_service->close_pending &&
604 				down_interruptible(&user_service->close_event))
605 				status = VCHIQ_RETRY;
606 		}
607 		else
608 			ret = -EINVAL;
609 	} break;
610 
611 	case VCHIQ_IOC_REMOVE_SERVICE: {
612 		VCHIQ_SERVICE_HANDLE_T handle;
613 
614 		memcpy(&handle, (const void*)arg, sizeof(handle));
615 
616 #ifdef VCHIQ_IOCTL_DEBUG
617 		printf("%s: [REMOVE SERVICE] handle = %08x\n", __func__, handle);
618 #endif
619 
620 		service = find_service_for_instance(instance, handle);
621 		if (service != NULL) {
622 			USER_SERVICE_T *user_service =
623 				(USER_SERVICE_T *)service->base.userdata;
624 			/* close_pending is false on first entry, and when the
625                            wait in vchiq_close_service has been interrupted. */
626 			if (!user_service->close_pending) {
627 				status = vchiq_remove_service(service->handle);
628 				if (status != VCHIQ_SUCCESS)
629 					break;
630 			}
631 
632 			/* close_pending is true once the underlying service
633 			   has been closed until the client library calls the
634 			   CLOSE_DELIVERED ioctl, signalling close_event. */
635 			if (user_service->close_pending &&
636 				down_interruptible(&user_service->close_event))
637 				status = VCHIQ_RETRY;
638 		}
639 		else
640 			ret = -EINVAL;
641 	} break;
642 
643 	case VCHIQ_IOC_USE_SERVICE:
644 	case VCHIQ_IOC_RELEASE_SERVICE:	{
645 		VCHIQ_SERVICE_HANDLE_T handle;
646 
647 		memcpy(&handle, (const void*)arg, sizeof(handle));
648 
649 #ifdef VCHIQ_IOCTL_DEBUG
650 		printf("%s: [%s SERVICE] handle = %08x\n", __func__,
651 		    cmd == VCHIQ_IOC_USE_SERVICE ? "USE" : "RELEASE", handle);
652 #endif
653 
654 		service = find_service_for_instance(instance, handle);
655 		if (service != NULL) {
656 			status = (cmd == VCHIQ_IOC_USE_SERVICE)	?
657 				vchiq_use_service_internal(service) :
658 				vchiq_release_service_internal(service);
659 			if (status != VCHIQ_SUCCESS) {
660 				vchiq_log_error(vchiq_susp_log_level,
661 					"%s: cmd %s returned error %d for "
662 					"service %c%c%c%c:%8x",
663 					__func__,
664 					(cmd == VCHIQ_IOC_USE_SERVICE) ?
665 						"VCHIQ_IOC_USE_SERVICE" :
666 						"VCHIQ_IOC_RELEASE_SERVICE",
667 					status,
668 					VCHIQ_FOURCC_AS_4CHARS(
669 						service->base.fourcc),
670 					service->client_id);
671 				ret = -EINVAL;
672 			}
673 		} else
674 			ret = -EINVAL;
675 	} break;
676 
677 	case VCHIQ_IOC_QUEUE_MESSAGE: {
678 		VCHIQ_QUEUE_MESSAGE_T args;
679 		memcpy(&args, (const void*)arg, sizeof(args));
680 
681 #ifdef VCHIQ_IOCTL_DEBUG
682 		printf("%s: [QUEUE MESSAGE] handle = %08x\n", __func__, args.handle);
683 #endif
684 
685 		service = find_service_for_instance(instance, args.handle);
686 
687 		if ((service != NULL) && (args.count <= MAX_ELEMENTS)) {
688 			/* Copy elements into kernel space */
689 			VCHIQ_ELEMENT_T elements[MAX_ELEMENTS];
690 			if (copy_from_user(elements, args.elements,
691 				args.count * sizeof(VCHIQ_ELEMENT_T)) == 0)
692 				status = vchiq_queue_message
693 					(args.handle,
694 					elements, args.count);
695 			else
696 				ret = -EFAULT;
697 		} else {
698 			ret = -EINVAL;
699 		}
700 	} break;
701 
702 	case VCHIQ_IOC_QUEUE_BULK_TRANSMIT:
703 	case VCHIQ_IOC_QUEUE_BULK_RECEIVE: {
704 		VCHIQ_QUEUE_BULK_TRANSFER_T args;
705 		struct bulk_waiter_node *waiter = NULL;
706 		VCHIQ_BULK_DIR_T dir =
707 			(cmd == VCHIQ_IOC_QUEUE_BULK_TRANSMIT) ?
708 			VCHIQ_BULK_TRANSMIT : VCHIQ_BULK_RECEIVE;
709 
710 		memcpy(&args, (const void*)arg, sizeof(args));
711 
712 		service = find_service_for_instance(instance, args.handle);
713 		if (!service) {
714 			ret = -EINVAL;
715 			break;
716 		}
717 
718 		if (args.mode == VCHIQ_BULK_MODE_BLOCKING) {
719 			waiter = kzalloc(sizeof(struct bulk_waiter_node),
720 				GFP_KERNEL);
721 			if (!waiter) {
722 				ret = -ENOMEM;
723 				break;
724 			}
725 			args.userdata = &waiter->bulk_waiter;
726 		} else if (args.mode == VCHIQ_BULK_MODE_WAITING) {
727 			struct list_head *pos;
728 			lmutex_lock(&instance->bulk_waiter_list_mutex);
729 			list_for_each(pos, &instance->bulk_waiter_list) {
730 				if (list_entry(pos, struct bulk_waiter_node,
731 					list)->pid == current->p_pid) {
732 					waiter = list_entry(pos,
733 						struct bulk_waiter_node,
734 						list);
735 					list_del(pos);
736 					break;
737 				}
738 
739 			}
740 			lmutex_unlock(&instance->bulk_waiter_list_mutex);
741 			if (!waiter) {
742 				vchiq_log_error(vchiq_arm_log_level,
743 					"no bulk_waiter found for pid %d",
744 					current->p_pid);
745 				ret = -ESRCH;
746 				break;
747 			}
748 			vchiq_log_info(vchiq_arm_log_level,
749 				"found bulk_waiter %x for pid %d",
750 				(unsigned int)waiter, current->p_pid);
751 			args.userdata = &waiter->bulk_waiter;
752 		}
753 		status = vchiq_bulk_transfer
754 			(args.handle,
755 			 VCHI_MEM_HANDLE_INVALID,
756 			 args.data, args.size,
757 			 args.userdata, args.mode,
758 			 dir);
759 		if (!waiter)
760 			break;
761 		if ((status != VCHIQ_RETRY) || fatal_signal_pending(current) ||
762 			!waiter->bulk_waiter.bulk) {
763 			if (waiter->bulk_waiter.bulk) {
764 				/* Cancel the signal when the transfer
765 				** completes. */
766 				spin_lock(&bulk_waiter_spinlock);
767 				waiter->bulk_waiter.bulk->userdata = NULL;
768 				spin_unlock(&bulk_waiter_spinlock);
769 			}
770 			_sema_destroy(&waiter->bulk_waiter.event);
771 			kfree(waiter);
772 		} else {
773 			const VCHIQ_BULK_MODE_T mode_waiting =
774 				VCHIQ_BULK_MODE_WAITING;
775 			waiter->pid = current->p_pid;
776 			lmutex_lock(&instance->bulk_waiter_list_mutex);
777 			list_add(&waiter->list, &instance->bulk_waiter_list);
778 			lmutex_unlock(&instance->bulk_waiter_list_mutex);
779 			vchiq_log_info(vchiq_arm_log_level,
780 				"saved bulk_waiter %x for pid %d",
781 				(unsigned int)waiter, current->p_pid);
782 
783 			memcpy((void *)
784 				&(((VCHIQ_QUEUE_BULK_TRANSFER_T *)
785 					arg)->mode),
786 				(const void *)&mode_waiting,
787 				sizeof(mode_waiting));
788 		}
789 	} break;
790 
791 	case VCHIQ_IOC_AWAIT_COMPLETION: {
792 		VCHIQ_AWAIT_COMPLETION_T args;
793 		int count = 0;
794 
795 		DEBUG_TRACE(AWAIT_COMPLETION_LINE);
796 		if (!instance->connected) {
797 			ret = -ENOTCONN;
798 			break;
799 		}
800 
801                 memcpy(&args, (const void*)arg, sizeof(args));
802 
803 		lmutex_lock(&instance->completion_mutex);
804 
805 		DEBUG_TRACE(AWAIT_COMPLETION_LINE);
806 		while ((instance->completion_remove ==
807 			instance->completion_insert)
808 			&& !instance->closing) {
809 
810 			DEBUG_TRACE(AWAIT_COMPLETION_LINE);
811 			lmutex_unlock(&instance->completion_mutex);
812 			rc = down_interruptible(&instance->insert_event);
813 			lmutex_lock(&instance->completion_mutex);
814 			if (rc != 0) {
815 				DEBUG_TRACE(AWAIT_COMPLETION_LINE);
816 				vchiq_log_info(vchiq_arm_log_level,
817 					"AWAIT_COMPLETION interrupted");
818 				ret = -EINTR;
819 				break;
820 			}
821 		}
822 		DEBUG_TRACE(AWAIT_COMPLETION_LINE);
823 
824 		if (ret == 0) {
825 			int msgbufcount = args.msgbufcount;
826 			int remove;
827 
828 			remove = instance->completion_remove;
829 
830 			for (count = 0; count < args.count; count++) {
831 				VCHIQ_COMPLETION_DATA_T *completion;
832 				VCHIQ_SERVICE_T *service1;
833 				USER_SERVICE_T *user_service;
834 				VCHIQ_HEADER_T *header;
835 
836 				if (remove == instance->completion_insert)
837 					break;
838 
839 				completion = &instance->completions[
840 					remove & (MAX_COMPLETIONS - 1)];
841 
842 
843 				/* A read memory barrier is needed to prevent
844 				** the prefetch of a stale completion record
845 				*/
846 				rmb();
847 
848 				service1 = completion->service_userdata;
849 				user_service = service1->base.userdata;
850 				completion->service_userdata =
851 					user_service->userdata;
852 
853 				header = completion->header;
854 				if (header) {
855 					void __user *msgbuf;
856 					int msglen;
857 
858 					msglen = header->size +
859 						sizeof(VCHIQ_HEADER_T);
860 					/* This must be a VCHIQ-style service */
861 					if (args.msgbufsize < msglen) {
862 						vchiq_log_error(
863 							vchiq_arm_log_level,
864 							"header %x: msgbufsize"
865 							" %x < msglen %x",
866 							(unsigned int)header,
867 							args.msgbufsize,
868 							msglen);
869 						WARN(1, "invalid message "
870 							"size\n");
871 						if (count == 0)
872 							ret = -EMSGSIZE;
873 						break;
874 					}
875 					if (msgbufcount <= 0)
876 						/* Stall here for lack of a
877 						** buffer for the message. */
878 						break;
879 					/* Get the pointer from user space */
880 					msgbufcount--;
881 					if (copy_from_user(&msgbuf,
882 						(const void __user *)
883 						&args.msgbufs[msgbufcount],
884 						sizeof(msgbuf)) != 0) {
885 						if (count == 0)
886 							ret = -EFAULT;
887 						break;
888 					}
889 
890 					/* Copy the message to user space */
891 					if (copy_to_user(msgbuf, header,
892 						msglen) != 0) {
893 						if (count == 0)
894 							ret = -EFAULT;
895 						break;
896 					}
897 
898 					/* Now it has been copied, the message
899 					** can be released. */
900 					vchiq_release_message(service1->handle,
901 						header);
902 
903 					/* The completion must point to the
904 					** msgbuf. */
905 					completion->header = msgbuf;
906 				}
907 
908 				if ((completion->reason ==
909 					VCHIQ_SERVICE_CLOSED) &&
910 					!instance->use_close_delivered)
911 					unlock_service(service1);
912 
913 				if (copy_to_user((void __user *)(
914 					(size_t)args.buf +
915 					count * sizeof(VCHIQ_COMPLETION_DATA_T)),
916 					completion,
917 					sizeof(VCHIQ_COMPLETION_DATA_T)) != 0) {
918 						if (ret == 0)
919 							ret = -EFAULT;
920 					break;
921 				}
922 
923 				/* Ensure that the above copy has completed
924 				** before advancing the remove pointer. */
925 				mb();
926 
927 				instance->completion_remove = ++remove;
928 			}
929 
930 			if (msgbufcount != args.msgbufcount) {
931 				memcpy((void __user *)
932 					&((VCHIQ_AWAIT_COMPLETION_T *)arg)->
933 						msgbufcount,
934 					&msgbufcount,
935 					sizeof(msgbufcount));
936 			}
937 
938 			 if (count != args.count)
939 			 {
940 				memcpy((void __user *)
941 					&((VCHIQ_AWAIT_COMPLETION_T *)arg)->count,
942 					&count, sizeof(count));
943 			}
944 		}
945 
946 		if (count != 0)
947 			up(&instance->remove_event);
948 
949 		if ((ret == 0) && instance->closing)
950 			ret = -ENOTCONN;
951 		/*
952 		 * XXXBSD: ioctl return codes are not negative as in linux, so
953 		 * we can not indicate success with positive number of passed
954 		 * messages
955 		 */
956 		if (ret > 0)
957 			ret = 0;
958 
959 		lmutex_unlock(&instance->completion_mutex);
960 		DEBUG_TRACE(AWAIT_COMPLETION_LINE);
961 	} break;
962 
963 	case VCHIQ_IOC_DEQUEUE_MESSAGE: {
964 		VCHIQ_DEQUEUE_MESSAGE_T args;
965 		USER_SERVICE_T *user_service;
966 		VCHIQ_HEADER_T *header;
967 
968 		DEBUG_TRACE(DEQUEUE_MESSAGE_LINE);
969 		memcpy(&args, (const void*)arg, sizeof(args));
970 		service = find_service_for_instance(instance, args.handle);
971 		if (!service) {
972 			ret = -EINVAL;
973 			break;
974 		}
975 		user_service = (USER_SERVICE_T *)service->base.userdata;
976 		if (user_service->is_vchi == 0) {
977 			ret = -EINVAL;
978 			break;
979 		}
980 
981 		spin_lock(&msg_queue_spinlock);
982 		if (user_service->msg_remove == user_service->msg_insert) {
983 			if (!args.blocking) {
984 				spin_unlock(&msg_queue_spinlock);
985 				DEBUG_TRACE(DEQUEUE_MESSAGE_LINE);
986 				ret = -EWOULDBLOCK;
987 				break;
988 			}
989 			user_service->dequeue_pending = 1;
990 			do {
991 				spin_unlock(&msg_queue_spinlock);
992 				DEBUG_TRACE(DEQUEUE_MESSAGE_LINE);
993 				if (down_interruptible(
994 					&user_service->insert_event) != 0) {
995 					vchiq_log_info(vchiq_arm_log_level,
996 						"DEQUEUE_MESSAGE interrupted");
997 					ret = -EINTR;
998 					break;
999 				}
1000 				spin_lock(&msg_queue_spinlock);
1001 			} while (user_service->msg_remove ==
1002 				user_service->msg_insert);
1003 
1004 			if (ret)
1005 				break;
1006 		}
1007 
1008 		BUG_ON((int)(user_service->msg_insert -
1009 			user_service->msg_remove) < 0);
1010 
1011 		header = user_service->msg_queue[user_service->msg_remove &
1012 			(MSG_QUEUE_SIZE - 1)];
1013 		user_service->msg_remove++;
1014 		spin_unlock(&msg_queue_spinlock);
1015 
1016 		up(&user_service->remove_event);
1017 		if (header == NULL)
1018 			ret = -ENOTCONN;
1019 		else if (header->size <= args.bufsize) {
1020 			/* Copy to user space if msgbuf is not NULL */
1021 			if ((args.buf == NULL) ||
1022 				(copy_to_user((void __user *)args.buf,
1023 				header->data,
1024 				header->size) == 0)) {
1025 				args.bufsize = header->size;
1026 				memcpy((void *)arg, &args,
1027 				    sizeof(args));
1028 				vchiq_release_message(
1029 					service->handle,
1030 					header);
1031 			} else
1032 				ret = -EFAULT;
1033 		} else {
1034 			vchiq_log_error(vchiq_arm_log_level,
1035 				"header %x: bufsize %x < size %x",
1036 				(unsigned int)header, args.bufsize,
1037 				header->size);
1038 			WARN(1, "invalid size\n");
1039 			ret = -EMSGSIZE;
1040 		}
1041 		DEBUG_TRACE(DEQUEUE_MESSAGE_LINE);
1042 	} break;
1043 
1044 	case VCHIQ_IOC_GET_CLIENT_ID: {
1045 		VCHIQ_SERVICE_HANDLE_T handle;
1046 
1047 		memcpy(&handle, (const void*)arg, sizeof(handle));
1048 
1049 		ret = vchiq_get_client_id(handle);
1050 	} break;
1051 
1052 	case VCHIQ_IOC_GET_CONFIG: {
1053 		VCHIQ_GET_CONFIG_T args;
1054 		VCHIQ_CONFIG_T config;
1055 
1056 		memcpy(&args, (const void*)arg, sizeof(args));
1057 		if (args.config_size > sizeof(config)) {
1058 			ret = -EINVAL;
1059 			break;
1060 		}
1061 		status = vchiq_get_config(instance, args.config_size, &config);
1062 		if (status == VCHIQ_SUCCESS) {
1063 			if (copy_to_user((void __user *)args.pconfig,
1064 				    &config, args.config_size) != 0) {
1065 				ret = -EFAULT;
1066 				break;
1067 			}
1068 		}
1069 	} break;
1070 
1071 	case VCHIQ_IOC_SET_SERVICE_OPTION: {
1072 		VCHIQ_SET_SERVICE_OPTION_T args;
1073 
1074 		memcpy(&args, (const void*)arg, sizeof(args));
1075 
1076 		service = find_service_for_instance(instance, args.handle);
1077 		if (!service) {
1078 			ret = -EINVAL;
1079 			break;
1080 		}
1081 
1082 		status = vchiq_set_service_option(
1083 				args.handle, args.option, args.value);
1084 	} break;
1085 
1086 	case VCHIQ_IOC_DUMP_PHYS_MEM: {
1087 		VCHIQ_DUMP_MEM_T  args;
1088 
1089 		memcpy(&args, (const void*)arg, sizeof(args));
1090 		printf("IMPLEMENT ME: %s:%d\n", __FILE__, __LINE__);
1091 #if 0
1092 		dump_phys_mem(args.virt_addr, args.num_bytes);
1093 #endif
1094 	} break;
1095 
1096 	case VCHIQ_IOC_LIB_VERSION: {
1097 		unsigned int lib_version = (unsigned int)arg;
1098 
1099 		if (lib_version < VCHIQ_VERSION_MIN)
1100 			ret = -EINVAL;
1101 		else if (lib_version >= VCHIQ_VERSION_CLOSE_DELIVERED)
1102 			instance->use_close_delivered = 1;
1103 	} break;
1104 
1105 	case VCHIQ_IOC_CLOSE_DELIVERED: {
1106 		VCHIQ_SERVICE_HANDLE_T handle;
1107 		memcpy(&handle, (const void*)arg, sizeof(handle));
1108 
1109 		service = find_closed_service_for_instance(instance, handle);
1110 		if (service != NULL) {
1111 			USER_SERVICE_T *user_service =
1112 				(USER_SERVICE_T *)service->base.userdata;
1113 			close_delivered(user_service);
1114 		}
1115 		else
1116 			ret = -EINVAL;
1117 	} break;
1118 
1119 	default:
1120 		ret = -ENOTTY;
1121 		break;
1122 	}
1123 
1124 	if (service)
1125 		unlock_service(service);
1126 
1127 	if (ret == 0) {
1128 		if (status == VCHIQ_ERROR)
1129 			ret = -EIO;
1130 		else if (status == VCHIQ_RETRY)
1131 			ret = -EINTR;
1132 	}
1133 
1134 	if ((status == VCHIQ_SUCCESS) && (ret < 0) && (ret != -EINTR) &&
1135 		(ret != -EWOULDBLOCK))
1136 		vchiq_log_info(vchiq_arm_log_level,
1137 			"  ioctl instance %lx, cmd %s -> status %d, %d",
1138 			(unsigned long)instance,
1139 			(_IOC_NR(cmd) <= VCHIQ_IOC_MAX) ?
1140 				ioctl_names[_IOC_NR(cmd)] :
1141 				"<invalid>",
1142 			status, ret);
1143 	else
1144 		vchiq_log_trace(vchiq_arm_log_level,
1145 			"  ioctl instance %lx, cmd %s -> status %d, %d",
1146 			(unsigned long)instance,
1147 			(_IOC_NR(cmd) <= VCHIQ_IOC_MAX) ?
1148 				ioctl_names[_IOC_NR(cmd)] :
1149 				"<invalid>",
1150 			status, ret);
1151 
1152 	/* XXXBSD: report BSD-style error to userland */
1153 	if (ret < 0)
1154 		ret = -ret;
1155 
1156 	return ret;
1157 }
1158 
1159 static void
1160 instance_dtr(void *data)
1161 {
1162 
1163 	kfree(data);
1164 }
1165 
1166 /****************************************************************************
1167 *
1168 *   vchiq_open
1169 *
1170 ***************************************************************************/
1171 
1172 static int
1173 vchiq_open(struct cdev *dev, int flags, int fmt __unused, struct thread *td)
1174 {
1175 	vchiq_log_info(vchiq_arm_log_level, "vchiq_open");
1176 	/* XXXBSD: do we really need this check? */
1177 	if (1) {
1178 		VCHIQ_STATE_T *state = vchiq_get_state();
1179 		VCHIQ_INSTANCE_T instance;
1180 
1181 		if (!state) {
1182 			vchiq_log_error(vchiq_arm_log_level,
1183 				"vchiq has no connection to VideoCore");
1184 			return -ENOTCONN;
1185 		}
1186 
1187 		instance = kmalloc(sizeof(*instance), GFP_KERNEL);
1188 		if (!instance)
1189 			return -ENOMEM;
1190 
1191 		instance->state = state;
1192 		/* XXXBSD: PID or thread ID? */
1193 		instance->pid = td->td_proc->p_pid;
1194 
1195 #ifdef notyet
1196 		ret = vchiq_proc_add_instance(instance);
1197 		if (ret != 0) {
1198 			kfree(instance);
1199 			return ret;
1200 		}
1201 #endif
1202 
1203 		_sema_init(&instance->insert_event, 0);
1204 		_sema_init(&instance->remove_event, 0);
1205 		lmutex_init(&instance->completion_mutex);
1206 		lmutex_init(&instance->bulk_waiter_list_mutex);
1207 		INIT_LIST_HEAD(&instance->bulk_waiter_list);
1208 
1209 		devfs_set_cdevpriv(instance, instance_dtr);
1210 	}
1211 	else {
1212 		vchiq_log_error(vchiq_arm_log_level,
1213 			"Unknown minor device");
1214 		return -ENXIO;
1215 	}
1216 
1217 	return 0;
1218 }
1219 
1220 /****************************************************************************
1221 *
1222 *   vchiq_release
1223 *
1224 ***************************************************************************/
1225 
1226 static int
1227 vchiq_close(struct cdev *dev, int flags __unused, int fmt __unused,
1228                 struct thread *td)
1229 {
1230 	int ret = 0;
1231 	if (1) {
1232 		VCHIQ_INSTANCE_T instance;
1233 		VCHIQ_STATE_T *state = vchiq_get_state();
1234 		VCHIQ_SERVICE_T *service;
1235 		int i;
1236 
1237 		if ((ret = devfs_get_cdevpriv((void**)&instance))) {
1238 			printf("devfs_get_cdevpriv failed: error %d\n", ret);
1239 			return (ret);
1240 		}
1241 
1242 		vchiq_log_info(vchiq_arm_log_level,
1243 			"vchiq_release: instance=%lx",
1244 			(unsigned long)instance);
1245 
1246 		if (!state) {
1247 			ret = -EPERM;
1248 			goto out;
1249 		}
1250 
1251 		/* Ensure videocore is awake to allow termination. */
1252 		vchiq_use_internal(instance->state, NULL,
1253 				USE_TYPE_VCHIQ);
1254 
1255 		lmutex_lock(&instance->completion_mutex);
1256 
1257 		/* Wake the completion thread and ask it to exit */
1258 		instance->closing = 1;
1259 		up(&instance->insert_event);
1260 
1261 		lmutex_unlock(&instance->completion_mutex);
1262 
1263 		/* Wake the slot handler if the completion queue is full. */
1264 		up(&instance->remove_event);
1265 
1266 		/* Mark all services for termination... */
1267 		i = 0;
1268 		while ((service = next_service_by_instance(state, instance,
1269 			&i)) !=	NULL) {
1270 			USER_SERVICE_T *user_service = service->base.userdata;
1271 
1272 			/* Wake the slot handler if the msg queue is full. */
1273 			up(&user_service->remove_event);
1274 
1275 			vchiq_terminate_service_internal(service);
1276 			unlock_service(service);
1277 		}
1278 
1279 		/* ...and wait for them to die */
1280 		i = 0;
1281 		while ((service = next_service_by_instance(state, instance, &i))
1282 			!= NULL) {
1283 			USER_SERVICE_T *user_service = service->base.userdata;
1284 
1285 			down(&service->remove_event);
1286 
1287 			BUG_ON(service->srvstate != VCHIQ_SRVSTATE_FREE);
1288 
1289 			spin_lock(&msg_queue_spinlock);
1290 
1291 			while (user_service->msg_remove !=
1292 				user_service->msg_insert) {
1293 				VCHIQ_HEADER_T *header = user_service->
1294 					msg_queue[user_service->msg_remove &
1295 						(MSG_QUEUE_SIZE - 1)];
1296 				user_service->msg_remove++;
1297 				spin_unlock(&msg_queue_spinlock);
1298 
1299 				if (header)
1300 					vchiq_release_message(
1301 						service->handle,
1302 						header);
1303 				spin_lock(&msg_queue_spinlock);
1304 			}
1305 
1306 			spin_unlock(&msg_queue_spinlock);
1307 
1308 			unlock_service(service);
1309 		}
1310 
1311 		/* Release any closed services */
1312 		while (instance->completion_remove !=
1313 			instance->completion_insert) {
1314 			VCHIQ_COMPLETION_DATA_T *completion;
1315 			VCHIQ_SERVICE_T *service1;
1316 			completion = &instance->completions[
1317 				instance->completion_remove &
1318 				(MAX_COMPLETIONS - 1)];
1319 			service1 = completion->service_userdata;
1320 			if (completion->reason == VCHIQ_SERVICE_CLOSED)
1321 			{
1322 				USER_SERVICE_T *user_service =
1323 					service->base.userdata;
1324 
1325 				/* Wake any blocked user-thread */
1326 				if (instance->use_close_delivered)
1327 					up(&user_service->close_event);
1328 				unlock_service(service1);
1329 			}
1330 			instance->completion_remove++;
1331 		}
1332 
1333 		/* Release the PEER service count. */
1334 		vchiq_release_internal(instance->state, NULL);
1335 
1336 		{
1337 			struct list_head *pos, *next;
1338 			list_for_each_safe(pos, next,
1339 				&instance->bulk_waiter_list) {
1340 				struct bulk_waiter_node *waiter;
1341 				waiter = list_entry(pos,
1342 					struct bulk_waiter_node,
1343 					list);
1344 				list_del(pos);
1345 				vchiq_log_info(vchiq_arm_log_level,
1346 					"bulk_waiter - cleaned up %x "
1347 					"for pid %d",
1348 					(unsigned int)waiter, waiter->pid);
1349 		                _sema_destroy(&waiter->bulk_waiter.event);
1350 				kfree(waiter);
1351 			}
1352 		}
1353 
1354 	}
1355 	else {
1356 		vchiq_log_error(vchiq_arm_log_level,
1357 			"Unknown minor device");
1358 		ret = -ENXIO;
1359 	}
1360 
1361 out:
1362 	return ret;
1363 }
1364 
1365 /****************************************************************************
1366 *
1367 *   vchiq_dump
1368 *
1369 ***************************************************************************/
1370 
1371 void
1372 vchiq_dump(void *dump_context, const char *str, int len)
1373 {
1374 	DUMP_CONTEXT_T *context = (DUMP_CONTEXT_T *)dump_context;
1375 
1376 	if (context->actual < context->space) {
1377 		int copy_bytes;
1378 		if (context->offset > 0) {
1379 			int skip_bytes = min(len, (int)context->offset);
1380 			str += skip_bytes;
1381 			len -= skip_bytes;
1382 			context->offset -= skip_bytes;
1383 			if (context->offset > 0)
1384 				return;
1385 		}
1386 		copy_bytes = min(len, (int)(context->space - context->actual));
1387 		if (copy_bytes == 0)
1388 			return;
1389 		memcpy(context->buf + context->actual, str, copy_bytes);
1390 		context->actual += copy_bytes;
1391 		len -= copy_bytes;
1392 
1393 		/* If tne terminating NUL is included in the length, then it
1394 		** marks the end of a line and should be replaced with a
1395 		** carriage return. */
1396 		if ((len == 0) && (str[copy_bytes - 1] == '\0')) {
1397 			char cr = '\n';
1398 			memcpy(context->buf + context->actual - 1, &cr, 1);
1399 		}
1400 	}
1401 }
1402 
1403 /****************************************************************************
1404 *
1405 *   vchiq_dump_platform_instance_state
1406 *
1407 ***************************************************************************/
1408 
1409 void
1410 vchiq_dump_platform_instances(void *dump_context)
1411 {
1412 	VCHIQ_STATE_T *state = vchiq_get_state();
1413 	char buf[80];
1414 	int len;
1415 	int i;
1416 
1417 	/* There is no list of instances, so instead scan all services,
1418 		marking those that have been dumped. */
1419 
1420 	for (i = 0; i < state->unused_service; i++) {
1421 		VCHIQ_SERVICE_T *service = state->services[i];
1422 		VCHIQ_INSTANCE_T instance;
1423 
1424 		if (service && (service->base.callback == service_callback)) {
1425 			instance = service->instance;
1426 			if (instance)
1427 				instance->mark = 0;
1428 		}
1429 	}
1430 
1431 	for (i = 0; i < state->unused_service; i++) {
1432 		VCHIQ_SERVICE_T *service = state->services[i];
1433 		VCHIQ_INSTANCE_T instance;
1434 
1435 		if (service && (service->base.callback == service_callback)) {
1436 			instance = service->instance;
1437 			if (instance && !instance->mark) {
1438 				len = snprintf(buf, sizeof(buf),
1439 					"Instance %x: pid %d,%s completions "
1440 						"%d/%d",
1441 					(unsigned int)instance, instance->pid,
1442 					instance->connected ? " connected, " :
1443 						"",
1444 					instance->completion_insert -
1445 						instance->completion_remove,
1446 					MAX_COMPLETIONS);
1447 
1448 				vchiq_dump(dump_context, buf, len + 1);
1449 
1450 				instance->mark = 1;
1451 			}
1452 		}
1453 	}
1454 }
1455 
1456 /****************************************************************************
1457 *
1458 *   vchiq_dump_platform_service_state
1459 *
1460 ***************************************************************************/
1461 
1462 void
1463 vchiq_dump_platform_service_state(void *dump_context, VCHIQ_SERVICE_T *service)
1464 {
1465 	USER_SERVICE_T *user_service = (USER_SERVICE_T *)service->base.userdata;
1466 	char buf[80];
1467 	int len;
1468 
1469 	len = snprintf(buf, sizeof(buf), "  instance %x",
1470 		(unsigned int)service->instance);
1471 
1472 	if ((service->base.callback == service_callback) &&
1473 		user_service->is_vchi) {
1474 		len += snprintf(buf + len, sizeof(buf) - len,
1475 			", %d/%d messages",
1476 			user_service->msg_insert - user_service->msg_remove,
1477 			MSG_QUEUE_SIZE);
1478 
1479 		if (user_service->dequeue_pending)
1480 			len += snprintf(buf + len, sizeof(buf) - len,
1481 				" (dequeue pending)");
1482 	}
1483 
1484 	vchiq_dump(dump_context, buf, len + 1);
1485 }
1486 
1487 #ifdef notyet
1488 /****************************************************************************
1489 *
1490 *   dump_user_mem
1491 *
1492 ***************************************************************************/
1493 
1494 static void
1495 dump_phys_mem(void *virt_addr, uint32_t num_bytes)
1496 {
1497 	int            rc;
1498 	uint8_t       *end_virt_addr = virt_addr + num_bytes;
1499 	int            num_pages;
1500 	int            offset;
1501 	int            end_offset;
1502 	int            page_idx;
1503 	int            prev_idx;
1504 	struct page   *page;
1505 	struct page  **pages;
1506 	uint8_t       *kmapped_virt_ptr;
1507 
1508 	/* Align virtAddr and endVirtAddr to 16 byte boundaries. */
1509 
1510 	virt_addr = (void *)((unsigned long)virt_addr & ~0x0fuL);
1511 	end_virt_addr = (void *)(((unsigned long)end_virt_addr + 15uL) &
1512 		~0x0fuL);
1513 
1514 	offset = (int)(long)virt_addr & (PAGE_SIZE - 1);
1515 	end_offset = (int)(long)end_virt_addr & (PAGE_SIZE - 1);
1516 
1517 	num_pages = (offset + num_bytes + PAGE_SIZE - 1) / PAGE_SIZE;
1518 
1519 	pages = kmalloc(sizeof(struct page *) * num_pages, GFP_KERNEL);
1520 	if (pages == NULL) {
1521 		vchiq_log_error(vchiq_arm_log_level,
1522 			"Unable to allocation memory for %d pages\n",
1523 			num_pages);
1524 		return;
1525 	}
1526 
1527 	down_read(&current->mm->mmap_sem);
1528 	rc = get_user_pages(current,      /* task */
1529 		current->mm,              /* mm */
1530 		(unsigned long)virt_addr, /* start */
1531 		num_pages,                /* len */
1532 		0,                        /* write */
1533 		0,                        /* force */
1534 		pages,                    /* pages (array of page pointers) */
1535 		NULL);                    /* vmas */
1536 	up_read(&current->mm->mmap_sem);
1537 
1538 	prev_idx = -1;
1539 	page = NULL;
1540 
1541 	while (offset < end_offset) {
1542 
1543 		int page_offset = offset % PAGE_SIZE;
1544 		page_idx = offset / PAGE_SIZE;
1545 
1546 		if (page_idx != prev_idx) {
1547 
1548 			if (page != NULL)
1549 				kunmap(page);
1550 			page = pages[page_idx];
1551 			kmapped_virt_ptr = kmap(page);
1552 
1553 			prev_idx = page_idx;
1554 		}
1555 
1556 		if (vchiq_arm_log_level >= VCHIQ_LOG_TRACE)
1557 			vchiq_log_dump_mem("ph",
1558 				(uint32_t)(unsigned long)&kmapped_virt_ptr[
1559 					page_offset],
1560 				&kmapped_virt_ptr[page_offset], 16);
1561 
1562 		offset += 16;
1563 	}
1564 	if (page != NULL)
1565 		kunmap(page);
1566 
1567 	for (page_idx = 0; page_idx < num_pages; page_idx++)
1568 		page_cache_release(pages[page_idx]);
1569 
1570 	kfree(pages);
1571 }
1572 
1573 /****************************************************************************
1574 *
1575 *   vchiq_read
1576 *
1577 ***************************************************************************/
1578 
1579 static ssize_t
1580 vchiq_read(struct file *file, char __user *buf,
1581 	size_t count, loff_t *ppos)
1582 {
1583 	DUMP_CONTEXT_T context;
1584 	context.buf = buf;
1585 	context.actual = 0;
1586 	context.space = count;
1587 	context.offset = *ppos;
1588 
1589 	vchiq_dump_state(&context, &g_state);
1590 
1591 	*ppos += context.actual;
1592 
1593 	return context.actual;
1594 }
1595 #endif
1596 
1597 VCHIQ_STATE_T *
1598 vchiq_get_state(void)
1599 {
1600 
1601 	if (g_state.remote == NULL)
1602 		printk(KERN_ERR "%s: g_state.remote == NULL\n", __func__);
1603 	else if (g_state.remote->initialised != 1)
1604 		printk(KERN_NOTICE "%s: g_state.remote->initialised != 1 (%d)\n",
1605 			__func__, g_state.remote->initialised);
1606 
1607 	return ((g_state.remote != NULL) &&
1608 		(g_state.remote->initialised == 1)) ? &g_state : NULL;
1609 }
1610 
1611 /*
1612  * Autosuspend related functionality
1613  */
1614 
1615 int
1616 vchiq_videocore_wanted(VCHIQ_STATE_T *state)
1617 {
1618 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
1619 	if (!arm_state)
1620 		/* autosuspend not supported - always return wanted */
1621 		return 1;
1622 	else if (arm_state->blocked_count)
1623 		return 1;
1624 	else if (!arm_state->videocore_use_count)
1625 		/* usage count zero - check for override unless we're forcing */
1626 		if (arm_state->resume_blocked)
1627 			return 0;
1628 		else
1629 			return vchiq_platform_videocore_wanted(state);
1630 	else
1631 		/* non-zero usage count - videocore still required */
1632 		return 1;
1633 }
1634 
1635 static VCHIQ_STATUS_T
1636 vchiq_keepalive_vchiq_callback(VCHIQ_REASON_T reason,
1637 	VCHIQ_HEADER_T *header,
1638 	VCHIQ_SERVICE_HANDLE_T service_user,
1639 	void *bulk_user)
1640 {
1641 	vchiq_log_error(vchiq_susp_log_level,
1642 		"%s callback reason %d", __func__, reason);
1643 	return 0;
1644 }
1645 
1646 static int
1647 vchiq_keepalive_thread_func(void *v)
1648 {
1649 	VCHIQ_STATE_T *state = (VCHIQ_STATE_T *) v;
1650 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
1651 
1652 	VCHIQ_STATUS_T status;
1653 	VCHIQ_INSTANCE_T instance;
1654 	VCHIQ_SERVICE_HANDLE_T ka_handle;
1655 
1656 	VCHIQ_SERVICE_PARAMS_T params = {
1657 		.fourcc      = VCHIQ_MAKE_FOURCC('K', 'E', 'E', 'P'),
1658 		.callback    = vchiq_keepalive_vchiq_callback,
1659 		.version     = KEEPALIVE_VER,
1660 		.version_min = KEEPALIVE_VER_MIN
1661 	};
1662 
1663 	status = vchiq_initialise(&instance);
1664 	if (status != VCHIQ_SUCCESS) {
1665 		vchiq_log_error(vchiq_susp_log_level,
1666 			"%s vchiq_initialise failed %d", __func__, status);
1667 		goto exit;
1668 	}
1669 
1670 	status = vchiq_connect(instance);
1671 	if (status != VCHIQ_SUCCESS) {
1672 		vchiq_log_error(vchiq_susp_log_level,
1673 			"%s vchiq_connect failed %d", __func__, status);
1674 		goto shutdown;
1675 	}
1676 
1677 	status = vchiq_add_service(instance, &params, &ka_handle);
1678 	if (status != VCHIQ_SUCCESS) {
1679 		vchiq_log_error(vchiq_susp_log_level,
1680 			"%s vchiq_open_service failed %d", __func__, status);
1681 		goto shutdown;
1682 	}
1683 
1684 	while (1) {
1685 		long rc = 0, uc = 0;
1686 		if (wait_for_completion_interruptible(&arm_state->ka_evt)
1687 				!= 0) {
1688 			vchiq_log_error(vchiq_susp_log_level,
1689 				"%s interrupted", __func__);
1690 			flush_signals(current);
1691 			continue;
1692 		}
1693 
1694 		/* read and clear counters.  Do release_count then use_count to
1695 		 * prevent getting more releases than uses */
1696 		rc = atomic_xchg(&arm_state->ka_release_count, 0);
1697 		uc = atomic_xchg(&arm_state->ka_use_count, 0);
1698 
1699 		/* Call use/release service the requisite number of times.
1700 		 * Process use before release so use counts don't go negative */
1701 		while (uc--) {
1702 			atomic_inc(&arm_state->ka_use_ack_count);
1703 			status = vchiq_use_service(ka_handle);
1704 			if (status != VCHIQ_SUCCESS) {
1705 				vchiq_log_error(vchiq_susp_log_level,
1706 					"%s vchiq_use_service error %d",
1707 					__func__, status);
1708 			}
1709 		}
1710 		while (rc--) {
1711 			status = vchiq_release_service(ka_handle);
1712 			if (status != VCHIQ_SUCCESS) {
1713 				vchiq_log_error(vchiq_susp_log_level,
1714 					"%s vchiq_release_service error %d",
1715 					__func__, status);
1716 			}
1717 		}
1718 	}
1719 
1720 shutdown:
1721 	vchiq_shutdown(instance);
1722 exit:
1723 	return 0;
1724 }
1725 
1726 VCHIQ_STATUS_T
1727 vchiq_arm_init_state(VCHIQ_STATE_T *state, VCHIQ_ARM_STATE_T *arm_state)
1728 {
1729 	VCHIQ_STATUS_T status = VCHIQ_SUCCESS;
1730 
1731 	if (arm_state) {
1732 		rwlock_init(&arm_state->susp_res_lock);
1733 
1734 		init_completion(&arm_state->ka_evt);
1735 		atomic_set(&arm_state->ka_use_count, 0);
1736 		atomic_set(&arm_state->ka_use_ack_count, 0);
1737 		atomic_set(&arm_state->ka_release_count, 0);
1738 
1739 		init_completion(&arm_state->vc_suspend_complete);
1740 
1741 		init_completion(&arm_state->vc_resume_complete);
1742 		/* Initialise to 'done' state.  We only want to block on resume
1743 		 * completion while videocore is suspended. */
1744 		set_resume_state(arm_state, VC_RESUME_RESUMED);
1745 
1746 		init_completion(&arm_state->resume_blocker);
1747 		/* Initialise to 'done' state.  We only want to block on this
1748 		 * completion while resume is blocked */
1749 		complete_all(&arm_state->resume_blocker);
1750 
1751 		init_completion(&arm_state->blocked_blocker);
1752 		/* Initialise to 'done' state.  We only want to block on this
1753 		 * completion while things are waiting on the resume blocker */
1754 		complete_all(&arm_state->blocked_blocker);
1755 
1756 		arm_state->suspend_timer_timeout = SUSPEND_TIMER_TIMEOUT_MS;
1757 		arm_state->suspend_timer_running = 0;
1758 		init_timer(&arm_state->suspend_timer);
1759 		arm_state->suspend_timer.data = (unsigned long)(state);
1760 		arm_state->suspend_timer.function = suspend_timer_callback;
1761 
1762 		arm_state->first_connect = 0;
1763 
1764 	}
1765 	return status;
1766 }
1767 
1768 /*
1769 ** Functions to modify the state variables;
1770 **	set_suspend_state
1771 **	set_resume_state
1772 **
1773 ** There are more state variables than we might like, so ensure they remain in
1774 ** step.  Suspend and resume state are maintained separately, since most of
1775 ** these state machines can operate independently.  However, there are a few
1776 ** states where state transitions in one state machine cause a reset to the
1777 ** other state machine.  In addition, there are some completion events which
1778 ** need to occur on state machine reset and end-state(s), so these are also
1779 ** dealt with in these functions.
1780 **
1781 ** In all states we set the state variable according to the input, but in some
1782 ** cases we perform additional steps outlined below;
1783 **
1784 ** VC_SUSPEND_IDLE - Initialise the suspend completion at the same time.
1785 **			The suspend completion is completed after any suspend
1786 **			attempt.  When we reset the state machine we also reset
1787 **			the completion.  This reset occurs when videocore is
1788 **			resumed, and also if we initiate suspend after a suspend
1789 **			failure.
1790 **
1791 ** VC_SUSPEND_IN_PROGRESS - This state is considered the point of no return for
1792 **			suspend - ie from this point on we must try to suspend
1793 **			before resuming can occur.  We therefore also reset the
1794 **			resume state machine to VC_RESUME_IDLE in this state.
1795 **
1796 ** VC_SUSPEND_SUSPENDED - Suspend has completed successfully. Also call
1797 **			complete_all on the suspend completion to notify
1798 **			anything waiting for suspend to happen.
1799 **
1800 ** VC_SUSPEND_REJECTED - Videocore rejected suspend. Videocore will also
1801 **			initiate resume, so no need to alter resume state.
1802 **			We call complete_all on the suspend completion to notify
1803 **			of suspend rejection.
1804 **
1805 ** VC_SUSPEND_FAILED - We failed to initiate videocore suspend.  We notify the
1806 **			suspend completion and reset the resume state machine.
1807 **
1808 ** VC_RESUME_IDLE - Initialise the resume completion at the same time.  The
1809 **			resume completion is in it's 'done' state whenever
1810 **			videcore is running.  Therfore, the VC_RESUME_IDLE state
1811 **			implies that videocore is suspended.
1812 **			Hence, any thread which needs to wait until videocore is
1813 **			running can wait on this completion - it will only block
1814 **			if videocore is suspended.
1815 **
1816 ** VC_RESUME_RESUMED - Resume has completed successfully.  Videocore is running.
1817 **			Call complete_all on the resume completion to unblock
1818 **			any threads waiting for resume.	 Also reset the suspend
1819 **			state machine to it's idle state.
1820 **
1821 ** VC_RESUME_FAILED - Currently unused - no mechanism to fail resume exists.
1822 */
1823 
1824 void
1825 set_suspend_state(VCHIQ_ARM_STATE_T *arm_state,
1826 	enum vc_suspend_status new_state)
1827 {
1828 	/* set the state in all cases */
1829 	arm_state->vc_suspend_state = new_state;
1830 
1831 	/* state specific additional actions */
1832 	switch (new_state) {
1833 	case VC_SUSPEND_FORCE_CANCELED:
1834 		complete_all(&arm_state->vc_suspend_complete);
1835 		break;
1836 	case VC_SUSPEND_REJECTED:
1837 		complete_all(&arm_state->vc_suspend_complete);
1838 		break;
1839 	case VC_SUSPEND_FAILED:
1840 		complete_all(&arm_state->vc_suspend_complete);
1841 		arm_state->vc_resume_state = VC_RESUME_RESUMED;
1842 		complete_all(&arm_state->vc_resume_complete);
1843 		break;
1844 	case VC_SUSPEND_IDLE:
1845 		/* TODO: reinit_completion */
1846 		INIT_COMPLETION(arm_state->vc_suspend_complete);
1847 		break;
1848 	case VC_SUSPEND_REQUESTED:
1849 		break;
1850 	case VC_SUSPEND_IN_PROGRESS:
1851 		set_resume_state(arm_state, VC_RESUME_IDLE);
1852 		break;
1853 	case VC_SUSPEND_SUSPENDED:
1854 		complete_all(&arm_state->vc_suspend_complete);
1855 		break;
1856 	default:
1857 		BUG();
1858 		break;
1859 	}
1860 }
1861 
1862 void
1863 set_resume_state(VCHIQ_ARM_STATE_T *arm_state,
1864 	enum vc_resume_status new_state)
1865 {
1866 	/* set the state in all cases */
1867 	arm_state->vc_resume_state = new_state;
1868 
1869 	/* state specific additional actions */
1870 	switch (new_state) {
1871 	case VC_RESUME_FAILED:
1872 		break;
1873 	case VC_RESUME_IDLE:
1874 		/* TODO: reinit_completion */
1875 		INIT_COMPLETION(arm_state->vc_resume_complete);
1876 		break;
1877 	case VC_RESUME_REQUESTED:
1878 		break;
1879 	case VC_RESUME_IN_PROGRESS:
1880 		break;
1881 	case VC_RESUME_RESUMED:
1882 		complete_all(&arm_state->vc_resume_complete);
1883 		set_suspend_state(arm_state, VC_SUSPEND_IDLE);
1884 		break;
1885 	default:
1886 		BUG();
1887 		break;
1888 	}
1889 }
1890 
1891 
1892 /* should be called with the write lock held */
1893 inline void
1894 start_suspend_timer(VCHIQ_ARM_STATE_T *arm_state)
1895 {
1896 	del_timer(&arm_state->suspend_timer);
1897 	arm_state->suspend_timer.expires = jiffies +
1898 		msecs_to_jiffies(arm_state->
1899 			suspend_timer_timeout);
1900 	add_timer(&arm_state->suspend_timer);
1901 	arm_state->suspend_timer_running = 1;
1902 }
1903 
1904 /* should be called with the write lock held */
1905 static inline void
1906 stop_suspend_timer(VCHIQ_ARM_STATE_T *arm_state)
1907 {
1908 	if (arm_state->suspend_timer_running) {
1909 		del_timer(&arm_state->suspend_timer);
1910 		arm_state->suspend_timer_running = 0;
1911 	}
1912 }
1913 
1914 static inline int
1915 need_resume(VCHIQ_STATE_T *state)
1916 {
1917 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
1918 	return (arm_state->vc_suspend_state > VC_SUSPEND_IDLE) &&
1919 			(arm_state->vc_resume_state < VC_RESUME_REQUESTED) &&
1920 			vchiq_videocore_wanted(state);
1921 }
1922 
1923 static int
1924 block_resume(VCHIQ_ARM_STATE_T *arm_state)
1925 {
1926 	int status = VCHIQ_SUCCESS;
1927 	const unsigned long timeout_val =
1928 				msecs_to_jiffies(FORCE_SUSPEND_TIMEOUT_MS);
1929 	int resume_count = 0;
1930 
1931 	/* Allow any threads which were blocked by the last force suspend to
1932 	 * complete if they haven't already.  Only give this one shot; if
1933 	 * blocked_count is incremented after blocked_blocker is completed
1934 	 * (which only happens when blocked_count hits 0) then those threads
1935 	 * will have to wait until next time around */
1936 	if (arm_state->blocked_count) {
1937 		/* TODO: reinit_completion */
1938 		INIT_COMPLETION(arm_state->blocked_blocker);
1939 		write_unlock_bh(&arm_state->susp_res_lock);
1940 		vchiq_log_info(vchiq_susp_log_level, "%s wait for previously "
1941 			"blocked clients", __func__);
1942 		if (wait_for_completion_interruptible_timeout(
1943 				&arm_state->blocked_blocker, timeout_val)
1944 					<= 0) {
1945 			vchiq_log_error(vchiq_susp_log_level, "%s wait for "
1946 				"previously blocked clients failed" , __func__);
1947 			status = VCHIQ_ERROR;
1948 			write_lock_bh(&arm_state->susp_res_lock);
1949 			goto out;
1950 		}
1951 		vchiq_log_info(vchiq_susp_log_level, "%s previously blocked "
1952 			"clients resumed", __func__);
1953 		write_lock_bh(&arm_state->susp_res_lock);
1954 	}
1955 
1956 	/* We need to wait for resume to complete if it's in process */
1957 	while (arm_state->vc_resume_state != VC_RESUME_RESUMED &&
1958 			arm_state->vc_resume_state > VC_RESUME_IDLE) {
1959 		if (resume_count > 1) {
1960 			status = VCHIQ_ERROR;
1961 			vchiq_log_error(vchiq_susp_log_level, "%s waited too "
1962 				"many times for resume" , __func__);
1963 			goto out;
1964 		}
1965 		write_unlock_bh(&arm_state->susp_res_lock);
1966 		vchiq_log_info(vchiq_susp_log_level, "%s wait for resume",
1967 			__func__);
1968 		if (wait_for_completion_interruptible_timeout(
1969 				&arm_state->vc_resume_complete, timeout_val)
1970 					<= 0) {
1971 			vchiq_log_error(vchiq_susp_log_level, "%s wait for "
1972 				"resume failed (%s)", __func__,
1973 				resume_state_names[arm_state->vc_resume_state +
1974 							VC_RESUME_NUM_OFFSET]);
1975 			status = VCHIQ_ERROR;
1976 			write_lock_bh(&arm_state->susp_res_lock);
1977 			goto out;
1978 		}
1979 		vchiq_log_info(vchiq_susp_log_level, "%s resumed", __func__);
1980 		write_lock_bh(&arm_state->susp_res_lock);
1981 		resume_count++;
1982 	}
1983 	/* TODO: reinit_completion */
1984 	INIT_COMPLETION(arm_state->resume_blocker);
1985 	arm_state->resume_blocked = 1;
1986 
1987 out:
1988 	return status;
1989 }
1990 
1991 static inline void
1992 unblock_resume(VCHIQ_ARM_STATE_T *arm_state)
1993 {
1994 	complete_all(&arm_state->resume_blocker);
1995 	arm_state->resume_blocked = 0;
1996 }
1997 
1998 /* Initiate suspend via slot handler. Should be called with the write lock
1999  * held */
2000 VCHIQ_STATUS_T
2001 vchiq_arm_vcsuspend(VCHIQ_STATE_T *state)
2002 {
2003 	VCHIQ_STATUS_T status = VCHIQ_ERROR;
2004 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
2005 
2006 	if (!arm_state)
2007 		goto out;
2008 
2009 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
2010 	status = VCHIQ_SUCCESS;
2011 
2012 
2013 	switch (arm_state->vc_suspend_state) {
2014 	case VC_SUSPEND_REQUESTED:
2015 		vchiq_log_info(vchiq_susp_log_level, "%s: suspend already "
2016 			"requested", __func__);
2017 		break;
2018 	case VC_SUSPEND_IN_PROGRESS:
2019 		vchiq_log_info(vchiq_susp_log_level, "%s: suspend already in "
2020 			"progress", __func__);
2021 		break;
2022 
2023 	default:
2024 		/* We don't expect to be in other states, so log but continue
2025 		 * anyway */
2026 		vchiq_log_error(vchiq_susp_log_level,
2027 			"%s unexpected suspend state %s", __func__,
2028 			suspend_state_names[arm_state->vc_suspend_state +
2029 						VC_SUSPEND_NUM_OFFSET]);
2030 		/* fall through */
2031 	case VC_SUSPEND_REJECTED:
2032 	case VC_SUSPEND_FAILED:
2033 		/* Ensure any idle state actions have been run */
2034 		set_suspend_state(arm_state, VC_SUSPEND_IDLE);
2035 		/* fall through */
2036 	case VC_SUSPEND_IDLE:
2037 		vchiq_log_info(vchiq_susp_log_level,
2038 			"%s: suspending", __func__);
2039 		set_suspend_state(arm_state, VC_SUSPEND_REQUESTED);
2040 		/* kick the slot handler thread to initiate suspend */
2041 		request_poll(state, NULL, 0);
2042 		break;
2043 	}
2044 
2045 out:
2046 	vchiq_log_trace(vchiq_susp_log_level, "%s exit %d", __func__, status);
2047 	return status;
2048 }
2049 
2050 void
2051 vchiq_platform_check_suspend(VCHIQ_STATE_T *state)
2052 {
2053 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
2054 	int susp = 0;
2055 
2056 	if (!arm_state)
2057 		goto out;
2058 
2059 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
2060 
2061 	write_lock_bh(&arm_state->susp_res_lock);
2062 	if (arm_state->vc_suspend_state == VC_SUSPEND_REQUESTED &&
2063 			arm_state->vc_resume_state == VC_RESUME_RESUMED) {
2064 		set_suspend_state(arm_state, VC_SUSPEND_IN_PROGRESS);
2065 		susp = 1;
2066 	}
2067 	write_unlock_bh(&arm_state->susp_res_lock);
2068 
2069 	if (susp)
2070 		vchiq_platform_suspend(state);
2071 
2072 out:
2073 	vchiq_log_trace(vchiq_susp_log_level, "%s exit", __func__);
2074 	return;
2075 }
2076 
2077 
2078 static void
2079 output_timeout_error(VCHIQ_STATE_T *state)
2080 {
2081 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
2082 	char service_err[50] = "";
2083 	int vc_use_count = arm_state->videocore_use_count;
2084 	int active_services = state->unused_service;
2085 	int i;
2086 
2087 	if (!arm_state->videocore_use_count) {
2088 		snprintf(service_err, 50, " Videocore usecount is 0");
2089 		goto output_msg;
2090 	}
2091 	for (i = 0; i < active_services; i++) {
2092 		VCHIQ_SERVICE_T *service_ptr = state->services[i];
2093 		if (service_ptr && service_ptr->service_use_count &&
2094 			(service_ptr->srvstate != VCHIQ_SRVSTATE_FREE)) {
2095 			snprintf(service_err, 50, " %c%c%c%c(%8x) service has "
2096 				"use count %d%s", VCHIQ_FOURCC_AS_4CHARS(
2097 					service_ptr->base.fourcc),
2098 				 service_ptr->client_id,
2099 				 service_ptr->service_use_count,
2100 				 service_ptr->service_use_count ==
2101 					 vc_use_count ? "" : " (+ more)");
2102 			break;
2103 		}
2104 	}
2105 
2106 output_msg:
2107 	vchiq_log_error(vchiq_susp_log_level,
2108 		"timed out waiting for vc suspend (%d).%s",
2109 		 arm_state->autosuspend_override, service_err);
2110 
2111 }
2112 
2113 /* Try to get videocore into suspended state, regardless of autosuspend state.
2114 ** We don't actually force suspend, since videocore may get into a bad state
2115 ** if we force suspend at a bad time.  Instead, we wait for autosuspend to
2116 ** determine a good point to suspend.  If this doesn't happen within 100ms we
2117 ** report failure.
2118 **
2119 ** Returns VCHIQ_SUCCESS if videocore suspended successfully, VCHIQ_RETRY if
2120 ** videocore failed to suspend in time or VCHIQ_ERROR if interrupted.
2121 */
2122 VCHIQ_STATUS_T
2123 vchiq_arm_force_suspend(VCHIQ_STATE_T *state)
2124 {
2125 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
2126 	VCHIQ_STATUS_T status = VCHIQ_ERROR;
2127 	long rc = 0;
2128 	int repeat = -1;
2129 
2130 	if (!arm_state)
2131 		goto out;
2132 
2133 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
2134 
2135 	write_lock_bh(&arm_state->susp_res_lock);
2136 
2137 	status = block_resume(arm_state);
2138 	if (status != VCHIQ_SUCCESS)
2139 		goto unlock;
2140 	if (arm_state->vc_suspend_state == VC_SUSPEND_SUSPENDED) {
2141 		/* Already suspended - just block resume and exit */
2142 		vchiq_log_info(vchiq_susp_log_level, "%s already suspended",
2143 			__func__);
2144 		status = VCHIQ_SUCCESS;
2145 		goto unlock;
2146 	} else if (arm_state->vc_suspend_state <= VC_SUSPEND_IDLE) {
2147 		/* initiate suspend immediately in the case that we're waiting
2148 		 * for the timeout */
2149 		stop_suspend_timer(arm_state);
2150 		if (!vchiq_videocore_wanted(state)) {
2151 			vchiq_log_info(vchiq_susp_log_level, "%s videocore "
2152 				"idle, initiating suspend", __func__);
2153 			status = vchiq_arm_vcsuspend(state);
2154 		} else if (arm_state->autosuspend_override <
2155 						FORCE_SUSPEND_FAIL_MAX) {
2156 			vchiq_log_info(vchiq_susp_log_level, "%s letting "
2157 				"videocore go idle", __func__);
2158 			status = VCHIQ_SUCCESS;
2159 		} else {
2160 			vchiq_log_warning(vchiq_susp_log_level, "%s failed too "
2161 				"many times - attempting suspend", __func__);
2162 			status = vchiq_arm_vcsuspend(state);
2163 		}
2164 	} else {
2165 		vchiq_log_info(vchiq_susp_log_level, "%s videocore suspend "
2166 			"in progress - wait for completion", __func__);
2167 		status = VCHIQ_SUCCESS;
2168 	}
2169 
2170 	/* Wait for suspend to happen due to system idle (not forced..) */
2171 	if (status != VCHIQ_SUCCESS)
2172 		goto unblock_resume;
2173 
2174 	do {
2175 		write_unlock_bh(&arm_state->susp_res_lock);
2176 
2177 		rc = wait_for_completion_interruptible_timeout(
2178 				&arm_state->vc_suspend_complete,
2179 				msecs_to_jiffies(FORCE_SUSPEND_TIMEOUT_MS));
2180 
2181 		write_lock_bh(&arm_state->susp_res_lock);
2182 		if (rc < 0) {
2183 			vchiq_log_warning(vchiq_susp_log_level, "%s "
2184 				"interrupted waiting for suspend", __func__);
2185 			status = VCHIQ_ERROR;
2186 			goto unblock_resume;
2187 		} else if (rc == 0) {
2188 			if (arm_state->vc_suspend_state > VC_SUSPEND_IDLE) {
2189 				/* Repeat timeout once if in progress */
2190 				if (repeat < 0) {
2191 					repeat = 1;
2192 					continue;
2193 				}
2194 			}
2195 			arm_state->autosuspend_override++;
2196 			output_timeout_error(state);
2197 
2198 			status = VCHIQ_RETRY;
2199 			goto unblock_resume;
2200 		}
2201 	} while (0 < (repeat--));
2202 
2203 	/* Check and report state in case we need to abort ARM suspend */
2204 	if (arm_state->vc_suspend_state != VC_SUSPEND_SUSPENDED) {
2205 		status = VCHIQ_RETRY;
2206 		vchiq_log_error(vchiq_susp_log_level,
2207 			"%s videocore suspend failed (state %s)", __func__,
2208 			suspend_state_names[arm_state->vc_suspend_state +
2209 						VC_SUSPEND_NUM_OFFSET]);
2210 		/* Reset the state only if it's still in an error state.
2211 		 * Something could have already initiated another suspend. */
2212 		if (arm_state->vc_suspend_state < VC_SUSPEND_IDLE)
2213 			set_suspend_state(arm_state, VC_SUSPEND_IDLE);
2214 
2215 		goto unblock_resume;
2216 	}
2217 
2218 	/* successfully suspended - unlock and exit */
2219 	goto unlock;
2220 
2221 unblock_resume:
2222 	/* all error states need to unblock resume before exit */
2223 	unblock_resume(arm_state);
2224 
2225 unlock:
2226 	write_unlock_bh(&arm_state->susp_res_lock);
2227 
2228 out:
2229 	vchiq_log_trace(vchiq_susp_log_level, "%s exit %d", __func__, status);
2230 	return status;
2231 }
2232 
2233 void
2234 vchiq_check_suspend(VCHIQ_STATE_T *state)
2235 {
2236 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
2237 
2238 	if (!arm_state)
2239 		goto out;
2240 
2241 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
2242 
2243 	write_lock_bh(&arm_state->susp_res_lock);
2244 	if (arm_state->vc_suspend_state != VC_SUSPEND_SUSPENDED &&
2245 			arm_state->first_connect &&
2246 			!vchiq_videocore_wanted(state)) {
2247 		vchiq_arm_vcsuspend(state);
2248 	}
2249 	write_unlock_bh(&arm_state->susp_res_lock);
2250 
2251 out:
2252 	vchiq_log_trace(vchiq_susp_log_level, "%s exit", __func__);
2253 	return;
2254 }
2255 
2256 
2257 int
2258 vchiq_arm_allow_resume(VCHIQ_STATE_T *state)
2259 {
2260 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
2261 	int resume = 0;
2262 	int ret = -1;
2263 
2264 	if (!arm_state)
2265 		goto out;
2266 
2267 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
2268 
2269 	write_lock_bh(&arm_state->susp_res_lock);
2270 	unblock_resume(arm_state);
2271 	resume = vchiq_check_resume(state);
2272 	write_unlock_bh(&arm_state->susp_res_lock);
2273 
2274 	if (resume) {
2275 		if (wait_for_completion_interruptible(
2276 			&arm_state->vc_resume_complete) < 0) {
2277 			vchiq_log_error(vchiq_susp_log_level,
2278 				"%s interrupted", __func__);
2279 			/* failed, cannot accurately derive suspend
2280 			 * state, so exit early. */
2281 			goto out;
2282 		}
2283 	}
2284 
2285 	read_lock_bh(&arm_state->susp_res_lock);
2286 	if (arm_state->vc_suspend_state == VC_SUSPEND_SUSPENDED) {
2287 		vchiq_log_info(vchiq_susp_log_level,
2288 				"%s: Videocore remains suspended", __func__);
2289 	} else {
2290 		vchiq_log_info(vchiq_susp_log_level,
2291 				"%s: Videocore resumed", __func__);
2292 		ret = 0;
2293 	}
2294 	read_unlock_bh(&arm_state->susp_res_lock);
2295 out:
2296 	vchiq_log_trace(vchiq_susp_log_level, "%s exit %d", __func__, ret);
2297 	return ret;
2298 }
2299 
2300 /* This function should be called with the write lock held */
2301 int
2302 vchiq_check_resume(VCHIQ_STATE_T *state)
2303 {
2304 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
2305 	int resume = 0;
2306 
2307 	if (!arm_state)
2308 		goto out;
2309 
2310 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
2311 
2312 	if (need_resume(state)) {
2313 		set_resume_state(arm_state, VC_RESUME_REQUESTED);
2314 		request_poll(state, NULL, 0);
2315 		resume = 1;
2316 	}
2317 
2318 out:
2319 	vchiq_log_trace(vchiq_susp_log_level, "%s exit", __func__);
2320 	return resume;
2321 }
2322 
2323 #ifdef notyet
2324 void
2325 vchiq_platform_check_resume(VCHIQ_STATE_T *state)
2326 {
2327 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
2328 	int res = 0;
2329 
2330 	if (!arm_state)
2331 		goto out;
2332 
2333 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
2334 
2335 	write_lock_bh(&arm_state->susp_res_lock);
2336 	if (arm_state->wake_address == 0) {
2337 		vchiq_log_info(vchiq_susp_log_level,
2338 					"%s: already awake", __func__);
2339 		goto unlock;
2340 	}
2341 	if (arm_state->vc_resume_state == VC_RESUME_IN_PROGRESS) {
2342 		vchiq_log_info(vchiq_susp_log_level,
2343 					"%s: already resuming", __func__);
2344 		goto unlock;
2345 	}
2346 
2347 	if (arm_state->vc_resume_state == VC_RESUME_REQUESTED) {
2348 		set_resume_state(arm_state, VC_RESUME_IN_PROGRESS);
2349 		res = 1;
2350 	} else
2351 		vchiq_log_trace(vchiq_susp_log_level,
2352 				"%s: not resuming (resume state %s)", __func__,
2353 				resume_state_names[arm_state->vc_resume_state +
2354 							VC_RESUME_NUM_OFFSET]);
2355 
2356 unlock:
2357 	write_unlock_bh(&arm_state->susp_res_lock);
2358 
2359 	if (res)
2360 		vchiq_platform_resume(state);
2361 
2362 out:
2363 	vchiq_log_trace(vchiq_susp_log_level, "%s exit", __func__);
2364 	return;
2365 
2366 }
2367 #endif
2368 
2369 
2370 
2371 VCHIQ_STATUS_T
2372 vchiq_use_internal(VCHIQ_STATE_T *state, VCHIQ_SERVICE_T *service,
2373 		enum USE_TYPE_E use_type)
2374 {
2375 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
2376 	VCHIQ_STATUS_T ret = VCHIQ_SUCCESS;
2377 	char entity[16];
2378 	int *entity_uc;
2379 	int local_uc, local_entity_uc;
2380 
2381 	if (!arm_state)
2382 		goto out;
2383 
2384 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
2385 
2386 	if (use_type == USE_TYPE_VCHIQ) {
2387 		snprintf(entity, sizeof(entity), "VCHIQ:   ");
2388 		entity_uc = &arm_state->peer_use_count;
2389 	} else if (service) {
2390 		snprintf(entity, sizeof(entity), "%c%c%c%c:%8x",
2391 			VCHIQ_FOURCC_AS_4CHARS(service->base.fourcc),
2392 			service->client_id);
2393 		entity_uc = &service->service_use_count;
2394 	} else {
2395 		vchiq_log_error(vchiq_susp_log_level, "%s null service "
2396 				"ptr", __func__);
2397 		ret = VCHIQ_ERROR;
2398 		goto out;
2399 	}
2400 
2401 	write_lock_bh(&arm_state->susp_res_lock);
2402 	while (arm_state->resume_blocked) {
2403 		/* If we call 'use' while force suspend is waiting for suspend,
2404 		 * then we're about to block the thread which the force is
2405 		 * waiting to complete, so we're bound to just time out. In this
2406 		 * case, set the suspend state such that the wait will be
2407 		 * canceled, so we can complete as quickly as possible. */
2408 		if (arm_state->resume_blocked && arm_state->vc_suspend_state ==
2409 				VC_SUSPEND_IDLE) {
2410 			set_suspend_state(arm_state, VC_SUSPEND_FORCE_CANCELED);
2411 			break;
2412 		}
2413 		/* If suspend is already in progress then we need to block */
2414 		if (!try_wait_for_completion(&arm_state->resume_blocker)) {
2415 			/* Indicate that there are threads waiting on the resume
2416 			 * blocker.  These need to be allowed to complete before
2417 			 * a _second_ call to force suspend can complete,
2418 			 * otherwise low priority threads might never actually
2419 			 * continue */
2420 			arm_state->blocked_count++;
2421 			write_unlock_bh(&arm_state->susp_res_lock);
2422 			vchiq_log_info(vchiq_susp_log_level, "%s %s resume "
2423 				"blocked - waiting...", __func__, entity);
2424 			if (wait_for_completion_killable(
2425 					&arm_state->resume_blocker) != 0) {
2426 				vchiq_log_error(vchiq_susp_log_level, "%s %s "
2427 					"wait for resume blocker interrupted",
2428 					__func__, entity);
2429 				ret = VCHIQ_ERROR;
2430 				write_lock_bh(&arm_state->susp_res_lock);
2431 				arm_state->blocked_count--;
2432 				write_unlock_bh(&arm_state->susp_res_lock);
2433 				goto out;
2434 			}
2435 			vchiq_log_info(vchiq_susp_log_level, "%s %s resume "
2436 				"unblocked", __func__, entity);
2437 			write_lock_bh(&arm_state->susp_res_lock);
2438 			if (--arm_state->blocked_count == 0)
2439 				complete_all(&arm_state->blocked_blocker);
2440 		}
2441 	}
2442 
2443 	stop_suspend_timer(arm_state);
2444 
2445 	local_uc = ++arm_state->videocore_use_count;
2446 	local_entity_uc = ++(*entity_uc);
2447 
2448 	/* If there's a pending request which hasn't yet been serviced then
2449 	 * just clear it.  If we're past VC_SUSPEND_REQUESTED state then
2450 	 * vc_resume_complete will block until we either resume or fail to
2451 	 * suspend */
2452 	if (arm_state->vc_suspend_state <= VC_SUSPEND_REQUESTED)
2453 		set_suspend_state(arm_state, VC_SUSPEND_IDLE);
2454 
2455 	if ((use_type != USE_TYPE_SERVICE_NO_RESUME) && need_resume(state)) {
2456 		set_resume_state(arm_state, VC_RESUME_REQUESTED);
2457 		vchiq_log_info(vchiq_susp_log_level,
2458 			"%s %s count %d, state count %d",
2459 			__func__, entity, local_entity_uc, local_uc);
2460 		request_poll(state, NULL, 0);
2461 	} else
2462 		vchiq_log_trace(vchiq_susp_log_level,
2463 			"%s %s count %d, state count %d",
2464 			__func__, entity, *entity_uc, local_uc);
2465 
2466 
2467 	write_unlock_bh(&arm_state->susp_res_lock);
2468 
2469 	/* Completion is in a done state when we're not suspended, so this won't
2470 	 * block for the non-suspended case. */
2471 	if (!try_wait_for_completion(&arm_state->vc_resume_complete)) {
2472 		vchiq_log_info(vchiq_susp_log_level, "%s %s wait for resume",
2473 			__func__, entity);
2474 		if (wait_for_completion_killable(
2475 				&arm_state->vc_resume_complete) != 0) {
2476 			vchiq_log_error(vchiq_susp_log_level, "%s %s wait for "
2477 				"resume interrupted", __func__, entity);
2478 			ret = VCHIQ_ERROR;
2479 			goto out;
2480 		}
2481 		vchiq_log_info(vchiq_susp_log_level, "%s %s resumed", __func__,
2482 			entity);
2483 	}
2484 
2485 	if (ret == VCHIQ_SUCCESS) {
2486 		VCHIQ_STATUS_T status = VCHIQ_SUCCESS;
2487 		long ack_cnt = atomic_xchg(&arm_state->ka_use_ack_count, 0);
2488 		while (ack_cnt && (status == VCHIQ_SUCCESS)) {
2489 			/* Send the use notify to videocore */
2490 			status = vchiq_send_remote_use_active(state);
2491 			if (status == VCHIQ_SUCCESS)
2492 				ack_cnt--;
2493 			else
2494 				atomic_add(ack_cnt,
2495 					&arm_state->ka_use_ack_count);
2496 		}
2497 	}
2498 
2499 out:
2500 	vchiq_log_trace(vchiq_susp_log_level, "%s exit %d", __func__, ret);
2501 	return ret;
2502 }
2503 
2504 VCHIQ_STATUS_T
2505 vchiq_release_internal(VCHIQ_STATE_T *state, VCHIQ_SERVICE_T *service)
2506 {
2507 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
2508 	VCHIQ_STATUS_T ret = VCHIQ_SUCCESS;
2509 	char entity[16];
2510 	int *entity_uc;
2511 
2512 	if (!arm_state)
2513 		goto out;
2514 
2515 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
2516 
2517 	if (service) {
2518 		snprintf(entity, sizeof(entity), "%c%c%c%c:%8x",
2519 			VCHIQ_FOURCC_AS_4CHARS(service->base.fourcc),
2520 			service->client_id);
2521 		entity_uc = &service->service_use_count;
2522 	} else {
2523 		snprintf(entity, sizeof(entity), "PEER:   ");
2524 		entity_uc = &arm_state->peer_use_count;
2525 	}
2526 
2527 	write_lock_bh(&arm_state->susp_res_lock);
2528 	if (!arm_state->videocore_use_count || !(*entity_uc)) {
2529 		/* Don't use BUG_ON - don't allow user thread to crash kernel */
2530 		WARN_ON(!arm_state->videocore_use_count);
2531 		WARN_ON(!(*entity_uc));
2532 		ret = VCHIQ_ERROR;
2533 		goto unlock;
2534 	}
2535 	--arm_state->videocore_use_count;
2536 	--(*entity_uc);
2537 
2538 	if (!vchiq_videocore_wanted(state)) {
2539 		if (vchiq_platform_use_suspend_timer() &&
2540 				!arm_state->resume_blocked) {
2541 			/* Only use the timer if we're not trying to force
2542 			 * suspend (=> resume_blocked) */
2543 			start_suspend_timer(arm_state);
2544 		} else {
2545 			vchiq_log_info(vchiq_susp_log_level,
2546 				"%s %s count %d, state count %d - suspending",
2547 				__func__, entity, *entity_uc,
2548 				arm_state->videocore_use_count);
2549 			vchiq_arm_vcsuspend(state);
2550 		}
2551 	} else
2552 		vchiq_log_trace(vchiq_susp_log_level,
2553 			"%s %s count %d, state count %d",
2554 			__func__, entity, *entity_uc,
2555 			arm_state->videocore_use_count);
2556 
2557 unlock:
2558 	write_unlock_bh(&arm_state->susp_res_lock);
2559 
2560 out:
2561 	vchiq_log_trace(vchiq_susp_log_level, "%s exit %d", __func__, ret);
2562 	return ret;
2563 }
2564 
2565 void
2566 vchiq_on_remote_use(VCHIQ_STATE_T *state)
2567 {
2568 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
2569 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
2570 	atomic_inc(&arm_state->ka_use_count);
2571 	complete(&arm_state->ka_evt);
2572 }
2573 
2574 void
2575 vchiq_on_remote_release(VCHIQ_STATE_T *state)
2576 {
2577 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
2578 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
2579 	atomic_inc(&arm_state->ka_release_count);
2580 	complete(&arm_state->ka_evt);
2581 }
2582 
2583 VCHIQ_STATUS_T
2584 vchiq_use_service_internal(VCHIQ_SERVICE_T *service)
2585 {
2586 	return vchiq_use_internal(service->state, service, USE_TYPE_SERVICE);
2587 }
2588 
2589 VCHIQ_STATUS_T
2590 vchiq_release_service_internal(VCHIQ_SERVICE_T *service)
2591 {
2592 	return vchiq_release_internal(service->state, service);
2593 }
2594 
2595 static void suspend_timer_callback(unsigned long context)
2596 {
2597 	VCHIQ_STATE_T *state = (VCHIQ_STATE_T *)context;
2598 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
2599 	if (!arm_state)
2600 		goto out;
2601 	vchiq_log_info(vchiq_susp_log_level,
2602 		"%s - suspend timer expired - check suspend", __func__);
2603 	vchiq_check_suspend(state);
2604 out:
2605 	return;
2606 }
2607 
2608 VCHIQ_STATUS_T
2609 vchiq_use_service_no_resume(VCHIQ_SERVICE_HANDLE_T handle)
2610 {
2611 	VCHIQ_STATUS_T ret = VCHIQ_ERROR;
2612 	VCHIQ_SERVICE_T *service = find_service_by_handle(handle);
2613 	if (service) {
2614 		ret = vchiq_use_internal(service->state, service,
2615 				USE_TYPE_SERVICE_NO_RESUME);
2616 		unlock_service(service);
2617 	}
2618 	return ret;
2619 }
2620 
2621 VCHIQ_STATUS_T
2622 vchiq_use_service(VCHIQ_SERVICE_HANDLE_T handle)
2623 {
2624 	VCHIQ_STATUS_T ret = VCHIQ_ERROR;
2625 	VCHIQ_SERVICE_T *service = find_service_by_handle(handle);
2626 	if (service) {
2627 		ret = vchiq_use_internal(service->state, service,
2628 				USE_TYPE_SERVICE);
2629 		unlock_service(service);
2630 	}
2631 	return ret;
2632 }
2633 
2634 VCHIQ_STATUS_T
2635 vchiq_release_service(VCHIQ_SERVICE_HANDLE_T handle)
2636 {
2637 	VCHIQ_STATUS_T ret = VCHIQ_ERROR;
2638 	VCHIQ_SERVICE_T *service = find_service_by_handle(handle);
2639 	if (service) {
2640 		ret = vchiq_release_internal(service->state, service);
2641 		unlock_service(service);
2642 	}
2643 	return ret;
2644 }
2645 
2646 void
2647 vchiq_dump_service_use_state(VCHIQ_STATE_T *state)
2648 {
2649 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
2650 	int i, j = 0;
2651 	/* Only dump 64 services */
2652 	static const int local_max_services = 64;
2653 	/* If there's more than 64 services, only dump ones with
2654 	 * non-zero counts */
2655 	int only_nonzero = 0;
2656 	static const char *nz = "<-- preventing suspend";
2657 
2658 	enum vc_suspend_status vc_suspend_state;
2659 	enum vc_resume_status  vc_resume_state;
2660 	int peer_count;
2661 	int vc_use_count;
2662 	int active_services;
2663 	struct service_data_struct {
2664 		int fourcc;
2665 		int clientid;
2666 		int use_count;
2667 	} service_data[local_max_services];
2668 
2669 	if (!arm_state)
2670 		return;
2671 
2672 	read_lock_bh(&arm_state->susp_res_lock);
2673 	vc_suspend_state = arm_state->vc_suspend_state;
2674 	vc_resume_state  = arm_state->vc_resume_state;
2675 	peer_count = arm_state->peer_use_count;
2676 	vc_use_count = arm_state->videocore_use_count;
2677 	active_services = state->unused_service;
2678 	if (active_services > local_max_services)
2679 		only_nonzero = 1;
2680 
2681 	for (i = 0; (i < active_services) && (j < local_max_services); i++) {
2682 		VCHIQ_SERVICE_T *service_ptr = state->services[i];
2683 		if (!service_ptr)
2684 			continue;
2685 
2686 		if (only_nonzero && !service_ptr->service_use_count)
2687 			continue;
2688 
2689 		if (service_ptr->srvstate != VCHIQ_SRVSTATE_FREE) {
2690 			service_data[j].fourcc = service_ptr->base.fourcc;
2691 			service_data[j].clientid = service_ptr->client_id;
2692 			service_data[j++].use_count = service_ptr->
2693 							service_use_count;
2694 		}
2695 	}
2696 
2697 	read_unlock_bh(&arm_state->susp_res_lock);
2698 
2699 	vchiq_log_warning(vchiq_susp_log_level,
2700 		"-- Videcore suspend state: %s --",
2701 		suspend_state_names[vc_suspend_state + VC_SUSPEND_NUM_OFFSET]);
2702 	vchiq_log_warning(vchiq_susp_log_level,
2703 		"-- Videcore resume state: %s --",
2704 		resume_state_names[vc_resume_state + VC_RESUME_NUM_OFFSET]);
2705 
2706 	if (only_nonzero)
2707 		vchiq_log_warning(vchiq_susp_log_level, "Too many active "
2708 			"services (%d).  Only dumping up to first %d services "
2709 			"with non-zero use-count", active_services,
2710 			local_max_services);
2711 
2712 	for (i = 0; i < j; i++) {
2713 		vchiq_log_warning(vchiq_susp_log_level,
2714 			"----- %c%c%c%c:%d service count %d %s",
2715 			VCHIQ_FOURCC_AS_4CHARS(service_data[i].fourcc),
2716 			service_data[i].clientid,
2717 			service_data[i].use_count,
2718 			service_data[i].use_count ? nz : "");
2719 	}
2720 	vchiq_log_warning(vchiq_susp_log_level,
2721 		"----- VCHIQ use count count %d", peer_count);
2722 	vchiq_log_warning(vchiq_susp_log_level,
2723 		"--- Overall vchiq instance use count %d", vc_use_count);
2724 
2725 	vchiq_dump_platform_use_state(state);
2726 }
2727 
2728 VCHIQ_STATUS_T
2729 vchiq_check_service(VCHIQ_SERVICE_T *service)
2730 {
2731 	VCHIQ_ARM_STATE_T *arm_state;
2732 	VCHIQ_STATUS_T ret = VCHIQ_ERROR;
2733 
2734 	if (!service || !service->state)
2735 		goto out;
2736 
2737 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
2738 
2739 	arm_state = vchiq_platform_get_arm_state(service->state);
2740 
2741 	read_lock_bh(&arm_state->susp_res_lock);
2742 	if (service->service_use_count)
2743 		ret = VCHIQ_SUCCESS;
2744 	read_unlock_bh(&arm_state->susp_res_lock);
2745 
2746 	if (ret == VCHIQ_ERROR) {
2747 		vchiq_log_error(vchiq_susp_log_level,
2748 			"%s ERROR - %c%c%c%c:%8x service count %d, "
2749 			"state count %d, videocore suspend state %s", __func__,
2750 			VCHIQ_FOURCC_AS_4CHARS(service->base.fourcc),
2751 			service->client_id, service->service_use_count,
2752 			arm_state->videocore_use_count,
2753 			suspend_state_names[arm_state->vc_suspend_state +
2754 						VC_SUSPEND_NUM_OFFSET]);
2755 		vchiq_dump_service_use_state(service->state);
2756 	}
2757 out:
2758 	return ret;
2759 }
2760 
2761 /* stub functions */
2762 void vchiq_on_remote_use_active(VCHIQ_STATE_T *state)
2763 {
2764 	(void)state;
2765 }
2766 
2767 void vchiq_platform_conn_state_changed(VCHIQ_STATE_T *state,
2768 	VCHIQ_CONNSTATE_T oldstate, VCHIQ_CONNSTATE_T newstate)
2769 {
2770 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
2771 	vchiq_log_info(vchiq_susp_log_level, "%d: %s->%s", state->id,
2772 		get_conn_state_name(oldstate), get_conn_state_name(newstate));
2773 	if (state->conn_state == VCHIQ_CONNSTATE_CONNECTED) {
2774 		write_lock_bh(&arm_state->susp_res_lock);
2775 		if (!arm_state->first_connect) {
2776 			char threadname[10];
2777 			arm_state->first_connect = 1;
2778 			write_unlock_bh(&arm_state->susp_res_lock);
2779 			snprintf(threadname, sizeof(threadname), "VCHIQka-%d",
2780 				state->id);
2781 			arm_state->ka_thread = vchiq_thread_create(
2782 				&vchiq_keepalive_thread_func,
2783 				(void *)state,
2784 				threadname);
2785 			if (arm_state->ka_thread == NULL) {
2786 				vchiq_log_error(vchiq_susp_log_level,
2787 					"vchiq: FATAL: couldn't create thread %s",
2788 					threadname);
2789 			} else {
2790 				wake_up_process(arm_state->ka_thread);
2791 			}
2792 		} else
2793 			write_unlock_bh(&arm_state->susp_res_lock);
2794 	}
2795 }
2796 
2797 /****************************************************************************
2798 *
2799 *   vchiq_init - called when the module is loaded.
2800 *
2801 ***************************************************************************/
2802 
2803 int __init vchiq_init(void);
2804 int __init
2805 vchiq_init(void)
2806 {
2807 	int err;
2808 
2809 #ifdef notyet
2810 	/* create proc entries */
2811 	err = vchiq_proc_init();
2812 	if (err != 0)
2813 		goto failed_proc_init;
2814 #endif
2815 
2816 	vchiq_cdev = make_dev(&vchiq_cdevsw, 0,
2817 	    UID_ROOT, GID_WHEEL, 0600, "vchiq");
2818 	if (!vchiq_cdev) {
2819 		printf("Failed to create /dev/vchiq");
2820 		return (-ENXIO);
2821 	}
2822 
2823 	spin_lock_init(&msg_queue_spinlock);
2824 
2825 	err = vchiq_platform_init(&g_state);
2826 	if (err != 0)
2827 		goto failed_platform_init;
2828 
2829 	vchiq_log_info(vchiq_arm_log_level,
2830 		"vchiq: initialised - version %d (min %d)",
2831 		VCHIQ_VERSION, VCHIQ_VERSION_MIN);
2832 
2833 	return 0;
2834 
2835 failed_platform_init:
2836 	if (vchiq_cdev) {
2837 		destroy_dev(vchiq_cdev);
2838 		vchiq_cdev = NULL;
2839 	}
2840 	vchiq_log_warning(vchiq_arm_log_level, "could not load vchiq");
2841 	return err;
2842 }
2843 
2844 #ifdef notyet
2845 static int vchiq_instance_get_use_count(VCHIQ_INSTANCE_T instance)
2846 {
2847 	VCHIQ_SERVICE_T *service;
2848 	int use_count = 0, i;
2849 	i = 0;
2850 	while ((service = next_service_by_instance(instance->state,
2851 		instance, &i)) != NULL) {
2852 		use_count += service->service_use_count;
2853 		unlock_service(service);
2854 	}
2855 	return use_count;
2856 }
2857 
2858 /* read the per-process use-count */
2859 static int proc_read_use_count(char *page, char **start,
2860 			       off_t off, int count,
2861 			       int *eof, void *data)
2862 {
2863 	VCHIQ_INSTANCE_T instance = data;
2864 	int len, use_count;
2865 
2866 	use_count = vchiq_instance_get_use_count(instance);
2867 	len = snprintf(page+off, count, "%d\n", use_count);
2868 
2869 	return len;
2870 }
2871 
2872 /* add an instance (process) to the proc entries */
2873 static int vchiq_proc_add_instance(VCHIQ_INSTANCE_T instance)
2874 {
2875 	char pidstr[32];
2876 	struct proc_dir_entry *top, *use_count;
2877 	struct proc_dir_entry *clients = vchiq_clients_top();
2878 	int pid = instance->pid;
2879 
2880 	snprintf(pidstr, sizeof(pidstr), "%d", pid);
2881 	top = proc_mkdir(pidstr, clients);
2882 	if (!top)
2883 		goto fail_top;
2884 
2885 	use_count = create_proc_read_entry("use_count",
2886 					   0444, top,
2887 					   proc_read_use_count,
2888 					   instance);
2889 	if (!use_count)
2890 		goto fail_use_count;
2891 
2892 	instance->proc_entry = top;
2893 
2894 	return 0;
2895 
2896 fail_use_count:
2897 	remove_proc_entry(top->name, clients);
2898 fail_top:
2899 	return -ENOMEM;
2900 }
2901 
2902 static void vchiq_proc_remove_instance(VCHIQ_INSTANCE_T instance)
2903 {
2904 	struct proc_dir_entry *clients = vchiq_clients_top();
2905 	remove_proc_entry("use_count", instance->proc_entry);
2906 	remove_proc_entry(instance->proc_entry->name, clients);
2907 }
2908 
2909 #endif
2910 
2911 /****************************************************************************
2912 *
2913 *   vchiq_exit - called when the module is unloaded.
2914 *
2915 ***************************************************************************/
2916 
2917 void vchiq_exit(void);
2918 void
2919 vchiq_exit(void)
2920 {
2921 	if (vchiq_ehtag == NULL)
2922 		EVENTHANDLER_DEREGISTER(dev_clone, vchiq_ehtag);
2923 	vchiq_ehtag = NULL;
2924 
2925 	vchiq_platform_exit(&g_state);
2926 	if (vchiq_cdev) {
2927 		destroy_dev(vchiq_cdev);
2928 		vchiq_cdev = NULL;
2929 	}
2930 }
2931