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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 #include <linux/kernel.h>
36 #include <linux/module.h>
37 #include <linux/types.h>
38 #include <linux/errno.h>
39 #include <linux/cdev.h>
40 #include <linux/fs.h>
41 #include <linux/device.h>
42 #include <linux/mm.h>
43 #include <linux/highmem.h>
44 #include <linux/pagemap.h>
45 #include <linux/bug.h>
46 #include <linux/semaphore.h>
47 #include <linux/list.h>
48 #include <linux/of.h>
49 #include <linux/platform_device.h>
50 #include <soc/bcm2835/raspberrypi-firmware.h>
51 
52 #include "vchiq_core.h"
53 #include "vchiq_ioctl.h"
54 #include "vchiq_arm.h"
55 #include "vchiq_debugfs.h"
56 #include "vchiq_killable.h"
57 
58 #define DEVICE_NAME "vchiq"
59 
60 /* Override the default prefix, which would be vchiq_arm (from the filename) */
61 #undef MODULE_PARAM_PREFIX
62 #define MODULE_PARAM_PREFIX DEVICE_NAME "."
63 
64 #define VCHIQ_MINOR 0
65 
66 /* Some per-instance constants */
67 #define MAX_COMPLETIONS 16
68 #define MAX_SERVICES 64
69 #define MAX_ELEMENTS 8
70 #define MSG_QUEUE_SIZE 64
71 
72 #define KEEPALIVE_VER 1
73 #define KEEPALIVE_VER_MIN KEEPALIVE_VER
74 
75 /* Run time control of log level, based on KERN_XXX level. */
76 int vchiq_arm_log_level = VCHIQ_LOG_DEFAULT;
77 int vchiq_susp_log_level = VCHIQ_LOG_ERROR;
78 
79 #define SUSPEND_TIMER_TIMEOUT_MS 100
80 #define SUSPEND_RETRY_TIMER_TIMEOUT_MS 1000
81 
82 #define VC_SUSPEND_NUM_OFFSET 3 /* number of values before idle which are -ve */
83 static const char *const suspend_state_names[] = {
84 	"VC_SUSPEND_FORCE_CANCELED",
85 	"VC_SUSPEND_REJECTED",
86 	"VC_SUSPEND_FAILED",
87 	"VC_SUSPEND_IDLE",
88 	"VC_SUSPEND_REQUESTED",
89 	"VC_SUSPEND_IN_PROGRESS",
90 	"VC_SUSPEND_SUSPENDED"
91 };
92 #define VC_RESUME_NUM_OFFSET 1 /* number of values before idle which are -ve */
93 static const char *const resume_state_names[] = {
94 	"VC_RESUME_FAILED",
95 	"VC_RESUME_IDLE",
96 	"VC_RESUME_REQUESTED",
97 	"VC_RESUME_IN_PROGRESS",
98 	"VC_RESUME_RESUMED"
99 };
100 /* The number of times we allow force suspend to timeout before actually
101 ** _forcing_ suspend.  This is to cater for SW which fails to release vchiq
102 ** correctly - we don't want to prevent ARM suspend indefinitely in this case.
103 */
104 #define FORCE_SUSPEND_FAIL_MAX 8
105 
106 /* The time in ms allowed for videocore to go idle when force suspend has been
107  * requested */
108 #define FORCE_SUSPEND_TIMEOUT_MS 200
109 
110 
111 static void suspend_timer_callback(unsigned long context);
112 
113 
114 typedef struct user_service_struct {
115 	VCHIQ_SERVICE_T *service;
116 	void *userdata;
117 	VCHIQ_INSTANCE_T instance;
118 	char is_vchi;
119 	char dequeue_pending;
120 	char close_pending;
121 	int message_available_pos;
122 	int msg_insert;
123 	int msg_remove;
124 	struct semaphore insert_event;
125 	struct semaphore remove_event;
126 	struct semaphore close_event;
127 	VCHIQ_HEADER_T * msg_queue[MSG_QUEUE_SIZE];
128 } USER_SERVICE_T;
129 
130 struct bulk_waiter_node {
131 	struct bulk_waiter bulk_waiter;
132 	int pid;
133 	struct list_head list;
134 };
135 
136 struct vchiq_instance_struct {
137 	VCHIQ_STATE_T *state;
138 	VCHIQ_COMPLETION_DATA_T completions[MAX_COMPLETIONS];
139 	int completion_insert;
140 	int completion_remove;
141 	struct semaphore insert_event;
142 	struct semaphore remove_event;
143 	struct mutex completion_mutex;
144 
145 	int connected;
146 	int closing;
147 	int pid;
148 	int mark;
149 	int use_close_delivered;
150 	int trace;
151 
152 	struct list_head bulk_waiter_list;
153 	struct mutex bulk_waiter_list_mutex;
154 
155 	VCHIQ_DEBUGFS_NODE_T debugfs_node;
156 };
157 
158 typedef struct dump_context_struct {
159 	char __user *buf;
160 	size_t actual;
161 	size_t space;
162 	loff_t offset;
163 } DUMP_CONTEXT_T;
164 
165 static struct cdev    vchiq_cdev;
166 static dev_t          vchiq_devid;
167 static VCHIQ_STATE_T g_state;
168 static struct class  *vchiq_class;
169 static struct device *vchiq_dev;
170 static DEFINE_SPINLOCK(msg_queue_spinlock);
171 
172 static const char *const ioctl_names[] = {
173 	"CONNECT",
174 	"SHUTDOWN",
175 	"CREATE_SERVICE",
176 	"REMOVE_SERVICE",
177 	"QUEUE_MESSAGE",
178 	"QUEUE_BULK_TRANSMIT",
179 	"QUEUE_BULK_RECEIVE",
180 	"AWAIT_COMPLETION",
181 	"DEQUEUE_MESSAGE",
182 	"GET_CLIENT_ID",
183 	"GET_CONFIG",
184 	"CLOSE_SERVICE",
185 	"USE_SERVICE",
186 	"RELEASE_SERVICE",
187 	"SET_SERVICE_OPTION",
188 	"DUMP_PHYS_MEM",
189 	"LIB_VERSION",
190 	"CLOSE_DELIVERED"
191 };
192 
193 vchiq_static_assert((sizeof(ioctl_names)/sizeof(ioctl_names[0])) ==
194 	(VCHIQ_IOC_MAX + 1));
195 
196 static void
197 dump_phys_mem(void *virt_addr, uint32_t num_bytes);
198 
199 /****************************************************************************
200 *
201 *   add_completion
202 *
203 ***************************************************************************/
204 
205 static VCHIQ_STATUS_T
add_completion(VCHIQ_INSTANCE_T instance,VCHIQ_REASON_T reason,VCHIQ_HEADER_T * header,USER_SERVICE_T * user_service,void * bulk_userdata)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 	DEBUG_INITIALISE(g_state.local)
212 
213 	while (instance->completion_insert ==
214 		(instance->completion_remove + MAX_COMPLETIONS)) {
215 		/* Out of space - wait for the client */
216 		DEBUG_TRACE(SERVICE_CALLBACK_LINE);
217 		vchiq_log_trace(vchiq_arm_log_level,
218 			"add_completion - completion queue full");
219 		DEBUG_COUNT(COMPLETION_QUEUE_FULL_COUNT);
220 		if (down_interruptible(&instance->remove_event) != 0) {
221 			vchiq_log_info(vchiq_arm_log_level,
222 				"service_callback interrupted");
223 			return VCHIQ_RETRY;
224 		} else if (instance->closing) {
225 			vchiq_log_info(vchiq_arm_log_level,
226 				"service_callback closing");
227 			return VCHIQ_ERROR;
228 		}
229 		DEBUG_TRACE(SERVICE_CALLBACK_LINE);
230 	}
231 
232 	completion =
233 		 &instance->completions[instance->completion_insert &
234 		 (MAX_COMPLETIONS - 1)];
235 
236 	completion->header = header;
237 	completion->reason = reason;
238 	/* N.B. service_userdata is updated while processing AWAIT_COMPLETION */
239 	completion->service_userdata = user_service->service;
240 	completion->bulk_userdata = bulk_userdata;
241 
242 	if (reason == VCHIQ_SERVICE_CLOSED) {
243 		/* Take an extra reference, to be held until
244 		   this CLOSED notification is delivered. */
245 		lock_service(user_service->service);
246 		if (instance->use_close_delivered)
247 			user_service->close_pending = 1;
248 	}
249 
250 	/* A write barrier is needed here to ensure that the entire completion
251 		record is written out before the insert point. */
252 	wmb();
253 
254 	if (reason == VCHIQ_MESSAGE_AVAILABLE)
255 		user_service->message_available_pos =
256 			instance->completion_insert;
257 	instance->completion_insert++;
258 
259 	up(&instance->insert_event);
260 
261 	return VCHIQ_SUCCESS;
262 }
263 
264 /****************************************************************************
265 *
266 *   service_callback
267 *
268 ***************************************************************************/
269 
270 static VCHIQ_STATUS_T
service_callback(VCHIQ_REASON_T reason,VCHIQ_HEADER_T * header,VCHIQ_SERVICE_HANDLE_T handle,void * bulk_userdata)271 service_callback(VCHIQ_REASON_T reason, VCHIQ_HEADER_T *header,
272 	VCHIQ_SERVICE_HANDLE_T handle, void *bulk_userdata)
273 {
274 	/* How do we ensure the callback goes to the right client?
275 	** The service_user data points to a USER_SERVICE_T record containing
276 	** the original callback and the user state structure, which contains a
277 	** circular buffer for completion records.
278 	*/
279 	USER_SERVICE_T *user_service;
280 	VCHIQ_SERVICE_T *service;
281 	VCHIQ_INSTANCE_T instance;
282 	DEBUG_INITIALISE(g_state.local)
283 
284 	DEBUG_TRACE(SERVICE_CALLBACK_LINE);
285 
286 	service = handle_to_service(handle);
287 	BUG_ON(!service);
288 	user_service = (USER_SERVICE_T *)service->base.userdata;
289 	instance = user_service->instance;
290 
291 	if (!instance || instance->closing)
292 		return VCHIQ_SUCCESS;
293 
294 	vchiq_log_trace(vchiq_arm_log_level,
295 		"service_callback - service %lx(%d,%p), reason %d, header %lx, "
296 		"instance %lx, bulk_userdata %lx",
297 		(unsigned long)user_service,
298 		service->localport, user_service->userdata,
299 		reason, (unsigned long)header,
300 		(unsigned long)instance, (unsigned long)bulk_userdata);
301 
302 	if (header && user_service->is_vchi) {
303 		spin_lock(&msg_queue_spinlock);
304 		while (user_service->msg_insert ==
305 			(user_service->msg_remove + MSG_QUEUE_SIZE)) {
306 			spin_unlock(&msg_queue_spinlock);
307 			DEBUG_TRACE(SERVICE_CALLBACK_LINE);
308 			DEBUG_COUNT(MSG_QUEUE_FULL_COUNT);
309 			vchiq_log_trace(vchiq_arm_log_level,
310 				"service_callback - msg queue full");
311 			/* If there is no MESSAGE_AVAILABLE in the completion
312 			** queue, add one
313 			*/
314 			if ((user_service->message_available_pos -
315 				instance->completion_remove) < 0) {
316 				VCHIQ_STATUS_T status;
317 				vchiq_log_info(vchiq_arm_log_level,
318 					"Inserting extra MESSAGE_AVAILABLE");
319 				DEBUG_TRACE(SERVICE_CALLBACK_LINE);
320 				status = add_completion(instance, reason,
321 					NULL, user_service, bulk_userdata);
322 				if (status != VCHIQ_SUCCESS) {
323 					DEBUG_TRACE(SERVICE_CALLBACK_LINE);
324 					return status;
325 				}
326 			}
327 
328 			DEBUG_TRACE(SERVICE_CALLBACK_LINE);
329 			if (down_interruptible(&user_service->remove_event)
330 				!= 0) {
331 				vchiq_log_info(vchiq_arm_log_level,
332 					"service_callback interrupted");
333 				DEBUG_TRACE(SERVICE_CALLBACK_LINE);
334 				return VCHIQ_RETRY;
335 			} else if (instance->closing) {
336 				vchiq_log_info(vchiq_arm_log_level,
337 					"service_callback closing");
338 				DEBUG_TRACE(SERVICE_CALLBACK_LINE);
339 				return VCHIQ_ERROR;
340 			}
341 			DEBUG_TRACE(SERVICE_CALLBACK_LINE);
342 			spin_lock(&msg_queue_spinlock);
343 		}
344 
345 		user_service->msg_queue[user_service->msg_insert &
346 			(MSG_QUEUE_SIZE - 1)] = header;
347 		user_service->msg_insert++;
348 		spin_unlock(&msg_queue_spinlock);
349 
350 		up(&user_service->insert_event);
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 			DEBUG_TRACE(SERVICE_CALLBACK_LINE);
360 			user_service->dequeue_pending = 0;
361 			return VCHIQ_SUCCESS;
362 		}
363 
364 		header = NULL;
365 	}
366 	DEBUG_TRACE(SERVICE_CALLBACK_LINE);
367 
368 	return add_completion(instance, reason, header, user_service,
369 		bulk_userdata);
370 }
371 
372 /****************************************************************************
373 *
374 *   user_service_free
375 *
376 ***************************************************************************/
377 static void
user_service_free(void * userdata)378 user_service_free(void *userdata)
379 {
380 	kfree(userdata);
381 }
382 
383 /****************************************************************************
384 *
385 *   close_delivered
386 *
387 ***************************************************************************/
close_delivered(USER_SERVICE_T * user_service)388 static void close_delivered(USER_SERVICE_T *user_service)
389 {
390 	vchiq_log_info(vchiq_arm_log_level,
391 		"close_delivered(handle=%x)",
392 		user_service->service->handle);
393 
394 	if (user_service->close_pending) {
395 		/* Allow the underlying service to be culled */
396 		unlock_service(user_service->service);
397 
398 		/* Wake the user-thread blocked in close_ or remove_service */
399 		up(&user_service->close_event);
400 
401 		user_service->close_pending = 0;
402 	}
403 }
404 
405 /****************************************************************************
406 *
407 *   vchiq_ioctl
408 *
409 ***************************************************************************/
410 static long
vchiq_ioctl(struct file * file,unsigned int cmd,unsigned long arg)411 vchiq_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
412 {
413 	VCHIQ_INSTANCE_T instance = file->private_data;
414 	VCHIQ_STATUS_T status = VCHIQ_SUCCESS;
415 	VCHIQ_SERVICE_T *service = NULL;
416 	long ret = 0;
417 	int i, rc;
418 	DEBUG_INITIALISE(g_state.local)
419 
420 	vchiq_log_trace(vchiq_arm_log_level,
421 		 "vchiq_ioctl - instance %x, cmd %s, arg %lx",
422 		(unsigned int)instance,
423 		((_IOC_TYPE(cmd) == VCHIQ_IOC_MAGIC) &&
424 		(_IOC_NR(cmd) <= VCHIQ_IOC_MAX)) ?
425 		ioctl_names[_IOC_NR(cmd)] : "<invalid>", arg);
426 
427 	switch (cmd) {
428 	case VCHIQ_IOC_SHUTDOWN:
429 		if (!instance->connected)
430 			break;
431 
432 		/* Remove all services */
433 		i = 0;
434 		while ((service = next_service_by_instance(instance->state,
435 			instance, &i)) != NULL) {
436 			status = vchiq_remove_service(service->handle);
437 			unlock_service(service);
438 			if (status != VCHIQ_SUCCESS)
439 				break;
440 		}
441 		service = NULL;
442 
443 		if (status == VCHIQ_SUCCESS) {
444 			/* Wake the completion thread and ask it to exit */
445 			instance->closing = 1;
446 			up(&instance->insert_event);
447 		}
448 
449 		break;
450 
451 	case VCHIQ_IOC_CONNECT:
452 		if (instance->connected) {
453 			ret = -EINVAL;
454 			break;
455 		}
456 		rc = mutex_lock_interruptible(&instance->state->mutex);
457 		if (rc != 0) {
458 			vchiq_log_error(vchiq_arm_log_level,
459 				"vchiq: connect: could not lock mutex for "
460 				"state %d: %d",
461 				instance->state->id, rc);
462 			ret = -EINTR;
463 			break;
464 		}
465 		status = vchiq_connect_internal(instance->state, instance);
466 		mutex_unlock(&instance->state->mutex);
467 
468 		if (status == VCHIQ_SUCCESS)
469 			instance->connected = 1;
470 		else
471 			vchiq_log_error(vchiq_arm_log_level,
472 				"vchiq: could not connect: %d", status);
473 		break;
474 
475 	case VCHIQ_IOC_CREATE_SERVICE: {
476 		VCHIQ_CREATE_SERVICE_T args;
477 		USER_SERVICE_T *user_service = NULL;
478 		void *userdata;
479 		int srvstate;
480 
481 		if (copy_from_user
482 			 (&args, (const void __user *)arg,
483 			  sizeof(args)) != 0) {
484 			ret = -EFAULT;
485 			break;
486 		}
487 
488 		user_service = kmalloc(sizeof(USER_SERVICE_T), GFP_KERNEL);
489 		if (!user_service) {
490 			ret = -ENOMEM;
491 			break;
492 		}
493 
494 		if (args.is_open) {
495 			if (!instance->connected) {
496 				ret = -ENOTCONN;
497 				kfree(user_service);
498 				break;
499 			}
500 			srvstate = VCHIQ_SRVSTATE_OPENING;
501 		} else {
502 			srvstate =
503 				 instance->connected ?
504 				 VCHIQ_SRVSTATE_LISTENING :
505 				 VCHIQ_SRVSTATE_HIDDEN;
506 		}
507 
508 		userdata = args.params.userdata;
509 		args.params.callback = service_callback;
510 		args.params.userdata = user_service;
511 		service = vchiq_add_service_internal(
512 				instance->state,
513 				&args.params, srvstate,
514 				instance, user_service_free);
515 
516 		if (service != NULL) {
517 			user_service->service = service;
518 			user_service->userdata = userdata;
519 			user_service->instance = instance;
520 			user_service->is_vchi = (args.is_vchi != 0);
521 			user_service->dequeue_pending = 0;
522 			user_service->close_pending = 0;
523 			user_service->message_available_pos =
524 				instance->completion_remove - 1;
525 			user_service->msg_insert = 0;
526 			user_service->msg_remove = 0;
527 			sema_init(&user_service->insert_event, 0);
528 			sema_init(&user_service->remove_event, 0);
529 			sema_init(&user_service->close_event, 0);
530 
531 			if (args.is_open) {
532 				status = vchiq_open_service_internal
533 					(service, instance->pid);
534 				if (status != VCHIQ_SUCCESS) {
535 					vchiq_remove_service(service->handle);
536 					service = NULL;
537 					ret = (status == VCHIQ_RETRY) ?
538 						-EINTR : -EIO;
539 					break;
540 				}
541 			}
542 
543 			if (copy_to_user((void __user *)
544 				&(((VCHIQ_CREATE_SERVICE_T __user *)
545 					arg)->handle),
546 				(const void *)&service->handle,
547 				sizeof(service->handle)) != 0) {
548 				ret = -EFAULT;
549 				vchiq_remove_service(service->handle);
550 			}
551 
552 			service = NULL;
553 		} else {
554 			ret = -EEXIST;
555 			kfree(user_service);
556 		}
557 	} break;
558 
559 	case VCHIQ_IOC_CLOSE_SERVICE: {
560 		VCHIQ_SERVICE_HANDLE_T handle = (VCHIQ_SERVICE_HANDLE_T)arg;
561 
562 		service = find_service_for_instance(instance, handle);
563 		if (service != NULL) {
564 			USER_SERVICE_T *user_service =
565 				(USER_SERVICE_T *)service->base.userdata;
566 			/* close_pending is false on first entry, and when the
567                            wait in vchiq_close_service has been interrupted. */
568 			if (!user_service->close_pending) {
569 				status = vchiq_close_service(service->handle);
570 				if (status != VCHIQ_SUCCESS)
571 					break;
572 			}
573 
574 			/* close_pending is true once the underlying service
575 			   has been closed until the client library calls the
576 			   CLOSE_DELIVERED ioctl, signalling close_event. */
577 			if (user_service->close_pending &&
578 				down_interruptible(&user_service->close_event))
579 				status = VCHIQ_RETRY;
580 		}
581 		else
582 			ret = -EINVAL;
583 	} break;
584 
585 	case VCHIQ_IOC_REMOVE_SERVICE: {
586 		VCHIQ_SERVICE_HANDLE_T handle = (VCHIQ_SERVICE_HANDLE_T)arg;
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_remove_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_USE_SERVICE:
612 	case VCHIQ_IOC_RELEASE_SERVICE:	{
613 		VCHIQ_SERVICE_HANDLE_T handle = (VCHIQ_SERVICE_HANDLE_T)arg;
614 
615 		service = find_service_for_instance(instance, handle);
616 		if (service != NULL) {
617 			status = (cmd == VCHIQ_IOC_USE_SERVICE)	?
618 				vchiq_use_service_internal(service) :
619 				vchiq_release_service_internal(service);
620 			if (status != VCHIQ_SUCCESS) {
621 				vchiq_log_error(vchiq_susp_log_level,
622 					"%s: cmd %s returned error %d for "
623 					"service %c%c%c%c:%03d",
624 					__func__,
625 					(cmd == VCHIQ_IOC_USE_SERVICE) ?
626 						"VCHIQ_IOC_USE_SERVICE" :
627 						"VCHIQ_IOC_RELEASE_SERVICE",
628 					status,
629 					VCHIQ_FOURCC_AS_4CHARS(
630 						service->base.fourcc),
631 					service->client_id);
632 				ret = -EINVAL;
633 			}
634 		} else
635 			ret = -EINVAL;
636 	} break;
637 
638 	case VCHIQ_IOC_QUEUE_MESSAGE: {
639 		VCHIQ_QUEUE_MESSAGE_T args;
640 		if (copy_from_user
641 			 (&args, (const void __user *)arg,
642 			  sizeof(args)) != 0) {
643 			ret = -EFAULT;
644 			break;
645 		}
646 
647 		service = find_service_for_instance(instance, args.handle);
648 
649 		if ((service != NULL) && (args.count <= MAX_ELEMENTS)) {
650 			/* Copy elements into kernel space */
651 			VCHIQ_ELEMENT_T elements[MAX_ELEMENTS];
652 			if (copy_from_user(elements, args.elements,
653 				args.count * sizeof(VCHIQ_ELEMENT_T)) == 0)
654 				status = vchiq_queue_message
655 					(args.handle,
656 					elements, args.count);
657 			else
658 				ret = -EFAULT;
659 		} else {
660 			ret = -EINVAL;
661 		}
662 	} break;
663 
664 	case VCHIQ_IOC_QUEUE_BULK_TRANSMIT:
665 	case VCHIQ_IOC_QUEUE_BULK_RECEIVE: {
666 		VCHIQ_QUEUE_BULK_TRANSFER_T args;
667 		struct bulk_waiter_node *waiter = NULL;
668 		VCHIQ_BULK_DIR_T dir =
669 			(cmd == VCHIQ_IOC_QUEUE_BULK_TRANSMIT) ?
670 			VCHIQ_BULK_TRANSMIT : VCHIQ_BULK_RECEIVE;
671 
672 		if (copy_from_user
673 			(&args, (const void __user *)arg,
674 			sizeof(args)) != 0) {
675 			ret = -EFAULT;
676 			break;
677 		}
678 
679 		service = find_service_for_instance(instance, args.handle);
680 		if (!service) {
681 			ret = -EINVAL;
682 			break;
683 		}
684 
685 		if (args.mode == VCHIQ_BULK_MODE_BLOCKING) {
686 			waiter = kzalloc(sizeof(struct bulk_waiter_node),
687 				GFP_KERNEL);
688 			if (!waiter) {
689 				ret = -ENOMEM;
690 				break;
691 			}
692 			args.userdata = &waiter->bulk_waiter;
693 		} else if (args.mode == VCHIQ_BULK_MODE_WAITING) {
694 			struct list_head *pos;
695 			mutex_lock(&instance->bulk_waiter_list_mutex);
696 			list_for_each(pos, &instance->bulk_waiter_list) {
697 				if (list_entry(pos, struct bulk_waiter_node,
698 					list)->pid == current->pid) {
699 					waiter = list_entry(pos,
700 						struct bulk_waiter_node,
701 						list);
702 					list_del(pos);
703 					break;
704 				}
705 
706 			}
707 			mutex_unlock(&instance->bulk_waiter_list_mutex);
708 			if (!waiter) {
709 				vchiq_log_error(vchiq_arm_log_level,
710 					"no bulk_waiter found for pid %d",
711 					current->pid);
712 				ret = -ESRCH;
713 				break;
714 			}
715 			vchiq_log_info(vchiq_arm_log_level,
716 				"found bulk_waiter %x for pid %d",
717 				(unsigned int)waiter, current->pid);
718 			args.userdata = &waiter->bulk_waiter;
719 		}
720 		status = vchiq_bulk_transfer
721 			(args.handle,
722 			 VCHI_MEM_HANDLE_INVALID,
723 			 args.data, args.size,
724 			 args.userdata, args.mode,
725 			 dir);
726 		if (!waiter)
727 			break;
728 		if ((status != VCHIQ_RETRY) || fatal_signal_pending(current) ||
729 			!waiter->bulk_waiter.bulk) {
730 			if (waiter->bulk_waiter.bulk) {
731 				/* Cancel the signal when the transfer
732 				** completes. */
733 				spin_lock(&bulk_waiter_spinlock);
734 				waiter->bulk_waiter.bulk->userdata = NULL;
735 				spin_unlock(&bulk_waiter_spinlock);
736 			}
737 			kfree(waiter);
738 		} else {
739 			const VCHIQ_BULK_MODE_T mode_waiting =
740 				VCHIQ_BULK_MODE_WAITING;
741 			waiter->pid = current->pid;
742 			mutex_lock(&instance->bulk_waiter_list_mutex);
743 			list_add(&waiter->list, &instance->bulk_waiter_list);
744 			mutex_unlock(&instance->bulk_waiter_list_mutex);
745 			vchiq_log_info(vchiq_arm_log_level,
746 				"saved bulk_waiter %x for pid %d",
747 				(unsigned int)waiter, current->pid);
748 
749 			if (copy_to_user((void __user *)
750 				&(((VCHIQ_QUEUE_BULK_TRANSFER_T __user *)
751 					arg)->mode),
752 				(const void *)&mode_waiting,
753 				sizeof(mode_waiting)) != 0)
754 				ret = -EFAULT;
755 		}
756 	} break;
757 
758 	case VCHIQ_IOC_AWAIT_COMPLETION: {
759 		VCHIQ_AWAIT_COMPLETION_T args;
760 
761 		DEBUG_TRACE(AWAIT_COMPLETION_LINE);
762 		if (!instance->connected) {
763 			ret = -ENOTCONN;
764 			break;
765 		}
766 
767 		if (copy_from_user(&args, (const void __user *)arg,
768 			sizeof(args)) != 0) {
769 			ret = -EFAULT;
770 			break;
771 		}
772 
773 		mutex_lock(&instance->completion_mutex);
774 
775 		DEBUG_TRACE(AWAIT_COMPLETION_LINE);
776 		while ((instance->completion_remove ==
777 			instance->completion_insert)
778 			&& !instance->closing) {
779 			int rc;
780 			DEBUG_TRACE(AWAIT_COMPLETION_LINE);
781 			mutex_unlock(&instance->completion_mutex);
782 			rc = down_interruptible(&instance->insert_event);
783 			mutex_lock(&instance->completion_mutex);
784 			if (rc != 0) {
785 				DEBUG_TRACE(AWAIT_COMPLETION_LINE);
786 				vchiq_log_info(vchiq_arm_log_level,
787 					"AWAIT_COMPLETION interrupted");
788 				ret = -EINTR;
789 				break;
790 			}
791 		}
792 		DEBUG_TRACE(AWAIT_COMPLETION_LINE);
793 
794 		/* A read memory barrier is needed to stop prefetch of a stale
795 		** completion record
796 		*/
797 		rmb();
798 
799 		if (ret == 0) {
800 			int msgbufcount = args.msgbufcount;
801 			for (ret = 0; ret < args.count; ret++) {
802 				VCHIQ_COMPLETION_DATA_T *completion;
803 				VCHIQ_SERVICE_T *service;
804 				USER_SERVICE_T *user_service;
805 				VCHIQ_HEADER_T *header;
806 				if (instance->completion_remove ==
807 					instance->completion_insert)
808 					break;
809 				completion = &instance->completions[
810 					instance->completion_remove &
811 					(MAX_COMPLETIONS - 1)];
812 
813 				service = completion->service_userdata;
814 				user_service = service->base.userdata;
815 				completion->service_userdata =
816 					user_service->userdata;
817 
818 				header = completion->header;
819 				if (header) {
820 					void __user *msgbuf;
821 					int msglen;
822 
823 					msglen = header->size +
824 						sizeof(VCHIQ_HEADER_T);
825 					/* This must be a VCHIQ-style service */
826 					if (args.msgbufsize < msglen) {
827 						vchiq_log_error(
828 							vchiq_arm_log_level,
829 							"header %x: msgbufsize"
830 							" %x < msglen %x",
831 							(unsigned int)header,
832 							args.msgbufsize,
833 							msglen);
834 						WARN(1, "invalid message "
835 							"size\n");
836 						if (ret == 0)
837 							ret = -EMSGSIZE;
838 						break;
839 					}
840 					if (msgbufcount <= 0)
841 						/* Stall here for lack of a
842 						** buffer for the message. */
843 						break;
844 					/* Get the pointer from user space */
845 					msgbufcount--;
846 					if (copy_from_user(&msgbuf,
847 						(const void __user *)
848 						&args.msgbufs[msgbufcount],
849 						sizeof(msgbuf)) != 0) {
850 						if (ret == 0)
851 							ret = -EFAULT;
852 						break;
853 					}
854 
855 					/* Copy the message to user space */
856 					if (copy_to_user(msgbuf, header,
857 						msglen) != 0) {
858 						if (ret == 0)
859 							ret = -EFAULT;
860 						break;
861 					}
862 
863 					/* Now it has been copied, the message
864 					** can be released. */
865 					vchiq_release_message(service->handle,
866 						header);
867 
868 					/* The completion must point to the
869 					** msgbuf. */
870 					completion->header = msgbuf;
871 				}
872 
873 				if ((completion->reason ==
874 					VCHIQ_SERVICE_CLOSED) &&
875 					!instance->use_close_delivered)
876 					unlock_service(service);
877 
878 				if (copy_to_user((void __user *)(
879 					(size_t)args.buf +
880 					ret * sizeof(VCHIQ_COMPLETION_DATA_T)),
881 					completion,
882 					sizeof(VCHIQ_COMPLETION_DATA_T)) != 0) {
883 						if (ret == 0)
884 							ret = -EFAULT;
885 					break;
886 				}
887 
888 				instance->completion_remove++;
889 			}
890 
891 			if (msgbufcount != args.msgbufcount) {
892 				if (copy_to_user((void __user *)
893 					&((VCHIQ_AWAIT_COMPLETION_T *)arg)->
894 						msgbufcount,
895 					&msgbufcount,
896 					sizeof(msgbufcount)) != 0) {
897 					ret = -EFAULT;
898 				}
899 			}
900 		}
901 
902 		if (ret != 0)
903 			up(&instance->remove_event);
904 		mutex_unlock(&instance->completion_mutex);
905 		DEBUG_TRACE(AWAIT_COMPLETION_LINE);
906 	} break;
907 
908 	case VCHIQ_IOC_DEQUEUE_MESSAGE: {
909 		VCHIQ_DEQUEUE_MESSAGE_T args;
910 		USER_SERVICE_T *user_service;
911 		VCHIQ_HEADER_T *header;
912 
913 		DEBUG_TRACE(DEQUEUE_MESSAGE_LINE);
914 		if (copy_from_user
915 			 (&args, (const void __user *)arg,
916 			  sizeof(args)) != 0) {
917 			ret = -EFAULT;
918 			break;
919 		}
920 		service = find_service_for_instance(instance, args.handle);
921 		if (!service) {
922 			ret = -EINVAL;
923 			break;
924 		}
925 		user_service = (USER_SERVICE_T *)service->base.userdata;
926 		if (user_service->is_vchi == 0) {
927 			ret = -EINVAL;
928 			break;
929 		}
930 
931 		spin_lock(&msg_queue_spinlock);
932 		if (user_service->msg_remove == user_service->msg_insert) {
933 			if (!args.blocking) {
934 				spin_unlock(&msg_queue_spinlock);
935 				DEBUG_TRACE(DEQUEUE_MESSAGE_LINE);
936 				ret = -EWOULDBLOCK;
937 				break;
938 			}
939 			user_service->dequeue_pending = 1;
940 			do {
941 				spin_unlock(&msg_queue_spinlock);
942 				DEBUG_TRACE(DEQUEUE_MESSAGE_LINE);
943 				if (down_interruptible(
944 					&user_service->insert_event) != 0) {
945 					vchiq_log_info(vchiq_arm_log_level,
946 						"DEQUEUE_MESSAGE interrupted");
947 					ret = -EINTR;
948 					break;
949 				}
950 				spin_lock(&msg_queue_spinlock);
951 			} while (user_service->msg_remove ==
952 				user_service->msg_insert);
953 
954 			if (ret)
955 				break;
956 		}
957 
958 		BUG_ON((int)(user_service->msg_insert -
959 			user_service->msg_remove) < 0);
960 
961 		header = user_service->msg_queue[user_service->msg_remove &
962 			(MSG_QUEUE_SIZE - 1)];
963 		user_service->msg_remove++;
964 		spin_unlock(&msg_queue_spinlock);
965 
966 		up(&user_service->remove_event);
967 		if (header == NULL)
968 			ret = -ENOTCONN;
969 		else if (header->size <= args.bufsize) {
970 			/* Copy to user space if msgbuf is not NULL */
971 			if ((args.buf == NULL) ||
972 				(copy_to_user((void __user *)args.buf,
973 				header->data,
974 				header->size) == 0)) {
975 				ret = header->size;
976 				vchiq_release_message(
977 					service->handle,
978 					header);
979 			} else
980 				ret = -EFAULT;
981 		} else {
982 			vchiq_log_error(vchiq_arm_log_level,
983 				"header %x: bufsize %x < size %x",
984 				(unsigned int)header, args.bufsize,
985 				header->size);
986 			WARN(1, "invalid size\n");
987 			ret = -EMSGSIZE;
988 		}
989 		DEBUG_TRACE(DEQUEUE_MESSAGE_LINE);
990 	} break;
991 
992 	case VCHIQ_IOC_GET_CLIENT_ID: {
993 		VCHIQ_SERVICE_HANDLE_T handle = (VCHIQ_SERVICE_HANDLE_T)arg;
994 
995 		ret = vchiq_get_client_id(handle);
996 	} break;
997 
998 	case VCHIQ_IOC_GET_CONFIG: {
999 		VCHIQ_GET_CONFIG_T args;
1000 		VCHIQ_CONFIG_T config;
1001 
1002 		if (copy_from_user(&args, (const void __user *)arg,
1003 			sizeof(args)) != 0) {
1004 			ret = -EFAULT;
1005 			break;
1006 		}
1007 		if (args.config_size > sizeof(config)) {
1008 			ret = -EINVAL;
1009 			break;
1010 		}
1011 		status = vchiq_get_config(instance, args.config_size, &config);
1012 		if (status == VCHIQ_SUCCESS) {
1013 			if (copy_to_user((void __user *)args.pconfig,
1014 				    &config, args.config_size) != 0) {
1015 				ret = -EFAULT;
1016 				break;
1017 			}
1018 		}
1019 	} break;
1020 
1021 	case VCHIQ_IOC_SET_SERVICE_OPTION: {
1022 		VCHIQ_SET_SERVICE_OPTION_T args;
1023 
1024 		if (copy_from_user(
1025 			&args, (const void __user *)arg,
1026 			sizeof(args)) != 0) {
1027 			ret = -EFAULT;
1028 			break;
1029 		}
1030 
1031 		service = find_service_for_instance(instance, args.handle);
1032 		if (!service) {
1033 			ret = -EINVAL;
1034 			break;
1035 		}
1036 
1037 		status = vchiq_set_service_option(
1038 				args.handle, args.option, args.value);
1039 	} break;
1040 
1041 	case VCHIQ_IOC_DUMP_PHYS_MEM: {
1042 		VCHIQ_DUMP_MEM_T  args;
1043 
1044 		if (copy_from_user
1045 			 (&args, (const void __user *)arg,
1046 			  sizeof(args)) != 0) {
1047 			ret = -EFAULT;
1048 			break;
1049 		}
1050 		dump_phys_mem(args.virt_addr, args.num_bytes);
1051 	} break;
1052 
1053 	case VCHIQ_IOC_LIB_VERSION: {
1054 		unsigned int lib_version = (unsigned int)arg;
1055 
1056 		if (lib_version < VCHIQ_VERSION_MIN)
1057 			ret = -EINVAL;
1058 		else if (lib_version >= VCHIQ_VERSION_CLOSE_DELIVERED)
1059 			instance->use_close_delivered = 1;
1060 	} break;
1061 
1062 	case VCHIQ_IOC_CLOSE_DELIVERED: {
1063 		VCHIQ_SERVICE_HANDLE_T handle = (VCHIQ_SERVICE_HANDLE_T)arg;
1064 
1065 		service = find_closed_service_for_instance(instance, handle);
1066 		if (service != NULL) {
1067 			USER_SERVICE_T *user_service =
1068 				(USER_SERVICE_T *)service->base.userdata;
1069 			close_delivered(user_service);
1070 		}
1071 		else
1072 			ret = -EINVAL;
1073 	} break;
1074 
1075 	default:
1076 		ret = -ENOTTY;
1077 		break;
1078 	}
1079 
1080 	if (service)
1081 		unlock_service(service);
1082 
1083 	if (ret == 0) {
1084 		if (status == VCHIQ_ERROR)
1085 			ret = -EIO;
1086 		else if (status == VCHIQ_RETRY)
1087 			ret = -EINTR;
1088 	}
1089 
1090 	if ((status == VCHIQ_SUCCESS) && (ret < 0) && (ret != -EINTR) &&
1091 		(ret != -EWOULDBLOCK))
1092 		vchiq_log_info(vchiq_arm_log_level,
1093 			"  ioctl instance %lx, cmd %s -> status %d, %ld",
1094 			(unsigned long)instance,
1095 			(_IOC_NR(cmd) <= VCHIQ_IOC_MAX) ?
1096 				ioctl_names[_IOC_NR(cmd)] :
1097 				"<invalid>",
1098 			status, ret);
1099 	else
1100 		vchiq_log_trace(vchiq_arm_log_level,
1101 			"  ioctl instance %lx, cmd %s -> status %d, %ld",
1102 			(unsigned long)instance,
1103 			(_IOC_NR(cmd) <= VCHIQ_IOC_MAX) ?
1104 				ioctl_names[_IOC_NR(cmd)] :
1105 				"<invalid>",
1106 			status, ret);
1107 
1108 	return ret;
1109 }
1110 
1111 /****************************************************************************
1112 *
1113 *   vchiq_open
1114 *
1115 ***************************************************************************/
1116 
1117 static int
vchiq_open(struct inode * inode,struct file * file)1118 vchiq_open(struct inode *inode, struct file *file)
1119 {
1120 	int dev = iminor(inode) & 0x0f;
1121 	vchiq_log_info(vchiq_arm_log_level, "vchiq_open");
1122 	switch (dev) {
1123 	case VCHIQ_MINOR: {
1124 		int ret;
1125 		VCHIQ_STATE_T *state = vchiq_get_state();
1126 		VCHIQ_INSTANCE_T instance;
1127 
1128 		if (!state) {
1129 			vchiq_log_error(vchiq_arm_log_level,
1130 				"vchiq has no connection to VideoCore");
1131 			return -ENOTCONN;
1132 		}
1133 
1134 		instance = kzalloc(sizeof(*instance), GFP_KERNEL);
1135 		if (!instance)
1136 			return -ENOMEM;
1137 
1138 		instance->state = state;
1139 		instance->pid = current->tgid;
1140 
1141 		ret = vchiq_debugfs_add_instance(instance);
1142 		if (ret != 0) {
1143 			kfree(instance);
1144 			return ret;
1145 		}
1146 
1147 		sema_init(&instance->insert_event, 0);
1148 		sema_init(&instance->remove_event, 0);
1149 		mutex_init(&instance->completion_mutex);
1150 		mutex_init(&instance->bulk_waiter_list_mutex);
1151 		INIT_LIST_HEAD(&instance->bulk_waiter_list);
1152 
1153 		file->private_data = instance;
1154 	} break;
1155 
1156 	default:
1157 		vchiq_log_error(vchiq_arm_log_level,
1158 			"Unknown minor device: %d", dev);
1159 		return -ENXIO;
1160 	}
1161 
1162 	return 0;
1163 }
1164 
1165 /****************************************************************************
1166 *
1167 *   vchiq_release
1168 *
1169 ***************************************************************************/
1170 
1171 static int
vchiq_release(struct inode * inode,struct file * file)1172 vchiq_release(struct inode *inode, struct file *file)
1173 {
1174 	int dev = iminor(inode) & 0x0f;
1175 	int ret = 0;
1176 	switch (dev) {
1177 	case VCHIQ_MINOR: {
1178 		VCHIQ_INSTANCE_T instance = file->private_data;
1179 		VCHIQ_STATE_T *state = vchiq_get_state();
1180 		VCHIQ_SERVICE_T *service;
1181 		int i;
1182 
1183 		vchiq_log_info(vchiq_arm_log_level,
1184 			"vchiq_release: instance=%lx",
1185 			(unsigned long)instance);
1186 
1187 		if (!state) {
1188 			ret = -EPERM;
1189 			goto out;
1190 		}
1191 
1192 		/* Ensure videocore is awake to allow termination. */
1193 		vchiq_use_internal(instance->state, NULL,
1194 				USE_TYPE_VCHIQ);
1195 
1196 		mutex_lock(&instance->completion_mutex);
1197 
1198 		/* Wake the completion thread and ask it to exit */
1199 		instance->closing = 1;
1200 		up(&instance->insert_event);
1201 
1202 		mutex_unlock(&instance->completion_mutex);
1203 
1204 		/* Wake the slot handler if the completion queue is full. */
1205 		up(&instance->remove_event);
1206 
1207 		/* Mark all services for termination... */
1208 		i = 0;
1209 		while ((service = next_service_by_instance(state, instance,
1210 			&i)) !=	NULL) {
1211 			USER_SERVICE_T *user_service = service->base.userdata;
1212 
1213 			/* Wake the slot handler if the msg queue is full. */
1214 			up(&user_service->remove_event);
1215 
1216 			vchiq_terminate_service_internal(service);
1217 			unlock_service(service);
1218 		}
1219 
1220 		/* ...and wait for them to die */
1221 		i = 0;
1222 		while ((service = next_service_by_instance(state, instance, &i))
1223 			!= NULL) {
1224 			USER_SERVICE_T *user_service = service->base.userdata;
1225 
1226 			down(&service->remove_event);
1227 
1228 			BUG_ON(service->srvstate != VCHIQ_SRVSTATE_FREE);
1229 
1230 			spin_lock(&msg_queue_spinlock);
1231 
1232 			while (user_service->msg_remove !=
1233 				user_service->msg_insert) {
1234 				VCHIQ_HEADER_T *header = user_service->
1235 					msg_queue[user_service->msg_remove &
1236 						(MSG_QUEUE_SIZE - 1)];
1237 				user_service->msg_remove++;
1238 				spin_unlock(&msg_queue_spinlock);
1239 
1240 				if (header)
1241 					vchiq_release_message(
1242 						service->handle,
1243 						header);
1244 				spin_lock(&msg_queue_spinlock);
1245 			}
1246 
1247 			spin_unlock(&msg_queue_spinlock);
1248 
1249 			unlock_service(service);
1250 		}
1251 
1252 		/* Release any closed services */
1253 		while (instance->completion_remove !=
1254 			instance->completion_insert) {
1255 			VCHIQ_COMPLETION_DATA_T *completion;
1256 			VCHIQ_SERVICE_T *service;
1257 			completion = &instance->completions[
1258 				instance->completion_remove &
1259 				(MAX_COMPLETIONS - 1)];
1260 			service = completion->service_userdata;
1261 			if (completion->reason == VCHIQ_SERVICE_CLOSED)
1262 			{
1263 				USER_SERVICE_T *user_service =
1264 					service->base.userdata;
1265 
1266 				/* Wake any blocked user-thread */
1267 				if (instance->use_close_delivered)
1268 					up(&user_service->close_event);
1269 				unlock_service(service);
1270 			}
1271 			instance->completion_remove++;
1272 		}
1273 
1274 		/* Release the PEER service count. */
1275 		vchiq_release_internal(instance->state, NULL);
1276 
1277 		{
1278 			struct list_head *pos, *next;
1279 			list_for_each_safe(pos, next,
1280 				&instance->bulk_waiter_list) {
1281 				struct bulk_waiter_node *waiter;
1282 				waiter = list_entry(pos,
1283 					struct bulk_waiter_node,
1284 					list);
1285 				list_del(pos);
1286 				vchiq_log_info(vchiq_arm_log_level,
1287 					"bulk_waiter - cleaned up %x "
1288 					"for pid %d",
1289 					(unsigned int)waiter, waiter->pid);
1290 				kfree(waiter);
1291 			}
1292 		}
1293 
1294 		vchiq_debugfs_remove_instance(instance);
1295 
1296 		kfree(instance);
1297 		file->private_data = NULL;
1298 	} break;
1299 
1300 	default:
1301 		vchiq_log_error(vchiq_arm_log_level,
1302 			"Unknown minor device: %d", dev);
1303 		ret = -ENXIO;
1304 	}
1305 
1306 out:
1307 	return ret;
1308 }
1309 
1310 /****************************************************************************
1311 *
1312 *   vchiq_dump
1313 *
1314 ***************************************************************************/
1315 
1316 void
vchiq_dump(void * dump_context,const char * str,int len)1317 vchiq_dump(void *dump_context, const char *str, int len)
1318 {
1319 	DUMP_CONTEXT_T *context = (DUMP_CONTEXT_T *)dump_context;
1320 
1321 	if (context->actual < context->space) {
1322 		int copy_bytes;
1323 		if (context->offset > 0) {
1324 			int skip_bytes = min(len, (int)context->offset);
1325 			str += skip_bytes;
1326 			len -= skip_bytes;
1327 			context->offset -= skip_bytes;
1328 			if (context->offset > 0)
1329 				return;
1330 		}
1331 		copy_bytes = min(len, (int)(context->space - context->actual));
1332 		if (copy_bytes == 0)
1333 			return;
1334 		if (copy_to_user(context->buf + context->actual, str,
1335 			copy_bytes))
1336 			context->actual = -EFAULT;
1337 		context->actual += copy_bytes;
1338 		len -= copy_bytes;
1339 
1340 		/* If tne terminating NUL is included in the length, then it
1341 		** marks the end of a line and should be replaced with a
1342 		** carriage return. */
1343 		if ((len == 0) && (str[copy_bytes - 1] == '\0')) {
1344 			char cr = '\n';
1345 			if (copy_to_user(context->buf + context->actual - 1,
1346 				&cr, 1))
1347 				context->actual = -EFAULT;
1348 		}
1349 	}
1350 }
1351 
1352 /****************************************************************************
1353 *
1354 *   vchiq_dump_platform_instance_state
1355 *
1356 ***************************************************************************/
1357 
1358 void
vchiq_dump_platform_instances(void * dump_context)1359 vchiq_dump_platform_instances(void *dump_context)
1360 {
1361 	VCHIQ_STATE_T *state = vchiq_get_state();
1362 	char buf[80];
1363 	int len;
1364 	int i;
1365 
1366 	/* There is no list of instances, so instead scan all services,
1367 		marking those that have been dumped. */
1368 
1369 	for (i = 0; i < state->unused_service; i++) {
1370 		VCHIQ_SERVICE_T *service = state->services[i];
1371 		VCHIQ_INSTANCE_T instance;
1372 
1373 		if (service && (service->base.callback == service_callback)) {
1374 			instance = service->instance;
1375 			if (instance)
1376 				instance->mark = 0;
1377 		}
1378 	}
1379 
1380 	for (i = 0; i < state->unused_service; i++) {
1381 		VCHIQ_SERVICE_T *service = state->services[i];
1382 		VCHIQ_INSTANCE_T instance;
1383 
1384 		if (service && (service->base.callback == service_callback)) {
1385 			instance = service->instance;
1386 			if (instance && !instance->mark) {
1387 				len = snprintf(buf, sizeof(buf),
1388 					"Instance %x: pid %d,%s completions "
1389 						"%d/%d",
1390 					(unsigned int)instance, instance->pid,
1391 					instance->connected ? " connected, " :
1392 						"",
1393 					instance->completion_insert -
1394 						instance->completion_remove,
1395 					MAX_COMPLETIONS);
1396 
1397 				vchiq_dump(dump_context, buf, len + 1);
1398 
1399 				instance->mark = 1;
1400 			}
1401 		}
1402 	}
1403 }
1404 
1405 /****************************************************************************
1406 *
1407 *   vchiq_dump_platform_service_state
1408 *
1409 ***************************************************************************/
1410 
1411 void
vchiq_dump_platform_service_state(void * dump_context,VCHIQ_SERVICE_T * service)1412 vchiq_dump_platform_service_state(void *dump_context, VCHIQ_SERVICE_T *service)
1413 {
1414 	USER_SERVICE_T *user_service = (USER_SERVICE_T *)service->base.userdata;
1415 	char buf[80];
1416 	int len;
1417 
1418 	len = snprintf(buf, sizeof(buf), "  instance %x",
1419 		(unsigned int)service->instance);
1420 
1421 	if ((service->base.callback == service_callback) &&
1422 		user_service->is_vchi) {
1423 		len += snprintf(buf + len, sizeof(buf) - len,
1424 			", %d/%d messages",
1425 			user_service->msg_insert - user_service->msg_remove,
1426 			MSG_QUEUE_SIZE);
1427 
1428 		if (user_service->dequeue_pending)
1429 			len += snprintf(buf + len, sizeof(buf) - len,
1430 				" (dequeue pending)");
1431 	}
1432 
1433 	vchiq_dump(dump_context, buf, len + 1);
1434 }
1435 
1436 /****************************************************************************
1437 *
1438 *   dump_user_mem
1439 *
1440 ***************************************************************************/
1441 
1442 static void
dump_phys_mem(void * virt_addr,uint32_t num_bytes)1443 dump_phys_mem(void *virt_addr, uint32_t num_bytes)
1444 {
1445 	int            rc;
1446 	uint8_t       *end_virt_addr = virt_addr + num_bytes;
1447 	int            num_pages;
1448 	int            offset;
1449 	int            end_offset;
1450 	int            page_idx;
1451 	int            prev_idx;
1452 	struct page   *page;
1453 	struct page  **pages;
1454 	uint8_t       *kmapped_virt_ptr;
1455 
1456 	/* Align virtAddr and endVirtAddr to 16 byte boundaries. */
1457 
1458 	virt_addr = (void *)((unsigned long)virt_addr & ~0x0fuL);
1459 	end_virt_addr = (void *)(((unsigned long)end_virt_addr + 15uL) &
1460 		~0x0fuL);
1461 
1462 	offset = (int)(long)virt_addr & (PAGE_SIZE - 1);
1463 	end_offset = (int)(long)end_virt_addr & (PAGE_SIZE - 1);
1464 
1465 	num_pages = (offset + num_bytes + PAGE_SIZE - 1) / PAGE_SIZE;
1466 
1467 	pages = kmalloc(sizeof(struct page *) * num_pages, GFP_KERNEL);
1468 	if (pages == NULL) {
1469 		vchiq_log_error(vchiq_arm_log_level,
1470 			"Unable to allocation memory for %d pages\n",
1471 			num_pages);
1472 		return;
1473 	}
1474 
1475 	down_read(&current->mm->mmap_sem);
1476 	rc = get_user_pages(current,      /* task */
1477 		current->mm,              /* mm */
1478 		(unsigned long)virt_addr, /* start */
1479 		num_pages,                /* len */
1480 		0,                        /* gup_flags */
1481 		pages,                    /* pages (array of page pointers) */
1482 		NULL);                    /* vmas */
1483 	up_read(&current->mm->mmap_sem);
1484 
1485 	prev_idx = -1;
1486 	page = NULL;
1487 
1488 	while (offset < end_offset) {
1489 
1490 		int page_offset = offset % PAGE_SIZE;
1491 		page_idx = offset / PAGE_SIZE;
1492 
1493 		if (page_idx != prev_idx) {
1494 
1495 			if (page != NULL)
1496 				kunmap(page);
1497 			page = pages[page_idx];
1498 			kmapped_virt_ptr = kmap(page);
1499 
1500 			prev_idx = page_idx;
1501 		}
1502 
1503 		if (vchiq_arm_log_level >= VCHIQ_LOG_TRACE)
1504 			vchiq_log_dump_mem("ph",
1505 				(uint32_t)(unsigned long)&kmapped_virt_ptr[
1506 					page_offset],
1507 				&kmapped_virt_ptr[page_offset], 16);
1508 
1509 		offset += 16;
1510 	}
1511 	if (page != NULL)
1512 		kunmap(page);
1513 
1514 	for (page_idx = 0; page_idx < num_pages; page_idx++)
1515 		page_cache_release(pages[page_idx]);
1516 
1517 	kfree(pages);
1518 }
1519 
1520 /****************************************************************************
1521 *
1522 *   vchiq_read
1523 *
1524 ***************************************************************************/
1525 
1526 static ssize_t
vchiq_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)1527 vchiq_read(struct file *file, char __user *buf,
1528 	size_t count, loff_t *ppos)
1529 {
1530 	DUMP_CONTEXT_T context;
1531 	context.buf = buf;
1532 	context.actual = 0;
1533 	context.space = count;
1534 	context.offset = *ppos;
1535 
1536 	vchiq_dump_state(&context, &g_state);
1537 
1538 	*ppos += context.actual;
1539 
1540 	return context.actual;
1541 }
1542 
1543 VCHIQ_STATE_T *
vchiq_get_state(void)1544 vchiq_get_state(void)
1545 {
1546 
1547 	if (g_state.remote == NULL)
1548 		printk(KERN_ERR "%s: g_state.remote == NULL\n", __func__);
1549 	else if (g_state.remote->initialised != 1)
1550 		printk(KERN_NOTICE "%s: g_state.remote->initialised != 1 (%d)\n",
1551 			__func__, g_state.remote->initialised);
1552 
1553 	return ((g_state.remote != NULL) &&
1554 		(g_state.remote->initialised == 1)) ? &g_state : NULL;
1555 }
1556 
1557 static const struct file_operations
1558 vchiq_fops = {
1559 	.owner = THIS_MODULE,
1560 	.unlocked_ioctl = vchiq_ioctl,
1561 	.open = vchiq_open,
1562 	.release = vchiq_release,
1563 	.read = vchiq_read
1564 };
1565 
1566 /*
1567  * Autosuspend related functionality
1568  */
1569 
1570 int
vchiq_videocore_wanted(VCHIQ_STATE_T * state)1571 vchiq_videocore_wanted(VCHIQ_STATE_T *state)
1572 {
1573 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
1574 	if (!arm_state)
1575 		/* autosuspend not supported - always return wanted */
1576 		return 1;
1577 	else if (arm_state->blocked_count)
1578 		return 1;
1579 	else if (!arm_state->videocore_use_count)
1580 		/* usage count zero - check for override unless we're forcing */
1581 		if (arm_state->resume_blocked)
1582 			return 0;
1583 		else
1584 			return vchiq_platform_videocore_wanted(state);
1585 	else
1586 		/* non-zero usage count - videocore still required */
1587 		return 1;
1588 }
1589 
1590 static VCHIQ_STATUS_T
vchiq_keepalive_vchiq_callback(VCHIQ_REASON_T reason,VCHIQ_HEADER_T * header,VCHIQ_SERVICE_HANDLE_T service_user,void * bulk_user)1591 vchiq_keepalive_vchiq_callback(VCHIQ_REASON_T reason,
1592 	VCHIQ_HEADER_T *header,
1593 	VCHIQ_SERVICE_HANDLE_T service_user,
1594 	void *bulk_user)
1595 {
1596 	vchiq_log_error(vchiq_susp_log_level,
1597 		"%s callback reason %d", __func__, reason);
1598 	return 0;
1599 }
1600 
1601 static int
vchiq_keepalive_thread_func(void * v)1602 vchiq_keepalive_thread_func(void *v)
1603 {
1604 	VCHIQ_STATE_T *state = (VCHIQ_STATE_T *) v;
1605 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
1606 
1607 	VCHIQ_STATUS_T status;
1608 	VCHIQ_INSTANCE_T instance;
1609 	VCHIQ_SERVICE_HANDLE_T ka_handle;
1610 
1611 	VCHIQ_SERVICE_PARAMS_T params = {
1612 		.fourcc      = VCHIQ_MAKE_FOURCC('K', 'E', 'E', 'P'),
1613 		.callback    = vchiq_keepalive_vchiq_callback,
1614 		.version     = KEEPALIVE_VER,
1615 		.version_min = KEEPALIVE_VER_MIN
1616 	};
1617 
1618 	status = vchiq_initialise(&instance);
1619 	if (status != VCHIQ_SUCCESS) {
1620 		vchiq_log_error(vchiq_susp_log_level,
1621 			"%s vchiq_initialise failed %d", __func__, status);
1622 		goto exit;
1623 	}
1624 
1625 	status = vchiq_connect(instance);
1626 	if (status != VCHIQ_SUCCESS) {
1627 		vchiq_log_error(vchiq_susp_log_level,
1628 			"%s vchiq_connect failed %d", __func__, status);
1629 		goto shutdown;
1630 	}
1631 
1632 	status = vchiq_add_service(instance, &params, &ka_handle);
1633 	if (status != VCHIQ_SUCCESS) {
1634 		vchiq_log_error(vchiq_susp_log_level,
1635 			"%s vchiq_open_service failed %d", __func__, status);
1636 		goto shutdown;
1637 	}
1638 
1639 	while (1) {
1640 		long rc = 0, uc = 0;
1641 		if (wait_for_completion_interruptible(&arm_state->ka_evt)
1642 				!= 0) {
1643 			vchiq_log_error(vchiq_susp_log_level,
1644 				"%s interrupted", __func__);
1645 			flush_signals(current);
1646 			continue;
1647 		}
1648 
1649 		/* read and clear counters.  Do release_count then use_count to
1650 		 * prevent getting more releases than uses */
1651 		rc = atomic_xchg(&arm_state->ka_release_count, 0);
1652 		uc = atomic_xchg(&arm_state->ka_use_count, 0);
1653 
1654 		/* Call use/release service the requisite number of times.
1655 		 * Process use before release so use counts don't go negative */
1656 		while (uc--) {
1657 			atomic_inc(&arm_state->ka_use_ack_count);
1658 			status = vchiq_use_service(ka_handle);
1659 			if (status != VCHIQ_SUCCESS) {
1660 				vchiq_log_error(vchiq_susp_log_level,
1661 					"%s vchiq_use_service error %d",
1662 					__func__, status);
1663 			}
1664 		}
1665 		while (rc--) {
1666 			status = vchiq_release_service(ka_handle);
1667 			if (status != VCHIQ_SUCCESS) {
1668 				vchiq_log_error(vchiq_susp_log_level,
1669 					"%s vchiq_release_service error %d",
1670 					__func__, status);
1671 			}
1672 		}
1673 	}
1674 
1675 shutdown:
1676 	vchiq_shutdown(instance);
1677 exit:
1678 	return 0;
1679 }
1680 
1681 
1682 
1683 VCHIQ_STATUS_T
vchiq_arm_init_state(VCHIQ_STATE_T * state,VCHIQ_ARM_STATE_T * arm_state)1684 vchiq_arm_init_state(VCHIQ_STATE_T *state, VCHIQ_ARM_STATE_T *arm_state)
1685 {
1686 	VCHIQ_STATUS_T status = VCHIQ_SUCCESS;
1687 
1688 	if (arm_state) {
1689 		rwlock_init(&arm_state->susp_res_lock);
1690 
1691 		init_completion(&arm_state->ka_evt);
1692 		atomic_set(&arm_state->ka_use_count, 0);
1693 		atomic_set(&arm_state->ka_use_ack_count, 0);
1694 		atomic_set(&arm_state->ka_release_count, 0);
1695 
1696 		init_completion(&arm_state->vc_suspend_complete);
1697 
1698 		init_completion(&arm_state->vc_resume_complete);
1699 		/* Initialise to 'done' state.  We only want to block on resume
1700 		 * completion while videocore is suspended. */
1701 		set_resume_state(arm_state, VC_RESUME_RESUMED);
1702 
1703 		init_completion(&arm_state->resume_blocker);
1704 		/* Initialise to 'done' state.  We only want to block on this
1705 		 * completion while resume is blocked */
1706 		complete_all(&arm_state->resume_blocker);
1707 
1708 		init_completion(&arm_state->blocked_blocker);
1709 		/* Initialise to 'done' state.  We only want to block on this
1710 		 * completion while things are waiting on the resume blocker */
1711 		complete_all(&arm_state->blocked_blocker);
1712 
1713 		arm_state->suspend_timer_timeout = SUSPEND_TIMER_TIMEOUT_MS;
1714 		arm_state->suspend_timer_running = 0;
1715 		init_timer(&arm_state->suspend_timer);
1716 		arm_state->suspend_timer.data = (unsigned long)(state);
1717 		arm_state->suspend_timer.function = suspend_timer_callback;
1718 
1719 		arm_state->first_connect = 0;
1720 
1721 	}
1722 	return status;
1723 }
1724 
1725 /*
1726 ** Functions to modify the state variables;
1727 **	set_suspend_state
1728 **	set_resume_state
1729 **
1730 ** There are more state variables than we might like, so ensure they remain in
1731 ** step.  Suspend and resume state are maintained separately, since most of
1732 ** these state machines can operate independently.  However, there are a few
1733 ** states where state transitions in one state machine cause a reset to the
1734 ** other state machine.  In addition, there are some completion events which
1735 ** need to occur on state machine reset and end-state(s), so these are also
1736 ** dealt with in these functions.
1737 **
1738 ** In all states we set the state variable according to the input, but in some
1739 ** cases we perform additional steps outlined below;
1740 **
1741 ** VC_SUSPEND_IDLE - Initialise the suspend completion at the same time.
1742 **			The suspend completion is completed after any suspend
1743 **			attempt.  When we reset the state machine we also reset
1744 **			the completion.  This reset occurs when videocore is
1745 **			resumed, and also if we initiate suspend after a suspend
1746 **			failure.
1747 **
1748 ** VC_SUSPEND_IN_PROGRESS - This state is considered the point of no return for
1749 **			suspend - ie from this point on we must try to suspend
1750 **			before resuming can occur.  We therefore also reset the
1751 **			resume state machine to VC_RESUME_IDLE in this state.
1752 **
1753 ** VC_SUSPEND_SUSPENDED - Suspend has completed successfully. Also call
1754 **			complete_all on the suspend completion to notify
1755 **			anything waiting for suspend to happen.
1756 **
1757 ** VC_SUSPEND_REJECTED - Videocore rejected suspend. Videocore will also
1758 **			initiate resume, so no need to alter resume state.
1759 **			We call complete_all on the suspend completion to notify
1760 **			of suspend rejection.
1761 **
1762 ** VC_SUSPEND_FAILED - We failed to initiate videocore suspend.  We notify the
1763 **			suspend completion and reset the resume state machine.
1764 **
1765 ** VC_RESUME_IDLE - Initialise the resume completion at the same time.  The
1766 **			resume completion is in it's 'done' state whenever
1767 **			videcore is running.  Therfore, the VC_RESUME_IDLE state
1768 **			implies that videocore is suspended.
1769 **			Hence, any thread which needs to wait until videocore is
1770 **			running can wait on this completion - it will only block
1771 **			if videocore is suspended.
1772 **
1773 ** VC_RESUME_RESUMED - Resume has completed successfully.  Videocore is running.
1774 **			Call complete_all on the resume completion to unblock
1775 **			any threads waiting for resume.	 Also reset the suspend
1776 **			state machine to it's idle state.
1777 **
1778 ** VC_RESUME_FAILED - Currently unused - no mechanism to fail resume exists.
1779 */
1780 
1781 void
set_suspend_state(VCHIQ_ARM_STATE_T * arm_state,enum vc_suspend_status new_state)1782 set_suspend_state(VCHIQ_ARM_STATE_T *arm_state,
1783 	enum vc_suspend_status new_state)
1784 {
1785 	/* set the state in all cases */
1786 	arm_state->vc_suspend_state = new_state;
1787 
1788 	/* state specific additional actions */
1789 	switch (new_state) {
1790 	case VC_SUSPEND_FORCE_CANCELED:
1791 		complete_all(&arm_state->vc_suspend_complete);
1792 		break;
1793 	case VC_SUSPEND_REJECTED:
1794 		complete_all(&arm_state->vc_suspend_complete);
1795 		break;
1796 	case VC_SUSPEND_FAILED:
1797 		complete_all(&arm_state->vc_suspend_complete);
1798 		arm_state->vc_resume_state = VC_RESUME_RESUMED;
1799 		complete_all(&arm_state->vc_resume_complete);
1800 		break;
1801 	case VC_SUSPEND_IDLE:
1802 		reinit_completion(&arm_state->vc_suspend_complete);
1803 		break;
1804 	case VC_SUSPEND_REQUESTED:
1805 		break;
1806 	case VC_SUSPEND_IN_PROGRESS:
1807 		set_resume_state(arm_state, VC_RESUME_IDLE);
1808 		break;
1809 	case VC_SUSPEND_SUSPENDED:
1810 		complete_all(&arm_state->vc_suspend_complete);
1811 		break;
1812 	default:
1813 		BUG();
1814 		break;
1815 	}
1816 }
1817 
1818 void
set_resume_state(VCHIQ_ARM_STATE_T * arm_state,enum vc_resume_status new_state)1819 set_resume_state(VCHIQ_ARM_STATE_T *arm_state,
1820 	enum vc_resume_status new_state)
1821 {
1822 	/* set the state in all cases */
1823 	arm_state->vc_resume_state = new_state;
1824 
1825 	/* state specific additional actions */
1826 	switch (new_state) {
1827 	case VC_RESUME_FAILED:
1828 		break;
1829 	case VC_RESUME_IDLE:
1830 		reinit_completion(&arm_state->vc_resume_complete);
1831 		break;
1832 	case VC_RESUME_REQUESTED:
1833 		break;
1834 	case VC_RESUME_IN_PROGRESS:
1835 		break;
1836 	case VC_RESUME_RESUMED:
1837 		complete_all(&arm_state->vc_resume_complete);
1838 		set_suspend_state(arm_state, VC_SUSPEND_IDLE);
1839 		break;
1840 	default:
1841 		BUG();
1842 		break;
1843 	}
1844 }
1845 
1846 
1847 /* should be called with the write lock held */
1848 inline void
start_suspend_timer(VCHIQ_ARM_STATE_T * arm_state)1849 start_suspend_timer(VCHIQ_ARM_STATE_T *arm_state)
1850 {
1851 	del_timer(&arm_state->suspend_timer);
1852 	arm_state->suspend_timer.expires = jiffies +
1853 		msecs_to_jiffies(arm_state->
1854 			suspend_timer_timeout);
1855 	add_timer(&arm_state->suspend_timer);
1856 	arm_state->suspend_timer_running = 1;
1857 }
1858 
1859 /* should be called with the write lock held */
1860 static inline void
stop_suspend_timer(VCHIQ_ARM_STATE_T * arm_state)1861 stop_suspend_timer(VCHIQ_ARM_STATE_T *arm_state)
1862 {
1863 	if (arm_state->suspend_timer_running) {
1864 		del_timer(&arm_state->suspend_timer);
1865 		arm_state->suspend_timer_running = 0;
1866 	}
1867 }
1868 
1869 static inline int
need_resume(VCHIQ_STATE_T * state)1870 need_resume(VCHIQ_STATE_T *state)
1871 {
1872 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
1873 	return (arm_state->vc_suspend_state > VC_SUSPEND_IDLE) &&
1874 			(arm_state->vc_resume_state < VC_RESUME_REQUESTED) &&
1875 			vchiq_videocore_wanted(state);
1876 }
1877 
1878 static int
block_resume(VCHIQ_ARM_STATE_T * arm_state)1879 block_resume(VCHIQ_ARM_STATE_T *arm_state)
1880 {
1881 	int status = VCHIQ_SUCCESS;
1882 	const unsigned long timeout_val =
1883 				msecs_to_jiffies(FORCE_SUSPEND_TIMEOUT_MS);
1884 	int resume_count = 0;
1885 
1886 	/* Allow any threads which were blocked by the last force suspend to
1887 	 * complete if they haven't already.  Only give this one shot; if
1888 	 * blocked_count is incremented after blocked_blocker is completed
1889 	 * (which only happens when blocked_count hits 0) then those threads
1890 	 * will have to wait until next time around */
1891 	if (arm_state->blocked_count) {
1892 		reinit_completion(&arm_state->blocked_blocker);
1893 		write_unlock_bh(&arm_state->susp_res_lock);
1894 		vchiq_log_info(vchiq_susp_log_level, "%s wait for previously "
1895 			"blocked clients", __func__);
1896 		if (wait_for_completion_interruptible_timeout(
1897 				&arm_state->blocked_blocker, timeout_val)
1898 					<= 0) {
1899 			vchiq_log_error(vchiq_susp_log_level, "%s wait for "
1900 				"previously blocked clients failed" , __func__);
1901 			status = VCHIQ_ERROR;
1902 			write_lock_bh(&arm_state->susp_res_lock);
1903 			goto out;
1904 		}
1905 		vchiq_log_info(vchiq_susp_log_level, "%s previously blocked "
1906 			"clients resumed", __func__);
1907 		write_lock_bh(&arm_state->susp_res_lock);
1908 	}
1909 
1910 	/* We need to wait for resume to complete if it's in process */
1911 	while (arm_state->vc_resume_state != VC_RESUME_RESUMED &&
1912 			arm_state->vc_resume_state > VC_RESUME_IDLE) {
1913 		if (resume_count > 1) {
1914 			status = VCHIQ_ERROR;
1915 			vchiq_log_error(vchiq_susp_log_level, "%s waited too "
1916 				"many times for resume" , __func__);
1917 			goto out;
1918 		}
1919 		write_unlock_bh(&arm_state->susp_res_lock);
1920 		vchiq_log_info(vchiq_susp_log_level, "%s wait for resume",
1921 			__func__);
1922 		if (wait_for_completion_interruptible_timeout(
1923 				&arm_state->vc_resume_complete, timeout_val)
1924 					<= 0) {
1925 			vchiq_log_error(vchiq_susp_log_level, "%s wait for "
1926 				"resume failed (%s)", __func__,
1927 				resume_state_names[arm_state->vc_resume_state +
1928 							VC_RESUME_NUM_OFFSET]);
1929 			status = VCHIQ_ERROR;
1930 			write_lock_bh(&arm_state->susp_res_lock);
1931 			goto out;
1932 		}
1933 		vchiq_log_info(vchiq_susp_log_level, "%s resumed", __func__);
1934 		write_lock_bh(&arm_state->susp_res_lock);
1935 		resume_count++;
1936 	}
1937 	reinit_completion(&arm_state->resume_blocker);
1938 	arm_state->resume_blocked = 1;
1939 
1940 out:
1941 	return status;
1942 }
1943 
1944 static inline void
unblock_resume(VCHIQ_ARM_STATE_T * arm_state)1945 unblock_resume(VCHIQ_ARM_STATE_T *arm_state)
1946 {
1947 	complete_all(&arm_state->resume_blocker);
1948 	arm_state->resume_blocked = 0;
1949 }
1950 
1951 /* Initiate suspend via slot handler. Should be called with the write lock
1952  * held */
1953 VCHIQ_STATUS_T
vchiq_arm_vcsuspend(VCHIQ_STATE_T * state)1954 vchiq_arm_vcsuspend(VCHIQ_STATE_T *state)
1955 {
1956 	VCHIQ_STATUS_T status = VCHIQ_ERROR;
1957 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
1958 
1959 	if (!arm_state)
1960 		goto out;
1961 
1962 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
1963 	status = VCHIQ_SUCCESS;
1964 
1965 
1966 	switch (arm_state->vc_suspend_state) {
1967 	case VC_SUSPEND_REQUESTED:
1968 		vchiq_log_info(vchiq_susp_log_level, "%s: suspend already "
1969 			"requested", __func__);
1970 		break;
1971 	case VC_SUSPEND_IN_PROGRESS:
1972 		vchiq_log_info(vchiq_susp_log_level, "%s: suspend already in "
1973 			"progress", __func__);
1974 		break;
1975 
1976 	default:
1977 		/* We don't expect to be in other states, so log but continue
1978 		 * anyway */
1979 		vchiq_log_error(vchiq_susp_log_level,
1980 			"%s unexpected suspend state %s", __func__,
1981 			suspend_state_names[arm_state->vc_suspend_state +
1982 						VC_SUSPEND_NUM_OFFSET]);
1983 		/* fall through */
1984 	case VC_SUSPEND_REJECTED:
1985 	case VC_SUSPEND_FAILED:
1986 		/* Ensure any idle state actions have been run */
1987 		set_suspend_state(arm_state, VC_SUSPEND_IDLE);
1988 		/* fall through */
1989 	case VC_SUSPEND_IDLE:
1990 		vchiq_log_info(vchiq_susp_log_level,
1991 			"%s: suspending", __func__);
1992 		set_suspend_state(arm_state, VC_SUSPEND_REQUESTED);
1993 		/* kick the slot handler thread to initiate suspend */
1994 		request_poll(state, NULL, 0);
1995 		break;
1996 	}
1997 
1998 out:
1999 	vchiq_log_trace(vchiq_susp_log_level, "%s exit %d", __func__, status);
2000 	return status;
2001 }
2002 
2003 void
vchiq_platform_check_suspend(VCHIQ_STATE_T * state)2004 vchiq_platform_check_suspend(VCHIQ_STATE_T *state)
2005 {
2006 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
2007 	int susp = 0;
2008 
2009 	if (!arm_state)
2010 		goto out;
2011 
2012 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
2013 
2014 	write_lock_bh(&arm_state->susp_res_lock);
2015 	if (arm_state->vc_suspend_state == VC_SUSPEND_REQUESTED &&
2016 			arm_state->vc_resume_state == VC_RESUME_RESUMED) {
2017 		set_suspend_state(arm_state, VC_SUSPEND_IN_PROGRESS);
2018 		susp = 1;
2019 	}
2020 	write_unlock_bh(&arm_state->susp_res_lock);
2021 
2022 	if (susp)
2023 		vchiq_platform_suspend(state);
2024 
2025 out:
2026 	vchiq_log_trace(vchiq_susp_log_level, "%s exit", __func__);
2027 	return;
2028 }
2029 
2030 
2031 static void
output_timeout_error(VCHIQ_STATE_T * state)2032 output_timeout_error(VCHIQ_STATE_T *state)
2033 {
2034 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
2035 	char service_err[50] = "";
2036 	int vc_use_count = arm_state->videocore_use_count;
2037 	int active_services = state->unused_service;
2038 	int i;
2039 
2040 	if (!arm_state->videocore_use_count) {
2041 		snprintf(service_err, 50, " Videocore usecount is 0");
2042 		goto output_msg;
2043 	}
2044 	for (i = 0; i < active_services; i++) {
2045 		VCHIQ_SERVICE_T *service_ptr = state->services[i];
2046 		if (service_ptr && service_ptr->service_use_count &&
2047 			(service_ptr->srvstate != VCHIQ_SRVSTATE_FREE)) {
2048 			snprintf(service_err, 50, " %c%c%c%c(%d) service has "
2049 				"use count %d%s", VCHIQ_FOURCC_AS_4CHARS(
2050 					service_ptr->base.fourcc),
2051 				 service_ptr->client_id,
2052 				 service_ptr->service_use_count,
2053 				 service_ptr->service_use_count ==
2054 					 vc_use_count ? "" : " (+ more)");
2055 			break;
2056 		}
2057 	}
2058 
2059 output_msg:
2060 	vchiq_log_error(vchiq_susp_log_level,
2061 		"timed out waiting for vc suspend (%d).%s",
2062 		 arm_state->autosuspend_override, service_err);
2063 
2064 }
2065 
2066 /* Try to get videocore into suspended state, regardless of autosuspend state.
2067 ** We don't actually force suspend, since videocore may get into a bad state
2068 ** if we force suspend at a bad time.  Instead, we wait for autosuspend to
2069 ** determine a good point to suspend.  If this doesn't happen within 100ms we
2070 ** report failure.
2071 **
2072 ** Returns VCHIQ_SUCCESS if videocore suspended successfully, VCHIQ_RETRY if
2073 ** videocore failed to suspend in time or VCHIQ_ERROR if interrupted.
2074 */
2075 VCHIQ_STATUS_T
vchiq_arm_force_suspend(VCHIQ_STATE_T * state)2076 vchiq_arm_force_suspend(VCHIQ_STATE_T *state)
2077 {
2078 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
2079 	VCHIQ_STATUS_T status = VCHIQ_ERROR;
2080 	long rc = 0;
2081 	int repeat = -1;
2082 
2083 	if (!arm_state)
2084 		goto out;
2085 
2086 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
2087 
2088 	write_lock_bh(&arm_state->susp_res_lock);
2089 
2090 	status = block_resume(arm_state);
2091 	if (status != VCHIQ_SUCCESS)
2092 		goto unlock;
2093 	if (arm_state->vc_suspend_state == VC_SUSPEND_SUSPENDED) {
2094 		/* Already suspended - just block resume and exit */
2095 		vchiq_log_info(vchiq_susp_log_level, "%s already suspended",
2096 			__func__);
2097 		status = VCHIQ_SUCCESS;
2098 		goto unlock;
2099 	} else if (arm_state->vc_suspend_state <= VC_SUSPEND_IDLE) {
2100 		/* initiate suspend immediately in the case that we're waiting
2101 		 * for the timeout */
2102 		stop_suspend_timer(arm_state);
2103 		if (!vchiq_videocore_wanted(state)) {
2104 			vchiq_log_info(vchiq_susp_log_level, "%s videocore "
2105 				"idle, initiating suspend", __func__);
2106 			status = vchiq_arm_vcsuspend(state);
2107 		} else if (arm_state->autosuspend_override <
2108 						FORCE_SUSPEND_FAIL_MAX) {
2109 			vchiq_log_info(vchiq_susp_log_level, "%s letting "
2110 				"videocore go idle", __func__);
2111 			status = VCHIQ_SUCCESS;
2112 		} else {
2113 			vchiq_log_warning(vchiq_susp_log_level, "%s failed too "
2114 				"many times - attempting suspend", __func__);
2115 			status = vchiq_arm_vcsuspend(state);
2116 		}
2117 	} else {
2118 		vchiq_log_info(vchiq_susp_log_level, "%s videocore suspend "
2119 			"in progress - wait for completion", __func__);
2120 		status = VCHIQ_SUCCESS;
2121 	}
2122 
2123 	/* Wait for suspend to happen due to system idle (not forced..) */
2124 	if (status != VCHIQ_SUCCESS)
2125 		goto unblock_resume;
2126 
2127 	do {
2128 		write_unlock_bh(&arm_state->susp_res_lock);
2129 
2130 		rc = wait_for_completion_interruptible_timeout(
2131 				&arm_state->vc_suspend_complete,
2132 				msecs_to_jiffies(FORCE_SUSPEND_TIMEOUT_MS));
2133 
2134 		write_lock_bh(&arm_state->susp_res_lock);
2135 		if (rc < 0) {
2136 			vchiq_log_warning(vchiq_susp_log_level, "%s "
2137 				"interrupted waiting for suspend", __func__);
2138 			status = VCHIQ_ERROR;
2139 			goto unblock_resume;
2140 		} else if (rc == 0) {
2141 			if (arm_state->vc_suspend_state > VC_SUSPEND_IDLE) {
2142 				/* Repeat timeout once if in progress */
2143 				if (repeat < 0) {
2144 					repeat = 1;
2145 					continue;
2146 				}
2147 			}
2148 			arm_state->autosuspend_override++;
2149 			output_timeout_error(state);
2150 
2151 			status = VCHIQ_RETRY;
2152 			goto unblock_resume;
2153 		}
2154 	} while (0 < (repeat--));
2155 
2156 	/* Check and report state in case we need to abort ARM suspend */
2157 	if (arm_state->vc_suspend_state != VC_SUSPEND_SUSPENDED) {
2158 		status = VCHIQ_RETRY;
2159 		vchiq_log_error(vchiq_susp_log_level,
2160 			"%s videocore suspend failed (state %s)", __func__,
2161 			suspend_state_names[arm_state->vc_suspend_state +
2162 						VC_SUSPEND_NUM_OFFSET]);
2163 		/* Reset the state only if it's still in an error state.
2164 		 * Something could have already initiated another suspend. */
2165 		if (arm_state->vc_suspend_state < VC_SUSPEND_IDLE)
2166 			set_suspend_state(arm_state, VC_SUSPEND_IDLE);
2167 
2168 		goto unblock_resume;
2169 	}
2170 
2171 	/* successfully suspended - unlock and exit */
2172 	goto unlock;
2173 
2174 unblock_resume:
2175 	/* all error states need to unblock resume before exit */
2176 	unblock_resume(arm_state);
2177 
2178 unlock:
2179 	write_unlock_bh(&arm_state->susp_res_lock);
2180 
2181 out:
2182 	vchiq_log_trace(vchiq_susp_log_level, "%s exit %d", __func__, status);
2183 	return status;
2184 }
2185 
2186 void
vchiq_check_suspend(VCHIQ_STATE_T * state)2187 vchiq_check_suspend(VCHIQ_STATE_T *state)
2188 {
2189 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
2190 
2191 	if (!arm_state)
2192 		goto out;
2193 
2194 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
2195 
2196 	write_lock_bh(&arm_state->susp_res_lock);
2197 	if (arm_state->vc_suspend_state != VC_SUSPEND_SUSPENDED &&
2198 			arm_state->first_connect &&
2199 			!vchiq_videocore_wanted(state)) {
2200 		vchiq_arm_vcsuspend(state);
2201 	}
2202 	write_unlock_bh(&arm_state->susp_res_lock);
2203 
2204 out:
2205 	vchiq_log_trace(vchiq_susp_log_level, "%s exit", __func__);
2206 	return;
2207 }
2208 
2209 
2210 int
vchiq_arm_allow_resume(VCHIQ_STATE_T * state)2211 vchiq_arm_allow_resume(VCHIQ_STATE_T *state)
2212 {
2213 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
2214 	int resume = 0;
2215 	int ret = -1;
2216 
2217 	if (!arm_state)
2218 		goto out;
2219 
2220 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
2221 
2222 	write_lock_bh(&arm_state->susp_res_lock);
2223 	unblock_resume(arm_state);
2224 	resume = vchiq_check_resume(state);
2225 	write_unlock_bh(&arm_state->susp_res_lock);
2226 
2227 	if (resume) {
2228 		if (wait_for_completion_interruptible(
2229 			&arm_state->vc_resume_complete) < 0) {
2230 			vchiq_log_error(vchiq_susp_log_level,
2231 				"%s interrupted", __func__);
2232 			/* failed, cannot accurately derive suspend
2233 			 * state, so exit early. */
2234 			goto out;
2235 		}
2236 	}
2237 
2238 	read_lock_bh(&arm_state->susp_res_lock);
2239 	if (arm_state->vc_suspend_state == VC_SUSPEND_SUSPENDED) {
2240 		vchiq_log_info(vchiq_susp_log_level,
2241 				"%s: Videocore remains suspended", __func__);
2242 	} else {
2243 		vchiq_log_info(vchiq_susp_log_level,
2244 				"%s: Videocore resumed", __func__);
2245 		ret = 0;
2246 	}
2247 	read_unlock_bh(&arm_state->susp_res_lock);
2248 out:
2249 	vchiq_log_trace(vchiq_susp_log_level, "%s exit %d", __func__, ret);
2250 	return ret;
2251 }
2252 
2253 /* This function should be called with the write lock held */
2254 int
vchiq_check_resume(VCHIQ_STATE_T * state)2255 vchiq_check_resume(VCHIQ_STATE_T *state)
2256 {
2257 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
2258 	int resume = 0;
2259 
2260 	if (!arm_state)
2261 		goto out;
2262 
2263 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
2264 
2265 	if (need_resume(state)) {
2266 		set_resume_state(arm_state, VC_RESUME_REQUESTED);
2267 		request_poll(state, NULL, 0);
2268 		resume = 1;
2269 	}
2270 
2271 out:
2272 	vchiq_log_trace(vchiq_susp_log_level, "%s exit", __func__);
2273 	return resume;
2274 }
2275 
2276 void
vchiq_platform_check_resume(VCHIQ_STATE_T * state)2277 vchiq_platform_check_resume(VCHIQ_STATE_T *state)
2278 {
2279 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
2280 	int res = 0;
2281 
2282 	if (!arm_state)
2283 		goto out;
2284 
2285 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
2286 
2287 	write_lock_bh(&arm_state->susp_res_lock);
2288 	if (arm_state->wake_address == 0) {
2289 		vchiq_log_info(vchiq_susp_log_level,
2290 					"%s: already awake", __func__);
2291 		goto unlock;
2292 	}
2293 	if (arm_state->vc_resume_state == VC_RESUME_IN_PROGRESS) {
2294 		vchiq_log_info(vchiq_susp_log_level,
2295 					"%s: already resuming", __func__);
2296 		goto unlock;
2297 	}
2298 
2299 	if (arm_state->vc_resume_state == VC_RESUME_REQUESTED) {
2300 		set_resume_state(arm_state, VC_RESUME_IN_PROGRESS);
2301 		res = 1;
2302 	} else
2303 		vchiq_log_trace(vchiq_susp_log_level,
2304 				"%s: not resuming (resume state %s)", __func__,
2305 				resume_state_names[arm_state->vc_resume_state +
2306 							VC_RESUME_NUM_OFFSET]);
2307 
2308 unlock:
2309 	write_unlock_bh(&arm_state->susp_res_lock);
2310 
2311 	if (res)
2312 		vchiq_platform_resume(state);
2313 
2314 out:
2315 	vchiq_log_trace(vchiq_susp_log_level, "%s exit", __func__);
2316 	return;
2317 
2318 }
2319 
2320 
2321 
2322 VCHIQ_STATUS_T
vchiq_use_internal(VCHIQ_STATE_T * state,VCHIQ_SERVICE_T * service,enum USE_TYPE_E use_type)2323 vchiq_use_internal(VCHIQ_STATE_T *state, VCHIQ_SERVICE_T *service,
2324 		enum USE_TYPE_E use_type)
2325 {
2326 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
2327 	VCHIQ_STATUS_T ret = VCHIQ_SUCCESS;
2328 	char entity[16];
2329 	int *entity_uc;
2330 	int local_uc, local_entity_uc;
2331 
2332 	if (!arm_state)
2333 		goto out;
2334 
2335 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
2336 
2337 	if (use_type == USE_TYPE_VCHIQ) {
2338 		sprintf(entity, "VCHIQ:   ");
2339 		entity_uc = &arm_state->peer_use_count;
2340 	} else if (service) {
2341 		sprintf(entity, "%c%c%c%c:%03d",
2342 			VCHIQ_FOURCC_AS_4CHARS(service->base.fourcc),
2343 			service->client_id);
2344 		entity_uc = &service->service_use_count;
2345 	} else {
2346 		vchiq_log_error(vchiq_susp_log_level, "%s null service "
2347 				"ptr", __func__);
2348 		ret = VCHIQ_ERROR;
2349 		goto out;
2350 	}
2351 
2352 	write_lock_bh(&arm_state->susp_res_lock);
2353 	while (arm_state->resume_blocked) {
2354 		/* If we call 'use' while force suspend is waiting for suspend,
2355 		 * then we're about to block the thread which the force is
2356 		 * waiting to complete, so we're bound to just time out. In this
2357 		 * case, set the suspend state such that the wait will be
2358 		 * canceled, so we can complete as quickly as possible. */
2359 		if (arm_state->resume_blocked && arm_state->vc_suspend_state ==
2360 				VC_SUSPEND_IDLE) {
2361 			set_suspend_state(arm_state, VC_SUSPEND_FORCE_CANCELED);
2362 			break;
2363 		}
2364 		/* If suspend is already in progress then we need to block */
2365 		if (!try_wait_for_completion(&arm_state->resume_blocker)) {
2366 			/* Indicate that there are threads waiting on the resume
2367 			 * blocker.  These need to be allowed to complete before
2368 			 * a _second_ call to force suspend can complete,
2369 			 * otherwise low priority threads might never actually
2370 			 * continue */
2371 			arm_state->blocked_count++;
2372 			write_unlock_bh(&arm_state->susp_res_lock);
2373 			vchiq_log_info(vchiq_susp_log_level, "%s %s resume "
2374 				"blocked - waiting...", __func__, entity);
2375 			if (wait_for_completion_killable(
2376 					&arm_state->resume_blocker) != 0) {
2377 				vchiq_log_error(vchiq_susp_log_level, "%s %s "
2378 					"wait for resume blocker interrupted",
2379 					__func__, entity);
2380 				ret = VCHIQ_ERROR;
2381 				write_lock_bh(&arm_state->susp_res_lock);
2382 				arm_state->blocked_count--;
2383 				write_unlock_bh(&arm_state->susp_res_lock);
2384 				goto out;
2385 			}
2386 			vchiq_log_info(vchiq_susp_log_level, "%s %s resume "
2387 				"unblocked", __func__, entity);
2388 			write_lock_bh(&arm_state->susp_res_lock);
2389 			if (--arm_state->blocked_count == 0)
2390 				complete_all(&arm_state->blocked_blocker);
2391 		}
2392 	}
2393 
2394 	stop_suspend_timer(arm_state);
2395 
2396 	local_uc = ++arm_state->videocore_use_count;
2397 	local_entity_uc = ++(*entity_uc);
2398 
2399 	/* If there's a pending request which hasn't yet been serviced then
2400 	 * just clear it.  If we're past VC_SUSPEND_REQUESTED state then
2401 	 * vc_resume_complete will block until we either resume or fail to
2402 	 * suspend */
2403 	if (arm_state->vc_suspend_state <= VC_SUSPEND_REQUESTED)
2404 		set_suspend_state(arm_state, VC_SUSPEND_IDLE);
2405 
2406 	if ((use_type != USE_TYPE_SERVICE_NO_RESUME) && need_resume(state)) {
2407 		set_resume_state(arm_state, VC_RESUME_REQUESTED);
2408 		vchiq_log_info(vchiq_susp_log_level,
2409 			"%s %s count %d, state count %d",
2410 			__func__, entity, local_entity_uc, local_uc);
2411 		request_poll(state, NULL, 0);
2412 	} else
2413 		vchiq_log_trace(vchiq_susp_log_level,
2414 			"%s %s count %d, state count %d",
2415 			__func__, entity, *entity_uc, local_uc);
2416 
2417 
2418 	write_unlock_bh(&arm_state->susp_res_lock);
2419 
2420 	/* Completion is in a done state when we're not suspended, so this won't
2421 	 * block for the non-suspended case. */
2422 	if (!try_wait_for_completion(&arm_state->vc_resume_complete)) {
2423 		vchiq_log_info(vchiq_susp_log_level, "%s %s wait for resume",
2424 			__func__, entity);
2425 		if (wait_for_completion_killable(
2426 				&arm_state->vc_resume_complete) != 0) {
2427 			vchiq_log_error(vchiq_susp_log_level, "%s %s wait for "
2428 				"resume interrupted", __func__, entity);
2429 			ret = VCHIQ_ERROR;
2430 			goto out;
2431 		}
2432 		vchiq_log_info(vchiq_susp_log_level, "%s %s resumed", __func__,
2433 			entity);
2434 	}
2435 
2436 	if (ret == VCHIQ_SUCCESS) {
2437 		VCHIQ_STATUS_T status = VCHIQ_SUCCESS;
2438 		long ack_cnt = atomic_xchg(&arm_state->ka_use_ack_count, 0);
2439 		while (ack_cnt && (status == VCHIQ_SUCCESS)) {
2440 			/* Send the use notify to videocore */
2441 			status = vchiq_send_remote_use_active(state);
2442 			if (status == VCHIQ_SUCCESS)
2443 				ack_cnt--;
2444 			else
2445 				atomic_add(ack_cnt,
2446 					&arm_state->ka_use_ack_count);
2447 		}
2448 	}
2449 
2450 out:
2451 	vchiq_log_trace(vchiq_susp_log_level, "%s exit %d", __func__, ret);
2452 	return ret;
2453 }
2454 
2455 VCHIQ_STATUS_T
vchiq_release_internal(VCHIQ_STATE_T * state,VCHIQ_SERVICE_T * service)2456 vchiq_release_internal(VCHIQ_STATE_T *state, VCHIQ_SERVICE_T *service)
2457 {
2458 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
2459 	VCHIQ_STATUS_T ret = VCHIQ_SUCCESS;
2460 	char entity[16];
2461 	int *entity_uc;
2462 	int local_uc, local_entity_uc;
2463 
2464 	if (!arm_state)
2465 		goto out;
2466 
2467 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
2468 
2469 	if (service) {
2470 		sprintf(entity, "%c%c%c%c:%03d",
2471 			VCHIQ_FOURCC_AS_4CHARS(service->base.fourcc),
2472 			service->client_id);
2473 		entity_uc = &service->service_use_count;
2474 	} else {
2475 		sprintf(entity, "PEER:   ");
2476 		entity_uc = &arm_state->peer_use_count;
2477 	}
2478 
2479 	write_lock_bh(&arm_state->susp_res_lock);
2480 	if (!arm_state->videocore_use_count || !(*entity_uc)) {
2481 		/* Don't use BUG_ON - don't allow user thread to crash kernel */
2482 		WARN_ON(!arm_state->videocore_use_count);
2483 		WARN_ON(!(*entity_uc));
2484 		ret = VCHIQ_ERROR;
2485 		goto unlock;
2486 	}
2487 	local_uc = --arm_state->videocore_use_count;
2488 	local_entity_uc = --(*entity_uc);
2489 
2490 	if (!vchiq_videocore_wanted(state)) {
2491 		if (vchiq_platform_use_suspend_timer() &&
2492 				!arm_state->resume_blocked) {
2493 			/* Only use the timer if we're not trying to force
2494 			 * suspend (=> resume_blocked) */
2495 			start_suspend_timer(arm_state);
2496 		} else {
2497 			vchiq_log_info(vchiq_susp_log_level,
2498 				"%s %s count %d, state count %d - suspending",
2499 				__func__, entity, *entity_uc,
2500 				arm_state->videocore_use_count);
2501 			vchiq_arm_vcsuspend(state);
2502 		}
2503 	} else
2504 		vchiq_log_trace(vchiq_susp_log_level,
2505 			"%s %s count %d, state count %d",
2506 			__func__, entity, *entity_uc,
2507 			arm_state->videocore_use_count);
2508 
2509 unlock:
2510 	write_unlock_bh(&arm_state->susp_res_lock);
2511 
2512 out:
2513 	vchiq_log_trace(vchiq_susp_log_level, "%s exit %d", __func__, ret);
2514 	return ret;
2515 }
2516 
2517 void
vchiq_on_remote_use(VCHIQ_STATE_T * state)2518 vchiq_on_remote_use(VCHIQ_STATE_T *state)
2519 {
2520 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
2521 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
2522 	atomic_inc(&arm_state->ka_use_count);
2523 	complete(&arm_state->ka_evt);
2524 }
2525 
2526 void
vchiq_on_remote_release(VCHIQ_STATE_T * state)2527 vchiq_on_remote_release(VCHIQ_STATE_T *state)
2528 {
2529 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
2530 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
2531 	atomic_inc(&arm_state->ka_release_count);
2532 	complete(&arm_state->ka_evt);
2533 }
2534 
2535 VCHIQ_STATUS_T
vchiq_use_service_internal(VCHIQ_SERVICE_T * service)2536 vchiq_use_service_internal(VCHIQ_SERVICE_T *service)
2537 {
2538 	return vchiq_use_internal(service->state, service, USE_TYPE_SERVICE);
2539 }
2540 
2541 VCHIQ_STATUS_T
vchiq_release_service_internal(VCHIQ_SERVICE_T * service)2542 vchiq_release_service_internal(VCHIQ_SERVICE_T *service)
2543 {
2544 	return vchiq_release_internal(service->state, service);
2545 }
2546 
2547 VCHIQ_DEBUGFS_NODE_T *
vchiq_instance_get_debugfs_node(VCHIQ_INSTANCE_T instance)2548 vchiq_instance_get_debugfs_node(VCHIQ_INSTANCE_T instance)
2549 {
2550 	return &instance->debugfs_node;
2551 }
2552 
2553 int
vchiq_instance_get_use_count(VCHIQ_INSTANCE_T instance)2554 vchiq_instance_get_use_count(VCHIQ_INSTANCE_T instance)
2555 {
2556 	VCHIQ_SERVICE_T *service;
2557 	int use_count = 0, i;
2558 	i = 0;
2559 	while ((service = next_service_by_instance(instance->state,
2560 		instance, &i)) != NULL) {
2561 		use_count += service->service_use_count;
2562 		unlock_service(service);
2563 	}
2564 	return use_count;
2565 }
2566 
2567 int
vchiq_instance_get_pid(VCHIQ_INSTANCE_T instance)2568 vchiq_instance_get_pid(VCHIQ_INSTANCE_T instance)
2569 {
2570 	return instance->pid;
2571 }
2572 
2573 int
vchiq_instance_get_trace(VCHIQ_INSTANCE_T instance)2574 vchiq_instance_get_trace(VCHIQ_INSTANCE_T instance)
2575 {
2576 	return instance->trace;
2577 }
2578 
2579 void
vchiq_instance_set_trace(VCHIQ_INSTANCE_T instance,int trace)2580 vchiq_instance_set_trace(VCHIQ_INSTANCE_T instance, int trace)
2581 {
2582 	VCHIQ_SERVICE_T *service;
2583 	int i;
2584 	i = 0;
2585 	while ((service = next_service_by_instance(instance->state,
2586 		instance, &i)) != NULL) {
2587 		service->trace = trace;
2588 		unlock_service(service);
2589 	}
2590 	instance->trace = (trace != 0);
2591 }
2592 
suspend_timer_callback(unsigned long context)2593 static void suspend_timer_callback(unsigned long context)
2594 {
2595 	VCHIQ_STATE_T *state = (VCHIQ_STATE_T *)context;
2596 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
2597 	if (!arm_state)
2598 		goto out;
2599 	vchiq_log_info(vchiq_susp_log_level,
2600 		"%s - suspend timer expired - check suspend", __func__);
2601 	vchiq_check_suspend(state);
2602 out:
2603 	return;
2604 }
2605 
2606 VCHIQ_STATUS_T
vchiq_use_service_no_resume(VCHIQ_SERVICE_HANDLE_T handle)2607 vchiq_use_service_no_resume(VCHIQ_SERVICE_HANDLE_T handle)
2608 {
2609 	VCHIQ_STATUS_T ret = VCHIQ_ERROR;
2610 	VCHIQ_SERVICE_T *service = find_service_by_handle(handle);
2611 	if (service) {
2612 		ret = vchiq_use_internal(service->state, service,
2613 				USE_TYPE_SERVICE_NO_RESUME);
2614 		unlock_service(service);
2615 	}
2616 	return ret;
2617 }
2618 
2619 VCHIQ_STATUS_T
vchiq_use_service(VCHIQ_SERVICE_HANDLE_T handle)2620 vchiq_use_service(VCHIQ_SERVICE_HANDLE_T handle)
2621 {
2622 	VCHIQ_STATUS_T ret = VCHIQ_ERROR;
2623 	VCHIQ_SERVICE_T *service = find_service_by_handle(handle);
2624 	if (service) {
2625 		ret = vchiq_use_internal(service->state, service,
2626 				USE_TYPE_SERVICE);
2627 		unlock_service(service);
2628 	}
2629 	return ret;
2630 }
2631 
2632 VCHIQ_STATUS_T
vchiq_release_service(VCHIQ_SERVICE_HANDLE_T handle)2633 vchiq_release_service(VCHIQ_SERVICE_HANDLE_T handle)
2634 {
2635 	VCHIQ_STATUS_T ret = VCHIQ_ERROR;
2636 	VCHIQ_SERVICE_T *service = find_service_by_handle(handle);
2637 	if (service) {
2638 		ret = vchiq_release_internal(service->state, service);
2639 		unlock_service(service);
2640 	}
2641 	return ret;
2642 }
2643 
2644 void
vchiq_dump_service_use_state(VCHIQ_STATE_T * state)2645 vchiq_dump_service_use_state(VCHIQ_STATE_T *state)
2646 {
2647 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
2648 	int i, j = 0;
2649 	/* Only dump 64 services */
2650 	static const int local_max_services = 64;
2651 	/* If there's more than 64 services, only dump ones with
2652 	 * non-zero counts */
2653 	int only_nonzero = 0;
2654 	static const char *nz = "<-- preventing suspend";
2655 
2656 	enum vc_suspend_status vc_suspend_state;
2657 	enum vc_resume_status  vc_resume_state;
2658 	int peer_count;
2659 	int vc_use_count;
2660 	int active_services;
2661 	struct service_data_struct {
2662 		int fourcc;
2663 		int clientid;
2664 		int use_count;
2665 	} service_data[local_max_services];
2666 
2667 	if (!arm_state)
2668 		return;
2669 
2670 	read_lock_bh(&arm_state->susp_res_lock);
2671 	vc_suspend_state = arm_state->vc_suspend_state;
2672 	vc_resume_state  = arm_state->vc_resume_state;
2673 	peer_count = arm_state->peer_use_count;
2674 	vc_use_count = arm_state->videocore_use_count;
2675 	active_services = state->unused_service;
2676 	if (active_services > local_max_services)
2677 		only_nonzero = 1;
2678 
2679 	for (i = 0; (i < active_services) && (j < local_max_services); i++) {
2680 		VCHIQ_SERVICE_T *service_ptr = state->services[i];
2681 		if (!service_ptr)
2682 			continue;
2683 
2684 		if (only_nonzero && !service_ptr->service_use_count)
2685 			continue;
2686 
2687 		if (service_ptr->srvstate != VCHIQ_SRVSTATE_FREE) {
2688 			service_data[j].fourcc = service_ptr->base.fourcc;
2689 			service_data[j].clientid = service_ptr->client_id;
2690 			service_data[j++].use_count = service_ptr->
2691 							service_use_count;
2692 		}
2693 	}
2694 
2695 	read_unlock_bh(&arm_state->susp_res_lock);
2696 
2697 	vchiq_log_warning(vchiq_susp_log_level,
2698 		"-- Videcore suspend state: %s --",
2699 		suspend_state_names[vc_suspend_state + VC_SUSPEND_NUM_OFFSET]);
2700 	vchiq_log_warning(vchiq_susp_log_level,
2701 		"-- Videcore resume state: %s --",
2702 		resume_state_names[vc_resume_state + VC_RESUME_NUM_OFFSET]);
2703 
2704 	if (only_nonzero)
2705 		vchiq_log_warning(vchiq_susp_log_level, "Too many active "
2706 			"services (%d).  Only dumping up to first %d services "
2707 			"with non-zero use-count", active_services,
2708 			local_max_services);
2709 
2710 	for (i = 0; i < j; i++) {
2711 		vchiq_log_warning(vchiq_susp_log_level,
2712 			"----- %c%c%c%c:%d service count %d %s",
2713 			VCHIQ_FOURCC_AS_4CHARS(service_data[i].fourcc),
2714 			service_data[i].clientid,
2715 			service_data[i].use_count,
2716 			service_data[i].use_count ? nz : "");
2717 	}
2718 	vchiq_log_warning(vchiq_susp_log_level,
2719 		"----- VCHIQ use count count %d", peer_count);
2720 	vchiq_log_warning(vchiq_susp_log_level,
2721 		"--- Overall vchiq instance use count %d", vc_use_count);
2722 
2723 	vchiq_dump_platform_use_state(state);
2724 }
2725 
2726 VCHIQ_STATUS_T
vchiq_check_service(VCHIQ_SERVICE_T * service)2727 vchiq_check_service(VCHIQ_SERVICE_T *service)
2728 {
2729 	VCHIQ_ARM_STATE_T *arm_state;
2730 	VCHIQ_STATUS_T ret = VCHIQ_ERROR;
2731 
2732 	if (!service || !service->state)
2733 		goto out;
2734 
2735 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
2736 
2737 	arm_state = vchiq_platform_get_arm_state(service->state);
2738 
2739 	read_lock_bh(&arm_state->susp_res_lock);
2740 	if (service->service_use_count)
2741 		ret = VCHIQ_SUCCESS;
2742 	read_unlock_bh(&arm_state->susp_res_lock);
2743 
2744 	if (ret == VCHIQ_ERROR) {
2745 		vchiq_log_error(vchiq_susp_log_level,
2746 			"%s ERROR - %c%c%c%c:%d service count %d, "
2747 			"state count %d, videocore suspend state %s", __func__,
2748 			VCHIQ_FOURCC_AS_4CHARS(service->base.fourcc),
2749 			service->client_id, service->service_use_count,
2750 			arm_state->videocore_use_count,
2751 			suspend_state_names[arm_state->vc_suspend_state +
2752 						VC_SUSPEND_NUM_OFFSET]);
2753 		vchiq_dump_service_use_state(service->state);
2754 	}
2755 out:
2756 	return ret;
2757 }
2758 
2759 /* stub functions */
vchiq_on_remote_use_active(VCHIQ_STATE_T * state)2760 void vchiq_on_remote_use_active(VCHIQ_STATE_T *state)
2761 {
2762 	(void)state;
2763 }
2764 
vchiq_platform_conn_state_changed(VCHIQ_STATE_T * state,VCHIQ_CONNSTATE_T oldstate,VCHIQ_CONNSTATE_T newstate)2765 void vchiq_platform_conn_state_changed(VCHIQ_STATE_T *state,
2766 	VCHIQ_CONNSTATE_T oldstate, VCHIQ_CONNSTATE_T newstate)
2767 {
2768 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
2769 	vchiq_log_info(vchiq_susp_log_level, "%d: %s->%s", state->id,
2770 		get_conn_state_name(oldstate), get_conn_state_name(newstate));
2771 	if (state->conn_state == VCHIQ_CONNSTATE_CONNECTED) {
2772 		write_lock_bh(&arm_state->susp_res_lock);
2773 		if (!arm_state->first_connect) {
2774 			char threadname[10];
2775 			arm_state->first_connect = 1;
2776 			write_unlock_bh(&arm_state->susp_res_lock);
2777 			snprintf(threadname, sizeof(threadname), "VCHIQka-%d",
2778 				state->id);
2779 			arm_state->ka_thread = kthread_create(
2780 				&vchiq_keepalive_thread_func,
2781 				(void *)state,
2782 				threadname);
2783 			if (arm_state->ka_thread == NULL) {
2784 				vchiq_log_error(vchiq_susp_log_level,
2785 					"vchiq: FATAL: couldn't create thread %s",
2786 					threadname);
2787 			} else {
2788 				wake_up_process(arm_state->ka_thread);
2789 			}
2790 		} else
2791 			write_unlock_bh(&arm_state->susp_res_lock);
2792 	}
2793 }
2794 
vchiq_probe(struct platform_device * pdev)2795 static int vchiq_probe(struct platform_device *pdev)
2796 {
2797 	struct device_node *fw_node;
2798 	struct rpi_firmware *fw;
2799 	int err;
2800 	void *ptr_err;
2801 
2802 	fw_node = of_parse_phandle(pdev->dev.of_node, "firmware", 0);
2803 /* Remove comment when booting without Device Tree is no longer supported
2804 	if (!fw_node) {
2805 		dev_err(&pdev->dev, "Missing firmware node\n");
2806 		return -ENOENT;
2807 	}
2808 */
2809 	fw = rpi_firmware_get(fw_node);
2810 	if (!fw)
2811 		return -EPROBE_DEFER;
2812 
2813 	platform_set_drvdata(pdev, fw);
2814 
2815 	/* create debugfs entries */
2816 	err = vchiq_debugfs_init();
2817 	if (err != 0)
2818 		goto failed_debugfs_init;
2819 
2820 	err = alloc_chrdev_region(&vchiq_devid, VCHIQ_MINOR, 1, DEVICE_NAME);
2821 	if (err != 0) {
2822 		vchiq_log_error(vchiq_arm_log_level,
2823 			"Unable to allocate device number");
2824 		goto failed_alloc_chrdev;
2825 	}
2826 	cdev_init(&vchiq_cdev, &vchiq_fops);
2827 	vchiq_cdev.owner = THIS_MODULE;
2828 	err = cdev_add(&vchiq_cdev, vchiq_devid, 1);
2829 	if (err != 0) {
2830 		vchiq_log_error(vchiq_arm_log_level,
2831 			"Unable to register device");
2832 		goto failed_cdev_add;
2833 	}
2834 
2835 	/* create sysfs entries */
2836 	vchiq_class = class_create(THIS_MODULE, DEVICE_NAME);
2837 	ptr_err = vchiq_class;
2838 	if (IS_ERR(ptr_err))
2839 		goto failed_class_create;
2840 
2841 	vchiq_dev = device_create(vchiq_class, NULL,
2842 		vchiq_devid, NULL, "vchiq");
2843 	ptr_err = vchiq_dev;
2844 	if (IS_ERR(ptr_err))
2845 		goto failed_device_create;
2846 
2847 	err = vchiq_platform_init(pdev, &g_state);
2848 	if (err != 0)
2849 		goto failed_platform_init;
2850 
2851 	vchiq_log_info(vchiq_arm_log_level,
2852 		"vchiq: initialised - version %d (min %d), device %d.%d",
2853 		VCHIQ_VERSION, VCHIQ_VERSION_MIN,
2854 		MAJOR(vchiq_devid), MINOR(vchiq_devid));
2855 
2856 	return 0;
2857 
2858 failed_platform_init:
2859 	device_destroy(vchiq_class, vchiq_devid);
2860 failed_device_create:
2861 	class_destroy(vchiq_class);
2862 failed_class_create:
2863 	cdev_del(&vchiq_cdev);
2864 	err = PTR_ERR(ptr_err);
2865 failed_cdev_add:
2866 	unregister_chrdev_region(vchiq_devid, 1);
2867 failed_alloc_chrdev:
2868 	vchiq_debugfs_deinit();
2869 failed_debugfs_init:
2870 	vchiq_log_warning(vchiq_arm_log_level, "could not load vchiq");
2871 	return err;
2872 }
2873 
vchiq_remove(struct platform_device * pdev)2874 static int vchiq_remove(struct platform_device *pdev)
2875 {
2876 	device_destroy(vchiq_class, vchiq_devid);
2877 	class_destroy(vchiq_class);
2878 	cdev_del(&vchiq_cdev);
2879 	unregister_chrdev_region(vchiq_devid, 1);
2880 
2881 	return 0;
2882 }
2883 
2884 static const struct of_device_id vchiq_of_match[] = {
2885 	{ .compatible = "brcm,bcm2835-vchiq", },
2886 	{},
2887 };
2888 MODULE_DEVICE_TABLE(of, vchiq_of_match);
2889 
2890 static struct platform_driver vchiq_driver = {
2891 	.driver = {
2892 		.name = "bcm2835_vchiq",
2893 		.owner = THIS_MODULE,
2894 		.of_match_table = vchiq_of_match,
2895 	},
2896 	.probe = vchiq_probe,
2897 	.remove = vchiq_remove,
2898 };
2899 module_platform_driver(vchiq_driver);
2900 
2901 MODULE_LICENSE("GPL");
2902 MODULE_AUTHOR("Broadcom Corporation");
2903