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vchiq_arm.c revision 1.11.2.1
      1 /**
      2  * Copyright (c) 2010-2012 Broadcom. All rights reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions
      6  * are met:
      7  * 1. Redistributions of source code must retain the above copyright
      8  *    notice, this list of conditions, and the following disclaimer,
      9  *    without modification.
     10  * 2. Redistributions in binary form must reproduce the above copyright
     11  *    notice, this list of conditions and the following disclaimer in the
     12  *    documentation and/or other materials provided with the distribution.
     13  * 3. The names of the above-listed copyright holders may not be used
     14  *    to endorse or promote products derived from this software without
     15  *    specific prior written permission.
     16  *
     17  * ALTERNATIVELY, this software may be distributed under the terms of the
     18  * GNU General Public License ("GPL") version 2, as published by the Free
     19  * Software Foundation.
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
     22  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
     23  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     24  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
     25  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     26  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     27  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     28  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
     29  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
     30  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
     31  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     32  */
     33 
     34 #include <sys/cdefs.h>
     35 #include <sys/systm.h>
     36 #include <sys/device.h>
     37 #include <sys/file.h>
     38 #include <sys/filedesc.h>
     39 
     40 #include "vchiq_core.h"
     41 #include "vchiq_ioctl.h"
     42 #include "vchiq_arm.h"
     43 
     44 #define DEVICE_NAME "vchiq"
     45 
     46 /* Override the default prefix, which would be vchiq_arm (from the filename) */
     47 #undef MODULE_PARAM_PREFIX
     48 #define MODULE_PARAM_PREFIX DEVICE_NAME "."
     49 
     50 #define VCHIQ_MINOR 0
     51 
     52 /* Some per-instance constants */
     53 #define MAX_COMPLETIONS 16
     54 #define MAX_SERVICES 64
     55 #define MAX_ELEMENTS 8
     56 #define MSG_QUEUE_SIZE 64
     57 
     58 #define KEEPALIVE_VER 1
     59 #define KEEPALIVE_VER_MIN KEEPALIVE_VER
     60 
     61 MALLOC_DEFINE(M_VCHIQ, "vchiq_cdev", "VideoCore cdev memory");
     62 
     63 /* Run time control of log level, based on KERN_XXX level. */
     64 int vchiq_arm_log_level = VCHIQ_LOG_DEFAULT;
     65 int vchiq_susp_log_level = VCHIQ_LOG_ERROR;
     66 
     67 #define SUSPEND_TIMER_TIMEOUT_MS 100
     68 #define SUSPEND_RETRY_TIMER_TIMEOUT_MS 1000
     69 
     70 #define VC_SUSPEND_NUM_OFFSET 3 /* number of values before idle which are -ve */
     71 static const char *const suspend_state_names[] = {
     72 	"VC_SUSPEND_FORCE_CANCELED",
     73 	"VC_SUSPEND_REJECTED",
     74 	"VC_SUSPEND_FAILED",
     75 	"VC_SUSPEND_IDLE",
     76 	"VC_SUSPEND_REQUESTED",
     77 	"VC_SUSPEND_IN_PROGRESS",
     78 	"VC_SUSPEND_SUSPENDED"
     79 };
     80 #define VC_RESUME_NUM_OFFSET 1 /* number of values before idle which are -ve */
     81 static const char *const resume_state_names[] = {
     82 	"VC_RESUME_FAILED",
     83 	"VC_RESUME_IDLE",
     84 	"VC_RESUME_REQUESTED",
     85 	"VC_RESUME_IN_PROGRESS",
     86 	"VC_RESUME_RESUMED"
     87 };
     88 /* The number of times we allow force suspend to timeout before actually
     89 ** _forcing_ suspend.  This is to cater for SW which fails to release vchiq
     90 ** correctly - we don't want to prevent ARM suspend indefinitely in this case.
     91 */
     92 #define FORCE_SUSPEND_FAIL_MAX 8
     93 
     94 /* The time in ms allowed for videocore to go idle when force suspend has been
     95  * requested */
     96 #define FORCE_SUSPEND_TIMEOUT_MS 200
     97 
     98 
     99 static void suspend_timer_callback(unsigned long context);
    100 #ifdef notyet
    101 static int vchiq_proc_add_instance(VCHIQ_INSTANCE_T instance);
    102 static void vchiq_proc_remove_instance(VCHIQ_INSTANCE_T instance);
    103 #endif
    104 
    105 
    106 typedef struct user_service_struct {
    107 	VCHIQ_SERVICE_T *service;
    108 	void *userdata;
    109 	VCHIQ_INSTANCE_T instance;
    110 	int is_vchi;
    111 	int dequeue_pending;
    112 	int message_available_pos;
    113 	int msg_insert;
    114 	int msg_remove;
    115 	struct semaphore insert_event;
    116 	struct semaphore remove_event;
    117 	VCHIQ_HEADER_T * msg_queue[MSG_QUEUE_SIZE];
    118 } USER_SERVICE_T;
    119 
    120 struct bulk_waiter_node {
    121 	struct bulk_waiter bulk_waiter;
    122 	struct lwp *l;
    123 	struct list_head list;
    124 };
    125 
    126 struct vchiq_instance_struct {
    127 	VCHIQ_STATE_T *state;
    128 	VCHIQ_COMPLETION_DATA_T completions[MAX_COMPLETIONS];
    129 	int completion_insert;
    130 	int completion_remove;
    131 	struct semaphore insert_event;
    132 	struct semaphore remove_event;
    133 	struct mutex completion_mutex;
    134 
    135 	int connected;
    136 	int closing;
    137 	struct lwp *l;
    138 	int mark;
    139 
    140 	struct list_head bulk_waiter_list;
    141 	struct mutex bulk_waiter_list_mutex;
    142 
    143 	struct proc_dir_entry *proc_entry;
    144 };
    145 
    146 typedef struct dump_context_struct {
    147 	char __user *buf;
    148 	size_t actual;
    149 	size_t space;
    150 	loff_t offset;
    151 } DUMP_CONTEXT_T;
    152 
    153 VCHIQ_STATE_T g_state;
    154 static DEFINE_SPINLOCK(msg_queue_spinlock);
    155 
    156 static const char *const ioctl_names[] = {
    157 	"CONNECT",
    158 	"SHUTDOWN",
    159 	"CREATE_SERVICE",
    160 	"REMOVE_SERVICE",
    161 	"QUEUE_MESSAGE",
    162 	"QUEUE_BULK_TRANSMIT",
    163 	"QUEUE_BULK_RECEIVE",
    164 	"AWAIT_COMPLETION",
    165 	"DEQUEUE_MESSAGE",
    166 	"GET_CLIENT_ID",
    167 	"GET_CONFIG",
    168 	"CLOSE_SERVICE",
    169 	"USE_SERVICE",
    170 	"RELEASE_SERVICE",
    171 	"SET_SERVICE_OPTION",
    172 	"DUMP_PHYS_MEM"
    173 };
    174 
    175 vchiq_static_assert((sizeof(ioctl_names)/sizeof(ioctl_names[0])) ==
    176 	(VCHIQ_IOC_MAX + 1));
    177 
    178 static dev_type_open(vchiq_open);
    179 
    180 struct cdevsw vchiq_cdevsw = {
    181 	.d_open = vchiq_open,
    182 	.d_close = noclose,
    183 	.d_read = noread,
    184 	.d_write = nowrite,
    185 	.d_ioctl = noioctl,
    186 	.d_stop = nostop,
    187 	.d_tty = notty,
    188 	.d_poll = nopoll,
    189 	.d_mmap = nommap,
    190 	.d_kqfilter = nokqfilter,
    191 	.d_discard = nodiscard,
    192 	.d_flag = D_OTHER | D_MPSAFE
    193 };
    194 
    195 extern struct cfdriver vchiq_cd;
    196 
    197 static int	vchiq_ioctl(struct file *, u_long, void *);
    198 static int	vchiq_close(struct file *);
    199 
    200 static const struct fileops vchiq_fileops = {
    201 	.fo_read = fbadop_read,
    202 	.fo_write = fbadop_write,
    203 	.fo_ioctl = vchiq_ioctl,
    204 	.fo_fcntl = fnullop_fcntl,
    205 	.fo_poll = fnullop_poll,
    206 	.fo_stat = fbadop_stat,
    207 	.fo_close = vchiq_close,
    208 	.fo_kqfilter = fnullop_kqfilter,
    209 };
    210 
    211 #if 0
    212 static void
    213 dump_phys_mem(void *virt_addr, uint32_t num_bytes);
    214 #endif
    215 
    216 /****************************************************************************
    217 *
    218 *   add_completion
    219 *
    220 ***************************************************************************/
    221 
    222 static VCHIQ_STATUS_T
    223 add_completion(VCHIQ_INSTANCE_T instance, VCHIQ_REASON_T reason,
    224 	VCHIQ_HEADER_T *header, USER_SERVICE_T *user_service,
    225 	void *bulk_userdata)
    226 {
    227 	VCHIQ_COMPLETION_DATA_T *completion;
    228 	DEBUG_INITIALISE(g_state.local)
    229 
    230 	while (instance->completion_insert ==
    231 		(instance->completion_remove + MAX_COMPLETIONS)) {
    232 		/* Out of space - wait for the client */
    233 		DEBUG_TRACE(SERVICE_CALLBACK_LINE);
    234 		vchiq_log_trace(vchiq_arm_log_level,
    235 			"add_completion - completion queue full");
    236 		DEBUG_COUNT(COMPLETION_QUEUE_FULL_COUNT);
    237 		if (down_interruptible(&instance->remove_event) != 0) {
    238 			vchiq_log_info(vchiq_arm_log_level,
    239 				"service_callback interrupted");
    240 			return VCHIQ_RETRY;
    241 		} else if (instance->closing) {
    242 			vchiq_log_info(vchiq_arm_log_level,
    243 				"service_callback closing");
    244 			return VCHIQ_ERROR;
    245 		}
    246 		DEBUG_TRACE(SERVICE_CALLBACK_LINE);
    247 	}
    248 
    249 	completion =
    250 		 &instance->completions[instance->completion_insert &
    251 		 (MAX_COMPLETIONS - 1)];
    252 
    253 	completion->header = header;
    254 	completion->reason = reason;
    255 	/* N.B. service_userdata is updated while processing AWAIT_COMPLETION */
    256 	completion->service_userdata = user_service->service;
    257 	completion->bulk_userdata = bulk_userdata;
    258 
    259 	if (reason == VCHIQ_SERVICE_CLOSED)
    260 		/* Take an extra reference, to be held until
    261 		   this CLOSED notification is delivered. */
    262 		lock_service(user_service->service);
    263 
    264 	/* A write barrier is needed here to ensure that the entire completion
    265 		record is written out before the insert point. */
    266 	wmb();
    267 
    268 	if (reason == VCHIQ_MESSAGE_AVAILABLE)
    269 		user_service->message_available_pos =
    270 			instance->completion_insert;
    271 	instance->completion_insert++;
    272 
    273 	up(&instance->insert_event);
    274 
    275 	return VCHIQ_SUCCESS;
    276 }
    277 
    278 /****************************************************************************
    279 *
    280 *   service_callback
    281 *
    282 ***************************************************************************/
    283 
    284 static VCHIQ_STATUS_T
    285 service_callback(VCHIQ_REASON_T reason, VCHIQ_HEADER_T *header,
    286 	VCHIQ_SERVICE_HANDLE_T handle, void *bulk_userdata)
    287 {
    288 	/* How do we ensure the callback goes to the right client?
    289 	** The service_user data points to a USER_SERVICE_T record containing
    290 	** the original callback and the user state structure, which contains a
    291 	** circular buffer for completion records.
    292 	*/
    293 	USER_SERVICE_T *user_service;
    294 	VCHIQ_SERVICE_T *service;
    295 	VCHIQ_INSTANCE_T instance;
    296 	DEBUG_INITIALISE(g_state.local)
    297 
    298 	DEBUG_TRACE(SERVICE_CALLBACK_LINE);
    299 
    300 	service = handle_to_service(handle);
    301 	BUG_ON(!service);
    302 	user_service = (USER_SERVICE_T *)service->base.userdata;
    303 	instance = user_service->instance;
    304 
    305 	if (!instance || instance->closing)
    306 		return VCHIQ_SUCCESS;
    307 
    308 	vchiq_log_trace(vchiq_arm_log_level,
    309 		"service_callback - service %lx(%d), handle %x, reason %d, header %lx, "
    310 		"instance %lx, bulk_userdata %lx",
    311 		(unsigned long)user_service,
    312 		service->localport, service->handle,
    313 		reason, (unsigned long)header,
    314 		(unsigned long)instance, (unsigned long)bulk_userdata);
    315 
    316 	if (header && user_service->is_vchi) {
    317 		spin_lock(&msg_queue_spinlock);
    318 		while (user_service->msg_insert ==
    319 			(user_service->msg_remove + MSG_QUEUE_SIZE)) {
    320 			spin_unlock(&msg_queue_spinlock);
    321 			DEBUG_TRACE(SERVICE_CALLBACK_LINE);
    322 			DEBUG_COUNT(MSG_QUEUE_FULL_COUNT);
    323 			vchiq_log_trace(vchiq_arm_log_level,
    324 				"service_callback - msg queue full");
    325 			/* If there is no MESSAGE_AVAILABLE in the completion
    326 			** queue, add one
    327 			*/
    328 			if ((user_service->message_available_pos -
    329 				instance->completion_remove) < 0) {
    330 				VCHIQ_STATUS_T status;
    331 				vchiq_log_info(vchiq_arm_log_level,
    332 					"Inserting extra MESSAGE_AVAILABLE");
    333 				DEBUG_TRACE(SERVICE_CALLBACK_LINE);
    334 				status = add_completion(instance, reason,
    335 					NULL, user_service, bulk_userdata);
    336 				if (status != VCHIQ_SUCCESS) {
    337 					DEBUG_TRACE(SERVICE_CALLBACK_LINE);
    338 					return status;
    339 				}
    340 			}
    341 
    342 			DEBUG_TRACE(SERVICE_CALLBACK_LINE);
    343 			if (down_interruptible(&user_service->remove_event)
    344 				!= 0) {
    345 				vchiq_log_info(vchiq_arm_log_level,
    346 					"service_callback interrupted");
    347 				DEBUG_TRACE(SERVICE_CALLBACK_LINE);
    348 				return VCHIQ_RETRY;
    349 			} else if (instance->closing) {
    350 				vchiq_log_info(vchiq_arm_log_level,
    351 					"service_callback closing");
    352 				DEBUG_TRACE(SERVICE_CALLBACK_LINE);
    353 				return VCHIQ_ERROR;
    354 			}
    355 			DEBUG_TRACE(SERVICE_CALLBACK_LINE);
    356 			spin_lock(&msg_queue_spinlock);
    357 		}
    358 
    359 		user_service->msg_queue[user_service->msg_insert &
    360 			(MSG_QUEUE_SIZE - 1)] = header;
    361 		user_service->msg_insert++;
    362 		spin_unlock(&msg_queue_spinlock);
    363 
    364 		up(&user_service->insert_event);
    365 
    366 		/* If there is a thread waiting in DEQUEUE_MESSAGE, or if
    367 		** there is a MESSAGE_AVAILABLE in the completion queue then
    368 		** bypass the completion queue.
    369 		*/
    370 		if (((user_service->message_available_pos -
    371 			instance->completion_remove) >= 0) ||
    372 			user_service->dequeue_pending) {
    373 			DEBUG_TRACE(SERVICE_CALLBACK_LINE);
    374 			user_service->dequeue_pending = 0;
    375 			return VCHIQ_SUCCESS;
    376 		}
    377 
    378 		header = NULL;
    379 	}
    380 	DEBUG_TRACE(SERVICE_CALLBACK_LINE);
    381 
    382 	return add_completion(instance, reason, header, user_service,
    383 		bulk_userdata);
    384 }
    385 
    386 /****************************************************************************
    387 *
    388 *   user_service_free
    389 *
    390 ***************************************************************************/
    391 static void
    392 user_service_free(void *userdata)
    393 {
    394 	USER_SERVICE_T *user_service = userdata;
    395 
    396 	_sema_destroy(&user_service->insert_event);
    397 	_sema_destroy(&user_service->remove_event);
    398 
    399 	kfree(user_service);
    400 }
    401 
    402 /****************************************************************************
    403 *
    404 *   vchiq_ioctl
    405 *
    406 ***************************************************************************/
    407 
    408 static int
    409 vchiq_ioctl(struct file *fp, u_long cmd, void *arg)
    410 {
    411 	VCHIQ_INSTANCE_T instance;
    412 	VCHIQ_STATUS_T status = VCHIQ_SUCCESS;
    413 	VCHIQ_SERVICE_T *service = NULL;
    414 	int ret = 0;
    415 	int i, rc;
    416 	DEBUG_INITIALISE(g_state.local)
    417 
    418 	instance = fp->f_data;
    419 
    420 /* XXXBSD: HACK! */
    421 #define _IOC_NR(x) ((x) & 0xff)
    422 #define	_IOC_TYPE(x)	IOCGROUP(x)
    423 
    424 	vchiq_log_trace(vchiq_arm_log_level,
    425 		 "vchiq_ioctl - instance %x, cmd %s, arg %p",
    426 		(unsigned int)instance,
    427 		((_IOC_TYPE(cmd) == VCHIQ_IOC_MAGIC) &&
    428 		(_IOC_NR(cmd) <= VCHIQ_IOC_MAX)) ?
    429 		ioctl_names[_IOC_NR(cmd)] : "<invalid>", arg);
    430 
    431 	switch (cmd) {
    432 	case VCHIQ_IOC_SHUTDOWN:
    433 		if (!instance->connected)
    434 			break;
    435 
    436 		/* Remove all services */
    437 		i = 0;
    438 		while ((service = next_service_by_instance(instance->state,
    439 			instance, &i)) != NULL) {
    440 			status = vchiq_remove_service(service->handle);
    441 			unlock_service(service);
    442 			if (status != VCHIQ_SUCCESS)
    443 				break;
    444 		}
    445 		service = NULL;
    446 
    447 		if (status == VCHIQ_SUCCESS) {
    448 			/* Wake the completion thread and ask it to exit */
    449 			instance->closing = 1;
    450 			up(&instance->insert_event);
    451 		}
    452 
    453 		break;
    454 
    455 	case VCHIQ_IOC_CONNECT:
    456 		if (instance->connected) {
    457 			ret = -EINVAL;
    458 			break;
    459 		}
    460 		rc = lmutex_lock_interruptible(&instance->state->mutex);
    461 		if (rc != 0) {
    462 			vchiq_log_error(vchiq_arm_log_level,
    463 				"vchiq: connect: could not lock mutex for "
    464 				"state %d: %d",
    465 				instance->state->id, rc);
    466 			ret = -EINTR;
    467 			break;
    468 		}
    469 		status = vchiq_connect_internal(instance->state, instance);
    470 		lmutex_unlock(&instance->state->mutex);
    471 
    472 		if (status == VCHIQ_SUCCESS)
    473 			instance->connected = 1;
    474 		else
    475 			vchiq_log_error(vchiq_arm_log_level,
    476 				"vchiq: could not connect: %d", status);
    477 		break;
    478 
    479 	case VCHIQ_IOC_CREATE_SERVICE: {
    480 		VCHIQ_CREATE_SERVICE_T *pargs = arg;
    481 		USER_SERVICE_T *user_service = NULL;
    482 		void *userdata;
    483 		int srvstate;
    484 
    485 		user_service = kzalloc(sizeof(USER_SERVICE_T), GFP_KERNEL);
    486 		if (!user_service) {
    487 			ret = -ENOMEM;
    488 			break;
    489 		}
    490 
    491 		if (pargs->is_open) {
    492 			if (!instance->connected) {
    493 				ret = -ENOTCONN;
    494 				kfree(user_service);
    495 				break;
    496 			}
    497 			srvstate = VCHIQ_SRVSTATE_OPENING;
    498 		} else {
    499 			srvstate =
    500 				 instance->connected ?
    501 				 VCHIQ_SRVSTATE_LISTENING :
    502 				 VCHIQ_SRVSTATE_HIDDEN;
    503 		}
    504 
    505 		userdata = pargs->params.userdata;
    506 		pargs->params.callback = service_callback;
    507 		pargs->params.userdata = user_service;
    508 		service = vchiq_add_service_internal(
    509 				instance->state,
    510 				&pargs->params, srvstate,
    511 				instance, user_service_free);
    512 
    513 		if (service != NULL) {
    514 			user_service->service = service;
    515 			user_service->userdata = userdata;
    516 			user_service->instance = instance;
    517 			user_service->is_vchi = pargs->is_vchi;
    518 			user_service->dequeue_pending = 0;
    519 			user_service->message_available_pos =
    520 				instance->completion_remove - 1;
    521 			user_service->msg_insert = 0;
    522 			user_service->msg_remove = 0;
    523 			_sema_init(&user_service->insert_event, 0);
    524 			_sema_init(&user_service->remove_event, 0);
    525 
    526 			if (pargs->is_open) {
    527 				status = vchiq_open_service_internal
    528 					(service, (uintptr_t)instance->l);
    529 				if (status != VCHIQ_SUCCESS) {
    530 					vchiq_remove_service(service->handle);
    531 					service = NULL;
    532 					ret = (status == VCHIQ_RETRY) ?
    533 						-EINTR : -EIO;
    534 					break;
    535 				}
    536 			}
    537 
    538 #ifdef VCHIQ_IOCTL_DEBUG
    539 			printf("%s: [CREATE SERVICE] handle = %08x\n", __func__, service->handle);
    540 #endif
    541 			pargs->handle = service->handle;
    542 
    543 			service = NULL;
    544 		} else {
    545 			ret = -EEXIST;
    546 			kfree(user_service);
    547 		}
    548 	} break;
    549 
    550 	case VCHIQ_IOC_CLOSE_SERVICE: {
    551 		VCHIQ_SERVICE_HANDLE_T handle = *(VCHIQ_SERVICE_HANDLE_T *)arg;
    552 
    553 #ifdef VCHIQ_IOCTL_DEBUG
    554 		printf("%s: [CLOSE SERVICE] handle = %08x\n", __func__, handle);
    555 #endif
    556 
    557 		service = find_service_for_instance(instance, handle);
    558 		if (service != NULL)
    559 			status = vchiq_close_service(service->handle);
    560 		else
    561 			ret = -EINVAL;
    562 	} break;
    563 
    564 	case VCHIQ_IOC_REMOVE_SERVICE: {
    565 		VCHIQ_SERVICE_HANDLE_T handle = *(VCHIQ_SERVICE_HANDLE_T *)arg;
    566 
    567 #ifdef VCHIQ_IOCTL_DEBUG
    568 		printf("%s: [REMOVE SERVICE] handle = %08x\n", __func__, handle);
    569 #endif
    570 
    571 		service = find_service_for_instance(instance, handle);
    572 		if (service != NULL)
    573 			status = vchiq_remove_service(service->handle);
    574 		else
    575 			ret = -EINVAL;
    576 	} break;
    577 
    578 	case VCHIQ_IOC_USE_SERVICE:
    579 	case VCHIQ_IOC_RELEASE_SERVICE:	{
    580 		VCHIQ_SERVICE_HANDLE_T handle = *(VCHIQ_SERVICE_HANDLE_T *)arg;
    581 
    582 #ifdef VCHIQ_IOCTL_DEBUG
    583 		printf("%s: [%s SERVICE] handle = %08x\n", __func__,
    584 		    cmd == VCHIQ_IOC_USE_SERVICE ? "USE" : "RELEASE", handle);
    585 #endif
    586 
    587 		service = find_service_for_instance(instance, handle);
    588 		if (service != NULL) {
    589 			status = (cmd == VCHIQ_IOC_USE_SERVICE)	?
    590 				vchiq_use_service_internal(service) :
    591 				vchiq_release_service_internal(service);
    592 			if (status != VCHIQ_SUCCESS) {
    593 				vchiq_log_error(vchiq_susp_log_level,
    594 					"%s: cmd %s returned error %d for "
    595 					"service %c%c%c%c:%8x",
    596 					__func__,
    597 					(cmd == VCHIQ_IOC_USE_SERVICE) ?
    598 						"VCHIQ_IOC_USE_SERVICE" :
    599 						"VCHIQ_IOC_RELEASE_SERVICE",
    600 					status,
    601 					VCHIQ_FOURCC_AS_4CHARS(
    602 						service->base.fourcc),
    603 					service->client_id);
    604 				ret = -EINVAL;
    605 			}
    606 		} else
    607 			ret = -EINVAL;
    608 	} break;
    609 
    610 	case VCHIQ_IOC_QUEUE_MESSAGE: {
    611 		VCHIQ_QUEUE_MESSAGE_T *pargs = arg;
    612 
    613 #ifdef VCHIQ_IOCTL_DEBUG
    614 		printf("%s: [QUEUE MESSAGE] handle = %08x\n", __func__, pargs->handle);
    615 #endif
    616 
    617 		service = find_service_for_instance(instance, pargs->handle);
    618 
    619 		if ((service != NULL) && (pargs->count <= MAX_ELEMENTS)) {
    620 			/* Copy elements into kernel space */
    621 			VCHIQ_ELEMENT_T elements[MAX_ELEMENTS];
    622 			if (copy_from_user(elements, pargs->elements,
    623 				pargs->count * sizeof(VCHIQ_ELEMENT_T)) == 0)
    624 				status = vchiq_queue_message
    625 					(pargs->handle,
    626 					elements, pargs->count);
    627 			else
    628 				ret = -EFAULT;
    629 		} else {
    630 			ret = -EINVAL;
    631 		}
    632 	} break;
    633 
    634 	case VCHIQ_IOC_QUEUE_BULK_TRANSMIT:
    635 	case VCHIQ_IOC_QUEUE_BULK_RECEIVE: {
    636 		VCHIQ_QUEUE_BULK_TRANSFER_T *pargs = arg;
    637 		struct bulk_waiter_node *waiter = NULL;
    638 		VCHIQ_BULK_DIR_T dir =
    639 			(cmd == VCHIQ_IOC_QUEUE_BULK_TRANSMIT) ?
    640 			VCHIQ_BULK_TRANSMIT : VCHIQ_BULK_RECEIVE;
    641 
    642 		service = find_service_for_instance(instance, pargs->handle);
    643 		if (!service) {
    644 			ret = -EINVAL;
    645 			break;
    646 		}
    647 
    648 		if (pargs->mode == VCHIQ_BULK_MODE_BLOCKING) {
    649 			waiter = kzalloc(sizeof(struct bulk_waiter_node),
    650 				GFP_KERNEL);
    651 			if (!waiter) {
    652 				ret = -ENOMEM;
    653 				break;
    654 			}
    655 			pargs->userdata = &waiter->bulk_waiter;
    656 		} else if (pargs->mode == VCHIQ_BULK_MODE_WAITING) {
    657 			struct list_head *pos;
    658 			lmutex_lock(&instance->bulk_waiter_list_mutex);
    659 			list_for_each(pos, &instance->bulk_waiter_list) {
    660 				if (list_entry(pos, struct bulk_waiter_node,
    661 					list)->l == current) {
    662 					waiter = list_entry(pos,
    663 						struct bulk_waiter_node,
    664 						list);
    665 					list_del(pos);
    666 					break;
    667 				}
    668 
    669 			}
    670 			lmutex_unlock(&instance->bulk_waiter_list_mutex);
    671 			if (!waiter) {
    672 				vchiq_log_error(vchiq_arm_log_level,
    673 					"no bulk_waiter found for lwp %p",
    674 					current);
    675 				ret = -ESRCH;
    676 				break;
    677 			}
    678 			vchiq_log_info(vchiq_arm_log_level,
    679 				"found bulk_waiter %x for lwp %p",
    680 				(unsigned int)waiter, current);
    681 			pargs->userdata = &waiter->bulk_waiter;
    682 		}
    683 		status = vchiq_bulk_transfer
    684 			(pargs->handle,
    685 			 VCHI_MEM_HANDLE_INVALID,
    686 			 pargs->data, pargs->size,
    687 			 pargs->userdata, pargs->mode,
    688 			 dir);
    689 		if (!waiter)
    690 			break;
    691 		if ((status != VCHIQ_RETRY) || fatal_signal_pending(current) ||
    692 			!waiter->bulk_waiter.bulk) {
    693 			if (waiter->bulk_waiter.bulk) {
    694 				/* Cancel the signal when the transfer
    695 				** completes. */
    696 				spin_lock(&bulk_waiter_spinlock);
    697 				waiter->bulk_waiter.bulk->userdata = NULL;
    698 				spin_unlock(&bulk_waiter_spinlock);
    699 			}
    700 			_sema_destroy(&waiter->bulk_waiter.event);
    701 			kfree(waiter);
    702 		} else {
    703 			const VCHIQ_BULK_MODE_T mode_waiting =
    704 				VCHIQ_BULK_MODE_WAITING;
    705 			waiter->l = current;
    706 			lmutex_lock(&instance->bulk_waiter_list_mutex);
    707 			list_add(&waiter->list, &instance->bulk_waiter_list);
    708 			lmutex_unlock(&instance->bulk_waiter_list_mutex);
    709 			vchiq_log_info(vchiq_arm_log_level,
    710 				"saved bulk_waiter %x for lwp %p",
    711 				(unsigned int)waiter, current);
    712 
    713 			pargs->mode = mode_waiting;
    714 		}
    715 	} break;
    716 
    717 	case VCHIQ_IOC_AWAIT_COMPLETION: {
    718 		VCHIQ_AWAIT_COMPLETION_T *pargs = arg;
    719 
    720 		DEBUG_TRACE(AWAIT_COMPLETION_LINE);
    721 		if (!instance->connected) {
    722 			ret = -ENOTCONN;
    723 			break;
    724 		}
    725 
    726 		lmutex_lock(&instance->completion_mutex);
    727 
    728 		DEBUG_TRACE(AWAIT_COMPLETION_LINE);
    729 		while ((instance->completion_remove ==
    730 			instance->completion_insert)
    731 			&& !instance->closing) {
    732 			DEBUG_TRACE(AWAIT_COMPLETION_LINE);
    733 			lmutex_unlock(&instance->completion_mutex);
    734 			rc = down_interruptible(&instance->insert_event);
    735 			lmutex_lock(&instance->completion_mutex);
    736 			if (rc != 0) {
    737 				DEBUG_TRACE(AWAIT_COMPLETION_LINE);
    738 				vchiq_log_info(vchiq_arm_log_level,
    739 					"AWAIT_COMPLETION interrupted");
    740 				ret = -EINTR;
    741 				break;
    742 			}
    743 		}
    744 		DEBUG_TRACE(AWAIT_COMPLETION_LINE);
    745 
    746 		/* A read memory barrier is needed to stop prefetch of a stale
    747 		** completion record
    748 		*/
    749 		rmb();
    750 
    751 		if (ret == 0) {
    752 			int msgbufcount = pargs->msgbufcount;
    753 			int count;
    754 
    755 			for (count = 0; count < pargs->count; count++) {
    756 				VCHIQ_COMPLETION_DATA_T *completion;
    757 				VCHIQ_SERVICE_T *service1;
    758 				USER_SERVICE_T *user_service;
    759 				VCHIQ_HEADER_T *header;
    760 				if (instance->completion_remove ==
    761 					instance->completion_insert)
    762 					break;
    763 				completion = &instance->completions[
    764 					instance->completion_remove &
    765 					(MAX_COMPLETIONS - 1)];
    766 
    767 				service1 = completion->service_userdata;
    768 				user_service = service1->base.userdata;
    769 				completion->service_userdata =
    770 					user_service->userdata;
    771 
    772 				header = completion->header;
    773 				if (header) {
    774 					void __user *msgbuf;
    775 					int msglen;
    776 
    777 					msglen = header->size +
    778 						sizeof(VCHIQ_HEADER_T);
    779 					/* This must be a VCHIQ-style service */
    780 					if (pargs->msgbufsize < msglen) {
    781 						vchiq_log_error(
    782 							vchiq_arm_log_level,
    783 							"header %x: msgbufsize"
    784 							" %x < msglen %x",
    785 							(unsigned int)header,
    786 							pargs->msgbufsize,
    787 							msglen);
    788 						WARN(1, "invalid message "
    789 							"size\n");
    790 						if (count == 0)
    791 							ret = -EMSGSIZE;
    792 						break;
    793 					}
    794 					if (msgbufcount <= 0)
    795 						/* Stall here for lack of a
    796 						** buffer for the message. */
    797 						break;
    798 					/* Get the pointer from user space */
    799 					msgbufcount--;
    800 					if (copy_from_user(&msgbuf,
    801 						(const void __user *)
    802 						&pargs->msgbufs[msgbufcount],
    803 						sizeof(msgbuf)) != 0) {
    804 						if (count == 0)
    805 							ret = -EFAULT;
    806 						break;
    807 					}
    808 
    809 					/* Copy the message to user space */
    810 					if (copy_to_user(msgbuf, header,
    811 						msglen) != 0) {
    812 						if (count == 0)
    813 							ret = -EFAULT;
    814 						break;
    815 					}
    816 
    817 					/* Now it has been copied, the message
    818 					** can be released. */
    819 					vchiq_release_message(service1->handle,
    820 						header);
    821 
    822 					/* The completion must point to the
    823 					** msgbuf. */
    824 					completion->header = msgbuf;
    825 				}
    826 
    827 				if (completion->reason ==
    828 					VCHIQ_SERVICE_CLOSED)
    829 					unlock_service(service1);
    830 
    831 				if (copy_to_user((void __user *)(
    832 					(size_t)pargs->buf +
    833 					count * sizeof(VCHIQ_COMPLETION_DATA_T)),
    834 					completion,
    835 					sizeof(VCHIQ_COMPLETION_DATA_T)) != 0) {
    836 						if (count == 0)
    837 							ret = -EFAULT;
    838 					break;
    839 				}
    840 
    841 				instance->completion_remove++;
    842 			}
    843 
    844 			pargs->msgbufcount = msgbufcount;
    845 			pargs->count = count;
    846 		}
    847 
    848 		if (ret != 0)
    849 			up(&instance->remove_event);
    850 		lmutex_unlock(&instance->completion_mutex);
    851 		DEBUG_TRACE(AWAIT_COMPLETION_LINE);
    852 	} break;
    853 
    854 	case VCHIQ_IOC_DEQUEUE_MESSAGE: {
    855 		VCHIQ_DEQUEUE_MESSAGE_T *pargs = arg;
    856 		USER_SERVICE_T *user_service;
    857 		VCHIQ_HEADER_T *header;
    858 
    859 		DEBUG_TRACE(DEQUEUE_MESSAGE_LINE);
    860 		service = find_service_for_instance(instance, pargs->handle);
    861 		if (!service) {
    862 			ret = -EINVAL;
    863 			break;
    864 		}
    865 		user_service = (USER_SERVICE_T *)service->base.userdata;
    866 		if (user_service->is_vchi == 0) {
    867 			ret = -EINVAL;
    868 			break;
    869 		}
    870 
    871 		spin_lock(&msg_queue_spinlock);
    872 		if (user_service->msg_remove == user_service->msg_insert) {
    873 			if (!pargs->blocking) {
    874 				spin_unlock(&msg_queue_spinlock);
    875 				DEBUG_TRACE(DEQUEUE_MESSAGE_LINE);
    876 				ret = -EWOULDBLOCK;
    877 				break;
    878 			}
    879 			user_service->dequeue_pending = 1;
    880 			do {
    881 				spin_unlock(&msg_queue_spinlock);
    882 				DEBUG_TRACE(DEQUEUE_MESSAGE_LINE);
    883 				if (down_interruptible(
    884 					&user_service->insert_event) != 0) {
    885 					vchiq_log_info(vchiq_arm_log_level,
    886 						"DEQUEUE_MESSAGE interrupted");
    887 					ret = -EINTR;
    888 					break;
    889 				}
    890 				spin_lock(&msg_queue_spinlock);
    891 			} while (user_service->msg_remove ==
    892 				user_service->msg_insert);
    893 
    894 			if (ret)
    895 				break;
    896 		}
    897 
    898 		BUG_ON((int)(user_service->msg_insert -
    899 			user_service->msg_remove) < 0);
    900 
    901 		header = user_service->msg_queue[user_service->msg_remove &
    902 			(MSG_QUEUE_SIZE - 1)];
    903 		user_service->msg_remove++;
    904 		spin_unlock(&msg_queue_spinlock);
    905 
    906 		up(&user_service->remove_event);
    907 		if (header == NULL)
    908 			ret = -ENOTCONN;
    909 		else if (header->size <= pargs->bufsize) {
    910 			/* Copy to user space if msgbuf is not NULL */
    911 			if ((pargs->buf == NULL) ||
    912 				(copy_to_user((void __user *)pargs->buf,
    913 				header->data,
    914 				header->size) == 0)) {
    915 				pargs->bufsize = header->size;
    916 				vchiq_release_message(
    917 					service->handle,
    918 					header);
    919 			} else
    920 				ret = -EFAULT;
    921 		} else {
    922 			vchiq_log_error(vchiq_arm_log_level,
    923 				"header %x: bufsize %x < size %x",
    924 				(unsigned int)header, pargs->bufsize,
    925 				header->size);
    926 			WARN(1, "invalid size\n");
    927 			ret = -EMSGSIZE;
    928 		}
    929 		DEBUG_TRACE(DEQUEUE_MESSAGE_LINE);
    930 	} break;
    931 
    932 	case VCHIQ_IOC_GET_CLIENT_ID: {
    933 		VCHIQ_SERVICE_HANDLE_T handle = (VCHIQ_SERVICE_HANDLE_T)arg;
    934 
    935 		ret = vchiq_get_client_id(handle);
    936 	} break;
    937 
    938 	case VCHIQ_IOC_GET_CONFIG: {
    939 		VCHIQ_GET_CONFIG_T *pargs = arg;
    940 		VCHIQ_CONFIG_T config;
    941 
    942 		if (pargs->config_size > sizeof(config)) {
    943 			ret = -EINVAL;
    944 			break;
    945 		}
    946 		status = vchiq_get_config(instance, pargs->config_size, &config);
    947 		if (status == VCHIQ_SUCCESS) {
    948 			if (copy_to_user((void __user *)pargs->pconfig,
    949 				&config, pargs->config_size) != 0) {
    950 				ret = -EFAULT;
    951 				break;
    952 			}
    953 		}
    954 	} break;
    955 
    956 	case VCHIQ_IOC_SET_SERVICE_OPTION: {
    957 		VCHIQ_SET_SERVICE_OPTION_T *pargs = arg;
    958 
    959 		service = find_service_for_instance(instance, pargs->handle);
    960 		if (!service) {
    961 			ret = -EINVAL;
    962 			break;
    963 		}
    964 
    965 		status = vchiq_set_service_option(
    966 				pargs->handle, pargs->option, pargs->value);
    967 	} break;
    968 
    969 	case VCHIQ_IOC_DUMP_PHYS_MEM: {
    970 #if 0
    971 		VCHIQ_DUMP_MEM_T *pargs = arg;
    972 #endif
    973 
    974 		printf("IMPLEMENT ME: %s:%d\n", __FILE__, __LINE__);
    975 #if 0
    976 		dump_phys_mem(pargs->virt_addr, pargs->num_bytes);
    977 #endif
    978 	} break;
    979 
    980 	default:
    981 		ret = -ENOTTY;
    982 		break;
    983 	}
    984 
    985 	if (service)
    986 		unlock_service(service);
    987 
    988 	if (ret == 0) {
    989 		if (status == VCHIQ_ERROR)
    990 			ret = -EIO;
    991 		else if (status == VCHIQ_RETRY)
    992 			ret = -EINTR;
    993 	}
    994 
    995 	if ((status == VCHIQ_SUCCESS) && (ret < 0) && (ret != -EINTR) &&
    996 		(ret != -EWOULDBLOCK))
    997 		vchiq_log_info(vchiq_arm_log_level,
    998 			"  ioctl instance %lx, cmd %s -> status %d, %d",
    999 			(unsigned long)instance,
   1000 			(_IOC_NR(cmd) <= VCHIQ_IOC_MAX) ?
   1001 				ioctl_names[_IOC_NR(cmd)] :
   1002 				"<invalid>",
   1003 			status, ret);
   1004 	else
   1005 		vchiq_log_trace(vchiq_arm_log_level,
   1006 			"  ioctl instance %lx, cmd %s -> status %d, %d",
   1007 			(unsigned long)instance,
   1008 			(_IOC_NR(cmd) <= VCHIQ_IOC_MAX) ?
   1009 				ioctl_names[_IOC_NR(cmd)] :
   1010 				"<invalid>",
   1011 			status, ret);
   1012 
   1013 	/* XXXBSD: report BSD-style error to userland */
   1014 	if (ret < 0)
   1015 		ret = -ret;
   1016 
   1017 	return ret;
   1018 }
   1019 
   1020 #if notyet
   1021 static void
   1022 instance_dtr(void *data)
   1023 {
   1024 
   1025    free(data, M_VCHIQ);
   1026 }
   1027 #endif
   1028 
   1029 /****************************************************************************
   1030 *
   1031 *   vchiq_open
   1032 *
   1033 ***************************************************************************/
   1034 
   1035 static int
   1036 vchiq_open(dev_t dev, int flags, int mode, lwp_t *l)
   1037 {
   1038 	VCHIQ_INSTANCE_T instance = NULL;
   1039 	struct file *fp;
   1040 	int err, fd;
   1041 
   1042 	vchiq_log_info(vchiq_arm_log_level, "vchiq_open");
   1043 
   1044 	/* XXXBSD: do we really need this check? */
   1045 	if (device_lookup_private(&vchiq_cd, minor(dev)) != NULL) {
   1046 		VCHIQ_STATE_T *state = vchiq_get_state();
   1047 
   1048 		if (!state) {
   1049 			vchiq_log_error(vchiq_arm_log_level,
   1050 				"vchiq has no connection to VideoCore");
   1051 			return -ENOTCONN;
   1052 		}
   1053 
   1054 		instance = kzalloc(sizeof(*instance), GFP_KERNEL);
   1055 		if (!instance)
   1056 			return -ENOMEM;
   1057 
   1058 		err = fd_allocfile(&fp, &fd);
   1059 		if (err) {
   1060 			kfree(instance);
   1061 			return -err;
   1062 		}
   1063 
   1064 		instance->state = state;
   1065 		instance->l = l;
   1066 
   1067 #ifdef notyet
   1068 		ret = vchiq_proc_add_instance(instance);
   1069 		if (ret != 0) {
   1070 			kfree(instance);
   1071 			return ret;
   1072 		}
   1073 #endif
   1074 
   1075 		_sema_init(&instance->insert_event, 0);
   1076 		_sema_init(&instance->remove_event, 0);
   1077 		lmutex_init(&instance->completion_mutex);
   1078 		lmutex_init(&instance->bulk_waiter_list_mutex);
   1079 		INIT_LIST_HEAD(&instance->bulk_waiter_list);
   1080 
   1081 	}
   1082 	else {
   1083 		vchiq_log_error(vchiq_arm_log_level,
   1084 			"Unknown minor device");
   1085 		return -ENXIO;
   1086 	}
   1087 
   1088 	return fd_clone(fp, fd, flags, &vchiq_fileops, instance);
   1089 }
   1090 
   1091 /****************************************************************************
   1092 *
   1093 *   vchiq_release
   1094 *
   1095 ***************************************************************************/
   1096 
   1097 static int
   1098 vchiq_close(struct file *fp)
   1099 {
   1100 	int ret = 0;
   1101 	if (1) {
   1102 		VCHIQ_INSTANCE_T instance;
   1103 		VCHIQ_STATE_T *state = vchiq_get_state();
   1104 		VCHIQ_SERVICE_T *service;
   1105 		int i;
   1106 
   1107 		instance = fp->f_data;
   1108 
   1109 		vchiq_log_info(vchiq_arm_log_level,
   1110 			"vchiq_release: instance=%lx",
   1111 			(unsigned long)instance);
   1112 
   1113 		if (!state) {
   1114 			ret = -EPERM;
   1115 			goto out;
   1116 		}
   1117 
   1118 		/* Ensure videocore is awake to allow termination. */
   1119 		vchiq_use_internal(instance->state, NULL,
   1120 				USE_TYPE_VCHIQ);
   1121 
   1122 		lmutex_lock(&instance->completion_mutex);
   1123 
   1124 		/* Wake the completion thread and ask it to exit */
   1125 		instance->closing = 1;
   1126 		up(&instance->insert_event);
   1127 
   1128 		lmutex_unlock(&instance->completion_mutex);
   1129 
   1130 		/* Wake the slot handler if the completion queue is full. */
   1131 		up(&instance->remove_event);
   1132 
   1133 		/* Mark all services for termination... */
   1134 		i = 0;
   1135 		while ((service = next_service_by_instance(state, instance,
   1136 			&i)) !=	NULL) {
   1137 			USER_SERVICE_T *user_service = service->base.userdata;
   1138 
   1139 			/* Wake the slot handler if the msg queue is full. */
   1140 			up(&user_service->remove_event);
   1141 
   1142 			vchiq_terminate_service_internal(service);
   1143 			unlock_service(service);
   1144 		}
   1145 
   1146 		/* ...and wait for them to die */
   1147 		i = 0;
   1148 		while ((service = next_service_by_instance(state, instance, &i))
   1149 			!= NULL) {
   1150 			USER_SERVICE_T *user_service = service->base.userdata;
   1151 
   1152 			down(&service->remove_event);
   1153 
   1154 			BUG_ON(service->srvstate != VCHIQ_SRVSTATE_FREE);
   1155 
   1156 			spin_lock(&msg_queue_spinlock);
   1157 
   1158 			while (user_service->msg_remove !=
   1159 				user_service->msg_insert) {
   1160 				VCHIQ_HEADER_T *header = user_service->
   1161 					msg_queue[user_service->msg_remove &
   1162 						(MSG_QUEUE_SIZE - 1)];
   1163 				user_service->msg_remove++;
   1164 				spin_unlock(&msg_queue_spinlock);
   1165 
   1166 				if (header)
   1167 					vchiq_release_message(
   1168 						service->handle,
   1169 						header);
   1170 				spin_lock(&msg_queue_spinlock);
   1171 			}
   1172 
   1173 			spin_unlock(&msg_queue_spinlock);
   1174 
   1175 			unlock_service(service);
   1176 		}
   1177 
   1178 		/* Release any closed services */
   1179 		while (instance->completion_remove !=
   1180 			instance->completion_insert) {
   1181 			VCHIQ_COMPLETION_DATA_T *completion;
   1182 			VCHIQ_SERVICE_T *service1;
   1183 			completion = &instance->completions[
   1184 				instance->completion_remove &
   1185 				(MAX_COMPLETIONS - 1)];
   1186 			service1 = completion->service_userdata;
   1187 			if (completion->reason == VCHIQ_SERVICE_CLOSED)
   1188 				unlock_service(service1);
   1189 			instance->completion_remove++;
   1190 		}
   1191 
   1192 		/* Release the PEER service count. */
   1193 		vchiq_release_internal(instance->state, NULL);
   1194 
   1195 		{
   1196 			struct list_head *pos, *next;
   1197 			list_for_each_safe(pos, next,
   1198 				&instance->bulk_waiter_list) {
   1199 				struct bulk_waiter_node *waiter;
   1200 				waiter = list_entry(pos,
   1201 					struct bulk_waiter_node,
   1202 					list);
   1203 				list_del(pos);
   1204 				vchiq_log_info(vchiq_arm_log_level,
   1205 					"bulk_waiter - cleaned up %x "
   1206 					"for lwp %p",
   1207 					(unsigned int)waiter, waiter->l);
   1208 		                _sema_destroy(&waiter->bulk_waiter.event);
   1209 				kfree(waiter);
   1210 			}
   1211 		}
   1212 
   1213 	}
   1214 	else {
   1215 		vchiq_log_error(vchiq_arm_log_level,
   1216 			"Unknown minor device");
   1217 		ret = -ENXIO;
   1218 	}
   1219 
   1220 out:
   1221 	return ret;
   1222 }
   1223 
   1224 /****************************************************************************
   1225 *
   1226 *   vchiq_dump
   1227 *
   1228 ***************************************************************************/
   1229 
   1230 void
   1231 vchiq_dump(void *dump_context, const char *str, int len)
   1232 {
   1233 	DUMP_CONTEXT_T *context = (DUMP_CONTEXT_T *)dump_context;
   1234 
   1235 	if (context->actual < context->space) {
   1236 		int copy_bytes;
   1237 		if (context->offset > 0) {
   1238 			int skip_bytes = min(len, (int)context->offset);
   1239 			str += skip_bytes;
   1240 			len -= skip_bytes;
   1241 			context->offset -= skip_bytes;
   1242 			if (context->offset > 0)
   1243 				return;
   1244 		}
   1245 		copy_bytes = min(len, (int)(context->space - context->actual));
   1246 		if (copy_bytes == 0)
   1247 			return;
   1248 		if (copy_to_user(context->buf + context->actual, str,
   1249 			copy_bytes))
   1250 			context->actual = -EFAULT;
   1251 		context->actual += copy_bytes;
   1252 		len -= copy_bytes;
   1253 
   1254 		/* If tne terminating NUL is included in the length, then it
   1255 		** marks the end of a line and should be replaced with a
   1256 		** carriage return. */
   1257 		if ((len == 0) && (str[copy_bytes - 1] == '\0')) {
   1258 			char cr = '\n';
   1259 			if (copy_to_user(context->buf + context->actual - 1,
   1260 				&cr, 1))
   1261 				context->actual = -EFAULT;
   1262 		}
   1263 	}
   1264 }
   1265 
   1266 /****************************************************************************
   1267 *
   1268 *   vchiq_dump_platform_instance_state
   1269 *
   1270 ***************************************************************************/
   1271 
   1272 void
   1273 vchiq_dump_platform_instances(void *dump_context)
   1274 {
   1275 	VCHIQ_STATE_T *state = vchiq_get_state();
   1276 	char buf[80];
   1277 	int len;
   1278 	int i;
   1279 
   1280 	/* There is no list of instances, so instead scan all services,
   1281 		marking those that have been dumped. */
   1282 
   1283 	for (i = 0; i < state->unused_service; i++) {
   1284 		VCHIQ_SERVICE_T *service = state->services[i];
   1285 		VCHIQ_INSTANCE_T instance;
   1286 
   1287 		if (service && (service->base.callback == service_callback)) {
   1288 			instance = service->instance;
   1289 			if (instance)
   1290 				instance->mark = 0;
   1291 		}
   1292 	}
   1293 
   1294 	for (i = 0; i < state->unused_service; i++) {
   1295 		VCHIQ_SERVICE_T *service = state->services[i];
   1296 		VCHIQ_INSTANCE_T instance;
   1297 
   1298 		if (service && (service->base.callback == service_callback)) {
   1299 			instance = service->instance;
   1300 			if (instance && !instance->mark) {
   1301 				len = snprintf(buf, sizeof(buf),
   1302 					"Instance %x: lwp %p,%s completions "
   1303 						"%d/%d",
   1304 					(unsigned int)instance, instance->l,
   1305 					instance->connected ? " connected, " :
   1306 						"",
   1307 					instance->completion_insert -
   1308 						instance->completion_remove,
   1309 					MAX_COMPLETIONS);
   1310 
   1311 				vchiq_dump(dump_context, buf, len + 1);
   1312 
   1313 				instance->mark = 1;
   1314 			}
   1315 		}
   1316 	}
   1317 }
   1318 
   1319 /****************************************************************************
   1320 *
   1321 *   vchiq_dump_platform_service_state
   1322 *
   1323 ***************************************************************************/
   1324 
   1325 void
   1326 vchiq_dump_platform_service_state(void *dump_context, VCHIQ_SERVICE_T *service)
   1327 {
   1328 	USER_SERVICE_T *user_service = (USER_SERVICE_T *)service->base.userdata;
   1329 	char buf[80];
   1330 	int len;
   1331 
   1332 	len = snprintf(buf, sizeof(buf), "  instance %x",
   1333 		(unsigned int)service->instance);
   1334 
   1335 	if ((service->base.callback == service_callback) &&
   1336 		user_service->is_vchi) {
   1337 		len += snprintf(buf + len, sizeof(buf) - len,
   1338 			", %d/%d messages",
   1339 			user_service->msg_insert - user_service->msg_remove,
   1340 			MSG_QUEUE_SIZE);
   1341 
   1342 		if (user_service->dequeue_pending)
   1343 			len += snprintf(buf + len, sizeof(buf) - len,
   1344 				" (dequeue pending)");
   1345 	}
   1346 
   1347 	vchiq_dump(dump_context, buf, len + 1);
   1348 }
   1349 
   1350 #ifdef notyet
   1351 /****************************************************************************
   1352 *
   1353 *   dump_user_mem
   1354 *
   1355 ***************************************************************************/
   1356 
   1357 static void
   1358 dump_phys_mem(void *virt_addr, uint32_t num_bytes)
   1359 {
   1360 	int            rc;
   1361 	uint8_t       *end_virt_addr = virt_addr + num_bytes;
   1362 	int            num_pages;
   1363 	int            offset;
   1364 	int            end_offset;
   1365 	int            page_idx;
   1366 	int            prev_idx;
   1367 	struct page   *page;
   1368 	struct page  **pages;
   1369 	uint8_t       *kmapped_virt_ptr;
   1370 
   1371 	/* Align virtAddr and endVirtAddr to 16 byte boundaries. */
   1372 
   1373 	virt_addr = (void *)((unsigned long)virt_addr & ~0x0fuL);
   1374 	end_virt_addr = (void *)(((unsigned long)end_virt_addr + 15uL) &
   1375 		~0x0fuL);
   1376 
   1377 	offset = (int)(long)virt_addr & (PAGE_SIZE - 1);
   1378 	end_offset = (int)(long)end_virt_addr & (PAGE_SIZE - 1);
   1379 
   1380 	num_pages = (offset + num_bytes + PAGE_SIZE - 1) / PAGE_SIZE;
   1381 
   1382 	pages = kmalloc(sizeof(struct page *) * num_pages, GFP_KERNEL);
   1383 	if (pages == NULL) {
   1384 		vchiq_log_error(vchiq_arm_log_level,
   1385 			"Unable to allocation memory for %d pages\n",
   1386 			num_pages);
   1387 		return;
   1388 	}
   1389 
   1390 	down_read(&current->mm->mmap_sem);
   1391 	rc = get_user_pages(current,      /* task */
   1392 		current->mm,              /* mm */
   1393 		(unsigned long)virt_addr, /* start */
   1394 		num_pages,                /* len */
   1395 		0,                        /* write */
   1396 		0,                        /* force */
   1397 		pages,                    /* pages (array of page pointers) */
   1398 		NULL);                    /* vmas */
   1399 	up_read(&current->mm->mmap_sem);
   1400 
   1401 	prev_idx = -1;
   1402 	page = NULL;
   1403 
   1404 	while (offset < end_offset) {
   1405 
   1406 		int page_offset = offset % PAGE_SIZE;
   1407 		page_idx = offset / PAGE_SIZE;
   1408 
   1409 		if (page_idx != prev_idx) {
   1410 
   1411 			if (page != NULL)
   1412 				kunmap(page);
   1413 			page = pages[page_idx];
   1414 			kmapped_virt_ptr = kmap(page);
   1415 
   1416 			prev_idx = page_idx;
   1417 		}
   1418 
   1419 		if (vchiq_arm_log_level >= VCHIQ_LOG_TRACE)
   1420 			vchiq_log_dump_mem("ph",
   1421 				(uint32_t)(unsigned long)&kmapped_virt_ptr[
   1422 					page_offset],
   1423 				&kmapped_virt_ptr[page_offset], 16);
   1424 
   1425 		offset += 16;
   1426 	}
   1427 	if (page != NULL)
   1428 		kunmap(page);
   1429 
   1430 	for (page_idx = 0; page_idx < num_pages; page_idx++)
   1431 		page_cache_release(pages[page_idx]);
   1432 
   1433 	kfree(pages);
   1434 }
   1435 
   1436 /****************************************************************************
   1437 *
   1438 *   vchiq_read
   1439 *
   1440 ***************************************************************************/
   1441 
   1442 static ssize_t
   1443 vchiq_read(struct file *file, char __user *buf,
   1444 	size_t count, loff_t *ppos)
   1445 {
   1446 	DUMP_CONTEXT_T context;
   1447 	context.buf = buf;
   1448 	context.actual = 0;
   1449 	context.space = count;
   1450 	context.offset = *ppos;
   1451 
   1452 	vchiq_dump_state(&context, &g_state);
   1453 
   1454 	*ppos += context.actual;
   1455 
   1456 	return context.actual;
   1457 }
   1458 #endif
   1459 
   1460 VCHIQ_STATE_T *
   1461 vchiq_get_state(void)
   1462 {
   1463 
   1464 	if (g_state.remote == NULL)
   1465 		printk(KERN_ERR "%s: g_state.remote == NULL\n", __func__);
   1466 	else if (g_state.remote->initialised != 1)
   1467 		printk(KERN_NOTICE "%s: g_state.remote->initialised != 1 (%d)\n",
   1468 			__func__, g_state.remote->initialised);
   1469 
   1470 	return ((g_state.remote != NULL) &&
   1471 		(g_state.remote->initialised == 1)) ? &g_state : NULL;
   1472 }
   1473 
   1474 /*
   1475  * Autosuspend related functionality
   1476  */
   1477 
   1478 int
   1479 vchiq_videocore_wanted(VCHIQ_STATE_T *state)
   1480 {
   1481 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
   1482 	if (!arm_state)
   1483 		/* autosuspend not supported - always return wanted */
   1484 		return 1;
   1485 	else if (arm_state->blocked_count)
   1486 		return 1;
   1487 	else if (!arm_state->videocore_use_count)
   1488 		/* usage count zero - check for override unless we're forcing */
   1489 		if (arm_state->resume_blocked)
   1490 			return 0;
   1491 		else
   1492 			return vchiq_platform_videocore_wanted(state);
   1493 	else
   1494 		/* non-zero usage count - videocore still required */
   1495 		return 1;
   1496 }
   1497 
   1498 static VCHIQ_STATUS_T
   1499 vchiq_keepalive_vchiq_callback(VCHIQ_REASON_T reason,
   1500 	VCHIQ_HEADER_T *header,
   1501 	VCHIQ_SERVICE_HANDLE_T service_user,
   1502 	void *bulk_user)
   1503 {
   1504 	vchiq_log_error(vchiq_susp_log_level,
   1505 		"%s callback reason %d", __func__, reason);
   1506 	return 0;
   1507 }
   1508 
   1509 static int
   1510 vchiq_keepalive_thread_func(void *v)
   1511 {
   1512 	VCHIQ_STATE_T *state = (VCHIQ_STATE_T *) v;
   1513 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
   1514 
   1515 	VCHIQ_STATUS_T status;
   1516 	VCHIQ_INSTANCE_T instance;
   1517 	VCHIQ_SERVICE_HANDLE_T ka_handle;
   1518 
   1519 	VCHIQ_SERVICE_PARAMS_T params = {
   1520 		.fourcc      = VCHIQ_MAKE_FOURCC('K', 'E', 'E', 'P'),
   1521 		.callback    = vchiq_keepalive_vchiq_callback,
   1522 		.version     = KEEPALIVE_VER,
   1523 		.version_min = KEEPALIVE_VER_MIN
   1524 	};
   1525 
   1526 	status = vchiq_initialise(&instance);
   1527 	if (status != VCHIQ_SUCCESS) {
   1528 		vchiq_log_error(vchiq_susp_log_level,
   1529 			"%s vchiq_initialise failed %d", __func__, status);
   1530 		goto exit;
   1531 	}
   1532 
   1533 	status = vchiq_connect(instance);
   1534 	if (status != VCHIQ_SUCCESS) {
   1535 		vchiq_log_error(vchiq_susp_log_level,
   1536 			"%s vchiq_connect failed %d", __func__, status);
   1537 		goto shutdown;
   1538 	}
   1539 
   1540 	status = vchiq_add_service(instance, &params, &ka_handle);
   1541 	if (status != VCHIQ_SUCCESS) {
   1542 		vchiq_log_error(vchiq_susp_log_level,
   1543 			"%s vchiq_open_service failed %d", __func__, status);
   1544 		goto shutdown;
   1545 	}
   1546 
   1547 	while (1) {
   1548 		long rc = 0, uc = 0;
   1549 		if (wait_for_completion_interruptible(&arm_state->ka_evt)
   1550 				!= 0) {
   1551 			vchiq_log_error(vchiq_susp_log_level,
   1552 				"%s interrupted", __func__);
   1553 			flush_signals(current);
   1554 			continue;
   1555 		}
   1556 
   1557 		/* read and clear counters.  Do release_count then use_count to
   1558 		 * prevent getting more releases than uses */
   1559 		rc = atomic_xchg(&arm_state->ka_release_count, 0);
   1560 		uc = atomic_xchg(&arm_state->ka_use_count, 0);
   1561 
   1562 		/* Call use/release service the requisite number of times.
   1563 		 * Process use before release so use counts don't go negative */
   1564 		while (uc--) {
   1565 			atomic_inc(&arm_state->ka_use_ack_count);
   1566 			status = vchiq_use_service(ka_handle);
   1567 			if (status != VCHIQ_SUCCESS) {
   1568 				vchiq_log_error(vchiq_susp_log_level,
   1569 					"%s vchiq_use_service error %d",
   1570 					__func__, status);
   1571 			}
   1572 		}
   1573 		while (rc--) {
   1574 			status = vchiq_release_service(ka_handle);
   1575 			if (status != VCHIQ_SUCCESS) {
   1576 				vchiq_log_error(vchiq_susp_log_level,
   1577 					"%s vchiq_release_service error %d",
   1578 					__func__, status);
   1579 			}
   1580 		}
   1581 	}
   1582 
   1583 shutdown:
   1584 	vchiq_shutdown(instance);
   1585 exit:
   1586 	return 0;
   1587 }
   1588 
   1589 VCHIQ_STATUS_T
   1590 vchiq_arm_init_state(VCHIQ_STATE_T *state, VCHIQ_ARM_STATE_T *arm_state)
   1591 {
   1592 	VCHIQ_STATUS_T status = VCHIQ_SUCCESS;
   1593 
   1594 	if (arm_state) {
   1595 		rwlock_init(&arm_state->susp_res_lock);
   1596 
   1597 		init_completion(&arm_state->ka_evt);
   1598 		atomic_set(&arm_state->ka_use_count, 0);
   1599 		atomic_set(&arm_state->ka_use_ack_count, 0);
   1600 		atomic_set(&arm_state->ka_release_count, 0);
   1601 
   1602 		init_completion(&arm_state->vc_suspend_complete);
   1603 
   1604 		init_completion(&arm_state->vc_resume_complete);
   1605 		/* Initialise to 'done' state.  We only want to block on resume
   1606 		 * completion while videocore is suspended. */
   1607 		set_resume_state(arm_state, VC_RESUME_RESUMED);
   1608 
   1609 		init_completion(&arm_state->resume_blocker);
   1610 		/* Initialise to 'done' state.  We only want to block on this
   1611 		 * completion while resume is blocked */
   1612 		complete_all(&arm_state->resume_blocker);
   1613 
   1614 		init_completion(&arm_state->blocked_blocker);
   1615 		/* Initialise to 'done' state.  We only want to block on this
   1616 		 * completion while things are waiting on the resume blocker */
   1617 		complete_all(&arm_state->blocked_blocker);
   1618 
   1619 		arm_state->suspend_timer_timeout = SUSPEND_TIMER_TIMEOUT_MS;
   1620 		arm_state->suspend_timer_running = 0;
   1621 		init_timer(&arm_state->suspend_timer);
   1622 		arm_state->suspend_timer.data = (unsigned long)(state);
   1623 		arm_state->suspend_timer.function = suspend_timer_callback;
   1624 
   1625 		arm_state->first_connect = 0;
   1626 
   1627 	}
   1628 	return status;
   1629 }
   1630 
   1631 /*
   1632 ** Functions to modify the state variables;
   1633 **	set_suspend_state
   1634 **	set_resume_state
   1635 **
   1636 ** There are more state variables than we might like, so ensure they remain in
   1637 ** step.  Suspend and resume state are maintained separately, since most of
   1638 ** these state machines can operate independently.  However, there are a few
   1639 ** states where state transitions in one state machine cause a reset to the
   1640 ** other state machine.  In addition, there are some completion events which
   1641 ** need to occur on state machine reset and end-state(s), so these are also
   1642 ** dealt with in these functions.
   1643 **
   1644 ** In all states we set the state variable according to the input, but in some
   1645 ** cases we perform additional steps outlined below;
   1646 **
   1647 ** VC_SUSPEND_IDLE - Initialise the suspend completion at the same time.
   1648 **			The suspend completion is completed after any suspend
   1649 **			attempt.  When we reset the state machine we also reset
   1650 **			the completion.  This reset occurs when videocore is
   1651 **			resumed, and also if we initiate suspend after a suspend
   1652 **			failure.
   1653 **
   1654 ** VC_SUSPEND_IN_PROGRESS - This state is considered the point of no return for
   1655 **			suspend - ie from this point on we must try to suspend
   1656 **			before resuming can occur.  We therefore also reset the
   1657 **			resume state machine to VC_RESUME_IDLE in this state.
   1658 **
   1659 ** VC_SUSPEND_SUSPENDED - Suspend has completed successfully. Also call
   1660 **			complete_all on the suspend completion to notify
   1661 **			anything waiting for suspend to happen.
   1662 **
   1663 ** VC_SUSPEND_REJECTED - Videocore rejected suspend. Videocore will also
   1664 **			initiate resume, so no need to alter resume state.
   1665 **			We call complete_all on the suspend completion to notify
   1666 **			of suspend rejection.
   1667 **
   1668 ** VC_SUSPEND_FAILED - We failed to initiate videocore suspend.  We notify the
   1669 **			suspend completion and reset the resume state machine.
   1670 **
   1671 ** VC_RESUME_IDLE - Initialise the resume completion at the same time.  The
   1672 **			resume completion is in it's 'done' state whenever
   1673 **			videcore is running.  Therfore, the VC_RESUME_IDLE state
   1674 **			implies that videocore is suspended.
   1675 **			Hence, any thread which needs to wait until videocore is
   1676 **			running can wait on this completion - it will only block
   1677 **			if videocore is suspended.
   1678 **
   1679 ** VC_RESUME_RESUMED - Resume has completed successfully.  Videocore is running.
   1680 **			Call complete_all on the resume completion to unblock
   1681 **			any threads waiting for resume.	 Also reset the suspend
   1682 **			state machine to it's idle state.
   1683 **
   1684 ** VC_RESUME_FAILED - Currently unused - no mechanism to fail resume exists.
   1685 */
   1686 
   1687 inline void
   1688 set_suspend_state(VCHIQ_ARM_STATE_T *arm_state,
   1689 	enum vc_suspend_status new_state)
   1690 {
   1691 	/* set the state in all cases */
   1692 	arm_state->vc_suspend_state = new_state;
   1693 
   1694 	/* state specific additional actions */
   1695 	switch (new_state) {
   1696 	case VC_SUSPEND_FORCE_CANCELED:
   1697 		complete_all(&arm_state->vc_suspend_complete);
   1698 		break;
   1699 	case VC_SUSPEND_REJECTED:
   1700 		complete_all(&arm_state->vc_suspend_complete);
   1701 		break;
   1702 	case VC_SUSPEND_FAILED:
   1703 		complete_all(&arm_state->vc_suspend_complete);
   1704 		arm_state->vc_resume_state = VC_RESUME_RESUMED;
   1705 		complete_all(&arm_state->vc_resume_complete);
   1706 		break;
   1707 	case VC_SUSPEND_IDLE:
   1708 		INIT_COMPLETION(arm_state->vc_suspend_complete);
   1709 		break;
   1710 	case VC_SUSPEND_REQUESTED:
   1711 		break;
   1712 	case VC_SUSPEND_IN_PROGRESS:
   1713 		set_resume_state(arm_state, VC_RESUME_IDLE);
   1714 		break;
   1715 	case VC_SUSPEND_SUSPENDED:
   1716 		complete_all(&arm_state->vc_suspend_complete);
   1717 		break;
   1718 	default:
   1719 		BUG();
   1720 		break;
   1721 	}
   1722 }
   1723 
   1724 inline void
   1725 set_resume_state(VCHIQ_ARM_STATE_T *arm_state,
   1726 	enum vc_resume_status new_state)
   1727 {
   1728 	/* set the state in all cases */
   1729 	arm_state->vc_resume_state = new_state;
   1730 
   1731 	/* state specific additional actions */
   1732 	switch (new_state) {
   1733 	case VC_RESUME_FAILED:
   1734 		break;
   1735 	case VC_RESUME_IDLE:
   1736 		INIT_COMPLETION(arm_state->vc_resume_complete);
   1737 		break;
   1738 	case VC_RESUME_REQUESTED:
   1739 		break;
   1740 	case VC_RESUME_IN_PROGRESS:
   1741 		break;
   1742 	case VC_RESUME_RESUMED:
   1743 		complete_all(&arm_state->vc_resume_complete);
   1744 		set_suspend_state(arm_state, VC_SUSPEND_IDLE);
   1745 		break;
   1746 	default:
   1747 		BUG();
   1748 		break;
   1749 	}
   1750 }
   1751 
   1752 
   1753 /* should be called with the write lock held */
   1754 inline void
   1755 start_suspend_timer(VCHIQ_ARM_STATE_T *arm_state)
   1756 {
   1757 	del_timer(&arm_state->suspend_timer);
   1758 	arm_state->suspend_timer.expires = jiffies +
   1759 		msecs_to_jiffies(arm_state->
   1760 			suspend_timer_timeout);
   1761 	add_timer(&arm_state->suspend_timer);
   1762 	arm_state->suspend_timer_running = 1;
   1763 }
   1764 
   1765 /* should be called with the write lock held */
   1766 static inline void
   1767 stop_suspend_timer(VCHIQ_ARM_STATE_T *arm_state)
   1768 {
   1769 	if (arm_state->suspend_timer_running) {
   1770 		del_timer(&arm_state->suspend_timer);
   1771 		arm_state->suspend_timer_running = 0;
   1772 	}
   1773 }
   1774 
   1775 static inline int
   1776 need_resume(VCHIQ_STATE_T *state)
   1777 {
   1778 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
   1779 	return (arm_state->vc_suspend_state > VC_SUSPEND_IDLE) &&
   1780 			(arm_state->vc_resume_state < VC_RESUME_REQUESTED) &&
   1781 			vchiq_videocore_wanted(state);
   1782 }
   1783 
   1784 static int
   1785 block_resume(VCHIQ_ARM_STATE_T *arm_state)
   1786 {
   1787 	int status = VCHIQ_SUCCESS;
   1788 	const unsigned long timeout_val =
   1789 				msecs_to_jiffies(FORCE_SUSPEND_TIMEOUT_MS);
   1790 	int resume_count = 0;
   1791 
   1792 	/* Allow any threads which were blocked by the last force suspend to
   1793 	 * complete if they haven't already.  Only give this one shot; if
   1794 	 * blocked_count is incremented after blocked_blocker is completed
   1795 	 * (which only happens when blocked_count hits 0) then those threads
   1796 	 * will have to wait until next time around */
   1797 	if (arm_state->blocked_count) {
   1798 		INIT_COMPLETION(arm_state->blocked_blocker);
   1799 		write_unlock_bh(&arm_state->susp_res_lock);
   1800 		vchiq_log_info(vchiq_susp_log_level, "%s wait for previously "
   1801 			"blocked clients", __func__);
   1802 		if (wait_for_completion_interruptible_timeout(
   1803 				&arm_state->blocked_blocker, timeout_val)
   1804 					<= 0) {
   1805 			vchiq_log_error(vchiq_susp_log_level, "%s wait for "
   1806 				"previously blocked clients failed" , __func__);
   1807 			status = VCHIQ_ERROR;
   1808 			write_lock_bh(&arm_state->susp_res_lock);
   1809 			goto out;
   1810 		}
   1811 		vchiq_log_info(vchiq_susp_log_level, "%s previously blocked "
   1812 			"clients resumed", __func__);
   1813 		write_lock_bh(&arm_state->susp_res_lock);
   1814 	}
   1815 
   1816 	/* We need to wait for resume to complete if it's in process */
   1817 	while (arm_state->vc_resume_state != VC_RESUME_RESUMED &&
   1818 			arm_state->vc_resume_state > VC_RESUME_IDLE) {
   1819 		if (resume_count > 1) {
   1820 			status = VCHIQ_ERROR;
   1821 			vchiq_log_error(vchiq_susp_log_level, "%s waited too "
   1822 				"many times for resume" , __func__);
   1823 			goto out;
   1824 		}
   1825 		write_unlock_bh(&arm_state->susp_res_lock);
   1826 		vchiq_log_info(vchiq_susp_log_level, "%s wait for resume",
   1827 			__func__);
   1828 		if (wait_for_completion_interruptible_timeout(
   1829 				&arm_state->vc_resume_complete, timeout_val)
   1830 					<= 0) {
   1831 			vchiq_log_error(vchiq_susp_log_level, "%s wait for "
   1832 				"resume failed (%s)", __func__,
   1833 				resume_state_names[arm_state->vc_resume_state +
   1834 							VC_RESUME_NUM_OFFSET]);
   1835 			status = VCHIQ_ERROR;
   1836 			write_lock_bh(&arm_state->susp_res_lock);
   1837 			goto out;
   1838 		}
   1839 		vchiq_log_info(vchiq_susp_log_level, "%s resumed", __func__);
   1840 		write_lock_bh(&arm_state->susp_res_lock);
   1841 		resume_count++;
   1842 	}
   1843 	INIT_COMPLETION(arm_state->resume_blocker);
   1844 	arm_state->resume_blocked = 1;
   1845 
   1846 out:
   1847 	return status;
   1848 }
   1849 
   1850 static inline void
   1851 unblock_resume(VCHIQ_ARM_STATE_T *arm_state)
   1852 {
   1853 	complete_all(&arm_state->resume_blocker);
   1854 	arm_state->resume_blocked = 0;
   1855 }
   1856 
   1857 /* Initiate suspend via slot handler. Should be called with the write lock
   1858  * held */
   1859 VCHIQ_STATUS_T
   1860 vchiq_arm_vcsuspend(VCHIQ_STATE_T *state)
   1861 {
   1862 	VCHIQ_STATUS_T status = VCHIQ_ERROR;
   1863 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
   1864 
   1865 	if (!arm_state)
   1866 		goto out;
   1867 
   1868 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
   1869 	status = VCHIQ_SUCCESS;
   1870 
   1871 
   1872 	switch (arm_state->vc_suspend_state) {
   1873 	case VC_SUSPEND_REQUESTED:
   1874 		vchiq_log_info(vchiq_susp_log_level, "%s: suspend already "
   1875 			"requested", __func__);
   1876 		break;
   1877 	case VC_SUSPEND_IN_PROGRESS:
   1878 		vchiq_log_info(vchiq_susp_log_level, "%s: suspend already in "
   1879 			"progress", __func__);
   1880 		break;
   1881 
   1882 	default:
   1883 		/* We don't expect to be in other states, so log but continue
   1884 		 * anyway */
   1885 		vchiq_log_error(vchiq_susp_log_level,
   1886 			"%s unexpected suspend state %s", __func__,
   1887 			suspend_state_names[arm_state->vc_suspend_state +
   1888 						VC_SUSPEND_NUM_OFFSET]);
   1889 		/* fall through */
   1890 	case VC_SUSPEND_REJECTED:
   1891 	case VC_SUSPEND_FAILED:
   1892 		/* Ensure any idle state actions have been run */
   1893 		set_suspend_state(arm_state, VC_SUSPEND_IDLE);
   1894 		/* fall through */
   1895 	case VC_SUSPEND_IDLE:
   1896 		vchiq_log_info(vchiq_susp_log_level,
   1897 			"%s: suspending", __func__);
   1898 		set_suspend_state(arm_state, VC_SUSPEND_REQUESTED);
   1899 		/* kick the slot handler thread to initiate suspend */
   1900 		request_poll(state, NULL, 0);
   1901 		break;
   1902 	}
   1903 
   1904 out:
   1905 	vchiq_log_trace(vchiq_susp_log_level, "%s exit %d", __func__, status);
   1906 	return status;
   1907 }
   1908 
   1909 void
   1910 vchiq_platform_check_suspend(VCHIQ_STATE_T *state)
   1911 {
   1912 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
   1913 	int susp = 0;
   1914 
   1915 	if (!arm_state)
   1916 		goto out;
   1917 
   1918 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
   1919 
   1920 	write_lock_bh(&arm_state->susp_res_lock);
   1921 	if (arm_state->vc_suspend_state == VC_SUSPEND_REQUESTED &&
   1922 			arm_state->vc_resume_state == VC_RESUME_RESUMED) {
   1923 		set_suspend_state(arm_state, VC_SUSPEND_IN_PROGRESS);
   1924 		susp = 1;
   1925 	}
   1926 	write_unlock_bh(&arm_state->susp_res_lock);
   1927 
   1928 	if (susp)
   1929 		vchiq_platform_suspend(state);
   1930 
   1931 out:
   1932 	vchiq_log_trace(vchiq_susp_log_level, "%s exit", __func__);
   1933 	return;
   1934 }
   1935 
   1936 
   1937 static void
   1938 output_timeout_error(VCHIQ_STATE_T *state)
   1939 {
   1940 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
   1941 	char service_err[50] = "";
   1942 	int vc_use_count = arm_state->videocore_use_count;
   1943 	int active_services = state->unused_service;
   1944 	int i;
   1945 
   1946 	if (!arm_state->videocore_use_count) {
   1947 		snprintf(service_err, 50, " Videocore usecount is 0");
   1948 		goto output_msg;
   1949 	}
   1950 	for (i = 0; i < active_services; i++) {
   1951 		VCHIQ_SERVICE_T *service_ptr = state->services[i];
   1952 		if (service_ptr && service_ptr->service_use_count &&
   1953 			(service_ptr->srvstate != VCHIQ_SRVSTATE_FREE)) {
   1954 			snprintf(service_err, 50, " %c%c%c%c(%8x) service has "
   1955 				"use count %d%s", VCHIQ_FOURCC_AS_4CHARS(
   1956 					service_ptr->base.fourcc),
   1957 				 service_ptr->client_id,
   1958 				 service_ptr->service_use_count,
   1959 				 service_ptr->service_use_count ==
   1960 					 vc_use_count ? "" : " (+ more)");
   1961 			break;
   1962 		}
   1963 	}
   1964 
   1965 output_msg:
   1966 	vchiq_log_error(vchiq_susp_log_level,
   1967 		"timed out waiting for vc suspend (%d).%s",
   1968 		 arm_state->autosuspend_override, service_err);
   1969 
   1970 }
   1971 
   1972 /* Try to get videocore into suspended state, regardless of autosuspend state.
   1973 ** We don't actually force suspend, since videocore may get into a bad state
   1974 ** if we force suspend at a bad time.  Instead, we wait for autosuspend to
   1975 ** determine a good point to suspend.  If this doesn't happen within 100ms we
   1976 ** report failure.
   1977 **
   1978 ** Returns VCHIQ_SUCCESS if videocore suspended successfully, VCHIQ_RETRY if
   1979 ** videocore failed to suspend in time or VCHIQ_ERROR if interrupted.
   1980 */
   1981 VCHIQ_STATUS_T
   1982 vchiq_arm_force_suspend(VCHIQ_STATE_T *state)
   1983 {
   1984 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
   1985 	VCHIQ_STATUS_T status = VCHIQ_ERROR;
   1986 	long rc = 0;
   1987 	int repeat = -1;
   1988 
   1989 	if (!arm_state)
   1990 		goto out;
   1991 
   1992 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
   1993 
   1994 	write_lock_bh(&arm_state->susp_res_lock);
   1995 
   1996 	status = block_resume(arm_state);
   1997 	if (status != VCHIQ_SUCCESS)
   1998 		goto unlock;
   1999 	if (arm_state->vc_suspend_state == VC_SUSPEND_SUSPENDED) {
   2000 		/* Already suspended - just block resume and exit */
   2001 		vchiq_log_info(vchiq_susp_log_level, "%s already suspended",
   2002 			__func__);
   2003 		status = VCHIQ_SUCCESS;
   2004 		goto unlock;
   2005 	} else if (arm_state->vc_suspend_state <= VC_SUSPEND_IDLE) {
   2006 		/* initiate suspend immediately in the case that we're waiting
   2007 		 * for the timeout */
   2008 		stop_suspend_timer(arm_state);
   2009 		if (!vchiq_videocore_wanted(state)) {
   2010 			vchiq_log_info(vchiq_susp_log_level, "%s videocore "
   2011 				"idle, initiating suspend", __func__);
   2012 			status = vchiq_arm_vcsuspend(state);
   2013 		} else if (arm_state->autosuspend_override <
   2014 						FORCE_SUSPEND_FAIL_MAX) {
   2015 			vchiq_log_info(vchiq_susp_log_level, "%s letting "
   2016 				"videocore go idle", __func__);
   2017 			status = VCHIQ_SUCCESS;
   2018 		} else {
   2019 			vchiq_log_warning(vchiq_susp_log_level, "%s failed too "
   2020 				"many times - attempting suspend", __func__);
   2021 			status = vchiq_arm_vcsuspend(state);
   2022 		}
   2023 	} else {
   2024 		vchiq_log_info(vchiq_susp_log_level, "%s videocore suspend "
   2025 			"in progress - wait for completion", __func__);
   2026 		status = VCHIQ_SUCCESS;
   2027 	}
   2028 
   2029 	/* Wait for suspend to happen due to system idle (not forced..) */
   2030 	if (status != VCHIQ_SUCCESS)
   2031 		goto unblock_resume;
   2032 
   2033 	do {
   2034 		write_unlock_bh(&arm_state->susp_res_lock);
   2035 
   2036 		rc = wait_for_completion_interruptible_timeout(
   2037 				&arm_state->vc_suspend_complete,
   2038 				msecs_to_jiffies(FORCE_SUSPEND_TIMEOUT_MS));
   2039 
   2040 		write_lock_bh(&arm_state->susp_res_lock);
   2041 		if (rc < 0) {
   2042 			vchiq_log_warning(vchiq_susp_log_level, "%s "
   2043 				"interrupted waiting for suspend", __func__);
   2044 			status = VCHIQ_ERROR;
   2045 			goto unblock_resume;
   2046 		} else if (rc == 0) {
   2047 			if (arm_state->vc_suspend_state > VC_SUSPEND_IDLE) {
   2048 				/* Repeat timeout once if in progress */
   2049 				if (repeat < 0) {
   2050 					repeat = 1;
   2051 					continue;
   2052 				}
   2053 			}
   2054 			arm_state->autosuspend_override++;
   2055 			output_timeout_error(state);
   2056 
   2057 			status = VCHIQ_RETRY;
   2058 			goto unblock_resume;
   2059 		}
   2060 	} while (0 < (repeat--));
   2061 
   2062 	/* Check and report state in case we need to abort ARM suspend */
   2063 	if (arm_state->vc_suspend_state != VC_SUSPEND_SUSPENDED) {
   2064 		status = VCHIQ_RETRY;
   2065 		vchiq_log_error(vchiq_susp_log_level,
   2066 			"%s videocore suspend failed (state %s)", __func__,
   2067 			suspend_state_names[arm_state->vc_suspend_state +
   2068 						VC_SUSPEND_NUM_OFFSET]);
   2069 		/* Reset the state only if it's still in an error state.
   2070 		 * Something could have already initiated another suspend. */
   2071 		if (arm_state->vc_suspend_state < VC_SUSPEND_IDLE)
   2072 			set_suspend_state(arm_state, VC_SUSPEND_IDLE);
   2073 
   2074 		goto unblock_resume;
   2075 	}
   2076 
   2077 	/* successfully suspended - unlock and exit */
   2078 	goto unlock;
   2079 
   2080 unblock_resume:
   2081 	/* all error states need to unblock resume before exit */
   2082 	unblock_resume(arm_state);
   2083 
   2084 unlock:
   2085 	write_unlock_bh(&arm_state->susp_res_lock);
   2086 
   2087 out:
   2088 	vchiq_log_trace(vchiq_susp_log_level, "%s exit %d", __func__, status);
   2089 	return status;
   2090 }
   2091 
   2092 void
   2093 vchiq_check_suspend(VCHIQ_STATE_T *state)
   2094 {
   2095 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
   2096 
   2097 	if (!arm_state)
   2098 		goto out;
   2099 
   2100 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
   2101 
   2102 	write_lock_bh(&arm_state->susp_res_lock);
   2103 	if (arm_state->vc_suspend_state != VC_SUSPEND_SUSPENDED &&
   2104 			arm_state->first_connect &&
   2105 			!vchiq_videocore_wanted(state)) {
   2106 		vchiq_arm_vcsuspend(state);
   2107 	}
   2108 	write_unlock_bh(&arm_state->susp_res_lock);
   2109 
   2110 out:
   2111 	vchiq_log_trace(vchiq_susp_log_level, "%s exit", __func__);
   2112 	return;
   2113 }
   2114 
   2115 
   2116 int
   2117 vchiq_arm_allow_resume(VCHIQ_STATE_T *state)
   2118 {
   2119 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
   2120 	int resume = 0;
   2121 	int ret = -1;
   2122 
   2123 	if (!arm_state)
   2124 		goto out;
   2125 
   2126 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
   2127 
   2128 	write_lock_bh(&arm_state->susp_res_lock);
   2129 	unblock_resume(arm_state);
   2130 	resume = vchiq_check_resume(state);
   2131 	write_unlock_bh(&arm_state->susp_res_lock);
   2132 
   2133 	if (resume) {
   2134 		if (wait_for_completion_interruptible(
   2135 			&arm_state->vc_resume_complete) < 0) {
   2136 			vchiq_log_error(vchiq_susp_log_level,
   2137 				"%s interrupted", __func__);
   2138 			/* failed, cannot accurately derive suspend
   2139 			 * state, so exit early. */
   2140 			goto out;
   2141 		}
   2142 	}
   2143 
   2144 	read_lock_bh(&arm_state->susp_res_lock);
   2145 	if (arm_state->vc_suspend_state == VC_SUSPEND_SUSPENDED) {
   2146 		vchiq_log_info(vchiq_susp_log_level,
   2147 				"%s: Videocore remains suspended", __func__);
   2148 	} else {
   2149 		vchiq_log_info(vchiq_susp_log_level,
   2150 				"%s: Videocore resumed", __func__);
   2151 		ret = 0;
   2152 	}
   2153 	read_unlock_bh(&arm_state->susp_res_lock);
   2154 out:
   2155 	vchiq_log_trace(vchiq_susp_log_level, "%s exit %d", __func__, ret);
   2156 	return ret;
   2157 }
   2158 
   2159 /* This function should be called with the write lock held */
   2160 int
   2161 vchiq_check_resume(VCHIQ_STATE_T *state)
   2162 {
   2163 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
   2164 	int resume = 0;
   2165 
   2166 	if (!arm_state)
   2167 		goto out;
   2168 
   2169 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
   2170 
   2171 	if (need_resume(state)) {
   2172 		set_resume_state(arm_state, VC_RESUME_REQUESTED);
   2173 		request_poll(state, NULL, 0);
   2174 		resume = 1;
   2175 	}
   2176 
   2177 out:
   2178 	vchiq_log_trace(vchiq_susp_log_level, "%s exit", __func__);
   2179 	return resume;
   2180 }
   2181 
   2182 #ifdef notyet
   2183 void
   2184 vchiq_platform_check_resume(VCHIQ_STATE_T *state)
   2185 {
   2186 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
   2187 	int res = 0;
   2188 
   2189 	if (!arm_state)
   2190 		goto out;
   2191 
   2192 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
   2193 
   2194 	write_lock_bh(&arm_state->susp_res_lock);
   2195 	if (arm_state->wake_address == 0) {
   2196 		vchiq_log_info(vchiq_susp_log_level,
   2197 					"%s: already awake", __func__);
   2198 		goto unlock;
   2199 	}
   2200 	if (arm_state->vc_resume_state == VC_RESUME_IN_PROGRESS) {
   2201 		vchiq_log_info(vchiq_susp_log_level,
   2202 					"%s: already resuming", __func__);
   2203 		goto unlock;
   2204 	}
   2205 
   2206 	if (arm_state->vc_resume_state == VC_RESUME_REQUESTED) {
   2207 		set_resume_state(arm_state, VC_RESUME_IN_PROGRESS);
   2208 		res = 1;
   2209 	} else
   2210 		vchiq_log_trace(vchiq_susp_log_level,
   2211 				"%s: not resuming (resume state %s)", __func__,
   2212 				resume_state_names[arm_state->vc_resume_state +
   2213 							VC_RESUME_NUM_OFFSET]);
   2214 
   2215 unlock:
   2216 	write_unlock_bh(&arm_state->susp_res_lock);
   2217 
   2218 	if (res)
   2219 		vchiq_platform_resume(state);
   2220 
   2221 out:
   2222 	vchiq_log_trace(vchiq_susp_log_level, "%s exit", __func__);
   2223 	return;
   2224 
   2225 }
   2226 #endif
   2227 
   2228 
   2229 
   2230 VCHIQ_STATUS_T
   2231 vchiq_use_internal(VCHIQ_STATE_T *state, VCHIQ_SERVICE_T *service,
   2232 		enum USE_TYPE_E use_type)
   2233 {
   2234 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
   2235 	VCHIQ_STATUS_T ret = VCHIQ_SUCCESS;
   2236 	char entity[16];
   2237 	int *entity_uc;
   2238 	int local_uc, local_entity_uc;
   2239 
   2240 	if (!arm_state)
   2241 		goto out;
   2242 
   2243 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
   2244 
   2245 	if (use_type == USE_TYPE_VCHIQ) {
   2246 		snprintf(entity, sizeof(entity), "VCHIQ:   ");
   2247 		entity_uc = &arm_state->peer_use_count;
   2248 	} else if (service) {
   2249 		snprintf(entity, sizeof(entity), "%c%c%c%c:%8x",
   2250 			VCHIQ_FOURCC_AS_4CHARS(service->base.fourcc),
   2251 			service->client_id);
   2252 		entity_uc = &service->service_use_count;
   2253 	} else {
   2254 		vchiq_log_error(vchiq_susp_log_level, "%s null service "
   2255 				"ptr", __func__);
   2256 		ret = VCHIQ_ERROR;
   2257 		goto out;
   2258 	}
   2259 
   2260 	write_lock_bh(&arm_state->susp_res_lock);
   2261 	while (arm_state->resume_blocked) {
   2262 		/* If we call 'use' while force suspend is waiting for suspend,
   2263 		 * then we're about to block the thread which the force is
   2264 		 * waiting to complete, so we're bound to just time out. In this
   2265 		 * case, set the suspend state such that the wait will be
   2266 		 * canceled, so we can complete as quickly as possible. */
   2267 		if (arm_state->resume_blocked && arm_state->vc_suspend_state ==
   2268 				VC_SUSPEND_IDLE) {
   2269 			set_suspend_state(arm_state, VC_SUSPEND_FORCE_CANCELED);
   2270 			break;
   2271 		}
   2272 		/* If suspend is already in progress then we need to block */
   2273 		if (!try_wait_for_completion(&arm_state->resume_blocker)) {
   2274 			/* Indicate that there are threads waiting on the resume
   2275 			 * blocker.  These need to be allowed to complete before
   2276 			 * a _second_ call to force suspend can complete,
   2277 			 * otherwise low priority threads might never actually
   2278 			 * continue */
   2279 			arm_state->blocked_count++;
   2280 			write_unlock_bh(&arm_state->susp_res_lock);
   2281 			vchiq_log_info(vchiq_susp_log_level, "%s %s resume "
   2282 				"blocked - waiting...", __func__, entity);
   2283 			if (wait_for_completion_killable(
   2284 					&arm_state->resume_blocker) != 0) {
   2285 				vchiq_log_error(vchiq_susp_log_level, "%s %s "
   2286 					"wait for resume blocker interrupted",
   2287 					__func__, entity);
   2288 				ret = VCHIQ_ERROR;
   2289 				write_lock_bh(&arm_state->susp_res_lock);
   2290 				arm_state->blocked_count--;
   2291 				write_unlock_bh(&arm_state->susp_res_lock);
   2292 				goto out;
   2293 			}
   2294 			vchiq_log_info(vchiq_susp_log_level, "%s %s resume "
   2295 				"unblocked", __func__, entity);
   2296 			write_lock_bh(&arm_state->susp_res_lock);
   2297 			if (--arm_state->blocked_count == 0)
   2298 				complete_all(&arm_state->blocked_blocker);
   2299 		}
   2300 	}
   2301 
   2302 	stop_suspend_timer(arm_state);
   2303 
   2304 	local_uc = ++arm_state->videocore_use_count;
   2305 	local_entity_uc = ++(*entity_uc);
   2306 
   2307 	/* If there's a pending request which hasn't yet been serviced then
   2308 	 * just clear it.  If we're past VC_SUSPEND_REQUESTED state then
   2309 	 * vc_resume_complete will block until we either resume or fail to
   2310 	 * suspend */
   2311 	if (arm_state->vc_suspend_state <= VC_SUSPEND_REQUESTED)
   2312 		set_suspend_state(arm_state, VC_SUSPEND_IDLE);
   2313 
   2314 	if ((use_type != USE_TYPE_SERVICE_NO_RESUME) && need_resume(state)) {
   2315 		set_resume_state(arm_state, VC_RESUME_REQUESTED);
   2316 		vchiq_log_info(vchiq_susp_log_level,
   2317 			"%s %s count %d, state count %d",
   2318 			__func__, entity, local_entity_uc, local_uc);
   2319 		request_poll(state, NULL, 0);
   2320 	} else
   2321 		vchiq_log_trace(vchiq_susp_log_level,
   2322 			"%s %s count %d, state count %d",
   2323 			__func__, entity, *entity_uc, local_uc);
   2324 
   2325 
   2326 	write_unlock_bh(&arm_state->susp_res_lock);
   2327 
   2328 	/* Completion is in a done state when we're not suspended, so this won't
   2329 	 * block for the non-suspended case. */
   2330 	if (!try_wait_for_completion(&arm_state->vc_resume_complete)) {
   2331 		vchiq_log_info(vchiq_susp_log_level, "%s %s wait for resume",
   2332 			__func__, entity);
   2333 		if (wait_for_completion_killable(
   2334 				&arm_state->vc_resume_complete) != 0) {
   2335 			vchiq_log_error(vchiq_susp_log_level, "%s %s wait for "
   2336 				"resume interrupted", __func__, entity);
   2337 			ret = VCHIQ_ERROR;
   2338 			goto out;
   2339 		}
   2340 		vchiq_log_info(vchiq_susp_log_level, "%s %s resumed", __func__,
   2341 			entity);
   2342 	}
   2343 
   2344 	if (ret == VCHIQ_SUCCESS) {
   2345 		VCHIQ_STATUS_T status = VCHIQ_SUCCESS;
   2346 		long ack_cnt = atomic_xchg(&arm_state->ka_use_ack_count, 0);
   2347 		while (ack_cnt && (status == VCHIQ_SUCCESS)) {
   2348 			/* Send the use notify to videocore */
   2349 			status = vchiq_send_remote_use_active(state);
   2350 			if (status == VCHIQ_SUCCESS)
   2351 				ack_cnt--;
   2352 			else
   2353 				atomic_add(ack_cnt,
   2354 					&arm_state->ka_use_ack_count);
   2355 		}
   2356 	}
   2357 
   2358 out:
   2359 	vchiq_log_trace(vchiq_susp_log_level, "%s exit %d", __func__, ret);
   2360 	return ret;
   2361 }
   2362 
   2363 VCHIQ_STATUS_T
   2364 vchiq_release_internal(VCHIQ_STATE_T *state, VCHIQ_SERVICE_T *service)
   2365 {
   2366 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
   2367 	VCHIQ_STATUS_T ret = VCHIQ_SUCCESS;
   2368 	char entity[16];
   2369 	int *entity_uc;
   2370 
   2371 	if (!arm_state)
   2372 		goto out;
   2373 
   2374 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
   2375 
   2376 	if (service) {
   2377 		snprintf(entity, sizeof(entity), "%c%c%c%c:%8x",
   2378 			VCHIQ_FOURCC_AS_4CHARS(service->base.fourcc),
   2379 			service->client_id);
   2380 		entity_uc = &service->service_use_count;
   2381 	} else {
   2382 		snprintf(entity, sizeof(entity), "PEER:   ");
   2383 		entity_uc = &arm_state->peer_use_count;
   2384 	}
   2385 
   2386 	write_lock_bh(&arm_state->susp_res_lock);
   2387 	if (!arm_state->videocore_use_count || !(*entity_uc)) {
   2388 		/* Don't use BUG_ON - don't allow user thread to crash kernel */
   2389 		WARN_ON(!arm_state->videocore_use_count);
   2390 		WARN_ON(!(*entity_uc));
   2391 		ret = VCHIQ_ERROR;
   2392 		goto unlock;
   2393 	}
   2394 	--arm_state->videocore_use_count;
   2395 	--(*entity_uc);
   2396 
   2397 	if (!vchiq_videocore_wanted(state)) {
   2398 		if (vchiq_platform_use_suspend_timer() &&
   2399 				!arm_state->resume_blocked) {
   2400 			/* Only use the timer if we're not trying to force
   2401 			 * suspend (=> resume_blocked) */
   2402 			start_suspend_timer(arm_state);
   2403 		} else {
   2404 			vchiq_log_info(vchiq_susp_log_level,
   2405 				"%s %s count %d, state count %d - suspending",
   2406 				__func__, entity, *entity_uc,
   2407 				arm_state->videocore_use_count);
   2408 			vchiq_arm_vcsuspend(state);
   2409 		}
   2410 	} else
   2411 		vchiq_log_trace(vchiq_susp_log_level,
   2412 			"%s %s count %d, state count %d",
   2413 			__func__, entity, *entity_uc,
   2414 			arm_state->videocore_use_count);
   2415 
   2416 unlock:
   2417 	write_unlock_bh(&arm_state->susp_res_lock);
   2418 
   2419 out:
   2420 	vchiq_log_trace(vchiq_susp_log_level, "%s exit %d", __func__, ret);
   2421 	return ret;
   2422 }
   2423 
   2424 void
   2425 vchiq_on_remote_use(VCHIQ_STATE_T *state)
   2426 {
   2427 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
   2428 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
   2429 	atomic_inc(&arm_state->ka_use_count);
   2430 	complete(&arm_state->ka_evt);
   2431 }
   2432 
   2433 void
   2434 vchiq_on_remote_release(VCHIQ_STATE_T *state)
   2435 {
   2436 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
   2437 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
   2438 	atomic_inc(&arm_state->ka_release_count);
   2439 	complete(&arm_state->ka_evt);
   2440 }
   2441 
   2442 VCHIQ_STATUS_T
   2443 vchiq_use_service_internal(VCHIQ_SERVICE_T *service)
   2444 {
   2445 	return vchiq_use_internal(service->state, service, USE_TYPE_SERVICE);
   2446 }
   2447 
   2448 VCHIQ_STATUS_T
   2449 vchiq_release_service_internal(VCHIQ_SERVICE_T *service)
   2450 {
   2451 	return vchiq_release_internal(service->state, service);
   2452 }
   2453 
   2454 static void suspend_timer_callback(unsigned long context)
   2455 {
   2456 	VCHIQ_STATE_T *state = (VCHIQ_STATE_T *)context;
   2457 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
   2458 	if (!arm_state)
   2459 		goto out;
   2460 	vchiq_log_info(vchiq_susp_log_level,
   2461 		"%s - suspend timer expired - check suspend", __func__);
   2462 	vchiq_check_suspend(state);
   2463 out:
   2464 	return;
   2465 }
   2466 
   2467 VCHIQ_STATUS_T
   2468 vchiq_use_service_no_resume(VCHIQ_SERVICE_HANDLE_T handle)
   2469 {
   2470 	VCHIQ_STATUS_T ret = VCHIQ_ERROR;
   2471 	VCHIQ_SERVICE_T *service = find_service_by_handle(handle);
   2472 	if (service) {
   2473 		ret = vchiq_use_internal(service->state, service,
   2474 				USE_TYPE_SERVICE_NO_RESUME);
   2475 		unlock_service(service);
   2476 	}
   2477 	return ret;
   2478 }
   2479 
   2480 VCHIQ_STATUS_T
   2481 vchiq_use_service(VCHIQ_SERVICE_HANDLE_T handle)
   2482 {
   2483 	VCHIQ_STATUS_T ret = VCHIQ_ERROR;
   2484 	VCHIQ_SERVICE_T *service = find_service_by_handle(handle);
   2485 	if (service) {
   2486 		ret = vchiq_use_internal(service->state, service,
   2487 				USE_TYPE_SERVICE);
   2488 		unlock_service(service);
   2489 	}
   2490 	return ret;
   2491 }
   2492 
   2493 VCHIQ_STATUS_T
   2494 vchiq_release_service(VCHIQ_SERVICE_HANDLE_T handle)
   2495 {
   2496 	VCHIQ_STATUS_T ret = VCHIQ_ERROR;
   2497 	VCHIQ_SERVICE_T *service = find_service_by_handle(handle);
   2498 	if (service) {
   2499 		ret = vchiq_release_internal(service->state, service);
   2500 		unlock_service(service);
   2501 	}
   2502 	return ret;
   2503 }
   2504 
   2505 void
   2506 vchiq_dump_service_use_state(VCHIQ_STATE_T *state)
   2507 {
   2508 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
   2509 	int i, j = 0;
   2510 	/* Only dump 64 services */
   2511 	static const int local_max_services = 64;
   2512 	/* If there's more than 64 services, only dump ones with
   2513 	 * non-zero counts */
   2514 	int only_nonzero = 0;
   2515 	static const char *nz = "<-- preventing suspend";
   2516 
   2517 	enum vc_suspend_status vc_suspend_state;
   2518 	enum vc_resume_status  vc_resume_state;
   2519 	int peer_count;
   2520 	int vc_use_count;
   2521 	int active_services;
   2522 	struct service_data_struct {
   2523 		int fourcc;
   2524 		int clientid;
   2525 		int use_count;
   2526 	} service_data[local_max_services];
   2527 
   2528 	if (!arm_state)
   2529 		return;
   2530 
   2531 	read_lock_bh(&arm_state->susp_res_lock);
   2532 	vc_suspend_state = arm_state->vc_suspend_state;
   2533 	vc_resume_state  = arm_state->vc_resume_state;
   2534 	peer_count = arm_state->peer_use_count;
   2535 	vc_use_count = arm_state->videocore_use_count;
   2536 	active_services = state->unused_service;
   2537 	if (active_services > local_max_services)
   2538 		only_nonzero = 1;
   2539 
   2540 	for (i = 0; (i < active_services) && (j < local_max_services); i++) {
   2541 		VCHIQ_SERVICE_T *service_ptr = state->services[i];
   2542 		if (!service_ptr)
   2543 			continue;
   2544 
   2545 		if (only_nonzero && !service_ptr->service_use_count)
   2546 			continue;
   2547 
   2548 		if (service_ptr->srvstate != VCHIQ_SRVSTATE_FREE) {
   2549 			service_data[j].fourcc = service_ptr->base.fourcc;
   2550 			service_data[j].clientid = service_ptr->client_id;
   2551 			service_data[j++].use_count = service_ptr->
   2552 							service_use_count;
   2553 		}
   2554 	}
   2555 
   2556 	read_unlock_bh(&arm_state->susp_res_lock);
   2557 
   2558 	vchiq_log_warning(vchiq_susp_log_level,
   2559 		"-- Videcore suspend state: %s --",
   2560 		suspend_state_names[vc_suspend_state + VC_SUSPEND_NUM_OFFSET]);
   2561 	vchiq_log_warning(vchiq_susp_log_level,
   2562 		"-- Videcore resume state: %s --",
   2563 		resume_state_names[vc_resume_state + VC_RESUME_NUM_OFFSET]);
   2564 
   2565 	if (only_nonzero)
   2566 		vchiq_log_warning(vchiq_susp_log_level, "Too many active "
   2567 			"services (%d).  Only dumping up to first %d services "
   2568 			"with non-zero use-count", active_services,
   2569 			local_max_services);
   2570 
   2571 	for (i = 0; i < j; i++) {
   2572 		vchiq_log_warning(vchiq_susp_log_level,
   2573 			"----- %c%c%c%c:%d service count %d %s",
   2574 			VCHIQ_FOURCC_AS_4CHARS(service_data[i].fourcc),
   2575 			service_data[i].clientid,
   2576 			service_data[i].use_count,
   2577 			service_data[i].use_count ? nz : "");
   2578 	}
   2579 	vchiq_log_warning(vchiq_susp_log_level,
   2580 		"----- VCHIQ use count count %d", peer_count);
   2581 	vchiq_log_warning(vchiq_susp_log_level,
   2582 		"--- Overall vchiq instance use count %d", vc_use_count);
   2583 
   2584 	vchiq_dump_platform_use_state(state);
   2585 }
   2586 
   2587 VCHIQ_STATUS_T
   2588 vchiq_check_service(VCHIQ_SERVICE_T *service)
   2589 {
   2590 	VCHIQ_ARM_STATE_T *arm_state;
   2591 	VCHIQ_STATUS_T ret = VCHIQ_ERROR;
   2592 
   2593 	if (!service || !service->state)
   2594 		goto out;
   2595 
   2596 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
   2597 
   2598 	arm_state = vchiq_platform_get_arm_state(service->state);
   2599 
   2600 	read_lock_bh(&arm_state->susp_res_lock);
   2601 	if (service->service_use_count)
   2602 		ret = VCHIQ_SUCCESS;
   2603 	read_unlock_bh(&arm_state->susp_res_lock);
   2604 
   2605 	if (ret == VCHIQ_ERROR) {
   2606 		vchiq_log_error(vchiq_susp_log_level,
   2607 			"%s ERROR - %c%c%c%c:%8x service count %d, "
   2608 			"state count %d, videocore suspend state %s", __func__,
   2609 			VCHIQ_FOURCC_AS_4CHARS(service->base.fourcc),
   2610 			service->client_id, service->service_use_count,
   2611 			arm_state->videocore_use_count,
   2612 			suspend_state_names[arm_state->vc_suspend_state +
   2613 						VC_SUSPEND_NUM_OFFSET]);
   2614 		vchiq_dump_service_use_state(service->state);
   2615 	}
   2616 out:
   2617 	return ret;
   2618 }
   2619 
   2620 /* stub functions */
   2621 void vchiq_on_remote_use_active(VCHIQ_STATE_T *state)
   2622 {
   2623 	(void)state;
   2624 }
   2625 
   2626 void vchiq_platform_conn_state_changed(VCHIQ_STATE_T *state,
   2627 	VCHIQ_CONNSTATE_T oldstate, VCHIQ_CONNSTATE_T newstate)
   2628 {
   2629 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
   2630 	vchiq_log_info(vchiq_susp_log_level, "%d: %s->%s", state->id,
   2631 		get_conn_state_name(oldstate), get_conn_state_name(newstate));
   2632 	if (state->conn_state == VCHIQ_CONNSTATE_CONNECTED) {
   2633 		write_lock_bh(&arm_state->susp_res_lock);
   2634 		if (!arm_state->first_connect) {
   2635 			char threadname[10];
   2636 			arm_state->first_connect = 1;
   2637 			write_unlock_bh(&arm_state->susp_res_lock);
   2638 			snprintf(threadname, sizeof(threadname), "VCHIQka-%d",
   2639 				state->id);
   2640 			arm_state->ka_thread = vchiq_thread_create(
   2641 				&vchiq_keepalive_thread_func,
   2642 				(void *)state,
   2643 				threadname);
   2644 			if (arm_state->ka_thread == NULL) {
   2645 				vchiq_log_error(vchiq_susp_log_level,
   2646 					"vchiq: FATAL: couldn't create thread %s",
   2647 					threadname);
   2648 			} else {
   2649 				wake_up_process(arm_state->ka_thread);
   2650 			}
   2651 		} else
   2652 			write_unlock_bh(&arm_state->susp_res_lock);
   2653 	}
   2654 }
   2655 
   2656 /****************************************************************************
   2657 *
   2658 *   vchiq_init - called when the module is loaded.
   2659 *
   2660 ***************************************************************************/
   2661 
   2662 int __init vchiq_init(void);
   2663 int __init
   2664 vchiq_init(void)
   2665 {
   2666 	int err;
   2667 
   2668 #ifdef notyet
   2669 	/* create proc entries */
   2670 	err = vchiq_proc_init();
   2671 	if (err != 0)
   2672 		goto failed_proc_init;
   2673 #endif
   2674 
   2675 	spin_lock_init(&msg_queue_spinlock);
   2676 
   2677 	err = vchiq_platform_init(&g_state);
   2678 	if (err != 0)
   2679 		goto failed_platform_init;
   2680 
   2681 	vchiq_log_info(vchiq_arm_log_level,
   2682 		"vchiq: initialised - version %d (min %d)",
   2683 		VCHIQ_VERSION, VCHIQ_VERSION_MIN);
   2684 
   2685 	return 0;
   2686 
   2687 failed_platform_init:
   2688 	vchiq_log_warning(vchiq_arm_log_level, "could not load vchiq");
   2689 	return err;
   2690 }
   2691 
   2692 #ifdef notyet
   2693 static int vchiq_instance_get_use_count(VCHIQ_INSTANCE_T instance)
   2694 {
   2695 	VCHIQ_SERVICE_T *service;
   2696 	int use_count = 0, i;
   2697 	i = 0;
   2698 	while ((service = next_service_by_instance(instance->state,
   2699 		instance, &i)) != NULL) {
   2700 		use_count += service->service_use_count;
   2701 		unlock_service(service);
   2702 	}
   2703 	return use_count;
   2704 }
   2705 
   2706 /* read the per-process use-count */
   2707 static int proc_read_use_count(char *page, char **start,
   2708 			       off_t off, int count,
   2709 			       int *eof, void *data)
   2710 {
   2711 	VCHIQ_INSTANCE_T instance = data;
   2712 	int len, use_count;
   2713 
   2714 	use_count = vchiq_instance_get_use_count(instance);
   2715 	len = snprintf(page+off, count, "%d\n", use_count);
   2716 
   2717 	return len;
   2718 }
   2719 
   2720 /* add an instance (process) to the proc entries */
   2721 static int vchiq_proc_add_instance(VCHIQ_INSTANCE_T instance)
   2722 {
   2723 	char pidstr[32];
   2724 	struct proc_dir_entry *top, *use_count;
   2725 	struct proc_dir_entry *clients = vchiq_clients_top();
   2726 	int pid = instance->pid;
   2727 
   2728 	snprintf(pidstr, sizeof(pidstr), "%d", pid);
   2729 	top = proc_mkdir(pidstr, clients);
   2730 	if (!top)
   2731 		goto fail_top;
   2732 
   2733 	use_count = create_proc_read_entry("use_count",
   2734 					   0444, top,
   2735 					   proc_read_use_count,
   2736 					   instance);
   2737 	if (!use_count)
   2738 		goto fail_use_count;
   2739 
   2740 	instance->proc_entry = top;
   2741 
   2742 	return 0;
   2743 
   2744 fail_use_count:
   2745 	remove_proc_entry(top->name, clients);
   2746 fail_top:
   2747 	return -ENOMEM;
   2748 }
   2749 
   2750 static void vchiq_proc_remove_instance(VCHIQ_INSTANCE_T instance)
   2751 {
   2752 	struct proc_dir_entry *clients = vchiq_clients_top();
   2753 	remove_proc_entry("use_count", instance->proc_entry);
   2754 	remove_proc_entry(instance->proc_entry->name, clients);
   2755 }
   2756 
   2757 #endif
   2758 
   2759 /****************************************************************************
   2760 *
   2761 *   vchiq_exit - called when the module is unloaded.
   2762 *
   2763 ***************************************************************************/
   2764 
   2765 void vchiq_exit(void);
   2766 void
   2767 vchiq_exit(void)
   2768 {
   2769 	vchiq_platform_exit(&g_state);
   2770 }
   2771