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vchiq_arm.c revision 1.13.2.2
      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 #include <sys/kmem.h>
     40 
     41 #include "vchiq_core.h"
     42 #include "vchiq_ioctl.h"
     43 #include "vchiq_arm.h"
     44 
     45 #define DEVICE_NAME "vchiq"
     46 
     47 /* Override the default prefix, which would be vchiq_arm (from the filename) */
     48 #undef MODULE_PARAM_PREFIX
     49 #define MODULE_PARAM_PREFIX DEVICE_NAME "."
     50 
     51 #define VCHIQ_MINOR 0
     52 
     53 /* Some per-instance constants */
     54 #define MAX_COMPLETIONS 16
     55 #define MAX_SERVICES 64
     56 #define MAX_ELEMENTS 8
     57 #define MSG_QUEUE_SIZE 64
     58 
     59 #define KEEPALIVE_VER 1
     60 #define KEEPALIVE_VER_MIN KEEPALIVE_VER
     61 
     62 MALLOC_DEFINE(M_VCHIQ, "vchiq_cdev", "VideoCore cdev memory");
     63 
     64 /* Run time control of log level, based on KERN_XXX level. */
     65 int vchiq_arm_log_level = VCHIQ_LOG_DEFAULT;
     66 int vchiq_susp_log_level = VCHIQ_LOG_ERROR;
     67 
     68 #define SUSPEND_TIMER_TIMEOUT_MS 100
     69 #define SUSPEND_RETRY_TIMER_TIMEOUT_MS 1000
     70 
     71 #define VC_SUSPEND_NUM_OFFSET 3 /* number of values before idle which are -ve */
     72 static const char *const suspend_state_names[] = {
     73 	"VC_SUSPEND_FORCE_CANCELED",
     74 	"VC_SUSPEND_REJECTED",
     75 	"VC_SUSPEND_FAILED",
     76 	"VC_SUSPEND_IDLE",
     77 	"VC_SUSPEND_REQUESTED",
     78 	"VC_SUSPEND_IN_PROGRESS",
     79 	"VC_SUSPEND_SUSPENDED"
     80 };
     81 #define VC_RESUME_NUM_OFFSET 1 /* number of values before idle which are -ve */
     82 static const char *const resume_state_names[] = {
     83 	"VC_RESUME_FAILED",
     84 	"VC_RESUME_IDLE",
     85 	"VC_RESUME_REQUESTED",
     86 	"VC_RESUME_IN_PROGRESS",
     87 	"VC_RESUME_RESUMED"
     88 };
     89 /* The number of times we allow force suspend to timeout before actually
     90 ** _forcing_ suspend.  This is to cater for SW which fails to release vchiq
     91 ** correctly - we don't want to prevent ARM suspend indefinitely in this case.
     92 */
     93 #define FORCE_SUSPEND_FAIL_MAX 8
     94 
     95 /* The time in ms allowed for videocore to go idle when force suspend has been
     96  * requested */
     97 #define FORCE_SUSPEND_TIMEOUT_MS 200
     98 
     99 
    100 static void suspend_timer_callback(unsigned long context);
    101 #ifdef notyet
    102 static int vchiq_proc_add_instance(VCHIQ_INSTANCE_T instance);
    103 static void vchiq_proc_remove_instance(VCHIQ_INSTANCE_T instance);
    104 #endif
    105 
    106 
    107 typedef struct user_service_struct {
    108 	VCHIQ_SERVICE_T *service;
    109 	void *userdata;
    110 	VCHIQ_INSTANCE_T instance;
    111 	int is_vchi;
    112 	int dequeue_pending;
    113 	int message_available_pos;
    114 	int msg_insert;
    115 	int msg_remove;
    116 	struct semaphore insert_event;
    117 	struct semaphore remove_event;
    118 	VCHIQ_HEADER_T * msg_queue[MSG_QUEUE_SIZE];
    119 } USER_SERVICE_T;
    120 
    121 struct bulk_waiter_node {
    122 	struct bulk_waiter bulk_waiter;
    123 	struct lwp *l;
    124 	struct list_head list;
    125 };
    126 
    127 struct vchiq_instance_struct {
    128 	VCHIQ_STATE_T *state;
    129 	VCHIQ_COMPLETION_DATA_T completions[MAX_COMPLETIONS];
    130 	int completion_insert;
    131 	int completion_remove;
    132 	struct semaphore insert_event;
    133 	struct semaphore remove_event;
    134 	struct mutex completion_mutex;
    135 
    136 	int connected;
    137 	int closing;
    138 	struct lwp *l;
    139 	int mark;
    140 
    141 	struct list_head bulk_waiter_list;
    142 	struct mutex bulk_waiter_list_mutex;
    143 
    144 	struct proc_dir_entry *proc_entry;
    145 };
    146 
    147 typedef struct dump_context_struct {
    148 	char __user *buf;
    149 	size_t actual;
    150 	size_t space;
    151 	loff_t offset;
    152 } DUMP_CONTEXT_T;
    153 
    154 VCHIQ_STATE_T g_state;
    155 static DEFINE_SPINLOCK(msg_queue_spinlock);
    156 
    157 static const char *const ioctl_names[] = {
    158 	"CONNECT",
    159 	"SHUTDOWN",
    160 	"CREATE_SERVICE",
    161 	"REMOVE_SERVICE",
    162 	"QUEUE_MESSAGE",
    163 	"QUEUE_BULK_TRANSMIT",
    164 	"QUEUE_BULK_RECEIVE",
    165 	"AWAIT_COMPLETION",
    166 	"DEQUEUE_MESSAGE",
    167 	"GET_CLIENT_ID",
    168 	"GET_CONFIG",
    169 	"CLOSE_SERVICE",
    170 	"USE_SERVICE",
    171 	"RELEASE_SERVICE",
    172 	"SET_SERVICE_OPTION",
    173 	"DUMP_PHYS_MEM"
    174 };
    175 
    176 vchiq_static_assert((sizeof(ioctl_names)/sizeof(ioctl_names[0])) ==
    177 	(VCHIQ_IOC_MAX + 1));
    178 
    179 static dev_type_open(vchiq_open);
    180 
    181 struct cdevsw vchiq_cdevsw = {
    182 	.d_open = vchiq_open,
    183 	.d_close = noclose,
    184 	.d_read = noread,
    185 	.d_write = nowrite,
    186 	.d_ioctl = noioctl,
    187 	.d_stop = nostop,
    188 	.d_tty = notty,
    189 	.d_poll = nopoll,
    190 	.d_mmap = nommap,
    191 	.d_kqfilter = nokqfilter,
    192 	.d_discard = nodiscard,
    193 	.d_flag = D_OTHER | D_MPSAFE
    194 };
    195 
    196 extern struct cfdriver vchiq_cd;
    197 
    198 static int	vchiq_ioctl(struct file *, u_long, void *);
    199 static int	vchiq_close(struct file *);
    200 static int	vchiq_read(struct file *, off_t *, struct uio *, kauth_cred_t, int);
    201 
    202 static const struct fileops vchiq_fileops = {
    203 	.fo_read = vchiq_read,
    204 	.fo_write = fbadop_write,
    205 	.fo_ioctl = vchiq_ioctl,
    206 	.fo_fcntl = fnullop_fcntl,
    207 	.fo_poll = fnullop_poll,
    208 	.fo_stat = fbadop_stat,
    209 	.fo_close = vchiq_close,
    210 	.fo_kqfilter = fnullop_kqfilter,
    211 };
    212 
    213 #if 0
    214 static void
    215 dump_phys_mem(void *virt_addr, uint32_t num_bytes);
    216 #endif
    217 
    218 /****************************************************************************
    219 *
    220 *   add_completion
    221 *
    222 ***************************************************************************/
    223 
    224 static VCHIQ_STATUS_T
    225 add_completion(VCHIQ_INSTANCE_T instance, VCHIQ_REASON_T reason,
    226 	VCHIQ_HEADER_T *header, USER_SERVICE_T *user_service,
    227 	void *bulk_userdata)
    228 {
    229 	VCHIQ_COMPLETION_DATA_T *completion;
    230 	DEBUG_INITIALISE(g_state.local)
    231 
    232 	while (instance->completion_insert ==
    233 		(instance->completion_remove + MAX_COMPLETIONS)) {
    234 		/* Out of space - wait for the client */
    235 		DEBUG_TRACE(SERVICE_CALLBACK_LINE);
    236 		vchiq_log_trace(vchiq_arm_log_level,
    237 			"add_completion - completion queue full");
    238 		DEBUG_COUNT(COMPLETION_QUEUE_FULL_COUNT);
    239 		if (down_interruptible(&instance->remove_event) != 0) {
    240 			vchiq_log_info(vchiq_arm_log_level,
    241 				"service_callback interrupted");
    242 			return VCHIQ_RETRY;
    243 		} else if (instance->closing) {
    244 			vchiq_log_info(vchiq_arm_log_level,
    245 				"service_callback closing");
    246 			return VCHIQ_ERROR;
    247 		}
    248 		DEBUG_TRACE(SERVICE_CALLBACK_LINE);
    249 	}
    250 
    251 	completion =
    252 		 &instance->completions[instance->completion_insert &
    253 		 (MAX_COMPLETIONS - 1)];
    254 
    255 	completion->header = header;
    256 	completion->reason = reason;
    257 	/* N.B. service_userdata is updated while processing AWAIT_COMPLETION */
    258 	completion->service_userdata = user_service->service;
    259 	completion->bulk_userdata = bulk_userdata;
    260 
    261 	if (reason == VCHIQ_SERVICE_CLOSED)
    262 		/* Take an extra reference, to be held until
    263 		   this CLOSED notification is delivered. */
    264 		lock_service(user_service->service);
    265 
    266 	/* A write barrier is needed here to ensure that the entire completion
    267 		record is written out before the insert point. */
    268 	wmb();
    269 
    270 	if (reason == VCHIQ_MESSAGE_AVAILABLE)
    271 		user_service->message_available_pos =
    272 			instance->completion_insert;
    273 	instance->completion_insert++;
    274 
    275 	up(&instance->insert_event);
    276 
    277 	return VCHIQ_SUCCESS;
    278 }
    279 
    280 /****************************************************************************
    281 *
    282 *   service_callback
    283 *
    284 ***************************************************************************/
    285 
    286 static VCHIQ_STATUS_T
    287 service_callback(VCHIQ_REASON_T reason, VCHIQ_HEADER_T *header,
    288 	VCHIQ_SERVICE_HANDLE_T handle, void *bulk_userdata)
    289 {
    290 	/* How do we ensure the callback goes to the right client?
    291 	** The service_user data points to a USER_SERVICE_T record containing
    292 	** the original callback and the user state structure, which contains a
    293 	** circular buffer for completion records.
    294 	*/
    295 	USER_SERVICE_T *user_service;
    296 	VCHIQ_SERVICE_T *service;
    297 	VCHIQ_INSTANCE_T instance;
    298 	DEBUG_INITIALISE(g_state.local)
    299 
    300 	DEBUG_TRACE(SERVICE_CALLBACK_LINE);
    301 
    302 	service = handle_to_service(handle);
    303 	BUG_ON(!service);
    304 	user_service = (USER_SERVICE_T *)service->base.userdata;
    305 	instance = user_service->instance;
    306 
    307 	if (!instance || instance->closing)
    308 		return VCHIQ_SUCCESS;
    309 
    310 	vchiq_log_trace(vchiq_arm_log_level,
    311 		"service_callback - service %lx(%d), handle %x, reason %d, header %lx, "
    312 		"instance %lx, bulk_userdata %lx",
    313 		(unsigned long)user_service,
    314 		service->localport, service->handle,
    315 		reason, (unsigned long)header,
    316 		(unsigned long)instance, (unsigned long)bulk_userdata);
    317 
    318 	if (header && user_service->is_vchi) {
    319 		spin_lock(&msg_queue_spinlock);
    320 		while (user_service->msg_insert ==
    321 			(user_service->msg_remove + MSG_QUEUE_SIZE)) {
    322 			spin_unlock(&msg_queue_spinlock);
    323 			DEBUG_TRACE(SERVICE_CALLBACK_LINE);
    324 			DEBUG_COUNT(MSG_QUEUE_FULL_COUNT);
    325 			vchiq_log_trace(vchiq_arm_log_level,
    326 				"service_callback - msg queue full");
    327 			/* If there is no MESSAGE_AVAILABLE in the completion
    328 			** queue, add one
    329 			*/
    330 			if ((user_service->message_available_pos -
    331 				instance->completion_remove) < 0) {
    332 				VCHIQ_STATUS_T status;
    333 				vchiq_log_info(vchiq_arm_log_level,
    334 					"Inserting extra MESSAGE_AVAILABLE");
    335 				DEBUG_TRACE(SERVICE_CALLBACK_LINE);
    336 				status = add_completion(instance, reason,
    337 					NULL, user_service, bulk_userdata);
    338 				if (status != VCHIQ_SUCCESS) {
    339 					DEBUG_TRACE(SERVICE_CALLBACK_LINE);
    340 					return status;
    341 				}
    342 			}
    343 
    344 			DEBUG_TRACE(SERVICE_CALLBACK_LINE);
    345 			if (down_interruptible(&user_service->remove_event)
    346 				!= 0) {
    347 				vchiq_log_info(vchiq_arm_log_level,
    348 					"service_callback interrupted");
    349 				DEBUG_TRACE(SERVICE_CALLBACK_LINE);
    350 				return VCHIQ_RETRY;
    351 			} else if (instance->closing) {
    352 				vchiq_log_info(vchiq_arm_log_level,
    353 					"service_callback closing");
    354 				DEBUG_TRACE(SERVICE_CALLBACK_LINE);
    355 				return VCHIQ_ERROR;
    356 			}
    357 			DEBUG_TRACE(SERVICE_CALLBACK_LINE);
    358 			spin_lock(&msg_queue_spinlock);
    359 		}
    360 
    361 		user_service->msg_queue[user_service->msg_insert &
    362 			(MSG_QUEUE_SIZE - 1)] = header;
    363 		user_service->msg_insert++;
    364 		spin_unlock(&msg_queue_spinlock);
    365 
    366 		up(&user_service->insert_event);
    367 
    368 		/* If there is a thread waiting in DEQUEUE_MESSAGE, or if
    369 		** there is a MESSAGE_AVAILABLE in the completion queue then
    370 		** bypass the completion queue.
    371 		*/
    372 		if (((user_service->message_available_pos -
    373 			instance->completion_remove) >= 0) ||
    374 			user_service->dequeue_pending) {
    375 			DEBUG_TRACE(SERVICE_CALLBACK_LINE);
    376 			user_service->dequeue_pending = 0;
    377 			return VCHIQ_SUCCESS;
    378 		}
    379 
    380 		header = NULL;
    381 	}
    382 	DEBUG_TRACE(SERVICE_CALLBACK_LINE);
    383 
    384 	return add_completion(instance, reason, header, user_service,
    385 		bulk_userdata);
    386 }
    387 
    388 /****************************************************************************
    389 *
    390 *   user_service_free
    391 *
    392 ***************************************************************************/
    393 static void
    394 user_service_free(void *userdata)
    395 {
    396 	USER_SERVICE_T *user_service = userdata;
    397 
    398 	_sema_destroy(&user_service->insert_event);
    399 	_sema_destroy(&user_service->remove_event);
    400 
    401 	kfree(user_service);
    402 }
    403 
    404 /****************************************************************************
    405 *
    406 *   vchiq_ioctl
    407 *
    408 ***************************************************************************/
    409 
    410 static int
    411 vchiq_ioctl(struct file *fp, u_long cmd, void *arg)
    412 {
    413 	VCHIQ_INSTANCE_T instance;
    414 	VCHIQ_STATUS_T status = VCHIQ_SUCCESS;
    415 	VCHIQ_SERVICE_T *service = NULL;
    416 	int ret = 0;
    417 	int i, rc;
    418 	DEBUG_INITIALISE(g_state.local)
    419 
    420 	instance = fp->f_data;
    421 
    422 /* XXXBSD: HACK! */
    423 #define _IOC_NR(x) ((x) & 0xff)
    424 #define	_IOC_TYPE(x)	IOCGROUP(x)
    425 
    426 	vchiq_log_trace(vchiq_arm_log_level,
    427 		 "vchiq_ioctl - instance %x, cmd %s, arg %p",
    428 		(unsigned int)instance,
    429 		((_IOC_TYPE(cmd) == VCHIQ_IOC_MAGIC) &&
    430 		(_IOC_NR(cmd) <= VCHIQ_IOC_MAX)) ?
    431 		ioctl_names[_IOC_NR(cmd)] : "<invalid>", arg);
    432 
    433 	switch (cmd) {
    434 	case VCHIQ_IOC_SHUTDOWN:
    435 		if (!instance->connected)
    436 			break;
    437 
    438 		/* Remove all services */
    439 		i = 0;
    440 		while ((service = next_service_by_instance(instance->state,
    441 			instance, &i)) != NULL) {
    442 			status = vchiq_remove_service(service->handle);
    443 			unlock_service(service);
    444 			if (status != VCHIQ_SUCCESS)
    445 				break;
    446 		}
    447 		service = NULL;
    448 
    449 		if (status == VCHIQ_SUCCESS) {
    450 			/* Wake the completion thread and ask it to exit */
    451 			instance->closing = 1;
    452 			up(&instance->insert_event);
    453 		}
    454 
    455 		break;
    456 
    457 	case VCHIQ_IOC_CONNECT:
    458 		if (instance->connected) {
    459 			ret = -EINVAL;
    460 			break;
    461 		}
    462 		rc = lmutex_lock_interruptible(&instance->state->mutex);
    463 		if (rc != 0) {
    464 			vchiq_log_error(vchiq_arm_log_level,
    465 				"vchiq: connect: could not lock mutex for "
    466 				"state %d: %d",
    467 				instance->state->id, rc);
    468 			ret = -EINTR;
    469 			break;
    470 		}
    471 		status = vchiq_connect_internal(instance->state, instance);
    472 		lmutex_unlock(&instance->state->mutex);
    473 
    474 		if (status == VCHIQ_SUCCESS)
    475 			instance->connected = 1;
    476 		else
    477 			vchiq_log_error(vchiq_arm_log_level,
    478 				"vchiq: could not connect: %d", status);
    479 		break;
    480 
    481 	case VCHIQ_IOC_CREATE_SERVICE: {
    482 		VCHIQ_CREATE_SERVICE_T *pargs = arg;
    483 		USER_SERVICE_T *user_service = NULL;
    484 		void *userdata;
    485 		int srvstate;
    486 
    487 		user_service = kzalloc(sizeof(USER_SERVICE_T), GFP_KERNEL);
    488 		if (!user_service) {
    489 			ret = -ENOMEM;
    490 			break;
    491 		}
    492 
    493 		if (pargs->is_open) {
    494 			if (!instance->connected) {
    495 				ret = -ENOTCONN;
    496 				kfree(user_service);
    497 				break;
    498 			}
    499 			srvstate = VCHIQ_SRVSTATE_OPENING;
    500 		} else {
    501 			srvstate =
    502 				 instance->connected ?
    503 				 VCHIQ_SRVSTATE_LISTENING :
    504 				 VCHIQ_SRVSTATE_HIDDEN;
    505 		}
    506 
    507 		userdata = pargs->params.userdata;
    508 		pargs->params.callback = service_callback;
    509 		pargs->params.userdata = user_service;
    510 		service = vchiq_add_service_internal(
    511 				instance->state,
    512 				&pargs->params, srvstate,
    513 				instance, user_service_free);
    514 
    515 		if (service != NULL) {
    516 			user_service->service = service;
    517 			user_service->userdata = userdata;
    518 			user_service->instance = instance;
    519 			user_service->is_vchi = pargs->is_vchi;
    520 			user_service->dequeue_pending = 0;
    521 			user_service->message_available_pos =
    522 				instance->completion_remove - 1;
    523 			user_service->msg_insert = 0;
    524 			user_service->msg_remove = 0;
    525 			_sema_init(&user_service->insert_event, 0);
    526 			_sema_init(&user_service->remove_event, 0);
    527 
    528 			if (pargs->is_open) {
    529 				status = vchiq_open_service_internal
    530 					(service, (uintptr_t)instance->l);
    531 				if (status != VCHIQ_SUCCESS) {
    532 					vchiq_remove_service(service->handle);
    533 					service = NULL;
    534 					ret = (status == VCHIQ_RETRY) ?
    535 						-EINTR : -EIO;
    536 					break;
    537 				}
    538 			}
    539 
    540 #ifdef VCHIQ_IOCTL_DEBUG
    541 			printf("%s: [CREATE SERVICE] handle = %08x\n", __func__, service->handle);
    542 #endif
    543 			pargs->handle = service->handle;
    544 
    545 			service = NULL;
    546 		} else {
    547 			ret = -EEXIST;
    548 			kfree(user_service);
    549 		}
    550 	} break;
    551 
    552 	case VCHIQ_IOC_CLOSE_SERVICE: {
    553 		VCHIQ_SERVICE_HANDLE_T handle = *(VCHIQ_SERVICE_HANDLE_T *)arg;
    554 
    555 #ifdef VCHIQ_IOCTL_DEBUG
    556 		printf("%s: [CLOSE SERVICE] handle = %08x\n", __func__, handle);
    557 #endif
    558 
    559 		service = find_service_for_instance(instance, handle);
    560 		if (service != NULL)
    561 			status = vchiq_close_service(service->handle);
    562 		else
    563 			ret = -EINVAL;
    564 	} break;
    565 
    566 	case VCHIQ_IOC_REMOVE_SERVICE: {
    567 		VCHIQ_SERVICE_HANDLE_T handle = *(VCHIQ_SERVICE_HANDLE_T *)arg;
    568 
    569 #ifdef VCHIQ_IOCTL_DEBUG
    570 		printf("%s: [REMOVE SERVICE] handle = %08x\n", __func__, handle);
    571 #endif
    572 
    573 		service = find_service_for_instance(instance, handle);
    574 		if (service != NULL)
    575 			status = vchiq_remove_service(service->handle);
    576 		else
    577 			ret = -EINVAL;
    578 	} break;
    579 
    580 	case VCHIQ_IOC_USE_SERVICE:
    581 	case VCHIQ_IOC_RELEASE_SERVICE:	{
    582 		VCHIQ_SERVICE_HANDLE_T handle = *(VCHIQ_SERVICE_HANDLE_T *)arg;
    583 
    584 #ifdef VCHIQ_IOCTL_DEBUG
    585 		printf("%s: [%s SERVICE] handle = %08x\n", __func__,
    586 		    cmd == VCHIQ_IOC_USE_SERVICE ? "USE" : "RELEASE", handle);
    587 #endif
    588 
    589 		service = find_service_for_instance(instance, handle);
    590 		if (service != NULL) {
    591 			status = (cmd == VCHIQ_IOC_USE_SERVICE)	?
    592 				vchiq_use_service_internal(service) :
    593 				vchiq_release_service_internal(service);
    594 			if (status != VCHIQ_SUCCESS) {
    595 				vchiq_log_error(vchiq_susp_log_level,
    596 					"%s: cmd %s returned error %d for "
    597 					"service %c%c%c%c:%8x",
    598 					__func__,
    599 					(cmd == VCHIQ_IOC_USE_SERVICE) ?
    600 						"VCHIQ_IOC_USE_SERVICE" :
    601 						"VCHIQ_IOC_RELEASE_SERVICE",
    602 					status,
    603 					VCHIQ_FOURCC_AS_4CHARS(
    604 						service->base.fourcc),
    605 					service->client_id);
    606 				ret = -EINVAL;
    607 			}
    608 		} else
    609 			ret = -EINVAL;
    610 	} break;
    611 
    612 	case VCHIQ_IOC_QUEUE_MESSAGE: {
    613 		VCHIQ_QUEUE_MESSAGE_T *pargs = arg;
    614 
    615 #ifdef VCHIQ_IOCTL_DEBUG
    616 		printf("%s: [QUEUE MESSAGE] handle = %08x\n", __func__, pargs->handle);
    617 #endif
    618 
    619 		service = find_service_for_instance(instance, pargs->handle);
    620 
    621 		if ((service != NULL) && (pargs->count <= MAX_ELEMENTS)) {
    622 			/* Copy elements into kernel space */
    623 			VCHIQ_ELEMENT_T elements[MAX_ELEMENTS];
    624 			if (copy_from_user(elements, pargs->elements,
    625 				pargs->count * sizeof(VCHIQ_ELEMENT_T)) == 0)
    626 				status = vchiq_queue_message
    627 					(pargs->handle,
    628 					elements, pargs->count);
    629 			else
    630 				ret = -EFAULT;
    631 		} else {
    632 			ret = -EINVAL;
    633 		}
    634 	} break;
    635 
    636 	case VCHIQ_IOC_QUEUE_BULK_TRANSMIT:
    637 	case VCHIQ_IOC_QUEUE_BULK_RECEIVE: {
    638 		VCHIQ_QUEUE_BULK_TRANSFER_T *pargs = arg;
    639 		struct bulk_waiter_node *waiter = NULL;
    640 		VCHIQ_BULK_DIR_T dir =
    641 			(cmd == VCHIQ_IOC_QUEUE_BULK_TRANSMIT) ?
    642 			VCHIQ_BULK_TRANSMIT : VCHIQ_BULK_RECEIVE;
    643 
    644 		service = find_service_for_instance(instance, pargs->handle);
    645 		if (!service) {
    646 			ret = -EINVAL;
    647 			break;
    648 		}
    649 
    650 		if (pargs->mode == VCHIQ_BULK_MODE_BLOCKING) {
    651 			waiter = kzalloc(sizeof(struct bulk_waiter_node),
    652 				GFP_KERNEL);
    653 			if (!waiter) {
    654 				ret = -ENOMEM;
    655 				break;
    656 			}
    657 			pargs->userdata = &waiter->bulk_waiter;
    658 		} else if (pargs->mode == VCHIQ_BULK_MODE_WAITING) {
    659 			struct list_head *pos;
    660 			lmutex_lock(&instance->bulk_waiter_list_mutex);
    661 			list_for_each(pos, &instance->bulk_waiter_list) {
    662 				if (list_entry(pos, struct bulk_waiter_node,
    663 					list)->l == current) {
    664 					waiter = list_entry(pos,
    665 						struct bulk_waiter_node,
    666 						list);
    667 					list_del(pos);
    668 					break;
    669 				}
    670 
    671 			}
    672 			lmutex_unlock(&instance->bulk_waiter_list_mutex);
    673 			if (!waiter) {
    674 				vchiq_log_error(vchiq_arm_log_level,
    675 					"no bulk_waiter found for lwp %p",
    676 					current);
    677 				ret = -ESRCH;
    678 				break;
    679 			}
    680 			vchiq_log_info(vchiq_arm_log_level,
    681 				"found bulk_waiter %x for lwp %p",
    682 				(unsigned int)waiter, current);
    683 			pargs->userdata = &waiter->bulk_waiter;
    684 		}
    685 		status = vchiq_bulk_transfer
    686 			(pargs->handle,
    687 			 VCHI_MEM_HANDLE_INVALID,
    688 			 pargs->data, pargs->size,
    689 			 pargs->userdata, pargs->mode,
    690 			 dir);
    691 		if (!waiter)
    692 			break;
    693 		if ((status != VCHIQ_RETRY) || fatal_signal_pending(current) ||
    694 			!waiter->bulk_waiter.bulk) {
    695 			if (waiter->bulk_waiter.bulk) {
    696 				/* Cancel the signal when the transfer
    697 				** completes. */
    698 				spin_lock(&bulk_waiter_spinlock);
    699 				waiter->bulk_waiter.bulk->userdata = NULL;
    700 				spin_unlock(&bulk_waiter_spinlock);
    701 			}
    702 			_sema_destroy(&waiter->bulk_waiter.event);
    703 			kfree(waiter);
    704 		} else {
    705 			const VCHIQ_BULK_MODE_T mode_waiting =
    706 				VCHIQ_BULK_MODE_WAITING;
    707 			waiter->l = current;
    708 			lmutex_lock(&instance->bulk_waiter_list_mutex);
    709 			list_add(&waiter->list, &instance->bulk_waiter_list);
    710 			lmutex_unlock(&instance->bulk_waiter_list_mutex);
    711 			vchiq_log_info(vchiq_arm_log_level,
    712 				"saved bulk_waiter %x for lwp %p",
    713 				(unsigned int)waiter, current);
    714 
    715 			pargs->mode = mode_waiting;
    716 		}
    717 	} break;
    718 
    719 	case VCHIQ_IOC_AWAIT_COMPLETION: {
    720 		VCHIQ_AWAIT_COMPLETION_T *pargs = arg;
    721 		int count = 0;
    722 
    723 		DEBUG_TRACE(AWAIT_COMPLETION_LINE);
    724 		if (!instance->connected) {
    725 			ret = -ENOTCONN;
    726 			break;
    727 		}
    728 
    729 		lmutex_lock(&instance->completion_mutex);
    730 
    731 		DEBUG_TRACE(AWAIT_COMPLETION_LINE);
    732 		while ((instance->completion_remove ==
    733 			instance->completion_insert)
    734 			&& !instance->closing) {
    735 			DEBUG_TRACE(AWAIT_COMPLETION_LINE);
    736 			lmutex_unlock(&instance->completion_mutex);
    737 			rc = down_interruptible(&instance->insert_event);
    738 			lmutex_lock(&instance->completion_mutex);
    739 			if (rc != 0) {
    740 				DEBUG_TRACE(AWAIT_COMPLETION_LINE);
    741 				vchiq_log_info(vchiq_arm_log_level,
    742 					"AWAIT_COMPLETION interrupted");
    743 				ret = -EINTR;
    744 				break;
    745 			}
    746 		}
    747 		DEBUG_TRACE(AWAIT_COMPLETION_LINE);
    748 
    749 		/* A read memory barrier is needed to stop prefetch of a stale
    750 		** completion record
    751 		*/
    752 		rmb();
    753 
    754 		if (ret == 0) {
    755 			int msgbufcount = pargs->msgbufcount;
    756 
    757 			for (; count < pargs->count; count++) {
    758 				VCHIQ_COMPLETION_DATA_T *completion;
    759 				VCHIQ_SERVICE_T *service1;
    760 				USER_SERVICE_T *user_service;
    761 				VCHIQ_HEADER_T *header;
    762 				if (instance->completion_remove ==
    763 					instance->completion_insert)
    764 					break;
    765 				completion = &instance->completions[
    766 					instance->completion_remove &
    767 					(MAX_COMPLETIONS - 1)];
    768 
    769 				service1 = completion->service_userdata;
    770 				user_service = service1->base.userdata;
    771 				completion->service_userdata =
    772 					user_service->userdata;
    773 
    774 				header = completion->header;
    775 				if (header) {
    776 					void __user *msgbuf;
    777 					int msglen;
    778 
    779 					msglen = header->size +
    780 						sizeof(VCHIQ_HEADER_T);
    781 					/* This must be a VCHIQ-style service */
    782 					if (pargs->msgbufsize < msglen) {
    783 						vchiq_log_error(
    784 							vchiq_arm_log_level,
    785 							"header %x: msgbufsize"
    786 							" %x < msglen %x",
    787 							(unsigned int)header,
    788 							pargs->msgbufsize,
    789 							msglen);
    790 						WARN(1, "invalid message "
    791 							"size\n");
    792 						if (count == 0)
    793 							ret = -EMSGSIZE;
    794 						break;
    795 					}
    796 					if (msgbufcount <= 0)
    797 						/* Stall here for lack of a
    798 						** buffer for the message. */
    799 						break;
    800 					/* Get the pointer from user space */
    801 					msgbufcount--;
    802 					if (copy_from_user(&msgbuf,
    803 						(const void __user *)
    804 						&pargs->msgbufs[msgbufcount],
    805 						sizeof(msgbuf)) != 0) {
    806 						if (count == 0)
    807 							ret = -EFAULT;
    808 						break;
    809 					}
    810 
    811 					/* Copy the message to user space */
    812 					if (copy_to_user(msgbuf, header,
    813 						msglen) != 0) {
    814 						if (count == 0)
    815 							ret = -EFAULT;
    816 						break;
    817 					}
    818 
    819 					/* Now it has been copied, the message
    820 					** can be released. */
    821 					vchiq_release_message(service1->handle,
    822 						header);
    823 
    824 					/* The completion must point to the
    825 					** msgbuf. */
    826 					completion->header = msgbuf;
    827 				}
    828 
    829 				if (completion->reason ==
    830 					VCHIQ_SERVICE_CLOSED)
    831 					unlock_service(service1);
    832 
    833 				if (copy_to_user((void __user *)(
    834 					(size_t)pargs->buf +
    835 					count * sizeof(VCHIQ_COMPLETION_DATA_T)),
    836 					completion,
    837 					sizeof(VCHIQ_COMPLETION_DATA_T)) != 0) {
    838 						if (count == 0)
    839 							ret = -EFAULT;
    840 					break;
    841 				}
    842 
    843 				instance->completion_remove++;
    844 			}
    845 
    846 			pargs->msgbufcount = msgbufcount;
    847 			pargs->count = count;
    848 		}
    849 
    850 		if (count != 0)
    851 			up(&instance->remove_event);
    852 		lmutex_unlock(&instance->completion_mutex);
    853 		DEBUG_TRACE(AWAIT_COMPLETION_LINE);
    854 	} break;
    855 
    856 	case VCHIQ_IOC_DEQUEUE_MESSAGE: {
    857 		VCHIQ_DEQUEUE_MESSAGE_T *pargs = arg;
    858 		USER_SERVICE_T *user_service;
    859 		VCHIQ_HEADER_T *header;
    860 
    861 		DEBUG_TRACE(DEQUEUE_MESSAGE_LINE);
    862 		service = find_service_for_instance(instance, pargs->handle);
    863 		if (!service) {
    864 			ret = -EINVAL;
    865 			break;
    866 		}
    867 		user_service = (USER_SERVICE_T *)service->base.userdata;
    868 		if (user_service->is_vchi == 0) {
    869 			ret = -EINVAL;
    870 			break;
    871 		}
    872 
    873 		spin_lock(&msg_queue_spinlock);
    874 		if (user_service->msg_remove == user_service->msg_insert) {
    875 			if (!pargs->blocking) {
    876 				spin_unlock(&msg_queue_spinlock);
    877 				DEBUG_TRACE(DEQUEUE_MESSAGE_LINE);
    878 				ret = -EWOULDBLOCK;
    879 				break;
    880 			}
    881 			user_service->dequeue_pending = 1;
    882 			do {
    883 				spin_unlock(&msg_queue_spinlock);
    884 				DEBUG_TRACE(DEQUEUE_MESSAGE_LINE);
    885 				if (down_interruptible(
    886 					&user_service->insert_event) != 0) {
    887 					vchiq_log_info(vchiq_arm_log_level,
    888 						"DEQUEUE_MESSAGE interrupted");
    889 					ret = -EINTR;
    890 					break;
    891 				}
    892 				spin_lock(&msg_queue_spinlock);
    893 			} while (user_service->msg_remove ==
    894 				user_service->msg_insert);
    895 
    896 			if (ret)
    897 				break;
    898 		}
    899 
    900 		BUG_ON((int)(user_service->msg_insert -
    901 			user_service->msg_remove) < 0);
    902 
    903 		header = user_service->msg_queue[user_service->msg_remove &
    904 			(MSG_QUEUE_SIZE - 1)];
    905 		user_service->msg_remove++;
    906 		spin_unlock(&msg_queue_spinlock);
    907 
    908 		up(&user_service->remove_event);
    909 		if (header == NULL)
    910 			ret = -ENOTCONN;
    911 		else if (header->size <= pargs->bufsize) {
    912 			/* Copy to user space if msgbuf is not NULL */
    913 			if ((pargs->buf == NULL) ||
    914 				(copy_to_user((void __user *)pargs->buf,
    915 				header->data,
    916 				header->size) == 0)) {
    917 				pargs->bufsize = header->size;
    918 				vchiq_release_message(
    919 					service->handle,
    920 					header);
    921 			} else
    922 				ret = -EFAULT;
    923 		} else {
    924 			vchiq_log_error(vchiq_arm_log_level,
    925 				"header %x: bufsize %x < size %x",
    926 				(unsigned int)header, pargs->bufsize,
    927 				header->size);
    928 			WARN(1, "invalid size\n");
    929 			ret = -EMSGSIZE;
    930 		}
    931 		DEBUG_TRACE(DEQUEUE_MESSAGE_LINE);
    932 	} break;
    933 
    934 	case VCHIQ_IOC_GET_CLIENT_ID: {
    935 		VCHIQ_SERVICE_HANDLE_T handle = (VCHIQ_SERVICE_HANDLE_T)arg;
    936 
    937 		ret = vchiq_get_client_id(handle);
    938 	} break;
    939 
    940 	case VCHIQ_IOC_GET_CONFIG: {
    941 		VCHIQ_GET_CONFIG_T *pargs = arg;
    942 		VCHIQ_CONFIG_T config;
    943 
    944 		if (pargs->config_size > sizeof(config)) {
    945 			ret = -EINVAL;
    946 			break;
    947 		}
    948 		status = vchiq_get_config(instance, pargs->config_size, &config);
    949 		if (status == VCHIQ_SUCCESS) {
    950 			if (copy_to_user((void __user *)pargs->pconfig,
    951 				&config, pargs->config_size) != 0) {
    952 				ret = -EFAULT;
    953 				break;
    954 			}
    955 		}
    956 	} break;
    957 
    958 	case VCHIQ_IOC_SET_SERVICE_OPTION: {
    959 		VCHIQ_SET_SERVICE_OPTION_T *pargs = arg;
    960 
    961 		service = find_service_for_instance(instance, pargs->handle);
    962 		if (!service) {
    963 			ret = -EINVAL;
    964 			break;
    965 		}
    966 
    967 		status = vchiq_set_service_option(
    968 				pargs->handle, pargs->option, pargs->value);
    969 	} break;
    970 
    971 	case VCHIQ_IOC_DUMP_PHYS_MEM: {
    972 #if 0
    973 		VCHIQ_DUMP_MEM_T *pargs = arg;
    974 #endif
    975 
    976 		printf("IMPLEMENT ME: %s:%d\n", __FILE__, __LINE__);
    977 #if 0
    978 		dump_phys_mem(pargs->virt_addr, pargs->num_bytes);
    979 #endif
    980 	} break;
    981 
    982 	default:
    983 		ret = -ENOTTY;
    984 		break;
    985 	}
    986 
    987 	if (service)
    988 		unlock_service(service);
    989 
    990 	if (ret == 0) {
    991 		if (status == VCHIQ_ERROR)
    992 			ret = -EIO;
    993 		else if (status == VCHIQ_RETRY)
    994 			ret = -EINTR;
    995 	}
    996 
    997 	if ((status == VCHIQ_SUCCESS) && (ret < 0) && (ret != -EINTR) &&
    998 		(ret != -EWOULDBLOCK))
    999 		vchiq_log_info(vchiq_arm_log_level,
   1000 			"  ioctl instance %lx, cmd %s -> status %d, %d",
   1001 			(unsigned long)instance,
   1002 			(_IOC_NR(cmd) <= VCHIQ_IOC_MAX) ?
   1003 				ioctl_names[_IOC_NR(cmd)] :
   1004 				"<invalid>",
   1005 			status, ret);
   1006 	else
   1007 		vchiq_log_trace(vchiq_arm_log_level,
   1008 			"  ioctl instance %lx, cmd %s -> status %d, %d",
   1009 			(unsigned long)instance,
   1010 			(_IOC_NR(cmd) <= VCHIQ_IOC_MAX) ?
   1011 				ioctl_names[_IOC_NR(cmd)] :
   1012 				"<invalid>",
   1013 			status, ret);
   1014 
   1015 	/* XXXBSD: report BSD-style error to userland */
   1016 	if (ret < 0)
   1017 		ret = -ret;
   1018 
   1019 	return ret;
   1020 }
   1021 
   1022 #if notyet
   1023 static void
   1024 instance_dtr(void *data)
   1025 {
   1026 
   1027    free(data, M_VCHIQ);
   1028 }
   1029 #endif
   1030 
   1031 /****************************************************************************
   1032 *
   1033 *   vchiq_open
   1034 *
   1035 ***************************************************************************/
   1036 
   1037 static int
   1038 vchiq_open(dev_t dev, int flags, int mode, lwp_t *l)
   1039 {
   1040 	VCHIQ_INSTANCE_T instance = NULL;
   1041 	struct file *fp;
   1042 	int err, fd;
   1043 
   1044 	vchiq_log_info(vchiq_arm_log_level, "vchiq_open");
   1045 
   1046 	/* XXXBSD: do we really need this check? */
   1047 	if (device_lookup_private(&vchiq_cd, minor(dev)) != NULL) {
   1048 		VCHIQ_STATE_T *state = vchiq_get_state();
   1049 
   1050 		if (!state) {
   1051 			vchiq_log_error(vchiq_arm_log_level,
   1052 				"vchiq has no connection to VideoCore");
   1053 			return -ENOTCONN;
   1054 		}
   1055 
   1056 		instance = kzalloc(sizeof(*instance), GFP_KERNEL);
   1057 		if (!instance)
   1058 			return -ENOMEM;
   1059 
   1060 		err = fd_allocfile(&fp, &fd);
   1061 		if (err) {
   1062 			kfree(instance);
   1063 			return -err;
   1064 		}
   1065 
   1066 		instance->state = state;
   1067 		instance->l = l;
   1068 
   1069 #ifdef notyet
   1070 		ret = vchiq_proc_add_instance(instance);
   1071 		if (ret != 0) {
   1072 			kfree(instance);
   1073 			return ret;
   1074 		}
   1075 #endif
   1076 
   1077 		_sema_init(&instance->insert_event, 0);
   1078 		_sema_init(&instance->remove_event, 0);
   1079 		lmutex_init(&instance->completion_mutex);
   1080 		lmutex_init(&instance->bulk_waiter_list_mutex);
   1081 		INIT_LIST_HEAD(&instance->bulk_waiter_list);
   1082 
   1083 	}
   1084 	else {
   1085 		vchiq_log_error(vchiq_arm_log_level,
   1086 			"Unknown minor device");
   1087 		return -ENXIO;
   1088 	}
   1089 
   1090 	return fd_clone(fp, fd, flags, &vchiq_fileops, instance);
   1091 }
   1092 
   1093 /****************************************************************************
   1094 *
   1095 *   vchiq_release
   1096 *
   1097 ***************************************************************************/
   1098 
   1099 static int
   1100 vchiq_close(struct file *fp)
   1101 {
   1102 	int ret = 0;
   1103 	if (1) {
   1104 		VCHIQ_INSTANCE_T instance;
   1105 		VCHIQ_STATE_T *state = vchiq_get_state();
   1106 		VCHIQ_SERVICE_T *service;
   1107 		int i;
   1108 
   1109 		instance = fp->f_data;
   1110 
   1111 		vchiq_log_info(vchiq_arm_log_level,
   1112 			"vchiq_release: instance=%lx",
   1113 			(unsigned long)instance);
   1114 
   1115 		if (!state) {
   1116 			ret = -EPERM;
   1117 			goto out;
   1118 		}
   1119 
   1120 		/* Ensure videocore is awake to allow termination. */
   1121 		vchiq_use_internal(instance->state, NULL,
   1122 				USE_TYPE_VCHIQ);
   1123 
   1124 		lmutex_lock(&instance->completion_mutex);
   1125 
   1126 		/* Wake the completion thread and ask it to exit */
   1127 		instance->closing = 1;
   1128 		up(&instance->insert_event);
   1129 
   1130 		lmutex_unlock(&instance->completion_mutex);
   1131 
   1132 		/* Wake the slot handler if the completion queue is full. */
   1133 		up(&instance->remove_event);
   1134 
   1135 		/* Mark all services for termination... */
   1136 		i = 0;
   1137 		while ((service = next_service_by_instance(state, instance,
   1138 			&i)) !=	NULL) {
   1139 			USER_SERVICE_T *user_service = service->base.userdata;
   1140 
   1141 			/* Wake the slot handler if the msg queue is full. */
   1142 			up(&user_service->remove_event);
   1143 
   1144 			vchiq_terminate_service_internal(service);
   1145 			unlock_service(service);
   1146 		}
   1147 
   1148 		/* ...and wait for them to die */
   1149 		i = 0;
   1150 		while ((service = next_service_by_instance(state, instance, &i))
   1151 			!= NULL) {
   1152 			USER_SERVICE_T *user_service = service->base.userdata;
   1153 
   1154 			down(&service->remove_event);
   1155 
   1156 			BUG_ON(service->srvstate != VCHIQ_SRVSTATE_FREE);
   1157 
   1158 			spin_lock(&msg_queue_spinlock);
   1159 
   1160 			while (user_service->msg_remove !=
   1161 				user_service->msg_insert) {
   1162 				VCHIQ_HEADER_T *header = user_service->
   1163 					msg_queue[user_service->msg_remove &
   1164 						(MSG_QUEUE_SIZE - 1)];
   1165 				user_service->msg_remove++;
   1166 				spin_unlock(&msg_queue_spinlock);
   1167 
   1168 				if (header)
   1169 					vchiq_release_message(
   1170 						service->handle,
   1171 						header);
   1172 				spin_lock(&msg_queue_spinlock);
   1173 			}
   1174 
   1175 			spin_unlock(&msg_queue_spinlock);
   1176 
   1177 			unlock_service(service);
   1178 		}
   1179 
   1180 		/* Release any closed services */
   1181 		while (instance->completion_remove !=
   1182 			instance->completion_insert) {
   1183 			VCHIQ_COMPLETION_DATA_T *completion;
   1184 			VCHIQ_SERVICE_T *service1;
   1185 			completion = &instance->completions[
   1186 				instance->completion_remove &
   1187 				(MAX_COMPLETIONS - 1)];
   1188 			service1 = completion->service_userdata;
   1189 			if (completion->reason == VCHIQ_SERVICE_CLOSED)
   1190 				unlock_service(service1);
   1191 			instance->completion_remove++;
   1192 		}
   1193 
   1194 		/* Release the PEER service count. */
   1195 		vchiq_release_internal(instance->state, NULL);
   1196 
   1197 		{
   1198 			struct list_head *pos, *next;
   1199 			list_for_each_safe(pos, next,
   1200 				&instance->bulk_waiter_list) {
   1201 				struct bulk_waiter_node *waiter;
   1202 				waiter = list_entry(pos,
   1203 					struct bulk_waiter_node,
   1204 					list);
   1205 				list_del(pos);
   1206 				vchiq_log_info(vchiq_arm_log_level,
   1207 					"bulk_waiter - cleaned up %x "
   1208 					"for lwp %p",
   1209 					(unsigned int)waiter, waiter->l);
   1210 		                _sema_destroy(&waiter->bulk_waiter.event);
   1211 				kfree(waiter);
   1212 			}
   1213 		}
   1214 
   1215 	}
   1216 	else {
   1217 		vchiq_log_error(vchiq_arm_log_level,
   1218 			"Unknown minor device");
   1219 		ret = -ENXIO;
   1220 	}
   1221 
   1222 out:
   1223 	return ret;
   1224 }
   1225 
   1226 /****************************************************************************
   1227 *
   1228 *   vchiq_dump
   1229 *
   1230 ***************************************************************************/
   1231 
   1232 void
   1233 vchiq_dump(void *dump_context, const char *str, int len)
   1234 {
   1235 	DUMP_CONTEXT_T *context = (DUMP_CONTEXT_T *)dump_context;
   1236 
   1237 	if (context->actual < context->space) {
   1238 		int copy_bytes;
   1239 		if (context->offset > 0) {
   1240 			int skip_bytes = min(len, (int)context->offset);
   1241 			str += skip_bytes;
   1242 			len -= skip_bytes;
   1243 			context->offset -= skip_bytes;
   1244 			if (context->offset > 0)
   1245 				return;
   1246 		}
   1247 		copy_bytes = min(len, (int)(context->space - context->actual));
   1248 		if (copy_bytes == 0)
   1249 			return;
   1250 		memcpy(context->buf + context->actual, str, copy_bytes);
   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 			memcpy(context->buf + context->actual - 1, &cr, 1);
   1260 		}
   1261 	}
   1262 }
   1263 
   1264 /****************************************************************************
   1265 *
   1266 *   vchiq_dump_platform_instance_state
   1267 *
   1268 ***************************************************************************/
   1269 
   1270 void
   1271 vchiq_dump_platform_instances(void *dump_context)
   1272 {
   1273 	VCHIQ_STATE_T *state = vchiq_get_state();
   1274 	char buf[80];
   1275 	int len;
   1276 	int i;
   1277 
   1278 	/* There is no list of instances, so instead scan all services,
   1279 		marking those that have been dumped. */
   1280 
   1281 	for (i = 0; i < state->unused_service; i++) {
   1282 		VCHIQ_SERVICE_T *service = state->services[i];
   1283 		VCHIQ_INSTANCE_T instance;
   1284 
   1285 		if (service && (service->base.callback == service_callback)) {
   1286 			instance = service->instance;
   1287 			if (instance)
   1288 				instance->mark = 0;
   1289 		}
   1290 	}
   1291 
   1292 	for (i = 0; i < state->unused_service; i++) {
   1293 		VCHIQ_SERVICE_T *service = state->services[i];
   1294 		VCHIQ_INSTANCE_T instance;
   1295 
   1296 		if (service && (service->base.callback == service_callback)) {
   1297 			instance = service->instance;
   1298 			if (instance && !instance->mark) {
   1299 				len = snprintf(buf, sizeof(buf),
   1300 					"Instance %x: lwp %p,%s completions "
   1301 						"%d/%d",
   1302 					(unsigned int)instance, instance->l,
   1303 					instance->connected ? " connected, " :
   1304 						"",
   1305 					instance->completion_insert -
   1306 						instance->completion_remove,
   1307 					MAX_COMPLETIONS);
   1308 
   1309 				vchiq_dump(dump_context, buf, len + 1);
   1310 
   1311 				instance->mark = 1;
   1312 			}
   1313 		}
   1314 	}
   1315 }
   1316 
   1317 /****************************************************************************
   1318 *
   1319 *   vchiq_dump_platform_service_state
   1320 *
   1321 ***************************************************************************/
   1322 
   1323 void
   1324 vchiq_dump_platform_service_state(void *dump_context, VCHIQ_SERVICE_T *service)
   1325 {
   1326 	USER_SERVICE_T *user_service = (USER_SERVICE_T *)service->base.userdata;
   1327 	char buf[80];
   1328 	int len;
   1329 
   1330 	len = snprintf(buf, sizeof(buf), "  instance %x",
   1331 		(unsigned int)service->instance);
   1332 
   1333 	if ((service->base.callback == service_callback) &&
   1334 		user_service->is_vchi) {
   1335 		len += snprintf(buf + len, sizeof(buf) - len,
   1336 			", %d/%d messages",
   1337 			user_service->msg_insert - user_service->msg_remove,
   1338 			MSG_QUEUE_SIZE);
   1339 
   1340 		if (user_service->dequeue_pending)
   1341 			len += snprintf(buf + len, sizeof(buf) - len,
   1342 				" (dequeue pending)");
   1343 	}
   1344 
   1345 	vchiq_dump(dump_context, buf, len + 1);
   1346 }
   1347 
   1348 #ifdef notyet
   1349 /****************************************************************************
   1350 *
   1351 *   dump_user_mem
   1352 *
   1353 ***************************************************************************/
   1354 
   1355 static void
   1356 dump_phys_mem(void *virt_addr, uint32_t num_bytes)
   1357 {
   1358 	int            rc;
   1359 	uint8_t       *end_virt_addr = virt_addr + num_bytes;
   1360 	int            num_pages;
   1361 	int            offset;
   1362 	int            end_offset;
   1363 	int            page_idx;
   1364 	int            prev_idx;
   1365 	struct page   *page;
   1366 	struct page  **pages;
   1367 	uint8_t       *kmapped_virt_ptr;
   1368 
   1369 	/* Align virtAddr and endVirtAddr to 16 byte boundaries. */
   1370 
   1371 	virt_addr = (void *)((unsigned long)virt_addr & ~0x0fuL);
   1372 	end_virt_addr = (void *)(((unsigned long)end_virt_addr + 15uL) &
   1373 		~0x0fuL);
   1374 
   1375 	offset = (int)(long)virt_addr & (PAGE_SIZE - 1);
   1376 	end_offset = (int)(long)end_virt_addr & (PAGE_SIZE - 1);
   1377 
   1378 	num_pages = (offset + num_bytes + PAGE_SIZE - 1) / PAGE_SIZE;
   1379 
   1380 	pages = kmalloc(sizeof(struct page *) * num_pages, GFP_KERNEL);
   1381 	if (pages == NULL) {
   1382 		vchiq_log_error(vchiq_arm_log_level,
   1383 			"Unable to allocation memory for %d pages\n",
   1384 			num_pages);
   1385 		return;
   1386 	}
   1387 
   1388 	down_read(&current->mm->mmap_sem);
   1389 	rc = get_user_pages(current,      /* task */
   1390 		current->mm,              /* mm */
   1391 		(unsigned long)virt_addr, /* start */
   1392 		num_pages,                /* len */
   1393 		0,                        /* write */
   1394 		0,                        /* force */
   1395 		pages,                    /* pages (array of page pointers) */
   1396 		NULL);                    /* vmas */
   1397 	up_read(&current->mm->mmap_sem);
   1398 
   1399 	prev_idx = -1;
   1400 	page = NULL;
   1401 
   1402 	while (offset < end_offset) {
   1403 
   1404 		int page_offset = offset % PAGE_SIZE;
   1405 		page_idx = offset / PAGE_SIZE;
   1406 
   1407 		if (page_idx != prev_idx) {
   1408 
   1409 			if (page != NULL)
   1410 				kunmap(page);
   1411 			page = pages[page_idx];
   1412 			kmapped_virt_ptr = kmap(page);
   1413 
   1414 			prev_idx = page_idx;
   1415 		}
   1416 
   1417 		if (vchiq_arm_log_level >= VCHIQ_LOG_TRACE)
   1418 			vchiq_log_dump_mem("ph",
   1419 				(uint32_t)(unsigned long)&kmapped_virt_ptr[
   1420 					page_offset],
   1421 				&kmapped_virt_ptr[page_offset], 16);
   1422 
   1423 		offset += 16;
   1424 	}
   1425 	if (page != NULL)
   1426 		kunmap(page);
   1427 
   1428 	for (page_idx = 0; page_idx < num_pages; page_idx++)
   1429 		page_cache_release(pages[page_idx]);
   1430 
   1431 	kfree(pages);
   1432 }
   1433 #endif
   1434 
   1435 /****************************************************************************
   1436 *
   1437 *   vchiq_read
   1438 *
   1439 ***************************************************************************/
   1440 
   1441 static int
   1442 vchiq_read(struct file *file, off_t *ppos, struct uio *uio, kauth_cred_t cred,
   1443     int flags)
   1444 {
   1445 	int result;
   1446 
   1447 	char *buf = kmem_zalloc(PAGE_SIZE, KM_SLEEP);
   1448 
   1449 	DUMP_CONTEXT_T context;
   1450 	context.buf = buf;
   1451 	context.actual = 0;
   1452 	context.space = PAGE_SIZE;
   1453 	context.offset = *ppos;
   1454 
   1455 	vchiq_dump_state(&context, &g_state);
   1456 
   1457 	*ppos += context.actual;
   1458 
   1459 	result = uiomove(buf, context.actual, uio);
   1460 	kmem_free(buf, PAGE_SIZE);
   1461 
   1462 	return result;
   1463 }
   1464 
   1465 VCHIQ_STATE_T *
   1466 vchiq_get_state(void)
   1467 {
   1468 
   1469 	if (g_state.remote == NULL)
   1470 		printk(KERN_ERR "%s: g_state.remote == NULL\n", __func__);
   1471 	else if (g_state.remote->initialised != 1)
   1472 		printk(KERN_NOTICE "%s: g_state.remote->initialised != 1 (%d)\n",
   1473 			__func__, g_state.remote->initialised);
   1474 
   1475 	return ((g_state.remote != NULL) &&
   1476 		(g_state.remote->initialised == 1)) ? &g_state : NULL;
   1477 }
   1478 
   1479 /*
   1480  * Autosuspend related functionality
   1481  */
   1482 
   1483 int
   1484 vchiq_videocore_wanted(VCHIQ_STATE_T *state)
   1485 {
   1486 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
   1487 	if (!arm_state)
   1488 		/* autosuspend not supported - always return wanted */
   1489 		return 1;
   1490 	else if (arm_state->blocked_count)
   1491 		return 1;
   1492 	else if (!arm_state->videocore_use_count)
   1493 		/* usage count zero - check for override unless we're forcing */
   1494 		if (arm_state->resume_blocked)
   1495 			return 0;
   1496 		else
   1497 			return vchiq_platform_videocore_wanted(state);
   1498 	else
   1499 		/* non-zero usage count - videocore still required */
   1500 		return 1;
   1501 }
   1502 
   1503 static VCHIQ_STATUS_T
   1504 vchiq_keepalive_vchiq_callback(VCHIQ_REASON_T reason,
   1505 	VCHIQ_HEADER_T *header,
   1506 	VCHIQ_SERVICE_HANDLE_T service_user,
   1507 	void *bulk_user)
   1508 {
   1509 	vchiq_log_error(vchiq_susp_log_level,
   1510 		"%s callback reason %d", __func__, reason);
   1511 	return 0;
   1512 }
   1513 
   1514 static int
   1515 vchiq_keepalive_thread_func(void *v)
   1516 {
   1517 	VCHIQ_STATE_T *state = (VCHIQ_STATE_T *) v;
   1518 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
   1519 
   1520 	VCHIQ_STATUS_T status;
   1521 	VCHIQ_INSTANCE_T instance;
   1522 	VCHIQ_SERVICE_HANDLE_T ka_handle;
   1523 
   1524 	VCHIQ_SERVICE_PARAMS_T params = {
   1525 		.fourcc      = VCHIQ_MAKE_FOURCC('K', 'E', 'E', 'P'),
   1526 		.callback    = vchiq_keepalive_vchiq_callback,
   1527 		.version     = KEEPALIVE_VER,
   1528 		.version_min = KEEPALIVE_VER_MIN
   1529 	};
   1530 
   1531 	status = vchiq_initialise(&instance);
   1532 	if (status != VCHIQ_SUCCESS) {
   1533 		vchiq_log_error(vchiq_susp_log_level,
   1534 			"%s vchiq_initialise failed %d", __func__, status);
   1535 		goto exit;
   1536 	}
   1537 
   1538 	status = vchiq_connect(instance);
   1539 	if (status != VCHIQ_SUCCESS) {
   1540 		vchiq_log_error(vchiq_susp_log_level,
   1541 			"%s vchiq_connect failed %d", __func__, status);
   1542 		goto shutdown;
   1543 	}
   1544 
   1545 	status = vchiq_add_service(instance, &params, &ka_handle);
   1546 	if (status != VCHIQ_SUCCESS) {
   1547 		vchiq_log_error(vchiq_susp_log_level,
   1548 			"%s vchiq_open_service failed %d", __func__, status);
   1549 		goto shutdown;
   1550 	}
   1551 
   1552 	while (1) {
   1553 		long rc = 0, uc = 0;
   1554 		if (wait_for_completion_interruptible(&arm_state->ka_evt)
   1555 				!= 0) {
   1556 			vchiq_log_error(vchiq_susp_log_level,
   1557 				"%s interrupted", __func__);
   1558 			flush_signals(current);
   1559 			continue;
   1560 		}
   1561 
   1562 		/* read and clear counters.  Do release_count then use_count to
   1563 		 * prevent getting more releases than uses */
   1564 		rc = atomic_xchg(&arm_state->ka_release_count, 0);
   1565 		uc = atomic_xchg(&arm_state->ka_use_count, 0);
   1566 
   1567 		/* Call use/release service the requisite number of times.
   1568 		 * Process use before release so use counts don't go negative */
   1569 		while (uc--) {
   1570 			atomic_inc(&arm_state->ka_use_ack_count);
   1571 			status = vchiq_use_service(ka_handle);
   1572 			if (status != VCHIQ_SUCCESS) {
   1573 				vchiq_log_error(vchiq_susp_log_level,
   1574 					"%s vchiq_use_service error %d",
   1575 					__func__, status);
   1576 			}
   1577 		}
   1578 		while (rc--) {
   1579 			status = vchiq_release_service(ka_handle);
   1580 			if (status != VCHIQ_SUCCESS) {
   1581 				vchiq_log_error(vchiq_susp_log_level,
   1582 					"%s vchiq_release_service error %d",
   1583 					__func__, status);
   1584 			}
   1585 		}
   1586 	}
   1587 
   1588 shutdown:
   1589 	vchiq_shutdown(instance);
   1590 exit:
   1591 	return 0;
   1592 }
   1593 
   1594 VCHIQ_STATUS_T
   1595 vchiq_arm_init_state(VCHIQ_STATE_T *state, VCHIQ_ARM_STATE_T *arm_state)
   1596 {
   1597 	VCHIQ_STATUS_T status = VCHIQ_SUCCESS;
   1598 
   1599 	if (arm_state) {
   1600 		rwlock_init(&arm_state->susp_res_lock);
   1601 
   1602 		init_completion(&arm_state->ka_evt);
   1603 		atomic_set(&arm_state->ka_use_count, 0);
   1604 		atomic_set(&arm_state->ka_use_ack_count, 0);
   1605 		atomic_set(&arm_state->ka_release_count, 0);
   1606 
   1607 		init_completion(&arm_state->vc_suspend_complete);
   1608 
   1609 		init_completion(&arm_state->vc_resume_complete);
   1610 		/* Initialise to 'done' state.  We only want to block on resume
   1611 		 * completion while videocore is suspended. */
   1612 		set_resume_state(arm_state, VC_RESUME_RESUMED);
   1613 
   1614 		init_completion(&arm_state->resume_blocker);
   1615 		/* Initialise to 'done' state.  We only want to block on this
   1616 		 * completion while resume is blocked */
   1617 		complete_all(&arm_state->resume_blocker);
   1618 
   1619 		init_completion(&arm_state->blocked_blocker);
   1620 		/* Initialise to 'done' state.  We only want to block on this
   1621 		 * completion while things are waiting on the resume blocker */
   1622 		complete_all(&arm_state->blocked_blocker);
   1623 
   1624 		arm_state->suspend_timer_timeout = SUSPEND_TIMER_TIMEOUT_MS;
   1625 		arm_state->suspend_timer_running = 0;
   1626 		init_timer(&arm_state->suspend_timer);
   1627 		arm_state->suspend_timer.data = (unsigned long)(state);
   1628 		arm_state->suspend_timer.function = suspend_timer_callback;
   1629 
   1630 		arm_state->first_connect = 0;
   1631 
   1632 	}
   1633 	return status;
   1634 }
   1635 
   1636 /*
   1637 ** Functions to modify the state variables;
   1638 **	set_suspend_state
   1639 **	set_resume_state
   1640 **
   1641 ** There are more state variables than we might like, so ensure they remain in
   1642 ** step.  Suspend and resume state are maintained separately, since most of
   1643 ** these state machines can operate independently.  However, there are a few
   1644 ** states where state transitions in one state machine cause a reset to the
   1645 ** other state machine.  In addition, there are some completion events which
   1646 ** need to occur on state machine reset and end-state(s), so these are also
   1647 ** dealt with in these functions.
   1648 **
   1649 ** In all states we set the state variable according to the input, but in some
   1650 ** cases we perform additional steps outlined below;
   1651 **
   1652 ** VC_SUSPEND_IDLE - Initialise the suspend completion at the same time.
   1653 **			The suspend completion is completed after any suspend
   1654 **			attempt.  When we reset the state machine we also reset
   1655 **			the completion.  This reset occurs when videocore is
   1656 **			resumed, and also if we initiate suspend after a suspend
   1657 **			failure.
   1658 **
   1659 ** VC_SUSPEND_IN_PROGRESS - This state is considered the point of no return for
   1660 **			suspend - ie from this point on we must try to suspend
   1661 **			before resuming can occur.  We therefore also reset the
   1662 **			resume state machine to VC_RESUME_IDLE in this state.
   1663 **
   1664 ** VC_SUSPEND_SUSPENDED - Suspend has completed successfully. Also call
   1665 **			complete_all on the suspend completion to notify
   1666 **			anything waiting for suspend to happen.
   1667 **
   1668 ** VC_SUSPEND_REJECTED - Videocore rejected suspend. Videocore will also
   1669 **			initiate resume, so no need to alter resume state.
   1670 **			We call complete_all on the suspend completion to notify
   1671 **			of suspend rejection.
   1672 **
   1673 ** VC_SUSPEND_FAILED - We failed to initiate videocore suspend.  We notify the
   1674 **			suspend completion and reset the resume state machine.
   1675 **
   1676 ** VC_RESUME_IDLE - Initialise the resume completion at the same time.  The
   1677 **			resume completion is in it's 'done' state whenever
   1678 **			videcore is running.  Therfore, the VC_RESUME_IDLE state
   1679 **			implies that videocore is suspended.
   1680 **			Hence, any thread which needs to wait until videocore is
   1681 **			running can wait on this completion - it will only block
   1682 **			if videocore is suspended.
   1683 **
   1684 ** VC_RESUME_RESUMED - Resume has completed successfully.  Videocore is running.
   1685 **			Call complete_all on the resume completion to unblock
   1686 **			any threads waiting for resume.	 Also reset the suspend
   1687 **			state machine to it's idle state.
   1688 **
   1689 ** VC_RESUME_FAILED - Currently unused - no mechanism to fail resume exists.
   1690 */
   1691 
   1692 inline void
   1693 set_suspend_state(VCHIQ_ARM_STATE_T *arm_state,
   1694 	enum vc_suspend_status new_state)
   1695 {
   1696 	/* set the state in all cases */
   1697 	arm_state->vc_suspend_state = new_state;
   1698 
   1699 	/* state specific additional actions */
   1700 	switch (new_state) {
   1701 	case VC_SUSPEND_FORCE_CANCELED:
   1702 		complete_all(&arm_state->vc_suspend_complete);
   1703 		break;
   1704 	case VC_SUSPEND_REJECTED:
   1705 		complete_all(&arm_state->vc_suspend_complete);
   1706 		break;
   1707 	case VC_SUSPEND_FAILED:
   1708 		complete_all(&arm_state->vc_suspend_complete);
   1709 		arm_state->vc_resume_state = VC_RESUME_RESUMED;
   1710 		complete_all(&arm_state->vc_resume_complete);
   1711 		break;
   1712 	case VC_SUSPEND_IDLE:
   1713 		INIT_COMPLETION(arm_state->vc_suspend_complete);
   1714 		break;
   1715 	case VC_SUSPEND_REQUESTED:
   1716 		break;
   1717 	case VC_SUSPEND_IN_PROGRESS:
   1718 		set_resume_state(arm_state, VC_RESUME_IDLE);
   1719 		break;
   1720 	case VC_SUSPEND_SUSPENDED:
   1721 		complete_all(&arm_state->vc_suspend_complete);
   1722 		break;
   1723 	default:
   1724 		BUG();
   1725 		break;
   1726 	}
   1727 }
   1728 
   1729 inline void
   1730 set_resume_state(VCHIQ_ARM_STATE_T *arm_state,
   1731 	enum vc_resume_status new_state)
   1732 {
   1733 	/* set the state in all cases */
   1734 	arm_state->vc_resume_state = new_state;
   1735 
   1736 	/* state specific additional actions */
   1737 	switch (new_state) {
   1738 	case VC_RESUME_FAILED:
   1739 		break;
   1740 	case VC_RESUME_IDLE:
   1741 		INIT_COMPLETION(arm_state->vc_resume_complete);
   1742 		break;
   1743 	case VC_RESUME_REQUESTED:
   1744 		break;
   1745 	case VC_RESUME_IN_PROGRESS:
   1746 		break;
   1747 	case VC_RESUME_RESUMED:
   1748 		complete_all(&arm_state->vc_resume_complete);
   1749 		set_suspend_state(arm_state, VC_SUSPEND_IDLE);
   1750 		break;
   1751 	default:
   1752 		BUG();
   1753 		break;
   1754 	}
   1755 }
   1756 
   1757 
   1758 /* should be called with the write lock held */
   1759 inline void
   1760 start_suspend_timer(VCHIQ_ARM_STATE_T *arm_state)
   1761 {
   1762 	del_timer(&arm_state->suspend_timer);
   1763 	arm_state->suspend_timer.expires = jiffies +
   1764 		msecs_to_jiffies(arm_state->
   1765 			suspend_timer_timeout);
   1766 	add_timer(&arm_state->suspend_timer);
   1767 	arm_state->suspend_timer_running = 1;
   1768 }
   1769 
   1770 /* should be called with the write lock held */
   1771 static inline void
   1772 stop_suspend_timer(VCHIQ_ARM_STATE_T *arm_state)
   1773 {
   1774 	if (arm_state->suspend_timer_running) {
   1775 		del_timer(&arm_state->suspend_timer);
   1776 		arm_state->suspend_timer_running = 0;
   1777 	}
   1778 }
   1779 
   1780 static inline int
   1781 need_resume(VCHIQ_STATE_T *state)
   1782 {
   1783 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
   1784 	return (arm_state->vc_suspend_state > VC_SUSPEND_IDLE) &&
   1785 			(arm_state->vc_resume_state < VC_RESUME_REQUESTED) &&
   1786 			vchiq_videocore_wanted(state);
   1787 }
   1788 
   1789 static int
   1790 block_resume(VCHIQ_ARM_STATE_T *arm_state)
   1791 {
   1792 	int status = VCHIQ_SUCCESS;
   1793 	const unsigned long timeout_val =
   1794 				msecs_to_jiffies(FORCE_SUSPEND_TIMEOUT_MS);
   1795 	int resume_count = 0;
   1796 
   1797 	/* Allow any threads which were blocked by the last force suspend to
   1798 	 * complete if they haven't already.  Only give this one shot; if
   1799 	 * blocked_count is incremented after blocked_blocker is completed
   1800 	 * (which only happens when blocked_count hits 0) then those threads
   1801 	 * will have to wait until next time around */
   1802 	if (arm_state->blocked_count) {
   1803 		INIT_COMPLETION(arm_state->blocked_blocker);
   1804 		write_unlock_bh(&arm_state->susp_res_lock);
   1805 		vchiq_log_info(vchiq_susp_log_level, "%s wait for previously "
   1806 			"blocked clients", __func__);
   1807 		if (wait_for_completion_interruptible_timeout(
   1808 				&arm_state->blocked_blocker, timeout_val)
   1809 					<= 0) {
   1810 			vchiq_log_error(vchiq_susp_log_level, "%s wait for "
   1811 				"previously blocked clients failed" , __func__);
   1812 			status = VCHIQ_ERROR;
   1813 			write_lock_bh(&arm_state->susp_res_lock);
   1814 			goto out;
   1815 		}
   1816 		vchiq_log_info(vchiq_susp_log_level, "%s previously blocked "
   1817 			"clients resumed", __func__);
   1818 		write_lock_bh(&arm_state->susp_res_lock);
   1819 	}
   1820 
   1821 	/* We need to wait for resume to complete if it's in process */
   1822 	while (arm_state->vc_resume_state != VC_RESUME_RESUMED &&
   1823 			arm_state->vc_resume_state > VC_RESUME_IDLE) {
   1824 		if (resume_count > 1) {
   1825 			status = VCHIQ_ERROR;
   1826 			vchiq_log_error(vchiq_susp_log_level, "%s waited too "
   1827 				"many times for resume" , __func__);
   1828 			goto out;
   1829 		}
   1830 		write_unlock_bh(&arm_state->susp_res_lock);
   1831 		vchiq_log_info(vchiq_susp_log_level, "%s wait for resume",
   1832 			__func__);
   1833 		if (wait_for_completion_interruptible_timeout(
   1834 				&arm_state->vc_resume_complete, timeout_val)
   1835 					<= 0) {
   1836 			vchiq_log_error(vchiq_susp_log_level, "%s wait for "
   1837 				"resume failed (%s)", __func__,
   1838 				resume_state_names[arm_state->vc_resume_state +
   1839 							VC_RESUME_NUM_OFFSET]);
   1840 			status = VCHIQ_ERROR;
   1841 			write_lock_bh(&arm_state->susp_res_lock);
   1842 			goto out;
   1843 		}
   1844 		vchiq_log_info(vchiq_susp_log_level, "%s resumed", __func__);
   1845 		write_lock_bh(&arm_state->susp_res_lock);
   1846 		resume_count++;
   1847 	}
   1848 	INIT_COMPLETION(arm_state->resume_blocker);
   1849 	arm_state->resume_blocked = 1;
   1850 
   1851 out:
   1852 	return status;
   1853 }
   1854 
   1855 static inline void
   1856 unblock_resume(VCHIQ_ARM_STATE_T *arm_state)
   1857 {
   1858 	complete_all(&arm_state->resume_blocker);
   1859 	arm_state->resume_blocked = 0;
   1860 }
   1861 
   1862 /* Initiate suspend via slot handler. Should be called with the write lock
   1863  * held */
   1864 VCHIQ_STATUS_T
   1865 vchiq_arm_vcsuspend(VCHIQ_STATE_T *state)
   1866 {
   1867 	VCHIQ_STATUS_T status = VCHIQ_ERROR;
   1868 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
   1869 
   1870 	if (!arm_state)
   1871 		goto out;
   1872 
   1873 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
   1874 	status = VCHIQ_SUCCESS;
   1875 
   1876 
   1877 	switch (arm_state->vc_suspend_state) {
   1878 	case VC_SUSPEND_REQUESTED:
   1879 		vchiq_log_info(vchiq_susp_log_level, "%s: suspend already "
   1880 			"requested", __func__);
   1881 		break;
   1882 	case VC_SUSPEND_IN_PROGRESS:
   1883 		vchiq_log_info(vchiq_susp_log_level, "%s: suspend already in "
   1884 			"progress", __func__);
   1885 		break;
   1886 
   1887 	default:
   1888 		/* We don't expect to be in other states, so log but continue
   1889 		 * anyway */
   1890 		vchiq_log_error(vchiq_susp_log_level,
   1891 			"%s unexpected suspend state %s", __func__,
   1892 			suspend_state_names[arm_state->vc_suspend_state +
   1893 						VC_SUSPEND_NUM_OFFSET]);
   1894 		/* fall through */
   1895 	case VC_SUSPEND_REJECTED:
   1896 	case VC_SUSPEND_FAILED:
   1897 		/* Ensure any idle state actions have been run */
   1898 		set_suspend_state(arm_state, VC_SUSPEND_IDLE);
   1899 		/* fall through */
   1900 	case VC_SUSPEND_IDLE:
   1901 		vchiq_log_info(vchiq_susp_log_level,
   1902 			"%s: suspending", __func__);
   1903 		set_suspend_state(arm_state, VC_SUSPEND_REQUESTED);
   1904 		/* kick the slot handler thread to initiate suspend */
   1905 		request_poll(state, NULL, 0);
   1906 		break;
   1907 	}
   1908 
   1909 out:
   1910 	vchiq_log_trace(vchiq_susp_log_level, "%s exit %d", __func__, status);
   1911 	return status;
   1912 }
   1913 
   1914 void
   1915 vchiq_platform_check_suspend(VCHIQ_STATE_T *state)
   1916 {
   1917 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
   1918 	int susp = 0;
   1919 
   1920 	if (!arm_state)
   1921 		goto out;
   1922 
   1923 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
   1924 
   1925 	write_lock_bh(&arm_state->susp_res_lock);
   1926 	if (arm_state->vc_suspend_state == VC_SUSPEND_REQUESTED &&
   1927 			arm_state->vc_resume_state == VC_RESUME_RESUMED) {
   1928 		set_suspend_state(arm_state, VC_SUSPEND_IN_PROGRESS);
   1929 		susp = 1;
   1930 	}
   1931 	write_unlock_bh(&arm_state->susp_res_lock);
   1932 
   1933 	if (susp)
   1934 		vchiq_platform_suspend(state);
   1935 
   1936 out:
   1937 	vchiq_log_trace(vchiq_susp_log_level, "%s exit", __func__);
   1938 	return;
   1939 }
   1940 
   1941 
   1942 static void
   1943 output_timeout_error(VCHIQ_STATE_T *state)
   1944 {
   1945 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
   1946 	char service_err[50] = "";
   1947 	int vc_use_count = arm_state->videocore_use_count;
   1948 	int active_services = state->unused_service;
   1949 	int i;
   1950 
   1951 	if (!arm_state->videocore_use_count) {
   1952 		snprintf(service_err, 50, " Videocore usecount is 0");
   1953 		goto output_msg;
   1954 	}
   1955 	for (i = 0; i < active_services; i++) {
   1956 		VCHIQ_SERVICE_T *service_ptr = state->services[i];
   1957 		if (service_ptr && service_ptr->service_use_count &&
   1958 			(service_ptr->srvstate != VCHIQ_SRVSTATE_FREE)) {
   1959 			snprintf(service_err, 50, " %c%c%c%c(%8x) service has "
   1960 				"use count %d%s", VCHIQ_FOURCC_AS_4CHARS(
   1961 					service_ptr->base.fourcc),
   1962 				 service_ptr->client_id,
   1963 				 service_ptr->service_use_count,
   1964 				 service_ptr->service_use_count ==
   1965 					 vc_use_count ? "" : " (+ more)");
   1966 			break;
   1967 		}
   1968 	}
   1969 
   1970 output_msg:
   1971 	vchiq_log_error(vchiq_susp_log_level,
   1972 		"timed out waiting for vc suspend (%d).%s",
   1973 		 arm_state->autosuspend_override, service_err);
   1974 
   1975 }
   1976 
   1977 /* Try to get videocore into suspended state, regardless of autosuspend state.
   1978 ** We don't actually force suspend, since videocore may get into a bad state
   1979 ** if we force suspend at a bad time.  Instead, we wait for autosuspend to
   1980 ** determine a good point to suspend.  If this doesn't happen within 100ms we
   1981 ** report failure.
   1982 **
   1983 ** Returns VCHIQ_SUCCESS if videocore suspended successfully, VCHIQ_RETRY if
   1984 ** videocore failed to suspend in time or VCHIQ_ERROR if interrupted.
   1985 */
   1986 VCHIQ_STATUS_T
   1987 vchiq_arm_force_suspend(VCHIQ_STATE_T *state)
   1988 {
   1989 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
   1990 	VCHIQ_STATUS_T status = VCHIQ_ERROR;
   1991 	long rc = 0;
   1992 	int repeat = -1;
   1993 
   1994 	if (!arm_state)
   1995 		goto out;
   1996 
   1997 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
   1998 
   1999 	write_lock_bh(&arm_state->susp_res_lock);
   2000 
   2001 	status = block_resume(arm_state);
   2002 	if (status != VCHIQ_SUCCESS)
   2003 		goto unlock;
   2004 	if (arm_state->vc_suspend_state == VC_SUSPEND_SUSPENDED) {
   2005 		/* Already suspended - just block resume and exit */
   2006 		vchiq_log_info(vchiq_susp_log_level, "%s already suspended",
   2007 			__func__);
   2008 		status = VCHIQ_SUCCESS;
   2009 		goto unlock;
   2010 	} else if (arm_state->vc_suspend_state <= VC_SUSPEND_IDLE) {
   2011 		/* initiate suspend immediately in the case that we're waiting
   2012 		 * for the timeout */
   2013 		stop_suspend_timer(arm_state);
   2014 		if (!vchiq_videocore_wanted(state)) {
   2015 			vchiq_log_info(vchiq_susp_log_level, "%s videocore "
   2016 				"idle, initiating suspend", __func__);
   2017 			status = vchiq_arm_vcsuspend(state);
   2018 		} else if (arm_state->autosuspend_override <
   2019 						FORCE_SUSPEND_FAIL_MAX) {
   2020 			vchiq_log_info(vchiq_susp_log_level, "%s letting "
   2021 				"videocore go idle", __func__);
   2022 			status = VCHIQ_SUCCESS;
   2023 		} else {
   2024 			vchiq_log_warning(vchiq_susp_log_level, "%s failed too "
   2025 				"many times - attempting suspend", __func__);
   2026 			status = vchiq_arm_vcsuspend(state);
   2027 		}
   2028 	} else {
   2029 		vchiq_log_info(vchiq_susp_log_level, "%s videocore suspend "
   2030 			"in progress - wait for completion", __func__);
   2031 		status = VCHIQ_SUCCESS;
   2032 	}
   2033 
   2034 	/* Wait for suspend to happen due to system idle (not forced..) */
   2035 	if (status != VCHIQ_SUCCESS)
   2036 		goto unblock_resume;
   2037 
   2038 	do {
   2039 		write_unlock_bh(&arm_state->susp_res_lock);
   2040 
   2041 		rc = wait_for_completion_interruptible_timeout(
   2042 				&arm_state->vc_suspend_complete,
   2043 				msecs_to_jiffies(FORCE_SUSPEND_TIMEOUT_MS));
   2044 
   2045 		write_lock_bh(&arm_state->susp_res_lock);
   2046 		if (rc < 0) {
   2047 			vchiq_log_warning(vchiq_susp_log_level, "%s "
   2048 				"interrupted waiting for suspend", __func__);
   2049 			status = VCHIQ_ERROR;
   2050 			goto unblock_resume;
   2051 		} else if (rc == 0) {
   2052 			if (arm_state->vc_suspend_state > VC_SUSPEND_IDLE) {
   2053 				/* Repeat timeout once if in progress */
   2054 				if (repeat < 0) {
   2055 					repeat = 1;
   2056 					continue;
   2057 				}
   2058 			}
   2059 			arm_state->autosuspend_override++;
   2060 			output_timeout_error(state);
   2061 
   2062 			status = VCHIQ_RETRY;
   2063 			goto unblock_resume;
   2064 		}
   2065 	} while (0 < (repeat--));
   2066 
   2067 	/* Check and report state in case we need to abort ARM suspend */
   2068 	if (arm_state->vc_suspend_state != VC_SUSPEND_SUSPENDED) {
   2069 		status = VCHIQ_RETRY;
   2070 		vchiq_log_error(vchiq_susp_log_level,
   2071 			"%s videocore suspend failed (state %s)", __func__,
   2072 			suspend_state_names[arm_state->vc_suspend_state +
   2073 						VC_SUSPEND_NUM_OFFSET]);
   2074 		/* Reset the state only if it's still in an error state.
   2075 		 * Something could have already initiated another suspend. */
   2076 		if (arm_state->vc_suspend_state < VC_SUSPEND_IDLE)
   2077 			set_suspend_state(arm_state, VC_SUSPEND_IDLE);
   2078 
   2079 		goto unblock_resume;
   2080 	}
   2081 
   2082 	/* successfully suspended - unlock and exit */
   2083 	goto unlock;
   2084 
   2085 unblock_resume:
   2086 	/* all error states need to unblock resume before exit */
   2087 	unblock_resume(arm_state);
   2088 
   2089 unlock:
   2090 	write_unlock_bh(&arm_state->susp_res_lock);
   2091 
   2092 out:
   2093 	vchiq_log_trace(vchiq_susp_log_level, "%s exit %d", __func__, status);
   2094 	return status;
   2095 }
   2096 
   2097 void
   2098 vchiq_check_suspend(VCHIQ_STATE_T *state)
   2099 {
   2100 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
   2101 
   2102 	if (!arm_state)
   2103 		goto out;
   2104 
   2105 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
   2106 
   2107 	write_lock_bh(&arm_state->susp_res_lock);
   2108 	if (arm_state->vc_suspend_state != VC_SUSPEND_SUSPENDED &&
   2109 			arm_state->first_connect &&
   2110 			!vchiq_videocore_wanted(state)) {
   2111 		vchiq_arm_vcsuspend(state);
   2112 	}
   2113 	write_unlock_bh(&arm_state->susp_res_lock);
   2114 
   2115 out:
   2116 	vchiq_log_trace(vchiq_susp_log_level, "%s exit", __func__);
   2117 	return;
   2118 }
   2119 
   2120 
   2121 int
   2122 vchiq_arm_allow_resume(VCHIQ_STATE_T *state)
   2123 {
   2124 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
   2125 	int resume = 0;
   2126 	int ret = -1;
   2127 
   2128 	if (!arm_state)
   2129 		goto out;
   2130 
   2131 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
   2132 
   2133 	write_lock_bh(&arm_state->susp_res_lock);
   2134 	unblock_resume(arm_state);
   2135 	resume = vchiq_check_resume(state);
   2136 	write_unlock_bh(&arm_state->susp_res_lock);
   2137 
   2138 	if (resume) {
   2139 		if (wait_for_completion_interruptible(
   2140 			&arm_state->vc_resume_complete) < 0) {
   2141 			vchiq_log_error(vchiq_susp_log_level,
   2142 				"%s interrupted", __func__);
   2143 			/* failed, cannot accurately derive suspend
   2144 			 * state, so exit early. */
   2145 			goto out;
   2146 		}
   2147 	}
   2148 
   2149 	read_lock_bh(&arm_state->susp_res_lock);
   2150 	if (arm_state->vc_suspend_state == VC_SUSPEND_SUSPENDED) {
   2151 		vchiq_log_info(vchiq_susp_log_level,
   2152 				"%s: Videocore remains suspended", __func__);
   2153 	} else {
   2154 		vchiq_log_info(vchiq_susp_log_level,
   2155 				"%s: Videocore resumed", __func__);
   2156 		ret = 0;
   2157 	}
   2158 	read_unlock_bh(&arm_state->susp_res_lock);
   2159 out:
   2160 	vchiq_log_trace(vchiq_susp_log_level, "%s exit %d", __func__, ret);
   2161 	return ret;
   2162 }
   2163 
   2164 /* This function should be called with the write lock held */
   2165 int
   2166 vchiq_check_resume(VCHIQ_STATE_T *state)
   2167 {
   2168 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
   2169 	int resume = 0;
   2170 
   2171 	if (!arm_state)
   2172 		goto out;
   2173 
   2174 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
   2175 
   2176 	if (need_resume(state)) {
   2177 		set_resume_state(arm_state, VC_RESUME_REQUESTED);
   2178 		request_poll(state, NULL, 0);
   2179 		resume = 1;
   2180 	}
   2181 
   2182 out:
   2183 	vchiq_log_trace(vchiq_susp_log_level, "%s exit", __func__);
   2184 	return resume;
   2185 }
   2186 
   2187 #ifdef notyet
   2188 void
   2189 vchiq_platform_check_resume(VCHIQ_STATE_T *state)
   2190 {
   2191 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
   2192 	int res = 0;
   2193 
   2194 	if (!arm_state)
   2195 		goto out;
   2196 
   2197 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
   2198 
   2199 	write_lock_bh(&arm_state->susp_res_lock);
   2200 	if (arm_state->wake_address == 0) {
   2201 		vchiq_log_info(vchiq_susp_log_level,
   2202 					"%s: already awake", __func__);
   2203 		goto unlock;
   2204 	}
   2205 	if (arm_state->vc_resume_state == VC_RESUME_IN_PROGRESS) {
   2206 		vchiq_log_info(vchiq_susp_log_level,
   2207 					"%s: already resuming", __func__);
   2208 		goto unlock;
   2209 	}
   2210 
   2211 	if (arm_state->vc_resume_state == VC_RESUME_REQUESTED) {
   2212 		set_resume_state(arm_state, VC_RESUME_IN_PROGRESS);
   2213 		res = 1;
   2214 	} else
   2215 		vchiq_log_trace(vchiq_susp_log_level,
   2216 				"%s: not resuming (resume state %s)", __func__,
   2217 				resume_state_names[arm_state->vc_resume_state +
   2218 							VC_RESUME_NUM_OFFSET]);
   2219 
   2220 unlock:
   2221 	write_unlock_bh(&arm_state->susp_res_lock);
   2222 
   2223 	if (res)
   2224 		vchiq_platform_resume(state);
   2225 
   2226 out:
   2227 	vchiq_log_trace(vchiq_susp_log_level, "%s exit", __func__);
   2228 	return;
   2229 
   2230 }
   2231 #endif
   2232 
   2233 
   2234 
   2235 VCHIQ_STATUS_T
   2236 vchiq_use_internal(VCHIQ_STATE_T *state, VCHIQ_SERVICE_T *service,
   2237 		enum USE_TYPE_E use_type)
   2238 {
   2239 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
   2240 	VCHIQ_STATUS_T ret = VCHIQ_SUCCESS;
   2241 	char entity[16];
   2242 	int *entity_uc;
   2243 	int local_uc, local_entity_uc;
   2244 
   2245 	if (!arm_state)
   2246 		goto out;
   2247 
   2248 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
   2249 
   2250 	if (use_type == USE_TYPE_VCHIQ) {
   2251 		snprintf(entity, sizeof(entity), "VCHIQ:   ");
   2252 		entity_uc = &arm_state->peer_use_count;
   2253 	} else if (service) {
   2254 		snprintf(entity, sizeof(entity), "%c%c%c%c:%8x",
   2255 			VCHIQ_FOURCC_AS_4CHARS(service->base.fourcc),
   2256 			service->client_id);
   2257 		entity_uc = &service->service_use_count;
   2258 	} else {
   2259 		vchiq_log_error(vchiq_susp_log_level, "%s null service "
   2260 				"ptr", __func__);
   2261 		ret = VCHIQ_ERROR;
   2262 		goto out;
   2263 	}
   2264 
   2265 	write_lock_bh(&arm_state->susp_res_lock);
   2266 	while (arm_state->resume_blocked) {
   2267 		/* If we call 'use' while force suspend is waiting for suspend,
   2268 		 * then we're about to block the thread which the force is
   2269 		 * waiting to complete, so we're bound to just time out. In this
   2270 		 * case, set the suspend state such that the wait will be
   2271 		 * canceled, so we can complete as quickly as possible. */
   2272 		if (arm_state->resume_blocked && arm_state->vc_suspend_state ==
   2273 				VC_SUSPEND_IDLE) {
   2274 			set_suspend_state(arm_state, VC_SUSPEND_FORCE_CANCELED);
   2275 			break;
   2276 		}
   2277 		/* If suspend is already in progress then we need to block */
   2278 		if (!try_wait_for_completion(&arm_state->resume_blocker)) {
   2279 			/* Indicate that there are threads waiting on the resume
   2280 			 * blocker.  These need to be allowed to complete before
   2281 			 * a _second_ call to force suspend can complete,
   2282 			 * otherwise low priority threads might never actually
   2283 			 * continue */
   2284 			arm_state->blocked_count++;
   2285 			write_unlock_bh(&arm_state->susp_res_lock);
   2286 			vchiq_log_info(vchiq_susp_log_level, "%s %s resume "
   2287 				"blocked - waiting...", __func__, entity);
   2288 			if (wait_for_completion_killable(
   2289 					&arm_state->resume_blocker) != 0) {
   2290 				vchiq_log_error(vchiq_susp_log_level, "%s %s "
   2291 					"wait for resume blocker interrupted",
   2292 					__func__, entity);
   2293 				ret = VCHIQ_ERROR;
   2294 				write_lock_bh(&arm_state->susp_res_lock);
   2295 				arm_state->blocked_count--;
   2296 				write_unlock_bh(&arm_state->susp_res_lock);
   2297 				goto out;
   2298 			}
   2299 			vchiq_log_info(vchiq_susp_log_level, "%s %s resume "
   2300 				"unblocked", __func__, entity);
   2301 			write_lock_bh(&arm_state->susp_res_lock);
   2302 			if (--arm_state->blocked_count == 0)
   2303 				complete_all(&arm_state->blocked_blocker);
   2304 		}
   2305 	}
   2306 
   2307 	stop_suspend_timer(arm_state);
   2308 
   2309 	local_uc = ++arm_state->videocore_use_count;
   2310 	local_entity_uc = ++(*entity_uc);
   2311 
   2312 	/* If there's a pending request which hasn't yet been serviced then
   2313 	 * just clear it.  If we're past VC_SUSPEND_REQUESTED state then
   2314 	 * vc_resume_complete will block until we either resume or fail to
   2315 	 * suspend */
   2316 	if (arm_state->vc_suspend_state <= VC_SUSPEND_REQUESTED)
   2317 		set_suspend_state(arm_state, VC_SUSPEND_IDLE);
   2318 
   2319 	if ((use_type != USE_TYPE_SERVICE_NO_RESUME) && need_resume(state)) {
   2320 		set_resume_state(arm_state, VC_RESUME_REQUESTED);
   2321 		vchiq_log_info(vchiq_susp_log_level,
   2322 			"%s %s count %d, state count %d",
   2323 			__func__, entity, local_entity_uc, local_uc);
   2324 		request_poll(state, NULL, 0);
   2325 	} else
   2326 		vchiq_log_trace(vchiq_susp_log_level,
   2327 			"%s %s count %d, state count %d",
   2328 			__func__, entity, *entity_uc, local_uc);
   2329 
   2330 
   2331 	write_unlock_bh(&arm_state->susp_res_lock);
   2332 
   2333 	/* Completion is in a done state when we're not suspended, so this won't
   2334 	 * block for the non-suspended case. */
   2335 	if (!try_wait_for_completion(&arm_state->vc_resume_complete)) {
   2336 		vchiq_log_info(vchiq_susp_log_level, "%s %s wait for resume",
   2337 			__func__, entity);
   2338 		if (wait_for_completion_killable(
   2339 				&arm_state->vc_resume_complete) != 0) {
   2340 			vchiq_log_error(vchiq_susp_log_level, "%s %s wait for "
   2341 				"resume interrupted", __func__, entity);
   2342 			ret = VCHIQ_ERROR;
   2343 			goto out;
   2344 		}
   2345 		vchiq_log_info(vchiq_susp_log_level, "%s %s resumed", __func__,
   2346 			entity);
   2347 	}
   2348 
   2349 	if (ret == VCHIQ_SUCCESS) {
   2350 		VCHIQ_STATUS_T status = VCHIQ_SUCCESS;
   2351 		long ack_cnt = atomic_xchg(&arm_state->ka_use_ack_count, 0);
   2352 		while (ack_cnt && (status == VCHIQ_SUCCESS)) {
   2353 			/* Send the use notify to videocore */
   2354 			status = vchiq_send_remote_use_active(state);
   2355 			if (status == VCHIQ_SUCCESS)
   2356 				ack_cnt--;
   2357 			else
   2358 				atomic_add(ack_cnt,
   2359 					&arm_state->ka_use_ack_count);
   2360 		}
   2361 	}
   2362 
   2363 out:
   2364 	vchiq_log_trace(vchiq_susp_log_level, "%s exit %d", __func__, ret);
   2365 	return ret;
   2366 }
   2367 
   2368 VCHIQ_STATUS_T
   2369 vchiq_release_internal(VCHIQ_STATE_T *state, VCHIQ_SERVICE_T *service)
   2370 {
   2371 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
   2372 	VCHIQ_STATUS_T ret = VCHIQ_SUCCESS;
   2373 	char entity[16];
   2374 	int *entity_uc;
   2375 
   2376 	if (!arm_state)
   2377 		goto out;
   2378 
   2379 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
   2380 
   2381 	if (service) {
   2382 		snprintf(entity, sizeof(entity), "%c%c%c%c:%8x",
   2383 			VCHIQ_FOURCC_AS_4CHARS(service->base.fourcc),
   2384 			service->client_id);
   2385 		entity_uc = &service->service_use_count;
   2386 	} else {
   2387 		snprintf(entity, sizeof(entity), "PEER:   ");
   2388 		entity_uc = &arm_state->peer_use_count;
   2389 	}
   2390 
   2391 	write_lock_bh(&arm_state->susp_res_lock);
   2392 	if (!arm_state->videocore_use_count || !(*entity_uc)) {
   2393 		/* Don't use BUG_ON - don't allow user thread to crash kernel */
   2394 		WARN_ON(!arm_state->videocore_use_count);
   2395 		WARN_ON(!(*entity_uc));
   2396 		ret = VCHIQ_ERROR;
   2397 		goto unlock;
   2398 	}
   2399 	--arm_state->videocore_use_count;
   2400 	--(*entity_uc);
   2401 
   2402 	if (!vchiq_videocore_wanted(state)) {
   2403 		if (vchiq_platform_use_suspend_timer() &&
   2404 				!arm_state->resume_blocked) {
   2405 			/* Only use the timer if we're not trying to force
   2406 			 * suspend (=> resume_blocked) */
   2407 			start_suspend_timer(arm_state);
   2408 		} else {
   2409 			vchiq_log_info(vchiq_susp_log_level,
   2410 				"%s %s count %d, state count %d - suspending",
   2411 				__func__, entity, *entity_uc,
   2412 				arm_state->videocore_use_count);
   2413 			vchiq_arm_vcsuspend(state);
   2414 		}
   2415 	} else
   2416 		vchiq_log_trace(vchiq_susp_log_level,
   2417 			"%s %s count %d, state count %d",
   2418 			__func__, entity, *entity_uc,
   2419 			arm_state->videocore_use_count);
   2420 
   2421 unlock:
   2422 	write_unlock_bh(&arm_state->susp_res_lock);
   2423 
   2424 out:
   2425 	vchiq_log_trace(vchiq_susp_log_level, "%s exit %d", __func__, ret);
   2426 	return ret;
   2427 }
   2428 
   2429 void
   2430 vchiq_on_remote_use(VCHIQ_STATE_T *state)
   2431 {
   2432 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
   2433 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
   2434 	atomic_inc(&arm_state->ka_use_count);
   2435 	complete(&arm_state->ka_evt);
   2436 }
   2437 
   2438 void
   2439 vchiq_on_remote_release(VCHIQ_STATE_T *state)
   2440 {
   2441 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
   2442 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
   2443 	atomic_inc(&arm_state->ka_release_count);
   2444 	complete(&arm_state->ka_evt);
   2445 }
   2446 
   2447 VCHIQ_STATUS_T
   2448 vchiq_use_service_internal(VCHIQ_SERVICE_T *service)
   2449 {
   2450 	return vchiq_use_internal(service->state, service, USE_TYPE_SERVICE);
   2451 }
   2452 
   2453 VCHIQ_STATUS_T
   2454 vchiq_release_service_internal(VCHIQ_SERVICE_T *service)
   2455 {
   2456 	return vchiq_release_internal(service->state, service);
   2457 }
   2458 
   2459 static void suspend_timer_callback(unsigned long context)
   2460 {
   2461 	VCHIQ_STATE_T *state = (VCHIQ_STATE_T *)context;
   2462 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
   2463 	if (!arm_state)
   2464 		goto out;
   2465 	vchiq_log_info(vchiq_susp_log_level,
   2466 		"%s - suspend timer expired - check suspend", __func__);
   2467 	vchiq_check_suspend(state);
   2468 out:
   2469 	return;
   2470 }
   2471 
   2472 VCHIQ_STATUS_T
   2473 vchiq_use_service_no_resume(VCHIQ_SERVICE_HANDLE_T handle)
   2474 {
   2475 	VCHIQ_STATUS_T ret = VCHIQ_ERROR;
   2476 	VCHIQ_SERVICE_T *service = find_service_by_handle(handle);
   2477 	if (service) {
   2478 		ret = vchiq_use_internal(service->state, service,
   2479 				USE_TYPE_SERVICE_NO_RESUME);
   2480 		unlock_service(service);
   2481 	}
   2482 	return ret;
   2483 }
   2484 
   2485 VCHIQ_STATUS_T
   2486 vchiq_use_service(VCHIQ_SERVICE_HANDLE_T handle)
   2487 {
   2488 	VCHIQ_STATUS_T ret = VCHIQ_ERROR;
   2489 	VCHIQ_SERVICE_T *service = find_service_by_handle(handle);
   2490 	if (service) {
   2491 		ret = vchiq_use_internal(service->state, service,
   2492 				USE_TYPE_SERVICE);
   2493 		unlock_service(service);
   2494 	}
   2495 	return ret;
   2496 }
   2497 
   2498 VCHIQ_STATUS_T
   2499 vchiq_release_service(VCHIQ_SERVICE_HANDLE_T handle)
   2500 {
   2501 	VCHIQ_STATUS_T ret = VCHIQ_ERROR;
   2502 	VCHIQ_SERVICE_T *service = find_service_by_handle(handle);
   2503 	if (service) {
   2504 		ret = vchiq_release_internal(service->state, service);
   2505 		unlock_service(service);
   2506 	}
   2507 	return ret;
   2508 }
   2509 
   2510 void
   2511 vchiq_dump_service_use_state(VCHIQ_STATE_T *state)
   2512 {
   2513 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
   2514 	int i, j = 0;
   2515 	/* Only dump 64 services */
   2516 	static const int local_max_services = 64;
   2517 	/* If there's more than 64 services, only dump ones with
   2518 	 * non-zero counts */
   2519 	int only_nonzero = 0;
   2520 	static const char *nz = "<-- preventing suspend";
   2521 
   2522 	enum vc_suspend_status vc_suspend_state;
   2523 	enum vc_resume_status  vc_resume_state;
   2524 	int peer_count;
   2525 	int vc_use_count;
   2526 	int active_services;
   2527 	struct service_data_struct {
   2528 		int fourcc;
   2529 		int clientid;
   2530 		int use_count;
   2531 	} service_data[local_max_services];
   2532 
   2533 	if (!arm_state)
   2534 		return;
   2535 
   2536 	read_lock_bh(&arm_state->susp_res_lock);
   2537 	vc_suspend_state = arm_state->vc_suspend_state;
   2538 	vc_resume_state  = arm_state->vc_resume_state;
   2539 	peer_count = arm_state->peer_use_count;
   2540 	vc_use_count = arm_state->videocore_use_count;
   2541 	active_services = state->unused_service;
   2542 	if (active_services > local_max_services)
   2543 		only_nonzero = 1;
   2544 
   2545 	for (i = 0; (i < active_services) && (j < local_max_services); i++) {
   2546 		VCHIQ_SERVICE_T *service_ptr = state->services[i];
   2547 		if (!service_ptr)
   2548 			continue;
   2549 
   2550 		if (only_nonzero && !service_ptr->service_use_count)
   2551 			continue;
   2552 
   2553 		if (service_ptr->srvstate != VCHIQ_SRVSTATE_FREE) {
   2554 			service_data[j].fourcc = service_ptr->base.fourcc;
   2555 			service_data[j].clientid = service_ptr->client_id;
   2556 			service_data[j++].use_count = service_ptr->
   2557 							service_use_count;
   2558 		}
   2559 	}
   2560 
   2561 	read_unlock_bh(&arm_state->susp_res_lock);
   2562 
   2563 	vchiq_log_warning(vchiq_susp_log_level,
   2564 		"-- Videcore suspend state: %s --",
   2565 		suspend_state_names[vc_suspend_state + VC_SUSPEND_NUM_OFFSET]);
   2566 	vchiq_log_warning(vchiq_susp_log_level,
   2567 		"-- Videcore resume state: %s --",
   2568 		resume_state_names[vc_resume_state + VC_RESUME_NUM_OFFSET]);
   2569 
   2570 	if (only_nonzero)
   2571 		vchiq_log_warning(vchiq_susp_log_level, "Too many active "
   2572 			"services (%d).  Only dumping up to first %d services "
   2573 			"with non-zero use-count", active_services,
   2574 			local_max_services);
   2575 
   2576 	for (i = 0; i < j; i++) {
   2577 		vchiq_log_warning(vchiq_susp_log_level,
   2578 			"----- %c%c%c%c:%d service count %d %s",
   2579 			VCHIQ_FOURCC_AS_4CHARS(service_data[i].fourcc),
   2580 			service_data[i].clientid,
   2581 			service_data[i].use_count,
   2582 			service_data[i].use_count ? nz : "");
   2583 	}
   2584 	vchiq_log_warning(vchiq_susp_log_level,
   2585 		"----- VCHIQ use count count %d", peer_count);
   2586 	vchiq_log_warning(vchiq_susp_log_level,
   2587 		"--- Overall vchiq instance use count %d", vc_use_count);
   2588 
   2589 	vchiq_dump_platform_use_state(state);
   2590 }
   2591 
   2592 VCHIQ_STATUS_T
   2593 vchiq_check_service(VCHIQ_SERVICE_T *service)
   2594 {
   2595 	VCHIQ_ARM_STATE_T *arm_state;
   2596 	VCHIQ_STATUS_T ret = VCHIQ_ERROR;
   2597 
   2598 	if (!service || !service->state)
   2599 		goto out;
   2600 
   2601 	vchiq_log_trace(vchiq_susp_log_level, "%s", __func__);
   2602 
   2603 	arm_state = vchiq_platform_get_arm_state(service->state);
   2604 
   2605 	read_lock_bh(&arm_state->susp_res_lock);
   2606 	if (service->service_use_count)
   2607 		ret = VCHIQ_SUCCESS;
   2608 	read_unlock_bh(&arm_state->susp_res_lock);
   2609 
   2610 	if (ret == VCHIQ_ERROR) {
   2611 		vchiq_log_error(vchiq_susp_log_level,
   2612 			"%s ERROR - %c%c%c%c:%8x service count %d, "
   2613 			"state count %d, videocore suspend state %s", __func__,
   2614 			VCHIQ_FOURCC_AS_4CHARS(service->base.fourcc),
   2615 			service->client_id, service->service_use_count,
   2616 			arm_state->videocore_use_count,
   2617 			suspend_state_names[arm_state->vc_suspend_state +
   2618 						VC_SUSPEND_NUM_OFFSET]);
   2619 		vchiq_dump_service_use_state(service->state);
   2620 	}
   2621 out:
   2622 	return ret;
   2623 }
   2624 
   2625 /* stub functions */
   2626 void vchiq_on_remote_use_active(VCHIQ_STATE_T *state)
   2627 {
   2628 	(void)state;
   2629 }
   2630 
   2631 void vchiq_platform_conn_state_changed(VCHIQ_STATE_T *state,
   2632 	VCHIQ_CONNSTATE_T oldstate, VCHIQ_CONNSTATE_T newstate)
   2633 {
   2634 	VCHIQ_ARM_STATE_T *arm_state = vchiq_platform_get_arm_state(state);
   2635 	vchiq_log_info(vchiq_susp_log_level, "%d: %s->%s", state->id,
   2636 		get_conn_state_name(oldstate), get_conn_state_name(newstate));
   2637 	if (state->conn_state == VCHIQ_CONNSTATE_CONNECTED) {
   2638 		write_lock_bh(&arm_state->susp_res_lock);
   2639 		if (!arm_state->first_connect) {
   2640 			char threadname[10];
   2641 			arm_state->first_connect = 1;
   2642 			write_unlock_bh(&arm_state->susp_res_lock);
   2643 			snprintf(threadname, sizeof(threadname), "VCHIQka-%d",
   2644 				state->id);
   2645 			arm_state->ka_thread = vchiq_thread_create(
   2646 				&vchiq_keepalive_thread_func,
   2647 				(void *)state,
   2648 				threadname);
   2649 			if (arm_state->ka_thread == NULL) {
   2650 				vchiq_log_error(vchiq_susp_log_level,
   2651 					"vchiq: FATAL: couldn't create thread %s",
   2652 					threadname);
   2653 			} else {
   2654 				wake_up_process(arm_state->ka_thread);
   2655 			}
   2656 		} else
   2657 			write_unlock_bh(&arm_state->susp_res_lock);
   2658 	}
   2659 }
   2660 
   2661 /****************************************************************************
   2662 *
   2663 *   vchiq_init - called when the module is loaded.
   2664 *
   2665 ***************************************************************************/
   2666 
   2667 int __init vchiq_init(void);
   2668 int __init
   2669 vchiq_init(void)
   2670 {
   2671 	int err;
   2672 
   2673 #ifdef notyet
   2674 	/* create proc entries */
   2675 	err = vchiq_proc_init();
   2676 	if (err != 0)
   2677 		goto failed_proc_init;
   2678 #endif
   2679 
   2680 	spin_lock_init(&msg_queue_spinlock);
   2681 
   2682 	err = vchiq_platform_init(&g_state);
   2683 	if (err != 0)
   2684 		goto failed_platform_init;
   2685 
   2686 	vchiq_log_info(vchiq_arm_log_level,
   2687 		"vchiq: initialised - version %d (min %d)",
   2688 		VCHIQ_VERSION, VCHIQ_VERSION_MIN);
   2689 
   2690 	return 0;
   2691 
   2692 failed_platform_init:
   2693 	vchiq_log_warning(vchiq_arm_log_level, "could not load vchiq");
   2694 	return err;
   2695 }
   2696 
   2697 #ifdef notyet
   2698 static int vchiq_instance_get_use_count(VCHIQ_INSTANCE_T instance)
   2699 {
   2700 	VCHIQ_SERVICE_T *service;
   2701 	int use_count = 0, i;
   2702 	i = 0;
   2703 	while ((service = next_service_by_instance(instance->state,
   2704 		instance, &i)) != NULL) {
   2705 		use_count += service->service_use_count;
   2706 		unlock_service(service);
   2707 	}
   2708 	return use_count;
   2709 }
   2710 
   2711 /* read the per-process use-count */
   2712 static int proc_read_use_count(char *page, char **start,
   2713 			       off_t off, int count,
   2714 			       int *eof, void *data)
   2715 {
   2716 	VCHIQ_INSTANCE_T instance = data;
   2717 	int len, use_count;
   2718 
   2719 	use_count = vchiq_instance_get_use_count(instance);
   2720 	len = snprintf(page+off, count, "%d\n", use_count);
   2721 
   2722 	return len;
   2723 }
   2724 
   2725 /* add an instance (process) to the proc entries */
   2726 static int vchiq_proc_add_instance(VCHIQ_INSTANCE_T instance)
   2727 {
   2728 	char pidstr[32];
   2729 	struct proc_dir_entry *top, *use_count;
   2730 	struct proc_dir_entry *clients = vchiq_clients_top();
   2731 	int pid = instance->pid;
   2732 
   2733 	snprintf(pidstr, sizeof(pidstr), "%d", pid);
   2734 	top = proc_mkdir(pidstr, clients);
   2735 	if (!top)
   2736 		goto fail_top;
   2737 
   2738 	use_count = create_proc_read_entry("use_count",
   2739 					   0444, top,
   2740 					   proc_read_use_count,
   2741 					   instance);
   2742 	if (!use_count)
   2743 		goto fail_use_count;
   2744 
   2745 	instance->proc_entry = top;
   2746 
   2747 	return 0;
   2748 
   2749 fail_use_count:
   2750 	remove_proc_entry(top->name, clients);
   2751 fail_top:
   2752 	return -ENOMEM;
   2753 }
   2754 
   2755 static void vchiq_proc_remove_instance(VCHIQ_INSTANCE_T instance)
   2756 {
   2757 	struct proc_dir_entry *clients = vchiq_clients_top();
   2758 	remove_proc_entry("use_count", instance->proc_entry);
   2759 	remove_proc_entry(instance->proc_entry->name, clients);
   2760 }
   2761 
   2762 #endif
   2763 
   2764 /****************************************************************************
   2765 *
   2766 *   vchiq_exit - called when the module is unloaded.
   2767 *
   2768 ***************************************************************************/
   2769 
   2770 void vchiq_exit(void);
   2771 void
   2772 vchiq_exit(void)
   2773 {
   2774 	vchiq_platform_exit(&g_state);
   2775 }
   2776