[mirror_ubuntu-artful-kernel.git] / drivers / acpi / executer / exmutex.c


/******************************************************************************
 *
 * Module Name: exmutex - ASL Mutex Acquire/Release functions
 *
 *****************************************************************************/

/*
 * Copyright (C) 2000 - 2007, R. Byron Moore
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions, and the following disclaimer,
 *    without modification.
 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 *    substantially similar to the "NO WARRANTY" disclaimer below
 *    ("Disclaimer") and any redistribution must be conditioned upon
 *    including a substantially similar Disclaimer requirement for further
 *    binary redistribution.
 * 3. Neither the names of the above-listed copyright holders nor the names
 *    of any contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * NO WARRANTY
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 */

#include <acpi/acpi.h>
#include <acpi/acinterp.h>
#include <acpi/acevents.h>

#define _COMPONENT          ACPI_EXECUTER
ACPI_MODULE_NAME("exmutex")

/* Local prototypes */
static void
acpi_ex_link_mutex(union acpi_operand_object *obj_desc,
		   struct acpi_thread_state *thread);

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_unlink_mutex
 *
 * PARAMETERS:  obj_desc            - The mutex to be unlinked
 *
 * RETURN:      None
 *
 * DESCRIPTION: Remove a mutex from the "AcquiredMutex" list
 *
 ******************************************************************************/

void acpi_ex_unlink_mutex(union acpi_operand_object *obj_desc)
{
	struct acpi_thread_state *thread = obj_desc->mutex.owner_thread;

	if (!thread) {
		return;
	}

	/* Doubly linked list */

	if (obj_desc->mutex.next) {
		(obj_desc->mutex.next)->mutex.prev = obj_desc->mutex.prev;
	}

	if (obj_desc->mutex.prev) {
		(obj_desc->mutex.prev)->mutex.next = obj_desc->mutex.next;
	} else {
		thread->acquired_mutex_list = obj_desc->mutex.next;
	}
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_link_mutex
 *
 * PARAMETERS:  obj_desc        - The mutex to be linked
 *              Thread          - Current executing thread object
 *
 * RETURN:      None
 *
 * DESCRIPTION: Add a mutex to the "AcquiredMutex" list for this walk
 *
 ******************************************************************************/

static void
acpi_ex_link_mutex(union acpi_operand_object *obj_desc,
		   struct acpi_thread_state *thread)
{
	union acpi_operand_object *list_head;

	list_head = thread->acquired_mutex_list;

	/* This object will be the first object in the list */

	obj_desc->mutex.prev = NULL;
	obj_desc->mutex.next = list_head;

	/* Update old first object to point back to this object */

	if (list_head) {
		list_head->mutex.prev = obj_desc;
	}

	/* Update list head */

	thread->acquired_mutex_list = obj_desc;
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_acquire_mutex_object
 *
 * PARAMETERS:  time_desc           - Timeout in milliseconds
 *              obj_desc            - Mutex object
 *              Thread              - Current thread state
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Acquire an AML mutex, low-level interface. Provides a common
 *              path that supports multiple acquires by the same thread.
 *
 * MUTEX:       Interpreter must be locked
 *
 * NOTE: This interface is called from three places:
 * 1) From acpi_ex_acquire_mutex, via an AML Acquire() operator
 * 2) From acpi_ex_acquire_global_lock when an AML Field access requires the
 *    global lock
 * 3) From the external interface, acpi_acquire_global_lock
 *
 ******************************************************************************/

acpi_status
acpi_ex_acquire_mutex_object(u16 timeout,
			     union acpi_operand_object *obj_desc,
			     acpi_thread_id thread_id)
{
	acpi_status status;

	ACPI_FUNCTION_TRACE_PTR(ex_acquire_mutex_object, obj_desc);

	/* Support for multiple acquires by the owning thread */

	if (obj_desc->mutex.thread_id == thread_id) {
		/*
		 * The mutex is already owned by this thread, just increment the
		 * acquisition depth
		 */
		obj_desc->mutex.acquisition_depth++;
		return_ACPI_STATUS(AE_OK);
	}

	/* Acquire the mutex, wait if necessary. Special case for Global Lock */

	if (obj_desc == acpi_gbl_global_lock_mutex) {
		status = acpi_ev_acquire_global_lock(timeout);
	} else {
		status = acpi_ex_system_wait_mutex(obj_desc->mutex.os_mutex,
						   timeout);
	}

	if (ACPI_FAILURE(status)) {

		/* Includes failure from a timeout on time_desc */

		return_ACPI_STATUS(status);
	}

	/* Acquired the mutex: update mutex object */

	obj_desc->mutex.thread_id = thread_id;
	obj_desc->mutex.acquisition_depth = 1;
	obj_desc->mutex.original_sync_level = 0;
	obj_desc->mutex.owner_thread = NULL;	/* Used only for AML Acquire() */

	return_ACPI_STATUS(AE_OK);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_acquire_mutex
 *
 * PARAMETERS:  time_desc           - Timeout integer
 *              obj_desc            - Mutex object
 *              walk_state          - Current method execution state
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Acquire an AML mutex
 *
 ******************************************************************************/

acpi_status
acpi_ex_acquire_mutex(union acpi_operand_object *time_desc,
		      union acpi_operand_object *obj_desc,
		      struct acpi_walk_state *walk_state)
{
	acpi_status status;

	ACPI_FUNCTION_TRACE_PTR(ex_acquire_mutex, obj_desc);

	if (!obj_desc) {
		return_ACPI_STATUS(AE_BAD_PARAMETER);
	}

	/* Must have a valid thread ID */

	if (!walk_state->thread) {
		ACPI_ERROR((AE_INFO,
			    "Cannot acquire Mutex [%4.4s], null thread info",
			    acpi_ut_get_node_name(obj_desc->mutex.node)));
		return_ACPI_STATUS(AE_AML_INTERNAL);
	}

	/*
	 * Current sync level must be less than or equal to the sync level of the
	 * mutex. This mechanism provides some deadlock prevention
	 */
	if (walk_state->thread->current_sync_level > obj_desc->mutex.sync_level) {
		ACPI_ERROR((AE_INFO,
			    "Cannot acquire Mutex [%4.4s], current SyncLevel is too large (%d)",
			    acpi_ut_get_node_name(obj_desc->mutex.node),
			    walk_state->thread->current_sync_level));
		return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
	}

	status = acpi_ex_acquire_mutex_object((u16) time_desc->integer.value,
					      obj_desc,
					      walk_state->thread->thread_id);
	if (ACPI_SUCCESS(status) && obj_desc->mutex.acquisition_depth == 1) {

		/* Save Thread object, original/current sync levels */

		obj_desc->mutex.owner_thread = walk_state->thread;
		obj_desc->mutex.original_sync_level =
		    walk_state->thread->current_sync_level;
		walk_state->thread->current_sync_level =
		    obj_desc->mutex.sync_level;

		/* Link the mutex to the current thread for force-unlock at method exit */

		acpi_ex_link_mutex(obj_desc, walk_state->thread);
	}

	return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_release_mutex_object
 *
 * PARAMETERS:  obj_desc            - The object descriptor for this op
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Release a previously acquired Mutex, low level interface.
 *              Provides a common path that supports multiple releases (after
 *              previous multiple acquires) by the same thread.
 *
 * MUTEX:       Interpreter must be locked
 *
 * NOTE: This interface is called from three places:
 * 1) From acpi_ex_release_mutex, via an AML Acquire() operator
 * 2) From acpi_ex_release_global_lock when an AML Field access requires the
 *    global lock
 * 3) From the external interface, acpi_release_global_lock
 *
 ******************************************************************************/

acpi_status acpi_ex_release_mutex_object(union acpi_operand_object *obj_desc)
{
	acpi_status status = AE_OK;

	ACPI_FUNCTION_TRACE(ex_release_mutex_object);

	/* Match multiple Acquires with multiple Releases */

	obj_desc->mutex.acquisition_depth--;
	if (obj_desc->mutex.acquisition_depth != 0) {

		/* Just decrement the depth and return */

		return_ACPI_STATUS(AE_OK);
	}

	if (obj_desc->mutex.owner_thread) {

		/* Unlink the mutex from the owner's list */

		acpi_ex_unlink_mutex(obj_desc);
		obj_desc->mutex.owner_thread = NULL;
	}

	/* Release the mutex, special case for Global Lock */

	if (obj_desc == acpi_gbl_global_lock_mutex) {
		status = acpi_ev_release_global_lock();
	} else {
		acpi_os_release_mutex(obj_desc->mutex.os_mutex);
	}

	/* Clear mutex info */

	obj_desc->mutex.thread_id = 0;
	return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_release_mutex
 *
 * PARAMETERS:  obj_desc            - The object descriptor for this op
 *              walk_state          - Current method execution state
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Release a previously acquired Mutex.
 *
 ******************************************************************************/

acpi_status
acpi_ex_release_mutex(union acpi_operand_object *obj_desc,
		      struct acpi_walk_state *walk_state)
{
	acpi_status status = AE_OK;

	ACPI_FUNCTION_TRACE(ex_release_mutex);

	if (!obj_desc) {
		return_ACPI_STATUS(AE_BAD_PARAMETER);
	}

	/* The mutex must have been previously acquired in order to release it */

	if (!obj_desc->mutex.owner_thread) {
		ACPI_ERROR((AE_INFO,
			    "Cannot release Mutex [%4.4s], not acquired",
			    acpi_ut_get_node_name(obj_desc->mutex.node)));
		return_ACPI_STATUS(AE_AML_MUTEX_NOT_ACQUIRED);
	}

	/*
	 * The Mutex is owned, but this thread must be the owner.
	 * Special case for Global Lock, any thread can release
	 */
	if ((obj_desc->mutex.owner_thread->thread_id !=
	     walk_state->thread->thread_id)
	    && (obj_desc != acpi_gbl_global_lock_mutex)) {
		ACPI_ERROR((AE_INFO,
			    "Thread %lX cannot release Mutex [%4.4s] acquired by thread %lX",
			    (unsigned long)walk_state->thread->thread_id,
			    acpi_ut_get_node_name(obj_desc->mutex.node),
			    (unsigned long)obj_desc->mutex.owner_thread->
			    thread_id));
		return_ACPI_STATUS(AE_AML_NOT_OWNER);
	}

	/* Must have a valid thread ID */

	if (!walk_state->thread) {
		ACPI_ERROR((AE_INFO,
			    "Cannot release Mutex [%4.4s], null thread info",
			    acpi_ut_get_node_name(obj_desc->mutex.node)));
		return_ACPI_STATUS(AE_AML_INTERNAL);
	}

	/*
	 * The sync level of the mutex must be less than or equal to the current
	 * sync level
	 */
	if (obj_desc->mutex.sync_level > walk_state->thread->current_sync_level) {
		ACPI_ERROR((AE_INFO,
			    "Cannot release Mutex [%4.4s], incorrect SyncLevel",
			    acpi_ut_get_node_name(obj_desc->mutex.node)));
		return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
	}

	status = acpi_ex_release_mutex_object(obj_desc);

	/* Restore the original sync_level */

	walk_state->thread->current_sync_level =
	    obj_desc->mutex.original_sync_level;
	return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ex_release_all_mutexes
 *
 * PARAMETERS:  Thread          - Current executing thread object
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Release all mutexes held by this thread
 *
 * NOTE: This function is called as the thread is exiting the interpreter.
 * Mutexes are not released when an individual control method is exited, but
 * only when the parent thread actually exits the interpreter. This allows one
 * method to acquire a mutex, and a different method to release it, as long as
 * this is performed underneath a single parent control method.
 *
 ******************************************************************************/

void acpi_ex_release_all_mutexes(struct acpi_thread_state *thread)
{
	union acpi_operand_object *next = thread->acquired_mutex_list;
	union acpi_operand_object *obj_desc;

	ACPI_FUNCTION_ENTRY();

	/* Traverse the list of owned mutexes, releasing each one */

	while (next) {
		obj_desc = next;
		next = obj_desc->mutex.next;

		obj_desc->mutex.prev = NULL;
		obj_desc->mutex.next = NULL;
		obj_desc->mutex.acquisition_depth = 0;

		/* Release the mutex, special case for Global Lock */

		if (obj_desc == acpi_gbl_global_lock_mutex) {

			/* Ignore errors */

			(void)acpi_ev_release_global_lock();
		} else {
			acpi_os_release_mutex(obj_desc->mutex.os_mutex);
		}

		/* Mark mutex unowned */

		obj_desc->mutex.owner_thread = NULL;
		obj_desc->mutex.thread_id = 0;

		/* Update Thread sync_level (Last mutex is the important one) */

		thread->current_sync_level =
		    obj_desc->mutex.original_sync_level;
	}
}
Commit	Line	Data
1da177e4 LT	1
	2	/******************************************************************************
	3	*
	4	* Module Name: exmutex - ASL Mutex Acquire/Release functions
	5	*
	6	*****************************************************************************/
	7
	8	/*
6c9deb72	9	* Copyright (C) 2000 - 2007, R. Byron Moore
1da177e4 LT	10	* All rights reserved.
	11	*
	12	* Redistribution and use in source and binary forms, with or without
	13	* modification, are permitted provided that the following conditions
	14	* are met:
	15	* 1. Redistributions of source code must retain the above copyright
	16	* notice, this list of conditions, and the following disclaimer,
	17	* without modification.
	18	* 2. Redistributions in binary form must reproduce at minimum a disclaimer
	19	* substantially similar to the "NO WARRANTY" disclaimer below
	20	* ("Disclaimer") and any redistribution must be conditioned upon
	21	* including a substantially similar Disclaimer requirement for further
	22	* binary redistribution.
	23	* 3. Neither the names of the above-listed copyright holders nor the names
	24	* of any contributors may be used to endorse or promote products derived
	25	* from this software without specific prior written permission.
	26	*
	27	* Alternatively, this software may be distributed under the terms of the
	28	* GNU General Public License ("GPL") version 2 as published by the Free
	29	* Software Foundation.
	30	*
	31	* NO WARRANTY
	32	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	33	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	34	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
	35	* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	36	* HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	37	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	38	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	39	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
	40	* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
	41	* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
	42	* POSSIBILITY OF SUCH DAMAGES.
	43	*/
	44
1da177e4 LT	45	#include <acpi/acpi.h>
1da177e4 LT	46	#include <acpi/acinterp.h>
c81da666	47	#include <acpi/acevents.h>
1da177e4 LT	48
1da177e4 LT	49	#define _COMPONENT ACPI_EXECUTER
4be44fcd	50	ACPI_MODULE_NAME("exmutex")
1da177e4	51
44f6c012	52	/* Local prototypes */
44f6c012	53	static void
4be44fcd LB	54	acpi_ex_link_mutex(union acpi_operand_object *obj_desc,
4be44fcd LB	55	struct acpi_thread_state *thread);
1da177e4 LT	56
	57	/*******************************************************************************
	58	*
	59	* FUNCTION: acpi_ex_unlink_mutex
	60	*
	61	* PARAMETERS: obj_desc - The mutex to be unlinked
	62	*
44f6c012	63	* RETURN: None
1da177e4	64	*
b229cf92	65	* DESCRIPTION: Remove a mutex from the "AcquiredMutex" list
1da177e4 LT	66	*
	67	******************************************************************************/
	68
262a7a28	69	void acpi_ex_unlink_mutex(union acpi_operand_object *obj_desc)
1da177e4	70	{
262a7a28 LB	71	struct acpi_thread_state *thread = obj_desc->mutex.owner_thread;
262a7a28 LB	72
1da177e4 LT	73	if (!thread) {
	74	return;
	75	}
	76
	77	/* Doubly linked list */
	78
	79	if (obj_desc->mutex.next) {
	80	(obj_desc->mutex.next)->mutex.prev = obj_desc->mutex.prev;
	81	}
	82
	83	if (obj_desc->mutex.prev) {
	84	(obj_desc->mutex.prev)->mutex.next = obj_desc->mutex.next;
4be44fcd	85	} else {
1da177e4 LT	86	thread->acquired_mutex_list = obj_desc->mutex.next;
	87	}
	88	}
	89
1da177e4 LT	90	/*******************************************************************************
	91	*
	92	* FUNCTION: acpi_ex_link_mutex
	93	*
44f6c012 RM	94	* PARAMETERS: obj_desc - The mutex to be linked
44f6c012 RM	95	* Thread - Current executing thread object
1da177e4	96	*
44f6c012	97	* RETURN: None
1da177e4	98	*
b229cf92	99	* DESCRIPTION: Add a mutex to the "AcquiredMutex" list for this walk
1da177e4 LT	100	*
	101	******************************************************************************/
	102
44f6c012	103	static void
4be44fcd LB	104	acpi_ex_link_mutex(union acpi_operand_object *obj_desc,
4be44fcd LB	105	struct acpi_thread_state *thread)
1da177e4	106	{
4be44fcd	107	union acpi_operand_object *list_head;
1da177e4 LT	108
	109	list_head = thread->acquired_mutex_list;
	110
	111	/* This object will be the first object in the list */
	112
	113	obj_desc->mutex.prev = NULL;
	114	obj_desc->mutex.next = list_head;
	115
	116	/* Update old first object to point back to this object */
	117
	118	if (list_head) {
	119	list_head->mutex.prev = obj_desc;
	120	}
	121
	122	/* Update list head */
	123
	124	thread->acquired_mutex_list = obj_desc;
	125	}
	126
ba886cd4 BM	127	/*******************************************************************************
	128	*
	129	* FUNCTION: acpi_ex_acquire_mutex_object
	130	*
	131	* PARAMETERS: time_desc - Timeout in milliseconds
	132	* obj_desc - Mutex object
	133	* Thread - Current thread state
	134	*
	135	* RETURN: Status
	136	*
91e38d10 BM	137	* DESCRIPTION: Acquire an AML mutex, low-level interface. Provides a common
	138	* path that supports multiple acquires by the same thread.
	139	*
	140	* MUTEX: Interpreter must be locked
	141	*
	142	* NOTE: This interface is called from three places:
	143	* 1) From acpi_ex_acquire_mutex, via an AML Acquire() operator
	144	* 2) From acpi_ex_acquire_global_lock when an AML Field access requires the
	145	* global lock
	146	* 3) From the external interface, acpi_acquire_global_lock
ba886cd4 BM	147	*
	148	******************************************************************************/
	149
	150	acpi_status
	151	acpi_ex_acquire_mutex_object(u16 timeout,
	152	union acpi_operand_object *obj_desc,
	153	acpi_thread_id thread_id)
	154	{
	155	acpi_status status;
	156
	157	ACPI_FUNCTION_TRACE_PTR(ex_acquire_mutex_object, obj_desc);
	158
	159	/* Support for multiple acquires by the owning thread */
	160
	161	if (obj_desc->mutex.thread_id == thread_id) {
	162	/*
	163	* The mutex is already owned by this thread, just increment the
	164	* acquisition depth
	165	*/
	166	obj_desc->mutex.acquisition_depth++;
	167	return_ACPI_STATUS(AE_OK);
	168	}
	169
	170	/* Acquire the mutex, wait if necessary. Special case for Global Lock */
	171
	172	if (obj_desc == acpi_gbl_global_lock_mutex) {
	173	status = acpi_ev_acquire_global_lock(timeout);
	174	} else {
	175	status = acpi_ex_system_wait_mutex(obj_desc->mutex.os_mutex,
	176	timeout);
	177	}
	178
	179	if (ACPI_FAILURE(status)) {
	180
	181	/* Includes failure from a timeout on time_desc */
	182
	183	return_ACPI_STATUS(status);
	184	}
	185
91e38d10	186	/* Acquired the mutex: update mutex object */
ba886cd4 BM	187
	188	obj_desc->mutex.thread_id = thread_id;
	189	obj_desc->mutex.acquisition_depth = 1;
	190	obj_desc->mutex.original_sync_level = 0;
	191	obj_desc->mutex.owner_thread = NULL; /* Used only for AML Acquire() */
	192
	193	return_ACPI_STATUS(AE_OK);
	194	}
	195
1da177e4 LT	196	/*******************************************************************************
	197	*
	198	* FUNCTION: acpi_ex_acquire_mutex
	199	*
44f6c012 RM	200	* PARAMETERS: time_desc - Timeout integer
	201	* obj_desc - Mutex object
	202	* walk_state - Current method execution state
1da177e4 LT	203	*
	204	* RETURN: Status
	205	*
	206	* DESCRIPTION: Acquire an AML mutex
	207	*
	208	******************************************************************************/
	209
	210	acpi_status
4be44fcd LB	211	acpi_ex_acquire_mutex(union acpi_operand_object *time_desc,
	212	union acpi_operand_object *obj_desc,
	213	struct acpi_walk_state *walk_state)
1da177e4	214	{
4be44fcd	215	acpi_status status;
1da177e4	216
b229cf92	217	ACPI_FUNCTION_TRACE_PTR(ex_acquire_mutex, obj_desc);
1da177e4 LT	218
1da177e4 LT	219	if (!obj_desc) {
4be44fcd	220	return_ACPI_STATUS(AE_BAD_PARAMETER);
1da177e4 LT	221	}
1da177e4 LT	222
91e38d10	223	/* Must have a valid thread ID */
1da177e4 LT	224
1da177e4 LT	225	if (!walk_state->thread) {
b8e4d893 BM	226	ACPI_ERROR((AE_INFO,
	227	"Cannot acquire Mutex [%4.4s], null thread info",
	228	acpi_ut_get_node_name(obj_desc->mutex.node)));
4be44fcd	229	return_ACPI_STATUS(AE_AML_INTERNAL);
1da177e4 LT	230	}
	231
	232	/*
91e38d10	233	* Current sync level must be less than or equal to the sync level of the
967440e3	234	* mutex. This mechanism provides some deadlock prevention
1da177e4 LT	235	*/
1da177e4 LT	236	if (walk_state->thread->current_sync_level > obj_desc->mutex.sync_level) {
b8e4d893	237	ACPI_ERROR((AE_INFO,
967440e3 BM	238	"Cannot acquire Mutex [%4.4s], current SyncLevel is too large (%d)",
	239	acpi_ut_get_node_name(obj_desc->mutex.node),
	240	walk_state->thread->current_sync_level));
4be44fcd	241	return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
1da177e4 LT	242	}
1da177e4 LT	243
ba886cd4 BM	244	status = acpi_ex_acquire_mutex_object((u16) time_desc->integer.value,
	245	obj_desc,
	246	walk_state->thread->thread_id);
	247	if (ACPI_SUCCESS(status) && obj_desc->mutex.acquisition_depth == 1) {
91e38d10 BM	248
	249	/* Save Thread object, original/current sync levels */
	250
ba886cd4 BM	251	obj_desc->mutex.owner_thread = walk_state->thread;
	252	obj_desc->mutex.original_sync_level =
	253	walk_state->thread->current_sync_level;
	254	walk_state->thread->current_sync_level =
	255	obj_desc->mutex.sync_level;
1da177e4	256
ba886cd4 BM	257	/* Link the mutex to the current thread for force-unlock at method exit */
	258
	259	acpi_ex_link_mutex(obj_desc, walk_state->thread);
1da177e4 LT	260	}
1da177e4 LT	261
ba886cd4 BM	262	return_ACPI_STATUS(status);
ba886cd4 BM	263	}
c81da666	264
ba886cd4 BM	265	/*******************************************************************************
	266	*
	267	* FUNCTION: acpi_ex_release_mutex_object
	268	*
	269	* PARAMETERS: obj_desc - The object descriptor for this op
	270	*
	271	* RETURN: Status
	272	*
	273	* DESCRIPTION: Release a previously acquired Mutex, low level interface.
91e38d10 BM	274	* Provides a common path that supports multiple releases (after
	275	* previous multiple acquires) by the same thread.
	276	*
	277	* MUTEX: Interpreter must be locked
	278	*
	279	* NOTE: This interface is called from three places:
	280	* 1) From acpi_ex_release_mutex, via an AML Acquire() operator
	281	* 2) From acpi_ex_release_global_lock when an AML Field access requires the
	282	* global lock
	283	* 3) From the external interface, acpi_release_global_lock
ba886cd4 BM	284	*
ba886cd4 BM	285	******************************************************************************/
1da177e4	286
ba886cd4 BM	287	acpi_status acpi_ex_release_mutex_object(union acpi_operand_object *obj_desc)
	288	{
	289	acpi_status status = AE_OK;
52fc0b02	290
ba886cd4	291	ACPI_FUNCTION_TRACE(ex_release_mutex_object);
1da177e4	292
ba886cd4 BM	293	/* Match multiple Acquires with multiple Releases */
	294
	295	obj_desc->mutex.acquisition_depth--;
	296	if (obj_desc->mutex.acquisition_depth != 0) {
	297
	298	/* Just decrement the depth and return */
	299
	300	return_ACPI_STATUS(AE_OK);
1da177e4 LT	301	}
1da177e4 LT	302
ba886cd4	303	if (obj_desc->mutex.owner_thread) {
1da177e4	304
ba886cd4 BM	305	/* Unlink the mutex from the owner's list */
	306
	307	acpi_ex_unlink_mutex(obj_desc);
	308	obj_desc->mutex.owner_thread = NULL;
	309	}
1da177e4	310
ba886cd4	311	/* Release the mutex, special case for Global Lock */
1da177e4	312
ba886cd4 BM	313	if (obj_desc == acpi_gbl_global_lock_mutex) {
	314	status = acpi_ev_release_global_lock();
	315	} else {
	316	acpi_os_release_mutex(obj_desc->mutex.os_mutex);
	317	}
1da177e4	318
91e38d10 BM	319	/* Clear mutex info */
91e38d10 BM	320
ba886cd4 BM	321	obj_desc->mutex.thread_id = 0;
ba886cd4 BM	322	return_ACPI_STATUS(status);
1da177e4 LT	323	}
1da177e4 LT	324
1da177e4 LT	325	/*******************************************************************************
	326	*
	327	* FUNCTION: acpi_ex_release_mutex
	328	*
	329	* PARAMETERS: obj_desc - The object descriptor for this op
44f6c012	330	* walk_state - Current method execution state
1da177e4 LT	331	*
	332	* RETURN: Status
	333	*
	334	* DESCRIPTION: Release a previously acquired Mutex.
	335	*
	336	******************************************************************************/
	337
	338	acpi_status
4be44fcd LB	339	acpi_ex_release_mutex(union acpi_operand_object *obj_desc,
4be44fcd LB	340	struct acpi_walk_state *walk_state)
1da177e4	341	{
c81da666	342	acpi_status status = AE_OK;
1da177e4	343
b229cf92	344	ACPI_FUNCTION_TRACE(ex_release_mutex);
1da177e4 LT	345
1da177e4 LT	346	if (!obj_desc) {
4be44fcd	347	return_ACPI_STATUS(AE_BAD_PARAMETER);
1da177e4 LT	348	}
	349
	350	/* The mutex must have been previously acquired in order to release it */
	351
262a7a28	352	if (!obj_desc->mutex.owner_thread) {
b8e4d893 BM	353	ACPI_ERROR((AE_INFO,
	354	"Cannot release Mutex [%4.4s], not acquired",
	355	acpi_ut_get_node_name(obj_desc->mutex.node)));
4be44fcd	356	return_ACPI_STATUS(AE_AML_MUTEX_NOT_ACQUIRED);
1da177e4 LT	357	}
1da177e4 LT	358
1da177e4 LT	359	/*
	360	* The Mutex is owned, but this thread must be the owner.
	361	* Special case for Global Lock, any thread can release
	362	*/
262a7a28	363	if ((obj_desc->mutex.owner_thread->thread_id !=
4be44fcd	364	walk_state->thread->thread_id)
ba886cd4	365	&& (obj_desc != acpi_gbl_global_lock_mutex)) {
b8e4d893	366	ACPI_ERROR((AE_INFO,
965a3d44 MB	367	"Thread %lX cannot release Mutex [%4.4s] acquired by thread %lX",
965a3d44 MB	368	(unsigned long)walk_state->thread->thread_id,
b8e4d893	369	acpi_ut_get_node_name(obj_desc->mutex.node),
fd350943 LB	370	(unsigned long)obj_desc->mutex.owner_thread->
fd350943 LB	371	thread_id));
4be44fcd	372	return_ACPI_STATUS(AE_AML_NOT_OWNER);
1da177e4 LT	373	}
1da177e4 LT	374
91e38d10	375	/* Must have a valid thread ID */
ba886cd4 BM	376
	377	if (!walk_state->thread) {
	378	ACPI_ERROR((AE_INFO,
	379	"Cannot release Mutex [%4.4s], null thread info",
	380	acpi_ut_get_node_name(obj_desc->mutex.node)));
	381	return_ACPI_STATUS(AE_AML_INTERNAL);
	382	}
	383
1da177e4	384	/*
c81da666 BM	385	* The sync level of the mutex must be less than or equal to the current
c81da666 BM	386	* sync level
1da177e4 LT	387	*/
1da177e4 LT	388	if (obj_desc->mutex.sync_level > walk_state->thread->current_sync_level) {
b8e4d893	389	ACPI_ERROR((AE_INFO,
b229cf92	390	"Cannot release Mutex [%4.4s], incorrect SyncLevel",
b8e4d893	391	acpi_ut_get_node_name(obj_desc->mutex.node)));
4be44fcd	392	return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
1da177e4 LT	393	}
1da177e4 LT	394
ba886cd4	395	status = acpi_ex_release_mutex_object(obj_desc);
1da177e4	396
91e38d10	397	/* Restore the original sync_level */
1da177e4	398
4be44fcd LB	399	walk_state->thread->current_sync_level =
4be44fcd LB	400	obj_desc->mutex.original_sync_level;
4be44fcd	401	return_ACPI_STATUS(status);
1da177e4 LT	402	}
1da177e4 LT	403
1da177e4 LT	404	/*******************************************************************************
	405	*
	406	* FUNCTION: acpi_ex_release_all_mutexes
	407	*
44f6c012	408	* PARAMETERS: Thread - Current executing thread object
1da177e4 LT	409	*
	410	* RETURN: Status
	411	*
44f6c012	412	* DESCRIPTION: Release all mutexes held by this thread
1da177e4	413	*
f70a5e7b BM	414	* NOTE: This function is called as the thread is exiting the interpreter.
	415	* Mutexes are not released when an individual control method is exited, but
	416	* only when the parent thread actually exits the interpreter. This allows one
	417	* method to acquire a mutex, and a different method to release it, as long as
	418	* this is performed underneath a single parent control method.
	419	*
1da177e4 LT	420	******************************************************************************/
1da177e4 LT	421
4be44fcd	422	void acpi_ex_release_all_mutexes(struct acpi_thread_state *thread)
1da177e4	423	{
4be44fcd	424	union acpi_operand_object *next = thread->acquired_mutex_list;
c81da666	425	union acpi_operand_object *obj_desc;
1da177e4	426
4be44fcd	427	ACPI_FUNCTION_ENTRY();
1da177e4 LT	428
	429	/* Traverse the list of owned mutexes, releasing each one */
	430
	431	while (next) {
c81da666 BM	432	obj_desc = next;
	433	next = obj_desc->mutex.next;
	434
	435	obj_desc->mutex.prev = NULL;
	436	obj_desc->mutex.next = NULL;
f70a5e7b	437	obj_desc->mutex.acquisition_depth = 0;
c81da666 BM	438
c81da666 BM	439	/* Release the mutex, special case for Global Lock */
1da177e4	440
ba886cd4	441	if (obj_desc == acpi_gbl_global_lock_mutex) {
1da177e4	442
c81da666	443	/* Ignore errors */
1da177e4	444
c81da666 BM	445	(void)acpi_ev_release_global_lock();
	446	} else {
	447	acpi_os_release_mutex(obj_desc->mutex.os_mutex);
1da177e4 LT	448	}
	449
	450	/* Mark mutex unowned */
	451
262a7a28	452	obj_desc->mutex.owner_thread = NULL;
ba886cd4	453	obj_desc->mutex.thread_id = 0;
1da177e4 LT	454
	455	/* Update Thread sync_level (Last mutex is the important one) */
	456
c81da666 BM	457	thread->current_sync_level =
c81da666 BM	458	obj_desc->mutex.original_sync_level;
1da177e4 LT	459	}
1da177e4 LT	460	}