[deliverable/linux.git] / drivers / acpi / executer / exmutex.c


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

/*
 * Copyright (C) 2000 - 2008, Intel Corp.
 * 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);

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

	/* 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);

	if (obj_desc->mutex.acquisition_depth == 0) {
		return (AE_NOT_ACQUIRED);
	}

	/* 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], SyncLevel mismatch: mutex %d current %d",
			    acpi_ut_get_node_name(obj_desc->mutex.node),
			    obj_desc->mutex.sync_level,
			    walk_state->thread->current_sync_level));
		return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
	}

	status = acpi_ex_release_mutex_object(obj_desc);

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

		/* 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	/*
75a44ce0	9	* Copyright (C) 2000 - 2008, Intel Corp.
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
f02e9fa1 BM	159	if (!obj_desc) {
	160	return_ACPI_STATUS(AE_BAD_PARAMETER);
	161	}
	162
ba886cd4 BM	163	/* Support for multiple acquires by the owning thread */
	164
	165	if (obj_desc->mutex.thread_id == thread_id) {
	166	/*
	167	* The mutex is already owned by this thread, just increment the
	168	* acquisition depth
	169	*/
	170	obj_desc->mutex.acquisition_depth++;
	171	return_ACPI_STATUS(AE_OK);
	172	}
	173
	174	/* Acquire the mutex, wait if necessary. Special case for Global Lock */
	175
	176	if (obj_desc == acpi_gbl_global_lock_mutex) {
	177	status = acpi_ev_acquire_global_lock(timeout);
	178	} else {
	179	status = acpi_ex_system_wait_mutex(obj_desc->mutex.os_mutex,
	180	timeout);
	181	}
	182
	183	if (ACPI_FAILURE(status)) {
	184
	185	/* Includes failure from a timeout on time_desc */
	186
	187	return_ACPI_STATUS(status);
	188	}
	189
91e38d10	190	/* Acquired the mutex: update mutex object */
ba886cd4 BM	191
	192	obj_desc->mutex.thread_id = thread_id;
	193	obj_desc->mutex.acquisition_depth = 1;
	194	obj_desc->mutex.original_sync_level = 0;
	195	obj_desc->mutex.owner_thread = NULL; /* Used only for AML Acquire() */
	196
	197	return_ACPI_STATUS(AE_OK);
	198	}
	199
1da177e4 LT	200	/*******************************************************************************
	201	*
	202	* FUNCTION: acpi_ex_acquire_mutex
	203	*
44f6c012 RM	204	* PARAMETERS: time_desc - Timeout integer
	205	* obj_desc - Mutex object
	206	* walk_state - Current method execution state
1da177e4 LT	207	*
	208	* RETURN: Status
	209	*
	210	* DESCRIPTION: Acquire an AML mutex
	211	*
	212	******************************************************************************/
	213
	214	acpi_status
4be44fcd LB	215	acpi_ex_acquire_mutex(union acpi_operand_object *time_desc,
	216	union acpi_operand_object *obj_desc,
	217	struct acpi_walk_state *walk_state)
1da177e4	218	{
4be44fcd	219	acpi_status status;
1da177e4	220
b229cf92	221	ACPI_FUNCTION_TRACE_PTR(ex_acquire_mutex, obj_desc);
1da177e4 LT	222
1da177e4 LT	223	if (!obj_desc) {
4be44fcd	224	return_ACPI_STATUS(AE_BAD_PARAMETER);
1da177e4 LT	225	}
1da177e4 LT	226
91e38d10	227	/* Must have a valid thread ID */
1da177e4 LT	228
1da177e4 LT	229	if (!walk_state->thread) {
b8e4d893 BM	230	ACPI_ERROR((AE_INFO,
	231	"Cannot acquire Mutex [%4.4s], null thread info",
	232	acpi_ut_get_node_name(obj_desc->mutex.node)));
4be44fcd	233	return_ACPI_STATUS(AE_AML_INTERNAL);
1da177e4 LT	234	}
	235
	236	/*
91e38d10	237	* Current sync level must be less than or equal to the sync level of the
967440e3	238	* mutex. This mechanism provides some deadlock prevention
1da177e4 LT	239	*/
1da177e4 LT	240	if (walk_state->thread->current_sync_level > obj_desc->mutex.sync_level) {
b8e4d893	241	ACPI_ERROR((AE_INFO,
967440e3 BM	242	"Cannot acquire Mutex [%4.4s], current SyncLevel is too large (%d)",
	243	acpi_ut_get_node_name(obj_desc->mutex.node),
	244	walk_state->thread->current_sync_level));
4be44fcd	245	return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
1da177e4 LT	246	}
1da177e4 LT	247
ba886cd4 BM	248	status = acpi_ex_acquire_mutex_object((u16) time_desc->integer.value,
	249	obj_desc,
	250	walk_state->thread->thread_id);
	251	if (ACPI_SUCCESS(status) && obj_desc->mutex.acquisition_depth == 1) {
91e38d10 BM	252
	253	/* Save Thread object, original/current sync levels */
	254
ba886cd4 BM	255	obj_desc->mutex.owner_thread = walk_state->thread;
	256	obj_desc->mutex.original_sync_level =
	257	walk_state->thread->current_sync_level;
	258	walk_state->thread->current_sync_level =
	259	obj_desc->mutex.sync_level;
1da177e4	260
ba886cd4 BM	261	/* Link the mutex to the current thread for force-unlock at method exit */
	262
	263	acpi_ex_link_mutex(obj_desc, walk_state->thread);
1da177e4 LT	264	}
1da177e4 LT	265
ba886cd4 BM	266	return_ACPI_STATUS(status);
ba886cd4 BM	267	}
c81da666	268
ba886cd4 BM	269	/*******************************************************************************
	270	*
	271	* FUNCTION: acpi_ex_release_mutex_object
	272	*
	273	* PARAMETERS: obj_desc - The object descriptor for this op
	274	*
	275	* RETURN: Status
	276	*
	277	* DESCRIPTION: Release a previously acquired Mutex, low level interface.
91e38d10 BM	278	* Provides a common path that supports multiple releases (after
	279	* previous multiple acquires) by the same thread.
	280	*
	281	* MUTEX: Interpreter must be locked
	282	*
	283	* NOTE: This interface is called from three places:
	284	* 1) From acpi_ex_release_mutex, via an AML Acquire() operator
	285	* 2) From acpi_ex_release_global_lock when an AML Field access requires the
	286	* global lock
	287	* 3) From the external interface, acpi_release_global_lock
ba886cd4 BM	288	*
ba886cd4 BM	289	******************************************************************************/
1da177e4	290
ba886cd4 BM	291	acpi_status acpi_ex_release_mutex_object(union acpi_operand_object *obj_desc)
	292	{
	293	acpi_status status = AE_OK;
52fc0b02	294
ba886cd4	295	ACPI_FUNCTION_TRACE(ex_release_mutex_object);
1da177e4	296
f02e9fa1 BM	297	if (obj_desc->mutex.acquisition_depth == 0) {
	298	return (AE_NOT_ACQUIRED);
	299	}
	300
ba886cd4 BM	301	/* Match multiple Acquires with multiple Releases */
	302
	303	obj_desc->mutex.acquisition_depth--;
	304	if (obj_desc->mutex.acquisition_depth != 0) {
	305
	306	/* Just decrement the depth and return */
	307
	308	return_ACPI_STATUS(AE_OK);
1da177e4 LT	309	}
1da177e4 LT	310
ba886cd4	311	if (obj_desc->mutex.owner_thread) {
1da177e4	312
ba886cd4 BM	313	/* Unlink the mutex from the owner's list */
	314
	315	acpi_ex_unlink_mutex(obj_desc);
	316	obj_desc->mutex.owner_thread = NULL;
	317	}
1da177e4	318
ba886cd4	319	/* Release the mutex, special case for Global Lock */
1da177e4	320
ba886cd4 BM	321	if (obj_desc == acpi_gbl_global_lock_mutex) {
	322	status = acpi_ev_release_global_lock();
	323	} else {
	324	acpi_os_release_mutex(obj_desc->mutex.os_mutex);
	325	}
1da177e4	326
91e38d10 BM	327	/* Clear mutex info */
91e38d10 BM	328
ba886cd4 BM	329	obj_desc->mutex.thread_id = 0;
ba886cd4 BM	330	return_ACPI_STATUS(status);
1da177e4 LT	331	}
1da177e4 LT	332
1da177e4 LT	333	/*******************************************************************************
	334	*
	335	* FUNCTION: acpi_ex_release_mutex
	336	*
	337	* PARAMETERS: obj_desc - The object descriptor for this op
44f6c012	338	* walk_state - Current method execution state
1da177e4 LT	339	*
	340	* RETURN: Status
	341	*
	342	* DESCRIPTION: Release a previously acquired Mutex.
	343	*
	344	******************************************************************************/
	345
	346	acpi_status
4be44fcd LB	347	acpi_ex_release_mutex(union acpi_operand_object *obj_desc,
4be44fcd LB	348	struct acpi_walk_state *walk_state)
1da177e4	349	{
c81da666	350	acpi_status status = AE_OK;
1da177e4	351
b229cf92	352	ACPI_FUNCTION_TRACE(ex_release_mutex);
1da177e4 LT	353
1da177e4 LT	354	if (!obj_desc) {
4be44fcd	355	return_ACPI_STATUS(AE_BAD_PARAMETER);
1da177e4 LT	356	}
	357
	358	/* The mutex must have been previously acquired in order to release it */
	359
262a7a28	360	if (!obj_desc->mutex.owner_thread) {
b8e4d893 BM	361	ACPI_ERROR((AE_INFO,
	362	"Cannot release Mutex [%4.4s], not acquired",
	363	acpi_ut_get_node_name(obj_desc->mutex.node)));
4be44fcd	364	return_ACPI_STATUS(AE_AML_MUTEX_NOT_ACQUIRED);
1da177e4 LT	365	}
1da177e4 LT	366
1da177e4 LT	367	/*
	368	* The Mutex is owned, but this thread must be the owner.
	369	* Special case for Global Lock, any thread can release
	370	*/
262a7a28	371	if ((obj_desc->mutex.owner_thread->thread_id !=
4be44fcd	372	walk_state->thread->thread_id)
ba886cd4	373	&& (obj_desc != acpi_gbl_global_lock_mutex)) {
b8e4d893	374	ACPI_ERROR((AE_INFO,
965a3d44 MB	375	"Thread %lX cannot release Mutex [%4.4s] acquired by thread %lX",
965a3d44 MB	376	(unsigned long)walk_state->thread->thread_id,
b8e4d893	377	acpi_ut_get_node_name(obj_desc->mutex.node),
fd350943 LB	378	(unsigned long)obj_desc->mutex.owner_thread->
fd350943 LB	379	thread_id));
4be44fcd	380	return_ACPI_STATUS(AE_AML_NOT_OWNER);
1da177e4 LT	381	}
1da177e4 LT	382
91e38d10	383	/* Must have a valid thread ID */
ba886cd4 BM	384
	385	if (!walk_state->thread) {
	386	ACPI_ERROR((AE_INFO,
	387	"Cannot release Mutex [%4.4s], null thread info",
	388	acpi_ut_get_node_name(obj_desc->mutex.node)));
	389	return_ACPI_STATUS(AE_AML_INTERNAL);
	390	}
	391
1da177e4	392	/*
c81da666 BM	393	* The sync level of the mutex must be less than or equal to the current
c81da666 BM	394	* sync level
1da177e4 LT	395	*/
1da177e4 LT	396	if (obj_desc->mutex.sync_level > walk_state->thread->current_sync_level) {
b8e4d893	397	ACPI_ERROR((AE_INFO,
f02e9fa1 BM	398	"Cannot release Mutex [%4.4s], SyncLevel mismatch: mutex %d current %d",
	399	acpi_ut_get_node_name(obj_desc->mutex.node),
	400	obj_desc->mutex.sync_level,
	401	walk_state->thread->current_sync_level));
4be44fcd	402	return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
1da177e4 LT	403	}
1da177e4 LT	404
ba886cd4	405	status = acpi_ex_release_mutex_object(obj_desc);
1da177e4	406
f02e9fa1	407	if (obj_desc->mutex.acquisition_depth == 0) {
1da177e4	408
f02e9fa1 BM	409	/* Restore the original sync_level */
	410
	411	walk_state->thread->current_sync_level =
	412	obj_desc->mutex.original_sync_level;
	413	}
4be44fcd	414	return_ACPI_STATUS(status);
1da177e4 LT	415	}
1da177e4 LT	416
1da177e4 LT	417	/*******************************************************************************
	418	*
	419	* FUNCTION: acpi_ex_release_all_mutexes
	420	*
44f6c012	421	* PARAMETERS: Thread - Current executing thread object
1da177e4 LT	422	*
	423	* RETURN: Status
	424	*
44f6c012	425	* DESCRIPTION: Release all mutexes held by this thread
1da177e4	426	*
f70a5e7b BM	427	* NOTE: This function is called as the thread is exiting the interpreter.
	428	* Mutexes are not released when an individual control method is exited, but
	429	* only when the parent thread actually exits the interpreter. This allows one
	430	* method to acquire a mutex, and a different method to release it, as long as
	431	* this is performed underneath a single parent control method.
	432	*
1da177e4 LT	433	******************************************************************************/
1da177e4 LT	434
4be44fcd	435	void acpi_ex_release_all_mutexes(struct acpi_thread_state *thread)
1da177e4	436	{
4be44fcd	437	union acpi_operand_object *next = thread->acquired_mutex_list;
c81da666	438	union acpi_operand_object *obj_desc;
1da177e4	439
4be44fcd	440	ACPI_FUNCTION_ENTRY();
1da177e4 LT	441
	442	/* Traverse the list of owned mutexes, releasing each one */
	443
	444	while (next) {
c81da666 BM	445	obj_desc = next;
	446	next = obj_desc->mutex.next;
	447
	448	obj_desc->mutex.prev = NULL;
	449	obj_desc->mutex.next = NULL;
f70a5e7b	450	obj_desc->mutex.acquisition_depth = 0;
c81da666 BM	451
c81da666 BM	452	/* Release the mutex, special case for Global Lock */
1da177e4	453
ba886cd4	454	if (obj_desc == acpi_gbl_global_lock_mutex) {
1da177e4	455
c81da666	456	/* Ignore errors */
1da177e4	457
c81da666 BM	458	(void)acpi_ev_release_global_lock();
	459	} else {
	460	acpi_os_release_mutex(obj_desc->mutex.os_mutex);
1da177e4 LT	461	}
	462
	463	/* Mark mutex unowned */
	464
262a7a28	465	obj_desc->mutex.owner_thread = NULL;
ba886cd4	466	obj_desc->mutex.thread_id = 0;
1da177e4 LT	467
	468	/* Update Thread sync_level (Last mutex is the important one) */
	469
c81da666 BM	470	thread->current_sync_level =
c81da666 BM	471	obj_desc->mutex.original_sync_level;
1da177e4 LT	472	}
1da177e4 LT	473	}