/****************************************************************************** * * 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 "accommon.h" #include "acinterp.h" #include "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; /* * Migrate the previous sync level associated with this mutex to the * previous mutex on the list so that it may be preserved. This handles * the case where several mutexes have been acquired at the same level, * but are not released in opposite order. */ (obj_desc->mutex.prev)->mutex.original_sync_level = obj_desc->mutex.original_sync_level; } 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 = NULL; 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; u8 previous_sync_level; 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 %p cannot release Mutex [%4.4s] acquired by thread %p", ACPI_CAST_PTR(void, walk_state->thread->thread_id), acpi_ut_get_node_name(obj_desc->mutex.node), ACPI_CAST_PTR(void, 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 equal to the current sync level. In * other words, the current level means that at least one mutex at that * level is currently being held. Attempting to release a mutex of a * different level can only mean that the mutex ordering rule is being * violated. This behavior is clarified in ACPI 4.0 specification. */ 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); } /* * Get the previous sync_level from the head of the acquired mutex list. * This handles the case where several mutexes at the same level have been * acquired, but are not released in reverse order. */ previous_sync_level = walk_state->thread->acquired_mutex_list->mutex.original_sync_level; status = acpi_ex_release_mutex_object(obj_desc); if (ACPI_FAILURE(status)) { return_ACPI_STATUS(status); } if (obj_desc->mutex.acquisition_depth == 0) { /* Restore the previous sync_level */ walk_state->thread->current_sync_level = previous_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 = NULL; /* Update Thread sync_level (Last mutex is the important one) */ thread->current_sync_level = obj_desc->mutex.original_sync_level; } }