| // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0 |
| /****************************************************************************** |
| * |
| * Module Name: exmutex - ASL Mutex Acquire/Release functions |
| * |
| * Copyright (C) 2000 - 2022, Intel Corp. |
| * |
| *****************************************************************************/ |
| |
| #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: timeout - Timeout in milliseconds |
| * obj_desc - Mutex object |
| * thread_id - 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 state struct */ |
| |
| 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 (%u)", |
| acpi_ut_get_node_name(obj_desc->mutex.node), |
| walk_state->thread->current_sync_level)); |
| return_ACPI_STATUS(AE_AML_MUTEX_ORDER); |
| } |
| |
| ACPI_DEBUG_PRINT((ACPI_DB_EXEC, |
| "Acquiring: Mutex SyncLevel %u, Thread SyncLevel %u, " |
| "Depth %u TID %p\n", |
| obj_desc->mutex.sync_level, |
| walk_state->thread->current_sync_level, |
| obj_desc->mutex.acquisition_depth, |
| walk_state->thread)); |
| |
| 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); |
| } |
| |
| ACPI_DEBUG_PRINT((ACPI_DB_EXEC, |
| "Acquired: Mutex SyncLevel %u, Thread SyncLevel %u, Depth %u\n", |
| obj_desc->mutex.sync_level, |
| walk_state->thread->current_sync_level, |
| obj_desc->mutex.acquisition_depth)); |
| |
| 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_ACPI_STATUS(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) |
| { |
| u8 previous_sync_level; |
| struct acpi_thread_state *owner_thread; |
| acpi_status status = AE_OK; |
| |
| ACPI_FUNCTION_TRACE(ex_release_mutex); |
| |
| if (!obj_desc) { |
| return_ACPI_STATUS(AE_BAD_PARAMETER); |
| } |
| |
| owner_thread = obj_desc->mutex.owner_thread; |
| |
| /* The mutex must have been previously acquired in order to release it */ |
| |
| if (!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); |
| } |
| |
| /* 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 Mutex is owned, but this thread must be the owner. |
| * Special case for Global Lock, any thread can release |
| */ |
| if ((owner_thread->thread_id != walk_state->thread->thread_id) && |
| (obj_desc != acpi_gbl_global_lock_mutex)) { |
| ACPI_ERROR((AE_INFO, |
| "Thread %u cannot release Mutex [%4.4s] acquired by thread %u", |
| (u32)walk_state->thread->thread_id, |
| acpi_ut_get_node_name(obj_desc->mutex.node), |
| (u32)owner_thread->thread_id)); |
| return_ACPI_STATUS(AE_AML_NOT_OWNER); |
| } |
| |
| /* |
| * 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 != owner_thread->current_sync_level) { |
| ACPI_ERROR((AE_INFO, |
| "Cannot release Mutex [%4.4s], SyncLevel mismatch: " |
| "mutex %u current %u", |
| 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 = |
| owner_thread->acquired_mutex_list->mutex.original_sync_level; |
| |
| ACPI_DEBUG_PRINT((ACPI_DB_EXEC, |
| "Releasing: Object SyncLevel %u, Thread SyncLevel %u, " |
| "Prev SyncLevel %u, Depth %u TID %p\n", |
| obj_desc->mutex.sync_level, |
| walk_state->thread->current_sync_level, |
| previous_sync_level, |
| obj_desc->mutex.acquisition_depth, |
| walk_state->thread)); |
| |
| 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 */ |
| |
| owner_thread->current_sync_level = previous_sync_level; |
| } |
| |
| ACPI_DEBUG_PRINT((ACPI_DB_EXEC, |
| "Released: Object SyncLevel %u, Thread SyncLevel, %u, " |
| "Prev SyncLevel %u, Depth %u\n", |
| obj_desc->mutex.sync_level, |
| walk_state->thread->current_sync_level, |
| previous_sync_level, |
| obj_desc->mutex.acquisition_depth)); |
| |
| 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_TRACE(ex_release_all_mutexes); |
| |
| /* Traverse the list of owned mutexes, releasing each one */ |
| |
| while (next) { |
| obj_desc = next; |
| ACPI_DEBUG_PRINT((ACPI_DB_EXEC, |
| "Mutex [%4.4s] force-release, SyncLevel %u Depth %u\n", |
| obj_desc->mutex.node->name.ascii, |
| obj_desc->mutex.sync_level, |
| obj_desc->mutex.acquisition_depth)); |
| |
| /* 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); |
| } |
| |
| /* Update Thread sync_level (Last mutex is the important one) */ |
| |
| thread->current_sync_level = |
| obj_desc->mutex.original_sync_level; |
| |
| /* Mark mutex unowned */ |
| |
| next = obj_desc->mutex.next; |
| |
| obj_desc->mutex.prev = NULL; |
| obj_desc->mutex.next = NULL; |
| obj_desc->mutex.acquisition_depth = 0; |
| obj_desc->mutex.owner_thread = NULL; |
| obj_desc->mutex.thread_id = 0; |
| } |
| |
| return_VOID; |
| } |