diff options
Diffstat (limited to 'drivers/acpi/acpica/exmutex.c')
-rw-r--r-- | drivers/acpi/acpica/exmutex.c | 506 |
1 files changed, 506 insertions, 0 deletions
diff --git a/drivers/acpi/acpica/exmutex.c b/drivers/acpi/acpica/exmutex.c new file mode 100644 index 000000000..e9dcfa1e9 --- /dev/null +++ b/drivers/acpi/acpica/exmutex.c @@ -0,0 +1,506 @@ +// 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; +} |