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path: root/drivers/acpi/acpica/exmutex.c
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Diffstat (limited to 'drivers/acpi/acpica/exmutex.c')
-rw-r--r--drivers/acpi/acpica/exmutex.c45
1 files changed, 35 insertions, 10 deletions
diff --git a/drivers/acpi/acpica/exmutex.c b/drivers/acpi/acpica/exmutex.c
index d301c1f363e..2f0114202b0 100644
--- a/drivers/acpi/acpica/exmutex.c
+++ b/drivers/acpi/acpica/exmutex.c
@@ -83,6 +83,15 @@ void acpi_ex_unlink_mutex(union acpi_operand_object *obj_desc)
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;
}
@@ -349,6 +358,7 @@ 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);
@@ -373,11 +383,12 @@ acpi_ex_release_mutex(union acpi_operand_object *obj_desc,
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,
+ "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),
- (unsigned long)obj_desc->mutex.owner_thread->
- thread_id));
+ ACPI_CAST_PTR(void,
+ obj_desc->mutex.owner_thread->
+ thread_id)));
return_ACPI_STATUS(AE_AML_NOT_OWNER);
}
@@ -391,10 +402,14 @@ acpi_ex_release_mutex(union acpi_operand_object *obj_desc,
}
/*
- * The sync level of the mutex must be less than or equal to the current
- * sync level
+ * 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) {
+ 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),
@@ -403,14 +418,24 @@ acpi_ex_release_mutex(union acpi_operand_object *obj_desc,
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 original sync_level */
+ /* Restore the previous sync_level */
- walk_state->thread->current_sync_level =
- obj_desc->mutex.original_sync_level;
+ walk_state->thread->current_sync_level = previous_sync_level;
}
return_ACPI_STATUS(status);
}