v4.19.13 snapshot.
diff --git a/drivers/acpi/acpica/dsmethod.c b/drivers/acpi/acpica/dsmethod.c
new file mode 100644
index 0000000..dd4deb6
--- /dev/null
+++ b/drivers/acpi/acpica/dsmethod.c
@@ -0,0 +1,828 @@
+// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
+/******************************************************************************
+ *
+ * Module Name: dsmethod - Parser/Interpreter interface - control method parsing
+ *
+ * Copyright (C) 2000 - 2018, Intel Corp.
+ *
+ *****************************************************************************/
+
+#include <acpi/acpi.h>
+#include "accommon.h"
+#include "acdispat.h"
+#include "acinterp.h"
+#include "acnamesp.h"
+#include "acparser.h"
+#include "amlcode.h"
+#include "acdebug.h"
+
+#define _COMPONENT ACPI_DISPATCHER
+ACPI_MODULE_NAME("dsmethod")
+
+/* Local prototypes */
+static acpi_status
+acpi_ds_detect_named_opcodes(struct acpi_walk_state *walk_state,
+ union acpi_parse_object **out_op);
+
+static acpi_status
+acpi_ds_create_method_mutex(union acpi_operand_object *method_desc);
+
+/*******************************************************************************
+ *
+ * FUNCTION: acpi_ds_auto_serialize_method
+ *
+ * PARAMETERS: node - Namespace Node of the method
+ * obj_desc - Method object attached to node
+ *
+ * RETURN: Status
+ *
+ * DESCRIPTION: Parse a control method AML to scan for control methods that
+ * need serialization due to the creation of named objects.
+ *
+ * NOTE: It is a bit of overkill to mark all such methods serialized, since
+ * there is only a problem if the method actually blocks during execution.
+ * A blocking operation is, for example, a Sleep() operation, or any access
+ * to an operation region. However, it is probably not possible to easily
+ * detect whether a method will block or not, so we simply mark all suspicious
+ * methods as serialized.
+ *
+ * NOTE2: This code is essentially a generic routine for parsing a single
+ * control method.
+ *
+ ******************************************************************************/
+
+acpi_status
+acpi_ds_auto_serialize_method(struct acpi_namespace_node *node,
+ union acpi_operand_object *obj_desc)
+{
+ acpi_status status;
+ union acpi_parse_object *op = NULL;
+ struct acpi_walk_state *walk_state;
+
+ ACPI_FUNCTION_TRACE_PTR(ds_auto_serialize_method, node);
+
+ ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
+ "Method auto-serialization parse [%4.4s] %p\n",
+ acpi_ut_get_node_name(node), node));
+
+ /* Create/Init a root op for the method parse tree */
+
+ op = acpi_ps_alloc_op(AML_METHOD_OP, obj_desc->method.aml_start);
+ if (!op) {
+ return_ACPI_STATUS(AE_NO_MEMORY);
+ }
+
+ acpi_ps_set_name(op, node->name.integer);
+ op->common.node = node;
+
+ /* Create and initialize a new walk state */
+
+ walk_state =
+ acpi_ds_create_walk_state(node->owner_id, NULL, NULL, NULL);
+ if (!walk_state) {
+ acpi_ps_free_op(op);
+ return_ACPI_STATUS(AE_NO_MEMORY);
+ }
+
+ status = acpi_ds_init_aml_walk(walk_state, op, node,
+ obj_desc->method.aml_start,
+ obj_desc->method.aml_length, NULL, 0);
+ if (ACPI_FAILURE(status)) {
+ acpi_ds_delete_walk_state(walk_state);
+ acpi_ps_free_op(op);
+ return_ACPI_STATUS(status);
+ }
+
+ walk_state->descending_callback = acpi_ds_detect_named_opcodes;
+
+ /* Parse the method, scan for creation of named objects */
+
+ status = acpi_ps_parse_aml(walk_state);
+
+ acpi_ps_delete_parse_tree(op);
+ return_ACPI_STATUS(status);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION: acpi_ds_detect_named_opcodes
+ *
+ * PARAMETERS: walk_state - Current state of the parse tree walk
+ * out_op - Unused, required for parser interface
+ *
+ * RETURN: Status
+ *
+ * DESCRIPTION: Descending callback used during the loading of ACPI tables.
+ * Currently used to detect methods that must be marked serialized
+ * in order to avoid problems with the creation of named objects.
+ *
+ ******************************************************************************/
+
+static acpi_status
+acpi_ds_detect_named_opcodes(struct acpi_walk_state *walk_state,
+ union acpi_parse_object **out_op)
+{
+
+ ACPI_FUNCTION_NAME(acpi_ds_detect_named_opcodes);
+
+ /* We are only interested in opcodes that create a new name */
+
+ if (!
+ (walk_state->op_info->
+ flags & (AML_NAMED | AML_CREATE | AML_FIELD))) {
+ return (AE_OK);
+ }
+
+ /*
+ * At this point, we know we have a Named object opcode.
+ * Mark the method as serialized. Later code will create a mutex for
+ * this method to enforce serialization.
+ *
+ * Note, ACPI_METHOD_IGNORE_SYNC_LEVEL flag means that we will ignore the
+ * Sync Level mechanism for this method, even though it is now serialized.
+ * Otherwise, there can be conflicts with existing ASL code that actually
+ * uses sync levels.
+ */
+ walk_state->method_desc->method.sync_level = 0;
+ walk_state->method_desc->method.info_flags |=
+ (ACPI_METHOD_SERIALIZED | ACPI_METHOD_IGNORE_SYNC_LEVEL);
+
+ ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+ "Method serialized [%4.4s] %p - [%s] (%4.4X)\n",
+ walk_state->method_node->name.ascii,
+ walk_state->method_node, walk_state->op_info->name,
+ walk_state->opcode));
+
+ /* Abort the parse, no need to examine this method any further */
+
+ return (AE_CTRL_TERMINATE);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION: acpi_ds_method_error
+ *
+ * PARAMETERS: status - Execution status
+ * walk_state - Current state
+ *
+ * RETURN: Status
+ *
+ * DESCRIPTION: Called on method error. Invoke the global exception handler if
+ * present, dump the method data if the debugger is configured
+ *
+ * Note: Allows the exception handler to change the status code
+ *
+ ******************************************************************************/
+
+acpi_status
+acpi_ds_method_error(acpi_status status, struct acpi_walk_state *walk_state)
+{
+ u32 aml_offset;
+ acpi_name name = 0;
+
+ ACPI_FUNCTION_ENTRY();
+
+ /* Ignore AE_OK and control exception codes */
+
+ if (ACPI_SUCCESS(status) || (status & AE_CODE_CONTROL)) {
+ return (status);
+ }
+
+ /* Invoke the global exception handler */
+
+ if (acpi_gbl_exception_handler) {
+
+ /* Exit the interpreter, allow handler to execute methods */
+
+ acpi_ex_exit_interpreter();
+
+ /*
+ * Handler can map the exception code to anything it wants, including
+ * AE_OK, in which case the executing method will not be aborted.
+ */
+ aml_offset = (u32)ACPI_PTR_DIFF(walk_state->aml,
+ walk_state->parser_state.
+ aml_start);
+
+ if (walk_state->method_node) {
+ name = walk_state->method_node->name.integer;
+ } else if (walk_state->deferred_node) {
+ name = walk_state->deferred_node->name.integer;
+ }
+
+ status = acpi_gbl_exception_handler(status, name,
+ walk_state->opcode,
+ aml_offset, NULL);
+ acpi_ex_enter_interpreter();
+ }
+
+ acpi_ds_clear_implicit_return(walk_state);
+
+ if (ACPI_FAILURE(status)) {
+ acpi_ds_dump_method_stack(status, walk_state, walk_state->op);
+
+ /* Display method locals/args if debugger is present */
+
+#ifdef ACPI_DEBUGGER
+ acpi_db_dump_method_info(status, walk_state);
+#endif
+ }
+
+ return (status);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION: acpi_ds_create_method_mutex
+ *
+ * PARAMETERS: obj_desc - The method object
+ *
+ * RETURN: Status
+ *
+ * DESCRIPTION: Create a mutex object for a serialized control method
+ *
+ ******************************************************************************/
+
+static acpi_status
+acpi_ds_create_method_mutex(union acpi_operand_object *method_desc)
+{
+ union acpi_operand_object *mutex_desc;
+ acpi_status status;
+
+ ACPI_FUNCTION_TRACE(ds_create_method_mutex);
+
+ /* Create the new mutex object */
+
+ mutex_desc = acpi_ut_create_internal_object(ACPI_TYPE_MUTEX);
+ if (!mutex_desc) {
+ return_ACPI_STATUS(AE_NO_MEMORY);
+ }
+
+ /* Create the actual OS Mutex */
+
+ status = acpi_os_create_mutex(&mutex_desc->mutex.os_mutex);
+ if (ACPI_FAILURE(status)) {
+ acpi_ut_delete_object_desc(mutex_desc);
+ return_ACPI_STATUS(status);
+ }
+
+ mutex_desc->mutex.sync_level = method_desc->method.sync_level;
+ method_desc->method.mutex = mutex_desc;
+ return_ACPI_STATUS(AE_OK);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION: acpi_ds_begin_method_execution
+ *
+ * PARAMETERS: method_node - Node of the method
+ * obj_desc - The method object
+ * walk_state - current state, NULL if not yet executing
+ * a method.
+ *
+ * RETURN: Status
+ *
+ * DESCRIPTION: Prepare a method for execution. Parses the method if necessary,
+ * increments the thread count, and waits at the method semaphore
+ * for clearance to execute.
+ *
+ ******************************************************************************/
+
+acpi_status
+acpi_ds_begin_method_execution(struct acpi_namespace_node *method_node,
+ union acpi_operand_object *obj_desc,
+ struct acpi_walk_state *walk_state)
+{
+ acpi_status status = AE_OK;
+
+ ACPI_FUNCTION_TRACE_PTR(ds_begin_method_execution, method_node);
+
+ if (!method_node) {
+ return_ACPI_STATUS(AE_NULL_ENTRY);
+ }
+
+ acpi_ex_start_trace_method(method_node, obj_desc, walk_state);
+
+ /* Prevent wraparound of thread count */
+
+ if (obj_desc->method.thread_count == ACPI_UINT8_MAX) {
+ ACPI_ERROR((AE_INFO,
+ "Method reached maximum reentrancy limit (255)"));
+ return_ACPI_STATUS(AE_AML_METHOD_LIMIT);
+ }
+
+ /*
+ * If this method is serialized, we need to acquire the method mutex.
+ */
+ if (obj_desc->method.info_flags & ACPI_METHOD_SERIALIZED) {
+ /*
+ * Create a mutex for the method if it is defined to be Serialized
+ * and a mutex has not already been created. We defer the mutex creation
+ * until a method is actually executed, to minimize the object count
+ */
+ if (!obj_desc->method.mutex) {
+ status = acpi_ds_create_method_mutex(obj_desc);
+ if (ACPI_FAILURE(status)) {
+ return_ACPI_STATUS(status);
+ }
+ }
+
+ /*
+ * The current_sync_level (per-thread) must be less than or equal to
+ * the sync level of the method. This mechanism provides some
+ * deadlock prevention.
+ *
+ * If the method was auto-serialized, we just ignore the sync level
+ * mechanism, because auto-serialization of methods can interfere
+ * with ASL code that actually uses sync levels.
+ *
+ * Top-level method invocation has no walk state at this point
+ */
+ if (walk_state &&
+ (!(obj_desc->method.
+ info_flags & ACPI_METHOD_IGNORE_SYNC_LEVEL))
+ && (walk_state->thread->current_sync_level >
+ obj_desc->method.mutex->mutex.sync_level)) {
+ ACPI_ERROR((AE_INFO,
+ "Cannot acquire Mutex for method [%4.4s]"
+ ", current SyncLevel is too large (%u)",
+ acpi_ut_get_node_name(method_node),
+ walk_state->thread->current_sync_level));
+
+ return_ACPI_STATUS(AE_AML_MUTEX_ORDER);
+ }
+
+ /*
+ * Obtain the method mutex if necessary. Do not acquire mutex for a
+ * recursive call.
+ */
+ if (!walk_state ||
+ !obj_desc->method.mutex->mutex.thread_id ||
+ (walk_state->thread->thread_id !=
+ obj_desc->method.mutex->mutex.thread_id)) {
+ /*
+ * Acquire the method mutex. This releases the interpreter if we
+ * block (and reacquires it before it returns)
+ */
+ status =
+ acpi_ex_system_wait_mutex(obj_desc->method.mutex->
+ mutex.os_mutex,
+ ACPI_WAIT_FOREVER);
+ if (ACPI_FAILURE(status)) {
+ return_ACPI_STATUS(status);
+ }
+
+ /* Update the mutex and walk info and save the original sync_level */
+
+ if (walk_state) {
+ obj_desc->method.mutex->mutex.
+ original_sync_level =
+ walk_state->thread->current_sync_level;
+
+ obj_desc->method.mutex->mutex.thread_id =
+ walk_state->thread->thread_id;
+
+ /*
+ * Update the current sync_level only if this is not an auto-
+ * serialized method. In the auto case, we have to ignore
+ * the sync level for the method mutex (created for the
+ * auto-serialization) because we have no idea of what the
+ * sync level should be. Therefore, just ignore it.
+ */
+ if (!(obj_desc->method.info_flags &
+ ACPI_METHOD_IGNORE_SYNC_LEVEL)) {
+ walk_state->thread->current_sync_level =
+ obj_desc->method.sync_level;
+ }
+ } else {
+ obj_desc->method.mutex->mutex.
+ original_sync_level =
+ obj_desc->method.mutex->mutex.sync_level;
+
+ obj_desc->method.mutex->mutex.thread_id =
+ acpi_os_get_thread_id();
+ }
+ }
+
+ /* Always increase acquisition depth */
+
+ obj_desc->method.mutex->mutex.acquisition_depth++;
+ }
+
+ /*
+ * Allocate an Owner ID for this method, only if this is the first thread
+ * to begin concurrent execution. We only need one owner_id, even if the
+ * method is invoked recursively.
+ */
+ if (!obj_desc->method.owner_id) {
+ status = acpi_ut_allocate_owner_id(&obj_desc->method.owner_id);
+ if (ACPI_FAILURE(status)) {
+ goto cleanup;
+ }
+ }
+
+ /*
+ * Increment the method parse tree thread count since it has been
+ * reentered one more time (even if it is the same thread)
+ */
+ obj_desc->method.thread_count++;
+ acpi_method_count++;
+ return_ACPI_STATUS(status);
+
+cleanup:
+ /* On error, must release the method mutex (if present) */
+
+ if (obj_desc->method.mutex) {
+ acpi_os_release_mutex(obj_desc->method.mutex->mutex.os_mutex);
+ }
+ return_ACPI_STATUS(status);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION: acpi_ds_call_control_method
+ *
+ * PARAMETERS: thread - Info for this thread
+ * this_walk_state - Current walk state
+ * op - Current Op to be walked
+ *
+ * RETURN: Status
+ *
+ * DESCRIPTION: Transfer execution to a called control method
+ *
+ ******************************************************************************/
+
+acpi_status
+acpi_ds_call_control_method(struct acpi_thread_state *thread,
+ struct acpi_walk_state *this_walk_state,
+ union acpi_parse_object *op)
+{
+ acpi_status status;
+ struct acpi_namespace_node *method_node;
+ struct acpi_walk_state *next_walk_state = NULL;
+ union acpi_operand_object *obj_desc;
+ struct acpi_evaluate_info *info;
+ u32 i;
+
+ ACPI_FUNCTION_TRACE_PTR(ds_call_control_method, this_walk_state);
+
+ ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
+ "Calling method %p, currentstate=%p\n",
+ this_walk_state->prev_op, this_walk_state));
+
+ /*
+ * Get the namespace entry for the control method we are about to call
+ */
+ method_node = this_walk_state->method_call_node;
+ if (!method_node) {
+ return_ACPI_STATUS(AE_NULL_ENTRY);
+ }
+
+ obj_desc = acpi_ns_get_attached_object(method_node);
+ if (!obj_desc) {
+ return_ACPI_STATUS(AE_NULL_OBJECT);
+ }
+
+ /* Init for new method, possibly wait on method mutex */
+
+ status =
+ acpi_ds_begin_method_execution(method_node, obj_desc,
+ this_walk_state);
+ if (ACPI_FAILURE(status)) {
+ return_ACPI_STATUS(status);
+ }
+
+ /* Begin method parse/execution. Create a new walk state */
+
+ next_walk_state =
+ acpi_ds_create_walk_state(obj_desc->method.owner_id, NULL, obj_desc,
+ thread);
+ if (!next_walk_state) {
+ status = AE_NO_MEMORY;
+ goto cleanup;
+ }
+
+ /*
+ * The resolved arguments were put on the previous walk state's operand
+ * stack. Operands on the previous walk state stack always
+ * start at index 0. Also, null terminate the list of arguments
+ */
+ this_walk_state->operands[this_walk_state->num_operands] = NULL;
+
+ /*
+ * Allocate and initialize the evaluation information block
+ * TBD: this is somewhat inefficient, should change interface to
+ * ds_init_aml_walk. For now, keeps this struct off the CPU stack
+ */
+ info = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_evaluate_info));
+ if (!info) {
+ status = AE_NO_MEMORY;
+ goto cleanup;
+ }
+
+ info->parameters = &this_walk_state->operands[0];
+
+ status = acpi_ds_init_aml_walk(next_walk_state, NULL, method_node,
+ obj_desc->method.aml_start,
+ obj_desc->method.aml_length, info,
+ ACPI_IMODE_EXECUTE);
+
+ ACPI_FREE(info);
+ if (ACPI_FAILURE(status)) {
+ goto cleanup;
+ }
+
+ /*
+ * Delete the operands on the previous walkstate operand stack
+ * (they were copied to new objects)
+ */
+ for (i = 0; i < obj_desc->method.param_count; i++) {
+ acpi_ut_remove_reference(this_walk_state->operands[i]);
+ this_walk_state->operands[i] = NULL;
+ }
+
+ /* Clear the operand stack */
+
+ this_walk_state->num_operands = 0;
+
+ ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
+ "**** Begin nested execution of [%4.4s] **** WalkState=%p\n",
+ method_node->name.ascii, next_walk_state));
+
+ /* Invoke an internal method if necessary */
+
+ if (obj_desc->method.info_flags & ACPI_METHOD_INTERNAL_ONLY) {
+ status =
+ obj_desc->method.dispatch.implementation(next_walk_state);
+ if (status == AE_OK) {
+ status = AE_CTRL_TERMINATE;
+ }
+ }
+
+ return_ACPI_STATUS(status);
+
+cleanup:
+
+ /* On error, we must terminate the method properly */
+
+ acpi_ds_terminate_control_method(obj_desc, next_walk_state);
+ acpi_ds_delete_walk_state(next_walk_state);
+
+ return_ACPI_STATUS(status);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION: acpi_ds_restart_control_method
+ *
+ * PARAMETERS: walk_state - State for preempted method (caller)
+ * return_desc - Return value from the called method
+ *
+ * RETURN: Status
+ *
+ * DESCRIPTION: Restart a method that was preempted by another (nested) method
+ * invocation. Handle the return value (if any) from the callee.
+ *
+ ******************************************************************************/
+
+acpi_status
+acpi_ds_restart_control_method(struct acpi_walk_state *walk_state,
+ union acpi_operand_object *return_desc)
+{
+ acpi_status status;
+ int same_as_implicit_return;
+
+ ACPI_FUNCTION_TRACE_PTR(ds_restart_control_method, walk_state);
+
+ ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
+ "****Restart [%4.4s] Op %p ReturnValueFromCallee %p\n",
+ acpi_ut_get_node_name(walk_state->method_node),
+ walk_state->method_call_op, return_desc));
+
+ ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
+ " ReturnFromThisMethodUsed?=%X ResStack %p Walk %p\n",
+ walk_state->return_used,
+ walk_state->results, walk_state));
+
+ /* Did the called method return a value? */
+
+ if (return_desc) {
+
+ /* Is the implicit return object the same as the return desc? */
+
+ same_as_implicit_return =
+ (walk_state->implicit_return_obj == return_desc);
+
+ /* Are we actually going to use the return value? */
+
+ if (walk_state->return_used) {
+
+ /* Save the return value from the previous method */
+
+ status = acpi_ds_result_push(return_desc, walk_state);
+ if (ACPI_FAILURE(status)) {
+ acpi_ut_remove_reference(return_desc);
+ return_ACPI_STATUS(status);
+ }
+
+ /*
+ * Save as THIS method's return value in case it is returned
+ * immediately to yet another method
+ */
+ walk_state->return_desc = return_desc;
+ }
+
+ /*
+ * The following code is the optional support for the so-called
+ * "implicit return". Some AML code assumes that the last value of the
+ * method is "implicitly" returned to the caller, in the absence of an
+ * explicit return value.
+ *
+ * Just save the last result of the method as the return value.
+ *
+ * NOTE: this is optional because the ASL language does not actually
+ * support this behavior.
+ */
+ else if (!acpi_ds_do_implicit_return
+ (return_desc, walk_state, FALSE)
+ || same_as_implicit_return) {
+ /*
+ * Delete the return value if it will not be used by the
+ * calling method or remove one reference if the explicit return
+ * is the same as the implicit return value.
+ */
+ acpi_ut_remove_reference(return_desc);
+ }
+ }
+
+ return_ACPI_STATUS(AE_OK);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION: acpi_ds_terminate_control_method
+ *
+ * PARAMETERS: method_desc - Method object
+ * walk_state - State associated with the method
+ *
+ * RETURN: None
+ *
+ * DESCRIPTION: Terminate a control method. Delete everything that the method
+ * created, delete all locals and arguments, and delete the parse
+ * tree if requested.
+ *
+ * MUTEX: Interpreter is locked
+ *
+ ******************************************************************************/
+
+void
+acpi_ds_terminate_control_method(union acpi_operand_object *method_desc,
+ struct acpi_walk_state *walk_state)
+{
+
+ ACPI_FUNCTION_TRACE_PTR(ds_terminate_control_method, walk_state);
+
+ /* method_desc is required, walk_state is optional */
+
+ if (!method_desc) {
+ return_VOID;
+ }
+
+ if (walk_state) {
+
+ /* Delete all arguments and locals */
+
+ acpi_ds_method_data_delete_all(walk_state);
+
+ /*
+ * Delete any namespace objects created anywhere within the
+ * namespace by the execution of this method. Unless:
+ * 1) This method is a module-level executable code method, in which
+ * case we want make the objects permanent.
+ * 2) There are other threads executing the method, in which case we
+ * will wait until the last thread has completed.
+ */
+ if (!(method_desc->method.info_flags & ACPI_METHOD_MODULE_LEVEL)
+ && (method_desc->method.thread_count == 1)) {
+
+ /* Delete any direct children of (created by) this method */
+
+ (void)acpi_ex_exit_interpreter();
+ acpi_ns_delete_namespace_subtree(walk_state->
+ method_node);
+ (void)acpi_ex_enter_interpreter();
+
+ /*
+ * Delete any objects that were created by this method
+ * elsewhere in the namespace (if any were created).
+ * Use of the ACPI_METHOD_MODIFIED_NAMESPACE optimizes the
+ * deletion such that we don't have to perform an entire
+ * namespace walk for every control method execution.
+ */
+ if (method_desc->method.
+ info_flags & ACPI_METHOD_MODIFIED_NAMESPACE) {
+ (void)acpi_ex_exit_interpreter();
+ acpi_ns_delete_namespace_by_owner(method_desc->
+ method.
+ owner_id);
+ (void)acpi_ex_enter_interpreter();
+ method_desc->method.info_flags &=
+ ~ACPI_METHOD_MODIFIED_NAMESPACE;
+ }
+ }
+
+ /*
+ * If method is serialized, release the mutex and restore the
+ * current sync level for this thread
+ */
+ if (method_desc->method.mutex) {
+
+ /* Acquisition Depth handles recursive calls */
+
+ method_desc->method.mutex->mutex.acquisition_depth--;
+ if (!method_desc->method.mutex->mutex.acquisition_depth) {
+ walk_state->thread->current_sync_level =
+ method_desc->method.mutex->mutex.
+ original_sync_level;
+
+ acpi_os_release_mutex(method_desc->method.
+ mutex->mutex.os_mutex);
+ method_desc->method.mutex->mutex.thread_id = 0;
+ }
+ }
+ }
+
+ /* Decrement the thread count on the method */
+
+ if (method_desc->method.thread_count) {
+ method_desc->method.thread_count--;
+ } else {
+ ACPI_ERROR((AE_INFO, "Invalid zero thread count in method"));
+ }
+
+ /* Are there any other threads currently executing this method? */
+
+ if (method_desc->method.thread_count) {
+ /*
+ * Additional threads. Do not release the owner_id in this case,
+ * we immediately reuse it for the next thread executing this method
+ */
+ ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
+ "*** Completed execution of one thread, %u threads remaining\n",
+ method_desc->method.thread_count));
+ } else {
+ /* This is the only executing thread for this method */
+
+ /*
+ * Support to dynamically change a method from not_serialized to
+ * Serialized if it appears that the method is incorrectly written and
+ * does not support multiple thread execution. The best example of this
+ * is if such a method creates namespace objects and blocks. A second
+ * thread will fail with an AE_ALREADY_EXISTS exception.
+ *
+ * This code is here because we must wait until the last thread exits
+ * before marking the method as serialized.
+ */
+ if (method_desc->method.
+ info_flags & ACPI_METHOD_SERIALIZED_PENDING) {
+ if (walk_state) {
+ ACPI_INFO(("Marking method %4.4s as Serialized "
+ "because of AE_ALREADY_EXISTS error",
+ walk_state->method_node->name.
+ ascii));
+ }
+
+ /*
+ * Method tried to create an object twice and was marked as
+ * "pending serialized". The probable cause is that the method
+ * cannot handle reentrancy.
+ *
+ * The method was created as not_serialized, but it tried to create
+ * a named object and then blocked, causing the second thread
+ * entrance to begin and then fail. Workaround this problem by
+ * marking the method permanently as Serialized when the last
+ * thread exits here.
+ */
+ method_desc->method.info_flags &=
+ ~ACPI_METHOD_SERIALIZED_PENDING;
+
+ method_desc->method.info_flags |=
+ (ACPI_METHOD_SERIALIZED |
+ ACPI_METHOD_IGNORE_SYNC_LEVEL);
+ method_desc->method.sync_level = 0;
+ }
+
+ /* No more threads, we can free the owner_id */
+
+ if (!
+ (method_desc->method.
+ info_flags & ACPI_METHOD_MODULE_LEVEL)) {
+ acpi_ut_release_owner_id(&method_desc->method.owner_id);
+ }
+ }
+
+ acpi_ex_stop_trace_method((struct acpi_namespace_node *)method_desc->
+ method.node, method_desc, walk_state);
+
+ return_VOID;
+}