1 files changed, 142 insertions, 90 deletions

diff --git a/drivers/acpi/dispatcher/dsmethod.c b/drivers/acpi/dispatcher/dsmethod.c
index c475546535b6..bc9aca4e7401 100644
--- a/drivers/acpi/dispatcher/dsmethod.c
+++ b/drivers/acpi/dispatcher/dsmethod.c
@@ -81,6 +81,7 @@ acpi_ds_method_error(acpi_status status, struct acpi_walk_state *walk_state)
 	/* Invoke the global exception handler */
 
 	if (acpi_gbl_exception_handler) {
+
 		/* Exit the interpreter, allow handler to execute methods */
 
 		acpi_ex_exit_interpreter();
@@ -100,6 +101,7 @@ acpi_ds_method_error(acpi_status status, struct acpi_walk_state *walk_state)
 	}
 #ifdef ACPI_DISASSEMBLER
 	if (ACPI_FAILURE(status)) {
+
 		/* Display method locals/args if disassembler is present */
 
 		acpi_dm_dump_method_info(status, walk_state, walk_state->op);
@@ -132,7 +134,7 @@ acpi_ds_begin_method_execution(struct acpi_namespace_node * method_node,
 {
 	acpi_status status = AE_OK;
 
-	ACPI_FUNCTION_TRACE_PTR("ds_begin_method_execution", method_node);
+	ACPI_FUNCTION_TRACE_PTR(ds_begin_method_execution, method_node);
 
 	if (!method_node) {
 		return_ACPI_STATUS(AE_NULL_ENTRY);
@@ -168,11 +170,14 @@ acpi_ds_begin_method_execution(struct acpi_namespace_node * method_node,
 
 		/*
 		 * Get a unit from the method semaphore. This releases the
-		 * interpreter if we block
+		 * interpreter if we block (then reacquires it)
 		 */
 		status =
 		    acpi_ex_system_wait_semaphore(obj_desc->method.semaphore,
 						  ACPI_WAIT_FOREVER);
+		if (ACPI_FAILURE(status)) {
+			return_ACPI_STATUS(status);
+		}
 	}
 
 	/*
@@ -183,7 +188,7 @@ acpi_ds_begin_method_execution(struct acpi_namespace_node * method_node,
 	if (!obj_desc->method.owner_id) {
 		status = acpi_ut_allocate_owner_id(&obj_desc->method.owner_id);
 		if (ACPI_FAILURE(status)) {
-			return_ACPI_STATUS(status);
+			goto cleanup;
 		}
 	}
 
@@ -193,6 +198,14 @@ acpi_ds_begin_method_execution(struct acpi_namespace_node * method_node,
 	 */
 	obj_desc->method.thread_count++;
 	return_ACPI_STATUS(status);
+
+      cleanup:
+	/* On error, must signal the method semaphore if present */
+
+	if (obj_desc->method.semaphore) {
+		(void)acpi_os_signal_semaphore(obj_desc->method.semaphore, 1);
+	}
+	return_ACPI_STATUS(status);
 }
 
 /*******************************************************************************
@@ -218,10 +231,10 @@ acpi_ds_call_control_method(struct acpi_thread_state *thread,
 	struct acpi_namespace_node *method_node;
 	struct acpi_walk_state *next_walk_state = NULL;
 	union acpi_operand_object *obj_desc;
-	struct acpi_parameter_info info;
+	struct acpi_evaluate_info *info;
 	u32 i;
 
-	ACPI_FUNCTION_TRACE_PTR("ds_call_control_method", this_walk_state);
+	ACPI_FUNCTION_TRACE_PTR(ds_call_control_method, this_walk_state);
 
 	ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
 			  "Execute method %p, currentstate=%p\n",
@@ -240,25 +253,31 @@ acpi_ds_call_control_method(struct acpi_thread_state *thread,
 		return_ACPI_STATUS(AE_NULL_OBJECT);
 	}
 
-	/* Init for new method, wait on concurrency semaphore */
+	/* Init for new method, possibly wait on concurrency semaphore */
 
 	status = acpi_ds_begin_method_execution(method_node, obj_desc,
 						this_walk_state->method_node);
 	if (ACPI_FAILURE(status)) {
-		goto cleanup;
+		return_ACPI_STATUS(status);
 	}
 
+	/*
+	 * 1) Parse the method. All "normal" methods are parsed for each execution.
+	 * Internal methods (_OSI, etc.) do not require parsing.
+	 */
 	if (!(obj_desc->method.method_flags & AML_METHOD_INTERNAL_ONLY)) {
-		/* 1) Parse: Create a new walk state for the preempting walk */
+
+		/* Create a new walk state for the parse */
 
 		next_walk_state =
 		    acpi_ds_create_walk_state(obj_desc->method.owner_id, op,
 					      obj_desc, NULL);
 		if (!next_walk_state) {
-			return_ACPI_STATUS(AE_NO_MEMORY);
+			status = AE_NO_MEMORY;
+			goto cleanup;
 		}
 
-		/* Create and init a Root Node */
+		/* Create and init a parse tree root */
 
 		op = acpi_ps_create_scope_op();
 		if (!op) {
@@ -271,17 +290,20 @@ acpi_ds_call_control_method(struct acpi_thread_state *thread,
 					       obj_desc->method.aml_length,
 					       NULL, 1);
 		if (ACPI_FAILURE(status)) {
-			acpi_ds_delete_walk_state(next_walk_state);
+			acpi_ps_delete_parse_tree(op);
 			goto cleanup;
 		}
 
-		/* Begin AML parse */
+		/* Begin AML parse (deletes next_walk_state) */
 
 		status = acpi_ps_parse_aml(next_walk_state);
 		acpi_ps_delete_parse_tree(op);
+		if (ACPI_FAILURE(status)) {
+			goto cleanup;
+		}
 	}
 
-	/* 2) Execute: Create a new state for the preempting walk */
+	/* 2) Begin method execution. Create a new walk state */
 
 	next_walk_state = acpi_ds_create_walk_state(obj_desc->method.owner_id,
 						    NULL, obj_desc, thread);
@@ -289,6 +311,7 @@ acpi_ds_call_control_method(struct acpi_thread_state *thread,
 		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
@@ -296,12 +319,24 @@ acpi_ds_call_control_method(struct acpi_thread_state *thread,
 	 */
 	this_walk_state->operands[this_walk_state->num_operands] = NULL;
 
-	info.parameters = &this_walk_state->operands[0];
-	info.parameter_type = ACPI_PARAM_ARGS;
+	/*
+	 * 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) {
+		return_ACPI_STATUS(AE_NO_MEMORY);
+	}
+
+	info->parameters = &this_walk_state->operands[0];
+	info->parameter_type = ACPI_PARAM_ARGS;
 
 	status = acpi_ds_init_aml_walk(next_walk_state, NULL, method_node,
 				       obj_desc->method.aml_start,
-				       obj_desc->method.aml_length, &info, 3);
+				       obj_desc->method.aml_length, info, 3);
+
+	ACPI_FREE(info);
 	if (ACPI_FAILURE(status)) {
 		goto cleanup;
 	}
@@ -323,6 +358,8 @@ acpi_ds_call_control_method(struct acpi_thread_state *thread,
 			  "Starting nested execution, newstate=%p\n",
 			  next_walk_state));
 
+	/* Invoke an internal method if necessary */
+
 	if (obj_desc->method.method_flags & AML_METHOD_INTERNAL_ONLY) {
 		status = obj_desc->method.implementation(next_walk_state);
 	}
@@ -330,16 +367,14 @@ acpi_ds_call_control_method(struct acpi_thread_state *thread,
 	return_ACPI_STATUS(status);
 
       cleanup:
-	/* Decrement the thread count on the method parse tree */
 
-	if (next_walk_state && (next_walk_state->method_desc)) {
-		next_walk_state->method_desc->method.thread_count--;
-	}
+	/* On error, we must terminate the method properly */
 
-	/* On error, we must delete the new walk state */
+	acpi_ds_terminate_control_method(obj_desc, next_walk_state);
+	if (next_walk_state) {
+		acpi_ds_delete_walk_state(next_walk_state);
+	}
 
-	acpi_ds_terminate_control_method(next_walk_state);
-	acpi_ds_delete_walk_state(next_walk_state);
 	return_ACPI_STATUS(status);
 }
 
@@ -362,25 +397,33 @@ 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_FUNCTION_TRACE_PTR(ds_restart_control_method, walk_state);
 
 	ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
-			  "****Restart [%4.4s] Op %p return_value_from_callee %p\n",
+			  "****Restart [%4.4s] Op %p ReturnValueFromCallee %p\n",
 			  (char *)&walk_state->method_node->name,
 			  walk_state->method_call_op, return_desc));
 
 	ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
-			  "    return_from_this_method_used?=%X res_stack %p Walk %p\n",
+			  "    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);
@@ -397,18 +440,23 @@ acpi_ds_restart_control_method(struct acpi_walk_state *walk_state,
 		}
 
 		/*
-		 * The following code is the
-		 * optional support for a so-called "implicit return". Some AML code
-		 * assumes that the last value of the method is "implicitly" returned
-		 * to the caller. Just save the last result as the return value.
+		 * 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)) {
+			 (return_desc, walk_state, FALSE)
+			 || same_as_implicit_return) {
 			/*
 			 * Delete the return value if it will not be used by the
-			 * calling method
+			 * calling method or remove one reference if the explicit return
+			 * is the same as the implicit return value.
 			 */
 			acpi_ut_remove_reference(return_desc);
 		}
@@ -421,7 +469,8 @@ acpi_ds_restart_control_method(struct acpi_walk_state *walk_state,
  *
  * FUNCTION:    acpi_ds_terminate_control_method
  *
- * PARAMETERS:  walk_state          - State of the method
+ * PARAMETERS:  method_desc         - Method object
+ *              walk_state          - State associated with the method
  *
  * RETURN:      None
  *
@@ -431,95 +480,100 @@ acpi_ds_restart_control_method(struct acpi_walk_state *walk_state,
  *
  ******************************************************************************/
 
-void acpi_ds_terminate_control_method(struct acpi_walk_state *walk_state)
+void
+acpi_ds_terminate_control_method(union acpi_operand_object *method_desc,
+				 struct acpi_walk_state *walk_state)
 {
-	union acpi_operand_object *obj_desc;
 	struct acpi_namespace_node *method_node;
 	acpi_status status;
 
-	ACPI_FUNCTION_TRACE_PTR("ds_terminate_control_method", walk_state);
+	ACPI_FUNCTION_TRACE_PTR(ds_terminate_control_method, walk_state);
 
-	if (!walk_state) {
-		return_VOID;
-	}
+	/* method_desc is required, walk_state is optional */
 
-	/* The current method object was saved in the walk state */
-
-	obj_desc = walk_state->method_desc;
-	if (!obj_desc) {
+	if (!method_desc) {
 		return_VOID;
 	}
 
-	/* Delete all arguments and locals */
+	if (walk_state) {
 
-	acpi_ds_method_data_delete_all(walk_state);
+		/* Delete all arguments and locals */
+
+		acpi_ds_method_data_delete_all(walk_state);
+	}
 
 	/*
 	 * Lock the parser while we terminate this method.
 	 * If this is the last thread executing the method,
 	 * we have additional cleanup to perform
 	 */
-	status = acpi_ut_acquire_mutex(ACPI_MTX_PARSER);
+	status = acpi_ut_acquire_mutex(ACPI_MTX_CONTROL_METHOD);
 	if (ACPI_FAILURE(status)) {
 		return_VOID;
 	}
 
 	/* Signal completion of the execution of this method if necessary */
 
-	if (walk_state->method_desc->method.semaphore) {
+	if (method_desc->method.semaphore) {
 		status =
-		    acpi_os_signal_semaphore(walk_state->method_desc->method.
-					     semaphore, 1);
+		    acpi_os_signal_semaphore(method_desc->method.semaphore, 1);
 		if (ACPI_FAILURE(status)) {
-			ACPI_ERROR((AE_INFO,
-				    "Could not signal method semaphore"));
 
-			/* Ignore error and continue cleanup */
+			/* Ignore error and continue */
+
+			ACPI_EXCEPTION((AE_INFO, status,
+					"Could not signal method semaphore"));
 		}
 	}
 
-	/*
-	 * There are no more threads executing this method.  Perform
-	 * additional cleanup.
-	 *
-	 * The method Node is stored in the walk state
-	 */
-	method_node = walk_state->method_node;
+	if (walk_state) {
+		/*
+		 * Delete any objects created by this method during execution.
+		 * The method Node is stored in the walk state
+		 */
+		method_node = walk_state->method_node;
 
-	/* Lock namespace for possible update */
+		/* Lock namespace for possible update */
 
-	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
-	if (ACPI_FAILURE(status)) {
-		goto exit;
-	}
+		status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
+		if (ACPI_FAILURE(status)) {
+			goto exit;
+		}
 
-	/*
-	 * Delete any namespace entries created immediately underneath
-	 * the method
-	 */
-	if (method_node->child) {
-		acpi_ns_delete_namespace_subtree(method_node);
+		/*
+		 * Delete any namespace entries created immediately underneath
+		 * the method
+		 */
+		if (method_node && method_node->child) {
+			acpi_ns_delete_namespace_subtree(method_node);
+		}
+
+		/*
+		 * Delete any namespace entries created anywhere else within
+		 * the namespace by the execution of this method
+		 */
+		acpi_ns_delete_namespace_by_owner(method_desc->method.owner_id);
+		status = acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
 	}
 
-	/*
-	 * Delete any namespace entries created anywhere else within
-	 * the namespace by the execution of this method
-	 */
-	acpi_ns_delete_namespace_by_owner(walk_state->method_desc->method.
-					  owner_id);
-	status = acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
+	/* 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 (walk_state->method_desc->method.thread_count) {
+	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, %d threads remaining\n",
-				  walk_state->method_desc->method.
-				  thread_count));
+				  method_desc->method.thread_count));
 	} else {
 		/* This is the only executing thread for this method */
 
@@ -533,22 +587,20 @@ void acpi_ds_terminate_control_method(struct acpi_walk_state *walk_state)
 		 * This code is here because we must wait until the last thread exits
 		 * before creating the synchronization semaphore.
 		 */
-		if ((walk_state->method_desc->method.concurrency == 1) &&
-		    (!walk_state->method_desc->method.semaphore)) {
+		if ((method_desc->method.concurrency == 1) &&
+		    (!method_desc->method.semaphore)) {
 			status = acpi_os_create_semaphore(1, 1,
-							  &walk_state->
-							  method_desc->method.
+							  &method_desc->method.
 							  semaphore);
 		}
 
 		/* No more threads, we can free the owner_id */
 
-		acpi_ut_release_owner_id(&walk_state->method_desc->method.
-					 owner_id);
+		acpi_ut_release_owner_id(&method_desc->method.owner_id);
 	}
 
       exit:
-	(void)acpi_ut_release_mutex(ACPI_MTX_PARSER);
+	(void)acpi_ut_release_mutex(ACPI_MTX_CONTROL_METHOD);
 	return_VOID;
 }
 
@@ -581,7 +633,7 @@ acpi_status acpi_ds_parse_method(struct acpi_namespace_node *node)
 	union acpi_parse_object *op;
 	struct acpi_walk_state *walk_state;
 
-	ACPI_FUNCTION_TRACE_PTR("ds_parse_method", node);
+	ACPI_FUNCTION_TRACE_PTR(ds_parse_method, node);
 
 	/* Parameter Validation */
 
@@ -590,7 +642,7 @@ acpi_status acpi_ds_parse_method(struct acpi_namespace_node *node)
 	}
 
 	ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
-			  "**** Parsing [%4.4s] **** named_obj=%p\n",
+			  "**** Parsing [%4.4s] **** NamedObj=%p\n",
 			  acpi_ut_get_node_name(node), node));
 
 	/* Extract the method object from the method Node */
@@ -669,7 +721,7 @@ acpi_status acpi_ds_parse_method(struct acpi_namespace_node *node)
 	}
 
 	ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
-			  "**** [%4.4s] Parsed **** named_obj=%p Op=%p\n",
+			  "**** [%4.4s] Parsed **** NamedObj=%p Op=%p\n",
 			  acpi_ut_get_node_name(node), node, op));
 
 	/*