dsmethod.c

linux-2.6.15.6

/******************************************************************************
 *
 * Module Name: dsmethod - Parser/Interpreter interface - control method parsing
 *
 *****************************************************************************/

/*
 * Copyright (C) 2000 - 2005, R. Byron Moore
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions, and the following disclaimer,
 *    without modification.
 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 *    substantially similar to the "NO WARRANTY" disclaimer below
 *    ("Disclaimer") and any redistribution must be conditioned upon
 *    including a substantially similar Disclaimer requirement for further
 *    binary redistribution.
 * 3. Neither the names of the above-listed copyright holders nor the names
 *    of any contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * NO WARRANTY
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 */

#include <acpi/acpi.h>
#include <acpi/acparser.h>
#include <acpi/amlcode.h>
#include <acpi/acdispat.h>
#include <acpi/acinterp.h>
#include <acpi/acnamesp.h>

#define _COMPONENT          ACPI_DISPATCHER
ACPI_MODULE_NAME("dsmethod")

/*******************************************************************************
 *
 * FUNCTION:    acpi_ds_parse_method
 *
 * PARAMETERS:  Node        - Method node
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Parse the AML that is associated with the method.
 *
 * MUTEX:       Assumes parser is locked
 *
 ******************************************************************************/
acpi_status acpi_ds_parse_method(struct acpi_namespace_node *node)
{
	acpi_status status;
	union acpi_operand_object *obj_desc;
	union acpi_parse_object *op;
	struct acpi_walk_state *walk_state;

	ACPI_FUNCTION_TRACE_PTR("ds_parse_method", node);

	/* Parameter Validation */

	if (!node) {
		return_ACPI_STATUS(AE_NULL_ENTRY);
	}

	ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
			  "**** Parsing [%4.4s] **** named_obj=%p\n",
			  acpi_ut_get_node_name(node), node));

	/* Extract the method object from the method Node */

	obj_desc = acpi_ns_get_attached_object(node);
	if (!obj_desc) {
		return_ACPI_STATUS(AE_NULL_OBJECT);
	}

	/* Create a mutex for the method if there is a concurrency limit */

	if ((obj_desc->method.concurrency != ACPI_INFINITE_CONCURRENCY) &&
	    (!obj_desc->method.semaphore)) {
		status = acpi_os_create_semaphore(obj_desc->method.concurrency,
						  obj_desc->method.concurrency,
						  &obj_desc->method.semaphore);
		if (ACPI_FAILURE(status)) {
			return_ACPI_STATUS(status);
		}
	}

	/*
	 * Allocate a new parser op to be the root of the parsed
	 * method tree
	 */
	op = acpi_ps_alloc_op(AML_METHOD_OP);
	if (!op) {
		return_ACPI_STATUS(AE_NO_MEMORY);
	}

	/* Init new op with the method name and pointer back to the Node */

	acpi_ps_set_name(op, node->name.integer);
	op->common.node = node;

	/*
	 * Get a new owner_id for objects created by this method. Namespace
	 * objects (such as Operation Regions) can be created during the
	 * first pass parse.
	 */
	status = acpi_ut_allocate_owner_id(&obj_desc->method.owner_id);
	if (ACPI_FAILURE(status)) {
		goto cleanup;
	}

	/* Create and initialize a new walk state */

	walk_state =
	    acpi_ds_create_walk_state(obj_desc->method.owner_id, NULL, NULL,
				      NULL);
	if (!walk_state) {
		status = AE_NO_MEMORY;
		goto cleanup2;
	}

	status = acpi_ds_init_aml_walk(walk_state, op, node,
				       obj_desc->method.aml_start,
				       obj_desc->method.aml_length, NULL, 1);
	if (ACPI_FAILURE(status)) {
		acpi_ds_delete_walk_state(walk_state);
		goto cleanup2;
	}

	/*
	 * Parse the method, first pass
	 *
	 * The first pass load is where newly declared named objects are added into
	 * the namespace.  Actual evaluation of the named objects (what would be
	 * called a "second pass") happens during the actual execution of the
	 * method so that operands to the named objects can take on dynamic
	 * run-time values.
	 */
	status = acpi_ps_parse_aml(walk_state);
	if (ACPI_FAILURE(status)) {
		goto cleanup2;
	}

	ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
			  "**** [%4.4s] Parsed **** named_obj=%p Op=%p\n",
			  acpi_ut_get_node_name(node), node, op));

	/*
	 * Delete the parse tree. We simply re-parse the method for every
	 * execution since there isn't much overhead (compared to keeping lots
	 * of parse trees around)
	 */
	acpi_ns_delete_namespace_subtree(node);
	acpi_ns_delete_namespace_by_owner(obj_desc->method.owner_id);

      cleanup2:
	acpi_ut_release_owner_id(&obj_desc->method.owner_id);

      cleanup:
	acpi_ps_delete_parse_tree(op);
	return_ACPI_STATUS(status);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ds_begin_method_execution
 *
 * PARAMETERS:  method_node         - Node of the method
 *              obj_desc            - The method object
 *              calling_method_node - Caller of this method (if non-null)
 *
 * 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_namespace_node *calling_method_node)
{
	acpi_status status = AE_OK;

	ACPI_FUNCTION_TRACE_PTR("ds_begin_method_execution", method_node);

	if (!method_node) {
		return_ACPI_STATUS(AE_NULL_ENTRY);
	}

	/* Prevent wraparound of thread count */

	if (obj_desc->method.thread_count == ACPI_UINT8_MAX) {
		ACPI_REPORT_ERROR(("Method reached maximum reentrancy limit (255)\n"));
		return_ACPI_STATUS(AE_AML_METHOD_LIMIT);
	}

	/*
	 * If there is a concurrency limit on this method, we need to
	 * obtain a unit from the method semaphore.
	 */
	if (obj_desc->method.semaphore) {
		/*
		 * Allow recursive method calls, up to the reentrancy/concurrency
		 * limit imposed by the SERIALIZED rule and the sync_level method
		 * parameter.
		 *
		 * The point of this code is to avoid permanently blocking a
		 * thread that is making recursive method calls.
		 */
		if (method_node == calling_method_node) {
			if (obj_desc->method.thread_count >=
			    obj_desc->method.concurrency) {
				return_ACPI_STATUS(AE_AML_METHOD_LIMIT);
			}
		}

		/*
		 * Get a unit from the method semaphore. This releases the
		 * interpreter if we block
		 */
		status =
		    acpi_ex_system_wait_semaphore(obj_desc->method.semaphore,
						  ACPI_WAIT_FOREVER);
	}

	/*
	 * 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)) {
			return_ACPI_STATUS(status);
		}
	}

	/*
	 * 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++;
	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_parameter_info info;
	u32 i;

	ACPI_FUNCTION_TRACE_PTR("ds_call_control_method", this_walk_state);

	ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
			  "Execute 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);
	}