dsmethod.c

来自「linux2.6.16版本」· C语言 代码 · 共 691 行 · 第 1/2 页

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

/*
 * Copyright (C) 2000 - 2006, 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>
#include <acpi/acdisasm.h>

#define _COMPONENT          ACPI_DISPATCHER
ACPI_MODULE_NAME("dsmethod")

/*******************************************************************************
 *
 * 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 disassembler 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)
{
	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.
		 */
		status = acpi_gbl_exception_handler(status,
						    walk_state->method_node ?
						    walk_state->method_node->
						    name.integer : 0,
						    walk_state->opcode,
						    walk_state->aml_offset,
						    NULL);
		(void)acpi_ex_enter_interpreter();
	}
#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);
	}
#endif

	return (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_ERROR((AE_INFO,
			    "Method reached maximum reentrancy limit (255)"));
		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);
	}

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

	/* Init for new method, 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;
	}

	if (!(obj_desc->method.method_flags & AML_METHOD_INTERNAL_ONLY)) {
		/* 1) Parse: Create a new walk state for the preempting walk */

		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);
		}

		/* Create and init a Root Node */

		op = acpi_ps_create_scope_op();
		if (!op) {
			status = AE_NO_MEMORY;
			goto cleanup;
		}

		status = acpi_ds_init_aml_walk(next_walk_state, op, method_node,
					       obj_desc->method.aml_start,
					       obj_desc->method.aml_length,
					       NULL, 1);
		if (ACPI_FAILURE(status)) {
			acpi_ds_delete_walk_state(next_walk_state);
			goto cleanup;
		}

		/* Begin AML parse */

		status = acpi_ps_parse_aml(next_walk_state);
		acpi_ps_delete_parse_tree(op);
	}

	/* 2) Execute: Create a new state for the preempting walk */

	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;

	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);
	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,
			  "Starting nested execution, newstate=%p\n",
			  next_walk_state));

	if (obj_desc->method.method_flags & AML_METHOD_INTERNAL_ONLY) {
		status = obj_desc->method.implementation(next_walk_state);
	}

	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 delete the new walk state */

	acpi_ds_terminate_control_method(next_walk_state);
	acpi_ds_delete_walk_state(next_walk_state);
	return_ACPI_STATUS(status);
}

/*******************************************************************************