dsopcode.c

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	/*
	 * Setup field according to the object type
	 */

	switch (src_desc->common.type)
	{

	/* Source_buff :=  Term_arg=>Buffer */

	case ACPI_TYPE_BUFFER:

		if (bit_offset + (u32) bit_count >
			(8 * (u32) src_desc->buffer.length))
		{
			status = AE_AML_BUFFER_LIMIT;
			goto cleanup;
		}


		/* Construct the remainder of the field object */

		field_desc->field_unit.access     = (u8) ACCESS_ANY_ACC;
		field_desc->field_unit.lock_rule  = (u8) GLOCK_NEVER_LOCK;
		field_desc->field_unit.update_rule = (u8) UPDATE_PRESERVE;
		field_desc->field_unit.length     = bit_count;
		field_desc->field_unit.bit_offset = (u8) (bit_offset % 8);
		field_desc->field_unit.offset     = DIV_8 (bit_offset);
		field_desc->field_unit.container  = src_desc;

		/* Reference count for Src_desc inherits Field_desc count */

		src_desc->common.reference_count = (u16) (src_desc->common.reference_count +
				   field_desc->common.reference_count);

		break;


	/* Improper object type */

	default:

		if ((src_desc->common.type > (u8) INTERNAL_TYPE_REFERENCE) ||
			!acpi_cm_valid_object_type (src_desc->common.type))


		status = AE_AML_OPERAND_TYPE;
		goto cleanup;
	}


	if (AML_CREATE_FIELD_OP == op->opcode) {
		/* Delete object descriptor unique to Create_field */

		acpi_cm_remove_reference (cnt_desc);
		cnt_desc = NULL;
	}


cleanup:

	/* Always delete the operands */

	acpi_cm_remove_reference (off_desc);
	acpi_cm_remove_reference (src_desc);

	if (AML_CREATE_FIELD_OP == op->opcode) {
		acpi_cm_remove_reference (cnt_desc);
	}

	/* On failure, delete the result descriptor */

	if (ACPI_FAILURE (status)) {
		acpi_cm_remove_reference (res_desc); /* Result descriptor */
	}

	else {
		/* Now the address and length are valid for this op_field_unit */

		field_desc->field_unit.flags |= AOPOBJ_DATA_VALID;
	}

	return (status);
}


/*****************************************************************************
 *
 * FUNCTION:    Acpi_ds_eval_region_operands
 *
 * PARAMETERS:  Op              - A valid region Op object
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Get region address and length
 *              Called from Acpi_ds_exec_end_op during Op_region parse tree walk
 *
 ****************************************************************************/

ACPI_STATUS
acpi_ds_eval_region_operands (
	ACPI_WALK_STATE         *walk_state,
	ACPI_PARSE_OBJECT       *op)
{
	ACPI_STATUS             status;
	ACPI_OPERAND_OBJECT     *obj_desc;
	ACPI_OPERAND_OBJECT     *operand_desc;
	ACPI_NAMESPACE_NODE     *node;
	ACPI_PARSE_OBJECT       *next_op;


	/*
	 * This is where we evaluate the address and length fields of the Op_region declaration
	 */

	node =  op->node;

	/* Next_op points to the op that holds the Space_iD */
	next_op = op->value.arg;

	/* Next_op points to address op */
	next_op = next_op->next;

	/* Acpi_evaluate/create the address and length operands */

	status = acpi_ds_create_operands (walk_state, next_op);
	if (ACPI_FAILURE (status)) {
		return (status);
	}

	/* Resolve the length and address operands to numbers */

	status = acpi_aml_resolve_operands (op->opcode, WALK_OPERANDS, walk_state);
	if (ACPI_FAILURE (status)) {
		return (status);
	}


	obj_desc = acpi_ns_get_attached_object (node);
	if (!obj_desc) {
		return (AE_NOT_EXIST);
	}

	/*
	 * Get the length operand and save it
	 * (at Top of stack)
	 */
	operand_desc = walk_state->operands[walk_state->num_operands - 1];

	obj_desc->region.length = (u32) operand_desc->number.value;
	acpi_cm_remove_reference (operand_desc);

	/*
	 * Get the address and save it
	 * (at top of stack - 1)
	 */
	operand_desc = walk_state->operands[walk_state->num_operands - 2];

	obj_desc->region.address = (ACPI_PHYSICAL_ADDRESS) operand_desc->number.value;
	acpi_cm_remove_reference (operand_desc);


	/* Now the address and length are valid for this opregion */

	obj_desc->region.flags |= AOPOBJ_DATA_VALID;

	return (status);
}


/*******************************************************************************
 *
 * FUNCTION:    Acpi_ds_exec_begin_control_op
 *
 * PARAMETERS:  Walk_list       - The list that owns the walk stack
 *              Op              - The control Op
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Handles all control ops encountered during control method
 *              execution.
 *
 ******************************************************************************/

ACPI_STATUS
acpi_ds_exec_begin_control_op (
	ACPI_WALK_STATE         *walk_state,
	ACPI_PARSE_OBJECT       *op)
{
	ACPI_STATUS             status = AE_OK;
	ACPI_GENERIC_STATE      *control_state;


	switch (op->opcode)
	{
	case AML_IF_OP:
	case AML_WHILE_OP:

		/*
		 * IF/WHILE: Create a new control state to manage these
		 * constructs. We need to manage these as a stack, in order
		 * to handle nesting.
		 */

		control_state = acpi_cm_create_control_state ();
		if (!control_state) {
			status = AE_NO_MEMORY;
			break;
		}

		acpi_cm_push_generic_state (&walk_state->control_state, control_state);

		/*
		 * Save a pointer to the predicate for multiple executions
		 * of a loop
		 */
		walk_state->control_state->control.aml_predicate_start =
				 walk_state->parser_state->aml - 1;
				 /* TBD: can this be removed? */
				 /*Acpi_ps_pkg_length_encoding_size (GET8 (Walk_state->Parser_state->Aml));*/
		break;


	case AML_ELSE_OP:

		/* Predicate is in the state object */
		/* If predicate is true, the IF was executed, ignore ELSE part */

		if (walk_state->last_predicate) {
			status = AE_CTRL_TRUE;
		}

		break;


	case AML_RETURN_OP:

		break;


	default:
		break;
	}

	return (status);
}


/*******************************************************************************
 *
 * FUNCTION:    Acpi_ds_exec_end_control_op
 *
 * PARAMETERS:  Walk_list       - The list that owns the walk stack
 *              Op              - The control Op
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Handles all control ops encountered during control method
 *              execution.
 *
 *
 ******************************************************************************/

ACPI_STATUS
acpi_ds_exec_end_control_op (
	ACPI_WALK_STATE         *walk_state,
	ACPI_PARSE_OBJECT       *op)
{
	ACPI_STATUS             status = AE_OK;
	ACPI_GENERIC_STATE      *control_state;


	switch (op->opcode)
	{
	case AML_IF_OP:

		/*
		 * Save the result of the predicate in case there is an
		 * ELSE to come
		 */

		walk_state->last_predicate =
				(u8) walk_state->control_state->common.value;

		/*
		 * Pop the control state that was created at the start
		 * of the IF and free it
		 */

		control_state =
				acpi_cm_pop_generic_state (&walk_state->control_state);

		acpi_cm_delete_generic_state (control_state);

		break;


	case AML_ELSE_OP:

		break;


	case AML_WHILE_OP:

		if (walk_state->control_state->common.value) {
			/* Predicate was true, go back and evaluate it again! */

			status = AE_CTRL_PENDING;
		}


		/* Pop this control state and free it */

		control_state =
				acpi_cm_pop_generic_state (&walk_state->control_state);

		walk_state->aml_last_while = control_state->control.aml_predicate_start;
		acpi_cm_delete_generic_state (control_state);

		break;


	case AML_RETURN_OP:


		/*
		 * One optional operand -- the return value
		 * It can be either an immediate operand or a result that
		 * has been bubbled up the tree
		 */
		if (op->value.arg) {
			/* Return statement has an immediate operand */

			status = acpi_ds_create_operands (walk_state, op->value.arg);
			if (ACPI_FAILURE (status)) {
				return (status);
			}

			/*
			 * If value being returned is a Reference (such as
			 * an arg or local), resolve it now because it may
			 * cease to exist at the end of the method.
			 */

			status = acpi_aml_resolve_to_value (&walk_state->operands [0], walk_state);
			if (ACPI_FAILURE (status)) {
				return (status);
			}

			/*
			 * Get the return value and save as the last result
			 * value.  This is the only place where Walk_state->Return_desc
			 * is set to anything other than zero!
			 */

			walk_state->return_desc = walk_state->operands[0];
		}

		else if ((walk_state->results) &&
				 (walk_state->results->results.num_results > 0))
		{
			/*
			 * The return value has come from a previous calculation.
			 *
			 * If value being returned is a Reference (such as
			 * an arg or local), resolve it now because it may
			 * cease to exist at the end of the method.
			 */

			status = acpi_aml_resolve_to_value (&walk_state->results->results.obj_desc [0], walk_state);
			if (ACPI_FAILURE (status)) {
				return (status);
			}

			walk_state->return_desc = walk_state->results->results.obj_desc [0];
		}

		else {
			/* No return operand */

			if (walk_state->num_operands) {
				acpi_cm_remove_reference (walk_state->operands [0]);
			}

			walk_state->operands [0]    = NULL;
			walk_state->num_operands    = 0;
			walk_state->return_desc     = NULL;
		}


		/* End the control method execution right now */
		status = AE_CTRL_TERMINATE;
		break;


	case AML_NOOP_OP:

		/* Just do nothing! */
		break;


	case AML_BREAK_POINT_OP:

		/* Call up to the OS dependent layer to handle this */

		acpi_os_breakpoint (NULL);

		/* If it returns, we are done! */

		break;


	case AML_BREAK_OP:

		/*
		 * As per the ACPI specification:
		 *      "The break operation causes the current package
		 *          execution to complete"
		 *      "Break -- Stop executing the current code package
		 *          at this point"
		 *
		 * Returning AE_FALSE here will cause termination of
		 * the current package, and execution will continue one
		 * level up, starting with the completion of the parent Op.
		 */

		status = AE_CTRL_FALSE;
		break;


	default:

		status = AE_AML_BAD_OPCODE;
		break;
	}


	return (status);
}