psparse.c

来自「讲述linux的初始化过程」· C语言 代码 · 共 1,234 行 · 第 1/2 页

				}


				/* We know that this arg is a name, move to next arg */

				INCREMENT_ARG_LIST (arg_types);

				if (walk_state->descending_callback != NULL) {
					/*
					 * Find the object.  This will either insert the object into
					 * the namespace or simply look it up
					 */
					status = walk_state->descending_callback (opcode, NULL, walk_state, &op);
					if (op == NULL) {
						continue;
					}
					status = acpi_ps_next_parse_state (walk_state, op, status);
					if (status == AE_CTRL_PENDING) {
						status = AE_OK;
						goto close_this_op;
					}

					if (ACPI_FAILURE (status)) {
						goto close_this_op;
					}
				}

				acpi_ps_append_arg (op, pre_op.value.arg);
				acpi_gbl_depth++;


				if (op->opcode == AML_REGION_OP) {
					deferred_op = acpi_ps_to_extended_op (op);
					if (deferred_op) {
						/*
						 * Defer final parsing of an Operation_region body,
						 * because we don't have enough info in the first pass
						 * to parse it correctly (i.e., there may be method
						 * calls within the Term_arg elements of the body.
						 *
						 * However, we must continue parsing because
						 * the opregion is not a standalone package --
						 * we don't know where the end is at this point.
						 *
						 * (Length is unknown until parse of the body complete)
						 */

						deferred_op->data   = aml_op_start;
						deferred_op->length = 0;
					}
				}
			}


			else {
				/* Not a named opcode, just allocate Op and append to parent */

				op = acpi_ps_alloc_op (opcode);
				if (!op) {
					return (AE_NO_MEMORY);
				}


				if ((op->opcode == AML_CREATE_FIELD_OP) ||
					(op->opcode == AML_BIT_FIELD_OP)    ||
					(op->opcode == AML_BYTE_FIELD_OP)   ||
					(op->opcode == AML_WORD_FIELD_OP)   ||
					(op->opcode == AML_DWORD_FIELD_OP))
				 {
					/*
					 * Backup to beginning of Create_xXXfield declaration
					 * Body_length is unknown until we parse the body
					 */
					deferred_op = (ACPI_PARSE2_OBJECT *) op;

					deferred_op->data   = aml_op_start;
					deferred_op->length = 0;
				}

				acpi_ps_append_arg (acpi_ps_get_parent_scope (parser_state), op);

				if ((walk_state->descending_callback != NULL)) {
					/*
					 * Find the object.  This will either insert the object into
					 * the namespace or simply look it up
					 */
					status = walk_state->descending_callback (opcode, op, walk_state, &op);
					status = acpi_ps_next_parse_state (walk_state, op, status);
					if (status == AE_CTRL_PENDING) {
						status = AE_OK;
						goto close_this_op;
					}

					if (ACPI_FAILURE (status)) {
						goto close_this_op;
					}
				}
			}

			op->aml_offset = aml_offset;

		}


		/* Start Arg_count at zero because we don't know if there are any args yet */

		arg_count = 0;


		if (arg_types)  /* Are there any arguments that must be processed? */ {
			/* get arguments */

			switch (op->opcode)
			{
			case AML_BYTE_OP:       /* AML_BYTEDATA_ARG */
			case AML_WORD_OP:       /* AML_WORDDATA_ARG */
			case AML_DWORD_OP:      /* AML_DWORDATA_ARG */
			case AML_STRING_OP:     /* AML_ASCIICHARLIST_ARG */

				/* fill in constant or string argument directly */

				acpi_ps_get_next_simple_arg (parser_state,
						 GET_CURRENT_ARG_TYPE (arg_types), op);
				break;

			case AML_NAMEPATH_OP:   /* AML_NAMESTRING_ARG */

				acpi_ps_get_next_namepath (parser_state, op, &arg_count, 1);
				arg_types = 0;
				break;


			default:

				/* Op is not a constant or string, append each argument */

				while (GET_CURRENT_ARG_TYPE (arg_types) && !arg_count) {
					aml_offset = parser_state->aml - parser_state->aml_start;
					arg = acpi_ps_get_next_arg (parser_state,
							 GET_CURRENT_ARG_TYPE (arg_types),
							 &arg_count);
					if (arg) {
						arg->aml_offset = aml_offset;
						acpi_ps_append_arg (op, arg);
					}

					INCREMENT_ARG_LIST (arg_types);
				}


				/* For a method, save the length and address of the body */

				if (op->opcode == AML_METHOD_OP) {
					deferred_op = acpi_ps_to_extended_op (op);
					if (deferred_op) {
						/*
						 * Skip parsing of control method or opregion body,
						 * because we don't have enough info in the first pass
						 * to parse them correctly.
						 */

						deferred_op->data   = parser_state->aml;
						deferred_op->length = parser_state->pkg_end -
								  parser_state->aml;

						/*
						 * Skip body of method.  For Op_regions, we must continue
						 * parsing because the opregion is not a standalone
						 * package (We don't know where the end is).
						 */
						parser_state->aml   = parser_state->pkg_end;
						arg_count           = 0;
					}
				}

				break;
			}
		}


		/*
		 * Zero Arg_count means that all arguments for this op have been processed
		 */
		if (!arg_count) {
			/* completed Op, prepare for next */

			if (acpi_ps_is_named_op (op->opcode)) {
				if (acpi_gbl_depth) {
					acpi_gbl_depth--;
				}

				if (op->opcode == AML_REGION_OP) {
					deferred_op = acpi_ps_to_extended_op (op);
					if (deferred_op) {
						/*
						 * Skip parsing of control method or opregion body,
						 * because we don't have enough info in the first pass
						 * to parse them correctly.
						 *
						 * Completed parsing an Op_region declaration, we now
						 * know the length.
						 */

						deferred_op->length = parser_state->aml -
								 deferred_op->data;
					}
				}
			}

			if ((op->opcode == AML_CREATE_FIELD_OP) ||
				(op->opcode == AML_BIT_FIELD_OP)    ||
				(op->opcode == AML_BYTE_FIELD_OP)   ||
				(op->opcode == AML_WORD_FIELD_OP)   ||
				(op->opcode == AML_DWORD_FIELD_OP)  ||
				(op->opcode == AML_QWORD_FIELD_OP))
			{
				/*
				 * Backup to beginning of Create_xXXfield declaration (1 for
				 * Opcode)
				 *
				 * Body_length is unknown until we parse the body
				 */
				deferred_op = (ACPI_PARSE2_OBJECT *) op;
				deferred_op->length = parser_state->aml - deferred_op->data;
			}

			/* This op complete, notify the dispatcher */

			if (walk_state->ascending_callback != NULL) {
				status = walk_state->ascending_callback (walk_state, op);
				status = acpi_ps_next_parse_state (walk_state, op, status);
				if (status == AE_CTRL_PENDING) {
					status = AE_OK;
					goto close_this_op;
				}
			}


close_this_op:

			/*
			 * Finished one argument of the containing scope
			 */
			parser_state->scope->parse_scope.arg_count--;

			/* Close this Op (may result in parse subtree deletion) */

			if (acpi_ps_complete_this_op (walk_state, op)) {
				op = NULL;
			}


			switch (status)
			{
			case AE_OK:
				break;


			case AE_CTRL_TRANSFER:

				/*
				 * We are about to transfer to a called method.
				 */
				walk_state->prev_op = op;
				walk_state->prev_arg_types = arg_types;
				return (status);
				break;


			case AE_CTRL_END:

				acpi_ps_pop_scope (parser_state, &op, &arg_types, &arg_count);

				status = walk_state->ascending_callback (walk_state, op);
				status = acpi_ps_next_parse_state (walk_state, op, status);

				acpi_ps_complete_this_op (walk_state, op);
				op = NULL;
				status = AE_OK;
				break;


			case AE_CTRL_TERMINATE:

				status = AE_OK;

				/* Clean up */
				do
				{
					if (op) {
						acpi_ps_complete_this_op (walk_state, op);
					}

					acpi_ps_pop_scope (parser_state, &op, &arg_types, &arg_count);
				} while (op);

				return (status);
				break;


			default:  /* All other non-AE_OK status */

				if (op == NULL) {
					acpi_ps_pop_scope (parser_state, &op, &arg_types, &arg_count);
				}
				walk_state->prev_op = op;
				walk_state->prev_arg_types = arg_types;

				/*
				 * TEMP:
				 */

				return (status);
				break;
			}


			/* This scope complete? */

			if (acpi_ps_has_completed_scope (parser_state)) {
				acpi_ps_pop_scope (parser_state, &op, &arg_types, &arg_count);
			}

			else {
				op = NULL;
			}

		}


		/* Arg_count is non-zero */

		else {
			/* complex argument, push Op and prepare for argument */

			acpi_ps_push_scope (parser_state, op, arg_types, arg_count);
			op = NULL;
		}

	} /* while Parser_state->Aml */


	/*
	 * Complete the last Op (if not completed), and clear the scope stack.
	 * It is easily possible to end an AML "package" with an unbounded number
	 * of open scopes (such as when several AML blocks are closed with
	 * sequential closing braces).  We want to terminate each one cleanly.
	 */

	do
	{
		if (op) {
			if (walk_state->ascending_callback != NULL) {
				status = walk_state->ascending_callback (walk_state, op);
				status = acpi_ps_next_parse_state (walk_state, op, status);
				if (status == AE_CTRL_PENDING) {
					status = AE_OK;
					goto close_this_op;
				}

				if (status == AE_CTRL_TERMINATE) {
					status = AE_OK;

					/* Clean up */
					do
					{
						if (op) {
							acpi_ps_complete_this_op (walk_state, op);
						}

						acpi_ps_pop_scope (parser_state, &op, &arg_types, &arg_count);

					} while (op);

					return (status);
				}

				else if (ACPI_FAILURE (status)) {
					acpi_ps_complete_this_op (walk_state, op);
					return (status);
				}
			}

			acpi_ps_complete_this_op (walk_state, op);
		}

		acpi_ps_pop_scope (parser_state, &op, &arg_types, &arg_count);

	} while (op);

	return (status);
}


/*******************************************************************************
 *
 * FUNCTION:    Acpi_ps_parse_aml
 *
 * PARAMETERS:  Start_scope     - The starting point of the parse.  Becomes the
 *                                root of the parsed op tree.
 *              Aml             - Pointer to the raw AML code to parse
 *              Aml_size        - Length of the AML to parse
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Parse raw AML and return a tree of ops
 *
 ******************************************************************************/

ACPI_STATUS
acpi_ps_parse_aml (
	ACPI_PARSE_OBJECT       *start_scope,
	u8                      *aml,
	u32                     aml_size,
	u32                     parse_flags,
	ACPI_NAMESPACE_NODE     *method_node,
	ACPI_OPERAND_OBJECT     **params,
	ACPI_OPERAND_OBJECT     **caller_return_desc,
	ACPI_PARSE_DOWNWARDS    descending_callback,
	ACPI_PARSE_UPWARDS      ascending_callback)
{
	ACPI_STATUS             status;
	ACPI_PARSE_STATE        *parser_state;
	ACPI_WALK_STATE         *walk_state;
	ACPI_WALK_LIST          walk_list;
	ACPI_NAMESPACE_NODE     *node = NULL;
	ACPI_WALK_LIST          *prev_walk_list = acpi_gbl_current_walk_list;
	ACPI_OPERAND_OBJECT     *return_desc;
	ACPI_OPERAND_OBJECT     *mth_desc = NULL;


	/* Create and initialize a new parser state */

	parser_state = acpi_ps_create_state (aml, aml_size);
	if (!parser_state) {
		return (AE_NO_MEMORY);
	}

	acpi_ps_init_scope (parser_state, start_scope);

	if (method_node) {
		mth_desc = acpi_ns_get_attached_object (method_node);
	}

	/* Create and initialize a new walk list */

	walk_list.walk_state = NULL;

	walk_state = acpi_ds_create_walk_state (TABLE_ID_DSDT, parser_state->start_op, mth_desc, &walk_list);
	if (!walk_state) {
		status = AE_NO_MEMORY;
		goto cleanup;
	}

	walk_state->method_node         = method_node;
	walk_state->parser_state        = parser_state;
	walk_state->parse_flags         = parse_flags;
	walk_state->descending_callback = descending_callback;
	walk_state->ascending_callback  = ascending_callback;

	/* TBD: [Restructure] TEMP until we pass Walk_state to the interpreter
	 */
	acpi_gbl_current_walk_list = &walk_list;


	if (method_node) {
		parser_state->start_node = method_node;
		walk_state->walk_type   = WALK_METHOD;

		/* Push start scope on scope stack and make it current  */

		status = acpi_ds_scope_stack_push (method_node, ACPI_TYPE_METHOD, walk_state);
		if (ACPI_FAILURE (status)) {
			return (status);
		}

		/* Init arguments if this is a control method */
		/* TBD: [Restructure] add walkstate as a param */

		acpi_ds_method_data_init_args (params, MTH_NUM_ARGS, walk_state);
	}

	else {
		/* Setup the current scope */

		node = parser_state->start_op->node;
		parser_state->start_node = node;

		if (node) {
			/* Push start scope on scope stack and make it current  */

			status = acpi_ds_scope_stack_push (node, node->type,
					   walk_state);
			if (ACPI_FAILURE (status)) {
				goto cleanup;
			}

		}
	}


	status = AE_OK;

	/*
	 * Execute the walk loop as long as there is a valid Walk State.  This
	 * handles nested control method invocations without recursion.
	 */

	while (walk_state) {
		if (ACPI_SUCCESS (status)) {
			status = acpi_ps_parse_loop (walk_state);
		}

		if (status == AE_CTRL_TRANSFER) {
			/*
			 * A method call was detected.
			 * Transfer control to the called control method
			 */

			status = acpi_ds_call_control_method (&walk_list, walk_state, NULL);

			/*
			 * If the transfer to the new method method call worked, a new walk
			 * state was created -- get it
			 */

			walk_state = acpi_ds_get_current_walk_state (&walk_list);
			continue;
		}

		else if (status == AE_CTRL_TERMINATE) {
			status = AE_OK;
		}

		/* We are done with this walk, move on to the parent if any */


		walk_state = acpi_ds_pop_walk_state (&walk_list);

		/* Extract return value before we delete Walk_state */

		return_desc = walk_state->return_desc;

		/* Reset the current scope to the beginning of scope stack */

		acpi_ds_scope_stack_clear (walk_state);

		/*
		 * If we just returned from the execution of a control method,
		 * there's lots of cleanup to do
		 */

		if ((walk_state->parse_flags & ACPI_PARSE_MODE_MASK) == ACPI_PARSE_EXECUTE) {
			acpi_ds_terminate_control_method (walk_state);
		}

		 /* Delete this walk state and all linked control states */

		acpi_ps_cleanup_scope (walk_state->parser_state);
		acpi_cm_free (walk_state->parser_state);
		acpi_ds_delete_walk_state (walk_state);

	   /* Check if we have restarted a preempted walk */

		walk_state = acpi_ds_get_current_walk_state (&walk_list);
		if (walk_state &&
			ACPI_SUCCESS (status))
		{
			/* There is another walk state, restart it */

			/*
			 * If the method returned value is not used by the parent,
			 * The object is deleted
			 */

			acpi_ds_restart_control_method (walk_state, return_desc);
			walk_state->walk_type |= WALK_METHOD_RESTART;
		}

		/*
		 * Just completed a 1st-level method, save the final internal return
		 * value (if any)
		 */

		else if (caller_return_desc) {
			*caller_return_desc = return_desc; /* NULL if no return value */
		}

		else if (return_desc) {
			/* Caller doesn't want it, must delete it */

			acpi_cm_remove_reference (return_desc);
		}
	}


	/* Normal exit */

	acpi_gbl_current_walk_list = prev_walk_list;
	return (status);


cleanup:

	/* Cleanup */

	acpi_ds_delete_walk_state (walk_state);
	acpi_ps_cleanup_scope (parser_state);
	acpi_cm_free (parser_state);

	acpi_gbl_current_walk_list = prev_walk_list;

	return (status);
}