// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/*******************************************************************************
*
* Module Name: dsutils - Dispatcher utilities
*
******************************************************************************/
#include <acpi/acpi.h>
#include "accommon.h"
#include "acparser.h"
#include "amlcode.h"
#include "acdispat.h"
#include "acinterp.h"
#include "acnamesp.h"
#include "acdebug.h"
#define _COMPONENT ACPI_DISPATCHER
ACPI_MODULE_NAME(
"dsutils")
/*******************************************************************************
*
* FUNCTION: acpi_ds_clear_implicit_return
*
* PARAMETERS: walk_state - Current State
*
* RETURN: None.
*
* DESCRIPTION: Clear and remove a reference on an implicit return value. Used
* to delete "stale" return values (if enabled, the return value
* from every operator is saved at least momentarily, in case the
* parent method exits.)
*
******************************************************************************/
void acpi_ds_clear_implicit_return(
struct acpi_walk_state *walk_state)
{
ACPI_FUNCTION_NAME(ds_clear_implicit_return);
/*
* Slack must be enabled for this feature
*/
if (!acpi_gbl_enable_interpreter_slack) {
return;
}
if (walk_state->implicit_return_obj) {
/*
* Delete any "stale" implicit return. However, in
* complex statements, the implicit return value can be
* bubbled up several levels.
*/
ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
"Removing reference on stale implicit return obj %p\n",
walk_state->implicit_return_obj));
acpi_ut_remove_reference(walk_state->implicit_return_obj);
walk_state->implicit_return_obj = NULL;
}
}
/*******************************************************************************
*
* FUNCTION: acpi_ds_do_implicit_return
*
* PARAMETERS: return_desc - The return value
* walk_state - Current State
* add_reference - True if a reference should be added to the
* return object
*
* RETURN: TRUE if implicit return enabled, FALSE otherwise
*
* DESCRIPTION: Implements the optional "implicit return". We save the result
* of every ASL operator and control method invocation in case the
* parent method exit. Before storing a new return value, we
* delete the previous return value.
*
******************************************************************************/
u8
acpi_ds_do_implicit_return(
union acpi_operand_object *return_desc,
struct acpi_walk_state *walk_state, u8 add_reference)
{
ACPI_FUNCTION_NAME(ds_do_implicit_return);
/*
* Slack must be enabled for this feature, and we must
* have a valid return object
*/
if ((!acpi_gbl_enable_interpreter_slack) || (!return_desc)) {
return (
FALSE);
}
ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
"Result %p will be implicitly returned; Prev=%p\n",
return_desc, walk_state->implicit_return_obj));
/*
* Delete any "stale" implicit return value first. However, in
* complex statements, the implicit return value can be
* bubbled up several levels, so we don't clear the value if it
* is the same as the return_desc.
*/
if (walk_state->implicit_return_obj) {
if (walk_state->implicit_return_obj == return_desc) {
return (
TRUE);
}
acpi_ds_clear_implicit_return(walk_state);
}
/* Save the implicit return value, add a reference if requested */
walk_state->implicit_return_obj = return_desc;
if (add_reference) {
acpi_ut_add_reference(return_desc);
}
return (
TRUE);
}
/*******************************************************************************
*
* FUNCTION: acpi_ds_is_result_used
*
* PARAMETERS: op - Current Op
* walk_state - Current State
*
* RETURN: TRUE if result is used, FALSE otherwise
*
* DESCRIPTION: Check if a result object will be used by the parent
*
******************************************************************************/
u8
acpi_ds_is_result_used(
union acpi_parse_object * op,
struct acpi_walk_state * walk_state)
{
const struct acpi_opcode_info *parent_info;
ACPI_FUNCTION_TRACE_PTR(ds_is_result_used, op);
/* Must have both an Op and a Result Object */
if (!op) {
ACPI_ERROR((AE_INFO,
"Null Op"));
return_UINT8(
TRUE);
}
/*
* We know that this operator is not a
* Return() operator (would not come here.) 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.
* NOTE: this is optional because the ASL language does not actually
* support this behavior.
*/
(
void)acpi_ds_do_implicit_return(walk_state->result_obj, walk_state,
TRUE);
/*
* Now determine if the parent will use the result
*
* If there is no parent, or the parent is a scope_op, we are executing
* at the method level. An executing method typically has no parent,
* since each method is parsed separately. A method invoked externally
* via execute_control_method has a scope_op as the parent.
*/
if ((!op->common.parent) ||
(op->common.parent->common.aml_opcode == AML_SCOPE_OP)) {
/* No parent, the return value cannot possibly be used */
ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
"At Method level, result of [%s] not used\n",
acpi_ps_get_opcode_name(op->common.
aml_opcode)));
return_UINT8(
FALSE);
}
/* Get info on the parent. The root_op is AML_SCOPE */
parent_info =
acpi_ps_get_opcode_info(op->common.parent->common.aml_opcode);
if (parent_info->
class == AML_CLASS_UNKNOWN) {
ACPI_ERROR((AE_INFO,
"Unknown parent opcode Op=%p", op));
return_UINT8(
FALSE);
}
/*
* Decide what to do with the result based on the parent. If
* the parent opcode will not use the result, delete the object.
* Otherwise leave it as is, it will be deleted when it is used
* as an operand later.
*/
switch (parent_info->
class) {
case AML_CLASS_CONTROL:
switch (op->common.parent->common.aml_opcode) {
case AML_RETURN_OP:
/* Never delete the return value associated with a return opcode */
goto result_used;
case AML_IF_OP:
case AML_WHILE_OP:
/*
* If we are executing the predicate AND this is the predicate op,
* we will use the return value
*/
if ((walk_state->control_state->common.state ==
ACPI_CONTROL_PREDICATE_EXECUTING) &&
(walk_state->control_state->control.predicate_op ==
op)) {
goto result_used;
}
break;
default:
/* Ignore other control opcodes */
break;
}
/* The general control opcode returns no result */
goto result_not_used;
case AML_CLASS_CREATE:
/*
* These opcodes allow term_arg(s) as operands and therefore
* the operands can be method calls. The result is used.
*/
goto result_used;
case AML_CLASS_NAMED_OBJECT:
if ((op->common.parent->common.aml_opcode == AML_REGION_OP) ||
(op->common.parent->common.aml_opcode == AML_DATA_REGION_OP)
|| (op->common.parent->common.aml_opcode == AML_PACKAGE_OP)
|| (op->common.parent->common.aml_opcode == AML_BUFFER_OP)
|| (op->common.parent->common.aml_opcode ==
AML_VARIABLE_PACKAGE_OP)
|| (op->common.parent->common.aml_opcode ==
AML_INT_EVAL_SUBTREE_OP)
|| (op->common.parent->common.aml_opcode ==
AML_BANK_FIELD_OP)) {
/*
* These opcodes allow term_arg(s) as operands and therefore
* the operands can be method calls. The result is used.
*/
goto result_used;
}
goto result_not_used;
default:
/*
* In all other cases. the parent will actually use the return
* object, so keep it.
*/
goto result_used;
}
result_used:
ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
"Result of [%s] used by Parent [%s] Op=%p\n",
acpi_ps_get_opcode_name(op->common.aml_opcode),
acpi_ps_get_opcode_name(op->common.parent->common.
aml_opcode), op));
return_UINT8(
TRUE);
result_not_used:
ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
"Result of [%s] not used by Parent [%s] Op=%p\n",
acpi_ps_get_opcode_name(op->common.aml_opcode),
acpi_ps_get_opcode_name(op->common.parent->common.
aml_opcode), op));
return_UINT8(
FALSE);
}
/*******************************************************************************
*
* FUNCTION: acpi_ds_delete_result_if_not_used
*
* PARAMETERS: op - Current parse Op
* result_obj - Result of the operation
* walk_state - Current state
*
* RETURN: Status
*
* DESCRIPTION: Used after interpretation of an opcode. If there is an internal
* result descriptor, check if the parent opcode will actually use
* this result. If not, delete the result now so that it will
* not become orphaned.
*
******************************************************************************/
void
acpi_ds_delete_result_if_not_used(
union acpi_parse_object *op,
union acpi_operand_object *result_obj,
struct acpi_walk_state *walk_state)
{
union acpi_operand_object *obj_desc;
acpi_status status;
ACPI_FUNCTION_TRACE_PTR(ds_delete_result_if_not_used, result_obj);
if (!op) {
ACPI_ERROR((AE_INFO,
"Null Op"));
return_VOID;
}
if (!result_obj) {
return_VOID;
}
if (!acpi_ds_is_result_used(op, walk_state)) {
/* Must pop the result stack (obj_desc should be equal to result_obj) */
status = acpi_ds_result_pop(&obj_desc, walk_state);
if (ACPI_SUCCESS(status)) {
acpi_ut_remove_reference(result_obj);
}
}
return_VOID;
}
/*******************************************************************************
*
* FUNCTION: acpi_ds_resolve_operands
*
* PARAMETERS: walk_state - Current walk state with operands on stack
*
* RETURN: Status
*
* DESCRIPTION: Resolve all operands to their values. Used to prepare
* arguments to a control method invocation (a call from one
* method to another.)
*
******************************************************************************/
acpi_status acpi_ds_resolve_operands(
struct acpi_walk_state *walk_state)
{
u32 i;
acpi_status status = AE_OK;
ACPI_FUNCTION_TRACE_PTR(ds_resolve_operands, walk_state);
/*
* Attempt to resolve each of the valid operands
* Method arguments are passed by reference, not by value. This means
* that the actual objects are passed, not copies of the objects.
*/
for (i = 0; i < walk_state->num_operands; i++) {
status =
acpi_ex_resolve_to_value(&walk_state->operands[i],
walk_state);
if (ACPI_FAILURE(status)) {
break;
}
}
return_ACPI_STATUS(status);
}
/*******************************************************************************
*
* FUNCTION: acpi_ds_clear_operands
*
* PARAMETERS: walk_state - Current walk state with operands on stack
*
* RETURN: None
*
* DESCRIPTION: Clear all operands on the current walk state operand stack.
*
******************************************************************************/
void acpi_ds_clear_operands(
struct acpi_walk_state *walk_state)
{
u32 i;
ACPI_FUNCTION_TRACE_PTR(ds_clear_operands, walk_state);
/* Remove a reference on each operand on the stack */
for (i = 0; i < walk_state->num_operands; i++) {
/*
* Remove a reference to all operands, including both
* "Arguments" and "Targets".
*/
acpi_ut_remove_reference(walk_state->operands[i]);
walk_state->operands[i] = NULL;
}
walk_state->num_operands = 0;
return_VOID;
}
/*******************************************************************************
*
* FUNCTION: acpi_ds_create_operand
*
* PARAMETERS: walk_state - Current walk state
* arg - Parse object for the argument
* arg_index - Which argument (zero based)
*
* RETURN: Status
*
* DESCRIPTION: Translate a parse tree object that is an argument to an AML
* opcode to the equivalent interpreter object. This may include
* looking up a name or entering a new name into the internal
* namespace.
*
******************************************************************************/
acpi_status
acpi_ds_create_operand(
struct acpi_walk_state *walk_state,
union acpi_parse_object *arg, u32 arg_index)
{
acpi_status status = AE_OK;
char *name_string;
u32 name_length;
union acpi_operand_object *obj_desc;
union acpi_parse_object *parent_op;
u16 opcode;
acpi_interpreter_mode interpreter_mode;
const struct acpi_opcode_info *op_info;
ACPI_FUNCTION_TRACE_PTR(ds_create_operand, arg);
/* A valid name must be looked up in the namespace */
if ((arg->common.aml_opcode == AML_INT_NAMEPATH_OP) &&
(arg->common.value.string) &&
!(arg->common.flags & ACPI_PARSEOP_IN_STACK)) {
ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
"Getting a name: Arg=%p\n",
arg));
/* Get the entire name string from the AML stream */
status = acpi_ex_get_name_string(ACPI_TYPE_ANY,
arg->common.value.buffer,
&name_string, &name_length);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
/* All prefixes have been handled, and the name is in name_string */
/*
* Special handling for buffer_field declarations. This is a deferred
* opcode that unfortunately defines the field name as the last
* parameter instead of the first. We get here when we are performing
* the deferred execution, so the actual name of the field is already
* in the namespace. We don't want to attempt to look it up again
* because we may be executing in a different scope than where the
* actual opcode exists.
*/
if ((walk_state->deferred_node) &&
(walk_state->deferred_node->type == ACPI_TYPE_BUFFER_FIELD)
&& (arg_index == (u32)
((walk_state->opcode == AML_CREATE_FIELD_OP) ? 3 : 2))) {
obj_desc =
ACPI_CAST_PTR(
union acpi_operand_object,
walk_state->deferred_node);
status = AE_OK;
}
else {
/* All other opcodes */
/*
* Differentiate between a namespace "create" operation
* versus a "lookup" operation (IMODE_LOAD_PASS2 vs.
* IMODE_EXECUTE) in order to support the creation of
* namespace objects during the execution of control methods.
*/
parent_op = arg->common.parent;
op_info =
acpi_ps_get_opcode_info(parent_op->common.
aml_opcode);
if ((op_info->flags & AML_NSNODE) &&
(parent_op->common.aml_opcode !=
AML_INT_METHODCALL_OP)
&& (parent_op->common.aml_opcode != AML_REGION_OP)
&& (parent_op->common.aml_opcode !=
AML_INT_NAMEPATH_OP)) {
/* Enter name into namespace if not found */
interpreter_mode = ACPI_IMODE_LOAD_PASS2;
}
else {
/* Return a failure if name not found */
interpreter_mode = ACPI_IMODE_EXECUTE;
}
status =
acpi_ns_lookup(walk_state->scope_info, name_string,
ACPI_TYPE_ANY, interpreter_mode,
ACPI_NS_SEARCH_PARENT |
ACPI_NS_DONT_OPEN_SCOPE, walk_state,
ACPI_CAST_INDIRECT_PTR(
struct
acpi_namespace_node,
&obj_desc));
/*
* The only case where we pass through (ignore) a NOT_FOUND
* error is for the cond_ref_of opcode.
*/
if (status == AE_NOT_FOUND) {
if (parent_op->common.aml_opcode ==
AML_CONDITIONAL_REF_OF_OP) {
/*
* For the Conditional Reference op, it's OK if
* the name is not found; We just need a way to
* indicate this to the interpreter, set the
* object to the root
*/
obj_desc =
ACPI_CAST_PTR(
union
acpi_operand_object,
acpi_gbl_root_node);
status = AE_OK;
}
else if (parent_op->common.aml_opcode ==
AML_EXTERNAL_OP) {
/*
* This opcode should never appear here. It is used only
* by AML disassemblers and is surrounded by an If(0)
* by the ASL compiler.
*
* Therefore, if we see it here, it is a serious error.
*/
status = AE_AML_BAD_OPCODE;
}
else {
/*
* We just plain didn't find it -- which is a
* very serious error at this point
*/
status = AE_AML_NAME_NOT_FOUND;
}
}
if (ACPI_FAILURE(status)) {
ACPI_ERROR_NAMESPACE(walk_state->scope_info,
name_string, status);
}
}
/* Free the namestring created above */
ACPI_FREE(name_string);
/* Check status from the lookup */
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
/* Put the resulting object onto the current object stack */
status = acpi_ds_obj_stack_push(obj_desc, walk_state);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
acpi_db_display_argument_object(obj_desc, walk_state);
}
else {
/* Check for null name case */
if ((arg->common.aml_opcode == AML_INT_NAMEPATH_OP) &&
!(arg->common.flags & ACPI_PARSEOP_IN_STACK)) {
/*
* If the name is null, this means that this is an
* optional result parameter that was not specified
* in the original ASL. Create a Zero Constant for a
* placeholder. (Store to a constant is a Noop.)
*/
opcode = AML_ZERO_OP;
/* Has no arguments! */
ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
"Null namepath: Arg=%p\n", arg));
}
else {
opcode = arg->common.aml_opcode;
}
/* Get the object type of the argument */
op_info = acpi_ps_get_opcode_info(opcode);
if (op_info->object_type == ACPI_TYPE_INVALID) {
return_ACPI_STATUS(AE_NOT_IMPLEMENTED);
}
if ((op_info->flags & AML_HAS_RETVAL) ||
(arg->common.flags & ACPI_PARSEOP_IN_STACK)) {
/*
* Use value that was already previously returned
* by the evaluation of this argument
*/
status = acpi_ds_result_pop(&obj_desc, walk_state);
if (ACPI_FAILURE(status)) {
/*
* Only error is underflow, and this indicates
* a missing or null operand!
*/
ACPI_EXCEPTION((AE_INFO, status,
"Missing or null operand"));
return_ACPI_STATUS(status);
}
}
else {
/* Create an ACPI_INTERNAL_OBJECT for the argument */
obj_desc =
acpi_ut_create_internal_object(op_info->
object_type);
if (!obj_desc) {
return_ACPI_STATUS(AE_NO_MEMORY);
}
/* Initialize the new object */
status =
acpi_ds_init_object_from_op(walk_state, arg, opcode,
&obj_desc);
if (ACPI_FAILURE(status)) {
acpi_ut_delete_object_desc(obj_desc);
return_ACPI_STATUS(status);
}
}
/* Put the operand object on the object stack */
status = acpi_ds_obj_stack_push(obj_desc, walk_state);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
acpi_db_display_argument_object(obj_desc, walk_state);
}
return_ACPI_STATUS(AE_OK);
}
/*******************************************************************************
*
* FUNCTION: acpi_ds_create_operands
*
* PARAMETERS: walk_state - Current state
* first_arg - First argument of a parser argument tree
*
* RETURN: Status
*
* DESCRIPTION: Convert an operator's arguments from a parse tree format to
* namespace objects and place those argument object on the object
* stack in preparation for evaluation by the interpreter.
*
******************************************************************************/
acpi_status
acpi_ds_create_operands(
struct acpi_walk_state *walk_state,
union acpi_parse_object *first_arg)
{
acpi_status status = AE_OK;
union acpi_parse_object *arg;
union acpi_parse_object *arguments[ACPI_OBJ_NUM_OPERANDS];
u32 arg_count = 0;
u32 index = walk_state->num_operands;
u32 prev_num_operands = walk_state->num_operands;
u32 new_num_operands;
u32 i;
ACPI_FUNCTION_TRACE_PTR(ds_create_operands, first_arg);
/* Get all arguments in the list */
arg = first_arg;
while (arg) {
if (index >= ACPI_OBJ_NUM_OPERANDS) {
return_ACPI_STATUS(AE_BAD_DATA);
}
arguments[index] = arg;
walk_state->operands[index] = NULL;
/* Move on to next argument, if any */
arg = arg->common.next;
arg_count++;
index++;
}
ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
"NumOperands %d, ArgCount %d, Index %d\n",
walk_state->num_operands, arg_count, index));
/* Create the interpreter arguments, in reverse order */
new_num_operands = index;
index--;
for (i = 0; i < arg_count; i++) {
arg = arguments[index];
walk_state->operand_index = (u8)index;
status = acpi_ds_create_operand(walk_state, arg, index);
if (ACPI_FAILURE(status)) {
goto cleanup;
}
ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH,
"Created Arg #%u (%p) %u args total\n",
index, arg, arg_count));
index--;
}
return_ACPI_STATUS(status);
cleanup:
/*
* We must undo everything done above; meaning that we must
* pop everything off of the operand stack and delete those
* objects
*/
walk_state->num_operands = (u8)(i);
acpi_ds_obj_stack_pop_and_delete(new_num_operands, walk_state);
/* Restore operand count */
walk_state->num_operands = (u8)(prev_num_operands);
ACPI_EXCEPTION((AE_INFO, status,
"While creating Arg %u", index));
return_ACPI_STATUS(status);
}
/*****************************************************************************
*
* FUNCTION: acpi_ds_evaluate_name_path
*
* PARAMETERS: walk_state - Current state of the parse tree walk,
* the opcode of current operation should be
* AML_INT_NAMEPATH_OP
*
* RETURN: Status
*
* DESCRIPTION: Translate the -name_path- parse tree object to the equivalent
* interpreter object, convert it to value, if needed, duplicate
* it, if needed, and push it onto the current result stack.
*
****************************************************************************/
acpi_status acpi_ds_evaluate_name_path(
struct acpi_walk_state *walk_state)
{
acpi_status status = AE_OK;
union acpi_parse_object *op = walk_state->op;
union acpi_operand_object **operand = &walk_state->operands[0];
union acpi_operand_object *new_obj_desc;
u8 type;
ACPI_FUNCTION_TRACE_PTR(ds_evaluate_name_path, walk_state);
if (!op->common.parent) {
/* This happens after certain exception processing */
goto exit;
}
if ((op->common.parent->common.aml_opcode == AML_PACKAGE_OP) ||
(op->common.parent->common.aml_opcode == AML_VARIABLE_PACKAGE_OP) ||
(op->common.parent->common.aml_opcode == AML_REF_OF_OP)) {
/* TBD: Should we specify this feature as a bit of op_info->Flags of these opcodes? */
goto exit;
}
status = acpi_ds_create_operand(walk_state, op, 0);
if (ACPI_FAILURE(status)) {
goto exit;
}
if (op->common.flags & ACPI_PARSEOP_TARGET) {
new_obj_desc = *operand;
goto push_result;
}
type = (*operand)->common.type;
status = acpi_ex_resolve_to_value(operand, walk_state);
if (ACPI_FAILURE(status)) {
goto exit;
}
if (type == ACPI_TYPE_INTEGER) {
/* It was incremented by acpi_ex_resolve_to_value */
acpi_ut_remove_reference(*operand);
status =
acpi_ut_copy_iobject_to_iobject(*operand, &new_obj_desc,
walk_state);
if (ACPI_FAILURE(status)) {
goto exit;
}
}
else {
/*
* The object either was anew created or is
* a Namespace node - don't decrement it.
*/
new_obj_desc = *operand;
}
/* Cleanup for name-path operand */
status = acpi_ds_obj_stack_pop(1, walk_state);
if (ACPI_FAILURE(status)) {
walk_state->result_obj = new_obj_desc;
goto exit;
}
push_result:
walk_state->result_obj = new_obj_desc;
status = acpi_ds_result_push(walk_state->result_obj, walk_state);
if (ACPI_SUCCESS(status)) {
/* Force to take it from stack */
op->common.flags |= ACPI_PARSEOP_IN_STACK;
}
exit:
return_ACPI_STATUS(status);
}
