// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/******************************************************************************
*
* Module Name: psparse - Parser top level AML parse routines
*
* Copyright (C) 2000 - 2023, Intel Corp.
*
*****************************************************************************/
/*
* Parse the AML and build an operation tree as most interpreters,
* like Perl, do. Parsing is done by hand rather than with a YACC
* generated parser to tightly constrain stack and dynamic memory
* usage. At the same time, parsing is kept flexible and the code
* fairly compact by parsing based on a list of AML opcode
* templates in aml_op_info[]
*/
#include <acpi/acpi.h>
#include "accommon.h"
#include "acparser.h"
#include "acdispat.h"
#include "amlcode.h"
#include "acinterp.h"
#include "acnamesp.h"
#define _COMPONENT ACPI_PARSER
ACPI_MODULE_NAME("psparse")
/*******************************************************************************
*
* FUNCTION: acpi_ps_get_opcode_size
*
* PARAMETERS: opcode - An AML opcode
*
* RETURN: Size of the opcode, in bytes (1 or 2)
*
* DESCRIPTION: Get the size of the current opcode.
*
******************************************************************************/
u32 acpi_ps_get_opcode_size(u32 opcode)
{
/* Extended (2-byte) opcode if > 255 */
if (opcode > 0x00FF) {
return (2);
}
/* Otherwise, just a single byte opcode */
return (1);
}
/*******************************************************************************
*
* FUNCTION: acpi_ps_peek_opcode
*
* PARAMETERS: parser_state - A parser state object
*
* RETURN: Next AML opcode
*
* DESCRIPTION: Get next AML opcode (without incrementing AML pointer)
*
******************************************************************************/
u16 acpi_ps_peek_opcode(struct acpi_parse_state * parser_state)
{
u8 *aml;
u16 opcode;
aml = parser_state->aml;
opcode = (u16) ACPI_GET8(aml);
if (opcode == AML_EXTENDED_PREFIX) {
/* Extended opcode, get the second opcode byte */
aml++;
opcode = (u16) ((opcode << 8) | ACPI_GET8(aml));
}
return (opcode);
}
/*******************************************************************************
*
* FUNCTION: acpi_ps_complete_this_op
*
* PARAMETERS: walk_state - Current State
* op - Op to complete
*
* RETURN: Status
*
* DESCRIPTION: Perform any cleanup at the completion of an Op.
*
******************************************************************************/
acpi_status
acpi_ps_complete_this_op(struct acpi_walk_state *walk_state,
union acpi_parse_object *op)
{
union acpi_parse_object *prev;
union acpi_parse_object *next;
const struct acpi_opcode_info *parent_info;
union acpi_parse_object *replacement_op = NULL;
acpi_status status = AE_OK;
ACPI_FUNCTION_TRACE_PTR(ps_complete_this_op, op);
/* Check for null Op, can happen if AML code is corrupt */
if (!op) {
return_ACPI_STATUS(AE_OK); /* OK for now */
}
acpi_ex_stop_trace_opcode(op, walk_state);
/* Delete this op and the subtree below it if asked to */
if (((walk_state->parse_flags & ACPI_PARSE_TREE_MASK) !=
ACPI_PARSE_DELETE_TREE)
|| (walk_state->op_info->class == AML_CLASS_ARGUMENT)) {
return_ACPI_STATUS(AE_OK);
}
/* Make sure that we only delete this subtree */
if (op->common.parent) {
prev = op->common.parent->common.value.arg;
if (!prev) {
/* Nothing more to do */
goto cleanup;
}
/*
* Check if we need to replace the operator and its subtree
* with a return value op (placeholder op)
*/
parent_info =
acpi_ps_get_opcode_info(op->common.parent->common.
aml_opcode);
switch (parent_info->class) {
case AML_CLASS_CONTROL:
break;
case AML_CLASS_CREATE:
/*
* These opcodes contain term_arg operands. The current
* op must be replaced by a placeholder return op
*/
replacement_op =
acpi_ps_alloc_op(AML_INT_RETURN_VALUE_OP,
op->common.aml);
if (!replacement_op) {
status = AE_NO_MEMORY;
}
break;
case AML_CLASS_NAMED_OBJECT:
/*
* These opcodes contain term_arg operands. The current
* op must be replaced by a placeholder return op
*/
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_BUFFER_OP)
|| (op->common.parent->common.aml_opcode ==
AML_PACKAGE_OP)
|| (op->common.parent->common.aml_opcode ==
AML_BANK_FIELD_OP)
|| (op->common.parent->common.aml_opcode ==
AML_VARIABLE_PACKAGE_OP)) {
replacement_op =
acpi_ps_alloc_op(AML_INT_RETURN_VALUE_OP,
op->common.aml);
if (!replacement_op) {
status = AE_NO_MEMORY;
}
} else
if ((op->common.parent->common.aml_opcode ==
AML_NAME_OP)
&& (walk_state->pass_number <=
ACPI_IMODE_LOAD_PASS2)) {
if ((op->common.aml_opcode == AML_BUFFER_OP)
|| (op->common.aml_opcode == AML_PACKAGE_OP)
|| (op->common.aml_opcode ==
AML_VARIABLE_PACKAGE_OP)) {
replacement_op =
acpi_ps_alloc_op(op->common.
aml_opcode,
op->common.aml);
if (!replacement_op) {
status = AE_NO_MEMORY;
} else {
replacement_op->named.data =
op->named.data;
replacement_op->named.length =
op->named.length;
}
}
}
break;
default:
replacement_op =
acpi_ps_alloc_op(AML_INT_RETURN_VALUE_OP,
op->common.aml);
if (!replacement_op) {
status = AE_NO_MEMORY;
}
}
/* We must unlink this op from the parent tree */
if (prev == op) {
/* This op is the first in the list */
if (replacement_op) {
replacement_op->common.parent =
op->common.parent;
replacement_op->common.value.arg = NULL;
replacement_op->common.node = op->common.node;
op->common.parent->common.value.arg =
replacement_op;
replacement_op->common.next = op->common.next;
} else {
op->common.parent->common.value.arg =
op->common.next;
}
}
/* Search the parent list */
else
while (prev) {
/* Traverse all siblings in the parent's argument list */
next = prev->common.next;
if (next == op) {
if (replacement_op) {
replacement_op->common.parent =
op->common.parent;
replacement_op->common.value.
arg = NULL;
replacement_op->common.node =
op->common.node;
prev->common.next =
replacement_op;
replacement_op->common.next =
op->common.next;
next = NULL;
} else {
prev->common.next =
op->common.next;
next = NULL;
}
}
prev = next;
}
}
cleanup:
/* Now we can actually delete the subtree rooted at Op */
acpi_ps_delete_parse_tree(op);
return_ACPI_STATUS(status);
}
/*******************************************************************************
*
* FUNCTION: acpi_ps_next_parse_state
*
* PARAMETERS: walk_state - Current state
* op - Current parse op
* callback_status - Status from previous operation
*
* RETURN: Status
*
* DESCRIPTION: Update the parser state based upon the return exception from
* the parser callback.
*
******************************************************************************/
acpi_status
acpi_ps_next_parse_state(struct acpi_walk_state *walk_state,
union acpi_parse_object *op,
acpi_status callback_status)
{
struct acpi_parse_state *parser_state = &walk_state->parser_state;
acpi_status status = AE_CTRL_PENDING;
ACPI_FUNCTION_TRACE_PTR(ps_next_parse_state, op);
switch (callback_status) {
case AE_CTRL_TERMINATE:
/*
* A control method was terminated via a RETURN statement.
* The walk of this method is complete.
*/
parser_state->aml = parser_state->aml_end;
status = AE_CTRL_TERMINATE;
break;
case AE_CTRL_BREAK:
parser_state->aml = walk_state->aml_last_while;
walk_state->control_state->common.value = FALSE;
status = AE_CTRL_BREAK;
break;
case AE_CTRL_CONTINUE:
parser_state->aml = walk_state->aml_last_while;
status = AE_CTRL_CONTINUE;
break;
case AE_CTRL_PENDING:
parser_state->aml = walk_state->aml_last_while;
break;
#if 0
case AE_CTRL_SKIP:
parser_state->aml = parser_state->scope->parse_scope.pkg_end;
status = AE_OK;
break;
#endif
case AE_CTRL_TRUE:
/*
* Predicate of an IF was true, and we are at the matching ELSE.
* Just close out this package
*/
parser_state->aml = acpi_ps_get_next_package_end(parser_state);
status = AE_CTRL_PENDING;
break;
case AE_CTRL_FALSE:
/*
* Either an IF/WHILE Predicate was false or we encountered a BREAK
* opcode. In both cases, we do not execute the rest of the
* package; We simply close out the parent (finishing the walk of
* this branch of the tree) and continue execution at the parent
* level.
*/
parser_state->aml = parser_state->scope->parse_scope.pkg_end;
/* In the case of a BREAK, just force a predicate (if any) to FALSE */
walk_state->control_state->common.value = FALSE;
status = AE_CTRL_END;
break;
case AE_CTRL_TRANSFER:
/* A method call (invocation) -- transfer control */
status = AE_CTRL_TRANSFER;
walk_state->prev_op = op;
walk_state->method_call_op = op;
walk_state->method_call_node =
(op->common.value.arg)->common.node;
/* Will return value (if any) be used by the caller? */
walk_state->return_used =
acpi_ds_is_result_used(op, walk_state);
break;
default:
status = callback_status;
if (ACPI_CNTL_EXCEPTION(callback_status)) {
status = AE_OK;
}
break;
}
return_ACPI_STATUS(status);
}
/*******************************************************************************
*
* FUNCTION: acpi_ps_parse_aml
*
* PARAMETERS: walk_state - Current state
*
*
* RETURN: Status
*
* DESCRIPTION: Parse raw AML and return a tree of ops
*
******************************************************************************/
acpi_status acpi_ps_parse_aml(struct acpi_walk_state *walk_state)
{
acpi_status status;
struct acpi_thread_state *thread;
struct acpi_thread_state *prev_walk_list = acpi_gbl_current_walk_list;
struct acpi_walk_state *previous_walk_state;
ACPI_FUNCTION_TRACE(ps_parse_aml);
ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
"Entered with WalkState=%p Aml=%p size=%X\n",
walk_state, walk_state->parser_state.aml,
walk_state->parser_state.aml_size));
if (!walk_state->parser_state.aml) {
return_ACPI_STATUS(AE_BAD_ADDRESS);
}
/* Create and initialize a new thread state */
thread = acpi_ut_create_thread_state();
if (!thread) {
if (walk_state->method_desc) {
/* Executing a control method - additional cleanup */
acpi_ds_terminate_control_method(walk_state->
method_desc,
walk_state);
}
acpi_ds_delete_walk_state(walk_state);
return_ACPI_STATUS(AE_NO_MEMORY);
}
walk_state->thread = thread;
/*
* If executing a method, the starting sync_level is this method's
* sync_level
*/
if (walk_state->method_desc) {
walk_state->thread->current_sync_level =
walk_state->method_desc->method.sync_level;
}
acpi_ds_push_walk_state(walk_state, thread);
/*
* This global allows the AML debugger to get a handle to the currently
* executing control method.
*/
acpi_gbl_current_walk_list = thread;
/*
* Execute the walk loop as long as there is a valid Walk State. This
* handles nested control method invocations without recursion.
*/
ACPI_DEBUG_PRINT((ACPI_DB_PARSE, "State=%p\n", walk_state));
status = AE_OK;
while (walk_state) {
if (ACPI_SUCCESS(status)) {
/*
* The parse_loop executes AML until the method terminates
* or calls another method.
*/
status = acpi_ps_parse_loop(walk_state);
}
ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
"Completed one call to walk loop, %s State=%p\n",
acpi_format_exception(status), walk_state));
if (walk_state->method_pathname && walk_state->method_is_nested) {
/* Optional object evaluation log */
ACPI_DEBUG_PRINT_RAW((ACPI_DB_EVALUATION,
"%-26s: %*s%s\n",
" Exit nested method",
(walk_state->
method_nesting_depth + 1) * 3,
" ",
&walk_state->method_pathname[1]));
ACPI_FREE(walk_state->method_pathname);
walk_state->method_is_nested = FALSE;
}
if (status == AE_CTRL_TRANSFER) {
/*
* A method call was detected.
* Transfer control to the called control method
*/
status =
acpi_ds_call_control_method(thread, walk_state,
NULL);
if (ACPI_FAILURE(status)) {
status =
acpi_ds_method_error(status, walk_state);
}
/*
* 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(thread);
continue;
} else if (status == AE_CTRL_TERMINATE) {
status = AE_OK;
} else if ((status != AE_OK) && (walk_state->method_desc)) {
/* Either the method parse or actual execution failed */
acpi_ex_exit_interpreter();
if (status == AE_ABORT_METHOD) {
acpi_ns_print_node_pathname(walk_state->
method_node,
"Aborting method");
acpi_os_printf("\n");
} else {
ACPI_ERROR_METHOD("Aborting method",
walk_state->method_node, NULL,
status);
}
acpi_ex_enter_interpreter();
/* Check for possible multi-thread reentrancy problem */
if ((status == AE_ALREADY_EXISTS) &&
(!(walk_state->method_desc->method.info_flags &
ACPI_METHOD_SERIALIZED))) {
/*
* Method is not serialized and tried to create an object
* twice. The probable cause is that the method cannot
* handle reentrancy. Mark as "pending serialized" now, and
* then mark "serialized" when the last thread exits.
*/
walk_state->method_desc->method.info_flags |=
ACPI_METHOD_SERIALIZED_PENDING;
}
}
/* We are done with this walk, move on to the parent if any */
walk_state = acpi_ds_pop_walk_state(thread);
/* 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 or if we
* encountered an error during the method parse phase, there's lots of
* cleanup to do
*/
if (((walk_state->parse_flags & ACPI_PARSE_MODE_MASK) ==
ACPI_PARSE_EXECUTE &&
!(walk_state->parse_flags & ACPI_PARSE_MODULE_LEVEL)) ||
(ACPI_FAILURE(status))) {
acpi_ds_terminate_control_method(walk_state->
method_desc,
walk_state);
}
/* Delete this walk state and all linked control states */
acpi_ps_cleanup_scope(&walk_state->parser_state);
previous_walk_state = walk_state;
ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
"ReturnValue=%p, ImplicitValue=%p State=%p\n",
walk_state->return_desc,
walk_state->implicit_return_obj, walk_state));
/* Check if we have restarted a preempted walk */
walk_state = acpi_ds_get_current_walk_state(thread);
if (walk_state) {
if (ACPI_SUCCESS(status)) {
/*
* There is another walk state, restart it.
* If the method return value is not used by the parent,
* The object is deleted
*/
if (!previous_walk_state->return_desc) {
/*
* In slack mode execution, if there is no return value
* we should implicitly return zero (0) as a default value.
*/
if (acpi_gbl_enable_interpreter_slack &&
!previous_walk_state->
implicit_return_obj) {
previous_walk_state->
implicit_return_obj =
acpi_ut_create_integer_object
((u64) 0);
if (!previous_walk_state->
implicit_return_obj) {
return_ACPI_STATUS
(AE_NO_MEMORY);
}
}
/* Restart the calling control method */
status =
acpi_ds_restart_control_method
(walk_state,
previous_walk_state->
implicit_return_obj);
} else {
/*
* We have a valid return value, delete any implicit
* return value.
*/
acpi_ds_clear_implicit_return
(previous_walk_state);
status =
acpi_ds_restart_control_method
(walk_state,
previous_walk_state->return_desc);
}
if (ACPI_SUCCESS(status)) {
walk_state->walk_type |=
ACPI_WALK_METHOD_RESTART;
}
} else {
/* On error, delete any return object or implicit return */
acpi_ut_remove_reference(previous_walk_state->
return_desc);
acpi_ds_clear_implicit_return
(previous_walk_state);
}
}
/*
* Just completed a 1st-level method, save the final internal return
* value (if any)
*/
else if (previous_walk_state->caller_return_desc) {
if (previous_walk_state->implicit_return_obj) {
*(previous_walk_state->caller_return_desc) =
previous_walk_state->implicit_return_obj;
} else {
/* NULL if no return value */
*(previous_walk_state->caller_return_desc) =
previous_walk_state->return_desc;
}
} else {
if (previous_walk_state->return_desc) {
/* Caller doesn't want it, must delete it */
acpi_ut_remove_reference(previous_walk_state->
return_desc);
}
if (previous_walk_state->implicit_return_obj) {
/* Caller doesn't want it, must delete it */
acpi_ut_remove_reference(previous_walk_state->
implicit_return_obj);
}
}
acpi_ds_delete_walk_state(previous_walk_state);
}
/* Normal exit */
acpi_ex_release_all_mutexes(thread);
acpi_ut_delete_generic_state(ACPI_CAST_PTR
(union acpi_generic_state, thread));
acpi_gbl_current_walk_list = prev_walk_list;
return_ACPI_STATUS(status);
}
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