// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/******************************************************************************
*
* Module Name: psloop - Main AML parse loop
*
* Copyright (C) 2000 - 2023, Intel Corp.
*
*****************************************************************************/
/*
* Parse the AML and build an operation tree as most interpreters, (such as
* Perl) do. Parsing is done by hand rather than with a YACC generated parser
* to tightly constrain stack and dynamic memory usage. 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 "acinterp.h"
#include "acparser.h"
#include "acdispat.h"
#include "amlcode.h"
#include "acconvert.h"
#include "acnamesp.h"
#define _COMPONENT ACPI_PARSER
ACPI_MODULE_NAME("psloop")
/* Local prototypes */
static acpi_status
acpi_ps_get_arguments(struct acpi_walk_state *walk_state,
u8 * aml_op_start, union acpi_parse_object *op);
/*******************************************************************************
*
* FUNCTION: acpi_ps_get_arguments
*
* PARAMETERS: walk_state - Current state
* aml_op_start - Op start in AML
* op - Current Op
*
* RETURN: Status
*
* DESCRIPTION: Get arguments for passed Op.
*
******************************************************************************/
static acpi_status
acpi_ps_get_arguments(struct acpi_walk_state *walk_state,
u8 * aml_op_start, union acpi_parse_object *op)
{
acpi_status status = AE_OK;
union acpi_parse_object *arg = NULL;
ACPI_FUNCTION_TRACE_PTR(ps_get_arguments, walk_state);
ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
"Get arguments for opcode [%s]\n",
op->common.aml_op_name));
switch (op->common.aml_opcode) {
case AML_BYTE_OP: /* AML_BYTEDATA_ARG */
case AML_WORD_OP: /* AML_WORDDATA_ARG */
case AML_DWORD_OP: /* AML_DWORDATA_ARG */
case AML_QWORD_OP: /* AML_QWORDATA_ARG */
case AML_STRING_OP: /* AML_ASCIICHARLIST_ARG */
/* Fill in constant or string argument directly */
acpi_ps_get_next_simple_arg(&(walk_state->parser_state),
GET_CURRENT_ARG_TYPE(walk_state->
arg_types),
op);
break;
case AML_INT_NAMEPATH_OP: /* AML_NAMESTRING_ARG */
status = acpi_ps_get_next_namepath(walk_state,
&(walk_state->parser_state),
op,
ACPI_POSSIBLE_METHOD_CALL);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
walk_state->arg_types = 0;
break;
default:
/*
* Op is not a constant or string, append each argument to the Op
*/
while (GET_CURRENT_ARG_TYPE(walk_state->arg_types) &&
!walk_state->arg_count) {
walk_state->aml = walk_state->parser_state.aml;
switch (op->common.aml_opcode) {
case AML_METHOD_OP:
case AML_BUFFER_OP:
case AML_PACKAGE_OP:
case AML_VARIABLE_PACKAGE_OP:
case AML_WHILE_OP:
break;
default:
ASL_CV_CAPTURE_COMMENTS(walk_state);
break;
}
status =
acpi_ps_get_next_arg(walk_state,
&(walk_state->parser_state),
GET_CURRENT_ARG_TYPE
(walk_state->arg_types), &arg);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
if (arg) {
acpi_ps_append_arg(op, arg);
}
INCREMENT_ARG_LIST(walk_state->arg_types);
}
ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
"Final argument count: %8.8X pass %u\n",
walk_state->arg_count,
walk_state->pass_number));
/* Special processing for certain opcodes */
switch (op->common.aml_opcode) {
case AML_METHOD_OP:
/*
* Skip parsing of control method because we don't have enough
* info in the first pass to parse it correctly.
*
* Save the length and address of the body
*/
op->named.data = walk_state->parser_state.aml;
op->named.length = (u32)
(walk_state->parser_state.pkg_end -
walk_state->parser_state.aml);
/* Skip body of method */
walk_state->parser_state.aml =
walk_state->parser_state.pkg_end;
walk_state->arg_count = 0;
break;
case AML_BUFFER_OP:
case AML_PACKAGE_OP:
case AML_VARIABLE_PACKAGE_OP:
if ((op->common.parent) &&
(op->common.parent->common.aml_opcode ==
AML_NAME_OP)
&& (walk_state->pass_number <=
ACPI_IMODE_LOAD_PASS2)) {
ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
"Setup Package/Buffer: Pass %u, AML Ptr: %p\n",
walk_state->pass_number,
aml_op_start));
/*
* Skip parsing of Buffers and Packages because we don't have
* enough info in the first pass to parse them correctly.
*/
op->named.data = aml_op_start;
op->named.length = (u32)
(walk_state->parser_state.pkg_end -
aml_op_start);
/* Skip body */
walk_state->parser_state.aml =
walk_state->parser_state.pkg_end;
walk_state->arg_count = 0;
}
break;
case AML_WHILE_OP:
if (walk_state->control_state) {
walk_state->control_state->control.package_end =
walk_state->parser_state.pkg_end;
}
break;
default:
/* No action for all other opcodes */
break;
}
break;
}
return_ACPI_STATUS(AE_OK);
}
/*******************************************************************************
*
* FUNCTION: acpi_ps_parse_loop
*
* PARAMETERS: walk_state - Current state
*
* RETURN: Status
*
* DESCRIPTION: Parse AML (pointed to by the current parser state) and return
* a tree of ops.
*
******************************************************************************/
acpi_status acpi_ps_parse_loop(struct acpi_walk_state *walk_state)
{
acpi_status status = AE_OK;
union acpi_parse_object *op = NULL; /* current op */
struct acpi_parse_state *parser_state;
u8 *aml_op_start = NULL;
u8 opcode_length;
ACPI_FUNCTION_TRACE_PTR(ps_parse_loop, walk_state);
if (walk_state->descending_callback == NULL) {
return_ACPI_STATUS(AE_BAD_PARAMETER);
}
parser_state = &walk_state->parser_state;
walk_state->arg_types = 0;
#ifndef ACPI_CONSTANT_EVAL_ONLY
if (walk_state->walk_type & ACPI_WALK_METHOD_RESTART) {
/* We are restarting a preempted control method */
if (acpi_ps_has_completed_scope(parser_state)) {
/*
* We must check if a predicate to an IF or WHILE statement
* was just completed
*/
if ((parser_state->scope->parse_scope.op) &&
((parser_state->scope->parse_scope.op->common.
aml_opcode == AML_IF_OP)
|| (parser_state->scope->parse_scope.op->common.
aml_opcode == AML_WHILE_OP))
&& (walk_state->control_state)
&& (walk_state->control_state->common.state ==
ACPI_CONTROL_PREDICATE_EXECUTING)) {
/*
* A predicate was just completed, get the value of the
* predicate and branch based on that value
*/
walk_state->op = NULL;
status =
acpi_ds_get_predicate_value(walk_state,
ACPI_TO_POINTER
(TRUE));
if (ACPI_FAILURE(status)
&& !ACPI_CNTL_EXCEPTION(status)) {
if (status == AE_AML_NO_RETURN_VALUE) {
ACPI_EXCEPTION((AE_INFO, status,
"Invoked method did not return a value"));
}
ACPI_EXCEPTION((AE_INFO, status,
"GetPredicate Failed"));
return_ACPI_STATUS(status);
}
status =
acpi_ps_next_parse_state(walk_state, op,
status);
}
acpi_ps_pop_scope(parser_state, &op,
&walk_state->arg_types,
&walk_state->arg_count);
ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
"Popped scope, Op=%p\n", op));
} else if (walk_state->prev_op) {
/* We were in the middle of an op */
op = walk_state->prev_op;
walk_state->arg_types = walk_state->prev_arg_types;
}
}
#endif
/* Iterative parsing loop, while there is more AML to process: */
while ((parser_state->aml < parser_state->aml_end) || (op)) {
ASL_CV_CAPTURE_COMMENTS(walk_state);
aml_op_start = parser_state->aml;
if (!op) {
status =
acpi_ps_create_op(walk_state, aml_op_start, &op);
if (ACPI_FAILURE(status)) {
/*
* ACPI_PARSE_MODULE_LEVEL means that we are loading a table by
* executing it as a control method. However, if we encounter
* an error while loading the table, we need to keep trying to
* load the table rather than aborting the table load. Set the
* status to AE_OK to proceed with the table load.
*/
if ((walk_state->
parse_flags & ACPI_PARSE_MODULE_LEVEL)
&& ((status == AE_ALREADY_EXISTS)
|| (status == AE_NOT_FOUND))) {
status = AE_OK;
}
if (status == AE_CTRL_PARSE_CONTINUE) {
continue;
}
if (status == AE_CTRL_PARSE_PENDING) {
status = AE_OK;
}
if (status == AE_CTRL_TERMINATE) {
return_ACPI_STATUS(status);
}
status =
acpi_ps_complete_op(walk_state, &op,
status);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
if (acpi_ns_opens_scope
(acpi_ps_get_opcode_info
(walk_state->opcode)->object_type)) {
/*
* If the scope/device op fails to parse, skip the body of
* the scope op because the parse failure indicates that
* the device may not exist.
*/
ACPI_INFO(("Skipping parse of AML opcode: %s (0x%4.4X)", acpi_ps_get_opcode_name(walk_state->opcode), walk_state->opcode));
/*
* Determine the opcode length before skipping the opcode.
* An opcode can be 1 byte or 2 bytes in length.
*/
opcode_length = 1;
if ((walk_state->opcode & 0xFF00) ==
AML_EXTENDED_OPCODE) {
opcode_length = 2;
}
walk_state->parser_state.aml =
walk_state->aml + opcode_length;
walk_state->parser_state.aml =
acpi_ps_get_next_package_end
(&walk_state->parser_state);
walk_state->aml =
walk_state->parser_state.aml;
}
continue;
}
acpi_ex_start_trace_opcode(op, walk_state);
}
/*
* Start arg_count at zero because we don't know if there are
* any args yet
*/
walk_state->arg_count = 0;
switch (op->common.aml_opcode) {
case AML_BYTE_OP:
case AML_WORD_OP:
case AML_DWORD_OP:
case AML_QWORD_OP:
break;
default:
ASL_CV_CAPTURE_COMMENTS(walk_state);
break;
}
/* Are there any arguments that must be processed? */
if (walk_state->arg_types) {
/* Get arguments */
status =
acpi_ps_get_arguments(walk_state, aml_op_start, op);
if (ACPI_FAILURE(status)) {
status =
acpi_ps_complete_op(walk_state, &op,
status);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
if ((walk_state->control_state) &&
((walk_state->control_state->control.
opcode == AML_IF_OP)
|| (walk_state->control_state->control.
opcode == AML_WHILE_OP))) {
/*
* If the if/while op fails to parse, we will skip parsing
* the body of the op.
*/
parser_state->aml =
walk_state->control_state->control.
aml_predicate_start + 1;
parser_state->aml =
acpi_ps_get_next_package_end
(parser_state);
walk_state->aml = parser_state->aml;
ACPI_ERROR((AE_INFO,
"Skipping While/If block"));
if (*walk_state->aml == AML_ELSE_OP) {
ACPI_ERROR((AE_INFO,
"Skipping Else block"));
walk_state->parser_state.aml =
walk_state->aml + 1;
walk_state->parser_state.aml =
acpi_ps_get_next_package_end
(parser_state);
walk_state->aml =
parser_state->aml;
}
ACPI_FREE(acpi_ut_pop_generic_state
(&walk_state->control_state));
}
op = NULL;
continue;
}
}
/* Check for arguments that need to be processed */
ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
"Parseloop: argument count: %8.8X\n",
walk_state->arg_count));
if (walk_state->arg_count) {
/*
* There are arguments (complex ones), push Op and
* prepare for argument
*/
status = acpi_ps_push_scope(parser_state, op,
walk_state->arg_types,
walk_state->arg_count);
if (ACPI_FAILURE(status)) {
status =
acpi_ps_complete_op(walk_state, &op,
status);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
continue;
}
op = NULL;
continue;
}
/*
* All arguments have been processed -- Op is complete,
* prepare for next
*/
walk_state->op_info =
acpi_ps_get_opcode_info(op->common.aml_opcode);
if (walk_state->op_info->flags & AML_NAMED) {
if (op->common.aml_opcode == AML_REGION_OP ||
op->common.aml_opcode == AML_DATA_REGION_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.
*/
op->named.length =
(u32) (parser_state->aml - op->named.data);
}
}
if (walk_state->op_info->flags & AML_CREATE) {
/*
* Backup to beginning of create_XXXfield declaration (1 for
* Opcode)
*
* body_length is unknown until we parse the body
*/
op->named.length =
(u32) (parser_state->aml - op->named.data);
}
if (op->common.aml_opcode == AML_BANK_FIELD_OP) {
/*
* Backup to beginning of bank_field declaration
*
* body_length is unknown until we parse the body
*/
op->named.length =
(u32) (parser_state->aml - op->named.data);
}
/* This op complete, notify the dispatcher */
if (walk_state->ascending_callback != NULL) {
walk_state->op = op;
walk_state->opcode = op->common.aml_opcode;
status = walk_state->ascending_callback(walk_state);
status =
acpi_ps_next_parse_state(walk_state, op, status);
if (status == AE_CTRL_PENDING) {
status = AE_OK;
} else
if ((walk_state->
parse_flags & ACPI_PARSE_MODULE_LEVEL)
&& (ACPI_AML_EXCEPTION(status)
|| status == AE_ALREADY_EXISTS
|| status == AE_NOT_FOUND)) {
/*
* ACPI_PARSE_MODULE_LEVEL flag means that we
* are currently loading a table by executing
* it as a control method. However, if we
* encounter an error while loading the table,
* we need to keep trying to load the table
* rather than aborting the table load (setting
* the status to AE_OK continues the table
* load). If we get a failure at this point, it
* means that the dispatcher got an error while
* trying to execute the Op.
*/
status = AE_OK;
}
}
status = acpi_ps_complete_op(walk_state, &op, status);
if (ACPI_FAILURE(status)) {
return_ACPI_STATUS(status);
}
} /* while parser_state->Aml */
status = acpi_ps_complete_final_op(walk_state, op, status);
return_ACPI_STATUS(status);
}
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