| // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0 |
| /****************************************************************************** |
| * |
| * Module Name: dscontrol - Support for execution control opcodes - |
| * if/else/while/return |
| * |
| * Copyright (C) 2000 - 2022, Intel Corp. |
| * |
| *****************************************************************************/ |
| |
| #include <acpi/acpi.h> |
| #include "accommon.h" |
| #include "amlcode.h" |
| #include "acdispat.h" |
| #include "acinterp.h" |
| #include "acdebug.h" |
| |
| #define _COMPONENT ACPI_DISPATCHER |
| ACPI_MODULE_NAME("dscontrol") |
| |
| /******************************************************************************* |
| * |
| * 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(struct acpi_walk_state *walk_state, |
| union acpi_parse_object *op) |
| { |
| acpi_status status = AE_OK; |
| union acpi_generic_state *control_state; |
| |
| ACPI_FUNCTION_NAME(ds_exec_begin_control_op); |
| |
| ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, "Op=%p Opcode=%2.2X State=%p\n", |
| op, op->common.aml_opcode, walk_state)); |
| |
| switch (op->common.aml_opcode) { |
| case AML_WHILE_OP: |
| /* |
| * If this is an additional iteration of a while loop, continue. |
| * There is no need to allocate a new control state. |
| */ |
| if (walk_state->control_state) { |
| if (walk_state->control_state->control. |
| aml_predicate_start == |
| (walk_state->parser_state.aml - 1)) { |
| |
| /* Reset the state to start-of-loop */ |
| |
| walk_state->control_state->common.state = |
| ACPI_CONTROL_CONDITIONAL_EXECUTING; |
| break; |
| } |
| } |
| |
| ACPI_FALLTHROUGH; |
| |
| case AML_IF_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_ut_create_control_state(); |
| if (!control_state) { |
| status = AE_NO_MEMORY; |
| break; |
| } |
| /* |
| * Save a pointer to the predicate for multiple executions |
| * of a loop |
| */ |
| control_state->control.aml_predicate_start = |
| walk_state->parser_state.aml - 1; |
| control_state->control.package_end = |
| walk_state->parser_state.pkg_end; |
| control_state->control.opcode = op->common.aml_opcode; |
| control_state->control.loop_timeout = acpi_os_get_timer() + |
| ((u64)acpi_gbl_max_loop_iterations * ACPI_100NSEC_PER_SEC); |
| |
| /* Push the control state on this walk's control stack */ |
| |
| acpi_ut_push_generic_state(&walk_state->control_state, |
| control_state); |
| 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(struct acpi_walk_state *walk_state, |
| union acpi_parse_object *op) |
| { |
| acpi_status status = AE_OK; |
| union acpi_generic_state *control_state; |
| |
| ACPI_FUNCTION_NAME(ds_exec_end_control_op); |
| |
| switch (op->common.aml_opcode) { |
| case AML_IF_OP: |
| |
| ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, "[IF_OP] Op=%p\n", 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_ut_pop_generic_state(&walk_state->control_state); |
| acpi_ut_delete_generic_state(control_state); |
| break; |
| |
| case AML_ELSE_OP: |
| |
| break; |
| |
| case AML_WHILE_OP: |
| |
| ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, "[WHILE_OP] Op=%p\n", op)); |
| |
| control_state = walk_state->control_state; |
| if (control_state->common.value) { |
| |
| /* Predicate was true, the body of the loop was just executed */ |
| |
| /* |
| * This infinite loop detection mechanism allows the interpreter |
| * to escape possibly infinite loops. This can occur in poorly |
| * written AML when the hardware does not respond within a while |
| * loop and the loop does not implement a timeout. |
| */ |
| if (ACPI_TIME_AFTER(acpi_os_get_timer(), |
| control_state->control. |
| loop_timeout)) { |
| status = AE_AML_LOOP_TIMEOUT; |
| break; |
| } |
| |
| /* |
| * Go back and evaluate the predicate and maybe execute the loop |
| * another time |
| */ |
| status = AE_CTRL_PENDING; |
| walk_state->aml_last_while = |
| control_state->control.aml_predicate_start; |
| break; |
| } |
| |
| /* Predicate was false, terminate this while loop */ |
| |
| ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, |
| "[WHILE_OP] termination! Op=%p\n", op)); |
| |
| /* Pop this control state and free it */ |
| |
| control_state = |
| acpi_ut_pop_generic_state(&walk_state->control_state); |
| acpi_ut_delete_generic_state(control_state); |
| break; |
| |
| case AML_RETURN_OP: |
| |
| ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, |
| "[RETURN_OP] Op=%p Arg=%p\n", op, |
| op->common.value.arg)); |
| |
| /* |
| * 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->common.value.arg) { |
| |
| /* Since we have a real Return(), delete any implicit return */ |
| |
| acpi_ds_clear_implicit_return(walk_state); |
| |
| /* Return statement has an immediate operand */ |
| |
| status = |
| acpi_ds_create_operands(walk_state, |
| op->common.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_ex_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->result_count) { |
| |
| /* Since we have a real Return(), delete any implicit return */ |
| |
| acpi_ds_clear_implicit_return(walk_state); |
| |
| /* |
| * 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. |
| * |
| * Allow references created by the Index operator to return |
| * unchanged. |
| */ |
| if ((ACPI_GET_DESCRIPTOR_TYPE |
| (walk_state->results->results.obj_desc[0]) == |
| ACPI_DESC_TYPE_OPERAND) |
| && ((walk_state->results->results.obj_desc[0])-> |
| common.type == ACPI_TYPE_LOCAL_REFERENCE) |
| && ((walk_state->results->results.obj_desc[0])-> |
| reference.class != ACPI_REFCLASS_INDEX)) { |
| status = |
| acpi_ex_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_ut_remove_reference(walk_state-> |
| operands[0]); |
| } |
| |
| walk_state->operands[0] = NULL; |
| walk_state->num_operands = 0; |
| walk_state->return_desc = NULL; |
| } |
| |
| ACPI_DEBUG_PRINT((ACPI_DB_DISPATCH, |
| "Completed RETURN_OP State=%p, RetVal=%p\n", |
| walk_state, walk_state->return_desc)); |
| |
| /* End the control method execution right now */ |
| |
| status = AE_CTRL_TERMINATE; |
| break; |
| |
| case AML_NOOP_OP: |
| |
| /* Just do nothing! */ |
| |
| break; |
| |
| case AML_BREAKPOINT_OP: |
| |
| acpi_db_signal_break_point(walk_state); |
| |
| /* Call to the OSL in case OS wants a piece of the action */ |
| |
| status = acpi_os_signal(ACPI_SIGNAL_BREAKPOINT, |
| "Executed AML Breakpoint opcode"); |
| break; |
| |
| case AML_BREAK_OP: |
| case AML_CONTINUE_OP: /* ACPI 2.0 */ |
| |
| /* Pop and delete control states until we find a while */ |
| |
| while (walk_state->control_state && |
| (walk_state->control_state->control.opcode != |
| AML_WHILE_OP)) { |
| control_state = |
| acpi_ut_pop_generic_state(&walk_state-> |
| control_state); |
| acpi_ut_delete_generic_state(control_state); |
| } |
| |
| /* No while found? */ |
| |
| if (!walk_state->control_state) { |
| return (AE_AML_NO_WHILE); |
| } |
| |
| /* Was: walk_state->aml_last_while = walk_state->control_state->Control.aml_predicate_start; */ |
| |
| walk_state->aml_last_while = |
| walk_state->control_state->control.package_end; |
| |
| /* Return status depending on opcode */ |
| |
| if (op->common.aml_opcode == AML_BREAK_OP) { |
| status = AE_CTRL_BREAK; |
| } else { |
| status = AE_CTRL_CONTINUE; |
| } |
| break; |
| |
| default: |
| |
| ACPI_ERROR((AE_INFO, "Unknown control opcode=0x%X Op=%p", |
| op->common.aml_opcode, op)); |
| |
| status = AE_AML_BAD_OPCODE; |
| break; |
| } |
| |
| return (status); |
| } |