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-rw-r--r--drivers/acpi/acpica/dscontrol.c372
1 files changed, 372 insertions, 0 deletions
diff --git a/drivers/acpi/acpica/dscontrol.c b/drivers/acpi/acpica/dscontrol.c
new file mode 100644
index 000000000..849261914
--- /dev/null
+++ b/drivers/acpi/acpica/dscontrol.c
@@ -0,0 +1,372 @@
+// 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);
+}
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