drivers/acpi/acpica/pswalk.c

   1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
   2 /******************************************************************************
   3  *
   4  * Module Name: pswalk - Parser routines to walk parsed op tree(s)
   5  *
   6  * Copyright (C) 2000 - 2018, Intel Corp.
   7  *
   8  *****************************************************************************/
   9
  10 #include <acpi/acpi.h>
  11 #include "accommon.h"
  12 #include "acparser.h"
  13
  14 #define _COMPONENT          ACPI_PARSER
  15 ACPI_MODULE_NAME("pswalk")
  16
  17 /*******************************************************************************
  18  *
  19  * FUNCTION:    acpi_ps_delete_parse_tree
  20  *
  21  * PARAMETERS:  subtree_root        - Root of tree (or subtree) to delete
  22  *
  23  * RETURN:      None
  24  *
  25  * DESCRIPTION: Delete a portion of or an entire parse tree.
  26  *
  27  ******************************************************************************/
  28 #include "amlcode.h"
  29 void acpi_ps_delete_parse_tree(union acpi_parse_object *subtree_root)
  30 {
  31         union acpi_parse_object *op = subtree_root;
  32         union acpi_parse_object *next = NULL;
  33         union acpi_parse_object *parent = NULL;
  34         u32 level = 0;
  35
  36         ACPI_FUNCTION_TRACE_PTR(ps_delete_parse_tree, subtree_root);
  37
  38         ACPI_DEBUG_PRINT((ACPI_DB_PARSE_TREES, " root %p\n", subtree_root));
  39
  40         /* Visit all nodes in the subtree */
  41
  42         while (op) {
  43                 if (op != parent) {
  44
  45                         /* This is the descending case */
  46
  47                         if (ACPI_IS_DEBUG_ENABLED
  48                             (ACPI_LV_PARSE_TREES, _COMPONENT)) {
  49
  50                                 /* This debug option will print the entire parse tree */
  51
  52                                 acpi_os_printf("      %*.s%s %p", (level * 4),
  53                                                " ",
  54                                                acpi_ps_get_opcode_name(op->
  55                                                                        common.
  56                                                                        aml_opcode),
  57                                                op);
  58
  59                                 if (op->named.aml_opcode == AML_INT_NAMEPATH_OP) {
  60                                         acpi_os_printf("  %4.4s",
  61                                                        op->common.value.string);
  62                                 }
  63                                 if (op->named.aml_opcode == AML_STRING_OP) {
  64                                         acpi_os_printf("  %s",
  65                                                        op->common.value.string);
  66                                 }
  67                                 acpi_os_printf("\n");
  68                         }
  69
  70                         /* Look for an argument or child of the current op */
  71
  72                         next = acpi_ps_get_arg(op, 0);
  73                         if (next) {
  74
  75                                 /* Still going downward in tree (Op is not completed yet) */
  76
  77                                 op = next;
  78                                 level++;
  79                                 continue;
  80                         }
  81                 }
  82
  83                 /* No more children, this Op is complete. */
  84
  85                 next = op->common.next;
  86                 parent = op->common.parent;
  87
  88                 acpi_ps_free_op(op);
  89
  90                 /* If we are back to the starting point, the walk is complete. */
  91
  92                 if (op == subtree_root) {
  93                         return_VOID;
  94                 }
  95
  96                 if (next) {
  97                         op = next;
  98                 } else {
  99                         level--;
 100                         op = parent;
 101                 }
 102         }
 103
 104         return_VOID;
 105 }