Linux Kernel  3.7.1
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
pswalk.c
Go to the documentation of this file.
1 /******************************************************************************
2  *
3  * Module Name: pswalk - Parser routines to walk parsed op tree(s)
4  *
5  *****************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2012, Intel Corp.
9  * All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  * notice, this list of conditions, and the following disclaimer,
16  * without modification.
17  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
18  * substantially similar to the "NO WARRANTY" disclaimer below
19  * ("Disclaimer") and any redistribution must be conditioned upon
20  * including a substantially similar Disclaimer requirement for further
21  * binary redistribution.
22  * 3. Neither the names of the above-listed copyright holders nor the names
23  * of any contributors may be used to endorse or promote products derived
24  * from this software without specific prior written permission.
25  *
26  * Alternatively, this software may be distributed under the terms of the
27  * GNU General Public License ("GPL") version 2 as published by the Free
28  * Software Foundation.
29  *
30  * NO WARRANTY
31  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
32  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
33  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
34  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
35  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
40  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
41  * POSSIBILITY OF SUCH DAMAGES.
42  */
43 
44 #include <acpi/acpi.h>
45 #include "accommon.h"
46 #include "acparser.h"
47 
48 #define _COMPONENT ACPI_PARSER
49 ACPI_MODULE_NAME("pswalk")
50 
51 /*******************************************************************************
52  *
53  * FUNCTION: acpi_ps_delete_parse_tree
54  *
55  * PARAMETERS: subtree_root - Root of tree (or subtree) to delete
56  *
57  * RETURN: None
58  *
59  * DESCRIPTION: Delete a portion of or an entire parse tree.
60  *
61  ******************************************************************************/
63 {
64  union acpi_parse_object *op = subtree_root;
65  union acpi_parse_object *next = NULL;
66  union acpi_parse_object *parent = NULL;
67 
68  ACPI_FUNCTION_TRACE_PTR(ps_delete_parse_tree, subtree_root);
69 
70  /* Visit all nodes in the subtree */
71 
72  while (op) {
73 
74  /* Check if we are not ascending */
75 
76  if (op != parent) {
77 
78  /* Look for an argument or child of the current op */
79 
80  next = acpi_ps_get_arg(op, 0);
81  if (next) {
82 
83  /* Still going downward in tree (Op is not completed yet) */
84 
85  op = next;
86  continue;
87  }
88  }
89 
90  /* No more children, this Op is complete. */
91 
92  next = op->common.next;
93  parent = op->common.parent;
94 
95  acpi_ps_free_op(op);
96 
97  /* If we are back to the starting point, the walk is complete. */
98 
99  if (op == subtree_root) {
100  return_VOID;
101  }
102  if (next) {
103  op = next;
104  } else {
105  op = parent;
106  }
107  }
108 
109  return_VOID;
110 }