1 files changed, 115 insertions, 0 deletions

diff --git a/drivers/acpi/parser/pswalk.c b/drivers/acpi/parser/pswalk.c
new file mode 100644
index 000000000000..110d2ce917b6
--- /dev/null
+++ b/drivers/acpi/parser/pswalk.c
@@ -0,0 +1,115 @@
+/******************************************************************************
+ *
+ * Module Name: pswalk - Parser routines to walk parsed op tree(s)
+ *
+ *****************************************************************************/
+
+/*
+ * Copyright (C) 2000 - 2005, R. Byron Moore
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions, and the following disclaimer,
+ *    without modification.
+ * 2. Redistributions in binary form must reproduce at minimum a disclaimer
+ *    substantially similar to the "NO WARRANTY" disclaimer below
+ *    ("Disclaimer") and any redistribution must be conditioned upon
+ *    including a substantially similar Disclaimer requirement for further
+ *    binary redistribution.
+ * 3. Neither the names of the above-listed copyright holders nor the names
+ *    of any contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2 as published by the Free
+ * Software Foundation.
+ *
+ * NO WARRANTY
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGES.
+ */
+
+
+#include <acpi/acpi.h>
+#include <acpi/acparser.h>
+
+#define _COMPONENT          ACPI_PARSER
+         ACPI_MODULE_NAME    ("pswalk")
+
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ps_delete_parse_tree
+ *
+ * PARAMETERS:  subtree_root        - Root of tree (or subtree) to delete
+ *
+ * RETURN:      None
+ *
+ * DESCRIPTION: Delete a portion of or an entire parse tree.
+ *
+ ******************************************************************************/
+
+void
+acpi_ps_delete_parse_tree (
+        union acpi_parse_object         *subtree_root)
+{
+        union acpi_parse_object         *op = subtree_root;
+        union acpi_parse_object         *next = NULL;
+        union acpi_parse_object         *parent = NULL;
+
+
+        ACPI_FUNCTION_TRACE_PTR ("ps_delete_parse_tree", subtree_root);
+
+
+        /* Visit all nodes in the subtree */
+
+        while (op) {
+                /* Check if we are not ascending */
+
+                if (op != parent) {
+                        /* Look for an argument or child of the current op */
+
+                        next = acpi_ps_get_arg (op, 0);
+                        if (next) {
+                                /* Still going downward in tree (Op is not completed yet) */
+
+                                op = next;
+                                continue;
+                        }
+                }
+
+                /*
+                 * No more children, this Op is complete.
+                 */
+                next = op->common.next;
+                parent = op->common.parent;
+
+                acpi_ps_free_op (op);
+
+                /*
+                 * If we are back to the starting point, the walk is complete.
+                 */
+                if (op == subtree_root) {
+                        return_VOID;
+                }
+                if (next) {
+                        op = next;
+                }
+                else {
+                        op = parent;
+                }
+        }
+        return_VOID;
+}