ia64/linux-2.6.18-xen.hg

view drivers/acpi/namespace/nswalk.c @ 912:dd42cdb0ab89

[IA64] Build blktap2 driver by default in x86 builds.

add CONFIG_XEN_BLKDEV_TAP2=y to buildconfigs/linux-defconfig_xen_ia64.

Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
author Isaku Yamahata <yamahata@valinux.co.jp>
date Mon Jun 29 12:09:16 2009 +0900 (2009-06-29)
parents 831230e53067
children
line source
1 /******************************************************************************
2 *
3 * Module Name: nswalk - Functions for walking the ACPI namespace
4 *
5 *****************************************************************************/
7 /*
8 * Copyright (C) 2000 - 2006, R. Byron Moore
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 */
44 #include <acpi/acpi.h>
45 #include <acpi/acnamesp.h>
47 #define _COMPONENT ACPI_NAMESPACE
48 ACPI_MODULE_NAME("nswalk")
50 /*******************************************************************************
51 *
52 * FUNCTION: acpi_ns_get_next_node
53 *
54 * PARAMETERS: Type - Type of node to be searched for
55 * parent_node - Parent node whose children we are
56 * getting
57 * child_node - Previous child that was found.
58 * The NEXT child will be returned
59 *
60 * RETURN: struct acpi_namespace_node - Pointer to the NEXT child or NULL if
61 * none is found.
62 *
63 * DESCRIPTION: Return the next peer node within the namespace. If Handle
64 * is valid, Scope is ignored. Otherwise, the first node
65 * within Scope is returned.
66 *
67 ******************************************************************************/
68 struct acpi_namespace_node *acpi_ns_get_next_node(acpi_object_type type,
69 struct acpi_namespace_node
70 *parent_node,
71 struct acpi_namespace_node
72 *child_node)
73 {
74 struct acpi_namespace_node *next_node = NULL;
76 ACPI_FUNCTION_ENTRY();
78 if (!child_node) {
80 /* It's really the parent's _scope_ that we want */
82 if (parent_node->child) {
83 next_node = parent_node->child;
84 }
85 }
87 else {
88 /* Start search at the NEXT node */
90 next_node = acpi_ns_get_next_valid_node(child_node);
91 }
93 /* If any type is OK, we are done */
95 if (type == ACPI_TYPE_ANY) {
97 /* next_node is NULL if we are at the end-of-list */
99 return (next_node);
100 }
102 /* Must search for the node -- but within this scope only */
104 while (next_node) {
106 /* If type matches, we are done */
108 if (next_node->type == type) {
109 return (next_node);
110 }
112 /* Otherwise, move on to the next node */
114 next_node = acpi_ns_get_next_valid_node(next_node);
115 }
117 /* Not found */
119 return (NULL);
120 }
122 /*******************************************************************************
123 *
124 * FUNCTION: acpi_ns_walk_namespace
125 *
126 * PARAMETERS: Type - acpi_object_type to search for
127 * start_node - Handle in namespace where search begins
128 * max_depth - Depth to which search is to reach
129 * unlock_before_callback- Whether to unlock the NS before invoking
130 * the callback routine
131 * user_function - Called when an object of "Type" is found
132 * Context - Passed to user function
133 * return_value - from the user_function if terminated early.
134 * Otherwise, returns NULL.
135 * RETURNS: Status
136 *
137 * DESCRIPTION: Performs a modified depth-first walk of the namespace tree,
138 * starting (and ending) at the node specified by start_handle.
139 * The user_function is called whenever a node that matches
140 * the type parameter is found. If the user function returns
141 * a non-zero value, the search is terminated immediately and this
142 * value is returned to the caller.
143 *
144 * The point of this procedure is to provide a generic namespace
145 * walk routine that can be called from multiple places to
146 * provide multiple services; the User Function can be tailored
147 * to each task, whether it is a print function, a compare
148 * function, etc.
149 *
150 ******************************************************************************/
152 acpi_status
153 acpi_ns_walk_namespace(acpi_object_type type,
154 acpi_handle start_node,
155 u32 max_depth,
156 u8 unlock_before_callback,
157 acpi_walk_callback user_function,
158 void *context, void **return_value)
159 {
160 acpi_status status;
161 acpi_status mutex_status;
162 struct acpi_namespace_node *child_node;
163 struct acpi_namespace_node *parent_node;
164 acpi_object_type child_type;
165 u32 level;
167 ACPI_FUNCTION_TRACE(ns_walk_namespace);
169 /* Special case for the namespace Root Node */
171 if (start_node == ACPI_ROOT_OBJECT) {
172 start_node = acpi_gbl_root_node;
173 }
175 /* Null child means "get first node" */
177 parent_node = start_node;
178 child_node = NULL;
179 child_type = ACPI_TYPE_ANY;
180 level = 1;
182 /*
183 * Traverse the tree of nodes until we bubble back up to where we
184 * started. When Level is zero, the loop is done because we have
185 * bubbled up to (and passed) the original parent handle (start_entry)
186 */
187 while (level > 0) {
189 /* Get the next node in this scope. Null if not found */
191 status = AE_OK;
192 child_node =
193 acpi_ns_get_next_node(ACPI_TYPE_ANY, parent_node,
194 child_node);
195 if (child_node) {
196 /*
197 * Found node, Get the type if we are not
198 * searching for ANY
199 */
200 if (type != ACPI_TYPE_ANY) {
201 child_type = child_node->type;
202 }
204 if (child_type == type) {
205 /*
206 * Found a matching node, invoke the user
207 * callback function
208 */
209 if (unlock_before_callback) {
210 mutex_status =
211 acpi_ut_release_mutex
212 (ACPI_MTX_NAMESPACE);
213 if (ACPI_FAILURE(mutex_status)) {
214 return_ACPI_STATUS
215 (mutex_status);
216 }
217 }
219 status = user_function(child_node, level,
220 context, return_value);
222 if (unlock_before_callback) {
223 mutex_status =
224 acpi_ut_acquire_mutex
225 (ACPI_MTX_NAMESPACE);
226 if (ACPI_FAILURE(mutex_status)) {
227 return_ACPI_STATUS
228 (mutex_status);
229 }
230 }
232 switch (status) {
233 case AE_OK:
234 case AE_CTRL_DEPTH:
236 /* Just keep going */
237 break;
239 case AE_CTRL_TERMINATE:
241 /* Exit now, with OK status */
243 return_ACPI_STATUS(AE_OK);
245 default:
247 /* All others are valid exceptions */
249 return_ACPI_STATUS(status);
250 }
251 }
253 /*
254 * Depth first search:
255 * Attempt to go down another level in the namespace
256 * if we are allowed to. Don't go any further if we
257 * have reached the caller specified maximum depth
258 * or if the user function has specified that the
259 * maximum depth has been reached.
260 */
261 if ((level < max_depth) && (status != AE_CTRL_DEPTH)) {
262 if (acpi_ns_get_next_node
263 (ACPI_TYPE_ANY, child_node, NULL)) {
264 /*
265 * There is at least one child of this
266 * node, visit the onde
267 */
268 level++;
269 parent_node = child_node;
270 child_node = NULL;
271 }
272 }
273 } else {
274 /*
275 * No more children of this node (acpi_ns_get_next_node
276 * failed), go back upwards in the namespace tree to
277 * the node's parent.
278 */
279 level--;
280 child_node = parent_node;
281 parent_node = acpi_ns_get_parent_node(parent_node);
282 }
283 }
285 /* Complete walk, not terminated by user function */
287 return_ACPI_STATUS(AE_OK);
288 }