1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
|
// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
/******************************************************************************
*
* Module Name: nswalk - Functions for walking the ACPI namespace
*
* Copyright (C) 2000 - 2019, Intel Corp.
*
*****************************************************************************/
#include <acpi/acpi.h>
#include "accommon.h"
#include "acnamesp.h"
#define _COMPONENT ACPI_NAMESPACE
ACPI_MODULE_NAME("nswalk")
/*******************************************************************************
*
* FUNCTION: acpi_ns_get_next_node
*
* PARAMETERS: parent_node - Parent node whose children we are
* getting
* child_node - Previous child that was found.
* The NEXT child will be returned
*
* RETURN: struct acpi_namespace_node - Pointer to the NEXT child or NULL if
* none is found.
*
* DESCRIPTION: Return the next peer node within the namespace. If Handle
* is valid, Scope is ignored. Otherwise, the first node
* within Scope is returned.
*
******************************************************************************/
struct acpi_namespace_node *acpi_ns_get_next_node(struct acpi_namespace_node
*parent_node,
struct acpi_namespace_node
*child_node)
{
ACPI_FUNCTION_ENTRY();
if (!child_node) {
/* It's really the parent's _scope_ that we want */
return (parent_node->child);
}
/* Otherwise just return the next peer */
return (child_node->peer);
}
/*******************************************************************************
*
* FUNCTION: acpi_ns_get_next_node_typed
*
* PARAMETERS: type - Type of node to be searched for
* parent_node - Parent node whose children we are
* getting
* child_node - Previous child that was found.
* The NEXT child will be returned
*
* RETURN: struct acpi_namespace_node - Pointer to the NEXT child or NULL if
* none is found.
*
* DESCRIPTION: Return the next peer node within the namespace. If Handle
* is valid, Scope is ignored. Otherwise, the first node
* within Scope is returned.
*
******************************************************************************/
struct acpi_namespace_node *acpi_ns_get_next_node_typed(acpi_object_type type,
struct
acpi_namespace_node
*parent_node,
struct
acpi_namespace_node
*child_node)
{
struct acpi_namespace_node *next_node = NULL;
ACPI_FUNCTION_ENTRY();
next_node = acpi_ns_get_next_node(parent_node, child_node);
/* If any type is OK, we are done */
if (type == ACPI_TYPE_ANY) {
/* next_node is NULL if we are at the end-of-list */
return (next_node);
}
/* Must search for the node -- but within this scope only */
while (next_node) {
/* If type matches, we are done */
if (next_node->type == type) {
return (next_node);
}
/* Otherwise, move on to the next peer node */
next_node = next_node->peer;
}
/* Not found */
return (NULL);
}
/*******************************************************************************
*
* FUNCTION: acpi_ns_walk_namespace
*
* PARAMETERS: type - acpi_object_type to search for
* start_node - Handle in namespace where search begins
* max_depth - Depth to which search is to reach
* flags - Whether to unlock the NS before invoking
* the callback routine
* descending_callback - Called during tree descent
* when an object of "Type" is found
* ascending_callback - Called during tree ascent
* when an object of "Type" is found
* context - Passed to user function(s) above
* return_value - from the user_function if terminated
* early. Otherwise, returns NULL.
* RETURNS: Status
*
* DESCRIPTION: Performs a modified depth-first walk of the namespace tree,
* starting (and ending) at the node specified by start_handle.
* The callback function is called whenever a node that matches
* the type parameter is found. If the callback function returns
* a non-zero value, the search is terminated immediately and
* this value is returned to the caller.
*
* The point of this procedure is to provide a generic namespace
* walk routine that can be called from multiple places to
* provide multiple services; the callback function(s) can be
* tailored to each task, whether it is a print function,
* a compare function, etc.
*
******************************************************************************/
acpi_status
acpi_ns_walk_namespace(acpi_object_type type,
acpi_handle start_node,
u32 max_depth,
u32 flags,
acpi_walk_callback descending_callback,
acpi_walk_callback ascending_callback,
void *context, void **return_value)
{
acpi_status status;
acpi_status mutex_status;
struct acpi_namespace_node *child_node;
struct acpi_namespace_node *parent_node;
acpi_object_type child_type;
u32 level;
u8 node_previously_visited = FALSE;
ACPI_FUNCTION_TRACE(ns_walk_namespace);
/* Special case for the namespace Root Node */
if (start_node == ACPI_ROOT_OBJECT) {
start_node = acpi_gbl_root_node;
}
/* Null child means "get first node" */
parent_node = start_node;
child_node = acpi_ns_get_next_node(parent_node, NULL);
child_type = ACPI_TYPE_ANY;
level = 1;
/*
* Traverse the tree of nodes until we bubble back up to where we
* started. When Level is zero, the loop is done because we have
* bubbled up to (and passed) the original parent handle (start_entry)
*/
while (level > 0 && child_node) {
status = AE_OK;
/* Found next child, get the type if we are not searching for ANY */
if (type != ACPI_TYPE_ANY) {
child_type = child_node->type;
}
/*
* Ignore all temporary namespace nodes (created during control
* method execution) unless told otherwise. These temporary nodes
* can cause a race condition because they can be deleted during
* the execution of the user function (if the namespace is
* unlocked before invocation of the user function.) Only the
* debugger namespace dump will examine the temporary nodes.
*/
if ((child_node->flags & ANOBJ_TEMPORARY) &&
!(flags & ACPI_NS_WALK_TEMP_NODES)) {
status = AE_CTRL_DEPTH;
}
/* Type must match requested type */
else if (child_type == type) {
/*
* Found a matching node, invoke the user callback function.
* Unlock the namespace if flag is set.
*/
if (flags & ACPI_NS_WALK_UNLOCK) {
mutex_status =
acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
if (ACPI_FAILURE(mutex_status)) {
return_ACPI_STATUS(mutex_status);
}
}
/*
* Invoke the user function, either descending, ascending,
* or both.
*/
if (!node_previously_visited) {
if (descending_callback) {
status =
descending_callback(child_node,
level, context,
return_value);
}
} else {
if (ascending_callback) {
status =
ascending_callback(child_node,
level, context,
return_value);
}
}
if (flags & ACPI_NS_WALK_UNLOCK) {
mutex_status =
acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
if (ACPI_FAILURE(mutex_status)) {
return_ACPI_STATUS(mutex_status);
}
}
switch (status) {
case AE_OK:
case AE_CTRL_DEPTH:
/* Just keep going */
break;
case AE_CTRL_TERMINATE:
/* Exit now, with OK status */
return_ACPI_STATUS(AE_OK);
default:
/* All others are valid exceptions */
return_ACPI_STATUS(status);
}
}
/*
* Depth first search: Attempt to go down another level in the
* namespace if we are allowed to. Don't go any further if we have
* reached the caller specified maximum depth or if the user
* function has specified that the maximum depth has been reached.
*/
if (!node_previously_visited &&
(level < max_depth) && (status != AE_CTRL_DEPTH)) {
if (child_node->child) {
/* There is at least one child of this node, visit it */
level++;
parent_node = child_node;
child_node =
acpi_ns_get_next_node(parent_node, NULL);
continue;
}
}
/* No more children, re-visit this node */
if (!node_previously_visited) {
node_previously_visited = TRUE;
continue;
}
/* No more children, visit peers */
child_node = acpi_ns_get_next_node(parent_node, child_node);
if (child_node) {
node_previously_visited = FALSE;
}
/* No peers, re-visit parent */
else {
/*
* No more children of this node (acpi_ns_get_next_node failed), go
* back upwards in the namespace tree to the node's parent.
*/
level--;
child_node = parent_node;
parent_node = parent_node->parent;
node_previously_visited = TRUE;
}
}
/* Complete walk, not terminated by user function */
return_ACPI_STATUS(AE_OK);
}
|
