summaryrefslogtreecommitdiffstats
path: root/drivers/acpi/namespace/nssearch.c
blob: 51adec5a23d6c111c2bdb65e9b7106274581a400 (plain)
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
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
/*******************************************************************************
 *
 * Module Name: nssearch - Namespace search
 *
 ******************************************************************************/

/*
 * Copyright (C) 2000 - 2006, 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/acnamesp.h>

#define _COMPONENT          ACPI_NAMESPACE
ACPI_MODULE_NAME("nssearch")

/* Local prototypes */
static acpi_status
acpi_ns_search_parent_tree(u32 target_name,
			   struct acpi_namespace_node *node,
			   acpi_object_type type,
			   struct acpi_namespace_node **return_node);

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_search_node
 *
 * PARAMETERS:  target_name     - Ascii ACPI name to search for
 *              Node            - Starting node where search will begin
 *              Type            - Object type to match
 *              return_node     - Where the matched Named obj is returned
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Search a single level of the namespace.  Performs a
 *              simple search of the specified level, and does not add
 *              entries or search parents.
 *
 *
 *      Named object lists are built (and subsequently dumped) in the
 *      order in which the names are encountered during the namespace load;
 *
 *      All namespace searching is linear in this implementation, but
 *      could be easily modified to support any improved search
 *      algorithm.  However, the linear search was chosen for simplicity
 *      and because the trees are small and the other interpreter
 *      execution overhead is relatively high.
 *
 ******************************************************************************/

acpi_status
acpi_ns_search_node(u32 target_name,
		    struct acpi_namespace_node *node,
		    acpi_object_type type,
		    struct acpi_namespace_node **return_node)
{
	struct acpi_namespace_node *next_node;

	ACPI_FUNCTION_TRACE("ns_search_node");

#ifdef ACPI_DEBUG_OUTPUT
	if (ACPI_LV_NAMES & acpi_dbg_level) {
		char *scope_name;

		scope_name = acpi_ns_get_external_pathname(node);
		if (scope_name) {
			ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
					  "Searching %s (%p) For [%4.4s] (%s)\n",
					  scope_name, node, ACPI_CAST_PTR(char,
									  &target_name),
					  acpi_ut_get_type_name(type)));

			ACPI_FREE(scope_name);
		}
	}
#endif

	/*
	 * Search for name at this namespace level, which is to say that we
	 * must search for the name among the children of this object
	 */
	next_node = node->child;
	while (next_node) {

		/* Check for match against the name */

		if (next_node->name.integer == target_name) {

			/* Resolve a control method alias if any */

			if (acpi_ns_get_type(next_node) ==
			    ACPI_TYPE_LOCAL_METHOD_ALIAS) {
				next_node =
				    ACPI_CAST_PTR(struct acpi_namespace_node,
						  next_node->object);
			}

			/* Found matching entry */

			ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
					  "Name [%4.4s] (%s) %p found in scope [%4.4s] %p\n",
					  ACPI_CAST_PTR(char, &target_name),
					  acpi_ut_get_type_name(next_node->
								type),
					  next_node,
					  acpi_ut_get_node_name(node), node));

			*return_node = next_node;
			return_ACPI_STATUS(AE_OK);
		}

		/*
		 * The last entry in the list points back to the parent,
		 * so a flag is used to indicate the end-of-list
		 */
		if (next_node->flags & ANOBJ_END_OF_PEER_LIST) {

			/* Searched entire list, we are done */

			break;
		}

		/* Didn't match name, move on to the next peer object */

		next_node = next_node->peer;
	}

	/* Searched entire namespace level, not found */

	ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
			  "Name [%4.4s] (%s) not found in search in scope [%4.4s] %p first child %p\n",
			  ACPI_CAST_PTR(char, &target_name),
			  acpi_ut_get_type_name(type),
			  acpi_ut_get_node_name(node), node, node->child));

	return_ACPI_STATUS(AE_NOT_FOUND);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_search_parent_tree
 *
 * PARAMETERS:  target_name     - Ascii ACPI name to search for
 *              Node            - Starting node where search will begin
 *              Type            - Object type to match
 *              return_node     - Where the matched Node is returned
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Called when a name has not been found in the current namespace
 *              level.  Before adding it or giving up, ACPI scope rules require
 *              searching enclosing scopes in cases identified by acpi_ns_local().
 *
 *              "A name is located by finding the matching name in the current
 *              name space, and then in the parent name space. If the parent
 *              name space does not contain the name, the search continues
 *              recursively until either the name is found or the name space
 *              does not have a parent (the root of the name space).  This
 *              indicates that the name is not found" (From ACPI Specification,
 *              section 5.3)
 *
 ******************************************************************************/

static acpi_status
acpi_ns_search_parent_tree(u32 target_name,
			   struct acpi_namespace_node *node,
			   acpi_object_type type,
			   struct acpi_namespace_node **return_node)
{
	acpi_status status;
	struct acpi_namespace_node *parent_node;

	ACPI_FUNCTION_TRACE("ns_search_parent_tree");

	parent_node = acpi_ns_get_parent_node(node);

	/*
	 * If there is no parent (i.e., we are at the root) or type is "local",
	 * we won't be searching the parent tree.
	 */
	if (!parent_node) {
		ACPI_DEBUG_PRINT((ACPI_DB_NAMES, "[%4.4s] has no parent\n",
				  ACPI_CAST_PTR(char, &target_name)));
		return_ACPI_STATUS(AE_NOT_FOUND);
	}

	if (acpi_ns_local(type)) {
		ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
				  "[%4.4s] type [%s] must be local to this scope (no parent search)\n",
				  ACPI_CAST_PTR(char, &target_name),
				  acpi_ut_get_type_name(type)));
		return_ACPI_STATUS(AE_NOT_FOUND);
	}

	/* Search the parent tree */

	ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
			  "Searching parent [%4.4s] for [%4.4s]\n",
			  acpi_ut_get_node_name(parent_node),
			  ACPI_CAST_PTR(char, &target_name)));

	/*
	 * Search parents until target is found or we have backed up to the root
	 */
	while (parent_node) {
		/*
		 * Search parent scope.  Use TYPE_ANY because we don't care about the
		 * object type at this point, we only care about the existence of
		 * the actual name we are searching for.  Typechecking comes later.
		 */
		status = acpi_ns_search_node(target_name, parent_node,
					     ACPI_TYPE_ANY, return_node);
		if (ACPI_SUCCESS(status)) {
			return_ACPI_STATUS(status);
		}

		/* Not found here, go up another level (until we reach the root) */

		parent_node = acpi_ns_get_parent_node(parent_node);
	}

	/* Not found in parent tree */

	return_ACPI_STATUS(AE_NOT_FOUND);
}

/*******************************************************************************
 *
 * FUNCTION:    acpi_ns_search_and_enter
 *
 * PARAMETERS:  target_name         - Ascii ACPI name to search for (4 chars)
 *              walk_state          - Current state of the walk
 *              Node                - Starting node where search will begin
 *              interpreter_mode    - Add names only in ACPI_MODE_LOAD_PASS_x.
 *                                    Otherwise,search only.
 *              Type                - Object type to match
 *              Flags               - Flags describing the search restrictions
 *              return_node         - Where the Node is returned
 *
 * RETURN:      Status
 *
 * DESCRIPTION: Search for a name segment in a single namespace level,
 *              optionally adding it if it is not found.  If the passed
 *              Type is not Any and the type previously stored in the
 *              entry was Any (i.e. unknown), update the stored type.
 *
 *              In ACPI_IMODE_EXECUTE, search only.
 *              In other modes, search and add if not found.
 *
 ******************************************************************************/

acpi_status
acpi_ns_search_and_enter(u32 target_name,
			 struct acpi_walk_state *walk_state,
			 struct acpi_namespace_node *node,
			 acpi_interpreter_mode interpreter_mode,
			 acpi_object_type type,
			 u32 flags, struct acpi_namespace_node **return_node)
{
	acpi_status status;
	struct acpi_namespace_node *new_node;

	ACPI_FUNCTION_TRACE("ns_search_and_enter");

	/* Parameter validation */

	if (!node || !target_name || !return_node) {
		ACPI_ERROR((AE_INFO,
			    "Null param: Node %p Name %X return_node %p",
			    node, target_name, return_node));
		return_ACPI_STATUS(AE_BAD_PARAMETER);
	}

	/*
	 * Name must consist of valid ACPI characters. We will repair the name if
	 * necessary because we don't want to abort because of this, but we want
	 * all namespace names to be printable. A warning message is appropriate.
	 *
	 * This issue came up because there are in fact machines that exhibit
	 * this problem, and we want to be able to enable ACPI support for them,
	 * even though there are a few bad names.
	 */
	if (!acpi_ut_valid_acpi_name(target_name)) {
		target_name = acpi_ut_repair_name(target_name);

		/* Report warning only if in strict mode or debug mode */

		if (!acpi_gbl_enable_interpreter_slack) {
			ACPI_WARNING((AE_INFO,
				      "Found bad character(s) in name, repaired: [%4.4s]\n",
				      ACPI_CAST_PTR(char, &target_name)));
		} else {
			ACPI_DEBUG_PRINT((ACPI_DB_WARN,
					  "Found bad character(s) in name, repaired: [%4.4s]\n",
					  ACPI_CAST_PTR(char, &target_name)));
		}
	}

	/* Try to find the name in the namespace level specified by the caller */

	*return_node = ACPI_ENTRY_NOT_FOUND;
	status = acpi_ns_search_node(target_name, node, type, return_node);
	if (status != AE_NOT_FOUND) {
		/*
		 * If we found it AND the request specifies that a find is an error,
		 * return the error
		 */
		if ((status == AE_OK) && (flags & ACPI_NS_ERROR_IF_FOUND)) {
			status = AE_ALREADY_EXISTS;
		}

		/* Either found it or there was an error: finished either way */

		return_ACPI_STATUS(status);
	}

	/*
	 * The name was not found.  If we are NOT performing the first pass
	 * (name entry) of loading the namespace, search the parent tree (all the
	 * way to the root if necessary.) We don't want to perform the parent
	 * search when the namespace is actually being loaded.  We want to perform
	 * the search when namespace references are being resolved (load pass 2)
	 * and during the execution phase.
	 */
	if ((interpreter_mode != ACPI_IMODE_LOAD_PASS1) &&
	    (flags & ACPI_NS_SEARCH_PARENT)) {
		/*
		 * Not found at this level - search parent tree according to the
		 * ACPI specification
		 */
		status =
		    acpi_ns_search_parent_tree(target_name, node, type,
					       return_node);
		if (ACPI_SUCCESS(status)) {
			return_ACPI_STATUS(status);
		}
	}

	/* In execute mode, just search, never add names. Exit now */

	if (interpreter_mode == ACPI_IMODE_EXECUTE) {
		ACPI_DEBUG_PRINT((ACPI_DB_NAMES,
				  "%4.4s Not found in %p [Not adding]\n",
				  ACPI_CAST_PTR(char, &target_name), node));

		return_ACPI_STATUS(AE_NOT_FOUND);
	}

	/* Create the new named object */

	new_node = acpi_ns_create_node(target_name);
	if (!new_node) {
		return_ACPI_STATUS(AE_NO_MEMORY);
	}

	/* Install the new object into the parent's list of children */

	acpi_ns_install_node(walk_state, node, new_node, type);
	*return_node = new_node;
	return_ACPI_STATUS(AE_OK);
}
OpenPOWER on IntegriCloud