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/drivers/acpi/namespace/nssearch.c

https://bitbucket.org/evzijst/gittest
C | 381 lines | 140 code | 64 blank | 177 comment | 26 complexity | 770252cb6d28e7f82efb042bd6d3a329 MD5 | raw file
  1/*******************************************************************************
  2 *
  3 * Module Name: nssearch - Namespace search
  4 *
  5 ******************************************************************************/
  6
  7/*
  8 * Copyright (C) 2000 - 2005, 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 */
 43
 44
 45#include <acpi/acpi.h>
 46#include <acpi/acnamesp.h>
 47
 48
 49#define _COMPONENT          ACPI_NAMESPACE
 50	 ACPI_MODULE_NAME    ("nssearch")
 51
 52
 53/*******************************************************************************
 54 *
 55 * FUNCTION:    acpi_ns_search_node
 56 *
 57 * PARAMETERS:  *target_name        - Ascii ACPI name to search for
 58 *              *Node               - Starting node where search will begin
 59 *              Type                - Object type to match
 60 *              **return_node       - Where the matched Named obj is returned
 61 *
 62 * RETURN:      Status
 63 *
 64 * DESCRIPTION: Search a single level of the namespace.  Performs a
 65 *              simple search of the specified level, and does not add
 66 *              entries or search parents.
 67 *
 68 *
 69 *      Named object lists are built (and subsequently dumped) in the
 70 *      order in which the names are encountered during the namespace load;
 71 *
 72 *      All namespace searching is linear in this implementation, but
 73 *      could be easily modified to support any improved search
 74 *      algorithm.  However, the linear search was chosen for simplicity
 75 *      and because the trees are small and the other interpreter
 76 *      execution overhead is relatively high.
 77 *
 78 ******************************************************************************/
 79
 80acpi_status
 81acpi_ns_search_node (
 82	u32                             target_name,
 83	struct acpi_namespace_node      *node,
 84	acpi_object_type                type,
 85	struct acpi_namespace_node      **return_node)
 86{
 87	struct acpi_namespace_node      *next_node;
 88
 89
 90	ACPI_FUNCTION_TRACE ("ns_search_node");
 91
 92
 93#ifdef ACPI_DEBUG_OUTPUT
 94	if (ACPI_LV_NAMES & acpi_dbg_level) {
 95		char                        *scope_name;
 96
 97		scope_name = acpi_ns_get_external_pathname (node);
 98		if (scope_name) {
 99			ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
100				"Searching %s (%p) For [%4.4s] (%s)\n",
101				scope_name, node, (char *) &target_name,
102				acpi_ut_get_type_name (type)));
103
104			ACPI_MEM_FREE (scope_name);
105		}
106	}
107#endif
108
109	/*
110	 * Search for name at this namespace level, which is to say that we
111	 * must search for the name among the children of this object
112	 */
113	next_node = node->child;
114	while (next_node) {
115		/* Check for match against the name */
116
117		if (next_node->name.integer == target_name) {
118			/* Resolve a control method alias if any */
119
120			if (acpi_ns_get_type (next_node) == ACPI_TYPE_LOCAL_METHOD_ALIAS) {
121				next_node = ACPI_CAST_PTR (struct acpi_namespace_node, next_node->object);
122			}
123
124			/*
125			 * Found matching entry.
126			 */
127			ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
128				"Name [%4.4s] (%s) %p found in scope [%4.4s] %p\n",
129				(char *) &target_name, acpi_ut_get_type_name (next_node->type),
130				next_node, acpi_ut_get_node_name (node), node));
131
132			*return_node = next_node;
133			return_ACPI_STATUS (AE_OK);
134		}
135
136		/*
137		 * The last entry in the list points back to the parent,
138		 * so a flag is used to indicate the end-of-list
139		 */
140		if (next_node->flags & ANOBJ_END_OF_PEER_LIST) {
141			/* Searched entire list, we are done */
142
143			break;
144		}
145
146		/* Didn't match name, move on to the next peer object */
147
148		next_node = next_node->peer;
149	}
150
151	/* Searched entire namespace level, not found */
152
153	ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
154		"Name [%4.4s] (%s) not found in search in scope [%4.4s] %p first child %p\n",
155		(char *) &target_name, acpi_ut_get_type_name (type),
156		acpi_ut_get_node_name (node), node, node->child));
157
158	return_ACPI_STATUS (AE_NOT_FOUND);
159}
160
161
162/*******************************************************************************
163 *
164 * FUNCTION:    acpi_ns_search_parent_tree
165 *
166 * PARAMETERS:  *target_name        - Ascii ACPI name to search for
167 *              *Node               - Starting node where search will begin
168 *              Type                - Object type to match
169 *              **return_node       - Where the matched Node is returned
170 *
171 * RETURN:      Status
172 *
173 * DESCRIPTION: Called when a name has not been found in the current namespace
174 *              level.  Before adding it or giving up, ACPI scope rules require
175 *              searching enclosing scopes in cases identified by acpi_ns_local().
176 *
177 *              "A name is located by finding the matching name in the current
178 *              name space, and then in the parent name space. If the parent
179 *              name space does not contain the name, the search continues
180 *              recursively until either the name is found or the name space
181 *              does not have a parent (the root of the name space).  This
182 *              indicates that the name is not found" (From ACPI Specification,
183 *              section 5.3)
184 *
185 ******************************************************************************/
186
187static acpi_status
188acpi_ns_search_parent_tree (
189	u32                             target_name,
190	struct acpi_namespace_node      *node,
191	acpi_object_type                type,
192	struct acpi_namespace_node      **return_node)
193{
194	acpi_status                     status;
195	struct acpi_namespace_node      *parent_node;
196
197
198	ACPI_FUNCTION_TRACE ("ns_search_parent_tree");
199
200
201	parent_node = acpi_ns_get_parent_node (node);
202
203	/*
204	 * If there is no parent (i.e., we are at the root) or type is "local",
205	 * we won't be searching the parent tree.
206	 */
207	if (!parent_node) {
208		ACPI_DEBUG_PRINT ((ACPI_DB_NAMES, "[%4.4s] has no parent\n",
209			(char *) &target_name));
210		return_ACPI_STATUS (AE_NOT_FOUND);
211	}
212
213	if (acpi_ns_local (type)) {
214		ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
215			"[%4.4s] type [%s] must be local to this scope (no parent search)\n",
216			(char *) &target_name, acpi_ut_get_type_name (type)));
217		return_ACPI_STATUS (AE_NOT_FOUND);
218	}
219
220	/* Search the parent tree */
221
222	ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
223		"Searching parent [%4.4s] for [%4.4s]\n",
224		acpi_ut_get_node_name (parent_node), (char *) &target_name));
225
226	/*
227	 * Search parents until target is found or we have backed up to the root
228	 */
229	while (parent_node) {
230		/*
231		 * Search parent scope.  Use TYPE_ANY because we don't care about the
232		 * object type at this point, we only care about the existence of
233		 * the actual name we are searching for.  Typechecking comes later.
234		 */
235		status = acpi_ns_search_node (target_name, parent_node,
236				  ACPI_TYPE_ANY, return_node);
237		if (ACPI_SUCCESS (status)) {
238			return_ACPI_STATUS (status);
239		}
240
241		/*
242		 * Not found here, go up another level
243		 * (until we reach the root)
244		 */
245		parent_node = acpi_ns_get_parent_node (parent_node);
246	}
247
248	/* Not found in parent tree */
249
250	return_ACPI_STATUS (AE_NOT_FOUND);
251}
252
253
254/*******************************************************************************
255 *
256 * FUNCTION:    acpi_ns_search_and_enter
257 *
258 * PARAMETERS:  target_name         - Ascii ACPI name to search for (4 chars)
259 *              walk_state          - Current state of the walk
260 *              *Node               - Starting node where search will begin
261 *              interpreter_mode    - Add names only in ACPI_MODE_LOAD_PASS_x.
262 *                                    Otherwise,search only.
263 *              Type                - Object type to match
264 *              Flags               - Flags describing the search restrictions
265 *              **return_node       - Where the Node is returned
266 *
267 * RETURN:      Status
268 *
269 * DESCRIPTION: Search for a name segment in a single namespace level,
270 *              optionally adding it if it is not found.  If the passed
271 *              Type is not Any and the type previously stored in the
272 *              entry was Any (i.e. unknown), update the stored type.
273 *
274 *              In ACPI_IMODE_EXECUTE, search only.
275 *              In other modes, search and add if not found.
276 *
277 ******************************************************************************/
278
279acpi_status
280acpi_ns_search_and_enter (
281	u32                             target_name,
282	struct acpi_walk_state          *walk_state,
283	struct acpi_namespace_node      *node,
284	acpi_interpreter_mode           interpreter_mode,
285	acpi_object_type                type,
286	u32                             flags,
287	struct acpi_namespace_node      **return_node)
288{
289	acpi_status                     status;
290	struct acpi_namespace_node      *new_node;
291
292
293	ACPI_FUNCTION_TRACE ("ns_search_and_enter");
294
295
296	/* Parameter validation */
297
298	if (!node || !target_name || !return_node) {
299		ACPI_DEBUG_PRINT ((ACPI_DB_ERROR,
300			"Null param: Node %p Name %X return_node %p\n",
301			node, target_name, return_node));
302
303		ACPI_REPORT_ERROR (("ns_search_and_enter: Null parameter\n"));
304		return_ACPI_STATUS (AE_BAD_PARAMETER);
305	}
306
307	/* Name must consist of printable characters */
308
309	if (!acpi_ut_valid_acpi_name (target_name)) {
310		ACPI_REPORT_ERROR (("ns_search_and_enter: Bad character in ACPI Name: %X\n",
311			target_name));
312		return_ACPI_STATUS (AE_BAD_CHARACTER);
313	}
314
315	/* Try to find the name in the namespace level specified by the caller */
316
317	*return_node = ACPI_ENTRY_NOT_FOUND;
318	status = acpi_ns_search_node (target_name, node, type, return_node);
319	if (status != AE_NOT_FOUND) {
320		/*
321		 * If we found it AND the request specifies that a find is an error,
322		 * return the error
323		 */
324		if ((status == AE_OK) &&
325			(flags & ACPI_NS_ERROR_IF_FOUND)) {
326			status = AE_ALREADY_EXISTS;
327		}
328
329		/*
330		 * Either found it or there was an error
331		 * -- finished either way
332		 */
333		return_ACPI_STATUS (status);
334	}
335
336	/*
337	 * The name was not found.  If we are NOT performing the first pass
338	 * (name entry) of loading the namespace, search the parent tree (all the
339	 * way to the root if necessary.) We don't want to perform the parent
340	 * search when the namespace is actually being loaded.  We want to perform
341	 * the search when namespace references are being resolved (load pass 2)
342	 * and during the execution phase.
343	 */
344	if ((interpreter_mode != ACPI_IMODE_LOAD_PASS1) &&
345		(flags & ACPI_NS_SEARCH_PARENT)) {
346		/*
347		 * Not found at this level - search parent tree according to the
348		 * ACPI specification
349		 */
350		status = acpi_ns_search_parent_tree (target_name, node, type, return_node);
351		if (ACPI_SUCCESS (status)) {
352			return_ACPI_STATUS (status);
353		}
354	}
355
356	/*
357	 * In execute mode, just search, never add names.  Exit now.
358	 */
359	if (interpreter_mode == ACPI_IMODE_EXECUTE) {
360		ACPI_DEBUG_PRINT ((ACPI_DB_NAMES,
361			"%4.4s Not found in %p [Not adding]\n",
362			(char *) &target_name, node));
363
364		return_ACPI_STATUS (AE_NOT_FOUND);
365	}
366
367	/* Create the new named object */
368
369	new_node = acpi_ns_create_node (target_name);
370	if (!new_node) {
371		return_ACPI_STATUS (AE_NO_MEMORY);
372	}
373
374	/* Install the new object into the parent's list of children */
375
376	acpi_ns_install_node (walk_state, node, new_node, type);
377	*return_node = new_node;
378
379	return_ACPI_STATUS (AE_OK);
380}
381