1/******************************************************************************
2 *
3 * Module Name: utcache - local cache allocation routines
4 *
5 *****************************************************************************/
6
7/*
8 * Copyright (C) 2000 - 2007, 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#include <acpi/acpi.h>
45
46#define _COMPONENT          ACPI_UTILITIES
47ACPI_MODULE_NAME("utcache")
48#ifdef ACPI_USE_LOCAL_CACHE
49/*******************************************************************************
50 *
51 * FUNCTION:    acpi_os_create_cache
52 *
53 * PARAMETERS:  cache_name      - Ascii name for the cache
54 *              object_size     - Size of each cached object
55 *              max_depth       - Maximum depth of the cache (in objects)
56 *              return_cache    - Where the new cache object is returned
57 *
58 * RETURN:      Status
59 *
60 * DESCRIPTION: Create a cache object
61 *
62 ******************************************************************************/
63acpi_status
64acpi_os_create_cache(char *cache_name,
65		     u16 object_size,
66		     u16 max_depth, struct acpi_memory_list ** return_cache)
67{
68	struct acpi_memory_list *cache;
69
70	ACPI_FUNCTION_ENTRY();
71
72	if (!cache_name || !return_cache || (object_size < 16)) {
73		return (AE_BAD_PARAMETER);
74	}
75
76	/* Create the cache object */
77
78	cache = acpi_os_allocate(sizeof(struct acpi_memory_list));
79	if (!cache) {
80		return (AE_NO_MEMORY);
81	}
82
83	/* Populate the cache object and return it */
84
85	ACPI_MEMSET(cache, 0, sizeof(struct acpi_memory_list));
86	cache->link_offset = 8;
87	cache->list_name = cache_name;
88	cache->object_size = object_size;
89	cache->max_depth = max_depth;
90
91	*return_cache = cache;
92	return (AE_OK);
93}
94
95/*******************************************************************************
96 *
97 * FUNCTION:    acpi_os_purge_cache
98 *
99 * PARAMETERS:  Cache           - Handle to cache object
100 *
101 * RETURN:      Status
102 *
103 * DESCRIPTION: Free all objects within the requested cache.
104 *
105 ******************************************************************************/
106
107acpi_status acpi_os_purge_cache(struct acpi_memory_list * cache)
108{
109	char *next;
110
111	ACPI_FUNCTION_ENTRY();
112
113	if (!cache) {
114		return (AE_BAD_PARAMETER);
115	}
116
117	/* Walk the list of objects in this cache */
118
119	while (cache->list_head) {
120
121		/* Delete and unlink one cached state object */
122
123		next = *(ACPI_CAST_INDIRECT_PTR(char,
124						&(((char *)cache->
125						   list_head)[cache->
126							      link_offset])));
127		ACPI_FREE(cache->list_head);
128
129		cache->list_head = next;
130		cache->current_depth--;
131	}
132
133	return (AE_OK);
134}
135
136/*******************************************************************************
137 *
138 * FUNCTION:    acpi_os_delete_cache
139 *
140 * PARAMETERS:  Cache           - Handle to cache object
141 *
142 * RETURN:      Status
143 *
144 * DESCRIPTION: Free all objects within the requested cache and delete the
145 *              cache object.
146 *
147 ******************************************************************************/
148
149acpi_status acpi_os_delete_cache(struct acpi_memory_list * cache)
150{
151	acpi_status status;
152
153	ACPI_FUNCTION_ENTRY();
154
155	/* Purge all objects in the cache */
156
157	status = acpi_os_purge_cache(cache);
158	if (ACPI_FAILURE(status)) {
159		return (status);
160	}
161
162	/* Now we can delete the cache object */
163
164	ACPI_FREE(cache);
165	return (AE_OK);
166}
167
168/*******************************************************************************
169 *
170 * FUNCTION:    acpi_os_release_object
171 *
172 * PARAMETERS:  Cache       - Handle to cache object
173 *              Object      - The object to be released
174 *
175 * RETURN:      None
176 *
177 * DESCRIPTION: Release an object to the specified cache.  If cache is full,
178 *              the object is deleted.
179 *
180 ******************************************************************************/
181
182acpi_status
183acpi_os_release_object(struct acpi_memory_list * cache, void *object)
184{
185	acpi_status status;
186
187	ACPI_FUNCTION_ENTRY();
188
189	if (!cache || !object) {
190		return (AE_BAD_PARAMETER);
191	}
192
193	/* If cache is full, just free this object */
194
195	if (cache->current_depth >= cache->max_depth) {
196		ACPI_FREE(object);
197		ACPI_MEM_TRACKING(cache->total_freed++);
198	}
199
200	/* Otherwise put this object back into the cache */
201
202	else {
203		status = acpi_ut_acquire_mutex(ACPI_MTX_CACHES);
204		if (ACPI_FAILURE(status)) {
205			return (status);
206		}
207
208		/* Mark the object as cached */
209
210		ACPI_MEMSET(object, 0xCA, cache->object_size);
211		ACPI_SET_DESCRIPTOR_TYPE(object, ACPI_DESC_TYPE_CACHED);
212
213		/* Put the object at the head of the cache list */
214
215		*(ACPI_CAST_INDIRECT_PTR(char,
216					 &(((char *)object)[cache->
217							    link_offset]))) =
218		    cache->list_head;
219		cache->list_head = object;
220		cache->current_depth++;
221
222		(void)acpi_ut_release_mutex(ACPI_MTX_CACHES);
223	}
224
225	return (AE_OK);
226}
227
228/*******************************************************************************
229 *
230 * FUNCTION:    acpi_os_acquire_object
231 *
232 * PARAMETERS:  Cache           - Handle to cache object
233 *
234 * RETURN:      the acquired object.  NULL on error
235 *
236 * DESCRIPTION: Get an object from the specified cache.  If cache is empty,
237 *              the object is allocated.
238 *
239 ******************************************************************************/
240
241void *acpi_os_acquire_object(struct acpi_memory_list *cache)
242{
243	acpi_status status;
244	void *object;
245
246	ACPI_FUNCTION_NAME(os_acquire_object);
247
248	if (!cache) {
249		return (NULL);
250	}
251
252	status = acpi_ut_acquire_mutex(ACPI_MTX_CACHES);
253	if (ACPI_FAILURE(status)) {
254		return (NULL);
255	}
256
257	ACPI_MEM_TRACKING(cache->requests++);
258
259	/* Check the cache first */
260
261	if (cache->list_head) {
262
263		/* There is an object available, use it */
264
265		object = cache->list_head;
266		cache->list_head = *(ACPI_CAST_INDIRECT_PTR(char,
267							    &(((char *)
268							       object)[cache->
269								       link_offset])));
270
271		cache->current_depth--;
272
273		ACPI_MEM_TRACKING(cache->hits++);
274		ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
275				  "Object %p from %s cache\n", object,
276				  cache->list_name));
277
278		status = acpi_ut_release_mutex(ACPI_MTX_CACHES);
279		if (ACPI_FAILURE(status)) {
280			return (NULL);
281		}
282
283		/* Clear (zero) the previously used Object */
284
285		ACPI_MEMSET(object, 0, cache->object_size);
286	} else {
287		/* The cache is empty, create a new object */
288
289		ACPI_MEM_TRACKING(cache->total_allocated++);
290
291#ifdef ACPI_DBG_TRACK_ALLOCATIONS
292		if ((cache->total_allocated - cache->total_freed) >
293		    cache->max_occupied) {
294			cache->max_occupied =
295			    cache->total_allocated - cache->total_freed;
296		}
297#endif
298
299		/* Avoid deadlock with ACPI_ALLOCATE_ZEROED */
300
301		status = acpi_ut_release_mutex(ACPI_MTX_CACHES);
302		if (ACPI_FAILURE(status)) {
303			return (NULL);
304		}
305
306		object = ACPI_ALLOCATE_ZEROED(cache->object_size);
307		if (!object) {
308			return (NULL);
309		}
310	}
311
312	return (object);
313}
314#endif				/* ACPI_USE_LOCAL_CACHE */
315