1 /******************************************************************************
3 * Module Name: utcache - local cache allocation routines
5 *****************************************************************************/
8 * Copyright (C) 2000 - 2005, R. Byron Moore
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
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.
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.
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.
45 #include <acpi/acpi.h>
47 #define _COMPONENT ACPI_UTILITIES
48 ACPI_MODULE_NAME ("utcache")
51 #ifdef ACPI_USE_LOCAL_CACHE
52 /*******************************************************************************
54 * FUNCTION: acpi_os_create_cache
56 * PARAMETERS: cache_name - Ascii name for the cache
57 * object_size - Size of each cached object
58 * max_depth - Maximum depth of the cache (in objects)
59 * return_cache - Where the new cache object is returned
63 * DESCRIPTION: Create a cache object
65 ******************************************************************************/
68 acpi_os_create_cache (
72 struct acpi_memory_list **return_cache)
74 struct acpi_memory_list *cache;
77 ACPI_FUNCTION_ENTRY ();
80 if (!cache_name || !return_cache || (object_size < 16)) {
81 return (AE_BAD_PARAMETER);
84 /* Create the cache object */
86 cache = acpi_os_allocate (sizeof (struct acpi_memory_list));
88 return (AE_NO_MEMORY);
91 /* Populate the cache object and return it */
93 ACPI_MEMSET (cache, 0, sizeof (struct acpi_memory_list));
94 cache->link_offset = 8;
95 cache->list_name = cache_name;
96 cache->object_size = object_size;
97 cache->max_depth = max_depth;
99 *return_cache = cache;
104 /*******************************************************************************
106 * FUNCTION: acpi_os_purge_cache
108 * PARAMETERS: Cache - Handle to cache object
112 * DESCRIPTION: Free all objects within the requested cache.
114 ******************************************************************************/
117 acpi_os_purge_cache (
118 struct acpi_memory_list *cache)
123 ACPI_FUNCTION_ENTRY ();
127 return (AE_BAD_PARAMETER);
130 /* Walk the list of objects in this cache */
132 while (cache->list_head) {
133 /* Delete and unlink one cached state object */
135 next = *(ACPI_CAST_INDIRECT_PTR (char,
136 &(((char *) cache->list_head)[cache->link_offset])));
137 ACPI_MEM_FREE (cache->list_head);
139 cache->list_head = next;
140 cache->current_depth--;
147 /*******************************************************************************
149 * FUNCTION: acpi_os_delete_cache
151 * PARAMETERS: Cache - Handle to cache object
155 * DESCRIPTION: Free all objects within the requested cache and delete the
158 ******************************************************************************/
161 acpi_os_delete_cache (
162 struct acpi_memory_list *cache)
167 ACPI_FUNCTION_ENTRY ();
170 /* Purge all objects in the cache */
172 status = acpi_os_purge_cache (cache);
173 if (ACPI_FAILURE (status)) {
177 /* Now we can delete the cache object */
179 acpi_os_free (cache);
184 /*******************************************************************************
186 * FUNCTION: acpi_os_release_object
188 * PARAMETERS: Cache - Handle to cache object
189 * Object - The object to be released
193 * DESCRIPTION: Release an object to the specified cache. If cache is full,
194 * the object is deleted.
196 ******************************************************************************/
199 acpi_os_release_object (
200 struct acpi_memory_list *cache,
206 ACPI_FUNCTION_ENTRY ();
209 if (!cache || !object) {
210 return (AE_BAD_PARAMETER);
213 /* If cache is full, just free this object */
215 if (cache->current_depth >= cache->max_depth) {
216 ACPI_MEM_FREE (object);
217 ACPI_MEM_TRACKING (cache->total_freed++);
220 /* Otherwise put this object back into the cache */
223 status = acpi_ut_acquire_mutex (ACPI_MTX_CACHES);
224 if (ACPI_FAILURE (status)) {
228 /* Mark the object as cached */
230 ACPI_MEMSET (object, 0xCA, cache->object_size);
231 ACPI_SET_DESCRIPTOR_TYPE (object, ACPI_DESC_TYPE_CACHED);
233 /* Put the object at the head of the cache list */
235 * (ACPI_CAST_INDIRECT_PTR (char,
236 &(((char *) object)[cache->link_offset]))) = cache->list_head;
237 cache->list_head = object;
238 cache->current_depth++;
240 (void) acpi_ut_release_mutex (ACPI_MTX_CACHES);
247 /*******************************************************************************
249 * FUNCTION: acpi_os_acquire_object
251 * PARAMETERS: Cache - Handle to cache object
253 * RETURN: the acquired object. NULL on error
255 * DESCRIPTION: Get an object from the specified cache. If cache is empty,
256 * the object is allocated.
258 ******************************************************************************/
261 acpi_os_acquire_object (
262 struct acpi_memory_list *cache)
268 ACPI_FUNCTION_NAME ("os_acquire_object");
275 status = acpi_ut_acquire_mutex (ACPI_MTX_CACHES);
276 if (ACPI_FAILURE (status)) {
280 ACPI_MEM_TRACKING (cache->requests++);
282 /* Check the cache first */
284 if (cache->list_head) {
285 /* There is an object available, use it */
287 object = cache->list_head;
288 cache->list_head = *(ACPI_CAST_INDIRECT_PTR (char,
289 &(((char *) object)[cache->link_offset])));
291 cache->current_depth--;
293 ACPI_MEM_TRACKING (cache->hits++);
294 ACPI_MEM_TRACKING (ACPI_DEBUG_PRINT ((ACPI_DB_EXEC,
295 "Object %p from %s cache\n", object, cache->list_name)));
297 status = acpi_ut_release_mutex (ACPI_MTX_CACHES);
298 if (ACPI_FAILURE (status)) {
302 /* Clear (zero) the previously used Object */
304 ACPI_MEMSET (object, 0, cache->object_size);
307 /* The cache is empty, create a new object */
309 ACPI_MEM_TRACKING (cache->total_allocated++);
311 /* Avoid deadlock with ACPI_MEM_CALLOCATE */
313 status = acpi_ut_release_mutex (ACPI_MTX_CACHES);
314 if (ACPI_FAILURE (status)) {
318 object = ACPI_MEM_CALLOCATE (cache->object_size);
326 #endif /* ACPI_USE_LOCAL_CACHE */