1 // SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
2 /******************************************************************************
3 *
4 * Module Name: utcache - local cache allocation routines
5 *
6 * Copyright (C) 2000 - 2019, Intel Corp.
7 *
8 *****************************************************************************/
9
10 #include <acpi/acpi.h>
11 #include "accommon.h"
12
13 #define _COMPONENT ACPI_UTILITIES
14 ACPI_MODULE_NAME("utcache")
15
16 #ifdef ACPI_USE_LOCAL_CACHE
17 /*******************************************************************************
18 *
19 * FUNCTION: acpi_os_create_cache
20 *
21 * PARAMETERS: cache_name - Ascii name for the cache
22 * object_size - Size of each cached object
23 * max_depth - Maximum depth of the cache (in objects)
24 * return_cache - Where the new cache object is returned
25 *
26 * RETURN: Status
27 *
28 * DESCRIPTION: Create a cache object
29 *
30 ******************************************************************************/
31 acpi_status
32 acpi_os_create_cache(char *cache_name,
33 u16 object_size,
34 u16 max_depth, struct acpi_memory_list **return_cache)
35 {
36 struct acpi_memory_list *cache;
37
38 ACPI_FUNCTION_ENTRY();
39
40 if (!cache_name || !return_cache || !object_size) {
41 return (AE_BAD_PARAMETER);
42 }
43
44 /* Create the cache object */
45
46 cache = acpi_os_allocate(sizeof(struct acpi_memory_list));
47 if (!cache) {
48 return (AE_NO_MEMORY);
49 }
50
51 /* Populate the cache object and return it */
52
53 memset(cache, 0, sizeof(struct acpi_memory_list));
54 cache->list_name = cache_name;
55 cache->object_size = object_size;
56 cache->max_depth = max_depth;
57
58 *return_cache = cache;
59 return (AE_OK);
60 }
61
62 /*******************************************************************************
63 *
64 * FUNCTION: acpi_os_purge_cache
65 *
66 * PARAMETERS: cache - Handle to cache object
67 *
68 * RETURN: Status
69 *
70 * DESCRIPTION: Free all objects within the requested cache.
71 *
72 ******************************************************************************/
73
74 acpi_status acpi_os_purge_cache(struct acpi_memory_list *cache)
75 {
76 void *next;
77 acpi_status status;
78
79 ACPI_FUNCTION_ENTRY();
80
81 if (!cache) {
82 return (AE_BAD_PARAMETER);
83 }
84
85 status = acpi_ut_acquire_mutex(ACPI_MTX_CACHES);
86 if (ACPI_FAILURE(status)) {
87 return (status);
88 }
89
90 /* Walk the list of objects in this cache */
91
92 while (cache->list_head) {
93
94 /* Delete and unlink one cached state object */
95
96 next = ACPI_GET_DESCRIPTOR_PTR(cache->list_head);
97 ACPI_FREE(cache->list_head);
98
99 cache->list_head = next;
100 cache->current_depth--;
101 }
102
103 (void)acpi_ut_release_mutex(ACPI_MTX_CACHES);
104 return (AE_OK);
105 }
106
107 /*******************************************************************************
108 *
109 * FUNCTION: acpi_os_delete_cache
110 *
111 * PARAMETERS: cache - Handle to cache object
112 *
113 * RETURN: Status
114 *
115 * DESCRIPTION: Free all objects within the requested cache and delete the
116 * cache object.
117 *
118 ******************************************************************************/
119
120 acpi_status acpi_os_delete_cache(struct acpi_memory_list *cache)
121 {
122 acpi_status status;
123
124 ACPI_FUNCTION_ENTRY();
125
126 /* Purge all objects in the cache */
127
128 status = acpi_os_purge_cache(cache);
129 if (ACPI_FAILURE(status)) {
130 return (status);
131 }
132
133 /* Now we can delete the cache object */
134
135 acpi_os_free(cache);
136 return (AE_OK);
137 }
138
139 /*******************************************************************************
140 *
141 * FUNCTION: acpi_os_release_object
142 *
143 * PARAMETERS: cache - Handle to cache object
144 * object - The object to be released
145 *
146 * RETURN: None
147 *
148 * DESCRIPTION: Release an object to the specified cache. If cache is full,
149 * the object is deleted.
150 *
151 ******************************************************************************/
152
153 acpi_status acpi_os_release_object(struct acpi_memory_list *cache, void *object)
154 {
155 acpi_status status;
156
157 ACPI_FUNCTION_ENTRY();
158
159 if (!cache || !object) {
160 return (AE_BAD_PARAMETER);
161 }
162
163 /* If cache is full, just free this object */
164
165 if (cache->current_depth >= cache->max_depth) {
166 ACPI_FREE(object);
167 ACPI_MEM_TRACKING(cache->total_freed++);
168 }
169
170 /* Otherwise put this object back into the cache */
171
172 else {
173 status = acpi_ut_acquire_mutex(ACPI_MTX_CACHES);
174 if (ACPI_FAILURE(status)) {
175 return (status);
176 }
177
178 /* Mark the object as cached */
179
180 memset(object, 0xCA, cache->object_size);
181 ACPI_SET_DESCRIPTOR_TYPE(object, ACPI_DESC_TYPE_CACHED);
182
183 /* Put the object at the head of the cache list */
184
185 ACPI_SET_DESCRIPTOR_PTR(object, cache->list_head);
186 cache->list_head = object;
187 cache->current_depth++;
188
189 (void)acpi_ut_release_mutex(ACPI_MTX_CACHES);
190 }
191
192 return (AE_OK);
193 }
194
195 /*******************************************************************************
196 *
197 * FUNCTION: acpi_os_acquire_object
198 *
199 * PARAMETERS: cache - Handle to cache object
200 *
201 * RETURN: the acquired object. NULL on error
202 *
203 * DESCRIPTION: Get an object from the specified cache. If cache is empty,
204 * the object is allocated.
205 *
206 ******************************************************************************/
207
208 void *acpi_os_acquire_object(struct acpi_memory_list *cache)
209 {
210 acpi_status status;
211 void *object;
212
213 ACPI_FUNCTION_TRACE(os_acquire_object);
214
215 if (!cache) {
216 return_PTR(NULL);
217 }
218
219 status = acpi_ut_acquire_mutex(ACPI_MTX_CACHES);
220 if (ACPI_FAILURE(status)) {
221 return_PTR(NULL);
222 }
223
224 ACPI_MEM_TRACKING(cache->requests++);
225
226 /* Check the cache first */
227
228 if (cache->list_head) {
229
230 /* There is an object available, use it */
231
232 object = cache->list_head;
233 cache->list_head = ACPI_GET_DESCRIPTOR_PTR(object);
234
235 cache->current_depth--;
236
237 ACPI_MEM_TRACKING(cache->hits++);
238 ACPI_DEBUG_PRINT_RAW((ACPI_DB_EXEC,
239 "%s: Object %p from %s cache\n",
240 ACPI_GET_FUNCTION_NAME, object,
241 cache->list_name));
242
243 status = acpi_ut_release_mutex(ACPI_MTX_CACHES);
244 if (ACPI_FAILURE(status)) {
245 return_PTR(NULL);
246 }
247
248 /* Clear (zero) the previously used Object */
249
250 memset(object, 0, cache->object_size);
251 } else {
252 /* The cache is empty, create a new object */
253
254 ACPI_MEM_TRACKING(cache->total_allocated++);
255
256 #ifdef ACPI_DBG_TRACK_ALLOCATIONS
257 if ((cache->total_allocated - cache->total_freed) >
258 cache->max_occupied) {
259 cache->max_occupied =
260 cache->total_allocated - cache->total_freed;
261 }
262 #endif
263
264 /* Avoid deadlock with ACPI_ALLOCATE_ZEROED */
265
266 status = acpi_ut_release_mutex(ACPI_MTX_CACHES);
267 if (ACPI_FAILURE(status)) {
268 return_PTR(NULL);
269 }
270
271 object = ACPI_ALLOCATE_ZEROED(cache->object_size);
272 if (!object) {
273 return_PTR(NULL);
274 }
275 }
276
277 return_PTR(object);
278 }
279 #endif /* ACPI_USE_LOCAL_CACHE */