xref: /linux/drivers/acpi/acpica/utcache.c (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
1 /******************************************************************************
2  *
3  * Module Name: utcache - local cache allocation routines
4  *
5  *****************************************************************************/
6 
7 /*
8  * Copyright (C) 2000 - 2015, Intel Corp.
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 #include "accommon.h"
46 
47 #define _COMPONENT          ACPI_UTILITIES
48 ACPI_MODULE_NAME("utcache")
49 
50 #ifdef ACPI_USE_LOCAL_CACHE
51 /*******************************************************************************
52  *
53  * FUNCTION:    acpi_os_create_cache
54  *
55  * PARAMETERS:  cache_name      - Ascii name for the cache
56  *              object_size     - Size of each cached object
57  *              max_depth       - Maximum depth of the cache (in objects)
58  *              return_cache    - Where the new cache object is returned
59  *
60  * RETURN:      Status
61  *
62  * DESCRIPTION: Create a cache object
63  *
64  ******************************************************************************/
65 acpi_status
66 acpi_os_create_cache(char *cache_name,
67 		     u16 object_size,
68 		     u16 max_depth, struct acpi_memory_list **return_cache)
69 {
70 	struct acpi_memory_list *cache;
71 
72 	ACPI_FUNCTION_ENTRY();
73 
74 	if (!cache_name || !return_cache || (object_size < 16)) {
75 		return (AE_BAD_PARAMETER);
76 	}
77 
78 	/* Create the cache object */
79 
80 	cache = acpi_os_allocate(sizeof(struct acpi_memory_list));
81 	if (!cache) {
82 		return (AE_NO_MEMORY);
83 	}
84 
85 	/* Populate the cache object and return it */
86 
87 	memset(cache, 0, sizeof(struct acpi_memory_list));
88 	cache->list_name = cache_name;
89 	cache->object_size = object_size;
90 	cache->max_depth = max_depth;
91 
92 	*return_cache = cache;
93 	return (AE_OK);
94 }
95 
96 /*******************************************************************************
97  *
98  * FUNCTION:    acpi_os_purge_cache
99  *
100  * PARAMETERS:  cache           - Handle to cache object
101  *
102  * RETURN:      Status
103  *
104  * DESCRIPTION: Free all objects within the requested cache.
105  *
106  ******************************************************************************/
107 
108 acpi_status acpi_os_purge_cache(struct acpi_memory_list * cache)
109 {
110 	void *next;
111 	acpi_status status;
112 
113 	ACPI_FUNCTION_ENTRY();
114 
115 	if (!cache) {
116 		return (AE_BAD_PARAMETER);
117 	}
118 
119 	status = acpi_ut_acquire_mutex(ACPI_MTX_CACHES);
120 	if (ACPI_FAILURE(status)) {
121 		return (status);
122 	}
123 
124 	/* Walk the list of objects in this cache */
125 
126 	while (cache->list_head) {
127 
128 		/* Delete and unlink one cached state object */
129 
130 		next = ACPI_GET_DESCRIPTOR_PTR(cache->list_head);
131 		ACPI_FREE(cache->list_head);
132 
133 		cache->list_head = next;
134 		cache->current_depth--;
135 	}
136 
137 	(void)acpi_ut_release_mutex(ACPI_MTX_CACHES);
138 	return (AE_OK);
139 }
140 
141 /*******************************************************************************
142  *
143  * FUNCTION:    acpi_os_delete_cache
144  *
145  * PARAMETERS:  cache           - Handle to cache object
146  *
147  * RETURN:      Status
148  *
149  * DESCRIPTION: Free all objects within the requested cache and delete the
150  *              cache object.
151  *
152  ******************************************************************************/
153 
154 acpi_status acpi_os_delete_cache(struct acpi_memory_list * cache)
155 {
156 	acpi_status status;
157 
158 	ACPI_FUNCTION_ENTRY();
159 
160 	/* Purge all objects in the cache */
161 
162 	status = acpi_os_purge_cache(cache);
163 	if (ACPI_FAILURE(status)) {
164 		return (status);
165 	}
166 
167 	/* Now we can delete the cache object */
168 
169 	acpi_os_free(cache);
170 	return (AE_OK);
171 }
172 
173 /*******************************************************************************
174  *
175  * FUNCTION:    acpi_os_release_object
176  *
177  * PARAMETERS:  cache       - Handle to cache object
178  *              object      - The object to be released
179  *
180  * RETURN:      None
181  *
182  * DESCRIPTION: Release an object to the specified cache. If cache is full,
183  *              the object is deleted.
184  *
185  ******************************************************************************/
186 
187 acpi_status
188 acpi_os_release_object(struct acpi_memory_list * cache, void *object)
189 {
190 	acpi_status status;
191 
192 	ACPI_FUNCTION_ENTRY();
193 
194 	if (!cache || !object) {
195 		return (AE_BAD_PARAMETER);
196 	}
197 
198 	/* If cache is full, just free this object */
199 
200 	if (cache->current_depth >= cache->max_depth) {
201 		ACPI_FREE(object);
202 		ACPI_MEM_TRACKING(cache->total_freed++);
203 	}
204 
205 	/* Otherwise put this object back into the cache */
206 
207 	else {
208 		status = acpi_ut_acquire_mutex(ACPI_MTX_CACHES);
209 		if (ACPI_FAILURE(status)) {
210 			return (status);
211 		}
212 
213 		/* Mark the object as cached */
214 
215 		memset(object, 0xCA, cache->object_size);
216 		ACPI_SET_DESCRIPTOR_TYPE(object, ACPI_DESC_TYPE_CACHED);
217 
218 		/* Put the object at the head of the cache list */
219 
220 		ACPI_SET_DESCRIPTOR_PTR(object, cache->list_head);
221 		cache->list_head = object;
222 		cache->current_depth++;
223 
224 		(void)acpi_ut_release_mutex(ACPI_MTX_CACHES);
225 	}
226 
227 	return (AE_OK);
228 }
229 
230 /*******************************************************************************
231  *
232  * FUNCTION:    acpi_os_acquire_object
233  *
234  * PARAMETERS:  cache           - Handle to cache object
235  *
236  * RETURN:      the acquired object. NULL on error
237  *
238  * DESCRIPTION: Get an object from the specified cache. If cache is empty,
239  *              the object is allocated.
240  *
241  ******************************************************************************/
242 
243 void *acpi_os_acquire_object(struct acpi_memory_list *cache)
244 {
245 	acpi_status status;
246 	void *object;
247 
248 	ACPI_FUNCTION_NAME(os_acquire_object);
249 
250 	if (!cache) {
251 		return_PTR(NULL);
252 	}
253 
254 	status = acpi_ut_acquire_mutex(ACPI_MTX_CACHES);
255 	if (ACPI_FAILURE(status)) {
256 		return_PTR(NULL);
257 	}
258 
259 	ACPI_MEM_TRACKING(cache->requests++);
260 
261 	/* Check the cache first */
262 
263 	if (cache->list_head) {
264 
265 		/* There is an object available, use it */
266 
267 		object = cache->list_head;
268 		cache->list_head = ACPI_GET_DESCRIPTOR_PTR(object);
269 
270 		cache->current_depth--;
271 
272 		ACPI_MEM_TRACKING(cache->hits++);
273 		ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
274 				  "Object %p from %s cache\n", object,
275 				  cache->list_name));
276 
277 		status = acpi_ut_release_mutex(ACPI_MTX_CACHES);
278 		if (ACPI_FAILURE(status)) {
279 			return_PTR(NULL);
280 		}
281 
282 		/* Clear (zero) the previously used Object */
283 
284 		memset(object, 0, cache->object_size);
285 	} else {
286 		/* The cache is empty, create a new object */
287 
288 		ACPI_MEM_TRACKING(cache->total_allocated++);
289 
290 #ifdef ACPI_DBG_TRACK_ALLOCATIONS
291 		if ((cache->total_allocated - cache->total_freed) >
292 		    cache->max_occupied) {
293 			cache->max_occupied =
294 			    cache->total_allocated - cache->total_freed;
295 		}
296 #endif
297 
298 		/* Avoid deadlock with ACPI_ALLOCATE_ZEROED */
299 
300 		status = acpi_ut_release_mutex(ACPI_MTX_CACHES);
301 		if (ACPI_FAILURE(status)) {
302 			return_PTR(NULL);
303 		}
304 
305 		object = ACPI_ALLOCATE_ZEROED(cache->object_size);
306 		if (!object) {
307 			return_PTR(NULL);
308 		}
309 	}
310 
311 	return_PTR(object);
312 }
313 #endif				/* ACPI_USE_LOCAL_CACHE */
314