drivers/acpi/acpica/utcache.c

   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 */