drivers/acpi/acpica/utcache.c

   1 /******************************************************************************
   2  *
   3  * Module Name: utcache - local cache allocation routines
   4  *
   5  *****************************************************************************/
   6
   7 /*
   8  * Copyright (C) 2000 - 2013, 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         ACPI_MEMSET(cache, 0, sizeof(struct acpi_memory_list));
  88         cache->link_offset = 8;
  89         cache->list_name = cache_name;
  90         cache->object_size = object_size;
  91         cache->max_depth = max_depth;
  92
  93         *return_cache = cache;
  94         return (AE_OK);
  95 }
  96
  97 /*******************************************************************************
  98  *
  99  * FUNCTION:    acpi_os_purge_cache
 100  *
 101  * PARAMETERS:  cache           - Handle to cache object
 102  *
 103  * RETURN:      Status
 104  *
 105  * DESCRIPTION: Free all objects within the requested cache.
 106  *
 107  ******************************************************************************/
 108
 109 acpi_status acpi_os_purge_cache(struct acpi_memory_list * cache)
 110 {
 111         char *next;
 112         acpi_status status;
 113
 114         ACPI_FUNCTION_ENTRY();
 115
 116         if (!cache) {
 117                 return (AE_BAD_PARAMETER);
 118         }
 119
 120         status = acpi_ut_acquire_mutex(ACPI_MTX_CACHES);
 121         if (ACPI_FAILURE(status)) {
 122                 return (status);
 123         }
 124
 125         /* Walk the list of objects in this cache */
 126
 127         while (cache->list_head) {
 128
 129                 /* Delete and unlink one cached state object */
 130
 131                 next = *(ACPI_CAST_INDIRECT_PTR(char,
 132                                                 &(((char *)cache->
 133                                                    list_head)[cache->
 134                                                               link_offset])));
 135                 ACPI_FREE(cache->list_head);
 136
 137                 cache->list_head = next;
 138                 cache->current_depth--;
 139         }
 140
 141         (void)acpi_ut_release_mutex(ACPI_MTX_CACHES);
 142         return (AE_OK);
 143 }
 144
 145 /*******************************************************************************
 146  *
 147  * FUNCTION:    acpi_os_delete_cache
 148  *
 149  * PARAMETERS:  cache           - Handle to cache object
 150  *
 151  * RETURN:      Status
 152  *
 153  * DESCRIPTION: Free all objects within the requested cache and delete the
 154  *              cache object.
 155  *
 156  ******************************************************************************/
 157
 158 acpi_status acpi_os_delete_cache(struct acpi_memory_list * cache)
 159 {
 160         acpi_status status;
 161
 162         ACPI_FUNCTION_ENTRY();
 163
 164         /* Purge all objects in the cache */
 165
 166         status = acpi_os_purge_cache(cache);
 167         if (ACPI_FAILURE(status)) {
 168                 return (status);
 169         }
 170
 171         /* Now we can delete the cache object */
 172
 173         acpi_os_free(cache);
 174         return (AE_OK);
 175 }
 176
 177 /*******************************************************************************
 178  *
 179  * FUNCTION:    acpi_os_release_object
 180  *
 181  * PARAMETERS:  cache       - Handle to cache object
 182  *              object      - The object to be released
 183  *
 184  * RETURN:      None
 185  *
 186  * DESCRIPTION: Release an object to the specified cache. If cache is full,
 187  *              the object is deleted.
 188  *
 189  ******************************************************************************/
 190
 191 acpi_status
 192 acpi_os_release_object(struct acpi_memory_list * cache, void *object)
 193 {
 194         acpi_status status;
 195
 196         ACPI_FUNCTION_ENTRY();
 197
 198         if (!cache || !object) {
 199                 return (AE_BAD_PARAMETER);
 200         }
 201
 202         /* If cache is full, just free this object */
 203
 204         if (cache->current_depth >= cache->max_depth) {
 205                 ACPI_FREE(object);
 206                 ACPI_MEM_TRACKING(cache->total_freed++);
 207         }
 208
 209         /* Otherwise put this object back into the cache */
 210
 211         else {
 212                 status = acpi_ut_acquire_mutex(ACPI_MTX_CACHES);
 213                 if (ACPI_FAILURE(status)) {
 214                         return (status);
 215                 }
 216
 217                 /* Mark the object as cached */
 218
 219                 ACPI_MEMSET(object, 0xCA, cache->object_size);
 220                 ACPI_SET_DESCRIPTOR_TYPE(object, ACPI_DESC_TYPE_CACHED);
 221
 222                 /* Put the object at the head of the cache list */
 223
 224                 *(ACPI_CAST_INDIRECT_PTR(char,
 225                                          &(((char *)object)[cache->
 226                                                             link_offset]))) =
 227                     cache->list_head;
 228                 cache->list_head = object;
 229                 cache->current_depth++;
 230
 231                 (void)acpi_ut_release_mutex(ACPI_MTX_CACHES);
 232         }
 233
 234         return (AE_OK);
 235 }
 236
 237 /*******************************************************************************
 238  *
 239  * FUNCTION:    acpi_os_acquire_object
 240  *
 241  * PARAMETERS:  cache           - Handle to cache object
 242  *
 243  * RETURN:      the acquired object. NULL on error
 244  *
 245  * DESCRIPTION: Get an object from the specified cache. If cache is empty,
 246  *              the object is allocated.
 247  *
 248  ******************************************************************************/
 249
 250 void *acpi_os_acquire_object(struct acpi_memory_list *cache)
 251 {
 252         acpi_status status;
 253         void *object;
 254
 255         ACPI_FUNCTION_NAME(os_acquire_object);
 256
 257         if (!cache) {
 258                 return (NULL);
 259         }
 260
 261         status = acpi_ut_acquire_mutex(ACPI_MTX_CACHES);
 262         if (ACPI_FAILURE(status)) {
 263                 return (NULL);
 264         }
 265
 266         ACPI_MEM_TRACKING(cache->requests++);
 267
 268         /* Check the cache first */
 269
 270         if (cache->list_head) {
 271
 272                 /* There is an object available, use it */
 273
 274                 object = cache->list_head;
 275                 cache->list_head = *(ACPI_CAST_INDIRECT_PTR(char,
 276                                                             &(((char *)
 277                                                                object)[cache->
 278                                                                        link_offset])));
 279
 280                 cache->current_depth--;
 281
 282                 ACPI_MEM_TRACKING(cache->hits++);
 283                 ACPI_DEBUG_PRINT((ACPI_DB_EXEC,
 284                                   "Object %p from %s cache\n", object,
 285                                   cache->list_name));
 286
 287                 status = acpi_ut_release_mutex(ACPI_MTX_CACHES);
 288                 if (ACPI_FAILURE(status)) {
 289                         return (NULL);
 290                 }
 291
 292                 /* Clear (zero) the previously used Object */
 293
 294                 ACPI_MEMSET(object, 0, cache->object_size);
 295         } else {
 296                 /* The cache is empty, create a new object */
 297
 298                 ACPI_MEM_TRACKING(cache->total_allocated++);
 299
 300 #ifdef ACPI_DBG_TRACK_ALLOCATIONS
 301                 if ((cache->total_allocated - cache->total_freed) >
 302                     cache->max_occupied) {
 303                         cache->max_occupied =
 304                             cache->total_allocated - cache->total_freed;
 305                 }
 306 #endif
 307
 308                 /* Avoid deadlock with ACPI_ALLOCATE_ZEROED */
 309
 310                 status = acpi_ut_release_mutex(ACPI_MTX_CACHES);
 311                 if (ACPI_FAILURE(status)) {
 312                         return (NULL);
 313                 }
 314
 315                 object = ACPI_ALLOCATE_ZEROED(cache->object_size);
 316                 if (!object) {
 317                         return (NULL);
 318                 }
 319         }
 320
 321         return (object);
 322 }
 323 #endif                          /* ACPI_USE_LOCAL_CACHE */