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Diffstat (limited to 'drivers/acpi/utilities/utcache.c')
-rw-r--r-- | drivers/acpi/utilities/utcache.c | 322 |
1 files changed, 322 insertions, 0 deletions
diff --git a/drivers/acpi/utilities/utcache.c b/drivers/acpi/utilities/utcache.c new file mode 100644 index 000000000000..07588812e72d --- /dev/null +++ b/drivers/acpi/utilities/utcache.c @@ -0,0 +1,322 @@ +/****************************************************************************** + * + * Module Name: utcache - local cache allocation routines + * + *****************************************************************************/ + +/* + * Copyright (C) 2000 - 2005, R. Byron Moore + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions, and the following disclaimer, + * without modification. + * 2. Redistributions in binary form must reproduce at minimum a disclaimer + * substantially similar to the "NO WARRANTY" disclaimer below + * ("Disclaimer") and any redistribution must be conditioned upon + * including a substantially similar Disclaimer requirement for further + * binary redistribution. + * 3. Neither the names of the above-listed copyright holders nor the names + * of any contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * Alternatively, this software may be distributed under the terms of the + * GNU General Public License ("GPL") version 2 as published by the Free + * Software Foundation. + * + * NO WARRANTY + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING + * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGES. + */ + + +#include <acpi/acpi.h> + +#define _COMPONENT ACPI_UTILITIES + ACPI_MODULE_NAME ("utcache") + + +#ifdef ACPI_USE_LOCAL_CACHE +/******************************************************************************* + * + * FUNCTION: acpi_os_create_cache + * + * PARAMETERS: cache_name - Ascii name for the cache + * object_size - Size of each cached object + * max_depth - Maximum depth of the cache (in objects) + * return_cache - Where the new cache object is returned + * + * RETURN: Status + * + * DESCRIPTION: Create a cache object + * + ******************************************************************************/ + +acpi_status +acpi_os_create_cache ( + char *cache_name, + u16 object_size, + u16 max_depth, + struct acpi_memory_list **return_cache) +{ + struct acpi_memory_list *cache; + + + if (!cache_name || !return_cache || (object_size < 16)) { + return (AE_BAD_PARAMETER); + } + + /* Create the cache object */ + + cache = acpi_os_allocate (sizeof (struct acpi_memory_list)); + if (!cache) { + return (AE_NO_MEMORY); + } + + /* Populate the cache object and return it */ + + ACPI_MEMSET (cache, 0, sizeof (struct acpi_memory_list)); + cache->link_offset = 8; + cache->list_name = cache_name; + cache->object_size = object_size; + cache->max_depth = max_depth; + + *return_cache = cache; + return (AE_OK); +} + + +/******************************************************************************* + * + * FUNCTION: acpi_os_purge_cache + * + * PARAMETERS: Cache - Handle to cache object + * + * RETURN: Status + * + * DESCRIPTION: Free all objects within the requested cache. + * + ******************************************************************************/ + +acpi_status +acpi_os_purge_cache ( + struct acpi_memory_list *cache) +{ + char *next; + + + ACPI_FUNCTION_ENTRY (); + + + if (!cache) { + return (AE_BAD_PARAMETER); + } + + /* Walk the list of objects in this cache */ + + while (cache->list_head) { + /* Delete and unlink one cached state object */ + + next = *(ACPI_CAST_INDIRECT_PTR (char, + &(((char *) cache->list_head)[cache->link_offset]))); + ACPI_MEM_FREE (cache->list_head); + + cache->list_head = next; + cache->current_depth--; + } + + return (AE_OK); +} + + +/******************************************************************************* + * + * FUNCTION: acpi_os_delete_cache + * + * PARAMETERS: Cache - Handle to cache object + * + * RETURN: Status + * + * DESCRIPTION: Free all objects within the requested cache and delete the + * cache object. + * + ******************************************************************************/ + +acpi_status +acpi_os_delete_cache ( + struct acpi_memory_list *cache) +{ + acpi_status status; + + + /* Purge all objects in the cache */ + + status = acpi_os_purge_cache (cache); + if (ACPI_FAILURE (status)) { + return (status); + } + + /* Now we can delete the cache object */ + + acpi_os_free (cache); + return (AE_OK); +} + + +/******************************************************************************* + * + * FUNCTION: acpi_os_release_object + * + * PARAMETERS: Cache - Handle to cache object + * Object - The object to be released + * + * RETURN: None + * + * DESCRIPTION: Release an object to the specified cache. If cache is full, + * the object is deleted. + * + ******************************************************************************/ + +acpi_status +acpi_os_release_object ( + struct acpi_memory_list *cache, + void *object) +{ + acpi_status status; + + + ACPI_FUNCTION_ENTRY (); + + + if (!cache || !object) { + return (AE_BAD_PARAMETER); + } + + /* If cache is full, just free this object */ + + if (cache->current_depth >= cache->max_depth) { + ACPI_MEM_FREE (object); + ACPI_MEM_TRACKING (cache->total_freed++); + } + + /* Otherwise put this object back into the cache */ + + else { + status = acpi_ut_acquire_mutex (ACPI_MTX_CACHES); + if (ACPI_FAILURE (status)) { + return (status); + } + + /* Mark the object as cached */ + + ACPI_MEMSET (object, 0xCA, cache->object_size); + ACPI_SET_DESCRIPTOR_TYPE (object, ACPI_DESC_TYPE_CACHED); + + /* Put the object at the head of the cache list */ + + * (ACPI_CAST_INDIRECT_PTR (char, + &(((char *) object)[cache->link_offset]))) = cache->list_head; + cache->list_head = object; + cache->current_depth++; + + (void) acpi_ut_release_mutex (ACPI_MTX_CACHES); + } + + return (AE_OK); +} + + +/******************************************************************************* + * + * FUNCTION: acpi_os_acquire_object + * + * PARAMETERS: Cache - Handle to cache object + * + * RETURN: the acquired object. NULL on error + * + * DESCRIPTION: Get an object from the specified cache. If cache is empty, + * the object is allocated. + * + ******************************************************************************/ + +void * +acpi_os_acquire_object ( + struct acpi_memory_list *cache) +{ + acpi_status status; + void *object; + + + ACPI_FUNCTION_NAME ("ut_acquire_from_cache"); + + + if (!cache) { + return (NULL); + } + + status = acpi_ut_acquire_mutex (ACPI_MTX_CACHES); + if (ACPI_FAILURE (status)) { + return (NULL); + } + + ACPI_MEM_TRACKING (cache->requests++); + + /* Check the cache first */ + + if (cache->list_head) { + /* There is an object available, use it */ + + object = cache->list_head; + cache->list_head = *(ACPI_CAST_INDIRECT_PTR (char, + &(((char *) object)[cache->link_offset]))); + + cache->current_depth--; + + ACPI_MEM_TRACKING (cache->hits++); + ACPI_MEM_TRACKING (ACPI_DEBUG_PRINT ((ACPI_DB_EXEC, + "Object %p from %s\n", object, cache->list_name))); + + status = acpi_ut_release_mutex (ACPI_MTX_CACHES); + if (ACPI_FAILURE (status)) { + return (NULL); + } + + /* Clear (zero) the previously used Object */ + + ACPI_MEMSET (object, 0, cache->object_size); + } + else { + /* The cache is empty, create a new object */ + + ACPI_MEM_TRACKING (cache->total_allocated++); + + /* Avoid deadlock with ACPI_MEM_CALLOCATE */ + + status = acpi_ut_release_mutex (ACPI_MTX_CACHES); + if (ACPI_FAILURE (status)) { + return (NULL); + } + + object = ACPI_MEM_CALLOCATE (cache->object_size); + if (!object) { + return (NULL); + } + } + + return (object); +} +#endif /* ACPI_USE_LOCAL_CACHE */ + + |