diff options
Diffstat (limited to 'drivers/block/zram/zcomp.h')
-rw-r--r-- | drivers/block/zram/zcomp.h | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/drivers/block/zram/zcomp.h b/drivers/block/zram/zcomp.h new file mode 100644 index 000000000000..c59d1fca72c0 --- /dev/null +++ b/drivers/block/zram/zcomp.h @@ -0,0 +1,68 @@ +/* + * Copyright (C) 2014 Sergey Senozhatsky. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#ifndef _ZCOMP_H_ +#define _ZCOMP_H_ + +#include <linux/mutex.h> + +struct zcomp_strm { + /* compression/decompression buffer */ + void *buffer; + /* + * The private data of the compression stream, only compression + * stream backend can touch this (e.g. compression algorithm + * working memory) + */ + void *private; + /* used in multi stream backend, protected by backend strm_lock */ + struct list_head list; +}; + +/* static compression backend */ +struct zcomp_backend { + int (*compress)(const unsigned char *src, unsigned char *dst, + size_t *dst_len, void *private); + + int (*decompress)(const unsigned char *src, size_t src_len, + unsigned char *dst); + + void *(*create)(void); + void (*destroy)(void *private); + + const char *name; +}; + +/* dynamic per-device compression frontend */ +struct zcomp { + void *stream; + struct zcomp_backend *backend; + + struct zcomp_strm *(*strm_find)(struct zcomp *comp); + void (*strm_release)(struct zcomp *comp, struct zcomp_strm *zstrm); + bool (*set_max_streams)(struct zcomp *comp, int num_strm); + void (*destroy)(struct zcomp *comp); +}; + +ssize_t zcomp_available_show(const char *comp, char *buf); + +struct zcomp *zcomp_create(const char *comp, int max_strm); +void zcomp_destroy(struct zcomp *comp); + +struct zcomp_strm *zcomp_strm_find(struct zcomp *comp); +void zcomp_strm_release(struct zcomp *comp, struct zcomp_strm *zstrm); + +int zcomp_compress(struct zcomp *comp, struct zcomp_strm *zstrm, + const unsigned char *src, size_t *dst_len); + +int zcomp_decompress(struct zcomp *comp, const unsigned char *src, + size_t src_len, unsigned char *dst); + +bool zcomp_set_max_streams(struct zcomp *comp, int num_strm); +#endif /* _ZCOMP_H_ */ |