1 /* 2 * Copyright (C) 2014 Sergey Senozhatsky. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation; either version 7 * 2 of the License, or (at your option) any later version. 8 */ 9 10 #ifndef _ZCOMP_H_ 11 #define _ZCOMP_H_ 12 13 struct zcomp_strm { 14 /* compression/decompression buffer */ 15 void *buffer; 16 /* 17 * The private data of the compression stream, only compression 18 * stream backend can touch this (e.g. compression algorithm 19 * working memory) 20 */ 21 void *private; 22 }; 23 24 /* static compression backend */ 25 struct zcomp_backend { 26 int (*compress)(const unsigned char *src, unsigned char *dst, 27 size_t *dst_len, void *private); 28 29 int (*decompress)(const unsigned char *src, size_t src_len, 30 unsigned char *dst); 31 32 void *(*create)(gfp_t flags); 33 void (*destroy)(void *private); 34 35 const char *name; 36 }; 37 38 /* dynamic per-device compression frontend */ 39 struct zcomp { 40 struct zcomp_strm * __percpu *stream; 41 struct zcomp_backend *backend; 42 struct notifier_block notifier; 43 }; 44 45 ssize_t zcomp_available_show(const char *comp, char *buf); 46 bool zcomp_available_algorithm(const char *comp); 47 48 struct zcomp *zcomp_create(const char *comp); 49 void zcomp_destroy(struct zcomp *comp); 50 51 struct zcomp_strm *zcomp_strm_find(struct zcomp *comp); 52 void zcomp_strm_release(struct zcomp *comp, struct zcomp_strm *zstrm); 53 54 int zcomp_compress(struct zcomp *comp, struct zcomp_strm *zstrm, 55 const unsigned char *src, size_t *dst_len); 56 57 int zcomp_decompress(struct zcomp *comp, const unsigned char *src, 58 size_t src_len, unsigned char *dst); 59 60 bool zcomp_set_max_streams(struct zcomp *comp, int num_strm); 61 #endif /* _ZCOMP_H_ */ 62