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 #include <linux/kernel.h>
11 #include <linux/slab.h>
12 #include <linux/lz4.h>
13 #include <linux/vmalloc.h>
14 #include <linux/mm.h>
15
16 #include "zcomp_lz4.h"
17
zcomp_lz4_create(gfp_t flags)18 static void *zcomp_lz4_create(gfp_t flags)
19 {
20 void *ret;
21
22 ret = kmalloc(LZ4_MEM_COMPRESS, flags);
23 if (!ret)
24 ret = __vmalloc(LZ4_MEM_COMPRESS,
25 flags | __GFP_HIGHMEM,
26 PAGE_KERNEL);
27 return ret;
28 }
29
zcomp_lz4_destroy(void * private)30 static void zcomp_lz4_destroy(void *private)
31 {
32 kvfree(private);
33 }
34
zcomp_lz4_compress(const unsigned char * src,unsigned char * dst,size_t * dst_len,void * private)35 static int zcomp_lz4_compress(const unsigned char *src, unsigned char *dst,
36 size_t *dst_len, void *private)
37 {
38 /* return : Success if return 0 */
39 return lz4_compress(src, PAGE_SIZE, dst, dst_len, private);
40 }
41
zcomp_lz4_decompress(const unsigned char * src,size_t src_len,unsigned char * dst)42 static int zcomp_lz4_decompress(const unsigned char *src, size_t src_len,
43 unsigned char *dst)
44 {
45 size_t dst_len = PAGE_SIZE;
46 /* return : Success if return 0 */
47 return lz4_decompress_unknownoutputsize(src, src_len, dst, &dst_len);
48 }
49
50 struct zcomp_backend zcomp_lz4 = {
51 .compress = zcomp_lz4_compress,
52 .decompress = zcomp_lz4_decompress,
53 .create = zcomp_lz4_create,
54 .destroy = zcomp_lz4_destroy,
55 .name = "lz4",
56 };
57