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/lzo.h>
13 #include <linux/vmalloc.h>
14 #include <linux/mm.h>
15
16 #include "zcomp_lzo.h"
17
lzo_create(void)18 static void *lzo_create(void)
19 {
20 void *ret;
21
22 /*
23 * This function can be called in swapout/fs write path
24 * so we can't use GFP_FS|IO. And it assumes we already
25 * have at least one stream in zram initialization so we
26 * don't do best effort to allocate more stream in here.
27 * A default stream will work well without further multiple
28 * streams. That's why we use NORETRY | NOWARN.
29 */
30 ret = kzalloc(LZO1X_MEM_COMPRESS, GFP_NOIO | __GFP_NORETRY |
31 __GFP_NOWARN);
32 if (!ret)
33 ret = __vmalloc(LZO1X_MEM_COMPRESS,
34 GFP_NOIO | __GFP_NORETRY | __GFP_NOWARN |
35 __GFP_ZERO | __GFP_HIGHMEM,
36 PAGE_KERNEL);
37 return ret;
38 }
39
lzo_destroy(void * private)40 static void lzo_destroy(void *private)
41 {
42 kvfree(private);
43 }
44
lzo_compress(const unsigned char * src,unsigned char * dst,size_t * dst_len,void * private)45 static int lzo_compress(const unsigned char *src, unsigned char *dst,
46 size_t *dst_len, void *private)
47 {
48 int ret = lzo1x_1_compress(src, PAGE_SIZE, dst, dst_len, private);
49 return ret == LZO_E_OK ? 0 : ret;
50 }
51
lzo_decompress(const unsigned char * src,size_t src_len,unsigned char * dst)52 static int lzo_decompress(const unsigned char *src, size_t src_len,
53 unsigned char *dst)
54 {
55 size_t dst_len = PAGE_SIZE;
56 int ret = lzo1x_decompress_safe(src, src_len, dst, &dst_len);
57 return ret == LZO_E_OK ? 0 : ret;
58 }
59
60 struct zcomp_backend zcomp_lzo = {
61 .compress = lzo_compress,
62 .decompress = lzo_decompress,
63 .create = lzo_create,
64 .destroy = lzo_destroy,
65 .name = "lzo",
66 };
67