1*4882a593Smuzhiyun /*
2*4882a593Smuzhiyun * JFFS2 -- Journalling Flash File System, Version 2.
3*4882a593Smuzhiyun *
4*4882a593Smuzhiyun * Copyright © 2007 Nokia Corporation. All rights reserved.
5*4882a593Smuzhiyun * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>
6*4882a593Smuzhiyun *
7*4882a593Smuzhiyun * Created by Richard Purdie <rpurdie@openedhand.com>
8*4882a593Smuzhiyun *
9*4882a593Smuzhiyun * For licensing information, see the file 'LICENCE' in this directory.
10*4882a593Smuzhiyun *
11*4882a593Smuzhiyun */
12*4882a593Smuzhiyun
13*4882a593Smuzhiyun #include <linux/kernel.h>
14*4882a593Smuzhiyun #include <linux/sched.h>
15*4882a593Smuzhiyun #include <linux/vmalloc.h>
16*4882a593Smuzhiyun #include <linux/init.h>
17*4882a593Smuzhiyun #include <linux/lzo.h>
18*4882a593Smuzhiyun #include "compr.h"
19*4882a593Smuzhiyun
20*4882a593Smuzhiyun static void *lzo_mem;
21*4882a593Smuzhiyun static void *lzo_compress_buf;
22*4882a593Smuzhiyun static DEFINE_MUTEX(deflate_mutex); /* for lzo_mem and lzo_compress_buf */
23*4882a593Smuzhiyun
free_workspace(void)24*4882a593Smuzhiyun static void free_workspace(void)
25*4882a593Smuzhiyun {
26*4882a593Smuzhiyun vfree(lzo_mem);
27*4882a593Smuzhiyun vfree(lzo_compress_buf);
28*4882a593Smuzhiyun }
29*4882a593Smuzhiyun
alloc_workspace(void)30*4882a593Smuzhiyun static int __init alloc_workspace(void)
31*4882a593Smuzhiyun {
32*4882a593Smuzhiyun lzo_mem = vmalloc(LZO1X_MEM_COMPRESS);
33*4882a593Smuzhiyun lzo_compress_buf = vmalloc(lzo1x_worst_compress(PAGE_SIZE));
34*4882a593Smuzhiyun
35*4882a593Smuzhiyun if (!lzo_mem || !lzo_compress_buf) {
36*4882a593Smuzhiyun free_workspace();
37*4882a593Smuzhiyun return -ENOMEM;
38*4882a593Smuzhiyun }
39*4882a593Smuzhiyun
40*4882a593Smuzhiyun return 0;
41*4882a593Smuzhiyun }
42*4882a593Smuzhiyun
jffs2_lzo_compress(unsigned char * data_in,unsigned char * cpage_out,uint32_t * sourcelen,uint32_t * dstlen)43*4882a593Smuzhiyun static int jffs2_lzo_compress(unsigned char *data_in, unsigned char *cpage_out,
44*4882a593Smuzhiyun uint32_t *sourcelen, uint32_t *dstlen)
45*4882a593Smuzhiyun {
46*4882a593Smuzhiyun size_t compress_size;
47*4882a593Smuzhiyun int ret;
48*4882a593Smuzhiyun
49*4882a593Smuzhiyun mutex_lock(&deflate_mutex);
50*4882a593Smuzhiyun ret = lzo1x_1_compress(data_in, *sourcelen, lzo_compress_buf, &compress_size, lzo_mem);
51*4882a593Smuzhiyun if (ret != LZO_E_OK)
52*4882a593Smuzhiyun goto fail;
53*4882a593Smuzhiyun
54*4882a593Smuzhiyun if (compress_size > *dstlen)
55*4882a593Smuzhiyun goto fail;
56*4882a593Smuzhiyun
57*4882a593Smuzhiyun memcpy(cpage_out, lzo_compress_buf, compress_size);
58*4882a593Smuzhiyun mutex_unlock(&deflate_mutex);
59*4882a593Smuzhiyun
60*4882a593Smuzhiyun *dstlen = compress_size;
61*4882a593Smuzhiyun return 0;
62*4882a593Smuzhiyun
63*4882a593Smuzhiyun fail:
64*4882a593Smuzhiyun mutex_unlock(&deflate_mutex);
65*4882a593Smuzhiyun return -1;
66*4882a593Smuzhiyun }
67*4882a593Smuzhiyun
jffs2_lzo_decompress(unsigned char * data_in,unsigned char * cpage_out,uint32_t srclen,uint32_t destlen)68*4882a593Smuzhiyun static int jffs2_lzo_decompress(unsigned char *data_in, unsigned char *cpage_out,
69*4882a593Smuzhiyun uint32_t srclen, uint32_t destlen)
70*4882a593Smuzhiyun {
71*4882a593Smuzhiyun size_t dl = destlen;
72*4882a593Smuzhiyun int ret;
73*4882a593Smuzhiyun
74*4882a593Smuzhiyun ret = lzo1x_decompress_safe(data_in, srclen, cpage_out, &dl);
75*4882a593Smuzhiyun
76*4882a593Smuzhiyun if (ret != LZO_E_OK || dl != destlen)
77*4882a593Smuzhiyun return -1;
78*4882a593Smuzhiyun
79*4882a593Smuzhiyun return 0;
80*4882a593Smuzhiyun }
81*4882a593Smuzhiyun
82*4882a593Smuzhiyun static struct jffs2_compressor jffs2_lzo_comp = {
83*4882a593Smuzhiyun .priority = JFFS2_LZO_PRIORITY,
84*4882a593Smuzhiyun .name = "lzo",
85*4882a593Smuzhiyun .compr = JFFS2_COMPR_LZO,
86*4882a593Smuzhiyun .compress = &jffs2_lzo_compress,
87*4882a593Smuzhiyun .decompress = &jffs2_lzo_decompress,
88*4882a593Smuzhiyun .disabled = 0,
89*4882a593Smuzhiyun };
90*4882a593Smuzhiyun
jffs2_lzo_init(void)91*4882a593Smuzhiyun int __init jffs2_lzo_init(void)
92*4882a593Smuzhiyun {
93*4882a593Smuzhiyun int ret;
94*4882a593Smuzhiyun
95*4882a593Smuzhiyun ret = alloc_workspace();
96*4882a593Smuzhiyun if (ret < 0)
97*4882a593Smuzhiyun return ret;
98*4882a593Smuzhiyun
99*4882a593Smuzhiyun ret = jffs2_register_compressor(&jffs2_lzo_comp);
100*4882a593Smuzhiyun if (ret)
101*4882a593Smuzhiyun free_workspace();
102*4882a593Smuzhiyun
103*4882a593Smuzhiyun return ret;
104*4882a593Smuzhiyun }
105*4882a593Smuzhiyun
jffs2_lzo_exit(void)106*4882a593Smuzhiyun void jffs2_lzo_exit(void)
107*4882a593Smuzhiyun {
108*4882a593Smuzhiyun jffs2_unregister_compressor(&jffs2_lzo_comp);
109*4882a593Smuzhiyun free_workspace();
110*4882a593Smuzhiyun }
111