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decompressor: Add LZ4 decompressor module 

This patch adds support for LZ4 decompression in the Linux Kernel.
LZ4 Decompression APIs for kernel are based on LZ4 implementation
by Yann Collet.

LZ4 homepage : http://fastcompression.blogspot.com/p/lz4.html
LZ4 source repository : http://code.google.com/p/lz4/

Signed-off-by: Kyungsik Lee <kyungsik.lee@lge.com>
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This commit is contained in:
Kyungsik Lee 2013-07-15 12:20:51 +02:00 committed by Sascha Hauer
parent 3f0642d383
commit e944e7f810
3 changed files with 569 additions and 0 deletions
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87
include/linux/lz4.h Normal file
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#ifndef __LZ4_H__
#define __LZ4_H__
/*
* LZ4 Kernel Interface
*
* Copyright (C) 2013, LG Electronics, Kyungsik Lee <kyungsik.lee@lge.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#define LZ4_MEM_COMPRESS (4096 * sizeof(unsigned char *))
#define LZ4HC_MEM_COMPRESS (65538 * sizeof(unsigned char *))
/*
* lz4_compressbound()
* Provides the maximum size that LZ4 may output in a "worst case" scenario
* (input data not compressible)
*/
static inline size_t lz4_compressbound(size_t isize)
{
return isize + (isize / 255) + 16;
}
/*
* lz4_compress()
* src : source address of the original data
* src_len : size of the original data
* dst : output buffer address of the compressed data
* This requires 'dst' of size LZ4_COMPRESSBOUND.
* dst_len : is the output size, which is returned after compress done
* workmem : address of the working memory.
* This requires 'workmem' of size LZ4_MEM_COMPRESS.
* return : Success if return 0
* Error if return (< 0)
* note : Destination buffer and workmem must be already allocated with
* the defined size.
*/
int lz4_compress(const unsigned char *src, size_t src_len,
unsigned char *dst, size_t *dst_len, void *wrkmem);
/*
* lz4hc_compress()
* src : source address of the original data
* src_len : size of the original data
* dst : output buffer address of the compressed data
* This requires 'dst' of size LZ4_COMPRESSBOUND.
* dst_len : is the output size, which is returned after compress done
* workmem : address of the working memory.
* This requires 'workmem' of size LZ4HC_MEM_COMPRESS.
* return : Success if return 0
* Error if return (< 0)
* note : Destination buffer and workmem must be already allocated with
* the defined size.
*/
int lz4hc_compress(const unsigned char *src, size_t src_len,
unsigned char *dst, size_t *dst_len, void *wrkmem);
/*
* lz4_decompress()
* src : source address of the compressed data
* src_len : is the input size, whcih is returned after decompress done
* dest : output buffer address of the decompressed data
* actual_dest_len: is the size of uncompressed data, supposing it's known
* return : Success if return 0
* Error if return (< 0)
* note : Destination buffer must be already allocated.
* slightly faster than lz4_decompress_unknownoutputsize()
*/
int lz4_decompress(const char *src, size_t *src_len, char *dest,
size_t actual_dest_len);
/*
* lz4_decompress_unknownoutputsize()
* src : source address of the compressed data
* src_len : is the input size, therefore the compressed size
* dest : output buffer address of the decompressed data
* dest_len: is the max size of the destination buffer, which is
* returned with actual size of decompressed data after
* decompress done
* return : Success if return 0
* Error if return (< 0)
* note : Destination buffer must be already allocated.
*/
int lz4_decompress_unknownoutputsize(const char *src, size_t src_len,
char *dest, size_t *dest_len);
#endif

326
lib/lz4/lz4_decompress.c Normal file
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/*
* LZ4 Decompressor for Linux kernel
*
* Copyright (C) 2013, LG Electronics, Kyungsik Lee <kyungsik.lee@lge.com>
*
* Based on LZ4 implementation by Yann Collet.
*
* LZ4 - Fast LZ compression algorithm
* Copyright (C) 2011-2012, Yann Collet.
* BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* You can contact the author at :
* - LZ4 homepage : http://fastcompression.blogspot.com/p/lz4.html
* - LZ4 source repository : http://code.google.com/p/lz4/
*/
#ifndef STATIC
#include <linux/module.h>
#include <linux/kernel.h>
#endif
#include <linux/lz4.h>
#include <asm/unaligned.h>
#include "lz4defs.h"
static int lz4_uncompress(const char *source, char *dest, int osize)
{
const BYTE *ip = (const BYTE *) source;
const BYTE *ref;
BYTE *op = (BYTE *) dest;
BYTE * const oend = op + osize;
BYTE *cpy;
unsigned token;
size_t length;
size_t dec32table[] = {0, 3, 2, 3, 0, 0, 0, 0};
#if LZ4_ARCH64
size_t dec64table[] = {0, 0, 0, -1, 0, 1, 2, 3};
#endif
while (1) {
/* get runlength */
token = *ip++;
length = (token >> ML_BITS);
if (length == RUN_MASK) {
size_t len;
len = *ip++;
for (; len == 255; length += 255)
len = *ip++;
length += len;
}
/* copy literals */
cpy = op + length;
if (unlikely(cpy > oend - COPYLENGTH)) {
/*
* Error: not enough place for another match
* (min 4) + 5 literals
*/
if (cpy != oend)
goto _output_error;
memcpy(op, ip, length);
ip += length;
break; /* EOF */
}
LZ4_WILDCOPY(ip, op, cpy);
ip -= (op - cpy);
op = cpy;
/* get offset */
LZ4_READ_LITTLEENDIAN_16(ref, cpy, ip);
ip += 2;
/* Error: offset create reference outside destination buffer */
if (unlikely(ref < (BYTE *const) dest))
goto _output_error;
/* get matchlength */
length = token & ML_MASK;
if (length == ML_MASK) {
for (; *ip == 255; length += 255)
ip++;
length += *ip++;
}
/* copy repeated sequence */
if (unlikely((op - ref) < STEPSIZE)) {
#if LZ4_ARCH64
size_t dec64 = dec64table[op - ref];
#else
const int dec64 = 0;
#endif
op[0] = ref[0];
op[1] = ref[1];
op[2] = ref[2];
op[3] = ref[3];
op += 4;
ref += 4;
ref -= dec32table[op-ref];
PUT4(ref, op);
op += STEPSIZE - 4;
ref -= dec64;
} else {
LZ4_COPYSTEP(ref, op);
}
cpy = op + length - (STEPSIZE - 4);
if (cpy > (oend - COPYLENGTH)) {
/* Error: request to write beyond destination buffer */
if (cpy > oend)
goto _output_error;
LZ4_SECURECOPY(ref, op, (oend - COPYLENGTH));
while (op < cpy)
*op++ = *ref++;
op = cpy;
/*
* Check EOF (should never happen, since last 5 bytes
* are supposed to be literals)
*/
if (op == oend)
goto _output_error;
continue;
}
LZ4_SECURECOPY(ref, op, cpy);
op = cpy; /* correction */
}
/* end of decoding */
return (int) (((char *)ip) - source);
/* write overflow error detected */
_output_error:
return (int) (-(((char *)ip) - source));
}
static int lz4_uncompress_unknownoutputsize(const char *source, char *dest,
int isize, size_t maxoutputsize)
{
const BYTE *ip = (const BYTE *) source;
const BYTE *const iend = ip + isize;
const BYTE *ref;
BYTE *op = (BYTE *) dest;
BYTE * const oend = op + maxoutputsize;
BYTE *cpy;
size_t dec32table[] = {0, 3, 2, 3, 0, 0, 0, 0};
#if LZ4_ARCH64
size_t dec64table[] = {0, 0, 0, -1, 0, 1, 2, 3};
#endif
/* Main Loop */
while (ip < iend) {
unsigned token;
size_t length;
/* get runlength */
token = *ip++;
length = (token >> ML_BITS);
if (length == RUN_MASK) {
int s = 255;
while ((ip < iend) && (s == 255)) {
s = *ip++;
length += s;
}
}
/* copy literals */
cpy = op + length;
if ((cpy > oend - COPYLENGTH) ||
(ip + length > iend - COPYLENGTH)) {
if (cpy > oend)
goto _output_error;/* writes beyond buffer */
if (ip + length != iend)
goto _output_error;/*
* Error: LZ4 format requires
* to consume all input
* at this stage
*/
memcpy(op, ip, length);
op += length;
break;/* Necessarily EOF, due to parsing restrictions */
}
LZ4_WILDCOPY(ip, op, cpy);
ip -= (op - cpy);
op = cpy;
/* get offset */
LZ4_READ_LITTLEENDIAN_16(ref, cpy, ip);
ip += 2;
if (ref < (BYTE * const) dest)
goto _output_error;
/*
* Error : offset creates reference
* outside of destination buffer
*/
/* get matchlength */
length = (token & ML_MASK);
if (length == ML_MASK) {
while (ip < iend) {
int s = *ip++;
length += s;
if (s == 255)
continue;
break;
}
}
/* copy repeated sequence */
if (unlikely((op - ref) < STEPSIZE)) {
#if LZ4_ARCH64
size_t dec64 = dec64table[op - ref];
#else
const int dec64 = 0;
#endif
op[0] = ref[0];
op[1] = ref[1];
op[2] = ref[2];
op[3] = ref[3];
op += 4;
ref += 4;
ref -= dec32table[op - ref];
PUT4(ref, op);
op += STEPSIZE - 4;
ref -= dec64;
} else {
LZ4_COPYSTEP(ref, op);
}
cpy = op + length - (STEPSIZE-4);
if (cpy > oend - COPYLENGTH) {
if (cpy > oend)
goto _output_error; /* write outside of buf */
LZ4_SECURECOPY(ref, op, (oend - COPYLENGTH));
while (op < cpy)
*op++ = *ref++;
op = cpy;
/*
* Check EOF (should never happen, since last 5 bytes
* are supposed to be literals)
*/
if (op == oend)
goto _output_error;
continue;
}
LZ4_SECURECOPY(ref, op, cpy);
op = cpy; /* correction */
}
/* end of decoding */
return (int) (((char *) op) - dest);
/* write overflow error detected */
_output_error:
return (int) (-(((char *) ip) - source));
}
int lz4_decompress(const char *src, size_t *src_len, char *dest,
size_t actual_dest_len)
{
int ret = -1;
int input_len = 0;
input_len = lz4_uncompress(src, dest, actual_dest_len);
if (input_len < 0)
goto exit_0;
*src_len = input_len;
return 0;
exit_0:
return ret;
}
#ifndef STATIC
EXPORT_SYMBOL_GPL(lz4_decompress);
#endif
int lz4_decompress_unknownoutputsize(const char *src, size_t src_len,
char *dest, size_t *dest_len)
{
int ret = -1;
int out_len = 0;
out_len = lz4_uncompress_unknownoutputsize(src, dest, src_len,
*dest_len);
if (out_len < 0)
goto exit_0;
*dest_len = out_len;
return 0;
exit_0:
return ret;
}
#ifndef STATIC
EXPORT_SYMBOL_GPL(lz4_decompress_unknownoutputsize);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("LZ4 Decompressor");
#endif

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lib/lz4/lz4defs.h Normal file
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/*
* lz4defs.h -- architecture specific defines
*
* Copyright (C) 2013, LG Electronics, Kyungsik Lee <kyungsik.lee@lge.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
/*
* Detects 64 bits mode
*/
#if (defined(__x86_64__) || defined(__x86_64) || defined(__amd64__) \
|| defined(__ppc64__) || defined(__LP64__))
#define LZ4_ARCH64 1
#else
#define LZ4_ARCH64 0
#endif
/*
* Architecture-specific macros
*/
#define BYTE u8
typedef struct _U16_S { u16 v; } U16_S;
typedef struct _U32_S { u32 v; } U32_S;
typedef struct _U64_S { u64 v; } U64_S;
#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) \
|| defined(CONFIG_ARM) && __LINUX_ARM_ARCH__ >= 6 \
&& defined(ARM_EFFICIENT_UNALIGNED_ACCESS)
#define A16(x) (((U16_S *)(x))->v)
#define A32(x) (((U32_S *)(x))->v)
#define A64(x) (((U64_S *)(x))->v)
#define PUT4(s, d) (A32(d) = A32(s))
#define PUT8(s, d) (A64(d) = A64(s))
#define LZ4_WRITE_LITTLEENDIAN_16(p, v) \
do { \
A16(p) = v; \
p += 2; \
} while (0)
#else /* CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS */
#define A64(x) get_unaligned((u64 *)&(((U16_S *)(x))->v))
#define A32(x) get_unaligned((u32 *)&(((U16_S *)(x))->v))
#define A16(x) get_unaligned((u16 *)&(((U16_S *)(x))->v))
#define PUT4(s, d) \
put_unaligned(get_unaligned((const u32 *) s), (u32 *) d)
#define PUT8(s, d) \
put_unaligned(get_unaligned((const u64 *) s), (u64 *) d)
#define LZ4_WRITE_LITTLEENDIAN_16(p, v) \
do { \
put_unaligned(v, (u16 *)(p)); \
p += 2; \
} while (0)
#endif
#define COPYLENGTH 8
#define ML_BITS 4
#define ML_MASK ((1U << ML_BITS) - 1)
#define RUN_BITS (8 - ML_BITS)
#define RUN_MASK ((1U << RUN_BITS) - 1)
#define MEMORY_USAGE 14
#define MINMATCH 4
#define SKIPSTRENGTH 6
#define LASTLITERALS 5
#define MFLIMIT (COPYLENGTH + MINMATCH)
#define MINLENGTH (MFLIMIT + 1)
#define MAXD_LOG 16
#define MAXD (1 << MAXD_LOG)
#define MAXD_MASK (u32)(MAXD - 1)
#define MAX_DISTANCE (MAXD - 1)
#define HASH_LOG (MAXD_LOG - 1)
#define HASHTABLESIZE (1 << HASH_LOG)
#define MAX_NB_ATTEMPTS 256
#define OPTIMAL_ML (int)((ML_MASK-1)+MINMATCH)
#define LZ4_64KLIMIT ((1<<16) + (MFLIMIT - 1))
#define HASHLOG64K ((MEMORY_USAGE - 2) + 1)
#define HASH64KTABLESIZE (1U << HASHLOG64K)
#define LZ4_HASH_VALUE(p) (((A32(p)) * 2654435761U) >> \
((MINMATCH * 8) - (MEMORY_USAGE-2)))
#define LZ4_HASH64K_VALUE(p) (((A32(p)) * 2654435761U) >> \
((MINMATCH * 8) - HASHLOG64K))
#define HASH_VALUE(p) (((A32(p)) * 2654435761U) >> \
((MINMATCH * 8) - HASH_LOG))
#if LZ4_ARCH64/* 64-bit */
#define STEPSIZE 8
#define LZ4_COPYSTEP(s, d) \
do { \
PUT8(s, d); \
d += 8; \
s += 8; \
} while (0)
#define LZ4_COPYPACKET(s, d) LZ4_COPYSTEP(s, d)
#define LZ4_SECURECOPY(s, d, e) \
do { \
if (d < e) { \
LZ4_WILDCOPY(s, d, e); \
} \
} while (0)
#define HTYPE u32
#ifdef __BIG_ENDIAN
#define LZ4_NBCOMMONBYTES(val) (__builtin_clzll(val) >> 3)
#else
#define LZ4_NBCOMMONBYTES(val) (__builtin_ctzll(val) >> 3)
#endif
#else /* 32-bit */
#define STEPSIZE 4
#define LZ4_COPYSTEP(s, d) \
do { \
PUT4(s, d); \
d += 4; \
s += 4; \
} while (0)
#define LZ4_COPYPACKET(s, d) \
do { \
LZ4_COPYSTEP(s, d); \
LZ4_COPYSTEP(s, d); \
} while (0)
#define LZ4_SECURECOPY LZ4_WILDCOPY
#define HTYPE const u8*
#ifdef __BIG_ENDIAN
#define LZ4_NBCOMMONBYTES(val) (__builtin_clz(val) >> 3)
#else
#define LZ4_NBCOMMONBYTES(val) (__builtin_ctz(val) >> 3)
#endif
#endif
#define LZ4_READ_LITTLEENDIAN_16(d, s, p) \
(d = s - get_unaligned_le16(p))
#define LZ4_WILDCOPY(s, d, e) \
do { \
LZ4_COPYPACKET(s, d); \
} while (d < e)
#define LZ4_BLINDCOPY(s, d, l) \
do { \
u8 *e = (d) + l; \
LZ4_WILDCOPY(s, d, e); \
d = e; \
} while (0)