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Diffstat (limited to 'lib/lz4/lz4defs.h')
-rw-r--r-- | lib/lz4/lz4defs.h | 247 |
1 files changed, 247 insertions, 0 deletions
diff --git a/lib/lz4/lz4defs.h b/lib/lz4/lz4defs.h new file mode 100644 index 000000000..330aa539b --- /dev/null +++ b/lib/lz4/lz4defs.h @@ -0,0 +1,247 @@ +#ifndef __LZ4DEFS_H__ +#define __LZ4DEFS_H__ + +/* + * lz4defs.h -- common and architecture specific defines for the kernel usage + + * LZ4 - Fast LZ compression algorithm + * Copyright (C) 2011-2016, 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://www.lz4.org + * - LZ4 source repository : https://github.com/lz4/lz4 + * + * Changed for kernel usage by: + * Sven Schmidt <4sschmid@informatik.uni-hamburg.de> + */ + +#include <asm/unaligned.h> + +#include <linux/bitops.h> +#include <linux/string.h> /* memset, memcpy */ + +#define FORCE_INLINE __always_inline + +/*-************************************ + * Basic Types + **************************************/ +#include <linux/types.h> + +typedef uint8_t BYTE; +typedef uint16_t U16; +typedef uint32_t U32; +typedef int32_t S32; +typedef uint64_t U64; +typedef uintptr_t uptrval; + +/*-************************************ + * Architecture specifics + **************************************/ +#if defined(CONFIG_64BIT) +#define LZ4_ARCH64 1 +#else +#define LZ4_ARCH64 0 +#endif + +#if defined(__LITTLE_ENDIAN) +#define LZ4_LITTLE_ENDIAN 1 +#else +#define LZ4_LITTLE_ENDIAN 0 +#endif + +/*-************************************ + * Constants + **************************************/ +#define MINMATCH 4 + +#define WILDCOPYLENGTH 8 +#define LASTLITERALS 5 +#define MFLIMIT (WILDCOPYLENGTH + MINMATCH) +/* + * ensure it's possible to write 2 x wildcopyLength + * without overflowing output buffer + */ +#define MATCH_SAFEGUARD_DISTANCE ((2 * WILDCOPYLENGTH) - MINMATCH) + +/* Increase this value ==> compression run slower on incompressible data */ +#define LZ4_SKIPTRIGGER 6 + +#define HASH_UNIT sizeof(size_t) + +#define KB (1 << 10) +#define MB (1 << 20) +#define GB (1U << 30) + +#define MAXD_LOG 16 +#define MAX_DISTANCE ((1 << MAXD_LOG) - 1) +#define STEPSIZE sizeof(size_t) + +#define ML_BITS 4 +#define ML_MASK ((1U << ML_BITS) - 1) +#define RUN_BITS (8 - ML_BITS) +#define RUN_MASK ((1U << RUN_BITS) - 1) + +/*-************************************ + * Reading and writing into memory + **************************************/ +static FORCE_INLINE U16 LZ4_read16(const void *ptr) +{ + return get_unaligned((const U16 *)ptr); +} + +static FORCE_INLINE U32 LZ4_read32(const void *ptr) +{ + return get_unaligned((const U32 *)ptr); +} + +static FORCE_INLINE size_t LZ4_read_ARCH(const void *ptr) +{ + return get_unaligned((const size_t *)ptr); +} + +static FORCE_INLINE void LZ4_write16(void *memPtr, U16 value) +{ + put_unaligned(value, (U16 *)memPtr); +} + +static FORCE_INLINE void LZ4_write32(void *memPtr, U32 value) +{ + put_unaligned(value, (U32 *)memPtr); +} + +static FORCE_INLINE U16 LZ4_readLE16(const void *memPtr) +{ + return get_unaligned_le16(memPtr); +} + +static FORCE_INLINE void LZ4_writeLE16(void *memPtr, U16 value) +{ + return put_unaligned_le16(value, memPtr); +} + +/* + * LZ4 relies on memcpy with a constant size being inlined. In freestanding + * environments, the compiler can't assume the implementation of memcpy() is + * standard compliant, so apply its specialized memcpy() inlining logic. When + * possible, use __builtin_memcpy() to tell the compiler to analyze memcpy() + * as-if it were standard compliant, so it can inline it in freestanding + * environments. This is needed when decompressing the Linux Kernel, for example. + */ +#define LZ4_memcpy(dst, src, size) __builtin_memcpy(dst, src, size) +#define LZ4_memmove(dst, src, size) __builtin_memmove(dst, src, size) + +static FORCE_INLINE void LZ4_copy8(void *dst, const void *src) +{ +#if LZ4_ARCH64 + U64 a = get_unaligned((const U64 *)src); + + put_unaligned(a, (U64 *)dst); +#else + U32 a = get_unaligned((const U32 *)src); + U32 b = get_unaligned((const U32 *)src + 1); + + put_unaligned(a, (U32 *)dst); + put_unaligned(b, (U32 *)dst + 1); +#endif +} + +/* + * customized variant of memcpy, + * which can overwrite up to 7 bytes beyond dstEnd + */ +static FORCE_INLINE void LZ4_wildCopy(void *dstPtr, + const void *srcPtr, void *dstEnd) +{ + BYTE *d = (BYTE *)dstPtr; + const BYTE *s = (const BYTE *)srcPtr; + BYTE *const e = (BYTE *)dstEnd; + + do { + LZ4_copy8(d, s); + d += 8; + s += 8; + } while (d < e); +} + +static FORCE_INLINE unsigned int LZ4_NbCommonBytes(register size_t val) +{ +#if LZ4_LITTLE_ENDIAN + return __ffs(val) >> 3; +#else + return (BITS_PER_LONG - 1 - __fls(val)) >> 3; +#endif +} + +static FORCE_INLINE unsigned int LZ4_count( + const BYTE *pIn, + const BYTE *pMatch, + const BYTE *pInLimit) +{ + const BYTE *const pStart = pIn; + + while (likely(pIn < pInLimit - (STEPSIZE - 1))) { + size_t const diff = LZ4_read_ARCH(pMatch) ^ LZ4_read_ARCH(pIn); + + if (!diff) { + pIn += STEPSIZE; + pMatch += STEPSIZE; + continue; + } + + pIn += LZ4_NbCommonBytes(diff); + + return (unsigned int)(pIn - pStart); + } + +#if LZ4_ARCH64 + if ((pIn < (pInLimit - 3)) + && (LZ4_read32(pMatch) == LZ4_read32(pIn))) { + pIn += 4; + pMatch += 4; + } +#endif + + if ((pIn < (pInLimit - 1)) + && (LZ4_read16(pMatch) == LZ4_read16(pIn))) { + pIn += 2; + pMatch += 2; + } + + if ((pIn < pInLimit) && (*pMatch == *pIn)) + pIn++; + + return (unsigned int)(pIn - pStart); +} + +typedef enum { noLimit = 0, limitedOutput = 1 } limitedOutput_directive; +typedef enum { byPtr, byU32, byU16 } tableType_t; + +typedef enum { noDict = 0, withPrefix64k, usingExtDict } dict_directive; +typedef enum { noDictIssue = 0, dictSmall } dictIssue_directive; + +typedef enum { endOnOutputSize = 0, endOnInputSize = 1 } endCondition_directive; +typedef enum { decode_full_block = 0, partial_decode = 1 } earlyEnd_directive; + +#define LZ4_STATIC_ASSERT(c) BUILD_BUG_ON(!(c)) + +#endif |