lib/lz4/lz4defs.h - linux - Git at Google

 #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
	#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