Merge branch 'akpm' (updates from Andrew Morton)

Merge second patch-bomb from Andrew Morton:
 - misc fixes
 - audit stuff
 - fanotify/inotify/dnotify things
 - most of the rest of MM.  The new cache shrinker code from Glauber and
   Dave Chinner probably isn't quite stabilized yet.
 - ptrace
 - ipc
 - partitions
 - reboot cleanups
 - add LZ4 decompressor, use it for kernel compression

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (118 commits)
  lib/scatterlist: error handling in __sg_alloc_table()
  scsi_debug: fix do_device_access() with wrap around range
  crypto: talitos: use sg_pcopy_to_buffer()
  lib/scatterlist: introduce sg_pcopy_from_buffer() and sg_pcopy_to_buffer()
  lib/scatterlist: factor out sg_miter_get_next_page() from sg_miter_next()
  crypto: add lz4 Cryptographic API
  lib: add lz4 compressor module
  arm: add support for LZ4-compressed kernel
  lib: add support for LZ4-compressed kernel
  decompressor: add LZ4 decompressor module
  lib: add weak clz/ctz functions
  reboot: move arch/x86 reboot= handling to generic kernel
  reboot: arm: change reboot_mode to use enum reboot_mode
  reboot: arm: prepare reboot_mode for moving to generic kernel code
  reboot: arm: remove unused restart_mode fields from some arm subarchs
  reboot: unicore32: prepare reboot_mode for moving to generic kernel code
  reboot: x86: prepare reboot_mode for moving to generic kernel code
  reboot: checkpatch.pl the new kernel/reboot.c file
  reboot: move shutdown/reboot related functions to kernel/reboot.c
  reboot: remove -stable friendly PF_THREAD_BOUND define
  ...

11 files changed, 1846 insertions, 23 deletions

diff --git a/lib/Kconfig b/lib/Kconfig
index f1ed53c3aa4..35da51359d4 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -194,6 +194,15 @@ config LZO_COMPRESS
 config LZO_DECOMPRESS
 	tristate
 
+config LZ4_COMPRESS
+	tristate
+
+config LZ4HC_COMPRESS
+	tristate
+
+config LZ4_DECOMPRESS
+	tristate
+
 source "lib/xz/Kconfig"
 
 #
@@ -218,6 +227,10 @@ config DECOMPRESS_LZO
 	select LZO_DECOMPRESS
 	tristate
 
+config DECOMPRESS_LZ4
+	select LZ4_DECOMPRESS
+	tristate
+
 #
 # Generic allocator support is selected if needed
 #
diff --git a/lib/Makefile b/lib/Makefile
index c09e38eca87..7baccfd8a4e 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -23,7 +23,7 @@ lib-y	+= kobject.o klist.o
 
 obj-y += bcd.o div64.o sort.o parser.o halfmd4.o debug_locks.o random32.o \
 	 bust_spinlocks.o hexdump.o kasprintf.o bitmap.o scatterlist.o \
-	 gcd.o lcm.o list_sort.o uuid.o flex_array.o iovec.o \
+	 gcd.o lcm.o list_sort.o uuid.o flex_array.o iovec.o clz_ctz.o \
 	 bsearch.o find_last_bit.o find_next_bit.o llist.o memweight.o kfifo.o
 obj-y += string_helpers.o
 obj-$(CONFIG_TEST_STRING_HELPERS) += test-string_helpers.o
@@ -75,6 +75,9 @@ obj-$(CONFIG_REED_SOLOMON) += reed_solomon/
 obj-$(CONFIG_BCH) += bch.o
 obj-$(CONFIG_LZO_COMPRESS) += lzo/
 obj-$(CONFIG_LZO_DECOMPRESS) += lzo/
+obj-$(CONFIG_LZ4_COMPRESS) += lz4/
+obj-$(CONFIG_LZ4HC_COMPRESS) += lz4/
+obj-$(CONFIG_LZ4_DECOMPRESS) += lz4/
 obj-$(CONFIG_XZ_DEC) += xz/
 obj-$(CONFIG_RAID6_PQ) += raid6/
 
@@ -83,6 +86,7 @@ lib-$(CONFIG_DECOMPRESS_BZIP2) += decompress_bunzip2.o
 lib-$(CONFIG_DECOMPRESS_LZMA) += decompress_unlzma.o
 lib-$(CONFIG_DECOMPRESS_XZ) += decompress_unxz.o
 lib-$(CONFIG_DECOMPRESS_LZO) += decompress_unlzo.o
+lib-$(CONFIG_DECOMPRESS_LZ4) += decompress_unlz4.o
 
 obj-$(CONFIG_TEXTSEARCH) += textsearch.o
 obj-$(CONFIG_TEXTSEARCH_KMP) += ts_kmp.o
diff --git a/lib/clz_ctz.c b/lib/clz_ctz.c
new file mode 100644
index 00000000000..a8f8379eb49
--- /dev/null
+++ b/lib/clz_ctz.c
@@ -0,0 +1,58 @@
+/*
+ * lib/clz_ctz.c
+ *
+ * Copyright (C) 2013 Chanho Min <chanho.min@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.
+ *
+ * __c[lt]z[sd]i2 can be overridden by linking arch-specific versions.
+ */
+
+#include <linux/export.h>
+#include <linux/kernel.h>
+
+int __weak __ctzsi2(int val)
+{
+	return __ffs(val);
+}
+EXPORT_SYMBOL(__ctzsi2);
+
+int __weak __clzsi2(int val)
+{
+	return 32 - fls(val);
+}
+EXPORT_SYMBOL(__clzsi2);
+
+#if BITS_PER_LONG == 32
+
+int __weak __clzdi2(long val)
+{
+	return 32 - fls((int)val);
+}
+EXPORT_SYMBOL(__clzdi2);
+
+int __weak __ctzdi2(long val)
+{
+	return __ffs((u32)val);
+}
+EXPORT_SYMBOL(__ctzdi2);
+
+#elif BITS_PER_LONG == 64
+
+int __weak __clzdi2(long val)
+{
+	return 64 - fls64((u64)val);
+}
+EXPORT_SYMBOL(__clzdi2);
+
+int __weak __ctzdi2(long val)
+{
+	return __ffs64((u64)val);
+}
+EXPORT_SYMBOL(__ctzdi2);
+
+#else
+#error BITS_PER_LONG not 32 or 64
+#endif
diff --git a/lib/decompress.c b/lib/decompress.c
index f8fdedaf7b3..4d1cd0397aa 100644
--- a/lib/decompress.c
+++ b/lib/decompress.c
@@ -11,6 +11,7 @@
 #include <linux/decompress/unxz.h>
 #include <linux/decompress/inflate.h>
 #include <linux/decompress/unlzo.h>
+#include <linux/decompress/unlz4.h>
 
 #include <linux/types.h>
 #include <linux/string.h>
@@ -31,6 +32,9 @@
 #ifndef CONFIG_DECOMPRESS_LZO
 # define unlzo NULL
 #endif
+#ifndef CONFIG_DECOMPRESS_LZ4
+# define unlz4 NULL
+#endif
 
 struct compress_format {
 	unsigned char magic[2];
@@ -45,6 +49,7 @@ static const struct compress_format compressed_formats[] __initconst = {
 	{ {0x5d, 0x00}, "lzma", unlzma },
 	{ {0xfd, 0x37}, "xz", unxz },
 	{ {0x89, 0x4c}, "lzo", unlzo },
+	{ {0x02, 0x21}, "lz4", unlz4 },
 	{ {0, 0}, NULL, NULL }
 };
 
diff --git a/lib/decompress_unlz4.c b/lib/decompress_unlz4.c
new file mode 100644
index 00000000000..3e67cfad16a
--- /dev/null
+++ b/lib/decompress_unlz4.c
@@ -0,0 +1,187 @@
+/*
+ * Wrapper for decompressing LZ4-compressed kernel, initramfs, and initrd
+ *
+ * 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.
+ */
+
+#ifdef STATIC
+#define PREBOOT
+#include "lz4/lz4_decompress.c"
+#else
+#include <linux/decompress/unlz4.h>
+#endif
+#include <linux/types.h>
+#include <linux/lz4.h>
+#include <linux/decompress/mm.h>
+#include <linux/compiler.h>
+
+#include <asm/unaligned.h>
+
+/*
+ * Note: Uncompressed chunk size is used in the compressor side
+ * (userspace side for compression).
+ * It is hardcoded because there is not proper way to extract it
+ * from the binary stream which is generated by the preliminary
+ * version of LZ4 tool so far.
+ */
+#define LZ4_DEFAULT_UNCOMPRESSED_CHUNK_SIZE (8 << 20)
+#define ARCHIVE_MAGICNUMBER 0x184C2102
+
+STATIC inline int INIT unlz4(u8 *input, int in_len,
+				int (*fill) (void *, unsigned int),
+				int (*flush) (void *, unsigned int),
+				u8 *output, int *posp,
+				void (*error) (char *x))
+{
+	int ret = -1;
+	size_t chunksize = 0;
+	size_t uncomp_chunksize = LZ4_DEFAULT_UNCOMPRESSED_CHUNK_SIZE;
+	u8 *inp;
+	u8 *inp_start;
+	u8 *outp;
+	int size = in_len;
+#ifdef PREBOOT
+	size_t out_len = get_unaligned_le32(input + in_len);
+#endif
+	size_t dest_len;
+
+
+	if (output) {
+		outp = output;
+	} else if (!flush) {
+		error("NULL output pointer and no flush function provided");
+		goto exit_0;
+	} else {
+		outp = large_malloc(uncomp_chunksize);
+		if (!outp) {
+			error("Could not allocate output buffer");
+			goto exit_0;
+		}
+	}
+
+	if (input && fill) {
+		error("Both input pointer and fill function provided,");
+		goto exit_1;
+	} else if (input) {
+		inp = input;
+	} else if (!fill) {
+		error("NULL input pointer and missing fill function");
+		goto exit_1;
+	} else {
+		inp = large_malloc(lz4_compressbound(uncomp_chunksize));
+		if (!inp) {
+			error("Could not allocate input buffer");
+			goto exit_1;
+		}
+	}
+	inp_start = inp;
+
+	if (posp)
+		*posp = 0;
+
+	if (fill)
+		fill(inp, 4);
+
+	chunksize = get_unaligned_le32(inp);
+	if (chunksize == ARCHIVE_MAGICNUMBER) {
+		inp += 4;
+		size -= 4;
+	} else {
+		error("invalid header");
+		goto exit_2;
+	}
+
+	if (posp)
+		*posp += 4;
+
+	for (;;) {
+
+		if (fill)
+			fill(inp, 4);
+
+		chunksize = get_unaligned_le32(inp);
+		if (chunksize == ARCHIVE_MAGICNUMBER) {
+			inp += 4;
+			size -= 4;
+			if (posp)
+				*posp += 4;
+			continue;
+		}
+		inp += 4;
+		size -= 4;
+
+		if (posp)
+			*posp += 4;
+
+		if (fill) {
+			if (chunksize > lz4_compressbound(uncomp_chunksize)) {
+				error("chunk length is longer than allocated");
+				goto exit_2;
+			}
+			fill(inp, chunksize);
+		}
+#ifdef PREBOOT
+		if (out_len >= uncomp_chunksize) {
+			dest_len = uncomp_chunksize;
+			out_len -= dest_len;
+		} else
+			dest_len = out_len;
+		ret = lz4_decompress(inp, &chunksize, outp, dest_len);
+#else
+		dest_len = uncomp_chunksize;
+		ret = lz4_decompress_unknownoutputsize(inp, chunksize, outp,
+				&dest_len);
+#endif
+		if (ret < 0) {
+			error("Decoding failed");
+			goto exit_2;
+		}
+
+		if (flush && flush(outp, dest_len) != dest_len)
+			goto exit_2;
+		if (output)
+			outp += dest_len;
+		if (posp)
+			*posp += chunksize;
+
+		size -= chunksize;
+
+		if (size == 0)
+			break;
+		else if (size < 0) {
+			error("data corrupted");
+			goto exit_2;
+		}
+
+		inp += chunksize;
+		if (fill)
+			inp = inp_start;
+	}
+
+	ret = 0;
+exit_2:
+	if (!input)
+		large_free(inp_start);
+exit_1:
+	if (!output)
+		large_free(outp);
+exit_0:
+	return ret;
+}
+
+#ifdef PREBOOT
+STATIC int INIT decompress(unsigned char *buf, int in_len,
+			      int(*fill)(void*, unsigned int),
+			      int(*flush)(void*, unsigned int),
+			      unsigned char *output,
+			      int *posp,
+			      void(*error)(char *x)
+	)
+{
+	return unlz4(buf, in_len - 4, fill, flush, output, posp, error);
+}
+#endif
diff --git a/lib/lz4/Makefile b/lib/lz4/Makefile
new file mode 100644
index 00000000000..8085d04e930
--- /dev/null
+++ b/lib/lz4/Makefile
@@ -0,0 +1,3 @@
+obj-$(CONFIG_LZ4_COMPRESS) += lz4_compress.o
+obj-$(CONFIG_LZ4HC_COMPRESS) += lz4hc_compress.o
+obj-$(CONFIG_LZ4_DECOMPRESS) += lz4_decompress.o
diff --git a/lib/lz4/lz4_compress.c b/lib/lz4/lz4_compress.c
new file mode 100644
index 00000000000..fd94058bd7f
--- /dev/null
+++ b/lib/lz4/lz4_compress.c
@@ -0,0 +1,443 @@
+/*
+ * 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/
+ *
+ *  Changed for kernel use by:
+ *  Chanho Min <chanho.min@lge.com>
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/lz4.h>
+#include <asm/unaligned.h>
+#include "lz4defs.h"
+
+/*
+ * LZ4_compressCtx :
+ * -----------------
+ * Compress 'isize' bytes from 'source' into an output buffer 'dest' of
+ * maximum size 'maxOutputSize'.  * If it cannot achieve it, compression
+ * will stop, and result of the function will be zero.
+ * return : the number of bytes written in buffer 'dest', or 0 if the
+ * compression fails
+ */
+static inline int lz4_compressctx(void *ctx,
+		const char *source,
+		char *dest,
+		int isize,
+		int maxoutputsize)
+{
+	HTYPE *hashtable = (HTYPE *)ctx;
+	const u8 *ip = (u8 *)source;
+#if LZ4_ARCH64
+	const BYTE * const base = ip;
+#else
+	const int base = 0;
+#endif
+	const u8 *anchor = ip;
+	const u8 *const iend = ip + isize;
+	const u8 *const mflimit = iend - MFLIMIT;
+	#define MATCHLIMIT (iend - LASTLITERALS)
+
+	u8 *op = (u8 *) dest;
+	u8 *const oend = op + maxoutputsize;
+	int length;
+	const int skipstrength = SKIPSTRENGTH;
+	u32 forwardh;
+	int lastrun;
+
+	/* Init */
+	if (isize < MINLENGTH)
+		goto _last_literals;
+
+	memset((void *)hashtable, 0, LZ4_MEM_COMPRESS);
+
+	/* First Byte */
+	hashtable[LZ4_HASH_VALUE(ip)] = ip - base;
+	ip++;
+	forwardh = LZ4_HASH_VALUE(ip);
+
+	/* Main Loop */
+	for (;;) {
+		int findmatchattempts = (1U << skipstrength) + 3;
+		const u8 *forwardip = ip;
+		const u8 *ref;
+		u8 *token;
+
+		/* Find a match */
+		do {
+			u32 h = forwardh;
+			int step = findmatchattempts++ >> skipstrength;
+			ip = forwardip;
+			forwardip = ip + step;
+
+			if (unlikely(forwardip > mflimit))
+				goto _last_literals;
+
+			forwardh = LZ4_HASH_VALUE(forwardip);
+			ref = base + hashtable[h];
+			hashtable[h] = ip - base;
+		} while ((ref < ip - MAX_DISTANCE) || (A32(ref) != A32(ip)));
+
+		/* Catch up */
+		while ((ip > anchor) && (ref > (u8 *)source) &&
+			unlikely(ip[-1] == ref[-1])) {
+			ip--;
+			ref--;
+		}
+
+		/* Encode Literal length */
+		length = (int)(ip - anchor);
+		token = op++;
+		/* check output limit */
+		if (unlikely(op + length + (2 + 1 + LASTLITERALS) +
+			(length >> 8) > oend))
+			return 0;
+
+		if (length >= (int)RUN_MASK) {
+			int len;
+			*token = (RUN_MASK << ML_BITS);
+			len = length - RUN_MASK;
+			for (; len > 254 ; len -= 255)
+				*op++ = 255;
+			*op++ = (u8)len;
+		} else
+			*token = (length << ML_BITS);
+
+		/* Copy Literals */
+		LZ4_BLINDCOPY(anchor, op, length);
+_next_match:
+		/* Encode Offset */
+		LZ4_WRITE_LITTLEENDIAN_16(op, (u16)(ip - ref));
+
+		/* Start Counting */
+		ip += MINMATCH;
+		/* MinMatch verified */
+		ref += MINMATCH;
+		anchor = ip;
+		while (likely(ip < MATCHLIMIT - (STEPSIZE - 1))) {
+			#if LZ4_ARCH64
+			u64 diff = A64(ref) ^ A64(ip);
+			#else
+			u32 diff = A32(ref) ^ A32(ip);
+			#endif
+			if (!diff) {
+				ip += STEPSIZE;
+				ref += STEPSIZE;
+				continue;
+			}
+			ip += LZ4_NBCOMMONBYTES(diff);
+			goto _endcount;
+		}
+		#if LZ4_ARCH64
+		if ((ip < (MATCHLIMIT - 3)) && (A32(ref) == A32(ip))) {
+			ip += 4;
+			ref += 4;
+		}
+		#endif
+		if ((ip < (MATCHLIMIT - 1)) && (A16(ref) == A16(ip))) {
+			ip += 2;
+			ref += 2;
+		}
+		if ((ip < MATCHLIMIT) && (*ref == *ip))
+			ip++;
+_endcount:
+		/* Encode MatchLength */
+		length = (int)(ip - anchor);
+		/* Check output limit */
+		if (unlikely(op + (1 + LASTLITERALS) + (length >> 8) > oend))
+			return 0;
+		if (length >= (int)ML_MASK) {
+			*token += ML_MASK;
+			length -= ML_MASK;
+			for (; length > 509 ; length -= 510) {
+				*op++ = 255;
+				*op++ = 255;
+			}
+			if (length > 254) {
+				length -= 255;
+				*op++ = 255;
+			}
+			*op++ = (u8)length;
+		} else
+			*token += length;
+
+		/* Test end of chunk */
+		if (ip > mflimit) {
+			anchor = ip;
+			break;
+		}
+
+		/* Fill table */
+		hashtable[LZ4_HASH_VALUE(ip-2)] = ip - 2 - base;
+
+		/* Test next position */
+		ref = base + hashtable[LZ4_HASH_VALUE(ip)];
+		hashtable[LZ4_HASH_VALUE(ip)] = ip - base;
+		if ((ref > ip - (MAX_DISTANCE + 1)) && (A32(ref) == A32(ip))) {
+			token = op++;
+			*token = 0;
+			goto _next_match;
+		}
+
+		/* Prepare next loop */
+		anchor = ip++;
+		forwardh = LZ4_HASH_VALUE(ip);
+	}
+
+_last_literals:
+	/* Encode Last Literals */
+	lastrun = (int)(iend - anchor);
+	if (((char *)op - dest) + lastrun + 1
+		+ ((lastrun + 255 - RUN_MASK) / 255) > (u32)maxoutputsize)
+		return 0;
+
+	if (lastrun >= (int)RUN_MASK) {
+		*op++ = (RUN_MASK << ML_BITS);
+		lastrun -= RUN_MASK;
+		for (; lastrun > 254 ; lastrun -= 255)
+			*op++ = 255;
+		*op++ = (u8)lastrun;
+	} else
+		*op++ = (lastrun << ML_BITS);
+	memcpy(op, anchor, iend - anchor);
+	op += iend - anchor;
+
+	/* End */
+	return (int)(((char *)op) - dest);
+}
+
+static inline int lz4_compress64kctx(void *ctx,
+		const char *source,
+		char *dest,
+		int isize,
+		int maxoutputsize)
+{
+	u16 *hashtable = (u16 *)ctx;
+	const u8 *ip = (u8 *) source;
+	const u8 *anchor = ip;
+	const u8 *const base = ip;
+	const u8 *const iend = ip + isize;
+	const u8 *const mflimit = iend - MFLIMIT;
+	#define MATCHLIMIT (iend - LASTLITERALS)
+
+	u8 *op = (u8 *) dest;
+	u8 *const oend = op + maxoutputsize;
+	int len, length;
+	const int skipstrength = SKIPSTRENGTH;
+	u32 forwardh;
+	int lastrun;
+
+	/* Init */
+	if (isize < MINLENGTH)
+		goto _last_literals;
+
+	memset((void *)hashtable, 0, LZ4_MEM_COMPRESS);
+
+	/* First Byte */
+	ip++;
+	forwardh = LZ4_HASH64K_VALUE(ip);
+
+	/* Main Loop */
+	for (;;) {
+		int findmatchattempts = (1U << skipstrength) + 3;
+		const u8 *forwardip = ip;
+		const u8 *ref;
+		u8 *token;
+
+		/* Find a match */
+		do {
+			u32 h = forwardh;
+			int step = findmatchattempts++ >> skipstrength;
+			ip = forwardip;
+			forwardip = ip + step;
+
+			if (forwardip > mflimit)
+				goto _last_literals;
+
+			forwardh = LZ4_HASH64K_VALUE(forwardip);
+			ref = base + hashtable[h];
+			hashtable[h] = (u16)(ip - base);
+		} while (A32(ref) != A32(ip));
+
+		/* Catch up */
+		while ((ip > anchor) && (ref > (u8 *)source)
+			&& (ip[-1] == ref[-1])) {
+			ip--;
+			ref--;
+		}
+
+		/* Encode Literal length */
+		length = (int)(ip - anchor);
+		token = op++;
+		/* Check output limit */
+		if (unlikely(op + length + (2 + 1 + LASTLITERALS)
+			+ (length >> 8) > oend))
+			return 0;
+		if (length >= (int)RUN_MASK) {
+			*token = (RUN_MASK << ML_BITS);
+			len = length - RUN_MASK;
+			for (; len > 254 ; len -= 255)
+				*op++ = 255;
+			*op++ = (u8)len;
+		} else
+			*token = (length << ML_BITS);
+
+		/* Copy Literals */
+		LZ4_BLINDCOPY(anchor, op, length);
+
+_next_match:
+		/* Encode Offset */
+		LZ4_WRITE_LITTLEENDIAN_16(op, (u16)(ip - ref));
+
+		/* Start Counting */
+		ip += MINMATCH;
+		/* MinMatch verified */
+		ref += MINMATCH;
+		anchor = ip;
+
+		while (ip < MATCHLIMIT - (STEPSIZE - 1)) {
+			#if LZ4_ARCH64
+			u64 diff = A64(ref) ^ A64(ip);
+			#else
+			u32 diff = A32(ref) ^ A32(ip);
+			#endif
+
+			if (!diff) {
+				ip += STEPSIZE;
+				ref += STEPSIZE;
+				continue;
+			}
+			ip += LZ4_NBCOMMONBYTES(diff);
+			goto _endcount;
+		}
+		#if LZ4_ARCH64
+		if ((ip < (MATCHLIMIT - 3)) && (A32(ref) == A32(ip))) {
+			ip += 4;
+			ref += 4;
+		}
+		#endif
+		if ((ip < (MATCHLIMIT - 1)) && (A16(ref) == A16(ip))) {
+			ip += 2;
+			ref += 2;
+		}
+		if ((ip < MATCHLIMIT) && (*ref == *ip))
+			ip++;
+_endcount:
+
+		/* Encode MatchLength */
+		len = (int)(ip - anchor);
+		/* Check output limit */
+		if (unlikely(op + (1 + LASTLITERALS) + (len >> 8) > oend))
+			return 0;
+		if (len >= (int)ML_MASK) {
+			*token += ML_MASK;
+			len -= ML_MASK;
+			for (; len > 509 ; len -= 510) {
+				*op++ = 255;
+				*op++ = 255;
+			}
+			if (len > 254) {
+				len -= 255;
+				*op++ = 255;
+			}
+			*op++ = (u8)len;
+		} else
+			*token += len;
+
+		/* Test end of chunk */
+		if (ip > mflimit) {
+			anchor = ip;
+			break;
+		}
+
+		/* Fill table */
+		hashtable[LZ4_HASH64K_VALUE(ip-2)] = (u16)(ip - 2 - base);
+
+		/* Test next position */
+		ref = base + hashtable[LZ4_HASH64K_VALUE(ip)];
+		hashtable[LZ4_HASH64K_VALUE(ip)] = (u16)(ip - base);
+		if (A32(ref) == A32(ip)) {
+			token = op++;
+			*token = 0;
+			goto _next_match;
+		}
+
+		/* Prepare next loop */
+		anchor = ip++;
+		forwardh = LZ4_HASH64K_VALUE(ip);
+	}
+
+_last_literals:
+	/* Encode Last Literals */
+	lastrun = (int)(iend - anchor);
+	if (op + lastrun + 1 + (lastrun - RUN_MASK + 255) / 255 > oend)
+		return 0;
+	if (lastrun >= (int)RUN_MASK) {
+		*op++ = (RUN_MASK << ML_BITS);
+		lastrun -= RUN_MASK;
+		for (; lastrun > 254 ; lastrun -= 255)
+			*op++ = 255;
+		*op++ = (u8)lastrun;
+	} else
+		*op++ = (lastrun << ML_BITS);
+	memcpy(op, anchor, iend - anchor);
+	op += iend - anchor;
+	/* End */
+	return (int)(((char *)op) - dest);
+}
+
+int lz4_compress(const unsigned char *src, size_t src_len,
+			unsigned char *dst, size_t *dst_len, void *wrkmem)
+{
+	int ret = -1;
+	int out_len = 0;
+
+	if (src_len < LZ4_64KLIMIT)
+		out_len = lz4_compress64kctx(wrkmem, src, dst, src_len,
+				lz4_compressbound(src_len));
+	else
+		out_len = lz4_compressctx(wrkmem, src, dst, src_len,
+				lz4_compressbound(src_len));
+
+	if (out_len < 0)
+		goto exit;
+
+	*dst_len = out_len;
+
+	return 0;
+exit:
+	return ret;
+}
+EXPORT_SYMBOL_GPL(lz4_compress);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("LZ4 compressor");
diff --git a/lib/lz4/lz4_decompress.c b/lib/lz4/lz4_decompress.c
new file mode 100644
index 00000000000..d3414eae73a
--- /dev/null
+++ b/lib/lz4/lz4_decompress.c
@@ -0,0 +1,326 @@
+/*
+ * 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");