decompressor: Add LZ4 decompressor module

Date	Tue, 26 Feb 2013 15:24:27 +0900

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>

v2:
- Clean up code
- Enable unaligned access for ARM v6 and above with
  CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
- Add lz4_decompress() for faster decompression with
  uncompressed output size

Signed-off-by: Paul Reioux <reioux@gmail.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
lib: Add support for LZ4-compressed kernel

Date	Tue, 26 Feb 2013 15:24:28 +0900

This patch adds support for extracting LZ4-compressed kernel images,
as well as LZ4-compressed ramdisk images in the kernel boot process.

This depends on the patch below
decompressor: Add LZ4 decompressor module

Signed-off-by: Kyungsik Lee <kyungsik.lee@lge.com>

v2:
- Clean up code
- Use lz4_decompress() for LZ4-compressed kernel during boot-process

Signed-off-by: Paul Reioux <reioux@gmail.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
arm: Add support for LZ4-compressed kernel
lib: Add lz4 compressor module

From	Chanho Min <>

This patch adds support for LZ4 compression in the Linux Kernel.
LZ4 Compression APIs for kernel are based on LZ4 implementation
by Yann Collet and changed with kernel coding style.

LZ4 homepage : http://fastcompression.blogspot.com/p/lz4.html
LZ4 source repository : http://code.google.com/p/lz4/
svn revision : r90

Two APIs are added:
lz4_compress() support basic lz4 compression whereas lz4hc_compress() support
high compression or CPU performance get lower but compression ratio get higher.
Also, we require the pre-allocated working memory with the defined size and
destination buffer must be allocated with the size of lz4_compressbound.

Signed-off-by: Chanho Min <chanho.min@lge.com>

Signed-off-by: Paul Reioux <reioux@gmail.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
lib/lz4/lz4_compress: fix macro usage error

Signed-off-by: Paul Reioux <reioux@gmail.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
LZ4: compression/decompression signedness mismatch (v2)

LZ4 compression and decompression functions require different
in signedness input/output parameters: unsigned char for
compression and signed char for decompression.

Change decompression API to require "(const) unsigned char *".

v2: minor coding style fix.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>

Signed-off-by: Paul Reioux <reioux@gmail.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
crypto: add lz4 Cryptographic API

Add support for lz4 and lz4hc compression algorithm using the lib/lz4/*
codebase.

[akpm@linux-foundation.org: fix warnings]
Signed-off-by: Chanho Min <chanho.min@lge.com>
Cc: "Darrick J. Wong" <djwong@us.ibm.com>
Cc: Bob Pearson <rpearson@systemfabricworks.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Herbert Xu <herbert@gondor.hengli.com.au>
Cc: Yann Collet <yann.collet.73@gmail.com>
Cc: Kyungsik Lee <kyungsik.lee@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
.gitignore: ignore *.lz4 files
lib/lz4: correct the LZ4 license

The LZ4 code is listed as using the "BSD 2-Clause License".

Signed-off-by: Richard Laager <rlaager@wiktel.com>
Acked-by: Kyungsik Lee <kyungsik.lee@lge.com>
Cc: Chanho Min <chanho.min@lge.com>
Cc: Richard Yao <ryao@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[ The 2-clause BSD can be just converted into GPL, but that's rude and
  pointless, so don't do it   - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
lz4: Squash sync with stable lz4

Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
lz4: Squash sync with stable lz4 #2

Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
lib: add weak clz/ctz functions

Some architectures need __c[lt]z[sd]i2() for __builtin_c[lt]z[ll] and
that causes a build failure.  They can be implemented using the
fls()/__ffs() and overridden by linking arch-specific versions may not
be implemented yet.

This is required by "lib: add lz4 compressor module".

Reference: https://lkml.org/lkml/2013/4/18/603

Signed-off-by: Chanho Min <chanho.min@lge.com>
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: "Darrick J. Wong" <djwong@us.ibm.com>
Cc: Bob Pearson <rpearson@systemfabricworks.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Herbert Xu <herbert@gondor.hengli.com.au>
Cc: Yann Collet <yann.collet.73@gmail.com>
Cc: Kyungsik Lee <kyungsik.lee@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
initramfs: read CONFIG_RD_ variables for initramfs compression

When expert configuration option(CONFIG_EXPERT) is enabled, menuconfig
offers a choice of compression algorithm to compress initial ramfs image;
This choice is stored into CONFIG_RD_* variables.  But usr/Makefile uses
earlier INITRAMFS_COMPRESSION_* macros to build initial ramfs file.  Since
none of them is defined, resulting 'initramfs_data.cpio' file remains
un-compressed.

This patch updates the Makefile to use CONFIG_RD_* variables and adds
support for LZ4 compression algorithm.  Also updates the
'gen_initramfs_list.sh' script to check whether a selected compression
command is accessible or not.  And fall-back to default gzip(1)
compression when it is not.

Signed-off-by: P J P <prasad@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>