decompressor: add LZ4 decompressor module

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

Benchmark Results(PATCH v3)
Compiler: Linaro ARM gcc 4.6.2

1. ARMv7, 1.5GHz based board
   Kernel: linux 3.4
   Uncompressed Kernel Size: 14MB
        Compressed Size  Decompression Speed
   LZO  6.7MB            20.1MB/s, 25.2MB/s(UA)
   LZ4  7.3MB            29.1MB/s, 45.6MB/s(UA)

2. ARMv7, 1.7GHz based board
   Kernel: linux 3.7
   Uncompressed Kernel Size: 14MB
        Compressed Size  Decompression Speed
   LZO  6.0MB            34.1MB/s, 52.2MB/s(UA)
   LZ4  6.5MB            86.7MB/s
- UA: Unaligned memory Access support
- Latest patch set for LZO applied

This patch set is for adding support for LZ4-compressed Kernel.  LZ4 is a
very fast lossless compression algorithm and it also features an extremely
fast decoder [1].

But we have five of decompressors already and one question which does
arise, however, is that of where do we stop adding new ones?  This issue
had been discussed and came to the conclusion [2].

Russell King said that we should have:

 - one decompressor which is the fastest
 - one decompressor for the highest compression ratio
 - one popular decompressor (eg conventional gzip)

If we have a replacement one for one of these, then it should do exactly
that: replace it.

The benchmark shows that an 8% increase in image size vs a 66% increase
in decompression speed compared to LZO(which has been known as the
fastest decompressor in the Kernel).  Therefore the "fast but may not be
small" compression title has clearly been taken by LZ4 [3].

[1] http://code.google.com/p/lz4/
[2] http://thread.gmane.org/gmane.linux.kbuild.devel/9157
[3] http://thread.gmane.org/gmane.linux.kbuild.devel/9347

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: Yann Collet <yann.collet.73@gmail.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Florian Fainelli <florian@openwrt.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
lib: add support for LZ4-compressed kernel

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

Signed-off-by: Kyungsik Lee <kyungsik.lee@lge.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Florian Fainelli <florian@openwrt.org>
Cc: Yann Collet <yann.collet.73@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Oarm: add support for LZ4-compressed kernel

Integrates the LZ4 decompression code to the arm pre-boot code.

Signed-off-by: Kyungsik Lee <kyungsik.lee@lge.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Florian Fainelli <florian@openwrt.org>
Cc: Yann Collet <yann.collet.73@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Conflicts:
	arch/x86/boot/compressed/Makefile
lib: add lz4 compressor module

This patchset is for supporting LZ4 compression and the crypto API using
it.

As shown below, the size of data is a little bit bigger but compressing
speed is faster under the enabled unaligned memory access.  We can use
lz4 de/compression through crypto API as well.  Also, It will be useful
for another potential user of lz4 compression.

lz4 Compression Benchmark:
Compiler: ARM gcc 4.6.4
ARMv7, 1 GHz based board
   Kernel: linux 3.4
   Uncompressed data Size: 101 MB
         Compressed Size  compression Speed
   LZO   72.1MB		  32.1MB/s, 33.0MB/s(UA)
   LZ4   75.1MB		  30.4MB/s, 35.9MB/s(UA)
   LZ4HC 59.8MB		   2.4MB/s,  2.5MB/s(UA)
- UA: Unaligned memory Access support
- Latest patch set for LZO applied

This patch:

Add support for LZ4 compression in the Linux Kernel.  LZ4 Compression APIs
for kernel are based on LZ4 implementation by Yann Collet and were changed
for 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.

[akpm@linux-foundation.org: make lz4_compresshcctx() static]
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>
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>
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>
lz4: fix compression/decompression signedness mismatch

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 *".

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Kyungsik Lee <kyungsik.lee@lge.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Yann Collet <yann.collet.73@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
arm: LZ4-compressed kernel v2:
- Apply CFLAGS, -Os to decompress.o to improve decompress
  performance during boot-up process

Signed-off-by: LaboDJ <jacopolabardi@gmail.com>
Enable lz4 config
ARM: 7583/1: decompressor: Enable unaligned memory access for v6 and above

Modern GCC can generate code which makes use of the CPU's native
unaligned memory access capabilities.  This is useful for the C
decompressor implementations used for unpacking compressed kernels.

This patch disables alignment faults and enables the v6 unaligned
access model on CPUs which support these features (i.e., v6 and
later), allowing full unaligned access support for C code in the
decompressor.

The decompressor C code must not be built to assume that unaligned
access works if support for v5 or older platforms is included in
the kernel.

For correct code generation, C decompressor code must always use
the get_unaligned and put_unaligned accessors when dealing with
unaligned pointers, regardless of this patch.

Signed-off-by: Dave Martin <dave.martin@linaro.org>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: Francisco Franco <franciscofranco.1990@gmail.com>
Enable UNALIGNED_ACCESS for the new LZO algorithm to use. LZO decrompression is used on QCACHE so we benefit a little from the new and improved LZO code.

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: Francisco Franco <franciscofranco.1990@gmail.com>
ARM: 7668/1: fix memset-related crashes caused by recent GCC (4.7.2) optimizations

Recent GCC versions (e.g. GCC-4.7.2) perform optimizations based on
assumptions about the implementation of memset and similar functions.
The current ARM optimized memset code does not return the value of
its first argument, as is usually expected from standard implementations.

For instance in the following function:

void debug_mutex_lock_common(struct mutex *lock, struct mutex_waiter *waiter)
{
	memset(waiter, MUTEX_DEBUG_INIT, sizeof(*waiter));
	waiter->magic = waiter;
	INIT_LIST_HEAD(&waiter->list);
}

compiled as:

800554d0 <debug_mutex_lock_common>:
800554d0:       e92d4008        push    {r3, lr}
800554d4:       e1a00001        mov     r0, r1
800554d8:       e3a02010        mov     r2, #16 ; 0x10
800554dc:       e3a01011        mov     r1, #17 ; 0x11
800554e0:       eb04426e        bl      80165ea0 <memset>
800554e4:       e1a03000        mov     r3, r0
800554e8:       e583000c        str     r0, [r3, #12]
800554ec:       e5830000        str     r0, [r3]
800554f0:       e5830004        str     r0, [r3, #4]
800554f4:       e8bd8008        pop     {r3, pc}

GCC assumes memset returns the value of pointer 'waiter' in register r0; causing
register/memory corruptions.

This patch fixes the return value of the assembly version of memset.
It adds a 'mov' instruction and merges an additional load+store into
existing load/store instructions.
For ease of review, here is a breakdown of the patch into 4 simple steps:

Step 1
======
Perform the following substitutions:
ip -> r8, then
r0 -> ip,
and insert 'mov ip, r0' as the first statement of the function.
At this point, we have a memset() implementation returning the proper result,
but corrupting r8 on some paths (the ones that were using ip).

Step 2
======
Make sure r8 is saved and restored when (! CALGN(1)+0) == 1:

save r8:
-       str     lr, [sp, #-4]!
+       stmfd   sp!, {r8, lr}

and restore r8 on both exit paths:
-       ldmeqfd sp!, {pc}               @ Now <64 bytes to go.
+       ldmeqfd sp!, {r8, pc}           @ Now <64 bytes to go.
(...)
        tst     r2, #16
        stmneia ip!, {r1, r3, r8, lr}
-       ldr     lr, [sp], #4
+       ldmfd   sp!, {r8, lr}

Step 3
======
Make sure r8 is saved and restored when (! CALGN(1)+0) == 0:

save r8:
-       stmfd   sp!, {r4-r7, lr}
+       stmfd   sp!, {r4-r8, lr}

and restore r8 on both exit paths:
        bgt     3b
-       ldmeqfd sp!, {r4-r7, pc}
+       ldmeqfd sp!, {r4-r8, pc}
(...)
        tst     r2, #16
        stmneia ip!, {r4-r7}
-       ldmfd   sp!, {r4-r7, lr}
+       ldmfd   sp!, {r4-r8, lr}

Step 4
======
Rewrite register list "r4-r7, r8" as "r4-r8".

Change-Id: I79a0d6897572b693d50f8ea8a94aa331bfcc59f8
Git-Commit: 455bd4c430b0c0a361f38e8658a0d6cb469942b5
Git-Repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Ivan Djelic <ivan.djelic@parrot.com>
Reviewed-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Dirk Behme <dirk.behme@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
ARM: 7670/1: fix the memset fix

Commit 455bd4c430b0 ("ARM: 7668/1: fix memset-related crashes caused by
recent GCC (4.7.2) optimizations") attempted to fix a compliance issue
with the memset return value.  However the memset itself became broken
by that patch for misaligned pointers.

This fixes the above by branching over the entry code from the
misaligned fixup code to avoid reloading the original pointer.

Also, because the function entry alignment is wrong in the Thumb mode
compilation, that fixup code is moved to the end.

While at it, the entry instructions are slightly reworked to help dual
issue pipelines.

Change-Id: I5db45a7de1e389bacb5d6e4513c0d446ae2c9440
Git-Commit: 418df63adac56841ef6b0f1fcf435bc64d4ed177
Git-Repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Alexander Holler <holler@ahsoftware.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Tweak config