fmem: add fmem API header file

Change-Id: Iea942e84106512ba4c1418fe10bd7f53e635451e
Signed-off-by: Larry Bassel <lbassel@codeaurora.org>
fmem: add qcache implementation

Part of this code is originally from the 3.1 version of the
tmem backend zcache.

The zcache code was copied to the qcache directory and
modifications were made, notably to the memory allocation
(from a block of pre-reserved contiguous memory rather
than from system memory), and to allow tmem and qcache to
be turned on and off either from a /sys file or using
an exported API.

A higher level driver (fmem) is provided that is
the interface to other (PMEM, ION, tmem/qcache) drivers.

Change-Id: Ieda939ed1ba7c5337dd4338b9d9caffde883e82b
Signed-off-by: Larry Bassel <lbassel@codeaurora.org>
decompressors: add XZ decompressor module

In userspace, the .lzma format has become mostly a legacy file format that
got superseded by the .xz format.  Similarly, LZMA Utils was superseded by
XZ Utils.

These patches add support for XZ decompression into the kernel.  Most of
the code is as is from XZ Embedded <http://tukaani.org/xz/embedded.html>.
It was written for the Linux kernel but is usable in other projects too.

Advantages of XZ over the current LZMA code in the kernel:
  - Nice API that can be used by other kernel modules; it's
    not limited to kernel, initramfs, and initrd decompression.
  - Integrity check support (CRC32)
  - BCJ filters improve compression of executable code on
    certain architectures. These together with LZMA2 can
    produce a few percent smaller kernel or Squashfs images
    than plain LZMA without making the decompression slower.

This patch: Add the main decompression code (xz_dec), testing module
(xz_dec_test), wrapper script (xz_wrap.sh) for the xz command line tool,
and documentation.  The xz_dec module is enough to have a usable XZ
decompressor e.g.  for Squashfs.

Signed-off-by: Lasse Collin <lasse.collin@tukaani.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Alain Knaff <alain@knaff.lu>
Cc: Albin Tonnerre <albin.tonnerre@free-electrons.com>
Cc: Phillip Lougher <phillip@lougher.demon.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
decompressors: add boot-time XZ support

This implements the API defined in <linux/decompress/generic.h> which is
used for kernel, initramfs, and initrd decompression.  This patch together
with the first patch is enough for XZ-compressed initramfs and initrd;
XZ-compressed kernel will need arch-specific changes.

The buffering requirements described in decompress_unxz.c are stricter
than with gzip, so the relevant changes should be done to the
arch-specific code when adding support for XZ-compressed kernel.
Similarly, the heap size in arch-specific pre-boot code may need to be
increased (30 KiB is enough).

The XZ decompressor needs memmove(), memeq() (memcmp() == 0), and
memzero() (memset(ptr, 0, size)), which aren't available in all
arch-specific pre-boot environments.  I'm including simple versions in
decompress_unxz.c, but a cleaner solution would naturally be nicer.

Signed-off-by: Lasse Collin <lasse.collin@tukaani.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Alain Knaff <alain@knaff.lu>
Cc: Albin Tonnerre <albin.tonnerre@free-electrons.com>
Cc: Phillip Lougher <phillip@lougher.demon.co.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
msm: htcleo: add new config options after XZ import
.gitignore: ignore *.xz files
XZ decompressor: Fix decoding of empty LZMA2 streams

The old code considered valid empty LZMA2 streams to be corrupt.
Note that a typical empty .xz file has no LZMA2 data at all,
and thus most .xz files having no uncompressed data are handled
correctly even without this fix.

Signed-off-by: Lasse Collin <lasse.collin@tukaani.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
XZ: Fix missing <linux/kernel.h> include

commit 81d67439855a7f928d90965d832aa4f2fb677342 upstream.

<linux/kernel.h> is needed for min_t. The old version
happened to work on x86 because <asm/unaligned.h>
indirectly includes <linux/kernel.h>, but it didn't
work on ARM.

<linux/kernel.h> includes <asm/byteorder.h> so it's
not necessary to include it explicitly anymore.

Signed-off-by: Lasse Collin <lasse.collin@tukaani.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
XZ: Fix incorrect XZ_BUF_ERROR

commit 9c1f8594df4814ebfd6822ca3c9444fb3445888d upstream.

xz_dec_run() could incorrectly return XZ_BUF_ERROR if all of the
following was true:

 - The caller knows how many bytes of output to expect and only provides
   that much output space.

 - When the last output bytes are decoded, the caller-provided input
   buffer ends right before the LZMA2 end of payload marker.  So LZMA2
   won't provide more output anymore, but it won't know it yet and thus
   won't return XZ_STREAM_END yet.

 - A BCJ filter is in use and it hasn't left any unfiltered bytes in the
   temp buffer.  This can happen with any BCJ filter, but in practice
   it's more likely with filters other than the x86 BCJ.

This fixes <https://bugzilla.redhat.com/show_bug.cgi?id=735408> where
Squashfs thinks that a valid file system is corrupt.

This also fixes a similar bug in single-call mode where the uncompressed
size of a block using BCJ + LZMA2 was 0 bytes and caller provided no
output space.  Many empty .xz files don't contain any blocks and thus
don't trigger this bug.

This also tweaks a closely related detail: xz_dec_bcj_run() could call
xz_dec_lzma2_run() to decode into temp buffer when it was known to be
useless.  This was harmless although it wasted a minuscule number of CPU
cycles.

Signed-off-by: Lasse Collin <lasse.collin@tukaani.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
ARM: support XZ compressed kernels
msm: htcleo: update defconfig for xz