powerpc/boot: Fix a typo in partial_decompress() comment

outbuf is the output buffer, output_size is the size of the output
buffer.

Signed-off-by: Zhang Jianhua <chris.zjh@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210510075134.252978-1-chris.zjh@huawei.com

powerpc: boot: include compiler_attributes.h

The kernel uses `-include` to include include/linux/compiler_types.h
into all translation units (see scripts/Makefile.lib), which #includes
compiler_attributes.h.

arch/powerpc/boot/ uses different compiler flags from the rest of the
kernel. As such, it doesn't contain the definitions from these headers,
and redefines a few that it needs.

For the purpose of enabling -Wimplicit-fallthrough for ppc, include
compiler_attributes.h via `-include`.

It was also noted in 6a9dc5fd6170 that we could -D__KERNEL__ and
-include compiler_types.h like the main kernel does, though testing that
produces a whole sea of warnings to cleanup. This approach is minimally
invasive. And it also helps to entice a cleanup.

Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Acked-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://github.com/ClangBuiltLinux/linux/issues/236
[ Gustavo: Massage a bit as per Miguel's suggestion. ]
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

powerpc/boot: Add support for XZ compression

This patch adds an option to use XZ compression for the kernel image.

Currently this is only enabled for 64-bit Book3S targets, which is
roughly equivalent to the platforms that use the kernel's zImage
wrapper, and that have been tested.

The bulk of the 32-bit platforms and 64-bit BookE use uboot images,
which relies on uboot implementing XZ. In future we can enable XZ
support for those targets once someone has tested it.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

powerpc/boot: Use the pre-boot decompression API

Currently the powerpc boot wrapper has its own wrapper around zlib to
handle decompressing gzipped kernels. The kernel decompressor library
functions now provide a generic interface that can be used in the
pre-boot environment. This allows boot wrappers to easily support
different compression algorithms. This patch converts the wrapper to use
this new API, but does not add support for using new algorithms.

Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>