Commit 9e005b76 authored Jul 05, 2019 by Masahiro Yamada Committed by Michael Ellerman Jul 10, 2019

powerpc/boot: add {get, put}_unaligned_be32 to xz_config.h



The next commit will make the way of passing CONFIG options more robust.
Unfortunately, it would uncover another hidden issue; without this
commit, skiroot_defconfig would be broken like this:

|   WRAP    arch/powerpc/boot/zImage.pseries
| arch/powerpc/boot/wrapper.a(decompress.o): In function `bcj_powerpc.isra.10':
| decompress.c:(.text+0x720): undefined reference to `get_unaligned_be32'
| decompress.c:(.text+0x7a8): undefined reference to `put_unaligned_be32'
| make[1]: *** [arch/powerpc/boot/Makefile;383: arch/powerpc/boot/zImage.pseries] Error 1
| make: *** [arch/powerpc/Makefile;295: zImage] Error 2

skiroot_defconfig is the only defconfig that enables CONFIG_KERNEL_XZ
for ppc, which has never been correctly built before.

I figured out the root cause in lib/decompress_unxz.c:

| #ifdef CONFIG_PPC
| #      define XZ_DEC_POWERPC
| #endif

CONFIG_PPC is undefined here in the ppc bootwrapper because autoconf.h
is not included except by arch/powerpc/boot/serial.c

XZ_DEC_POWERPC is not defined, therefore, bcj_powerpc() is not compiled
for the bootwrapper.

With the next commit passing CONFIG_PPC correctly, we would realize that
{get,put}_unaligned_be32 was missing.

Unlike the other decompressors, the ppc bootwrapper duplicates all the
necessary helpers in arch/powerpc/boot/.

The other architectures define __KERNEL__ and pull in helpers for
building the decompressors.

If ppc bootwrapper had defined __KERNEL__, lib/xz/xz_private.h would
have included <asm/unaligned.h>:

| #ifdef __KERNEL__
| #       include <linux/xz.h>
| #       include <linux/kernel.h>
| #       include <asm/unaligned.h>

However, doing so would cause tons of definition conflicts since the
bootwrapper has duplicated everything.

I just added copies of {get,put}_unaligned_be32, following the
bootwrapper coding convention.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190705100144.28785-1-yamada.masahiro@socionext.com

parent 0fc12c02

arch/powerpc/boot/xz_config.h

+20 −0

Original line number	Diff line number	Diff line
		@@ -20,10 +20,30 @@ static inline uint32_t swab32p(void *p)

		#ifdef __LITTLE_ENDIAN__
		#define get_le32(p) (((uint32_t ) (p)))
		#define cpu_to_be32(x) swab32(x)
		static inline u32 be32_to_cpup(const u32 *p)
		{
		return swab32p((u32 *)p);
		}
		#else
		#define get_le32(p) swab32p(p)
		#define cpu_to_be32(x) (x)
		static inline u32 be32_to_cpup(const u32 *p)
		{
		return *p;
		}
		#endif

		static inline uint32_t get_unaligned_be32(const void *p)
		{
		return be32_to_cpup(p);
		}

		static inline void put_unaligned_be32(u32 val, void *p)
		{
		((u32 )p) = cpu_to_be32(val);
		}

		#define memeq(a, b, size) (memcmp(a, b, size) == 0)
		#define memzero(buf, size) memset(buf, 0, size)