From: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx> [ Upstream commit 9e005b761e7ad153dcf40a6cba1d681fe0830ac6 ] 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@xxxxxxxxxxxxx> Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20190705100144.28785-1-yamada.masahiro@xxxxxxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- arch/powerpc/boot/xz_config.h | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/arch/powerpc/boot/xz_config.h b/arch/powerpc/boot/xz_config.h index 5c6afdbca642..21b52c15aafc 100644 --- a/arch/powerpc/boot/xz_config.h +++ b/arch/powerpc/boot/xz_config.h @@ -19,10 +19,30 @@ 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) -- 2.20.1