Cache instructions (dcbz, dcbi, dcbf and dcbst) take two registers that are summed to obtain the target address. Using 'Z' constraint and '%y0' argument gives GCC the opportunity to use both registers instead of only one with the second being forced to 0.
Suggested-by: Segher Boessenkool <seg...@kernel.crashing.org> Signed-off-by: Christophe Leroy <christophe.le...@c-s.fr> --- arch/powerpc/include/asm/cache.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/include/asm/cache.h b/arch/powerpc/include/asm/cache.h index 40ea5b3781c6..df8e4c407366 100644 --- a/arch/powerpc/include/asm/cache.h +++ b/arch/powerpc/include/asm/cache.h @@ -85,22 +85,22 @@ extern void _set_L3CR(unsigned long); static inline void dcbz(void *addr) { - __asm__ __volatile__ ("dcbz 0, %0" : : "r"(addr) : "memory"); + __asm__ __volatile__ ("dcbz %y0" : : "Z"(*(u8 *)addr) : "memory"); } static inline void dcbi(void *addr) { - __asm__ __volatile__ ("dcbi 0, %0" : : "r"(addr) : "memory"); + __asm__ __volatile__ ("dcbi %y0" : : "Z"(*(u8 *)addr) : "memory"); } static inline void dcbf(void *addr) { - __asm__ __volatile__ ("dcbf 0, %0" : : "r"(addr) : "memory"); + __asm__ __volatile__ ("dcbf %y0" : : "Z"(*(u8 *)addr) : "memory"); } static inline void dcbst(void *addr) { - __asm__ __volatile__ ("dcbst 0, %0" : : "r"(addr) : "memory"); + __asm__ __volatile__ ("dcbst %y0" : : "Z"(*(u8 *)addr) : "memory"); } #endif /* !__ASSEMBLY__ */ #endif /* __KERNEL__ */ -- 2.13.3