On Tue, 2012-07-10 at 15:59 +0800, Tiejun Chen wrote: > Add "memory" attribute in inline assembly language as a compiler > barrier to make sure 4.6.x GCC don't reorder mfmsr().
Out of curiosity, did you see a case where it was re-ordered improperly ? Cheers, Ben. > Signed-off-by: Tiejun Chen <tiejun.c...@windriver.com> > --- > arch/powerpc/include/asm/reg.h | 3 ++- > 1 files changed, 2 insertions(+), 1 deletions(-) > > diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h > index 559da19..578e5a0 100644 > --- a/arch/powerpc/include/asm/reg.h > +++ b/arch/powerpc/include/asm/reg.h > @@ -1016,7 +1016,8 @@ > /* Macros for setting and retrieving special purpose registers */ > #ifndef __ASSEMBLY__ > #define mfmsr() ({unsigned long rval; \ > - asm volatile("mfmsr %0" : "=r" (rval)); rval;}) > + asm volatile("mfmsr %0" : "=r" (rval) : \ > + : "memory"); rval;}) > #ifdef CONFIG_PPC_BOOK3S_64 > #define __mtmsrd(v, l) asm volatile("mtmsrd %0," __stringify(l) \ > : : "r" (v) : "memory") _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev