On Wed, Oct 25, 2023 at 08:42:55AM +0900, Masami Hiramatsu wrote: > On Tue, 24 Oct 2023 16:08:12 +0100 > Mark Rutland <mark.rutl...@arm.com> wrote: > > > On Tue, Oct 24, 2023 at 11:52:54PM +0900, Masami Hiramatsu (Google) wrote: > > > From: Masami Hiramatsu (Google) <mhira...@kernel.org> > > > > > > Use generic_cmpxchg_local() for arch_cmpxchg_local() implementation > > > in SH architecture because it does not implement arch_cmpxchg_local(). > > > > I do not think this is correct. > > > > The implementation in <asm-generic/cmpxchg-local.h> is UP-only (and it only > > disables interrupts), whereas arch/sh can be built SMP. We should probably > > add > > some guards into <asm-generic/cmpxchg-local.h> for that as we have in > > <asm-generic/cmpxchg.h>. > > Isn't cmpxchg_local for the data which only needs to ensure to do cmpxchg > on local CPU? > So I think it doesn't care about the other CPUs (IOW, it should not touched by > other CPUs), so it only considers UP case. E.g. on x86, arch_cmpxchg_local() > is > defined as raw "cmpxchg" without lock prefix. > > #define __cmpxchg_local(ptr, old, new, size) \ > __raw_cmpxchg((ptr), (old), (new), (size), "") >
Yes, you're right; sorry for the noise. For your original patch: Acked-by: Mark Rutland <mark.rutl...@arm.com> Mark. > > Thank you, > > > > > > I think the right thing to do here is to define arch_cmpxchg_local() in > > terms > > of arch_cmpxchg(), i.e. at the bottom of arch/sh's <asm/cmpxchg.h> add: > > > > #define arch_cmpxchg_local arch_cmpxchg > > > > Mark. > > > > > > > > Reported-by: kernel test robot <l...@intel.com> > > > Closes: > > > https://lore.kernel.org/oe-kbuild-all/202310241310.ir5uukog-...@intel.com/ > > > Signed-off-by: Masami Hiramatsu (Google) <mhira...@kernel.org> > > > --- > > > arch/sh/include/asm/cmpxchg.h | 2 ++ > > > 1 file changed, 2 insertions(+) > > > > > > diff --git a/arch/sh/include/asm/cmpxchg.h b/arch/sh/include/asm/cmpxchg.h > > > index 288f6f38d98f..e920e61fb817 100644 > > > --- a/arch/sh/include/asm/cmpxchg.h > > > +++ b/arch/sh/include/asm/cmpxchg.h > > > @@ -71,4 +71,6 @@ static inline unsigned long __cmpxchg(volatile void * > > > ptr, unsigned long old, > > > (unsigned long)_n_, sizeof(*(ptr))); \ > > > }) > > > > > > +#include <asm-generic/cmpxchg-local.h> > > > + > > > #endif /* __ASM_SH_CMPXCHG_H */ > > > > > > -- > Masami Hiramatsu (Google) <mhira...@kernel.org>
