On Sat, 4 Nov 2023 17:16:15 +0800 "wuqiang.matt" <wuqiang.m...@bytedance.com> wrote:
> For architectures that support native cmpxchg, we'd like to > implement arch_cmpxchg[64]_local with the native variants of > supported data size. If not, the generci_cmpxchg[64]_local > will be used. > > Reported-by: kernel test robot <l...@intel.com> > Closes: > https://lore.kernel.org/oe-kbuild-all/202310272207.tlpflya4-...@intel.com/ > Looks good to me. Reviewed-by: Masami Hiramatsu (Google) <mhira...@kernel.org> But I need hexagon's maintainer's comment too. Thank you, > Signed-off-by: wuqiang.matt <wuqiang.m...@bytedance.com> > --- > arch/hexagon/include/asm/cmpxchg.h | 51 +++++++++++++++++++++++++++++- > 1 file changed, 50 insertions(+), 1 deletion(-) > > diff --git a/arch/hexagon/include/asm/cmpxchg.h > b/arch/hexagon/include/asm/cmpxchg.h > index bf6cf5579cf4..2b5e5bbaf807 100644 > --- a/arch/hexagon/include/asm/cmpxchg.h > +++ b/arch/hexagon/include/asm/cmpxchg.h > @@ -8,6 +8,8 @@ > #ifndef _ASM_CMPXCHG_H > #define _ASM_CMPXCHG_H > > +#include <linux/build_bug.h> > + > /* > * __arch_xchg - atomically exchange a register and a memory location > * @x: value to swap > @@ -51,13 +53,15 @@ __arch_xchg(unsigned long x, volatile void *ptr, int size) > * variable casting. > */ > > -#define arch_cmpxchg(ptr, old, new) \ > +#define __cmpxchg_32(ptr, old, new) \ > ({ \ > __typeof__(ptr) __ptr = (ptr); \ > __typeof__(*(ptr)) __old = (old); \ > __typeof__(*(ptr)) __new = (new); \ > __typeof__(*(ptr)) __oldval = 0; \ > \ > + BUILD_BUG_ON(sizeof(*(ptr)) != 4); \ > + \ > asm volatile( \ > "1: %0 = memw_locked(%1);\n" \ > " { P0 = cmp.eq(%0,%2);\n" \ > @@ -72,4 +76,49 @@ __arch_xchg(unsigned long x, volatile void *ptr, int size) > __oldval; \ > }) > > +#define __cmpxchg(ptr, old, val, size) \ > +({ \ > + __typeof__(*(ptr)) oldval; \ > + \ > + switch (size) { \ > + case 4: \ > + oldval = __cmpxchg_32(ptr, old, val); \ > + break; \ > + default: \ > + BUILD_BUG(); \ > + oldval = val; \ > + break; \ > + } \ > + \ > + oldval; \ > +}) > + > +#define arch_cmpxchg(ptr, o, n) __cmpxchg((ptr), (o), (n), > sizeof(*(ptr))) > + > +/* > + * always make arch_cmpxchg[64]_local available, native cmpxchg > + * will be used if available, then generic_cmpxchg[64]_local > + */ > +#include <asm-generic/cmpxchg-local.h> > + > +#define arch_cmpxchg_local(ptr, old, val) \ > +({ \ > + __typeof__(*(ptr)) retval; \ > + int size = sizeof(*(ptr)); \ > + \ > + switch (size) { \ > + case 4: \ > + retval = __cmpxchg_32(ptr, old, val); \ > + break; \ > + default: \ > + retval = __generic_cmpxchg_local(ptr, old, \ > + val, size); \ > + break; \ > + } \ > + \ > + retval; \ > +}) > + > +#define arch_cmpxchg64_local(ptr, o, n) __generic_cmpxchg64_local((ptr), > (o), (n)) > + > #endif /* _ASM_CMPXCHG_H */ > -- > 2.40.1 > -- Masami Hiramatsu (Google) <mhira...@kernel.org>
