On Tue, Jan 23, 2024 at 09:02:04PM -0800, Lucas De Marchi wrote: > Implement fixed-type BIT() to help drivers add stricter checks, like was > done for GENMASK. > > Signed-off-by: Lucas De Marchi <lucas.demarchi@xxxxxxxxx> Reviewed-by: Yury Norov <yury.norov@xxxxxxxxx> > --- > include/linux/bits.h | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/include/linux/bits.h b/include/linux/bits.h > index cb94128171b2..5754a1251078 100644 > --- a/include/linux/bits.h > +++ b/include/linux/bits.h > @@ -24,12 +24,16 @@ > #define GENMASK_INPUT_CHECK(h, l) \ > (BUILD_BUG_ON_ZERO(__builtin_choose_expr( \ > __is_constexpr((l) > (h)), (l) > (h), 0))) > +#define BIT_INPUT_CHECK(type, b) \ > + ((BUILD_BUG_ON_ZERO(__builtin_choose_expr( \ > + __is_constexpr(b), (b) >= BITS_PER_TYPE(type), 0)))) > #else > /* > * BUILD_BUG_ON_ZERO is not available in h files included from asm files, > * disable the input check if that is the case. > */ > #define GENMASK_INPUT_CHECK(h, l) 0 > +#define BIT_INPUT_CHECK(type, b) 0 > #endif > > #define __GENMASK(t, h, l) \ > @@ -44,4 +48,9 @@ > #define GENMASK_U32(h, l) __GENMASK(u32, h, l) > #define GENMASK_U64(h, l) __GENMASK(u64, h, l) > > +#define BIT_U8(b) ((u8)(BIT_INPUT_CHECK(u8, b) + BIT(b))) > +#define BIT_U16(b) ((u16)(BIT_INPUT_CHECK(u16, b) + BIT(b))) > +#define BIT_U32(b) ((u32)(BIT_INPUT_CHECK(u32, b) + BIT(b))) > +#define BIT_U64(b) ((u64)(BIT_INPUT_CHECK(u64, b) + BIT(b))) > + > #endif /* __LINUX_BITS_H */ > -- > 2.43.0
