On Wed, Feb 07, 2024 at 11:45:20PM -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> > Acked-by: Jani Nikula <jani.nikula@xxxxxxxxx> So I get v1 from Jan.23 in my mailbox, and this one is v3. Did I miss a v2? Anyways, please bear my reviewed-by from v1 for this patch. Thanks, Yury > --- > include/linux/bits.h | 17 +++++++++++++++++ > 1 file changed, 17 insertions(+) > > diff --git a/include/linux/bits.h b/include/linux/bits.h > index bd56f32de44e..811846ce110e 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 > > /* > @@ -54,4 +58,17 @@ > #define GENMASK_U32(h, l) __GENMASK(u32, h, l) > #define GENMASK_U64(h, l) __GENMASK(u64, h, l) > > +/* > + * Fixed-type variants of BIT(), with additional checks like __GENMASK(). The > + * following examples generate compiler warnings due to shift-count-overflow: > + * > + * - BIT_U8(8) > + * - BIT_U32(-1) > + * - BIT_U32(40) > + */ > +#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
