diff options
Diffstat (limited to 'include/linux/bits.h')
| -rw-r--r-- | include/linux/bits.h | 20 |
1 files changed, 17 insertions, 3 deletions
diff --git a/include/linux/bits.h b/include/linux/bits.h index 0eb24d21aac2..14fd0ca9a6cd 100644 --- a/include/linux/bits.h +++ b/include/linux/bits.h @@ -20,9 +20,8 @@ */ #if !defined(__ASSEMBLY__) #include <linux/build_bug.h> -#define GENMASK_INPUT_CHECK(h, l) \ - (BUILD_BUG_ON_ZERO(__builtin_choose_expr( \ - __is_constexpr((l) > (h)), (l) > (h), 0))) +#include <linux/compiler.h> +#define GENMASK_INPUT_CHECK(h, l) BUILD_BUG_ON_ZERO(const_true((l) > (h))) #else /* * BUILD_BUG_ON_ZERO is not available in h files included from asm files, @@ -36,4 +35,19 @@ #define GENMASK_ULL(h, l) \ (GENMASK_INPUT_CHECK(h, l) + __GENMASK_ULL(h, l)) +#if !defined(__ASSEMBLY__) +/* + * Missing asm support + * + * __GENMASK_U128() depends on _BIT128() which would not work + * in the asm code, as it shifts an 'unsigned __int128' data + * type instead of direct representation of 128 bit constants + * such as long and unsigned long. The fundamental problem is + * that a 128 bit constant will get silently truncated by the + * gcc compiler. + */ +#define GENMASK_U128(h, l) \ + (GENMASK_INPUT_CHECK(h, l) + __GENMASK_U128(h, l)) +#endif + #endif /* __LINUX_BITS_H */ |