diff options
Diffstat (limited to 'include/linux/bits.h')
| -rw-r--r-- | include/linux/bits.h | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/include/linux/bits.h b/include/linux/bits.h new file mode 100644 index 000000000..87d112650 --- /dev/null +++ b/include/linux/bits.h @@ -0,0 +1,46 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __LINUX_BITS_H +#define __LINUX_BITS_H + +#include <linux/const.h> +#include <vdso/bits.h> +#include <asm/bitsperlong.h> + +#define BIT_ULL(nr) (ULL(1) << (nr)) +#define BIT_MASK(nr) (UL(1) << ((nr) % BITS_PER_LONG)) +#define BIT_WORD(nr) ((nr) / BITS_PER_LONG) +#define BIT_ULL_MASK(nr) (ULL(1) << ((nr) % BITS_PER_LONG_LONG)) +#define BIT_ULL_WORD(nr) ((nr) / BITS_PER_LONG_LONG) +#define BITS_PER_BYTE 8 + +/* + * Create a contiguous bitmask starting at bit position @l and ending at + * position @h. For example + * GENMASK_ULL(39, 21) gives us the 64bit vector 0x000000ffffe00000. + */ +#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))) +#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 +#endif + +#define __GENMASK(h, l) \ + (((~UL(0)) - (UL(1) << (l)) + 1) & \ + (~UL(0) >> (BITS_PER_LONG - 1 - (h)))) +#define GENMASK(h, l) \ + (GENMASK_INPUT_CHECK(h, l) + __GENMASK(h, l)) + +#define __GENMASK_ULL(h, l) \ + (((~ULL(0)) - (ULL(1) << (l)) + 1) & \ + (~ULL(0) >> (BITS_PER_LONG_LONG - 1 - (h)))) +#define GENMASK_ULL(h, l) \ + (GENMASK_INPUT_CHECK(h, l) + __GENMASK_ULL(h, l)) + +#endif /* __LINUX_BITS_H */ |