bits.h 1.4 KB

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  1. /* SPDX-License-Identifier: GPL-2.0 */
  2. #ifndef __LINUX_BITS_H
  3. #define __LINUX_BITS_H
  4. #include <linux/const.h>
  5. #include <vdso/bits.h>
  6. #include <asm/bitsperlong.h>
  7. #define BIT_ULL(nr) (ULL(1) << (nr))
  8. #define BIT_MASK(nr) (UL(1) << ((nr) % BITS_PER_LONG))
  9. #define BIT_WORD(nr) ((nr) / BITS_PER_LONG)
  10. #define BIT_ULL_MASK(nr) (ULL(1) << ((nr) % BITS_PER_LONG_LONG))
  11. #define BIT_ULL_WORD(nr) ((nr) / BITS_PER_LONG_LONG)
  12. #define BITS_PER_BYTE 8
  13. /*
  14. * Create a contiguous bitmask starting at bit position @l and ending at
  15. * position @h. For example
  16. * GENMASK_ULL(39, 21) gives us the 64bit vector 0x000000ffffe00000.
  17. */
  18. #if !defined(__ASSEMBLY__)
  19. #include <linux/build_bug.h>
  20. #define GENMASK_INPUT_CHECK(h, l) \
  21. (BUILD_BUG_ON_ZERO(__builtin_choose_expr( \
  22. __is_constexpr((l) > (h)), (l) > (h), 0)))
  23. #else
  24. /*
  25. * BUILD_BUG_ON_ZERO is not available in h files included from asm files,
  26. * disable the input check if that is the case.
  27. */
  28. #define GENMASK_INPUT_CHECK(h, l) 0
  29. #endif
  30. #define __GENMASK(h, l) \
  31. (((~UL(0)) - (UL(1) << (l)) + 1) & \
  32. (~UL(0) >> (BITS_PER_LONG - 1 - (h))))
  33. #define GENMASK(h, l) \
  34. (GENMASK_INPUT_CHECK(h, l) + __GENMASK(h, l))
  35. #define __GENMASK_ULL(h, l) \
  36. (((~ULL(0)) - (ULL(1) << (l)) + 1) & \
  37. (~ULL(0) >> (BITS_PER_LONG_LONG - 1 - (h))))
  38. #define GENMASK_ULL(h, l) \
  39. (GENMASK_INPUT_CHECK(h, l) + __GENMASK_ULL(h, l))
  40. #endif /* __LINUX_BITS_H */