include/linux/bits.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef __LINUX_BITS_H
   3 #define __LINUX_BITS_H
   4 #include <asm/bitsperlong.h>
   5
   6 #define BIT(nr)                 (1UL << (nr))
   7 #define BIT_ULL(nr)             (1ULL << (nr))
   8 #define BIT_MASK(nr)            (1UL << ((nr) % BITS_PER_LONG))
   9 #define BIT_WORD(nr)            ((nr) / BITS_PER_LONG)
  10 #define BIT_ULL_MASK(nr)        (1ULL << ((nr) % BITS_PER_LONG_LONG))
  11 #define BIT_ULL_WORD(nr)        ((nr) / BITS_PER_LONG_LONG)
  12 #define BITS_PER_BYTE           8
  13
  14 /*
  15  * Create a contiguous bitmask starting at bit position @l and ending at
  16  * position @h. For example
  17  * GENMASK_ULL(39, 21) gives us the 64bit vector 0x000000ffffe00000.
  18  */
  19 #define GENMASK(h, l) \
  20         (((~0UL) - (1UL << (l)) + 1) & (~0UL >> (BITS_PER_LONG - 1 - (h))))
  21
  22 #define GENMASK_ULL(h, l) \
  23         (((~0ULL) - (1ULL << (l)) + 1) & \
  24          (~0ULL >> (BITS_PER_LONG_LONG - 1 - (h))))
  25
  26 #endif  /* __LINUX_BITS_H */