LXR linux/tools/include/linux/bits.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef __LINUX_BITS_H
   3#define __LINUX_BITS_H
   4
   5#include <linux/const.h>
   6#include <vdso/bits.h>
   7#include <asm/bitsperlong.h>
   8
   9#define BIT_ULL(nr)             (ULL(1) << (nr))
  10#define BIT_MASK(nr)            (UL(1) << ((nr) % BITS_PER_LONG))
  11#define BIT_WORD(nr)            ((nr) / BITS_PER_LONG)
  12#define BIT_ULL_MASK(nr)        (ULL(1) << ((nr) % BITS_PER_LONG_LONG))
  13#define BIT_ULL_WORD(nr)        ((nr) / BITS_PER_LONG_LONG)
  14#define BITS_PER_BYTE           8
  15
  16/*
  17 * Create a contiguous bitmask starting at bit position @l and ending at
  18 * position @h. For example
  19 * GENMASK_ULL(39, 21) gives us the 64bit vector 0x000000ffffe00000.
  20 */
  21#if !defined(__ASSEMBLY__)
  22#include <linux/build_bug.h>
  23#define GENMASK_INPUT_CHECK(h, l) \
  24        (BUILD_BUG_ON_ZERO(__builtin_choose_expr( \
  25                __is_constexpr((l) > (h)), (l) > (h), 0)))
  26#else
  27/*
  28 * BUILD_BUG_ON_ZERO is not available in h files included from asm files,
  29 * disable the input check if that is the case.
  30 */
  31#define GENMASK_INPUT_CHECK(h, l) 0
  32#endif
  33
  34#define __GENMASK(h, l) \
  35        (((~UL(0)) - (UL(1) << (l)) + 1) & \
  36         (~UL(0) >> (BITS_PER_LONG - 1 - (h))))
  37#define GENMASK(h, l) \
  38        (GENMASK_INPUT_CHECK(h, l) + __GENMASK(h, l))
  39
  40#define __GENMASK_ULL(h, l) \
  41        (((~ULL(0)) - (ULL(1) << (l)) + 1) & \
  42         (~ULL(0) >> (BITS_PER_LONG_LONG - 1 - (h))))
  43#define GENMASK_ULL(h, l) \
  44        (GENMASK_INPUT_CHECK(h, l) + __GENMASK_ULL(h, l))
  45
  46#endif  /* __LINUX_BITS_H */
  47