LXR linux/arch/x86/boot/bitops.h

   1/* SPDX-License-Identifier: GPL-2.0-only */
   2/* -*- linux-c -*- ------------------------------------------------------- *
   3 *
   4 *   Copyright (C) 1991, 1992 Linus Torvalds
   5 *   Copyright 2007 rPath, Inc. - All Rights Reserved
   6 *
   7 * ----------------------------------------------------------------------- */
   8
   9/*
  10 * Very simple bitops for the boot code.
  11 */
  12
  13#ifndef BOOT_BITOPS_H
  14#define BOOT_BITOPS_H
  15#define _LINUX_BITOPS_H         /* Inhibit inclusion of <linux/bitops.h> */
  16
  17#include <linux/types.h>
  18#include <asm/asm.h>
  19
  20static inline bool constant_test_bit(int nr, const void *addr)
  21{
  22        const u32 *p = (const u32 *)addr;
  23        return ((1UL << (nr & 31)) & (p[nr >> 5])) != 0;
  24}
  25static inline bool variable_test_bit(int nr, const void *addr)
  26{
  27        bool v;
  28        const u32 *p = (const u32 *)addr;
  29
  30        asm("btl %2,%1" CC_SET(c) : CC_OUT(c) (v) : "m" (*p), "Ir" (nr));
  31        return v;
  32}
  33
  34#define test_bit(nr,addr) \
  35(__builtin_constant_p(nr) ? \
  36 constant_test_bit((nr),(addr)) : \
  37 variable_test_bit((nr),(addr)))
  38
  39static inline void set_bit(int nr, void *addr)
  40{
  41        asm("btsl %1,%0" : "+m" (*(u32 *)addr) : "Ir" (nr));
  42}
  43
  44#endif /* BOOT_BITOPS_H */
  45