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 = 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 = 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

source code of linux/arch/x86/boot/bitops.h