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