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Diffstat (limited to 'kernel/arch/x86/boot/bitops.h')
-rw-r--r-- | kernel/arch/x86/boot/bitops.h | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/kernel/arch/x86/boot/bitops.h b/kernel/arch/x86/boot/bitops.h new file mode 100644 index 000000000..878e4b994 --- /dev/null +++ b/kernel/arch/x86/boot/bitops.h @@ -0,0 +1,43 @@ +/* -*- linux-c -*- ------------------------------------------------------- * + * + * Copyright (C) 1991, 1992 Linus Torvalds + * Copyright 2007 rPath, Inc. - All Rights Reserved + * + * This file is part of the Linux kernel, and is made available under + * the terms of the GNU General Public License version 2. + * + * ----------------------------------------------------------------------- */ + +/* + * Very simple bitops for the boot code. + */ + +#ifndef BOOT_BITOPS_H +#define BOOT_BITOPS_H +#define _LINUX_BITOPS_H /* Inhibit inclusion of <linux/bitops.h> */ + +static inline int constant_test_bit(int nr, const void *addr) +{ + const u32 *p = (const u32 *)addr; + return ((1UL << (nr & 31)) & (p[nr >> 5])) != 0; +} +static inline int variable_test_bit(int nr, const void *addr) +{ + u8 v; + const u32 *p = (const u32 *)addr; + + asm("btl %2,%1; setc %0" : "=qm" (v) : "m" (*p), "Ir" (nr)); + return v; +} + +#define test_bit(nr,addr) \ +(__builtin_constant_p(nr) ? \ + constant_test_bit((nr),(addr)) : \ + variable_test_bit((nr),(addr))) + +static inline void set_bit(int nr, void *addr) +{ + asm("btsl %1,%0" : "+m" (*(u32 *)addr) : "Ir" (nr)); +} + +#endif /* BOOT_BITOPS_H */ |