ad7e906d56
A simple collection of bitops for the new x86 setup code. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
46 lines
1.2 KiB
C
46 lines
1.2 KiB
C
/* -*- linux-c -*- ------------------------------------------------------- *
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*
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* Copyright (C) 1991, 1992 Linus Torvalds
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* Copyright 2007 rPath, Inc. - All Rights Reserved
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*
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* This file is part of the Linux kernel, and is made available under
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* the terms of the GNU General Public License version 2.
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*
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* ----------------------------------------------------------------------- */
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/*
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* arch/i386/boot/bitops.h
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*
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* Very simple bitops for the boot code.
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*/
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#ifndef BOOT_BITOPS_H
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#define BOOT_BITOPS_H
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#define _LINUX_BITOPS_H /* Inhibit inclusion of <linux/bitops.h> */
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static inline int constant_test_bit(int nr, const void *addr)
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{
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const u32 *p = (const u32 *)addr;
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return ((1UL << (nr & 31)) & (p[nr >> 5])) != 0;
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}
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static inline int variable_test_bit(int nr, const void *addr)
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{
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u8 v;
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const u32 *p = (const u32 *)addr;
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asm("btl %2,%1; setc %0" : "=qm" (v) : "m" (*p), "Ir" (nr));
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return v;
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}
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#define test_bit(nr,addr) \
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(__builtin_constant_p(nr) ? \
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constant_test_bit((nr),(addr)) : \
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variable_test_bit((nr),(addr)))
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static inline void set_bit(int nr, void *addr)
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{
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asm("btsl %1,%0" : "+m" (*(u32 *)addr) : "Ir" (nr));
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}
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#endif /* BOOT_BITOPS_H */
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