6d29ea23da
This patch introduces the C-language equivalent of the function: int sched_find_first_bit(const unsigned long *b); In include/asm-generic/bitops/sched.h This code largely copied from: include/asm-powerpc/bitops.h Signed-off-by: Akinobu Mita <mita@miraclelinux.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
37 lines
899 B
C
37 lines
899 B
C
#ifndef _ASM_GENERIC_BITOPS_SCHED_H_
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#define _ASM_GENERIC_BITOPS_SCHED_H_
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#include <linux/compiler.h> /* unlikely() */
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#include <asm/types.h>
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/*
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* Every architecture must define this function. It's the fastest
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* way of searching a 140-bit bitmap where the first 100 bits are
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* unlikely to be set. It's guaranteed that at least one of the 140
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* bits is cleared.
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*/
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static inline int sched_find_first_bit(const unsigned long *b)
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{
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#if BITS_PER_LONG == 64
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if (unlikely(b[0]))
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return __ffs(b[0]);
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if (unlikely(b[1]))
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return __ffs(b[1]) + 64;
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return __ffs(b[2]) + 128;
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#elif BITS_PER_LONG == 32
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if (unlikely(b[0]))
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return __ffs(b[0]);
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if (unlikely(b[1]))
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return __ffs(b[1]) + 32;
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if (unlikely(b[2]))
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return __ffs(b[2]) + 64;
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if (b[3])
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return __ffs(b[3]) + 96;
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return __ffs(b[4]) + 128;
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#else
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#error BITS_PER_LONG not defined
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#endif
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}
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#endif /* _ASM_GENERIC_BITOPS_SCHED_H_ */
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