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bb9707077b
We use it in bitops/__ffs.h and bitops/atomic.h, that we also got from the kernel, but were getting it from either newer systems that carry it in /usr/include, or from the kernel sources, that we decided not to touch from tools/ code. Fix it. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/n/tip-lwqvgbuitjmrdpjmjp6zqnyx@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
45 lines
805 B
C
45 lines
805 B
C
#ifndef _TOOLS_LINUX_ASM_GENERIC_BITOPS___FFS_H_
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#define _TOOLS_LINUX_ASM_GENERIC_BITOPS___FFS_H_
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#include <asm/types.h>
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#include <asm/bitsperlong.h>
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/**
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* __ffs - find first bit in word.
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* @word: The word to search
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*
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* Undefined if no bit exists, so code should check against 0 first.
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*/
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static __always_inline unsigned long __ffs(unsigned long word)
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{
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int num = 0;
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#if __BITS_PER_LONG == 64
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if ((word & 0xffffffff) == 0) {
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num += 32;
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word >>= 32;
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}
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#endif
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if ((word & 0xffff) == 0) {
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num += 16;
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word >>= 16;
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}
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if ((word & 0xff) == 0) {
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num += 8;
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word >>= 8;
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}
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if ((word & 0xf) == 0) {
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num += 4;
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word >>= 4;
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}
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if ((word & 0x3) == 0) {
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num += 2;
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word >>= 2;
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}
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if ((word & 0x1) == 0)
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num += 1;
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return num;
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}
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#endif /* _TOOLS_LINUX_ASM_GENERIC_BITOPS___FFS_H_ */
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