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1/* SPDX-License-Identifier: GPL-2.0 */2#ifndef _TOOLS_LINUX_ASM_GENERIC_BITOPS___FFS_H_3#define _TOOLS_LINUX_ASM_GENERIC_BITOPS___FFS_H_4 5#include <asm/types.h>6#include <asm/bitsperlong.h>7 8/**9 * __ffs - find first bit in word.10 * @word: The word to search11 *12 * Undefined if no bit exists, so code should check against 0 first.13 */14static __always_inline unsigned int __ffs(unsigned long word)15{16 unsigned int num = 0;17 18#if __BITS_PER_LONG == 6419 if ((word & 0xffffffff) == 0) {20 num += 32;21 word >>= 32;22 }23#endif24 if ((word & 0xffff) == 0) {25 num += 16;26 word >>= 16;27 }28 if ((word & 0xff) == 0) {29 num += 8;30 word >>= 8;31 }32 if ((word & 0xf) == 0) {33 num += 4;34 word >>= 4;35 }36 if ((word & 0x3) == 0) {37 num += 2;38 word >>= 2;39 }40 if ((word & 0x1) == 0)41 num += 1;42 return num;43}44 45#endif /* _TOOLS_LINUX_ASM_GENERIC_BITOPS___FFS_H_ */46