/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _ASM_GENERIC_BITOPS___FFS_H_ #define _ASM_GENERIC_BITOPS___FFS_H_ #include <asm/types.h> /** * __ffs - find first bit in word. * @word: The word to search * * Undefined if no bit exists, so code should check against 0 first. */ static __always_inline unsigned long __ffs(unsigned long word) { int num = 0; #if BITS_PER_LONG == 64 if ((word & 0xffffffff) == 0) { num += 32; word >>= 32; } #endif if ((word & 0xffff) == 0) { num += 16; word >>= 16; } if ((word & 0xff) == 0) { num += 8; word >>= 8; } if ((word & 0xf) == 0) { num += 4; word >>= 4; } if ((word & 0x3) == 0) { num += 2; word >>= 2; } if ((word & 0x1) == 0) num += 1; return num; } #endif /* _ASM_GENERIC_BITOPS___FFS_H_ */