162306a36Sopenharmony_ci/* SPDX-License-Identifier: GPL-2.0 */ 262306a36Sopenharmony_ci#ifndef _ASM_GENERIC_BITOPS___FLS_H_ 362306a36Sopenharmony_ci#define _ASM_GENERIC_BITOPS___FLS_H_ 462306a36Sopenharmony_ci 562306a36Sopenharmony_ci#include <asm/types.h> 662306a36Sopenharmony_ci 762306a36Sopenharmony_ci/** 862306a36Sopenharmony_ci * __fls - find last (most-significant) set bit in a long word 962306a36Sopenharmony_ci * @word: the word to search 1062306a36Sopenharmony_ci * 1162306a36Sopenharmony_ci * Undefined if no set bit exists, so code should check against 0 first. 1262306a36Sopenharmony_ci */ 1362306a36Sopenharmony_cistatic __always_inline unsigned long __fls(unsigned long word) 1462306a36Sopenharmony_ci{ 1562306a36Sopenharmony_ci int num = BITS_PER_LONG - 1; 1662306a36Sopenharmony_ci 1762306a36Sopenharmony_ci#if BITS_PER_LONG == 64 1862306a36Sopenharmony_ci if (!(word & (~0ul << 32))) { 1962306a36Sopenharmony_ci num -= 32; 2062306a36Sopenharmony_ci word <<= 32; 2162306a36Sopenharmony_ci } 2262306a36Sopenharmony_ci#endif 2362306a36Sopenharmony_ci if (!(word & (~0ul << (BITS_PER_LONG-16)))) { 2462306a36Sopenharmony_ci num -= 16; 2562306a36Sopenharmony_ci word <<= 16; 2662306a36Sopenharmony_ci } 2762306a36Sopenharmony_ci if (!(word & (~0ul << (BITS_PER_LONG-8)))) { 2862306a36Sopenharmony_ci num -= 8; 2962306a36Sopenharmony_ci word <<= 8; 3062306a36Sopenharmony_ci } 3162306a36Sopenharmony_ci if (!(word & (~0ul << (BITS_PER_LONG-4)))) { 3262306a36Sopenharmony_ci num -= 4; 3362306a36Sopenharmony_ci word <<= 4; 3462306a36Sopenharmony_ci } 3562306a36Sopenharmony_ci if (!(word & (~0ul << (BITS_PER_LONG-2)))) { 3662306a36Sopenharmony_ci num -= 2; 3762306a36Sopenharmony_ci word <<= 2; 3862306a36Sopenharmony_ci } 3962306a36Sopenharmony_ci if (!(word & (~0ul << (BITS_PER_LONG-1)))) 4062306a36Sopenharmony_ci num -= 1; 4162306a36Sopenharmony_ci return num; 4262306a36Sopenharmony_ci} 4362306a36Sopenharmony_ci 4462306a36Sopenharmony_ci#endif /* _ASM_GENERIC_BITOPS___FLS_H_ */ 45