18c2ecf20Sopenharmony_ci/* SPDX-License-Identifier: GPL-2.0 */ 28c2ecf20Sopenharmony_ci#ifndef _ASM_GENERIC_BITOPS___FLS_H_ 38c2ecf20Sopenharmony_ci#define _ASM_GENERIC_BITOPS___FLS_H_ 48c2ecf20Sopenharmony_ci 58c2ecf20Sopenharmony_ci#include <asm/types.h> 68c2ecf20Sopenharmony_ci 78c2ecf20Sopenharmony_ci/** 88c2ecf20Sopenharmony_ci * __fls - find last (most-significant) set bit in a long word 98c2ecf20Sopenharmony_ci * @word: the word to search 108c2ecf20Sopenharmony_ci * 118c2ecf20Sopenharmony_ci * Undefined if no set bit exists, so code should check against 0 first. 128c2ecf20Sopenharmony_ci */ 138c2ecf20Sopenharmony_cistatic __always_inline unsigned long __fls(unsigned long word) 148c2ecf20Sopenharmony_ci{ 158c2ecf20Sopenharmony_ci int num = BITS_PER_LONG - 1; 168c2ecf20Sopenharmony_ci 178c2ecf20Sopenharmony_ci#if BITS_PER_LONG == 64 188c2ecf20Sopenharmony_ci if (!(word & (~0ul << 32))) { 198c2ecf20Sopenharmony_ci num -= 32; 208c2ecf20Sopenharmony_ci word <<= 32; 218c2ecf20Sopenharmony_ci } 228c2ecf20Sopenharmony_ci#endif 238c2ecf20Sopenharmony_ci if (!(word & (~0ul << (BITS_PER_LONG-16)))) { 248c2ecf20Sopenharmony_ci num -= 16; 258c2ecf20Sopenharmony_ci word <<= 16; 268c2ecf20Sopenharmony_ci } 278c2ecf20Sopenharmony_ci if (!(word & (~0ul << (BITS_PER_LONG-8)))) { 288c2ecf20Sopenharmony_ci num -= 8; 298c2ecf20Sopenharmony_ci word <<= 8; 308c2ecf20Sopenharmony_ci } 318c2ecf20Sopenharmony_ci if (!(word & (~0ul << (BITS_PER_LONG-4)))) { 328c2ecf20Sopenharmony_ci num -= 4; 338c2ecf20Sopenharmony_ci word <<= 4; 348c2ecf20Sopenharmony_ci } 358c2ecf20Sopenharmony_ci if (!(word & (~0ul << (BITS_PER_LONG-2)))) { 368c2ecf20Sopenharmony_ci num -= 2; 378c2ecf20Sopenharmony_ci word <<= 2; 388c2ecf20Sopenharmony_ci } 398c2ecf20Sopenharmony_ci if (!(word & (~0ul << (BITS_PER_LONG-1)))) 408c2ecf20Sopenharmony_ci num -= 1; 418c2ecf20Sopenharmony_ci return num; 428c2ecf20Sopenharmony_ci} 438c2ecf20Sopenharmony_ci 448c2ecf20Sopenharmony_ci#endif /* _ASM_GENERIC_BITOPS___FLS_H_ */ 45