1b2441318SGreg Kroah-Hartman /* SPDX-License-Identifier: GPL-2.0 */ 209020adbSAkinobu Mita #ifndef _ASM_GENERIC_BITOPS_FFS_H_ 309020adbSAkinobu Mita #define _ASM_GENERIC_BITOPS_FFS_H_ 409020adbSAkinobu Mita 509020adbSAkinobu Mita /** 609020adbSAkinobu Mita * ffs - find first bit set 709020adbSAkinobu Mita * @x: the word to search 809020adbSAkinobu Mita * 909020adbSAkinobu Mita * This is defined the same way as 1009020adbSAkinobu Mita * the libc and compiler builtin ffs routines, therefore 11*fc062ad8SGeert Uytterhoeven * differs in spirit from ffz (man ffs). 1209020adbSAkinobu Mita */ ffs(int x)1309020adbSAkinobu Mitastatic inline int ffs(int x) 1409020adbSAkinobu Mita { 1509020adbSAkinobu Mita int r = 1; 1609020adbSAkinobu Mita 1709020adbSAkinobu Mita if (!x) 1809020adbSAkinobu Mita return 0; 1909020adbSAkinobu Mita if (!(x & 0xffff)) { 2009020adbSAkinobu Mita x >>= 16; 2109020adbSAkinobu Mita r += 16; 2209020adbSAkinobu Mita } 2309020adbSAkinobu Mita if (!(x & 0xff)) { 2409020adbSAkinobu Mita x >>= 8; 2509020adbSAkinobu Mita r += 8; 2609020adbSAkinobu Mita } 2709020adbSAkinobu Mita if (!(x & 0xf)) { 2809020adbSAkinobu Mita x >>= 4; 2909020adbSAkinobu Mita r += 4; 3009020adbSAkinobu Mita } 3109020adbSAkinobu Mita if (!(x & 3)) { 3209020adbSAkinobu Mita x >>= 2; 3309020adbSAkinobu Mita r += 2; 3409020adbSAkinobu Mita } 3509020adbSAkinobu Mita if (!(x & 1)) { 3609020adbSAkinobu Mita x >>= 1; 3709020adbSAkinobu Mita r += 1; 3809020adbSAkinobu Mita } 3909020adbSAkinobu Mita return r; 4009020adbSAkinobu Mita } 4109020adbSAkinobu Mita 4209020adbSAkinobu Mita #endif /* _ASM_GENERIC_BITOPS_FFS_H_ */ 43