1/* SPDX-License-Identifier: GPL-2.0 */
 2#ifndef _ASM_GENERIC_BITOPS___FLS_H_
 3#define _ASM_GENERIC_BITOPS___FLS_H_
 4
 5#include <asm/types.h>
 6
 7/**
 8 * generic___fls - find last (most-significant) set bit in a long word
 9 * @word: the word to search
10 *
11 * Undefined if no set bit exists, so code should check against 0 first.
12 */
13static __always_inline unsigned int generic___fls(unsigned long word)
14{
15	unsigned int num = BITS_PER_LONG - 1;
16
17#if BITS_PER_LONG == 64
18	if (!(word & (~0ul << 32))) {
19		num -= 32;
20		word <<= 32;
21	}
22#endif
23	if (!(word & (~0ul << (BITS_PER_LONG-16)))) {
24		num -= 16;
25		word <<= 16;
26	}
27	if (!(word & (~0ul << (BITS_PER_LONG-8)))) {
28		num -= 8;
29		word <<= 8;
30	}
31	if (!(word & (~0ul << (BITS_PER_LONG-4)))) {
32		num -= 4;
33		word <<= 4;
34	}
35	if (!(word & (~0ul << (BITS_PER_LONG-2)))) {
36		num -= 2;
37		word <<= 2;
38	}
39	if (!(word & (~0ul << (BITS_PER_LONG-1))))
40		num -= 1;
41	return num;
42}
43
44#ifndef __HAVE_ARCH___FLS
45#define __fls(word) generic___fls(word)
46#endif
47
48#endif /* _ASM_GENERIC_BITOPS___FLS_H_ */

 
 1#ifndef _ASM_GENERIC_BITOPS___FLS_H_
 2#define _ASM_GENERIC_BITOPS___FLS_H_
 3
 4#include <asm/types.h>
 5
 6/**
 7 * __fls - find last (most-significant) set bit in a long word
 8 * @word: the word to search
 9 *
10 * Undefined if no set bit exists, so code should check against 0 first.
11 */
12static __always_inline unsigned long __fls(unsigned long word)
13{
14	int num = BITS_PER_LONG - 1;
15
16#if BITS_PER_LONG == 64
17	if (!(word & (~0ul << 32))) {
18		num -= 32;
19		word <<= 32;
20	}
21#endif
22	if (!(word & (~0ul << (BITS_PER_LONG-16)))) {
23		num -= 16;
24		word <<= 16;
25	}
26	if (!(word & (~0ul << (BITS_PER_LONG-8)))) {
27		num -= 8;
28		word <<= 8;
29	}
30	if (!(word & (~0ul << (BITS_PER_LONG-4)))) {
31		num -= 4;
32		word <<= 4;
33	}
34	if (!(word & (~0ul << (BITS_PER_LONG-2)))) {
35		num -= 2;
36		word <<= 2;
37	}
38	if (!(word & (~0ul << (BITS_PER_LONG-1))))
39		num -= 1;
40	return num;
41}
 
 
 
 
42
43#endif /* _ASM_GENERIC_BITOPS___FLS_H_ */