1/* SPDX-License-Identifier: GPL-2.0 */
 2#ifndef _ASM_GENERIC_BITOPS___FFS_H_
 3#define _ASM_GENERIC_BITOPS___FFS_H_
 4
 5#include <asm/types.h>
 6
 7/**
 8 * generic___ffs - find first bit in word.
 9 * @word: The word to search
10 *
11 * Undefined if no bit exists, so code should check against 0 first.
12 */
13static __always_inline unsigned int generic___ffs(unsigned long word)
14{
15	unsigned int num = 0;
16
17#if BITS_PER_LONG == 64
18	if ((word & 0xffffffff) == 0) {
19		num += 32;
20		word >>= 32;
21	}
22#endif
23	if ((word & 0xffff) == 0) {
24		num += 16;
25		word >>= 16;
26	}
27	if ((word & 0xff) == 0) {
28		num += 8;
29		word >>= 8;
30	}
31	if ((word & 0xf) == 0) {
32		num += 4;
33		word >>= 4;
34	}
35	if ((word & 0x3) == 0) {
36		num += 2;
37		word >>= 2;
38	}
39	if ((word & 0x1) == 0)
40		num += 1;
41	return num;
42}
43
44#ifndef __HAVE_ARCH___FFS
45#define __ffs(word) generic___ffs(word)
46#endif
47
48#endif /* _ASM_GENERIC_BITOPS___FFS_H_ */

 
 1#ifndef _ASM_GENERIC_BITOPS___FFS_H_
 2#define _ASM_GENERIC_BITOPS___FFS_H_
 3
 4#include <asm/types.h>
 5
 6/**
 7 * __ffs - find first bit in word.
 8 * @word: The word to search
 9 *
10 * Undefined if no bit exists, so code should check against 0 first.
11 */
12static __always_inline unsigned long __ffs(unsigned long word)
13{
14	int num = 0;
15
16#if BITS_PER_LONG == 64
17	if ((word & 0xffffffff) == 0) {
18		num += 32;
19		word >>= 32;
20	}
21#endif
22	if ((word & 0xffff) == 0) {
23		num += 16;
24		word >>= 16;
25	}
26	if ((word & 0xff) == 0) {
27		num += 8;
28		word >>= 8;
29	}
30	if ((word & 0xf) == 0) {
31		num += 4;
32		word >>= 4;
33	}
34	if ((word & 0x3) == 0) {
35		num += 2;
36		word >>= 2;
37	}
38	if ((word & 0x1) == 0)
39		num += 1;
40	return num;
41}
 
 
 
 
42
43#endif /* _ASM_GENERIC_BITOPS___FFS_H_ */