xref: /linux/include/asm-generic/bitops/sched.h (revision 906fd46a65383cd639e5eec72a047efc33045d86)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_GENERIC_BITOPS_SCHED_H_
3 #define _ASM_GENERIC_BITOPS_SCHED_H_
4 
5 #include <linux/compiler.h>	/* unlikely() */
6 #include <asm/types.h>
7 
8 /*
9  * Every architecture must define this function. It's the fastest
10  * way of searching a 100-bit bitmap.  It's guaranteed that at least
11  * one of the 100 bits is cleared.
12  */
13 static inline int sched_find_first_bit(const unsigned long *b)
14 {
15 #if BITS_PER_LONG == 64
16 	if (b[0])
17 		return __ffs(b[0]);
18 	return __ffs(b[1]) + 64;
19 #elif BITS_PER_LONG == 32
20 	if (b[0])
21 		return __ffs(b[0]);
22 	if (b[1])
23 		return __ffs(b[1]) + 32;
24 	if (b[2])
25 		return __ffs(b[2]) + 64;
26 	return __ffs(b[3]) + 96;
27 #else
28 #error BITS_PER_LONG not defined
29 #endif
30 }
31 
32 #endif /* _ASM_GENERIC_BITOPS_SCHED_H_ */
33