asm-generic/bitops/sched.h

0001 /* SPDX-License-Identifier: GPL-2.0 */
0002 #ifndef _ASM_GENERIC_BITOPS_SCHED_H_
0003 #define _ASM_GENERIC_BITOPS_SCHED_H_
0004
0005 #include <linux/compiler.h> /* unlikely() */
0006 #include <asm/types.h>
0007
0008 /*
0009  * Every architecture must define this function. It's the fastest
0010  * way of searching a 100-bit bitmap.  It's guaranteed that at least
0011  * one of the 100 bits is cleared.
0012  */
0013 static inline int sched_find_first_bit(const unsigned long *b)
0014 {
0015 #if BITS_PER_LONG == 64
0016     if (b[0])
0017         return __ffs(b[0]);
0018     return __ffs(b[1]) + 64;
0019 #elif BITS_PER_LONG == 32
0020     if (b[0])
0021         return __ffs(b[0]);
0022     if (b[1])
0023         return __ffs(b[1]) + 32;
0024     if (b[2])
0025         return __ffs(b[2]) + 64;
0026     return __ffs(b[3]) + 96;
0027 #else
0028 #error BITS_PER_LONG not defined
0029 #endif
0030 }
0031
0032 #endif /* _ASM_GENERIC_BITOPS_SCHED_H_ */