| Akinobu Mita | 6d29ea2 | 2006-03-26 01:39:12 -0800 | [diff] [blame] | 1 | #ifndef _ASM_GENERIC_BITOPS_SCHED_H_ |
| 2 | #define _ASM_GENERIC_BITOPS_SCHED_H_ |
| 3 | |
| 4 | #include <linux/compiler.h> /* unlikely() */ |
| 5 | #include <asm/types.h> |
| 6 | |
| 7 | /* |
| 8 | * Every architecture must define this function. It's the fastest |
| 9 | * way of searching a 140-bit bitmap where the first 100 bits are |
| 10 | * unlikely to be set. It's guaranteed that at least one of the 140 |
| 11 | * 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 (unlikely(b[0])) |
| 17 | return __ffs(b[0]); |
| 18 | if (unlikely(b[1])) |
| 19 | return __ffs(b[1]) + 64; |
| 20 | return __ffs(b[2]) + 128; |
| 21 | #elif BITS_PER_LONG == 32 |
| 22 | if (unlikely(b[0])) |
| 23 | return __ffs(b[0]); |
| 24 | if (unlikely(b[1])) |
| 25 | return __ffs(b[1]) + 32; |
| 26 | if (unlikely(b[2])) |
| 27 | return __ffs(b[2]) + 64; |
| 28 | if (b[3]) |
| 29 | return __ffs(b[3]) + 96; |
| 30 | return __ffs(b[4]) + 128; |
| 31 | #else |
| 32 | #error BITS_PER_LONG not defined |
| 33 | #endif |
| 34 | } |
| 35 | |
| 36 | #endif /* _ASM_GENERIC_BITOPS_SCHED_H_ */ |