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| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2017-06-23 15:55:15 +0200 |
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| committer | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2017-06-23 15:55:15 +0200 |
| commit | 5315486b2da90bcfa1ce5c791aafebb4c3534cf1 (patch) | |
| tree | c3c215962edb82708210606574417efc1b84abe0 /include/linux/log2.h | |
| parent | 351dce074b70b19c7f8b1b737a862577e822a508 (diff) | |
| parent | 050639ef5810e8ad17fb6a426eff3c63e616350c (diff) | |
| download | linux-rt-5315486b2da90bcfa1ce5c791aafebb4c3534cf1.tar.gz | |
Merge tag 'v4.9.33' into linux-4.9.y-rt
This is the 4.9.33 stable release
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Diffstat (limited to 'include/linux/log2.h')
| -rw-r--r-- | include/linux/log2.h | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/include/linux/log2.h b/include/linux/log2.h index f38fae23bdac..c373295f359f 100644 --- a/include/linux/log2.h +++ b/include/linux/log2.h @@ -194,6 +194,17 @@ unsigned long __rounddown_pow_of_two(unsigned long n) * ... and so on. */ -#define order_base_2(n) ilog2(roundup_pow_of_two(n)) +static inline __attribute_const__ +int __order_base_2(unsigned long n) +{ + return n > 1 ? ilog2(n - 1) + 1 : 0; +} +#define order_base_2(n) \ +( \ + __builtin_constant_p(n) ? ( \ + ((n) == 0 || (n) == 1) ? 0 : \ + ilog2((n) - 1) + 1) : \ + __order_base_2(n) \ +) #endif /* _LINUX_LOG2_H */ |