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| author | Thomas Gleixner <tglx@linutronix.de> | 2017-02-16 19:51:27 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2017-02-16 19:51:27 +0100 |
| commit | 5b1ad68f9b1951ef78312d2935906cc8a8bd2e12 (patch) | |
| tree | e81b71c961e885cef0d3992e083acec845166870 /include/linux/log2.h | |
| parent | 1013fe32a63d1139b1b32049ea46c0c462738d8b (diff) | |
| parent | 7089db84e356562f8ba737c29e472cc42d530dbc (diff) | |
Merge branch 'linus' into x86/mm
Make sure to get the latest fixes before applying the ptdump enhancements.
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 fd7ff3d91e6a..ef3d4f67118c 100644 --- a/include/linux/log2.h +++ b/include/linux/log2.h @@ -203,6 +203,17 @@ 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 */ |