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| author | Daniel Vetter <daniel.vetter@ffwll.ch> | 2017-02-26 21:34:42 +0100 |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2017-02-26 21:34:42 +0100 |
| commit | 8e22e1b3499a446df48c2b26667ca36c55bf864c (patch) | |
| tree | 5329f98b3eb3c95a9dcbab0fa4f9b6e62f0e788d /include/linux/log2.h | |
| parent | 00d3c14f14d51babd8aeafd5fa734ccf04f5ca3d (diff) | |
| parent | 64a577196d66b44e37384bc5c4d78c61f59d5b2a (diff) | |
Merge airlied/drm-next into drm-misc-next
Backmerge the main pull request to sync up with all the newly landed
drivers. Otherwise we'll have chaos even before 4.12 started in
earnest.
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
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 */ |