These changes are the raw update to linux-4.4.6-rt14. Kernel sources

[kvmfornfv.git] / kernel / include / linux / average.h

diff --git a/kernel/include/linux/average.h b/kernel/include/linux/average.h
index c6028fd..d04aa58 100644 (file)
--- a/kernel/include/linux/average.h
+++ b/kernel/include/linux/average.h
@@ -3,28 +3,43 @@
 
 /* Exponentially weighted moving average (EWMA) */
 
-/* For more documentation see lib/average.c */
-
-struct ewma {
-       unsigned long internal;
-       unsigned long factor;
-       unsigned long weight;
-};
-
-extern void ewma_init(struct ewma *avg, unsigned long factor,
-                     unsigned long weight);
-
-extern struct ewma *ewma_add(struct ewma *avg, unsigned long val);
-
-/**
- * ewma_read() - Get average value
- * @avg: Average structure
- *
- * Returns the average value held in @avg.
- */
-static inline unsigned long ewma_read(const struct ewma *avg)
-{
-       return avg->internal >> avg->factor;
-}
+#define DECLARE_EWMA(name, _factor, _weight)                           \
+       struct ewma_##name {                                            \
+               unsigned long internal;                                 \
+       };                                                              \
+       static inline void ewma_##name##_init(struct ewma_##name *e)    \
+       {                                                               \
+               BUILD_BUG_ON(!__builtin_constant_p(_factor));           \
+               BUILD_BUG_ON(!__builtin_constant_p(_weight));           \
+               BUILD_BUG_ON_NOT_POWER_OF_2(_factor);                   \
+               BUILD_BUG_ON_NOT_POWER_OF_2(_weight);                   \
+               e->internal = 0;                                        \
+       }                                                               \
+       static inline unsigned long                                     \
+       ewma_##name##_read(struct ewma_##name *e)                       \
+       {                                                               \
+               BUILD_BUG_ON(!__builtin_constant_p(_factor));           \
+               BUILD_BUG_ON(!__builtin_constant_p(_weight));           \
+               BUILD_BUG_ON_NOT_POWER_OF_2(_factor);                   \
+               BUILD_BUG_ON_NOT_POWER_OF_2(_weight);                   \
+               return e->internal >> ilog2(_factor);                   \
+       }                                                               \
+       static inline void ewma_##name##_add(struct ewma_##name *e,     \
+                                            unsigned long val)         \
+       {                                                               \
+               unsigned long internal = ACCESS_ONCE(e->internal);      \
+               unsigned long weight = ilog2(_weight);                  \
+               unsigned long factor = ilog2(_factor);                  \
+                                                                       \
+               BUILD_BUG_ON(!__builtin_constant_p(_factor));           \
+               BUILD_BUG_ON(!__builtin_constant_p(_weight));           \
+               BUILD_BUG_ON_NOT_POWER_OF_2(_factor);                   \
+               BUILD_BUG_ON_NOT_POWER_OF_2(_weight);                   \
+                                                                       \
+               ACCESS_ONCE(e->internal) = internal ?                   \
+                       (((internal << weight) - internal) +            \
+                               (val << factor)) >> weight :            \
+                       (val << factor);                                \
+       }
 
 #endif /* _LINUX_AVERAGE_H */