Merge branch 'for-linus' of git://git.o-hand.com/linux-rpurdie-backlight

[pandora-kernel.git] / include / linux / random.h

diff --git a/include/linux/random.h b/include/linux/random.h
index 25d02fe..fb7ab9d 100644 (file)
--- a/include/linux/random.h
+++ b/include/linux/random.h
@@ -40,6 +40,10 @@ struct rand_pool_info {
        __u32   buf[0];
 };
 
+struct rnd_state {
+       __u32 s1, s2, s3;
+};
+
 /* Exported functions */
 
 #ifdef __KERNEL__
@@ -74,6 +78,30 @@ unsigned long randomize_range(unsigned long start, unsigned long end, unsigned l
 u32 random32(void);
 void srandom32(u32 seed);
 
+u32 prandom32(struct rnd_state *);
+
+/*
+ * Handle minimum values for seeds
+ */
+static inline u32 __seed(u32 x, u32 m)
+{
+       return (x < m) ? x + m : x;
+}
+
+/**
+ * prandom32_seed - set seed for prandom32().
+ * @state: pointer to state structure to receive the seed.
+ * @seed: arbitrary 64-bit value to use as a seed.
+ */
+static inline void prandom32_seed(struct rnd_state *state, u64 seed)
+{
+       u32 i = (seed >> 32) ^ (seed << 10) ^ seed;
+
+       state->s1 = __seed(i, 1);
+       state->s2 = __seed(i, 7);
+       state->s3 = __seed(i, 15);
+}
+
 #endif /* __KERNEL___ */
 
 #endif /* _LINUX_RANDOM_H */