summaryrefslogtreecommitdiffstats
path: root/include/linux/random.h
diff options
context:
space:
mode:
authorRussell King <rmk+kernel@arm.linux.org.uk>2010-06-08 19:40:08 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2010-06-08 19:40:08 +0100
commit76962be8491b18ae7ff4fd6a4accd398bdb402a2 (patch)
tree976958bf8e4989a69901bfbb25dd6463728c6cb5 /include/linux/random.h
parent5e27fb78df95e027723af2c90ecc9b4527ae59e9 (diff)
parentd30e5d897c3da7c2d17c8112331b66ed953eec78 (diff)
Merge branch 'fix' of git://git.kernel.org/pub/scm/linux/kernel/git/ycmiao/pxa-linux-2.6
Diffstat (limited to 'include/linux/random.h')
-rw-r--r--include/linux/random.h28
1 files changed, 28 insertions, 0 deletions
diff --git a/include/linux/random.h b/include/linux/random.h
index 25d02fe5c9b..fb7ab9de5f3 100644
--- 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 */