2 files changed, 45 insertions, 21 deletions

diff --git a/include/linux/random.h b/include/linux/random.h
index 25d02fe5c9b5..fb7ab9de5f36 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 */
diff --git a/lib/random32.c b/lib/random32.c
index 217d5c4b666d..870dc3fc0f0f 100644
--- a/lib/random32.c
+++ b/lib/random32.c
@@ -39,13 +39,16 @@
 #include <linux/jiffies.h>
 #include <linux/random.h>
 
-struct rnd_state {
-	u32 s1, s2, s3;
-};
-
 static DEFINE_PER_CPU(struct rnd_state, net_rand_state);
 
-static u32 __random32(struct rnd_state *state)
+/**
+ *	prandom32 - seeded pseudo-random number generator.
+ *	@state: pointer to state structure holding seeded state.
+ *
+ *	This is used for pseudo-randomness with no outside seeding.
+ *	For more random results, use random32().
+ */
+u32 prandom32(struct rnd_state *state)
 {
 #define TAUSWORTHE(s,a,b,c,d) ((s&c)<<d) ^ (((s <<a) ^ s)>>b)
 
@@ -55,14 +58,7 @@ static u32 __random32(struct rnd_state *state)
 
 	return (state->s1 ^ state->s2 ^ state->s3);
 }
-
-/*
- * Handle minimum values for seeds
- */
-static inline u32 __seed(u32 x, u32 m)
-{
-	return (x < m) ? x + m : x;
-}
+EXPORT_SYMBOL(prandom32);
 
 /**
  *	random32 - pseudo random number generator
@@ -75,7 +71,7 @@ u32 random32(void)
 {
 	unsigned long r;
 	struct rnd_state *state = &get_cpu_var(net_rand_state);
-	r = __random32(state);
+	r = prandom32(state);
 	put_cpu_var(state);
 	return r;
 }
@@ -118,12 +114,12 @@ static int __init random32_init(void)
 		state->s3 = __seed(LCG(state->s2), 15);
 
 		/* "warm it up" */
-		__random32(state);
-		__random32(state);
-		__random32(state);
-		__random32(state);
-		__random32(state);
-		__random32(state);
+		prandom32(state);
+		prandom32(state);
+		prandom32(state);
+		prandom32(state);
+		prandom32(state);
+		prandom32(state);
 	}
 	return 0;
 }
@@ -147,7 +143,7 @@ static int __init random32_reseed(void)
 		state->s3 = __seed(seeds[2], 15);
 
 		/* mix it in */
-		__random32(state);
+		prandom32(state);
 	}
 	return 0;
 }