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authorJiri Kosina <jkosina@suse.cz>2010-06-16 18:08:13 +0200
committerJiri Kosina <jkosina@suse.cz>2010-06-16 18:08:13 +0200
commitf1bbbb6912662b9f6070c5bfc4ca9eb1f06a9d5b (patch)
treec2c130a74be25b0b2dff992e1a195e2728bdaadd /lib/random32.c
parentfd0961ff67727482bb20ca7e8ea97b83e9de2ddb (diff)
parent7e27d6e778cd87b6f2415515d7127eba53fe5d02 (diff)
downloadlinux-linaro-precise-f1bbbb6912662b9f6070c5bfc4ca9eb1f06a9d5b.tar.gz
Merge branch 'master' into for-next
Diffstat (limited to 'lib/random32.c')
-rw-r--r--lib/random32.c38
1 files changed, 17 insertions, 21 deletions
diff --git a/lib/random32.c b/lib/random32.c
index 556d5ffe110..fc3545a3277 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;
}