diff options
author | Jiri Kosina <jkosina@suse.cz> | 2010-06-16 20:08:13 +0400 |
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committer | Jiri Kosina <jkosina@suse.cz> | 2010-06-16 20:08:13 +0400 |
commit | f1bbbb6912662b9f6070c5bfc4ca9eb1f06a9d5b (patch) | |
tree | c2c130a74be25b0b2dff992e1a195e2728bdaadd /lib/random32.c | |
parent | fd0961ff67727482bb20ca7e8ea97b83e9de2ddb (diff) | |
parent | 7e27d6e778cd87b6f2415515d7127eba53fe5d02 (diff) |
Merge branch 'master' into for-next
Diffstat (limited to 'lib/random32.c')
-rw-r--r-- | lib/random32.c | 38 |
1 files changed, 17 insertions, 21 deletions
diff --git a/lib/random32.c b/lib/random32.c index 556d5ffe1106..fc3545a32771 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; } |