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authorUwe Kleine-König <u.kleine-koenig@pengutronix.de>2010-06-30 12:16:24 +0200
committerUwe Kleine-König <u.kleine-koenig@pengutronix.de>2010-07-26 14:27:25 +0200
commit2dcf78c0eeae3bd07082821557014f25f02ca2e9 (patch)
tree8ca5c4c7f35c9a9ab07fcd9732124c905e609aa1 /lib/random32.c
parent6b6322676add0fa2713d0ec89a28390fd4d907f5 (diff)
parent5109a4597f7e758b8d20694392d0361a0b4c43b1 (diff)
Merge branch 'imx/for-2.6.36' of git://git.pengutronix.de/git/ukl/linux-2.6 into HEAD
There are some more conflicts than detected by git, namely support for the newly added cpuimx machines needed to be converted to dynamic device registration. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Conflicts: arch/arm/mach-imx/Makefile arch/arm/mach-imx/devices.c arch/arm/mach-imx/devices.h arch/arm/mach-imx/eukrea_mbimx27-baseboard.c arch/arm/mach-mx2/Kconfig arch/arm/mach-mx25/Makefile arch/arm/mach-mx25/devices.c arch/arm/plat-mxc/include/mach/mx25.h arch/arm/plat-mxc/include/mach/mxc_nand.h
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 217d5c4b666..870dc3fc0f0 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;
}