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author | David S. Miller <davem@davemloft.net> | 2010-05-31 05:46:45 -0700 |
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committer | David S. Miller <davem@davemloft.net> | 2010-05-31 05:46:45 -0700 |
commit | 64960848abd18d0bcde3f53ffa7ed0b631e6b25d (patch) | |
tree | 8424a1c550a98ce09f127425fde9b7b5f2f5027a /include/linux/random.h | |
parent | 2903037400a26e7c0cc93ab75a7d62abfacdf485 (diff) | |
parent | 67a3e12b05e055c0415c556a315a3d3eb637e29e (diff) |
Merge branch 'master' of /home/davem/src/GIT/linux-2.6/
Diffstat (limited to 'include/linux/random.h')
-rw-r--r-- | include/linux/random.h | 28 |
1 files changed, 28 insertions, 0 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 */ |