diff options
Diffstat (limited to 'include/linux/prandom.h')
| -rw-r--r-- | include/linux/prandom.h | 21 |
1 files changed, 1 insertions, 20 deletions
diff --git a/include/linux/prandom.h b/include/linux/prandom.h index e0a0759dd09c..f2ed5b72b3d6 100644 --- a/include/linux/prandom.h +++ b/include/linux/prandom.h @@ -9,6 +9,7 @@ #define _LINUX_PRANDOM_H #include <linux/types.h> +#include <linux/once.h> #include <linux/percpu.h> #include <linux/random.h> @@ -23,26 +24,6 @@ void prandom_seed_full_state(struct rnd_state __percpu *pcpu_state); #define prandom_init_once(pcpu_state) \ DO_ONCE(prandom_seed_full_state, (pcpu_state)) -/** - * prandom_u32_max - returns a pseudo-random number in interval [0, ep_ro) - * @ep_ro: right open interval endpoint - * - * Returns a pseudo-random number that is in interval [0, ep_ro). This is - * useful when requesting a random index of an array containing ep_ro elements, - * for example. The result is somewhat biased when ep_ro is not a power of 2, - * so do not use this for cryptographic purposes. - * - * Returns: pseudo-random number in interval [0, ep_ro) - */ -static inline u32 prandom_u32_max(u32 ep_ro) -{ - if (__builtin_constant_p(ep_ro <= 1U << 8) && ep_ro <= 1U << 8) - return (get_random_u8() * ep_ro) >> 8; - if (__builtin_constant_p(ep_ro <= 1U << 16) && ep_ro <= 1U << 16) - return (get_random_u16() * ep_ro) >> 16; - return ((u64)get_random_u32() * ep_ro) >> 32; -} - /* * Handle minimum values for seeds */ |