[linux-2.6-block.git] / include / linux / random.h

/*
 * include/linux/random.h
 *
 * Include file for the random number generator.
 */
#ifndef _LINUX_RANDOM_H
#define _LINUX_RANDOM_H

#include <linux/list.h>
#include <linux/once.h>

#include <uapi/linux/random.h>

struct random_ready_callback {
	struct list_head list;
	void (*func)(struct random_ready_callback *rdy);
	struct module *owner;
};

extern void add_device_randomness(const void *, unsigned int);
extern void add_input_randomness(unsigned int type, unsigned int code,
				 unsigned int value);
extern void add_interrupt_randomness(int irq, int irq_flags);

extern void get_random_bytes(void *buf, int nbytes);
extern int add_random_ready_callback(struct random_ready_callback *rdy);
extern void del_random_ready_callback(struct random_ready_callback *rdy);
extern void get_random_bytes_arch(void *buf, int nbytes);
extern int random_int_secret_init(void);

#ifndef MODULE
extern const struct file_operations random_fops, urandom_fops;
#endif

unsigned int get_random_int(void);
unsigned long get_random_long(void);
unsigned long randomize_range(unsigned long start, unsigned long end, unsigned long len);

u32 prandom_u32(void);
void prandom_bytes(void *buf, size_t nbytes);
void prandom_seed(u32 seed);
void prandom_reseed_late(void);

struct rnd_state {
	__u32 s1, s2, s3, s4;
};

u32 prandom_u32_state(struct rnd_state *state);
void prandom_bytes_state(struct rnd_state *state, void *buf, size_t nbytes);
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). Note
 * that the result depends on PRNG being well distributed in [0, ~0U]
 * u32 space. Here we use maximally equidistributed combined Tausworthe
 * generator, that is, prandom_u32(). This is useful when requesting a
 * random index of an array containing ep_ro elements, for example.
 *
 * Returns: pseudo-random number in interval [0, ep_ro)
 */
static inline u32 prandom_u32_max(u32 ep_ro)
{
	return (u32)(((u64) prandom_u32() * ep_ro) >> 32);
}

/*
 * Handle minimum values for seeds
 */
static inline u32 __seed(u32 x, u32 m)
{
	return (x < m) ? x + m : x;
}

/**
 * prandom_seed_state - set seed for prandom_u32_state().
 * @state: pointer to state structure to receive the seed.
 * @seed: arbitrary 64-bit value to use as a seed.
 */
static inline void prandom_seed_state(struct rnd_state *state, u64 seed)
{
	u32 i = (seed >> 32) ^ (seed << 10) ^ seed;

	state->s1 = __seed(i,   2U);
	state->s2 = __seed(i,   8U);
	state->s3 = __seed(i,  16U);
	state->s4 = __seed(i, 128U);
}

#ifdef CONFIG_ARCH_RANDOM
# include <asm/archrandom.h>
#else
static inline bool arch_get_random_long(unsigned long *v)
{
	return 0;
}
static inline bool arch_get_random_int(unsigned int *v)
{
	return 0;
}
static inline bool arch_has_random(void)
{
	return 0;
}
static inline bool arch_get_random_seed_long(unsigned long *v)
{
	return 0;
}
static inline bool arch_get_random_seed_int(unsigned int *v)
{
	return 0;
}
static inline bool arch_has_random_seed(void)
{
	return 0;
}
#endif

/* Pseudo random number generator from numerical recipes. */
static inline u32 next_pseudo_random32(u32 seed)
{
	return seed * 1664525 + 1013904223;
}

#endif /* _LINUX_RANDOM_H */
Commit	Line	Data
1da177e4 LT	1	/*
	2	* include/linux/random.h
	3	*
	4	* Include file for the random number generator.
	5	*/
1da177e4 LT	6	#ifndef _LINUX_RANDOM_H
	7	#define _LINUX_RANDOM_H
	8
205a525c	9	#include <linux/list.h>
897ece56 DB	10	#include <linux/once.h>
897ece56 DB	11
607ca46e	12	#include <uapi/linux/random.h>
1da177e4	13
205a525c HX	14	struct random_ready_callback {
	15	struct list_head list;
	16	void (func)(struct random_ready_callback rdy);
	17	struct module *owner;
	18	};
	19
a2080a67	20	extern void add_device_randomness(const void *, unsigned int);
1da177e4 LT	21	extern void add_input_randomness(unsigned int type, unsigned int code,
1da177e4 LT	22	unsigned int value);
775f4b29	23	extern void add_interrupt_randomness(int irq, int irq_flags);
1da177e4 LT	24
1da177e4 LT	25	extern void get_random_bytes(void *buf, int nbytes);
205a525c HX	26	extern int add_random_ready_callback(struct random_ready_callback *rdy);
205a525c HX	27	extern void del_random_ready_callback(struct random_ready_callback *rdy);
c2557a30	28	extern void get_random_bytes_arch(void *buf, int nbytes);
47d06e53	29	extern int random_int_secret_init(void);
1da177e4	30
1da177e4	31	#ifndef MODULE
54047320	32	extern const struct file_operations random_fops, urandom_fops;
1da177e4 LT	33	#endif
	34
	35	unsigned int get_random_int(void);
ec9ee4ac	36	unsigned long get_random_long(void);
1da177e4 LT	37	unsigned long randomize_range(unsigned long start, unsigned long end, unsigned long len);
1da177e4 LT	38
496f2f93	39	u32 prandom_u32(void);
a98406e2	40	void prandom_bytes(void *buf, size_t nbytes);
496f2f93	41	void prandom_seed(u32 seed);
4af712e8	42	void prandom_reseed_late(void);
aaa248f6	43
38e9efcd	44	struct rnd_state {
a98814ce	45	__u32 s1, s2, s3, s4;
38e9efcd DB	46	};
38e9efcd DB	47
a98814ce	48	u32 prandom_u32_state(struct rnd_state *state);
a98406e2	49	void prandom_bytes_state(struct rnd_state state, void buf, size_t nbytes);
897ece56 DB	50	void prandom_seed_full_state(struct rnd_state __percpu *pcpu_state);
	51
	52	#define prandom_init_once(pcpu_state) \
	53	DO_ONCE(prandom_seed_full_state, (pcpu_state))
5960164f	54
f337db64 DB	55	/**
	56	* prandom_u32_max - returns a pseudo-random number in interval [0, ep_ro)
	57	* @ep_ro: right open interval endpoint
	58	*
	59	* Returns a pseudo-random number that is in interval [0, ep_ro). Note
	60	* that the result depends on PRNG being well distributed in [0, ~0U]
	61	* u32 space. Here we use maximally equidistributed combined Tausworthe
	62	* generator, that is, prandom_u32(). This is useful when requesting a
	63	* random index of an array containing ep_ro elements, for example.
	64	*
	65	* Returns: pseudo-random number in interval [0, ep_ro)
	66	*/
	67	static inline u32 prandom_u32_max(u32 ep_ro)
	68	{
	69	return (u32)(((u64) prandom_u32() * ep_ro) >> 32);
	70	}
	71
5960164f JE	72	/*
	73	* Handle minimum values for seeds
	74	*/
	75	static inline u32 __seed(u32 x, u32 m)
	76	{
	77	return (x < m) ? x + m : x;
	78	}
	79
	80	/**
496f2f93	81	* prandom_seed_state - set seed for prandom_u32_state().
5960164f JE	82	* @state: pointer to state structure to receive the seed.
	83	* @seed: arbitrary 64-bit value to use as a seed.
	84	*/
496f2f93	85	static inline void prandom_seed_state(struct rnd_state *state, u64 seed)
5960164f JE	86	{
	87	u32 i = (seed >> 32) ^ (seed << 10) ^ seed;
	88
a98814ce DB	89	state->s1 = __seed(i, 2U);
	90	state->s2 = __seed(i, 8U);
	91	state->s3 = __seed(i, 16U);
	92	state->s4 = __seed(i, 128U);
5960164f JE	93	}
5960164f JE	94
63d77173 PA	95	#ifdef CONFIG_ARCH_RANDOM
	96	# include <asm/archrandom.h>
	97	#else
117780ee	98	static inline bool arch_get_random_long(unsigned long *v)
63d77173 PA	99	{
	100	return 0;
	101	}
117780ee	102	static inline bool arch_get_random_int(unsigned int *v)
63d77173 PA	103	{
	104	return 0;
	105	}
117780ee	106	static inline bool arch_has_random(void)
7b878d4b PA	107	{
	108	return 0;
	109	}
117780ee	110	static inline bool arch_get_random_seed_long(unsigned long *v)
d20f78d2 PA	111	{
	112	return 0;
	113	}
117780ee	114	static inline bool arch_get_random_seed_int(unsigned int *v)
d20f78d2 PA	115	{
	116	return 0;
	117	}
117780ee	118	static inline bool arch_has_random_seed(void)
7b878d4b PA	119	{
	120	return 0;
	121	}
63d77173 PA	122	#endif
63d77173 PA	123
055dc21a TH	124	/* Pseudo random number generator from numerical recipes. */
	125	static inline u32 next_pseudo_random32(u32 seed)
	126	{
	127	return seed * 1664525 + 1013904223;
	128	}
	129
1da177e4	130	#endif /* _LINUX_RANDOM_H */