[mirror_ubuntu-bionic-kernel.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);

#if defined(CONFIG_GCC_PLUGIN_LATENT_ENTROPY) && !defined(__CHECKER__)
static inline void add_latent_entropy(void)
{
	add_device_randomness((const void *)&latent_entropy,
			      sizeof(latent_entropy));
}
#else
static inline void add_latent_entropy(void) {}
#endif

extern void add_input_randomness(unsigned int type, unsigned int code,
				 unsigned int value) __latent_entropy;
extern void add_interrupt_randomness(int irq, int irq_flags) __latent_entropy;

extern void get_random_bytes(void *buf, int nbytes);
extern int wait_for_random_bytes(void);
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);

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

u32 get_random_u32(void);
u64 get_random_u64(void);
static inline unsigned int get_random_int(void)
{
	return get_random_u32();
}
static inline unsigned long get_random_long(void)
{
#if BITS_PER_LONG == 64
	return get_random_u64();
#else
	return get_random_u32();
#endif
}

unsigned long randomize_page(unsigned long start, unsigned long range);

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
	1	/*
	2	* include/linux/random.h
	3	*
	4	* Include file for the random number generator.
	5	*/
	6	#ifndef _LINUX_RANDOM_H
	7	#define _LINUX_RANDOM_H
	8
	9	#include <linux/list.h>
	10	#include <linux/once.h>
	11
	12	#include <uapi/linux/random.h>
	13
	14	struct random_ready_callback {
	15	struct list_head list;
	16	void (func)(struct random_ready_callback rdy);
	17	struct module *owner;
	18	};
	19
	20	extern void add_device_randomness(const void *, unsigned int);
	21
	22	#if defined(CONFIG_GCC_PLUGIN_LATENT_ENTROPY) && !defined(__CHECKER__)
	23	static inline void add_latent_entropy(void)
	24	{
	25	add_device_randomness((const void *)&latent_entropy,
	26	sizeof(latent_entropy));
	27	}
	28	#else
	29	static inline void add_latent_entropy(void) {}
	30	#endif
	31
	32	extern void add_input_randomness(unsigned int type, unsigned int code,
	33	unsigned int value) __latent_entropy;
	34	extern void add_interrupt_randomness(int irq, int irq_flags) __latent_entropy;
	35
	36	extern void get_random_bytes(void *buf, int nbytes);
	37	extern int wait_for_random_bytes(void);
	38	extern int add_random_ready_callback(struct random_ready_callback *rdy);
	39	extern void del_random_ready_callback(struct random_ready_callback *rdy);
	40	extern void get_random_bytes_arch(void *buf, int nbytes);
	41
	42	#ifndef MODULE
	43	extern const struct file_operations random_fops, urandom_fops;
	44	#endif
	45
	46	u32 get_random_u32(void);
	47	u64 get_random_u64(void);
	48	static inline unsigned int get_random_int(void)
	49	{
	50	return get_random_u32();
	51	}
	52	static inline unsigned long get_random_long(void)
	53	{
	54	#if BITS_PER_LONG == 64
	55	return get_random_u64();
	56	#else
	57	return get_random_u32();
	58	#endif
	59	}
	60
	61	unsigned long randomize_page(unsigned long start, unsigned long range);
	62
	63	u32 prandom_u32(void);
	64	void prandom_bytes(void *buf, size_t nbytes);
	65	void prandom_seed(u32 seed);
	66	void prandom_reseed_late(void);
	67
	68	struct rnd_state {
	69	__u32 s1, s2, s3, s4;
	70	};
	71
	72	u32 prandom_u32_state(struct rnd_state *state);
	73	void prandom_bytes_state(struct rnd_state state, void buf, size_t nbytes);
	74	void prandom_seed_full_state(struct rnd_state __percpu *pcpu_state);
	75
	76	#define prandom_init_once(pcpu_state) \
	77	DO_ONCE(prandom_seed_full_state, (pcpu_state))
	78
	79	/**
	80	* prandom_u32_max - returns a pseudo-random number in interval [0, ep_ro)
	81	* @ep_ro: right open interval endpoint
	82	*
	83	* Returns a pseudo-random number that is in interval [0, ep_ro). Note
	84	* that the result depends on PRNG being well distributed in [0, ~0U]
	85	* u32 space. Here we use maximally equidistributed combined Tausworthe
	86	* generator, that is, prandom_u32(). This is useful when requesting a
	87	* random index of an array containing ep_ro elements, for example.
	88	*
	89	* Returns: pseudo-random number in interval [0, ep_ro)
	90	*/
	91	static inline u32 prandom_u32_max(u32 ep_ro)
	92	{
	93	return (u32)(((u64) prandom_u32() * ep_ro) >> 32);
	94	}
	95
	96	/*
	97	* Handle minimum values for seeds
	98	*/
	99	static inline u32 __seed(u32 x, u32 m)
	100	{
	101	return (x < m) ? x + m : x;
	102	}
	103
	104	/**
	105	* prandom_seed_state - set seed for prandom_u32_state().
	106	* @state: pointer to state structure to receive the seed.
	107	* @seed: arbitrary 64-bit value to use as a seed.
	108	*/
	109	static inline void prandom_seed_state(struct rnd_state *state, u64 seed)
	110	{
	111	u32 i = (seed >> 32) ^ (seed << 10) ^ seed;
	112
	113	state->s1 = __seed(i, 2U);
	114	state->s2 = __seed(i, 8U);
	115	state->s3 = __seed(i, 16U);
	116	state->s4 = __seed(i, 128U);
	117	}
	118
	119	#ifdef CONFIG_ARCH_RANDOM
	120	# include <asm/archrandom.h>
	121	#else
	122	static inline bool arch_get_random_long(unsigned long *v)
	123	{
	124	return 0;
	125	}
	126	static inline bool arch_get_random_int(unsigned int *v)
	127	{
	128	return 0;
	129	}
	130	static inline bool arch_has_random(void)
	131	{
	132	return 0;
	133	}
	134	static inline bool arch_get_random_seed_long(unsigned long *v)
	135	{
	136	return 0;
	137	}
	138	static inline bool arch_get_random_seed_int(unsigned int *v)
	139	{
	140	return 0;
	141	}
	142	static inline bool arch_has_random_seed(void)
	143	{
	144	return 0;
	145	}
	146	#endif
	147
	148	/* Pseudo random number generator from numerical recipes. */
	149	static inline u32 next_pseudo_random32(u32 seed)
	150	{
	151	return seed * 1664525 + 1013904223;
	152	}
	153
	154	#endif /* _LINUX_RANDOM_H */