source: src/linux/universal/linux-4.9/include/linux/random.h @ 31859

Last change on this file since 31859 was 31859, checked in by brainslayer, 11 days ago

kernel update

File size: 3.7 KB
Line 
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
14struct random_ready_callback {
15        struct list_head list;
16        void (*func)(struct random_ready_callback *rdy);
17        struct module *owner;
18};
19
20extern void add_device_randomness(const void *, unsigned int);
21
22#if defined(CONFIG_GCC_PLUGIN_LATENT_ENTROPY) && !defined(__CHECKER__)
23static inline void add_latent_entropy(void)
24{
25        add_device_randomness((const void *)&latent_entropy,
26                              sizeof(latent_entropy));
27}
28#else
29static inline void add_latent_entropy(void) {}
30#endif
31
32extern void add_input_randomness(unsigned int type, unsigned int code,
33                                 unsigned int value) __latent_entropy;
34extern void add_interrupt_randomness(int irq, int irq_flags) __latent_entropy;
35
36extern void random_input_words(__u32 *buf, size_t wordcount, int ent_count);
37extern int random_input_wait(void);
38#define HAS_RANDOM_INPUT_WAIT 1
39
40extern void get_random_bytes(void *buf, int nbytes);
41extern int add_random_ready_callback(struct random_ready_callback *rdy);
42extern void del_random_ready_callback(struct random_ready_callback *rdy);
43extern void get_random_bytes_arch(void *buf, int nbytes);
44
45#ifndef MODULE
46extern const struct file_operations random_fops, urandom_fops;
47#endif
48
49unsigned int get_random_int(void);
50unsigned long get_random_long(void);
51unsigned long randomize_page(unsigned long start, unsigned long range);
52
53u32 prandom_u32(void);
54void prandom_bytes(void *buf, size_t nbytes);
55void prandom_seed(u32 seed);
56void prandom_reseed_late(void);
57
58struct rnd_state {
59        __u32 s1, s2, s3, s4;
60};
61
62u32 prandom_u32_state(struct rnd_state *state);
63void prandom_bytes_state(struct rnd_state *state, void *buf, size_t nbytes);
64void prandom_seed_full_state(struct rnd_state __percpu *pcpu_state);
65
66#define prandom_init_once(pcpu_state)                   \
67        DO_ONCE(prandom_seed_full_state, (pcpu_state))
68
69/**
70 * prandom_u32_max - returns a pseudo-random number in interval [0, ep_ro)
71 * @ep_ro: right open interval endpoint
72 *
73 * Returns a pseudo-random number that is in interval [0, ep_ro). Note
74 * that the result depends on PRNG being well distributed in [0, ~0U]
75 * u32 space. Here we use maximally equidistributed combined Tausworthe
76 * generator, that is, prandom_u32(). This is useful when requesting a
77 * random index of an array containing ep_ro elements, for example.
78 *
79 * Returns: pseudo-random number in interval [0, ep_ro)
80 */
81static inline u32 prandom_u32_max(u32 ep_ro)
82{
83        return (u32)(((u64) prandom_u32() * ep_ro) >> 32);
84}
85
86/*
87 * Handle minimum values for seeds
88 */
89static inline u32 __seed(u32 x, u32 m)
90{
91        return (x < m) ? x + m : x;
92}
93
94/**
95 * prandom_seed_state - set seed for prandom_u32_state().
96 * @state: pointer to state structure to receive the seed.
97 * @seed: arbitrary 64-bit value to use as a seed.
98 */
99static inline void prandom_seed_state(struct rnd_state *state, u64 seed)
100{
101        u32 i = (seed >> 32) ^ (seed << 10) ^ seed;
102
103        state->s1 = __seed(i,   2U);
104        state->s2 = __seed(i,   8U);
105        state->s3 = __seed(i,  16U);
106        state->s4 = __seed(i, 128U);
107}
108
109#ifdef CONFIG_ARCH_RANDOM
110# include <asm/archrandom.h>
111#else
112static inline bool arch_get_random_long(unsigned long *v)
113{
114        return 0;
115}
116static inline bool arch_get_random_int(unsigned int *v)
117{
118        return 0;
119}
120static inline bool arch_has_random(void)
121{
122        return 0;
123}
124static inline bool arch_get_random_seed_long(unsigned long *v)
125{
126        return 0;
127}
128static inline bool arch_get_random_seed_int(unsigned int *v)
129{
130        return 0;
131}
132static inline bool arch_has_random_seed(void)
133{
134        return 0;
135}
136#endif
137
138/* Pseudo random number generator from numerical recipes. */
139static inline u32 next_pseudo_random32(u32 seed)
140{
141        return seed * 1664525 + 1013904223;
142}
143
144#endif /* _LINUX_RANDOM_H */
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