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Commit | Line | Data |
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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> |
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); |
38addce8 ER |
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 | ||
1da177e4 | 32 | extern void add_input_randomness(unsigned int type, unsigned int code, |
0766f788 ER |
33 | unsigned int value) __latent_entropy; |
34 | extern void add_interrupt_randomness(int irq, int irq_flags) __latent_entropy; | |
1da177e4 LT |
35 | |
36 | extern void get_random_bytes(void *buf, int nbytes); | |
205a525c HX |
37 | extern int add_random_ready_callback(struct random_ready_callback *rdy); |
38 | extern void del_random_ready_callback(struct random_ready_callback *rdy); | |
c2557a30 | 39 | extern void get_random_bytes_arch(void *buf, int nbytes); |
1da177e4 | 40 | |
1da177e4 | 41 | #ifndef MODULE |
54047320 | 42 | extern const struct file_operations random_fops, urandom_fops; |
1da177e4 LT |
43 | #endif |
44 | ||
c440408c JD |
45 | u32 get_random_u32(void); |
46 | u64 get_random_u64(void); | |
47 | static inline unsigned int get_random_int(void) | |
48 | { | |
49 | return get_random_u32(); | |
50 | } | |
51 | static inline unsigned long get_random_long(void) | |
52 | { | |
53 | #if BITS_PER_LONG == 64 | |
54 | return get_random_u64(); | |
55 | #else | |
56 | return get_random_u32(); | |
57 | #endif | |
58 | } | |
59 | ||
99fdafde | 60 | unsigned long randomize_page(unsigned long start, unsigned long range); |
1da177e4 | 61 | |
496f2f93 | 62 | u32 prandom_u32(void); |
a98406e2 | 63 | void prandom_bytes(void *buf, size_t nbytes); |
496f2f93 | 64 | void prandom_seed(u32 seed); |
4af712e8 | 65 | void prandom_reseed_late(void); |
aaa248f6 | 66 | |
38e9efcd | 67 | struct rnd_state { |
a98814ce | 68 | __u32 s1, s2, s3, s4; |
38e9efcd DB |
69 | }; |
70 | ||
a98814ce | 71 | u32 prandom_u32_state(struct rnd_state *state); |
a98406e2 | 72 | void prandom_bytes_state(struct rnd_state *state, void *buf, size_t nbytes); |
897ece56 DB |
73 | void prandom_seed_full_state(struct rnd_state __percpu *pcpu_state); |
74 | ||
75 | #define prandom_init_once(pcpu_state) \ | |
76 | DO_ONCE(prandom_seed_full_state, (pcpu_state)) | |
5960164f | 77 | |
f337db64 DB |
78 | /** |
79 | * prandom_u32_max - returns a pseudo-random number in interval [0, ep_ro) | |
80 | * @ep_ro: right open interval endpoint | |
81 | * | |
82 | * Returns a pseudo-random number that is in interval [0, ep_ro). Note | |
83 | * that the result depends on PRNG being well distributed in [0, ~0U] | |
84 | * u32 space. Here we use maximally equidistributed combined Tausworthe | |
85 | * generator, that is, prandom_u32(). This is useful when requesting a | |
86 | * random index of an array containing ep_ro elements, for example. | |
87 | * | |
88 | * Returns: pseudo-random number in interval [0, ep_ro) | |
89 | */ | |
90 | static inline u32 prandom_u32_max(u32 ep_ro) | |
91 | { | |
92 | return (u32)(((u64) prandom_u32() * ep_ro) >> 32); | |
93 | } | |
94 | ||
5960164f JE |
95 | /* |
96 | * Handle minimum values for seeds | |
97 | */ | |
98 | static inline u32 __seed(u32 x, u32 m) | |
99 | { | |
100 | return (x < m) ? x + m : x; | |
101 | } | |
102 | ||
103 | /** | |
496f2f93 | 104 | * prandom_seed_state - set seed for prandom_u32_state(). |
5960164f JE |
105 | * @state: pointer to state structure to receive the seed. |
106 | * @seed: arbitrary 64-bit value to use as a seed. | |
107 | */ | |
496f2f93 | 108 | static inline void prandom_seed_state(struct rnd_state *state, u64 seed) |
5960164f JE |
109 | { |
110 | u32 i = (seed >> 32) ^ (seed << 10) ^ seed; | |
111 | ||
a98814ce DB |
112 | state->s1 = __seed(i, 2U); |
113 | state->s2 = __seed(i, 8U); | |
114 | state->s3 = __seed(i, 16U); | |
115 | state->s4 = __seed(i, 128U); | |
5960164f JE |
116 | } |
117 | ||
63d77173 PA |
118 | #ifdef CONFIG_ARCH_RANDOM |
119 | # include <asm/archrandom.h> | |
120 | #else | |
117780ee | 121 | static inline bool arch_get_random_long(unsigned long *v) |
63d77173 PA |
122 | { |
123 | return 0; | |
124 | } | |
117780ee | 125 | static inline bool arch_get_random_int(unsigned int *v) |
63d77173 PA |
126 | { |
127 | return 0; | |
128 | } | |
117780ee | 129 | static inline bool arch_has_random(void) |
7b878d4b PA |
130 | { |
131 | return 0; | |
132 | } | |
117780ee | 133 | static inline bool arch_get_random_seed_long(unsigned long *v) |
d20f78d2 PA |
134 | { |
135 | return 0; | |
136 | } | |
117780ee | 137 | static inline bool arch_get_random_seed_int(unsigned int *v) |
d20f78d2 PA |
138 | { |
139 | return 0; | |
140 | } | |
117780ee | 141 | static inline bool arch_has_random_seed(void) |
7b878d4b PA |
142 | { |
143 | return 0; | |
144 | } | |
63d77173 PA |
145 | #endif |
146 | ||
055dc21a TH |
147 | /* Pseudo random number generator from numerical recipes. */ |
148 | static inline u32 next_pseudo_random32(u32 seed) | |
149 | { | |
150 | return seed * 1664525 + 1013904223; | |
151 | } | |
152 | ||
1da177e4 | 153 | #endif /* _LINUX_RANDOM_H */ |