xref: /linux-6.15/include/linux/random.h (revision 93f14468)
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 <uapi/linux/random.h>
10 
11 
12 extern void add_device_randomness(const void *, unsigned int);
13 extern void add_input_randomness(unsigned int type, unsigned int code,
14 				 unsigned int value);
15 extern void add_interrupt_randomness(int irq, int irq_flags);
16 
17 extern void get_random_bytes(void *buf, int nbytes);
18 extern void get_random_bytes_arch(void *buf, int nbytes);
19 void generate_random_uuid(unsigned char uuid_out[16]);
20 
21 #ifndef MODULE
22 extern const struct file_operations random_fops, urandom_fops;
23 #endif
24 
25 unsigned int get_random_int(void);
26 unsigned long randomize_range(unsigned long start, unsigned long end, unsigned long len);
27 
28 u32 prandom_u32(void);
29 void prandom_bytes(void *buf, int nbytes);
30 void prandom_seed(u32 seed);
31 
32 u32 prandom_u32_state(struct rnd_state *);
33 void prandom_bytes_state(struct rnd_state *state, void *buf, int nbytes);
34 
35 /*
36  * Handle minimum values for seeds
37  */
38 static inline u32 __seed(u32 x, u32 m)
39 {
40 	return (x < m) ? x + m : x;
41 }
42 
43 /**
44  * prandom_seed_state - set seed for prandom_u32_state().
45  * @state: pointer to state structure to receive the seed.
46  * @seed: arbitrary 64-bit value to use as a seed.
47  */
48 static inline void prandom_seed_state(struct rnd_state *state, u64 seed)
49 {
50 	u32 i = (seed >> 32) ^ (seed << 10) ^ seed;
51 
52 	state->s1 = __seed(i, 1);
53 	state->s2 = __seed(i, 7);
54 	state->s3 = __seed(i, 15);
55 }
56 
57 #ifdef CONFIG_ARCH_RANDOM
58 # include <asm/archrandom.h>
59 #else
60 static inline int arch_get_random_long(unsigned long *v)
61 {
62 	return 0;
63 }
64 static inline int arch_get_random_int(unsigned int *v)
65 {
66 	return 0;
67 }
68 #endif
69 
70 /* Pseudo random number generator from numerical recipes. */
71 static inline u32 next_pseudo_random32(u32 seed)
72 {
73 	return seed * 1664525 + 1013904223;
74 }
75 
76 #endif /* _LINUX_RANDOM_H */
77