1 | /* |
2 | Hardware Random Number Generator |
3 | |
4 | Please read Documentation/admin-guide/hw_random.rst for details on use. |
5 | |
6 | ---------------------------------------------------------- |
7 | This software may be used and distributed according to the terms |
8 | of the GNU General Public License, incorporated herein by reference. |
9 | |
10 | */ |
11 | |
12 | #ifndef LINUX_HWRANDOM_H_ |
13 | #define LINUX_HWRANDOM_H_ |
14 | |
15 | #include <linux/completion.h> |
16 | #include <linux/types.h> |
17 | #include <linux/list.h> |
18 | #include <linux/kref.h> |
19 | |
20 | /** |
21 | * struct hwrng - Hardware Random Number Generator driver |
22 | * @name: Unique RNG name. |
23 | * @init: Initialization callback (can be NULL). |
24 | * @cleanup: Cleanup callback (can be NULL). |
25 | * @data_present: Callback to determine if data is available |
26 | * on the RNG. If NULL, it is assumed that |
27 | * there is always data available. *OBSOLETE* |
28 | * @data_read: Read data from the RNG device. |
29 | * Returns the number of lower random bytes in "data". |
30 | * Must not be NULL. *OBSOLETE* |
31 | * @read: New API. drivers can fill up to max bytes of data |
32 | * into the buffer. The buffer is aligned for any type |
33 | * and max is a multiple of 4 and >= 32 bytes. |
34 | * @priv: Private data, for use by the RNG driver. |
35 | * @quality: Estimation of true entropy in RNG's bitstream |
36 | * (in bits of entropy per 1024 bits of input; |
37 | * valid values: 1 to 1024, or 0 for maximum). |
38 | */ |
39 | struct hwrng { |
40 | const char *name; |
41 | int (*init)(struct hwrng *rng); |
42 | void (*cleanup)(struct hwrng *rng); |
43 | int (*data_present)(struct hwrng *rng, int wait); |
44 | int (*data_read)(struct hwrng *rng, u32 *data); |
45 | int (*read)(struct hwrng *rng, void *data, size_t max, bool wait); |
46 | unsigned long priv; |
47 | unsigned short quality; |
48 | |
49 | /* internal. */ |
50 | struct list_head list; |
51 | struct kref ref; |
52 | struct completion cleanup_done; |
53 | struct completion dying; |
54 | }; |
55 | |
56 | struct device; |
57 | |
58 | /** Register a new Hardware Random Number Generator driver. */ |
59 | extern int hwrng_register(struct hwrng *rng); |
60 | extern int devm_hwrng_register(struct device *dev, struct hwrng *rng); |
61 | /** Unregister a Hardware Random Number Generator driver. */ |
62 | extern void hwrng_unregister(struct hwrng *rng); |
63 | extern void devm_hwrng_unregister(struct device *dve, struct hwrng *rng); |
64 | |
65 | extern long hwrng_msleep(struct hwrng *rng, unsigned int msecs); |
66 | extern long hwrng_yield(struct hwrng *rng); |
67 | |
68 | #endif /* LINUX_HWRANDOM_H_ */ |
69 | |