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Michael Buesch844dd052006-06-26 00:24:59 -07001/*
2 Hardware Random Number Generator
3
4 Please read Documentation/hw_random.txt 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_
Michael Buesch844dd052006-06-26 00:24:59 -070014
Herbert Xu77584ee2014-12-23 16:40:17 +110015#include <linux/completion.h>
Michael Buesch844dd052006-06-26 00:24:59 -070016#include <linux/types.h>
17#include <linux/list.h>
Rusty Russell3a2c0ba2014-12-08 16:50:37 +080018#include <linux/kref.h>
Michael Buesch844dd052006-06-26 00:24:59 -070019
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
Ian Molton99965082009-12-01 14:47:32 +080027 * there is always data available. *OBSOLETE*
Michael Buesch844dd052006-06-26 00:24:59 -070028 * @data_read: Read data from the RNG device.
29 * Returns the number of lower random bytes in "data".
Sasha Levin988acec2011-05-25 15:12:20 +030030 * Must not be NULL. *OBSOLETE*
Ian Molton99965082009-12-01 14:47:32 +080031 * @read: New API. drivers can fill up to max bytes of data
32 * into the buffer. The buffer is aligned for any type.
Michael Buesch844dd052006-06-26 00:24:59 -070033 * @priv: Private data, for use by the RNG driver.
Torsten Duwe0f734e62014-06-14 23:48:41 -040034 * @quality: Estimation of true entropy in RNG's bitstream
35 * (per mill).
Michael Buesch844dd052006-06-26 00:24:59 -070036 */
37struct hwrng {
38 const char *name;
39 int (*init)(struct hwrng *rng);
40 void (*cleanup)(struct hwrng *rng);
Patrick McHardy984e9762007-11-21 12:24:45 +080041 int (*data_present)(struct hwrng *rng, int wait);
Michael Buesch844dd052006-06-26 00:24:59 -070042 int (*data_read)(struct hwrng *rng, u32 *data);
Ian Molton99965082009-12-01 14:47:32 +080043 int (*read)(struct hwrng *rng, void *data, size_t max, bool wait);
Michael Buesch844dd052006-06-26 00:24:59 -070044 unsigned long priv;
Torsten Duwe0f734e62014-06-14 23:48:41 -040045 unsigned short quality;
Michael Buesch844dd052006-06-26 00:24:59 -070046
47 /* internal. */
48 struct list_head list;
Rusty Russell3a2c0ba2014-12-08 16:50:37 +080049 struct kref ref;
Herbert Xu77584ee2014-12-23 16:40:17 +110050 struct completion cleanup_done;
Michael Buesch844dd052006-06-26 00:24:59 -070051};
52
53/** Register a new Hardware Random Number Generator driver. */
54extern int hwrng_register(struct hwrng *rng);
55/** Unregister a Hardware Random Number Generator driver. */
Rafael J. Wysockib844eba2008-03-23 20:28:24 +010056extern void hwrng_unregister(struct hwrng *rng);
Torsten Duwec84dbf62014-06-14 23:38:36 -040057/** Feed random bits into the pool. */
58extern void add_hwgenerator_randomness(const char *buffer, size_t count, size_t entropy);
Michael Buesch844dd052006-06-26 00:24:59 -070059
Michael Buesch844dd052006-06-26 00:24:59 -070060#endif /* LINUX_HWRANDOM_H_ */