1 /* 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_ 14 15 #include <linux/types.h> 16 #include <linux/list.h> 17 #include <linux/kref.h> 18 19 /** 20 * struct hwrng - Hardware Random Number Generator driver 21 * @name: Unique RNG name. 22 * @init: Initialization callback (can be NULL). 23 * @cleanup: Cleanup callback (can be NULL). 24 * @data_present: Callback to determine if data is available 25 * on the RNG. If NULL, it is assumed that 26 * there is always data available. *OBSOLETE* 27 * @data_read: Read data from the RNG device. 28 * Returns the number of lower random bytes in "data". 29 * Must not be NULL. *OBSOLETE* 30 * @read: New API. drivers can fill up to max bytes of data 31 * into the buffer. The buffer is aligned for any type. 32 * @priv: Private data, for use by the RNG driver. 33 * @quality: Estimation of true entropy in RNG's bitstream 34 * (per mill). 35 */ 36 struct hwrng { 37 const char *name; 38 int (*init)(struct hwrng *rng); 39 void (*cleanup)(struct hwrng *rng); 40 int (*data_present)(struct hwrng *rng, int wait); 41 int (*data_read)(struct hwrng *rng, u32 *data); 42 int (*read)(struct hwrng *rng, void *data, size_t max, bool wait); 43 unsigned long priv; 44 unsigned short quality; 45 46 /* internal. */ 47 struct list_head list; 48 struct kref ref; 49 bool cleanup_done; 50 }; 51 52 /** Register a new Hardware Random Number Generator driver. */ 53 extern int hwrng_register(struct hwrng *rng); 54 /** Unregister a Hardware Random Number Generator driver. */ 55 extern void hwrng_unregister(struct hwrng *rng); 56 /** Feed random bits into the pool. */ 57 extern void add_hwgenerator_randomness(const char *buffer, size_t count, size_t entropy); 58 59 #endif /* LINUX_HWRANDOM_H_ */ 60