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/kref.h> 17 #include <linux/types.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 * and max is a multiple of 4 and >= 32 bytes. 33 * @priv: Private data, for use by the RNG driver. 34 * @quality: Estimation of true entropy in RNG's bitstream 35 * (in bits of entropy per 1024 bits of input; 36 * valid values: 1 to 1024, or 0 for maximum). 37 */ 38 struct hwrng { 39 const char *name; 40 int (*init)(struct hwrng *rng); 41 void (*cleanup)(struct hwrng *rng); 42 int (*data_present)(struct hwrng *rng, int wait); 43 int (*data_read)(struct hwrng *rng, u32 *data); 44 int (*read)(struct hwrng *rng, void *data, size_t max, bool wait); 45 unsigned long priv; 46 unsigned short quality; 47 48 /* internal. */ 49 struct list_head list; 50 struct kref ref; 51 struct completion cleanup_done; 52 struct completion dying; 53 }; 54 55 struct device; 56 57 /** Register a new Hardware Random Number Generator driver. */ 58 extern int hwrng_register(struct hwrng *rng); 59 extern int devm_hwrng_register(struct device *dev, struct hwrng *rng); 60 /** Unregister a Hardware Random Number Generator driver. */ 61 extern void hwrng_unregister(struct hwrng *rng); 62 extern void devm_hwrng_unregister(struct device *dve, struct hwrng *rng); 63 64 extern long hwrng_msleep(struct hwrng *rng, unsigned int msecs); 65 extern long hwrng_yield(struct hwrng *rng); 66 67 #endif /* LINUX_HWRANDOM_H_ */ 68