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 67 #endif /* LINUX_HWRANDOM_H_ */ 68
