linux-stable/include/linux/hw_random.h
Jason A. Donenfeld b777c38239 random: pull add_hwgenerator_randomness() declaration into random.h
add_hwgenerator_randomness() is a function implemented and documented
inside of random.c. It is the way that hardware RNGs push data into it.
Therefore, it should be declared in random.h. Otherwise sparse complains
with:

random.c:1137:6: warning: symbol 'add_hwgenerator_randomness' was not declared. Should it be static?

The alternative would be to include hw_random.h into random.c, but that
wouldn't really be good for anything except slowing down compile time.

Cc: Matt Mackall <mpm@selenic.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-02-21 21:14:21 +01:00

64 lines
2.1 KiB
C

/*
Hardware Random Number Generator
Please read Documentation/admin-guide/hw_random.rst for details on use.
----------------------------------------------------------
This software may be used and distributed according to the terms
of the GNU General Public License, incorporated herein by reference.
*/
#ifndef LINUX_HWRANDOM_H_
#define LINUX_HWRANDOM_H_
#include <linux/completion.h>
#include <linux/types.h>
#include <linux/list.h>
#include <linux/kref.h>
/**
* struct hwrng - Hardware Random Number Generator driver
* @name: Unique RNG name.
* @init: Initialization callback (can be NULL).
* @cleanup: Cleanup callback (can be NULL).
* @data_present: Callback to determine if data is available
* on the RNG. If NULL, it is assumed that
* there is always data available. *OBSOLETE*
* @data_read: Read data from the RNG device.
* Returns the number of lower random bytes in "data".
* Must not be NULL. *OBSOLETE*
* @read: New API. drivers can fill up to max bytes of data
* into the buffer. The buffer is aligned for any type
* and max is a multiple of 4 and >= 32 bytes.
* @priv: Private data, for use by the RNG driver.
* @quality: Estimation of true entropy in RNG's bitstream
* (in bits of entropy per 1024 bits of input;
* valid values: 1 to 1024, or 0 for unknown).
*/
struct hwrng {
const char *name;
int (*init)(struct hwrng *rng);
void (*cleanup)(struct hwrng *rng);
int (*data_present)(struct hwrng *rng, int wait);
int (*data_read)(struct hwrng *rng, u32 *data);
int (*read)(struct hwrng *rng, void *data, size_t max, bool wait);
unsigned long priv;
unsigned short quality;
/* internal. */
struct list_head list;
struct kref ref;
struct completion cleanup_done;
};
struct device;
/** Register a new Hardware Random Number Generator driver. */
extern int hwrng_register(struct hwrng *rng);
extern int devm_hwrng_register(struct device *dev, struct hwrng *rng);
/** Unregister a Hardware Random Number Generator driver. */
extern void hwrng_unregister(struct hwrng *rng);
extern void devm_hwrng_unregister(struct device *dve, struct hwrng *rng);
#endif /* LINUX_HWRANDOM_H_ */