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Commit 4d9b519c authored by Dmitry Torokhov's avatar Dmitry Torokhov Committed by Herbert Xu
Browse files

hwrng: add devm_* interfaces 



This change adds devm_hwrng_register and devm_hwrng_unregister which
use can simplify error unwinding and unbinding code paths in device
drivers.

Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 05713ba9

drivers/char/hw_random/core.c

+42 −0
Original line number Diff line number Diff line
@@ -536,6 +536,48 @@ void hwrng_unregister(struct hwrng *rng) 
}

EXPORT_SYMBOL_GPL(hwrng_unregister);



static void devm_hwrng_release(struct device *dev, void *res)

{

	hwrng_unregister(*(struct hwrng **)res);

}



static int devm_hwrng_match(struct device *dev, void *res, void *data)

{

	struct hwrng **r = res;



	if (WARN_ON(!r || !*r))

		return 0;



	return *r == data;

}



int devm_hwrng_register(struct device *dev, struct hwrng *rng)

{

	struct hwrng **ptr;

	int error;



	ptr = devres_alloc(devm_hwrng_release, sizeof(*ptr), GFP_KERNEL);

	if (!ptr)

		return -ENOMEM;



	error = hwrng_register(rng);

	if (error) {

		devres_free(ptr);

		return error;

	}



	*ptr = rng;

	devres_add(dev, ptr);

	return 0;

}

EXPORT_SYMBOL_GPL(devm_hwrng_register);



void devm_hwrng_unregister(struct device *dev, struct hwrng *rng)

{

	devres_release(dev, devm_hwrng_release, devm_hwrng_match, rng);

}

EXPORT_SYMBOL_GPL(devm_hwrng_unregister);



static int __init hwrng_modinit(void)

{

	return register_miscdev();

include/linux/hw_random.h

+4 −0
Original line number Diff line number Diff line
@@ -50,10 +50,14 @@ struct hwrng { 
	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);

/** Feed random bits into the pool. */

extern void add_hwgenerator_randomness(const char *buffer, size_t count, size_t entropy);