Commit fcd06755 authored by Patrick McHardy's avatar Patrick McHardy Committed by Herbert Xu
Browse files

[HIFN]: Add support for using the random number generator 



Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
Acked-by: default avatarEvgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 37a8023c

drivers/crypto/hifn_795x.c

+81 −1
Original line number Diff line number Diff line
@@ -31,6 +31,8 @@ 
#include <linux/highmem.h>

#include <linux/interrupt.h>

#include <linux/crypto.h>

#include <linux/hw_random.h>

#include <linux/ktime.h>



#include <crypto/algapi.h>

#include <crypto/des.h>
@@ -458,6 +460,14 @@ struct hifn_device 


	struct crypto_queue 	queue;

	struct list_head	alg_list;



	unsigned int		pk_clk_freq;



#if defined(CONFIG_HW_RANDOM) || defined(CONFIG_HW_RANDOM_MODULE)

	unsigned int		rng_wait_time;

	ktime_t			rngtime;

	struct hwrng		rng;

#endif

};



#define	HIFN_D_LENGTH			0x0000ffff
@@ -785,6 +795,56 @@ static struct pci2id { 
	}

};



#if defined(CONFIG_HW_RANDOM) || defined(CONFIG_HW_RANDOM_MODULE)

static int hifn_rng_data_present(struct hwrng *rng, int wait)

{

	struct hifn_device *dev = (struct hifn_device *)rng->priv;

	s64 nsec;



	nsec = ktime_to_ns(ktime_sub(ktime_get(), dev->rngtime));

	nsec -= dev->rng_wait_time;

	if (nsec <= 0)

		return 1;

	if (!wait)

		return 0;

	ndelay(nsec);

	return 1;

}



static int hifn_rng_data_read(struct hwrng *rng, u32 *data)

{

	struct hifn_device *dev = (struct hifn_device *)rng->priv;



	*data = hifn_read_1(dev, HIFN_1_RNG_DATA);

	dev->rngtime = ktime_get();

	return 4;

}



static int hifn_register_rng(struct hifn_device *dev)

{

	/*

	 * We must wait at least 256 Pk_clk cycles between two reads of the rng.

	 */

	dev->rng_wait_time	= DIV_ROUND_UP(NSEC_PER_SEC, dev->pk_clk_freq) *

				  256;



	dev->rng.name		= dev->name;

	dev->rng.data_present	= hifn_rng_data_present,

	dev->rng.data_read	= hifn_rng_data_read,

	dev->rng.priv		= (unsigned long)dev;



	return hwrng_register(&dev->rng);

}



static void hifn_unregister_rng(struct hifn_device *dev)

{

	hwrng_unregister(&dev->rng);

}

#else

#define hifn_register_rng(dev)		0

#define hifn_unregister_rng(dev)

#endif



static int hifn_init_pubrng(struct hifn_device *dev)

{

	int i;
@@ -820,6 +880,11 @@ static int hifn_init_pubrng(struct hifn_device *dev) 
	dprintk("Chip %s: RNG engine has been successfully initialised.\n",

			dev->name);



#if defined(CONFIG_HW_RANDOM) || defined(CONFIG_HW_RANDOM_MODULE)

	/* First value must be discarded */

	hifn_read_1(dev, HIFN_1_RNG_DATA);

	dev->rngtime = ktime_get();

#endif

	return 0;

}
@@ -952,6 +1017,14 @@ static void hifn_init_pll(struct hifn_device *dev) 
	/* Switch the engines to the PLL */

	hifn_write_1(dev, HIFN_1_PLL, pllcfg |

		     HIFN_PLL_PK_CLK_PLL | HIFN_PLL_PE_CLK_PLL);



	/*

	 * The Fpk_clk runs at half the total speed. Its frequency is needed to

	 * calculate the minimum time between two reads of the rng. Since 33MHz

	 * is actually 33.333... we overestimate the frequency here, resulting

	 * in slightly larger intervals.

	 */

	dev->pk_clk_freq = 1000000 * (freq + 1) * m / 2;

}



static void hifn_init_registers(struct hifn_device *dev)
@@ -2609,10 +2682,14 @@ static int hifn_probe(struct pci_dev *pdev, const struct pci_device_id *id) 
	if (err)

		goto err_out_stop_device;



	err = hifn_register_alg(dev);

	err = hifn_register_rng(dev);

	if (err)

		goto err_out_stop_device;



	err = hifn_register_alg(dev);

	if (err)

		goto err_out_unregister_rng;



	INIT_DELAYED_WORK(&dev->work, hifn_work);

	schedule_delayed_work(&dev->work, HZ);
@@ -2622,6 +2699,8 @@ static int hifn_probe(struct pci_dev *pdev, const struct pci_device_id *id) 


	return 0;



err_out_unregister_rng:

	hifn_unregister_rng(dev);

err_out_stop_device:

	hifn_reset_dma(dev, 1);

	hifn_stop_device(dev);
@@ -2662,6 +2741,7 @@ static void hifn_remove(struct pci_dev *pdev) 
		cancel_delayed_work(&dev->work);

		flush_scheduled_work();



		hifn_unregister_rng(dev);

		hifn_unregister_alg(dev);

		hifn_reset_dma(dev, 1);

		hifn_stop_device(dev);