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

Signed-off-by: Patrick McHardy <kaber@trash.net>
Acked-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
hifive-unleashed-5.1
Patrick McHardy 2007-11-21 12:51:52 +08:00 committed by Herbert Xu
parent 37a8023ce5
commit fcd0675593
1 changed files with 81 additions and 1 deletions
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82
drivers/crypto/hifn_795x.c
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@ -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);