diff options
| -rw-r--r-- | drivers/crypto/hifn_795x.c | 82 |
1 files changed, 81 insertions, 1 deletions
diff --git a/drivers/crypto/hifn_795x.c b/drivers/crypto/hifn_795x.c index de594bc97742..1a197003f1a2 100644 --- a/drivers/crypto/hifn_795x.c +++ b/drivers/crypto/hifn_795x.c @@ -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); |