linux-imx

/*

 * Hardware Random Number Generator support for Cavium, Inc.

 * Thunder processor family.

 *

 * This file is subject to the terms and conditions of the GNU General Public

 * License.  See the file "COPYING" in the main directory of this archive

 * for more details.

 *

 * Copyright (C) 2016 Cavium, Inc.

 */

​

#include <linux/hw_random.h>

#include <linux/io.h>

#include <linux/module.h>

#include <linux/pci.h>

#include <linux/pci_ids.h>

​

struct cavium_rng {

    struct hwrng ops;

    void __iomem *result;

};

​

/* Read data from the RNG unit */

static int cavium_rng_read(struct hwrng *rng, void *dat, size_t max, bool wait)

{

    struct cavium_rng *p = container_of(rng, struct cavium_rng, ops);

    unsigned int size = max;

​

    while (size >= 8) {

        *((u64 *)dat) = readq(p->result);

        size -= 8;

        dat += 8;

    }

    while (size > 0) {

        *((u8 *)dat) = readb(p->result);

        size--;

        dat++;

    }

    return max;

}

​

/* Map Cavium RNG to an HWRNG object */

static int cavium_rng_probe_vf(struct   pci_dev     *pdev,

             const struct   pci_device_id   *id)

{

    struct  cavium_rng *rng;

    int ret;

​

    rng = devm_kzalloc(&pdev->dev, sizeof(*rng), GFP_KERNEL);

    if (!rng)

        return -ENOMEM;

​

    /* Map the RNG result */

    rng->result = pcim_iomap(pdev, 0, 0);

    if (!rng->result) {

        dev_err(&pdev->dev, "Error iomap failed retrieving result.\n");

        return -ENOMEM;

    }

​

    rng->ops.name = devm_kasprintf(&pdev->dev, GFP_KERNEL,

                       "cavium-rng-%s", dev_name(&pdev->dev));

    if (!rng->ops.name)

        return -ENOMEM;