huawei-mrd-kernel/drivers/char/hw_random/cavium-rng-vf.c

99 lines
2.2 KiB
C

/*
* 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 = "cavium rng";
rng->ops.read = cavium_rng_read;
rng->ops.quality = 1000;
pci_set_drvdata(pdev, rng);
ret = hwrng_register(&rng->ops);
if (ret) {
dev_err(&pdev->dev, "Error registering device as HWRNG.\n");
return ret;
}
return 0;
}
/* Remove the VF */
void cavium_rng_remove_vf(struct pci_dev *pdev)
{
struct cavium_rng *rng;
rng = pci_get_drvdata(pdev);
hwrng_unregister(&rng->ops);
}
static const struct pci_device_id cavium_rng_vf_id_table[] = {
{ PCI_DEVICE(PCI_VENDOR_ID_CAVIUM, 0xa033), 0, 0, 0},
{0,},
};
MODULE_DEVICE_TABLE(pci, cavium_rng_vf_id_table);
static struct pci_driver cavium_rng_vf_driver = {
.name = "cavium_rng_vf",
.id_table = cavium_rng_vf_id_table,
.probe = cavium_rng_probe_vf,
.remove = cavium_rng_remove_vf,
};
module_pci_driver(cavium_rng_vf_driver);
MODULE_AUTHOR("Omer Khaliq <okhaliq@caviumnetworks.com>");
MODULE_LICENSE("GPL");