diff options
Diffstat (limited to 'drivers/char/hw_random/cavium-rng-vf.c')
-rw-r--r-- | drivers/char/hw_random/cavium-rng-vf.c | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/drivers/char/hw_random/cavium-rng-vf.c b/drivers/char/hw_random/cavium-rng-vf.c new file mode 100644 index 000000000..2d1352b67 --- /dev/null +++ b/drivers/char/hw_random/cavium-rng-vf.c @@ -0,0 +1,103 @@ +/* + * 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; + + 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 */ +static 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"); |