diff options
Diffstat (limited to 'drivers/char/hw_random/cavium-rng.c')
-rw-r--r-- | drivers/char/hw_random/cavium-rng.c | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/drivers/char/hw_random/cavium-rng.c b/drivers/char/hw_random/cavium-rng.c new file mode 100644 index 000000000..63d6e68c2 --- /dev/null +++ b/drivers/char/hw_random/cavium-rng.c @@ -0,0 +1,94 @@ +/* + * 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> + +#define THUNDERX_RNM_ENT_EN 0x1 +#define THUNDERX_RNM_RNG_EN 0x2 + +struct cavium_rng_pf { + void __iomem *control_status; +}; + +/* Enable the RNG hardware and activate the VF */ +static int cavium_rng_probe(struct pci_dev *pdev, + const struct pci_device_id *id) +{ + struct cavium_rng_pf *rng; + int iov_err; + + rng = devm_kzalloc(&pdev->dev, sizeof(*rng), GFP_KERNEL); + if (!rng) + return -ENOMEM; + + /*Map the RNG control */ + rng->control_status = pcim_iomap(pdev, 0, 0); + if (!rng->control_status) { + dev_err(&pdev->dev, + "Error iomap failed retrieving control_status.\n"); + return -ENOMEM; + } + + /* Enable the RNG hardware and entropy source */ + writeq(THUNDERX_RNM_RNG_EN | THUNDERX_RNM_ENT_EN, + rng->control_status); + + pci_set_drvdata(pdev, rng); + + /* Enable the Cavium RNG as a VF */ + iov_err = pci_enable_sriov(pdev, 1); + if (iov_err != 0) { + /* Disable the RNG hardware and entropy source */ + writeq(0, rng->control_status); + dev_err(&pdev->dev, + "Error initializing RNG virtual function,(%i).\n", + iov_err); + return iov_err; + } + + return 0; +} + +/* Disable VF and RNG Hardware */ +static void cavium_rng_remove(struct pci_dev *pdev) +{ + struct cavium_rng_pf *rng; + + rng = pci_get_drvdata(pdev); + + /* Remove the VF */ + pci_disable_sriov(pdev); + + /* Disable the RNG hardware and entropy source */ + writeq(0, rng->control_status); +} + +static const struct pci_device_id cavium_rng_pf_id_table[] = { + { PCI_DEVICE(PCI_VENDOR_ID_CAVIUM, 0xa018), 0, 0, 0}, /* Thunder RNM */ + {0,}, +}; + +MODULE_DEVICE_TABLE(pci, cavium_rng_pf_id_table); + +static struct pci_driver cavium_rng_pf_driver = { + .name = "cavium_rng_pf", + .id_table = cavium_rng_pf_id_table, + .probe = cavium_rng_probe, + .remove = cavium_rng_remove, +}; + +module_pci_driver(cavium_rng_pf_driver); +MODULE_AUTHOR("Omer Khaliq <okhaliq@caviumnetworks.com>"); +MODULE_LICENSE("GPL"); |