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/* * 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 = devm_hwrng_register(&pdev->dev, &rng->ops); if (ret) { dev_err(&pdev->dev, "Error registering device as HWRNG.\n"); return ret; } return 0; } 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, }; module_pci_driver(cavium_rng_vf_driver); MODULE_AUTHOR("Omer Khaliq <okhaliq@caviumnetworks.com>"); MODULE_LICENSE("GPL");