1 /* 2 * Hardware Random Number Generator support for Cavium, Inc. 3 * Thunder processor family. 4 * 5 * This file is subject to the terms and conditions of the GNU General Public 6 * License. See the file "COPYING" in the main directory of this archive 7 * for more details. 8 * 9 * Copyright (C) 2016 Cavium, Inc. 10 */ 11 12 #include <linux/hw_random.h> 13 #include <linux/io.h> 14 #include <linux/module.h> 15 #include <linux/pci.h> 16 #include <linux/pci_ids.h> 17 18 struct cavium_rng { 19 struct hwrng ops; 20 void __iomem *result; 21 }; 22 23 /* Read data from the RNG unit */ 24 static int cavium_rng_read(struct hwrng *rng, void *dat, size_t max, bool wait) 25 { 26 struct cavium_rng *p = container_of(rng, struct cavium_rng, ops); 27 unsigned int size = max; 28 29 while (size >= 8) { 30 *((u64 *)dat) = readq(p->result); 31 size -= 8; 32 dat += 8; 33 } 34 while (size > 0) { 35 *((u8 *)dat) = readb(p->result); 36 size--; 37 dat++; 38 } 39 return max; 40 } 41 42 /* Map Cavium RNG to an HWRNG object */ 43 static int cavium_rng_probe_vf(struct pci_dev *pdev, 44 const struct pci_device_id *id) 45 { 46 struct cavium_rng *rng; 47 int ret; 48 49 rng = devm_kzalloc(&pdev->dev, sizeof(*rng), GFP_KERNEL); 50 if (!rng) 51 return -ENOMEM; 52 53 /* Map the RNG result */ 54 rng->result = pcim_iomap(pdev, 0, 0); 55 if (!rng->result) { 56 dev_err(&pdev->dev, "Error iomap failed retrieving result.\n"); 57 return -ENOMEM; 58 } 59 60 rng->ops.name = devm_kasprintf(&pdev->dev, GFP_KERNEL, 61 "cavium-rng-%s", dev_name(&pdev->dev)); 62 if (!rng->ops.name) 63 return -ENOMEM; 64 65 rng->ops.read = cavium_rng_read; 66 rng->ops.quality = 1000; 67 68 pci_set_drvdata(pdev, rng); 69 70 ret = devm_hwrng_register(&pdev->dev, &rng->ops); 71 if (ret) { 72 dev_err(&pdev->dev, "Error registering device as HWRNG.\n"); 73 return ret; 74 } 75 76 return 0; 77 } 78 79 80 static const struct pci_device_id cavium_rng_vf_id_table[] = { 81 { PCI_DEVICE(PCI_VENDOR_ID_CAVIUM, 0xa033), 0, 0, 0}, 82 {0,}, 83 }; 84 MODULE_DEVICE_TABLE(pci, cavium_rng_vf_id_table); 85 86 static struct pci_driver cavium_rng_vf_driver = { 87 .name = "cavium_rng_vf", 88 .id_table = cavium_rng_vf_id_table, 89 .probe = cavium_rng_probe_vf, 90 }; 91 module_pci_driver(cavium_rng_vf_driver); 92 93 MODULE_AUTHOR("Omer Khaliq <okhaliq@caviumnetworks.com>"); 94 MODULE_LICENSE("GPL"); 95