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 #define THUNDERX_RNM_ENT_EN 0x1 19 #define THUNDERX_RNM_RNG_EN 0x2 20 21 struct cavium_rng_pf { 22 void __iomem *control_status; 23 }; 24 25 /* Enable the RNG hardware and activate the VF */ 26 static int cavium_rng_probe(struct pci_dev *pdev, 27 const struct pci_device_id *id) 28 { 29 struct cavium_rng_pf *rng; 30 int iov_err; 31 32 rng = devm_kzalloc(&pdev->dev, sizeof(*rng), GFP_KERNEL); 33 if (!rng) 34 return -ENOMEM; 35 36 /*Map the RNG control */ 37 rng->control_status = pcim_iomap(pdev, 0, 0); 38 if (!rng->control_status) { 39 dev_err(&pdev->dev, 40 "Error iomap failed retrieving control_status.\n"); 41 return -ENOMEM; 42 } 43 44 /* Enable the RNG hardware and entropy source */ 45 writeq(THUNDERX_RNM_RNG_EN | THUNDERX_RNM_ENT_EN, 46 rng->control_status); 47 48 pci_set_drvdata(pdev, rng); 49 50 /* Enable the Cavium RNG as a VF */ 51 iov_err = pci_enable_sriov(pdev, 1); 52 if (iov_err != 0) { 53 /* Disable the RNG hardware and entropy source */ 54 writeq(0, rng->control_status); 55 dev_err(&pdev->dev, 56 "Error initializing RNG virtual function,(%i).\n", 57 iov_err); 58 return iov_err; 59 } 60 61 return 0; 62 } 63 64 /* Disable VF and RNG Hardware */ 65 static void cavium_rng_remove(struct pci_dev *pdev) 66 { 67 struct cavium_rng_pf *rng; 68 69 rng = pci_get_drvdata(pdev); 70 71 /* Remove the VF */ 72 pci_disable_sriov(pdev); 73 74 /* Disable the RNG hardware and entropy source */ 75 writeq(0, rng->control_status); 76 } 77 78 static const struct pci_device_id cavium_rng_pf_id_table[] = { 79 { PCI_DEVICE(PCI_VENDOR_ID_CAVIUM, 0xa018), 0, 0, 0}, /* Thunder RNM */ 80 {0,}, 81 }; 82 83 MODULE_DEVICE_TABLE(pci, cavium_rng_pf_id_table); 84 85 static struct pci_driver cavium_rng_pf_driver = { 86 .name = "cavium_rng_pf", 87 .id_table = cavium_rng_pf_id_table, 88 .probe = cavium_rng_probe, 89 .remove = cavium_rng_remove, 90 }; 91 92 module_pci_driver(cavium_rng_pf_driver); 93 MODULE_AUTHOR("Omer Khaliq <okhaliq@caviumnetworks.com>"); 94 MODULE_LICENSE("GPL"); 95