1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Hardware Random Number Generator support. 4 * Cavium Thunder, Marvell OcteonTx/Tx2 processor families. 5 * 6 * Copyright (C) 2016 Cavium, Inc. 7 */ 8 9 #include <linux/hw_random.h> 10 #include <linux/io.h> 11 #include <linux/module.h> 12 #include <linux/pci.h> 13 #include <linux/pci_ids.h> 14 15 #define THUNDERX_RNM_ENT_EN 0x1 16 #define THUNDERX_RNM_RNG_EN 0x2 17 18 struct cavium_rng_pf { 19 void __iomem *control_status; 20 }; 21 22 /* Enable the RNG hardware and activate the VF */ 23 static int cavium_rng_probe(struct pci_dev *pdev, 24 const struct pci_device_id *id) 25 { 26 struct cavium_rng_pf *rng; 27 int iov_err; 28 29 rng = devm_kzalloc(&pdev->dev, sizeof(*rng), GFP_KERNEL); 30 if (!rng) 31 return -ENOMEM; 32 33 /*Map the RNG control */ 34 rng->control_status = pcim_iomap(pdev, 0, 0); 35 if (!rng->control_status) { 36 dev_err(&pdev->dev, 37 "Error iomap failed retrieving control_status.\n"); 38 return -ENOMEM; 39 } 40 41 /* Enable the RNG hardware and entropy source */ 42 writeq(THUNDERX_RNM_RNG_EN | THUNDERX_RNM_ENT_EN, 43 rng->control_status); 44 45 pci_set_drvdata(pdev, rng); 46 47 /* Enable the Cavium RNG as a VF */ 48 iov_err = pci_enable_sriov(pdev, 1); 49 if (iov_err != 0) { 50 /* Disable the RNG hardware and entropy source */ 51 writeq(0, rng->control_status); 52 dev_err(&pdev->dev, 53 "Error initializing RNG virtual function,(%i).\n", 54 iov_err); 55 return iov_err; 56 } 57 58 return 0; 59 } 60 61 /* Disable VF and RNG Hardware */ 62 static void cavium_rng_remove(struct pci_dev *pdev) 63 { 64 struct cavium_rng_pf *rng; 65 66 rng = pci_get_drvdata(pdev); 67 68 /* Remove the VF */ 69 pci_disable_sriov(pdev); 70 71 /* Disable the RNG hardware and entropy source */ 72 writeq(0, rng->control_status); 73 } 74 75 static const struct pci_device_id cavium_rng_pf_id_table[] = { 76 { PCI_DEVICE(PCI_VENDOR_ID_CAVIUM, 0xa018), 0, 0, 0}, /* Thunder RNM */ 77 {0,}, 78 }; 79 80 MODULE_DEVICE_TABLE(pci, cavium_rng_pf_id_table); 81 82 static struct pci_driver cavium_rng_pf_driver = { 83 .name = "cavium_rng_pf", 84 .id_table = cavium_rng_pf_id_table, 85 .probe = cavium_rng_probe, 86 .remove = cavium_rng_remove, 87 }; 88 89 module_pci_driver(cavium_rng_pf_driver); 90 MODULE_AUTHOR("Omer Khaliq <okhaliq@caviumnetworks.com>"); 91 MODULE_LICENSE("GPL v2"); 92