tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
18struct cavium_rng {
19 struct hwrng ops;
20 void __iomem *result;
21};
22
23/* Read data from the RNG unit */
24static 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 */
43static 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
80static const struct pci_device_id cavium_rng_vf_id_table[] = {
81 { PCI_DEVICE(PCI_VENDOR_ID_CAVIUM, 0xa033), 0, 0, 0},
82 {0,},
83};
84MODULE_DEVICE_TABLE(pci, cavium_rng_vf_id_table);
85
86static 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};
91module_pci_driver(cavium_rng_vf_driver);
92
93MODULE_AUTHOR("Omer Khaliq <okhaliq@caviumnetworks.com>");
94MODULE_LICENSE("GPL");