1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
|
/*
* RNG driver for AMD RNGs
*
* Copyright 2005 (c) MontaVista Software, Inc.
*
* with the majority of the code coming from:
*
* Hardware driver for the Intel/AMD/VIA Random Number Generators (RNG)
* (c) Copyright 2003 Red Hat Inc <jgarzik@redhat.com>
*
* derived from
*
* Hardware driver for the AMD 768 Random Number Generator (RNG)
* (c) Copyright 2001 Red Hat Inc
*
* derived from
*
* Hardware driver for Intel i810 Random Number Generator (RNG)
* Copyright 2000,2001 Jeff Garzik <jgarzik@pobox.com>
* Copyright 2000,2001 Philipp Rumpf <prumpf@mandrakesoft.com>
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/hw_random.h>
#include <linux/delay.h>
#include <asm/io.h>
#define PFX KBUILD_MODNAME ": "
/*
* Data for PCI driver interface
*
* This data only exists for exporting the supported
* PCI ids via MODULE_DEVICE_TABLE. We do not actually
* register a pci_driver, because someone else might one day
* want to register another driver on the same PCI id.
*/
static const struct pci_device_id pci_tbl[] = {
{ 0x1022, 0x7443, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, },
{ 0x1022, 0x746b, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, },
{ 0, }, /* terminate list */
};
MODULE_DEVICE_TABLE(pci, pci_tbl);
static struct pci_dev *amd_pdev;
static int amd_rng_data_present(struct hwrng *rng, int wait)
{
u32 pmbase = (u32)rng->priv;
int data, i;
for (i = 0; i < 20; i++) {
data = !!(inl(pmbase + 0xF4) & 1);
if (data || !wait)
break;
udelay(10);
}
return data;
}
static int amd_rng_data_read(struct hwrng *rng, u32 *data)
{
u32 pmbase = (u32)rng->priv;
*data = inl(pmbase + 0xF0);
return 4;
}
static int amd_rng_init(struct hwrng *rng)
{
u8 rnen;
pci_read_config_byte(amd_pdev, 0x40, &rnen);
rnen |= (1 << 7); /* RNG on */
pci_write_config_byte(amd_pdev, 0x40, rnen);
pci_read_config_byte(amd_pdev, 0x41, &rnen);
rnen |= (1 << 7); /* PMIO enable */
pci_write_config_byte(amd_pdev, 0x41, rnen);
return 0;
}
static void amd_rng_cleanup(struct hwrng *rng)
{
u8 rnen;
pci_read_config_byte(amd_pdev, 0x40, &rnen);
rnen &= ~(1 << 7); /* RNG off */
pci_write_config_byte(amd_pdev, 0x40, rnen);
}
static struct hwrng amd_rng = {
.name = "amd",
.init = amd_rng_init,
.cleanup = amd_rng_cleanup,
.data_present = amd_rng_data_present,
.data_read = amd_rng_data_read,
};
static int __init mod_init(void)
{
int err = -ENODEV;
struct pci_dev *pdev = NULL;
const struct pci_device_id *ent;
u32 pmbase;
for_each_pci_dev(pdev) {
ent = pci_match_id(pci_tbl, pdev);
if (ent)
goto found;
}
/* Device not found. */
goto out;
found:
err = pci_read_config_dword(pdev, 0x58, &pmbase);
if (err)
goto out;
err = -EIO;
pmbase &= 0x0000FF00;
if (pmbase == 0)
goto out;
amd_rng.priv = (unsigned long)pmbase;
amd_pdev = pdev;
printk(KERN_INFO "AMD768 RNG detected\n");
err = hwrng_register(&amd_rng);
if (err) {
printk(KERN_ERR PFX "RNG registering failed (%d)\n",
err);
goto out;
}
out:
return err;
}
static void __exit mod_exit(void)
{
hwrng_unregister(&amd_rng);
}
module_init(mod_init);
module_exit(mod_exit);
MODULE_AUTHOR("The Linux Kernel team");
MODULE_DESCRIPTION("H/W RNG driver for AMD chipsets");
MODULE_LICENSE("GPL");
|
