Loading...
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 | /*
* 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[] = {
{ PCI_VDEVICE(AMD, 0x7443), 0, },
{ PCI_VDEVICE(AMD, 0x746b), 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;
if (!request_region(pmbase + 0xF0, 8, "AMD HWRNG")) {
dev_err(&pdev->dev, "AMD HWRNG region 0x%x already in use!\n",
pmbase + 0xF0);
err = -EBUSY;
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);
release_region(pmbase + 0xF0, 8);
goto out;
}
out:
return err;
}
static void __exit mod_exit(void)
{
u32 pmbase = (unsigned long)amd_rng.priv;
release_region(pmbase + 0xF0, 8);
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");
|