Commit 0ed5c741 authored by Alan Cox's avatar Alan Cox Committed by Linus Torvalds

[PATCH] Forward port AMD random number generator

parent 4f94e73f
......@@ -648,6 +648,21 @@ CONFIG_INTEL_RNG
If unsure, say N.
CONFIG_AMD_RNG
This driver provides kernel-side support for the Random Number
Generator hardware found on AMD 76x based motherboards.
Both a character driver, used to read() entropy data, and a timer
function which automatically adds entropy directly into the
kernel pool, are exported by this driver.
To compile this driver as a module ( = code which can be inserted in
and removed from the running kernel whenever you want), say M here
and read <file:Documentation/modules.txt>. The module will be called
i810_rng.o.
If unsure, say N.
CONFIG_WATCHDOG
If you say Y here (and to one of the following options) and create a
character special file /dev/watchdog with major number 10 and minor
......
......@@ -149,6 +149,9 @@ fi
if [ "$CONFIG_X86" = "y" -o "$CONFIG_IA64" = "y" ]; then
dep_tristate 'Intel i8x0 Random Number Generator support' CONFIG_INTEL_RNG $CONFIG_PCI
fi
if [ "$CONFIG_X86" = "y" ]; then
dep_tristate 'AMD 768 Random Number Generator support' CONFIG_AMD_RNG $CONFIG_PCI
fi
tristate '/dev/nvram support' CONFIG_NVRAM
tristate 'Enhanced Real Time Clock Support' CONFIG_RTC
if [ "$CONFIG_RTC" != "y" ]; then
......
......@@ -67,6 +67,7 @@ obj-$(CONFIG_TOSHIBA) += toshiba.o
obj-$(CONFIG_I8K) += i8k.o
obj-$(CONFIG_DS1620) += ds1620.o
obj-$(CONFIG_INTEL_RNG) += i810_rng.o
obj-$(CONFIG_AMD_RNG) += amd768_rng.o
obj-$(CONFIG_QIC02_TAPE) += tpqic02.o
obj-$(CONFIG_FTAPE) += ftape/
obj-$(CONFIG_H8) += h8.o
......
/*
Hardware driver for the AMD 768 Random Number Generator (RNG)
(c) Copyright 2001 Red Hat Inc <alan@redhat.com>
derived from
Hardware driver for Intel i810 Random Number Generator (RNG)
Copyright 2000,2001 Jeff Garzik <jgarzik@mandrakesoft.com>
Copyright 2000,2001 Philipp Rumpf <prumpf@mandrakesoft.com>
Please read Documentation/i810_rng.txt for details on use.
----------------------------------------------------------
This software may be used and distributed according to the terms
of the GNU General Public License, incorporated herein by reference.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/random.h>
#include <linux/miscdevice.h>
#include <linux/smp_lock.h>
#include <linux/mm.h>
#include <linux/delay.h>
#include <asm/io.h>
#include <asm/uaccess.h>
/*
* core module and version information
*/
#define RNG_VERSION "0.1.0"
#define RNG_MODULE_NAME "amd768_rng"
#define RNG_DRIVER_NAME RNG_MODULE_NAME " hardware driver " RNG_VERSION
#define PFX RNG_MODULE_NAME ": "
/*
* debugging macros
*/
#undef RNG_DEBUG /* define to enable copious debugging info */
#ifdef RNG_DEBUG
/* note: prints function name for you */
#define DPRINTK(fmt, args...) printk(KERN_DEBUG "%s: " fmt, __FUNCTION__ , ## args)
#else
#define DPRINTK(fmt, args...)
#endif
#undef RNG_NDEBUG /* define to disable lightweight runtime checks */
#ifdef RNG_NDEBUG
#define assert(expr)
#else
#define assert(expr) \
if(!(expr)) { \
printk( "Assertion failed! %s,%s,%s,line=%d\n", \
#expr,__FILE__,__FUNCTION__,__LINE__); \
}
#endif
#define RNG_MISCDEV_MINOR 183 /* official */
/*
* various RNG status variables. they are globals
* as we only support a single RNG device
*/
static u32 pmbase; /* PMxx I/O base */
static struct semaphore rng_open_sem; /* Semaphore for serializing rng_open/release */
/*
* inlined helper functions for accessing RNG registers
*/
static inline int rng_data_present (void)
{
return inl(pmbase+0xF4) & 1;
}
static inline int rng_data_read (void)
{
return inl(pmbase+0xF0);
}
static int rng_dev_open (struct inode *inode, struct file *filp)
{
if ((filp->f_mode & FMODE_READ) == 0)
return -EINVAL;
if (filp->f_mode & FMODE_WRITE)
return -EINVAL;
/* wait for device to become free */
if (filp->f_flags & O_NONBLOCK) {
if (down_trylock (&rng_open_sem))
return -EAGAIN;
} else {
if (down_interruptible (&rng_open_sem))
return -ERESTARTSYS;
}
return 0;
}
static int rng_dev_release (struct inode *inode, struct file *filp)
{
up(&rng_open_sem);
return 0;
}
static ssize_t rng_dev_read (struct file *filp, char *buf, size_t size,
loff_t * offp)
{
static spinlock_t rng_lock = SPIN_LOCK_UNLOCKED;
int have_data;
u32 data = 0;
ssize_t ret = 0;
while (size) {
spin_lock(&rng_lock);
have_data = 0;
if (rng_data_present()) {
data = rng_data_read();
have_data = 4;
}
spin_unlock (&rng_lock);
while (have_data > 0) {
if (put_user((u8)data, buf++)) {
ret = ret ? : -EFAULT;
break;
}
size--;
ret++;
have_data--;
data>>=8;
}
if (filp->f_flags & O_NONBLOCK)
return ret ? : -EAGAIN;
if(need_resched())
{
current->state = TASK_INTERRUPTIBLE;
schedule_timeout(1);
}
else
udelay(200); /* FIXME: We could poll for 250uS ?? */
if (signal_pending (current))
return ret ? : -ERESTARTSYS;
}
return ret;
}
static struct file_operations rng_chrdev_ops = {
owner: THIS_MODULE,
open: rng_dev_open,
release: rng_dev_release,
read: rng_dev_read,
};
static struct miscdevice rng_miscdev = {
RNG_MISCDEV_MINOR,
RNG_MODULE_NAME,
&rng_chrdev_ops,
};
/*
* rng_init_one - look for and attempt to init a single RNG
*/
static int __init rng_init_one (struct pci_dev *dev)
{
int rc;
u8 rnen;
DPRINTK ("ENTER\n");
rc = misc_register (&rng_miscdev);
if (rc) {
printk (KERN_ERR PFX "cannot register misc device\n");
DPRINTK ("EXIT, returning %d\n", rc);
goto err_out;
}
pci_read_config_dword(dev, 0x58, &pmbase);
pmbase&=0x0000FF00;
if(pmbase == 0)
{
printk (KERN_ERR PFX "power management base not set\n");
DPRINTK ("EXIT, returning %d\n", rc);
goto err_out_free_miscdev;
}
pci_read_config_byte(dev, 0x40, &rnen);
rnen|=(1<<7); /* RNG on */
pci_write_config_byte(dev, 0x40, rnen);
pci_read_config_byte(dev, 0x41, &rnen);
rnen|=(1<<7); /* PMIO enable */
pci_write_config_byte(dev, 0x41, rnen);
printk(KERN_INFO PFX "AMD768 system management I/O registers at 0x%X.\n", pmbase);
DPRINTK ("EXIT, returning 0\n");
return 0;
err_out_free_miscdev:
misc_deregister (&rng_miscdev);
err_out:
return rc;
}
/*
* 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 struct pci_device_id rng_pci_tbl[] __initdata = {
{ 0x1022, 0x7443, PCI_ANY_ID, PCI_ANY_ID, },
{ 0, },
};
MODULE_DEVICE_TABLE (pci, rng_pci_tbl);
MODULE_AUTHOR("Alan Cox, Jeff Garzik, Philipp Rumpf, Matt Sottek");
MODULE_DESCRIPTION("AMD 768 Random Number Generator (RNG) driver");
MODULE_LICENSE("GPL");
/*
* rng_init - initialize RNG module
*/
static int __init rng_init (void)
{
int rc;
struct pci_dev *pdev;
DPRINTK ("ENTER\n");
init_MUTEX (&rng_open_sem);
pci_for_each_dev(pdev) {
if (pci_match_device (rng_pci_tbl, pdev) != NULL)
goto match;
}
DPRINTK ("EXIT, returning -ENODEV\n");
return -ENODEV;
match:
rc = rng_init_one (pdev);
if (rc)
return rc;
printk (KERN_INFO RNG_DRIVER_NAME " loaded\n");
DPRINTK ("EXIT, returning 0\n");
return 0;
}
/*
* rng_init - shutdown RNG module
*/
static void __exit rng_cleanup (void)
{
DPRINTK ("ENTER\n");
misc_deregister (&rng_miscdev);
DPRINTK ("EXIT\n");
}
module_init (rng_init);
module_exit (rng_cleanup);
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment