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/*
Added support for the AMD Geode LX RNG
(c) Copyright 2004-2005 Advanced Micro Devices, Inc.
derived 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 <alan@redhat.com>
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>
Please read Documentation/hw_random.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>
#ifdef __i386__
#include <asm/msr.h>
#include <asm/cpufeature.h>
#endif
#include <asm/io.h>
#include <asm/uaccess.h>
/*
* core module and version information
*/
#define RNG_VERSION "1.0.0"
#define RNG_MODULE_NAME "hw_random"
#define RNG_DRIVER_NAME RNG_MODULE_NAME " hardware driver " RNG_VERSION
#define PFX RNG_MODULE_NAME ": "
/*
* debugging macros
*/
/* pr_debug() collapses to a no-op if DEBUG is not defined */
#define DPRINTK(fmt, args...) pr_debug(PFX "%s: " fmt, __FUNCTION__ , ## args)
#undef RNG_NDEBUG /* define to enable lightweight runtime checks */
#ifdef RNG_NDEBUG
#define assert(expr) \
if(!(expr)) { \
printk(KERN_DEBUG PFX "Assertion failed! %s,%s,%s," \
"line=%d\n", #expr, __FILE__, __FUNCTION__, __LINE__); \
}
#else
#define assert(expr)
#endif
#define RNG_MISCDEV_MINOR 183 /* official */
static int rng_dev_open (struct inode *inode, struct file *filp);
static ssize_t rng_dev_read (struct file *filp, char __user *buf, size_t size,
loff_t * offp);
static int __init intel_init (struct pci_dev *dev);
static void intel_cleanup(void);
static unsigned int intel_data_present (void);
static u32 intel_data_read (void);
static int __init amd_init (struct pci_dev *dev);
static void amd_cleanup(void);
static unsigned int amd_data_present (void);
static u32 amd_data_read (void);
#ifdef __i386__
static int __init via_init(struct pci_dev *dev);
static void via_cleanup(void);
static unsigned int via_data_present (void);
static u32 via_data_read (void);
#endif
static int __init geode_init(struct pci_dev *dev);
static void geode_cleanup(void);
static unsigned int geode_data_present (void);
static u32 geode_data_read (void);
struct rng_operations {
int (*init) (struct pci_dev *dev);
void (*cleanup) (void);
unsigned int (*data_present) (void);
u32 (*data_read) (void);
unsigned int n_bytes; /* number of bytes per ->data_read */
};
static struct rng_operations *rng_ops;
static struct file_operations rng_chrdev_ops = {
.owner = THIS_MODULE,
.open = rng_dev_open,
.read = rng_dev_read,
};
static struct miscdevice rng_miscdev = {
RNG_MISCDEV_MINOR,
RNG_MODULE_NAME,
&rng_chrdev_ops,
};
enum {
rng_hw_none,
rng_hw_intel,
rng_hw_amd,
#ifdef __i386__
rng_hw_via,
#endif
rng_hw_geode,
};
static struct rng_operations rng_vendor_ops[] = {
/* rng_hw_none */
{ },
/* rng_hw_intel */
{ intel_init, intel_cleanup, intel_data_present,
intel_data_read, 1 },
/* rng_hw_amd */
{ amd_init, amd_cleanup, amd_data_present, amd_data_read, 4 },
#ifdef __i386__
/* rng_hw_via */
{ via_init, via_cleanup, via_data_present, via_data_read, 1 },
#endif
/* rng_hw_geode */
{ geode_init, geode_cleanup, geode_data_present, geode_data_read, 4 }
};
/*
* 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[] = {
{ 0x1022, 0x7443, PCI_ANY_ID, PCI_ANY_ID, 0, 0, rng_hw_amd },
{ 0x1022, 0x746b, PCI_ANY_ID, PCI_ANY_ID, 0, 0, rng_hw_amd },
{ 0x8086, 0x2418, PCI_ANY_ID, PCI_ANY_ID, 0, 0, rng_hw_intel },
{ 0x8086, 0x2428, PCI_ANY_ID, PCI_ANY_ID, 0, 0, rng_hw_intel },
{ 0x8086, 0x2430, PCI_ANY_ID, PCI_ANY_ID, 0, 0, rng_hw_intel },
{ 0x8086, 0x2448, PCI_ANY_ID, PCI_ANY_ID, 0, 0, rng_hw_intel },
{ 0x8086, 0x244e, PCI_ANY_ID, PCI_ANY_ID, 0, 0, rng_hw_intel },
{ 0x8086, 0x245e, PCI_ANY_ID, PCI_ANY_ID, 0, 0, rng_hw_intel },
{ PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_LX_AES,
PCI_ANY_ID, PCI_ANY_ID, 0, 0, rng_hw_geode },
{ 0, }, /* terminate list */
};
MODULE_DEVICE_TABLE (pci, rng_pci_tbl);
/***********************************************************************
*
* Intel RNG operations
*
*/
/*
* RNG registers (offsets from rng_mem)
*/
#define INTEL_RNG_HW_STATUS 0
#define INTEL_RNG_PRESENT 0x40
#define INTEL_RNG_ENABLED 0x01
#define INTEL_RNG_STATUS 1
#define INTEL_RNG_DATA_PRESENT 0x01
#define INTEL_RNG_DATA 2
/*
* Magic address at which Intel PCI bridges locate the RNG
*/
#define INTEL_RNG_ADDR 0xFFBC015F
#define INTEL_RNG_ADDR_LEN 3
/* token to our ioremap'd RNG register area */
static void __iomem *rng_mem;
static inline u8 intel_hwstatus (void)
{
assert (rng_mem != NULL);
return readb (rng_mem + INTEL_RNG_HW_STATUS);
}
static inline u8 intel_hwstatus_set (u8 hw_status)
{
assert (rng_mem != NULL);
writeb (hw_status, rng_mem + INTEL_RNG_HW_STATUS);
return intel_hwstatus ();
}
static unsigned int intel_data_present(void)
{
assert (rng_mem != NULL);
return (readb (rng_mem + INTEL_RNG_STATUS) & INTEL_RNG_DATA_PRESENT) ?
1 : 0;
}
static u32 intel_data_read(void)
{
assert (rng_mem != NULL);
return readb (rng_mem + INTEL_RNG_DATA);
}
static int __init intel_init (struct pci_dev *dev)
{
int rc;
u8 hw_status;
DPRINTK ("ENTER\n");
rng_mem = ioremap (INTEL_RNG_ADDR, INTEL_RNG_ADDR_LEN);
if (rng_mem == NULL) {
printk (KERN_ERR PFX "cannot ioremap RNG Memory\n");
rc = -EBUSY;
goto err_out;
}
/* Check for Intel 82802 */
hw_status = intel_hwstatus ();
if ((hw_status & INTEL_RNG_PRESENT) == 0) {
printk (KERN_ERR PFX
|