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/*
* Intel CPU Microcode Update Driver for Linux
*
* Copyright (C) 2000-2004 Tigran Aivazian
*
* This driver allows to upgrade microcode on Intel processors
* belonging to IA-32 family - PentiumPro, Pentium II,
* Pentium III, Xeon, Pentium 4, etc.
*
* Reference: Section 8.10 of Volume III, Intel Pentium 4 Manual,
* Order Number 245472 or free download from:
*
* http://developer.intel.com/design/pentium4/manuals/245472.htm
*
* For more information, go to http://www.urbanmyth.org/microcode
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
//#define DEBUG /* pr_debug */
#include <linux/capability.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/cpumask.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/miscdevice.h>
#include <linux/spinlock.h>
#include <linux/mm.h>
#include <linux/syscalls.h>
#include <asm/msr.h>
#include <asm/uaccess.h>
#include <asm/processor.h>
MODULE_DESCRIPTION("Intel CPU (IA-32) Microcode Update Driver");
MODULE_AUTHOR("Tigran Aivazian <tigran@veritas.com>");
MODULE_LICENSE("GPL");
#define MICROCODE_VERSION "1.14-xen"
#define DEFAULT_UCODE_DATASIZE (2000) /* 2000 bytes */
#define MC_HEADER_SIZE (sizeof (microcode_header_t)) /* 48 bytes */
#define DEFAULT_UCODE_TOTALSIZE (DEFAULT_UCODE_DATASIZE + MC_HEADER_SIZE) /* 2048 bytes */
/* no concurrent ->write()s are allowed on /dev/cpu/microcode */
static DECLARE_MUTEX(microcode_sem);
static int microcode_open (struct inode *unused1, struct file *unused2)
{
return capable(CAP_SYS_RAWIO) ? 0 : -EPERM;
}
static int do_microcode_update (const void __user *ubuf, size_t len)
{
int err;
void *kbuf;
kbuf = vmalloc(len);
if (!kbuf)
return -ENOMEM;
if (copy_from_user(kbuf, ubuf, len) == 0) {
dom0_op_t op;
op.cmd = DOM0_MICROCODE;
set_xen_guest_handle(op.u.microcode.data, kbuf);
op.u.microcode.length = len;
err = HYPERVISOR_dom0_op(&op);
} else
err = -EFAULT;
vfree(kbuf);
return err;
}
static ssize_t microcode_write (struct file *file, const char __user *buf, size_t len, loff_t *ppos)
{
ssize_t ret;
if (len < DEFAULT_UCODE_TOTALSIZE) {
printk(KERN_ERR "microcode: not enough data\n");
return -EINVAL;
}
down(µcode_sem);
ret = do_microcode_update(buf, len);
if (!ret)
ret = (ssize_t)len;
up(µcode_sem);
return ret;
}
static int microcode_ioctl (struct inode *inode, struct file *file,
unsigned int cmd, unsigned long arg)
{
switch (cmd) {
/*
* XXX: will be removed after microcode_ctl
* is updated to ignore failure of this ioctl()
*/
case MICROCODE_IOCFREE:
return 0;
default:
return -EINVAL;
}
return -EINVAL;
}
static struct file_operations microcode_fops = {
.owner = THIS_MODULE,
.write = microcode_write,
.ioctl = microcode_ioctl,
.open = microcode_open,
};
static struct miscdevice microcode_dev = {
.minor = MICROCODE_MINOR,
.name = "microcode",
.devfs_name = "cpu/microcode",
.fops = µcode_fops,
};
static int __init microcode_init (void)
{
int error;
error = misc_register(µcode_dev);
if (error) {
printk(KERN_ERR
"microcode: can't misc_register on minor=%d\n",
MICROCODE_MINOR);
return error;
}
printk(KERN_INFO
"IA-32 Microcode Update Driver: v" MICROCODE_VERSION " <tigran@veritas.com>\n");
return 0;
}
static void __exit microcode_exit (void)
{
misc_deregister(µcode_dev);
printk(KERN_INFO "IA-32 Microcode Update Driver v" MICROCODE_VERSION " unregistered\n");
}
module_init(microcode_init)
module_exit(microcode_exit)
MODULE_ALIAS_MISCDEV(MICROCODE_MINOR);
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