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1/*
2 * Intel CPU Microcode Update Driver for Linux
3 *
4 * Copyright (C) 2000-2006 Tigran Aivazian <tigran@aivazian.fsnet.co.uk>
5 * 2006 Shaohua Li <shaohua.li@intel.com>
6 *
7 * This driver allows to upgrade microcode on Intel processors
8 * belonging to IA-32 family - PentiumPro, Pentium II,
9 * Pentium III, Xeon, Pentium 4, etc.
10 *
11 * Reference: Section 8.11 of Volume 3a, IA-32 Intel? Architecture
12 * Software Developer's Manual
13 * Order Number 253668 or free download from:
14 *
15 * http://developer.intel.com/design/pentium4/manuals/253668.htm
16 *
17 * For more information, go to http://www.urbanmyth.org/microcode
18 *
19 * This program is free software; you can redistribute it and/or
20 * modify it under the terms of the GNU General Public License
21 * as published by the Free Software Foundation; either version
22 * 2 of the License, or (at your option) any later version.
23 *
24 * 1.0 16 Feb 2000, Tigran Aivazian <tigran@sco.com>
25 * Initial release.
26 * 1.01 18 Feb 2000, Tigran Aivazian <tigran@sco.com>
27 * Added read() support + cleanups.
28 * 1.02 21 Feb 2000, Tigran Aivazian <tigran@sco.com>
29 * Added 'device trimming' support. open(O_WRONLY) zeroes
30 * and frees the saved copy of applied microcode.
31 * 1.03 29 Feb 2000, Tigran Aivazian <tigran@sco.com>
32 * Made to use devfs (/dev/cpu/microcode) + cleanups.
33 * 1.04 06 Jun 2000, Simon Trimmer <simon@veritas.com>
34 * Added misc device support (now uses both devfs and misc).
35 * Added MICROCODE_IOCFREE ioctl to clear memory.
36 * 1.05 09 Jun 2000, Simon Trimmer <simon@veritas.com>
37 * Messages for error cases (non Intel & no suitable microcode).
38 * 1.06 03 Aug 2000, Tigran Aivazian <tigran@veritas.com>
39 * Removed ->release(). Removed exclusive open and status bitmap.
40 * Added microcode_rwsem to serialize read()/write()/ioctl().
41 * Removed global kernel lock usage.
42 * 1.07 07 Sep 2000, Tigran Aivazian <tigran@veritas.com>
43 * Write 0 to 0x8B msr and then cpuid before reading revision,
44 * so that it works even if there were no update done by the
45 * BIOS. Otherwise, reading from 0x8B gives junk (which happened
46 * to be 0 on my machine which is why it worked even when I
47 * disabled update by the BIOS)
48 * Thanks to Eric W. Biederman <ebiederman@lnxi.com> for the fix.
49 * 1.08 11 Dec 2000, Richard Schaal <richard.schaal@intel.com> and
50 * Tigran Aivazian <tigran@veritas.com>
51 * Intel Pentium 4 processor support and bugfixes.
52 * 1.09 30 Oct 2001, Tigran Aivazian <tigran@veritas.com>
53 * Bugfix for HT (Hyper-Threading) enabled processors
54 * whereby processor resources are shared by all logical processors
55 * in a single CPU package.
56 * 1.10 28 Feb 2002 Asit K Mallick <asit.k.mallick@intel.com> and
57 * Tigran Aivazian <tigran@veritas.com>,
58 * Serialize updates as required on HT processors due to
59 * speculative nature of implementation.
60 * 1.11 22 Mar 2002 Tigran Aivazian <tigran@veritas.com>
61 * Fix the panic when writing zero-length microcode chunk.
62 * 1.12 29 Sep 2003 Nitin Kamble <nitin.a.kamble@intel.com>,
63 * Jun Nakajima <jun.nakajima@intel.com>
64 * Support for the microcode updates in the new format.
65 * 1.13 10 Oct 2003 Tigran Aivazian <tigran@veritas.com>
66 * Removed ->read() method and obsoleted MICROCODE_IOCFREE ioctl
67 * because we no longer hold a copy of applied microcode
68 * in kernel memory.
69 * 1.14 25 Jun 2004 Tigran Aivazian <tigran@veritas.com>
70 * Fix sigmatch() macro to handle old CPUs with pf == 0.
71 * Thanks to Stuart Swales for pointing out this bug.
72 */
73#include <linux/capability.h>
74#include <linux/kernel.h>
75#include <linux/init.h>
76#include <linux/sched.h>
77#include <linux/smp_lock.h>
78#include <linux/cpumask.h>
79#include <linux/module.h>
80#include <linux/slab.h>
81#include <linux/vmalloc.h>
82#include <linux/miscdevice.h>
83#include <linux/spinlock.h>
84#include <linux/mm.h>
85#include <linux/fs.h>
86#include <linux/mutex.h>
87#include <linux/cpu.h>
88#include <linux/firmware.h>
89#include <linux/platform_device.h>
90
91#include <asm/msr.h>
92#include <asm/uaccess.h>
93#include <asm/processor.h>
94#include <asm/microcode.h>
95
96MODULE_DESCRIPTION("Microcode Update Driver");
97MODULE_AUTHOR("Tigran Aivazian <tigran@aivazian.fsnet.co.uk>");
98MODULE_LICENSE("GPL");
99
100#define MICROCODE_VERSION "2.00"
101
102struct microcode_ops *microcode_ops;
103
104/* no concurrent ->write()s are allowed on /dev/cpu/microcode */
105static DEFINE_MUTEX(microcode_mutex);
106
107struct ucode_cpu_info ucode_cpu_info[NR_CPUS];
108EXPORT_SYMBOL_GPL(ucode_cpu_info);
109
110#ifdef CONFIG_MICROCODE_OLD_INTERFACE
111static int do_microcode_update(const void __user *buf, size_t size)
112{
113 cpumask_t old;
114 int error = 0;
115 int cpu;
116
117 old = current->cpus_allowed;
118
119 for_each_online_cpu(cpu) {
120 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
121
122 if (!uci->valid)
123 continue;
124
125 set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
126 error = microcode_ops->request_microcode_user(cpu, buf, size);
127 if (error < 0)
128 goto out;
129 if (!error)
130 microcode_ops->apply_microcode(cpu);
131 }
132out:
133 set_cpus_allowed_ptr(current, &old);
134 return error;
135}
136
137static int microcode_open(struct inode *unused1, struct file *unused2)
138{
139 cycle_kernel_lock();
140 return capable(CAP_SYS_RAWIO) ? 0 : -EPERM;
141}
142
143static ssize_t microcode_write(struct file *file, const char __user *buf,
144 size_t len, loff_t *ppos)
145{
146 ssize_t ret;
147
148 if ((len >> PAGE_SHIFT) > num_physpages) {
149 printk(KERN_ERR "microcode: too much data (max %ld pages)\n",
150 num_physpages);
151 return -EINVAL;
152 }
153
154 get_online_cpus();
155 mutex_lock(&microcode_mutex);
156
157 ret = do_microcode_update(buf, len);
158 if (!ret)
159 ret = (ssize_t)len;
160
161 mutex_unlock(&microcode_mutex);
162 put_online_cpus();
163
164 return ret;
165}
166
167static const struct file_operations microcode_fops = {
168 .owner = THIS_MODULE,
169 .write = microcode_write,
170 .open = microcode_open,
171};
172
173static struct miscdevice microcode_dev = {
174 .minor = MICROCODE_MINOR,
175 .name = "microcode",
176 .fops = &microcode_fops,
177};
178
179static int __init microcode_dev_init(void)
180{
181 int error;
182
183 error = misc_register(&microcode_dev);
184 if (error) {
185 printk(KERN_ERR
186 "microcode: can't misc_register on minor=%d\n",
187 MICROCODE_MINOR);
188 return error;
189 }
190
191 return 0;
192}