2 * Intel CPU Microcode Update Driver for Linux
4 * Copyright (C) 2000-2004 Tigran Aivazian
6 * This driver allows to upgrade microcode on Intel processors
7 * belonging to IA-32 family - PentiumPro, Pentium II,
8 * Pentium III, Xeon, Pentium 4, etc.
10 * Reference: Section 8.10 of Volume III, Intel Pentium 4 Manual,
11 * Order Number 245472 or free download from:
13 * http://developer.intel.com/design/pentium4/manuals/245472.htm
15 * For more information, go to http://www.urbanmyth.org/microcode
17 * This program is free software; you can redistribute it and/or
18 * modify it under the terms of the GNU General Public License
19 * as published by the Free Software Foundation; either version
20 * 2 of the License, or (at your option) any later version.
22 * 1.0 16 Feb 2000, Tigran Aivazian <tigran@sco.com>
24 * 1.01 18 Feb 2000, Tigran Aivazian <tigran@sco.com>
25 * Added read() support + cleanups.
26 * 1.02 21 Feb 2000, Tigran Aivazian <tigran@sco.com>
27 * Added 'device trimming' support. open(O_WRONLY) zeroes
28 * and frees the saved copy of applied microcode.
29 * 1.03 29 Feb 2000, Tigran Aivazian <tigran@sco.com>
30 * Made to use devfs (/dev/cpu/microcode) + cleanups.
31 * 1.04 06 Jun 2000, Simon Trimmer <simon@veritas.com>
32 * Added misc device support (now uses both devfs and misc).
33 * Added MICROCODE_IOCFREE ioctl to clear memory.
34 * 1.05 09 Jun 2000, Simon Trimmer <simon@veritas.com>
35 * Messages for error cases (non Intel & no suitable microcode).
36 * 1.06 03 Aug 2000, Tigran Aivazian <tigran@veritas.com>
37 * Removed ->release(). Removed exclusive open and status bitmap.
38 * Added microcode_rwsem to serialize read()/write()/ioctl().
39 * Removed global kernel lock usage.
40 * 1.07 07 Sep 2000, Tigran Aivazian <tigran@veritas.com>
41 * Write 0 to 0x8B msr and then cpuid before reading revision,
42 * so that it works even if there were no update done by the
43 * BIOS. Otherwise, reading from 0x8B gives junk (which happened
44 * to be 0 on my machine which is why it worked even when I
45 * disabled update by the BIOS)
46 * Thanks to Eric W. Biederman <ebiederman@lnxi.com> for the fix.
47 * 1.08 11 Dec 2000, Richard Schaal <richard.schaal@intel.com> and
48 * Tigran Aivazian <tigran@veritas.com>
49 * Intel Pentium 4 processor support and bugfixes.
50 * 1.09 30 Oct 2001, Tigran Aivazian <tigran@veritas.com>
51 * Bugfix for HT (Hyper-Threading) enabled processors
52 * whereby processor resources are shared by all logical processors
53 * in a single CPU package.
54 * 1.10 28 Feb 2002 Asit K Mallick <asit.k.mallick@intel.com> and
55 * Tigran Aivazian <tigran@veritas.com>,
56 * Serialize updates as required on HT processors due to speculative
57 * nature of implementation.
58 * 1.11 22 Mar 2002 Tigran Aivazian <tigran@veritas.com>
59 * Fix the panic when writing zero-length microcode chunk.
60 * 1.12 29 Sep 2003 Nitin Kamble <nitin.a.kamble@intel.com>,
61 * Jun Nakajima <jun.nakajima@intel.com>
62 * Support for the microcode updates in the new format.
63 * 1.13 10 Oct 2003 Tigran Aivazian <tigran@veritas.com>
64 * Removed ->read() method and obsoleted MICROCODE_IOCFREE ioctl
65 * because we no longer hold a copy of applied microcode
67 * 1.14 25 Jun 2004 Tigran Aivazian <tigran@veritas.com>
68 * Fix sigmatch() macro to handle old CPUs with pf == 0.
69 * Thanks to Stuart Swales for pointing out this bug.
72 //#define DEBUG /* pr_debug */
73 #include <linux/capability.h>
74 #include <linux/kernel.h>
75 #include <linux/init.h>
76 #include <linux/sched.h>
77 #include <linux/cpumask.h>
78 #include <linux/module.h>
79 #include <linux/slab.h>
80 #include <linux/vmalloc.h>
81 #include <linux/miscdevice.h>
82 #include <linux/spinlock.h>
84 #include <linux/mutex.h>
87 #include <asm/uaccess.h>
88 #include <asm/processor.h>
90 MODULE_DESCRIPTION("Intel CPU (IA-32) Microcode Update Driver");
91 MODULE_AUTHOR("Tigran Aivazian <tigran@veritas.com>");
92 MODULE_LICENSE("GPL");
94 #define MICROCODE_VERSION "1.14"
96 #define DEFAULT_UCODE_DATASIZE (2000) /* 2000 bytes */
97 #define MC_HEADER_SIZE (sizeof (microcode_header_t)) /* 48 bytes */
98 #define DEFAULT_UCODE_TOTALSIZE (DEFAULT_UCODE_DATASIZE + MC_HEADER_SIZE) /* 2048 bytes */
99 #define EXT_HEADER_SIZE (sizeof (struct extended_sigtable)) /* 20 bytes */
100 #define EXT_SIGNATURE_SIZE (sizeof (struct extended_signature)) /* 12 bytes */
101 #define DWSIZE (sizeof (u32))
102 #define get_totalsize(mc) \
103 (((microcode_t *)mc)->hdr.totalsize ? \
104 ((microcode_t *)mc)->hdr.totalsize : DEFAULT_UCODE_TOTALSIZE)
105 #define get_datasize(mc) \
106 (((microcode_t *)mc)->hdr.datasize ? \
107 ((microcode_t *)mc)->hdr.datasize : DEFAULT_UCODE_DATASIZE)
109 #define sigmatch(s1, s2, p1, p2) \
110 (((s1) == (s2)) && (((p1) & (p2)) || (((p1) == 0) && ((p2) == 0))))
112 #define exttable_size(et) ((et)->count * EXT_SIGNATURE_SIZE + EXT_HEADER_SIZE)
114 /* serialize access to the physical write to MSR 0x79 */
115 static DEFINE_SPINLOCK(microcode_update_lock
);
117 /* no concurrent ->write()s are allowed on /dev/cpu/microcode */
118 static DEFINE_MUTEX(microcode_mutex
);
120 static void __user
*user_buffer
; /* user area microcode data buffer */
121 static unsigned int user_buffer_size
; /* it's size */
123 typedef enum mc_error_code
{
130 static struct ucode_cpu_info
{
137 } ucode_cpu_info
[NR_CPUS
];
139 static int microcode_open (struct inode
*unused1
, struct file
*unused2
)
141 return capable(CAP_SYS_RAWIO
) ? 0 : -EPERM
;
144 static void collect_cpu_info (void *unused
)
146 int cpu_num
= smp_processor_id();
147 struct cpuinfo_x86
*c
= cpu_data
+ cpu_num
;
148 struct ucode_cpu_info
*uci
= ucode_cpu_info
+ cpu_num
;
151 uci
->sig
= uci
->pf
= uci
->rev
= uci
->cksum
= 0;
152 uci
->err
= MC_NOTFOUND
;
155 if (c
->x86_vendor
!= X86_VENDOR_INTEL
|| c
->x86
< 6 ||
156 cpu_has(c
, X86_FEATURE_IA64
)) {
157 printk(KERN_ERR
"microcode: CPU%d not a capable Intel processor\n", cpu_num
);
160 uci
->sig
= cpuid_eax(0x00000001);
162 if ((c
->x86_model
>= 5) || (c
->x86
> 6)) {
163 /* get processor flags from MSR 0x17 */
164 rdmsr(MSR_IA32_PLATFORM_ID
, val
[0], val
[1]);
165 uci
->pf
= 1 << ((val
[1] >> 18) & 7);
169 wrmsr(MSR_IA32_UCODE_REV
, 0, 0);
170 /* see notes above for revision 1.07. Apparent chip bug */
172 /* get the current revision from MSR 0x8B */
173 rdmsr(MSR_IA32_UCODE_REV
, val
[0], uci
->rev
);
174 pr_debug("microcode: collect_cpu_info : sig=0x%x, pf=0x%x, rev=0x%x\n",
175 uci
->sig
, uci
->pf
, uci
->rev
);
178 static inline void mark_microcode_update (int cpu_num
, microcode_header_t
*mc_header
, int sig
, int pf
, int cksum
)
180 struct ucode_cpu_info
*uci
= ucode_cpu_info
+ cpu_num
;
182 pr_debug("Microcode Found.\n");
183 pr_debug(" Header Revision 0x%x\n", mc_header
->hdrver
);
184 pr_debug(" Loader Revision 0x%x\n", mc_header
->ldrver
);
185 pr_debug(" Revision 0x%x \n", mc_header
->rev
);
186 pr_debug(" Date %x/%x/%x\n",
187 ((mc_header
->date
>> 24 ) & 0xff),
188 ((mc_header
->date
>> 16 ) & 0xff),
189 (mc_header
->date
& 0xFFFF));
190 pr_debug(" Signature 0x%x\n", sig
);
191 pr_debug(" Type 0x%x Family 0x%x Model 0x%x Stepping 0x%x\n",
196 pr_debug(" Processor Flags 0x%x\n", pf
);
197 pr_debug(" Checksum 0x%x\n", cksum
);
199 if (mc_header
->rev
< uci
->rev
) {
200 printk(KERN_ERR
"microcode: CPU%d not 'upgrading' to earlier revision"
201 " 0x%x (current=0x%x)\n", cpu_num
, mc_header
->rev
, uci
->rev
);
203 } else if (mc_header
->rev
== uci
->rev
) {
204 /* notify the caller of success on this cpu */
205 uci
->err
= MC_SUCCESS
;
209 pr_debug("microcode: CPU%d found a matching microcode update with "
210 " revision 0x%x (current=0x%x)\n", cpu_num
, mc_header
->rev
, uci
->rev
);
212 uci
->pf
= pf
; /* keep the original mc pf for cksum calculation */
213 uci
->err
= MC_MARKED
; /* found the match */
218 static int find_matching_ucodes (void)
223 while (cursor
+ MC_HEADER_SIZE
< user_buffer_size
) {
224 microcode_header_t mc_header
;
226 int i
, sum
, cpu_num
, allocated_flag
, total_size
, data_size
, ext_table_size
;
228 if (copy_from_user(&mc_header
, user_buffer
+ cursor
, MC_HEADER_SIZE
)) {
229 printk(KERN_ERR
"microcode: error! Can not read user data\n");
234 total_size
= get_totalsize(&mc_header
);
235 if ((cursor
+ total_size
> user_buffer_size
) || (total_size
< DEFAULT_UCODE_TOTALSIZE
)) {
236 printk(KERN_ERR
"microcode: error! Bad data in microcode data file\n");
241 data_size
= get_datasize(&mc_header
);
242 if ((data_size
+ MC_HEADER_SIZE
> total_size
) || (data_size
< DEFAULT_UCODE_DATASIZE
)) {
243 printk(KERN_ERR
"microcode: error! Bad data in microcode data file\n");
248 if (mc_header
.ldrver
!= 1 || mc_header
.hdrver
!= 1) {
249 printk(KERN_ERR
"microcode: error! Unknown microcode update format\n");
254 for_each_online_cpu(cpu_num
) {
255 struct ucode_cpu_info
*uci
= ucode_cpu_info
+ cpu_num
;
256 if (uci
->err
!= MC_NOTFOUND
) /* already found a match or not an online cpu*/
259 if (sigmatch(mc_header
.sig
, uci
->sig
, mc_header
.pf
, uci
->pf
))
260 mark_microcode_update(cpu_num
, &mc_header
, mc_header
.sig
, mc_header
.pf
, mc_header
.cksum
);
263 ext_table_size
= total_size
- (MC_HEADER_SIZE
+ data_size
);
264 if (ext_table_size
) {
265 struct extended_sigtable ext_header
;
266 struct extended_signature ext_sig
;
269 if ((ext_table_size
< EXT_HEADER_SIZE
)
270 || ((ext_table_size
- EXT_HEADER_SIZE
) % EXT_SIGNATURE_SIZE
)) {
271 printk(KERN_ERR
"microcode: error! Bad data in microcode data file\n");
275 if (copy_from_user(&ext_header
, user_buffer
+ cursor
276 + MC_HEADER_SIZE
+ data_size
, EXT_HEADER_SIZE
)) {
277 printk(KERN_ERR
"microcode: error! Can not read user data\n");
281 if (ext_table_size
!= exttable_size(&ext_header
)) {
282 printk(KERN_ERR
"microcode: error! Bad data in microcode data file\n");
287 ext_sigcount
= ext_header
.count
;
289 for (i
= 0; i
< ext_sigcount
; i
++) {
290 if (copy_from_user(&ext_sig
, user_buffer
+ cursor
+ MC_HEADER_SIZE
+ data_size
+ EXT_HEADER_SIZE
291 + EXT_SIGNATURE_SIZE
* i
, EXT_SIGNATURE_SIZE
)) {
292 printk(KERN_ERR
"microcode: error! Can not read user data\n");
296 for_each_online_cpu(cpu_num
) {
297 struct ucode_cpu_info
*uci
= ucode_cpu_info
+ cpu_num
;
298 if (uci
->err
!= MC_NOTFOUND
) /* already found a match or not an online cpu*/
300 if (sigmatch(ext_sig
.sig
, uci
->sig
, ext_sig
.pf
, uci
->pf
)) {
301 mark_microcode_update(cpu_num
, &mc_header
, ext_sig
.sig
, ext_sig
.pf
, ext_sig
.cksum
);
306 /* now check if any cpu has matched */
309 for_each_online_cpu(cpu_num
) {
310 if (ucode_cpu_info
[cpu_num
].err
== MC_MARKED
) {
311 struct ucode_cpu_info
*uci
= ucode_cpu_info
+ cpu_num
;
312 if (!allocated_flag
) {
314 newmc
= vmalloc(total_size
);
316 printk(KERN_ERR
"microcode: error! Can not allocate memory\n");
320 if (copy_from_user(newmc
+ MC_HEADER_SIZE
,
321 user_buffer
+ cursor
+ MC_HEADER_SIZE
,
322 total_size
- MC_HEADER_SIZE
)) {
323 printk(KERN_ERR
"microcode: error! Can not read user data\n");
328 memcpy(newmc
, &mc_header
, MC_HEADER_SIZE
);
329 /* check extended table checksum */
330 if (ext_table_size
) {
331 int ext_table_sum
= 0;
332 int * ext_tablep
= (((void *) newmc
) + MC_HEADER_SIZE
+ data_size
);
333 i
= ext_table_size
/ DWSIZE
;
334 while (i
--) ext_table_sum
+= ext_tablep
[i
];
336 printk(KERN_WARNING
"microcode: aborting, bad extended signature table checksum\n");
343 /* calculate the checksum */
344 i
= (MC_HEADER_SIZE
+ data_size
) / DWSIZE
;
345 while (i
--) sum
+= ((int *)newmc
)[i
];
346 sum
-= (mc_header
.sig
+ mc_header
.pf
+ mc_header
.cksum
);
348 ucode_cpu_info
[cpu_num
].mc
= newmc
;
349 ucode_cpu_info
[cpu_num
].err
= MC_ALLOCATED
; /* mc updated */
350 if (sum
+ uci
->sig
+ uci
->pf
+ uci
->cksum
!= 0) {
351 printk(KERN_ERR
"microcode: CPU%d aborting, bad checksum\n", cpu_num
);
357 cursor
+= total_size
; /* goto the next update patch */
363 static void do_update_one (void * unused
)
367 int cpu_num
= smp_processor_id();
368 struct ucode_cpu_info
*uci
= ucode_cpu_info
+ cpu_num
;
370 if (uci
->mc
== NULL
) {
374 /* serialize access to the physical write to MSR 0x79 */
375 spin_lock_irqsave(µcode_update_lock
, flags
);
377 /* write microcode via MSR 0x79 */
378 wrmsr(MSR_IA32_UCODE_WRITE
,
379 (unsigned long) uci
->mc
->bits
,
380 (unsigned long) uci
->mc
->bits
>> 16 >> 16);
381 wrmsr(MSR_IA32_UCODE_REV
, 0, 0);
383 /* see notes above for revision 1.07. Apparent chip bug */
386 /* get the current revision from MSR 0x8B */
387 rdmsr(MSR_IA32_UCODE_REV
, val
[0], val
[1]);
389 /* notify the caller of success on this cpu */
390 uci
->err
= MC_SUCCESS
;
391 spin_unlock_irqrestore(µcode_update_lock
, flags
);
392 printk(KERN_INFO
"microcode: CPU%d updated from revision "
393 "0x%x to 0x%x, date = %08x \n",
394 cpu_num
, uci
->rev
, val
[1], uci
->mc
->hdr
.date
);
398 static int do_microcode_update (void)
402 if (on_each_cpu(collect_cpu_info
, NULL
, 1, 1) != 0) {
403 printk(KERN_ERR
"microcode: Error! Could not run on all processors\n");
408 if ((error
= find_matching_ucodes())) {
409 printk(KERN_ERR
"microcode: Error in the microcode data\n");
413 if (on_each_cpu(do_update_one
, NULL
, 1, 1) != 0) {
414 printk(KERN_ERR
"microcode: Error! Could not run on all processors\n");
419 for_each_online_cpu(i
) {
420 if (ucode_cpu_info
[i
].mc
) {
422 void *tmp
= ucode_cpu_info
[i
].mc
;
424 for_each_online_cpu(j
) {
425 if (ucode_cpu_info
[j
].mc
== tmp
)
426 ucode_cpu_info
[j
].mc
= NULL
;
434 static ssize_t
microcode_write (struct file
*file
, const char __user
*buf
, size_t len
, loff_t
*ppos
)
438 if (len
< DEFAULT_UCODE_TOTALSIZE
) {
439 printk(KERN_ERR
"microcode: not enough data\n");
443 if ((len
>> PAGE_SHIFT
) > num_physpages
) {
444 printk(KERN_ERR
"microcode: too much data (max %ld pages)\n", num_physpages
);
448 mutex_lock(µcode_mutex
);
450 user_buffer
= (void __user
*) buf
;
451 user_buffer_size
= (int) len
;
453 ret
= do_microcode_update();
457 mutex_unlock(µcode_mutex
);
462 static struct file_operations microcode_fops
= {
463 .owner
= THIS_MODULE
,
464 .write
= microcode_write
,
465 .open
= microcode_open
,
468 static struct miscdevice microcode_dev
= {
469 .minor
= MICROCODE_MINOR
,
471 .devfs_name
= "cpu/microcode",
472 .fops
= µcode_fops
,
475 static int __init
microcode_init (void)
479 error
= misc_register(µcode_dev
);
482 "microcode: can't misc_register on minor=%d\n",
488 "IA-32 Microcode Update Driver: v" MICROCODE_VERSION
" <tigran@veritas.com>\n");
492 static void __exit
microcode_exit (void)
494 misc_deregister(µcode_dev
);
497 module_init(microcode_init
)
498 module_exit(microcode_exit
)
499 MODULE_ALIAS_MISCDEV(MICROCODE_MINOR
);