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
96 MODULE_DESCRIPTION("Microcode Update Driver");
97 MODULE_AUTHOR("Tigran Aivazian <tigran@aivazian.fsnet.co.uk>");
98 MODULE_LICENSE("GPL");
99
100 #define MICROCODE_VERSION "2.00"
101
102 static struct microcode_ops *microcode_ops;
103
104 /* no concurrent ->write()s are allowed on /dev/cpu/microcode */
105 static DEFINE_MUTEX(microcode_mutex);
106
107 struct ucode_cpu_info ucode_cpu_info[NR_CPUS];
108 EXPORT_SYMBOL_GPL(ucode_cpu_info);
109
110 #ifdef CONFIG_MICROCODE_OLD_INTERFACE
do_microcode_update(const void __user * buf,size_t size)111 static 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 }
132 out:
133 set_cpus_allowed_ptr(current, &old);
134 return error;
135 }
136
microcode_open(struct inode * unused1,struct file * unused2)137 static int microcode_open(struct inode *unused1, struct file *unused2)
138 {
139 cycle_kernel_lock();
140 return capable(CAP_SYS_RAWIO) ? 0 : -EPERM;
141 }
142
microcode_write(struct file * file,const char __user * buf,size_t len,loff_t * ppos)143 static 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(µcode_mutex);
156
157 ret = do_microcode_update(buf, len);
158 if (!ret)
159 ret = (ssize_t)len;
160
161 mutex_unlock(µcode_mutex);
162 put_online_cpus();
163
164 return ret;
165 }
166
167 static const struct file_operations microcode_fops = {
168 .owner = THIS_MODULE,
169 .write = microcode_write,
170 .open = microcode_open,
171 };
172
173 static struct miscdevice microcode_dev = {
174 .minor = MICROCODE_MINOR,
175 .name = "microcode",
176 .fops = µcode_fops,
177 };
178
microcode_dev_init(void)179 static int __init microcode_dev_init(void)
180 {
181 int error;
182
183 error = misc_register(µcode_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 }
193
microcode_dev_exit(void)194 static void microcode_dev_exit(void)
195 {
196 misc_deregister(µcode_dev);
197 }
198
199 MODULE_ALIAS_MISCDEV(MICROCODE_MINOR);
200 #else
201 #define microcode_dev_init() 0
202 #define microcode_dev_exit() do { } while (0)
203 #endif
204
205 /* fake device for request_firmware */
206 static struct platform_device *microcode_pdev;
207
reload_store(struct sys_device * dev,struct sysdev_attribute * attr,const char * buf,size_t sz)208 static ssize_t reload_store(struct sys_device *dev,
209 struct sysdev_attribute *attr,
210 const char *buf, size_t sz)
211 {
212 struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
213 char *end;
214 unsigned long val = simple_strtoul(buf, &end, 0);
215 int err = 0;
216 int cpu = dev->id;
217
218 if (end == buf)
219 return -EINVAL;
220 if (val == 1) {
221 cpumask_t old = current->cpus_allowed;
222
223 get_online_cpus();
224 if (cpu_online(cpu)) {
225 set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
226 mutex_lock(µcode_mutex);
227 if (uci->valid) {
228 err = microcode_ops->request_microcode_fw(cpu,
229 µcode_pdev->dev);
230 if (!err)
231 microcode_ops->apply_microcode(cpu);
232 }
233 mutex_unlock(µcode_mutex);
234 set_cpus_allowed_ptr(current, &old);
235 }
236 put_online_cpus();
237 }
238 if (err)
239 return err;
240 return sz;
241 }
242
version_show(struct sys_device * dev,struct sysdev_attribute * attr,char * buf)243 static ssize_t version_show(struct sys_device *dev,
244 struct sysdev_attribute *attr, char *buf)
245 {
246 struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
247
248 return sprintf(buf, "0x%x\n", uci->cpu_sig.rev);
249 }
250
pf_show(struct sys_device * dev,struct sysdev_attribute * attr,char * buf)251 static ssize_t pf_show(struct sys_device *dev,
252 struct sysdev_attribute *attr, char *buf)
253 {
254 struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
255
256 return sprintf(buf, "0x%x\n", uci->cpu_sig.pf);
257 }
258
259 static SYSDEV_ATTR(reload, 0200, NULL, reload_store);
260 static SYSDEV_ATTR(version, 0400, version_show, NULL);
261 static SYSDEV_ATTR(processor_flags, 0400, pf_show, NULL);
262
263 static struct attribute *mc_default_attrs[] = {
264 &attr_reload.attr,
265 &attr_version.attr,
266 &attr_processor_flags.attr,
267 NULL
268 };
269
270 static struct attribute_group mc_attr_group = {
271 .attrs = mc_default_attrs,
272 .name = "microcode",
273 };
274
__microcode_fini_cpu(int cpu)275 static void __microcode_fini_cpu(int cpu)
276 {
277 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
278
279 microcode_ops->microcode_fini_cpu(cpu);
280 uci->valid = 0;
281 }
282
microcode_fini_cpu(int cpu)283 static void microcode_fini_cpu(int cpu)
284 {
285 mutex_lock(µcode_mutex);
286 __microcode_fini_cpu(cpu);
287 mutex_unlock(µcode_mutex);
288 }
289
collect_cpu_info(int cpu)290 static void collect_cpu_info(int cpu)
291 {
292 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
293
294 memset(uci, 0, sizeof(*uci));
295 if (!microcode_ops->collect_cpu_info(cpu, &uci->cpu_sig))
296 uci->valid = 1;
297 }
298
microcode_resume_cpu(int cpu)299 static int microcode_resume_cpu(int cpu)
300 {
301 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
302 struct cpu_signature nsig;
303
304 pr_debug("microcode: CPU%d resumed\n", cpu);
305
306 if (!uci->mc)
307 return 1;
308
309 /*
310 * Let's verify that the 'cached' ucode does belong
311 * to this cpu (a bit of paranoia):
312 */
313 if (microcode_ops->collect_cpu_info(cpu, &nsig)) {
314 __microcode_fini_cpu(cpu);
315 printk(KERN_ERR "failed to collect_cpu_info for resuming cpu #%d\n",
316 cpu);
317 return -1;
318 }
319
320 if ((nsig.sig != uci->cpu_sig.sig) || (nsig.pf != uci->cpu_sig.pf)) {
321 __microcode_fini_cpu(cpu);
322 printk(KERN_ERR "cached ucode doesn't match the resuming cpu #%d\n",
323 cpu);
324 /* Should we look for a new ucode here? */
325 return 1;
326 }
327
328 return 0;
329 }
330
microcode_update_cpu(int cpu)331 static void microcode_update_cpu(int cpu)
332 {
333 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
334 int err = 0;
335
336 /*
337 * Check if the system resume is in progress (uci->valid != NULL),
338 * otherwise just request a firmware:
339 */
340 if (uci->valid) {
341 err = microcode_resume_cpu(cpu);
342 } else {
343 collect_cpu_info(cpu);
344 if (uci->valid && system_state == SYSTEM_RUNNING)
345 err = microcode_ops->request_microcode_fw(cpu,
346 µcode_pdev->dev);
347 }
348 if (!err)
349 microcode_ops->apply_microcode(cpu);
350 }
351
microcode_init_cpu(int cpu)352 static void microcode_init_cpu(int cpu)
353 {
354 cpumask_t old = current->cpus_allowed;
355
356 set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu));
357 /* We should bind the task to the CPU */
358 BUG_ON(raw_smp_processor_id() != cpu);
359
360 mutex_lock(µcode_mutex);
361 microcode_update_cpu(cpu);
362 mutex_unlock(µcode_mutex);
363
364 set_cpus_allowed_ptr(current, &old);
365 }
366
mc_sysdev_add(struct sys_device * sys_dev)367 static int mc_sysdev_add(struct sys_device *sys_dev)
368 {
369 int err, cpu = sys_dev->id;
370 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
371
372 if (!cpu_online(cpu))
373 return 0;
374
375 pr_debug("microcode: CPU%d added\n", cpu);
376 memset(uci, 0, sizeof(*uci));
377
378 err = sysfs_create_group(&sys_dev->kobj, &mc_attr_group);
379 if (err)
380 return err;
381
382 microcode_init_cpu(cpu);
383 return 0;
384 }
385
mc_sysdev_remove(struct sys_device * sys_dev)386 static int mc_sysdev_remove(struct sys_device *sys_dev)
387 {
388 int cpu = sys_dev->id;
389
390 if (!cpu_online(cpu))
391 return 0;
392
393 pr_debug("microcode: CPU%d removed\n", cpu);
394 microcode_fini_cpu(cpu);
395 sysfs_remove_group(&sys_dev->kobj, &mc_attr_group);
396 return 0;
397 }
398
mc_sysdev_resume(struct sys_device * dev)399 static int mc_sysdev_resume(struct sys_device *dev)
400 {
401 int cpu = dev->id;
402
403 if (!cpu_online(cpu))
404 return 0;
405
406 /* only CPU 0 will apply ucode here */
407 microcode_update_cpu(0);
408 return 0;
409 }
410
411 static struct sysdev_driver mc_sysdev_driver = {
412 .add = mc_sysdev_add,
413 .remove = mc_sysdev_remove,
414 .resume = mc_sysdev_resume,
415 };
416
417 static __cpuinit int
mc_cpu_callback(struct notifier_block * nb,unsigned long action,void * hcpu)418 mc_cpu_callback(struct notifier_block *nb, unsigned long action, void *hcpu)
419 {
420 unsigned int cpu = (unsigned long)hcpu;
421 struct sys_device *sys_dev;
422
423 sys_dev = get_cpu_sysdev(cpu);
424 switch (action) {
425 case CPU_ONLINE:
426 case CPU_ONLINE_FROZEN:
427 microcode_init_cpu(cpu);
428 case CPU_DOWN_FAILED:
429 case CPU_DOWN_FAILED_FROZEN:
430 pr_debug("microcode: CPU%d added\n", cpu);
431 if (sysfs_create_group(&sys_dev->kobj, &mc_attr_group))
432 printk(KERN_ERR "microcode: Failed to create the sysfs "
433 "group for CPU%d\n", cpu);
434 break;
435 case CPU_DOWN_PREPARE:
436 case CPU_DOWN_PREPARE_FROZEN:
437 /* Suspend is in progress, only remove the interface */
438 sysfs_remove_group(&sys_dev->kobj, &mc_attr_group);
439 pr_debug("microcode: CPU%d removed\n", cpu);
440 break;
441 case CPU_DEAD:
442 case CPU_UP_CANCELED_FROZEN:
443 /* The CPU refused to come up during a system resume */
444 microcode_fini_cpu(cpu);
445 break;
446 }
447 return NOTIFY_OK;
448 }
449
450 static struct notifier_block __refdata mc_cpu_notifier = {
451 .notifier_call = mc_cpu_callback,
452 };
453
microcode_init(void)454 static int __init microcode_init(void)
455 {
456 struct cpuinfo_x86 *c = &cpu_data(0);
457 int error;
458
459 if (c->x86_vendor == X86_VENDOR_INTEL)
460 microcode_ops = init_intel_microcode();
461 else if (c->x86_vendor == X86_VENDOR_AMD)
462 microcode_ops = init_amd_microcode();
463
464 if (!microcode_ops) {
465 printk(KERN_ERR "microcode: no support for this CPU vendor\n");
466 return -ENODEV;
467 }
468
469 error = microcode_dev_init();
470 if (error)
471 return error;
472 microcode_pdev = platform_device_register_simple("microcode", -1,
473 NULL, 0);
474 if (IS_ERR(microcode_pdev)) {
475 microcode_dev_exit();
476 return PTR_ERR(microcode_pdev);
477 }
478
479 get_online_cpus();
480 error = sysdev_driver_register(&cpu_sysdev_class, &mc_sysdev_driver);
481 put_online_cpus();
482 if (error) {
483 microcode_dev_exit();
484 platform_device_unregister(microcode_pdev);
485 return error;
486 }
487
488 register_hotcpu_notifier(&mc_cpu_notifier);
489
490 printk(KERN_INFO
491 "Microcode Update Driver: v" MICROCODE_VERSION
492 " <tigran@aivazian.fsnet.co.uk>,"
493 " Peter Oruba\n");
494
495 return 0;
496 }
497
microcode_exit(void)498 static void __exit microcode_exit(void)
499 {
500 microcode_dev_exit();
501
502 unregister_hotcpu_notifier(&mc_cpu_notifier);
503
504 get_online_cpus();
505 sysdev_driver_unregister(&cpu_sysdev_class, &mc_sysdev_driver);
506 put_online_cpus();
507
508 platform_device_unregister(microcode_pdev);
509
510 microcode_ops = NULL;
511
512 printk(KERN_INFO
513 "Microcode Update Driver: v" MICROCODE_VERSION " removed.\n");
514 }
515
516 module_init(microcode_init);
517 module_exit(microcode_exit);
518