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/platform_device.h>
74 #include <linux/miscdevice.h>
75 #include <linux/capability.h>
76 #include <linux/smp_lock.h>
77 #include <linux/kernel.h>
78 #include <linux/module.h>
79 #include <linux/mutex.h>
80 #include <linux/cpu.h>
81 #include <linux/fs.h>
82 #include <linux/mm.h>
83
84 #include <asm/microcode.h>
85 #include <asm/processor.h>
86
87 MODULE_DESCRIPTION("Microcode Update Driver");
88 MODULE_AUTHOR("Tigran Aivazian <tigran@aivazian.fsnet.co.uk>");
89 MODULE_LICENSE("GPL");
90
91 #define MICROCODE_VERSION "2.00"
92
93 static struct microcode_ops *microcode_ops;
94
95 /*
96 * Synchronization.
97 *
98 * All non cpu-hotplug-callback call sites use:
99 *
100 * - microcode_mutex to synchronize with each other;
101 * - get/put_online_cpus() to synchronize with
102 * the cpu-hotplug-callback call sites.
103 *
104 * We guarantee that only a single cpu is being
105 * updated at any particular moment of time.
106 */
107 static DEFINE_MUTEX(microcode_mutex);
108
109 struct ucode_cpu_info ucode_cpu_info[NR_CPUS];
110 EXPORT_SYMBOL_GPL(ucode_cpu_info);
111
112 /*
113 * Operations that are run on a target cpu:
114 */
115
116 struct cpu_info_ctx {
117 struct cpu_signature *cpu_sig;
118 int err;
119 };
120
121 static void collect_cpu_info_local(void *arg)
122 {
123 struct cpu_info_ctx *ctx = arg;
124
125 ctx->err = microcode_ops->collect_cpu_info(smp_processor_id(),
126 ctx->cpu_sig);
127 }
128
129 static int collect_cpu_info_on_target(int cpu, struct cpu_signature *cpu_sig)
130 {
131 struct cpu_info_ctx ctx = { .cpu_sig = cpu_sig, .err = 0 };
132 int ret;
133
134 ret = smp_call_function_single(cpu, collect_cpu_info_local, &ctx, 1);
135 if (!ret)
136 ret = ctx.err;
137
138 return ret;
139 }
140
141 static int collect_cpu_info(int cpu)
142 {
143 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
144 int ret;
145
146 memset(uci, 0, sizeof(*uci));
147
148 ret = collect_cpu_info_on_target(cpu, &uci->cpu_sig);
149 if (!ret)
150 uci->valid = 1;
151
152 return ret;
153 }
154
155 struct apply_microcode_ctx {
156 int err;
157 };
158
159 static void apply_microcode_local(void *arg)
160 {
161 struct apply_microcode_ctx *ctx = arg;
162
163 ctx->err = microcode_ops->apply_microcode(smp_processor_id());
164 }
165
166 static int apply_microcode_on_target(int cpu)
167 {
168 struct apply_microcode_ctx ctx = { .err = 0 };
169 int ret;
170
171 ret = smp_call_function_single(cpu, apply_microcode_local, &ctx, 1);
172 if (!ret)
173 ret = ctx.err;
174
175 return ret;
176 }
177
178 #ifdef CONFIG_MICROCODE_OLD_INTERFACE
179 static int do_microcode_update(const void __user *buf, size_t size)
180 {
181 int error = 0;
182 int cpu;
183
184 for_each_online_cpu(cpu) {
185 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
186 enum ucode_state ustate;
187
188 if (!uci->valid)
189 continue;
190
191 ustate = microcode_ops->request_microcode_user(cpu, buf, size);
192 if (ustate == UCODE_ERROR) {
193 error = -1;
194 break;
195 } else if (ustate == UCODE_OK)
196 apply_microcode_on_target(cpu);
197 }
198
199 return error;
200 }
201
202 static int microcode_open(struct inode *unused1, struct file *unused2)
203 {
204 cycle_kernel_lock();
205 return capable(CAP_SYS_RAWIO) ? 0 : -EPERM;
206 }
207
208 static ssize_t microcode_write(struct file *file, const char __user *buf,
209 size_t len, loff_t *ppos)
210 {
211 ssize_t ret = -EINVAL;
212
213 if ((len >> PAGE_SHIFT) > totalram_pages) {
214 pr_err("microcode: too much data (max %ld pages)\n", totalram_pages);
215 return ret;
216 }
217
218 get_online_cpus();
219 mutex_lock(µcode_mutex);
220
221 if (do_microcode_update(buf, len) == 0)
222 ret = (ssize_t)len;
223
224 mutex_unlock(µcode_mutex);
225 put_online_cpus();
226
227 return ret;
228 }
229
230 static const struct file_operations microcode_fops = {
231 .owner = THIS_MODULE,
232 .write = microcode_write,
233 .open = microcode_open,
234 };
235
236 static struct miscdevice microcode_dev = {
237 .minor = MICROCODE_MINOR,
238 .name = "microcode",
239 .devnode = "cpu/microcode",
240 .fops = µcode_fops,
241 };
242
243 static int __init microcode_dev_init(void)
244 {
245 int error;
246
247 error = misc_register(µcode_dev);
248 if (error) {
249 pr_err("microcode: can't misc_register on minor=%d\n", MICROCODE_MINOR);
250 return error;
251 }
252
253 return 0;
254 }
255
256 static void microcode_dev_exit(void)
257 {
258 misc_deregister(µcode_dev);
259 }
260
261 MODULE_ALIAS_MISCDEV(MICROCODE_MINOR);
262 #else
263 #define microcode_dev_init() 0
264 #define microcode_dev_exit() do { } while (0)
265 #endif
266
267 /* fake device for request_firmware */
268 static struct platform_device *microcode_pdev;
269
270 static int reload_for_cpu(int cpu)
271 {
272 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
273 int err = 0;
274
275 mutex_lock(µcode_mutex);
276 if (uci->valid) {
277 enum ucode_state ustate;
278
279 ustate = microcode_ops->request_microcode_fw(cpu, µcode_pdev->dev);
280 if (ustate == UCODE_OK)
281 apply_microcode_on_target(cpu);
282 else
283 if (ustate == UCODE_ERROR)
284 err = -EINVAL;
285 }
286 mutex_unlock(µcode_mutex);
287
288 return err;
289 }
290
291 static ssize_t reload_store(struct sys_device *dev,
292 struct sysdev_attribute *attr,
293 const char *buf, size_t size)
294 {
295 unsigned long val;
296 int cpu = dev->id;
297 int ret = 0;
298 char *end;
299
300 val = simple_strtoul(buf, &end, 0);
301 if (end == buf)
302 return -EINVAL;
303
304 if (val == 1) {
305 get_online_cpus();
306 if (cpu_online(cpu))
307 ret = reload_for_cpu(cpu);
308 put_online_cpus();
309 }
310
311 if (!ret)
312 ret = size;
313
314 return ret;
315 }
316
317 static ssize_t version_show(struct sys_device *dev,
318 struct sysdev_attribute *attr, char *buf)
319 {
320 struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
321
322 return sprintf(buf, "0x%x\n", uci->cpu_sig.rev);
323 }
324
325 static ssize_t pf_show(struct sys_device *dev,
326 struct sysdev_attribute *attr, char *buf)
327 {
328 struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
329
330 return sprintf(buf, "0x%x\n", uci->cpu_sig.pf);
331 }
332
333 static SYSDEV_ATTR(reload, 0200, NULL, reload_store);
334 static SYSDEV_ATTR(version, 0400, version_show, NULL);
335 static SYSDEV_ATTR(processor_flags, 0400, pf_show, NULL);
336
337 static struct attribute *mc_default_attrs[] = {
338 &attr_reload.attr,
339 &attr_version.attr,
340 &attr_processor_flags.attr,
341 NULL
342 };
343
344 static struct attribute_group mc_attr_group = {
345 .attrs = mc_default_attrs,
346 .name = "microcode",
347 };
348
349 static void microcode_fini_cpu(int cpu)
350 {
351 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
352
353 microcode_ops->microcode_fini_cpu(cpu);
354 uci->valid = 0;
355 }
356
357 static enum ucode_state microcode_resume_cpu(int cpu)
358 {
359 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
360
361 if (!uci->mc)
362 return UCODE_NFOUND;
363
364 pr_debug("microcode: CPU%d updated upon resume\n", cpu);
365 apply_microcode_on_target(cpu);
366
367 return UCODE_OK;
368 }
369
370 static enum ucode_state microcode_init_cpu(int cpu)
371 {
372 enum ucode_state ustate;
373
374 if (collect_cpu_info(cpu))
375 return UCODE_ERROR;
376
377 /* --dimm. Trigger a delayed update? */
378 if (system_state != SYSTEM_RUNNING)
379 return UCODE_NFOUND;
380
381 ustate = microcode_ops->request_microcode_fw(cpu, µcode_pdev->dev);
382
383 if (ustate == UCODE_OK) {
384 pr_debug("microcode: CPU%d updated upon init\n", cpu);
385 apply_microcode_on_target(cpu);
386 }
387
388 return ustate;
389 }
390
391 static enum ucode_state microcode_update_cpu(int cpu)
392 {
393 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
394 enum ucode_state ustate;
395
396 if (uci->valid)
397 ustate = microcode_resume_cpu(cpu);
398 else
399 ustate = microcode_init_cpu(cpu);
400
401 return ustate;
402 }
403
404 static int mc_sysdev_add(struct sys_device *sys_dev)
405 {
406 int err, cpu = sys_dev->id;
407
408 if (!cpu_online(cpu))
409 return 0;
410
411 pr_debug("microcode: CPU%d added\n", cpu);
412
413 err = sysfs_create_group(&sys_dev->kobj, &mc_attr_group);
414 if (err)
415 return err;
416
417 if (microcode_init_cpu(cpu) == UCODE_ERROR)
418 err = -EINVAL;
419
420 return err;
421 }
422
423 static int mc_sysdev_remove(struct sys_device *sys_dev)
424 {
425 int cpu = sys_dev->id;
426
427 if (!cpu_online(cpu))
428 return 0;
429
430 pr_debug("microcode: CPU%d removed\n", cpu);
431 microcode_fini_cpu(cpu);
432 sysfs_remove_group(&sys_dev->kobj, &mc_attr_group);
433 return 0;
434 }
435
436 static int mc_sysdev_resume(struct sys_device *dev)
437 {
438 int cpu = dev->id;
439 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
440
441 if (!cpu_online(cpu))
442 return 0;
443
444 /*
445 * All non-bootup cpus are still disabled,
446 * so only CPU 0 will apply ucode here.
447 *
448 * Moreover, there can be no concurrent
449 * updates from any other places at this point.
450 */
451 WARN_ON(cpu != 0);
452
453 if (uci->valid && uci->mc)
454 microcode_ops->apply_microcode(cpu);
455
456 return 0;
457 }
458
459 static struct sysdev_driver mc_sysdev_driver = {
460 .add = mc_sysdev_add,
461 .remove = mc_sysdev_remove,
462 .resume = mc_sysdev_resume,
463 };
464
465 static __cpuinit int
466 mc_cpu_callback(struct notifier_block *nb, unsigned long action, void *hcpu)
467 {
468 unsigned int cpu = (unsigned long)hcpu;
469 struct sys_device *sys_dev;
470
471 sys_dev = get_cpu_sysdev(cpu);
472 switch (action) {
473 case CPU_ONLINE:
474 case CPU_ONLINE_FROZEN:
475 microcode_update_cpu(cpu);
476 case CPU_DOWN_FAILED:
477 case CPU_DOWN_FAILED_FROZEN:
478 pr_debug("microcode: CPU%d added\n", cpu);
479 if (sysfs_create_group(&sys_dev->kobj, &mc_attr_group))
480 pr_err("microcode: Failed to create group for CPU%d\n", cpu);
481 break;
482 case CPU_DOWN_PREPARE:
483 case CPU_DOWN_PREPARE_FROZEN:
484 /* Suspend is in progress, only remove the interface */
485 sysfs_remove_group(&sys_dev->kobj, &mc_attr_group);
486 pr_debug("microcode: CPU%d removed\n", cpu);
487 break;
488 case CPU_DEAD:
489 case CPU_UP_CANCELED_FROZEN:
490 /* The CPU refused to come up during a system resume */
491 microcode_fini_cpu(cpu);
492 break;
493 }
494 return NOTIFY_OK;
495 }
496
497 static struct notifier_block __refdata mc_cpu_notifier = {
498 .notifier_call = mc_cpu_callback,
499 };
500
501 static int __init microcode_init(void)
502 {
503 struct cpuinfo_x86 *c = &cpu_data(0);
504 int error;
505
506 if (c->x86_vendor == X86_VENDOR_INTEL)
507 microcode_ops = init_intel_microcode();
508 else if (c->x86_vendor == X86_VENDOR_AMD)
509 microcode_ops = init_amd_microcode();
510
511 if (!microcode_ops) {
512 pr_err("microcode: no support for this CPU vendor\n");
513 return -ENODEV;
514 }
515
516 microcode_pdev = platform_device_register_simple("microcode", -1,
517 NULL, 0);
518 if (IS_ERR(microcode_pdev)) {
519 microcode_dev_exit();
520 return PTR_ERR(microcode_pdev);
521 }
522
523 get_online_cpus();
524 mutex_lock(µcode_mutex);
525
526 error = sysdev_driver_register(&cpu_sysdev_class, &mc_sysdev_driver);
527
528 mutex_unlock(µcode_mutex);
529 put_online_cpus();
530
531 if (error) {
532 platform_device_unregister(microcode_pdev);
533 return error;
534 }
535
536 error = microcode_dev_init();
537 if (error)
538 return error;
539
540 register_hotcpu_notifier(&mc_cpu_notifier);
541
542 pr_info("Microcode Update Driver: v" MICROCODE_VERSION
543 " <tigran@aivazian.fsnet.co.uk>,"
544 " Peter Oruba\n");
545
546 return 0;
547 }
548 module_init(microcode_init);
549
550 static void __exit microcode_exit(void)
551 {
552 microcode_dev_exit();
553
554 unregister_hotcpu_notifier(&mc_cpu_notifier);
555
556 get_online_cpus();
557 mutex_lock(µcode_mutex);
558
559 sysdev_driver_unregister(&cpu_sysdev_class, &mc_sysdev_driver);
560
561 mutex_unlock(µcode_mutex);
562 put_online_cpus();
563
564 platform_device_unregister(microcode_pdev);
565
566 microcode_ops = NULL;
567
568 pr_info("Microcode Update Driver: v" MICROCODE_VERSION " removed.\n");
569 }
570 module_exit(microcode_exit);
571
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