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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * CPU Microcode Update Driver for Linux
4 *
5 * Copyright (C) 2000-2006 Tigran Aivazian <aivazian.tigran@gmail.com>
6 * 2006 Shaohua Li <shaohua.li@intel.com>
7 * 2013-2016 Borislav Petkov <bp@alien8.de>
8 *
9 * X86 CPU microcode early update for Linux:
10 *
11 * Copyright (C) 2012 Fenghua Yu <fenghua.yu@intel.com>
12 * H Peter Anvin" <hpa@zytor.com>
13 * (C) 2015 Borislav Petkov <bp@alien8.de>
14 *
15 * This driver allows to upgrade microcode on x86 processors.
16 */
17
18#define pr_fmt(fmt) "microcode: " fmt
19
20#include <linux/platform_device.h>
21#include <linux/stop_machine.h>
22#include <linux/syscore_ops.h>
23#include <linux/miscdevice.h>
24#include <linux/capability.h>
25#include <linux/firmware.h>
26#include <linux/kernel.h>
27#include <linux/delay.h>
28#include <linux/mutex.h>
29#include <linux/cpu.h>
30#include <linux/nmi.h>
31#include <linux/fs.h>
32#include <linux/mm.h>
33
34#include <asm/microcode_intel.h>
35#include <asm/cpu_device_id.h>
36#include <asm/microcode_amd.h>
37#include <asm/perf_event.h>
38#include <asm/microcode.h>
39#include <asm/processor.h>
40#include <asm/cmdline.h>
41#include <asm/setup.h>
42
43#define DRIVER_VERSION "2.2"
44
45static struct microcode_ops *microcode_ops;
46static bool dis_ucode_ldr = true;
47
48bool initrd_gone;
49
50LIST_HEAD(microcode_cache);
51
52/*
53 * Synchronization.
54 *
55 * All non cpu-hotplug-callback call sites use:
56 *
57 * - microcode_mutex to synchronize with each other;
58 * - cpus_read_lock/unlock() to synchronize with
59 * the cpu-hotplug-callback call sites.
60 *
61 * We guarantee that only a single cpu is being
62 * updated at any particular moment of time.
63 */
64static DEFINE_MUTEX(microcode_mutex);
65
66struct ucode_cpu_info ucode_cpu_info[NR_CPUS];
67
68struct cpu_info_ctx {
69 struct cpu_signature *cpu_sig;
70 int err;
71};
72
73/*
74 * Those patch levels cannot be updated to newer ones and thus should be final.
75 */
76static u32 final_levels[] = {
77 0x01000098,
78 0x0100009f,
79 0x010000af,
80 0, /* T-101 terminator */
81};
82
83/*
84 * Check the current patch level on this CPU.
85 *
86 * Returns:
87 * - true: if update should stop
88 * - false: otherwise
89 */
90static bool amd_check_current_patch_level(void)
91{
92 u32 lvl, dummy, i;
93 u32 *levels;
94
95 native_rdmsr(MSR_AMD64_PATCH_LEVEL, lvl, dummy);
96
97 if (IS_ENABLED(CONFIG_X86_32))
98 levels = (u32 *)__pa_nodebug(&final_levels);
99 else
100 levels = final_levels;
101
102 for (i = 0; levels[i]; i++) {
103 if (lvl == levels[i])
104 return true;
105 }
106 return false;
107}
108
109static bool __init check_loader_disabled_bsp(void)
110{
111 static const char *__dis_opt_str = "dis_ucode_ldr";
112
113#ifdef CONFIG_X86_32
114 const char *cmdline = (const char *)__pa_nodebug(boot_command_line);
115 const char *option = (const char *)__pa_nodebug(__dis_opt_str);
116 bool *res = (bool *)__pa_nodebug(&dis_ucode_ldr);
117
118#else /* CONFIG_X86_64 */
119 const char *cmdline = boot_command_line;
120 const char *option = __dis_opt_str;
121 bool *res = &dis_ucode_ldr;
122#endif
123
124 /*
125 * CPUID(1).ECX[31]: reserved for hypervisor use. This is still not
126 * completely accurate as xen pv guests don't see that CPUID bit set but
127 * that's good enough as they don't land on the BSP path anyway.
128 */
129 if (native_cpuid_ecx(1) & BIT(31))
130 return *res;
131
132 if (x86_cpuid_vendor() == X86_VENDOR_AMD) {
133 if (amd_check_current_patch_level())
134 return *res;
135 }
136
137 if (cmdline_find_option_bool(cmdline, option) <= 0)
138 *res = false;
139
140 return *res;
141}
142
143void __init load_ucode_bsp(void)
144{
145 unsigned int cpuid_1_eax;
146 bool intel = true;
147
148 if (!have_cpuid_p())
149 return;
150
151 cpuid_1_eax = native_cpuid_eax(1);
152
153 switch (x86_cpuid_vendor()) {
154 case X86_VENDOR_INTEL:
155 if (x86_family(cpuid_1_eax) < 6)
156 return;
157 break;
158
159 case X86_VENDOR_AMD:
160 if (x86_family(cpuid_1_eax) < 0x10)
161 return;
162 intel = false;
163 break;
164
165 default:
166 return;
167 }
168
169 if (check_loader_disabled_bsp())
170 return;
171
172 if (intel)
173 load_ucode_intel_bsp();
174 else
175 load_ucode_amd_bsp(cpuid_1_eax);
176}
177
178static bool check_loader_disabled_ap(void)
179{
180#ifdef CONFIG_X86_32
181 return *((bool *)__pa_nodebug(&dis_ucode_ldr));
182#else
183 return dis_ucode_ldr;
184#endif
185}
186
187void load_ucode_ap(void)
188{
189 unsigned int cpuid_1_eax;
190
191 if (check_loader_disabled_ap())
192 return;
193
194 cpuid_1_eax = native_cpuid_eax(1);
195
196 switch (x86_cpuid_vendor()) {
197 case X86_VENDOR_INTEL:
198 if (x86_family(cpuid_1_eax) >= 6)
199 load_ucode_intel_ap();
200 break;
201 case X86_VENDOR_AMD:
202 if (x86_family(cpuid_1_eax) >= 0x10)
203 load_ucode_amd_ap(cpuid_1_eax);
204 break;
205 default:
206 break;
207 }
208}
209
210static int __init save_microcode_in_initrd(void)
211{
212 struct cpuinfo_x86 *c = &boot_cpu_data;
213 int ret = -EINVAL;
214
215 switch (c->x86_vendor) {
216 case X86_VENDOR_INTEL:
217 if (c->x86 >= 6)
218 ret = save_microcode_in_initrd_intel();
219 break;
220 case X86_VENDOR_AMD:
221 if (c->x86 >= 0x10)
222 ret = save_microcode_in_initrd_amd(cpuid_eax(1));
223 break;
224 default:
225 break;
226 }
227
228 initrd_gone = true;
229
230 return ret;
231}
232
233struct cpio_data find_microcode_in_initrd(const char *path, bool use_pa)
234{
235#ifdef CONFIG_BLK_DEV_INITRD
236 unsigned long start = 0;
237 size_t size;
238
239#ifdef CONFIG_X86_32
240 struct boot_params *params;
241
242 if (use_pa)
243 params = (struct boot_params *)__pa_nodebug(&boot_params);
244 else
245 params = &boot_params;
246
247 size = params->hdr.ramdisk_size;
248
249 /*
250 * Set start only if we have an initrd image. We cannot use initrd_start
251 * because it is not set that early yet.
252 */
253 if (size)
254 start = params->hdr.ramdisk_image;
255
256# else /* CONFIG_X86_64 */
257 size = (unsigned long)boot_params.ext_ramdisk_size << 32;
258 size |= boot_params.hdr.ramdisk_size;
259
260 if (size) {
261 start = (unsigned long)boot_params.ext_ramdisk_image << 32;
262 start |= boot_params.hdr.ramdisk_image;
263
264 start += PAGE_OFFSET;
265 }
266# endif
267
268 /*
269 * Fixup the start address: after reserve_initrd() runs, initrd_start
270 * has the virtual address of the beginning of the initrd. It also
271 * possibly relocates the ramdisk. In either case, initrd_start contains
272 * the updated address so use that instead.
273 *
274 * initrd_gone is for the hotplug case where we've thrown out initrd
275 * already.
276 */
277 if (!use_pa) {
278 if (initrd_gone)
279 return (struct cpio_data){ NULL, 0, "" };
280 if (initrd_start)
281 start = initrd_start;
282 } else {
283 /*
284 * The picture with physical addresses is a bit different: we
285 * need to get the *physical* address to which the ramdisk was
286 * relocated, i.e., relocated_ramdisk (not initrd_start) and
287 * since we're running from physical addresses, we need to access
288 * relocated_ramdisk through its *physical* address too.
289 */
290 u64 *rr = (u64 *)__pa_nodebug(&relocated_ramdisk);
291 if (*rr)
292 start = *rr;
293 }
294
295 return find_cpio_data(path, (void *)start, size, NULL);
296#else /* !CONFIG_BLK_DEV_INITRD */
297 return (struct cpio_data){ NULL, 0, "" };
298#endif
299}
300
301void reload_early_microcode(void)
302{
303 int vendor, family;
304
305 vendor = x86_cpuid_vendor();
306 family = x86_cpuid_family();
307
308 switch (vendor) {
309 case X86_VENDOR_INTEL:
310 if (family >= 6)
311 reload_ucode_intel();
312 break;
313 case X86_VENDOR_AMD:
314 if (family >= 0x10)
315 reload_ucode_amd();
316 break;
317 default:
318 break;
319 }
320}
321
322/* fake device for request_firmware */
323static struct platform_device *microcode_pdev;
324
325#ifdef CONFIG_MICROCODE_LATE_LOADING
326/*
327 * Late loading dance. Why the heavy-handed stomp_machine effort?
328 *
329 * - HT siblings must be idle and not execute other code while the other sibling
330 * is loading microcode in order to avoid any negative interactions caused by
331 * the loading.
332 *
333 * - In addition, microcode update on the cores must be serialized until this
334 * requirement can be relaxed in the future. Right now, this is conservative
335 * and good.
336 */
337#define SPINUNIT 100 /* 100 nsec */
338
339static int check_online_cpus(void)
340{
341 unsigned int cpu;
342
343 /*
344 * Make sure all CPUs are online. It's fine for SMT to be disabled if
345 * all the primary threads are still online.
346 */
347 for_each_present_cpu(cpu) {
348 if (topology_is_primary_thread(cpu) && !cpu_online(cpu)) {
349 pr_err("Not all CPUs online, aborting microcode update.\n");
350 return -EINVAL;
351 }
352 }
353
354 return 0;
355}
356
357static atomic_t late_cpus_in;
358static atomic_t late_cpus_out;
359
360static int __wait_for_cpus(atomic_t *t, long long timeout)
361{
362 int all_cpus = num_online_cpus();
363
364 atomic_inc(t);
365
366 while (atomic_read(t) < all_cpus) {
367 if (timeout < SPINUNIT) {
368 pr_err("Timeout while waiting for CPUs rendezvous, remaining: %d\n",
369 all_cpus - atomic_read(t));
370 return 1;
371 }
372
373 ndelay(SPINUNIT);
374 timeout -= SPINUNIT;
375
376 touch_nmi_watchdog();
377 }
378 return 0;
379}
380
381/*
382 * Returns:
383 * < 0 - on error
384 * 0 - success (no update done or microcode was updated)
385 */
386static int __reload_late(void *info)
387{
388 int cpu = smp_processor_id();
389 enum ucode_state err;
390 int ret = 0;
391
392 /*
393 * Wait for all CPUs to arrive. A load will not be attempted unless all
394 * CPUs show up.
395 * */
396 if (__wait_for_cpus(&late_cpus_in, NSEC_PER_SEC))
397 return -1;
398
399 /*
400 * On an SMT system, it suffices to load the microcode on one sibling of
401 * the core because the microcode engine is shared between the threads.
402 * Synchronization still needs to take place so that no concurrent
403 * loading attempts happen on multiple threads of an SMT core. See
404 * below.
405 */
406 if (cpumask_first(topology_sibling_cpumask(cpu)) == cpu)
407 err = microcode_ops->apply_microcode(cpu);
408 else
409 goto wait_for_siblings;
410
411 if (err >= UCODE_NFOUND) {
412 if (err == UCODE_ERROR)
413 pr_warn("Error reloading microcode on CPU %d\n", cpu);
414
415 ret = -1;
416 }
417
418wait_for_siblings:
419 if (__wait_for_cpus(&late_cpus_out, NSEC_PER_SEC))
420 panic("Timeout during microcode update!\n");
421
422 /*
423 * At least one thread has completed update on each core.
424 * For others, simply call the update to make sure the
425 * per-cpu cpuinfo can be updated with right microcode
426 * revision.
427 */
428 if (cpumask_first(topology_sibling_cpumask(cpu)) != cpu)
429 err = microcode_ops->apply_microcode(cpu);
430
431 return ret;
432}
433
434/*
435 * Reload microcode late on all CPUs. Wait for a sec until they
436 * all gather together.
437 */
438static int microcode_reload_late(void)
439{
440 int old = boot_cpu_data.microcode, ret;
441
442 pr_err("Attempting late microcode loading - it is dangerous and taints the kernel.\n");
443 pr_err("You should switch to early loading, if possible.\n");
444
445 atomic_set(&late_cpus_in, 0);
446 atomic_set(&late_cpus_out, 0);
447
448 ret = stop_machine_cpuslocked(__reload_late, NULL, cpu_online_mask);
449 if (ret == 0)
450 microcode_check();
451
452 pr_info("Reload completed, microcode revision: 0x%x -> 0x%x\n",
453 old, boot_cpu_data.microcode);
454
455 return ret;
456}
457
458static ssize_t reload_store(struct device *dev,
459 struct device_attribute *attr,
460 const char *buf, size_t size)
461{
462 enum ucode_state tmp_ret = UCODE_OK;
463 int bsp = boot_cpu_data.cpu_index;
464 unsigned long val;
465 ssize_t ret = 0;
466
467 ret = kstrtoul(buf, 0, &val);
468 if (ret)
469 return ret;
470
471 if (val != 1)
472 return size;
473
474 cpus_read_lock();
475
476 ret = check_online_cpus();
477 if (ret)
478 goto put;
479
480 tmp_ret = microcode_ops->request_microcode_fw(bsp, µcode_pdev->dev);
481 if (tmp_ret != UCODE_NEW)
482 goto put;
483
484 mutex_lock(µcode_mutex);
485 ret = microcode_reload_late();
486 mutex_unlock(µcode_mutex);
487
488put:
489 cpus_read_unlock();
490
491 if (ret == 0)
492 ret = size;
493
494 add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_STILL_OK);
495
496 return ret;
497}
498
499static DEVICE_ATTR_WO(reload);
500#endif
501
502static ssize_t version_show(struct device *dev,
503 struct device_attribute *attr, char *buf)
504{
505 struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
506
507 return sprintf(buf, "0x%x\n", uci->cpu_sig.rev);
508}
509
510static ssize_t pf_show(struct device *dev,
511 struct device_attribute *attr, char *buf)
512{
513 struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
514
515 return sprintf(buf, "0x%x\n", uci->cpu_sig.pf);
516}
517
518static DEVICE_ATTR(version, 0444, version_show, NULL);
519static DEVICE_ATTR(processor_flags, 0444, pf_show, NULL);
520
521static struct attribute *mc_default_attrs[] = {
522 &dev_attr_version.attr,
523 &dev_attr_processor_flags.attr,
524 NULL
525};
526
527static const struct attribute_group mc_attr_group = {
528 .attrs = mc_default_attrs,
529 .name = "microcode",
530};
531
532static void microcode_fini_cpu(int cpu)
533{
534 if (microcode_ops->microcode_fini_cpu)
535 microcode_ops->microcode_fini_cpu(cpu);
536}
537
538static enum ucode_state microcode_init_cpu(int cpu)
539{
540 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
541
542 memset(uci, 0, sizeof(*uci));
543
544 microcode_ops->collect_cpu_info(cpu, &uci->cpu_sig);
545
546 return microcode_ops->apply_microcode(cpu);
547}
548
549/**
550 * microcode_bsp_resume - Update boot CPU microcode during resume.
551 */
552void microcode_bsp_resume(void)
553{
554 int cpu = smp_processor_id();
555 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
556
557 if (uci->mc)
558 microcode_ops->apply_microcode(cpu);
559 else
560 reload_early_microcode();
561}
562
563static struct syscore_ops mc_syscore_ops = {
564 .resume = microcode_bsp_resume,
565};
566
567static int mc_cpu_starting(unsigned int cpu)
568{
569 enum ucode_state err = microcode_ops->apply_microcode(cpu);
570
571 pr_debug("%s: CPU%d, err: %d\n", __func__, cpu, err);
572
573 return err == UCODE_ERROR;
574}
575
576static int mc_cpu_online(unsigned int cpu)
577{
578 struct device *dev = get_cpu_device(cpu);
579
580 if (sysfs_create_group(&dev->kobj, &mc_attr_group))
581 pr_err("Failed to create group for CPU%d\n", cpu);
582 return 0;
583}
584
585static int mc_cpu_down_prep(unsigned int cpu)
586{
587 struct device *dev;
588
589 dev = get_cpu_device(cpu);
590
591 microcode_fini_cpu(cpu);
592
593 /* Suspend is in progress, only remove the interface */
594 sysfs_remove_group(&dev->kobj, &mc_attr_group);
595 pr_debug("%s: CPU%d\n", __func__, cpu);
596
597 return 0;
598}
599
600static void setup_online_cpu(struct work_struct *work)
601{
602 int cpu = smp_processor_id();
603 enum ucode_state err;
604
605 err = microcode_init_cpu(cpu);
606 if (err == UCODE_ERROR) {
607 pr_err("Error applying microcode on CPU%d\n", cpu);
608 return;
609 }
610
611 mc_cpu_online(cpu);
612}
613
614static struct attribute *cpu_root_microcode_attrs[] = {
615#ifdef CONFIG_MICROCODE_LATE_LOADING
616 &dev_attr_reload.attr,
617#endif
618 NULL
619};
620
621static const struct attribute_group cpu_root_microcode_group = {
622 .name = "microcode",
623 .attrs = cpu_root_microcode_attrs,
624};
625
626static int __init microcode_init(void)
627{
628 struct cpuinfo_x86 *c = &boot_cpu_data;
629 int error;
630
631 if (dis_ucode_ldr)
632 return -EINVAL;
633
634 if (c->x86_vendor == X86_VENDOR_INTEL)
635 microcode_ops = init_intel_microcode();
636 else if (c->x86_vendor == X86_VENDOR_AMD)
637 microcode_ops = init_amd_microcode();
638 else
639 pr_err("no support for this CPU vendor\n");
640
641 if (!microcode_ops)
642 return -ENODEV;
643
644 microcode_pdev = platform_device_register_simple("microcode", -1, NULL, 0);
645 if (IS_ERR(microcode_pdev))
646 return PTR_ERR(microcode_pdev);
647
648 error = sysfs_create_group(&cpu_subsys.dev_root->kobj, &cpu_root_microcode_group);
649 if (error) {
650 pr_err("Error creating microcode group!\n");
651 goto out_pdev;
652 }
653
654 /* Do per-CPU setup */
655 schedule_on_each_cpu(setup_online_cpu);
656
657 register_syscore_ops(&mc_syscore_ops);
658 cpuhp_setup_state_nocalls(CPUHP_AP_MICROCODE_LOADER, "x86/microcode:starting",
659 mc_cpu_starting, NULL);
660 cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "x86/microcode:online",
661 mc_cpu_online, mc_cpu_down_prep);
662
663 pr_info("Microcode Update Driver: v%s.", DRIVER_VERSION);
664
665 return 0;
666
667 out_pdev:
668 platform_device_unregister(microcode_pdev);
669 return error;
670
671}
672fs_initcall(save_microcode_in_initrd);
673late_initcall(microcode_init);
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/Assets/PDF/manual/253668.pdf
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
74#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
75
76#include <linux/platform_device.h>
77#include <linux/miscdevice.h>
78#include <linux/capability.h>
79#include <linux/kernel.h>
80#include <linux/module.h>
81#include <linux/mutex.h>
82#include <linux/cpu.h>
83#include <linux/fs.h>
84#include <linux/mm.h>
85#include <linux/syscore_ops.h>
86
87#include <asm/microcode.h>
88#include <asm/processor.h>
89#include <asm/cpu_device_id.h>
90#include <asm/perf_event.h>
91
92MODULE_DESCRIPTION("Microcode Update Driver");
93MODULE_AUTHOR("Tigran Aivazian <tigran@aivazian.fsnet.co.uk>");
94MODULE_LICENSE("GPL");
95
96#define MICROCODE_VERSION "2.00"
97
98static struct microcode_ops *microcode_ops;
99
100/*
101 * Synchronization.
102 *
103 * All non cpu-hotplug-callback call sites use:
104 *
105 * - microcode_mutex to synchronize with each other;
106 * - get/put_online_cpus() to synchronize with
107 * the cpu-hotplug-callback call sites.
108 *
109 * We guarantee that only a single cpu is being
110 * updated at any particular moment of time.
111 */
112static DEFINE_MUTEX(microcode_mutex);
113
114struct ucode_cpu_info ucode_cpu_info[NR_CPUS];
115EXPORT_SYMBOL_GPL(ucode_cpu_info);
116
117/*
118 * Operations that are run on a target cpu:
119 */
120
121struct cpu_info_ctx {
122 struct cpu_signature *cpu_sig;
123 int err;
124};
125
126static void collect_cpu_info_local(void *arg)
127{
128 struct cpu_info_ctx *ctx = arg;
129
130 ctx->err = microcode_ops->collect_cpu_info(smp_processor_id(),
131 ctx->cpu_sig);
132}
133
134static int collect_cpu_info_on_target(int cpu, struct cpu_signature *cpu_sig)
135{
136 struct cpu_info_ctx ctx = { .cpu_sig = cpu_sig, .err = 0 };
137 int ret;
138
139 ret = smp_call_function_single(cpu, collect_cpu_info_local, &ctx, 1);
140 if (!ret)
141 ret = ctx.err;
142
143 return ret;
144}
145
146static int collect_cpu_info(int cpu)
147{
148 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
149 int ret;
150
151 memset(uci, 0, sizeof(*uci));
152
153 ret = collect_cpu_info_on_target(cpu, &uci->cpu_sig);
154 if (!ret)
155 uci->valid = 1;
156
157 return ret;
158}
159
160struct apply_microcode_ctx {
161 int err;
162};
163
164static void apply_microcode_local(void *arg)
165{
166 struct apply_microcode_ctx *ctx = arg;
167
168 ctx->err = microcode_ops->apply_microcode(smp_processor_id());
169}
170
171static int apply_microcode_on_target(int cpu)
172{
173 struct apply_microcode_ctx ctx = { .err = 0 };
174 int ret;
175
176 ret = smp_call_function_single(cpu, apply_microcode_local, &ctx, 1);
177 if (!ret)
178 ret = ctx.err;
179
180 return ret;
181}
182
183#ifdef CONFIG_MICROCODE_OLD_INTERFACE
184static int do_microcode_update(const void __user *buf, size_t size)
185{
186 int error = 0;
187 int cpu;
188
189 for_each_online_cpu(cpu) {
190 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
191 enum ucode_state ustate;
192
193 if (!uci->valid)
194 continue;
195
196 ustate = microcode_ops->request_microcode_user(cpu, buf, size);
197 if (ustate == UCODE_ERROR) {
198 error = -1;
199 break;
200 } else if (ustate == UCODE_OK)
201 apply_microcode_on_target(cpu);
202 }
203
204 return error;
205}
206
207static int microcode_open(struct inode *inode, struct file *file)
208{
209 return capable(CAP_SYS_RAWIO) ? nonseekable_open(inode, file) : -EPERM;
210}
211
212static ssize_t microcode_write(struct file *file, const char __user *buf,
213 size_t len, loff_t *ppos)
214{
215 ssize_t ret = -EINVAL;
216
217 if ((len >> PAGE_SHIFT) > totalram_pages) {
218 pr_err("too much data (max %ld pages)\n", totalram_pages);
219 return ret;
220 }
221
222 get_online_cpus();
223 mutex_lock(µcode_mutex);
224
225 if (do_microcode_update(buf, len) == 0)
226 ret = (ssize_t)len;
227
228 if (ret > 0)
229 perf_check_microcode();
230
231 mutex_unlock(µcode_mutex);
232 put_online_cpus();
233
234 return ret;
235}
236
237static const struct file_operations microcode_fops = {
238 .owner = THIS_MODULE,
239 .write = microcode_write,
240 .open = microcode_open,
241 .llseek = no_llseek,
242};
243
244static struct miscdevice microcode_dev = {
245 .minor = MICROCODE_MINOR,
246 .name = "microcode",
247 .nodename = "cpu/microcode",
248 .fops = µcode_fops,
249};
250
251static int __init microcode_dev_init(void)
252{
253 int error;
254
255 error = misc_register(µcode_dev);
256 if (error) {
257 pr_err("can't misc_register on minor=%d\n", MICROCODE_MINOR);
258 return error;
259 }
260
261 return 0;
262}
263
264static void __exit microcode_dev_exit(void)
265{
266 misc_deregister(µcode_dev);
267}
268
269MODULE_ALIAS_MISCDEV(MICROCODE_MINOR);
270MODULE_ALIAS("devname:cpu/microcode");
271#else
272#define microcode_dev_init() 0
273#define microcode_dev_exit() do { } while (0)
274#endif
275
276/* fake device for request_firmware */
277static struct platform_device *microcode_pdev;
278
279static int reload_for_cpu(int cpu)
280{
281 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
282 enum ucode_state ustate;
283 int err = 0;
284
285 if (!uci->valid)
286 return err;
287
288 ustate = microcode_ops->request_microcode_fw(cpu, µcode_pdev->dev, true);
289 if (ustate == UCODE_OK)
290 apply_microcode_on_target(cpu);
291 else
292 if (ustate == UCODE_ERROR)
293 err = -EINVAL;
294 return err;
295}
296
297static ssize_t reload_store(struct device *dev,
298 struct device_attribute *attr,
299 const char *buf, size_t size)
300{
301 unsigned long val;
302 int cpu;
303 ssize_t ret = 0, tmp_ret;
304
305 ret = kstrtoul(buf, 0, &val);
306 if (ret)
307 return ret;
308
309 if (val != 1)
310 return size;
311
312 get_online_cpus();
313 mutex_lock(µcode_mutex);
314 for_each_online_cpu(cpu) {
315 tmp_ret = reload_for_cpu(cpu);
316 if (tmp_ret != 0)
317 pr_warn("Error reloading microcode on CPU %d\n", cpu);
318
319 /* save retval of the first encountered reload error */
320 if (!ret)
321 ret = tmp_ret;
322 }
323 if (!ret)
324 perf_check_microcode();
325 mutex_unlock(µcode_mutex);
326 put_online_cpus();
327
328 if (!ret)
329 ret = size;
330
331 return ret;
332}
333
334static ssize_t version_show(struct device *dev,
335 struct device_attribute *attr, char *buf)
336{
337 struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
338
339 return sprintf(buf, "0x%x\n", uci->cpu_sig.rev);
340}
341
342static ssize_t pf_show(struct device *dev,
343 struct device_attribute *attr, char *buf)
344{
345 struct ucode_cpu_info *uci = ucode_cpu_info + dev->id;
346
347 return sprintf(buf, "0x%x\n", uci->cpu_sig.pf);
348}
349
350static DEVICE_ATTR(reload, 0200, NULL, reload_store);
351static DEVICE_ATTR(version, 0400, version_show, NULL);
352static DEVICE_ATTR(processor_flags, 0400, pf_show, NULL);
353
354static struct attribute *mc_default_attrs[] = {
355 &dev_attr_version.attr,
356 &dev_attr_processor_flags.attr,
357 NULL
358};
359
360static struct attribute_group mc_attr_group = {
361 .attrs = mc_default_attrs,
362 .name = "microcode",
363};
364
365static void microcode_fini_cpu(int cpu)
366{
367 microcode_ops->microcode_fini_cpu(cpu);
368}
369
370static enum ucode_state microcode_resume_cpu(int cpu)
371{
372 pr_debug("CPU%d updated upon resume\n", cpu);
373
374 if (apply_microcode_on_target(cpu))
375 return UCODE_ERROR;
376
377 return UCODE_OK;
378}
379
380static enum ucode_state microcode_init_cpu(int cpu, bool refresh_fw)
381{
382 enum ucode_state ustate;
383 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
384
385 if (uci && uci->valid)
386 return UCODE_OK;
387
388 if (collect_cpu_info(cpu))
389 return UCODE_ERROR;
390
391 /* --dimm. Trigger a delayed update? */
392 if (system_state != SYSTEM_RUNNING)
393 return UCODE_NFOUND;
394
395 ustate = microcode_ops->request_microcode_fw(cpu, µcode_pdev->dev,
396 refresh_fw);
397
398 if (ustate == UCODE_OK) {
399 pr_debug("CPU%d updated upon init\n", cpu);
400 apply_microcode_on_target(cpu);
401 }
402
403 return ustate;
404}
405
406static enum ucode_state microcode_update_cpu(int cpu)
407{
408 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
409
410 if (uci->valid)
411 return microcode_resume_cpu(cpu);
412
413 return microcode_init_cpu(cpu, false);
414}
415
416static int mc_device_add(struct device *dev, struct subsys_interface *sif)
417{
418 int err, cpu = dev->id;
419
420 if (!cpu_online(cpu))
421 return 0;
422
423 pr_debug("CPU%d added\n", cpu);
424
425 err = sysfs_create_group(&dev->kobj, &mc_attr_group);
426 if (err)
427 return err;
428
429 if (microcode_init_cpu(cpu, true) == UCODE_ERROR)
430 return -EINVAL;
431
432 return err;
433}
434
435static int mc_device_remove(struct device *dev, struct subsys_interface *sif)
436{
437 int cpu = dev->id;
438
439 if (!cpu_online(cpu))
440 return 0;
441
442 pr_debug("CPU%d removed\n", cpu);
443 microcode_fini_cpu(cpu);
444 sysfs_remove_group(&dev->kobj, &mc_attr_group);
445 return 0;
446}
447
448static struct subsys_interface mc_cpu_interface = {
449 .name = "microcode",
450 .subsys = &cpu_subsys,
451 .add_dev = mc_device_add,
452 .remove_dev = mc_device_remove,
453};
454
455/**
456 * mc_bp_resume - Update boot CPU microcode during resume.
457 */
458static void mc_bp_resume(void)
459{
460 int cpu = smp_processor_id();
461 struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
462
463 if (uci->valid && uci->mc)
464 microcode_ops->apply_microcode(cpu);
465}
466
467static struct syscore_ops mc_syscore_ops = {
468 .resume = mc_bp_resume,
469};
470
471static int
472mc_cpu_callback(struct notifier_block *nb, unsigned long action, void *hcpu)
473{
474 unsigned int cpu = (unsigned long)hcpu;
475 struct device *dev;
476
477 dev = get_cpu_device(cpu);
478
479 switch (action & ~CPU_TASKS_FROZEN) {
480 case CPU_ONLINE:
481 microcode_update_cpu(cpu);
482 pr_debug("CPU%d added\n", cpu);
483 /*
484 * "break" is missing on purpose here because we want to fall
485 * through in order to create the sysfs group.
486 */
487
488 case CPU_DOWN_FAILED:
489 if (sysfs_create_group(&dev->kobj, &mc_attr_group))
490 pr_err("Failed to create group for CPU%d\n", cpu);
491 break;
492
493 case CPU_DOWN_PREPARE:
494 /* Suspend is in progress, only remove the interface */
495 sysfs_remove_group(&dev->kobj, &mc_attr_group);
496 pr_debug("CPU%d removed\n", cpu);
497 break;
498
499 /*
500 * case CPU_DEAD:
501 *
502 * When a CPU goes offline, don't free up or invalidate the copy of
503 * the microcode in kernel memory, so that we can reuse it when the
504 * CPU comes back online without unnecessarily requesting the userspace
505 * for it again.
506 */
507 }
508
509 /* The CPU refused to come up during a system resume */
510 if (action == CPU_UP_CANCELED_FROZEN)
511 microcode_fini_cpu(cpu);
512
513 return NOTIFY_OK;
514}
515
516static struct notifier_block __refdata mc_cpu_notifier = {
517 .notifier_call = mc_cpu_callback,
518};
519
520#ifdef MODULE
521/* Autoload on Intel and AMD systems */
522static const struct x86_cpu_id __initconst microcode_id[] = {
523#ifdef CONFIG_MICROCODE_INTEL
524 { X86_VENDOR_INTEL, X86_FAMILY_ANY, X86_MODEL_ANY, },
525#endif
526#ifdef CONFIG_MICROCODE_AMD
527 { X86_VENDOR_AMD, X86_FAMILY_ANY, X86_MODEL_ANY, },
528#endif
529 {}
530};
531MODULE_DEVICE_TABLE(x86cpu, microcode_id);
532#endif
533
534static struct attribute *cpu_root_microcode_attrs[] = {
535 &dev_attr_reload.attr,
536 NULL
537};
538
539static struct attribute_group cpu_root_microcode_group = {
540 .name = "microcode",
541 .attrs = cpu_root_microcode_attrs,
542};
543
544static int __init microcode_init(void)
545{
546 struct cpuinfo_x86 *c = &cpu_data(0);
547 int error;
548
549 if (c->x86_vendor == X86_VENDOR_INTEL)
550 microcode_ops = init_intel_microcode();
551 else if (c->x86_vendor == X86_VENDOR_AMD)
552 microcode_ops = init_amd_microcode();
553 else
554 pr_err("no support for this CPU vendor\n");
555
556 if (!microcode_ops)
557 return -ENODEV;
558
559 microcode_pdev = platform_device_register_simple("microcode", -1,
560 NULL, 0);
561 if (IS_ERR(microcode_pdev))
562 return PTR_ERR(microcode_pdev);
563
564 get_online_cpus();
565 mutex_lock(µcode_mutex);
566
567 error = subsys_interface_register(&mc_cpu_interface);
568 if (!error)
569 perf_check_microcode();
570 mutex_unlock(µcode_mutex);
571 put_online_cpus();
572
573 if (error)
574 goto out_pdev;
575
576 error = sysfs_create_group(&cpu_subsys.dev_root->kobj,
577 &cpu_root_microcode_group);
578
579 if (error) {
580 pr_err("Error creating microcode group!\n");
581 goto out_driver;
582 }
583
584 error = microcode_dev_init();
585 if (error)
586 goto out_ucode_group;
587
588 register_syscore_ops(&mc_syscore_ops);
589 register_hotcpu_notifier(&mc_cpu_notifier);
590
591 pr_info("Microcode Update Driver: v" MICROCODE_VERSION
592 " <tigran@aivazian.fsnet.co.uk>, Peter Oruba\n");
593
594 return 0;
595
596 out_ucode_group:
597 sysfs_remove_group(&cpu_subsys.dev_root->kobj,
598 &cpu_root_microcode_group);
599
600 out_driver:
601 get_online_cpus();
602 mutex_lock(µcode_mutex);
603
604 subsys_interface_unregister(&mc_cpu_interface);
605
606 mutex_unlock(µcode_mutex);
607 put_online_cpus();
608
609 out_pdev:
610 platform_device_unregister(microcode_pdev);
611 return error;
612
613}
614module_init(microcode_init);
615
616static void __exit microcode_exit(void)
617{
618 struct cpuinfo_x86 *c = &cpu_data(0);
619
620 microcode_dev_exit();
621
622 unregister_hotcpu_notifier(&mc_cpu_notifier);
623 unregister_syscore_ops(&mc_syscore_ops);
624
625 sysfs_remove_group(&cpu_subsys.dev_root->kobj,
626 &cpu_root_microcode_group);
627
628 get_online_cpus();
629 mutex_lock(µcode_mutex);
630
631 subsys_interface_unregister(&mc_cpu_interface);
632
633 mutex_unlock(µcode_mutex);
634 put_online_cpus();
635
636 platform_device_unregister(microcode_pdev);
637
638 microcode_ops = NULL;
639
640 if (c->x86_vendor == X86_VENDOR_AMD)
641 exit_amd_microcode();
642
643 pr_info("Microcode Update Driver: v" MICROCODE_VERSION " removed.\n");
644}
645module_exit(microcode_exit);