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1// SPDX-License-Identifier: GPL-2.0
2#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
3
4#include <linux/export.h>
5#include <linux/reboot.h>
6#include <linux/init.h>
7#include <linux/pm.h>
8#include <linux/efi.h>
9#include <linux/dmi.h>
10#include <linux/sched.h>
11#include <linux/tboot.h>
12#include <linux/delay.h>
13#include <linux/objtool.h>
14#include <linux/pgtable.h>
15#include <acpi/reboot.h>
16#include <asm/io.h>
17#include <asm/apic.h>
18#include <asm/io_apic.h>
19#include <asm/desc.h>
20#include <asm/hpet.h>
21#include <asm/proto.h>
22#include <asm/reboot_fixups.h>
23#include <asm/reboot.h>
24#include <asm/pci_x86.h>
25#include <asm/cpu.h>
26#include <asm/nmi.h>
27#include <asm/smp.h>
28
29#include <linux/ctype.h>
30#include <linux/mc146818rtc.h>
31#include <asm/realmode.h>
32#include <asm/x86_init.h>
33#include <asm/efi.h>
34
35/*
36 * Power off function, if any
37 */
38void (*pm_power_off)(void);
39EXPORT_SYMBOL(pm_power_off);
40
41/*
42 * This is set if we need to go through the 'emergency' path.
43 * When machine_emergency_restart() is called, we may be on
44 * an inconsistent state and won't be able to do a clean cleanup
45 */
46static int reboot_emergency;
47
48/* This is set by the PCI code if either type 1 or type 2 PCI is detected */
49bool port_cf9_safe = false;
50
51/*
52 * Reboot options and system auto-detection code provided by
53 * Dell Inc. so their systems "just work". :-)
54 */
55
56/*
57 * Some machines require the "reboot=a" commandline options
58 */
59static int __init set_acpi_reboot(const struct dmi_system_id *d)
60{
61 if (reboot_type != BOOT_ACPI) {
62 reboot_type = BOOT_ACPI;
63 pr_info("%s series board detected. Selecting %s-method for reboots.\n",
64 d->ident, "ACPI");
65 }
66 return 0;
67}
68
69/*
70 * Some machines require the "reboot=b" or "reboot=k" commandline options,
71 * this quirk makes that automatic.
72 */
73static int __init set_bios_reboot(const struct dmi_system_id *d)
74{
75 if (reboot_type != BOOT_BIOS) {
76 reboot_type = BOOT_BIOS;
77 pr_info("%s series board detected. Selecting %s-method for reboots.\n",
78 d->ident, "BIOS");
79 }
80 return 0;
81}
82
83/*
84 * Some machines don't handle the default ACPI reboot method and
85 * require the EFI reboot method:
86 */
87static int __init set_efi_reboot(const struct dmi_system_id *d)
88{
89 if (reboot_type != BOOT_EFI && !efi_runtime_disabled()) {
90 reboot_type = BOOT_EFI;
91 pr_info("%s series board detected. Selecting EFI-method for reboot.\n", d->ident);
92 }
93 return 0;
94}
95
96void __noreturn machine_real_restart(unsigned int type)
97{
98 local_irq_disable();
99
100 /*
101 * Write zero to CMOS register number 0x0f, which the BIOS POST
102 * routine will recognize as telling it to do a proper reboot. (Well
103 * that's what this book in front of me says -- it may only apply to
104 * the Phoenix BIOS though, it's not clear). At the same time,
105 * disable NMIs by setting the top bit in the CMOS address register,
106 * as we're about to do peculiar things to the CPU. I'm not sure if
107 * `outb_p' is needed instead of just `outb'. Use it to be on the
108 * safe side. (Yes, CMOS_WRITE does outb_p's. - Paul G.)
109 */
110 spin_lock(&rtc_lock);
111 CMOS_WRITE(0x00, 0x8f);
112 spin_unlock(&rtc_lock);
113
114 /*
115 * Switch to the trampoline page table.
116 */
117 load_trampoline_pgtable();
118
119 /* Jump to the identity-mapped low memory code */
120#ifdef CONFIG_X86_32
121 asm volatile("jmpl *%0" : :
122 "rm" (real_mode_header->machine_real_restart_asm),
123 "a" (type));
124#else
125 asm volatile("ljmpl *%0" : :
126 "m" (real_mode_header->machine_real_restart_asm),
127 "D" (type));
128#endif
129 unreachable();
130}
131#ifdef CONFIG_APM_MODULE
132EXPORT_SYMBOL(machine_real_restart);
133#endif
134STACK_FRAME_NON_STANDARD(machine_real_restart);
135
136/*
137 * Some Apple MacBook and MacBookPro's needs reboot=p to be able to reboot
138 */
139static int __init set_pci_reboot(const struct dmi_system_id *d)
140{
141 if (reboot_type != BOOT_CF9_FORCE) {
142 reboot_type = BOOT_CF9_FORCE;
143 pr_info("%s series board detected. Selecting %s-method for reboots.\n",
144 d->ident, "PCI");
145 }
146 return 0;
147}
148
149static int __init set_kbd_reboot(const struct dmi_system_id *d)
150{
151 if (reboot_type != BOOT_KBD) {
152 reboot_type = BOOT_KBD;
153 pr_info("%s series board detected. Selecting %s-method for reboot.\n",
154 d->ident, "KBD");
155 }
156 return 0;
157}
158
159/*
160 * This is a single dmi_table handling all reboot quirks.
161 */
162static const struct dmi_system_id reboot_dmi_table[] __initconst = {
163
164 /* Acer */
165 { /* Handle reboot issue on Acer Aspire one */
166 .callback = set_kbd_reboot,
167 .ident = "Acer Aspire One A110",
168 .matches = {
169 DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
170 DMI_MATCH(DMI_PRODUCT_NAME, "AOA110"),
171 },
172 },
173 { /* Handle reboot issue on Acer TravelMate X514-51T */
174 .callback = set_efi_reboot,
175 .ident = "Acer TravelMate X514-51T",
176 .matches = {
177 DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
178 DMI_MATCH(DMI_PRODUCT_NAME, "TravelMate X514-51T"),
179 },
180 },
181
182 /* Apple */
183 { /* Handle problems with rebooting on Apple MacBook5 */
184 .callback = set_pci_reboot,
185 .ident = "Apple MacBook5",
186 .matches = {
187 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
188 DMI_MATCH(DMI_PRODUCT_NAME, "MacBook5"),
189 },
190 },
191 { /* Handle problems with rebooting on Apple MacBook6,1 */
192 .callback = set_pci_reboot,
193 .ident = "Apple MacBook6,1",
194 .matches = {
195 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
196 DMI_MATCH(DMI_PRODUCT_NAME, "MacBook6,1"),
197 },
198 },
199 { /* Handle problems with rebooting on Apple MacBookPro5 */
200 .callback = set_pci_reboot,
201 .ident = "Apple MacBookPro5",
202 .matches = {
203 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
204 DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro5"),
205 },
206 },
207 { /* Handle problems with rebooting on Apple Macmini3,1 */
208 .callback = set_pci_reboot,
209 .ident = "Apple Macmini3,1",
210 .matches = {
211 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
212 DMI_MATCH(DMI_PRODUCT_NAME, "Macmini3,1"),
213 },
214 },
215 { /* Handle problems with rebooting on the iMac9,1. */
216 .callback = set_pci_reboot,
217 .ident = "Apple iMac9,1",
218 .matches = {
219 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
220 DMI_MATCH(DMI_PRODUCT_NAME, "iMac9,1"),
221 },
222 },
223 { /* Handle problems with rebooting on the iMac10,1. */
224 .callback = set_pci_reboot,
225 .ident = "Apple iMac10,1",
226 .matches = {
227 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
228 DMI_MATCH(DMI_PRODUCT_NAME, "iMac10,1"),
229 },
230 },
231
232 /* ASRock */
233 { /* Handle problems with rebooting on ASRock Q1900DC-ITX */
234 .callback = set_pci_reboot,
235 .ident = "ASRock Q1900DC-ITX",
236 .matches = {
237 DMI_MATCH(DMI_BOARD_VENDOR, "ASRock"),
238 DMI_MATCH(DMI_BOARD_NAME, "Q1900DC-ITX"),
239 },
240 },
241
242 /* ASUS */
243 { /* Handle problems with rebooting on ASUS P4S800 */
244 .callback = set_bios_reboot,
245 .ident = "ASUS P4S800",
246 .matches = {
247 DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
248 DMI_MATCH(DMI_BOARD_NAME, "P4S800"),
249 },
250 },
251 { /* Handle problems with rebooting on ASUS EeeBook X205TA */
252 .callback = set_acpi_reboot,
253 .ident = "ASUS EeeBook X205TA",
254 .matches = {
255 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
256 DMI_MATCH(DMI_PRODUCT_NAME, "X205TA"),
257 },
258 },
259 { /* Handle problems with rebooting on ASUS EeeBook X205TAW */
260 .callback = set_acpi_reboot,
261 .ident = "ASUS EeeBook X205TAW",
262 .matches = {
263 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
264 DMI_MATCH(DMI_PRODUCT_NAME, "X205TAW"),
265 },
266 },
267
268 /* Certec */
269 { /* Handle problems with rebooting on Certec BPC600 */
270 .callback = set_pci_reboot,
271 .ident = "Certec BPC600",
272 .matches = {
273 DMI_MATCH(DMI_SYS_VENDOR, "Certec"),
274 DMI_MATCH(DMI_PRODUCT_NAME, "BPC600"),
275 },
276 },
277
278 /* Dell */
279 { /* Handle problems with rebooting on Dell DXP061 */
280 .callback = set_bios_reboot,
281 .ident = "Dell DXP061",
282 .matches = {
283 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
284 DMI_MATCH(DMI_PRODUCT_NAME, "Dell DXP061"),
285 },
286 },
287 { /* Handle problems with rebooting on Dell E520's */
288 .callback = set_bios_reboot,
289 .ident = "Dell E520",
290 .matches = {
291 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
292 DMI_MATCH(DMI_PRODUCT_NAME, "Dell DM061"),
293 },
294 },
295 { /* Handle problems with rebooting on the Latitude E5410. */
296 .callback = set_pci_reboot,
297 .ident = "Dell Latitude E5410",
298 .matches = {
299 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
300 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E5410"),
301 },
302 },
303 { /* Handle problems with rebooting on the Latitude E5420. */
304 .callback = set_pci_reboot,
305 .ident = "Dell Latitude E5420",
306 .matches = {
307 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
308 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E5420"),
309 },
310 },
311 { /* Handle problems with rebooting on the Latitude E6320. */
312 .callback = set_pci_reboot,
313 .ident = "Dell Latitude E6320",
314 .matches = {
315 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
316 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6320"),
317 },
318 },
319 { /* Handle problems with rebooting on the Latitude E6420. */
320 .callback = set_pci_reboot,
321 .ident = "Dell Latitude E6420",
322 .matches = {
323 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
324 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6420"),
325 },
326 },
327 { /* Handle problems with rebooting on Dell Optiplex 330 with 0KP561 */
328 .callback = set_bios_reboot,
329 .ident = "Dell OptiPlex 330",
330 .matches = {
331 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
332 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 330"),
333 DMI_MATCH(DMI_BOARD_NAME, "0KP561"),
334 },
335 },
336 { /* Handle problems with rebooting on Dell Optiplex 360 with 0T656F */
337 .callback = set_bios_reboot,
338 .ident = "Dell OptiPlex 360",
339 .matches = {
340 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
341 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 360"),
342 DMI_MATCH(DMI_BOARD_NAME, "0T656F"),
343 },
344 },
345 { /* Handle problems with rebooting on Dell Optiplex 745's SFF */
346 .callback = set_bios_reboot,
347 .ident = "Dell OptiPlex 745",
348 .matches = {
349 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
350 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
351 },
352 },
353 { /* Handle problems with rebooting on Dell Optiplex 745's DFF */
354 .callback = set_bios_reboot,
355 .ident = "Dell OptiPlex 745",
356 .matches = {
357 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
358 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
359 DMI_MATCH(DMI_BOARD_NAME, "0MM599"),
360 },
361 },
362 { /* Handle problems with rebooting on Dell Optiplex 745 with 0KW626 */
363 .callback = set_bios_reboot,
364 .ident = "Dell OptiPlex 745",
365 .matches = {
366 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
367 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
368 DMI_MATCH(DMI_BOARD_NAME, "0KW626"),
369 },
370 },
371 { /* Handle problems with rebooting on Dell OptiPlex 760 with 0G919G */
372 .callback = set_bios_reboot,
373 .ident = "Dell OptiPlex 760",
374 .matches = {
375 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
376 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 760"),
377 DMI_MATCH(DMI_BOARD_NAME, "0G919G"),
378 },
379 },
380 { /* Handle problems with rebooting on the OptiPlex 990. */
381 .callback = set_pci_reboot,
382 .ident = "Dell OptiPlex 990 BIOS A0x",
383 .matches = {
384 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
385 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 990"),
386 DMI_MATCH(DMI_BIOS_VERSION, "A0"),
387 },
388 },
389 { /* Handle problems with rebooting on Dell 300's */
390 .callback = set_bios_reboot,
391 .ident = "Dell PowerEdge 300",
392 .matches = {
393 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
394 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"),
395 },
396 },
397 { /* Handle problems with rebooting on Dell 1300's */
398 .callback = set_bios_reboot,
399 .ident = "Dell PowerEdge 1300",
400 .matches = {
401 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
402 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1300/"),
403 },
404 },
405 { /* Handle problems with rebooting on Dell 2400's */
406 .callback = set_bios_reboot,
407 .ident = "Dell PowerEdge 2400",
408 .matches = {
409 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
410 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"),
411 },
412 },
413 { /* Handle problems with rebooting on the Dell PowerEdge C6100. */
414 .callback = set_pci_reboot,
415 .ident = "Dell PowerEdge C6100",
416 .matches = {
417 DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
418 DMI_MATCH(DMI_PRODUCT_NAME, "C6100"),
419 },
420 },
421 { /* Handle problems with rebooting on the Precision M6600. */
422 .callback = set_pci_reboot,
423 .ident = "Dell Precision M6600",
424 .matches = {
425 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
426 DMI_MATCH(DMI_PRODUCT_NAME, "Precision M6600"),
427 },
428 },
429 { /* Handle problems with rebooting on Dell T5400's */
430 .callback = set_bios_reboot,
431 .ident = "Dell Precision T5400",
432 .matches = {
433 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
434 DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T5400"),
435 },
436 },
437 { /* Handle problems with rebooting on Dell T7400's */
438 .callback = set_bios_reboot,
439 .ident = "Dell Precision T7400",
440 .matches = {
441 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
442 DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T7400"),
443 },
444 },
445 { /* Handle problems with rebooting on Dell XPS710 */
446 .callback = set_bios_reboot,
447 .ident = "Dell XPS710",
448 .matches = {
449 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
450 DMI_MATCH(DMI_PRODUCT_NAME, "Dell XPS710"),
451 },
452 },
453 { /* Handle problems with rebooting on Dell Optiplex 7450 AIO */
454 .callback = set_acpi_reboot,
455 .ident = "Dell OptiPlex 7450 AIO",
456 .matches = {
457 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
458 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 7450 AIO"),
459 },
460 },
461
462 /* Hewlett-Packard */
463 { /* Handle problems with rebooting on HP laptops */
464 .callback = set_bios_reboot,
465 .ident = "HP Compaq Laptop",
466 .matches = {
467 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
468 DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"),
469 },
470 },
471
472 { /* PCIe Wifi card isn't detected after reboot otherwise */
473 .callback = set_pci_reboot,
474 .ident = "Zotac ZBOX CI327 nano",
475 .matches = {
476 DMI_MATCH(DMI_SYS_VENDOR, "NA"),
477 DMI_MATCH(DMI_PRODUCT_NAME, "ZBOX-CI327NANO-GS-01"),
478 },
479 },
480
481 /* Sony */
482 { /* Handle problems with rebooting on Sony VGN-Z540N */
483 .callback = set_bios_reboot,
484 .ident = "Sony VGN-Z540N",
485 .matches = {
486 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
487 DMI_MATCH(DMI_PRODUCT_NAME, "VGN-Z540N"),
488 },
489 },
490
491 { }
492};
493
494static int __init reboot_init(void)
495{
496 int rv;
497
498 /*
499 * Only do the DMI check if reboot_type hasn't been overridden
500 * on the command line
501 */
502 if (!reboot_default)
503 return 0;
504
505 /*
506 * The DMI quirks table takes precedence. If no quirks entry
507 * matches and the ACPI Hardware Reduced bit is set and EFI
508 * runtime services are enabled, force EFI reboot.
509 */
510 rv = dmi_check_system(reboot_dmi_table);
511
512 if (!rv && efi_reboot_required() && !efi_runtime_disabled())
513 reboot_type = BOOT_EFI;
514
515 return 0;
516}
517core_initcall(reboot_init);
518
519static inline void kb_wait(void)
520{
521 int i;
522
523 for (i = 0; i < 0x10000; i++) {
524 if ((inb(0x64) & 0x02) == 0)
525 break;
526 udelay(2);
527 }
528}
529
530static inline void nmi_shootdown_cpus_on_restart(void);
531
532#if IS_ENABLED(CONFIG_KVM_INTEL) || IS_ENABLED(CONFIG_KVM_AMD)
533/* RCU-protected callback to disable virtualization prior to reboot. */
534static cpu_emergency_virt_cb __rcu *cpu_emergency_virt_callback;
535
536void cpu_emergency_register_virt_callback(cpu_emergency_virt_cb *callback)
537{
538 if (WARN_ON_ONCE(rcu_access_pointer(cpu_emergency_virt_callback)))
539 return;
540
541 rcu_assign_pointer(cpu_emergency_virt_callback, callback);
542}
543EXPORT_SYMBOL_GPL(cpu_emergency_register_virt_callback);
544
545void cpu_emergency_unregister_virt_callback(cpu_emergency_virt_cb *callback)
546{
547 if (WARN_ON_ONCE(rcu_access_pointer(cpu_emergency_virt_callback) != callback))
548 return;
549
550 rcu_assign_pointer(cpu_emergency_virt_callback, NULL);
551 synchronize_rcu();
552}
553EXPORT_SYMBOL_GPL(cpu_emergency_unregister_virt_callback);
554
555/*
556 * Disable virtualization, i.e. VMX or SVM, to ensure INIT is recognized during
557 * reboot. VMX blocks INIT if the CPU is post-VMXON, and SVM blocks INIT if
558 * GIF=0, i.e. if the crash occurred between CLGI and STGI.
559 */
560void cpu_emergency_disable_virtualization(void)
561{
562 cpu_emergency_virt_cb *callback;
563
564 /*
565 * IRQs must be disabled as KVM enables virtualization in hardware via
566 * function call IPIs, i.e. IRQs need to be disabled to guarantee
567 * virtualization stays disabled.
568 */
569 lockdep_assert_irqs_disabled();
570
571 rcu_read_lock();
572 callback = rcu_dereference(cpu_emergency_virt_callback);
573 if (callback)
574 callback();
575 rcu_read_unlock();
576}
577
578static void emergency_reboot_disable_virtualization(void)
579{
580 local_irq_disable();
581
582 /*
583 * Disable virtualization on all CPUs before rebooting to avoid hanging
584 * the system, as VMX and SVM block INIT when running in the host.
585 *
586 * We can't take any locks and we may be on an inconsistent state, so
587 * use NMIs as IPIs to tell the other CPUs to disable VMX/SVM and halt.
588 *
589 * Do the NMI shootdown even if virtualization is off on _this_ CPU, as
590 * other CPUs may have virtualization enabled.
591 */
592 if (rcu_access_pointer(cpu_emergency_virt_callback)) {
593 /* Safely force _this_ CPU out of VMX/SVM operation. */
594 cpu_emergency_disable_virtualization();
595
596 /* Disable VMX/SVM and halt on other CPUs. */
597 nmi_shootdown_cpus_on_restart();
598 }
599}
600#else
601static void emergency_reboot_disable_virtualization(void) { }
602#endif /* CONFIG_KVM_INTEL || CONFIG_KVM_AMD */
603
604void __attribute__((weak)) mach_reboot_fixups(void)
605{
606}
607
608/*
609 * To the best of our knowledge Windows compatible x86 hardware expects
610 * the following on reboot:
611 *
612 * 1) If the FADT has the ACPI reboot register flag set, try it
613 * 2) If still alive, write to the keyboard controller
614 * 3) If still alive, write to the ACPI reboot register again
615 * 4) If still alive, write to the keyboard controller again
616 * 5) If still alive, call the EFI runtime service to reboot
617 * 6) If no EFI runtime service, call the BIOS to do a reboot
618 *
619 * We default to following the same pattern. We also have
620 * two other reboot methods: 'triple fault' and 'PCI', which
621 * can be triggered via the reboot= kernel boot option or
622 * via quirks.
623 *
624 * This means that this function can never return, it can misbehave
625 * by not rebooting properly and hanging.
626 */
627static void native_machine_emergency_restart(void)
628{
629 int i;
630 int attempt = 0;
631 int orig_reboot_type = reboot_type;
632 unsigned short mode;
633
634 if (reboot_emergency)
635 emergency_reboot_disable_virtualization();
636
637 tboot_shutdown(TB_SHUTDOWN_REBOOT);
638
639 /* Tell the BIOS if we want cold or warm reboot */
640 mode = reboot_mode == REBOOT_WARM ? 0x1234 : 0;
641 *((unsigned short *)__va(0x472)) = mode;
642
643 /*
644 * If an EFI capsule has been registered with the firmware then
645 * override the reboot= parameter.
646 */
647 if (efi_capsule_pending(NULL)) {
648 pr_info("EFI capsule is pending, forcing EFI reboot.\n");
649 reboot_type = BOOT_EFI;
650 }
651
652 for (;;) {
653 /* Could also try the reset bit in the Hammer NB */
654 switch (reboot_type) {
655 case BOOT_ACPI:
656 acpi_reboot();
657 reboot_type = BOOT_KBD;
658 break;
659
660 case BOOT_KBD:
661 mach_reboot_fixups(); /* For board specific fixups */
662
663 for (i = 0; i < 10; i++) {
664 kb_wait();
665 udelay(50);
666 outb(0xfe, 0x64); /* Pulse reset low */
667 udelay(50);
668 }
669 if (attempt == 0 && orig_reboot_type == BOOT_ACPI) {
670 attempt = 1;
671 reboot_type = BOOT_ACPI;
672 } else {
673 reboot_type = BOOT_EFI;
674 }
675 break;
676
677 case BOOT_EFI:
678 efi_reboot(reboot_mode, NULL);
679 reboot_type = BOOT_BIOS;
680 break;
681
682 case BOOT_BIOS:
683 machine_real_restart(MRR_BIOS);
684
685 /* We're probably dead after this, but... */
686 reboot_type = BOOT_CF9_SAFE;
687 break;
688
689 case BOOT_CF9_FORCE:
690 port_cf9_safe = true;
691 fallthrough;
692
693 case BOOT_CF9_SAFE:
694 if (port_cf9_safe) {
695 u8 reboot_code = reboot_mode == REBOOT_WARM ? 0x06 : 0x0E;
696 u8 cf9 = inb(0xcf9) & ~reboot_code;
697 outb(cf9|2, 0xcf9); /* Request hard reset */
698 udelay(50);
699 /* Actually do the reset */
700 outb(cf9|reboot_code, 0xcf9);
701 udelay(50);
702 }
703 reboot_type = BOOT_TRIPLE;
704 break;
705
706 case BOOT_TRIPLE:
707 idt_invalidate();
708 __asm__ __volatile__("int3");
709
710 /* We're probably dead after this, but... */
711 reboot_type = BOOT_KBD;
712 break;
713 }
714 }
715}
716
717void native_machine_shutdown(void)
718{
719 /* Stop the cpus and apics */
720#ifdef CONFIG_X86_IO_APIC
721 /*
722 * Disabling IO APIC before local APIC is a workaround for
723 * erratum AVR31 in "Intel Atom Processor C2000 Product Family
724 * Specification Update". In this situation, interrupts that target
725 * a Logical Processor whose Local APIC is either in the process of
726 * being hardware disabled or software disabled are neither delivered
727 * nor discarded. When this erratum occurs, the processor may hang.
728 *
729 * Even without the erratum, it still makes sense to quiet IO APIC
730 * before disabling Local APIC.
731 */
732 clear_IO_APIC();
733#endif
734
735#ifdef CONFIG_SMP
736 /*
737 * Stop all of the others. Also disable the local irq to
738 * not receive the per-cpu timer interrupt which may trigger
739 * scheduler's load balance.
740 */
741 local_irq_disable();
742 stop_other_cpus();
743#endif
744
745 lapic_shutdown();
746 restore_boot_irq_mode();
747
748#ifdef CONFIG_HPET_TIMER
749 hpet_disable();
750#endif
751
752#ifdef CONFIG_X86_64
753 x86_platform.iommu_shutdown();
754#endif
755}
756
757static void __machine_emergency_restart(int emergency)
758{
759 reboot_emergency = emergency;
760 machine_ops.emergency_restart();
761}
762
763static void native_machine_restart(char *__unused)
764{
765 pr_notice("machine restart\n");
766
767 if (!reboot_force)
768 machine_shutdown();
769 __machine_emergency_restart(0);
770}
771
772static void native_machine_halt(void)
773{
774 /* Stop other cpus and apics */
775 machine_shutdown();
776
777 tboot_shutdown(TB_SHUTDOWN_HALT);
778
779 stop_this_cpu(NULL);
780}
781
782static void native_machine_power_off(void)
783{
784 if (kernel_can_power_off()) {
785 if (!reboot_force)
786 machine_shutdown();
787 do_kernel_power_off();
788 }
789 /* A fallback in case there is no PM info available */
790 tboot_shutdown(TB_SHUTDOWN_HALT);
791}
792
793struct machine_ops machine_ops __ro_after_init = {
794 .power_off = native_machine_power_off,
795 .shutdown = native_machine_shutdown,
796 .emergency_restart = native_machine_emergency_restart,
797 .restart = native_machine_restart,
798 .halt = native_machine_halt,
799#ifdef CONFIG_KEXEC_CORE
800 .crash_shutdown = native_machine_crash_shutdown,
801#endif
802};
803
804void machine_power_off(void)
805{
806 machine_ops.power_off();
807}
808
809void machine_shutdown(void)
810{
811 machine_ops.shutdown();
812}
813
814void machine_emergency_restart(void)
815{
816 __machine_emergency_restart(1);
817}
818
819void machine_restart(char *cmd)
820{
821 machine_ops.restart(cmd);
822}
823
824void machine_halt(void)
825{
826 machine_ops.halt();
827}
828
829#ifdef CONFIG_KEXEC_CORE
830void machine_crash_shutdown(struct pt_regs *regs)
831{
832 machine_ops.crash_shutdown(regs);
833}
834#endif
835
836/* This is the CPU performing the emergency shutdown work. */
837int crashing_cpu = -1;
838
839#if defined(CONFIG_SMP)
840
841static nmi_shootdown_cb shootdown_callback;
842
843static atomic_t waiting_for_crash_ipi;
844static int crash_ipi_issued;
845
846static int crash_nmi_callback(unsigned int val, struct pt_regs *regs)
847{
848 int cpu;
849
850 cpu = raw_smp_processor_id();
851
852 /*
853 * Don't do anything if this handler is invoked on crashing cpu.
854 * Otherwise, system will completely hang. Crashing cpu can get
855 * an NMI if system was initially booted with nmi_watchdog parameter.
856 */
857 if (cpu == crashing_cpu)
858 return NMI_HANDLED;
859 local_irq_disable();
860
861 if (shootdown_callback)
862 shootdown_callback(cpu, regs);
863
864 /*
865 * Prepare the CPU for reboot _after_ invoking the callback so that the
866 * callback can safely use virtualization instructions, e.g. VMCLEAR.
867 */
868 cpu_emergency_disable_virtualization();
869
870 atomic_dec(&waiting_for_crash_ipi);
871 /* Assume hlt works */
872 halt();
873 for (;;)
874 cpu_relax();
875
876 return NMI_HANDLED;
877}
878
879/**
880 * nmi_shootdown_cpus - Stop other CPUs via NMI
881 * @callback: Optional callback to be invoked from the NMI handler
882 *
883 * The NMI handler on the remote CPUs invokes @callback, if not
884 * NULL, first and then disables virtualization to ensure that
885 * INIT is recognized during reboot.
886 *
887 * nmi_shootdown_cpus() can only be invoked once. After the first
888 * invocation all other CPUs are stuck in crash_nmi_callback() and
889 * cannot respond to a second NMI.
890 */
891void nmi_shootdown_cpus(nmi_shootdown_cb callback)
892{
893 unsigned long msecs;
894
895 local_irq_disable();
896
897 /*
898 * Avoid certain doom if a shootdown already occurred; re-registering
899 * the NMI handler will cause list corruption, modifying the callback
900 * will do who knows what, etc...
901 */
902 if (WARN_ON_ONCE(crash_ipi_issued))
903 return;
904
905 /* Make a note of crashing cpu. Will be used in NMI callback. */
906 crashing_cpu = safe_smp_processor_id();
907
908 shootdown_callback = callback;
909
910 atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
911 /* Would it be better to replace the trap vector here? */
912 if (register_nmi_handler(NMI_LOCAL, crash_nmi_callback,
913 NMI_FLAG_FIRST, "crash"))
914 return; /* Return what? */
915 /*
916 * Ensure the new callback function is set before sending
917 * out the NMI
918 */
919 wmb();
920
921 apic_send_IPI_allbutself(NMI_VECTOR);
922
923 /* Kick CPUs looping in NMI context. */
924 WRITE_ONCE(crash_ipi_issued, 1);
925
926 msecs = 1000; /* Wait at most a second for the other cpus to stop */
927 while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
928 mdelay(1);
929 msecs--;
930 }
931
932 /*
933 * Leave the nmi callback set, shootdown is a one-time thing. Clearing
934 * the callback could result in a NULL pointer dereference if a CPU
935 * (finally) responds after the timeout expires.
936 */
937}
938
939static inline void nmi_shootdown_cpus_on_restart(void)
940{
941 if (!crash_ipi_issued)
942 nmi_shootdown_cpus(NULL);
943}
944
945/*
946 * Check if the crash dumping IPI got issued and if so, call its callback
947 * directly. This function is used when we have already been in NMI handler.
948 * It doesn't return.
949 */
950void run_crash_ipi_callback(struct pt_regs *regs)
951{
952 if (crash_ipi_issued)
953 crash_nmi_callback(0, regs);
954}
955
956/* Override the weak function in kernel/panic.c */
957void __noreturn nmi_panic_self_stop(struct pt_regs *regs)
958{
959 while (1) {
960 /* If no CPU is preparing crash dump, we simply loop here. */
961 run_crash_ipi_callback(regs);
962 cpu_relax();
963 }
964}
965
966#else /* !CONFIG_SMP */
967void nmi_shootdown_cpus(nmi_shootdown_cb callback)
968{
969 /* No other CPUs to shoot down */
970}
971
972static inline void nmi_shootdown_cpus_on_restart(void) { }
973
974void run_crash_ipi_callback(struct pt_regs *regs)
975{
976}
977#endif
1#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
2
3#include <linux/export.h>
4#include <linux/reboot.h>
5#include <linux/init.h>
6#include <linux/pm.h>
7#include <linux/efi.h>
8#include <linux/dmi.h>
9#include <linux/sched.h>
10#include <linux/tboot.h>
11#include <linux/delay.h>
12#include <acpi/reboot.h>
13#include <asm/io.h>
14#include <asm/apic.h>
15#include <asm/io_apic.h>
16#include <asm/desc.h>
17#include <asm/hpet.h>
18#include <asm/pgtable.h>
19#include <asm/proto.h>
20#include <asm/reboot_fixups.h>
21#include <asm/reboot.h>
22#include <asm/pci_x86.h>
23#include <asm/virtext.h>
24#include <asm/cpu.h>
25#include <asm/nmi.h>
26#include <asm/smp.h>
27
28#include <linux/ctype.h>
29#include <linux/mc146818rtc.h>
30#include <asm/realmode.h>
31#include <asm/x86_init.h>
32#include <asm/efi.h>
33
34/*
35 * Power off function, if any
36 */
37void (*pm_power_off)(void);
38EXPORT_SYMBOL(pm_power_off);
39
40static const struct desc_ptr no_idt = {};
41
42/*
43 * This is set if we need to go through the 'emergency' path.
44 * When machine_emergency_restart() is called, we may be on
45 * an inconsistent state and won't be able to do a clean cleanup
46 */
47static int reboot_emergency;
48
49/* This is set by the PCI code if either type 1 or type 2 PCI is detected */
50bool port_cf9_safe = false;
51
52/*
53 * Reboot options and system auto-detection code provided by
54 * Dell Inc. so their systems "just work". :-)
55 */
56
57/*
58 * Some machines require the "reboot=a" commandline options
59 */
60static int __init set_acpi_reboot(const struct dmi_system_id *d)
61{
62 if (reboot_type != BOOT_ACPI) {
63 reboot_type = BOOT_ACPI;
64 pr_info("%s series board detected. Selecting %s-method for reboots.\n",
65 d->ident, "ACPI");
66 }
67 return 0;
68}
69
70/*
71 * Some machines require the "reboot=b" or "reboot=k" commandline options,
72 * this quirk makes that automatic.
73 */
74static int __init set_bios_reboot(const struct dmi_system_id *d)
75{
76 if (reboot_type != BOOT_BIOS) {
77 reboot_type = BOOT_BIOS;
78 pr_info("%s series board detected. Selecting %s-method for reboots.\n",
79 d->ident, "BIOS");
80 }
81 return 0;
82}
83
84void __noreturn machine_real_restart(unsigned int type)
85{
86 local_irq_disable();
87
88 /*
89 * Write zero to CMOS register number 0x0f, which the BIOS POST
90 * routine will recognize as telling it to do a proper reboot. (Well
91 * that's what this book in front of me says -- it may only apply to
92 * the Phoenix BIOS though, it's not clear). At the same time,
93 * disable NMIs by setting the top bit in the CMOS address register,
94 * as we're about to do peculiar things to the CPU. I'm not sure if
95 * `outb_p' is needed instead of just `outb'. Use it to be on the
96 * safe side. (Yes, CMOS_WRITE does outb_p's. - Paul G.)
97 */
98 spin_lock(&rtc_lock);
99 CMOS_WRITE(0x00, 0x8f);
100 spin_unlock(&rtc_lock);
101
102 /*
103 * Switch back to the initial page table.
104 */
105#ifdef CONFIG_X86_32
106 load_cr3(initial_page_table);
107#else
108 write_cr3(real_mode_header->trampoline_pgd);
109#endif
110
111 /* Jump to the identity-mapped low memory code */
112#ifdef CONFIG_X86_32
113 asm volatile("jmpl *%0" : :
114 "rm" (real_mode_header->machine_real_restart_asm),
115 "a" (type));
116#else
117 asm volatile("ljmpl *%0" : :
118 "m" (real_mode_header->machine_real_restart_asm),
119 "D" (type));
120#endif
121 unreachable();
122}
123#ifdef CONFIG_APM_MODULE
124EXPORT_SYMBOL(machine_real_restart);
125#endif
126
127/*
128 * Some Apple MacBook and MacBookPro's needs reboot=p to be able to reboot
129 */
130static int __init set_pci_reboot(const struct dmi_system_id *d)
131{
132 if (reboot_type != BOOT_CF9_FORCE) {
133 reboot_type = BOOT_CF9_FORCE;
134 pr_info("%s series board detected. Selecting %s-method for reboots.\n",
135 d->ident, "PCI");
136 }
137 return 0;
138}
139
140static int __init set_kbd_reboot(const struct dmi_system_id *d)
141{
142 if (reboot_type != BOOT_KBD) {
143 reboot_type = BOOT_KBD;
144 pr_info("%s series board detected. Selecting %s-method for reboot.\n",
145 d->ident, "KBD");
146 }
147 return 0;
148}
149
150/*
151 * This is a single dmi_table handling all reboot quirks.
152 */
153static struct dmi_system_id __initdata reboot_dmi_table[] = {
154
155 /* Acer */
156 { /* Handle reboot issue on Acer Aspire one */
157 .callback = set_kbd_reboot,
158 .ident = "Acer Aspire One A110",
159 .matches = {
160 DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
161 DMI_MATCH(DMI_PRODUCT_NAME, "AOA110"),
162 },
163 },
164
165 /* Apple */
166 { /* Handle problems with rebooting on Apple MacBook5 */
167 .callback = set_pci_reboot,
168 .ident = "Apple MacBook5",
169 .matches = {
170 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
171 DMI_MATCH(DMI_PRODUCT_NAME, "MacBook5"),
172 },
173 },
174 { /* Handle problems with rebooting on Apple MacBookPro5 */
175 .callback = set_pci_reboot,
176 .ident = "Apple MacBookPro5",
177 .matches = {
178 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
179 DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro5"),
180 },
181 },
182 { /* Handle problems with rebooting on Apple Macmini3,1 */
183 .callback = set_pci_reboot,
184 .ident = "Apple Macmini3,1",
185 .matches = {
186 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
187 DMI_MATCH(DMI_PRODUCT_NAME, "Macmini3,1"),
188 },
189 },
190 { /* Handle problems with rebooting on the iMac9,1. */
191 .callback = set_pci_reboot,
192 .ident = "Apple iMac9,1",
193 .matches = {
194 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
195 DMI_MATCH(DMI_PRODUCT_NAME, "iMac9,1"),
196 },
197 },
198 { /* Handle problems with rebooting on the iMac10,1. */
199 .callback = set_pci_reboot,
200 .ident = "Apple iMac10,1",
201 .matches = {
202 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
203 DMI_MATCH(DMI_PRODUCT_NAME, "iMac10,1"),
204 },
205 },
206
207 /* ASRock */
208 { /* Handle problems with rebooting on ASRock Q1900DC-ITX */
209 .callback = set_pci_reboot,
210 .ident = "ASRock Q1900DC-ITX",
211 .matches = {
212 DMI_MATCH(DMI_BOARD_VENDOR, "ASRock"),
213 DMI_MATCH(DMI_BOARD_NAME, "Q1900DC-ITX"),
214 },
215 },
216
217 /* ASUS */
218 { /* Handle problems with rebooting on ASUS P4S800 */
219 .callback = set_bios_reboot,
220 .ident = "ASUS P4S800",
221 .matches = {
222 DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
223 DMI_MATCH(DMI_BOARD_NAME, "P4S800"),
224 },
225 },
226 { /* Handle problems with rebooting on ASUS EeeBook X205TA */
227 .callback = set_acpi_reboot,
228 .ident = "ASUS EeeBook X205TA",
229 .matches = {
230 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
231 DMI_MATCH(DMI_PRODUCT_NAME, "X205TA"),
232 },
233 },
234 { /* Handle problems with rebooting on ASUS EeeBook X205TAW */
235 .callback = set_acpi_reboot,
236 .ident = "ASUS EeeBook X205TAW",
237 .matches = {
238 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
239 DMI_MATCH(DMI_PRODUCT_NAME, "X205TAW"),
240 },
241 },
242
243 /* Certec */
244 { /* Handle problems with rebooting on Certec BPC600 */
245 .callback = set_pci_reboot,
246 .ident = "Certec BPC600",
247 .matches = {
248 DMI_MATCH(DMI_SYS_VENDOR, "Certec"),
249 DMI_MATCH(DMI_PRODUCT_NAME, "BPC600"),
250 },
251 },
252
253 /* Dell */
254 { /* Handle problems with rebooting on Dell DXP061 */
255 .callback = set_bios_reboot,
256 .ident = "Dell DXP061",
257 .matches = {
258 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
259 DMI_MATCH(DMI_PRODUCT_NAME, "Dell DXP061"),
260 },
261 },
262 { /* Handle problems with rebooting on Dell E520's */
263 .callback = set_bios_reboot,
264 .ident = "Dell E520",
265 .matches = {
266 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
267 DMI_MATCH(DMI_PRODUCT_NAME, "Dell DM061"),
268 },
269 },
270 { /* Handle problems with rebooting on the Latitude E5410. */
271 .callback = set_pci_reboot,
272 .ident = "Dell Latitude E5410",
273 .matches = {
274 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
275 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E5410"),
276 },
277 },
278 { /* Handle problems with rebooting on the Latitude E5420. */
279 .callback = set_pci_reboot,
280 .ident = "Dell Latitude E5420",
281 .matches = {
282 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
283 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E5420"),
284 },
285 },
286 { /* Handle problems with rebooting on the Latitude E6320. */
287 .callback = set_pci_reboot,
288 .ident = "Dell Latitude E6320",
289 .matches = {
290 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
291 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6320"),
292 },
293 },
294 { /* Handle problems with rebooting on the Latitude E6420. */
295 .callback = set_pci_reboot,
296 .ident = "Dell Latitude E6420",
297 .matches = {
298 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
299 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6420"),
300 },
301 },
302 { /* Handle problems with rebooting on Dell Optiplex 330 with 0KP561 */
303 .callback = set_bios_reboot,
304 .ident = "Dell OptiPlex 330",
305 .matches = {
306 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
307 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 330"),
308 DMI_MATCH(DMI_BOARD_NAME, "0KP561"),
309 },
310 },
311 { /* Handle problems with rebooting on Dell Optiplex 360 with 0T656F */
312 .callback = set_bios_reboot,
313 .ident = "Dell OptiPlex 360",
314 .matches = {
315 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
316 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 360"),
317 DMI_MATCH(DMI_BOARD_NAME, "0T656F"),
318 },
319 },
320 { /* Handle problems with rebooting on Dell Optiplex 745's SFF */
321 .callback = set_bios_reboot,
322 .ident = "Dell OptiPlex 745",
323 .matches = {
324 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
325 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
326 },
327 },
328 { /* Handle problems with rebooting on Dell Optiplex 745's DFF */
329 .callback = set_bios_reboot,
330 .ident = "Dell OptiPlex 745",
331 .matches = {
332 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
333 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
334 DMI_MATCH(DMI_BOARD_NAME, "0MM599"),
335 },
336 },
337 { /* Handle problems with rebooting on Dell Optiplex 745 with 0KW626 */
338 .callback = set_bios_reboot,
339 .ident = "Dell OptiPlex 745",
340 .matches = {
341 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
342 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
343 DMI_MATCH(DMI_BOARD_NAME, "0KW626"),
344 },
345 },
346 { /* Handle problems with rebooting on Dell OptiPlex 760 with 0G919G */
347 .callback = set_bios_reboot,
348 .ident = "Dell OptiPlex 760",
349 .matches = {
350 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
351 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 760"),
352 DMI_MATCH(DMI_BOARD_NAME, "0G919G"),
353 },
354 },
355 { /* Handle problems with rebooting on the OptiPlex 990. */
356 .callback = set_pci_reboot,
357 .ident = "Dell OptiPlex 990",
358 .matches = {
359 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
360 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 990"),
361 },
362 },
363 { /* Handle problems with rebooting on Dell 300's */
364 .callback = set_bios_reboot,
365 .ident = "Dell PowerEdge 300",
366 .matches = {
367 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
368 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"),
369 },
370 },
371 { /* Handle problems with rebooting on Dell 1300's */
372 .callback = set_bios_reboot,
373 .ident = "Dell PowerEdge 1300",
374 .matches = {
375 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
376 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1300/"),
377 },
378 },
379 { /* Handle problems with rebooting on Dell 2400's */
380 .callback = set_bios_reboot,
381 .ident = "Dell PowerEdge 2400",
382 .matches = {
383 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
384 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"),
385 },
386 },
387 { /* Handle problems with rebooting on the Dell PowerEdge C6100. */
388 .callback = set_pci_reboot,
389 .ident = "Dell PowerEdge C6100",
390 .matches = {
391 DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
392 DMI_MATCH(DMI_PRODUCT_NAME, "C6100"),
393 },
394 },
395 { /* Handle problems with rebooting on the Precision M6600. */
396 .callback = set_pci_reboot,
397 .ident = "Dell Precision M6600",
398 .matches = {
399 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
400 DMI_MATCH(DMI_PRODUCT_NAME, "Precision M6600"),
401 },
402 },
403 { /* Handle problems with rebooting on Dell T5400's */
404 .callback = set_bios_reboot,
405 .ident = "Dell Precision T5400",
406 .matches = {
407 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
408 DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T5400"),
409 },
410 },
411 { /* Handle problems with rebooting on Dell T7400's */
412 .callback = set_bios_reboot,
413 .ident = "Dell Precision T7400",
414 .matches = {
415 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
416 DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T7400"),
417 },
418 },
419 { /* Handle problems with rebooting on Dell XPS710 */
420 .callback = set_bios_reboot,
421 .ident = "Dell XPS710",
422 .matches = {
423 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
424 DMI_MATCH(DMI_PRODUCT_NAME, "Dell XPS710"),
425 },
426 },
427 { /* Handle problems with rebooting on Dell Optiplex 7450 AIO */
428 .callback = set_acpi_reboot,
429 .ident = "Dell OptiPlex 7450 AIO",
430 .matches = {
431 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
432 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 7450 AIO"),
433 },
434 },
435
436 /* Hewlett-Packard */
437 { /* Handle problems with rebooting on HP laptops */
438 .callback = set_bios_reboot,
439 .ident = "HP Compaq Laptop",
440 .matches = {
441 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
442 DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"),
443 },
444 },
445
446 /* Sony */
447 { /* Handle problems with rebooting on Sony VGN-Z540N */
448 .callback = set_bios_reboot,
449 .ident = "Sony VGN-Z540N",
450 .matches = {
451 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
452 DMI_MATCH(DMI_PRODUCT_NAME, "VGN-Z540N"),
453 },
454 },
455
456 { }
457};
458
459static int __init reboot_init(void)
460{
461 int rv;
462
463 /*
464 * Only do the DMI check if reboot_type hasn't been overridden
465 * on the command line
466 */
467 if (!reboot_default)
468 return 0;
469
470 /*
471 * The DMI quirks table takes precedence. If no quirks entry
472 * matches and the ACPI Hardware Reduced bit is set, force EFI
473 * reboot.
474 */
475 rv = dmi_check_system(reboot_dmi_table);
476
477 if (!rv && efi_reboot_required())
478 reboot_type = BOOT_EFI;
479
480 return 0;
481}
482core_initcall(reboot_init);
483
484static inline void kb_wait(void)
485{
486 int i;
487
488 for (i = 0; i < 0x10000; i++) {
489 if ((inb(0x64) & 0x02) == 0)
490 break;
491 udelay(2);
492 }
493}
494
495static void vmxoff_nmi(int cpu, struct pt_regs *regs)
496{
497 cpu_emergency_vmxoff();
498}
499
500/* Use NMIs as IPIs to tell all CPUs to disable virtualization */
501static void emergency_vmx_disable_all(void)
502{
503 /* Just make sure we won't change CPUs while doing this */
504 local_irq_disable();
505
506 /*
507 * We need to disable VMX on all CPUs before rebooting, otherwise
508 * we risk hanging up the machine, because the CPU ignore INIT
509 * signals when VMX is enabled.
510 *
511 * We can't take any locks and we may be on an inconsistent
512 * state, so we use NMIs as IPIs to tell the other CPUs to disable
513 * VMX and halt.
514 *
515 * For safety, we will avoid running the nmi_shootdown_cpus()
516 * stuff unnecessarily, but we don't have a way to check
517 * if other CPUs have VMX enabled. So we will call it only if the
518 * CPU we are running on has VMX enabled.
519 *
520 * We will miss cases where VMX is not enabled on all CPUs. This
521 * shouldn't do much harm because KVM always enable VMX on all
522 * CPUs anyway. But we can miss it on the small window where KVM
523 * is still enabling VMX.
524 */
525 if (cpu_has_vmx() && cpu_vmx_enabled()) {
526 /* Disable VMX on this CPU. */
527 cpu_vmxoff();
528
529 /* Halt and disable VMX on the other CPUs */
530 nmi_shootdown_cpus(vmxoff_nmi);
531
532 }
533}
534
535
536void __attribute__((weak)) mach_reboot_fixups(void)
537{
538}
539
540/*
541 * To the best of our knowledge Windows compatible x86 hardware expects
542 * the following on reboot:
543 *
544 * 1) If the FADT has the ACPI reboot register flag set, try it
545 * 2) If still alive, write to the keyboard controller
546 * 3) If still alive, write to the ACPI reboot register again
547 * 4) If still alive, write to the keyboard controller again
548 * 5) If still alive, call the EFI runtime service to reboot
549 * 6) If no EFI runtime service, call the BIOS to do a reboot
550 *
551 * We default to following the same pattern. We also have
552 * two other reboot methods: 'triple fault' and 'PCI', which
553 * can be triggered via the reboot= kernel boot option or
554 * via quirks.
555 *
556 * This means that this function can never return, it can misbehave
557 * by not rebooting properly and hanging.
558 */
559static void native_machine_emergency_restart(void)
560{
561 int i;
562 int attempt = 0;
563 int orig_reboot_type = reboot_type;
564 unsigned short mode;
565
566 if (reboot_emergency)
567 emergency_vmx_disable_all();
568
569 tboot_shutdown(TB_SHUTDOWN_REBOOT);
570
571 /* Tell the BIOS if we want cold or warm reboot */
572 mode = reboot_mode == REBOOT_WARM ? 0x1234 : 0;
573 *((unsigned short *)__va(0x472)) = mode;
574
575 /*
576 * If an EFI capsule has been registered with the firmware then
577 * override the reboot= parameter.
578 */
579 if (efi_capsule_pending(NULL)) {
580 pr_info("EFI capsule is pending, forcing EFI reboot.\n");
581 reboot_type = BOOT_EFI;
582 }
583
584 for (;;) {
585 /* Could also try the reset bit in the Hammer NB */
586 switch (reboot_type) {
587 case BOOT_ACPI:
588 acpi_reboot();
589 reboot_type = BOOT_KBD;
590 break;
591
592 case BOOT_KBD:
593 mach_reboot_fixups(); /* For board specific fixups */
594
595 for (i = 0; i < 10; i++) {
596 kb_wait();
597 udelay(50);
598 outb(0xfe, 0x64); /* Pulse reset low */
599 udelay(50);
600 }
601 if (attempt == 0 && orig_reboot_type == BOOT_ACPI) {
602 attempt = 1;
603 reboot_type = BOOT_ACPI;
604 } else {
605 reboot_type = BOOT_EFI;
606 }
607 break;
608
609 case BOOT_EFI:
610 efi_reboot(reboot_mode, NULL);
611 reboot_type = BOOT_BIOS;
612 break;
613
614 case BOOT_BIOS:
615 machine_real_restart(MRR_BIOS);
616
617 /* We're probably dead after this, but... */
618 reboot_type = BOOT_CF9_SAFE;
619 break;
620
621 case BOOT_CF9_FORCE:
622 port_cf9_safe = true;
623 /* Fall through */
624
625 case BOOT_CF9_SAFE:
626 if (port_cf9_safe) {
627 u8 reboot_code = reboot_mode == REBOOT_WARM ? 0x06 : 0x0E;
628 u8 cf9 = inb(0xcf9) & ~reboot_code;
629 outb(cf9|2, 0xcf9); /* Request hard reset */
630 udelay(50);
631 /* Actually do the reset */
632 outb(cf9|reboot_code, 0xcf9);
633 udelay(50);
634 }
635 reboot_type = BOOT_TRIPLE;
636 break;
637
638 case BOOT_TRIPLE:
639 load_idt(&no_idt);
640 __asm__ __volatile__("int3");
641
642 /* We're probably dead after this, but... */
643 reboot_type = BOOT_KBD;
644 break;
645 }
646 }
647}
648
649void native_machine_shutdown(void)
650{
651 /* Stop the cpus and apics */
652#ifdef CONFIG_X86_IO_APIC
653 /*
654 * Disabling IO APIC before local APIC is a workaround for
655 * erratum AVR31 in "Intel Atom Processor C2000 Product Family
656 * Specification Update". In this situation, interrupts that target
657 * a Logical Processor whose Local APIC is either in the process of
658 * being hardware disabled or software disabled are neither delivered
659 * nor discarded. When this erratum occurs, the processor may hang.
660 *
661 * Even without the erratum, it still makes sense to quiet IO APIC
662 * before disabling Local APIC.
663 */
664 disable_IO_APIC();
665#endif
666
667#ifdef CONFIG_SMP
668 /*
669 * Stop all of the others. Also disable the local irq to
670 * not receive the per-cpu timer interrupt which may trigger
671 * scheduler's load balance.
672 */
673 local_irq_disable();
674 stop_other_cpus();
675#endif
676
677 lapic_shutdown();
678
679#ifdef CONFIG_HPET_TIMER
680 hpet_disable();
681#endif
682
683#ifdef CONFIG_X86_64
684 x86_platform.iommu_shutdown();
685#endif
686}
687
688static void __machine_emergency_restart(int emergency)
689{
690 reboot_emergency = emergency;
691 machine_ops.emergency_restart();
692}
693
694static void native_machine_restart(char *__unused)
695{
696 pr_notice("machine restart\n");
697
698 if (!reboot_force)
699 machine_shutdown();
700 __machine_emergency_restart(0);
701}
702
703static void native_machine_halt(void)
704{
705 /* Stop other cpus and apics */
706 machine_shutdown();
707
708 tboot_shutdown(TB_SHUTDOWN_HALT);
709
710 stop_this_cpu(NULL);
711}
712
713static void native_machine_power_off(void)
714{
715 if (pm_power_off) {
716 if (!reboot_force)
717 machine_shutdown();
718 pm_power_off();
719 }
720 /* A fallback in case there is no PM info available */
721 tboot_shutdown(TB_SHUTDOWN_HALT);
722}
723
724struct machine_ops machine_ops __ro_after_init = {
725 .power_off = native_machine_power_off,
726 .shutdown = native_machine_shutdown,
727 .emergency_restart = native_machine_emergency_restart,
728 .restart = native_machine_restart,
729 .halt = native_machine_halt,
730#ifdef CONFIG_KEXEC_CORE
731 .crash_shutdown = native_machine_crash_shutdown,
732#endif
733};
734
735void machine_power_off(void)
736{
737 machine_ops.power_off();
738}
739
740void machine_shutdown(void)
741{
742 machine_ops.shutdown();
743}
744
745void machine_emergency_restart(void)
746{
747 __machine_emergency_restart(1);
748}
749
750void machine_restart(char *cmd)
751{
752 machine_ops.restart(cmd);
753}
754
755void machine_halt(void)
756{
757 machine_ops.halt();
758}
759
760#ifdef CONFIG_KEXEC_CORE
761void machine_crash_shutdown(struct pt_regs *regs)
762{
763 machine_ops.crash_shutdown(regs);
764}
765#endif
766
767
768#if defined(CONFIG_SMP)
769
770/* This keeps a track of which one is crashing cpu. */
771static int crashing_cpu;
772static nmi_shootdown_cb shootdown_callback;
773
774static atomic_t waiting_for_crash_ipi;
775static int crash_ipi_issued;
776
777static int crash_nmi_callback(unsigned int val, struct pt_regs *regs)
778{
779 int cpu;
780
781 cpu = raw_smp_processor_id();
782
783 /*
784 * Don't do anything if this handler is invoked on crashing cpu.
785 * Otherwise, system will completely hang. Crashing cpu can get
786 * an NMI if system was initially booted with nmi_watchdog parameter.
787 */
788 if (cpu == crashing_cpu)
789 return NMI_HANDLED;
790 local_irq_disable();
791
792 shootdown_callback(cpu, regs);
793
794 atomic_dec(&waiting_for_crash_ipi);
795 /* Assume hlt works */
796 halt();
797 for (;;)
798 cpu_relax();
799
800 return NMI_HANDLED;
801}
802
803static void smp_send_nmi_allbutself(void)
804{
805 apic->send_IPI_allbutself(NMI_VECTOR);
806}
807
808/*
809 * Halt all other CPUs, calling the specified function on each of them
810 *
811 * This function can be used to halt all other CPUs on crash
812 * or emergency reboot time. The function passed as parameter
813 * will be called inside a NMI handler on all CPUs.
814 */
815void nmi_shootdown_cpus(nmi_shootdown_cb callback)
816{
817 unsigned long msecs;
818 local_irq_disable();
819
820 /* Make a note of crashing cpu. Will be used in NMI callback. */
821 crashing_cpu = safe_smp_processor_id();
822
823 shootdown_callback = callback;
824
825 atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
826 /* Would it be better to replace the trap vector here? */
827 if (register_nmi_handler(NMI_LOCAL, crash_nmi_callback,
828 NMI_FLAG_FIRST, "crash"))
829 return; /* Return what? */
830 /*
831 * Ensure the new callback function is set before sending
832 * out the NMI
833 */
834 wmb();
835
836 smp_send_nmi_allbutself();
837
838 /* Kick CPUs looping in NMI context. */
839 WRITE_ONCE(crash_ipi_issued, 1);
840
841 msecs = 1000; /* Wait at most a second for the other cpus to stop */
842 while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
843 mdelay(1);
844 msecs--;
845 }
846
847 /* Leave the nmi callback set */
848}
849
850/*
851 * Check if the crash dumping IPI got issued and if so, call its callback
852 * directly. This function is used when we have already been in NMI handler.
853 * It doesn't return.
854 */
855void run_crash_ipi_callback(struct pt_regs *regs)
856{
857 if (crash_ipi_issued)
858 crash_nmi_callback(0, regs);
859}
860
861/* Override the weak function in kernel/panic.c */
862void nmi_panic_self_stop(struct pt_regs *regs)
863{
864 while (1) {
865 /* If no CPU is preparing crash dump, we simply loop here. */
866 run_crash_ipi_callback(regs);
867 cpu_relax();
868 }
869}
870
871#else /* !CONFIG_SMP */
872void nmi_shootdown_cpus(nmi_shootdown_cb callback)
873{
874 /* No other CPUs to shoot down */
875}
876
877void run_crash_ipi_callback(struct pt_regs *regs)
878{
879}
880#endif