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1#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
2
3#include <linux/module.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/desc.h>
16#include <asm/hpet.h>
17#include <asm/pgtable.h>
18#include <asm/proto.h>
19#include <asm/reboot_fixups.h>
20#include <asm/reboot.h>
21#include <asm/pci_x86.h>
22#include <asm/virtext.h>
23#include <asm/cpu.h>
24#include <asm/nmi.h>
25#include <asm/smp.h>
26
27#include <linux/ctype.h>
28#include <linux/mc146818rtc.h>
29#include <asm/realmode.h>
30#include <asm/x86_init.h>
31
32/*
33 * Power off function, if any
34 */
35void (*pm_power_off)(void);
36EXPORT_SYMBOL(pm_power_off);
37
38static const struct desc_ptr no_idt = {};
39
40/*
41 * This is set if we need to go through the 'emergency' path.
42 * When machine_emergency_restart() is called, we may be on
43 * an inconsistent state and won't be able to do a clean cleanup
44 */
45static int reboot_emergency;
46
47/* This is set by the PCI code if either type 1 or type 2 PCI is detected */
48bool port_cf9_safe = false;
49
50/*
51 * Reboot options and system auto-detection code provided by
52 * Dell Inc. so their systems "just work". :-)
53 */
54
55/*
56 * Some machines require the "reboot=b" or "reboot=k" commandline options,
57 * this quirk makes that automatic.
58 */
59static int __init set_bios_reboot(const struct dmi_system_id *d)
60{
61 if (reboot_type != BOOT_BIOS) {
62 reboot_type = BOOT_BIOS;
63 pr_info("%s series board detected. Selecting %s-method for reboots.\n",
64 d->ident, "BIOS");
65 }
66 return 0;
67}
68
69void __noreturn machine_real_restart(unsigned int type)
70{
71 local_irq_disable();
72
73 /*
74 * Write zero to CMOS register number 0x0f, which the BIOS POST
75 * routine will recognize as telling it to do a proper reboot. (Well
76 * that's what this book in front of me says -- it may only apply to
77 * the Phoenix BIOS though, it's not clear). At the same time,
78 * disable NMIs by setting the top bit in the CMOS address register,
79 * as we're about to do peculiar things to the CPU. I'm not sure if
80 * `outb_p' is needed instead of just `outb'. Use it to be on the
81 * safe side. (Yes, CMOS_WRITE does outb_p's. - Paul G.)
82 */
83 spin_lock(&rtc_lock);
84 CMOS_WRITE(0x00, 0x8f);
85 spin_unlock(&rtc_lock);
86
87 /*
88 * Switch back to the initial page table.
89 */
90#ifdef CONFIG_X86_32
91 load_cr3(initial_page_table);
92#else
93 write_cr3(real_mode_header->trampoline_pgd);
94#endif
95
96 /* Jump to the identity-mapped low memory code */
97#ifdef CONFIG_X86_32
98 asm volatile("jmpl *%0" : :
99 "rm" (real_mode_header->machine_real_restart_asm),
100 "a" (type));
101#else
102 asm volatile("ljmpl *%0" : :
103 "m" (real_mode_header->machine_real_restart_asm),
104 "D" (type));
105#endif
106 unreachable();
107}
108#ifdef CONFIG_APM_MODULE
109EXPORT_SYMBOL(machine_real_restart);
110#endif
111
112/*
113 * Some Apple MacBook and MacBookPro's needs reboot=p to be able to reboot
114 */
115static int __init set_pci_reboot(const struct dmi_system_id *d)
116{
117 if (reboot_type != BOOT_CF9_FORCE) {
118 reboot_type = BOOT_CF9_FORCE;
119 pr_info("%s series board detected. Selecting %s-method for reboots.\n",
120 d->ident, "PCI");
121 }
122 return 0;
123}
124
125static int __init set_kbd_reboot(const struct dmi_system_id *d)
126{
127 if (reboot_type != BOOT_KBD) {
128 reboot_type = BOOT_KBD;
129 pr_info("%s series board detected. Selecting %s-method for reboot.\n",
130 d->ident, "KBD");
131 }
132 return 0;
133}
134
135/*
136 * This is a single dmi_table handling all reboot quirks.
137 */
138static struct dmi_system_id __initdata reboot_dmi_table[] = {
139
140 /* Acer */
141 { /* Handle reboot issue on Acer Aspire one */
142 .callback = set_kbd_reboot,
143 .ident = "Acer Aspire One A110",
144 .matches = {
145 DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
146 DMI_MATCH(DMI_PRODUCT_NAME, "AOA110"),
147 },
148 },
149
150 /* Apple */
151 { /* Handle problems with rebooting on Apple MacBook5 */
152 .callback = set_pci_reboot,
153 .ident = "Apple MacBook5",
154 .matches = {
155 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
156 DMI_MATCH(DMI_PRODUCT_NAME, "MacBook5"),
157 },
158 },
159 { /* Handle problems with rebooting on Apple MacBookPro5 */
160 .callback = set_pci_reboot,
161 .ident = "Apple MacBookPro5",
162 .matches = {
163 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
164 DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro5"),
165 },
166 },
167 { /* Handle problems with rebooting on Apple Macmini3,1 */
168 .callback = set_pci_reboot,
169 .ident = "Apple Macmini3,1",
170 .matches = {
171 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
172 DMI_MATCH(DMI_PRODUCT_NAME, "Macmini3,1"),
173 },
174 },
175 { /* Handle problems with rebooting on the iMac9,1. */
176 .callback = set_pci_reboot,
177 .ident = "Apple iMac9,1",
178 .matches = {
179 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
180 DMI_MATCH(DMI_PRODUCT_NAME, "iMac9,1"),
181 },
182 },
183
184 /* ASUS */
185 { /* Handle problems with rebooting on ASUS P4S800 */
186 .callback = set_bios_reboot,
187 .ident = "ASUS P4S800",
188 .matches = {
189 DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
190 DMI_MATCH(DMI_BOARD_NAME, "P4S800"),
191 },
192 },
193
194 /* Certec */
195 { /* Handle problems with rebooting on Certec BPC600 */
196 .callback = set_pci_reboot,
197 .ident = "Certec BPC600",
198 .matches = {
199 DMI_MATCH(DMI_SYS_VENDOR, "Certec"),
200 DMI_MATCH(DMI_PRODUCT_NAME, "BPC600"),
201 },
202 },
203
204 /* Dell */
205 { /* Handle problems with rebooting on Dell DXP061 */
206 .callback = set_bios_reboot,
207 .ident = "Dell DXP061",
208 .matches = {
209 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
210 DMI_MATCH(DMI_PRODUCT_NAME, "Dell DXP061"),
211 },
212 },
213 { /* Handle problems with rebooting on Dell E520's */
214 .callback = set_bios_reboot,
215 .ident = "Dell E520",
216 .matches = {
217 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
218 DMI_MATCH(DMI_PRODUCT_NAME, "Dell DM061"),
219 },
220 },
221 { /* Handle problems with rebooting on the Latitude E5410. */
222 .callback = set_pci_reboot,
223 .ident = "Dell Latitude E5410",
224 .matches = {
225 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
226 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E5410"),
227 },
228 },
229 { /* Handle problems with rebooting on the Latitude E5420. */
230 .callback = set_pci_reboot,
231 .ident = "Dell Latitude E5420",
232 .matches = {
233 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
234 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E5420"),
235 },
236 },
237 { /* Handle problems with rebooting on the Latitude E6320. */
238 .callback = set_pci_reboot,
239 .ident = "Dell Latitude E6320",
240 .matches = {
241 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
242 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6320"),
243 },
244 },
245 { /* Handle problems with rebooting on the Latitude E6420. */
246 .callback = set_pci_reboot,
247 .ident = "Dell Latitude E6420",
248 .matches = {
249 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
250 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6420"),
251 },
252 },
253 { /* Handle problems with rebooting on Dell Optiplex 330 with 0KP561 */
254 .callback = set_bios_reboot,
255 .ident = "Dell OptiPlex 330",
256 .matches = {
257 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
258 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 330"),
259 DMI_MATCH(DMI_BOARD_NAME, "0KP561"),
260 },
261 },
262 { /* Handle problems with rebooting on Dell Optiplex 360 with 0T656F */
263 .callback = set_bios_reboot,
264 .ident = "Dell OptiPlex 360",
265 .matches = {
266 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
267 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 360"),
268 DMI_MATCH(DMI_BOARD_NAME, "0T656F"),
269 },
270 },
271 { /* Handle problems with rebooting on Dell Optiplex 745's SFF */
272 .callback = set_bios_reboot,
273 .ident = "Dell OptiPlex 745",
274 .matches = {
275 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
276 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
277 },
278 },
279 { /* Handle problems with rebooting on Dell Optiplex 745's DFF */
280 .callback = set_bios_reboot,
281 .ident = "Dell OptiPlex 745",
282 .matches = {
283 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
284 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
285 DMI_MATCH(DMI_BOARD_NAME, "0MM599"),
286 },
287 },
288 { /* Handle problems with rebooting on Dell Optiplex 745 with 0KW626 */
289 .callback = set_bios_reboot,
290 .ident = "Dell OptiPlex 745",
291 .matches = {
292 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
293 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
294 DMI_MATCH(DMI_BOARD_NAME, "0KW626"),
295 },
296 },
297 { /* Handle problems with rebooting on Dell OptiPlex 760 with 0G919G */
298 .callback = set_bios_reboot,
299 .ident = "Dell OptiPlex 760",
300 .matches = {
301 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
302 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 760"),
303 DMI_MATCH(DMI_BOARD_NAME, "0G919G"),
304 },
305 },
306 { /* Handle problems with rebooting on the OptiPlex 990. */
307 .callback = set_pci_reboot,
308 .ident = "Dell OptiPlex 990",
309 .matches = {
310 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
311 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 990"),
312 },
313 },
314 { /* Handle problems with rebooting on Dell 300's */
315 .callback = set_bios_reboot,
316 .ident = "Dell PowerEdge 300",
317 .matches = {
318 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
319 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"),
320 },
321 },
322 { /* Handle problems with rebooting on Dell 1300's */
323 .callback = set_bios_reboot,
324 .ident = "Dell PowerEdge 1300",
325 .matches = {
326 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
327 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1300/"),
328 },
329 },
330 { /* Handle problems with rebooting on Dell 2400's */
331 .callback = set_bios_reboot,
332 .ident = "Dell PowerEdge 2400",
333 .matches = {
334 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
335 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"),
336 },
337 },
338 { /* Handle problems with rebooting on the Dell PowerEdge C6100. */
339 .callback = set_pci_reboot,
340 .ident = "Dell PowerEdge C6100",
341 .matches = {
342 DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
343 DMI_MATCH(DMI_PRODUCT_NAME, "C6100"),
344 },
345 },
346 { /* Handle problems with rebooting on the Precision M6600. */
347 .callback = set_pci_reboot,
348 .ident = "Dell Precision M6600",
349 .matches = {
350 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
351 DMI_MATCH(DMI_PRODUCT_NAME, "Precision M6600"),
352 },
353 },
354 { /* Handle problems with rebooting on Dell T5400's */
355 .callback = set_bios_reboot,
356 .ident = "Dell Precision T5400",
357 .matches = {
358 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
359 DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T5400"),
360 },
361 },
362 { /* Handle problems with rebooting on Dell T7400's */
363 .callback = set_bios_reboot,
364 .ident = "Dell Precision T7400",
365 .matches = {
366 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
367 DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T7400"),
368 },
369 },
370 { /* Handle problems with rebooting on Dell XPS710 */
371 .callback = set_bios_reboot,
372 .ident = "Dell XPS710",
373 .matches = {
374 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
375 DMI_MATCH(DMI_PRODUCT_NAME, "Dell XPS710"),
376 },
377 },
378
379 /* Hewlett-Packard */
380 { /* Handle problems with rebooting on HP laptops */
381 .callback = set_bios_reboot,
382 .ident = "HP Compaq Laptop",
383 .matches = {
384 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
385 DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"),
386 },
387 },
388
389 /* Sony */
390 { /* Handle problems with rebooting on Sony VGN-Z540N */
391 .callback = set_bios_reboot,
392 .ident = "Sony VGN-Z540N",
393 .matches = {
394 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
395 DMI_MATCH(DMI_PRODUCT_NAME, "VGN-Z540N"),
396 },
397 },
398
399 { }
400};
401
402static int __init reboot_init(void)
403{
404 /*
405 * Only do the DMI check if reboot_type hasn't been overridden
406 * on the command line
407 */
408 if (reboot_default)
409 dmi_check_system(reboot_dmi_table);
410 return 0;
411}
412core_initcall(reboot_init);
413
414static inline void kb_wait(void)
415{
416 int i;
417
418 for (i = 0; i < 0x10000; i++) {
419 if ((inb(0x64) & 0x02) == 0)
420 break;
421 udelay(2);
422 }
423}
424
425static void vmxoff_nmi(int cpu, struct pt_regs *regs)
426{
427 cpu_emergency_vmxoff();
428}
429
430/* Use NMIs as IPIs to tell all CPUs to disable virtualization */
431static void emergency_vmx_disable_all(void)
432{
433 /* Just make sure we won't change CPUs while doing this */
434 local_irq_disable();
435
436 /*
437 * We need to disable VMX on all CPUs before rebooting, otherwise
438 * we risk hanging up the machine, because the CPU ignore INIT
439 * signals when VMX is enabled.
440 *
441 * We can't take any locks and we may be on an inconsistent
442 * state, so we use NMIs as IPIs to tell the other CPUs to disable
443 * VMX and halt.
444 *
445 * For safety, we will avoid running the nmi_shootdown_cpus()
446 * stuff unnecessarily, but we don't have a way to check
447 * if other CPUs have VMX enabled. So we will call it only if the
448 * CPU we are running on has VMX enabled.
449 *
450 * We will miss cases where VMX is not enabled on all CPUs. This
451 * shouldn't do much harm because KVM always enable VMX on all
452 * CPUs anyway. But we can miss it on the small window where KVM
453 * is still enabling VMX.
454 */
455 if (cpu_has_vmx() && cpu_vmx_enabled()) {
456 /* Disable VMX on this CPU. */
457 cpu_vmxoff();
458
459 /* Halt and disable VMX on the other CPUs */
460 nmi_shootdown_cpus(vmxoff_nmi);
461
462 }
463}
464
465
466void __attribute__((weak)) mach_reboot_fixups(void)
467{
468}
469
470/*
471 * To the best of our knowledge Windows compatible x86 hardware expects
472 * the following on reboot:
473 *
474 * 1) If the FADT has the ACPI reboot register flag set, try it
475 * 2) If still alive, write to the keyboard controller
476 * 3) If still alive, write to the ACPI reboot register again
477 * 4) If still alive, write to the keyboard controller again
478 * 5) If still alive, call the EFI runtime service to reboot
479 * 6) If no EFI runtime service, call the BIOS to do a reboot
480 *
481 * We default to following the same pattern. We also have
482 * two other reboot methods: 'triple fault' and 'PCI', which
483 * can be triggered via the reboot= kernel boot option or
484 * via quirks.
485 *
486 * This means that this function can never return, it can misbehave
487 * by not rebooting properly and hanging.
488 */
489static void native_machine_emergency_restart(void)
490{
491 int i;
492 int attempt = 0;
493 int orig_reboot_type = reboot_type;
494 unsigned short mode;
495
496 if (reboot_emergency)
497 emergency_vmx_disable_all();
498
499 tboot_shutdown(TB_SHUTDOWN_REBOOT);
500
501 /* Tell the BIOS if we want cold or warm reboot */
502 mode = reboot_mode == REBOOT_WARM ? 0x1234 : 0;
503 *((unsigned short *)__va(0x472)) = mode;
504
505 for (;;) {
506 /* Could also try the reset bit in the Hammer NB */
507 switch (reboot_type) {
508 case BOOT_ACPI:
509 acpi_reboot();
510 reboot_type = BOOT_KBD;
511 break;
512
513 case BOOT_KBD:
514 mach_reboot_fixups(); /* For board specific fixups */
515
516 for (i = 0; i < 10; i++) {
517 kb_wait();
518 udelay(50);
519 outb(0xfe, 0x64); /* Pulse reset low */
520 udelay(50);
521 }
522 if (attempt == 0 && orig_reboot_type == BOOT_ACPI) {
523 attempt = 1;
524 reboot_type = BOOT_ACPI;
525 } else {
526 reboot_type = BOOT_EFI;
527 }
528 break;
529
530 case BOOT_EFI:
531 if (efi_enabled(EFI_RUNTIME_SERVICES))
532 efi.reset_system(reboot_mode == REBOOT_WARM ?
533 EFI_RESET_WARM :
534 EFI_RESET_COLD,
535 EFI_SUCCESS, 0, NULL);
536 reboot_type = BOOT_BIOS;
537 break;
538
539 case BOOT_BIOS:
540 machine_real_restart(MRR_BIOS);
541
542 /* We're probably dead after this, but... */
543 reboot_type = BOOT_CF9_SAFE;
544 break;
545
546 case BOOT_CF9_FORCE:
547 port_cf9_safe = true;
548 /* Fall through */
549
550 case BOOT_CF9_SAFE:
551 if (port_cf9_safe) {
552 u8 reboot_code = reboot_mode == REBOOT_WARM ? 0x06 : 0x0E;
553 u8 cf9 = inb(0xcf9) & ~reboot_code;
554 outb(cf9|2, 0xcf9); /* Request hard reset */
555 udelay(50);
556 /* Actually do the reset */
557 outb(cf9|reboot_code, 0xcf9);
558 udelay(50);
559 }
560 reboot_type = BOOT_TRIPLE;
561 break;
562
563 case BOOT_TRIPLE:
564 load_idt(&no_idt);
565 __asm__ __volatile__("int3");
566
567 /* We're probably dead after this, but... */
568 reboot_type = BOOT_KBD;
569 break;
570 }
571 }
572}
573
574void native_machine_shutdown(void)
575{
576 /* Stop the cpus and apics */
577#ifdef CONFIG_X86_IO_APIC
578 /*
579 * Disabling IO APIC before local APIC is a workaround for
580 * erratum AVR31 in "Intel Atom Processor C2000 Product Family
581 * Specification Update". In this situation, interrupts that target
582 * a Logical Processor whose Local APIC is either in the process of
583 * being hardware disabled or software disabled are neither delivered
584 * nor discarded. When this erratum occurs, the processor may hang.
585 *
586 * Even without the erratum, it still makes sense to quiet IO APIC
587 * before disabling Local APIC.
588 */
589 disable_IO_APIC();
590#endif
591
592#ifdef CONFIG_SMP
593 /*
594 * Stop all of the others. Also disable the local irq to
595 * not receive the per-cpu timer interrupt which may trigger
596 * scheduler's load balance.
597 */
598 local_irq_disable();
599 stop_other_cpus();
600#endif
601
602 lapic_shutdown();
603
604#ifdef CONFIG_HPET_TIMER
605 hpet_disable();
606#endif
607
608#ifdef CONFIG_X86_64
609 x86_platform.iommu_shutdown();
610#endif
611}
612
613static void __machine_emergency_restart(int emergency)
614{
615 reboot_emergency = emergency;
616 machine_ops.emergency_restart();
617}
618
619static void native_machine_restart(char *__unused)
620{
621 pr_notice("machine restart\n");
622
623 if (!reboot_force)
624 machine_shutdown();
625 __machine_emergency_restart(0);
626}
627
628static void native_machine_halt(void)
629{
630 /* Stop other cpus and apics */
631 machine_shutdown();
632
633 tboot_shutdown(TB_SHUTDOWN_HALT);
634
635 stop_this_cpu(NULL);
636}
637
638static void native_machine_power_off(void)
639{
640 if (pm_power_off) {
641 if (!reboot_force)
642 machine_shutdown();
643 pm_power_off();
644 }
645 /* A fallback in case there is no PM info available */
646 tboot_shutdown(TB_SHUTDOWN_HALT);
647}
648
649struct machine_ops machine_ops = {
650 .power_off = native_machine_power_off,
651 .shutdown = native_machine_shutdown,
652 .emergency_restart = native_machine_emergency_restart,
653 .restart = native_machine_restart,
654 .halt = native_machine_halt,
655#ifdef CONFIG_KEXEC
656 .crash_shutdown = native_machine_crash_shutdown,
657#endif
658};
659
660void machine_power_off(void)
661{
662 machine_ops.power_off();
663}
664
665void machine_shutdown(void)
666{
667 machine_ops.shutdown();
668}
669
670void machine_emergency_restart(void)
671{
672 __machine_emergency_restart(1);
673}
674
675void machine_restart(char *cmd)
676{
677 machine_ops.restart(cmd);
678}
679
680void machine_halt(void)
681{
682 machine_ops.halt();
683}
684
685#ifdef CONFIG_KEXEC
686void machine_crash_shutdown(struct pt_regs *regs)
687{
688 machine_ops.crash_shutdown(regs);
689}
690#endif
691
692
693#if defined(CONFIG_SMP)
694
695/* This keeps a track of which one is crashing cpu. */
696static int crashing_cpu;
697static nmi_shootdown_cb shootdown_callback;
698
699static atomic_t waiting_for_crash_ipi;
700
701static int crash_nmi_callback(unsigned int val, struct pt_regs *regs)
702{
703 int cpu;
704
705 cpu = raw_smp_processor_id();
706
707 /*
708 * Don't do anything if this handler is invoked on crashing cpu.
709 * Otherwise, system will completely hang. Crashing cpu can get
710 * an NMI if system was initially booted with nmi_watchdog parameter.
711 */
712 if (cpu == crashing_cpu)
713 return NMI_HANDLED;
714 local_irq_disable();
715
716 shootdown_callback(cpu, regs);
717
718 atomic_dec(&waiting_for_crash_ipi);
719 /* Assume hlt works */
720 halt();
721 for (;;)
722 cpu_relax();
723
724 return NMI_HANDLED;
725}
726
727static void smp_send_nmi_allbutself(void)
728{
729 apic->send_IPI_allbutself(NMI_VECTOR);
730}
731
732/*
733 * Halt all other CPUs, calling the specified function on each of them
734 *
735 * This function can be used to halt all other CPUs on crash
736 * or emergency reboot time. The function passed as parameter
737 * will be called inside a NMI handler on all CPUs.
738 */
739void nmi_shootdown_cpus(nmi_shootdown_cb callback)
740{
741 unsigned long msecs;
742 local_irq_disable();
743
744 /* Make a note of crashing cpu. Will be used in NMI callback. */
745 crashing_cpu = safe_smp_processor_id();
746
747 shootdown_callback = callback;
748
749 atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
750 /* Would it be better to replace the trap vector here? */
751 if (register_nmi_handler(NMI_LOCAL, crash_nmi_callback,
752 NMI_FLAG_FIRST, "crash"))
753 return; /* Return what? */
754 /*
755 * Ensure the new callback function is set before sending
756 * out the NMI
757 */
758 wmb();
759
760 smp_send_nmi_allbutself();
761
762 msecs = 1000; /* Wait at most a second for the other cpus to stop */
763 while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
764 mdelay(1);
765 msecs--;
766 }
767
768 /* Leave the nmi callback set */
769}
770#else /* !CONFIG_SMP */
771void nmi_shootdown_cpus(nmi_shootdown_cb callback)
772{
773 /* No other CPUs to shoot down */
774}
775#endif
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_CRASH_DUMP
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_CRASH_DUMP
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