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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/frame.h>
14#include <acpi/reboot.h>
15#include <asm/io.h>
16#include <asm/apic.h>
17#include <asm/io_apic.h>
18#include <asm/desc.h>
19#include <asm/hpet.h>
20#include <asm/pgtable.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/virtext.h>
26#include <asm/cpu.h>
27#include <asm/nmi.h>
28#include <asm/smp.h>
29
30#include <linux/ctype.h>
31#include <linux/mc146818rtc.h>
32#include <asm/realmode.h>
33#include <asm/x86_init.h>
34#include <asm/efi.h>
35
36/*
37 * Power off function, if any
38 */
39void (*pm_power_off)(void);
40EXPORT_SYMBOL(pm_power_off);
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
110 /* Exiting long mode will fail if CR4.PCIDE is set. */
111 if (static_cpu_has(X86_FEATURE_PCID))
112 cr4_clear_bits(X86_CR4_PCIDE);
113#endif
114
115 /* Jump to the identity-mapped low memory code */
116#ifdef CONFIG_X86_32
117 asm volatile("jmpl *%0" : :
118 "rm" (real_mode_header->machine_real_restart_asm),
119 "a" (type));
120#else
121 asm volatile("ljmpl *%0" : :
122 "m" (real_mode_header->machine_real_restart_asm),
123 "D" (type));
124#endif
125 unreachable();
126}
127#ifdef CONFIG_APM_MODULE
128EXPORT_SYMBOL(machine_real_restart);
129#endif
130STACK_FRAME_NON_STANDARD(machine_real_restart);
131
132/*
133 * Some Apple MacBook and MacBookPro's needs reboot=p to be able to reboot
134 */
135static int __init set_pci_reboot(const struct dmi_system_id *d)
136{
137 if (reboot_type != BOOT_CF9_FORCE) {
138 reboot_type = BOOT_CF9_FORCE;
139 pr_info("%s series board detected. Selecting %s-method for reboots.\n",
140 d->ident, "PCI");
141 }
142 return 0;
143}
144
145static int __init set_kbd_reboot(const struct dmi_system_id *d)
146{
147 if (reboot_type != BOOT_KBD) {
148 reboot_type = BOOT_KBD;
149 pr_info("%s series board detected. Selecting %s-method for reboot.\n",
150 d->ident, "KBD");
151 }
152 return 0;
153}
154
155/*
156 * This is a single dmi_table handling all reboot quirks.
157 */
158static const struct dmi_system_id reboot_dmi_table[] __initconst = {
159
160 /* Acer */
161 { /* Handle reboot issue on Acer Aspire one */
162 .callback = set_kbd_reboot,
163 .ident = "Acer Aspire One A110",
164 .matches = {
165 DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
166 DMI_MATCH(DMI_PRODUCT_NAME, "AOA110"),
167 },
168 },
169
170 /* Apple */
171 { /* Handle problems with rebooting on Apple MacBook5 */
172 .callback = set_pci_reboot,
173 .ident = "Apple MacBook5",
174 .matches = {
175 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
176 DMI_MATCH(DMI_PRODUCT_NAME, "MacBook5"),
177 },
178 },
179 { /* Handle problems with rebooting on Apple MacBookPro5 */
180 .callback = set_pci_reboot,
181 .ident = "Apple MacBookPro5",
182 .matches = {
183 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
184 DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro5"),
185 },
186 },
187 { /* Handle problems with rebooting on Apple Macmini3,1 */
188 .callback = set_pci_reboot,
189 .ident = "Apple Macmini3,1",
190 .matches = {
191 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
192 DMI_MATCH(DMI_PRODUCT_NAME, "Macmini3,1"),
193 },
194 },
195 { /* Handle problems with rebooting on the iMac9,1. */
196 .callback = set_pci_reboot,
197 .ident = "Apple iMac9,1",
198 .matches = {
199 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
200 DMI_MATCH(DMI_PRODUCT_NAME, "iMac9,1"),
201 },
202 },
203 { /* Handle problems with rebooting on the iMac10,1. */
204 .callback = set_pci_reboot,
205 .ident = "Apple iMac10,1",
206 .matches = {
207 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
208 DMI_MATCH(DMI_PRODUCT_NAME, "iMac10,1"),
209 },
210 },
211
212 /* ASRock */
213 { /* Handle problems with rebooting on ASRock Q1900DC-ITX */
214 .callback = set_pci_reboot,
215 .ident = "ASRock Q1900DC-ITX",
216 .matches = {
217 DMI_MATCH(DMI_BOARD_VENDOR, "ASRock"),
218 DMI_MATCH(DMI_BOARD_NAME, "Q1900DC-ITX"),
219 },
220 },
221
222 /* ASUS */
223 { /* Handle problems with rebooting on ASUS P4S800 */
224 .callback = set_bios_reboot,
225 .ident = "ASUS P4S800",
226 .matches = {
227 DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
228 DMI_MATCH(DMI_BOARD_NAME, "P4S800"),
229 },
230 },
231 { /* Handle problems with rebooting on ASUS EeeBook X205TA */
232 .callback = set_acpi_reboot,
233 .ident = "ASUS EeeBook X205TA",
234 .matches = {
235 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
236 DMI_MATCH(DMI_PRODUCT_NAME, "X205TA"),
237 },
238 },
239 { /* Handle problems with rebooting on ASUS EeeBook X205TAW */
240 .callback = set_acpi_reboot,
241 .ident = "ASUS EeeBook X205TAW",
242 .matches = {
243 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
244 DMI_MATCH(DMI_PRODUCT_NAME, "X205TAW"),
245 },
246 },
247
248 /* Certec */
249 { /* Handle problems with rebooting on Certec BPC600 */
250 .callback = set_pci_reboot,
251 .ident = "Certec BPC600",
252 .matches = {
253 DMI_MATCH(DMI_SYS_VENDOR, "Certec"),
254 DMI_MATCH(DMI_PRODUCT_NAME, "BPC600"),
255 },
256 },
257
258 /* Dell */
259 { /* Handle problems with rebooting on Dell DXP061 */
260 .callback = set_bios_reboot,
261 .ident = "Dell DXP061",
262 .matches = {
263 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
264 DMI_MATCH(DMI_PRODUCT_NAME, "Dell DXP061"),
265 },
266 },
267 { /* Handle problems with rebooting on Dell E520's */
268 .callback = set_bios_reboot,
269 .ident = "Dell E520",
270 .matches = {
271 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
272 DMI_MATCH(DMI_PRODUCT_NAME, "Dell DM061"),
273 },
274 },
275 { /* Handle problems with rebooting on the Latitude E5410. */
276 .callback = set_pci_reboot,
277 .ident = "Dell Latitude E5410",
278 .matches = {
279 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
280 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E5410"),
281 },
282 },
283 { /* Handle problems with rebooting on the Latitude E5420. */
284 .callback = set_pci_reboot,
285 .ident = "Dell Latitude E5420",
286 .matches = {
287 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
288 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E5420"),
289 },
290 },
291 { /* Handle problems with rebooting on the Latitude E6320. */
292 .callback = set_pci_reboot,
293 .ident = "Dell Latitude E6320",
294 .matches = {
295 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
296 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6320"),
297 },
298 },
299 { /* Handle problems with rebooting on the Latitude E6420. */
300 .callback = set_pci_reboot,
301 .ident = "Dell Latitude E6420",
302 .matches = {
303 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
304 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6420"),
305 },
306 },
307 { /* Handle problems with rebooting on Dell Optiplex 330 with 0KP561 */
308 .callback = set_bios_reboot,
309 .ident = "Dell OptiPlex 330",
310 .matches = {
311 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
312 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 330"),
313 DMI_MATCH(DMI_BOARD_NAME, "0KP561"),
314 },
315 },
316 { /* Handle problems with rebooting on Dell Optiplex 360 with 0T656F */
317 .callback = set_bios_reboot,
318 .ident = "Dell OptiPlex 360",
319 .matches = {
320 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
321 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 360"),
322 DMI_MATCH(DMI_BOARD_NAME, "0T656F"),
323 },
324 },
325 { /* Handle problems with rebooting on Dell Optiplex 745's SFF */
326 .callback = set_bios_reboot,
327 .ident = "Dell OptiPlex 745",
328 .matches = {
329 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
330 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
331 },
332 },
333 { /* Handle problems with rebooting on Dell Optiplex 745's DFF */
334 .callback = set_bios_reboot,
335 .ident = "Dell OptiPlex 745",
336 .matches = {
337 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
338 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
339 DMI_MATCH(DMI_BOARD_NAME, "0MM599"),
340 },
341 },
342 { /* Handle problems with rebooting on Dell Optiplex 745 with 0KW626 */
343 .callback = set_bios_reboot,
344 .ident = "Dell OptiPlex 745",
345 .matches = {
346 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
347 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
348 DMI_MATCH(DMI_BOARD_NAME, "0KW626"),
349 },
350 },
351 { /* Handle problems with rebooting on Dell OptiPlex 760 with 0G919G */
352 .callback = set_bios_reboot,
353 .ident = "Dell OptiPlex 760",
354 .matches = {
355 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
356 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 760"),
357 DMI_MATCH(DMI_BOARD_NAME, "0G919G"),
358 },
359 },
360 { /* Handle problems with rebooting on the OptiPlex 990. */
361 .callback = set_pci_reboot,
362 .ident = "Dell OptiPlex 990",
363 .matches = {
364 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
365 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 990"),
366 },
367 },
368 { /* Handle problems with rebooting on Dell 300's */
369 .callback = set_bios_reboot,
370 .ident = "Dell PowerEdge 300",
371 .matches = {
372 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
373 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"),
374 },
375 },
376 { /* Handle problems with rebooting on Dell 1300's */
377 .callback = set_bios_reboot,
378 .ident = "Dell PowerEdge 1300",
379 .matches = {
380 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
381 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1300/"),
382 },
383 },
384 { /* Handle problems with rebooting on Dell 2400's */
385 .callback = set_bios_reboot,
386 .ident = "Dell PowerEdge 2400",
387 .matches = {
388 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
389 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"),
390 },
391 },
392 { /* Handle problems with rebooting on the Dell PowerEdge C6100. */
393 .callback = set_pci_reboot,
394 .ident = "Dell PowerEdge C6100",
395 .matches = {
396 DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
397 DMI_MATCH(DMI_PRODUCT_NAME, "C6100"),
398 },
399 },
400 { /* Handle problems with rebooting on the Precision M6600. */
401 .callback = set_pci_reboot,
402 .ident = "Dell Precision M6600",
403 .matches = {
404 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
405 DMI_MATCH(DMI_PRODUCT_NAME, "Precision M6600"),
406 },
407 },
408 { /* Handle problems with rebooting on Dell T5400's */
409 .callback = set_bios_reboot,
410 .ident = "Dell Precision T5400",
411 .matches = {
412 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
413 DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T5400"),
414 },
415 },
416 { /* Handle problems with rebooting on Dell T7400's */
417 .callback = set_bios_reboot,
418 .ident = "Dell Precision T7400",
419 .matches = {
420 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
421 DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T7400"),
422 },
423 },
424 { /* Handle problems with rebooting on Dell XPS710 */
425 .callback = set_bios_reboot,
426 .ident = "Dell XPS710",
427 .matches = {
428 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
429 DMI_MATCH(DMI_PRODUCT_NAME, "Dell XPS710"),
430 },
431 },
432 { /* Handle problems with rebooting on Dell Optiplex 7450 AIO */
433 .callback = set_acpi_reboot,
434 .ident = "Dell OptiPlex 7450 AIO",
435 .matches = {
436 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
437 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 7450 AIO"),
438 },
439 },
440
441 /* Hewlett-Packard */
442 { /* Handle problems with rebooting on HP laptops */
443 .callback = set_bios_reboot,
444 .ident = "HP Compaq Laptop",
445 .matches = {
446 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
447 DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"),
448 },
449 },
450
451 /* Sony */
452 { /* Handle problems with rebooting on Sony VGN-Z540N */
453 .callback = set_bios_reboot,
454 .ident = "Sony VGN-Z540N",
455 .matches = {
456 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
457 DMI_MATCH(DMI_PRODUCT_NAME, "VGN-Z540N"),
458 },
459 },
460
461 { }
462};
463
464static int __init reboot_init(void)
465{
466 int rv;
467
468 /*
469 * Only do the DMI check if reboot_type hasn't been overridden
470 * on the command line
471 */
472 if (!reboot_default)
473 return 0;
474
475 /*
476 * The DMI quirks table takes precedence. If no quirks entry
477 * matches and the ACPI Hardware Reduced bit is set and EFI
478 * runtime services are enabled, force EFI reboot.
479 */
480 rv = dmi_check_system(reboot_dmi_table);
481
482 if (!rv && efi_reboot_required() && !efi_runtime_disabled())
483 reboot_type = BOOT_EFI;
484
485 return 0;
486}
487core_initcall(reboot_init);
488
489static inline void kb_wait(void)
490{
491 int i;
492
493 for (i = 0; i < 0x10000; i++) {
494 if ((inb(0x64) & 0x02) == 0)
495 break;
496 udelay(2);
497 }
498}
499
500static void vmxoff_nmi(int cpu, struct pt_regs *regs)
501{
502 cpu_emergency_vmxoff();
503}
504
505/* Use NMIs as IPIs to tell all CPUs to disable virtualization */
506static void emergency_vmx_disable_all(void)
507{
508 /* Just make sure we won't change CPUs while doing this */
509 local_irq_disable();
510
511 /*
512 * We need to disable VMX on all CPUs before rebooting, otherwise
513 * we risk hanging up the machine, because the CPU ignore INIT
514 * signals when VMX is enabled.
515 *
516 * We can't take any locks and we may be on an inconsistent
517 * state, so we use NMIs as IPIs to tell the other CPUs to disable
518 * VMX and halt.
519 *
520 * For safety, we will avoid running the nmi_shootdown_cpus()
521 * stuff unnecessarily, but we don't have a way to check
522 * if other CPUs have VMX enabled. So we will call it only if the
523 * CPU we are running on has VMX enabled.
524 *
525 * We will miss cases where VMX is not enabled on all CPUs. This
526 * shouldn't do much harm because KVM always enable VMX on all
527 * CPUs anyway. But we can miss it on the small window where KVM
528 * is still enabling VMX.
529 */
530 if (cpu_has_vmx() && cpu_vmx_enabled()) {
531 /* Disable VMX on this CPU. */
532 cpu_vmxoff();
533
534 /* Halt and disable VMX on the other CPUs */
535 nmi_shootdown_cpus(vmxoff_nmi);
536
537 }
538}
539
540
541void __attribute__((weak)) mach_reboot_fixups(void)
542{
543}
544
545/*
546 * To the best of our knowledge Windows compatible x86 hardware expects
547 * the following on reboot:
548 *
549 * 1) If the FADT has the ACPI reboot register flag set, try it
550 * 2) If still alive, write to the keyboard controller
551 * 3) If still alive, write to the ACPI reboot register again
552 * 4) If still alive, write to the keyboard controller again
553 * 5) If still alive, call the EFI runtime service to reboot
554 * 6) If no EFI runtime service, call the BIOS to do a reboot
555 *
556 * We default to following the same pattern. We also have
557 * two other reboot methods: 'triple fault' and 'PCI', which
558 * can be triggered via the reboot= kernel boot option or
559 * via quirks.
560 *
561 * This means that this function can never return, it can misbehave
562 * by not rebooting properly and hanging.
563 */
564static void native_machine_emergency_restart(void)
565{
566 int i;
567 int attempt = 0;
568 int orig_reboot_type = reboot_type;
569 unsigned short mode;
570
571 if (reboot_emergency)
572 emergency_vmx_disable_all();
573
574 tboot_shutdown(TB_SHUTDOWN_REBOOT);
575
576 /* Tell the BIOS if we want cold or warm reboot */
577 mode = reboot_mode == REBOOT_WARM ? 0x1234 : 0;
578 *((unsigned short *)__va(0x472)) = mode;
579
580 /*
581 * If an EFI capsule has been registered with the firmware then
582 * override the reboot= parameter.
583 */
584 if (efi_capsule_pending(NULL)) {
585 pr_info("EFI capsule is pending, forcing EFI reboot.\n");
586 reboot_type = BOOT_EFI;
587 }
588
589 for (;;) {
590 /* Could also try the reset bit in the Hammer NB */
591 switch (reboot_type) {
592 case BOOT_ACPI:
593 acpi_reboot();
594 reboot_type = BOOT_KBD;
595 break;
596
597 case BOOT_KBD:
598 mach_reboot_fixups(); /* For board specific fixups */
599
600 for (i = 0; i < 10; i++) {
601 kb_wait();
602 udelay(50);
603 outb(0xfe, 0x64); /* Pulse reset low */
604 udelay(50);
605 }
606 if (attempt == 0 && orig_reboot_type == BOOT_ACPI) {
607 attempt = 1;
608 reboot_type = BOOT_ACPI;
609 } else {
610 reboot_type = BOOT_EFI;
611 }
612 break;
613
614 case BOOT_EFI:
615 efi_reboot(reboot_mode, NULL);
616 reboot_type = BOOT_BIOS;
617 break;
618
619 case BOOT_BIOS:
620 machine_real_restart(MRR_BIOS);
621
622 /* We're probably dead after this, but... */
623 reboot_type = BOOT_CF9_SAFE;
624 break;
625
626 case BOOT_CF9_FORCE:
627 port_cf9_safe = true;
628 /* Fall through */
629
630 case BOOT_CF9_SAFE:
631 if (port_cf9_safe) {
632 u8 reboot_code = reboot_mode == REBOOT_WARM ? 0x06 : 0x0E;
633 u8 cf9 = inb(0xcf9) & ~reboot_code;
634 outb(cf9|2, 0xcf9); /* Request hard reset */
635 udelay(50);
636 /* Actually do the reset */
637 outb(cf9|reboot_code, 0xcf9);
638 udelay(50);
639 }
640 reboot_type = BOOT_TRIPLE;
641 break;
642
643 case BOOT_TRIPLE:
644 idt_invalidate(NULL);
645 __asm__ __volatile__("int3");
646
647 /* We're probably dead after this, but... */
648 reboot_type = BOOT_KBD;
649 break;
650 }
651 }
652}
653
654void native_machine_shutdown(void)
655{
656 /* Stop the cpus and apics */
657#ifdef CONFIG_X86_IO_APIC
658 /*
659 * Disabling IO APIC before local APIC is a workaround for
660 * erratum AVR31 in "Intel Atom Processor C2000 Product Family
661 * Specification Update". In this situation, interrupts that target
662 * a Logical Processor whose Local APIC is either in the process of
663 * being hardware disabled or software disabled are neither delivered
664 * nor discarded. When this erratum occurs, the processor may hang.
665 *
666 * Even without the erratum, it still makes sense to quiet IO APIC
667 * before disabling Local APIC.
668 */
669 clear_IO_APIC();
670#endif
671
672#ifdef CONFIG_SMP
673 /*
674 * Stop all of the others. Also disable the local irq to
675 * not receive the per-cpu timer interrupt which may trigger
676 * scheduler's load balance.
677 */
678 local_irq_disable();
679 stop_other_cpus();
680#endif
681
682 lapic_shutdown();
683 restore_boot_irq_mode();
684
685#ifdef CONFIG_HPET_TIMER
686 hpet_disable();
687#endif
688
689#ifdef CONFIG_X86_64
690 x86_platform.iommu_shutdown();
691#endif
692}
693
694static void __machine_emergency_restart(int emergency)
695{
696 reboot_emergency = emergency;
697 machine_ops.emergency_restart();
698}
699
700static void native_machine_restart(char *__unused)
701{
702 pr_notice("machine restart\n");
703
704 if (!reboot_force)
705 machine_shutdown();
706 __machine_emergency_restart(0);
707}
708
709static void native_machine_halt(void)
710{
711 /* Stop other cpus and apics */
712 machine_shutdown();
713
714 tboot_shutdown(TB_SHUTDOWN_HALT);
715
716 stop_this_cpu(NULL);
717}
718
719static void native_machine_power_off(void)
720{
721 if (pm_power_off) {
722 if (!reboot_force)
723 machine_shutdown();
724 pm_power_off();
725 }
726 /* A fallback in case there is no PM info available */
727 tboot_shutdown(TB_SHUTDOWN_HALT);
728}
729
730struct machine_ops machine_ops __ro_after_init = {
731 .power_off = native_machine_power_off,
732 .shutdown = native_machine_shutdown,
733 .emergency_restart = native_machine_emergency_restart,
734 .restart = native_machine_restart,
735 .halt = native_machine_halt,
736#ifdef CONFIG_KEXEC_CORE
737 .crash_shutdown = native_machine_crash_shutdown,
738#endif
739};
740
741void machine_power_off(void)
742{
743 machine_ops.power_off();
744}
745
746void machine_shutdown(void)
747{
748 machine_ops.shutdown();
749}
750
751void machine_emergency_restart(void)
752{
753 __machine_emergency_restart(1);
754}
755
756void machine_restart(char *cmd)
757{
758 machine_ops.restart(cmd);
759}
760
761void machine_halt(void)
762{
763 machine_ops.halt();
764}
765
766#ifdef CONFIG_KEXEC_CORE
767void machine_crash_shutdown(struct pt_regs *regs)
768{
769 machine_ops.crash_shutdown(regs);
770}
771#endif
772
773
774/* This is the CPU performing the emergency shutdown work. */
775int crashing_cpu = -1;
776
777#if defined(CONFIG_SMP)
778
779static nmi_shootdown_cb shootdown_callback;
780
781static atomic_t waiting_for_crash_ipi;
782static int crash_ipi_issued;
783
784static int crash_nmi_callback(unsigned int val, struct pt_regs *regs)
785{
786 int cpu;
787
788 cpu = raw_smp_processor_id();
789
790 /*
791 * Don't do anything if this handler is invoked on crashing cpu.
792 * Otherwise, system will completely hang. Crashing cpu can get
793 * an NMI if system was initially booted with nmi_watchdog parameter.
794 */
795 if (cpu == crashing_cpu)
796 return NMI_HANDLED;
797 local_irq_disable();
798
799 shootdown_callback(cpu, regs);
800
801 atomic_dec(&waiting_for_crash_ipi);
802 /* Assume hlt works */
803 halt();
804 for (;;)
805 cpu_relax();
806
807 return NMI_HANDLED;
808}
809
810static void smp_send_nmi_allbutself(void)
811{
812 apic->send_IPI_allbutself(NMI_VECTOR);
813}
814
815/*
816 * Halt all other CPUs, calling the specified function on each of them
817 *
818 * This function can be used to halt all other CPUs on crash
819 * or emergency reboot time. The function passed as parameter
820 * will be called inside a NMI handler on all CPUs.
821 */
822void nmi_shootdown_cpus(nmi_shootdown_cb callback)
823{
824 unsigned long msecs;
825 local_irq_disable();
826
827 /* Make a note of crashing cpu. Will be used in NMI callback. */
828 crashing_cpu = safe_smp_processor_id();
829
830 shootdown_callback = callback;
831
832 atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
833 /* Would it be better to replace the trap vector here? */
834 if (register_nmi_handler(NMI_LOCAL, crash_nmi_callback,
835 NMI_FLAG_FIRST, "crash"))
836 return; /* Return what? */
837 /*
838 * Ensure the new callback function is set before sending
839 * out the NMI
840 */
841 wmb();
842
843 smp_send_nmi_allbutself();
844
845 /* Kick CPUs looping in NMI context. */
846 WRITE_ONCE(crash_ipi_issued, 1);
847
848 msecs = 1000; /* Wait at most a second for the other cpus to stop */
849 while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
850 mdelay(1);
851 msecs--;
852 }
853
854 /* Leave the nmi callback set */
855}
856
857/*
858 * Check if the crash dumping IPI got issued and if so, call its callback
859 * directly. This function is used when we have already been in NMI handler.
860 * It doesn't return.
861 */
862void run_crash_ipi_callback(struct pt_regs *regs)
863{
864 if (crash_ipi_issued)
865 crash_nmi_callback(0, regs);
866}
867
868/* Override the weak function in kernel/panic.c */
869void nmi_panic_self_stop(struct pt_regs *regs)
870{
871 while (1) {
872 /* If no CPU is preparing crash dump, we simply loop here. */
873 run_crash_ipi_callback(regs);
874 cpu_relax();
875 }
876}
877
878#else /* !CONFIG_SMP */
879void nmi_shootdown_cpus(nmi_shootdown_cb callback)
880{
881 /* No other CPUs to shoot down */
882}
883
884void run_crash_ipi_callback(struct pt_regs *regs)
885{
886}
887#endif
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/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=b" or "reboot=k" commandline options,
59 * this quirk makes that automatic.
60 */
61static int __init set_bios_reboot(const struct dmi_system_id *d)
62{
63 if (reboot_type != BOOT_BIOS) {
64 reboot_type = BOOT_BIOS;
65 pr_info("%s series board detected. Selecting %s-method for reboots.\n",
66 d->ident, "BIOS");
67 }
68 return 0;
69}
70
71void __noreturn machine_real_restart(unsigned int type)
72{
73 local_irq_disable();
74
75 /*
76 * Write zero to CMOS register number 0x0f, which the BIOS POST
77 * routine will recognize as telling it to do a proper reboot. (Well
78 * that's what this book in front of me says -- it may only apply to
79 * the Phoenix BIOS though, it's not clear). At the same time,
80 * disable NMIs by setting the top bit in the CMOS address register,
81 * as we're about to do peculiar things to the CPU. I'm not sure if
82 * `outb_p' is needed instead of just `outb'. Use it to be on the
83 * safe side. (Yes, CMOS_WRITE does outb_p's. - Paul G.)
84 */
85 spin_lock(&rtc_lock);
86 CMOS_WRITE(0x00, 0x8f);
87 spin_unlock(&rtc_lock);
88
89 /*
90 * Switch back to the initial page table.
91 */
92#ifdef CONFIG_X86_32
93 load_cr3(initial_page_table);
94#else
95 write_cr3(real_mode_header->trampoline_pgd);
96#endif
97
98 /* Jump to the identity-mapped low memory code */
99#ifdef CONFIG_X86_32
100 asm volatile("jmpl *%0" : :
101 "rm" (real_mode_header->machine_real_restart_asm),
102 "a" (type));
103#else
104 asm volatile("ljmpl *%0" : :
105 "m" (real_mode_header->machine_real_restart_asm),
106 "D" (type));
107#endif
108 unreachable();
109}
110#ifdef CONFIG_APM_MODULE
111EXPORT_SYMBOL(machine_real_restart);
112#endif
113
114/*
115 * Some Apple MacBook and MacBookPro's needs reboot=p to be able to reboot
116 */
117static int __init set_pci_reboot(const struct dmi_system_id *d)
118{
119 if (reboot_type != BOOT_CF9_FORCE) {
120 reboot_type = BOOT_CF9_FORCE;
121 pr_info("%s series board detected. Selecting %s-method for reboots.\n",
122 d->ident, "PCI");
123 }
124 return 0;
125}
126
127static int __init set_kbd_reboot(const struct dmi_system_id *d)
128{
129 if (reboot_type != BOOT_KBD) {
130 reboot_type = BOOT_KBD;
131 pr_info("%s series board detected. Selecting %s-method for reboot.\n",
132 d->ident, "KBD");
133 }
134 return 0;
135}
136
137/*
138 * This is a single dmi_table handling all reboot quirks.
139 */
140static struct dmi_system_id __initdata reboot_dmi_table[] = {
141
142 /* Acer */
143 { /* Handle reboot issue on Acer Aspire one */
144 .callback = set_kbd_reboot,
145 .ident = "Acer Aspire One A110",
146 .matches = {
147 DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
148 DMI_MATCH(DMI_PRODUCT_NAME, "AOA110"),
149 },
150 },
151
152 /* Apple */
153 { /* Handle problems with rebooting on Apple MacBook5 */
154 .callback = set_pci_reboot,
155 .ident = "Apple MacBook5",
156 .matches = {
157 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
158 DMI_MATCH(DMI_PRODUCT_NAME, "MacBook5"),
159 },
160 },
161 { /* Handle problems with rebooting on Apple MacBookPro5 */
162 .callback = set_pci_reboot,
163 .ident = "Apple MacBookPro5",
164 .matches = {
165 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
166 DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro5"),
167 },
168 },
169 { /* Handle problems with rebooting on Apple Macmini3,1 */
170 .callback = set_pci_reboot,
171 .ident = "Apple Macmini3,1",
172 .matches = {
173 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
174 DMI_MATCH(DMI_PRODUCT_NAME, "Macmini3,1"),
175 },
176 },
177 { /* Handle problems with rebooting on the iMac9,1. */
178 .callback = set_pci_reboot,
179 .ident = "Apple iMac9,1",
180 .matches = {
181 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
182 DMI_MATCH(DMI_PRODUCT_NAME, "iMac9,1"),
183 },
184 },
185 { /* Handle problems with rebooting on the iMac10,1. */
186 .callback = set_pci_reboot,
187 .ident = "Apple iMac10,1",
188 .matches = {
189 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
190 DMI_MATCH(DMI_PRODUCT_NAME, "iMac10,1"),
191 },
192 },
193
194 /* ASRock */
195 { /* Handle problems with rebooting on ASRock Q1900DC-ITX */
196 .callback = set_pci_reboot,
197 .ident = "ASRock Q1900DC-ITX",
198 .matches = {
199 DMI_MATCH(DMI_BOARD_VENDOR, "ASRock"),
200 DMI_MATCH(DMI_BOARD_NAME, "Q1900DC-ITX"),
201 },
202 },
203
204 /* ASUS */
205 { /* Handle problems with rebooting on ASUS P4S800 */
206 .callback = set_bios_reboot,
207 .ident = "ASUS P4S800",
208 .matches = {
209 DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
210 DMI_MATCH(DMI_BOARD_NAME, "P4S800"),
211 },
212 },
213
214 /* Certec */
215 { /* Handle problems with rebooting on Certec BPC600 */
216 .callback = set_pci_reboot,
217 .ident = "Certec BPC600",
218 .matches = {
219 DMI_MATCH(DMI_SYS_VENDOR, "Certec"),
220 DMI_MATCH(DMI_PRODUCT_NAME, "BPC600"),
221 },
222 },
223
224 /* Dell */
225 { /* Handle problems with rebooting on Dell DXP061 */
226 .callback = set_bios_reboot,
227 .ident = "Dell DXP061",
228 .matches = {
229 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
230 DMI_MATCH(DMI_PRODUCT_NAME, "Dell DXP061"),
231 },
232 },
233 { /* Handle problems with rebooting on Dell E520's */
234 .callback = set_bios_reboot,
235 .ident = "Dell E520",
236 .matches = {
237 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
238 DMI_MATCH(DMI_PRODUCT_NAME, "Dell DM061"),
239 },
240 },
241 { /* Handle problems with rebooting on the Latitude E5410. */
242 .callback = set_pci_reboot,
243 .ident = "Dell Latitude E5410",
244 .matches = {
245 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
246 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E5410"),
247 },
248 },
249 { /* Handle problems with rebooting on the Latitude E5420. */
250 .callback = set_pci_reboot,
251 .ident = "Dell Latitude E5420",
252 .matches = {
253 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
254 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E5420"),
255 },
256 },
257 { /* Handle problems with rebooting on the Latitude E6320. */
258 .callback = set_pci_reboot,
259 .ident = "Dell Latitude E6320",
260 .matches = {
261 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
262 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6320"),
263 },
264 },
265 { /* Handle problems with rebooting on the Latitude E6420. */
266 .callback = set_pci_reboot,
267 .ident = "Dell Latitude E6420",
268 .matches = {
269 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
270 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6420"),
271 },
272 },
273 { /* Handle problems with rebooting on Dell Optiplex 330 with 0KP561 */
274 .callback = set_bios_reboot,
275 .ident = "Dell OptiPlex 330",
276 .matches = {
277 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
278 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 330"),
279 DMI_MATCH(DMI_BOARD_NAME, "0KP561"),
280 },
281 },
282 { /* Handle problems with rebooting on Dell Optiplex 360 with 0T656F */
283 .callback = set_bios_reboot,
284 .ident = "Dell OptiPlex 360",
285 .matches = {
286 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
287 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 360"),
288 DMI_MATCH(DMI_BOARD_NAME, "0T656F"),
289 },
290 },
291 { /* Handle problems with rebooting on Dell Optiplex 745's SFF */
292 .callback = set_bios_reboot,
293 .ident = "Dell OptiPlex 745",
294 .matches = {
295 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
296 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
297 },
298 },
299 { /* Handle problems with rebooting on Dell Optiplex 745's DFF */
300 .callback = set_bios_reboot,
301 .ident = "Dell OptiPlex 745",
302 .matches = {
303 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
304 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
305 DMI_MATCH(DMI_BOARD_NAME, "0MM599"),
306 },
307 },
308 { /* Handle problems with rebooting on Dell Optiplex 745 with 0KW626 */
309 .callback = set_bios_reboot,
310 .ident = "Dell OptiPlex 745",
311 .matches = {
312 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
313 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
314 DMI_MATCH(DMI_BOARD_NAME, "0KW626"),
315 },
316 },
317 { /* Handle problems with rebooting on Dell OptiPlex 760 with 0G919G */
318 .callback = set_bios_reboot,
319 .ident = "Dell OptiPlex 760",
320 .matches = {
321 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
322 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 760"),
323 DMI_MATCH(DMI_BOARD_NAME, "0G919G"),
324 },
325 },
326 { /* Handle problems with rebooting on the OptiPlex 990. */
327 .callback = set_pci_reboot,
328 .ident = "Dell OptiPlex 990",
329 .matches = {
330 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
331 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 990"),
332 },
333 },
334 { /* Handle problems with rebooting on Dell 300's */
335 .callback = set_bios_reboot,
336 .ident = "Dell PowerEdge 300",
337 .matches = {
338 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
339 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"),
340 },
341 },
342 { /* Handle problems with rebooting on Dell 1300's */
343 .callback = set_bios_reboot,
344 .ident = "Dell PowerEdge 1300",
345 .matches = {
346 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
347 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1300/"),
348 },
349 },
350 { /* Handle problems with rebooting on Dell 2400's */
351 .callback = set_bios_reboot,
352 .ident = "Dell PowerEdge 2400",
353 .matches = {
354 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
355 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"),
356 },
357 },
358 { /* Handle problems with rebooting on the Dell PowerEdge C6100. */
359 .callback = set_pci_reboot,
360 .ident = "Dell PowerEdge C6100",
361 .matches = {
362 DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
363 DMI_MATCH(DMI_PRODUCT_NAME, "C6100"),
364 },
365 },
366 { /* Handle problems with rebooting on the Precision M6600. */
367 .callback = set_pci_reboot,
368 .ident = "Dell Precision M6600",
369 .matches = {
370 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
371 DMI_MATCH(DMI_PRODUCT_NAME, "Precision M6600"),
372 },
373 },
374 { /* Handle problems with rebooting on Dell T5400's */
375 .callback = set_bios_reboot,
376 .ident = "Dell Precision T5400",
377 .matches = {
378 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
379 DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T5400"),
380 },
381 },
382 { /* Handle problems with rebooting on Dell T7400's */
383 .callback = set_bios_reboot,
384 .ident = "Dell Precision T7400",
385 .matches = {
386 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
387 DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T7400"),
388 },
389 },
390 { /* Handle problems with rebooting on Dell XPS710 */
391 .callback = set_bios_reboot,
392 .ident = "Dell XPS710",
393 .matches = {
394 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
395 DMI_MATCH(DMI_PRODUCT_NAME, "Dell XPS710"),
396 },
397 },
398
399 /* Hewlett-Packard */
400 { /* Handle problems with rebooting on HP laptops */
401 .callback = set_bios_reboot,
402 .ident = "HP Compaq Laptop",
403 .matches = {
404 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
405 DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"),
406 },
407 },
408
409 /* Sony */
410 { /* Handle problems with rebooting on Sony VGN-Z540N */
411 .callback = set_bios_reboot,
412 .ident = "Sony VGN-Z540N",
413 .matches = {
414 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
415 DMI_MATCH(DMI_PRODUCT_NAME, "VGN-Z540N"),
416 },
417 },
418
419 { }
420};
421
422static int __init reboot_init(void)
423{
424 int rv;
425
426 /*
427 * Only do the DMI check if reboot_type hasn't been overridden
428 * on the command line
429 */
430 if (!reboot_default)
431 return 0;
432
433 /*
434 * The DMI quirks table takes precedence. If no quirks entry
435 * matches and the ACPI Hardware Reduced bit is set, force EFI
436 * reboot.
437 */
438 rv = dmi_check_system(reboot_dmi_table);
439
440 if (!rv && efi_reboot_required())
441 reboot_type = BOOT_EFI;
442
443 return 0;
444}
445core_initcall(reboot_init);
446
447static inline void kb_wait(void)
448{
449 int i;
450
451 for (i = 0; i < 0x10000; i++) {
452 if ((inb(0x64) & 0x02) == 0)
453 break;
454 udelay(2);
455 }
456}
457
458static void vmxoff_nmi(int cpu, struct pt_regs *regs)
459{
460 cpu_emergency_vmxoff();
461}
462
463/* Use NMIs as IPIs to tell all CPUs to disable virtualization */
464static void emergency_vmx_disable_all(void)
465{
466 /* Just make sure we won't change CPUs while doing this */
467 local_irq_disable();
468
469 /*
470 * We need to disable VMX on all CPUs before rebooting, otherwise
471 * we risk hanging up the machine, because the CPU ignore INIT
472 * signals when VMX is enabled.
473 *
474 * We can't take any locks and we may be on an inconsistent
475 * state, so we use NMIs as IPIs to tell the other CPUs to disable
476 * VMX and halt.
477 *
478 * For safety, we will avoid running the nmi_shootdown_cpus()
479 * stuff unnecessarily, but we don't have a way to check
480 * if other CPUs have VMX enabled. So we will call it only if the
481 * CPU we are running on has VMX enabled.
482 *
483 * We will miss cases where VMX is not enabled on all CPUs. This
484 * shouldn't do much harm because KVM always enable VMX on all
485 * CPUs anyway. But we can miss it on the small window where KVM
486 * is still enabling VMX.
487 */
488 if (cpu_has_vmx() && cpu_vmx_enabled()) {
489 /* Disable VMX on this CPU. */
490 cpu_vmxoff();
491
492 /* Halt and disable VMX on the other CPUs */
493 nmi_shootdown_cpus(vmxoff_nmi);
494
495 }
496}
497
498
499void __attribute__((weak)) mach_reboot_fixups(void)
500{
501}
502
503/*
504 * To the best of our knowledge Windows compatible x86 hardware expects
505 * the following on reboot:
506 *
507 * 1) If the FADT has the ACPI reboot register flag set, try it
508 * 2) If still alive, write to the keyboard controller
509 * 3) If still alive, write to the ACPI reboot register again
510 * 4) If still alive, write to the keyboard controller again
511 * 5) If still alive, call the EFI runtime service to reboot
512 * 6) If no EFI runtime service, call the BIOS to do a reboot
513 *
514 * We default to following the same pattern. We also have
515 * two other reboot methods: 'triple fault' and 'PCI', which
516 * can be triggered via the reboot= kernel boot option or
517 * via quirks.
518 *
519 * This means that this function can never return, it can misbehave
520 * by not rebooting properly and hanging.
521 */
522static void native_machine_emergency_restart(void)
523{
524 int i;
525 int attempt = 0;
526 int orig_reboot_type = reboot_type;
527 unsigned short mode;
528
529 if (reboot_emergency)
530 emergency_vmx_disable_all();
531
532 tboot_shutdown(TB_SHUTDOWN_REBOOT);
533
534 /* Tell the BIOS if we want cold or warm reboot */
535 mode = reboot_mode == REBOOT_WARM ? 0x1234 : 0;
536 *((unsigned short *)__va(0x472)) = mode;
537
538 for (;;) {
539 /* Could also try the reset bit in the Hammer NB */
540 switch (reboot_type) {
541 case BOOT_ACPI:
542 acpi_reboot();
543 reboot_type = BOOT_KBD;
544 break;
545
546 case BOOT_KBD:
547 mach_reboot_fixups(); /* For board specific fixups */
548
549 for (i = 0; i < 10; i++) {
550 kb_wait();
551 udelay(50);
552 outb(0xfe, 0x64); /* Pulse reset low */
553 udelay(50);
554 }
555 if (attempt == 0 && orig_reboot_type == BOOT_ACPI) {
556 attempt = 1;
557 reboot_type = BOOT_ACPI;
558 } else {
559 reboot_type = BOOT_EFI;
560 }
561 break;
562
563 case BOOT_EFI:
564 efi_reboot(reboot_mode, NULL);
565 reboot_type = BOOT_BIOS;
566 break;
567
568 case BOOT_BIOS:
569 machine_real_restart(MRR_BIOS);
570
571 /* We're probably dead after this, but... */
572 reboot_type = BOOT_CF9_SAFE;
573 break;
574
575 case BOOT_CF9_FORCE:
576 port_cf9_safe = true;
577 /* Fall through */
578
579 case BOOT_CF9_SAFE:
580 if (port_cf9_safe) {
581 u8 reboot_code = reboot_mode == REBOOT_WARM ? 0x06 : 0x0E;
582 u8 cf9 = inb(0xcf9) & ~reboot_code;
583 outb(cf9|2, 0xcf9); /* Request hard reset */
584 udelay(50);
585 /* Actually do the reset */
586 outb(cf9|reboot_code, 0xcf9);
587 udelay(50);
588 }
589 reboot_type = BOOT_TRIPLE;
590 break;
591
592 case BOOT_TRIPLE:
593 load_idt(&no_idt);
594 __asm__ __volatile__("int3");
595
596 /* We're probably dead after this, but... */
597 reboot_type = BOOT_KBD;
598 break;
599 }
600 }
601}
602
603void native_machine_shutdown(void)
604{
605 /* Stop the cpus and apics */
606#ifdef CONFIG_X86_IO_APIC
607 /*
608 * Disabling IO APIC before local APIC is a workaround for
609 * erratum AVR31 in "Intel Atom Processor C2000 Product Family
610 * Specification Update". In this situation, interrupts that target
611 * a Logical Processor whose Local APIC is either in the process of
612 * being hardware disabled or software disabled are neither delivered
613 * nor discarded. When this erratum occurs, the processor may hang.
614 *
615 * Even without the erratum, it still makes sense to quiet IO APIC
616 * before disabling Local APIC.
617 */
618 disable_IO_APIC();
619#endif
620
621#ifdef CONFIG_SMP
622 /*
623 * Stop all of the others. Also disable the local irq to
624 * not receive the per-cpu timer interrupt which may trigger
625 * scheduler's load balance.
626 */
627 local_irq_disable();
628 stop_other_cpus();
629#endif
630
631 lapic_shutdown();
632
633#ifdef CONFIG_HPET_TIMER
634 hpet_disable();
635#endif
636
637#ifdef CONFIG_X86_64
638 x86_platform.iommu_shutdown();
639#endif
640}
641
642static void __machine_emergency_restart(int emergency)
643{
644 reboot_emergency = emergency;
645 machine_ops.emergency_restart();
646}
647
648static void native_machine_restart(char *__unused)
649{
650 pr_notice("machine restart\n");
651
652 if (!reboot_force)
653 machine_shutdown();
654 __machine_emergency_restart(0);
655}
656
657static void native_machine_halt(void)
658{
659 /* Stop other cpus and apics */
660 machine_shutdown();
661
662 tboot_shutdown(TB_SHUTDOWN_HALT);
663
664 stop_this_cpu(NULL);
665}
666
667static void native_machine_power_off(void)
668{
669 if (pm_power_off) {
670 if (!reboot_force)
671 machine_shutdown();
672 pm_power_off();
673 }
674 /* A fallback in case there is no PM info available */
675 tboot_shutdown(TB_SHUTDOWN_HALT);
676}
677
678struct machine_ops machine_ops = {
679 .power_off = native_machine_power_off,
680 .shutdown = native_machine_shutdown,
681 .emergency_restart = native_machine_emergency_restart,
682 .restart = native_machine_restart,
683 .halt = native_machine_halt,
684#ifdef CONFIG_KEXEC_CORE
685 .crash_shutdown = native_machine_crash_shutdown,
686#endif
687};
688
689void machine_power_off(void)
690{
691 machine_ops.power_off();
692}
693
694void machine_shutdown(void)
695{
696 machine_ops.shutdown();
697}
698
699void machine_emergency_restart(void)
700{
701 __machine_emergency_restart(1);
702}
703
704void machine_restart(char *cmd)
705{
706 machine_ops.restart(cmd);
707}
708
709void machine_halt(void)
710{
711 machine_ops.halt();
712}
713
714#ifdef CONFIG_KEXEC_CORE
715void machine_crash_shutdown(struct pt_regs *regs)
716{
717 machine_ops.crash_shutdown(regs);
718}
719#endif
720
721
722#if defined(CONFIG_SMP)
723
724/* This keeps a track of which one is crashing cpu. */
725static int crashing_cpu;
726static nmi_shootdown_cb shootdown_callback;
727
728static atomic_t waiting_for_crash_ipi;
729static int crash_ipi_issued;
730
731static int crash_nmi_callback(unsigned int val, struct pt_regs *regs)
732{
733 int cpu;
734
735 cpu = raw_smp_processor_id();
736
737 /*
738 * Don't do anything if this handler is invoked on crashing cpu.
739 * Otherwise, system will completely hang. Crashing cpu can get
740 * an NMI if system was initially booted with nmi_watchdog parameter.
741 */
742 if (cpu == crashing_cpu)
743 return NMI_HANDLED;
744 local_irq_disable();
745
746 shootdown_callback(cpu, regs);
747
748 atomic_dec(&waiting_for_crash_ipi);
749 /* Assume hlt works */
750 halt();
751 for (;;)
752 cpu_relax();
753
754 return NMI_HANDLED;
755}
756
757static void smp_send_nmi_allbutself(void)
758{
759 apic->send_IPI_allbutself(NMI_VECTOR);
760}
761
762/*
763 * Halt all other CPUs, calling the specified function on each of them
764 *
765 * This function can be used to halt all other CPUs on crash
766 * or emergency reboot time. The function passed as parameter
767 * will be called inside a NMI handler on all CPUs.
768 */
769void nmi_shootdown_cpus(nmi_shootdown_cb callback)
770{
771 unsigned long msecs;
772 local_irq_disable();
773
774 /* Make a note of crashing cpu. Will be used in NMI callback. */
775 crashing_cpu = safe_smp_processor_id();
776
777 shootdown_callback = callback;
778
779 atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
780 /* Would it be better to replace the trap vector here? */
781 if (register_nmi_handler(NMI_LOCAL, crash_nmi_callback,
782 NMI_FLAG_FIRST, "crash"))
783 return; /* Return what? */
784 /*
785 * Ensure the new callback function is set before sending
786 * out the NMI
787 */
788 wmb();
789
790 smp_send_nmi_allbutself();
791
792 /* Kick CPUs looping in NMI context. */
793 WRITE_ONCE(crash_ipi_issued, 1);
794
795 msecs = 1000; /* Wait at most a second for the other cpus to stop */
796 while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
797 mdelay(1);
798 msecs--;
799 }
800
801 /* Leave the nmi callback set */
802}
803
804/*
805 * Check if the crash dumping IPI got issued and if so, call its callback
806 * directly. This function is used when we have already been in NMI handler.
807 * It doesn't return.
808 */
809void run_crash_ipi_callback(struct pt_regs *regs)
810{
811 if (crash_ipi_issued)
812 crash_nmi_callback(0, regs);
813}
814
815/* Override the weak function in kernel/panic.c */
816void nmi_panic_self_stop(struct pt_regs *regs)
817{
818 while (1) {
819 /* If no CPU is preparing crash dump, we simply loop here. */
820 run_crash_ipi_callback(regs);
821 cpu_relax();
822 }
823}
824
825#else /* !CONFIG_SMP */
826void nmi_shootdown_cpus(nmi_shootdown_cb callback)
827{
828 /* No other CPUs to shoot down */
829}
830
831void run_crash_ipi_callback(struct pt_regs *regs)
832{
833}
834#endif