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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#include <linux/module.h>
2#include <linux/reboot.h>
3#include <linux/init.h>
4#include <linux/pm.h>
5#include <linux/efi.h>
6#include <linux/dmi.h>
7#include <linux/sched.h>
8#include <linux/tboot.h>
9#include <linux/delay.h>
10#include <acpi/reboot.h>
11#include <asm/io.h>
12#include <asm/apic.h>
13#include <asm/desc.h>
14#include <asm/hpet.h>
15#include <asm/pgtable.h>
16#include <asm/proto.h>
17#include <asm/reboot_fixups.h>
18#include <asm/reboot.h>
19#include <asm/pci_x86.h>
20#include <asm/virtext.h>
21#include <asm/cpu.h>
22#include <asm/nmi.h>
23
24#ifdef CONFIG_X86_32
25# include <linux/ctype.h>
26# include <linux/mc146818rtc.h>
27#else
28# include <asm/x86_init.h>
29#endif
30
31/*
32 * Power off function, if any
33 */
34void (*pm_power_off)(void);
35EXPORT_SYMBOL(pm_power_off);
36
37static const struct desc_ptr no_idt = {};
38static int reboot_mode;
39enum reboot_type reboot_type = BOOT_ACPI;
40int reboot_force;
41
42#if defined(CONFIG_X86_32) && defined(CONFIG_SMP)
43static int reboot_cpu = -1;
44#endif
45
46/* This is set if we need to go through the 'emergency' path.
47 * When machine_emergency_restart() is called, we may be on
48 * an inconsistent state and won't be able to do a clean cleanup
49 */
50static int reboot_emergency;
51
52/* This is set by the PCI code if either type 1 or type 2 PCI is detected */
53bool port_cf9_safe = false;
54
55/* reboot=b[ios] | s[mp] | t[riple] | k[bd] | e[fi] [, [w]arm | [c]old] | p[ci]
56 warm Don't set the cold reboot flag
57 cold Set the cold reboot flag
58 bios Reboot by jumping through the BIOS (only for X86_32)
59 smp Reboot by executing reset on BSP or other CPU (only for X86_32)
60 triple Force a triple fault (init)
61 kbd Use the keyboard controller. cold reset (default)
62 acpi Use the RESET_REG in the FADT
63 efi Use efi reset_system runtime service
64 pci Use the so-called "PCI reset register", CF9
65 force Avoid anything that could hang.
66 */
67static int __init reboot_setup(char *str)
68{
69 for (;;) {
70 switch (*str) {
71 case 'w':
72 reboot_mode = 0x1234;
73 break;
74
75 case 'c':
76 reboot_mode = 0;
77 break;
78
79#ifdef CONFIG_X86_32
80#ifdef CONFIG_SMP
81 case 's':
82 if (isdigit(*(str+1))) {
83 reboot_cpu = (int) (*(str+1) - '0');
84 if (isdigit(*(str+2)))
85 reboot_cpu = reboot_cpu*10 + (int)(*(str+2) - '0');
86 }
87 /* we will leave sorting out the final value
88 when we are ready to reboot, since we might not
89 have detected BSP APIC ID or smp_num_cpu */
90 break;
91#endif /* CONFIG_SMP */
92
93 case 'b':
94#endif
95 case 'a':
96 case 'k':
97 case 't':
98 case 'e':
99 case 'p':
100 reboot_type = *str;
101 break;
102
103 case 'f':
104 reboot_force = 1;
105 break;
106 }
107
108 str = strchr(str, ',');
109 if (str)
110 str++;
111 else
112 break;
113 }
114 return 1;
115}
116
117__setup("reboot=", reboot_setup);
118
119
120#ifdef CONFIG_X86_32
121/*
122 * Reboot options and system auto-detection code provided by
123 * Dell Inc. so their systems "just work". :-)
124 */
125
126/*
127 * Some machines require the "reboot=b" commandline option,
128 * this quirk makes that automatic.
129 */
130static int __init set_bios_reboot(const struct dmi_system_id *d)
131{
132 if (reboot_type != BOOT_BIOS) {
133 reboot_type = BOOT_BIOS;
134 printk(KERN_INFO "%s series board detected. Selecting BIOS-method for reboots.\n", d->ident);
135 }
136 return 0;
137}
138
139static struct dmi_system_id __initdata reboot_dmi_table[] = {
140 { /* Handle problems with rebooting on Dell E520's */
141 .callback = set_bios_reboot,
142 .ident = "Dell E520",
143 .matches = {
144 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
145 DMI_MATCH(DMI_PRODUCT_NAME, "Dell DM061"),
146 },
147 },
148 { /* Handle problems with rebooting on Dell 1300's */
149 .callback = set_bios_reboot,
150 .ident = "Dell PowerEdge 1300",
151 .matches = {
152 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
153 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1300/"),
154 },
155 },
156 { /* Handle problems with rebooting on Dell 300's */
157 .callback = set_bios_reboot,
158 .ident = "Dell PowerEdge 300",
159 .matches = {
160 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
161 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"),
162 },
163 },
164 { /* Handle problems with rebooting on Dell Optiplex 745's SFF*/
165 .callback = set_bios_reboot,
166 .ident = "Dell OptiPlex 745",
167 .matches = {
168 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
169 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
170 },
171 },
172 { /* Handle problems with rebooting on Dell Optiplex 745's DFF*/
173 .callback = set_bios_reboot,
174 .ident = "Dell OptiPlex 745",
175 .matches = {
176 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
177 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
178 DMI_MATCH(DMI_BOARD_NAME, "0MM599"),
179 },
180 },
181 { /* Handle problems with rebooting on Dell Optiplex 745 with 0KW626 */
182 .callback = set_bios_reboot,
183 .ident = "Dell OptiPlex 745",
184 .matches = {
185 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
186 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
187 DMI_MATCH(DMI_BOARD_NAME, "0KW626"),
188 },
189 },
190 { /* Handle problems with rebooting on Dell Optiplex 330 with 0KP561 */
191 .callback = set_bios_reboot,
192 .ident = "Dell OptiPlex 330",
193 .matches = {
194 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
195 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 330"),
196 DMI_MATCH(DMI_BOARD_NAME, "0KP561"),
197 },
198 },
199 { /* Handle problems with rebooting on Dell Optiplex 360 with 0T656F */
200 .callback = set_bios_reboot,
201 .ident = "Dell OptiPlex 360",
202 .matches = {
203 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
204 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 360"),
205 DMI_MATCH(DMI_BOARD_NAME, "0T656F"),
206 },
207 },
208 { /* Handle problems with rebooting on Dell OptiPlex 760 with 0G919G*/
209 .callback = set_bios_reboot,
210 .ident = "Dell OptiPlex 760",
211 .matches = {
212 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
213 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 760"),
214 DMI_MATCH(DMI_BOARD_NAME, "0G919G"),
215 },
216 },
217 { /* Handle problems with rebooting on Dell 2400's */
218 .callback = set_bios_reboot,
219 .ident = "Dell PowerEdge 2400",
220 .matches = {
221 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
222 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"),
223 },
224 },
225 { /* Handle problems with rebooting on Dell T5400's */
226 .callback = set_bios_reboot,
227 .ident = "Dell Precision T5400",
228 .matches = {
229 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
230 DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T5400"),
231 },
232 },
233 { /* Handle problems with rebooting on Dell T7400's */
234 .callback = set_bios_reboot,
235 .ident = "Dell Precision T7400",
236 .matches = {
237 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
238 DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T7400"),
239 },
240 },
241 { /* Handle problems with rebooting on HP laptops */
242 .callback = set_bios_reboot,
243 .ident = "HP Compaq Laptop",
244 .matches = {
245 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
246 DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"),
247 },
248 },
249 { /* Handle problems with rebooting on Dell XPS710 */
250 .callback = set_bios_reboot,
251 .ident = "Dell XPS710",
252 .matches = {
253 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
254 DMI_MATCH(DMI_PRODUCT_NAME, "Dell XPS710"),
255 },
256 },
257 { /* Handle problems with rebooting on Dell DXP061 */
258 .callback = set_bios_reboot,
259 .ident = "Dell DXP061",
260 .matches = {
261 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
262 DMI_MATCH(DMI_PRODUCT_NAME, "Dell DXP061"),
263 },
264 },
265 { /* Handle problems with rebooting on Sony VGN-Z540N */
266 .callback = set_bios_reboot,
267 .ident = "Sony VGN-Z540N",
268 .matches = {
269 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
270 DMI_MATCH(DMI_PRODUCT_NAME, "VGN-Z540N"),
271 },
272 },
273 { /* Handle problems with rebooting on CompuLab SBC-FITPC2 */
274 .callback = set_bios_reboot,
275 .ident = "CompuLab SBC-FITPC2",
276 .matches = {
277 DMI_MATCH(DMI_SYS_VENDOR, "CompuLab"),
278 DMI_MATCH(DMI_PRODUCT_NAME, "SBC-FITPC2"),
279 },
280 },
281 { /* Handle problems with rebooting on ASUS P4S800 */
282 .callback = set_bios_reboot,
283 .ident = "ASUS P4S800",
284 .matches = {
285 DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
286 DMI_MATCH(DMI_BOARD_NAME, "P4S800"),
287 },
288 },
289 { /* Handle problems with rebooting on VersaLogic Menlow boards */
290 .callback = set_bios_reboot,
291 .ident = "VersaLogic Menlow based board",
292 .matches = {
293 DMI_MATCH(DMI_BOARD_VENDOR, "VersaLogic Corporation"),
294 DMI_MATCH(DMI_BOARD_NAME, "VersaLogic Menlow board"),
295 },
296 },
297 { /* Handle reboot issue on Acer Aspire one */
298 .callback = set_bios_reboot,
299 .ident = "Acer Aspire One A110",
300 .matches = {
301 DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
302 DMI_MATCH(DMI_PRODUCT_NAME, "AOA110"),
303 },
304 },
305 { }
306};
307
308static int __init reboot_init(void)
309{
310 dmi_check_system(reboot_dmi_table);
311 return 0;
312}
313core_initcall(reboot_init);
314
315extern const unsigned char machine_real_restart_asm[];
316extern const u64 machine_real_restart_gdt[3];
317
318void machine_real_restart(unsigned int type)
319{
320 void *restart_va;
321 unsigned long restart_pa;
322 void (*restart_lowmem)(unsigned int);
323 u64 *lowmem_gdt;
324
325 local_irq_disable();
326
327 /* Write zero to CMOS register number 0x0f, which the BIOS POST
328 routine will recognize as telling it to do a proper reboot. (Well
329 that's what this book in front of me says -- it may only apply to
330 the Phoenix BIOS though, it's not clear). At the same time,
331 disable NMIs by setting the top bit in the CMOS address register,
332 as we're about to do peculiar things to the CPU. I'm not sure if
333 `outb_p' is needed instead of just `outb'. Use it to be on the
334 safe side. (Yes, CMOS_WRITE does outb_p's. - Paul G.)
335 */
336 spin_lock(&rtc_lock);
337 CMOS_WRITE(0x00, 0x8f);
338 spin_unlock(&rtc_lock);
339
340 /*
341 * Switch back to the initial page table.
342 */
343 load_cr3(initial_page_table);
344
345 /* Write 0x1234 to absolute memory location 0x472. The BIOS reads
346 this on booting to tell it to "Bypass memory test (also warm
347 boot)". This seems like a fairly standard thing that gets set by
348 REBOOT.COM programs, and the previous reset routine did this
349 too. */
350 *((unsigned short *)0x472) = reboot_mode;
351
352 /* Patch the GDT in the low memory trampoline */
353 lowmem_gdt = TRAMPOLINE_SYM(machine_real_restart_gdt);
354
355 restart_va = TRAMPOLINE_SYM(machine_real_restart_asm);
356 restart_pa = virt_to_phys(restart_va);
357 restart_lowmem = (void (*)(unsigned int))restart_pa;
358
359 /* GDT[0]: GDT self-pointer */
360 lowmem_gdt[0] =
361 (u64)(sizeof(machine_real_restart_gdt) - 1) +
362 ((u64)virt_to_phys(lowmem_gdt) << 16);
363 /* GDT[1]: 64K real mode code segment */
364 lowmem_gdt[1] =
365 GDT_ENTRY(0x009b, restart_pa, 0xffff);
366
367 /* Jump to the identity-mapped low memory code */
368 restart_lowmem(type);
369}
370#ifdef CONFIG_APM_MODULE
371EXPORT_SYMBOL(machine_real_restart);
372#endif
373
374#endif /* CONFIG_X86_32 */
375
376/*
377 * Some Apple MacBook and MacBookPro's needs reboot=p to be able to reboot
378 */
379static int __init set_pci_reboot(const struct dmi_system_id *d)
380{
381 if (reboot_type != BOOT_CF9) {
382 reboot_type = BOOT_CF9;
383 printk(KERN_INFO "%s series board detected. "
384 "Selecting PCI-method for reboots.\n", d->ident);
385 }
386 return 0;
387}
388
389static struct dmi_system_id __initdata pci_reboot_dmi_table[] = {
390 { /* Handle problems with rebooting on Apple MacBook5 */
391 .callback = set_pci_reboot,
392 .ident = "Apple MacBook5",
393 .matches = {
394 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
395 DMI_MATCH(DMI_PRODUCT_NAME, "MacBook5"),
396 },
397 },
398 { /* Handle problems with rebooting on Apple MacBookPro5 */
399 .callback = set_pci_reboot,
400 .ident = "Apple MacBookPro5",
401 .matches = {
402 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
403 DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro5"),
404 },
405 },
406 { /* Handle problems with rebooting on Apple Macmini3,1 */
407 .callback = set_pci_reboot,
408 .ident = "Apple Macmini3,1",
409 .matches = {
410 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
411 DMI_MATCH(DMI_PRODUCT_NAME, "Macmini3,1"),
412 },
413 },
414 { /* Handle problems with rebooting on the iMac9,1. */
415 .callback = set_pci_reboot,
416 .ident = "Apple iMac9,1",
417 .matches = {
418 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
419 DMI_MATCH(DMI_PRODUCT_NAME, "iMac9,1"),
420 },
421 },
422 { /* Handle problems with rebooting on the Latitude E6320. */
423 .callback = set_pci_reboot,
424 .ident = "Dell Latitude E6320",
425 .matches = {
426 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
427 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6320"),
428 },
429 },
430 { /* Handle problems with rebooting on the Latitude E5420. */
431 .callback = set_pci_reboot,
432 .ident = "Dell Latitude E5420",
433 .matches = {
434 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
435 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E5420"),
436 },
437 },
438 { /* Handle problems with rebooting on the Latitude E6420. */
439 .callback = set_pci_reboot,
440 .ident = "Dell Latitude E6420",
441 .matches = {
442 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
443 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6420"),
444 },
445 },
446 { }
447};
448
449static int __init pci_reboot_init(void)
450{
451 dmi_check_system(pci_reboot_dmi_table);
452 return 0;
453}
454core_initcall(pci_reboot_init);
455
456static inline void kb_wait(void)
457{
458 int i;
459
460 for (i = 0; i < 0x10000; i++) {
461 if ((inb(0x64) & 0x02) == 0)
462 break;
463 udelay(2);
464 }
465}
466
467static void vmxoff_nmi(int cpu, struct die_args *args)
468{
469 cpu_emergency_vmxoff();
470}
471
472/* Use NMIs as IPIs to tell all CPUs to disable virtualization
473 */
474static void emergency_vmx_disable_all(void)
475{
476 /* Just make sure we won't change CPUs while doing this */
477 local_irq_disable();
478
479 /* We need to disable VMX on all CPUs before rebooting, otherwise
480 * we risk hanging up the machine, because the CPU ignore INIT
481 * signals when VMX is enabled.
482 *
483 * We can't take any locks and we may be on an inconsistent
484 * state, so we use NMIs as IPIs to tell the other CPUs to disable
485 * VMX and halt.
486 *
487 * For safety, we will avoid running the nmi_shootdown_cpus()
488 * stuff unnecessarily, but we don't have a way to check
489 * if other CPUs have VMX enabled. So we will call it only if the
490 * CPU we are running on has VMX enabled.
491 *
492 * We will miss cases where VMX is not enabled on all CPUs. This
493 * shouldn't do much harm because KVM always enable VMX on all
494 * CPUs anyway. But we can miss it on the small window where KVM
495 * is still enabling VMX.
496 */
497 if (cpu_has_vmx() && cpu_vmx_enabled()) {
498 /* Disable VMX on this CPU.
499 */
500 cpu_vmxoff();
501
502 /* Halt and disable VMX on the other CPUs */
503 nmi_shootdown_cpus(vmxoff_nmi);
504
505 }
506}
507
508
509void __attribute__((weak)) mach_reboot_fixups(void)
510{
511}
512
513/*
514 * Windows compatible x86 hardware expects the following on reboot:
515 *
516 * 1) If the FADT has the ACPI reboot register flag set, try it
517 * 2) If still alive, write to the keyboard controller
518 * 3) If still alive, write to the ACPI reboot register again
519 * 4) If still alive, write to the keyboard controller again
520 *
521 * If the machine is still alive at this stage, it gives up. We default to
522 * following the same pattern, except that if we're still alive after (4) we'll
523 * try to force a triple fault and then cycle between hitting the keyboard
524 * controller and doing that
525 */
526static void native_machine_emergency_restart(void)
527{
528 int i;
529 int attempt = 0;
530 int orig_reboot_type = reboot_type;
531
532 if (reboot_emergency)
533 emergency_vmx_disable_all();
534
535 tboot_shutdown(TB_SHUTDOWN_REBOOT);
536
537 /* Tell the BIOS if we want cold or warm reboot */
538 *((unsigned short *)__va(0x472)) = reboot_mode;
539
540 for (;;) {
541 /* Could also try the reset bit in the Hammer NB */
542 switch (reboot_type) {
543 case BOOT_KBD:
544 mach_reboot_fixups(); /* for board specific fixups */
545
546 for (i = 0; i < 10; i++) {
547 kb_wait();
548 udelay(50);
549 outb(0xfe, 0x64); /* pulse reset low */
550 udelay(50);
551 }
552 if (attempt == 0 && orig_reboot_type == BOOT_ACPI) {
553 attempt = 1;
554 reboot_type = BOOT_ACPI;
555 } else {
556 reboot_type = BOOT_TRIPLE;
557 }
558 break;
559
560 case BOOT_TRIPLE:
561 load_idt(&no_idt);
562 __asm__ __volatile__("int3");
563
564 reboot_type = BOOT_KBD;
565 break;
566
567#ifdef CONFIG_X86_32
568 case BOOT_BIOS:
569 machine_real_restart(MRR_BIOS);
570
571 reboot_type = BOOT_KBD;
572 break;
573#endif
574
575 case BOOT_ACPI:
576 acpi_reboot();
577 reboot_type = BOOT_KBD;
578 break;
579
580 case BOOT_EFI:
581 if (efi_enabled)
582 efi.reset_system(reboot_mode ?
583 EFI_RESET_WARM :
584 EFI_RESET_COLD,
585 EFI_SUCCESS, 0, NULL);
586 reboot_type = BOOT_KBD;
587 break;
588
589 case BOOT_CF9:
590 port_cf9_safe = true;
591 /* fall through */
592
593 case BOOT_CF9_COND:
594 if (port_cf9_safe) {
595 u8 cf9 = inb(0xcf9) & ~6;
596 outb(cf9|2, 0xcf9); /* Request hard reset */
597 udelay(50);
598 outb(cf9|6, 0xcf9); /* Actually do the reset */
599 udelay(50);
600 }
601 reboot_type = BOOT_KBD;
602 break;
603 }
604 }
605}
606
607void native_machine_shutdown(void)
608{
609 /* Stop the cpus and apics */
610#ifdef CONFIG_SMP
611
612 /* The boot cpu is always logical cpu 0 */
613 int reboot_cpu_id = 0;
614
615#ifdef CONFIG_X86_32
616 /* See if there has been given a command line override */
617 if ((reboot_cpu != -1) && (reboot_cpu < nr_cpu_ids) &&
618 cpu_online(reboot_cpu))
619 reboot_cpu_id = reboot_cpu;
620#endif
621
622 /* Make certain the cpu I'm about to reboot on is online */
623 if (!cpu_online(reboot_cpu_id))
624 reboot_cpu_id = smp_processor_id();
625
626 /* Make certain I only run on the appropriate processor */
627 set_cpus_allowed_ptr(current, cpumask_of(reboot_cpu_id));
628
629 /* O.K Now that I'm on the appropriate processor,
630 * stop all of the others.
631 */
632 stop_other_cpus();
633#endif
634
635 lapic_shutdown();
636
637#ifdef CONFIG_X86_IO_APIC
638 disable_IO_APIC();
639#endif
640
641#ifdef CONFIG_HPET_TIMER
642 hpet_disable();
643#endif
644
645#ifdef CONFIG_X86_64
646 x86_platform.iommu_shutdown();
647#endif
648}
649
650static void __machine_emergency_restart(int emergency)
651{
652 reboot_emergency = emergency;
653 machine_ops.emergency_restart();
654}
655
656static void native_machine_restart(char *__unused)
657{
658 printk("machine restart\n");
659
660 if (!reboot_force)
661 machine_shutdown();
662 __machine_emergency_restart(0);
663}
664
665static void native_machine_halt(void)
666{
667 /* stop other cpus and apics */
668 machine_shutdown();
669
670 tboot_shutdown(TB_SHUTDOWN_HALT);
671
672 /* stop this cpu */
673 stop_this_cpu(NULL);
674}
675
676static void native_machine_power_off(void)
677{
678 if (pm_power_off) {
679 if (!reboot_force)
680 machine_shutdown();
681 pm_power_off();
682 }
683 /* a fallback in case there is no PM info available */
684 tboot_shutdown(TB_SHUTDOWN_HALT);
685}
686
687struct machine_ops machine_ops = {
688 .power_off = native_machine_power_off,
689 .shutdown = native_machine_shutdown,
690 .emergency_restart = native_machine_emergency_restart,
691 .restart = native_machine_restart,
692 .halt = native_machine_halt,
693#ifdef CONFIG_KEXEC
694 .crash_shutdown = native_machine_crash_shutdown,
695#endif
696};
697
698void machine_power_off(void)
699{
700 machine_ops.power_off();
701}
702
703void machine_shutdown(void)
704{
705 machine_ops.shutdown();
706}
707
708void machine_emergency_restart(void)
709{
710 __machine_emergency_restart(1);
711}
712
713void machine_restart(char *cmd)
714{
715 machine_ops.restart(cmd);
716}
717
718void machine_halt(void)
719{
720 machine_ops.halt();
721}
722
723#ifdef CONFIG_KEXEC
724void machine_crash_shutdown(struct pt_regs *regs)
725{
726 machine_ops.crash_shutdown(regs);
727}
728#endif
729
730
731#if defined(CONFIG_SMP)
732
733/* This keeps a track of which one is crashing cpu. */
734static int crashing_cpu;
735static nmi_shootdown_cb shootdown_callback;
736
737static atomic_t waiting_for_crash_ipi;
738
739static int crash_nmi_callback(struct notifier_block *self,
740 unsigned long val, void *data)
741{
742 int cpu;
743
744 if (val != DIE_NMI)
745 return NOTIFY_OK;
746
747 cpu = raw_smp_processor_id();
748
749 /* Don't do anything if this handler is invoked on crashing cpu.
750 * Otherwise, system will completely hang. Crashing cpu can get
751 * an NMI if system was initially booted with nmi_watchdog parameter.
752 */
753 if (cpu == crashing_cpu)
754 return NOTIFY_STOP;
755 local_irq_disable();
756
757 shootdown_callback(cpu, (struct die_args *)data);
758
759 atomic_dec(&waiting_for_crash_ipi);
760 /* Assume hlt works */
761 halt();
762 for (;;)
763 cpu_relax();
764
765 return 1;
766}
767
768static void smp_send_nmi_allbutself(void)
769{
770 apic->send_IPI_allbutself(NMI_VECTOR);
771}
772
773static struct notifier_block crash_nmi_nb = {
774 .notifier_call = crash_nmi_callback,
775 /* we want to be the first one called */
776 .priority = NMI_LOCAL_HIGH_PRIOR+1,
777};
778
779/* Halt all other CPUs, calling the specified function on each of them
780 *
781 * This function can be used to halt all other CPUs on crash
782 * or emergency reboot time. The function passed as parameter
783 * will be called inside a NMI handler on all CPUs.
784 */
785void nmi_shootdown_cpus(nmi_shootdown_cb callback)
786{
787 unsigned long msecs;
788 local_irq_disable();
789
790 /* Make a note of crashing cpu. Will be used in NMI callback.*/
791 crashing_cpu = safe_smp_processor_id();
792
793 shootdown_callback = callback;
794
795 atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
796 /* Would it be better to replace the trap vector here? */
797 if (register_die_notifier(&crash_nmi_nb))
798 return; /* return what? */
799 /* Ensure the new callback function is set before sending
800 * out the NMI
801 */
802 wmb();
803
804 smp_send_nmi_allbutself();
805
806 msecs = 1000; /* Wait at most a second for the other cpus to stop */
807 while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
808 mdelay(1);
809 msecs--;
810 }
811
812 /* Leave the nmi callback set */
813}
814#else /* !CONFIG_SMP */
815void nmi_shootdown_cpus(nmi_shootdown_cb callback)
816{
817 /* No other CPUs to shoot down */
818}
819#endif