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