1 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
2
3 #include <linux/export.h>
4 #include <linux/reboot.h>
5 #include <linux/init.h>
6 #include <linux/pm.h>
7 #include <linux/efi.h>
8 #include <linux/dmi.h>
9 #include <linux/sched.h>
10 #include <linux/tboot.h>
11 #include <linux/delay.h>
12 #include <acpi/reboot.h>
13 #include <asm/io.h>
14 #include <asm/apic.h>
15 #include <asm/io_apic.h>
16 #include <asm/desc.h>
17 #include <asm/hpet.h>
18 #include <asm/pgtable.h>
19 #include <asm/proto.h>
20 #include <asm/reboot_fixups.h>
21 #include <asm/reboot.h>
22 #include <asm/pci_x86.h>
23 #include <asm/virtext.h>
24 #include <asm/cpu.h>
25 #include <asm/nmi.h>
26 #include <asm/smp.h>
27
28 #include <linux/ctype.h>
29 #include <linux/mc146818rtc.h>
30 #include <asm/realmode.h>
31 #include <asm/x86_init.h>
32 #include <asm/efi.h>
33
34 /*
35 * Power off function, if any
36 */
37 void (*pm_power_off)(void);
38 EXPORT_SYMBOL(pm_power_off);
39
40 static 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 */
47 static int reboot_emergency;
48
49 /* This is set by the PCI code if either type 1 or type 2 PCI is detected */
50 bool 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 */
set_acpi_reboot(const struct dmi_system_id * d)60 static 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 */
set_bios_reboot(const struct dmi_system_id * d)74 static 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
machine_real_restart(unsigned int type)84 void __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
128 EXPORT_SYMBOL(machine_real_restart);
129 #endif
130
131 /*
132 * Some Apple MacBook and MacBookPro's needs reboot=p to be able to reboot
133 */
set_pci_reboot(const struct dmi_system_id * d)134 static int __init set_pci_reboot(const struct dmi_system_id *d)
135 {
136 if (reboot_type != BOOT_CF9_FORCE) {
137 reboot_type = BOOT_CF9_FORCE;
138 pr_info("%s series board detected. Selecting %s-method for reboots.\n",
139 d->ident, "PCI");
140 }
141 return 0;
142 }
143
set_kbd_reboot(const struct dmi_system_id * d)144 static int __init set_kbd_reboot(const struct dmi_system_id *d)
145 {
146 if (reboot_type != BOOT_KBD) {
147 reboot_type = BOOT_KBD;
148 pr_info("%s series board detected. Selecting %s-method for reboot.\n",
149 d->ident, "KBD");
150 }
151 return 0;
152 }
153
154 /*
155 * This is a single dmi_table handling all reboot quirks.
156 */
157 static struct dmi_system_id __initdata reboot_dmi_table[] = {
158
159 /* Acer */
160 { /* Handle reboot issue on Acer Aspire one */
161 .callback = set_kbd_reboot,
162 .ident = "Acer Aspire One A110",
163 .matches = {
164 DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
165 DMI_MATCH(DMI_PRODUCT_NAME, "AOA110"),
166 },
167 },
168
169 /* Apple */
170 { /* Handle problems with rebooting on Apple MacBook5 */
171 .callback = set_pci_reboot,
172 .ident = "Apple MacBook5",
173 .matches = {
174 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
175 DMI_MATCH(DMI_PRODUCT_NAME, "MacBook5"),
176 },
177 },
178 { /* Handle problems with rebooting on Apple MacBookPro5 */
179 .callback = set_pci_reboot,
180 .ident = "Apple MacBookPro5",
181 .matches = {
182 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
183 DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro5"),
184 },
185 },
186 { /* Handle problems with rebooting on Apple Macmini3,1 */
187 .callback = set_pci_reboot,
188 .ident = "Apple Macmini3,1",
189 .matches = {
190 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
191 DMI_MATCH(DMI_PRODUCT_NAME, "Macmini3,1"),
192 },
193 },
194 { /* Handle problems with rebooting on the iMac9,1. */
195 .callback = set_pci_reboot,
196 .ident = "Apple iMac9,1",
197 .matches = {
198 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
199 DMI_MATCH(DMI_PRODUCT_NAME, "iMac9,1"),
200 },
201 },
202 { /* Handle problems with rebooting on the iMac10,1. */
203 .callback = set_pci_reboot,
204 .ident = "Apple iMac10,1",
205 .matches = {
206 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
207 DMI_MATCH(DMI_PRODUCT_NAME, "iMac10,1"),
208 },
209 },
210
211 /* ASRock */
212 { /* Handle problems with rebooting on ASRock Q1900DC-ITX */
213 .callback = set_pci_reboot,
214 .ident = "ASRock Q1900DC-ITX",
215 .matches = {
216 DMI_MATCH(DMI_BOARD_VENDOR, "ASRock"),
217 DMI_MATCH(DMI_BOARD_NAME, "Q1900DC-ITX"),
218 },
219 },
220
221 /* ASUS */
222 { /* Handle problems with rebooting on ASUS P4S800 */
223 .callback = set_bios_reboot,
224 .ident = "ASUS P4S800",
225 .matches = {
226 DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
227 DMI_MATCH(DMI_BOARD_NAME, "P4S800"),
228 },
229 },
230 { /* Handle problems with rebooting on ASUS EeeBook X205TA */
231 .callback = set_acpi_reboot,
232 .ident = "ASUS EeeBook X205TA",
233 .matches = {
234 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
235 DMI_MATCH(DMI_PRODUCT_NAME, "X205TA"),
236 },
237 },
238 { /* Handle problems with rebooting on ASUS EeeBook X205TAW */
239 .callback = set_acpi_reboot,
240 .ident = "ASUS EeeBook X205TAW",
241 .matches = {
242 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
243 DMI_MATCH(DMI_PRODUCT_NAME, "X205TAW"),
244 },
245 },
246
247 /* Certec */
248 { /* Handle problems with rebooting on Certec BPC600 */
249 .callback = set_pci_reboot,
250 .ident = "Certec BPC600",
251 .matches = {
252 DMI_MATCH(DMI_SYS_VENDOR, "Certec"),
253 DMI_MATCH(DMI_PRODUCT_NAME, "BPC600"),
254 },
255 },
256
257 /* Dell */
258 { /* Handle problems with rebooting on Dell DXP061 */
259 .callback = set_bios_reboot,
260 .ident = "Dell DXP061",
261 .matches = {
262 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
263 DMI_MATCH(DMI_PRODUCT_NAME, "Dell DXP061"),
264 },
265 },
266 { /* Handle problems with rebooting on Dell E520's */
267 .callback = set_bios_reboot,
268 .ident = "Dell E520",
269 .matches = {
270 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
271 DMI_MATCH(DMI_PRODUCT_NAME, "Dell DM061"),
272 },
273 },
274 { /* Handle problems with rebooting on the Latitude E5410. */
275 .callback = set_pci_reboot,
276 .ident = "Dell Latitude E5410",
277 .matches = {
278 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
279 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E5410"),
280 },
281 },
282 { /* Handle problems with rebooting on the Latitude E5420. */
283 .callback = set_pci_reboot,
284 .ident = "Dell Latitude E5420",
285 .matches = {
286 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
287 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E5420"),
288 },
289 },
290 { /* Handle problems with rebooting on the Latitude E6320. */
291 .callback = set_pci_reboot,
292 .ident = "Dell Latitude E6320",
293 .matches = {
294 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
295 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6320"),
296 },
297 },
298 { /* Handle problems with rebooting on the Latitude E6420. */
299 .callback = set_pci_reboot,
300 .ident = "Dell Latitude E6420",
301 .matches = {
302 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
303 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6420"),
304 },
305 },
306 { /* Handle problems with rebooting on Dell Optiplex 330 with 0KP561 */
307 .callback = set_bios_reboot,
308 .ident = "Dell OptiPlex 330",
309 .matches = {
310 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
311 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 330"),
312 DMI_MATCH(DMI_BOARD_NAME, "0KP561"),
313 },
314 },
315 { /* Handle problems with rebooting on Dell Optiplex 360 with 0T656F */
316 .callback = set_bios_reboot,
317 .ident = "Dell OptiPlex 360",
318 .matches = {
319 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
320 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 360"),
321 DMI_MATCH(DMI_BOARD_NAME, "0T656F"),
322 },
323 },
324 { /* Handle problems with rebooting on Dell Optiplex 745's SFF */
325 .callback = set_bios_reboot,
326 .ident = "Dell OptiPlex 745",
327 .matches = {
328 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
329 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
330 },
331 },
332 { /* Handle problems with rebooting on Dell Optiplex 745's DFF */
333 .callback = set_bios_reboot,
334 .ident = "Dell OptiPlex 745",
335 .matches = {
336 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
337 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
338 DMI_MATCH(DMI_BOARD_NAME, "0MM599"),
339 },
340 },
341 { /* Handle problems with rebooting on Dell Optiplex 745 with 0KW626 */
342 .callback = set_bios_reboot,
343 .ident = "Dell OptiPlex 745",
344 .matches = {
345 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
346 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
347 DMI_MATCH(DMI_BOARD_NAME, "0KW626"),
348 },
349 },
350 { /* Handle problems with rebooting on Dell OptiPlex 760 with 0G919G */
351 .callback = set_bios_reboot,
352 .ident = "Dell OptiPlex 760",
353 .matches = {
354 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
355 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 760"),
356 DMI_MATCH(DMI_BOARD_NAME, "0G919G"),
357 },
358 },
359 { /* Handle problems with rebooting on the OptiPlex 990. */
360 .callback = set_pci_reboot,
361 .ident = "Dell OptiPlex 990",
362 .matches = {
363 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
364 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 990"),
365 },
366 },
367 { /* Handle problems with rebooting on Dell 300's */
368 .callback = set_bios_reboot,
369 .ident = "Dell PowerEdge 300",
370 .matches = {
371 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
372 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"),
373 },
374 },
375 { /* Handle problems with rebooting on Dell 1300's */
376 .callback = set_bios_reboot,
377 .ident = "Dell PowerEdge 1300",
378 .matches = {
379 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
380 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1300/"),
381 },
382 },
383 { /* Handle problems with rebooting on Dell 2400's */
384 .callback = set_bios_reboot,
385 .ident = "Dell PowerEdge 2400",
386 .matches = {
387 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
388 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"),
389 },
390 },
391 { /* Handle problems with rebooting on the Dell PowerEdge C6100. */
392 .callback = set_pci_reboot,
393 .ident = "Dell PowerEdge C6100",
394 .matches = {
395 DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
396 DMI_MATCH(DMI_PRODUCT_NAME, "C6100"),
397 },
398 },
399 { /* Handle problems with rebooting on the Precision M6600. */
400 .callback = set_pci_reboot,
401 .ident = "Dell Precision M6600",
402 .matches = {
403 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
404 DMI_MATCH(DMI_PRODUCT_NAME, "Precision M6600"),
405 },
406 },
407 { /* Handle problems with rebooting on Dell T5400's */
408 .callback = set_bios_reboot,
409 .ident = "Dell Precision T5400",
410 .matches = {
411 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
412 DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T5400"),
413 },
414 },
415 { /* Handle problems with rebooting on Dell T7400's */
416 .callback = set_bios_reboot,
417 .ident = "Dell Precision T7400",
418 .matches = {
419 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
420 DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T7400"),
421 },
422 },
423 { /* Handle problems with rebooting on Dell XPS710 */
424 .callback = set_bios_reboot,
425 .ident = "Dell XPS710",
426 .matches = {
427 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
428 DMI_MATCH(DMI_PRODUCT_NAME, "Dell XPS710"),
429 },
430 },
431 { /* Handle problems with rebooting on Dell Optiplex 7450 AIO */
432 .callback = set_acpi_reboot,
433 .ident = "Dell OptiPlex 7450 AIO",
434 .matches = {
435 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
436 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 7450 AIO"),
437 },
438 },
439
440 /* Hewlett-Packard */
441 { /* Handle problems with rebooting on HP laptops */
442 .callback = set_bios_reboot,
443 .ident = "HP Compaq Laptop",
444 .matches = {
445 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
446 DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"),
447 },
448 },
449
450 /* Sony */
451 { /* Handle problems with rebooting on Sony VGN-Z540N */
452 .callback = set_bios_reboot,
453 .ident = "Sony VGN-Z540N",
454 .matches = {
455 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
456 DMI_MATCH(DMI_PRODUCT_NAME, "VGN-Z540N"),
457 },
458 },
459
460 { }
461 };
462
reboot_init(void)463 static int __init reboot_init(void)
464 {
465 int rv;
466
467 /*
468 * Only do the DMI check if reboot_type hasn't been overridden
469 * on the command line
470 */
471 if (!reboot_default)
472 return 0;
473
474 /*
475 * The DMI quirks table takes precedence. If no quirks entry
476 * matches and the ACPI Hardware Reduced bit is set, force EFI
477 * reboot.
478 */
479 rv = dmi_check_system(reboot_dmi_table);
480
481 if (!rv && efi_reboot_required())
482 reboot_type = BOOT_EFI;
483
484 return 0;
485 }
486 core_initcall(reboot_init);
487
kb_wait(void)488 static inline void kb_wait(void)
489 {
490 int i;
491
492 for (i = 0; i < 0x10000; i++) {
493 if ((inb(0x64) & 0x02) == 0)
494 break;
495 udelay(2);
496 }
497 }
498
vmxoff_nmi(int cpu,struct pt_regs * regs)499 static void vmxoff_nmi(int cpu, struct pt_regs *regs)
500 {
501 cpu_emergency_vmxoff();
502 }
503
504 /* Use NMIs as IPIs to tell all CPUs to disable virtualization */
emergency_vmx_disable_all(void)505 static void emergency_vmx_disable_all(void)
506 {
507 /* Just make sure we won't change CPUs while doing this */
508 local_irq_disable();
509
510 /*
511 * We need to disable VMX on all CPUs before rebooting, otherwise
512 * we risk hanging up the machine, because the CPU ignore INIT
513 * signals when VMX is enabled.
514 *
515 * We can't take any locks and we may be on an inconsistent
516 * state, so we use NMIs as IPIs to tell the other CPUs to disable
517 * VMX and halt.
518 *
519 * For safety, we will avoid running the nmi_shootdown_cpus()
520 * stuff unnecessarily, but we don't have a way to check
521 * if other CPUs have VMX enabled. So we will call it only if the
522 * CPU we are running on has VMX enabled.
523 *
524 * We will miss cases where VMX is not enabled on all CPUs. This
525 * shouldn't do much harm because KVM always enable VMX on all
526 * CPUs anyway. But we can miss it on the small window where KVM
527 * is still enabling VMX.
528 */
529 if (cpu_has_vmx() && cpu_vmx_enabled()) {
530 /* Disable VMX on this CPU. */
531 cpu_vmxoff();
532
533 /* Halt and disable VMX on the other CPUs */
534 nmi_shootdown_cpus(vmxoff_nmi);
535
536 }
537 }
538
539
mach_reboot_fixups(void)540 void __attribute__((weak)) mach_reboot_fixups(void)
541 {
542 }
543
544 /*
545 * To the best of our knowledge Windows compatible x86 hardware expects
546 * the following on reboot:
547 *
548 * 1) If the FADT has the ACPI reboot register flag set, try it
549 * 2) If still alive, write to the keyboard controller
550 * 3) If still alive, write to the ACPI reboot register again
551 * 4) If still alive, write to the keyboard controller again
552 * 5) If still alive, call the EFI runtime service to reboot
553 * 6) If no EFI runtime service, call the BIOS to do a reboot
554 *
555 * We default to following the same pattern. We also have
556 * two other reboot methods: 'triple fault' and 'PCI', which
557 * can be triggered via the reboot= kernel boot option or
558 * via quirks.
559 *
560 * This means that this function can never return, it can misbehave
561 * by not rebooting properly and hanging.
562 */
native_machine_emergency_restart(void)563 static void native_machine_emergency_restart(void)
564 {
565 int i;
566 int attempt = 0;
567 int orig_reboot_type = reboot_type;
568 unsigned short mode;
569
570 if (reboot_emergency)
571 emergency_vmx_disable_all();
572
573 tboot_shutdown(TB_SHUTDOWN_REBOOT);
574
575 /* Tell the BIOS if we want cold or warm reboot */
576 mode = reboot_mode == REBOOT_WARM ? 0x1234 : 0;
577 *((unsigned short *)__va(0x472)) = mode;
578
579 /*
580 * If an EFI capsule has been registered with the firmware then
581 * override the reboot= parameter.
582 */
583 if (efi_capsule_pending(NULL)) {
584 pr_info("EFI capsule is pending, forcing EFI reboot.\n");
585 reboot_type = BOOT_EFI;
586 }
587
588 for (;;) {
589 /* Could also try the reset bit in the Hammer NB */
590 switch (reboot_type) {
591 case BOOT_ACPI:
592 acpi_reboot();
593 reboot_type = BOOT_KBD;
594 break;
595
596 case BOOT_KBD:
597 mach_reboot_fixups(); /* For board specific fixups */
598
599 for (i = 0; i < 10; i++) {
600 kb_wait();
601 udelay(50);
602 outb(0xfe, 0x64); /* Pulse reset low */
603 udelay(50);
604 }
605 if (attempt == 0 && orig_reboot_type == BOOT_ACPI) {
606 attempt = 1;
607 reboot_type = BOOT_ACPI;
608 } else {
609 reboot_type = BOOT_EFI;
610 }
611 break;
612
613 case BOOT_EFI:
614 efi_reboot(reboot_mode, NULL);
615 reboot_type = BOOT_BIOS;
616 break;
617
618 case BOOT_BIOS:
619 machine_real_restart(MRR_BIOS);
620
621 /* We're probably dead after this, but... */
622 reboot_type = BOOT_CF9_SAFE;
623 break;
624
625 case BOOT_CF9_FORCE:
626 port_cf9_safe = true;
627 /* Fall through */
628
629 case BOOT_CF9_SAFE:
630 if (port_cf9_safe) {
631 u8 reboot_code = reboot_mode == REBOOT_WARM ? 0x06 : 0x0E;
632 u8 cf9 = inb(0xcf9) & ~reboot_code;
633 outb(cf9|2, 0xcf9); /* Request hard reset */
634 udelay(50);
635 /* Actually do the reset */
636 outb(cf9|reboot_code, 0xcf9);
637 udelay(50);
638 }
639 reboot_type = BOOT_TRIPLE;
640 break;
641
642 case BOOT_TRIPLE:
643 load_idt(&no_idt);
644 __asm__ __volatile__("int3");
645
646 /* We're probably dead after this, but... */
647 reboot_type = BOOT_KBD;
648 break;
649 }
650 }
651 }
652
native_machine_shutdown(void)653 void native_machine_shutdown(void)
654 {
655 /* Stop the cpus and apics */
656 #ifdef CONFIG_X86_IO_APIC
657 /*
658 * Disabling IO APIC before local APIC is a workaround for
659 * erratum AVR31 in "Intel Atom Processor C2000 Product Family
660 * Specification Update". In this situation, interrupts that target
661 * a Logical Processor whose Local APIC is either in the process of
662 * being hardware disabled or software disabled are neither delivered
663 * nor discarded. When this erratum occurs, the processor may hang.
664 *
665 * Even without the erratum, it still makes sense to quiet IO APIC
666 * before disabling Local APIC.
667 */
668 disable_IO_APIC();
669 #endif
670
671 #ifdef CONFIG_SMP
672 /*
673 * Stop all of the others. Also disable the local irq to
674 * not receive the per-cpu timer interrupt which may trigger
675 * scheduler's load balance.
676 */
677 local_irq_disable();
678 stop_other_cpus();
679 #endif
680
681 lapic_shutdown();
682
683 #ifdef CONFIG_HPET_TIMER
684 hpet_disable();
685 #endif
686
687 #ifdef CONFIG_X86_64
688 x86_platform.iommu_shutdown();
689 #endif
690 }
691
__machine_emergency_restart(int emergency)692 static void __machine_emergency_restart(int emergency)
693 {
694 reboot_emergency = emergency;
695 machine_ops.emergency_restart();
696 }
697
native_machine_restart(char * __unused)698 static void native_machine_restart(char *__unused)
699 {
700 pr_notice("machine restart\n");
701
702 if (!reboot_force)
703 machine_shutdown();
704 __machine_emergency_restart(0);
705 }
706
native_machine_halt(void)707 static void native_machine_halt(void)
708 {
709 /* Stop other cpus and apics */
710 machine_shutdown();
711
712 tboot_shutdown(TB_SHUTDOWN_HALT);
713
714 stop_this_cpu(NULL);
715 }
716
native_machine_power_off(void)717 static void native_machine_power_off(void)
718 {
719 if (pm_power_off) {
720 if (!reboot_force)
721 machine_shutdown();
722 pm_power_off();
723 }
724 /* A fallback in case there is no PM info available */
725 tboot_shutdown(TB_SHUTDOWN_HALT);
726 }
727
728 struct machine_ops machine_ops __ro_after_init = {
729 .power_off = native_machine_power_off,
730 .shutdown = native_machine_shutdown,
731 .emergency_restart = native_machine_emergency_restart,
732 .restart = native_machine_restart,
733 .halt = native_machine_halt,
734 #ifdef CONFIG_KEXEC_CORE
735 .crash_shutdown = native_machine_crash_shutdown,
736 #endif
737 };
738
machine_power_off(void)739 void machine_power_off(void)
740 {
741 machine_ops.power_off();
742 }
743
machine_shutdown(void)744 void machine_shutdown(void)
745 {
746 machine_ops.shutdown();
747 }
748
machine_emergency_restart(void)749 void machine_emergency_restart(void)
750 {
751 __machine_emergency_restart(1);
752 }
753
machine_restart(char * cmd)754 void machine_restart(char *cmd)
755 {
756 machine_ops.restart(cmd);
757 }
758
machine_halt(void)759 void machine_halt(void)
760 {
761 machine_ops.halt();
762 }
763
764 #ifdef CONFIG_KEXEC_CORE
machine_crash_shutdown(struct pt_regs * regs)765 void machine_crash_shutdown(struct pt_regs *regs)
766 {
767 machine_ops.crash_shutdown(regs);
768 }
769 #endif
770
771
772 /* This is the CPU performing the emergency shutdown work. */
773 int crashing_cpu = -1;
774
775 #if defined(CONFIG_SMP)
776
777 static nmi_shootdown_cb shootdown_callback;
778
779 static atomic_t waiting_for_crash_ipi;
780 static int crash_ipi_issued;
781
crash_nmi_callback(unsigned int val,struct pt_regs * regs)782 static int crash_nmi_callback(unsigned int val, struct pt_regs *regs)
783 {
784 int cpu;
785
786 cpu = raw_smp_processor_id();
787
788 /*
789 * Don't do anything if this handler is invoked on crashing cpu.
790 * Otherwise, system will completely hang. Crashing cpu can get
791 * an NMI if system was initially booted with nmi_watchdog parameter.
792 */
793 if (cpu == crashing_cpu)
794 return NMI_HANDLED;
795 local_irq_disable();
796
797 shootdown_callback(cpu, regs);
798
799 atomic_dec(&waiting_for_crash_ipi);
800 /* Assume hlt works */
801 halt();
802 for (;;)
803 cpu_relax();
804
805 return NMI_HANDLED;
806 }
807
smp_send_nmi_allbutself(void)808 static void smp_send_nmi_allbutself(void)
809 {
810 apic->send_IPI_allbutself(NMI_VECTOR);
811 }
812
813 /*
814 * Halt all other CPUs, calling the specified function on each of them
815 *
816 * This function can be used to halt all other CPUs on crash
817 * or emergency reboot time. The function passed as parameter
818 * will be called inside a NMI handler on all CPUs.
819 */
nmi_shootdown_cpus(nmi_shootdown_cb callback)820 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
821 {
822 unsigned long msecs;
823 local_irq_disable();
824
825 /* Make a note of crashing cpu. Will be used in NMI callback. */
826 crashing_cpu = safe_smp_processor_id();
827
828 shootdown_callback = callback;
829
830 atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
831 /* Would it be better to replace the trap vector here? */
832 if (register_nmi_handler(NMI_LOCAL, crash_nmi_callback,
833 NMI_FLAG_FIRST, "crash"))
834 return; /* Return what? */
835 /*
836 * Ensure the new callback function is set before sending
837 * out the NMI
838 */
839 wmb();
840
841 smp_send_nmi_allbutself();
842
843 /* Kick CPUs looping in NMI context. */
844 WRITE_ONCE(crash_ipi_issued, 1);
845
846 msecs = 1000; /* Wait at most a second for the other cpus to stop */
847 while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
848 mdelay(1);
849 msecs--;
850 }
851
852 /* Leave the nmi callback set */
853 }
854
855 /*
856 * Check if the crash dumping IPI got issued and if so, call its callback
857 * directly. This function is used when we have already been in NMI handler.
858 * It doesn't return.
859 */
run_crash_ipi_callback(struct pt_regs * regs)860 void run_crash_ipi_callback(struct pt_regs *regs)
861 {
862 if (crash_ipi_issued)
863 crash_nmi_callback(0, regs);
864 }
865
866 /* Override the weak function in kernel/panic.c */
nmi_panic_self_stop(struct pt_regs * regs)867 void nmi_panic_self_stop(struct pt_regs *regs)
868 {
869 while (1) {
870 /* If no CPU is preparing crash dump, we simply loop here. */
871 run_crash_ipi_callback(regs);
872 cpu_relax();
873 }
874 }
875
876 #else /* !CONFIG_SMP */
nmi_shootdown_cpus(nmi_shootdown_cb callback)877 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
878 {
879 /* No other CPUs to shoot down */
880 }
881
run_crash_ipi_callback(struct pt_regs * regs)882 void run_crash_ipi_callback(struct pt_regs *regs)
883 {
884 }
885 #endif
886