1 // SPDX-License-Identifier: GPL-2.0
2 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
3
4 #include <linux/export.h>
5 #include <linux/reboot.h>
6 #include <linux/init.h>
7 #include <linux/pm.h>
8 #include <linux/efi.h>
9 #include <linux/dmi.h>
10 #include <linux/sched.h>
11 #include <linux/tboot.h>
12 #include <linux/delay.h>
13 #include <linux/objtool.h>
14 #include <linux/pgtable.h>
15 #include <acpi/reboot.h>
16 #include <asm/io.h>
17 #include <asm/apic.h>
18 #include <asm/io_apic.h>
19 #include <asm/desc.h>
20 #include <asm/hpet.h>
21 #include <asm/proto.h>
22 #include <asm/reboot_fixups.h>
23 #include <asm/reboot.h>
24 #include <asm/pci_x86.h>
25 #include <asm/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 */
39 void (*pm_power_off)(void);
40 EXPORT_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 */
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
84 /*
85 * Some machines don't handle the default ACPI reboot method and
86 * require the EFI reboot method:
87 */
set_efi_reboot(const struct dmi_system_id * d)88 static int __init set_efi_reboot(const struct dmi_system_id *d)
89 {
90 if (reboot_type != BOOT_EFI && !efi_runtime_disabled()) {
91 reboot_type = BOOT_EFI;
92 pr_info("%s series board detected. Selecting EFI-method for reboot.\n", d->ident);
93 }
94 return 0;
95 }
96
machine_real_restart(unsigned int type)97 void __noreturn machine_real_restart(unsigned int type)
98 {
99 local_irq_disable();
100
101 /*
102 * Write zero to CMOS register number 0x0f, which the BIOS POST
103 * routine will recognize as telling it to do a proper reboot. (Well
104 * that's what this book in front of me says -- it may only apply to
105 * the Phoenix BIOS though, it's not clear). At the same time,
106 * disable NMIs by setting the top bit in the CMOS address register,
107 * as we're about to do peculiar things to the CPU. I'm not sure if
108 * `outb_p' is needed instead of just `outb'. Use it to be on the
109 * safe side. (Yes, CMOS_WRITE does outb_p's. - Paul G.)
110 */
111 spin_lock(&rtc_lock);
112 CMOS_WRITE(0x00, 0x8f);
113 spin_unlock(&rtc_lock);
114
115 /*
116 * Switch to the trampoline page table.
117 */
118 load_trampoline_pgtable();
119
120 /* Jump to the identity-mapped low memory code */
121 #ifdef CONFIG_X86_32
122 asm volatile("jmpl *%0" : :
123 "rm" (real_mode_header->machine_real_restart_asm),
124 "a" (type));
125 #else
126 asm volatile("ljmpl *%0" : :
127 "m" (real_mode_header->machine_real_restart_asm),
128 "D" (type));
129 #endif
130 unreachable();
131 }
132 #ifdef CONFIG_APM_MODULE
133 EXPORT_SYMBOL(machine_real_restart);
134 #endif
135 STACK_FRAME_NON_STANDARD(machine_real_restart);
136
137 /*
138 * Some Apple MacBook and MacBookPro's needs reboot=p to be able to reboot
139 */
set_pci_reboot(const struct dmi_system_id * d)140 static int __init set_pci_reboot(const struct dmi_system_id *d)
141 {
142 if (reboot_type != BOOT_CF9_FORCE) {
143 reboot_type = BOOT_CF9_FORCE;
144 pr_info("%s series board detected. Selecting %s-method for reboots.\n",
145 d->ident, "PCI");
146 }
147 return 0;
148 }
149
set_kbd_reboot(const struct dmi_system_id * d)150 static int __init set_kbd_reboot(const struct dmi_system_id *d)
151 {
152 if (reboot_type != BOOT_KBD) {
153 reboot_type = BOOT_KBD;
154 pr_info("%s series board detected. Selecting %s-method for reboot.\n",
155 d->ident, "KBD");
156 }
157 return 0;
158 }
159
160 /*
161 * This is a single dmi_table handling all reboot quirks.
162 */
163 static const struct dmi_system_id reboot_dmi_table[] __initconst = {
164
165 /* Acer */
166 { /* Handle reboot issue on Acer Aspire one */
167 .callback = set_kbd_reboot,
168 .ident = "Acer Aspire One A110",
169 .matches = {
170 DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
171 DMI_MATCH(DMI_PRODUCT_NAME, "AOA110"),
172 },
173 },
174 { /* Handle reboot issue on Acer TravelMate X514-51T */
175 .callback = set_efi_reboot,
176 .ident = "Acer TravelMate X514-51T",
177 .matches = {
178 DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
179 DMI_MATCH(DMI_PRODUCT_NAME, "TravelMate X514-51T"),
180 },
181 },
182
183 /* Apple */
184 { /* Handle problems with rebooting on Apple MacBook5 */
185 .callback = set_pci_reboot,
186 .ident = "Apple MacBook5",
187 .matches = {
188 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
189 DMI_MATCH(DMI_PRODUCT_NAME, "MacBook5"),
190 },
191 },
192 { /* Handle problems with rebooting on Apple MacBook6,1 */
193 .callback = set_pci_reboot,
194 .ident = "Apple MacBook6,1",
195 .matches = {
196 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
197 DMI_MATCH(DMI_PRODUCT_NAME, "MacBook6,1"),
198 },
199 },
200 { /* Handle problems with rebooting on Apple MacBookPro5 */
201 .callback = set_pci_reboot,
202 .ident = "Apple MacBookPro5",
203 .matches = {
204 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
205 DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro5"),
206 },
207 },
208 { /* Handle problems with rebooting on Apple Macmini3,1 */
209 .callback = set_pci_reboot,
210 .ident = "Apple Macmini3,1",
211 .matches = {
212 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
213 DMI_MATCH(DMI_PRODUCT_NAME, "Macmini3,1"),
214 },
215 },
216 { /* Handle problems with rebooting on the iMac9,1. */
217 .callback = set_pci_reboot,
218 .ident = "Apple iMac9,1",
219 .matches = {
220 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
221 DMI_MATCH(DMI_PRODUCT_NAME, "iMac9,1"),
222 },
223 },
224 { /* Handle problems with rebooting on the iMac10,1. */
225 .callback = set_pci_reboot,
226 .ident = "Apple iMac10,1",
227 .matches = {
228 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
229 DMI_MATCH(DMI_PRODUCT_NAME, "iMac10,1"),
230 },
231 },
232
233 /* ASRock */
234 { /* Handle problems with rebooting on ASRock Q1900DC-ITX */
235 .callback = set_pci_reboot,
236 .ident = "ASRock Q1900DC-ITX",
237 .matches = {
238 DMI_MATCH(DMI_BOARD_VENDOR, "ASRock"),
239 DMI_MATCH(DMI_BOARD_NAME, "Q1900DC-ITX"),
240 },
241 },
242
243 /* ASUS */
244 { /* Handle problems with rebooting on ASUS P4S800 */
245 .callback = set_bios_reboot,
246 .ident = "ASUS P4S800",
247 .matches = {
248 DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
249 DMI_MATCH(DMI_BOARD_NAME, "P4S800"),
250 },
251 },
252 { /* Handle problems with rebooting on ASUS EeeBook X205TA */
253 .callback = set_acpi_reboot,
254 .ident = "ASUS EeeBook X205TA",
255 .matches = {
256 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
257 DMI_MATCH(DMI_PRODUCT_NAME, "X205TA"),
258 },
259 },
260 { /* Handle problems with rebooting on ASUS EeeBook X205TAW */
261 .callback = set_acpi_reboot,
262 .ident = "ASUS EeeBook X205TAW",
263 .matches = {
264 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
265 DMI_MATCH(DMI_PRODUCT_NAME, "X205TAW"),
266 },
267 },
268
269 /* Certec */
270 { /* Handle problems with rebooting on Certec BPC600 */
271 .callback = set_pci_reboot,
272 .ident = "Certec BPC600",
273 .matches = {
274 DMI_MATCH(DMI_SYS_VENDOR, "Certec"),
275 DMI_MATCH(DMI_PRODUCT_NAME, "BPC600"),
276 },
277 },
278
279 /* Dell */
280 { /* Handle problems with rebooting on Dell DXP061 */
281 .callback = set_bios_reboot,
282 .ident = "Dell DXP061",
283 .matches = {
284 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
285 DMI_MATCH(DMI_PRODUCT_NAME, "Dell DXP061"),
286 },
287 },
288 { /* Handle problems with rebooting on Dell E520's */
289 .callback = set_bios_reboot,
290 .ident = "Dell E520",
291 .matches = {
292 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
293 DMI_MATCH(DMI_PRODUCT_NAME, "Dell DM061"),
294 },
295 },
296 { /* Handle problems with rebooting on the Latitude E5410. */
297 .callback = set_pci_reboot,
298 .ident = "Dell Latitude E5410",
299 .matches = {
300 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
301 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E5410"),
302 },
303 },
304 { /* Handle problems with rebooting on the Latitude E5420. */
305 .callback = set_pci_reboot,
306 .ident = "Dell Latitude E5420",
307 .matches = {
308 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
309 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E5420"),
310 },
311 },
312 { /* Handle problems with rebooting on the Latitude E6320. */
313 .callback = set_pci_reboot,
314 .ident = "Dell Latitude E6320",
315 .matches = {
316 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
317 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6320"),
318 },
319 },
320 { /* Handle problems with rebooting on the Latitude E6420. */
321 .callback = set_pci_reboot,
322 .ident = "Dell Latitude E6420",
323 .matches = {
324 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
325 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6420"),
326 },
327 },
328 { /* Handle problems with rebooting on Dell Optiplex 330 with 0KP561 */
329 .callback = set_bios_reboot,
330 .ident = "Dell OptiPlex 330",
331 .matches = {
332 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
333 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 330"),
334 DMI_MATCH(DMI_BOARD_NAME, "0KP561"),
335 },
336 },
337 { /* Handle problems with rebooting on Dell Optiplex 360 with 0T656F */
338 .callback = set_bios_reboot,
339 .ident = "Dell OptiPlex 360",
340 .matches = {
341 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
342 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 360"),
343 DMI_MATCH(DMI_BOARD_NAME, "0T656F"),
344 },
345 },
346 { /* Handle problems with rebooting on Dell Optiplex 745's SFF */
347 .callback = set_bios_reboot,
348 .ident = "Dell OptiPlex 745",
349 .matches = {
350 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
351 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
352 },
353 },
354 { /* Handle problems with rebooting on Dell Optiplex 745's DFF */
355 .callback = set_bios_reboot,
356 .ident = "Dell OptiPlex 745",
357 .matches = {
358 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
359 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
360 DMI_MATCH(DMI_BOARD_NAME, "0MM599"),
361 },
362 },
363 { /* Handle problems with rebooting on Dell Optiplex 745 with 0KW626 */
364 .callback = set_bios_reboot,
365 .ident = "Dell OptiPlex 745",
366 .matches = {
367 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
368 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
369 DMI_MATCH(DMI_BOARD_NAME, "0KW626"),
370 },
371 },
372 { /* Handle problems with rebooting on Dell OptiPlex 760 with 0G919G */
373 .callback = set_bios_reboot,
374 .ident = "Dell OptiPlex 760",
375 .matches = {
376 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
377 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 760"),
378 DMI_MATCH(DMI_BOARD_NAME, "0G919G"),
379 },
380 },
381 { /* Handle problems with rebooting on the OptiPlex 990. */
382 .callback = set_pci_reboot,
383 .ident = "Dell OptiPlex 990 BIOS A0x",
384 .matches = {
385 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
386 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 990"),
387 DMI_MATCH(DMI_BIOS_VERSION, "A0"),
388 },
389 },
390 { /* Handle problems with rebooting on Dell 300's */
391 .callback = set_bios_reboot,
392 .ident = "Dell PowerEdge 300",
393 .matches = {
394 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
395 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"),
396 },
397 },
398 { /* Handle problems with rebooting on Dell 1300's */
399 .callback = set_bios_reboot,
400 .ident = "Dell PowerEdge 1300",
401 .matches = {
402 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
403 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1300/"),
404 },
405 },
406 { /* Handle problems with rebooting on Dell 2400's */
407 .callback = set_bios_reboot,
408 .ident = "Dell PowerEdge 2400",
409 .matches = {
410 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
411 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"),
412 },
413 },
414 { /* Handle problems with rebooting on the Dell PowerEdge C6100. */
415 .callback = set_pci_reboot,
416 .ident = "Dell PowerEdge C6100",
417 .matches = {
418 DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
419 DMI_MATCH(DMI_PRODUCT_NAME, "C6100"),
420 },
421 },
422 { /* Handle problems with rebooting on the Precision M6600. */
423 .callback = set_pci_reboot,
424 .ident = "Dell Precision M6600",
425 .matches = {
426 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
427 DMI_MATCH(DMI_PRODUCT_NAME, "Precision M6600"),
428 },
429 },
430 { /* Handle problems with rebooting on Dell T5400's */
431 .callback = set_bios_reboot,
432 .ident = "Dell Precision T5400",
433 .matches = {
434 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
435 DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T5400"),
436 },
437 },
438 { /* Handle problems with rebooting on Dell T7400's */
439 .callback = set_bios_reboot,
440 .ident = "Dell Precision T7400",
441 .matches = {
442 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
443 DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T7400"),
444 },
445 },
446 { /* Handle problems with rebooting on Dell XPS710 */
447 .callback = set_bios_reboot,
448 .ident = "Dell XPS710",
449 .matches = {
450 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
451 DMI_MATCH(DMI_PRODUCT_NAME, "Dell XPS710"),
452 },
453 },
454 { /* Handle problems with rebooting on Dell Optiplex 7450 AIO */
455 .callback = set_acpi_reboot,
456 .ident = "Dell OptiPlex 7450 AIO",
457 .matches = {
458 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
459 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 7450 AIO"),
460 },
461 },
462
463 /* Hewlett-Packard */
464 { /* Handle problems with rebooting on HP laptops */
465 .callback = set_bios_reboot,
466 .ident = "HP Compaq Laptop",
467 .matches = {
468 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
469 DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"),
470 },
471 },
472
473 { /* PCIe Wifi card isn't detected after reboot otherwise */
474 .callback = set_pci_reboot,
475 .ident = "Zotac ZBOX CI327 nano",
476 .matches = {
477 DMI_MATCH(DMI_SYS_VENDOR, "NA"),
478 DMI_MATCH(DMI_PRODUCT_NAME, "ZBOX-CI327NANO-GS-01"),
479 },
480 },
481
482 /* Sony */
483 { /* Handle problems with rebooting on Sony VGN-Z540N */
484 .callback = set_bios_reboot,
485 .ident = "Sony VGN-Z540N",
486 .matches = {
487 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
488 DMI_MATCH(DMI_PRODUCT_NAME, "VGN-Z540N"),
489 },
490 },
491
492 { }
493 };
494
reboot_init(void)495 static int __init reboot_init(void)
496 {
497 int rv;
498
499 /*
500 * Only do the DMI check if reboot_type hasn't been overridden
501 * on the command line
502 */
503 if (!reboot_default)
504 return 0;
505
506 /*
507 * The DMI quirks table takes precedence. If no quirks entry
508 * matches and the ACPI Hardware Reduced bit is set and EFI
509 * runtime services are enabled, force EFI reboot.
510 */
511 rv = dmi_check_system(reboot_dmi_table);
512
513 if (!rv && efi_reboot_required() && !efi_runtime_disabled())
514 reboot_type = BOOT_EFI;
515
516 return 0;
517 }
518 core_initcall(reboot_init);
519
kb_wait(void)520 static inline void kb_wait(void)
521 {
522 int i;
523
524 for (i = 0; i < 0x10000; i++) {
525 if ((inb(0x64) & 0x02) == 0)
526 break;
527 udelay(2);
528 }
529 }
530
531 static inline void nmi_shootdown_cpus_on_restart(void);
532
emergency_reboot_disable_virtualization(void)533 static void emergency_reboot_disable_virtualization(void)
534 {
535 /* Just make sure we won't change CPUs while doing this */
536 local_irq_disable();
537
538 /*
539 * Disable virtualization on all CPUs before rebooting to avoid hanging
540 * the system, as VMX and SVM block INIT when running in the host.
541 *
542 * We can't take any locks and we may be on an inconsistent state, so
543 * use NMIs as IPIs to tell the other CPUs to disable VMX/SVM and halt.
544 *
545 * Do the NMI shootdown even if virtualization is off on _this_ CPU, as
546 * other CPUs may have virtualization enabled.
547 */
548 if (cpu_has_vmx() || cpu_has_svm(NULL)) {
549 /* Safely force _this_ CPU out of VMX/SVM operation. */
550 cpu_emergency_disable_virtualization();
551
552 /* Disable VMX/SVM and halt on other CPUs. */
553 nmi_shootdown_cpus_on_restart();
554 }
555 }
556
557
mach_reboot_fixups(void)558 void __attribute__((weak)) mach_reboot_fixups(void)
559 {
560 }
561
562 /*
563 * To the best of our knowledge Windows compatible x86 hardware expects
564 * the following on reboot:
565 *
566 * 1) If the FADT has the ACPI reboot register flag set, try it
567 * 2) If still alive, write to the keyboard controller
568 * 3) If still alive, write to the ACPI reboot register again
569 * 4) If still alive, write to the keyboard controller again
570 * 5) If still alive, call the EFI runtime service to reboot
571 * 6) If no EFI runtime service, call the BIOS to do a reboot
572 *
573 * We default to following the same pattern. We also have
574 * two other reboot methods: 'triple fault' and 'PCI', which
575 * can be triggered via the reboot= kernel boot option or
576 * via quirks.
577 *
578 * This means that this function can never return, it can misbehave
579 * by not rebooting properly and hanging.
580 */
native_machine_emergency_restart(void)581 static void native_machine_emergency_restart(void)
582 {
583 int i;
584 int attempt = 0;
585 int orig_reboot_type = reboot_type;
586 unsigned short mode;
587
588 if (reboot_emergency)
589 emergency_reboot_disable_virtualization();
590
591 tboot_shutdown(TB_SHUTDOWN_REBOOT);
592
593 /* Tell the BIOS if we want cold or warm reboot */
594 mode = reboot_mode == REBOOT_WARM ? 0x1234 : 0;
595 *((unsigned short *)__va(0x472)) = mode;
596
597 /*
598 * If an EFI capsule has been registered with the firmware then
599 * override the reboot= parameter.
600 */
601 if (efi_capsule_pending(NULL)) {
602 pr_info("EFI capsule is pending, forcing EFI reboot.\n");
603 reboot_type = BOOT_EFI;
604 }
605
606 for (;;) {
607 /* Could also try the reset bit in the Hammer NB */
608 switch (reboot_type) {
609 case BOOT_ACPI:
610 acpi_reboot();
611 reboot_type = BOOT_KBD;
612 break;
613
614 case BOOT_KBD:
615 mach_reboot_fixups(); /* For board specific fixups */
616
617 for (i = 0; i < 10; i++) {
618 kb_wait();
619 udelay(50);
620 outb(0xfe, 0x64); /* Pulse reset low */
621 udelay(50);
622 }
623 if (attempt == 0 && orig_reboot_type == BOOT_ACPI) {
624 attempt = 1;
625 reboot_type = BOOT_ACPI;
626 } else {
627 reboot_type = BOOT_EFI;
628 }
629 break;
630
631 case BOOT_EFI:
632 efi_reboot(reboot_mode, NULL);
633 reboot_type = BOOT_BIOS;
634 break;
635
636 case BOOT_BIOS:
637 machine_real_restart(MRR_BIOS);
638
639 /* We're probably dead after this, but... */
640 reboot_type = BOOT_CF9_SAFE;
641 break;
642
643 case BOOT_CF9_FORCE:
644 port_cf9_safe = true;
645 fallthrough;
646
647 case BOOT_CF9_SAFE:
648 if (port_cf9_safe) {
649 u8 reboot_code = reboot_mode == REBOOT_WARM ? 0x06 : 0x0E;
650 u8 cf9 = inb(0xcf9) & ~reboot_code;
651 outb(cf9|2, 0xcf9); /* Request hard reset */
652 udelay(50);
653 /* Actually do the reset */
654 outb(cf9|reboot_code, 0xcf9);
655 udelay(50);
656 }
657 reboot_type = BOOT_TRIPLE;
658 break;
659
660 case BOOT_TRIPLE:
661 idt_invalidate();
662 __asm__ __volatile__("int3");
663
664 /* We're probably dead after this, but... */
665 reboot_type = BOOT_KBD;
666 break;
667 }
668 }
669 }
670
native_machine_shutdown(void)671 void native_machine_shutdown(void)
672 {
673 /* Stop the cpus and apics */
674 #ifdef CONFIG_X86_IO_APIC
675 /*
676 * Disabling IO APIC before local APIC is a workaround for
677 * erratum AVR31 in "Intel Atom Processor C2000 Product Family
678 * Specification Update". In this situation, interrupts that target
679 * a Logical Processor whose Local APIC is either in the process of
680 * being hardware disabled or software disabled are neither delivered
681 * nor discarded. When this erratum occurs, the processor may hang.
682 *
683 * Even without the erratum, it still makes sense to quiet IO APIC
684 * before disabling Local APIC.
685 */
686 clear_IO_APIC();
687 #endif
688
689 #ifdef CONFIG_SMP
690 /*
691 * Stop all of the others. Also disable the local irq to
692 * not receive the per-cpu timer interrupt which may trigger
693 * scheduler's load balance.
694 */
695 local_irq_disable();
696 stop_other_cpus();
697 #endif
698
699 lapic_shutdown();
700 restore_boot_irq_mode();
701
702 #ifdef CONFIG_HPET_TIMER
703 hpet_disable();
704 #endif
705
706 #ifdef CONFIG_X86_64
707 x86_platform.iommu_shutdown();
708 #endif
709 }
710
__machine_emergency_restart(int emergency)711 static void __machine_emergency_restart(int emergency)
712 {
713 reboot_emergency = emergency;
714 machine_ops.emergency_restart();
715 }
716
native_machine_restart(char * __unused)717 static void native_machine_restart(char *__unused)
718 {
719 pr_notice("machine restart\n");
720
721 if (!reboot_force)
722 machine_shutdown();
723 __machine_emergency_restart(0);
724 }
725
native_machine_halt(void)726 static void native_machine_halt(void)
727 {
728 /* Stop other cpus and apics */
729 machine_shutdown();
730
731 tboot_shutdown(TB_SHUTDOWN_HALT);
732
733 stop_this_cpu(NULL);
734 }
735
native_machine_power_off(void)736 static void native_machine_power_off(void)
737 {
738 if (pm_power_off) {
739 if (!reboot_force)
740 machine_shutdown();
741 pm_power_off();
742 }
743 /* A fallback in case there is no PM info available */
744 tboot_shutdown(TB_SHUTDOWN_HALT);
745 }
746
747 struct machine_ops machine_ops __ro_after_init = {
748 .power_off = native_machine_power_off,
749 .shutdown = native_machine_shutdown,
750 .emergency_restart = native_machine_emergency_restart,
751 .restart = native_machine_restart,
752 .halt = native_machine_halt,
753 #ifdef CONFIG_KEXEC_CORE
754 .crash_shutdown = native_machine_crash_shutdown,
755 #endif
756 };
757
machine_power_off(void)758 void machine_power_off(void)
759 {
760 machine_ops.power_off();
761 }
762
machine_shutdown(void)763 void machine_shutdown(void)
764 {
765 machine_ops.shutdown();
766 }
767
machine_emergency_restart(void)768 void machine_emergency_restart(void)
769 {
770 __machine_emergency_restart(1);
771 }
772
machine_restart(char * cmd)773 void machine_restart(char *cmd)
774 {
775 machine_ops.restart(cmd);
776 }
777
machine_halt(void)778 void machine_halt(void)
779 {
780 machine_ops.halt();
781 }
782
783 #ifdef CONFIG_KEXEC_CORE
machine_crash_shutdown(struct pt_regs * regs)784 void machine_crash_shutdown(struct pt_regs *regs)
785 {
786 machine_ops.crash_shutdown(regs);
787 }
788 #endif
789
790
791 /* This is the CPU performing the emergency shutdown work. */
792 int crashing_cpu = -1;
793
794 /*
795 * Disable virtualization, i.e. VMX or SVM, to ensure INIT is recognized during
796 * reboot. VMX blocks INIT if the CPU is post-VMXON, and SVM blocks INIT if
797 * GIF=0, i.e. if the crash occurred between CLGI and STGI.
798 */
cpu_emergency_disable_virtualization(void)799 void cpu_emergency_disable_virtualization(void)
800 {
801 cpu_emergency_vmxoff();
802 cpu_emergency_svm_disable();
803 }
804
805 #if defined(CONFIG_SMP)
806
807 static nmi_shootdown_cb shootdown_callback;
808
809 static atomic_t waiting_for_crash_ipi;
810 static int crash_ipi_issued;
811
crash_nmi_callback(unsigned int val,struct pt_regs * regs)812 static int crash_nmi_callback(unsigned int val, struct pt_regs *regs)
813 {
814 int cpu;
815
816 cpu = raw_smp_processor_id();
817
818 /*
819 * Don't do anything if this handler is invoked on crashing cpu.
820 * Otherwise, system will completely hang. Crashing cpu can get
821 * an NMI if system was initially booted with nmi_watchdog parameter.
822 */
823 if (cpu == crashing_cpu)
824 return NMI_HANDLED;
825 local_irq_disable();
826
827 if (shootdown_callback)
828 shootdown_callback(cpu, regs);
829
830 /*
831 * Prepare the CPU for reboot _after_ invoking the callback so that the
832 * callback can safely use virtualization instructions, e.g. VMCLEAR.
833 */
834 cpu_emergency_disable_virtualization();
835
836 atomic_dec(&waiting_for_crash_ipi);
837 /* Assume hlt works */
838 halt();
839 for (;;)
840 cpu_relax();
841
842 return NMI_HANDLED;
843 }
844
845 /**
846 * nmi_shootdown_cpus - Stop other CPUs via NMI
847 * @callback: Optional callback to be invoked from the NMI handler
848 *
849 * The NMI handler on the remote CPUs invokes @callback, if not
850 * NULL, first and then disables virtualization to ensure that
851 * INIT is recognized during reboot.
852 *
853 * nmi_shootdown_cpus() can only be invoked once. After the first
854 * invocation all other CPUs are stuck in crash_nmi_callback() and
855 * cannot respond to a second NMI.
856 */
nmi_shootdown_cpus(nmi_shootdown_cb callback)857 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
858 {
859 unsigned long msecs;
860
861 local_irq_disable();
862
863 /*
864 * Avoid certain doom if a shootdown already occurred; re-registering
865 * the NMI handler will cause list corruption, modifying the callback
866 * will do who knows what, etc...
867 */
868 if (WARN_ON_ONCE(crash_ipi_issued))
869 return;
870
871 /* Make a note of crashing cpu. Will be used in NMI callback. */
872 crashing_cpu = safe_smp_processor_id();
873
874 shootdown_callback = callback;
875
876 atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
877 /* Would it be better to replace the trap vector here? */
878 if (register_nmi_handler(NMI_LOCAL, crash_nmi_callback,
879 NMI_FLAG_FIRST, "crash"))
880 return; /* Return what? */
881 /*
882 * Ensure the new callback function is set before sending
883 * out the NMI
884 */
885 wmb();
886
887 apic_send_IPI_allbutself(NMI_VECTOR);
888
889 /* Kick CPUs looping in NMI context. */
890 WRITE_ONCE(crash_ipi_issued, 1);
891
892 msecs = 1000; /* Wait at most a second for the other cpus to stop */
893 while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
894 mdelay(1);
895 msecs--;
896 }
897
898 /*
899 * Leave the nmi callback set, shootdown is a one-time thing. Clearing
900 * the callback could result in a NULL pointer dereference if a CPU
901 * (finally) responds after the timeout expires.
902 */
903 }
904
nmi_shootdown_cpus_on_restart(void)905 static inline void nmi_shootdown_cpus_on_restart(void)
906 {
907 if (!crash_ipi_issued)
908 nmi_shootdown_cpus(NULL);
909 }
910
911 /*
912 * Check if the crash dumping IPI got issued and if so, call its callback
913 * directly. This function is used when we have already been in NMI handler.
914 * It doesn't return.
915 */
run_crash_ipi_callback(struct pt_regs * regs)916 void run_crash_ipi_callback(struct pt_regs *regs)
917 {
918 if (crash_ipi_issued)
919 crash_nmi_callback(0, regs);
920 }
921
922 /* Override the weak function in kernel/panic.c */
nmi_panic_self_stop(struct pt_regs * regs)923 void nmi_panic_self_stop(struct pt_regs *regs)
924 {
925 while (1) {
926 /* If no CPU is preparing crash dump, we simply loop here. */
927 run_crash_ipi_callback(regs);
928 cpu_relax();
929 }
930 }
931
932 #else /* !CONFIG_SMP */
nmi_shootdown_cpus(nmi_shootdown_cb callback)933 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
934 {
935 /* No other CPUs to shoot down */
936 }
937
nmi_shootdown_cpus_on_restart(void)938 static inline void nmi_shootdown_cpus_on_restart(void) { }
939
run_crash_ipi_callback(struct pt_regs * regs)940 void run_crash_ipi_callback(struct pt_regs *regs)
941 {
942 }
943 #endif
944