1 // SPDX-License-Identifier: GPL-2.0
2 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
3
4 #include <linux/export.h>
5 #include <linux/reboot.h>
6 #include <linux/init.h>
7 #include <linux/pm.h>
8 #include <linux/efi.h>
9 #include <linux/dmi.h>
10 #include <linux/sched.h>
11 #include <linux/tboot.h>
12 #include <linux/delay.h>
13 #include <linux/frame.h>
14 #include <acpi/reboot.h>
15 #include <asm/io.h>
16 #include <asm/apic.h>
17 #include <asm/io_apic.h>
18 #include <asm/desc.h>
19 #include <asm/hpet.h>
20 #include <asm/pgtable.h>
21 #include <asm/proto.h>
22 #include <asm/reboot_fixups.h>
23 #include <asm/reboot.h>
24 #include <asm/pci_x86.h>
25 #include <asm/virtext.h>
26 #include <asm/cpu.h>
27 #include <asm/nmi.h>
28 #include <asm/smp.h>
29
30 #include <linux/ctype.h>
31 #include <linux/mc146818rtc.h>
32 #include <asm/realmode.h>
33 #include <asm/x86_init.h>
34 #include <asm/efi.h>
35
36 /*
37 * Power off function, if any
38 */
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
558
mach_reboot_fixups(void)559 void __attribute__((weak)) mach_reboot_fixups(void)
560 {
561 }
562
563 /*
564 * To the best of our knowledge Windows compatible x86 hardware expects
565 * the following on reboot:
566 *
567 * 1) If the FADT has the ACPI reboot register flag set, try it
568 * 2) If still alive, write to the keyboard controller
569 * 3) If still alive, write to the ACPI reboot register again
570 * 4) If still alive, write to the keyboard controller again
571 * 5) If still alive, call the EFI runtime service to reboot
572 * 6) If no EFI runtime service, call the BIOS to do a reboot
573 *
574 * We default to following the same pattern. We also have
575 * two other reboot methods: 'triple fault' and 'PCI', which
576 * can be triggered via the reboot= kernel boot option or
577 * via quirks.
578 *
579 * This means that this function can never return, it can misbehave
580 * by not rebooting properly and hanging.
581 */
native_machine_emergency_restart(void)582 static void native_machine_emergency_restart(void)
583 {
584 int i;
585 int attempt = 0;
586 int orig_reboot_type = reboot_type;
587 unsigned short mode;
588
589 if (reboot_emergency)
590 emergency_reboot_disable_virtualization();
591
592 tboot_shutdown(TB_SHUTDOWN_REBOOT);
593
594 /* Tell the BIOS if we want cold or warm reboot */
595 mode = reboot_mode == REBOOT_WARM ? 0x1234 : 0;
596 *((unsigned short *)__va(0x472)) = mode;
597
598 /*
599 * If an EFI capsule has been registered with the firmware then
600 * override the reboot= parameter.
601 */
602 if (efi_capsule_pending(NULL)) {
603 pr_info("EFI capsule is pending, forcing EFI reboot.\n");
604 reboot_type = BOOT_EFI;
605 }
606
607 for (;;) {
608 /* Could also try the reset bit in the Hammer NB */
609 switch (reboot_type) {
610 case BOOT_ACPI:
611 acpi_reboot();
612 reboot_type = BOOT_KBD;
613 break;
614
615 case BOOT_KBD:
616 mach_reboot_fixups(); /* For board specific fixups */
617
618 for (i = 0; i < 10; i++) {
619 kb_wait();
620 udelay(50);
621 outb(0xfe, 0x64); /* Pulse reset low */
622 udelay(50);
623 }
624 if (attempt == 0 && orig_reboot_type == BOOT_ACPI) {
625 attempt = 1;
626 reboot_type = BOOT_ACPI;
627 } else {
628 reboot_type = BOOT_EFI;
629 }
630 break;
631
632 case BOOT_EFI:
633 efi_reboot(reboot_mode, NULL);
634 reboot_type = BOOT_BIOS;
635 break;
636
637 case BOOT_BIOS:
638 machine_real_restart(MRR_BIOS);
639
640 /* We're probably dead after this, but... */
641 reboot_type = BOOT_CF9_SAFE;
642 break;
643
644 case BOOT_CF9_FORCE:
645 port_cf9_safe = true;
646 /* Fall through */
647
648 case BOOT_CF9_SAFE:
649 if (port_cf9_safe) {
650 u8 reboot_code = reboot_mode == REBOOT_WARM ? 0x06 : 0x0E;
651 u8 cf9 = inb(0xcf9) & ~reboot_code;
652 outb(cf9|2, 0xcf9); /* Request hard reset */
653 udelay(50);
654 /* Actually do the reset */
655 outb(cf9|reboot_code, 0xcf9);
656 udelay(50);
657 }
658 reboot_type = BOOT_TRIPLE;
659 break;
660
661 case BOOT_TRIPLE:
662 idt_invalidate(NULL);
663 __asm__ __volatile__("int3");
664
665 /* We're probably dead after this, but... */
666 reboot_type = BOOT_KBD;
667 break;
668 }
669 }
670 }
671
native_machine_shutdown(void)672 void native_machine_shutdown(void)
673 {
674 /* Stop the cpus and apics */
675 #ifdef CONFIG_X86_IO_APIC
676 /*
677 * Disabling IO APIC before local APIC is a workaround for
678 * erratum AVR31 in "Intel Atom Processor C2000 Product Family
679 * Specification Update". In this situation, interrupts that target
680 * a Logical Processor whose Local APIC is either in the process of
681 * being hardware disabled or software disabled are neither delivered
682 * nor discarded. When this erratum occurs, the processor may hang.
683 *
684 * Even without the erratum, it still makes sense to quiet IO APIC
685 * before disabling Local APIC.
686 */
687 clear_IO_APIC();
688 #endif
689
690 #ifdef CONFIG_SMP
691 /*
692 * Stop all of the others. Also disable the local irq to
693 * not receive the per-cpu timer interrupt which may trigger
694 * scheduler's load balance.
695 */
696 local_irq_disable();
697 stop_other_cpus();
698 #endif
699
700 lapic_shutdown();
701 restore_boot_irq_mode();
702
703 #ifdef CONFIG_HPET_TIMER
704 hpet_disable();
705 #endif
706
707 #ifdef CONFIG_X86_64
708 x86_platform.iommu_shutdown();
709 #endif
710 }
711
__machine_emergency_restart(int emergency)712 static void __machine_emergency_restart(int emergency)
713 {
714 reboot_emergency = emergency;
715 machine_ops.emergency_restart();
716 }
717
native_machine_restart(char * __unused)718 static void native_machine_restart(char *__unused)
719 {
720 pr_notice("machine restart\n");
721
722 if (!reboot_force)
723 machine_shutdown();
724 __machine_emergency_restart(0);
725 }
726
native_machine_halt(void)727 static void native_machine_halt(void)
728 {
729 /* Stop other cpus and apics */
730 machine_shutdown();
731
732 tboot_shutdown(TB_SHUTDOWN_HALT);
733
734 stop_this_cpu(NULL);
735 }
736
native_machine_power_off(void)737 static void native_machine_power_off(void)
738 {
739 if (pm_power_off) {
740 if (!reboot_force)
741 machine_shutdown();
742 pm_power_off();
743 }
744 /* A fallback in case there is no PM info available */
745 tboot_shutdown(TB_SHUTDOWN_HALT);
746 }
747
748 struct machine_ops machine_ops __ro_after_init = {
749 .power_off = native_machine_power_off,
750 .shutdown = native_machine_shutdown,
751 .emergency_restart = native_machine_emergency_restart,
752 .restart = native_machine_restart,
753 .halt = native_machine_halt,
754 #ifdef CONFIG_KEXEC_CORE
755 .crash_shutdown = native_machine_crash_shutdown,
756 #endif
757 };
758
machine_power_off(void)759 void machine_power_off(void)
760 {
761 machine_ops.power_off();
762 }
763
machine_shutdown(void)764 void machine_shutdown(void)
765 {
766 machine_ops.shutdown();
767 }
768
machine_emergency_restart(void)769 void machine_emergency_restart(void)
770 {
771 __machine_emergency_restart(1);
772 }
773
machine_restart(char * cmd)774 void machine_restart(char *cmd)
775 {
776 machine_ops.restart(cmd);
777 }
778
machine_halt(void)779 void machine_halt(void)
780 {
781 machine_ops.halt();
782 }
783
784 #ifdef CONFIG_KEXEC_CORE
machine_crash_shutdown(struct pt_regs * regs)785 void machine_crash_shutdown(struct pt_regs *regs)
786 {
787 machine_ops.crash_shutdown(regs);
788 }
789 #endif
790
791
792 /* This is the CPU performing the emergency shutdown work. */
793 int crashing_cpu = -1;
794
795 /*
796 * Disable virtualization, i.e. VMX or SVM, to ensure INIT is recognized during
797 * reboot. VMX blocks INIT if the CPU is post-VMXON, and SVM blocks INIT if
798 * GIF=0, i.e. if the crash occurred between CLGI and STGI.
799 */
cpu_emergency_disable_virtualization(void)800 void cpu_emergency_disable_virtualization(void)
801 {
802 cpu_emergency_vmxoff();
803 cpu_emergency_svm_disable();
804 }
805
806 #if defined(CONFIG_SMP)
807
808 static nmi_shootdown_cb shootdown_callback;
809
810 static atomic_t waiting_for_crash_ipi;
811 static int crash_ipi_issued;
812
crash_nmi_callback(unsigned int val,struct pt_regs * regs)813 static int crash_nmi_callback(unsigned int val, struct pt_regs *regs)
814 {
815 int cpu;
816
817 cpu = raw_smp_processor_id();
818
819 /*
820 * Don't do anything if this handler is invoked on crashing cpu.
821 * Otherwise, system will completely hang. Crashing cpu can get
822 * an NMI if system was initially booted with nmi_watchdog parameter.
823 */
824 if (cpu == crashing_cpu)
825 return NMI_HANDLED;
826 local_irq_disable();
827
828 if (shootdown_callback)
829 shootdown_callback(cpu, regs);
830
831 /*
832 * Prepare the CPU for reboot _after_ invoking the callback so that the
833 * callback can safely use virtualization instructions, e.g. VMCLEAR.
834 */
835 cpu_emergency_disable_virtualization();
836
837 atomic_dec(&waiting_for_crash_ipi);
838 /* Assume hlt works */
839 halt();
840 for (;;)
841 cpu_relax();
842
843 return NMI_HANDLED;
844 }
845
846 /**
847 * nmi_shootdown_cpus - Stop other CPUs via NMI
848 * @callback: Optional callback to be invoked from the NMI handler
849 *
850 * The NMI handler on the remote CPUs invokes @callback, if not
851 * NULL, first and then disables virtualization to ensure that
852 * INIT is recognized during reboot.
853 *
854 * nmi_shootdown_cpus() can only be invoked once. After the first
855 * invocation all other CPUs are stuck in crash_nmi_callback() and
856 * cannot respond to a second NMI.
857 */
nmi_shootdown_cpus(nmi_shootdown_cb callback)858 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
859 {
860 unsigned long msecs;
861
862 local_irq_disable();
863
864 /*
865 * Avoid certain doom if a shootdown already occurred; re-registering
866 * the NMI handler will cause list corruption, modifying the callback
867 * will do who knows what, etc...
868 */
869 if (WARN_ON_ONCE(crash_ipi_issued))
870 return;
871
872 /* Make a note of crashing cpu. Will be used in NMI callback. */
873 crashing_cpu = safe_smp_processor_id();
874
875 shootdown_callback = callback;
876
877 atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
878 /* Would it be better to replace the trap vector here? */
879 if (register_nmi_handler(NMI_LOCAL, crash_nmi_callback,
880 NMI_FLAG_FIRST, "crash"))
881 return; /* Return what? */
882 /*
883 * Ensure the new callback function is set before sending
884 * out the NMI
885 */
886 wmb();
887
888 apic_send_IPI_allbutself(NMI_VECTOR);
889
890 /* Kick CPUs looping in NMI context. */
891 WRITE_ONCE(crash_ipi_issued, 1);
892
893 msecs = 1000; /* Wait at most a second for the other cpus to stop */
894 while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
895 mdelay(1);
896 msecs--;
897 }
898
899 /*
900 * Leave the nmi callback set, shootdown is a one-time thing. Clearing
901 * the callback could result in a NULL pointer dereference if a CPU
902 * (finally) responds after the timeout expires.
903 */
904 }
905
nmi_shootdown_cpus_on_restart(void)906 static inline void nmi_shootdown_cpus_on_restart(void)
907 {
908 if (!crash_ipi_issued)
909 nmi_shootdown_cpus(NULL);
910 }
911
912 /*
913 * Check if the crash dumping IPI got issued and if so, call its callback
914 * directly. This function is used when we have already been in NMI handler.
915 * It doesn't return.
916 */
run_crash_ipi_callback(struct pt_regs * regs)917 void run_crash_ipi_callback(struct pt_regs *regs)
918 {
919 if (crash_ipi_issued)
920 crash_nmi_callback(0, regs);
921 }
922
923 /* Override the weak function in kernel/panic.c */
nmi_panic_self_stop(struct pt_regs * regs)924 void nmi_panic_self_stop(struct pt_regs *regs)
925 {
926 while (1) {
927 /* If no CPU is preparing crash dump, we simply loop here. */
928 run_crash_ipi_callback(regs);
929 cpu_relax();
930 }
931 }
932
933 #else /* !CONFIG_SMP */
nmi_shootdown_cpus(nmi_shootdown_cb callback)934 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
935 {
936 /* No other CPUs to shoot down */
937 }
938
nmi_shootdown_cpus_on_restart(void)939 static inline void nmi_shootdown_cpus_on_restart(void) { }
940
run_crash_ipi_callback(struct pt_regs * regs)941 void run_crash_ipi_callback(struct pt_regs *regs)
942 {
943 }
944 #endif
945