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 back to the initial page table.
117 */
118 #ifdef CONFIG_X86_32
119 load_cr3(initial_page_table);
120 #else
121 write_cr3(real_mode_header->trampoline_pgd);
122
123 /* Exiting long mode will fail if CR4.PCIDE is set. */
124 if (boot_cpu_has(X86_FEATURE_PCID))
125 cr4_clear_bits(X86_CR4_PCIDE);
126 #endif
127
128 /* Jump to the identity-mapped low memory code */
129 #ifdef CONFIG_X86_32
130 asm volatile("jmpl *%0" : :
131 "rm" (real_mode_header->machine_real_restart_asm),
132 "a" (type));
133 #else
134 asm volatile("ljmpl *%0" : :
135 "m" (real_mode_header->machine_real_restart_asm),
136 "D" (type));
137 #endif
138 unreachable();
139 }
140 #ifdef CONFIG_APM_MODULE
141 EXPORT_SYMBOL(machine_real_restart);
142 #endif
143 STACK_FRAME_NON_STANDARD(machine_real_restart);
144
145 /*
146 * Some Apple MacBook and MacBookPro's needs reboot=p to be able to reboot
147 */
set_pci_reboot(const struct dmi_system_id * d)148 static int __init set_pci_reboot(const struct dmi_system_id *d)
149 {
150 if (reboot_type != BOOT_CF9_FORCE) {
151 reboot_type = BOOT_CF9_FORCE;
152 pr_info("%s series board detected. Selecting %s-method for reboots.\n",
153 d->ident, "PCI");
154 }
155 return 0;
156 }
157
set_kbd_reboot(const struct dmi_system_id * d)158 static int __init set_kbd_reboot(const struct dmi_system_id *d)
159 {
160 if (reboot_type != BOOT_KBD) {
161 reboot_type = BOOT_KBD;
162 pr_info("%s series board detected. Selecting %s-method for reboot.\n",
163 d->ident, "KBD");
164 }
165 return 0;
166 }
167
168 /*
169 * This is a single dmi_table handling all reboot quirks.
170 */
171 static const struct dmi_system_id reboot_dmi_table[] __initconst = {
172
173 /* Acer */
174 { /* Handle reboot issue on Acer Aspire one */
175 .callback = set_kbd_reboot,
176 .ident = "Acer Aspire One A110",
177 .matches = {
178 DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
179 DMI_MATCH(DMI_PRODUCT_NAME, "AOA110"),
180 },
181 },
182 { /* Handle reboot issue on Acer TravelMate X514-51T */
183 .callback = set_efi_reboot,
184 .ident = "Acer TravelMate X514-51T",
185 .matches = {
186 DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
187 DMI_MATCH(DMI_PRODUCT_NAME, "TravelMate X514-51T"),
188 },
189 },
190
191 /* Apple */
192 { /* Handle problems with rebooting on Apple MacBook5 */
193 .callback = set_pci_reboot,
194 .ident = "Apple MacBook5",
195 .matches = {
196 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
197 DMI_MATCH(DMI_PRODUCT_NAME, "MacBook5"),
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",
384 .matches = {
385 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
386 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 990"),
387 },
388 },
389 { /* Handle problems with rebooting on Dell 300's */
390 .callback = set_bios_reboot,
391 .ident = "Dell PowerEdge 300",
392 .matches = {
393 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
394 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"),
395 },
396 },
397 { /* Handle problems with rebooting on Dell 1300's */
398 .callback = set_bios_reboot,
399 .ident = "Dell PowerEdge 1300",
400 .matches = {
401 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
402 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1300/"),
403 },
404 },
405 { /* Handle problems with rebooting on Dell 2400's */
406 .callback = set_bios_reboot,
407 .ident = "Dell PowerEdge 2400",
408 .matches = {
409 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
410 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"),
411 },
412 },
413 { /* Handle problems with rebooting on the Dell PowerEdge C6100. */
414 .callback = set_pci_reboot,
415 .ident = "Dell PowerEdge C6100",
416 .matches = {
417 DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
418 DMI_MATCH(DMI_PRODUCT_NAME, "C6100"),
419 },
420 },
421 { /* Handle problems with rebooting on the Precision M6600. */
422 .callback = set_pci_reboot,
423 .ident = "Dell Precision M6600",
424 .matches = {
425 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
426 DMI_MATCH(DMI_PRODUCT_NAME, "Precision M6600"),
427 },
428 },
429 { /* Handle problems with rebooting on Dell T5400's */
430 .callback = set_bios_reboot,
431 .ident = "Dell Precision T5400",
432 .matches = {
433 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
434 DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T5400"),
435 },
436 },
437 { /* Handle problems with rebooting on Dell T7400's */
438 .callback = set_bios_reboot,
439 .ident = "Dell Precision T7400",
440 .matches = {
441 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
442 DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T7400"),
443 },
444 },
445 { /* Handle problems with rebooting on Dell XPS710 */
446 .callback = set_bios_reboot,
447 .ident = "Dell XPS710",
448 .matches = {
449 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
450 DMI_MATCH(DMI_PRODUCT_NAME, "Dell XPS710"),
451 },
452 },
453 { /* Handle problems with rebooting on Dell Optiplex 7450 AIO */
454 .callback = set_acpi_reboot,
455 .ident = "Dell OptiPlex 7450 AIO",
456 .matches = {
457 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
458 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 7450 AIO"),
459 },
460 },
461
462 /* Hewlett-Packard */
463 { /* Handle problems with rebooting on HP laptops */
464 .callback = set_bios_reboot,
465 .ident = "HP Compaq Laptop",
466 .matches = {
467 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
468 DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"),
469 },
470 },
471
472 /* Sony */
473 { /* Handle problems with rebooting on Sony VGN-Z540N */
474 .callback = set_bios_reboot,
475 .ident = "Sony VGN-Z540N",
476 .matches = {
477 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
478 DMI_MATCH(DMI_PRODUCT_NAME, "VGN-Z540N"),
479 },
480 },
481
482 { }
483 };
484
reboot_init(void)485 static int __init reboot_init(void)
486 {
487 int rv;
488
489 /*
490 * Only do the DMI check if reboot_type hasn't been overridden
491 * on the command line
492 */
493 if (!reboot_default)
494 return 0;
495
496 /*
497 * The DMI quirks table takes precedence. If no quirks entry
498 * matches and the ACPI Hardware Reduced bit is set and EFI
499 * runtime services are enabled, force EFI reboot.
500 */
501 rv = dmi_check_system(reboot_dmi_table);
502
503 if (!rv && efi_reboot_required() && !efi_runtime_disabled())
504 reboot_type = BOOT_EFI;
505
506 return 0;
507 }
508 core_initcall(reboot_init);
509
kb_wait(void)510 static inline void kb_wait(void)
511 {
512 int i;
513
514 for (i = 0; i < 0x10000; i++) {
515 if ((inb(0x64) & 0x02) == 0)
516 break;
517 udelay(2);
518 }
519 }
520
vmxoff_nmi(int cpu,struct pt_regs * regs)521 static void vmxoff_nmi(int cpu, struct pt_regs *regs)
522 {
523 cpu_emergency_vmxoff();
524 }
525
526 /* Use NMIs as IPIs to tell all CPUs to disable virtualization */
emergency_vmx_disable_all(void)527 static void emergency_vmx_disable_all(void)
528 {
529 /* Just make sure we won't change CPUs while doing this */
530 local_irq_disable();
531
532 /*
533 * We need to disable VMX on all CPUs before rebooting, otherwise
534 * we risk hanging up the machine, because the CPU ignore INIT
535 * signals when VMX is enabled.
536 *
537 * We can't take any locks and we may be on an inconsistent
538 * state, so we use NMIs as IPIs to tell the other CPUs to disable
539 * VMX and halt.
540 *
541 * For safety, we will avoid running the nmi_shootdown_cpus()
542 * stuff unnecessarily, but we don't have a way to check
543 * if other CPUs have VMX enabled. So we will call it only if the
544 * CPU we are running on has VMX enabled.
545 *
546 * We will miss cases where VMX is not enabled on all CPUs. This
547 * shouldn't do much harm because KVM always enable VMX on all
548 * CPUs anyway. But we can miss it on the small window where KVM
549 * is still enabling VMX.
550 */
551 if (cpu_has_vmx() && cpu_vmx_enabled()) {
552 /* Disable VMX on this CPU. */
553 cpu_vmxoff();
554
555 /* Halt and disable VMX on the other CPUs */
556 nmi_shootdown_cpus(vmxoff_nmi);
557
558 }
559 }
560
561
mach_reboot_fixups(void)562 void __attribute__((weak)) mach_reboot_fixups(void)
563 {
564 }
565
566 /*
567 * To the best of our knowledge Windows compatible x86 hardware expects
568 * the following on reboot:
569 *
570 * 1) If the FADT has the ACPI reboot register flag set, try it
571 * 2) If still alive, write to the keyboard controller
572 * 3) If still alive, write to the ACPI reboot register again
573 * 4) If still alive, write to the keyboard controller again
574 * 5) If still alive, call the EFI runtime service to reboot
575 * 6) If no EFI runtime service, call the BIOS to do a reboot
576 *
577 * We default to following the same pattern. We also have
578 * two other reboot methods: 'triple fault' and 'PCI', which
579 * can be triggered via the reboot= kernel boot option or
580 * via quirks.
581 *
582 * This means that this function can never return, it can misbehave
583 * by not rebooting properly and hanging.
584 */
native_machine_emergency_restart(void)585 static void native_machine_emergency_restart(void)
586 {
587 int i;
588 int attempt = 0;
589 int orig_reboot_type = reboot_type;
590 unsigned short mode;
591
592 if (reboot_emergency)
593 emergency_vmx_disable_all();
594
595 tboot_shutdown(TB_SHUTDOWN_REBOOT);
596
597 /* Tell the BIOS if we want cold or warm reboot */
598 mode = reboot_mode == REBOOT_WARM ? 0x1234 : 0;
599 *((unsigned short *)__va(0x472)) = mode;
600
601 /*
602 * If an EFI capsule has been registered with the firmware then
603 * override the reboot= parameter.
604 */
605 if (efi_capsule_pending(NULL)) {
606 pr_info("EFI capsule is pending, forcing EFI reboot.\n");
607 reboot_type = BOOT_EFI;
608 }
609
610 for (;;) {
611 /* Could also try the reset bit in the Hammer NB */
612 switch (reboot_type) {
613 case BOOT_ACPI:
614 acpi_reboot();
615 reboot_type = BOOT_KBD;
616 break;
617
618 case BOOT_KBD:
619 mach_reboot_fixups(); /* For board specific fixups */
620
621 for (i = 0; i < 10; i++) {
622 kb_wait();
623 udelay(50);
624 outb(0xfe, 0x64); /* Pulse reset low */
625 udelay(50);
626 }
627 if (attempt == 0 && orig_reboot_type == BOOT_ACPI) {
628 attempt = 1;
629 reboot_type = BOOT_ACPI;
630 } else {
631 reboot_type = BOOT_EFI;
632 }
633 break;
634
635 case BOOT_EFI:
636 efi_reboot(reboot_mode, NULL);
637 reboot_type = BOOT_BIOS;
638 break;
639
640 case BOOT_BIOS:
641 machine_real_restart(MRR_BIOS);
642
643 /* We're probably dead after this, but... */
644 reboot_type = BOOT_CF9_SAFE;
645 break;
646
647 case BOOT_CF9_FORCE:
648 port_cf9_safe = true;
649 /* Fall through */
650
651 case BOOT_CF9_SAFE:
652 if (port_cf9_safe) {
653 u8 reboot_code = reboot_mode == REBOOT_WARM ? 0x06 : 0x0E;
654 u8 cf9 = inb(0xcf9) & ~reboot_code;
655 outb(cf9|2, 0xcf9); /* Request hard reset */
656 udelay(50);
657 /* Actually do the reset */
658 outb(cf9|reboot_code, 0xcf9);
659 udelay(50);
660 }
661 reboot_type = BOOT_TRIPLE;
662 break;
663
664 case BOOT_TRIPLE:
665 idt_invalidate(NULL);
666 __asm__ __volatile__("int3");
667
668 /* We're probably dead after this, but... */
669 reboot_type = BOOT_KBD;
670 break;
671 }
672 }
673 }
674
native_machine_shutdown(void)675 void native_machine_shutdown(void)
676 {
677 /* Stop the cpus and apics */
678 #ifdef CONFIG_X86_IO_APIC
679 /*
680 * Disabling IO APIC before local APIC is a workaround for
681 * erratum AVR31 in "Intel Atom Processor C2000 Product Family
682 * Specification Update". In this situation, interrupts that target
683 * a Logical Processor whose Local APIC is either in the process of
684 * being hardware disabled or software disabled are neither delivered
685 * nor discarded. When this erratum occurs, the processor may hang.
686 *
687 * Even without the erratum, it still makes sense to quiet IO APIC
688 * before disabling Local APIC.
689 */
690 clear_IO_APIC();
691 #endif
692
693 #ifdef CONFIG_SMP
694 /*
695 * Stop all of the others. Also disable the local irq to
696 * not receive the per-cpu timer interrupt which may trigger
697 * scheduler's load balance.
698 */
699 local_irq_disable();
700 stop_other_cpus();
701 #endif
702
703 lapic_shutdown();
704 restore_boot_irq_mode();
705
706 #ifdef CONFIG_HPET_TIMER
707 hpet_disable();
708 #endif
709
710 #ifdef CONFIG_X86_64
711 x86_platform.iommu_shutdown();
712 #endif
713 }
714
__machine_emergency_restart(int emergency)715 static void __machine_emergency_restart(int emergency)
716 {
717 reboot_emergency = emergency;
718 machine_ops.emergency_restart();
719 }
720
native_machine_restart(char * __unused)721 static void native_machine_restart(char *__unused)
722 {
723 pr_notice("machine restart\n");
724
725 if (!reboot_force)
726 machine_shutdown();
727 __machine_emergency_restart(0);
728 }
729
native_machine_halt(void)730 static void native_machine_halt(void)
731 {
732 /* Stop other cpus and apics */
733 machine_shutdown();
734
735 tboot_shutdown(TB_SHUTDOWN_HALT);
736
737 stop_this_cpu(NULL);
738 }
739
native_machine_power_off(void)740 static void native_machine_power_off(void)
741 {
742 if (pm_power_off) {
743 if (!reboot_force)
744 machine_shutdown();
745 pm_power_off();
746 }
747 /* A fallback in case there is no PM info available */
748 tboot_shutdown(TB_SHUTDOWN_HALT);
749 }
750
751 struct machine_ops machine_ops __ro_after_init = {
752 .power_off = native_machine_power_off,
753 .shutdown = native_machine_shutdown,
754 .emergency_restart = native_machine_emergency_restart,
755 .restart = native_machine_restart,
756 .halt = native_machine_halt,
757 #ifdef CONFIG_KEXEC_CORE
758 .crash_shutdown = native_machine_crash_shutdown,
759 #endif
760 };
761
machine_power_off(void)762 void machine_power_off(void)
763 {
764 machine_ops.power_off();
765 }
766
machine_shutdown(void)767 void machine_shutdown(void)
768 {
769 machine_ops.shutdown();
770 }
771
machine_emergency_restart(void)772 void machine_emergency_restart(void)
773 {
774 __machine_emergency_restart(1);
775 }
776
machine_restart(char * cmd)777 void machine_restart(char *cmd)
778 {
779 machine_ops.restart(cmd);
780 }
781
machine_halt(void)782 void machine_halt(void)
783 {
784 machine_ops.halt();
785 }
786
787 #ifdef CONFIG_KEXEC_CORE
machine_crash_shutdown(struct pt_regs * regs)788 void machine_crash_shutdown(struct pt_regs *regs)
789 {
790 machine_ops.crash_shutdown(regs);
791 }
792 #endif
793
794
795 /* This is the CPU performing the emergency shutdown work. */
796 int crashing_cpu = -1;
797
798 #if defined(CONFIG_SMP)
799
800 static nmi_shootdown_cb shootdown_callback;
801
802 static atomic_t waiting_for_crash_ipi;
803 static int crash_ipi_issued;
804
crash_nmi_callback(unsigned int val,struct pt_regs * regs)805 static int crash_nmi_callback(unsigned int val, struct pt_regs *regs)
806 {
807 int cpu;
808
809 cpu = raw_smp_processor_id();
810
811 /*
812 * Don't do anything if this handler is invoked on crashing cpu.
813 * Otherwise, system will completely hang. Crashing cpu can get
814 * an NMI if system was initially booted with nmi_watchdog parameter.
815 */
816 if (cpu == crashing_cpu)
817 return NMI_HANDLED;
818 local_irq_disable();
819
820 shootdown_callback(cpu, regs);
821
822 atomic_dec(&waiting_for_crash_ipi);
823 /* Assume hlt works */
824 halt();
825 for (;;)
826 cpu_relax();
827
828 return NMI_HANDLED;
829 }
830
831 /*
832 * Halt all other CPUs, calling the specified function on each of them
833 *
834 * This function can be used to halt all other CPUs on crash
835 * or emergency reboot time. The function passed as parameter
836 * will be called inside a NMI handler on all CPUs.
837 */
nmi_shootdown_cpus(nmi_shootdown_cb callback)838 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
839 {
840 unsigned long msecs;
841 local_irq_disable();
842
843 /* Make a note of crashing cpu. Will be used in NMI callback. */
844 crashing_cpu = safe_smp_processor_id();
845
846 shootdown_callback = callback;
847
848 atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
849 /* Would it be better to replace the trap vector here? */
850 if (register_nmi_handler(NMI_LOCAL, crash_nmi_callback,
851 NMI_FLAG_FIRST, "crash"))
852 return; /* Return what? */
853 /*
854 * Ensure the new callback function is set before sending
855 * out the NMI
856 */
857 wmb();
858
859 apic_send_IPI_allbutself(NMI_VECTOR);
860
861 /* Kick CPUs looping in NMI context. */
862 WRITE_ONCE(crash_ipi_issued, 1);
863
864 msecs = 1000; /* Wait at most a second for the other cpus to stop */
865 while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
866 mdelay(1);
867 msecs--;
868 }
869
870 /* Leave the nmi callback set */
871 }
872
873 /*
874 * Check if the crash dumping IPI got issued and if so, call its callback
875 * directly. This function is used when we have already been in NMI handler.
876 * It doesn't return.
877 */
run_crash_ipi_callback(struct pt_regs * regs)878 void run_crash_ipi_callback(struct pt_regs *regs)
879 {
880 if (crash_ipi_issued)
881 crash_nmi_callback(0, regs);
882 }
883
884 /* Override the weak function in kernel/panic.c */
nmi_panic_self_stop(struct pt_regs * regs)885 void nmi_panic_self_stop(struct pt_regs *regs)
886 {
887 while (1) {
888 /* If no CPU is preparing crash dump, we simply loop here. */
889 run_crash_ipi_callback(regs);
890 cpu_relax();
891 }
892 }
893
894 #else /* !CONFIG_SMP */
nmi_shootdown_cpus(nmi_shootdown_cb callback)895 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
896 {
897 /* No other CPUs to shoot down */
898 }
899
run_crash_ipi_callback(struct pt_regs * regs)900 void run_crash_ipi_callback(struct pt_regs *regs)
901 {
902 }
903 #endif
904
