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 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 MacBook6,1 */
201 .callback = set_pci_reboot,
202 .ident = "Apple MacBook6,1",
203 .matches = {
204 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
205 DMI_MATCH(DMI_PRODUCT_NAME, "MacBook6,1"),
206 },
207 },
208 { /* Handle problems with rebooting on Apple MacBookPro5 */
209 .callback = set_pci_reboot,
210 .ident = "Apple MacBookPro5",
211 .matches = {
212 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
213 DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro5"),
214 },
215 },
216 { /* Handle problems with rebooting on Apple Macmini3,1 */
217 .callback = set_pci_reboot,
218 .ident = "Apple Macmini3,1",
219 .matches = {
220 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
221 DMI_MATCH(DMI_PRODUCT_NAME, "Macmini3,1"),
222 },
223 },
224 { /* Handle problems with rebooting on the iMac9,1. */
225 .callback = set_pci_reboot,
226 .ident = "Apple iMac9,1",
227 .matches = {
228 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
229 DMI_MATCH(DMI_PRODUCT_NAME, "iMac9,1"),
230 },
231 },
232 { /* Handle problems with rebooting on the iMac10,1. */
233 .callback = set_pci_reboot,
234 .ident = "Apple iMac10,1",
235 .matches = {
236 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
237 DMI_MATCH(DMI_PRODUCT_NAME, "iMac10,1"),
238 },
239 },
240
241 /* ASRock */
242 { /* Handle problems with rebooting on ASRock Q1900DC-ITX */
243 .callback = set_pci_reboot,
244 .ident = "ASRock Q1900DC-ITX",
245 .matches = {
246 DMI_MATCH(DMI_BOARD_VENDOR, "ASRock"),
247 DMI_MATCH(DMI_BOARD_NAME, "Q1900DC-ITX"),
248 },
249 },
250
251 /* ASUS */
252 { /* Handle problems with rebooting on ASUS P4S800 */
253 .callback = set_bios_reboot,
254 .ident = "ASUS P4S800",
255 .matches = {
256 DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
257 DMI_MATCH(DMI_BOARD_NAME, "P4S800"),
258 },
259 },
260 { /* Handle problems with rebooting on ASUS EeeBook X205TA */
261 .callback = set_acpi_reboot,
262 .ident = "ASUS EeeBook X205TA",
263 .matches = {
264 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
265 DMI_MATCH(DMI_PRODUCT_NAME, "X205TA"),
266 },
267 },
268 { /* Handle problems with rebooting on ASUS EeeBook X205TAW */
269 .callback = set_acpi_reboot,
270 .ident = "ASUS EeeBook X205TAW",
271 .matches = {
272 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
273 DMI_MATCH(DMI_PRODUCT_NAME, "X205TAW"),
274 },
275 },
276
277 /* Certec */
278 { /* Handle problems with rebooting on Certec BPC600 */
279 .callback = set_pci_reboot,
280 .ident = "Certec BPC600",
281 .matches = {
282 DMI_MATCH(DMI_SYS_VENDOR, "Certec"),
283 DMI_MATCH(DMI_PRODUCT_NAME, "BPC600"),
284 },
285 },
286
287 /* Dell */
288 { /* Handle problems with rebooting on Dell DXP061 */
289 .callback = set_bios_reboot,
290 .ident = "Dell DXP061",
291 .matches = {
292 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
293 DMI_MATCH(DMI_PRODUCT_NAME, "Dell DXP061"),
294 },
295 },
296 { /* Handle problems with rebooting on Dell E520's */
297 .callback = set_bios_reboot,
298 .ident = "Dell E520",
299 .matches = {
300 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
301 DMI_MATCH(DMI_PRODUCT_NAME, "Dell DM061"),
302 },
303 },
304 { /* Handle problems with rebooting on the Latitude E5410. */
305 .callback = set_pci_reboot,
306 .ident = "Dell Latitude E5410",
307 .matches = {
308 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
309 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E5410"),
310 },
311 },
312 { /* Handle problems with rebooting on the Latitude E5420. */
313 .callback = set_pci_reboot,
314 .ident = "Dell Latitude E5420",
315 .matches = {
316 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
317 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E5420"),
318 },
319 },
320 { /* Handle problems with rebooting on the Latitude E6320. */
321 .callback = set_pci_reboot,
322 .ident = "Dell Latitude E6320",
323 .matches = {
324 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
325 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6320"),
326 },
327 },
328 { /* Handle problems with rebooting on the Latitude E6420. */
329 .callback = set_pci_reboot,
330 .ident = "Dell Latitude E6420",
331 .matches = {
332 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
333 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6420"),
334 },
335 },
336 { /* Handle problems with rebooting on Dell Optiplex 330 with 0KP561 */
337 .callback = set_bios_reboot,
338 .ident = "Dell OptiPlex 330",
339 .matches = {
340 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
341 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 330"),
342 DMI_MATCH(DMI_BOARD_NAME, "0KP561"),
343 },
344 },
345 { /* Handle problems with rebooting on Dell Optiplex 360 with 0T656F */
346 .callback = set_bios_reboot,
347 .ident = "Dell OptiPlex 360",
348 .matches = {
349 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
350 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 360"),
351 DMI_MATCH(DMI_BOARD_NAME, "0T656F"),
352 },
353 },
354 { /* Handle problems with rebooting on Dell Optiplex 745's SFF */
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 },
361 },
362 { /* Handle problems with rebooting on Dell Optiplex 745's DFF */
363 .callback = set_bios_reboot,
364 .ident = "Dell OptiPlex 745",
365 .matches = {
366 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
367 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
368 DMI_MATCH(DMI_BOARD_NAME, "0MM599"),
369 },
370 },
371 { /* Handle problems with rebooting on Dell Optiplex 745 with 0KW626 */
372 .callback = set_bios_reboot,
373 .ident = "Dell OptiPlex 745",
374 .matches = {
375 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
376 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
377 DMI_MATCH(DMI_BOARD_NAME, "0KW626"),
378 },
379 },
380 { /* Handle problems with rebooting on Dell OptiPlex 760 with 0G919G */
381 .callback = set_bios_reboot,
382 .ident = "Dell OptiPlex 760",
383 .matches = {
384 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
385 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 760"),
386 DMI_MATCH(DMI_BOARD_NAME, "0G919G"),
387 },
388 },
389 { /* Handle problems with rebooting on the OptiPlex 990. */
390 .callback = set_pci_reboot,
391 .ident = "Dell OptiPlex 990",
392 .matches = {
393 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
394 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 990"),
395 },
396 },
397 { /* Handle problems with rebooting on Dell 300's */
398 .callback = set_bios_reboot,
399 .ident = "Dell PowerEdge 300",
400 .matches = {
401 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
402 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"),
403 },
404 },
405 { /* Handle problems with rebooting on Dell 1300's */
406 .callback = set_bios_reboot,
407 .ident = "Dell PowerEdge 1300",
408 .matches = {
409 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
410 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1300/"),
411 },
412 },
413 { /* Handle problems with rebooting on Dell 2400's */
414 .callback = set_bios_reboot,
415 .ident = "Dell PowerEdge 2400",
416 .matches = {
417 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
418 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"),
419 },
420 },
421 { /* Handle problems with rebooting on the Dell PowerEdge C6100. */
422 .callback = set_pci_reboot,
423 .ident = "Dell PowerEdge C6100",
424 .matches = {
425 DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
426 DMI_MATCH(DMI_PRODUCT_NAME, "C6100"),
427 },
428 },
429 { /* Handle problems with rebooting on the Precision M6600. */
430 .callback = set_pci_reboot,
431 .ident = "Dell Precision M6600",
432 .matches = {
433 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
434 DMI_MATCH(DMI_PRODUCT_NAME, "Precision M6600"),
435 },
436 },
437 { /* Handle problems with rebooting on Dell T5400's */
438 .callback = set_bios_reboot,
439 .ident = "Dell Precision T5400",
440 .matches = {
441 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
442 DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T5400"),
443 },
444 },
445 { /* Handle problems with rebooting on Dell T7400's */
446 .callback = set_bios_reboot,
447 .ident = "Dell Precision T7400",
448 .matches = {
449 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
450 DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T7400"),
451 },
452 },
453 { /* Handle problems with rebooting on Dell XPS710 */
454 .callback = set_bios_reboot,
455 .ident = "Dell XPS710",
456 .matches = {
457 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
458 DMI_MATCH(DMI_PRODUCT_NAME, "Dell XPS710"),
459 },
460 },
461 { /* Handle problems with rebooting on Dell Optiplex 7450 AIO */
462 .callback = set_acpi_reboot,
463 .ident = "Dell OptiPlex 7450 AIO",
464 .matches = {
465 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
466 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 7450 AIO"),
467 },
468 },
469
470 /* Hewlett-Packard */
471 { /* Handle problems with rebooting on HP laptops */
472 .callback = set_bios_reboot,
473 .ident = "HP Compaq Laptop",
474 .matches = {
475 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
476 DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"),
477 },
478 },
479
480 { /* PCIe Wifi card isn't detected after reboot otherwise */
481 .callback = set_pci_reboot,
482 .ident = "Zotac ZBOX CI327 nano",
483 .matches = {
484 DMI_MATCH(DMI_SYS_VENDOR, "NA"),
485 DMI_MATCH(DMI_PRODUCT_NAME, "ZBOX-CI327NANO-GS-01"),
486 },
487 },
488
489 /* Sony */
490 { /* Handle problems with rebooting on Sony VGN-Z540N */
491 .callback = set_bios_reboot,
492 .ident = "Sony VGN-Z540N",
493 .matches = {
494 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
495 DMI_MATCH(DMI_PRODUCT_NAME, "VGN-Z540N"),
496 },
497 },
498
499 { }
500 };
501
reboot_init(void)502 static int __init reboot_init(void)
503 {
504 int rv;
505
506 /*
507 * Only do the DMI check if reboot_type hasn't been overridden
508 * on the command line
509 */
510 if (!reboot_default)
511 return 0;
512
513 /*
514 * The DMI quirks table takes precedence. If no quirks entry
515 * matches and the ACPI Hardware Reduced bit is set and EFI
516 * runtime services are enabled, force EFI reboot.
517 */
518 rv = dmi_check_system(reboot_dmi_table);
519
520 if (!rv && efi_reboot_required() && !efi_runtime_disabled())
521 reboot_type = BOOT_EFI;
522
523 return 0;
524 }
525 core_initcall(reboot_init);
526
kb_wait(void)527 static inline void kb_wait(void)
528 {
529 int i;
530
531 for (i = 0; i < 0x10000; i++) {
532 if ((inb(0x64) & 0x02) == 0)
533 break;
534 udelay(2);
535 }
536 }
537
vmxoff_nmi(int cpu,struct pt_regs * regs)538 static void vmxoff_nmi(int cpu, struct pt_regs *regs)
539 {
540 cpu_emergency_vmxoff();
541 }
542
543 /* Use NMIs as IPIs to tell all CPUs to disable virtualization */
emergency_vmx_disable_all(void)544 static void emergency_vmx_disable_all(void)
545 {
546 /* Just make sure we won't change CPUs while doing this */
547 local_irq_disable();
548
549 /*
550 * Disable VMX on all CPUs before rebooting, otherwise we risk hanging
551 * the machine, because the CPU blocks INIT when it's in VMX root.
552 *
553 * We can't take any locks and we may be on an inconsistent state, so
554 * use NMIs as IPIs to tell the other CPUs to exit VMX root and halt.
555 *
556 * Do the NMI shootdown even if VMX if off on _this_ CPU, as that
557 * doesn't prevent a different CPU from being in VMX root operation.
558 */
559 if (cpu_has_vmx()) {
560 /* Safely force _this_ CPU out of VMX root operation. */
561 __cpu_emergency_vmxoff();
562
563 /* Halt and exit VMX root operation on the other CPUs. */
564 nmi_shootdown_cpus(vmxoff_nmi);
565 }
566 }
567
568
mach_reboot_fixups(void)569 void __attribute__((weak)) mach_reboot_fixups(void)
570 {
571 }
572
573 /*
574 * To the best of our knowledge Windows compatible x86 hardware expects
575 * the following on reboot:
576 *
577 * 1) If the FADT has the ACPI reboot register flag set, try it
578 * 2) If still alive, write to the keyboard controller
579 * 3) If still alive, write to the ACPI reboot register again
580 * 4) If still alive, write to the keyboard controller again
581 * 5) If still alive, call the EFI runtime service to reboot
582 * 6) If no EFI runtime service, call the BIOS to do a reboot
583 *
584 * We default to following the same pattern. We also have
585 * two other reboot methods: 'triple fault' and 'PCI', which
586 * can be triggered via the reboot= kernel boot option or
587 * via quirks.
588 *
589 * This means that this function can never return, it can misbehave
590 * by not rebooting properly and hanging.
591 */
native_machine_emergency_restart(void)592 static void native_machine_emergency_restart(void)
593 {
594 int i;
595 int attempt = 0;
596 int orig_reboot_type = reboot_type;
597 unsigned short mode;
598
599 if (reboot_emergency)
600 emergency_vmx_disable_all();
601
602 tboot_shutdown(TB_SHUTDOWN_REBOOT);
603
604 /* Tell the BIOS if we want cold or warm reboot */
605 mode = reboot_mode == REBOOT_WARM ? 0x1234 : 0;
606 *((unsigned short *)__va(0x472)) = mode;
607
608 /*
609 * If an EFI capsule has been registered with the firmware then
610 * override the reboot= parameter.
611 */
612 if (efi_capsule_pending(NULL)) {
613 pr_info("EFI capsule is pending, forcing EFI reboot.\n");
614 reboot_type = BOOT_EFI;
615 }
616
617 for (;;) {
618 /* Could also try the reset bit in the Hammer NB */
619 switch (reboot_type) {
620 case BOOT_ACPI:
621 acpi_reboot();
622 reboot_type = BOOT_KBD;
623 break;
624
625 case BOOT_KBD:
626 mach_reboot_fixups(); /* For board specific fixups */
627
628 for (i = 0; i < 10; i++) {
629 kb_wait();
630 udelay(50);
631 outb(0xfe, 0x64); /* Pulse reset low */
632 udelay(50);
633 }
634 if (attempt == 0 && orig_reboot_type == BOOT_ACPI) {
635 attempt = 1;
636 reboot_type = BOOT_ACPI;
637 } else {
638 reboot_type = BOOT_EFI;
639 }
640 break;
641
642 case BOOT_EFI:
643 efi_reboot(reboot_mode, NULL);
644 reboot_type = BOOT_BIOS;
645 break;
646
647 case BOOT_BIOS:
648 machine_real_restart(MRR_BIOS);
649
650 /* We're probably dead after this, but... */
651 reboot_type = BOOT_CF9_SAFE;
652 break;
653
654 case BOOT_CF9_FORCE:
655 port_cf9_safe = true;
656 fallthrough;
657
658 case BOOT_CF9_SAFE:
659 if (port_cf9_safe) {
660 u8 reboot_code = reboot_mode == REBOOT_WARM ? 0x06 : 0x0E;
661 u8 cf9 = inb(0xcf9) & ~reboot_code;
662 outb(cf9|2, 0xcf9); /* Request hard reset */
663 udelay(50);
664 /* Actually do the reset */
665 outb(cf9|reboot_code, 0xcf9);
666 udelay(50);
667 }
668 reboot_type = BOOT_TRIPLE;
669 break;
670
671 case BOOT_TRIPLE:
672 idt_invalidate(NULL);
673 __asm__ __volatile__("int3");
674
675 /* We're probably dead after this, but... */
676 reboot_type = BOOT_KBD;
677 break;
678 }
679 }
680 }
681
native_machine_shutdown(void)682 void native_machine_shutdown(void)
683 {
684 /* Stop the cpus and apics */
685 #ifdef CONFIG_X86_IO_APIC
686 /*
687 * Disabling IO APIC before local APIC is a workaround for
688 * erratum AVR31 in "Intel Atom Processor C2000 Product Family
689 * Specification Update". In this situation, interrupts that target
690 * a Logical Processor whose Local APIC is either in the process of
691 * being hardware disabled or software disabled are neither delivered
692 * nor discarded. When this erratum occurs, the processor may hang.
693 *
694 * Even without the erratum, it still makes sense to quiet IO APIC
695 * before disabling Local APIC.
696 */
697 clear_IO_APIC();
698 #endif
699
700 #ifdef CONFIG_SMP
701 /*
702 * Stop all of the others. Also disable the local irq to
703 * not receive the per-cpu timer interrupt which may trigger
704 * scheduler's load balance.
705 */
706 local_irq_disable();
707 stop_other_cpus();
708 #endif
709
710 lapic_shutdown();
711 restore_boot_irq_mode();
712
713 #ifdef CONFIG_HPET_TIMER
714 hpet_disable();
715 #endif
716
717 #ifdef CONFIG_X86_64
718 x86_platform.iommu_shutdown();
719 #endif
720 }
721
__machine_emergency_restart(int emergency)722 static void __machine_emergency_restart(int emergency)
723 {
724 reboot_emergency = emergency;
725 machine_ops.emergency_restart();
726 }
727
native_machine_restart(char * __unused)728 static void native_machine_restart(char *__unused)
729 {
730 pr_notice("machine restart\n");
731
732 if (!reboot_force)
733 machine_shutdown();
734 __machine_emergency_restart(0);
735 }
736
native_machine_halt(void)737 static void native_machine_halt(void)
738 {
739 /* Stop other cpus and apics */
740 machine_shutdown();
741
742 tboot_shutdown(TB_SHUTDOWN_HALT);
743
744 stop_this_cpu(NULL);
745 }
746
native_machine_power_off(void)747 static void native_machine_power_off(void)
748 {
749 if (pm_power_off) {
750 if (!reboot_force)
751 machine_shutdown();
752 pm_power_off();
753 }
754 /* A fallback in case there is no PM info available */
755 tboot_shutdown(TB_SHUTDOWN_HALT);
756 }
757
758 struct machine_ops machine_ops __ro_after_init = {
759 .power_off = native_machine_power_off,
760 .shutdown = native_machine_shutdown,
761 .emergency_restart = native_machine_emergency_restart,
762 .restart = native_machine_restart,
763 .halt = native_machine_halt,
764 #ifdef CONFIG_KEXEC_CORE
765 .crash_shutdown = native_machine_crash_shutdown,
766 #endif
767 };
768
machine_power_off(void)769 void machine_power_off(void)
770 {
771 machine_ops.power_off();
772 }
773
machine_shutdown(void)774 void machine_shutdown(void)
775 {
776 machine_ops.shutdown();
777 }
778
machine_emergency_restart(void)779 void machine_emergency_restart(void)
780 {
781 __machine_emergency_restart(1);
782 }
783
machine_restart(char * cmd)784 void machine_restart(char *cmd)
785 {
786 machine_ops.restart(cmd);
787 }
788
machine_halt(void)789 void machine_halt(void)
790 {
791 machine_ops.halt();
792 }
793
794 #ifdef CONFIG_KEXEC_CORE
machine_crash_shutdown(struct pt_regs * regs)795 void machine_crash_shutdown(struct pt_regs *regs)
796 {
797 machine_ops.crash_shutdown(regs);
798 }
799 #endif
800
801
802 /* This is the CPU performing the emergency shutdown work. */
803 int crashing_cpu = -1;
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 shootdown_callback(cpu, regs);
828
829 atomic_dec(&waiting_for_crash_ipi);
830 /* Assume hlt works */
831 halt();
832 for (;;)
833 cpu_relax();
834
835 return NMI_HANDLED;
836 }
837
838 /*
839 * Halt all other CPUs, calling the specified function on each of them
840 *
841 * This function can be used to halt all other CPUs on crash
842 * or emergency reboot time. The function passed as parameter
843 * will be called inside a NMI handler on all CPUs.
844 */
nmi_shootdown_cpus(nmi_shootdown_cb callback)845 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
846 {
847 unsigned long msecs;
848 local_irq_disable();
849
850 /* Make a note of crashing cpu. Will be used in NMI callback. */
851 crashing_cpu = safe_smp_processor_id();
852
853 shootdown_callback = callback;
854
855 atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
856 /* Would it be better to replace the trap vector here? */
857 if (register_nmi_handler(NMI_LOCAL, crash_nmi_callback,
858 NMI_FLAG_FIRST, "crash"))
859 return; /* Return what? */
860 /*
861 * Ensure the new callback function is set before sending
862 * out the NMI
863 */
864 wmb();
865
866 apic_send_IPI_allbutself(NMI_VECTOR);
867
868 /* Kick CPUs looping in NMI context. */
869 WRITE_ONCE(crash_ipi_issued, 1);
870
871 msecs = 1000; /* Wait at most a second for the other cpus to stop */
872 while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
873 mdelay(1);
874 msecs--;
875 }
876
877 /* Leave the nmi callback set */
878 }
879
880 /*
881 * Check if the crash dumping IPI got issued and if so, call its callback
882 * directly. This function is used when we have already been in NMI handler.
883 * It doesn't return.
884 */
run_crash_ipi_callback(struct pt_regs * regs)885 void run_crash_ipi_callback(struct pt_regs *regs)
886 {
887 if (crash_ipi_issued)
888 crash_nmi_callback(0, regs);
889 }
890
891 /* Override the weak function in kernel/panic.c */
nmi_panic_self_stop(struct pt_regs * regs)892 void nmi_panic_self_stop(struct pt_regs *regs)
893 {
894 while (1) {
895 /* If no CPU is preparing crash dump, we simply loop here. */
896 run_crash_ipi_callback(regs);
897 cpu_relax();
898 }
899 }
900
901 #else /* !CONFIG_SMP */
nmi_shootdown_cpus(nmi_shootdown_cb callback)902 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
903 {
904 /* No other CPUs to shoot down */
905 }
906
run_crash_ipi_callback(struct pt_regs * regs)907 void run_crash_ipi_callback(struct pt_regs *regs)
908 {
909 }
910 #endif
911