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 /* Sony */
481 { /* Handle problems with rebooting on Sony VGN-Z540N */
482 .callback = set_bios_reboot,
483 .ident = "Sony VGN-Z540N",
484 .matches = {
485 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
486 DMI_MATCH(DMI_PRODUCT_NAME, "VGN-Z540N"),
487 },
488 },
489
490 { }
491 };
492
reboot_init(void)493 static int __init reboot_init(void)
494 {
495 int rv;
496
497 /*
498 * Only do the DMI check if reboot_type hasn't been overridden
499 * on the command line
500 */
501 if (!reboot_default)
502 return 0;
503
504 /*
505 * The DMI quirks table takes precedence. If no quirks entry
506 * matches and the ACPI Hardware Reduced bit is set and EFI
507 * runtime services are enabled, force EFI reboot.
508 */
509 rv = dmi_check_system(reboot_dmi_table);
510
511 if (!rv && efi_reboot_required() && !efi_runtime_disabled())
512 reboot_type = BOOT_EFI;
513
514 return 0;
515 }
516 core_initcall(reboot_init);
517
kb_wait(void)518 static inline void kb_wait(void)
519 {
520 int i;
521
522 for (i = 0; i < 0x10000; i++) {
523 if ((inb(0x64) & 0x02) == 0)
524 break;
525 udelay(2);
526 }
527 }
528
vmxoff_nmi(int cpu,struct pt_regs * regs)529 static void vmxoff_nmi(int cpu, struct pt_regs *regs)
530 {
531 cpu_emergency_vmxoff();
532 }
533
534 /* Use NMIs as IPIs to tell all CPUs to disable virtualization */
emergency_vmx_disable_all(void)535 static void emergency_vmx_disable_all(void)
536 {
537 /* Just make sure we won't change CPUs while doing this */
538 local_irq_disable();
539
540 /*
541 * We need to disable VMX on all CPUs before rebooting, otherwise
542 * we risk hanging up the machine, because the CPU ignores INIT
543 * signals when VMX is enabled.
544 *
545 * We can't take any locks and we may be on an inconsistent
546 * state, so we use NMIs as IPIs to tell the other CPUs to disable
547 * VMX and halt.
548 *
549 * For safety, we will avoid running the nmi_shootdown_cpus()
550 * stuff unnecessarily, but we don't have a way to check
551 * if other CPUs have VMX enabled. So we will call it only if the
552 * CPU we are running on has VMX enabled.
553 *
554 * We will miss cases where VMX is not enabled on all CPUs. This
555 * shouldn't do much harm because KVM always enable VMX on all
556 * CPUs anyway. But we can miss it on the small window where KVM
557 * is still enabling VMX.
558 */
559 if (cpu_has_vmx() && cpu_vmx_enabled()) {
560 /* Disable VMX on this CPU. */
561 cpu_vmxoff();
562
563 /* Halt and disable VMX on the other CPUs */
564 nmi_shootdown_cpus(vmxoff_nmi);
565
566 }
567 }
568
569
mach_reboot_fixups(void)570 void __attribute__((weak)) mach_reboot_fixups(void)
571 {
572 }
573
574 /*
575 * To the best of our knowledge Windows compatible x86 hardware expects
576 * the following on reboot:
577 *
578 * 1) If the FADT has the ACPI reboot register flag set, try it
579 * 2) If still alive, write to the keyboard controller
580 * 3) If still alive, write to the ACPI reboot register again
581 * 4) If still alive, write to the keyboard controller again
582 * 5) If still alive, call the EFI runtime service to reboot
583 * 6) If no EFI runtime service, call the BIOS to do a reboot
584 *
585 * We default to following the same pattern. We also have
586 * two other reboot methods: 'triple fault' and 'PCI', which
587 * can be triggered via the reboot= kernel boot option or
588 * via quirks.
589 *
590 * This means that this function can never return, it can misbehave
591 * by not rebooting properly and hanging.
592 */
native_machine_emergency_restart(void)593 static void native_machine_emergency_restart(void)
594 {
595 int i;
596 int attempt = 0;
597 int orig_reboot_type = reboot_type;
598 unsigned short mode;
599
600 if (reboot_emergency)
601 emergency_vmx_disable_all();
602
603 tboot_shutdown(TB_SHUTDOWN_REBOOT);
604
605 /* Tell the BIOS if we want cold or warm reboot */
606 mode = reboot_mode == REBOOT_WARM ? 0x1234 : 0;
607 *((unsigned short *)__va(0x472)) = mode;
608
609 /*
610 * If an EFI capsule has been registered with the firmware then
611 * override the reboot= parameter.
612 */
613 if (efi_capsule_pending(NULL)) {
614 pr_info("EFI capsule is pending, forcing EFI reboot.\n");
615 reboot_type = BOOT_EFI;
616 }
617
618 for (;;) {
619 /* Could also try the reset bit in the Hammer NB */
620 switch (reboot_type) {
621 case BOOT_ACPI:
622 acpi_reboot();
623 reboot_type = BOOT_KBD;
624 break;
625
626 case BOOT_KBD:
627 mach_reboot_fixups(); /* For board specific fixups */
628
629 for (i = 0; i < 10; i++) {
630 kb_wait();
631 udelay(50);
632 outb(0xfe, 0x64); /* Pulse reset low */
633 udelay(50);
634 }
635 if (attempt == 0 && orig_reboot_type == BOOT_ACPI) {
636 attempt = 1;
637 reboot_type = BOOT_ACPI;
638 } else {
639 reboot_type = BOOT_EFI;
640 }
641 break;
642
643 case BOOT_EFI:
644 efi_reboot(reboot_mode, NULL);
645 reboot_type = BOOT_BIOS;
646 break;
647
648 case BOOT_BIOS:
649 machine_real_restart(MRR_BIOS);
650
651 /* We're probably dead after this, but... */
652 reboot_type = BOOT_CF9_SAFE;
653 break;
654
655 case BOOT_CF9_FORCE:
656 port_cf9_safe = true;
657 fallthrough;
658
659 case BOOT_CF9_SAFE:
660 if (port_cf9_safe) {
661 u8 reboot_code = reboot_mode == REBOOT_WARM ? 0x06 : 0x0E;
662 u8 cf9 = inb(0xcf9) & ~reboot_code;
663 outb(cf9|2, 0xcf9); /* Request hard reset */
664 udelay(50);
665 /* Actually do the reset */
666 outb(cf9|reboot_code, 0xcf9);
667 udelay(50);
668 }
669 reboot_type = BOOT_TRIPLE;
670 break;
671
672 case BOOT_TRIPLE:
673 idt_invalidate(NULL);
674 __asm__ __volatile__("int3");
675
676 /* We're probably dead after this, but... */
677 reboot_type = BOOT_KBD;
678 break;
679 }
680 }
681 }
682
native_machine_shutdown(void)683 void native_machine_shutdown(void)
684 {
685 /* Stop the cpus and apics */
686 #ifdef CONFIG_X86_IO_APIC
687 /*
688 * Disabling IO APIC before local APIC is a workaround for
689 * erratum AVR31 in "Intel Atom Processor C2000 Product Family
690 * Specification Update". In this situation, interrupts that target
691 * a Logical Processor whose Local APIC is either in the process of
692 * being hardware disabled or software disabled are neither delivered
693 * nor discarded. When this erratum occurs, the processor may hang.
694 *
695 * Even without the erratum, it still makes sense to quiet IO APIC
696 * before disabling Local APIC.
697 */
698 clear_IO_APIC();
699 #endif
700
701 #ifdef CONFIG_SMP
702 /*
703 * Stop all of the others. Also disable the local irq to
704 * not receive the per-cpu timer interrupt which may trigger
705 * scheduler's load balance.
706 */
707 local_irq_disable();
708 stop_other_cpus();
709 #endif
710
711 lapic_shutdown();
712 restore_boot_irq_mode();
713
714 #ifdef CONFIG_HPET_TIMER
715 hpet_disable();
716 #endif
717
718 #ifdef CONFIG_X86_64
719 x86_platform.iommu_shutdown();
720 #endif
721 }
722
__machine_emergency_restart(int emergency)723 static void __machine_emergency_restart(int emergency)
724 {
725 reboot_emergency = emergency;
726 machine_ops.emergency_restart();
727 }
728
native_machine_restart(char * __unused)729 static void native_machine_restart(char *__unused)
730 {
731 pr_notice("machine restart\n");
732
733 if (!reboot_force)
734 machine_shutdown();
735 __machine_emergency_restart(0);
736 }
737
native_machine_halt(void)738 static void native_machine_halt(void)
739 {
740 /* Stop other cpus and apics */
741 machine_shutdown();
742
743 tboot_shutdown(TB_SHUTDOWN_HALT);
744
745 stop_this_cpu(NULL);
746 }
747
native_machine_power_off(void)748 static void native_machine_power_off(void)
749 {
750 if (pm_power_off) {
751 if (!reboot_force)
752 machine_shutdown();
753 pm_power_off();
754 }
755 /* A fallback in case there is no PM info available */
756 tboot_shutdown(TB_SHUTDOWN_HALT);
757 }
758
759 struct machine_ops machine_ops __ro_after_init = {
760 .power_off = native_machine_power_off,
761 .shutdown = native_machine_shutdown,
762 .emergency_restart = native_machine_emergency_restart,
763 .restart = native_machine_restart,
764 .halt = native_machine_halt,
765 #ifdef CONFIG_KEXEC_CORE
766 .crash_shutdown = native_machine_crash_shutdown,
767 #endif
768 };
769
machine_power_off(void)770 void machine_power_off(void)
771 {
772 machine_ops.power_off();
773 }
774
machine_shutdown(void)775 void machine_shutdown(void)
776 {
777 machine_ops.shutdown();
778 }
779
machine_emergency_restart(void)780 void machine_emergency_restart(void)
781 {
782 __machine_emergency_restart(1);
783 }
784
machine_restart(char * cmd)785 void machine_restart(char *cmd)
786 {
787 machine_ops.restart(cmd);
788 }
789
machine_halt(void)790 void machine_halt(void)
791 {
792 machine_ops.halt();
793 }
794
795 #ifdef CONFIG_KEXEC_CORE
machine_crash_shutdown(struct pt_regs * regs)796 void machine_crash_shutdown(struct pt_regs *regs)
797 {
798 machine_ops.crash_shutdown(regs);
799 }
800 #endif
801
802
803 /* This is the CPU performing the emergency shutdown work. */
804 int crashing_cpu = -1;
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 shootdown_callback(cpu, regs);
829
830 atomic_dec(&waiting_for_crash_ipi);
831 /* Assume hlt works */
832 halt();
833 for (;;)
834 cpu_relax();
835
836 return NMI_HANDLED;
837 }
838
839 /*
840 * Halt all other CPUs, calling the specified function on each of them
841 *
842 * This function can be used to halt all other CPUs on crash
843 * or emergency reboot time. The function passed as parameter
844 * will be called inside a NMI handler on all CPUs.
845 */
nmi_shootdown_cpus(nmi_shootdown_cb callback)846 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
847 {
848 unsigned long msecs;
849 local_irq_disable();
850
851 /* Make a note of crashing cpu. Will be used in NMI callback. */
852 crashing_cpu = safe_smp_processor_id();
853
854 shootdown_callback = callback;
855
856 atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
857 /* Would it be better to replace the trap vector here? */
858 if (register_nmi_handler(NMI_LOCAL, crash_nmi_callback,
859 NMI_FLAG_FIRST, "crash"))
860 return; /* Return what? */
861 /*
862 * Ensure the new callback function is set before sending
863 * out the NMI
864 */
865 wmb();
866
867 apic_send_IPI_allbutself(NMI_VECTOR);
868
869 /* Kick CPUs looping in NMI context. */
870 WRITE_ONCE(crash_ipi_issued, 1);
871
872 msecs = 1000; /* Wait at most a second for the other cpus to stop */
873 while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
874 mdelay(1);
875 msecs--;
876 }
877
878 /* Leave the nmi callback set */
879 }
880
881 /*
882 * Check if the crash dumping IPI got issued and if so, call its callback
883 * directly. This function is used when we have already been in NMI handler.
884 * It doesn't return.
885 */
run_crash_ipi_callback(struct pt_regs * regs)886 void run_crash_ipi_callback(struct pt_regs *regs)
887 {
888 if (crash_ipi_issued)
889 crash_nmi_callback(0, regs);
890 }
891
892 /* Override the weak function in kernel/panic.c */
nmi_panic_self_stop(struct pt_regs * regs)893 void nmi_panic_self_stop(struct pt_regs *regs)
894 {
895 while (1) {
896 /* If no CPU is preparing crash dump, we simply loop here. */
897 run_crash_ipi_callback(regs);
898 cpu_relax();
899 }
900 }
901
902 #else /* !CONFIG_SMP */
nmi_shootdown_cpus(nmi_shootdown_cb callback)903 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
904 {
905 /* No other CPUs to shoot down */
906 }
907
run_crash_ipi_callback(struct pt_regs * regs)908 void run_crash_ipi_callback(struct pt_regs *regs)
909 {
910 }
911 #endif
912
