drm/panthor: Don't add write fences to the shared BOs
[drm/drm-misc.git] / arch / x86 / kernel / reboot.c
blob0e0a4cf6b5eb1702d61a94583e69f26a228d1940
1 // SPDX-License-Identifier: GPL-2.0
2 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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 <linux/kexec.h>
16 #include <acpi/reboot.h>
17 #include <asm/io.h>
18 #include <asm/apic.h>
19 #include <asm/io_apic.h>
20 #include <asm/desc.h>
21 #include <asm/hpet.h>
22 #include <asm/proto.h>
23 #include <asm/reboot_fixups.h>
24 #include <asm/reboot.h>
25 #include <asm/pci_x86.h>
26 #include <asm/cpu.h>
27 #include <asm/nmi.h>
28 #include <asm/smp.h>
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>
37 * Power off function, if any
39 void (*pm_power_off)(void);
40 EXPORT_SYMBOL(pm_power_off);
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
47 static int reboot_emergency;
49 /* This is set by the PCI code if either type 1 or type 2 PCI is detected */
50 bool port_cf9_safe = false;
53 * Reboot options and system auto-detection code provided by
54 * Dell Inc. so their systems "just work". :-)
58 * Some machines require the "reboot=a" commandline options
60 static int __init set_acpi_reboot(const struct dmi_system_id *d)
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");
67 return 0;
71 * Some machines require the "reboot=b" or "reboot=k" commandline options,
72 * this quirk makes that automatic.
74 static int __init set_bios_reboot(const struct dmi_system_id *d)
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");
81 return 0;
85 * Some machines don't handle the default ACPI reboot method and
86 * require the EFI reboot method:
88 static int __init set_efi_reboot(const struct dmi_system_id *d)
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);
94 return 0;
97 void __noreturn machine_real_restart(unsigned int type)
99 local_irq_disable();
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.)
111 spin_lock(&rtc_lock);
112 CMOS_WRITE(0x00, 0x8f);
113 spin_unlock(&rtc_lock);
116 * Switch to the trampoline page table.
118 load_trampoline_pgtable();
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();
132 #ifdef CONFIG_APM_MODULE
133 EXPORT_SYMBOL(machine_real_restart);
134 #endif
135 STACK_FRAME_NON_STANDARD(machine_real_restart);
138 * Some Apple MacBook and MacBookPro's needs reboot=p to be able to reboot
140 static int __init set_pci_reboot(const struct dmi_system_id *d)
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");
147 return 0;
150 static int __init set_kbd_reboot(const struct dmi_system_id *d)
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");
157 return 0;
161 * This is a single dmi_table handling all reboot quirks.
163 static const struct dmi_system_id reboot_dmi_table[] __initconst = {
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"),
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"),
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"),
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"),
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"),
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"),
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"),
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"),
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"),
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"),
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"),
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"),
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"),
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"),
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"),
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"),
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"),
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"),
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"),
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"),
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"),
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"),
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"),
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"),
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"),
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"),
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/"),
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/"),
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"),
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"),
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"),
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"),
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"),
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"),
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"),
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"),
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"),
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"),
495 static int __init reboot_init(void)
497 int rv;
500 * Only do the DMI check if reboot_type hasn't been overridden
501 * on the command line
503 if (!reboot_default)
504 return 0;
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.
511 rv = dmi_check_system(reboot_dmi_table);
513 if (!rv && efi_reboot_required() && !efi_runtime_disabled())
514 reboot_type = BOOT_EFI;
516 return 0;
518 core_initcall(reboot_init);
520 static inline void kb_wait(void)
522 int i;
524 for (i = 0; i < 0x10000; i++) {
525 if ((inb(0x64) & 0x02) == 0)
526 break;
527 udelay(2);
531 static inline void nmi_shootdown_cpus_on_restart(void);
533 #if IS_ENABLED(CONFIG_KVM_INTEL) || IS_ENABLED(CONFIG_KVM_AMD)
534 /* RCU-protected callback to disable virtualization prior to reboot. */
535 static cpu_emergency_virt_cb __rcu *cpu_emergency_virt_callback;
537 void cpu_emergency_register_virt_callback(cpu_emergency_virt_cb *callback)
539 if (WARN_ON_ONCE(rcu_access_pointer(cpu_emergency_virt_callback)))
540 return;
542 rcu_assign_pointer(cpu_emergency_virt_callback, callback);
544 EXPORT_SYMBOL_GPL(cpu_emergency_register_virt_callback);
546 void cpu_emergency_unregister_virt_callback(cpu_emergency_virt_cb *callback)
548 if (WARN_ON_ONCE(rcu_access_pointer(cpu_emergency_virt_callback) != callback))
549 return;
551 rcu_assign_pointer(cpu_emergency_virt_callback, NULL);
552 synchronize_rcu();
554 EXPORT_SYMBOL_GPL(cpu_emergency_unregister_virt_callback);
557 * Disable virtualization, i.e. VMX or SVM, to ensure INIT is recognized during
558 * reboot. VMX blocks INIT if the CPU is post-VMXON, and SVM blocks INIT if
559 * GIF=0, i.e. if the crash occurred between CLGI and STGI.
561 void cpu_emergency_disable_virtualization(void)
563 cpu_emergency_virt_cb *callback;
566 * IRQs must be disabled as KVM enables virtualization in hardware via
567 * function call IPIs, i.e. IRQs need to be disabled to guarantee
568 * virtualization stays disabled.
570 lockdep_assert_irqs_disabled();
572 rcu_read_lock();
573 callback = rcu_dereference(cpu_emergency_virt_callback);
574 if (callback)
575 callback();
576 rcu_read_unlock();
579 static void emergency_reboot_disable_virtualization(void)
581 local_irq_disable();
584 * Disable virtualization on all CPUs before rebooting to avoid hanging
585 * the system, as VMX and SVM block INIT when running in the host.
587 * We can't take any locks and we may be on an inconsistent state, so
588 * use NMIs as IPIs to tell the other CPUs to disable VMX/SVM and halt.
590 * Do the NMI shootdown even if virtualization is off on _this_ CPU, as
591 * other CPUs may have virtualization enabled.
593 if (rcu_access_pointer(cpu_emergency_virt_callback)) {
594 /* Safely force _this_ CPU out of VMX/SVM operation. */
595 cpu_emergency_disable_virtualization();
597 /* Disable VMX/SVM and halt on other CPUs. */
598 nmi_shootdown_cpus_on_restart();
601 #else
602 static void emergency_reboot_disable_virtualization(void) { }
603 #endif /* CONFIG_KVM_INTEL || CONFIG_KVM_AMD */
605 void __attribute__((weak)) mach_reboot_fixups(void)
610 * To the best of our knowledge Windows compatible x86 hardware expects
611 * the following on reboot:
613 * 1) If the FADT has the ACPI reboot register flag set, try it
614 * 2) If still alive, write to the keyboard controller
615 * 3) If still alive, write to the ACPI reboot register again
616 * 4) If still alive, write to the keyboard controller again
617 * 5) If still alive, call the EFI runtime service to reboot
618 * 6) If no EFI runtime service, call the BIOS to do a reboot
620 * We default to following the same pattern. We also have
621 * two other reboot methods: 'triple fault' and 'PCI', which
622 * can be triggered via the reboot= kernel boot option or
623 * via quirks.
625 * This means that this function can never return, it can misbehave
626 * by not rebooting properly and hanging.
628 static void native_machine_emergency_restart(void)
630 int i;
631 int attempt = 0;
632 int orig_reboot_type = reboot_type;
633 unsigned short mode;
635 if (reboot_emergency)
636 emergency_reboot_disable_virtualization();
638 tboot_shutdown(TB_SHUTDOWN_REBOOT);
640 /* Tell the BIOS if we want cold or warm reboot */
641 mode = reboot_mode == REBOOT_WARM ? 0x1234 : 0;
642 *((unsigned short *)__va(0x472)) = mode;
645 * If an EFI capsule has been registered with the firmware then
646 * override the reboot= parameter.
648 if (efi_capsule_pending(NULL)) {
649 pr_info("EFI capsule is pending, forcing EFI reboot.\n");
650 reboot_type = BOOT_EFI;
653 for (;;) {
654 /* Could also try the reset bit in the Hammer NB */
655 switch (reboot_type) {
656 case BOOT_ACPI:
657 acpi_reboot();
658 reboot_type = BOOT_KBD;
659 break;
661 case BOOT_KBD:
662 mach_reboot_fixups(); /* For board specific fixups */
664 for (i = 0; i < 10; i++) {
665 kb_wait();
666 udelay(50);
667 outb(0xfe, 0x64); /* Pulse reset low */
668 udelay(50);
670 if (attempt == 0 && orig_reboot_type == BOOT_ACPI) {
671 attempt = 1;
672 reboot_type = BOOT_ACPI;
673 } else {
674 reboot_type = BOOT_EFI;
676 break;
678 case BOOT_EFI:
679 efi_reboot(reboot_mode, NULL);
680 reboot_type = BOOT_BIOS;
681 break;
683 case BOOT_BIOS:
684 machine_real_restart(MRR_BIOS);
686 /* We're probably dead after this, but... */
687 reboot_type = BOOT_CF9_SAFE;
688 break;
690 case BOOT_CF9_FORCE:
691 port_cf9_safe = true;
692 fallthrough;
694 case BOOT_CF9_SAFE:
695 if (port_cf9_safe) {
696 u8 reboot_code = reboot_mode == REBOOT_WARM ? 0x06 : 0x0E;
697 u8 cf9 = inb(0xcf9) & ~reboot_code;
698 outb(cf9|2, 0xcf9); /* Request hard reset */
699 udelay(50);
700 /* Actually do the reset */
701 outb(cf9|reboot_code, 0xcf9);
702 udelay(50);
704 reboot_type = BOOT_TRIPLE;
705 break;
707 case BOOT_TRIPLE:
708 idt_invalidate();
709 __asm__ __volatile__("int3");
711 /* We're probably dead after this, but... */
712 reboot_type = BOOT_KBD;
713 break;
718 void native_machine_shutdown(void)
721 * Call enc_kexec_begin() while all CPUs are still active and
722 * interrupts are enabled. This will allow all in-flight memory
723 * conversions to finish cleanly.
725 if (kexec_in_progress)
726 x86_platform.guest.enc_kexec_begin();
728 /* Stop the cpus and apics */
729 #ifdef CONFIG_X86_IO_APIC
731 * Disabling IO APIC before local APIC is a workaround for
732 * erratum AVR31 in "Intel Atom Processor C2000 Product Family
733 * Specification Update". In this situation, interrupts that target
734 * a Logical Processor whose Local APIC is either in the process of
735 * being hardware disabled or software disabled are neither delivered
736 * nor discarded. When this erratum occurs, the processor may hang.
738 * Even without the erratum, it still makes sense to quiet IO APIC
739 * before disabling Local APIC.
741 clear_IO_APIC();
742 #endif
744 #ifdef CONFIG_SMP
746 * Stop all of the others. Also disable the local irq to
747 * not receive the per-cpu timer interrupt which may trigger
748 * scheduler's load balance.
750 local_irq_disable();
751 stop_other_cpus();
752 #endif
754 lapic_shutdown();
755 restore_boot_irq_mode();
757 #ifdef CONFIG_HPET_TIMER
758 hpet_disable();
759 #endif
761 #ifdef CONFIG_X86_64
762 x86_platform.iommu_shutdown();
763 #endif
765 if (kexec_in_progress)
766 x86_platform.guest.enc_kexec_finish();
769 static void __machine_emergency_restart(int emergency)
771 reboot_emergency = emergency;
772 machine_ops.emergency_restart();
775 static void native_machine_restart(char *__unused)
777 pr_notice("machine restart\n");
779 if (!reboot_force)
780 machine_shutdown();
781 __machine_emergency_restart(0);
784 static void native_machine_halt(void)
786 /* Stop other cpus and apics */
787 machine_shutdown();
789 tboot_shutdown(TB_SHUTDOWN_HALT);
791 stop_this_cpu(NULL);
794 static void native_machine_power_off(void)
796 if (kernel_can_power_off()) {
797 if (!reboot_force)
798 machine_shutdown();
799 do_kernel_power_off();
801 /* A fallback in case there is no PM info available */
802 tboot_shutdown(TB_SHUTDOWN_HALT);
805 struct machine_ops machine_ops __ro_after_init = {
806 .power_off = native_machine_power_off,
807 .shutdown = native_machine_shutdown,
808 .emergency_restart = native_machine_emergency_restart,
809 .restart = native_machine_restart,
810 .halt = native_machine_halt,
811 #ifdef CONFIG_CRASH_DUMP
812 .crash_shutdown = native_machine_crash_shutdown,
813 #endif
816 void machine_power_off(void)
818 machine_ops.power_off();
821 void machine_shutdown(void)
823 machine_ops.shutdown();
826 void machine_emergency_restart(void)
828 __machine_emergency_restart(1);
831 void machine_restart(char *cmd)
833 machine_ops.restart(cmd);
836 void machine_halt(void)
838 machine_ops.halt();
841 #ifdef CONFIG_CRASH_DUMP
842 void machine_crash_shutdown(struct pt_regs *regs)
844 machine_ops.crash_shutdown(regs);
846 #endif
848 /* This is the CPU performing the emergency shutdown work. */
849 int crashing_cpu = -1;
851 #if defined(CONFIG_SMP)
853 static nmi_shootdown_cb shootdown_callback;
855 static atomic_t waiting_for_crash_ipi;
856 static int crash_ipi_issued;
858 static int crash_nmi_callback(unsigned int val, struct pt_regs *regs)
860 int cpu;
862 cpu = raw_smp_processor_id();
865 * Don't do anything if this handler is invoked on crashing cpu.
866 * Otherwise, system will completely hang. Crashing cpu can get
867 * an NMI if system was initially booted with nmi_watchdog parameter.
869 if (cpu == crashing_cpu)
870 return NMI_HANDLED;
871 local_irq_disable();
873 if (shootdown_callback)
874 shootdown_callback(cpu, regs);
877 * Prepare the CPU for reboot _after_ invoking the callback so that the
878 * callback can safely use virtualization instructions, e.g. VMCLEAR.
880 cpu_emergency_disable_virtualization();
882 atomic_dec(&waiting_for_crash_ipi);
884 if (smp_ops.stop_this_cpu) {
885 smp_ops.stop_this_cpu();
886 unreachable();
889 /* Assume hlt works */
890 halt();
891 for (;;)
892 cpu_relax();
894 return NMI_HANDLED;
898 * nmi_shootdown_cpus - Stop other CPUs via NMI
899 * @callback: Optional callback to be invoked from the NMI handler
901 * The NMI handler on the remote CPUs invokes @callback, if not
902 * NULL, first and then disables virtualization to ensure that
903 * INIT is recognized during reboot.
905 * nmi_shootdown_cpus() can only be invoked once. After the first
906 * invocation all other CPUs are stuck in crash_nmi_callback() and
907 * cannot respond to a second NMI.
909 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
911 unsigned long msecs;
913 local_irq_disable();
916 * Avoid certain doom if a shootdown already occurred; re-registering
917 * the NMI handler will cause list corruption, modifying the callback
918 * will do who knows what, etc...
920 if (WARN_ON_ONCE(crash_ipi_issued))
921 return;
923 /* Make a note of crashing cpu. Will be used in NMI callback. */
924 crashing_cpu = safe_smp_processor_id();
926 shootdown_callback = callback;
928 atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
929 /* Would it be better to replace the trap vector here? */
930 if (register_nmi_handler(NMI_LOCAL, crash_nmi_callback,
931 NMI_FLAG_FIRST, "crash"))
932 return; /* Return what? */
934 * Ensure the new callback function is set before sending
935 * out the NMI
937 wmb();
939 apic_send_IPI_allbutself(NMI_VECTOR);
941 /* Kick CPUs looping in NMI context. */
942 WRITE_ONCE(crash_ipi_issued, 1);
944 msecs = 1000; /* Wait at most a second for the other cpus to stop */
945 while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
946 mdelay(1);
947 msecs--;
951 * Leave the nmi callback set, shootdown is a one-time thing. Clearing
952 * the callback could result in a NULL pointer dereference if a CPU
953 * (finally) responds after the timeout expires.
957 static inline void nmi_shootdown_cpus_on_restart(void)
959 if (!crash_ipi_issued)
960 nmi_shootdown_cpus(NULL);
964 * Check if the crash dumping IPI got issued and if so, call its callback
965 * directly. This function is used when we have already been in NMI handler.
966 * It doesn't return.
968 void run_crash_ipi_callback(struct pt_regs *regs)
970 if (crash_ipi_issued)
971 crash_nmi_callback(0, regs);
974 /* Override the weak function in kernel/panic.c */
975 void __noreturn nmi_panic_self_stop(struct pt_regs *regs)
977 while (1) {
978 /* If no CPU is preparing crash dump, we simply loop here. */
979 run_crash_ipi_callback(regs);
980 cpu_relax();
984 #else /* !CONFIG_SMP */
985 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
987 /* No other CPUs to shoot down */
990 static inline void nmi_shootdown_cpus_on_restart(void) { }
992 void run_crash_ipi_callback(struct pt_regs *regs)
995 #endif