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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 <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>
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 */
39void (*pm_power_off)(void);
40EXPORT_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 */
47static int reboot_emergency;
48
49/* This is set by the PCI code if either type 1 or type 2 PCI is detected */
50bool 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 */
60static 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 */
74static 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 */
88static 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
97void __noreturn machine_real_restart(unsigned int type)
98{
99 local_irq_disable();
100
101 /*
102 * Write zero to CMOS register number 0x0f, which the BIOS POST
103 * routine will recognize as telling it to do a proper reboot. (Well
104 * that's what this book in front of me says -- it may only apply to
105 * the Phoenix BIOS though, it's not clear). At the same time,
106 * disable NMIs by setting the top bit in the CMOS address register,
107 * as we're about to do peculiar things to the CPU. I'm not sure if
108 * `outb_p' is needed instead of just `outb'. Use it to be on the
109 * safe side. (Yes, CMOS_WRITE does outb_p's. - Paul G.)
110 */
111 spin_lock(&rtc_lock);
112 CMOS_WRITE(0x00, 0x8f);
113 spin_unlock(&rtc_lock);
114
115 /*
116 * Switch to the trampoline page table.
117 */
118 load_trampoline_pgtable();
119
120 /* Jump to the identity-mapped low memory code */
121#ifdef CONFIG_X86_32
122 asm volatile("jmpl *%0" : :
123 "rm" (real_mode_header->machine_real_restart_asm),
124 "a" (type));
125#else
126 asm volatile("ljmpl *%0" : :
127 "m" (real_mode_header->machine_real_restart_asm),
128 "D" (type));
129#endif
130 unreachable();
131}
132#ifdef CONFIG_APM_MODULE
133EXPORT_SYMBOL(machine_real_restart);
134#endif
135STACK_FRAME_NON_STANDARD(machine_real_restart);
136
137/*
138 * Some Apple MacBook and MacBookPro's needs reboot=p to be able to reboot
139 */
140static int __init set_pci_reboot(const struct dmi_system_id *d)
141{
142 if (reboot_type != BOOT_CF9_FORCE) {
143 reboot_type = BOOT_CF9_FORCE;
144 pr_info("%s series board detected. Selecting %s-method for reboots.\n",
145 d->ident, "PCI");
146 }
147 return 0;
148}
149
150static int __init set_kbd_reboot(const struct dmi_system_id *d)
151{
152 if (reboot_type != BOOT_KBD) {
153 reboot_type = BOOT_KBD;
154 pr_info("%s series board detected. Selecting %s-method for reboot.\n",
155 d->ident, "KBD");
156 }
157 return 0;
158}
159
160/*
161 * This is a single dmi_table handling all reboot quirks.
162 */
163static const struct dmi_system_id reboot_dmi_table[] __initconst = {
164
165 /* Acer */
166 { /* Handle reboot issue on Acer Aspire one */
167 .callback = set_kbd_reboot,
168 .ident = "Acer Aspire One A110",
169 .matches = {
170 DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
171 DMI_MATCH(DMI_PRODUCT_NAME, "AOA110"),
172 },
173 },
174 { /* Handle reboot issue on Acer TravelMate X514-51T */
175 .callback = set_efi_reboot,
176 .ident = "Acer TravelMate X514-51T",
177 .matches = {
178 DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
179 DMI_MATCH(DMI_PRODUCT_NAME, "TravelMate X514-51T"),
180 },
181 },
182
183 /* Apple */
184 { /* Handle problems with rebooting on Apple MacBook5 */
185 .callback = set_pci_reboot,
186 .ident = "Apple MacBook5",
187 .matches = {
188 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
189 DMI_MATCH(DMI_PRODUCT_NAME, "MacBook5"),
190 },
191 },
192 { /* Handle problems with rebooting on Apple MacBook6,1 */
193 .callback = set_pci_reboot,
194 .ident = "Apple MacBook6,1",
195 .matches = {
196 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
197 DMI_MATCH(DMI_PRODUCT_NAME, "MacBook6,1"),
198 },
199 },
200 { /* Handle problems with rebooting on Apple MacBookPro5 */
201 .callback = set_pci_reboot,
202 .ident = "Apple MacBookPro5",
203 .matches = {
204 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
205 DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro5"),
206 },
207 },
208 { /* Handle problems with rebooting on Apple Macmini3,1 */
209 .callback = set_pci_reboot,
210 .ident = "Apple Macmini3,1",
211 .matches = {
212 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
213 DMI_MATCH(DMI_PRODUCT_NAME, "Macmini3,1"),
214 },
215 },
216 { /* Handle problems with rebooting on the iMac9,1. */
217 .callback = set_pci_reboot,
218 .ident = "Apple iMac9,1",
219 .matches = {
220 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
221 DMI_MATCH(DMI_PRODUCT_NAME, "iMac9,1"),
222 },
223 },
224 { /* Handle problems with rebooting on the iMac10,1. */
225 .callback = set_pci_reboot,
226 .ident = "Apple iMac10,1",
227 .matches = {
228 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
229 DMI_MATCH(DMI_PRODUCT_NAME, "iMac10,1"),
230 },
231 },
232
233 /* ASRock */
234 { /* Handle problems with rebooting on ASRock Q1900DC-ITX */
235 .callback = set_pci_reboot,
236 .ident = "ASRock Q1900DC-ITX",
237 .matches = {
238 DMI_MATCH(DMI_BOARD_VENDOR, "ASRock"),
239 DMI_MATCH(DMI_BOARD_NAME, "Q1900DC-ITX"),
240 },
241 },
242
243 /* ASUS */
244 { /* Handle problems with rebooting on ASUS P4S800 */
245 .callback = set_bios_reboot,
246 .ident = "ASUS P4S800",
247 .matches = {
248 DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
249 DMI_MATCH(DMI_BOARD_NAME, "P4S800"),
250 },
251 },
252 { /* Handle problems with rebooting on ASUS EeeBook X205TA */
253 .callback = set_acpi_reboot,
254 .ident = "ASUS EeeBook X205TA",
255 .matches = {
256 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
257 DMI_MATCH(DMI_PRODUCT_NAME, "X205TA"),
258 },
259 },
260 { /* Handle problems with rebooting on ASUS EeeBook X205TAW */
261 .callback = set_acpi_reboot,
262 .ident = "ASUS EeeBook X205TAW",
263 .matches = {
264 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
265 DMI_MATCH(DMI_PRODUCT_NAME, "X205TAW"),
266 },
267 },
268
269 /* Certec */
270 { /* Handle problems with rebooting on Certec BPC600 */
271 .callback = set_pci_reboot,
272 .ident = "Certec BPC600",
273 .matches = {
274 DMI_MATCH(DMI_SYS_VENDOR, "Certec"),
275 DMI_MATCH(DMI_PRODUCT_NAME, "BPC600"),
276 },
277 },
278
279 /* Dell */
280 { /* Handle problems with rebooting on Dell DXP061 */
281 .callback = set_bios_reboot,
282 .ident = "Dell DXP061",
283 .matches = {
284 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
285 DMI_MATCH(DMI_PRODUCT_NAME, "Dell DXP061"),
286 },
287 },
288 { /* Handle problems with rebooting on Dell E520's */
289 .callback = set_bios_reboot,
290 .ident = "Dell E520",
291 .matches = {
292 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
293 DMI_MATCH(DMI_PRODUCT_NAME, "Dell DM061"),
294 },
295 },
296 { /* Handle problems with rebooting on the Latitude E5410. */
297 .callback = set_pci_reboot,
298 .ident = "Dell Latitude E5410",
299 .matches = {
300 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
301 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E5410"),
302 },
303 },
304 { /* Handle problems with rebooting on the Latitude E5420. */
305 .callback = set_pci_reboot,
306 .ident = "Dell Latitude E5420",
307 .matches = {
308 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
309 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E5420"),
310 },
311 },
312 { /* Handle problems with rebooting on the Latitude E6320. */
313 .callback = set_pci_reboot,
314 .ident = "Dell Latitude E6320",
315 .matches = {
316 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
317 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6320"),
318 },
319 },
320 { /* Handle problems with rebooting on the Latitude E6420. */
321 .callback = set_pci_reboot,
322 .ident = "Dell Latitude E6420",
323 .matches = {
324 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
325 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6420"),
326 },
327 },
328 { /* Handle problems with rebooting on Dell Optiplex 330 with 0KP561 */
329 .callback = set_bios_reboot,
330 .ident = "Dell OptiPlex 330",
331 .matches = {
332 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
333 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 330"),
334 DMI_MATCH(DMI_BOARD_NAME, "0KP561"),
335 },
336 },
337 { /* Handle problems with rebooting on Dell Optiplex 360 with 0T656F */
338 .callback = set_bios_reboot,
339 .ident = "Dell OptiPlex 360",
340 .matches = {
341 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
342 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 360"),
343 DMI_MATCH(DMI_BOARD_NAME, "0T656F"),
344 },
345 },
346 { /* Handle problems with rebooting on Dell Optiplex 745's SFF */
347 .callback = set_bios_reboot,
348 .ident = "Dell OptiPlex 745",
349 .matches = {
350 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
351 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
352 },
353 },
354 { /* Handle problems with rebooting on Dell Optiplex 745's DFF */
355 .callback = set_bios_reboot,
356 .ident = "Dell OptiPlex 745",
357 .matches = {
358 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
359 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
360 DMI_MATCH(DMI_BOARD_NAME, "0MM599"),
361 },
362 },
363 { /* Handle problems with rebooting on Dell Optiplex 745 with 0KW626 */
364 .callback = set_bios_reboot,
365 .ident = "Dell OptiPlex 745",
366 .matches = {
367 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
368 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
369 DMI_MATCH(DMI_BOARD_NAME, "0KW626"),
370 },
371 },
372 { /* Handle problems with rebooting on Dell OptiPlex 760 with 0G919G */
373 .callback = set_bios_reboot,
374 .ident = "Dell OptiPlex 760",
375 .matches = {
376 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
377 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 760"),
378 DMI_MATCH(DMI_BOARD_NAME, "0G919G"),
379 },
380 },
381 { /* Handle problems with rebooting on the OptiPlex 990. */
382 .callback = set_pci_reboot,
383 .ident = "Dell OptiPlex 990 BIOS A0x",
384 .matches = {
385 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
386 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 990"),
387 DMI_MATCH(DMI_BIOS_VERSION, "A0"),
388 },
389 },
390 { /* Handle problems with rebooting on Dell 300's */
391 .callback = set_bios_reboot,
392 .ident = "Dell PowerEdge 300",
393 .matches = {
394 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
395 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"),
396 },
397 },
398 { /* Handle problems with rebooting on Dell 1300's */
399 .callback = set_bios_reboot,
400 .ident = "Dell PowerEdge 1300",
401 .matches = {
402 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
403 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1300/"),
404 },
405 },
406 { /* Handle problems with rebooting on Dell 2400's */
407 .callback = set_bios_reboot,
408 .ident = "Dell PowerEdge 2400",
409 .matches = {
410 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
411 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"),
412 },
413 },
414 { /* Handle problems with rebooting on the Dell PowerEdge C6100. */
415 .callback = set_pci_reboot,
416 .ident = "Dell PowerEdge C6100",
417 .matches = {
418 DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
419 DMI_MATCH(DMI_PRODUCT_NAME, "C6100"),
420 },
421 },
422 { /* Handle problems with rebooting on the Precision M6600. */
423 .callback = set_pci_reboot,
424 .ident = "Dell Precision M6600",
425 .matches = {
426 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
427 DMI_MATCH(DMI_PRODUCT_NAME, "Precision M6600"),
428 },
429 },
430 { /* Handle problems with rebooting on Dell T5400's */
431 .callback = set_bios_reboot,
432 .ident = "Dell Precision T5400",
433 .matches = {
434 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
435 DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T5400"),
436 },
437 },
438 { /* Handle problems with rebooting on Dell T7400's */
439 .callback = set_bios_reboot,
440 .ident = "Dell Precision T7400",
441 .matches = {
442 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
443 DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T7400"),
444 },
445 },
446 { /* Handle problems with rebooting on Dell XPS710 */
447 .callback = set_bios_reboot,
448 .ident = "Dell XPS710",
449 .matches = {
450 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
451 DMI_MATCH(DMI_PRODUCT_NAME, "Dell XPS710"),
452 },
453 },
454 { /* Handle problems with rebooting on Dell Optiplex 7450 AIO */
455 .callback = set_acpi_reboot,
456 .ident = "Dell OptiPlex 7450 AIO",
457 .matches = {
458 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
459 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 7450 AIO"),
460 },
461 },
462
463 /* Hewlett-Packard */
464 { /* Handle problems with rebooting on HP laptops */
465 .callback = set_bios_reboot,
466 .ident = "HP Compaq Laptop",
467 .matches = {
468 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
469 DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"),
470 },
471 },
472
473 { /* PCIe Wifi card isn't detected after reboot otherwise */
474 .callback = set_pci_reboot,
475 .ident = "Zotac ZBOX CI327 nano",
476 .matches = {
477 DMI_MATCH(DMI_SYS_VENDOR, "NA"),
478 DMI_MATCH(DMI_PRODUCT_NAME, "ZBOX-CI327NANO-GS-01"),
479 },
480 },
481
482 /* Sony */
483 { /* Handle problems with rebooting on Sony VGN-Z540N */
484 .callback = set_bios_reboot,
485 .ident = "Sony VGN-Z540N",
486 .matches = {
487 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
488 DMI_MATCH(DMI_PRODUCT_NAME, "VGN-Z540N"),
489 },
490 },
491
492 { }
493};
494
495static int __init reboot_init(void)
496{
497 int rv;
498
499 /*
500 * Only do the DMI check if reboot_type hasn't been overridden
501 * on the command line
502 */
503 if (!reboot_default)
504 return 0;
505
506 /*
507 * The DMI quirks table takes precedence. If no quirks entry
508 * matches and the ACPI Hardware Reduced bit is set and EFI
509 * runtime services are enabled, force EFI reboot.
510 */
511 rv = dmi_check_system(reboot_dmi_table);
512
513 if (!rv && efi_reboot_required() && !efi_runtime_disabled())
514 reboot_type = BOOT_EFI;
515
516 return 0;
517}
518core_initcall(reboot_init);
519
520static inline void kb_wait(void)
521{
522 int i;
523
524 for (i = 0; i < 0x10000; i++) {
525 if ((inb(0x64) & 0x02) == 0)
526 break;
527 udelay(2);
528 }
529}
530
531static inline void nmi_shootdown_cpus_on_restart(void);
532
533#if IS_ENABLED(CONFIG_KVM_X86)
534/* RCU-protected callback to disable virtualization prior to reboot. */
535static cpu_emergency_virt_cb __rcu *cpu_emergency_virt_callback;
536
537void cpu_emergency_register_virt_callback(cpu_emergency_virt_cb *callback)
538{
539 if (WARN_ON_ONCE(rcu_access_pointer(cpu_emergency_virt_callback)))
540 return;
541
542 rcu_assign_pointer(cpu_emergency_virt_callback, callback);
543}
544EXPORT_SYMBOL_GPL(cpu_emergency_register_virt_callback);
545
546void cpu_emergency_unregister_virt_callback(cpu_emergency_virt_cb *callback)
547{
548 if (WARN_ON_ONCE(rcu_access_pointer(cpu_emergency_virt_callback) != callback))
549 return;
550
551 rcu_assign_pointer(cpu_emergency_virt_callback, NULL);
552 synchronize_rcu();
553}
554EXPORT_SYMBOL_GPL(cpu_emergency_unregister_virt_callback);
555
556/*
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.
560 */
561void cpu_emergency_disable_virtualization(void)
562{
563 cpu_emergency_virt_cb *callback;
564
565 /*
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.
569 */
570 lockdep_assert_irqs_disabled();
571
572 rcu_read_lock();
573 callback = rcu_dereference(cpu_emergency_virt_callback);
574 if (callback)
575 callback();
576 rcu_read_unlock();
577}
578
579static void emergency_reboot_disable_virtualization(void)
580{
581 local_irq_disable();
582
583 /*
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.
586 *
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.
589 *
590 * Do the NMI shootdown even if virtualization is off on _this_ CPU, as
591 * other CPUs may have virtualization enabled.
592 */
593 if (rcu_access_pointer(cpu_emergency_virt_callback)) {
594 /* Safely force _this_ CPU out of VMX/SVM operation. */
595 cpu_emergency_disable_virtualization();
596
597 /* Disable VMX/SVM and halt on other CPUs. */
598 nmi_shootdown_cpus_on_restart();
599 }
600}
601#else
602static void emergency_reboot_disable_virtualization(void) { }
603#endif /* CONFIG_KVM_X86 */
604
605void __attribute__((weak)) mach_reboot_fixups(void)
606{
607}
608
609/*
610 * To the best of our knowledge Windows compatible x86 hardware expects
611 * the following on reboot:
612 *
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
619 *
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.
624 *
625 * This means that this function can never return, it can misbehave
626 * by not rebooting properly and hanging.
627 */
628static void native_machine_emergency_restart(void)
629{
630 int i;
631 int attempt = 0;
632 int orig_reboot_type = reboot_type;
633 unsigned short mode;
634
635 if (reboot_emergency)
636 emergency_reboot_disable_virtualization();
637
638 tboot_shutdown(TB_SHUTDOWN_REBOOT);
639
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;
643
644 /*
645 * If an EFI capsule has been registered with the firmware then
646 * override the reboot= parameter.
647 */
648 if (efi_capsule_pending(NULL)) {
649 pr_info("EFI capsule is pending, forcing EFI reboot.\n");
650 reboot_type = BOOT_EFI;
651 }
652
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;
660
661 case BOOT_KBD:
662 mach_reboot_fixups(); /* For board specific fixups */
663
664 for (i = 0; i < 10; i++) {
665 kb_wait();
666 udelay(50);
667 outb(0xfe, 0x64); /* Pulse reset low */
668 udelay(50);
669 }
670 if (attempt == 0 && orig_reboot_type == BOOT_ACPI) {
671 attempt = 1;
672 reboot_type = BOOT_ACPI;
673 } else {
674 reboot_type = BOOT_EFI;
675 }
676 break;
677
678 case BOOT_EFI:
679 efi_reboot(reboot_mode, NULL);
680 reboot_type = BOOT_BIOS;
681 break;
682
683 case BOOT_BIOS:
684 machine_real_restart(MRR_BIOS);
685
686 /* We're probably dead after this, but... */
687 reboot_type = BOOT_CF9_SAFE;
688 break;
689
690 case BOOT_CF9_FORCE:
691 port_cf9_safe = true;
692 fallthrough;
693
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);
703 }
704 reboot_type = BOOT_TRIPLE;
705 break;
706
707 case BOOT_TRIPLE:
708 idt_invalidate();
709 __asm__ __volatile__("int3");
710
711 /* We're probably dead after this, but... */
712 reboot_type = BOOT_KBD;
713 break;
714 }
715 }
716}
717
718void native_machine_shutdown(void)
719{
720 /*
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.
724 */
725 if (kexec_in_progress)
726 x86_platform.guest.enc_kexec_begin();
727
728 /* Stop the cpus and apics */
729#ifdef CONFIG_X86_IO_APIC
730 /*
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.
737 *
738 * Even without the erratum, it still makes sense to quiet IO APIC
739 * before disabling Local APIC.
740 */
741 clear_IO_APIC();
742#endif
743
744#ifdef CONFIG_SMP
745 /*
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.
749 */
750 local_irq_disable();
751 stop_other_cpus();
752#endif
753
754 lapic_shutdown();
755 restore_boot_irq_mode();
756
757#ifdef CONFIG_HPET_TIMER
758 hpet_disable();
759#endif
760
761#ifdef CONFIG_X86_64
762 x86_platform.iommu_shutdown();
763#endif
764
765 if (kexec_in_progress)
766 x86_platform.guest.enc_kexec_finish();
767}
768
769static void __machine_emergency_restart(int emergency)
770{
771 reboot_emergency = emergency;
772 machine_ops.emergency_restart();
773}
774
775static void native_machine_restart(char *__unused)
776{
777 pr_notice("machine restart\n");
778
779 if (!reboot_force)
780 machine_shutdown();
781 __machine_emergency_restart(0);
782}
783
784static void native_machine_halt(void)
785{
786 /* Stop other cpus and apics */
787 machine_shutdown();
788
789 tboot_shutdown(TB_SHUTDOWN_HALT);
790
791 stop_this_cpu(NULL);
792}
793
794static void native_machine_power_off(void)
795{
796 if (kernel_can_power_off()) {
797 if (!reboot_force)
798 machine_shutdown();
799 do_kernel_power_off();
800 }
801 /* A fallback in case there is no PM info available */
802 tboot_shutdown(TB_SHUTDOWN_HALT);
803}
804
805struct 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
814};
815
816void machine_power_off(void)
817{
818 machine_ops.power_off();
819}
820
821void machine_shutdown(void)
822{
823 machine_ops.shutdown();
824}
825
826void machine_emergency_restart(void)
827{
828 __machine_emergency_restart(1);
829}
830
831void machine_restart(char *cmd)
832{
833 machine_ops.restart(cmd);
834}
835
836void machine_halt(void)
837{
838 machine_ops.halt();
839}
840
841#ifdef CONFIG_CRASH_DUMP
842void machine_crash_shutdown(struct pt_regs *regs)
843{
844 machine_ops.crash_shutdown(regs);
845}
846#endif
847
848/* This is the CPU performing the emergency shutdown work. */
849int crashing_cpu = -1;
850
851#if defined(CONFIG_SMP)
852
853static nmi_shootdown_cb shootdown_callback;
854
855static atomic_t waiting_for_crash_ipi;
856static int crash_ipi_issued;
857
858static int crash_nmi_callback(unsigned int val, struct pt_regs *regs)
859{
860 int cpu;
861
862 cpu = raw_smp_processor_id();
863
864 /*
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.
868 */
869 if (cpu == crashing_cpu)
870 return NMI_HANDLED;
871 local_irq_disable();
872
873 if (shootdown_callback)
874 shootdown_callback(cpu, regs);
875
876 /*
877 * Prepare the CPU for reboot _after_ invoking the callback so that the
878 * callback can safely use virtualization instructions, e.g. VMCLEAR.
879 */
880 cpu_emergency_disable_virtualization();
881
882 atomic_dec(&waiting_for_crash_ipi);
883
884 if (smp_ops.stop_this_cpu) {
885 smp_ops.stop_this_cpu();
886 BUG();
887 }
888
889 /* Assume hlt works */
890 halt();
891 for (;;)
892 cpu_relax();
893
894 return NMI_HANDLED;
895}
896
897/**
898 * nmi_shootdown_cpus - Stop other CPUs via NMI
899 * @callback: Optional callback to be invoked from the NMI handler
900 *
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.
904 *
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.
908 */
909void nmi_shootdown_cpus(nmi_shootdown_cb callback)
910{
911 unsigned long msecs;
912
913 local_irq_disable();
914
915 /*
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...
919 */
920 if (WARN_ON_ONCE(crash_ipi_issued))
921 return;
922
923 /* Make a note of crashing cpu. Will be used in NMI callback. */
924 crashing_cpu = safe_smp_processor_id();
925
926 shootdown_callback = callback;
927
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? */
933 /*
934 * Ensure the new callback function is set before sending
935 * out the NMI
936 */
937 wmb();
938
939 apic_send_IPI_allbutself(NMI_VECTOR);
940
941 /* Kick CPUs looping in NMI context. */
942 WRITE_ONCE(crash_ipi_issued, 1);
943
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--;
948 }
949
950 /*
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.
954 */
955}
956
957static inline void nmi_shootdown_cpus_on_restart(void)
958{
959 if (!crash_ipi_issued)
960 nmi_shootdown_cpus(NULL);
961}
962
963/*
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.
967 */
968void run_crash_ipi_callback(struct pt_regs *regs)
969{
970 if (crash_ipi_issued)
971 crash_nmi_callback(0, regs);
972}
973
974/* Override the weak function in kernel/panic.c */
975void __noreturn nmi_panic_self_stop(struct pt_regs *regs)
976{
977 while (1) {
978 /* If no CPU is preparing crash dump, we simply loop here. */
979 run_crash_ipi_callback(regs);
980 cpu_relax();
981 }
982}
983
984#else /* !CONFIG_SMP */
985void nmi_shootdown_cpus(nmi_shootdown_cb callback)
986{
987 /* No other CPUs to shoot down */
988}
989
990static inline void nmi_shootdown_cpus_on_restart(void) { }
991
992void run_crash_ipi_callback(struct pt_regs *regs)
993{
994}
995#endif
1#include <linux/module.h>
2#include <linux/reboot.h>
3#include <linux/init.h>
4#include <linux/pm.h>
5#include <linux/efi.h>
6#include <linux/dmi.h>
7#include <linux/sched.h>
8#include <linux/tboot.h>
9#include <linux/delay.h>
10#include <acpi/reboot.h>
11#include <asm/io.h>
12#include <asm/apic.h>
13#include <asm/desc.h>
14#include <asm/hpet.h>
15#include <asm/pgtable.h>
16#include <asm/proto.h>
17#include <asm/reboot_fixups.h>
18#include <asm/reboot.h>
19#include <asm/pci_x86.h>
20#include <asm/virtext.h>
21#include <asm/cpu.h>
22#include <asm/nmi.h>
23
24#ifdef CONFIG_X86_32
25# include <linux/ctype.h>
26# include <linux/mc146818rtc.h>
27#else
28# include <asm/x86_init.h>
29#endif
30
31/*
32 * Power off function, if any
33 */
34void (*pm_power_off)(void);
35EXPORT_SYMBOL(pm_power_off);
36
37static const struct desc_ptr no_idt = {};
38static int reboot_mode;
39enum reboot_type reboot_type = BOOT_ACPI;
40int reboot_force;
41
42#if defined(CONFIG_X86_32) && defined(CONFIG_SMP)
43static int reboot_cpu = -1;
44#endif
45
46/* This is set if we need to go through the 'emergency' path.
47 * When machine_emergency_restart() is called, we may be on
48 * an inconsistent state and won't be able to do a clean cleanup
49 */
50static int reboot_emergency;
51
52/* This is set by the PCI code if either type 1 or type 2 PCI is detected */
53bool port_cf9_safe = false;
54
55/* reboot=b[ios] | s[mp] | t[riple] | k[bd] | e[fi] [, [w]arm | [c]old] | p[ci]
56 warm Don't set the cold reboot flag
57 cold Set the cold reboot flag
58 bios Reboot by jumping through the BIOS (only for X86_32)
59 smp Reboot by executing reset on BSP or other CPU (only for X86_32)
60 triple Force a triple fault (init)
61 kbd Use the keyboard controller. cold reset (default)
62 acpi Use the RESET_REG in the FADT
63 efi Use efi reset_system runtime service
64 pci Use the so-called "PCI reset register", CF9
65 force Avoid anything that could hang.
66 */
67static int __init reboot_setup(char *str)
68{
69 for (;;) {
70 switch (*str) {
71 case 'w':
72 reboot_mode = 0x1234;
73 break;
74
75 case 'c':
76 reboot_mode = 0;
77 break;
78
79#ifdef CONFIG_X86_32
80#ifdef CONFIG_SMP
81 case 's':
82 if (isdigit(*(str+1))) {
83 reboot_cpu = (int) (*(str+1) - '0');
84 if (isdigit(*(str+2)))
85 reboot_cpu = reboot_cpu*10 + (int)(*(str+2) - '0');
86 }
87 /* we will leave sorting out the final value
88 when we are ready to reboot, since we might not
89 have detected BSP APIC ID or smp_num_cpu */
90 break;
91#endif /* CONFIG_SMP */
92
93 case 'b':
94#endif
95 case 'a':
96 case 'k':
97 case 't':
98 case 'e':
99 case 'p':
100 reboot_type = *str;
101 break;
102
103 case 'f':
104 reboot_force = 1;
105 break;
106 }
107
108 str = strchr(str, ',');
109 if (str)
110 str++;
111 else
112 break;
113 }
114 return 1;
115}
116
117__setup("reboot=", reboot_setup);
118
119
120#ifdef CONFIG_X86_32
121/*
122 * Reboot options and system auto-detection code provided by
123 * Dell Inc. so their systems "just work". :-)
124 */
125
126/*
127 * Some machines require the "reboot=b" commandline option,
128 * this quirk makes that automatic.
129 */
130static int __init set_bios_reboot(const struct dmi_system_id *d)
131{
132 if (reboot_type != BOOT_BIOS) {
133 reboot_type = BOOT_BIOS;
134 printk(KERN_INFO "%s series board detected. Selecting BIOS-method for reboots.\n", d->ident);
135 }
136 return 0;
137}
138
139static struct dmi_system_id __initdata reboot_dmi_table[] = {
140 { /* Handle problems with rebooting on Dell E520's */
141 .callback = set_bios_reboot,
142 .ident = "Dell E520",
143 .matches = {
144 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
145 DMI_MATCH(DMI_PRODUCT_NAME, "Dell DM061"),
146 },
147 },
148 { /* Handle problems with rebooting on Dell 1300's */
149 .callback = set_bios_reboot,
150 .ident = "Dell PowerEdge 1300",
151 .matches = {
152 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
153 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1300/"),
154 },
155 },
156 { /* Handle problems with rebooting on Dell 300's */
157 .callback = set_bios_reboot,
158 .ident = "Dell PowerEdge 300",
159 .matches = {
160 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
161 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"),
162 },
163 },
164 { /* Handle problems with rebooting on Dell Optiplex 745's SFF*/
165 .callback = set_bios_reboot,
166 .ident = "Dell OptiPlex 745",
167 .matches = {
168 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
169 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
170 },
171 },
172 { /* Handle problems with rebooting on Dell Optiplex 745's DFF*/
173 .callback = set_bios_reboot,
174 .ident = "Dell OptiPlex 745",
175 .matches = {
176 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
177 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
178 DMI_MATCH(DMI_BOARD_NAME, "0MM599"),
179 },
180 },
181 { /* Handle problems with rebooting on Dell Optiplex 745 with 0KW626 */
182 .callback = set_bios_reboot,
183 .ident = "Dell OptiPlex 745",
184 .matches = {
185 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
186 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
187 DMI_MATCH(DMI_BOARD_NAME, "0KW626"),
188 },
189 },
190 { /* Handle problems with rebooting on Dell Optiplex 330 with 0KP561 */
191 .callback = set_bios_reboot,
192 .ident = "Dell OptiPlex 330",
193 .matches = {
194 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
195 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 330"),
196 DMI_MATCH(DMI_BOARD_NAME, "0KP561"),
197 },
198 },
199 { /* Handle problems with rebooting on Dell Optiplex 360 with 0T656F */
200 .callback = set_bios_reboot,
201 .ident = "Dell OptiPlex 360",
202 .matches = {
203 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
204 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 360"),
205 DMI_MATCH(DMI_BOARD_NAME, "0T656F"),
206 },
207 },
208 { /* Handle problems with rebooting on Dell OptiPlex 760 with 0G919G*/
209 .callback = set_bios_reboot,
210 .ident = "Dell OptiPlex 760",
211 .matches = {
212 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
213 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 760"),
214 DMI_MATCH(DMI_BOARD_NAME, "0G919G"),
215 },
216 },
217 { /* Handle problems with rebooting on Dell 2400's */
218 .callback = set_bios_reboot,
219 .ident = "Dell PowerEdge 2400",
220 .matches = {
221 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
222 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"),
223 },
224 },
225 { /* Handle problems with rebooting on Dell T5400's */
226 .callback = set_bios_reboot,
227 .ident = "Dell Precision T5400",
228 .matches = {
229 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
230 DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T5400"),
231 },
232 },
233 { /* Handle problems with rebooting on Dell T7400's */
234 .callback = set_bios_reboot,
235 .ident = "Dell Precision T7400",
236 .matches = {
237 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
238 DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T7400"),
239 },
240 },
241 { /* Handle problems with rebooting on HP laptops */
242 .callback = set_bios_reboot,
243 .ident = "HP Compaq Laptop",
244 .matches = {
245 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
246 DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"),
247 },
248 },
249 { /* Handle problems with rebooting on Dell XPS710 */
250 .callback = set_bios_reboot,
251 .ident = "Dell XPS710",
252 .matches = {
253 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
254 DMI_MATCH(DMI_PRODUCT_NAME, "Dell XPS710"),
255 },
256 },
257 { /* Handle problems with rebooting on Dell DXP061 */
258 .callback = set_bios_reboot,
259 .ident = "Dell DXP061",
260 .matches = {
261 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
262 DMI_MATCH(DMI_PRODUCT_NAME, "Dell DXP061"),
263 },
264 },
265 { /* Handle problems with rebooting on Sony VGN-Z540N */
266 .callback = set_bios_reboot,
267 .ident = "Sony VGN-Z540N",
268 .matches = {
269 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
270 DMI_MATCH(DMI_PRODUCT_NAME, "VGN-Z540N"),
271 },
272 },
273 { /* Handle problems with rebooting on CompuLab SBC-FITPC2 */
274 .callback = set_bios_reboot,
275 .ident = "CompuLab SBC-FITPC2",
276 .matches = {
277 DMI_MATCH(DMI_SYS_VENDOR, "CompuLab"),
278 DMI_MATCH(DMI_PRODUCT_NAME, "SBC-FITPC2"),
279 },
280 },
281 { /* Handle problems with rebooting on ASUS P4S800 */
282 .callback = set_bios_reboot,
283 .ident = "ASUS P4S800",
284 .matches = {
285 DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
286 DMI_MATCH(DMI_BOARD_NAME, "P4S800"),
287 },
288 },
289 { /* Handle problems with rebooting on VersaLogic Menlow boards */
290 .callback = set_bios_reboot,
291 .ident = "VersaLogic Menlow based board",
292 .matches = {
293 DMI_MATCH(DMI_BOARD_VENDOR, "VersaLogic Corporation"),
294 DMI_MATCH(DMI_BOARD_NAME, "VersaLogic Menlow board"),
295 },
296 },
297 { /* Handle reboot issue on Acer Aspire one */
298 .callback = set_bios_reboot,
299 .ident = "Acer Aspire One A110",
300 .matches = {
301 DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
302 DMI_MATCH(DMI_PRODUCT_NAME, "AOA110"),
303 },
304 },
305 { }
306};
307
308static int __init reboot_init(void)
309{
310 dmi_check_system(reboot_dmi_table);
311 return 0;
312}
313core_initcall(reboot_init);
314
315extern const unsigned char machine_real_restart_asm[];
316extern const u64 machine_real_restart_gdt[3];
317
318void machine_real_restart(unsigned int type)
319{
320 void *restart_va;
321 unsigned long restart_pa;
322 void (*restart_lowmem)(unsigned int);
323 u64 *lowmem_gdt;
324
325 local_irq_disable();
326
327 /* Write zero to CMOS register number 0x0f, which the BIOS POST
328 routine will recognize as telling it to do a proper reboot. (Well
329 that's what this book in front of me says -- it may only apply to
330 the Phoenix BIOS though, it's not clear). At the same time,
331 disable NMIs by setting the top bit in the CMOS address register,
332 as we're about to do peculiar things to the CPU. I'm not sure if
333 `outb_p' is needed instead of just `outb'. Use it to be on the
334 safe side. (Yes, CMOS_WRITE does outb_p's. - Paul G.)
335 */
336 spin_lock(&rtc_lock);
337 CMOS_WRITE(0x00, 0x8f);
338 spin_unlock(&rtc_lock);
339
340 /*
341 * Switch back to the initial page table.
342 */
343 load_cr3(initial_page_table);
344
345 /* Write 0x1234 to absolute memory location 0x472. The BIOS reads
346 this on booting to tell it to "Bypass memory test (also warm
347 boot)". This seems like a fairly standard thing that gets set by
348 REBOOT.COM programs, and the previous reset routine did this
349 too. */
350 *((unsigned short *)0x472) = reboot_mode;
351
352 /* Patch the GDT in the low memory trampoline */
353 lowmem_gdt = TRAMPOLINE_SYM(machine_real_restart_gdt);
354
355 restart_va = TRAMPOLINE_SYM(machine_real_restart_asm);
356 restart_pa = virt_to_phys(restart_va);
357 restart_lowmem = (void (*)(unsigned int))restart_pa;
358
359 /* GDT[0]: GDT self-pointer */
360 lowmem_gdt[0] =
361 (u64)(sizeof(machine_real_restart_gdt) - 1) +
362 ((u64)virt_to_phys(lowmem_gdt) << 16);
363 /* GDT[1]: 64K real mode code segment */
364 lowmem_gdt[1] =
365 GDT_ENTRY(0x009b, restart_pa, 0xffff);
366
367 /* Jump to the identity-mapped low memory code */
368 restart_lowmem(type);
369}
370#ifdef CONFIG_APM_MODULE
371EXPORT_SYMBOL(machine_real_restart);
372#endif
373
374#endif /* CONFIG_X86_32 */
375
376/*
377 * Some Apple MacBook and MacBookPro's needs reboot=p to be able to reboot
378 */
379static int __init set_pci_reboot(const struct dmi_system_id *d)
380{
381 if (reboot_type != BOOT_CF9) {
382 reboot_type = BOOT_CF9;
383 printk(KERN_INFO "%s series board detected. "
384 "Selecting PCI-method for reboots.\n", d->ident);
385 }
386 return 0;
387}
388
389static struct dmi_system_id __initdata pci_reboot_dmi_table[] = {
390 { /* Handle problems with rebooting on Apple MacBook5 */
391 .callback = set_pci_reboot,
392 .ident = "Apple MacBook5",
393 .matches = {
394 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
395 DMI_MATCH(DMI_PRODUCT_NAME, "MacBook5"),
396 },
397 },
398 { /* Handle problems with rebooting on Apple MacBookPro5 */
399 .callback = set_pci_reboot,
400 .ident = "Apple MacBookPro5",
401 .matches = {
402 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
403 DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro5"),
404 },
405 },
406 { /* Handle problems with rebooting on Apple Macmini3,1 */
407 .callback = set_pci_reboot,
408 .ident = "Apple Macmini3,1",
409 .matches = {
410 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
411 DMI_MATCH(DMI_PRODUCT_NAME, "Macmini3,1"),
412 },
413 },
414 { /* Handle problems with rebooting on the iMac9,1. */
415 .callback = set_pci_reboot,
416 .ident = "Apple iMac9,1",
417 .matches = {
418 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
419 DMI_MATCH(DMI_PRODUCT_NAME, "iMac9,1"),
420 },
421 },
422 { /* Handle problems with rebooting on the Latitude E6320. */
423 .callback = set_pci_reboot,
424 .ident = "Dell Latitude E6320",
425 .matches = {
426 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
427 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6320"),
428 },
429 },
430 { /* Handle problems with rebooting on the Latitude E5420. */
431 .callback = set_pci_reboot,
432 .ident = "Dell Latitude E5420",
433 .matches = {
434 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
435 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E5420"),
436 },
437 },
438 { /* Handle problems with rebooting on the Latitude E6420. */
439 .callback = set_pci_reboot,
440 .ident = "Dell Latitude E6420",
441 .matches = {
442 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
443 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6420"),
444 },
445 },
446 { }
447};
448
449static int __init pci_reboot_init(void)
450{
451 dmi_check_system(pci_reboot_dmi_table);
452 return 0;
453}
454core_initcall(pci_reboot_init);
455
456static inline void kb_wait(void)
457{
458 int i;
459
460 for (i = 0; i < 0x10000; i++) {
461 if ((inb(0x64) & 0x02) == 0)
462 break;
463 udelay(2);
464 }
465}
466
467static void vmxoff_nmi(int cpu, struct die_args *args)
468{
469 cpu_emergency_vmxoff();
470}
471
472/* Use NMIs as IPIs to tell all CPUs to disable virtualization
473 */
474static void emergency_vmx_disable_all(void)
475{
476 /* Just make sure we won't change CPUs while doing this */
477 local_irq_disable();
478
479 /* We need to disable VMX on all CPUs before rebooting, otherwise
480 * we risk hanging up the machine, because the CPU ignore INIT
481 * signals when VMX is enabled.
482 *
483 * We can't take any locks and we may be on an inconsistent
484 * state, so we use NMIs as IPIs to tell the other CPUs to disable
485 * VMX and halt.
486 *
487 * For safety, we will avoid running the nmi_shootdown_cpus()
488 * stuff unnecessarily, but we don't have a way to check
489 * if other CPUs have VMX enabled. So we will call it only if the
490 * CPU we are running on has VMX enabled.
491 *
492 * We will miss cases where VMX is not enabled on all CPUs. This
493 * shouldn't do much harm because KVM always enable VMX on all
494 * CPUs anyway. But we can miss it on the small window where KVM
495 * is still enabling VMX.
496 */
497 if (cpu_has_vmx() && cpu_vmx_enabled()) {
498 /* Disable VMX on this CPU.
499 */
500 cpu_vmxoff();
501
502 /* Halt and disable VMX on the other CPUs */
503 nmi_shootdown_cpus(vmxoff_nmi);
504
505 }
506}
507
508
509void __attribute__((weak)) mach_reboot_fixups(void)
510{
511}
512
513/*
514 * Windows compatible x86 hardware expects the following on reboot:
515 *
516 * 1) If the FADT has the ACPI reboot register flag set, try it
517 * 2) If still alive, write to the keyboard controller
518 * 3) If still alive, write to the ACPI reboot register again
519 * 4) If still alive, write to the keyboard controller again
520 *
521 * If the machine is still alive at this stage, it gives up. We default to
522 * following the same pattern, except that if we're still alive after (4) we'll
523 * try to force a triple fault and then cycle between hitting the keyboard
524 * controller and doing that
525 */
526static void native_machine_emergency_restart(void)
527{
528 int i;
529 int attempt = 0;
530 int orig_reboot_type = reboot_type;
531
532 if (reboot_emergency)
533 emergency_vmx_disable_all();
534
535 tboot_shutdown(TB_SHUTDOWN_REBOOT);
536
537 /* Tell the BIOS if we want cold or warm reboot */
538 *((unsigned short *)__va(0x472)) = reboot_mode;
539
540 for (;;) {
541 /* Could also try the reset bit in the Hammer NB */
542 switch (reboot_type) {
543 case BOOT_KBD:
544 mach_reboot_fixups(); /* for board specific fixups */
545
546 for (i = 0; i < 10; i++) {
547 kb_wait();
548 udelay(50);
549 outb(0xfe, 0x64); /* pulse reset low */
550 udelay(50);
551 }
552 if (attempt == 0 && orig_reboot_type == BOOT_ACPI) {
553 attempt = 1;
554 reboot_type = BOOT_ACPI;
555 } else {
556 reboot_type = BOOT_TRIPLE;
557 }
558 break;
559
560 case BOOT_TRIPLE:
561 load_idt(&no_idt);
562 __asm__ __volatile__("int3");
563
564 reboot_type = BOOT_KBD;
565 break;
566
567#ifdef CONFIG_X86_32
568 case BOOT_BIOS:
569 machine_real_restart(MRR_BIOS);
570
571 reboot_type = BOOT_KBD;
572 break;
573#endif
574
575 case BOOT_ACPI:
576 acpi_reboot();
577 reboot_type = BOOT_KBD;
578 break;
579
580 case BOOT_EFI:
581 if (efi_enabled)
582 efi.reset_system(reboot_mode ?
583 EFI_RESET_WARM :
584 EFI_RESET_COLD,
585 EFI_SUCCESS, 0, NULL);
586 reboot_type = BOOT_KBD;
587 break;
588
589 case BOOT_CF9:
590 port_cf9_safe = true;
591 /* fall through */
592
593 case BOOT_CF9_COND:
594 if (port_cf9_safe) {
595 u8 cf9 = inb(0xcf9) & ~6;
596 outb(cf9|2, 0xcf9); /* Request hard reset */
597 udelay(50);
598 outb(cf9|6, 0xcf9); /* Actually do the reset */
599 udelay(50);
600 }
601 reboot_type = BOOT_KBD;
602 break;
603 }
604 }
605}
606
607void native_machine_shutdown(void)
608{
609 /* Stop the cpus and apics */
610#ifdef CONFIG_SMP
611
612 /* The boot cpu is always logical cpu 0 */
613 int reboot_cpu_id = 0;
614
615#ifdef CONFIG_X86_32
616 /* See if there has been given a command line override */
617 if ((reboot_cpu != -1) && (reboot_cpu < nr_cpu_ids) &&
618 cpu_online(reboot_cpu))
619 reboot_cpu_id = reboot_cpu;
620#endif
621
622 /* Make certain the cpu I'm about to reboot on is online */
623 if (!cpu_online(reboot_cpu_id))
624 reboot_cpu_id = smp_processor_id();
625
626 /* Make certain I only run on the appropriate processor */
627 set_cpus_allowed_ptr(current, cpumask_of(reboot_cpu_id));
628
629 /* O.K Now that I'm on the appropriate processor,
630 * stop all of the others.
631 */
632 stop_other_cpus();
633#endif
634
635 lapic_shutdown();
636
637#ifdef CONFIG_X86_IO_APIC
638 disable_IO_APIC();
639#endif
640
641#ifdef CONFIG_HPET_TIMER
642 hpet_disable();
643#endif
644
645#ifdef CONFIG_X86_64
646 x86_platform.iommu_shutdown();
647#endif
648}
649
650static void __machine_emergency_restart(int emergency)
651{
652 reboot_emergency = emergency;
653 machine_ops.emergency_restart();
654}
655
656static void native_machine_restart(char *__unused)
657{
658 printk("machine restart\n");
659
660 if (!reboot_force)
661 machine_shutdown();
662 __machine_emergency_restart(0);
663}
664
665static void native_machine_halt(void)
666{
667 /* stop other cpus and apics */
668 machine_shutdown();
669
670 tboot_shutdown(TB_SHUTDOWN_HALT);
671
672 /* stop this cpu */
673 stop_this_cpu(NULL);
674}
675
676static void native_machine_power_off(void)
677{
678 if (pm_power_off) {
679 if (!reboot_force)
680 machine_shutdown();
681 pm_power_off();
682 }
683 /* a fallback in case there is no PM info available */
684 tboot_shutdown(TB_SHUTDOWN_HALT);
685}
686
687struct machine_ops machine_ops = {
688 .power_off = native_machine_power_off,
689 .shutdown = native_machine_shutdown,
690 .emergency_restart = native_machine_emergency_restart,
691 .restart = native_machine_restart,
692 .halt = native_machine_halt,
693#ifdef CONFIG_KEXEC
694 .crash_shutdown = native_machine_crash_shutdown,
695#endif
696};
697
698void machine_power_off(void)
699{
700 machine_ops.power_off();
701}
702
703void machine_shutdown(void)
704{
705 machine_ops.shutdown();
706}
707
708void machine_emergency_restart(void)
709{
710 __machine_emergency_restart(1);
711}
712
713void machine_restart(char *cmd)
714{
715 machine_ops.restart(cmd);
716}
717
718void machine_halt(void)
719{
720 machine_ops.halt();
721}
722
723#ifdef CONFIG_KEXEC
724void machine_crash_shutdown(struct pt_regs *regs)
725{
726 machine_ops.crash_shutdown(regs);
727}
728#endif
729
730
731#if defined(CONFIG_SMP)
732
733/* This keeps a track of which one is crashing cpu. */
734static int crashing_cpu;
735static nmi_shootdown_cb shootdown_callback;
736
737static atomic_t waiting_for_crash_ipi;
738
739static int crash_nmi_callback(struct notifier_block *self,
740 unsigned long val, void *data)
741{
742 int cpu;
743
744 if (val != DIE_NMI)
745 return NOTIFY_OK;
746
747 cpu = raw_smp_processor_id();
748
749 /* Don't do anything if this handler is invoked on crashing cpu.
750 * Otherwise, system will completely hang. Crashing cpu can get
751 * an NMI if system was initially booted with nmi_watchdog parameter.
752 */
753 if (cpu == crashing_cpu)
754 return NOTIFY_STOP;
755 local_irq_disable();
756
757 shootdown_callback(cpu, (struct die_args *)data);
758
759 atomic_dec(&waiting_for_crash_ipi);
760 /* Assume hlt works */
761 halt();
762 for (;;)
763 cpu_relax();
764
765 return 1;
766}
767
768static void smp_send_nmi_allbutself(void)
769{
770 apic->send_IPI_allbutself(NMI_VECTOR);
771}
772
773static struct notifier_block crash_nmi_nb = {
774 .notifier_call = crash_nmi_callback,
775 /* we want to be the first one called */
776 .priority = NMI_LOCAL_HIGH_PRIOR+1,
777};
778
779/* Halt all other CPUs, calling the specified function on each of them
780 *
781 * This function can be used to halt all other CPUs on crash
782 * or emergency reboot time. The function passed as parameter
783 * will be called inside a NMI handler on all CPUs.
784 */
785void nmi_shootdown_cpus(nmi_shootdown_cb callback)
786{
787 unsigned long msecs;
788 local_irq_disable();
789
790 /* Make a note of crashing cpu. Will be used in NMI callback.*/
791 crashing_cpu = safe_smp_processor_id();
792
793 shootdown_callback = callback;
794
795 atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
796 /* Would it be better to replace the trap vector here? */
797 if (register_die_notifier(&crash_nmi_nb))
798 return; /* return what? */
799 /* Ensure the new callback function is set before sending
800 * out the NMI
801 */
802 wmb();
803
804 smp_send_nmi_allbutself();
805
806 msecs = 1000; /* Wait at most a second for the other cpus to stop */
807 while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
808 mdelay(1);
809 msecs--;
810 }
811
812 /* Leave the nmi callback set */
813}
814#else /* !CONFIG_SMP */
815void nmi_shootdown_cpus(nmi_shootdown_cb callback)
816{
817 /* No other CPUs to shoot down */
818}
819#endif