x86, tsc: Fix SMI induced variation in quick_pit_calibrate()
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / arch / x86 / kernel / reboot.c
blob37a458b521a6020598b69305c782a0f28bd75b27
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>
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
32 * Power off function, if any
34 void (*pm_power_off)(void);
35 EXPORT_SYMBOL(pm_power_off);
37 static const struct desc_ptr no_idt = {};
38 static int reboot_mode;
39 enum reboot_type reboot_type = BOOT_ACPI;
40 int reboot_force;
42 #if defined(CONFIG_X86_32) && defined(CONFIG_SMP)
43 static int reboot_cpu = -1;
44 #endif
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
50 static int reboot_emergency;
52 /* This is set by the PCI code if either type 1 or type 2 PCI is detected */
53 bool port_cf9_safe = false;
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.
67 static int __init reboot_setup(char *str)
69 for (;;) {
70 switch (*str) {
71 case 'w':
72 reboot_mode = 0x1234;
73 break;
75 case 'c':
76 reboot_mode = 0;
77 break;
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');
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 */
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;
103 case 'f':
104 reboot_force = 1;
105 break;
108 str = strchr(str, ',');
109 if (str)
110 str++;
111 else
112 break;
114 return 1;
117 __setup("reboot=", reboot_setup);
120 #ifdef CONFIG_X86_32
122 * Reboot options and system auto-detection code provided by
123 * Dell Inc. so their systems "just work". :-)
127 * Some machines require the "reboot=b" or "reboot=k" commandline options,
128 * this quirk makes that automatic.
130 static int __init set_bios_reboot(const struct dmi_system_id *d)
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);
136 return 0;
139 static int __init set_kbd_reboot(const struct dmi_system_id *d)
141 if (reboot_type != BOOT_KBD) {
142 reboot_type = BOOT_KBD;
143 printk(KERN_INFO "%s series board detected. Selecting KBD-method for reboot.\n", d->ident);
145 return 0;
148 static struct dmi_system_id __initdata reboot_dmi_table[] = {
149 { /* Handle problems with rebooting on Dell E520's */
150 .callback = set_bios_reboot,
151 .ident = "Dell E520",
152 .matches = {
153 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
154 DMI_MATCH(DMI_PRODUCT_NAME, "Dell DM061"),
157 { /* Handle problems with rebooting on Dell 1300's */
158 .callback = set_bios_reboot,
159 .ident = "Dell PowerEdge 1300",
160 .matches = {
161 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
162 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1300/"),
165 { /* Handle problems with rebooting on Dell 300's */
166 .callback = set_bios_reboot,
167 .ident = "Dell PowerEdge 300",
168 .matches = {
169 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
170 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"),
173 { /* Handle problems with rebooting on Dell Optiplex 745's SFF*/
174 .callback = set_bios_reboot,
175 .ident = "Dell OptiPlex 745",
176 .matches = {
177 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
178 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
181 { /* Handle problems with rebooting on Dell Optiplex 745's DFF*/
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, "0MM599"),
190 { /* Handle problems with rebooting on Dell Optiplex 745 with 0KW626 */
191 .callback = set_bios_reboot,
192 .ident = "Dell OptiPlex 745",
193 .matches = {
194 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
195 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
196 DMI_MATCH(DMI_BOARD_NAME, "0KW626"),
199 { /* Handle problems with rebooting on Dell Optiplex 330 with 0KP561 */
200 .callback = set_bios_reboot,
201 .ident = "Dell OptiPlex 330",
202 .matches = {
203 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
204 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 330"),
205 DMI_MATCH(DMI_BOARD_NAME, "0KP561"),
208 { /* Handle problems with rebooting on Dell Optiplex 360 with 0T656F */
209 .callback = set_bios_reboot,
210 .ident = "Dell OptiPlex 360",
211 .matches = {
212 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
213 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 360"),
214 DMI_MATCH(DMI_BOARD_NAME, "0T656F"),
217 { /* Handle problems with rebooting on Dell OptiPlex 760 with 0G919G*/
218 .callback = set_bios_reboot,
219 .ident = "Dell OptiPlex 760",
220 .matches = {
221 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
222 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 760"),
223 DMI_MATCH(DMI_BOARD_NAME, "0G919G"),
226 { /* Handle problems with rebooting on Dell 2400's */
227 .callback = set_bios_reboot,
228 .ident = "Dell PowerEdge 2400",
229 .matches = {
230 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
231 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"),
234 { /* Handle problems with rebooting on Dell T5400's */
235 .callback = set_bios_reboot,
236 .ident = "Dell Precision T5400",
237 .matches = {
238 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
239 DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T5400"),
242 { /* Handle problems with rebooting on Dell T7400's */
243 .callback = set_bios_reboot,
244 .ident = "Dell Precision T7400",
245 .matches = {
246 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
247 DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T7400"),
250 { /* Handle problems with rebooting on HP laptops */
251 .callback = set_bios_reboot,
252 .ident = "HP Compaq Laptop",
253 .matches = {
254 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
255 DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"),
258 { /* Handle problems with rebooting on Dell XPS710 */
259 .callback = set_bios_reboot,
260 .ident = "Dell XPS710",
261 .matches = {
262 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
263 DMI_MATCH(DMI_PRODUCT_NAME, "Dell XPS710"),
266 { /* Handle problems with rebooting on Dell DXP061 */
267 .callback = set_bios_reboot,
268 .ident = "Dell DXP061",
269 .matches = {
270 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
271 DMI_MATCH(DMI_PRODUCT_NAME, "Dell DXP061"),
274 { /* Handle problems with rebooting on Sony VGN-Z540N */
275 .callback = set_bios_reboot,
276 .ident = "Sony VGN-Z540N",
277 .matches = {
278 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
279 DMI_MATCH(DMI_PRODUCT_NAME, "VGN-Z540N"),
282 { /* Handle problems with rebooting on CompuLab SBC-FITPC2 */
283 .callback = set_bios_reboot,
284 .ident = "CompuLab SBC-FITPC2",
285 .matches = {
286 DMI_MATCH(DMI_SYS_VENDOR, "CompuLab"),
287 DMI_MATCH(DMI_PRODUCT_NAME, "SBC-FITPC2"),
290 { /* Handle problems with rebooting on ASUS P4S800 */
291 .callback = set_bios_reboot,
292 .ident = "ASUS P4S800",
293 .matches = {
294 DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
295 DMI_MATCH(DMI_BOARD_NAME, "P4S800"),
298 { /* Handle problems with rebooting on VersaLogic Menlow boards */
299 .callback = set_bios_reboot,
300 .ident = "VersaLogic Menlow based board",
301 .matches = {
302 DMI_MATCH(DMI_BOARD_VENDOR, "VersaLogic Corporation"),
303 DMI_MATCH(DMI_BOARD_NAME, "VersaLogic Menlow board"),
306 { /* Handle reboot issue on Acer Aspire one */
307 .callback = set_kbd_reboot,
308 .ident = "Acer Aspire One A110",
309 .matches = {
310 DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
311 DMI_MATCH(DMI_PRODUCT_NAME, "AOA110"),
317 static int __init reboot_init(void)
319 dmi_check_system(reboot_dmi_table);
320 return 0;
322 core_initcall(reboot_init);
324 extern const unsigned char machine_real_restart_asm[];
325 extern const u64 machine_real_restart_gdt[3];
327 void machine_real_restart(unsigned int type)
329 void *restart_va;
330 unsigned long restart_pa;
331 void (*restart_lowmem)(unsigned int);
332 u64 *lowmem_gdt;
334 local_irq_disable();
336 /* Write zero to CMOS register number 0x0f, which the BIOS POST
337 routine will recognize as telling it to do a proper reboot. (Well
338 that's what this book in front of me says -- it may only apply to
339 the Phoenix BIOS though, it's not clear). At the same time,
340 disable NMIs by setting the top bit in the CMOS address register,
341 as we're about to do peculiar things to the CPU. I'm not sure if
342 `outb_p' is needed instead of just `outb'. Use it to be on the
343 safe side. (Yes, CMOS_WRITE does outb_p's. - Paul G.)
345 spin_lock(&rtc_lock);
346 CMOS_WRITE(0x00, 0x8f);
347 spin_unlock(&rtc_lock);
350 * Switch back to the initial page table.
352 load_cr3(initial_page_table);
354 /* Write 0x1234 to absolute memory location 0x472. The BIOS reads
355 this on booting to tell it to "Bypass memory test (also warm
356 boot)". This seems like a fairly standard thing that gets set by
357 REBOOT.COM programs, and the previous reset routine did this
358 too. */
359 *((unsigned short *)0x472) = reboot_mode;
361 /* Patch the GDT in the low memory trampoline */
362 lowmem_gdt = TRAMPOLINE_SYM(machine_real_restart_gdt);
364 restart_va = TRAMPOLINE_SYM(machine_real_restart_asm);
365 restart_pa = virt_to_phys(restart_va);
366 restart_lowmem = (void (*)(unsigned int))restart_pa;
368 /* GDT[0]: GDT self-pointer */
369 lowmem_gdt[0] =
370 (u64)(sizeof(machine_real_restart_gdt) - 1) +
371 ((u64)virt_to_phys(lowmem_gdt) << 16);
372 /* GDT[1]: 64K real mode code segment */
373 lowmem_gdt[1] =
374 GDT_ENTRY(0x009b, restart_pa, 0xffff);
376 /* Jump to the identity-mapped low memory code */
377 restart_lowmem(type);
379 #ifdef CONFIG_APM_MODULE
380 EXPORT_SYMBOL(machine_real_restart);
381 #endif
383 #endif /* CONFIG_X86_32 */
386 * Some Apple MacBook and MacBookPro's needs reboot=p to be able to reboot
388 static int __init set_pci_reboot(const struct dmi_system_id *d)
390 if (reboot_type != BOOT_CF9) {
391 reboot_type = BOOT_CF9;
392 printk(KERN_INFO "%s series board detected. "
393 "Selecting PCI-method for reboots.\n", d->ident);
395 return 0;
398 static struct dmi_system_id __initdata pci_reboot_dmi_table[] = {
399 { /* Handle problems with rebooting on Apple MacBook5 */
400 .callback = set_pci_reboot,
401 .ident = "Apple MacBook5",
402 .matches = {
403 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
404 DMI_MATCH(DMI_PRODUCT_NAME, "MacBook5"),
407 { /* Handle problems with rebooting on Apple MacBookPro5 */
408 .callback = set_pci_reboot,
409 .ident = "Apple MacBookPro5",
410 .matches = {
411 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
412 DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro5"),
415 { /* Handle problems with rebooting on Apple Macmini3,1 */
416 .callback = set_pci_reboot,
417 .ident = "Apple Macmini3,1",
418 .matches = {
419 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
420 DMI_MATCH(DMI_PRODUCT_NAME, "Macmini3,1"),
423 { /* Handle problems with rebooting on the iMac9,1. */
424 .callback = set_pci_reboot,
425 .ident = "Apple iMac9,1",
426 .matches = {
427 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
428 DMI_MATCH(DMI_PRODUCT_NAME, "iMac9,1"),
431 { /* Handle problems with rebooting on the Latitude E6320. */
432 .callback = set_pci_reboot,
433 .ident = "Dell Latitude E6320",
434 .matches = {
435 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
436 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6320"),
439 { /* Handle problems with rebooting on the Latitude E5420. */
440 .callback = set_pci_reboot,
441 .ident = "Dell Latitude E5420",
442 .matches = {
443 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
444 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E5420"),
447 { /* Handle problems with rebooting on the Latitude E6420. */
448 .callback = set_pci_reboot,
449 .ident = "Dell Latitude E6420",
450 .matches = {
451 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
452 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6420"),
455 { /* Handle problems with rebooting on the OptiPlex 990. */
456 .callback = set_pci_reboot,
457 .ident = "Dell OptiPlex 990",
458 .matches = {
459 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
460 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 990"),
466 static int __init pci_reboot_init(void)
468 dmi_check_system(pci_reboot_dmi_table);
469 return 0;
471 core_initcall(pci_reboot_init);
473 static inline void kb_wait(void)
475 int i;
477 for (i = 0; i < 0x10000; i++) {
478 if ((inb(0x64) & 0x02) == 0)
479 break;
480 udelay(2);
484 static void vmxoff_nmi(int cpu, struct pt_regs *regs)
486 cpu_emergency_vmxoff();
489 /* Use NMIs as IPIs to tell all CPUs to disable virtualization
491 static void emergency_vmx_disable_all(void)
493 /* Just make sure we won't change CPUs while doing this */
494 local_irq_disable();
496 /* We need to disable VMX on all CPUs before rebooting, otherwise
497 * we risk hanging up the machine, because the CPU ignore INIT
498 * signals when VMX is enabled.
500 * We can't take any locks and we may be on an inconsistent
501 * state, so we use NMIs as IPIs to tell the other CPUs to disable
502 * VMX and halt.
504 * For safety, we will avoid running the nmi_shootdown_cpus()
505 * stuff unnecessarily, but we don't have a way to check
506 * if other CPUs have VMX enabled. So we will call it only if the
507 * CPU we are running on has VMX enabled.
509 * We will miss cases where VMX is not enabled on all CPUs. This
510 * shouldn't do much harm because KVM always enable VMX on all
511 * CPUs anyway. But we can miss it on the small window where KVM
512 * is still enabling VMX.
514 if (cpu_has_vmx() && cpu_vmx_enabled()) {
515 /* Disable VMX on this CPU.
517 cpu_vmxoff();
519 /* Halt and disable VMX on the other CPUs */
520 nmi_shootdown_cpus(vmxoff_nmi);
526 void __attribute__((weak)) mach_reboot_fixups(void)
531 * Windows compatible x86 hardware expects the following on reboot:
533 * 1) If the FADT has the ACPI reboot register flag set, try it
534 * 2) If still alive, write to the keyboard controller
535 * 3) If still alive, write to the ACPI reboot register again
536 * 4) If still alive, write to the keyboard controller again
538 * If the machine is still alive at this stage, it gives up. We default to
539 * following the same pattern, except that if we're still alive after (4) we'll
540 * try to force a triple fault and then cycle between hitting the keyboard
541 * controller and doing that
543 static void native_machine_emergency_restart(void)
545 int i;
546 int attempt = 0;
547 int orig_reboot_type = reboot_type;
549 if (reboot_emergency)
550 emergency_vmx_disable_all();
552 tboot_shutdown(TB_SHUTDOWN_REBOOT);
554 /* Tell the BIOS if we want cold or warm reboot */
555 *((unsigned short *)__va(0x472)) = reboot_mode;
557 for (;;) {
558 /* Could also try the reset bit in the Hammer NB */
559 switch (reboot_type) {
560 case BOOT_KBD:
561 mach_reboot_fixups(); /* for board specific fixups */
563 for (i = 0; i < 10; i++) {
564 kb_wait();
565 udelay(50);
566 outb(0xfe, 0x64); /* pulse reset low */
567 udelay(50);
569 if (attempt == 0 && orig_reboot_type == BOOT_ACPI) {
570 attempt = 1;
571 reboot_type = BOOT_ACPI;
572 } else {
573 reboot_type = BOOT_TRIPLE;
575 break;
577 case BOOT_TRIPLE:
578 load_idt(&no_idt);
579 __asm__ __volatile__("int3");
581 reboot_type = BOOT_KBD;
582 break;
584 #ifdef CONFIG_X86_32
585 case BOOT_BIOS:
586 machine_real_restart(MRR_BIOS);
588 reboot_type = BOOT_KBD;
589 break;
590 #endif
592 case BOOT_ACPI:
593 acpi_reboot();
594 reboot_type = BOOT_KBD;
595 break;
597 case BOOT_EFI:
598 if (efi_enabled)
599 efi.reset_system(reboot_mode ?
600 EFI_RESET_WARM :
601 EFI_RESET_COLD,
602 EFI_SUCCESS, 0, NULL);
603 reboot_type = BOOT_KBD;
604 break;
606 case BOOT_CF9:
607 port_cf9_safe = true;
608 /* fall through */
610 case BOOT_CF9_COND:
611 if (port_cf9_safe) {
612 u8 cf9 = inb(0xcf9) & ~6;
613 outb(cf9|2, 0xcf9); /* Request hard reset */
614 udelay(50);
615 outb(cf9|6, 0xcf9); /* Actually do the reset */
616 udelay(50);
618 reboot_type = BOOT_KBD;
619 break;
624 void native_machine_shutdown(void)
626 /* Stop the cpus and apics */
627 #ifdef CONFIG_SMP
629 /* The boot cpu is always logical cpu 0 */
630 int reboot_cpu_id = 0;
632 #ifdef CONFIG_X86_32
633 /* See if there has been given a command line override */
634 if ((reboot_cpu != -1) && (reboot_cpu < nr_cpu_ids) &&
635 cpu_online(reboot_cpu))
636 reboot_cpu_id = reboot_cpu;
637 #endif
639 /* Make certain the cpu I'm about to reboot on is online */
640 if (!cpu_online(reboot_cpu_id))
641 reboot_cpu_id = smp_processor_id();
643 /* Make certain I only run on the appropriate processor */
644 set_cpus_allowed_ptr(current, cpumask_of(reboot_cpu_id));
646 /* O.K Now that I'm on the appropriate processor,
647 * stop all of the others.
649 stop_other_cpus();
650 #endif
652 lapic_shutdown();
654 #ifdef CONFIG_X86_IO_APIC
655 disable_IO_APIC();
656 #endif
658 #ifdef CONFIG_HPET_TIMER
659 hpet_disable();
660 #endif
662 #ifdef CONFIG_X86_64
663 x86_platform.iommu_shutdown();
664 #endif
667 static void __machine_emergency_restart(int emergency)
669 reboot_emergency = emergency;
670 machine_ops.emergency_restart();
673 static void native_machine_restart(char *__unused)
675 printk("machine restart\n");
677 if (!reboot_force)
678 machine_shutdown();
679 __machine_emergency_restart(0);
682 static void native_machine_halt(void)
684 /* stop other cpus and apics */
685 machine_shutdown();
687 tboot_shutdown(TB_SHUTDOWN_HALT);
689 /* stop this cpu */
690 stop_this_cpu(NULL);
693 static void native_machine_power_off(void)
695 if (pm_power_off) {
696 if (!reboot_force)
697 machine_shutdown();
698 pm_power_off();
700 /* a fallback in case there is no PM info available */
701 tboot_shutdown(TB_SHUTDOWN_HALT);
704 struct machine_ops machine_ops = {
705 .power_off = native_machine_power_off,
706 .shutdown = native_machine_shutdown,
707 .emergency_restart = native_machine_emergency_restart,
708 .restart = native_machine_restart,
709 .halt = native_machine_halt,
710 #ifdef CONFIG_KEXEC
711 .crash_shutdown = native_machine_crash_shutdown,
712 #endif
715 void machine_power_off(void)
717 machine_ops.power_off();
720 void machine_shutdown(void)
722 machine_ops.shutdown();
725 void machine_emergency_restart(void)
727 __machine_emergency_restart(1);
730 void machine_restart(char *cmd)
732 machine_ops.restart(cmd);
735 void machine_halt(void)
737 machine_ops.halt();
740 #ifdef CONFIG_KEXEC
741 void machine_crash_shutdown(struct pt_regs *regs)
743 machine_ops.crash_shutdown(regs);
745 #endif
748 #if defined(CONFIG_SMP)
750 /* This keeps a track of which one is crashing cpu. */
751 static int crashing_cpu;
752 static nmi_shootdown_cb shootdown_callback;
754 static atomic_t waiting_for_crash_ipi;
756 static int crash_nmi_callback(unsigned int val, struct pt_regs *regs)
758 int cpu;
760 cpu = raw_smp_processor_id();
762 /* Don't do anything if this handler is invoked on crashing cpu.
763 * Otherwise, system will completely hang. Crashing cpu can get
764 * an NMI if system was initially booted with nmi_watchdog parameter.
766 if (cpu == crashing_cpu)
767 return NMI_HANDLED;
768 local_irq_disable();
770 shootdown_callback(cpu, regs);
772 atomic_dec(&waiting_for_crash_ipi);
773 /* Assume hlt works */
774 halt();
775 for (;;)
776 cpu_relax();
778 return NMI_HANDLED;
781 static void smp_send_nmi_allbutself(void)
783 apic->send_IPI_allbutself(NMI_VECTOR);
786 /* Halt all other CPUs, calling the specified function on each of them
788 * This function can be used to halt all other CPUs on crash
789 * or emergency reboot time. The function passed as parameter
790 * will be called inside a NMI handler on all CPUs.
792 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
794 unsigned long msecs;
795 local_irq_disable();
797 /* Make a note of crashing cpu. Will be used in NMI callback.*/
798 crashing_cpu = safe_smp_processor_id();
800 shootdown_callback = callback;
802 atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
803 /* Would it be better to replace the trap vector here? */
804 if (register_nmi_handler(NMI_LOCAL, crash_nmi_callback,
805 NMI_FLAG_FIRST, "crash"))
806 return; /* return what? */
807 /* Ensure the new callback function is set before sending
808 * out the NMI
810 wmb();
812 smp_send_nmi_allbutself();
814 msecs = 1000; /* Wait at most a second for the other cpus to stop */
815 while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
816 mdelay(1);
817 msecs--;
820 /* Leave the nmi callback set */
822 #else /* !CONFIG_SMP */
823 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
825 /* No other CPUs to shoot down */
827 #endif