Version:  2.0.40 2.2.26 2.4.37 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1

Linux/arch/x86/kernel/reboot.c

  1 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  2 
  3 #include <linux/module.h>
  4 #include <linux/reboot.h>
  5 #include <linux/init.h>
  6 #include <linux/pm.h>
  7 #include <linux/efi.h>
  8 #include <linux/dmi.h>
  9 #include <linux/sched.h>
 10 #include <linux/tboot.h>
 11 #include <linux/delay.h>
 12 #include <acpi/reboot.h>
 13 #include <asm/io.h>
 14 #include <asm/apic.h>
 15 #include <asm/io_apic.h>
 16 #include <asm/desc.h>
 17 #include <asm/hpet.h>
 18 #include <asm/pgtable.h>
 19 #include <asm/proto.h>
 20 #include <asm/reboot_fixups.h>
 21 #include <asm/reboot.h>
 22 #include <asm/pci_x86.h>
 23 #include <asm/virtext.h>
 24 #include <asm/cpu.h>
 25 #include <asm/nmi.h>
 26 #include <asm/smp.h>
 27 
 28 #include <linux/ctype.h>
 29 #include <linux/mc146818rtc.h>
 30 #include <asm/realmode.h>
 31 #include <asm/x86_init.h>
 32 #include <asm/efi.h>
 33 
 34 /*
 35  * Power off function, if any
 36  */
 37 void (*pm_power_off)(void);
 38 EXPORT_SYMBOL(pm_power_off);
 39 
 40 static const struct desc_ptr no_idt = {};
 41 
 42 /*
 43  * This is set if we need to go through the 'emergency' path.
 44  * When machine_emergency_restart() is called, we may be on
 45  * an inconsistent state and won't be able to do a clean cleanup
 46  */
 47 static int reboot_emergency;
 48 
 49 /* This is set by the PCI code if either type 1 or type 2 PCI is detected */
 50 bool port_cf9_safe = false;
 51 
 52 /*
 53  * Reboot options and system auto-detection code provided by
 54  * Dell Inc. so their systems "just work". :-)
 55  */
 56 
 57 /*
 58  * Some machines require the "reboot=b" or "reboot=k"  commandline options,
 59  * this quirk makes that automatic.
 60  */
 61 static int __init set_bios_reboot(const struct dmi_system_id *d)
 62 {
 63         if (reboot_type != BOOT_BIOS) {
 64                 reboot_type = BOOT_BIOS;
 65                 pr_info("%s series board detected. Selecting %s-method for reboots.\n",
 66                         d->ident, "BIOS");
 67         }
 68         return 0;
 69 }
 70 
 71 void __noreturn machine_real_restart(unsigned int type)
 72 {
 73         local_irq_disable();
 74 
 75         /*
 76          * Write zero to CMOS register number 0x0f, which the BIOS POST
 77          * routine will recognize as telling it to do a proper reboot.  (Well
 78          * that's what this book in front of me says -- it may only apply to
 79          * the Phoenix BIOS though, it's not clear).  At the same time,
 80          * disable NMIs by setting the top bit in the CMOS address register,
 81          * as we're about to do peculiar things to the CPU.  I'm not sure if
 82          * `outb_p' is needed instead of just `outb'.  Use it to be on the
 83          * safe side.  (Yes, CMOS_WRITE does outb_p's. -  Paul G.)
 84          */
 85         spin_lock(&rtc_lock);
 86         CMOS_WRITE(0x00, 0x8f);
 87         spin_unlock(&rtc_lock);
 88 
 89         /*
 90          * Switch back to the initial page table.
 91          */
 92 #ifdef CONFIG_X86_32
 93         load_cr3(initial_page_table);
 94 #else
 95         write_cr3(real_mode_header->trampoline_pgd);
 96 #endif
 97 
 98         /* Jump to the identity-mapped low memory code */
 99 #ifdef CONFIG_X86_32
100         asm volatile("jmpl *%0" : :
101                      "rm" (real_mode_header->machine_real_restart_asm),
102                      "a" (type));
103 #else
104         asm volatile("ljmpl *%0" : :
105                      "m" (real_mode_header->machine_real_restart_asm),
106                      "D" (type));
107 #endif
108         unreachable();
109 }
110 #ifdef CONFIG_APM_MODULE
111 EXPORT_SYMBOL(machine_real_restart);
112 #endif
113 
114 /*
115  * Some Apple MacBook and MacBookPro's needs reboot=p to be able to reboot
116  */
117 static int __init set_pci_reboot(const struct dmi_system_id *d)
118 {
119         if (reboot_type != BOOT_CF9_FORCE) {
120                 reboot_type = BOOT_CF9_FORCE;
121                 pr_info("%s series board detected. Selecting %s-method for reboots.\n",
122                         d->ident, "PCI");
123         }
124         return 0;
125 }
126 
127 static int __init set_kbd_reboot(const struct dmi_system_id *d)
128 {
129         if (reboot_type != BOOT_KBD) {
130                 reboot_type = BOOT_KBD;
131                 pr_info("%s series board detected. Selecting %s-method for reboot.\n",
132                         d->ident, "KBD");
133         }
134         return 0;
135 }
136 
137 /*
138  * This is a single dmi_table handling all reboot quirks.
139  */
140 static struct dmi_system_id __initdata reboot_dmi_table[] = {
141 
142         /* Acer */
143         {       /* Handle reboot issue on Acer Aspire one */
144                 .callback = set_kbd_reboot,
145                 .ident = "Acer Aspire One A110",
146                 .matches = {
147                         DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
148                         DMI_MATCH(DMI_PRODUCT_NAME, "AOA110"),
149                 },
150         },
151 
152         /* Apple */
153         {       /* Handle problems with rebooting on Apple MacBook5 */
154                 .callback = set_pci_reboot,
155                 .ident = "Apple MacBook5",
156                 .matches = {
157                         DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
158                         DMI_MATCH(DMI_PRODUCT_NAME, "MacBook5"),
159                 },
160         },
161         {       /* Handle problems with rebooting on Apple MacBookPro5 */
162                 .callback = set_pci_reboot,
163                 .ident = "Apple MacBookPro5",
164                 .matches = {
165                         DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
166                         DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro5"),
167                 },
168         },
169         {       /* Handle problems with rebooting on Apple Macmini3,1 */
170                 .callback = set_pci_reboot,
171                 .ident = "Apple Macmini3,1",
172                 .matches = {
173                         DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
174                         DMI_MATCH(DMI_PRODUCT_NAME, "Macmini3,1"),
175                 },
176         },
177         {       /* Handle problems with rebooting on the iMac9,1. */
178                 .callback = set_pci_reboot,
179                 .ident = "Apple iMac9,1",
180                 .matches = {
181                         DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
182                         DMI_MATCH(DMI_PRODUCT_NAME, "iMac9,1"),
183                 },
184         },
185 
186         /* ASRock */
187         {       /* Handle problems with rebooting on ASRock Q1900DC-ITX */
188                 .callback = set_pci_reboot,
189                 .ident = "ASRock Q1900DC-ITX",
190                 .matches = {
191                         DMI_MATCH(DMI_BOARD_VENDOR, "ASRock"),
192                         DMI_MATCH(DMI_BOARD_NAME, "Q1900DC-ITX"),
193                 },
194         },
195 
196         /* ASUS */
197         {       /* Handle problems with rebooting on ASUS P4S800 */
198                 .callback = set_bios_reboot,
199                 .ident = "ASUS P4S800",
200                 .matches = {
201                         DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
202                         DMI_MATCH(DMI_BOARD_NAME, "P4S800"),
203                 },
204         },
205 
206         /* Certec */
207         {       /* Handle problems with rebooting on Certec BPC600 */
208                 .callback = set_pci_reboot,
209                 .ident = "Certec BPC600",
210                 .matches = {
211                         DMI_MATCH(DMI_SYS_VENDOR, "Certec"),
212                         DMI_MATCH(DMI_PRODUCT_NAME, "BPC600"),
213                 },
214         },
215 
216         /* Dell */
217         {       /* Handle problems with rebooting on Dell DXP061 */
218                 .callback = set_bios_reboot,
219                 .ident = "Dell DXP061",
220                 .matches = {
221                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
222                         DMI_MATCH(DMI_PRODUCT_NAME, "Dell DXP061"),
223                 },
224         },
225         {       /* Handle problems with rebooting on Dell E520's */
226                 .callback = set_bios_reboot,
227                 .ident = "Dell E520",
228                 .matches = {
229                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
230                         DMI_MATCH(DMI_PRODUCT_NAME, "Dell DM061"),
231                 },
232         },
233         {       /* Handle problems with rebooting on the Latitude E5410. */
234                 .callback = set_pci_reboot,
235                 .ident = "Dell Latitude E5410",
236                 .matches = {
237                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
238                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E5410"),
239                 },
240         },
241         {       /* Handle problems with rebooting on the Latitude E5420. */
242                 .callback = set_pci_reboot,
243                 .ident = "Dell Latitude E5420",
244                 .matches = {
245                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
246                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E5420"),
247                 },
248         },
249         {       /* Handle problems with rebooting on the Latitude E6320. */
250                 .callback = set_pci_reboot,
251                 .ident = "Dell Latitude E6320",
252                 .matches = {
253                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
254                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6320"),
255                 },
256         },
257         {       /* Handle problems with rebooting on the Latitude E6420. */
258                 .callback = set_pci_reboot,
259                 .ident = "Dell Latitude E6420",
260                 .matches = {
261                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
262                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6420"),
263                 },
264         },
265         {       /* Handle problems with rebooting on Dell Optiplex 330 with 0KP561 */
266                 .callback = set_bios_reboot,
267                 .ident = "Dell OptiPlex 330",
268                 .matches = {
269                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
270                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 330"),
271                         DMI_MATCH(DMI_BOARD_NAME, "0KP561"),
272                 },
273         },
274         {       /* Handle problems with rebooting on Dell Optiplex 360 with 0T656F */
275                 .callback = set_bios_reboot,
276                 .ident = "Dell OptiPlex 360",
277                 .matches = {
278                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
279                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 360"),
280                         DMI_MATCH(DMI_BOARD_NAME, "0T656F"),
281                 },
282         },
283         {       /* Handle problems with rebooting on Dell Optiplex 745's SFF */
284                 .callback = set_bios_reboot,
285                 .ident = "Dell OptiPlex 745",
286                 .matches = {
287                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
288                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
289                 },
290         },
291         {       /* Handle problems with rebooting on Dell Optiplex 745's DFF */
292                 .callback = set_bios_reboot,
293                 .ident = "Dell OptiPlex 745",
294                 .matches = {
295                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
296                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
297                         DMI_MATCH(DMI_BOARD_NAME, "0MM599"),
298                 },
299         },
300         {       /* Handle problems with rebooting on Dell Optiplex 745 with 0KW626 */
301                 .callback = set_bios_reboot,
302                 .ident = "Dell OptiPlex 745",
303                 .matches = {
304                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
305                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
306                         DMI_MATCH(DMI_BOARD_NAME, "0KW626"),
307                 },
308         },
309         {       /* Handle problems with rebooting on Dell OptiPlex 760 with 0G919G */
310                 .callback = set_bios_reboot,
311                 .ident = "Dell OptiPlex 760",
312                 .matches = {
313                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
314                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 760"),
315                         DMI_MATCH(DMI_BOARD_NAME, "0G919G"),
316                 },
317         },
318         {       /* Handle problems with rebooting on the OptiPlex 990. */
319                 .callback = set_pci_reboot,
320                 .ident = "Dell OptiPlex 990",
321                 .matches = {
322                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
323                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 990"),
324                 },
325         },
326         {       /* Handle problems with rebooting on Dell 300's */
327                 .callback = set_bios_reboot,
328                 .ident = "Dell PowerEdge 300",
329                 .matches = {
330                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
331                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"),
332                 },
333         },
334         {       /* Handle problems with rebooting on Dell 1300's */
335                 .callback = set_bios_reboot,
336                 .ident = "Dell PowerEdge 1300",
337                 .matches = {
338                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
339                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1300/"),
340                 },
341         },
342         {       /* Handle problems with rebooting on Dell 2400's */
343                 .callback = set_bios_reboot,
344                 .ident = "Dell PowerEdge 2400",
345                 .matches = {
346                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
347                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"),
348                 },
349         },
350         {       /* Handle problems with rebooting on the Dell PowerEdge C6100. */
351                 .callback = set_pci_reboot,
352                 .ident = "Dell PowerEdge C6100",
353                 .matches = {
354                         DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
355                         DMI_MATCH(DMI_PRODUCT_NAME, "C6100"),
356                 },
357         },
358         {       /* Handle problems with rebooting on the Precision M6600. */
359                 .callback = set_pci_reboot,
360                 .ident = "Dell Precision M6600",
361                 .matches = {
362                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
363                         DMI_MATCH(DMI_PRODUCT_NAME, "Precision M6600"),
364                 },
365         },
366         {       /* Handle problems with rebooting on Dell T5400's */
367                 .callback = set_bios_reboot,
368                 .ident = "Dell Precision T5400",
369                 .matches = {
370                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
371                         DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T5400"),
372                 },
373         },
374         {       /* Handle problems with rebooting on Dell T7400's */
375                 .callback = set_bios_reboot,
376                 .ident = "Dell Precision T7400",
377                 .matches = {
378                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
379                         DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T7400"),
380                 },
381         },
382         {       /* Handle problems with rebooting on Dell XPS710 */
383                 .callback = set_bios_reboot,
384                 .ident = "Dell XPS710",
385                 .matches = {
386                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
387                         DMI_MATCH(DMI_PRODUCT_NAME, "Dell XPS710"),
388                 },
389         },
390 
391         /* Hewlett-Packard */
392         {       /* Handle problems with rebooting on HP laptops */
393                 .callback = set_bios_reboot,
394                 .ident = "HP Compaq Laptop",
395                 .matches = {
396                         DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
397                         DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"),
398                 },
399         },
400 
401         /* Sony */
402         {       /* Handle problems with rebooting on Sony VGN-Z540N */
403                 .callback = set_bios_reboot,
404                 .ident = "Sony VGN-Z540N",
405                 .matches = {
406                         DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
407                         DMI_MATCH(DMI_PRODUCT_NAME, "VGN-Z540N"),
408                 },
409         },
410 
411         { }
412 };
413 
414 static int __init reboot_init(void)
415 {
416         int rv;
417 
418         /*
419          * Only do the DMI check if reboot_type hasn't been overridden
420          * on the command line
421          */
422         if (!reboot_default)
423                 return 0;
424 
425         /*
426          * The DMI quirks table takes precedence. If no quirks entry
427          * matches and the ACPI Hardware Reduced bit is set, force EFI
428          * reboot.
429          */
430         rv = dmi_check_system(reboot_dmi_table);
431 
432         if (!rv && efi_reboot_required())
433                 reboot_type = BOOT_EFI;
434 
435         return 0;
436 }
437 core_initcall(reboot_init);
438 
439 static inline void kb_wait(void)
440 {
441         int i;
442 
443         for (i = 0; i < 0x10000; i++) {
444                 if ((inb(0x64) & 0x02) == 0)
445                         break;
446                 udelay(2);
447         }
448 }
449 
450 static void vmxoff_nmi(int cpu, struct pt_regs *regs)
451 {
452         cpu_emergency_vmxoff();
453 }
454 
455 /* Use NMIs as IPIs to tell all CPUs to disable virtualization */
456 static void emergency_vmx_disable_all(void)
457 {
458         /* Just make sure we won't change CPUs while doing this */
459         local_irq_disable();
460 
461         /*
462          * We need to disable VMX on all CPUs before rebooting, otherwise
463          * we risk hanging up the machine, because the CPU ignore INIT
464          * signals when VMX is enabled.
465          *
466          * We can't take any locks and we may be on an inconsistent
467          * state, so we use NMIs as IPIs to tell the other CPUs to disable
468          * VMX and halt.
469          *
470          * For safety, we will avoid running the nmi_shootdown_cpus()
471          * stuff unnecessarily, but we don't have a way to check
472          * if other CPUs have VMX enabled. So we will call it only if the
473          * CPU we are running on has VMX enabled.
474          *
475          * We will miss cases where VMX is not enabled on all CPUs. This
476          * shouldn't do much harm because KVM always enable VMX on all
477          * CPUs anyway. But we can miss it on the small window where KVM
478          * is still enabling VMX.
479          */
480         if (cpu_has_vmx() && cpu_vmx_enabled()) {
481                 /* Disable VMX on this CPU. */
482                 cpu_vmxoff();
483 
484                 /* Halt and disable VMX on the other CPUs */
485                 nmi_shootdown_cpus(vmxoff_nmi);
486 
487         }
488 }
489 
490 
491 void __attribute__((weak)) mach_reboot_fixups(void)
492 {
493 }
494 
495 /*
496  * To the best of our knowledge Windows compatible x86 hardware expects
497  * the following on reboot:
498  *
499  * 1) If the FADT has the ACPI reboot register flag set, try it
500  * 2) If still alive, write to the keyboard controller
501  * 3) If still alive, write to the ACPI reboot register again
502  * 4) If still alive, write to the keyboard controller again
503  * 5) If still alive, call the EFI runtime service to reboot
504  * 6) If no EFI runtime service, call the BIOS to do a reboot
505  *
506  * We default to following the same pattern. We also have
507  * two other reboot methods: 'triple fault' and 'PCI', which
508  * can be triggered via the reboot= kernel boot option or
509  * via quirks.
510  *
511  * This means that this function can never return, it can misbehave
512  * by not rebooting properly and hanging.
513  */
514 static void native_machine_emergency_restart(void)
515 {
516         int i;
517         int attempt = 0;
518         int orig_reboot_type = reboot_type;
519         unsigned short mode;
520 
521         if (reboot_emergency)
522                 emergency_vmx_disable_all();
523 
524         tboot_shutdown(TB_SHUTDOWN_REBOOT);
525 
526         /* Tell the BIOS if we want cold or warm reboot */
527         mode = reboot_mode == REBOOT_WARM ? 0x1234 : 0;
528         *((unsigned short *)__va(0x472)) = mode;
529 
530         for (;;) {
531                 /* Could also try the reset bit in the Hammer NB */
532                 switch (reboot_type) {
533                 case BOOT_ACPI:
534                         acpi_reboot();
535                         reboot_type = BOOT_KBD;
536                         break;
537 
538                 case BOOT_KBD:
539                         mach_reboot_fixups(); /* For board specific fixups */
540 
541                         for (i = 0; i < 10; i++) {
542                                 kb_wait();
543                                 udelay(50);
544                                 outb(0xfe, 0x64); /* Pulse reset low */
545                                 udelay(50);
546                         }
547                         if (attempt == 0 && orig_reboot_type == BOOT_ACPI) {
548                                 attempt = 1;
549                                 reboot_type = BOOT_ACPI;
550                         } else {
551                                 reboot_type = BOOT_EFI;
552                         }
553                         break;
554 
555                 case BOOT_EFI:
556                         efi_reboot(reboot_mode, NULL);
557                         reboot_type = BOOT_BIOS;
558                         break;
559 
560                 case BOOT_BIOS:
561                         machine_real_restart(MRR_BIOS);
562 
563                         /* We're probably dead after this, but... */
564                         reboot_type = BOOT_CF9_SAFE;
565                         break;
566 
567                 case BOOT_CF9_FORCE:
568                         port_cf9_safe = true;
569                         /* Fall through */
570 
571                 case BOOT_CF9_SAFE:
572                         if (port_cf9_safe) {
573                                 u8 reboot_code = reboot_mode == REBOOT_WARM ?  0x06 : 0x0E;
574                                 u8 cf9 = inb(0xcf9) & ~reboot_code;
575                                 outb(cf9|2, 0xcf9); /* Request hard reset */
576                                 udelay(50);
577                                 /* Actually do the reset */
578                                 outb(cf9|reboot_code, 0xcf9);
579                                 udelay(50);
580                         }
581                         reboot_type = BOOT_TRIPLE;
582                         break;
583 
584                 case BOOT_TRIPLE:
585                         load_idt(&no_idt);
586                         __asm__ __volatile__("int3");
587 
588                         /* We're probably dead after this, but... */
589                         reboot_type = BOOT_KBD;
590                         break;
591                 }
592         }
593 }
594 
595 void native_machine_shutdown(void)
596 {
597         /* Stop the cpus and apics */
598 #ifdef CONFIG_X86_IO_APIC
599         /*
600          * Disabling IO APIC before local APIC is a workaround for
601          * erratum AVR31 in "Intel Atom Processor C2000 Product Family
602          * Specification Update". In this situation, interrupts that target
603          * a Logical Processor whose Local APIC is either in the process of
604          * being hardware disabled or software disabled are neither delivered
605          * nor discarded. When this erratum occurs, the processor may hang.
606          *
607          * Even without the erratum, it still makes sense to quiet IO APIC
608          * before disabling Local APIC.
609          */
610         disable_IO_APIC();
611 #endif
612 
613 #ifdef CONFIG_SMP
614         /*
615          * Stop all of the others. Also disable the local irq to
616          * not receive the per-cpu timer interrupt which may trigger
617          * scheduler's load balance.
618          */
619         local_irq_disable();
620         stop_other_cpus();
621 #endif
622 
623         lapic_shutdown();
624 
625 #ifdef CONFIG_HPET_TIMER
626         hpet_disable();
627 #endif
628 
629 #ifdef CONFIG_X86_64
630         x86_platform.iommu_shutdown();
631 #endif
632 }
633 
634 static void __machine_emergency_restart(int emergency)
635 {
636         reboot_emergency = emergency;
637         machine_ops.emergency_restart();
638 }
639 
640 static void native_machine_restart(char *__unused)
641 {
642         pr_notice("machine restart\n");
643 
644         if (!reboot_force)
645                 machine_shutdown();
646         __machine_emergency_restart(0);
647 }
648 
649 static void native_machine_halt(void)
650 {
651         /* Stop other cpus and apics */
652         machine_shutdown();
653 
654         tboot_shutdown(TB_SHUTDOWN_HALT);
655 
656         stop_this_cpu(NULL);
657 }
658 
659 static void native_machine_power_off(void)
660 {
661         if (pm_power_off) {
662                 if (!reboot_force)
663                         machine_shutdown();
664                 pm_power_off();
665         }
666         /* A fallback in case there is no PM info available */
667         tboot_shutdown(TB_SHUTDOWN_HALT);
668 }
669 
670 struct machine_ops machine_ops = {
671         .power_off = native_machine_power_off,
672         .shutdown = native_machine_shutdown,
673         .emergency_restart = native_machine_emergency_restart,
674         .restart = native_machine_restart,
675         .halt = native_machine_halt,
676 #ifdef CONFIG_KEXEC
677         .crash_shutdown = native_machine_crash_shutdown,
678 #endif
679 };
680 
681 void machine_power_off(void)
682 {
683         machine_ops.power_off();
684 }
685 
686 void machine_shutdown(void)
687 {
688         machine_ops.shutdown();
689 }
690 
691 void machine_emergency_restart(void)
692 {
693         __machine_emergency_restart(1);
694 }
695 
696 void machine_restart(char *cmd)
697 {
698         machine_ops.restart(cmd);
699 }
700 
701 void machine_halt(void)
702 {
703         machine_ops.halt();
704 }
705 
706 #ifdef CONFIG_KEXEC
707 void machine_crash_shutdown(struct pt_regs *regs)
708 {
709         machine_ops.crash_shutdown(regs);
710 }
711 #endif
712 
713 
714 #if defined(CONFIG_SMP)
715 
716 /* This keeps a track of which one is crashing cpu. */
717 static int crashing_cpu;
718 static nmi_shootdown_cb shootdown_callback;
719 
720 static atomic_t waiting_for_crash_ipi;
721 
722 static int crash_nmi_callback(unsigned int val, struct pt_regs *regs)
723 {
724         int cpu;
725 
726         cpu = raw_smp_processor_id();
727 
728         /*
729          * Don't do anything if this handler is invoked on crashing cpu.
730          * Otherwise, system will completely hang. Crashing cpu can get
731          * an NMI if system was initially booted with nmi_watchdog parameter.
732          */
733         if (cpu == crashing_cpu)
734                 return NMI_HANDLED;
735         local_irq_disable();
736 
737         shootdown_callback(cpu, regs);
738 
739         atomic_dec(&waiting_for_crash_ipi);
740         /* Assume hlt works */
741         halt();
742         for (;;)
743                 cpu_relax();
744 
745         return NMI_HANDLED;
746 }
747 
748 static void smp_send_nmi_allbutself(void)
749 {
750         apic->send_IPI_allbutself(NMI_VECTOR);
751 }
752 
753 /*
754  * Halt all other CPUs, calling the specified function on each of them
755  *
756  * This function can be used to halt all other CPUs on crash
757  * or emergency reboot time. The function passed as parameter
758  * will be called inside a NMI handler on all CPUs.
759  */
760 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
761 {
762         unsigned long msecs;
763         local_irq_disable();
764 
765         /* Make a note of crashing cpu. Will be used in NMI callback. */
766         crashing_cpu = safe_smp_processor_id();
767 
768         shootdown_callback = callback;
769 
770         atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
771         /* Would it be better to replace the trap vector here? */
772         if (register_nmi_handler(NMI_LOCAL, crash_nmi_callback,
773                                  NMI_FLAG_FIRST, "crash"))
774                 return;         /* Return what? */
775         /*
776          * Ensure the new callback function is set before sending
777          * out the NMI
778          */
779         wmb();
780 
781         smp_send_nmi_allbutself();
782 
783         msecs = 1000; /* Wait at most a second for the other cpus to stop */
784         while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
785                 mdelay(1);
786                 msecs--;
787         }
788 
789         /* Leave the nmi callback set */
790 }
791 #else /* !CONFIG_SMP */
792 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
793 {
794         /* No other CPUs to shoot down */
795 }
796 #endif
797 

This page was automatically generated by LXR 0.3.1 (source).  •  Linux is a registered trademark of Linus Torvalds  •  Contact us