Version:  2.0.40 2.2.26 2.4.37 2.6.39 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15

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

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