arch/x86/kernel/reboot.c

   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 <acpi/reboot.h>
  10 #include <asm/io.h>
  11 #include <asm/apic.h>
  12 #include <asm/desc.h>
  13 #include <asm/hpet.h>
  14 #include <asm/pgtable.h>
  15 #include <asm/proto.h>
  16 #include <asm/reboot_fixups.h>
  17 #include <asm/reboot.h>
  18 #include <asm/pci_x86.h>
  19 #include <asm/virtext.h>
  20 #include <asm/cpu.h>
  21 #include <asm/nmi.h>
  22
  23 #ifdef CONFIG_X86_32
  24 # include <linux/ctype.h>
  25 # include <linux/mc146818rtc.h>
  26 #else
  27 # include <asm/x86_init.h>
  28 #endif
  29
  30 /*
  31  * Power off function, if any
  32  */
  33 void (*pm_power_off)(void);
  34 EXPORT_SYMBOL(pm_power_off);
  35
  36 static const struct desc_ptr no_idt = {};
  37 static int reboot_mode;
  38 enum reboot_type reboot_type = BOOT_KBD;
  39 int reboot_force;
  40
  41 #if defined(CONFIG_X86_32) && defined(CONFIG_SMP)
  42 static int reboot_cpu = -1;
  43 #endif
  44
  45 /* This is set if we need to go through the 'emergency' path.
  46  * When machine_emergency_restart() is called, we may be on
  47  * an inconsistent state and won't be able to do a clean cleanup
  48  */
  49 static int reboot_emergency;
  50
  51 /* This is set by the PCI code if either type 1 or type 2 PCI is detected */
  52 bool port_cf9_safe = false;
  53
  54 /* reboot=b[ios] | s[mp] | t[riple] | k[bd] | e[fi] [, [w]arm | [c]old] | p[ci]
  55    warm   Don't set the cold reboot flag
  56    cold   Set the cold reboot flag
  57    bios   Reboot by jumping through the BIOS (only for X86_32)
  58    smp    Reboot by executing reset on BSP or other CPU (only for X86_32)
  59    triple Force a triple fault (init)
  60    kbd    Use the keyboard controller. cold reset (default)
  61    acpi   Use the RESET_REG in the FADT
  62    efi    Use efi reset_system runtime service
  63    pci    Use the so-called "PCI reset register", CF9
  64    force  Avoid anything that could hang.
  65  */
  66 static int __init reboot_setup(char *str)
  67 {
  68         for (;;) {
  69                 switch (*str) {
  70                 case 'w':
  71                         reboot_mode = 0x1234;
  72                         break;
  73
  74                 case 'c':
  75                         reboot_mode = 0;
  76                         break;
  77
  78 #ifdef CONFIG_X86_32
  79 #ifdef CONFIG_SMP
  80                 case 's':
  81                         if (isdigit(*(str+1))) {
  82                                 reboot_cpu = (int) (*(str+1) - '0');
  83                                 if (isdigit(*(str+2)))
  84                                         reboot_cpu = reboot_cpu*10 + (int)(*(str+2) - '0');
  85                         }
  86                                 /* we will leave sorting out the final value
  87                                    when we are ready to reboot, since we might not
  88                                    have detected BSP APIC ID or smp_num_cpu */
  89                         break;
  90 #endif /* CONFIG_SMP */
  91
  92                 case 'b':
  93 #endif
  94                 case 'a':
  95                 case 'k':
  96                 case 't':
  97                 case 'e':
  98                 case 'p':
  99                         reboot_type = *str;
 100                         break;
 101
 102                 case 'f':
 103                         reboot_force = 1;
 104                         break;
 105                 }
 106
 107                 str = strchr(str, ',');
 108                 if (str)
 109                         str++;
 110                 else
 111                         break;
 112         }
 113         return 1;
 114 }
 115
 116 __setup("reboot=", reboot_setup);
 117
 118
 119 #ifdef CONFIG_X86_32
 120 /*
 121  * Reboot options and system auto-detection code provided by
 122  * Dell Inc. so their systems "just work". :-)
 123  */
 124
 125 /*
 126  * Some machines require the "reboot=b"  commandline option,
 127  * this quirk makes that automatic.
 128  */
 129 static int __init set_bios_reboot(const struct dmi_system_id *d)
 130 {
 131         if (reboot_type != BOOT_BIOS) {
 132                 reboot_type = BOOT_BIOS;
 133                 printk(KERN_INFO "%s series board detected. Selecting BIOS-method for reboots.\n", d->ident);
 134         }
 135         return 0;
 136 }
 137
 138 static struct dmi_system_id __initdata reboot_dmi_table[] = {
 139         {       /* Handle problems with rebooting on Dell E520's */
 140                 .callback = set_bios_reboot,
 141                 .ident = "Dell E520",
 142                 .matches = {
 143                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 144                         DMI_MATCH(DMI_PRODUCT_NAME, "Dell DM061"),
 145                 },
 146         },
 147         {       /* Handle problems with rebooting on Dell 1300's */
 148                 .callback = set_bios_reboot,
 149                 .ident = "Dell PowerEdge 1300",
 150                 .matches = {
 151                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 152                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1300/"),
 153                 },
 154         },
 155         {       /* Handle problems with rebooting on Dell 300's */
 156                 .callback = set_bios_reboot,
 157                 .ident = "Dell PowerEdge 300",
 158                 .matches = {
 159                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 160                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"),
 161                 },
 162         },
 163         {       /* Handle problems with rebooting on Dell Optiplex 745's SFF*/
 164                 .callback = set_bios_reboot,
 165                 .ident = "Dell OptiPlex 745",
 166                 .matches = {
 167                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 168                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
 169                 },
 170         },
 171         {       /* Handle problems with rebooting on Dell Optiplex 745's DFF*/
 172                 .callback = set_bios_reboot,
 173                 .ident = "Dell OptiPlex 745",
 174                 .matches = {
 175                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 176                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
 177                         DMI_MATCH(DMI_BOARD_NAME, "0MM599"),
 178                 },
 179         },
 180         {       /* Handle problems with rebooting on Dell Optiplex 745 with 0KW626 */
 181                 .callback = set_bios_reboot,
 182                 .ident = "Dell OptiPlex 745",
 183                 .matches = {
 184                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 185                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
 186                         DMI_MATCH(DMI_BOARD_NAME, "0KW626"),
 187                 },
 188         },
 189         {   /* Handle problems with rebooting on Dell Optiplex 330 with 0KP561 */
 190                 .callback = set_bios_reboot,
 191                 .ident = "Dell OptiPlex 330",
 192                 .matches = {
 193                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 194                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 330"),
 195                         DMI_MATCH(DMI_BOARD_NAME, "0KP561"),
 196                 },
 197         },
 198         {   /* Handle problems with rebooting on Dell Optiplex 360 with 0T656F */
 199                 .callback = set_bios_reboot,
 200                 .ident = "Dell OptiPlex 360",
 201                 .matches = {
 202                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 203                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 360"),
 204                         DMI_MATCH(DMI_BOARD_NAME, "0T656F"),
 205                 },
 206         },
 207         {       /* Handle problems with rebooting on Dell OptiPlex 760 with 0G919G*/
 208                 .callback = set_bios_reboot,
 209                 .ident = "Dell OptiPlex 760",
 210                 .matches = {
 211                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 212                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 760"),
 213                         DMI_MATCH(DMI_BOARD_NAME, "0G919G"),
 214                 },
 215         },
 216         {       /* Handle problems with rebooting on Dell 2400's */
 217                 .callback = set_bios_reboot,
 218                 .ident = "Dell PowerEdge 2400",
 219                 .matches = {
 220                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 221                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"),
 222                 },
 223         },
 224         {       /* Handle problems with rebooting on Dell T5400's */
 225                 .callback = set_bios_reboot,
 226                 .ident = "Dell Precision T5400",
 227                 .matches = {
 228                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 229                         DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T5400"),
 230                 },
 231         },
 232         {       /* Handle problems with rebooting on Dell T7400's */
 233                 .callback = set_bios_reboot,
 234                 .ident = "Dell Precision T7400",
 235                 .matches = {
 236                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 237                         DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T7400"),
 238                 },
 239         },
 240         {       /* Handle problems with rebooting on HP laptops */
 241                 .callback = set_bios_reboot,
 242                 .ident = "HP Compaq Laptop",
 243                 .matches = {
 244                         DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 245                         DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"),
 246                 },
 247         },
 248         {       /* Handle problems with rebooting on Dell XPS710 */
 249                 .callback = set_bios_reboot,
 250                 .ident = "Dell XPS710",
 251                 .matches = {
 252                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 253                         DMI_MATCH(DMI_PRODUCT_NAME, "Dell XPS710"),
 254                 },
 255         },
 256         {       /* Handle problems with rebooting on Dell DXP061 */
 257                 .callback = set_bios_reboot,
 258                 .ident = "Dell DXP061",
 259                 .matches = {
 260                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 261                         DMI_MATCH(DMI_PRODUCT_NAME, "Dell DXP061"),
 262                 },
 263         },
 264         {       /* Handle problems with rebooting on Sony VGN-Z540N */
 265                 .callback = set_bios_reboot,
 266                 .ident = "Sony VGN-Z540N",
 267                 .matches = {
 268                         DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
 269                         DMI_MATCH(DMI_PRODUCT_NAME, "VGN-Z540N"),
 270                 },
 271         },
 272         {       /* Handle problems with rebooting on CompuLab SBC-FITPC2 */
 273                 .callback = set_bios_reboot,
 274                 .ident = "CompuLab SBC-FITPC2",
 275                 .matches = {
 276                         DMI_MATCH(DMI_SYS_VENDOR, "CompuLab"),
 277                         DMI_MATCH(DMI_PRODUCT_NAME, "SBC-FITPC2"),
 278                 },
 279         },
 280         {       /* Handle problems with rebooting on ASUS P4S800 */
 281                 .callback = set_bios_reboot,
 282                 .ident = "ASUS P4S800",
 283                 .matches = {
 284                         DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
 285                         DMI_MATCH(DMI_BOARD_NAME, "P4S800"),
 286                 },
 287         },
 288         {       /* Handle problems with rebooting on VersaLogic Menlow boards */
 289                 .callback = set_bios_reboot,
 290                 .ident = "VersaLogic Menlow based board",
 291                 .matches = {
 292                         DMI_MATCH(DMI_BOARD_VENDOR, "VersaLogic Corporation"),
 293                         DMI_MATCH(DMI_BOARD_NAME, "VersaLogic Menlow board"),
 294                 },
 295         },
 296         { }
 297 };
 298
 299 static int __init reboot_init(void)
 300 {
 301         dmi_check_system(reboot_dmi_table);
 302         return 0;
 303 }
 304 core_initcall(reboot_init);
 305
 306 extern const unsigned char machine_real_restart_asm[];
 307 extern const u64 machine_real_restart_gdt[3];
 308
 309 void machine_real_restart(unsigned int type)
 310 {
 311         void *restart_va;
 312         unsigned long restart_pa;
 313         void (*restart_lowmem)(unsigned int);
 314         u64 *lowmem_gdt;
 315
 316         local_irq_disable();
 317
 318         /* Write zero to CMOS register number 0x0f, which the BIOS POST
 319            routine will recognize as telling it to do a proper reboot.  (Well
 320            that's what this book in front of me says -- it may only apply to
 321            the Phoenix BIOS though, it's not clear).  At the same time,
 322            disable NMIs by setting the top bit in the CMOS address register,
 323            as we're about to do peculiar things to the CPU.  I'm not sure if
 324            `outb_p' is needed instead of just `outb'.  Use it to be on the
 325            safe side.  (Yes, CMOS_WRITE does outb_p's. -  Paul G.)
 326          */
 327         spin_lock(&rtc_lock);
 328         CMOS_WRITE(0x00, 0x8f);
 329         spin_unlock(&rtc_lock);
 330
 331         /*
 332          * Switch back to the initial page table.
 333          */
 334         load_cr3(initial_page_table);
 335
 336         /* Write 0x1234 to absolute memory location 0x472.  The BIOS reads
 337            this on booting to tell it to "Bypass memory test (also warm
 338            boot)".  This seems like a fairly standard thing that gets set by
 339            REBOOT.COM programs, and the previous reset routine did this
 340            too. */
 341         *((unsigned short *)0x472) = reboot_mode;
 342
 343         /* Patch the GDT in the low memory trampoline */
 344         lowmem_gdt = TRAMPOLINE_SYM(machine_real_restart_gdt);
 345
 346         restart_va = TRAMPOLINE_SYM(machine_real_restart_asm);
 347         restart_pa = virt_to_phys(restart_va);
 348         restart_lowmem = (void (*)(unsigned int))restart_pa;
 349
 350         /* GDT[0]: GDT self-pointer */
 351         lowmem_gdt[0] =
 352                 (u64)(sizeof(machine_real_restart_gdt) - 1) +
 353                 ((u64)virt_to_phys(lowmem_gdt) << 16);
 354         /* GDT[1]: 64K real mode code segment */
 355         lowmem_gdt[1] =
 356                 GDT_ENTRY(0x009b, restart_pa, 0xffff);
 357
 358         /* Jump to the identity-mapped low memory code */
 359         restart_lowmem(type);
 360 }
 361 #ifdef CONFIG_APM_MODULE
 362 EXPORT_SYMBOL(machine_real_restart);
 363 #endif
 364
 365 #endif /* CONFIG_X86_32 */
 366
 367 /*
 368  * Some Apple MacBook and MacBookPro's needs reboot=p to be able to reboot
 369  */
 370 static int __init set_pci_reboot(const struct dmi_system_id *d)
 371 {
 372         if (reboot_type != BOOT_CF9) {
 373                 reboot_type = BOOT_CF9;
 374                 printk(KERN_INFO "%s series board detected. "
 375                        "Selecting PCI-method for reboots.\n", d->ident);
 376         }
 377         return 0;
 378 }
 379
 380 static struct dmi_system_id __initdata pci_reboot_dmi_table[] = {
 381         {       /* Handle problems with rebooting on Apple MacBook5 */
 382                 .callback = set_pci_reboot,
 383                 .ident = "Apple MacBook5",
 384                 .matches = {
 385                         DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 386                         DMI_MATCH(DMI_PRODUCT_NAME, "MacBook5"),
 387                 },
 388         },
 389         {       /* Handle problems with rebooting on Apple MacBookPro5 */
 390                 .callback = set_pci_reboot,
 391                 .ident = "Apple MacBookPro5",
 392                 .matches = {
 393                         DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 394                         DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro5"),
 395                 },
 396         },
 397         {       /* Handle problems with rebooting on Apple Macmini3,1 */
 398                 .callback = set_pci_reboot,
 399                 .ident = "Apple Macmini3,1",
 400                 .matches = {
 401                         DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 402                         DMI_MATCH(DMI_PRODUCT_NAME, "Macmini3,1"),
 403                 },
 404         },
 405         {       /* Handle problems with rebooting on the iMac9,1. */
 406                 .callback = set_pci_reboot,
 407                 .ident = "Apple iMac9,1",
 408                 .matches = {
 409                         DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 410                         DMI_MATCH(DMI_PRODUCT_NAME, "iMac9,1"),
 411                 },
 412         },
 413         { }
 414 };
 415
 416 static int __init pci_reboot_init(void)
 417 {
 418         dmi_check_system(pci_reboot_dmi_table);
 419         return 0;
 420 }
 421 core_initcall(pci_reboot_init);
 422
 423 static inline void kb_wait(void)
 424 {
 425         int i;
 426
 427         for (i = 0; i < 0x10000; i++) {
 428                 if ((inb(0x64) & 0x02) == 0)
 429                         break;
 430                 udelay(2);
 431         }
 432 }
 433
 434 static void vmxoff_nmi(int cpu, struct die_args *args)
 435 {
 436         cpu_emergency_vmxoff();
 437 }
 438
 439 /* Use NMIs as IPIs to tell all CPUs to disable virtualization
 440  */
 441 static void emergency_vmx_disable_all(void)
 442 {
 443         /* Just make sure we won't change CPUs while doing this */
 444         local_irq_disable();
 445
 446         /* We need to disable VMX on all CPUs before rebooting, otherwise
 447          * we risk hanging up the machine, because the CPU ignore INIT
 448          * signals when VMX is enabled.
 449          *
 450          * We can't take any locks and we may be on an inconsistent
 451          * state, so we use NMIs as IPIs to tell the other CPUs to disable
 452          * VMX and halt.
 453          *
 454          * For safety, we will avoid running the nmi_shootdown_cpus()
 455          * stuff unnecessarily, but we don't have a way to check
 456          * if other CPUs have VMX enabled. So we will call it only if the
 457          * CPU we are running on has VMX enabled.
 458          *
 459          * We will miss cases where VMX is not enabled on all CPUs. This
 460          * shouldn't do much harm because KVM always enable VMX on all
 461          * CPUs anyway. But we can miss it on the small window where KVM
 462          * is still enabling VMX.
 463          */
 464         if (cpu_has_vmx() && cpu_vmx_enabled()) {
 465                 /* Disable VMX on this CPU.
 466                  */
 467                 cpu_vmxoff();
 468
 469                 /* Halt and disable VMX on the other CPUs */
 470                 nmi_shootdown_cpus(vmxoff_nmi);
 471
 472         }
 473 }
 474
 475
 476 void __attribute__((weak)) mach_reboot_fixups(void)
 477 {
 478 }
 479
 480 static void native_machine_emergency_restart(void)
 481 {
 482         int i;
 483
 484         if (reboot_emergency)
 485                 emergency_vmx_disable_all();
 486
 487         tboot_shutdown(TB_SHUTDOWN_REBOOT);
 488
 489         /* Tell the BIOS if we want cold or warm reboot */
 490         *((unsigned short *)__va(0x472)) = reboot_mode;
 491
 492         for (;;) {
 493                 /* Could also try the reset bit in the Hammer NB */
 494                 switch (reboot_type) {
 495                 case BOOT_KBD:
 496                         mach_reboot_fixups(); /* for board specific fixups */
 497
 498                         for (i = 0; i < 10; i++) {
 499                                 kb_wait();
 500                                 udelay(50);
 501                                 outb(0xfe, 0x64); /* pulse reset low */
 502                                 udelay(50);
 503                         }
 504
 505                 case BOOT_TRIPLE:
 506                         load_idt(&no_idt);
 507                         __asm__ __volatile__("int3");
 508
 509                         reboot_type = BOOT_KBD;
 510                         break;
 511
 512 #ifdef CONFIG_X86_32
 513                 case BOOT_BIOS:
 514                         machine_real_restart(MRR_BIOS);
 515
 516                         reboot_type = BOOT_KBD;
 517                         break;
 518 #endif
 519
 520                 case BOOT_ACPI:
 521                         acpi_reboot();
 522                         reboot_type = BOOT_KBD;
 523                         break;
 524
 525                 case BOOT_EFI:
 526                         if (efi_enabled)
 527                                 efi.reset_system(reboot_mode ?
 528                                                  EFI_RESET_WARM :
 529                                                  EFI_RESET_COLD,
 530                                                  EFI_SUCCESS, 0, NULL);
 531                         reboot_type = BOOT_KBD;
 532                         break;
 533
 534                 case BOOT_CF9:
 535                         port_cf9_safe = true;
 536                         /* fall through */
 537
 538                 case BOOT_CF9_COND:
 539                         if (port_cf9_safe) {
 540                                 u8 cf9 = inb(0xcf9) & ~6;
 541                                 outb(cf9|2, 0xcf9); /* Request hard reset */
 542                                 udelay(50);
 543                                 outb(cf9|6, 0xcf9); /* Actually do the reset */
 544                                 udelay(50);
 545                         }
 546                         reboot_type = BOOT_KBD;
 547                         break;
 548                 }
 549         }
 550 }
 551
 552 void native_machine_shutdown(void)
 553 {
 554         /* Stop the cpus and apics */
 555 #ifdef CONFIG_SMP
 556
 557         /* The boot cpu is always logical cpu 0 */
 558         int reboot_cpu_id = 0;
 559
 560 #ifdef CONFIG_X86_32
 561         /* See if there has been given a command line override */
 562         if ((reboot_cpu != -1) && (reboot_cpu < nr_cpu_ids) &&
 563                 cpu_online(reboot_cpu))
 564                 reboot_cpu_id = reboot_cpu;
 565 #endif
 566
 567         /* Make certain the cpu I'm about to reboot on is online */
 568         if (!cpu_online(reboot_cpu_id))
 569                 reboot_cpu_id = smp_processor_id();
 570
 571         /* Make certain I only run on the appropriate processor */
 572         set_cpus_allowed_ptr(current, cpumask_of(reboot_cpu_id));
 573
 574         /* O.K Now that I'm on the appropriate processor,
 575          * stop all of the others.
 576          */
 577         stop_other_cpus();
 578 #endif
 579
 580         lapic_shutdown();
 581
 582 #ifdef CONFIG_X86_IO_APIC
 583         disable_IO_APIC();
 584 #endif
 585
 586 #ifdef CONFIG_HPET_TIMER
 587         hpet_disable();
 588 #endif
 589
 590 #ifdef CONFIG_X86_64
 591         x86_platform.iommu_shutdown();
 592 #endif
 593 }
 594
 595 static void __machine_emergency_restart(int emergency)
 596 {
 597         reboot_emergency = emergency;
 598         machine_ops.emergency_restart();
 599 }
 600
 601 static void native_machine_restart(char *__unused)
 602 {
 603         printk("machine restart\n");
 604
 605         if (!reboot_force)
 606                 machine_shutdown();
 607         __machine_emergency_restart(0);
 608 }
 609
 610 static void native_machine_halt(void)
 611 {
 612         /* stop other cpus and apics */
 613         machine_shutdown();
 614
 615         tboot_shutdown(TB_SHUTDOWN_HALT);
 616
 617         /* stop this cpu */
 618         stop_this_cpu(NULL);
 619 }
 620
 621 static void native_machine_power_off(void)
 622 {
 623         if (pm_power_off) {
 624                 if (!reboot_force)
 625                         machine_shutdown();
 626                 pm_power_off();
 627         }
 628         /* a fallback in case there is no PM info available */
 629         tboot_shutdown(TB_SHUTDOWN_HALT);
 630 }
 631
 632 struct machine_ops machine_ops = {
 633         .power_off = native_machine_power_off,
 634         .shutdown = native_machine_shutdown,
 635         .emergency_restart = native_machine_emergency_restart,
 636         .restart = native_machine_restart,
 637         .halt = native_machine_halt,
 638 #ifdef CONFIG_KEXEC
 639         .crash_shutdown = native_machine_crash_shutdown,
 640 #endif
 641 };
 642
 643 void machine_power_off(void)
 644 {
 645         machine_ops.power_off();
 646 }
 647
 648 void machine_shutdown(void)
 649 {
 650         machine_ops.shutdown();
 651 }
 652
 653 void machine_emergency_restart(void)
 654 {
 655         __machine_emergency_restart(1);
 656 }
 657
 658 void machine_restart(char *cmd)
 659 {
 660         machine_ops.restart(cmd);
 661 }
 662
 663 void machine_halt(void)
 664 {
 665         machine_ops.halt();
 666 }
 667
 668 #ifdef CONFIG_KEXEC
 669 void machine_crash_shutdown(struct pt_regs *regs)
 670 {
 671         machine_ops.crash_shutdown(regs);
 672 }
 673 #endif
 674
 675
 676 #if defined(CONFIG_SMP)
 677
 678 /* This keeps a track of which one is crashing cpu. */
 679 static int crashing_cpu;
 680 static nmi_shootdown_cb shootdown_callback;
 681
 682 static atomic_t waiting_for_crash_ipi;
 683
 684 static int crash_nmi_callback(struct notifier_block *self,
 685                         unsigned long val, void *data)
 686 {
 687         int cpu;
 688
 689         if (val != DIE_NMI)
 690                 return NOTIFY_OK;
 691
 692         cpu = raw_smp_processor_id();
 693
 694         /* Don't do anything if this handler is invoked on crashing cpu.
 695          * Otherwise, system will completely hang. Crashing cpu can get
 696          * an NMI if system was initially booted with nmi_watchdog parameter.
 697          */
 698         if (cpu == crashing_cpu)
 699                 return NOTIFY_STOP;
 700         local_irq_disable();
 701
 702         shootdown_callback(cpu, (struct die_args *)data);
 703
 704         atomic_dec(&waiting_for_crash_ipi);
 705         /* Assume hlt works */
 706         halt();
 707         for (;;)
 708                 cpu_relax();
 709
 710         return 1;
 711 }
 712
 713 static void smp_send_nmi_allbutself(void)
 714 {
 715         apic->send_IPI_allbutself(NMI_VECTOR);
 716 }
 717
 718 static struct notifier_block crash_nmi_nb = {
 719         .notifier_call = crash_nmi_callback,
 720         /* we want to be the first one called */
 721         .priority = NMI_LOCAL_HIGH_PRIOR+1,
 722 };
 723
 724 /* Halt all other CPUs, calling the specified function on each of them
 725  *
 726  * This function can be used to halt all other CPUs on crash
 727  * or emergency reboot time. The function passed as parameter
 728  * will be called inside a NMI handler on all CPUs.
 729  */
 730 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
 731 {
 732         unsigned long msecs;
 733         local_irq_disable();
 734
 735         /* Make a note of crashing cpu. Will be used in NMI callback.*/
 736         crashing_cpu = safe_smp_processor_id();
 737
 738         shootdown_callback = callback;
 739
 740         atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
 741         /* Would it be better to replace the trap vector here? */
 742         if (register_die_notifier(&crash_nmi_nb))
 743                 return;         /* return what? */
 744         /* Ensure the new callback function is set before sending
 745          * out the NMI
 746          */
 747         wmb();
 748
 749         smp_send_nmi_allbutself();
 750
 751         msecs = 1000; /* Wait at most a second for the other cpus to stop */
 752         while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
 753                 mdelay(1);
 754                 msecs--;
 755         }
 756
 757         /* Leave the nmi callback set */
 758 }
 759 #else /* !CONFIG_SMP */
 760 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
 761 {
 762         /* No other CPUs to shoot down */
 763 }
 764 #endif