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