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) {
 118                 reboot_type = BOOT_CF9;
 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         /* Dell */
 195         {       /* Handle problems with rebooting on Dell DXP061 */
 196                 .callback = set_bios_reboot,
 197                 .ident = "Dell DXP061",
 198                 .matches = {
 199                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 200                         DMI_MATCH(DMI_PRODUCT_NAME, "Dell DXP061"),
 201                 },
 202         },
 203         {       /* Handle problems with rebooting on Dell E520's */
 204                 .callback = set_bios_reboot,
 205                 .ident = "Dell E520",
 206                 .matches = {
 207                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 208                         DMI_MATCH(DMI_PRODUCT_NAME, "Dell DM061"),
 209                 },
 210         },
 211         {       /* Handle problems with rebooting on the Latitude E5410. */
 212                 .callback = set_pci_reboot,
 213                 .ident = "Dell Latitude E5410",
 214                 .matches = {
 215                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 216                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E5410"),
 217                 },
 218         },
 219         {       /* Handle problems with rebooting on the Latitude E5420. */
 220                 .callback = set_pci_reboot,
 221                 .ident = "Dell Latitude E5420",
 222                 .matches = {
 223                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 224                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E5420"),
 225                 },
 226         },
 227         {       /* Handle problems with rebooting on the Latitude E6320. */
 228                 .callback = set_pci_reboot,
 229                 .ident = "Dell Latitude E6320",
 230                 .matches = {
 231                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 232                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6320"),
 233                 },
 234         },
 235         {       /* Handle problems with rebooting on the Latitude E6420. */
 236                 .callback = set_pci_reboot,
 237                 .ident = "Dell Latitude E6420",
 238                 .matches = {
 239                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 240                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6420"),
 241                 },
 242         },
 243         {       /* Handle problems with rebooting on Dell Optiplex 330 with 0KP561 */
 244                 .callback = set_bios_reboot,
 245                 .ident = "Dell OptiPlex 330",
 246                 .matches = {
 247                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 248                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 330"),
 249                         DMI_MATCH(DMI_BOARD_NAME, "0KP561"),
 250                 },
 251         },
 252         {       /* Handle problems with rebooting on Dell Optiplex 360 with 0T656F */
 253                 .callback = set_bios_reboot,
 254                 .ident = "Dell OptiPlex 360",
 255                 .matches = {
 256                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 257                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 360"),
 258                         DMI_MATCH(DMI_BOARD_NAME, "0T656F"),
 259                 },
 260         },
 261         {       /* Handle problems with rebooting on Dell Optiplex 745's SFF */
 262                 .callback = set_bios_reboot,
 263                 .ident = "Dell OptiPlex 745",
 264                 .matches = {
 265                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 266                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
 267                 },
 268         },
 269         {       /* Handle problems with rebooting on Dell Optiplex 745's DFF */
 270                 .callback = set_bios_reboot,
 271                 .ident = "Dell OptiPlex 745",
 272                 .matches = {
 273                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 274                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
 275                         DMI_MATCH(DMI_BOARD_NAME, "0MM599"),
 276                 },
 277         },
 278         {       /* Handle problems with rebooting on Dell Optiplex 745 with 0KW626 */
 279                 .callback = set_bios_reboot,
 280                 .ident = "Dell OptiPlex 745",
 281                 .matches = {
 282                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 283                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
 284                         DMI_MATCH(DMI_BOARD_NAME, "0KW626"),
 285                 },
 286         },
 287         {       /* Handle problems with rebooting on Dell OptiPlex 760 with 0G919G */
 288                 .callback = set_bios_reboot,
 289                 .ident = "Dell OptiPlex 760",
 290                 .matches = {
 291                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 292                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 760"),
 293                         DMI_MATCH(DMI_BOARD_NAME, "0G919G"),
 294                 },
 295         },
 296         {       /* Handle problems with rebooting on the OptiPlex 990. */
 297                 .callback = set_pci_reboot,
 298                 .ident = "Dell OptiPlex 990",
 299                 .matches = {
 300                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 301                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 990"),
 302                 },
 303         },
 304         {       /* Handle problems with rebooting on Dell 300's */
 305                 .callback = set_bios_reboot,
 306                 .ident = "Dell PowerEdge 300",
 307                 .matches = {
 308                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 309                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"),
 310                 },
 311         },
 312         {       /* Handle problems with rebooting on Dell 1300's */
 313                 .callback = set_bios_reboot,
 314                 .ident = "Dell PowerEdge 1300",
 315                 .matches = {
 316                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 317                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1300/"),
 318                 },
 319         },
 320         {       /* Handle problems with rebooting on Dell 2400's */
 321                 .callback = set_bios_reboot,
 322                 .ident = "Dell PowerEdge 2400",
 323                 .matches = {
 324                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 325                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"),
 326                 },
 327         },
 328         {       /* Handle problems with rebooting on the Dell PowerEdge C6100. */
 329                 .callback = set_pci_reboot,
 330                 .ident = "Dell PowerEdge C6100",
 331                 .matches = {
 332                         DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
 333                         DMI_MATCH(DMI_PRODUCT_NAME, "C6100"),
 334                 },
 335         },
 336         {       /* Handle problems with rebooting on the Precision M6600. */
 337                 .callback = set_pci_reboot,
 338                 .ident = "Dell Precision M6600",
 339                 .matches = {
 340                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 341                         DMI_MATCH(DMI_PRODUCT_NAME, "Precision M6600"),
 342                 },
 343         },
 344         {       /* Handle problems with rebooting on Dell T5400's */
 345                 .callback = set_bios_reboot,
 346                 .ident = "Dell Precision T5400",
 347                 .matches = {
 348                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 349                         DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T5400"),
 350                 },
 351         },
 352         {       /* Handle problems with rebooting on Dell T7400's */
 353                 .callback = set_bios_reboot,
 354                 .ident = "Dell Precision T7400",
 355                 .matches = {
 356                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 357                         DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T7400"),
 358                 },
 359         },
 360         {       /* Handle problems with rebooting on Dell XPS710 */
 361                 .callback = set_bios_reboot,
 362                 .ident = "Dell XPS710",
 363                 .matches = {
 364                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 365                         DMI_MATCH(DMI_PRODUCT_NAME, "Dell XPS710"),
 366                 },
 367         },
 368
 369         /* Hewlett-Packard */
 370         {       /* Handle problems with rebooting on HP laptops */
 371                 .callback = set_bios_reboot,
 372                 .ident = "HP Compaq Laptop",
 373                 .matches = {
 374                         DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 375                         DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"),
 376                 },
 377         },
 378
 379         /* Sony */
 380         {       /* Handle problems with rebooting on Sony VGN-Z540N */
 381                 .callback = set_bios_reboot,
 382                 .ident = "Sony VGN-Z540N",
 383                 .matches = {
 384                         DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
 385                         DMI_MATCH(DMI_PRODUCT_NAME, "VGN-Z540N"),
 386                 },
 387         },
 388
 389         { }
 390 };
 391
 392 static int __init reboot_init(void)
 393 {
 394         /*
 395          * Only do the DMI check if reboot_type hasn't been overridden
 396          * on the command line
 397          */
 398         if (reboot_default)
 399                 dmi_check_system(reboot_dmi_table);
 400         return 0;
 401 }
 402 core_initcall(reboot_init);
 403
 404 static inline void kb_wait(void)
 405 {
 406         int i;
 407
 408         for (i = 0; i < 0x10000; i++) {
 409                 if ((inb(0x64) & 0x02) == 0)
 410                         break;
 411                 udelay(2);
 412         }
 413 }
 414
 415 static void vmxoff_nmi(int cpu, struct pt_regs *regs)
 416 {
 417         cpu_emergency_vmxoff();
 418 }
 419
 420 /* Use NMIs as IPIs to tell all CPUs to disable virtualization */
 421 static void emergency_vmx_disable_all(void)
 422 {
 423         /* Just make sure we won't change CPUs while doing this */
 424         local_irq_disable();
 425
 426         /*
 427          * We need to disable VMX on all CPUs before rebooting, otherwise
 428          * we risk hanging up the machine, because the CPU ignore INIT
 429          * signals when VMX is enabled.
 430          *
 431          * We can't take any locks and we may be on an inconsistent
 432          * state, so we use NMIs as IPIs to tell the other CPUs to disable
 433          * VMX and halt.
 434          *
 435          * For safety, we will avoid running the nmi_shootdown_cpus()
 436          * stuff unnecessarily, but we don't have a way to check
 437          * if other CPUs have VMX enabled. So we will call it only if the
 438          * CPU we are running on has VMX enabled.
 439          *
 440          * We will miss cases where VMX is not enabled on all CPUs. This
 441          * shouldn't do much harm because KVM always enable VMX on all
 442          * CPUs anyway. But we can miss it on the small window where KVM
 443          * is still enabling VMX.
 444          */
 445         if (cpu_has_vmx() && cpu_vmx_enabled()) {
 446                 /* Disable VMX on this CPU. */
 447                 cpu_vmxoff();
 448
 449                 /* Halt and disable VMX on the other CPUs */
 450                 nmi_shootdown_cpus(vmxoff_nmi);
 451
 452         }
 453 }
 454
 455
 456 void __attribute__((weak)) mach_reboot_fixups(void)
 457 {
 458 }
 459
 460 /*
 461  * Windows compatible x86 hardware expects the following on reboot:
 462  *
 463  * 1) If the FADT has the ACPI reboot register flag set, try it
 464  * 2) If still alive, write to the keyboard controller
 465  * 3) If still alive, write to the ACPI reboot register again
 466  * 4) If still alive, write to the keyboard controller again
 467  *
 468  * If the machine is still alive at this stage, it gives up. We default to
 469  * following the same pattern, except that if we're still alive after (4) we'll
 470  * try to force a triple fault and then cycle between hitting the keyboard
 471  * controller and doing that
 472  */
 473 static void native_machine_emergency_restart(void)
 474 {
 475         int i;
 476         int attempt = 0;
 477         int orig_reboot_type = reboot_type;
 478         unsigned short mode;
 479
 480         if (reboot_emergency)
 481                 emergency_vmx_disable_all();
 482
 483         tboot_shutdown(TB_SHUTDOWN_REBOOT);
 484
 485         /* Tell the BIOS if we want cold or warm reboot */
 486         mode = reboot_mode == REBOOT_WARM ? 0x1234 : 0;
 487         *((unsigned short *)__va(0x472)) = mode;
 488
 489         for (;;) {
 490                 /* Could also try the reset bit in the Hammer NB */
 491                 switch (reboot_type) {
 492                 case BOOT_KBD:
 493                         mach_reboot_fixups(); /* For board specific fixups */
 494
 495                         for (i = 0; i < 10; i++) {
 496                                 kb_wait();
 497                                 udelay(50);
 498                                 outb(0xfe, 0x64); /* Pulse reset low */
 499                                 udelay(50);
 500                         }
 501                         if (attempt == 0 && orig_reboot_type == BOOT_ACPI) {
 502                                 attempt = 1;
 503                                 reboot_type = BOOT_ACPI;
 504                         } else {
 505                                 reboot_type = BOOT_TRIPLE;
 506                         }
 507                         break;
 508
 509                 case BOOT_TRIPLE:
 510                         load_idt(&no_idt);
 511                         __asm__ __volatile__("int3");
 512
 513                         reboot_type = BOOT_KBD;
 514                         break;
 515
 516                 case BOOT_BIOS:
 517                         machine_real_restart(MRR_BIOS);
 518
 519                         reboot_type = BOOT_KBD;
 520                         break;
 521
 522                 case BOOT_ACPI:
 523                         acpi_reboot();
 524                         reboot_type = BOOT_KBD;
 525                         break;
 526
 527                 case BOOT_EFI:
 528                         if (efi_enabled(EFI_RUNTIME_SERVICES))
 529                                 efi.reset_system(reboot_mode == REBOOT_WARM ?
 530                                                  EFI_RESET_WARM :
 531                                                  EFI_RESET_COLD,
 532                                                  EFI_SUCCESS, 0, NULL);
 533                         reboot_type = BOOT_KBD;
 534                         break;
 535
 536                 case BOOT_CF9:
 537                         port_cf9_safe = true;
 538                         /* Fall through */
 539
 540                 case BOOT_CF9_COND:
 541                         if (port_cf9_safe) {
 542                                 u8 reboot_code = reboot_mode == REBOOT_WARM ?
 543                                         0x06 : 0x0E;
 544                                 u8 cf9 = inb(0xcf9) & ~reboot_code;
 545                                 outb(cf9|2, 0xcf9); /* Request hard reset */
 546                                 udelay(50);
 547                                 /* Actually do the reset */
 548                                 outb(cf9|reboot_code, 0xcf9);
 549                                 udelay(50);
 550                         }
 551                         reboot_type = BOOT_KBD;
 552                         break;
 553                 }
 554         }
 555 }
 556
 557 void native_machine_shutdown(void)
 558 {
 559         /* Stop the cpus and apics */
 560 #ifdef CONFIG_X86_IO_APIC
 561         disable_IO_APIC();
 562 #endif
 563
 564 #ifdef CONFIG_SMP
 565         /*
 566          * Stop all of the others. Also disable the local irq to
 567          * not receive the per-cpu timer interrupt which may trigger
 568          * scheduler's load balance.
 569          */
 570         local_irq_disable();
 571         stop_other_cpus();
 572 #endif
 573
 574         lapic_shutdown();
 575
 576 #ifdef CONFIG_HPET_TIMER
 577         hpet_disable();
 578 #endif
 579
 580 #ifdef CONFIG_X86_64
 581         x86_platform.iommu_shutdown();
 582 #endif
 583 }
 584
 585 static void __machine_emergency_restart(int emergency)
 586 {
 587         reboot_emergency = emergency;
 588         machine_ops.emergency_restart();
 589 }
 590
 591 static void native_machine_restart(char *__unused)
 592 {
 593         pr_notice("machine restart\n");
 594
 595         if (!reboot_force)
 596                 machine_shutdown();
 597         __machine_emergency_restart(0);
 598 }
 599
 600 static void native_machine_halt(void)
 601 {
 602         /* Stop other cpus and apics */
 603         machine_shutdown();
 604
 605         tboot_shutdown(TB_SHUTDOWN_HALT);
 606
 607         stop_this_cpu(NULL);
 608 }
 609
 610 static void native_machine_power_off(void)
 611 {
 612         if (pm_power_off) {
 613                 if (!reboot_force)
 614                         machine_shutdown();
 615                 pm_power_off();
 616         }
 617         /* A fallback in case there is no PM info available */
 618         tboot_shutdown(TB_SHUTDOWN_HALT);
 619 }
 620
 621 struct machine_ops machine_ops = {
 622         .power_off = native_machine_power_off,
 623         .shutdown = native_machine_shutdown,
 624         .emergency_restart = native_machine_emergency_restart,
 625         .restart = native_machine_restart,
 626         .halt = native_machine_halt,
 627 #ifdef CONFIG_KEXEC
 628         .crash_shutdown = native_machine_crash_shutdown,
 629 #endif
 630 };
 631
 632 void machine_power_off(void)
 633 {
 634         machine_ops.power_off();
 635 }
 636
 637 void machine_shutdown(void)
 638 {
 639         machine_ops.shutdown();
 640 }
 641
 642 void machine_emergency_restart(void)
 643 {
 644         __machine_emergency_restart(1);
 645 }
 646
 647 void machine_restart(char *cmd)
 648 {
 649         machine_ops.restart(cmd);
 650 }
 651
 652 void machine_halt(void)
 653 {
 654         machine_ops.halt();
 655 }
 656
 657 #ifdef CONFIG_KEXEC
 658 void machine_crash_shutdown(struct pt_regs *regs)
 659 {
 660         machine_ops.crash_shutdown(regs);
 661 }
 662 #endif
 663
 664
 665 #if defined(CONFIG_SMP)
 666
 667 /* This keeps a track of which one is crashing cpu. */
 668 static int crashing_cpu;
 669 static nmi_shootdown_cb shootdown_callback;
 670
 671 static atomic_t waiting_for_crash_ipi;
 672
 673 static int crash_nmi_callback(unsigned int val, struct pt_regs *regs)
 674 {
 675         int cpu;
 676
 677         cpu = raw_smp_processor_id();
 678
 679         /*
 680          * Don't do anything if this handler is invoked on crashing cpu.
 681          * Otherwise, system will completely hang. Crashing cpu can get
 682          * an NMI if system was initially booted with nmi_watchdog parameter.
 683          */
 684         if (cpu == crashing_cpu)
 685                 return NMI_HANDLED;
 686         local_irq_disable();
 687
 688         shootdown_callback(cpu, regs);
 689
 690         atomic_dec(&waiting_for_crash_ipi);
 691         /* Assume hlt works */
 692         halt();
 693         for (;;)
 694                 cpu_relax();
 695
 696         return NMI_HANDLED;
 697 }
 698
 699 static void smp_send_nmi_allbutself(void)
 700 {
 701         apic->send_IPI_allbutself(NMI_VECTOR);
 702 }
 703
 704 /*
 705  * Halt all other CPUs, calling the specified function on each of them
 706  *
 707  * This function can be used to halt all other CPUs on crash
 708  * or emergency reboot time. The function passed as parameter
 709  * will be called inside a NMI handler on all CPUs.
 710  */
 711 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
 712 {
 713         unsigned long msecs;
 714         local_irq_disable();
 715
 716         /* Make a note of crashing cpu. Will be used in NMI callback. */
 717         crashing_cpu = safe_smp_processor_id();
 718
 719         shootdown_callback = callback;
 720
 721         atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
 722         /* Would it be better to replace the trap vector here? */
 723         if (register_nmi_handler(NMI_LOCAL, crash_nmi_callback,
 724                                  NMI_FLAG_FIRST, "crash"))
 725                 return;         /* Return what? */
 726         /*
 727          * Ensure the new callback function is set before sending
 728          * out the NMI
 729          */
 730         wmb();
 731
 732         smp_send_nmi_allbutself();
 733
 734         msecs = 1000; /* Wait at most a second for the other cpus to stop */
 735         while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
 736                 mdelay(1);
 737                 msecs--;
 738         }
 739
 740         /* Leave the nmi callback set */
 741 }
 742 #else /* !CONFIG_SMP */
 743 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
 744 {
 745         /* No other CPUs to shoot down */
 746 }
 747 #endif