arch/x86/kernel/reboot.c

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