arch/x86/kernel/reboot.c

   1 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   2
   3 #include <linux/export.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=a" commandline options
  59  */
  60 static int __init set_acpi_reboot(const struct dmi_system_id *d)
  61 {
  62         if (reboot_type != BOOT_ACPI) {
  63                 reboot_type = BOOT_ACPI;
  64                 pr_info("%s series board detected. Selecting %s-method for reboots.\n",
  65                         d->ident, "ACPI");
  66         }
  67         return 0;
  68 }
  69
  70 /*
  71  * Some machines require the "reboot=b" or "reboot=k"  commandline options,
  72  * this quirk makes that automatic.
  73  */
  74 static int __init set_bios_reboot(const struct dmi_system_id *d)
  75 {
  76         if (reboot_type != BOOT_BIOS) {
  77                 reboot_type = BOOT_BIOS;
  78                 pr_info("%s series board detected. Selecting %s-method for reboots.\n",
  79                         d->ident, "BIOS");
  80         }
  81         return 0;
  82 }
  83
  84 void __noreturn machine_real_restart(unsigned int type)
  85 {
  86         local_irq_disable();
  87
  88         /*
  89          * Write zero to CMOS register number 0x0f, which the BIOS POST
  90          * routine will recognize as telling it to do a proper reboot.  (Well
  91          * that's what this book in front of me says -- it may only apply to
  92          * the Phoenix BIOS though, it's not clear).  At the same time,
  93          * disable NMIs by setting the top bit in the CMOS address register,
  94          * as we're about to do peculiar things to the CPU.  I'm not sure if
  95          * `outb_p' is needed instead of just `outb'.  Use it to be on the
  96          * safe side.  (Yes, CMOS_WRITE does outb_p's. -  Paul G.)
  97          */
  98         spin_lock(&rtc_lock);
  99         CMOS_WRITE(0x00, 0x8f);
 100         spin_unlock(&rtc_lock);
 101
 102         /*
 103          * Switch back to the initial page table.
 104          */
 105 #ifdef CONFIG_X86_32
 106         load_cr3(initial_page_table);
 107 #else
 108         write_cr3(real_mode_header->trampoline_pgd);
 109 #endif
 110
 111         /* Jump to the identity-mapped low memory code */
 112 #ifdef CONFIG_X86_32
 113         asm volatile("jmpl *%0" : :
 114                      "rm" (real_mode_header->machine_real_restart_asm),
 115                      "a" (type));
 116 #else
 117         asm volatile("ljmpl *%0" : :
 118                      "m" (real_mode_header->machine_real_restart_asm),
 119                      "D" (type));
 120 #endif
 121         unreachable();
 122 }
 123 #ifdef CONFIG_APM_MODULE
 124 EXPORT_SYMBOL(machine_real_restart);
 125 #endif
 126
 127 /*
 128  * Some Apple MacBook and MacBookPro's needs reboot=p to be able to reboot
 129  */
 130 static int __init set_pci_reboot(const struct dmi_system_id *d)
 131 {
 132         if (reboot_type != BOOT_CF9_FORCE) {
 133                 reboot_type = BOOT_CF9_FORCE;
 134                 pr_info("%s series board detected. Selecting %s-method for reboots.\n",
 135                         d->ident, "PCI");
 136         }
 137         return 0;
 138 }
 139
 140 static int __init set_kbd_reboot(const struct dmi_system_id *d)
 141 {
 142         if (reboot_type != BOOT_KBD) {
 143                 reboot_type = BOOT_KBD;
 144                 pr_info("%s series board detected. Selecting %s-method for reboot.\n",
 145                         d->ident, "KBD");
 146         }
 147         return 0;
 148 }
 149
 150 /*
 151  * This is a single dmi_table handling all reboot quirks.
 152  */
 153 static struct dmi_system_id __initdata reboot_dmi_table[] = {
 154
 155         /* Acer */
 156         {       /* Handle reboot issue on Acer Aspire one */
 157                 .callback = set_kbd_reboot,
 158                 .ident = "Acer Aspire One A110",
 159                 .matches = {
 160                         DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
 161                         DMI_MATCH(DMI_PRODUCT_NAME, "AOA110"),
 162                 },
 163         },
 164
 165         /* Apple */
 166         {       /* Handle problems with rebooting on Apple MacBook5 */
 167                 .callback = set_pci_reboot,
 168                 .ident = "Apple MacBook5",
 169                 .matches = {
 170                         DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 171                         DMI_MATCH(DMI_PRODUCT_NAME, "MacBook5"),
 172                 },
 173         },
 174         {       /* Handle problems with rebooting on Apple MacBookPro5 */
 175                 .callback = set_pci_reboot,
 176                 .ident = "Apple MacBookPro5",
 177                 .matches = {
 178                         DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 179                         DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro5"),
 180                 },
 181         },
 182         {       /* Handle problems with rebooting on Apple Macmini3,1 */
 183                 .callback = set_pci_reboot,
 184                 .ident = "Apple Macmini3,1",
 185                 .matches = {
 186                         DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 187                         DMI_MATCH(DMI_PRODUCT_NAME, "Macmini3,1"),
 188                 },
 189         },
 190         {       /* Handle problems with rebooting on the iMac9,1. */
 191                 .callback = set_pci_reboot,
 192                 .ident = "Apple iMac9,1",
 193                 .matches = {
 194                         DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 195                         DMI_MATCH(DMI_PRODUCT_NAME, "iMac9,1"),
 196                 },
 197         },
 198         {       /* Handle problems with rebooting on the iMac10,1. */
 199                 .callback = set_pci_reboot,
 200                 .ident = "Apple iMac10,1",
 201                 .matches = {
 202                     DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 203                     DMI_MATCH(DMI_PRODUCT_NAME, "iMac10,1"),
 204                 },
 205         },
 206
 207         /* ASRock */
 208         {       /* Handle problems with rebooting on ASRock Q1900DC-ITX */
 209                 .callback = set_pci_reboot,
 210                 .ident = "ASRock Q1900DC-ITX",
 211                 .matches = {
 212                         DMI_MATCH(DMI_BOARD_VENDOR, "ASRock"),
 213                         DMI_MATCH(DMI_BOARD_NAME, "Q1900DC-ITX"),
 214                 },
 215         },
 216
 217         /* ASUS */
 218         {       /* Handle problems with rebooting on ASUS P4S800 */
 219                 .callback = set_bios_reboot,
 220                 .ident = "ASUS P4S800",
 221                 .matches = {
 222                         DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
 223                         DMI_MATCH(DMI_BOARD_NAME, "P4S800"),
 224                 },
 225         },
 226         {       /* Handle problems with rebooting on ASUS EeeBook X205TA */
 227                 .callback = set_acpi_reboot,
 228                 .ident = "ASUS EeeBook X205TA",
 229                 .matches = {
 230                         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
 231                         DMI_MATCH(DMI_PRODUCT_NAME, "X205TA"),
 232                 },
 233         },
 234         {       /* Handle problems with rebooting on ASUS EeeBook X205TAW */
 235                 .callback = set_acpi_reboot,
 236                 .ident = "ASUS EeeBook X205TAW",
 237                 .matches = {
 238                         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
 239                         DMI_MATCH(DMI_PRODUCT_NAME, "X205TAW"),
 240                 },
 241         },
 242
 243         /* Certec */
 244         {       /* Handle problems with rebooting on Certec BPC600 */
 245                 .callback = set_pci_reboot,
 246                 .ident = "Certec BPC600",
 247                 .matches = {
 248                         DMI_MATCH(DMI_SYS_VENDOR, "Certec"),
 249                         DMI_MATCH(DMI_PRODUCT_NAME, "BPC600"),
 250                 },
 251         },
 252
 253         /* Dell */
 254         {       /* Handle problems with rebooting on Dell DXP061 */
 255                 .callback = set_bios_reboot,
 256                 .ident = "Dell DXP061",
 257                 .matches = {
 258                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 259                         DMI_MATCH(DMI_PRODUCT_NAME, "Dell DXP061"),
 260                 },
 261         },
 262         {       /* Handle problems with rebooting on Dell E520's */
 263                 .callback = set_bios_reboot,
 264                 .ident = "Dell E520",
 265                 .matches = {
 266                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 267                         DMI_MATCH(DMI_PRODUCT_NAME, "Dell DM061"),
 268                 },
 269         },
 270         {       /* Handle problems with rebooting on the Latitude E5410. */
 271                 .callback = set_pci_reboot,
 272                 .ident = "Dell Latitude E5410",
 273                 .matches = {
 274                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 275                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E5410"),
 276                 },
 277         },
 278         {       /* Handle problems with rebooting on the Latitude E5420. */
 279                 .callback = set_pci_reboot,
 280                 .ident = "Dell Latitude E5420",
 281                 .matches = {
 282                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 283                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E5420"),
 284                 },
 285         },
 286         {       /* Handle problems with rebooting on the Latitude E6320. */
 287                 .callback = set_pci_reboot,
 288                 .ident = "Dell Latitude E6320",
 289                 .matches = {
 290                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 291                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6320"),
 292                 },
 293         },
 294         {       /* Handle problems with rebooting on the Latitude E6420. */
 295                 .callback = set_pci_reboot,
 296                 .ident = "Dell Latitude E6420",
 297                 .matches = {
 298                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 299                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6420"),
 300                 },
 301         },
 302         {       /* Handle problems with rebooting on Dell Optiplex 330 with 0KP561 */
 303                 .callback = set_bios_reboot,
 304                 .ident = "Dell OptiPlex 330",
 305                 .matches = {
 306                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 307                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 330"),
 308                         DMI_MATCH(DMI_BOARD_NAME, "0KP561"),
 309                 },
 310         },
 311         {       /* Handle problems with rebooting on Dell Optiplex 360 with 0T656F */
 312                 .callback = set_bios_reboot,
 313                 .ident = "Dell OptiPlex 360",
 314                 .matches = {
 315                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 316                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 360"),
 317                         DMI_MATCH(DMI_BOARD_NAME, "0T656F"),
 318                 },
 319         },
 320         {       /* Handle problems with rebooting on Dell Optiplex 745's SFF */
 321                 .callback = set_bios_reboot,
 322                 .ident = "Dell OptiPlex 745",
 323                 .matches = {
 324                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 325                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
 326                 },
 327         },
 328         {       /* Handle problems with rebooting on Dell Optiplex 745's DFF */
 329                 .callback = set_bios_reboot,
 330                 .ident = "Dell OptiPlex 745",
 331                 .matches = {
 332                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 333                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
 334                         DMI_MATCH(DMI_BOARD_NAME, "0MM599"),
 335                 },
 336         },
 337         {       /* Handle problems with rebooting on Dell Optiplex 745 with 0KW626 */
 338                 .callback = set_bios_reboot,
 339                 .ident = "Dell OptiPlex 745",
 340                 .matches = {
 341                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 342                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
 343                         DMI_MATCH(DMI_BOARD_NAME, "0KW626"),
 344                 },
 345         },
 346         {       /* Handle problems with rebooting on Dell OptiPlex 760 with 0G919G */
 347                 .callback = set_bios_reboot,
 348                 .ident = "Dell OptiPlex 760",
 349                 .matches = {
 350                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 351                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 760"),
 352                         DMI_MATCH(DMI_BOARD_NAME, "0G919G"),
 353                 },
 354         },
 355         {       /* Handle problems with rebooting on the OptiPlex 990. */
 356                 .callback = set_pci_reboot,
 357                 .ident = "Dell OptiPlex 990",
 358                 .matches = {
 359                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 360                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 990"),
 361                 },
 362         },
 363         {       /* Handle problems with rebooting on Dell 300's */
 364                 .callback = set_bios_reboot,
 365                 .ident = "Dell PowerEdge 300",
 366                 .matches = {
 367                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 368                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"),
 369                 },
 370         },
 371         {       /* Handle problems with rebooting on Dell 1300's */
 372                 .callback = set_bios_reboot,
 373                 .ident = "Dell PowerEdge 1300",
 374                 .matches = {
 375                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 376                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1300/"),
 377                 },
 378         },
 379         {       /* Handle problems with rebooting on Dell 2400's */
 380                 .callback = set_bios_reboot,
 381                 .ident = "Dell PowerEdge 2400",
 382                 .matches = {
 383                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 384                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"),
 385                 },
 386         },
 387         {       /* Handle problems with rebooting on the Dell PowerEdge C6100. */
 388                 .callback = set_pci_reboot,
 389                 .ident = "Dell PowerEdge C6100",
 390                 .matches = {
 391                         DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
 392                         DMI_MATCH(DMI_PRODUCT_NAME, "C6100"),
 393                 },
 394         },
 395         {       /* Handle problems with rebooting on the Precision M6600. */
 396                 .callback = set_pci_reboot,
 397                 .ident = "Dell Precision M6600",
 398                 .matches = {
 399                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 400                         DMI_MATCH(DMI_PRODUCT_NAME, "Precision M6600"),
 401                 },
 402         },
 403         {       /* Handle problems with rebooting on Dell T5400's */
 404                 .callback = set_bios_reboot,
 405                 .ident = "Dell Precision T5400",
 406                 .matches = {
 407                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 408                         DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T5400"),
 409                 },
 410         },
 411         {       /* Handle problems with rebooting on Dell T7400's */
 412                 .callback = set_bios_reboot,
 413                 .ident = "Dell Precision T7400",
 414                 .matches = {
 415                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 416                         DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T7400"),
 417                 },
 418         },
 419         {       /* Handle problems with rebooting on Dell XPS710 */
 420                 .callback = set_bios_reboot,
 421                 .ident = "Dell XPS710",
 422                 .matches = {
 423                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 424                         DMI_MATCH(DMI_PRODUCT_NAME, "Dell XPS710"),
 425                 },
 426         },
 427         {       /* Handle problems with rebooting on Dell Optiplex 7450 AIO */
 428                 .callback = set_acpi_reboot,
 429                 .ident = "Dell OptiPlex 7450 AIO",
 430                 .matches = {
 431                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 432                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 7450 AIO"),
 433                 },
 434         },
 435
 436         /* Hewlett-Packard */
 437         {       /* Handle problems with rebooting on HP laptops */
 438                 .callback = set_bios_reboot,
 439                 .ident = "HP Compaq Laptop",
 440                 .matches = {
 441                         DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 442                         DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"),
 443                 },
 444         },
 445
 446         /* Sony */
 447         {       /* Handle problems with rebooting on Sony VGN-Z540N */
 448                 .callback = set_bios_reboot,
 449                 .ident = "Sony VGN-Z540N",
 450                 .matches = {
 451                         DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
 452                         DMI_MATCH(DMI_PRODUCT_NAME, "VGN-Z540N"),
 453                 },
 454         },
 455
 456         { }
 457 };
 458
 459 static int __init reboot_init(void)
 460 {
 461         int rv;
 462
 463         /*
 464          * Only do the DMI check if reboot_type hasn't been overridden
 465          * on the command line
 466          */
 467         if (!reboot_default)
 468                 return 0;
 469
 470         /*
 471          * The DMI quirks table takes precedence. If no quirks entry
 472          * matches and the ACPI Hardware Reduced bit is set, force EFI
 473          * reboot.
 474          */
 475         rv = dmi_check_system(reboot_dmi_table);
 476
 477         if (!rv && efi_reboot_required())
 478                 reboot_type = BOOT_EFI;
 479
 480         return 0;
 481 }
 482 core_initcall(reboot_init);
 483
 484 static inline void kb_wait(void)
 485 {
 486         int i;
 487
 488         for (i = 0; i < 0x10000; i++) {
 489                 if ((inb(0x64) & 0x02) == 0)
 490                         break;
 491                 udelay(2);
 492         }
 493 }
 494
 495 static void vmxoff_nmi(int cpu, struct pt_regs *regs)
 496 {
 497         cpu_emergency_vmxoff();
 498 }
 499
 500 /* Use NMIs as IPIs to tell all CPUs to disable virtualization */
 501 static void emergency_vmx_disable_all(void)
 502 {
 503         /* Just make sure we won't change CPUs while doing this */
 504         local_irq_disable();
 505
 506         /*
 507          * We need to disable VMX on all CPUs before rebooting, otherwise
 508          * we risk hanging up the machine, because the CPU ignore INIT
 509          * signals when VMX is enabled.
 510          *
 511          * We can't take any locks and we may be on an inconsistent
 512          * state, so we use NMIs as IPIs to tell the other CPUs to disable
 513          * VMX and halt.
 514          *
 515          * For safety, we will avoid running the nmi_shootdown_cpus()
 516          * stuff unnecessarily, but we don't have a way to check
 517          * if other CPUs have VMX enabled. So we will call it only if the
 518          * CPU we are running on has VMX enabled.
 519          *
 520          * We will miss cases where VMX is not enabled on all CPUs. This
 521          * shouldn't do much harm because KVM always enable VMX on all
 522          * CPUs anyway. But we can miss it on the small window where KVM
 523          * is still enabling VMX.
 524          */
 525         if (cpu_has_vmx() && cpu_vmx_enabled()) {
 526                 /* Disable VMX on this CPU. */
 527                 cpu_vmxoff();
 528
 529                 /* Halt and disable VMX on the other CPUs */
 530                 nmi_shootdown_cpus(vmxoff_nmi);
 531
 532         }
 533 }
 534
 535
 536 void __attribute__((weak)) mach_reboot_fixups(void)
 537 {
 538 }
 539
 540 /*
 541  * To the best of our knowledge Windows compatible x86 hardware expects
 542  * the following on reboot:
 543  *
 544  * 1) If the FADT has the ACPI reboot register flag set, try it
 545  * 2) If still alive, write to the keyboard controller
 546  * 3) If still alive, write to the ACPI reboot register again
 547  * 4) If still alive, write to the keyboard controller again
 548  * 5) If still alive, call the EFI runtime service to reboot
 549  * 6) If no EFI runtime service, call the BIOS to do a reboot
 550  *
 551  * We default to following the same pattern. We also have
 552  * two other reboot methods: 'triple fault' and 'PCI', which
 553  * can be triggered via the reboot= kernel boot option or
 554  * via quirks.
 555  *
 556  * This means that this function can never return, it can misbehave
 557  * by not rebooting properly and hanging.
 558  */
 559 static void native_machine_emergency_restart(void)
 560 {
 561         int i;
 562         int attempt = 0;
 563         int orig_reboot_type = reboot_type;
 564         unsigned short mode;
 565
 566         if (reboot_emergency)
 567                 emergency_vmx_disable_all();
 568
 569         tboot_shutdown(TB_SHUTDOWN_REBOOT);
 570
 571         /* Tell the BIOS if we want cold or warm reboot */
 572         mode = reboot_mode == REBOOT_WARM ? 0x1234 : 0;
 573         *((unsigned short *)__va(0x472)) = mode;
 574
 575         /*
 576          * If an EFI capsule has been registered with the firmware then
 577          * override the reboot= parameter.
 578          */
 579         if (efi_capsule_pending(NULL)) {
 580                 pr_info("EFI capsule is pending, forcing EFI reboot.\n");
 581                 reboot_type = BOOT_EFI;
 582         }
 583
 584         for (;;) {
 585                 /* Could also try the reset bit in the Hammer NB */
 586                 switch (reboot_type) {
 587                 case BOOT_ACPI:
 588                         acpi_reboot();
 589                         reboot_type = BOOT_KBD;
 590                         break;
 591
 592                 case BOOT_KBD:
 593                         mach_reboot_fixups(); /* For board specific fixups */
 594
 595                         for (i = 0; i < 10; i++) {
 596                                 kb_wait();
 597                                 udelay(50);
 598                                 outb(0xfe, 0x64); /* Pulse reset low */
 599                                 udelay(50);
 600                         }
 601                         if (attempt == 0 && orig_reboot_type == BOOT_ACPI) {
 602                                 attempt = 1;
 603                                 reboot_type = BOOT_ACPI;
 604                         } else {
 605                                 reboot_type = BOOT_EFI;
 606                         }
 607                         break;
 608
 609                 case BOOT_EFI:
 610                         efi_reboot(reboot_mode, NULL);
 611                         reboot_type = BOOT_BIOS;
 612                         break;
 613
 614                 case BOOT_BIOS:
 615                         machine_real_restart(MRR_BIOS);
 616
 617                         /* We're probably dead after this, but... */
 618                         reboot_type = BOOT_CF9_SAFE;
 619                         break;
 620
 621                 case BOOT_CF9_FORCE:
 622                         port_cf9_safe = true;
 623                         /* Fall through */
 624
 625                 case BOOT_CF9_SAFE:
 626                         if (port_cf9_safe) {
 627                                 u8 reboot_code = reboot_mode == REBOOT_WARM ?  0x06 : 0x0E;
 628                                 u8 cf9 = inb(0xcf9) & ~reboot_code;
 629                                 outb(cf9|2, 0xcf9); /* Request hard reset */
 630                                 udelay(50);
 631                                 /* Actually do the reset */
 632                                 outb(cf9|reboot_code, 0xcf9);
 633                                 udelay(50);
 634                         }
 635                         reboot_type = BOOT_TRIPLE;
 636                         break;
 637
 638                 case BOOT_TRIPLE:
 639                         load_idt(&no_idt);
 640                         __asm__ __volatile__("int3");
 641
 642                         /* We're probably dead after this, but... */
 643                         reboot_type = BOOT_KBD;
 644                         break;
 645                 }
 646         }
 647 }
 648
 649 void native_machine_shutdown(void)
 650 {
 651         /* Stop the cpus and apics */
 652 #ifdef CONFIG_X86_IO_APIC
 653         /*
 654          * Disabling IO APIC before local APIC is a workaround for
 655          * erratum AVR31 in "Intel Atom Processor C2000 Product Family
 656          * Specification Update". In this situation, interrupts that target
 657          * a Logical Processor whose Local APIC is either in the process of
 658          * being hardware disabled or software disabled are neither delivered
 659          * nor discarded. When this erratum occurs, the processor may hang.
 660          *
 661          * Even without the erratum, it still makes sense to quiet IO APIC
 662          * before disabling Local APIC.
 663          */
 664         disable_IO_APIC();
 665 #endif
 666
 667 #ifdef CONFIG_SMP
 668         /*
 669          * Stop all of the others. Also disable the local irq to
 670          * not receive the per-cpu timer interrupt which may trigger
 671          * scheduler's load balance.
 672          */
 673         local_irq_disable();
 674         stop_other_cpus();
 675 #endif
 676
 677         lapic_shutdown();
 678
 679 #ifdef CONFIG_HPET_TIMER
 680         hpet_disable();
 681 #endif
 682
 683 #ifdef CONFIG_X86_64
 684         x86_platform.iommu_shutdown();
 685 #endif
 686 }
 687
 688 static void __machine_emergency_restart(int emergency)
 689 {
 690         reboot_emergency = emergency;
 691         machine_ops.emergency_restart();
 692 }
 693
 694 static void native_machine_restart(char *__unused)
 695 {
 696         pr_notice("machine restart\n");
 697
 698         if (!reboot_force)
 699                 machine_shutdown();
 700         __machine_emergency_restart(0);
 701 }
 702
 703 static void native_machine_halt(void)
 704 {
 705         /* Stop other cpus and apics */
 706         machine_shutdown();
 707
 708         tboot_shutdown(TB_SHUTDOWN_HALT);
 709
 710         stop_this_cpu(NULL);
 711 }
 712
 713 static void native_machine_power_off(void)
 714 {
 715         if (pm_power_off) {
 716                 if (!reboot_force)
 717                         machine_shutdown();
 718                 pm_power_off();
 719         }
 720         /* A fallback in case there is no PM info available */
 721         tboot_shutdown(TB_SHUTDOWN_HALT);
 722 }
 723
 724 struct machine_ops machine_ops __ro_after_init = {
 725         .power_off = native_machine_power_off,
 726         .shutdown = native_machine_shutdown,
 727         .emergency_restart = native_machine_emergency_restart,
 728         .restart = native_machine_restart,
 729         .halt = native_machine_halt,
 730 #ifdef CONFIG_KEXEC_CORE
 731         .crash_shutdown = native_machine_crash_shutdown,
 732 #endif
 733 };
 734
 735 void machine_power_off(void)
 736 {
 737         machine_ops.power_off();
 738 }
 739
 740 void machine_shutdown(void)
 741 {
 742         machine_ops.shutdown();
 743 }
 744
 745 void machine_emergency_restart(void)
 746 {
 747         __machine_emergency_restart(1);
 748 }
 749
 750 void machine_restart(char *cmd)
 751 {
 752         machine_ops.restart(cmd);
 753 }
 754
 755 void machine_halt(void)
 756 {
 757         machine_ops.halt();
 758 }
 759
 760 #ifdef CONFIG_KEXEC_CORE
 761 void machine_crash_shutdown(struct pt_regs *regs)
 762 {
 763         machine_ops.crash_shutdown(regs);
 764 }
 765 #endif
 766
 767
 768 #if defined(CONFIG_SMP)
 769
 770 /* This keeps a track of which one is crashing cpu. */
 771 static int crashing_cpu;
 772 static nmi_shootdown_cb shootdown_callback;
 773
 774 static atomic_t waiting_for_crash_ipi;
 775 static int crash_ipi_issued;
 776
 777 static int crash_nmi_callback(unsigned int val, struct pt_regs *regs)
 778 {
 779         int cpu;
 780
 781         cpu = raw_smp_processor_id();
 782
 783         /*
 784          * Don't do anything if this handler is invoked on crashing cpu.
 785          * Otherwise, system will completely hang. Crashing cpu can get
 786          * an NMI if system was initially booted with nmi_watchdog parameter.
 787          */
 788         if (cpu == crashing_cpu)
 789                 return NMI_HANDLED;
 790         local_irq_disable();
 791
 792         shootdown_callback(cpu, regs);
 793
 794         atomic_dec(&waiting_for_crash_ipi);
 795         /* Assume hlt works */
 796         halt();
 797         for (;;)
 798                 cpu_relax();
 799
 800         return NMI_HANDLED;
 801 }
 802
 803 static void smp_send_nmi_allbutself(void)
 804 {
 805         apic->send_IPI_allbutself(NMI_VECTOR);
 806 }
 807
 808 /*
 809  * Halt all other CPUs, calling the specified function on each of them
 810  *
 811  * This function can be used to halt all other CPUs on crash
 812  * or emergency reboot time. The function passed as parameter
 813  * will be called inside a NMI handler on all CPUs.
 814  */
 815 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
 816 {
 817         unsigned long msecs;
 818         local_irq_disable();
 819
 820         /* Make a note of crashing cpu. Will be used in NMI callback. */
 821         crashing_cpu = safe_smp_processor_id();
 822
 823         shootdown_callback = callback;
 824
 825         atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
 826         /* Would it be better to replace the trap vector here? */
 827         if (register_nmi_handler(NMI_LOCAL, crash_nmi_callback,
 828                                  NMI_FLAG_FIRST, "crash"))
 829                 return;         /* Return what? */
 830         /*
 831          * Ensure the new callback function is set before sending
 832          * out the NMI
 833          */
 834         wmb();
 835
 836         smp_send_nmi_allbutself();
 837
 838         /* Kick CPUs looping in NMI context. */
 839         WRITE_ONCE(crash_ipi_issued, 1);
 840
 841         msecs = 1000; /* Wait at most a second for the other cpus to stop */
 842         while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
 843                 mdelay(1);
 844                 msecs--;
 845         }
 846
 847         /* Leave the nmi callback set */
 848 }
 849
 850 /*
 851  * Check if the crash dumping IPI got issued and if so, call its callback
 852  * directly. This function is used when we have already been in NMI handler.
 853  * It doesn't return.
 854  */
 855 void run_crash_ipi_callback(struct pt_regs *regs)
 856 {
 857         if (crash_ipi_issued)
 858                 crash_nmi_callback(0, regs);
 859 }
 860
 861 /* Override the weak function in kernel/panic.c */
 862 void nmi_panic_self_stop(struct pt_regs *regs)
 863 {
 864         while (1) {
 865                 /* If no CPU is preparing crash dump, we simply loop here. */
 866                 run_crash_ipi_callback(regs);
 867                 cpu_relax();
 868         }
 869 }
 870
 871 #else /* !CONFIG_SMP */
 872 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
 873 {
 874         /* No other CPUs to shoot down */
 875 }
 876
 877 void run_crash_ipi_callback(struct pt_regs *regs)
 878 {
 879 }
 880 #endif