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
 227         /* Certec */
 228         {       /* Handle problems with rebooting on Certec BPC600 */
 229                 .callback = set_pci_reboot,
 230                 .ident = "Certec BPC600",
 231                 .matches = {
 232                         DMI_MATCH(DMI_SYS_VENDOR, "Certec"),
 233                         DMI_MATCH(DMI_PRODUCT_NAME, "BPC600"),
 234                 },
 235         },
 236
 237         /* Dell */
 238         {       /* Handle problems with rebooting on Dell DXP061 */
 239                 .callback = set_bios_reboot,
 240                 .ident = "Dell DXP061",
 241                 .matches = {
 242                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 243                         DMI_MATCH(DMI_PRODUCT_NAME, "Dell DXP061"),
 244                 },
 245         },
 246         {       /* Handle problems with rebooting on Dell E520's */
 247                 .callback = set_bios_reboot,
 248                 .ident = "Dell E520",
 249                 .matches = {
 250                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 251                         DMI_MATCH(DMI_PRODUCT_NAME, "Dell DM061"),
 252                 },
 253         },
 254         {       /* Handle problems with rebooting on the Latitude E5410. */
 255                 .callback = set_pci_reboot,
 256                 .ident = "Dell Latitude E5410",
 257                 .matches = {
 258                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 259                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E5410"),
 260                 },
 261         },
 262         {       /* Handle problems with rebooting on the Latitude E5420. */
 263                 .callback = set_pci_reboot,
 264                 .ident = "Dell Latitude E5420",
 265                 .matches = {
 266                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 267                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E5420"),
 268                 },
 269         },
 270         {       /* Handle problems with rebooting on the Latitude E6320. */
 271                 .callback = set_pci_reboot,
 272                 .ident = "Dell Latitude E6320",
 273                 .matches = {
 274                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 275                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6320"),
 276                 },
 277         },
 278         {       /* Handle problems with rebooting on the Latitude E6420. */
 279                 .callback = set_pci_reboot,
 280                 .ident = "Dell Latitude E6420",
 281                 .matches = {
 282                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 283                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6420"),
 284                 },
 285         },
 286         {       /* Handle problems with rebooting on Dell Optiplex 330 with 0KP561 */
 287                 .callback = set_bios_reboot,
 288                 .ident = "Dell OptiPlex 330",
 289                 .matches = {
 290                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 291                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 330"),
 292                         DMI_MATCH(DMI_BOARD_NAME, "0KP561"),
 293                 },
 294         },
 295         {       /* Handle problems with rebooting on Dell Optiplex 360 with 0T656F */
 296                 .callback = set_bios_reboot,
 297                 .ident = "Dell OptiPlex 360",
 298                 .matches = {
 299                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 300                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 360"),
 301                         DMI_MATCH(DMI_BOARD_NAME, "0T656F"),
 302                 },
 303         },
 304         {       /* Handle problems with rebooting on Dell Optiplex 745's SFF */
 305                 .callback = set_bios_reboot,
 306                 .ident = "Dell OptiPlex 745",
 307                 .matches = {
 308                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 309                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
 310                 },
 311         },
 312         {       /* Handle problems with rebooting on Dell Optiplex 745's DFF */
 313                 .callback = set_bios_reboot,
 314                 .ident = "Dell OptiPlex 745",
 315                 .matches = {
 316                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 317                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
 318                         DMI_MATCH(DMI_BOARD_NAME, "0MM599"),
 319                 },
 320         },
 321         {       /* Handle problems with rebooting on Dell Optiplex 745 with 0KW626 */
 322                 .callback = set_bios_reboot,
 323                 .ident = "Dell OptiPlex 745",
 324                 .matches = {
 325                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 326                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
 327                         DMI_MATCH(DMI_BOARD_NAME, "0KW626"),
 328                 },
 329         },
 330         {       /* Handle problems with rebooting on Dell OptiPlex 760 with 0G919G */
 331                 .callback = set_bios_reboot,
 332                 .ident = "Dell OptiPlex 760",
 333                 .matches = {
 334                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 335                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 760"),
 336                         DMI_MATCH(DMI_BOARD_NAME, "0G919G"),
 337                 },
 338         },
 339         {       /* Handle problems with rebooting on the OptiPlex 990. */
 340                 .callback = set_pci_reboot,
 341                 .ident = "Dell OptiPlex 990",
 342                 .matches = {
 343                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 344                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 990"),
 345                 },
 346         },
 347         {       /* Handle problems with rebooting on Dell 300's */
 348                 .callback = set_bios_reboot,
 349                 .ident = "Dell PowerEdge 300",
 350                 .matches = {
 351                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 352                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"),
 353                 },
 354         },
 355         {       /* Handle problems with rebooting on Dell 1300's */
 356                 .callback = set_bios_reboot,
 357                 .ident = "Dell PowerEdge 1300",
 358                 .matches = {
 359                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 360                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1300/"),
 361                 },
 362         },
 363         {       /* Handle problems with rebooting on Dell 2400's */
 364                 .callback = set_bios_reboot,
 365                 .ident = "Dell PowerEdge 2400",
 366                 .matches = {
 367                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 368                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"),
 369                 },
 370         },
 371         {       /* Handle problems with rebooting on the Dell PowerEdge C6100. */
 372                 .callback = set_pci_reboot,
 373                 .ident = "Dell PowerEdge C6100",
 374                 .matches = {
 375                         DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
 376                         DMI_MATCH(DMI_PRODUCT_NAME, "C6100"),
 377                 },
 378         },
 379         {       /* Handle problems with rebooting on the Precision M6600. */
 380                 .callback = set_pci_reboot,
 381                 .ident = "Dell Precision M6600",
 382                 .matches = {
 383                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 384                         DMI_MATCH(DMI_PRODUCT_NAME, "Precision M6600"),
 385                 },
 386         },
 387         {       /* Handle problems with rebooting on Dell T5400's */
 388                 .callback = set_bios_reboot,
 389                 .ident = "Dell Precision T5400",
 390                 .matches = {
 391                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 392                         DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T5400"),
 393                 },
 394         },
 395         {       /* Handle problems with rebooting on Dell T7400's */
 396                 .callback = set_bios_reboot,
 397                 .ident = "Dell Precision T7400",
 398                 .matches = {
 399                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 400                         DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T7400"),
 401                 },
 402         },
 403         {       /* Handle problems with rebooting on Dell XPS710 */
 404                 .callback = set_bios_reboot,
 405                 .ident = "Dell XPS710",
 406                 .matches = {
 407                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 408                         DMI_MATCH(DMI_PRODUCT_NAME, "Dell XPS710"),
 409                 },
 410         },
 411         {       /* Handle problems with rebooting on Dell Optiplex 7450 AIO */
 412                 .callback = set_acpi_reboot,
 413                 .ident = "Dell OptiPlex 7450 AIO",
 414                 .matches = {
 415                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 416                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 7450 AIO"),
 417                 },
 418         },
 419
 420         /* Hewlett-Packard */
 421         {       /* Handle problems with rebooting on HP laptops */
 422                 .callback = set_bios_reboot,
 423                 .ident = "HP Compaq Laptop",
 424                 .matches = {
 425                         DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 426                         DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"),
 427                 },
 428         },
 429
 430         /* Sony */
 431         {       /* Handle problems with rebooting on Sony VGN-Z540N */
 432                 .callback = set_bios_reboot,
 433                 .ident = "Sony VGN-Z540N",
 434                 .matches = {
 435                         DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
 436                         DMI_MATCH(DMI_PRODUCT_NAME, "VGN-Z540N"),
 437                 },
 438         },
 439         {       /* Handle problems with rebooting on the Latitude E6520. */
 440                 .callback = set_pci_reboot,
 441                 .ident = "Dell Latitude E6520",
 442                 .matches = {
 443                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 444                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6520"),
 445                 },
 446         },
 447         { }
 448 };
 449
 450 static int __init reboot_init(void)
 451 {
 452         int rv;
 453
 454         /*
 455          * Only do the DMI check if reboot_type hasn't been overridden
 456          * on the command line
 457          */
 458         if (!reboot_default)
 459                 return 0;
 460
 461         /*
 462          * The DMI quirks table takes precedence. If no quirks entry
 463          * matches and the ACPI Hardware Reduced bit is set, force EFI
 464          * reboot.
 465          */
 466         rv = dmi_check_system(reboot_dmi_table);
 467
 468         if (!rv && efi_reboot_required())
 469                 reboot_type = BOOT_EFI;
 470
 471         return 0;
 472 }
 473 core_initcall(reboot_init);
 474
 475 static inline void kb_wait(void)
 476 {
 477         int i;
 478
 479         for (i = 0; i < 0x10000; i++) {
 480                 if ((inb(0x64) & 0x02) == 0)
 481                         break;
 482                 udelay(2);
 483         }
 484 }
 485
 486 static void vmxoff_nmi(int cpu, struct pt_regs *regs)
 487 {
 488         cpu_emergency_vmxoff();
 489 }
 490
 491 /* Use NMIs as IPIs to tell all CPUs to disable virtualization */
 492 static void emergency_vmx_disable_all(void)
 493 {
 494         /* Just make sure we won't change CPUs while doing this */
 495         local_irq_disable();
 496
 497         /*
 498          * We need to disable VMX on all CPUs before rebooting, otherwise
 499          * we risk hanging up the machine, because the CPU ignore INIT
 500          * signals when VMX is enabled.
 501          *
 502          * We can't take any locks and we may be on an inconsistent
 503          * state, so we use NMIs as IPIs to tell the other CPUs to disable
 504          * VMX and halt.
 505          *
 506          * For safety, we will avoid running the nmi_shootdown_cpus()
 507          * stuff unnecessarily, but we don't have a way to check
 508          * if other CPUs have VMX enabled. So we will call it only if the
 509          * CPU we are running on has VMX enabled.
 510          *
 511          * We will miss cases where VMX is not enabled on all CPUs. This
 512          * shouldn't do much harm because KVM always enable VMX on all
 513          * CPUs anyway. But we can miss it on the small window where KVM
 514          * is still enabling VMX.
 515          */
 516         if (cpu_has_vmx() && cpu_vmx_enabled()) {
 517                 /* Disable VMX on this CPU. */
 518                 cpu_vmxoff();
 519
 520                 /* Halt and disable VMX on the other CPUs */
 521                 nmi_shootdown_cpus(vmxoff_nmi);
 522
 523         }
 524 }
 525
 526
 527 void __attribute__((weak)) mach_reboot_fixups(void)
 528 {
 529 }
 530
 531 /*
 532  * To the best of our knowledge Windows compatible x86 hardware expects
 533  * the following on reboot:
 534  *
 535  * 1) If the FADT has the ACPI reboot register flag set, try it
 536  * 2) If still alive, write to the keyboard controller
 537  * 3) If still alive, write to the ACPI reboot register again
 538  * 4) If still alive, write to the keyboard controller again
 539  * 5) If still alive, call the EFI runtime service to reboot
 540  * 6) If no EFI runtime service, call the BIOS to do a reboot
 541  *
 542  * We default to following the same pattern. We also have
 543  * two other reboot methods: 'triple fault' and 'PCI', which
 544  * can be triggered via the reboot= kernel boot option or
 545  * via quirks.
 546  *
 547  * This means that this function can never return, it can misbehave
 548  * by not rebooting properly and hanging.
 549  */
 550 static void native_machine_emergency_restart(void)
 551 {
 552         int i;
 553         int attempt = 0;
 554         int orig_reboot_type = reboot_type;
 555         unsigned short mode;
 556
 557         if (reboot_emergency)
 558                 emergency_vmx_disable_all();
 559
 560         tboot_shutdown(TB_SHUTDOWN_REBOOT);
 561
 562         /* Tell the BIOS if we want cold or warm reboot */
 563         mode = reboot_mode == REBOOT_WARM ? 0x1234 : 0;
 564         *((unsigned short *)__va(0x472)) = mode;
 565
 566         /*
 567          * If an EFI capsule has been registered with the firmware then
 568          * override the reboot= parameter.
 569          */
 570         if (efi_capsule_pending(NULL)) {
 571                 pr_info("EFI capsule is pending, forcing EFI reboot.\n");
 572                 reboot_type = BOOT_EFI;
 573         }
 574
 575         for (;;) {
 576                 /* Could also try the reset bit in the Hammer NB */
 577                 switch (reboot_type) {
 578                 case BOOT_ACPI:
 579                         acpi_reboot();
 580                         reboot_type = BOOT_KBD;
 581                         break;
 582
 583                 case BOOT_KBD:
 584                         mach_reboot_fixups(); /* For board specific fixups */
 585
 586                         for (i = 0; i < 10; i++) {
 587                                 kb_wait();
 588                                 udelay(50);
 589                                 outb(0xfe, 0x64); /* Pulse reset low */
 590                                 udelay(50);
 591                         }
 592                         if (attempt == 0 && orig_reboot_type == BOOT_ACPI) {
 593                                 attempt = 1;
 594                                 reboot_type = BOOT_ACPI;
 595                         } else {
 596                                 reboot_type = BOOT_EFI;
 597                         }
 598                         break;
 599
 600                 case BOOT_EFI:
 601                         efi_reboot(reboot_mode, NULL);
 602                         reboot_type = BOOT_BIOS;
 603                         break;
 604
 605                 case BOOT_BIOS:
 606                         machine_real_restart(MRR_BIOS);
 607
 608                         /* We're probably dead after this, but... */
 609                         reboot_type = BOOT_CF9_SAFE;
 610                         break;
 611
 612                 case BOOT_CF9_FORCE:
 613                         port_cf9_safe = true;
 614                         /* Fall through */
 615
 616                 case BOOT_CF9_SAFE:
 617                         if (port_cf9_safe) {
 618                                 u8 reboot_code = reboot_mode == REBOOT_WARM ?  0x06 : 0x0E;
 619                                 u8 cf9 = inb(0xcf9) & ~reboot_code;
 620                                 outb(cf9|2, 0xcf9); /* Request hard reset */
 621                                 udelay(50);
 622                                 /* Actually do the reset */
 623                                 outb(cf9|reboot_code, 0xcf9);
 624                                 udelay(50);
 625                         }
 626                         reboot_type = BOOT_TRIPLE;
 627                         break;
 628
 629                 case BOOT_TRIPLE:
 630                         load_idt(&no_idt);
 631                         __asm__ __volatile__("int3");
 632
 633                         /* We're probably dead after this, but... */
 634                         reboot_type = BOOT_KBD;
 635                         break;
 636                 }
 637         }
 638 }
 639
 640 void native_machine_shutdown(void)
 641 {
 642         /* Stop the cpus and apics */
 643 #ifdef CONFIG_X86_IO_APIC
 644         /*
 645          * Disabling IO APIC before local APIC is a workaround for
 646          * erratum AVR31 in "Intel Atom Processor C2000 Product Family
 647          * Specification Update". In this situation, interrupts that target
 648          * a Logical Processor whose Local APIC is either in the process of
 649          * being hardware disabled or software disabled are neither delivered
 650          * nor discarded. When this erratum occurs, the processor may hang.
 651          *
 652          * Even without the erratum, it still makes sense to quiet IO APIC
 653          * before disabling Local APIC.
 654          */
 655         disable_IO_APIC();
 656 #endif
 657
 658 #ifdef CONFIG_SMP
 659         /*
 660          * Stop all of the others. Also disable the local irq to
 661          * not receive the per-cpu timer interrupt which may trigger
 662          * scheduler's load balance.
 663          */
 664         local_irq_disable();
 665         stop_other_cpus();
 666 #endif
 667
 668         lapic_shutdown();
 669
 670 #ifdef CONFIG_HPET_TIMER
 671         hpet_disable();
 672 #endif
 673
 674 #ifdef CONFIG_X86_64
 675         x86_platform.iommu_shutdown();
 676 #endif
 677 }
 678
 679 static void __machine_emergency_restart(int emergency)
 680 {
 681         reboot_emergency = emergency;
 682         machine_ops.emergency_restart();
 683 }
 684
 685 static void native_machine_restart(char *__unused)
 686 {
 687         pr_notice("machine restart\n");
 688
 689         if (!reboot_force)
 690                 machine_shutdown();
 691         __machine_emergency_restart(0);
 692 }
 693
 694 static void native_machine_halt(void)
 695 {
 696         /* Stop other cpus and apics */
 697         machine_shutdown();
 698
 699         tboot_shutdown(TB_SHUTDOWN_HALT);
 700
 701         stop_this_cpu(NULL);
 702 }
 703
 704 static void native_machine_power_off(void)
 705 {
 706         if (pm_power_off) {
 707                 if (!reboot_force)
 708                         machine_shutdown();
 709                 pm_power_off();
 710         }
 711         /* A fallback in case there is no PM info available */
 712         tboot_shutdown(TB_SHUTDOWN_HALT);
 713 }
 714
 715 struct machine_ops machine_ops __ro_after_init = {
 716         .power_off = native_machine_power_off,
 717         .shutdown = native_machine_shutdown,
 718         .emergency_restart = native_machine_emergency_restart,
 719         .restart = native_machine_restart,
 720         .halt = native_machine_halt,
 721 #ifdef CONFIG_KEXEC_CORE
 722         .crash_shutdown = native_machine_crash_shutdown,
 723 #endif
 724 };
 725
 726 void machine_power_off(void)
 727 {
 728         machine_ops.power_off();
 729 }
 730
 731 void machine_shutdown(void)
 732 {
 733         machine_ops.shutdown();
 734 }
 735
 736 void machine_emergency_restart(void)
 737 {
 738         __machine_emergency_restart(1);
 739 }
 740
 741 void machine_restart(char *cmd)
 742 {
 743         machine_ops.restart(cmd);
 744 }
 745
 746 void machine_halt(void)
 747 {
 748         machine_ops.halt();
 749 }
 750
 751 #ifdef CONFIG_KEXEC_CORE
 752 void machine_crash_shutdown(struct pt_regs *regs)
 753 {
 754         machine_ops.crash_shutdown(regs);
 755 }
 756 #endif
 757
 758
 759 #if defined(CONFIG_SMP)
 760
 761 /* This keeps a track of which one is crashing cpu. */
 762 static int crashing_cpu;
 763 static nmi_shootdown_cb shootdown_callback;
 764
 765 static atomic_t waiting_for_crash_ipi;
 766 static int crash_ipi_issued;
 767
 768 static int crash_nmi_callback(unsigned int val, struct pt_regs *regs)
 769 {
 770         int cpu;
 771
 772         cpu = raw_smp_processor_id();
 773
 774         /*
 775          * Don't do anything if this handler is invoked on crashing cpu.
 776          * Otherwise, system will completely hang. Crashing cpu can get
 777          * an NMI if system was initially booted with nmi_watchdog parameter.
 778          */
 779         if (cpu == crashing_cpu)
 780                 return NMI_HANDLED;
 781         local_irq_disable();
 782
 783         shootdown_callback(cpu, regs);
 784
 785         atomic_dec(&waiting_for_crash_ipi);
 786         /* Assume hlt works */
 787         halt();
 788         for (;;)
 789                 cpu_relax();
 790
 791         return NMI_HANDLED;
 792 }
 793
 794 static void smp_send_nmi_allbutself(void)
 795 {
 796         apic->send_IPI_allbutself(NMI_VECTOR);
 797 }
 798
 799 /*
 800  * Halt all other CPUs, calling the specified function on each of them
 801  *
 802  * This function can be used to halt all other CPUs on crash
 803  * or emergency reboot time. The function passed as parameter
 804  * will be called inside a NMI handler on all CPUs.
 805  */
 806 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
 807 {
 808         unsigned long msecs;
 809         local_irq_disable();
 810
 811         /* Make a note of crashing cpu. Will be used in NMI callback. */
 812         crashing_cpu = safe_smp_processor_id();
 813
 814         shootdown_callback = callback;
 815
 816         atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
 817         /* Would it be better to replace the trap vector here? */
 818         if (register_nmi_handler(NMI_LOCAL, crash_nmi_callback,
 819                                  NMI_FLAG_FIRST, "crash"))
 820                 return;         /* Return what? */
 821         /*
 822          * Ensure the new callback function is set before sending
 823          * out the NMI
 824          */
 825         wmb();
 826
 827         smp_send_nmi_allbutself();
 828
 829         /* Kick CPUs looping in NMI context. */
 830         WRITE_ONCE(crash_ipi_issued, 1);
 831
 832         msecs = 1000; /* Wait at most a second for the other cpus to stop */
 833         while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
 834                 mdelay(1);
 835                 msecs--;
 836         }
 837
 838         /* Leave the nmi callback set */
 839 }
 840
 841 /*
 842  * Check if the crash dumping IPI got issued and if so, call its callback
 843  * directly. This function is used when we have already been in NMI handler.
 844  * It doesn't return.
 845  */
 846 void run_crash_ipi_callback(struct pt_regs *regs)
 847 {
 848         if (crash_ipi_issued)
 849                 crash_nmi_callback(0, regs);
 850 }
 851
 852 /* Override the weak function in kernel/panic.c */
 853 void nmi_panic_self_stop(struct pt_regs *regs)
 854 {
 855         while (1) {
 856                 /* If no CPU is preparing crash dump, we simply loop here. */
 857                 run_crash_ipi_callback(regs);
 858                 cpu_relax();
 859         }
 860 }
 861
 862 #else /* !CONFIG_SMP */
 863 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
 864 {
 865         /* No other CPUs to shoot down */
 866 }
 867
 868 void run_crash_ipi_callback(struct pt_regs *regs)
 869 {
 870 }
 871 #endif