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
 440         { }
 441 };
 442
 443 static int __init reboot_init(void)
 444 {
 445         int rv;
 446
 447         /*
 448          * Only do the DMI check if reboot_type hasn't been overridden
 449          * on the command line
 450          */
 451         if (!reboot_default)
 452                 return 0;
 453
 454         /*
 455          * The DMI quirks table takes precedence. If no quirks entry
 456          * matches and the ACPI Hardware Reduced bit is set, force EFI
 457          * reboot.
 458          */
 459         rv = dmi_check_system(reboot_dmi_table);
 460
 461         if (!rv && efi_reboot_required())
 462                 reboot_type = BOOT_EFI;
 463
 464         return 0;
 465 }
 466 core_initcall(reboot_init);
 467
 468 static inline void kb_wait(void)
 469 {
 470         int i;
 471
 472         for (i = 0; i < 0x10000; i++) {
 473                 if ((inb(0x64) & 0x02) == 0)
 474                         break;
 475                 udelay(2);
 476         }
 477 }
 478
 479 static void vmxoff_nmi(int cpu, struct pt_regs *regs)
 480 {
 481         cpu_emergency_vmxoff();
 482 }
 483
 484 /* Use NMIs as IPIs to tell all CPUs to disable virtualization */
 485 static void emergency_vmx_disable_all(void)
 486 {
 487         /* Just make sure we won't change CPUs while doing this */
 488         local_irq_disable();
 489
 490         /*
 491          * We need to disable VMX on all CPUs before rebooting, otherwise
 492          * we risk hanging up the machine, because the CPU ignore INIT
 493          * signals when VMX is enabled.
 494          *
 495          * We can't take any locks and we may be on an inconsistent
 496          * state, so we use NMIs as IPIs to tell the other CPUs to disable
 497          * VMX and halt.
 498          *
 499          * For safety, we will avoid running the nmi_shootdown_cpus()
 500          * stuff unnecessarily, but we don't have a way to check
 501          * if other CPUs have VMX enabled. So we will call it only if the
 502          * CPU we are running on has VMX enabled.
 503          *
 504          * We will miss cases where VMX is not enabled on all CPUs. This
 505          * shouldn't do much harm because KVM always enable VMX on all
 506          * CPUs anyway. But we can miss it on the small window where KVM
 507          * is still enabling VMX.
 508          */
 509         if (cpu_has_vmx() && cpu_vmx_enabled()) {
 510                 /* Disable VMX on this CPU. */
 511                 cpu_vmxoff();
 512
 513                 /* Halt and disable VMX on the other CPUs */
 514                 nmi_shootdown_cpus(vmxoff_nmi);
 515
 516         }
 517 }
 518
 519
 520 void __attribute__((weak)) mach_reboot_fixups(void)
 521 {
 522 }
 523
 524 /*
 525  * To the best of our knowledge Windows compatible x86 hardware expects
 526  * the following on reboot:
 527  *
 528  * 1) If the FADT has the ACPI reboot register flag set, try it
 529  * 2) If still alive, write to the keyboard controller
 530  * 3) If still alive, write to the ACPI reboot register again
 531  * 4) If still alive, write to the keyboard controller again
 532  * 5) If still alive, call the EFI runtime service to reboot
 533  * 6) If no EFI runtime service, call the BIOS to do a reboot
 534  *
 535  * We default to following the same pattern. We also have
 536  * two other reboot methods: 'triple fault' and 'PCI', which
 537  * can be triggered via the reboot= kernel boot option or
 538  * via quirks.
 539  *
 540  * This means that this function can never return, it can misbehave
 541  * by not rebooting properly and hanging.
 542  */
 543 static void native_machine_emergency_restart(void)
 544 {
 545         int i;
 546         int attempt = 0;
 547         int orig_reboot_type = reboot_type;
 548         unsigned short mode;
 549
 550         if (reboot_emergency)
 551                 emergency_vmx_disable_all();
 552
 553         tboot_shutdown(TB_SHUTDOWN_REBOOT);
 554
 555         /* Tell the BIOS if we want cold or warm reboot */
 556         mode = reboot_mode == REBOOT_WARM ? 0x1234 : 0;
 557         *((unsigned short *)__va(0x472)) = mode;
 558
 559         /*
 560          * If an EFI capsule has been registered with the firmware then
 561          * override the reboot= parameter.
 562          */
 563         if (efi_capsule_pending(NULL)) {
 564                 pr_info("EFI capsule is pending, forcing EFI reboot.\n");
 565                 reboot_type = BOOT_EFI;
 566         }
 567
 568         for (;;) {
 569                 /* Could also try the reset bit in the Hammer NB */
 570                 switch (reboot_type) {
 571                 case BOOT_ACPI:
 572                         acpi_reboot();
 573                         reboot_type = BOOT_KBD;
 574                         break;
 575
 576                 case BOOT_KBD:
 577                         mach_reboot_fixups(); /* For board specific fixups */
 578
 579                         for (i = 0; i < 10; i++) {
 580                                 kb_wait();
 581                                 udelay(50);
 582                                 outb(0xfe, 0x64); /* Pulse reset low */
 583                                 udelay(50);
 584                         }
 585                         if (attempt == 0 && orig_reboot_type == BOOT_ACPI) {
 586                                 attempt = 1;
 587                                 reboot_type = BOOT_ACPI;
 588                         } else {
 589                                 reboot_type = BOOT_EFI;
 590                         }
 591                         break;
 592
 593                 case BOOT_EFI:
 594                         efi_reboot(reboot_mode, NULL);
 595                         reboot_type = BOOT_BIOS;
 596                         break;
 597
 598                 case BOOT_BIOS:
 599                         machine_real_restart(MRR_BIOS);
 600
 601                         /* We're probably dead after this, but... */
 602                         reboot_type = BOOT_CF9_SAFE;
 603                         break;
 604
 605                 case BOOT_CF9_FORCE:
 606                         port_cf9_safe = true;
 607                         /* Fall through */
 608
 609                 case BOOT_CF9_SAFE:
 610                         if (port_cf9_safe) {
 611                                 u8 reboot_code = reboot_mode == REBOOT_WARM ?  0x06 : 0x0E;
 612                                 u8 cf9 = inb(0xcf9) & ~reboot_code;
 613                                 outb(cf9|2, 0xcf9); /* Request hard reset */
 614                                 udelay(50);
 615                                 /* Actually do the reset */
 616                                 outb(cf9|reboot_code, 0xcf9);
 617                                 udelay(50);
 618                         }
 619                         reboot_type = BOOT_TRIPLE;
 620                         break;
 621
 622                 case BOOT_TRIPLE:
 623                         load_idt(&no_idt);
 624                         __asm__ __volatile__("int3");
 625
 626                         /* We're probably dead after this, but... */
 627                         reboot_type = BOOT_KBD;
 628                         break;
 629                 }
 630         }
 631 }
 632
 633 void native_machine_shutdown(void)
 634 {
 635         /* Stop the cpus and apics */
 636 #ifdef CONFIG_X86_IO_APIC
 637         /*
 638          * Disabling IO APIC before local APIC is a workaround for
 639          * erratum AVR31 in "Intel Atom Processor C2000 Product Family
 640          * Specification Update". In this situation, interrupts that target
 641          * a Logical Processor whose Local APIC is either in the process of
 642          * being hardware disabled or software disabled are neither delivered
 643          * nor discarded. When this erratum occurs, the processor may hang.
 644          *
 645          * Even without the erratum, it still makes sense to quiet IO APIC
 646          * before disabling Local APIC.
 647          */
 648         disable_IO_APIC();
 649 #endif
 650
 651 #ifdef CONFIG_SMP
 652         /*
 653          * Stop all of the others. Also disable the local irq to
 654          * not receive the per-cpu timer interrupt which may trigger
 655          * scheduler's load balance.
 656          */
 657         local_irq_disable();
 658         stop_other_cpus();
 659 #endif
 660
 661         lapic_shutdown();
 662
 663 #ifdef CONFIG_HPET_TIMER
 664         hpet_disable();
 665 #endif
 666
 667 #ifdef CONFIG_X86_64
 668         x86_platform.iommu_shutdown();
 669 #endif
 670 }
 671
 672 static void __machine_emergency_restart(int emergency)
 673 {
 674         reboot_emergency = emergency;
 675         machine_ops.emergency_restart();
 676 }
 677
 678 static void native_machine_restart(char *__unused)
 679 {
 680         pr_notice("machine restart\n");
 681
 682         if (!reboot_force)
 683                 machine_shutdown();
 684         __machine_emergency_restart(0);
 685 }
 686
 687 static void native_machine_halt(void)
 688 {
 689         /* Stop other cpus and apics */
 690         machine_shutdown();
 691
 692         tboot_shutdown(TB_SHUTDOWN_HALT);
 693
 694         stop_this_cpu(NULL);
 695 }
 696
 697 static void native_machine_power_off(void)
 698 {
 699         if (pm_power_off) {
 700                 if (!reboot_force)
 701                         machine_shutdown();
 702                 pm_power_off();
 703         }
 704         /* A fallback in case there is no PM info available */
 705         tboot_shutdown(TB_SHUTDOWN_HALT);
 706 }
 707
 708 struct machine_ops machine_ops = {
 709         .power_off = native_machine_power_off,
 710         .shutdown = native_machine_shutdown,
 711         .emergency_restart = native_machine_emergency_restart,
 712         .restart = native_machine_restart,
 713         .halt = native_machine_halt,
 714 #ifdef CONFIG_KEXEC_CORE
 715         .crash_shutdown = native_machine_crash_shutdown,
 716 #endif
 717 };
 718
 719 void machine_power_off(void)
 720 {
 721         machine_ops.power_off();
 722 }
 723
 724 void machine_shutdown(void)
 725 {
 726         machine_ops.shutdown();
 727 }
 728
 729 void machine_emergency_restart(void)
 730 {
 731         __machine_emergency_restart(1);
 732 }
 733
 734 void machine_restart(char *cmd)
 735 {
 736         machine_ops.restart(cmd);
 737 }
 738
 739 void machine_halt(void)
 740 {
 741         machine_ops.halt();
 742 }
 743
 744 #ifdef CONFIG_KEXEC_CORE
 745 void machine_crash_shutdown(struct pt_regs *regs)
 746 {
 747         machine_ops.crash_shutdown(regs);
 748 }
 749 #endif
 750
 751
 752 #if defined(CONFIG_SMP)
 753
 754 /* This keeps a track of which one is crashing cpu. */
 755 static int crashing_cpu;
 756 static nmi_shootdown_cb shootdown_callback;
 757
 758 static atomic_t waiting_for_crash_ipi;
 759 static int crash_ipi_issued;
 760
 761 static int crash_nmi_callback(unsigned int val, struct pt_regs *regs)
 762 {
 763         int cpu;
 764
 765         cpu = raw_smp_processor_id();
 766
 767         /*
 768          * Don't do anything if this handler is invoked on crashing cpu.
 769          * Otherwise, system will completely hang. Crashing cpu can get
 770          * an NMI if system was initially booted with nmi_watchdog parameter.
 771          */
 772         if (cpu == crashing_cpu)
 773                 return NMI_HANDLED;
 774         local_irq_disable();
 775
 776         shootdown_callback(cpu, regs);
 777
 778         atomic_dec(&waiting_for_crash_ipi);
 779         /* Assume hlt works */
 780         halt();
 781         for (;;)
 782                 cpu_relax();
 783
 784         return NMI_HANDLED;
 785 }
 786
 787 static void smp_send_nmi_allbutself(void)
 788 {
 789         apic->send_IPI_allbutself(NMI_VECTOR);
 790 }
 791
 792 /*
 793  * Halt all other CPUs, calling the specified function on each of them
 794  *
 795  * This function can be used to halt all other CPUs on crash
 796  * or emergency reboot time. The function passed as parameter
 797  * will be called inside a NMI handler on all CPUs.
 798  */
 799 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
 800 {
 801         unsigned long msecs;
 802         local_irq_disable();
 803
 804         /* Make a note of crashing cpu. Will be used in NMI callback. */
 805         crashing_cpu = safe_smp_processor_id();
 806
 807         shootdown_callback = callback;
 808
 809         atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
 810         /* Would it be better to replace the trap vector here? */
 811         if (register_nmi_handler(NMI_LOCAL, crash_nmi_callback,
 812                                  NMI_FLAG_FIRST, "crash"))
 813                 return;         /* Return what? */
 814         /*
 815          * Ensure the new callback function is set before sending
 816          * out the NMI
 817          */
 818         wmb();
 819
 820         smp_send_nmi_allbutself();
 821
 822         /* Kick CPUs looping in NMI context. */
 823         WRITE_ONCE(crash_ipi_issued, 1);
 824
 825         msecs = 1000; /* Wait at most a second for the other cpus to stop */
 826         while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
 827                 mdelay(1);
 828                 msecs--;
 829         }
 830
 831         /* Leave the nmi callback set */
 832 }
 833
 834 /*
 835  * Check if the crash dumping IPI got issued and if so, call its callback
 836  * directly. This function is used when we have already been in NMI handler.
 837  * It doesn't return.
 838  */
 839 void run_crash_ipi_callback(struct pt_regs *regs)
 840 {
 841         if (crash_ipi_issued)
 842                 crash_nmi_callback(0, regs);
 843 }
 844
 845 /* Override the weak function in kernel/panic.c */
 846 void nmi_panic_self_stop(struct pt_regs *regs)
 847 {
 848         while (1) {
 849                 /* If no CPU is preparing crash dump, we simply loop here. */
 850                 run_crash_ipi_callback(regs);
 851                 cpu_relax();
 852         }
 853 }
 854
 855 #else /* !CONFIG_SMP */
 856 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
 857 {
 858         /* No other CPUs to shoot down */
 859 }
 860
 861 void run_crash_ipi_callback(struct pt_regs *regs)
 862 {
 863 }
 864 #endif