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 <linux/frame.h>
  13 #include <acpi/reboot.h>
  14 #include <asm/io.h>
  15 #include <asm/apic.h>
  16 #include <asm/io_apic.h>
  17 #include <asm/desc.h>
  18 #include <asm/hpet.h>
  19 #include <asm/pgtable.h>
  20 #include <asm/proto.h>
  21 #include <asm/reboot_fixups.h>
  22 #include <asm/reboot.h>
  23 #include <asm/pci_x86.h>
  24 #include <asm/virtext.h>
  25 #include <asm/cpu.h>
  26 #include <asm/nmi.h>
  27 #include <asm/smp.h>
  28
  29 #include <linux/ctype.h>
  30 #include <linux/mc146818rtc.h>
  31 #include <asm/realmode.h>
  32 #include <asm/x86_init.h>
  33 #include <asm/efi.h>
  34
  35 /*
  36  * Power off function, if any
  37  */
  38 void (*pm_power_off)(void);
  39 EXPORT_SYMBOL(pm_power_off);
  40
  41 static const struct desc_ptr no_idt = {};
  42
  43 /*
  44  * This is set if we need to go through the 'emergency' path.
  45  * When machine_emergency_restart() is called, we may be on
  46  * an inconsistent state and won't be able to do a clean cleanup
  47  */
  48 static int reboot_emergency;
  49
  50 /* This is set by the PCI code if either type 1 or type 2 PCI is detected */
  51 bool port_cf9_safe = false;
  52
  53 /*
  54  * Reboot options and system auto-detection code provided by
  55  * Dell Inc. so their systems "just work". :-)
  56  */
  57
  58 /*
  59  * Some machines require the "reboot=a" commandline options
  60  */
  61 static int __init set_acpi_reboot(const struct dmi_system_id *d)
  62 {
  63         if (reboot_type != BOOT_ACPI) {
  64                 reboot_type = BOOT_ACPI;
  65                 pr_info("%s series board detected. Selecting %s-method for reboots.\n",
  66                         d->ident, "ACPI");
  67         }
  68         return 0;
  69 }
  70
  71 /*
  72  * Some machines require the "reboot=b" or "reboot=k"  commandline options,
  73  * this quirk makes that automatic.
  74  */
  75 static int __init set_bios_reboot(const struct dmi_system_id *d)
  76 {
  77         if (reboot_type != BOOT_BIOS) {
  78                 reboot_type = BOOT_BIOS;
  79                 pr_info("%s series board detected. Selecting %s-method for reboots.\n",
  80                         d->ident, "BIOS");
  81         }
  82         return 0;
  83 }
  84
  85 void __noreturn machine_real_restart(unsigned int type)
  86 {
  87         local_irq_disable();
  88
  89         /*
  90          * Write zero to CMOS register number 0x0f, which the BIOS POST
  91          * routine will recognize as telling it to do a proper reboot.  (Well
  92          * that's what this book in front of me says -- it may only apply to
  93          * the Phoenix BIOS though, it's not clear).  At the same time,
  94          * disable NMIs by setting the top bit in the CMOS address register,
  95          * as we're about to do peculiar things to the CPU.  I'm not sure if
  96          * `outb_p' is needed instead of just `outb'.  Use it to be on the
  97          * safe side.  (Yes, CMOS_WRITE does outb_p's. -  Paul G.)
  98          */
  99         spin_lock(&rtc_lock);
 100         CMOS_WRITE(0x00, 0x8f);
 101         spin_unlock(&rtc_lock);
 102
 103         /*
 104          * Switch back to the initial page table.
 105          */
 106 #ifdef CONFIG_X86_32
 107         load_cr3(initial_page_table);
 108 #else
 109         write_cr3(real_mode_header->trampoline_pgd);
 110 #endif
 111
 112         /* Jump to the identity-mapped low memory code */
 113 #ifdef CONFIG_X86_32
 114         asm volatile("jmpl *%0" : :
 115                      "rm" (real_mode_header->machine_real_restart_asm),
 116                      "a" (type));
 117 #else
 118         asm volatile("ljmpl *%0" : :
 119                      "m" (real_mode_header->machine_real_restart_asm),
 120                      "D" (type));
 121 #endif
 122         unreachable();
 123 }
 124 #ifdef CONFIG_APM_MODULE
 125 EXPORT_SYMBOL(machine_real_restart);
 126 #endif
 127 STACK_FRAME_NON_STANDARD(machine_real_restart);
 128
 129 /*
 130  * Some Apple MacBook and MacBookPro's needs reboot=p to be able to reboot
 131  */
 132 static int __init set_pci_reboot(const struct dmi_system_id *d)
 133 {
 134         if (reboot_type != BOOT_CF9_FORCE) {
 135                 reboot_type = BOOT_CF9_FORCE;
 136                 pr_info("%s series board detected. Selecting %s-method for reboots.\n",
 137                         d->ident, "PCI");
 138         }
 139         return 0;
 140 }
 141
 142 static int __init set_kbd_reboot(const struct dmi_system_id *d)
 143 {
 144         if (reboot_type != BOOT_KBD) {
 145                 reboot_type = BOOT_KBD;
 146                 pr_info("%s series board detected. Selecting %s-method for reboot.\n",
 147                         d->ident, "KBD");
 148         }
 149         return 0;
 150 }
 151
 152 /*
 153  * This is a single dmi_table handling all reboot quirks.
 154  */
 155 static struct dmi_system_id __initdata reboot_dmi_table[] = {
 156
 157         /* Acer */
 158         {       /* Handle reboot issue on Acer Aspire one */
 159                 .callback = set_kbd_reboot,
 160                 .ident = "Acer Aspire One A110",
 161                 .matches = {
 162                         DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
 163                         DMI_MATCH(DMI_PRODUCT_NAME, "AOA110"),
 164                 },
 165         },
 166
 167         /* Apple */
 168         {       /* Handle problems with rebooting on Apple MacBook5 */
 169                 .callback = set_pci_reboot,
 170                 .ident = "Apple MacBook5",
 171                 .matches = {
 172                         DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 173                         DMI_MATCH(DMI_PRODUCT_NAME, "MacBook5"),
 174                 },
 175         },
 176         {       /* Handle problems with rebooting on Apple MacBookPro5 */
 177                 .callback = set_pci_reboot,
 178                 .ident = "Apple MacBookPro5",
 179                 .matches = {
 180                         DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 181                         DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro5"),
 182                 },
 183         },
 184         {       /* Handle problems with rebooting on Apple Macmini3,1 */
 185                 .callback = set_pci_reboot,
 186                 .ident = "Apple Macmini3,1",
 187                 .matches = {
 188                         DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 189                         DMI_MATCH(DMI_PRODUCT_NAME, "Macmini3,1"),
 190                 },
 191         },
 192         {       /* Handle problems with rebooting on the iMac9,1. */
 193                 .callback = set_pci_reboot,
 194                 .ident = "Apple iMac9,1",
 195                 .matches = {
 196                         DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 197                         DMI_MATCH(DMI_PRODUCT_NAME, "iMac9,1"),
 198                 },
 199         },
 200         {       /* Handle problems with rebooting on the iMac10,1. */
 201                 .callback = set_pci_reboot,
 202                 .ident = "Apple iMac10,1",
 203                 .matches = {
 204                     DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 205                     DMI_MATCH(DMI_PRODUCT_NAME, "iMac10,1"),
 206                 },
 207         },
 208
 209         /* ASRock */
 210         {       /* Handle problems with rebooting on ASRock Q1900DC-ITX */
 211                 .callback = set_pci_reboot,
 212                 .ident = "ASRock Q1900DC-ITX",
 213                 .matches = {
 214                         DMI_MATCH(DMI_BOARD_VENDOR, "ASRock"),
 215                         DMI_MATCH(DMI_BOARD_NAME, "Q1900DC-ITX"),
 216                 },
 217         },
 218
 219         /* ASUS */
 220         {       /* Handle problems with rebooting on ASUS P4S800 */
 221                 .callback = set_bios_reboot,
 222                 .ident = "ASUS P4S800",
 223                 .matches = {
 224                         DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
 225                         DMI_MATCH(DMI_BOARD_NAME, "P4S800"),
 226                 },
 227         },
 228         {       /* Handle problems with rebooting on ASUS EeeBook X205TA */
 229                 .callback = set_acpi_reboot,
 230                 .ident = "ASUS EeeBook X205TA",
 231                 .matches = {
 232                         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
 233                         DMI_MATCH(DMI_PRODUCT_NAME, "X205TA"),
 234                 },
 235         },
 236         {       /* Handle problems with rebooting on ASUS EeeBook X205TAW */
 237                 .callback = set_acpi_reboot,
 238                 .ident = "ASUS EeeBook X205TAW",
 239                 .matches = {
 240                         DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
 241                         DMI_MATCH(DMI_PRODUCT_NAME, "X205TAW"),
 242                 },
 243         },
 244
 245         /* Certec */
 246         {       /* Handle problems with rebooting on Certec BPC600 */
 247                 .callback = set_pci_reboot,
 248                 .ident = "Certec BPC600",
 249                 .matches = {
 250                         DMI_MATCH(DMI_SYS_VENDOR, "Certec"),
 251                         DMI_MATCH(DMI_PRODUCT_NAME, "BPC600"),
 252                 },
 253         },
 254
 255         /* Dell */
 256         {       /* Handle problems with rebooting on Dell DXP061 */
 257                 .callback = set_bios_reboot,
 258                 .ident = "Dell DXP061",
 259                 .matches = {
 260                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 261                         DMI_MATCH(DMI_PRODUCT_NAME, "Dell DXP061"),
 262                 },
 263         },
 264         {       /* Handle problems with rebooting on Dell E520's */
 265                 .callback = set_bios_reboot,
 266                 .ident = "Dell E520",
 267                 .matches = {
 268                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 269                         DMI_MATCH(DMI_PRODUCT_NAME, "Dell DM061"),
 270                 },
 271         },
 272         {       /* Handle problems with rebooting on the Latitude E5410. */
 273                 .callback = set_pci_reboot,
 274                 .ident = "Dell Latitude E5410",
 275                 .matches = {
 276                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 277                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E5410"),
 278                 },
 279         },
 280         {       /* Handle problems with rebooting on the Latitude E5420. */
 281                 .callback = set_pci_reboot,
 282                 .ident = "Dell Latitude E5420",
 283                 .matches = {
 284                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 285                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E5420"),
 286                 },
 287         },
 288         {       /* Handle problems with rebooting on the Latitude E6320. */
 289                 .callback = set_pci_reboot,
 290                 .ident = "Dell Latitude E6320",
 291                 .matches = {
 292                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 293                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6320"),
 294                 },
 295         },
 296         {       /* Handle problems with rebooting on the Latitude E6420. */
 297                 .callback = set_pci_reboot,
 298                 .ident = "Dell Latitude E6420",
 299                 .matches = {
 300                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 301                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6420"),
 302                 },
 303         },
 304         {       /* Handle problems with rebooting on Dell Optiplex 330 with 0KP561 */
 305                 .callback = set_bios_reboot,
 306                 .ident = "Dell OptiPlex 330",
 307                 .matches = {
 308                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 309                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 330"),
 310                         DMI_MATCH(DMI_BOARD_NAME, "0KP561"),
 311                 },
 312         },
 313         {       /* Handle problems with rebooting on Dell Optiplex 360 with 0T656F */
 314                 .callback = set_bios_reboot,
 315                 .ident = "Dell OptiPlex 360",
 316                 .matches = {
 317                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 318                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 360"),
 319                         DMI_MATCH(DMI_BOARD_NAME, "0T656F"),
 320                 },
 321         },
 322         {       /* Handle problems with rebooting on Dell Optiplex 745's SFF */
 323                 .callback = set_bios_reboot,
 324                 .ident = "Dell OptiPlex 745",
 325                 .matches = {
 326                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 327                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
 328                 },
 329         },
 330         {       /* Handle problems with rebooting on Dell Optiplex 745's DFF */
 331                 .callback = set_bios_reboot,
 332                 .ident = "Dell OptiPlex 745",
 333                 .matches = {
 334                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 335                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
 336                         DMI_MATCH(DMI_BOARD_NAME, "0MM599"),
 337                 },
 338         },
 339         {       /* Handle problems with rebooting on Dell Optiplex 745 with 0KW626 */
 340                 .callback = set_bios_reboot,
 341                 .ident = "Dell OptiPlex 745",
 342                 .matches = {
 343                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 344                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
 345                         DMI_MATCH(DMI_BOARD_NAME, "0KW626"),
 346                 },
 347         },
 348         {       /* Handle problems with rebooting on Dell OptiPlex 760 with 0G919G */
 349                 .callback = set_bios_reboot,
 350                 .ident = "Dell OptiPlex 760",
 351                 .matches = {
 352                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 353                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 760"),
 354                         DMI_MATCH(DMI_BOARD_NAME, "0G919G"),
 355                 },
 356         },
 357         {       /* Handle problems with rebooting on the OptiPlex 990. */
 358                 .callback = set_pci_reboot,
 359                 .ident = "Dell OptiPlex 990",
 360                 .matches = {
 361                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 362                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 990"),
 363                 },
 364         },
 365         {       /* Handle problems with rebooting on Dell 300's */
 366                 .callback = set_bios_reboot,
 367                 .ident = "Dell PowerEdge 300",
 368                 .matches = {
 369                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 370                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"),
 371                 },
 372         },
 373         {       /* Handle problems with rebooting on Dell 1300's */
 374                 .callback = set_bios_reboot,
 375                 .ident = "Dell PowerEdge 1300",
 376                 .matches = {
 377                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 378                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1300/"),
 379                 },
 380         },
 381         {       /* Handle problems with rebooting on Dell 2400's */
 382                 .callback = set_bios_reboot,
 383                 .ident = "Dell PowerEdge 2400",
 384                 .matches = {
 385                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 386                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"),
 387                 },
 388         },
 389         {       /* Handle problems with rebooting on the Dell PowerEdge C6100. */
 390                 .callback = set_pci_reboot,
 391                 .ident = "Dell PowerEdge C6100",
 392                 .matches = {
 393                         DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
 394                         DMI_MATCH(DMI_PRODUCT_NAME, "C6100"),
 395                 },
 396         },
 397         {       /* Handle problems with rebooting on the Precision M6600. */
 398                 .callback = set_pci_reboot,
 399                 .ident = "Dell Precision M6600",
 400                 .matches = {
 401                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 402                         DMI_MATCH(DMI_PRODUCT_NAME, "Precision M6600"),
 403                 },
 404         },
 405         {       /* Handle problems with rebooting on Dell T5400's */
 406                 .callback = set_bios_reboot,
 407                 .ident = "Dell Precision T5400",
 408                 .matches = {
 409                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 410                         DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T5400"),
 411                 },
 412         },
 413         {       /* Handle problems with rebooting on Dell T7400's */
 414                 .callback = set_bios_reboot,
 415                 .ident = "Dell Precision T7400",
 416                 .matches = {
 417                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 418                         DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T7400"),
 419                 },
 420         },
 421         {       /* Handle problems with rebooting on Dell XPS710 */
 422                 .callback = set_bios_reboot,
 423                 .ident = "Dell XPS710",
 424                 .matches = {
 425                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 426                         DMI_MATCH(DMI_PRODUCT_NAME, "Dell XPS710"),
 427                 },
 428         },
 429         {       /* Handle problems with rebooting on Dell Optiplex 7450 AIO */
 430                 .callback = set_acpi_reboot,
 431                 .ident = "Dell OptiPlex 7450 AIO",
 432                 .matches = {
 433                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 434                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 7450 AIO"),
 435                 },
 436         },
 437
 438         /* Hewlett-Packard */
 439         {       /* Handle problems with rebooting on HP laptops */
 440                 .callback = set_bios_reboot,
 441                 .ident = "HP Compaq Laptop",
 442                 .matches = {
 443                         DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 444                         DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"),
 445                 },
 446         },
 447
 448         /* Sony */
 449         {       /* Handle problems with rebooting on Sony VGN-Z540N */
 450                 .callback = set_bios_reboot,
 451                 .ident = "Sony VGN-Z540N",
 452                 .matches = {
 453                         DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
 454                         DMI_MATCH(DMI_PRODUCT_NAME, "VGN-Z540N"),
 455                 },
 456         },
 457
 458         { }
 459 };
 460
 461 static int __init reboot_init(void)
 462 {
 463         int rv;
 464
 465         /*
 466          * Only do the DMI check if reboot_type hasn't been overridden
 467          * on the command line
 468          */
 469         if (!reboot_default)
 470                 return 0;
 471
 472         /*
 473          * The DMI quirks table takes precedence. If no quirks entry
 474          * matches and the ACPI Hardware Reduced bit is set and EFI
 475          * runtime services are enabled, force EFI reboot.
 476          */
 477         rv = dmi_check_system(reboot_dmi_table);
 478
 479         if (!rv && efi_reboot_required() && !efi_runtime_disabled())
 480                 reboot_type = BOOT_EFI;
 481
 482         return 0;
 483 }
 484 core_initcall(reboot_init);
 485
 486 static inline void kb_wait(void)
 487 {
 488         int i;
 489
 490         for (i = 0; i < 0x10000; i++) {
 491                 if ((inb(0x64) & 0x02) == 0)
 492                         break;
 493                 udelay(2);
 494         }
 495 }
 496
 497 static void vmxoff_nmi(int cpu, struct pt_regs *regs)
 498 {
 499         cpu_emergency_vmxoff();
 500 }
 501
 502 /* Use NMIs as IPIs to tell all CPUs to disable virtualization */
 503 static void emergency_vmx_disable_all(void)
 504 {
 505         /* Just make sure we won't change CPUs while doing this */
 506         local_irq_disable();
 507
 508         /*
 509          * We need to disable VMX on all CPUs before rebooting, otherwise
 510          * we risk hanging up the machine, because the CPU ignore INIT
 511          * signals when VMX is enabled.
 512          *
 513          * We can't take any locks and we may be on an inconsistent
 514          * state, so we use NMIs as IPIs to tell the other CPUs to disable
 515          * VMX and halt.
 516          *
 517          * For safety, we will avoid running the nmi_shootdown_cpus()
 518          * stuff unnecessarily, but we don't have a way to check
 519          * if other CPUs have VMX enabled. So we will call it only if the
 520          * CPU we are running on has VMX enabled.
 521          *
 522          * We will miss cases where VMX is not enabled on all CPUs. This
 523          * shouldn't do much harm because KVM always enable VMX on all
 524          * CPUs anyway. But we can miss it on the small window where KVM
 525          * is still enabling VMX.
 526          */
 527         if (cpu_has_vmx() && cpu_vmx_enabled()) {
 528                 /* Disable VMX on this CPU. */
 529                 cpu_vmxoff();
 530
 531                 /* Halt and disable VMX on the other CPUs */
 532                 nmi_shootdown_cpus(vmxoff_nmi);
 533
 534         }
 535 }
 536
 537
 538 void __attribute__((weak)) mach_reboot_fixups(void)
 539 {
 540 }
 541
 542 /*
 543  * To the best of our knowledge Windows compatible x86 hardware expects
 544  * the following on reboot:
 545  *
 546  * 1) If the FADT has the ACPI reboot register flag set, try it
 547  * 2) If still alive, write to the keyboard controller
 548  * 3) If still alive, write to the ACPI reboot register again
 549  * 4) If still alive, write to the keyboard controller again
 550  * 5) If still alive, call the EFI runtime service to reboot
 551  * 6) If no EFI runtime service, call the BIOS to do a reboot
 552  *
 553  * We default to following the same pattern. We also have
 554  * two other reboot methods: 'triple fault' and 'PCI', which
 555  * can be triggered via the reboot= kernel boot option or
 556  * via quirks.
 557  *
 558  * This means that this function can never return, it can misbehave
 559  * by not rebooting properly and hanging.
 560  */
 561 static void native_machine_emergency_restart(void)
 562 {
 563         int i;
 564         int attempt = 0;
 565         int orig_reboot_type = reboot_type;
 566         unsigned short mode;
 567
 568         if (reboot_emergency)
 569                 emergency_vmx_disable_all();
 570
 571         tboot_shutdown(TB_SHUTDOWN_REBOOT);
 572
 573         /* Tell the BIOS if we want cold or warm reboot */
 574         mode = reboot_mode == REBOOT_WARM ? 0x1234 : 0;
 575         *((unsigned short *)__va(0x472)) = mode;
 576
 577         /*
 578          * If an EFI capsule has been registered with the firmware then
 579          * override the reboot= parameter.
 580          */
 581         if (efi_capsule_pending(NULL)) {
 582                 pr_info("EFI capsule is pending, forcing EFI reboot.\n");
 583                 reboot_type = BOOT_EFI;
 584         }
 585
 586         for (;;) {
 587                 /* Could also try the reset bit in the Hammer NB */
 588                 switch (reboot_type) {
 589                 case BOOT_ACPI:
 590                         acpi_reboot();
 591                         reboot_type = BOOT_KBD;
 592                         break;
 593
 594                 case BOOT_KBD:
 595                         mach_reboot_fixups(); /* For board specific fixups */
 596
 597                         for (i = 0; i < 10; i++) {
 598                                 kb_wait();
 599                                 udelay(50);
 600                                 outb(0xfe, 0x64); /* Pulse reset low */
 601                                 udelay(50);
 602                         }
 603                         if (attempt == 0 && orig_reboot_type == BOOT_ACPI) {
 604                                 attempt = 1;
 605                                 reboot_type = BOOT_ACPI;
 606                         } else {
 607                                 reboot_type = BOOT_EFI;
 608                         }
 609                         break;
 610
 611                 case BOOT_EFI:
 612                         efi_reboot(reboot_mode, NULL);
 613                         reboot_type = BOOT_BIOS;
 614                         break;
 615
 616                 case BOOT_BIOS:
 617                         machine_real_restart(MRR_BIOS);
 618
 619                         /* We're probably dead after this, but... */
 620                         reboot_type = BOOT_CF9_SAFE;
 621                         break;
 622
 623                 case BOOT_CF9_FORCE:
 624                         port_cf9_safe = true;
 625                         /* Fall through */
 626
 627                 case BOOT_CF9_SAFE:
 628                         if (port_cf9_safe) {
 629                                 u8 reboot_code = reboot_mode == REBOOT_WARM ?  0x06 : 0x0E;
 630                                 u8 cf9 = inb(0xcf9) & ~reboot_code;
 631                                 outb(cf9|2, 0xcf9); /* Request hard reset */
 632                                 udelay(50);
 633                                 /* Actually do the reset */
 634                                 outb(cf9|reboot_code, 0xcf9);
 635                                 udelay(50);
 636                         }
 637                         reboot_type = BOOT_TRIPLE;
 638                         break;
 639
 640                 case BOOT_TRIPLE:
 641                         load_idt(&no_idt);
 642                         __asm__ __volatile__("int3");
 643
 644                         /* We're probably dead after this, but... */
 645                         reboot_type = BOOT_KBD;
 646                         break;
 647                 }
 648         }
 649 }
 650
 651 void native_machine_shutdown(void)
 652 {
 653         /* Stop the cpus and apics */
 654 #ifdef CONFIG_X86_IO_APIC
 655         /*
 656          * Disabling IO APIC before local APIC is a workaround for
 657          * erratum AVR31 in "Intel Atom Processor C2000 Product Family
 658          * Specification Update". In this situation, interrupts that target
 659          * a Logical Processor whose Local APIC is either in the process of
 660          * being hardware disabled or software disabled are neither delivered
 661          * nor discarded. When this erratum occurs, the processor may hang.
 662          *
 663          * Even without the erratum, it still makes sense to quiet IO APIC
 664          * before disabling Local APIC.
 665          */
 666         disable_IO_APIC();
 667 #endif
 668
 669 #ifdef CONFIG_SMP
 670         /*
 671          * Stop all of the others. Also disable the local irq to
 672          * not receive the per-cpu timer interrupt which may trigger
 673          * scheduler's load balance.
 674          */
 675         local_irq_disable();
 676         stop_other_cpus();
 677 #endif
 678
 679         lapic_shutdown();
 680
 681 #ifdef CONFIG_HPET_TIMER
 682         hpet_disable();
 683 #endif
 684
 685 #ifdef CONFIG_X86_64
 686         x86_platform.iommu_shutdown();
 687 #endif
 688 }
 689
 690 static void __machine_emergency_restart(int emergency)
 691 {
 692         reboot_emergency = emergency;
 693         machine_ops.emergency_restart();
 694 }
 695
 696 static void native_machine_restart(char *__unused)
 697 {
 698         pr_notice("machine restart\n");
 699
 700         if (!reboot_force)
 701                 machine_shutdown();
 702         __machine_emergency_restart(0);
 703 }
 704
 705 static void native_machine_halt(void)
 706 {
 707         /* Stop other cpus and apics */
 708         machine_shutdown();
 709
 710         tboot_shutdown(TB_SHUTDOWN_HALT);
 711
 712         stop_this_cpu(NULL);
 713 }
 714
 715 static void native_machine_power_off(void)
 716 {
 717         if (pm_power_off) {
 718                 if (!reboot_force)
 719                         machine_shutdown();
 720                 pm_power_off();
 721         }
 722         /* A fallback in case there is no PM info available */
 723         tboot_shutdown(TB_SHUTDOWN_HALT);
 724 }
 725
 726 struct machine_ops machine_ops __ro_after_init = {
 727         .power_off = native_machine_power_off,
 728         .shutdown = native_machine_shutdown,
 729         .emergency_restart = native_machine_emergency_restart,
 730         .restart = native_machine_restart,
 731         .halt = native_machine_halt,
 732 #ifdef CONFIG_KEXEC_CORE
 733         .crash_shutdown = native_machine_crash_shutdown,
 734 #endif
 735 };
 736
 737 void machine_power_off(void)
 738 {
 739         machine_ops.power_off();
 740 }
 741
 742 void machine_shutdown(void)
 743 {
 744         machine_ops.shutdown();
 745 }
 746
 747 void machine_emergency_restart(void)
 748 {
 749         __machine_emergency_restart(1);
 750 }
 751
 752 void machine_restart(char *cmd)
 753 {
 754         machine_ops.restart(cmd);
 755 }
 756
 757 void machine_halt(void)
 758 {
 759         machine_ops.halt();
 760 }
 761
 762 #ifdef CONFIG_KEXEC_CORE
 763 void machine_crash_shutdown(struct pt_regs *regs)
 764 {
 765         machine_ops.crash_shutdown(regs);
 766 }
 767 #endif
 768
 769
 770 /* This is the CPU performing the emergency shutdown work. */
 771 int crashing_cpu = -1;
 772
 773 #if defined(CONFIG_SMP)
 774
 775 static nmi_shootdown_cb shootdown_callback;
 776
 777 static atomic_t waiting_for_crash_ipi;
 778 static int crash_ipi_issued;
 779
 780 static int crash_nmi_callback(unsigned int val, struct pt_regs *regs)
 781 {
 782         int cpu;
 783
 784         cpu = raw_smp_processor_id();
 785
 786         /*
 787          * Don't do anything if this handler is invoked on crashing cpu.
 788          * Otherwise, system will completely hang. Crashing cpu can get
 789          * an NMI if system was initially booted with nmi_watchdog parameter.
 790          */
 791         if (cpu == crashing_cpu)
 792                 return NMI_HANDLED;
 793         local_irq_disable();
 794
 795         shootdown_callback(cpu, regs);
 796
 797         atomic_dec(&waiting_for_crash_ipi);
 798         /* Assume hlt works */
 799         halt();
 800         for (;;)
 801                 cpu_relax();
 802
 803         return NMI_HANDLED;
 804 }
 805
 806 static void smp_send_nmi_allbutself(void)
 807 {
 808         apic->send_IPI_allbutself(NMI_VECTOR);
 809 }
 810
 811 /*
 812  * Halt all other CPUs, calling the specified function on each of them
 813  *
 814  * This function can be used to halt all other CPUs on crash
 815  * or emergency reboot time. The function passed as parameter
 816  * will be called inside a NMI handler on all CPUs.
 817  */
 818 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
 819 {
 820         unsigned long msecs;
 821         local_irq_disable();
 822
 823         /* Make a note of crashing cpu. Will be used in NMI callback. */
 824         crashing_cpu = safe_smp_processor_id();
 825
 826         shootdown_callback = callback;
 827
 828         atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
 829         /* Would it be better to replace the trap vector here? */
 830         if (register_nmi_handler(NMI_LOCAL, crash_nmi_callback,
 831                                  NMI_FLAG_FIRST, "crash"))
 832                 return;         /* Return what? */
 833         /*
 834          * Ensure the new callback function is set before sending
 835          * out the NMI
 836          */
 837         wmb();
 838
 839         smp_send_nmi_allbutself();
 840
 841         /* Kick CPUs looping in NMI context. */
 842         WRITE_ONCE(crash_ipi_issued, 1);
 843
 844         msecs = 1000; /* Wait at most a second for the other cpus to stop */
 845         while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
 846                 mdelay(1);
 847                 msecs--;
 848         }
 849
 850         /* Leave the nmi callback set */
 851 }
 852
 853 /*
 854  * Check if the crash dumping IPI got issued and if so, call its callback
 855  * directly. This function is used when we have already been in NMI handler.
 856  * It doesn't return.
 857  */
 858 void run_crash_ipi_callback(struct pt_regs *regs)
 859 {
 860         if (crash_ipi_issued)
 861                 crash_nmi_callback(0, regs);
 862 }
 863
 864 /* Override the weak function in kernel/panic.c */
 865 void nmi_panic_self_stop(struct pt_regs *regs)
 866 {
 867         while (1) {
 868                 /* If no CPU is preparing crash dump, we simply loop here. */
 869                 run_crash_ipi_callback(regs);
 870                 cpu_relax();
 871         }
 872 }
 873
 874 #else /* !CONFIG_SMP */
 875 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
 876 {
 877         /* No other CPUs to shoot down */
 878 }
 879
 880 void run_crash_ipi_callback(struct pt_regs *regs)
 881 {
 882 }
 883 #endif