arch/x86/kernel/reboot.c

   1 #include <linux/module.h>
   2 #include <linux/reboot.h>
   3 #include <linux/init.h>
   4 #include <linux/pm.h>
   5 #include <linux/efi.h>
   6 #include <linux/dmi.h>
   7 #include <linux/sched.h>
   8 #include <linux/tboot.h>
   9 #include <linux/delay.h>
  10 #include <acpi/reboot.h>
  11 #include <asm/io.h>
  12 #include <asm/apic.h>
  13 #include <asm/desc.h>
  14 #include <asm/hpet.h>
  15 #include <asm/pgtable.h>
  16 #include <asm/proto.h>
  17 #include <asm/reboot_fixups.h>
  18 #include <asm/reboot.h>
  19 #include <asm/pci_x86.h>
  20 #include <asm/virtext.h>
  21 #include <asm/cpu.h>
  22 #include <asm/nmi.h>
  23
  24 #ifdef CONFIG_X86_32
  25 # include <linux/ctype.h>
  26 # include <linux/mc146818rtc.h>
  27 # include <asm/realmode.h>
  28 #else
  29 # include <asm/x86_init.h>
  30 #endif
  31
  32 /*
  33  * Power off function, if any
  34  */
  35 void (*pm_power_off)(void);
  36 EXPORT_SYMBOL(pm_power_off);
  37
  38 static const struct desc_ptr no_idt = {};
  39 static int reboot_mode;
  40 enum reboot_type reboot_type = BOOT_ACPI;
  41 int reboot_force;
  42
  43 /*
  44  * This variable is used privately to keep track of whether or not
  45  * reboot_type is still set to its default value (i.e., reboot= hasn't
  46  * been set on the command line).  This is needed so that we can
  47  * suppress DMI scanning for reboot quirks.  Without it, it's
  48  * impossible to override a faulty reboot quirk without recompiling.
  49  */
  50 static int reboot_default = 1;
  51
  52 #if defined(CONFIG_X86_32) && defined(CONFIG_SMP)
  53 static int reboot_cpu = -1;
  54 #endif
  55
  56 /*
  57  * This is set if we need to go through the 'emergency' path.
  58  * When machine_emergency_restart() is called, we may be on
  59  * an inconsistent state and won't be able to do a clean cleanup
  60  */
  61 static int reboot_emergency;
  62
  63 /* This is set by the PCI code if either type 1 or type 2 PCI is detected */
  64 bool port_cf9_safe = false;
  65
  66 /*
  67  * reboot=b[ios] | s[mp] | t[riple] | k[bd] | e[fi] [, [w]arm | [c]old] | p[ci]
  68  * warm   Don't set the cold reboot flag
  69  * cold   Set the cold reboot flag
  70  * bios   Reboot by jumping through the BIOS (only for X86_32)
  71  * smp    Reboot by executing reset on BSP or other CPU (only for X86_32)
  72  * triple Force a triple fault (init)
  73  * kbd    Use the keyboard controller. cold reset (default)
  74  * acpi   Use the RESET_REG in the FADT
  75  * efi    Use efi reset_system runtime service
  76  * pci    Use the so-called "PCI reset register", CF9
  77  * force  Avoid anything that could hang.
  78  */
  79 static int __init reboot_setup(char *str)
  80 {
  81         for (;;) {
  82                 /*
  83                  * Having anything passed on the command line via
  84                  * reboot= will cause us to disable DMI checking
  85                  * below.
  86                  */
  87                 reboot_default = 0;
  88
  89                 switch (*str) {
  90                 case 'w':
  91                         reboot_mode = 0x1234;
  92                         break;
  93
  94                 case 'c':
  95                         reboot_mode = 0;
  96                         break;
  97
  98 #ifdef CONFIG_X86_32
  99 #ifdef CONFIG_SMP
 100                 case 's':
 101                         if (isdigit(*(str+1))) {
 102                                 reboot_cpu = (int) (*(str+1) - '0');
 103                                 if (isdigit(*(str+2)))
 104                                         reboot_cpu = reboot_cpu*10 + (int)(*(str+2) - '0');
 105                         }
 106                         /*
 107                          * We will leave sorting out the final value
 108                          * when we are ready to reboot, since we might not
 109                          * have detected BSP APIC ID or smp_num_cpu
 110                          */
 111                         break;
 112 #endif /* CONFIG_SMP */
 113
 114                 case 'b':
 115 #endif
 116                 case 'a':
 117                 case 'k':
 118                 case 't':
 119                 case 'e':
 120                 case 'p':
 121                         reboot_type = *str;
 122                         break;
 123
 124                 case 'f':
 125                         reboot_force = 1;
 126                         break;
 127                 }
 128
 129                 str = strchr(str, ',');
 130                 if (str)
 131                         str++;
 132                 else
 133                         break;
 134         }
 135         return 1;
 136 }
 137
 138 __setup("reboot=", reboot_setup);
 139
 140
 141 #ifdef CONFIG_X86_32
 142 /*
 143  * Reboot options and system auto-detection code provided by
 144  * Dell Inc. so their systems "just work". :-)
 145  */
 146
 147 /*
 148  * Some machines require the "reboot=b" or "reboot=k"  commandline options,
 149  * this quirk makes that automatic.
 150  */
 151 static int __init set_bios_reboot(const struct dmi_system_id *d)
 152 {
 153         if (reboot_type != BOOT_BIOS) {
 154                 reboot_type = BOOT_BIOS;
 155                 printk(KERN_INFO "%s series board detected. Selecting BIOS-method for reboots.\n", d->ident);
 156         }
 157         return 0;
 158 }
 159
 160 void machine_real_restart(unsigned int type)
 161 {
 162         void (*restart_lowmem)(unsigned int) = (void (*)(unsigned int))
 163                 real_mode_header->machine_real_restart_asm;
 164
 165         local_irq_disable();
 166
 167         /*
 168          * Write zero to CMOS register number 0x0f, which the BIOS POST
 169          * routine will recognize as telling it to do a proper reboot.  (Well
 170          * that's what this book in front of me says -- it may only apply to
 171          * the Phoenix BIOS though, it's not clear).  At the same time,
 172          * disable NMIs by setting the top bit in the CMOS address register,
 173          * as we're about to do peculiar things to the CPU.  I'm not sure if
 174          * `outb_p' is needed instead of just `outb'.  Use it to be on the
 175          * safe side.  (Yes, CMOS_WRITE does outb_p's. -  Paul G.)
 176          */
 177         spin_lock(&rtc_lock);
 178         CMOS_WRITE(0x00, 0x8f);
 179         spin_unlock(&rtc_lock);
 180
 181         /*
 182          * Switch back to the initial page table.
 183          */
 184         load_cr3(initial_page_table);
 185
 186         /*
 187          * Write 0x1234 to absolute memory location 0x472.  The BIOS reads
 188          * this on booting to tell it to "Bypass memory test (also warm
 189          * boot)".  This seems like a fairly standard thing that gets set by
 190          * REBOOT.COM programs, and the previous reset routine did this
 191          * too. */
 192         *((unsigned short *)0x472) = reboot_mode;
 193
 194         /* Jump to the identity-mapped low memory code */
 195         restart_lowmem(type);
 196 }
 197 #ifdef CONFIG_APM_MODULE
 198 EXPORT_SYMBOL(machine_real_restart);
 199 #endif
 200
 201 #endif /* CONFIG_X86_32 */
 202
 203 /*
 204  * Some Apple MacBook and MacBookPro's needs reboot=p to be able to reboot
 205  */
 206 static int __init set_pci_reboot(const struct dmi_system_id *d)
 207 {
 208         if (reboot_type != BOOT_CF9) {
 209                 reboot_type = BOOT_CF9;
 210                 printk(KERN_INFO "%s series board detected. "
 211                        "Selecting PCI-method for reboots.\n", d->ident);
 212         }
 213         return 0;
 214 }
 215
 216 static int __init set_kbd_reboot(const struct dmi_system_id *d)
 217 {
 218         if (reboot_type != BOOT_KBD) {
 219                 reboot_type = BOOT_KBD;
 220                 printk(KERN_INFO "%s series board detected. Selecting KBD-method for reboot.\n", d->ident);
 221         }
 222         return 0;
 223 }
 224
 225 /*
 226  * This is a single dmi_table handling all reboot quirks.  Note that
 227  * REBOOT_BIOS is only available for 32bit
 228  */
 229 static struct dmi_system_id __initdata reboot_dmi_table[] = {
 230 #ifdef CONFIG_X86_32
 231         {       /* Handle problems with rebooting on Dell E520's */
 232                 .callback = set_bios_reboot,
 233                 .ident = "Dell E520",
 234                 .matches = {
 235                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 236                         DMI_MATCH(DMI_PRODUCT_NAME, "Dell DM061"),
 237                 },
 238         },
 239         {       /* Handle problems with rebooting on Dell 1300's */
 240                 .callback = set_bios_reboot,
 241                 .ident = "Dell PowerEdge 1300",
 242                 .matches = {
 243                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 244                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1300/"),
 245                 },
 246         },
 247         {       /* Handle problems with rebooting on Dell 300's */
 248                 .callback = set_bios_reboot,
 249                 .ident = "Dell PowerEdge 300",
 250                 .matches = {
 251                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 252                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"),
 253                 },
 254         },
 255         {       /* Handle problems with rebooting on Dell Optiplex 745's SFF */
 256                 .callback = set_bios_reboot,
 257                 .ident = "Dell OptiPlex 745",
 258                 .matches = {
 259                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 260                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
 261                 },
 262         },
 263         {       /* Handle problems with rebooting on Dell Optiplex 745's DFF */
 264                 .callback = set_bios_reboot,
 265                 .ident = "Dell OptiPlex 745",
 266                 .matches = {
 267                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 268                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
 269                         DMI_MATCH(DMI_BOARD_NAME, "0MM599"),
 270                 },
 271         },
 272         {       /* Handle problems with rebooting on Dell Optiplex 745 with 0KW626 */
 273                 .callback = set_bios_reboot,
 274                 .ident = "Dell OptiPlex 745",
 275                 .matches = {
 276                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 277                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
 278                         DMI_MATCH(DMI_BOARD_NAME, "0KW626"),
 279                 },
 280         },
 281         {       /* Handle problems with rebooting on Dell Optiplex 330 with 0KP561 */
 282                 .callback = set_bios_reboot,
 283                 .ident = "Dell OptiPlex 330",
 284                 .matches = {
 285                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 286                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 330"),
 287                         DMI_MATCH(DMI_BOARD_NAME, "0KP561"),
 288                 },
 289         },
 290         {       /* Handle problems with rebooting on Dell Optiplex 360 with 0T656F */
 291                 .callback = set_bios_reboot,
 292                 .ident = "Dell OptiPlex 360",
 293                 .matches = {
 294                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 295                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 360"),
 296                         DMI_MATCH(DMI_BOARD_NAME, "0T656F"),
 297                 },
 298         },
 299         {       /* Handle problems with rebooting on Dell OptiPlex 760 with 0G919G */
 300                 .callback = set_bios_reboot,
 301                 .ident = "Dell OptiPlex 760",
 302                 .matches = {
 303                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 304                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 760"),
 305                         DMI_MATCH(DMI_BOARD_NAME, "0G919G"),
 306                 },
 307         },
 308         {       /* Handle problems with rebooting on Dell 2400's */
 309                 .callback = set_bios_reboot,
 310                 .ident = "Dell PowerEdge 2400",
 311                 .matches = {
 312                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 313                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"),
 314                 },
 315         },
 316         {       /* Handle problems with rebooting on Dell T5400's */
 317                 .callback = set_bios_reboot,
 318                 .ident = "Dell Precision T5400",
 319                 .matches = {
 320                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 321                         DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T5400"),
 322                 },
 323         },
 324         {       /* Handle problems with rebooting on Dell T7400's */
 325                 .callback = set_bios_reboot,
 326                 .ident = "Dell Precision T7400",
 327                 .matches = {
 328                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 329                         DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T7400"),
 330                 },
 331         },
 332         {       /* Handle problems with rebooting on HP laptops */
 333                 .callback = set_bios_reboot,
 334                 .ident = "HP Compaq Laptop",
 335                 .matches = {
 336                         DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 337                         DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"),
 338                 },
 339         },
 340         {       /* Handle problems with rebooting on Dell XPS710 */
 341                 .callback = set_bios_reboot,
 342                 .ident = "Dell XPS710",
 343                 .matches = {
 344                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 345                         DMI_MATCH(DMI_PRODUCT_NAME, "Dell XPS710"),
 346                 },
 347         },
 348         {       /* Handle problems with rebooting on Dell DXP061 */
 349                 .callback = set_bios_reboot,
 350                 .ident = "Dell DXP061",
 351                 .matches = {
 352                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 353                         DMI_MATCH(DMI_PRODUCT_NAME, "Dell DXP061"),
 354                 },
 355         },
 356         {       /* Handle problems with rebooting on Sony VGN-Z540N */
 357                 .callback = set_bios_reboot,
 358                 .ident = "Sony VGN-Z540N",
 359                 .matches = {
 360                         DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
 361                         DMI_MATCH(DMI_PRODUCT_NAME, "VGN-Z540N"),
 362                 },
 363         },
 364         {       /* Handle problems with rebooting on CompuLab SBC-FITPC2 */
 365                 .callback = set_bios_reboot,
 366                 .ident = "CompuLab SBC-FITPC2",
 367                 .matches = {
 368                         DMI_MATCH(DMI_SYS_VENDOR, "CompuLab"),
 369                         DMI_MATCH(DMI_PRODUCT_NAME, "SBC-FITPC2"),
 370                 },
 371         },
 372         {       /* Handle problems with rebooting on ASUS P4S800 */
 373                 .callback = set_bios_reboot,
 374                 .ident = "ASUS P4S800",
 375                 .matches = {
 376                         DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
 377                         DMI_MATCH(DMI_BOARD_NAME, "P4S800"),
 378                 },
 379         },
 380 #endif /* CONFIG_X86_32 */
 381
 382         {       /* Handle reboot issue on Acer Aspire one */
 383                 .callback = set_kbd_reboot,
 384                 .ident = "Acer Aspire One A110",
 385                 .matches = {
 386                         DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
 387                         DMI_MATCH(DMI_PRODUCT_NAME, "AOA110"),
 388                 },
 389         },
 390         {       /* Handle problems with rebooting on Apple MacBook5 */
 391                 .callback = set_pci_reboot,
 392                 .ident = "Apple MacBook5",
 393                 .matches = {
 394                         DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 395                         DMI_MATCH(DMI_PRODUCT_NAME, "MacBook5"),
 396                 },
 397         },
 398         {       /* Handle problems with rebooting on Apple MacBookPro5 */
 399                 .callback = set_pci_reboot,
 400                 .ident = "Apple MacBookPro5",
 401                 .matches = {
 402                         DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 403                         DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro5"),
 404                 },
 405         },
 406         {       /* Handle problems with rebooting on Apple Macmini3,1 */
 407                 .callback = set_pci_reboot,
 408                 .ident = "Apple Macmini3,1",
 409                 .matches = {
 410                         DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 411                         DMI_MATCH(DMI_PRODUCT_NAME, "Macmini3,1"),
 412                 },
 413         },
 414         {       /* Handle problems with rebooting on the iMac9,1. */
 415                 .callback = set_pci_reboot,
 416                 .ident = "Apple iMac9,1",
 417                 .matches = {
 418                         DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 419                         DMI_MATCH(DMI_PRODUCT_NAME, "iMac9,1"),
 420                 },
 421         },
 422         {       /* Handle problems with rebooting on the Latitude E6320. */
 423                 .callback = set_pci_reboot,
 424                 .ident = "Dell Latitude E6320",
 425                 .matches = {
 426                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 427                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6320"),
 428                 },
 429         },
 430         {       /* Handle problems with rebooting on the Latitude E5420. */
 431                 .callback = set_pci_reboot,
 432                 .ident = "Dell Latitude E5420",
 433                 .matches = {
 434                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 435                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E5420"),
 436                 },
 437         },
 438         {       /* Handle problems with rebooting on the Latitude E6420. */
 439                 .callback = set_pci_reboot,
 440                 .ident = "Dell Latitude E6420",
 441                 .matches = {
 442                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 443                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6420"),
 444                 },
 445         },
 446         {       /* Handle problems with rebooting on the OptiPlex 990. */
 447                 .callback = set_pci_reboot,
 448                 .ident = "Dell OptiPlex 990",
 449                 .matches = {
 450                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 451                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 990"),
 452                 },
 453         },
 454         { }
 455 };
 456
 457 static int __init reboot_init(void)
 458 {
 459         /*
 460          * Only do the DMI check if reboot_type hasn't been overridden
 461          * on the command line
 462          */
 463         if (reboot_default)
 464                 dmi_check_system(reboot_dmi_table);
 465         return 0;
 466 }
 467 core_initcall(reboot_init);
 468
 469 static inline void kb_wait(void)
 470 {
 471         int i;
 472
 473         for (i = 0; i < 0x10000; i++) {
 474                 if ((inb(0x64) & 0x02) == 0)
 475                         break;
 476                 udelay(2);
 477         }
 478 }
 479
 480 static void vmxoff_nmi(int cpu, struct pt_regs *regs)
 481 {
 482         cpu_emergency_vmxoff();
 483 }
 484
 485 /* Use NMIs as IPIs to tell all CPUs to disable virtualization */
 486 static void emergency_vmx_disable_all(void)
 487 {
 488         /* Just make sure we won't change CPUs while doing this */
 489         local_irq_disable();
 490
 491         /*
 492          * We need to disable VMX on all CPUs before rebooting, otherwise
 493          * we risk hanging up the machine, because the CPU ignore INIT
 494          * signals when VMX is enabled.
 495          *
 496          * We can't take any locks and we may be on an inconsistent
 497          * state, so we use NMIs as IPIs to tell the other CPUs to disable
 498          * VMX and halt.
 499          *
 500          * For safety, we will avoid running the nmi_shootdown_cpus()
 501          * stuff unnecessarily, but we don't have a way to check
 502          * if other CPUs have VMX enabled. So we will call it only if the
 503          * CPU we are running on has VMX enabled.
 504          *
 505          * We will miss cases where VMX is not enabled on all CPUs. This
 506          * shouldn't do much harm because KVM always enable VMX on all
 507          * CPUs anyway. But we can miss it on the small window where KVM
 508          * is still enabling VMX.
 509          */
 510         if (cpu_has_vmx() && cpu_vmx_enabled()) {
 511                 /* Disable VMX on this CPU. */
 512                 cpu_vmxoff();
 513
 514                 /* Halt and disable VMX on the other CPUs */
 515                 nmi_shootdown_cpus(vmxoff_nmi);
 516
 517         }
 518 }
 519
 520
 521 void __attribute__((weak)) mach_reboot_fixups(void)
 522 {
 523 }
 524
 525 /*
 526  * Windows compatible x86 hardware expects 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  *
 533  * If the machine is still alive at this stage, it gives up. We default to
 534  * following the same pattern, except that if we're still alive after (4) we'll
 535  * try to force a triple fault and then cycle between hitting the keyboard
 536  * controller and doing that
 537  */
 538 static void native_machine_emergency_restart(void)
 539 {
 540         int i;
 541         int attempt = 0;
 542         int orig_reboot_type = reboot_type;
 543
 544         if (reboot_emergency)
 545                 emergency_vmx_disable_all();
 546
 547         tboot_shutdown(TB_SHUTDOWN_REBOOT);
 548
 549         /* Tell the BIOS if we want cold or warm reboot */
 550         *((unsigned short *)__va(0x472)) = reboot_mode;
 551
 552         for (;;) {
 553                 /* Could also try the reset bit in the Hammer NB */
 554                 switch (reboot_type) {
 555                 case BOOT_KBD:
 556                         mach_reboot_fixups(); /* For board specific fixups */
 557
 558                         for (i = 0; i < 10; i++) {
 559                                 kb_wait();
 560                                 udelay(50);
 561                                 outb(0xfe, 0x64); /* Pulse reset low */
 562                                 udelay(50);
 563                         }
 564                         if (attempt == 0 && orig_reboot_type == BOOT_ACPI) {
 565                                 attempt = 1;
 566                                 reboot_type = BOOT_ACPI;
 567                         } else {
 568                                 reboot_type = BOOT_TRIPLE;
 569                         }
 570                         break;
 571
 572                 case BOOT_TRIPLE:
 573                         load_idt(&no_idt);
 574                         __asm__ __volatile__("int3");
 575
 576                         reboot_type = BOOT_KBD;
 577                         break;
 578
 579 #ifdef CONFIG_X86_32
 580                 case BOOT_BIOS:
 581                         machine_real_restart(MRR_BIOS);
 582
 583                         reboot_type = BOOT_KBD;
 584                         break;
 585 #endif
 586
 587                 case BOOT_ACPI:
 588                         acpi_reboot();
 589                         reboot_type = BOOT_KBD;
 590                         break;
 591
 592                 case BOOT_EFI:
 593                         if (efi_enabled)
 594                                 efi.reset_system(reboot_mode ?
 595                                                  EFI_RESET_WARM :
 596                                                  EFI_RESET_COLD,
 597                                                  EFI_SUCCESS, 0, NULL);
 598                         reboot_type = BOOT_KBD;
 599                         break;
 600
 601                 case BOOT_CF9:
 602                         port_cf9_safe = true;
 603                         /* Fall through */
 604
 605                 case BOOT_CF9_COND:
 606                         if (port_cf9_safe) {
 607                                 u8 cf9 = inb(0xcf9) & ~6;
 608                                 outb(cf9|2, 0xcf9); /* Request hard reset */
 609                                 udelay(50);
 610                                 outb(cf9|6, 0xcf9); /* Actually do the reset */
 611                                 udelay(50);
 612                         }
 613                         reboot_type = BOOT_KBD;
 614                         break;
 615                 }
 616         }
 617 }
 618
 619 void native_machine_shutdown(void)
 620 {
 621         /* Stop the cpus and apics */
 622 #ifdef CONFIG_SMP
 623
 624         /* The boot cpu is always logical cpu 0 */
 625         int reboot_cpu_id = 0;
 626
 627 #ifdef CONFIG_X86_32
 628         /* See if there has been given a command line override */
 629         if ((reboot_cpu != -1) && (reboot_cpu < nr_cpu_ids) &&
 630                 cpu_online(reboot_cpu))
 631                 reboot_cpu_id = reboot_cpu;
 632 #endif
 633
 634         /* Make certain the cpu I'm about to reboot on is online */
 635         if (!cpu_online(reboot_cpu_id))
 636                 reboot_cpu_id = smp_processor_id();
 637
 638         /* Make certain I only run on the appropriate processor */
 639         set_cpus_allowed_ptr(current, cpumask_of(reboot_cpu_id));
 640
 641         /*
 642          * O.K Now that I'm on the appropriate processor,
 643          * stop all of the others.
 644          */
 645         stop_other_cpus();
 646 #endif
 647
 648         lapic_shutdown();
 649
 650 #ifdef CONFIG_X86_IO_APIC
 651         disable_IO_APIC();
 652 #endif
 653
 654 #ifdef CONFIG_HPET_TIMER
 655         hpet_disable();
 656 #endif
 657
 658 #ifdef CONFIG_X86_64
 659         x86_platform.iommu_shutdown();
 660 #endif
 661 }
 662
 663 static void __machine_emergency_restart(int emergency)
 664 {
 665         reboot_emergency = emergency;
 666         machine_ops.emergency_restart();
 667 }
 668
 669 static void native_machine_restart(char *__unused)
 670 {
 671         printk("machine restart\n");
 672
 673         if (!reboot_force)
 674                 machine_shutdown();
 675         __machine_emergency_restart(0);
 676 }
 677
 678 static void native_machine_halt(void)
 679 {
 680         /* Stop other cpus and apics */
 681         machine_shutdown();
 682
 683         tboot_shutdown(TB_SHUTDOWN_HALT);
 684
 685         stop_this_cpu(NULL);
 686 }
 687
 688 static void native_machine_power_off(void)
 689 {
 690         if (pm_power_off) {
 691                 if (!reboot_force)
 692                         machine_shutdown();
 693                 pm_power_off();
 694         }
 695         /* A fallback in case there is no PM info available */
 696         tboot_shutdown(TB_SHUTDOWN_HALT);
 697 }
 698
 699 struct machine_ops machine_ops = {
 700         .power_off = native_machine_power_off,
 701         .shutdown = native_machine_shutdown,
 702         .emergency_restart = native_machine_emergency_restart,
 703         .restart = native_machine_restart,
 704         .halt = native_machine_halt,
 705 #ifdef CONFIG_KEXEC
 706         .crash_shutdown = native_machine_crash_shutdown,
 707 #endif
 708 };
 709
 710 void machine_power_off(void)
 711 {
 712         machine_ops.power_off();
 713 }
 714
 715 void machine_shutdown(void)
 716 {
 717         machine_ops.shutdown();
 718 }
 719
 720 void machine_emergency_restart(void)
 721 {
 722         __machine_emergency_restart(1);
 723 }
 724
 725 void machine_restart(char *cmd)
 726 {
 727         machine_ops.restart(cmd);
 728 }
 729
 730 void machine_halt(void)
 731 {
 732         machine_ops.halt();
 733 }
 734
 735 #ifdef CONFIG_KEXEC
 736 void machine_crash_shutdown(struct pt_regs *regs)
 737 {
 738         machine_ops.crash_shutdown(regs);
 739 }
 740 #endif
 741
 742
 743 #if defined(CONFIG_SMP)
 744
 745 /* This keeps a track of which one is crashing cpu. */
 746 static int crashing_cpu;
 747 static nmi_shootdown_cb shootdown_callback;
 748
 749 static atomic_t waiting_for_crash_ipi;
 750
 751 static int crash_nmi_callback(unsigned int val, struct pt_regs *regs)
 752 {
 753         int cpu;
 754
 755         cpu = raw_smp_processor_id();
 756
 757         /*
 758          * Don't do anything if this handler is invoked on crashing cpu.
 759          * Otherwise, system will completely hang. Crashing cpu can get
 760          * an NMI if system was initially booted with nmi_watchdog parameter.
 761          */
 762         if (cpu == crashing_cpu)
 763                 return NMI_HANDLED;
 764         local_irq_disable();
 765
 766         shootdown_callback(cpu, regs);
 767
 768         atomic_dec(&waiting_for_crash_ipi);
 769         /* Assume hlt works */
 770         halt();
 771         for (;;)
 772                 cpu_relax();
 773
 774         return NMI_HANDLED;
 775 }
 776
 777 static void smp_send_nmi_allbutself(void)
 778 {
 779         apic->send_IPI_allbutself(NMI_VECTOR);
 780 }
 781
 782 /*
 783  * Halt all other CPUs, calling the specified function on each of them
 784  *
 785  * This function can be used to halt all other CPUs on crash
 786  * or emergency reboot time. The function passed as parameter
 787  * will be called inside a NMI handler on all CPUs.
 788  */
 789 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
 790 {
 791         unsigned long msecs;
 792         local_irq_disable();
 793
 794         /* Make a note of crashing cpu. Will be used in NMI callback. */
 795         crashing_cpu = safe_smp_processor_id();
 796
 797         shootdown_callback = callback;
 798
 799         atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
 800         /* Would it be better to replace the trap vector here? */
 801         if (register_nmi_handler(NMI_LOCAL, crash_nmi_callback,
 802                                  NMI_FLAG_FIRST, "crash"))
 803                 return;         /* Return what? */
 804         /*
 805          * Ensure the new callback function is set before sending
 806          * out the NMI
 807          */
 808         wmb();
 809
 810         smp_send_nmi_allbutself();
 811
 812         msecs = 1000; /* Wait at most a second for the other cpus to stop */
 813         while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
 814                 mdelay(1);
 815                 msecs--;
 816         }
 817
 818         /* Leave the nmi callback set */
 819 }
 820 #else /* !CONFIG_SMP */
 821 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
 822 {
 823         /* No other CPUs to shoot down */
 824 }
 825 #endif