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 <acpi/reboot.h>
  10 #include <asm/io.h>
  11 #include <asm/apic.h>
  12 #include <asm/desc.h>
  13 #include <asm/hpet.h>
  14 #include <asm/pgtable.h>
  15 #include <asm/proto.h>
  16 #include <asm/reboot_fixups.h>
  17 #include <asm/reboot.h>
  18 #include <asm/pci_x86.h>
  19 #include <asm/virtext.h>
  20 #include <asm/cpu.h>
  21
  22 #ifdef CONFIG_X86_32
  23 # include <linux/ctype.h>
  24 # include <linux/mc146818rtc.h>
  25 #else
  26 # include <asm/iommu.h>
  27 #endif
  28
  29 /*
  30  * Power off function, if any
  31  */
  32 void (*pm_power_off)(void);
  33 EXPORT_SYMBOL(pm_power_off);
  34
  35 static const struct desc_ptr no_idt = {};
  36 static int reboot_mode;
  37 enum reboot_type reboot_type = BOOT_KBD;
  38 int reboot_force;
  39
  40 #if defined(CONFIG_X86_32) && defined(CONFIG_SMP)
  41 static int reboot_cpu = -1;
  42 #endif
  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 /* reboot=b[ios] | s[mp] | t[riple] | k[bd] | e[fi] [, [w]arm | [c]old] | p[ci]
  54    warm   Don't set the cold reboot flag
  55    cold   Set the cold reboot flag
  56    bios   Reboot by jumping through the BIOS (only for X86_32)
  57    smp    Reboot by executing reset on BSP or other CPU (only for X86_32)
  58    triple Force a triple fault (init)
  59    kbd    Use the keyboard controller. cold reset (default)
  60    acpi   Use the RESET_REG in the FADT
  61    efi    Use efi reset_system runtime service
  62    pci    Use the so-called "PCI reset register", CF9
  63    force  Avoid anything that could hang.
  64  */
  65 static int __init reboot_setup(char *str)
  66 {
  67         for (;;) {
  68                 switch (*str) {
  69                 case 'w':
  70                         reboot_mode = 0x1234;
  71                         break;
  72
  73                 case 'c':
  74                         reboot_mode = 0;
  75                         break;
  76
  77 #ifdef CONFIG_X86_32
  78 #ifdef CONFIG_SMP
  79                 case 's':
  80                         if (isdigit(*(str+1))) {
  81                                 reboot_cpu = (int) (*(str+1) - '0');
  82                                 if (isdigit(*(str+2)))
  83                                         reboot_cpu = reboot_cpu*10 + (int)(*(str+2) - '0');
  84                         }
  85                                 /* we will leave sorting out the final value
  86                                    when we are ready to reboot, since we might not
  87                                    have set up boot_cpu_id or smp_num_cpu */
  88                         break;
  89 #endif /* CONFIG_SMP */
  90
  91                 case 'b':
  92 #endif
  93                 case 'a':
  94                 case 'k':
  95                 case 't':
  96                 case 'e':
  97                 case 'p':
  98                         reboot_type = *str;
  99                         break;
 100
 101                 case 'f':
 102                         reboot_force = 1;
 103                         break;
 104                 }
 105
 106                 str = strchr(str, ',');
 107                 if (str)
 108                         str++;
 109                 else
 110                         break;
 111         }
 112         return 1;
 113 }
 114
 115 __setup("reboot=", reboot_setup);
 116
 117
 118 #ifdef CONFIG_X86_32
 119 /*
 120  * Reboot options and system auto-detection code provided by
 121  * Dell Inc. so their systems "just work". :-)
 122  */
 123
 124 /*
 125  * Some machines require the "reboot=b"  commandline option,
 126  * this quirk makes that automatic.
 127  */
 128 static int __init set_bios_reboot(const struct dmi_system_id *d)
 129 {
 130         if (reboot_type != BOOT_BIOS) {
 131                 reboot_type = BOOT_BIOS;
 132                 printk(KERN_INFO "%s series board detected. Selecting BIOS-method for reboots.\n", d->ident);
 133         }
 134         return 0;
 135 }
 136
 137 static struct dmi_system_id __initdata reboot_dmi_table[] = {
 138         {       /* Handle problems with rebooting on Dell E520's */
 139                 .callback = set_bios_reboot,
 140                 .ident = "Dell E520",
 141                 .matches = {
 142                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 143                         DMI_MATCH(DMI_PRODUCT_NAME, "Dell DM061"),
 144                 },
 145         },
 146         {       /* Handle problems with rebooting on Dell 1300's */
 147                 .callback = set_bios_reboot,
 148                 .ident = "Dell PowerEdge 1300",
 149                 .matches = {
 150                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 151                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1300/"),
 152                 },
 153         },
 154         {       /* Handle problems with rebooting on Dell 300's */
 155                 .callback = set_bios_reboot,
 156                 .ident = "Dell PowerEdge 300",
 157                 .matches = {
 158                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 159                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"),
 160                 },
 161         },
 162         {       /* Handle problems with rebooting on Dell Optiplex 745's SFF*/
 163                 .callback = set_bios_reboot,
 164                 .ident = "Dell OptiPlex 745",
 165                 .matches = {
 166                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 167                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
 168                 },
 169         },
 170         {       /* Handle problems with rebooting on Dell Optiplex 745's DFF*/
 171                 .callback = set_bios_reboot,
 172                 .ident = "Dell OptiPlex 745",
 173                 .matches = {
 174                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 175                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
 176                         DMI_MATCH(DMI_BOARD_NAME, "0MM599"),
 177                 },
 178         },
 179         {       /* Handle problems with rebooting on Dell Optiplex 745 with 0KW626 */
 180                 .callback = set_bios_reboot,
 181                 .ident = "Dell OptiPlex 745",
 182                 .matches = {
 183                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 184                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
 185                         DMI_MATCH(DMI_BOARD_NAME, "0KW626"),
 186                 },
 187         },
 188         {   /* Handle problems with rebooting on Dell Optiplex 330 with 0KP561 */
 189                 .callback = set_bios_reboot,
 190                 .ident = "Dell OptiPlex 330",
 191                 .matches = {
 192                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 193                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 330"),
 194                         DMI_MATCH(DMI_BOARD_NAME, "0KP561"),
 195                 },
 196         },
 197         {   /* Handle problems with rebooting on Dell Optiplex 360 with 0T656F */
 198                 .callback = set_bios_reboot,
 199                 .ident = "Dell OptiPlex 360",
 200                 .matches = {
 201                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 202                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 360"),
 203                         DMI_MATCH(DMI_BOARD_NAME, "0T656F"),
 204                 },
 205         },
 206         {       /* Handle problems with rebooting on Dell 2400's */
 207                 .callback = set_bios_reboot,
 208                 .ident = "Dell PowerEdge 2400",
 209                 .matches = {
 210                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 211                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"),
 212                 },
 213         },
 214         {       /* Handle problems with rebooting on Dell T5400's */
 215                 .callback = set_bios_reboot,
 216                 .ident = "Dell Precision T5400",
 217                 .matches = {
 218                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 219                         DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T5400"),
 220                 },
 221         },
 222         {       /* Handle problems with rebooting on HP laptops */
 223                 .callback = set_bios_reboot,
 224                 .ident = "HP Compaq Laptop",
 225                 .matches = {
 226                         DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 227                         DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"),
 228                 },
 229         },
 230         {       /* Handle problems with rebooting on Dell XPS710 */
 231                 .callback = set_bios_reboot,
 232                 .ident = "Dell XPS710",
 233                 .matches = {
 234                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 235                         DMI_MATCH(DMI_PRODUCT_NAME, "Dell XPS710"),
 236                 },
 237         },
 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 Sony VGN-Z540N */
 247                 .callback = set_bios_reboot,
 248                 .ident = "Sony VGN-Z540N",
 249                 .matches = {
 250                         DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
 251                         DMI_MATCH(DMI_PRODUCT_NAME, "VGN-Z540N"),
 252                 },
 253         },
 254         {       /* Handle problems with rebooting on CompuLab SBC-FITPC2 */
 255                 .callback = set_bios_reboot,
 256                 .ident = "CompuLab SBC-FITPC2",
 257                 .matches = {
 258                         DMI_MATCH(DMI_SYS_VENDOR, "CompuLab"),
 259                         DMI_MATCH(DMI_PRODUCT_NAME, "SBC-FITPC2"),
 260                 },
 261         },
 262         { }
 263 };
 264
 265 static int __init reboot_init(void)
 266 {
 267         dmi_check_system(reboot_dmi_table);
 268         return 0;
 269 }
 270 core_initcall(reboot_init);
 271
 272 /* The following code and data reboots the machine by switching to real
 273    mode and jumping to the BIOS reset entry point, as if the CPU has
 274    really been reset.  The previous version asked the keyboard
 275    controller to pulse the CPU reset line, which is more thorough, but
 276    doesn't work with at least one type of 486 motherboard.  It is easy
 277    to stop this code working; hence the copious comments. */
 278 static const unsigned long long
 279 real_mode_gdt_entries [3] =
 280 {
 281         0x0000000000000000ULL,  /* Null descriptor */
 282         0x00009b000000ffffULL,  /* 16-bit real-mode 64k code at 0x00000000 */
 283         0x000093000100ffffULL   /* 16-bit real-mode 64k data at 0x00000100 */
 284 };
 285
 286 static const struct desc_ptr
 287 real_mode_gdt = { sizeof (real_mode_gdt_entries) - 1, (long)real_mode_gdt_entries },
 288 real_mode_idt = { 0x3ff, 0 };
 289
 290 /* This is 16-bit protected mode code to disable paging and the cache,
 291    switch to real mode and jump to the BIOS reset code.
 292
 293    The instruction that switches to real mode by writing to CR0 must be
 294    followed immediately by a far jump instruction, which set CS to a
 295    valid value for real mode, and flushes the prefetch queue to avoid
 296    running instructions that have already been decoded in protected
 297    mode.
 298
 299    Clears all the flags except ET, especially PG (paging), PE
 300    (protected-mode enable) and TS (task switch for coprocessor state
 301    save).  Flushes the TLB after paging has been disabled.  Sets CD and
 302    NW, to disable the cache on a 486, and invalidates the cache.  This
 303    is more like the state of a 486 after reset.  I don't know if
 304    something else should be done for other chips.
 305
 306    More could be done here to set up the registers as if a CPU reset had
 307    occurred; hopefully real BIOSs don't assume much. */
 308 static const unsigned char real_mode_switch [] =
 309 {
 310         0x66, 0x0f, 0x20, 0xc0,                 /*    movl  %cr0,%eax        */
 311         0x66, 0x83, 0xe0, 0x11,                 /*    andl  $0x00000011,%eax */
 312         0x66, 0x0d, 0x00, 0x00, 0x00, 0x60,     /*    orl   $0x60000000,%eax */
 313         0x66, 0x0f, 0x22, 0xc0,                 /*    movl  %eax,%cr0        */
 314         0x66, 0x0f, 0x22, 0xd8,                 /*    movl  %eax,%cr3        */
 315         0x66, 0x0f, 0x20, 0xc3,                 /*    movl  %cr0,%ebx        */
 316         0x66, 0x81, 0xe3, 0x00, 0x00, 0x00, 0x60,       /*    andl  $0x60000000,%ebx */
 317         0x74, 0x02,                             /*    jz    f                */
 318         0x0f, 0x09,                             /*    wbinvd                 */
 319         0x24, 0x10,                             /* f: andb  $0x10,al         */
 320         0x66, 0x0f, 0x22, 0xc0                  /*    movl  %eax,%cr0        */
 321 };
 322 static const unsigned char jump_to_bios [] =
 323 {
 324         0xea, 0x00, 0x00, 0xff, 0xff            /*    ljmp  $0xffff,$0x0000  */
 325 };
 326
 327 /*
 328  * Switch to real mode and then execute the code
 329  * specified by the code and length parameters.
 330  * We assume that length will aways be less that 100!
 331  */
 332 void machine_real_restart(const unsigned char *code, int length)
 333 {
 334         local_irq_disable();
 335
 336         /* Write zero to CMOS register number 0x0f, which the BIOS POST
 337            routine will recognize as telling it to do a proper reboot.  (Well
 338            that's what this book in front of me says -- it may only apply to
 339            the Phoenix BIOS though, it's not clear).  At the same time,
 340            disable NMIs by setting the top bit in the CMOS address register,
 341            as we're about to do peculiar things to the CPU.  I'm not sure if
 342            `outb_p' is needed instead of just `outb'.  Use it to be on the
 343            safe side.  (Yes, CMOS_WRITE does outb_p's. -  Paul G.)
 344          */
 345         spin_lock(&rtc_lock);
 346         CMOS_WRITE(0x00, 0x8f);
 347         spin_unlock(&rtc_lock);
 348
 349         /* Remap the kernel at virtual address zero, as well as offset zero
 350            from the kernel segment.  This assumes the kernel segment starts at
 351            virtual address PAGE_OFFSET. */
 352         memcpy(swapper_pg_dir, swapper_pg_dir + KERNEL_PGD_BOUNDARY,
 353                 sizeof(swapper_pg_dir [0]) * KERNEL_PGD_PTRS);
 354
 355         /*
 356          * Use `swapper_pg_dir' as our page directory.
 357          */
 358         load_cr3(swapper_pg_dir);
 359
 360         /* Write 0x1234 to absolute memory location 0x472.  The BIOS reads
 361            this on booting to tell it to "Bypass memory test (also warm
 362            boot)".  This seems like a fairly standard thing that gets set by
 363            REBOOT.COM programs, and the previous reset routine did this
 364            too. */
 365         *((unsigned short *)0x472) = reboot_mode;
 366
 367         /* For the switch to real mode, copy some code to low memory.  It has
 368            to be in the first 64k because it is running in 16-bit mode, and it
 369            has to have the same physical and virtual address, because it turns
 370            off paging.  Copy it near the end of the first page, out of the way
 371            of BIOS variables. */
 372         memcpy((void *)(0x1000 - sizeof(real_mode_switch) - 100),
 373                 real_mode_switch, sizeof (real_mode_switch));
 374         memcpy((void *)(0x1000 - 100), code, length);
 375
 376         /* Set up the IDT for real mode. */
 377         load_idt(&real_mode_idt);
 378
 379         /* Set up a GDT from which we can load segment descriptors for real
 380            mode.  The GDT is not used in real mode; it is just needed here to
 381            prepare the descriptors. */
 382         load_gdt(&real_mode_gdt);
 383
 384         /* Load the data segment registers, and thus the descriptors ready for
 385            real mode.  The base address of each segment is 0x100, 16 times the
 386            selector value being loaded here.  This is so that the segment
 387            registers don't have to be reloaded after switching to real mode:
 388            the values are consistent for real mode operation already. */
 389         __asm__ __volatile__ ("movl $0x0010,%%eax\n"
 390                                 "\tmovl %%eax,%%ds\n"
 391                                 "\tmovl %%eax,%%es\n"
 392                                 "\tmovl %%eax,%%fs\n"
 393                                 "\tmovl %%eax,%%gs\n"
 394                                 "\tmovl %%eax,%%ss" : : : "eax");
 395
 396         /* Jump to the 16-bit code that we copied earlier.  It disables paging
 397            and the cache, switches to real mode, and jumps to the BIOS reset
 398            entry point. */
 399         __asm__ __volatile__ ("ljmp $0x0008,%0"
 400                                 :
 401                                 : "i" ((void *)(0x1000 - sizeof (real_mode_switch) - 100)));
 402 }
 403 #ifdef CONFIG_APM_MODULE
 404 EXPORT_SYMBOL(machine_real_restart);
 405 #endif
 406
 407 #endif /* CONFIG_X86_32 */
 408
 409 /*
 410  * Some Apple MacBook and MacBookPro's needs reboot=p to be able to reboot
 411  */
 412 static int __init set_pci_reboot(const struct dmi_system_id *d)
 413 {
 414         if (reboot_type != BOOT_CF9) {
 415                 reboot_type = BOOT_CF9;
 416                 printk(KERN_INFO "%s series board detected. "
 417                        "Selecting PCI-method for reboots.\n", d->ident);
 418         }
 419         return 0;
 420 }
 421
 422 static struct dmi_system_id __initdata pci_reboot_dmi_table[] = {
 423         {       /* Handle problems with rebooting on Apple MacBook5 */
 424                 .callback = set_pci_reboot,
 425                 .ident = "Apple MacBook5",
 426                 .matches = {
 427                         DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 428                         DMI_MATCH(DMI_PRODUCT_NAME, "MacBook5"),
 429                 },
 430         },
 431         {       /* Handle problems with rebooting on Apple MacBookPro5 */
 432                 .callback = set_pci_reboot,
 433                 .ident = "Apple MacBookPro5",
 434                 .matches = {
 435                         DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 436                         DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro5"),
 437                 },
 438         },
 439         { }
 440 };
 441
 442 static int __init pci_reboot_init(void)
 443 {
 444         dmi_check_system(pci_reboot_dmi_table);
 445         return 0;
 446 }
 447 core_initcall(pci_reboot_init);
 448
 449 static inline void kb_wait(void)
 450 {
 451         int i;
 452
 453         for (i = 0; i < 0x10000; i++) {
 454                 if ((inb(0x64) & 0x02) == 0)
 455                         break;
 456                 udelay(2);
 457         }
 458 }
 459
 460 static void vmxoff_nmi(int cpu, struct die_args *args)
 461 {
 462         cpu_emergency_vmxoff();
 463 }
 464
 465 /* Use NMIs as IPIs to tell all CPUs to disable virtualization
 466  */
 467 static void emergency_vmx_disable_all(void)
 468 {
 469         /* Just make sure we won't change CPUs while doing this */
 470         local_irq_disable();
 471
 472         /* We need to disable VMX on all CPUs before rebooting, otherwise
 473          * we risk hanging up the machine, because the CPU ignore INIT
 474          * signals when VMX is enabled.
 475          *
 476          * We can't take any locks and we may be on an inconsistent
 477          * state, so we use NMIs as IPIs to tell the other CPUs to disable
 478          * VMX and halt.
 479          *
 480          * For safety, we will avoid running the nmi_shootdown_cpus()
 481          * stuff unnecessarily, but we don't have a way to check
 482          * if other CPUs have VMX enabled. So we will call it only if the
 483          * CPU we are running on has VMX enabled.
 484          *
 485          * We will miss cases where VMX is not enabled on all CPUs. This
 486          * shouldn't do much harm because KVM always enable VMX on all
 487          * CPUs anyway. But we can miss it on the small window where KVM
 488          * is still enabling VMX.
 489          */
 490         if (cpu_has_vmx() && cpu_vmx_enabled()) {
 491                 /* Disable VMX on this CPU.
 492                  */
 493                 cpu_vmxoff();
 494
 495                 /* Halt and disable VMX on the other CPUs */
 496                 nmi_shootdown_cpus(vmxoff_nmi);
 497
 498         }
 499 }
 500
 501
 502 void __attribute__((weak)) mach_reboot_fixups(void)
 503 {
 504 }
 505
 506 static void native_machine_emergency_restart(void)
 507 {
 508         int i;
 509
 510         if (reboot_emergency)
 511                 emergency_vmx_disable_all();
 512
 513         tboot_shutdown(TB_SHUTDOWN_REBOOT);
 514
 515         /* Tell the BIOS if we want cold or warm reboot */
 516         *((unsigned short *)__va(0x472)) = reboot_mode;
 517
 518         for (;;) {
 519                 /* Could also try the reset bit in the Hammer NB */
 520                 switch (reboot_type) {
 521                 case BOOT_KBD:
 522                         mach_reboot_fixups(); /* for board specific fixups */
 523
 524                         for (i = 0; i < 10; i++) {
 525                                 kb_wait();
 526                                 udelay(50);
 527                                 outb(0xfe, 0x64); /* pulse reset low */
 528                                 udelay(50);
 529                         }
 530
 531                 case BOOT_TRIPLE:
 532                         load_idt(&no_idt);
 533                         __asm__ __volatile__("int3");
 534
 535                         reboot_type = BOOT_KBD;
 536                         break;
 537
 538 #ifdef CONFIG_X86_32
 539                 case BOOT_BIOS:
 540                         machine_real_restart(jump_to_bios, sizeof(jump_to_bios));
 541
 542                         reboot_type = BOOT_KBD;
 543                         break;
 544 #endif
 545
 546                 case BOOT_ACPI:
 547                         acpi_reboot();
 548                         reboot_type = BOOT_KBD;
 549                         break;
 550
 551                 case BOOT_EFI:
 552                         if (efi_enabled)
 553                                 efi.reset_system(reboot_mode ?
 554                                                  EFI_RESET_WARM :
 555                                                  EFI_RESET_COLD,
 556                                                  EFI_SUCCESS, 0, NULL);
 557                         reboot_type = BOOT_KBD;
 558                         break;
 559
 560                 case BOOT_CF9:
 561                         port_cf9_safe = true;
 562                         /* fall through */
 563
 564                 case BOOT_CF9_COND:
 565                         if (port_cf9_safe) {
 566                                 u8 cf9 = inb(0xcf9) & ~6;
 567                                 outb(cf9|2, 0xcf9); /* Request hard reset */
 568                                 udelay(50);
 569                                 outb(cf9|6, 0xcf9); /* Actually do the reset */
 570                                 udelay(50);
 571                         }
 572                         reboot_type = BOOT_KBD;
 573                         break;
 574                 }
 575         }
 576 }
 577
 578 void native_machine_shutdown(void)
 579 {
 580         /* Stop the cpus and apics */
 581 #ifdef CONFIG_SMP
 582
 583         /* The boot cpu is always logical cpu 0 */
 584         int reboot_cpu_id = 0;
 585
 586 #ifdef CONFIG_X86_32
 587         /* See if there has been given a command line override */
 588         if ((reboot_cpu != -1) && (reboot_cpu < nr_cpu_ids) &&
 589                 cpu_online(reboot_cpu))
 590                 reboot_cpu_id = reboot_cpu;
 591 #endif
 592
 593         /* Make certain the cpu I'm about to reboot on is online */
 594         if (!cpu_online(reboot_cpu_id))
 595                 reboot_cpu_id = smp_processor_id();
 596
 597         /* Make certain I only run on the appropriate processor */
 598         set_cpus_allowed_ptr(current, cpumask_of(reboot_cpu_id));
 599
 600         /* O.K Now that I'm on the appropriate processor,
 601          * stop all of the others.
 602          */
 603         smp_send_stop();
 604 #endif
 605
 606         lapic_shutdown();
 607
 608 #ifdef CONFIG_X86_IO_APIC
 609         disable_IO_APIC();
 610 #endif
 611
 612 #ifdef CONFIG_HPET_TIMER
 613         hpet_disable();
 614 #endif
 615
 616 #ifdef CONFIG_X86_64
 617         pci_iommu_shutdown();
 618 #endif
 619 }
 620
 621 static void __machine_emergency_restart(int emergency)
 622 {
 623         reboot_emergency = emergency;
 624         machine_ops.emergency_restart();
 625 }
 626
 627 static void native_machine_restart(char *__unused)
 628 {
 629         printk("machine restart\n");
 630
 631         if (!reboot_force)
 632                 machine_shutdown();
 633         __machine_emergency_restart(0);
 634 }
 635
 636 static void native_machine_halt(void)
 637 {
 638         /* stop other cpus and apics */
 639         machine_shutdown();
 640
 641         tboot_shutdown(TB_SHUTDOWN_HALT);
 642
 643         /* stop this cpu */
 644         stop_this_cpu(NULL);
 645 }
 646
 647 static void native_machine_power_off(void)
 648 {
 649         if (pm_power_off) {
 650                 if (!reboot_force)
 651                         machine_shutdown();
 652                 pm_power_off();
 653         }
 654         /* a fallback in case there is no PM info available */
 655         tboot_shutdown(TB_SHUTDOWN_HALT);
 656 }
 657
 658 struct machine_ops machine_ops = {
 659         .power_off = native_machine_power_off,
 660         .shutdown = native_machine_shutdown,
 661         .emergency_restart = native_machine_emergency_restart,
 662         .restart = native_machine_restart,
 663         .halt = native_machine_halt,
 664 #ifdef CONFIG_KEXEC
 665         .crash_shutdown = native_machine_crash_shutdown,
 666 #endif
 667 };
 668
 669 void machine_power_off(void)
 670 {
 671         machine_ops.power_off();
 672 }
 673
 674 void machine_shutdown(void)
 675 {
 676         machine_ops.shutdown();
 677 }
 678
 679 void machine_emergency_restart(void)
 680 {
 681         __machine_emergency_restart(1);
 682 }
 683
 684 void machine_restart(char *cmd)
 685 {
 686         machine_ops.restart(cmd);
 687 }
 688
 689 void machine_halt(void)
 690 {
 691         machine_ops.halt();
 692 }
 693
 694 #ifdef CONFIG_KEXEC
 695 void machine_crash_shutdown(struct pt_regs *regs)
 696 {
 697         machine_ops.crash_shutdown(regs);
 698 }
 699 #endif
 700
 701
 702 #if defined(CONFIG_SMP)
 703
 704 /* This keeps a track of which one is crashing cpu. */
 705 static int crashing_cpu;
 706 static nmi_shootdown_cb shootdown_callback;
 707
 708 static atomic_t waiting_for_crash_ipi;
 709
 710 static int crash_nmi_callback(struct notifier_block *self,
 711                         unsigned long val, void *data)
 712 {
 713         int cpu;
 714
 715         if (val != DIE_NMI_IPI)
 716                 return NOTIFY_OK;
 717
 718         cpu = raw_smp_processor_id();
 719
 720         /* Don't do anything if this handler is invoked on crashing cpu.
 721          * Otherwise, system will completely hang. Crashing cpu can get
 722          * an NMI if system was initially booted with nmi_watchdog parameter.
 723          */
 724         if (cpu == crashing_cpu)
 725                 return NOTIFY_STOP;
 726         local_irq_disable();
 727
 728         shootdown_callback(cpu, (struct die_args *)data);
 729
 730         atomic_dec(&waiting_for_crash_ipi);
 731         /* Assume hlt works */
 732         halt();
 733         for (;;)
 734                 cpu_relax();
 735
 736         return 1;
 737 }
 738
 739 static void smp_send_nmi_allbutself(void)
 740 {
 741         apic->send_IPI_allbutself(NMI_VECTOR);
 742 }
 743
 744 static struct notifier_block crash_nmi_nb = {
 745         .notifier_call = crash_nmi_callback,
 746 };
 747
 748 /* Halt all other CPUs, calling the specified function on each of them
 749  *
 750  * This function can be used to halt all other CPUs on crash
 751  * or emergency reboot time. The function passed as parameter
 752  * will be called inside a NMI handler on all CPUs.
 753  */
 754 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
 755 {
 756         unsigned long msecs;
 757         local_irq_disable();
 758
 759         /* Make a note of crashing cpu. Will be used in NMI callback.*/
 760         crashing_cpu = safe_smp_processor_id();
 761
 762         shootdown_callback = callback;
 763
 764         atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
 765         /* Would it be better to replace the trap vector here? */
 766         if (register_die_notifier(&crash_nmi_nb))
 767                 return;         /* return what? */
 768         /* Ensure the new callback function is set before sending
 769          * out the NMI
 770          */
 771         wmb();
 772
 773         smp_send_nmi_allbutself();
 774
 775         msecs = 1000; /* Wait at most a second for the other cpus to stop */
 776         while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
 777                 mdelay(1);
 778                 msecs--;
 779         }
 780
 781         /* Leave the nmi callback set */
 782 }
 783 #else /* !CONFIG_SMP */
 784 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
 785 {
 786         /* No other CPUs to shoot down */
 787 }
 788 #endif