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/x86_init.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         {       /* Handle problems with rebooting on ASUS P4S800 */
 263                 .callback = set_bios_reboot,
 264                 .ident = "ASUS P4S800",
 265                 .matches = {
 266                         DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
 267                         DMI_MATCH(DMI_BOARD_NAME, "P4S800"),
 268                 },
 269         },
 270         { }
 271 };
 272
 273 static int __init reboot_init(void)
 274 {
 275         dmi_check_system(reboot_dmi_table);
 276         return 0;
 277 }
 278 core_initcall(reboot_init);
 279
 280 /* The following code and data reboots the machine by switching to real
 281    mode and jumping to the BIOS reset entry point, as if the CPU has
 282    really been reset.  The previous version asked the keyboard
 283    controller to pulse the CPU reset line, which is more thorough, but
 284    doesn't work with at least one type of 486 motherboard.  It is easy
 285    to stop this code working; hence the copious comments. */
 286 static const unsigned long long
 287 real_mode_gdt_entries [3] =
 288 {
 289         0x0000000000000000ULL,  /* Null descriptor */
 290         0x00009b000000ffffULL,  /* 16-bit real-mode 64k code at 0x00000000 */
 291         0x000093000100ffffULL   /* 16-bit real-mode 64k data at 0x00000100 */
 292 };
 293
 294 static const struct desc_ptr
 295 real_mode_gdt = { sizeof (real_mode_gdt_entries) - 1, (long)real_mode_gdt_entries },
 296 real_mode_idt = { 0x3ff, 0 };
 297
 298 /* This is 16-bit protected mode code to disable paging and the cache,
 299    switch to real mode and jump to the BIOS reset code.
 300
 301    The instruction that switches to real mode by writing to CR0 must be
 302    followed immediately by a far jump instruction, which set CS to a
 303    valid value for real mode, and flushes the prefetch queue to avoid
 304    running instructions that have already been decoded in protected
 305    mode.
 306
 307    Clears all the flags except ET, especially PG (paging), PE
 308    (protected-mode enable) and TS (task switch for coprocessor state
 309    save).  Flushes the TLB after paging has been disabled.  Sets CD and
 310    NW, to disable the cache on a 486, and invalidates the cache.  This
 311    is more like the state of a 486 after reset.  I don't know if
 312    something else should be done for other chips.
 313
 314    More could be done here to set up the registers as if a CPU reset had
 315    occurred; hopefully real BIOSs don't assume much. */
 316 static const unsigned char real_mode_switch [] =
 317 {
 318         0x66, 0x0f, 0x20, 0xc0,                 /*    movl  %cr0,%eax        */
 319         0x66, 0x83, 0xe0, 0x11,                 /*    andl  $0x00000011,%eax */
 320         0x66, 0x0d, 0x00, 0x00, 0x00, 0x60,     /*    orl   $0x60000000,%eax */
 321         0x66, 0x0f, 0x22, 0xc0,                 /*    movl  %eax,%cr0        */
 322         0x66, 0x0f, 0x22, 0xd8,                 /*    movl  %eax,%cr3        */
 323         0x66, 0x0f, 0x20, 0xc3,                 /*    movl  %cr0,%ebx        */
 324         0x66, 0x81, 0xe3, 0x00, 0x00, 0x00, 0x60,       /*    andl  $0x60000000,%ebx */
 325         0x74, 0x02,                             /*    jz    f                */
 326         0x0f, 0x09,                             /*    wbinvd                 */
 327         0x24, 0x10,                             /* f: andb  $0x10,al         */
 328         0x66, 0x0f, 0x22, 0xc0                  /*    movl  %eax,%cr0        */
 329 };
 330 static const unsigned char jump_to_bios [] =
 331 {
 332         0xea, 0x00, 0x00, 0xff, 0xff            /*    ljmp  $0xffff,$0x0000  */
 333 };
 334
 335 /*
 336  * Switch to real mode and then execute the code
 337  * specified by the code and length parameters.
 338  * We assume that length will aways be less that 100!
 339  */
 340 void machine_real_restart(const unsigned char *code, int length)
 341 {
 342         local_irq_disable();
 343
 344         /* Write zero to CMOS register number 0x0f, which the BIOS POST
 345            routine will recognize as telling it to do a proper reboot.  (Well
 346            that's what this book in front of me says -- it may only apply to
 347            the Phoenix BIOS though, it's not clear).  At the same time,
 348            disable NMIs by setting the top bit in the CMOS address register,
 349            as we're about to do peculiar things to the CPU.  I'm not sure if
 350            `outb_p' is needed instead of just `outb'.  Use it to be on the
 351            safe side.  (Yes, CMOS_WRITE does outb_p's. -  Paul G.)
 352          */
 353         spin_lock(&rtc_lock);
 354         CMOS_WRITE(0x00, 0x8f);
 355         spin_unlock(&rtc_lock);
 356
 357         /* Remap the kernel at virtual address zero, as well as offset zero
 358            from the kernel segment.  This assumes the kernel segment starts at
 359            virtual address PAGE_OFFSET. */
 360         memcpy(swapper_pg_dir, swapper_pg_dir + KERNEL_PGD_BOUNDARY,
 361                 sizeof(swapper_pg_dir [0]) * KERNEL_PGD_PTRS);
 362
 363         /*
 364          * Use `swapper_pg_dir' as our page directory.
 365          */
 366         load_cr3(swapper_pg_dir);
 367
 368         /* Write 0x1234 to absolute memory location 0x472.  The BIOS reads
 369            this on booting to tell it to "Bypass memory test (also warm
 370            boot)".  This seems like a fairly standard thing that gets set by
 371            REBOOT.COM programs, and the previous reset routine did this
 372            too. */
 373         *((unsigned short *)0x472) = reboot_mode;
 374
 375         /* For the switch to real mode, copy some code to low memory.  It has
 376            to be in the first 64k because it is running in 16-bit mode, and it
 377            has to have the same physical and virtual address, because it turns
 378            off paging.  Copy it near the end of the first page, out of the way
 379            of BIOS variables. */
 380         memcpy((void *)(0x1000 - sizeof(real_mode_switch) - 100),
 381                 real_mode_switch, sizeof (real_mode_switch));
 382         memcpy((void *)(0x1000 - 100), code, length);
 383
 384         /* Set up the IDT for real mode. */
 385         load_idt(&real_mode_idt);
 386
 387         /* Set up a GDT from which we can load segment descriptors for real
 388            mode.  The GDT is not used in real mode; it is just needed here to
 389            prepare the descriptors. */
 390         load_gdt(&real_mode_gdt);
 391
 392         /* Load the data segment registers, and thus the descriptors ready for
 393            real mode.  The base address of each segment is 0x100, 16 times the
 394            selector value being loaded here.  This is so that the segment
 395            registers don't have to be reloaded after switching to real mode:
 396            the values are consistent for real mode operation already. */
 397         __asm__ __volatile__ ("movl $0x0010,%%eax\n"
 398                                 "\tmovl %%eax,%%ds\n"
 399                                 "\tmovl %%eax,%%es\n"
 400                                 "\tmovl %%eax,%%fs\n"
 401                                 "\tmovl %%eax,%%gs\n"
 402                                 "\tmovl %%eax,%%ss" : : : "eax");
 403
 404         /* Jump to the 16-bit code that we copied earlier.  It disables paging
 405            and the cache, switches to real mode, and jumps to the BIOS reset
 406            entry point. */
 407         __asm__ __volatile__ ("ljmp $0x0008,%0"
 408                                 :
 409                                 : "i" ((void *)(0x1000 - sizeof (real_mode_switch) - 100)));
 410 }
 411 #ifdef CONFIG_APM_MODULE
 412 EXPORT_SYMBOL(machine_real_restart);
 413 #endif
 414
 415 #endif /* CONFIG_X86_32 */
 416
 417 /*
 418  * Some Apple MacBook and MacBookPro's needs reboot=p to be able to reboot
 419  */
 420 static int __init set_pci_reboot(const struct dmi_system_id *d)
 421 {
 422         if (reboot_type != BOOT_CF9) {
 423                 reboot_type = BOOT_CF9;
 424                 printk(KERN_INFO "%s series board detected. "
 425                        "Selecting PCI-method for reboots.\n", d->ident);
 426         }
 427         return 0;
 428 }
 429
 430 static struct dmi_system_id __initdata pci_reboot_dmi_table[] = {
 431         {       /* Handle problems with rebooting on Apple MacBook5 */
 432                 .callback = set_pci_reboot,
 433                 .ident = "Apple MacBook5",
 434                 .matches = {
 435                         DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 436                         DMI_MATCH(DMI_PRODUCT_NAME, "MacBook5"),
 437                 },
 438         },
 439         {       /* Handle problems with rebooting on Apple MacBookPro5 */
 440                 .callback = set_pci_reboot,
 441                 .ident = "Apple MacBookPro5",
 442                 .matches = {
 443                         DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 444                         DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro5"),
 445                 },
 446         },
 447         {       /* Handle problems with rebooting on Apple Macmini3,1 */
 448                 .callback = set_pci_reboot,
 449                 .ident = "Apple Macmini3,1",
 450                 .matches = {
 451                         DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 452                         DMI_MATCH(DMI_PRODUCT_NAME, "Macmini3,1"),
 453                 },
 454         },
 455         { }
 456 };
 457
 458 static int __init pci_reboot_init(void)
 459 {
 460         dmi_check_system(pci_reboot_dmi_table);
 461         return 0;
 462 }
 463 core_initcall(pci_reboot_init);
 464
 465 static inline void kb_wait(void)
 466 {
 467         int i;
 468
 469         for (i = 0; i < 0x10000; i++) {
 470                 if ((inb(0x64) & 0x02) == 0)
 471                         break;
 472                 udelay(2);
 473         }
 474 }
 475
 476 static void vmxoff_nmi(int cpu, struct die_args *args)
 477 {
 478         cpu_emergency_vmxoff();
 479 }
 480
 481 /* Use NMIs as IPIs to tell all CPUs to disable virtualization
 482  */
 483 static void emergency_vmx_disable_all(void)
 484 {
 485         /* Just make sure we won't change CPUs while doing this */
 486         local_irq_disable();
 487
 488         /* We need to disable VMX on all CPUs before rebooting, otherwise
 489          * we risk hanging up the machine, because the CPU ignore INIT
 490          * signals when VMX is enabled.
 491          *
 492          * We can't take any locks and we may be on an inconsistent
 493          * state, so we use NMIs as IPIs to tell the other CPUs to disable
 494          * VMX and halt.
 495          *
 496          * For safety, we will avoid running the nmi_shootdown_cpus()
 497          * stuff unnecessarily, but we don't have a way to check
 498          * if other CPUs have VMX enabled. So we will call it only if the
 499          * CPU we are running on has VMX enabled.
 500          *
 501          * We will miss cases where VMX is not enabled on all CPUs. This
 502          * shouldn't do much harm because KVM always enable VMX on all
 503          * CPUs anyway. But we can miss it on the small window where KVM
 504          * is still enabling VMX.
 505          */
 506         if (cpu_has_vmx() && cpu_vmx_enabled()) {
 507                 /* Disable VMX on this CPU.
 508                  */
 509                 cpu_vmxoff();
 510
 511                 /* Halt and disable VMX on the other CPUs */
 512                 nmi_shootdown_cpus(vmxoff_nmi);
 513
 514         }
 515 }
 516
 517
 518 void __attribute__((weak)) mach_reboot_fixups(void)
 519 {
 520 }
 521
 522 static void native_machine_emergency_restart(void)
 523 {
 524         int i;
 525
 526         if (reboot_emergency)
 527                 emergency_vmx_disable_all();
 528
 529         tboot_shutdown(TB_SHUTDOWN_REBOOT);
 530
 531         /* Tell the BIOS if we want cold or warm reboot */
 532         *((unsigned short *)__va(0x472)) = reboot_mode;
 533
 534         for (;;) {
 535                 /* Could also try the reset bit in the Hammer NB */
 536                 switch (reboot_type) {
 537                 case BOOT_KBD:
 538                         mach_reboot_fixups(); /* for board specific fixups */
 539
 540                         for (i = 0; i < 10; i++) {
 541                                 kb_wait();
 542                                 udelay(50);
 543                                 outb(0xfe, 0x64); /* pulse reset low */
 544                                 udelay(50);
 545                         }
 546
 547                 case BOOT_TRIPLE:
 548                         load_idt(&no_idt);
 549                         __asm__ __volatile__("int3");
 550
 551                         reboot_type = BOOT_KBD;
 552                         break;
 553
 554 #ifdef CONFIG_X86_32
 555                 case BOOT_BIOS:
 556                         machine_real_restart(jump_to_bios, sizeof(jump_to_bios));
 557
 558                         reboot_type = BOOT_KBD;
 559                         break;
 560 #endif
 561
 562                 case BOOT_ACPI:
 563                         acpi_reboot();
 564                         reboot_type = BOOT_KBD;
 565                         break;
 566
 567                 case BOOT_EFI:
 568                         if (efi_enabled)
 569                                 efi.reset_system(reboot_mode ?
 570                                                  EFI_RESET_WARM :
 571                                                  EFI_RESET_COLD,
 572                                                  EFI_SUCCESS, 0, NULL);
 573                         reboot_type = BOOT_KBD;
 574                         break;
 575
 576                 case BOOT_CF9:
 577                         port_cf9_safe = true;
 578                         /* fall through */
 579
 580                 case BOOT_CF9_COND:
 581                         if (port_cf9_safe) {
 582                                 u8 cf9 = inb(0xcf9) & ~6;
 583                                 outb(cf9|2, 0xcf9); /* Request hard reset */
 584                                 udelay(50);
 585                                 outb(cf9|6, 0xcf9); /* Actually do the reset */
 586                                 udelay(50);
 587                         }
 588                         reboot_type = BOOT_KBD;
 589                         break;
 590                 }
 591         }
 592 }
 593
 594 void native_machine_shutdown(void)
 595 {
 596         /* Stop the cpus and apics */
 597 #ifdef CONFIG_SMP
 598
 599         /* The boot cpu is always logical cpu 0 */
 600         int reboot_cpu_id = 0;
 601
 602 #ifdef CONFIG_X86_32
 603         /* See if there has been given a command line override */
 604         if ((reboot_cpu != -1) && (reboot_cpu < nr_cpu_ids) &&
 605                 cpu_online(reboot_cpu))
 606                 reboot_cpu_id = reboot_cpu;
 607 #endif
 608
 609         /* Make certain the cpu I'm about to reboot on is online */
 610         if (!cpu_online(reboot_cpu_id))
 611                 reboot_cpu_id = smp_processor_id();
 612
 613         /* Make certain I only run on the appropriate processor */
 614         set_cpus_allowed_ptr(current, cpumask_of(reboot_cpu_id));
 615
 616         /* O.K Now that I'm on the appropriate processor,
 617          * stop all of the others.
 618          */
 619         smp_send_stop();
 620 #endif
 621
 622         lapic_shutdown();
 623
 624 #ifdef CONFIG_X86_IO_APIC
 625         disable_IO_APIC();
 626 #endif
 627
 628 #ifdef CONFIG_HPET_TIMER
 629         hpet_disable();
 630 #endif
 631
 632 #ifdef CONFIG_X86_64
 633         x86_platform.iommu_shutdown();
 634 #endif
 635 }
 636
 637 static void __machine_emergency_restart(int emergency)
 638 {
 639         reboot_emergency = emergency;
 640         machine_ops.emergency_restart();
 641 }
 642
 643 static void native_machine_restart(char *__unused)
 644 {
 645         printk("machine restart\n");
 646
 647         if (!reboot_force)
 648                 machine_shutdown();
 649         __machine_emergency_restart(0);
 650 }
 651
 652 static void native_machine_halt(void)
 653 {
 654         /* stop other cpus and apics */
 655         machine_shutdown();
 656
 657         tboot_shutdown(TB_SHUTDOWN_HALT);
 658
 659         /* stop this cpu */
 660         stop_this_cpu(NULL);
 661 }
 662
 663 static void native_machine_power_off(void)
 664 {
 665         if (pm_power_off) {
 666                 if (!reboot_force)
 667                         machine_shutdown();
 668                 pm_power_off();
 669         }
 670         /* a fallback in case there is no PM info available */
 671         tboot_shutdown(TB_SHUTDOWN_HALT);
 672 }
 673
 674 struct machine_ops machine_ops = {
 675         .power_off = native_machine_power_off,
 676         .shutdown = native_machine_shutdown,
 677         .emergency_restart = native_machine_emergency_restart,
 678         .restart = native_machine_restart,
 679         .halt = native_machine_halt,
 680 #ifdef CONFIG_KEXEC
 681         .crash_shutdown = native_machine_crash_shutdown,
 682 #endif
 683 };
 684
 685 void machine_power_off(void)
 686 {
 687         machine_ops.power_off();
 688 }
 689
 690 void machine_shutdown(void)
 691 {
 692         machine_ops.shutdown();
 693 }
 694
 695 void machine_emergency_restart(void)
 696 {
 697         __machine_emergency_restart(1);
 698 }
 699
 700 void machine_restart(char *cmd)
 701 {
 702         machine_ops.restart(cmd);
 703 }
 704
 705 void machine_halt(void)
 706 {
 707         machine_ops.halt();
 708 }
 709
 710 #ifdef CONFIG_KEXEC
 711 void machine_crash_shutdown(struct pt_regs *regs)
 712 {
 713         machine_ops.crash_shutdown(regs);
 714 }
 715 #endif
 716
 717
 718 #if defined(CONFIG_SMP)
 719
 720 /* This keeps a track of which one is crashing cpu. */
 721 static int crashing_cpu;
 722 static nmi_shootdown_cb shootdown_callback;
 723
 724 static atomic_t waiting_for_crash_ipi;
 725
 726 static int crash_nmi_callback(struct notifier_block *self,
 727                         unsigned long val, void *data)
 728 {
 729         int cpu;
 730
 731         if (val != DIE_NMI_IPI)
 732                 return NOTIFY_OK;
 733
 734         cpu = raw_smp_processor_id();
 735
 736         /* Don't do anything if this handler is invoked on crashing cpu.
 737          * Otherwise, system will completely hang. Crashing cpu can get
 738          * an NMI if system was initially booted with nmi_watchdog parameter.
 739          */
 740         if (cpu == crashing_cpu)
 741                 return NOTIFY_STOP;
 742         local_irq_disable();
 743
 744         shootdown_callback(cpu, (struct die_args *)data);
 745
 746         atomic_dec(&waiting_for_crash_ipi);
 747         /* Assume hlt works */
 748         halt();
 749         for (;;)
 750                 cpu_relax();
 751
 752         return 1;
 753 }
 754
 755 static void smp_send_nmi_allbutself(void)
 756 {
 757         apic->send_IPI_allbutself(NMI_VECTOR);
 758 }
 759
 760 static struct notifier_block crash_nmi_nb = {
 761         .notifier_call = crash_nmi_callback,
 762 };
 763
 764 /* Halt all other CPUs, calling the specified function on each of them
 765  *
 766  * This function can be used to halt all other CPUs on crash
 767  * or emergency reboot time. The function passed as parameter
 768  * will be called inside a NMI handler on all CPUs.
 769  */
 770 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
 771 {
 772         unsigned long msecs;
 773         local_irq_disable();
 774
 775         /* Make a note of crashing cpu. Will be used in NMI callback.*/
 776         crashing_cpu = safe_smp_processor_id();
 777
 778         shootdown_callback = callback;
 779
 780         atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
 781         /* Would it be better to replace the trap vector here? */
 782         if (register_die_notifier(&crash_nmi_nb))
 783                 return;         /* return what? */
 784         /* Ensure the new callback function is set before sending
 785          * out the NMI
 786          */
 787         wmb();
 788
 789         smp_send_nmi_allbutself();
 790
 791         msecs = 1000; /* Wait at most a second for the other cpus to stop */
 792         while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
 793                 mdelay(1);
 794                 msecs--;
 795         }
 796
 797         /* Leave the nmi callback set */
 798 }
 799 #else /* !CONFIG_SMP */
 800 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
 801 {
 802         /* No other CPUs to shoot down */
 803 }
 804 #endif