arch/x86/kernel/reboot.c

   1 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   2
   3 #include <linux/module.h>
   4 #include <linux/reboot.h>
   5 #include <linux/init.h>
   6 #include <linux/pm.h>
   7 #include <linux/efi.h>
   8 #include <linux/dmi.h>
   9 #include <linux/sched.h>
  10 #include <linux/tboot.h>
  11 #include <linux/delay.h>
  12 #include <acpi/reboot.h>
  13 #include <asm/io.h>
  14 #include <asm/apic.h>
  15 #include <asm/desc.h>
  16 #include <asm/hpet.h>
  17 #include <asm/pgtable.h>
  18 #include <asm/proto.h>
  19 #include <asm/reboot_fixups.h>
  20 #include <asm/reboot.h>
  21 #include <asm/pci_x86.h>
  22 #include <asm/virtext.h>
  23 #include <asm/cpu.h>
  24 #include <asm/nmi.h>
  25 #include <asm/smp.h>
  26
  27 #include <linux/ctype.h>
  28 #include <linux/mc146818rtc.h>
  29 #include <asm/realmode.h>
  30 #include <asm/x86_init.h>
  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 #ifdef 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
  71  * smp    Reboot by executing reset on BSP or other CPU
  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_SMP
  99                 case 's':
 100                         if (isdigit(*(str+1))) {
 101                                 reboot_cpu = (int) (*(str+1) - '0');
 102                                 if (isdigit(*(str+2)))
 103                                         reboot_cpu = reboot_cpu*10 + (int)(*(str+2) - '0');
 104                         }
 105                         /*
 106                          * We will leave sorting out the final value
 107                          * when we are ready to reboot, since we might not
 108                          * have detected BSP APIC ID or smp_num_cpu
 109                          */
 110                         break;
 111 #endif /* CONFIG_SMP */
 112
 113                 case 'b':
 114                 case 'a':
 115                 case 'k':
 116                 case 't':
 117                 case 'e':
 118                 case 'p':
 119                         reboot_type = *str;
 120                         break;
 121
 122                 case 'f':
 123                         reboot_force = 1;
 124                         break;
 125                 }
 126
 127                 str = strchr(str, ',');
 128                 if (str)
 129                         str++;
 130                 else
 131                         break;
 132         }
 133         return 1;
 134 }
 135
 136 __setup("reboot=", reboot_setup);
 137
 138
 139 /*
 140  * Reboot options and system auto-detection code provided by
 141  * Dell Inc. so their systems "just work". :-)
 142  */
 143
 144 /*
 145  * Some machines require the "reboot=b" or "reboot=k"  commandline options,
 146  * this quirk makes that automatic.
 147  */
 148 static int __init set_bios_reboot(const struct dmi_system_id *d)
 149 {
 150         if (reboot_type != BOOT_BIOS) {
 151                 reboot_type = BOOT_BIOS;
 152                 pr_info("%s series board detected. Selecting %s-method for reboots.\n",
 153                         "BIOS", d->ident);
 154         }
 155         return 0;
 156 }
 157
 158 void __noreturn machine_real_restart(unsigned int type)
 159 {
 160         local_irq_disable();
 161
 162         /*
 163          * Write zero to CMOS register number 0x0f, which the BIOS POST
 164          * routine will recognize as telling it to do a proper reboot.  (Well
 165          * that's what this book in front of me says -- it may only apply to
 166          * the Phoenix BIOS though, it's not clear).  At the same time,
 167          * disable NMIs by setting the top bit in the CMOS address register,
 168          * as we're about to do peculiar things to the CPU.  I'm not sure if
 169          * `outb_p' is needed instead of just `outb'.  Use it to be on the
 170          * safe side.  (Yes, CMOS_WRITE does outb_p's. -  Paul G.)
 171          */
 172         spin_lock(&rtc_lock);
 173         CMOS_WRITE(0x00, 0x8f);
 174         spin_unlock(&rtc_lock);
 175
 176         /*
 177          * Switch back to the initial page table.
 178          */
 179 #ifdef CONFIG_X86_32
 180         load_cr3(initial_page_table);
 181 #else
 182         write_cr3(real_mode_header->trampoline_pgd);
 183 #endif
 184
 185         /* Jump to the identity-mapped low memory code */
 186 #ifdef CONFIG_X86_32
 187         asm volatile("jmpl *%0" : :
 188                      "rm" (real_mode_header->machine_real_restart_asm),
 189                      "a" (type));
 190 #else
 191         asm volatile("ljmpl *%0" : :
 192                      "m" (real_mode_header->machine_real_restart_asm),
 193                      "D" (type));
 194 #endif
 195         unreachable();
 196 }
 197 #ifdef CONFIG_APM_MODULE
 198 EXPORT_SYMBOL(machine_real_restart);
 199 #endif
 200
 201 /*
 202  * Some Apple MacBook and MacBookPro's needs reboot=p to be able to reboot
 203  */
 204 static int __init set_pci_reboot(const struct dmi_system_id *d)
 205 {
 206         if (reboot_type != BOOT_CF9) {
 207                 reboot_type = BOOT_CF9;
 208                 pr_info("%s series board detected. Selecting %s-method for reboots.\n",
 209                         "PCI", d->ident);
 210         }
 211         return 0;
 212 }
 213
 214 static int __init set_kbd_reboot(const struct dmi_system_id *d)
 215 {
 216         if (reboot_type != BOOT_KBD) {
 217                 reboot_type = BOOT_KBD;
 218                 pr_info("%s series board detected. Selecting %s-method for reboot.\n",
 219                         "KBD", d->ident);
 220         }
 221         return 0;
 222 }
 223
 224 /*
 225  * This is a single dmi_table handling all reboot quirks.
 226  */
 227 static struct dmi_system_id __initdata reboot_dmi_table[] = {
 228         {       /* Handle problems with rebooting on Dell E520's */
 229                 .callback = set_bios_reboot,
 230                 .ident = "Dell E520",
 231                 .matches = {
 232                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 233                         DMI_MATCH(DMI_PRODUCT_NAME, "Dell DM061"),
 234                 },
 235         },
 236         {       /* Handle problems with rebooting on Dell 1300's */
 237                 .callback = set_bios_reboot,
 238                 .ident = "Dell PowerEdge 1300",
 239                 .matches = {
 240                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 241                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1300/"),
 242                 },
 243         },
 244         {       /* Handle problems with rebooting on Dell 300's */
 245                 .callback = set_bios_reboot,
 246                 .ident = "Dell PowerEdge 300",
 247                 .matches = {
 248                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 249                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"),
 250                 },
 251         },
 252         {       /* Handle problems with rebooting on Dell Optiplex 745's SFF */
 253                 .callback = set_bios_reboot,
 254                 .ident = "Dell OptiPlex 745",
 255                 .matches = {
 256                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 257                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
 258                 },
 259         },
 260         {       /* Handle problems with rebooting on Dell Optiplex 745's DFF */
 261                 .callback = set_bios_reboot,
 262                 .ident = "Dell OptiPlex 745",
 263                 .matches = {
 264                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 265                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
 266                         DMI_MATCH(DMI_BOARD_NAME, "0MM599"),
 267                 },
 268         },
 269         {       /* Handle problems with rebooting on Dell Optiplex 745 with 0KW626 */
 270                 .callback = set_bios_reboot,
 271                 .ident = "Dell OptiPlex 745",
 272                 .matches = {
 273                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 274                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
 275                         DMI_MATCH(DMI_BOARD_NAME, "0KW626"),
 276                 },
 277         },
 278         {       /* Handle problems with rebooting on Dell Optiplex 330 with 0KP561 */
 279                 .callback = set_bios_reboot,
 280                 .ident = "Dell OptiPlex 330",
 281                 .matches = {
 282                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 283                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 330"),
 284                         DMI_MATCH(DMI_BOARD_NAME, "0KP561"),
 285                 },
 286         },
 287         {       /* Handle problems with rebooting on Dell Optiplex 360 with 0T656F */
 288                 .callback = set_bios_reboot,
 289                 .ident = "Dell OptiPlex 360",
 290                 .matches = {
 291                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 292                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 360"),
 293                         DMI_MATCH(DMI_BOARD_NAME, "0T656F"),
 294                 },
 295         },
 296         {       /* Handle problems with rebooting on Dell OptiPlex 760 with 0G919G */
 297                 .callback = set_bios_reboot,
 298                 .ident = "Dell OptiPlex 760",
 299                 .matches = {
 300                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 301                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 760"),
 302                         DMI_MATCH(DMI_BOARD_NAME, "0G919G"),
 303                 },
 304         },
 305         {       /* Handle problems with rebooting on Dell 2400's */
 306                 .callback = set_bios_reboot,
 307                 .ident = "Dell PowerEdge 2400",
 308                 .matches = {
 309                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 310                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"),
 311                 },
 312         },
 313         {       /* Handle problems with rebooting on Dell T5400's */
 314                 .callback = set_bios_reboot,
 315                 .ident = "Dell Precision T5400",
 316                 .matches = {
 317                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 318                         DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T5400"),
 319                 },
 320         },
 321         {       /* Handle problems with rebooting on Dell T7400's */
 322                 .callback = set_bios_reboot,
 323                 .ident = "Dell Precision T7400",
 324                 .matches = {
 325                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 326                         DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T7400"),
 327                 },
 328         },
 329         {       /* Handle problems with rebooting on HP laptops */
 330                 .callback = set_bios_reboot,
 331                 .ident = "HP Compaq Laptop",
 332                 .matches = {
 333                         DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 334                         DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"),
 335                 },
 336         },
 337         {       /* Handle problems with rebooting on Dell XPS710 */
 338                 .callback = set_bios_reboot,
 339                 .ident = "Dell XPS710",
 340                 .matches = {
 341                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 342                         DMI_MATCH(DMI_PRODUCT_NAME, "Dell XPS710"),
 343                 },
 344         },
 345         {       /* Handle problems with rebooting on Dell DXP061 */
 346                 .callback = set_bios_reboot,
 347                 .ident = "Dell DXP061",
 348                 .matches = {
 349                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 350                         DMI_MATCH(DMI_PRODUCT_NAME, "Dell DXP061"),
 351                 },
 352         },
 353         {       /* Handle problems with rebooting on Sony VGN-Z540N */
 354                 .callback = set_bios_reboot,
 355                 .ident = "Sony VGN-Z540N",
 356                 .matches = {
 357                         DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
 358                         DMI_MATCH(DMI_PRODUCT_NAME, "VGN-Z540N"),
 359                 },
 360         },
 361         {       /* Handle problems with rebooting on ASUS P4S800 */
 362                 .callback = set_bios_reboot,
 363                 .ident = "ASUS P4S800",
 364                 .matches = {
 365                         DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
 366                         DMI_MATCH(DMI_BOARD_NAME, "P4S800"),
 367                 },
 368         },
 369
 370         {       /* Handle reboot issue on Acer Aspire one */
 371                 .callback = set_kbd_reboot,
 372                 .ident = "Acer Aspire One A110",
 373                 .matches = {
 374                         DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
 375                         DMI_MATCH(DMI_PRODUCT_NAME, "AOA110"),
 376                 },
 377         },
 378         {       /* Handle problems with rebooting on Apple MacBook5 */
 379                 .callback = set_pci_reboot,
 380                 .ident = "Apple MacBook5",
 381                 .matches = {
 382                         DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 383                         DMI_MATCH(DMI_PRODUCT_NAME, "MacBook5"),
 384                 },
 385         },
 386         {       /* Handle problems with rebooting on Apple MacBookPro5 */
 387                 .callback = set_pci_reboot,
 388                 .ident = "Apple MacBookPro5",
 389                 .matches = {
 390                         DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 391                         DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro5"),
 392                 },
 393         },
 394         {       /* Handle problems with rebooting on Apple Macmini3,1 */
 395                 .callback = set_pci_reboot,
 396                 .ident = "Apple Macmini3,1",
 397                 .matches = {
 398                         DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 399                         DMI_MATCH(DMI_PRODUCT_NAME, "Macmini3,1"),
 400                 },
 401         },
 402         {       /* Handle problems with rebooting on the iMac9,1. */
 403                 .callback = set_pci_reboot,
 404                 .ident = "Apple iMac9,1",
 405                 .matches = {
 406                         DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 407                         DMI_MATCH(DMI_PRODUCT_NAME, "iMac9,1"),
 408                 },
 409         },
 410         {       /* Handle problems with rebooting on the Latitude E6320. */
 411                 .callback = set_pci_reboot,
 412                 .ident = "Dell Latitude E6320",
 413                 .matches = {
 414                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 415                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6320"),
 416                 },
 417         },
 418         {       /* Handle problems with rebooting on the Latitude E5420. */
 419                 .callback = set_pci_reboot,
 420                 .ident = "Dell Latitude E5420",
 421                 .matches = {
 422                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 423                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E5420"),
 424                 },
 425         },
 426         {       /* Handle problems with rebooting on the Latitude E6420. */
 427                 .callback = set_pci_reboot,
 428                 .ident = "Dell Latitude E6420",
 429                 .matches = {
 430                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 431                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6420"),
 432                 },
 433         },
 434         {       /* Handle problems with rebooting on the OptiPlex 990. */
 435                 .callback = set_pci_reboot,
 436                 .ident = "Dell OptiPlex 990",
 437                 .matches = {
 438                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 439                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 990"),
 440                 },
 441         },
 442         {       /* Handle problems with rebooting on the Precision M6600. */
 443                 .callback = set_pci_reboot,
 444                 .ident = "Dell OptiPlex 990",
 445                 .matches = {
 446                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 447                         DMI_MATCH(DMI_PRODUCT_NAME, "Precision M6600"),
 448                 },
 449         },
 450         { }
 451 };
 452
 453 static int __init reboot_init(void)
 454 {
 455         /*
 456          * Only do the DMI check if reboot_type hasn't been overridden
 457          * on the command line
 458          */
 459         if (reboot_default)
 460                 dmi_check_system(reboot_dmi_table);
 461         return 0;
 462 }
 463 core_initcall(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 pt_regs *regs)
 477 {
 478         cpu_emergency_vmxoff();
 479 }
 480
 481 /* Use NMIs as IPIs to tell all CPUs to disable virtualization */
 482 static void emergency_vmx_disable_all(void)
 483 {
 484         /* Just make sure we won't change CPUs while doing this */
 485         local_irq_disable();
 486
 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                 cpu_vmxoff();
 509
 510                 /* Halt and disable VMX on the other CPUs */
 511                 nmi_shootdown_cpus(vmxoff_nmi);
 512
 513         }
 514 }
 515
 516
 517 void __attribute__((weak)) mach_reboot_fixups(void)
 518 {
 519 }
 520
 521 /*
 522  * Windows compatible x86 hardware expects the following on reboot:
 523  *
 524  * 1) If the FADT has the ACPI reboot register flag set, try it
 525  * 2) If still alive, write to the keyboard controller
 526  * 3) If still alive, write to the ACPI reboot register again
 527  * 4) If still alive, write to the keyboard controller again
 528  *
 529  * If the machine is still alive at this stage, it gives up. We default to
 530  * following the same pattern, except that if we're still alive after (4) we'll
 531  * try to force a triple fault and then cycle between hitting the keyboard
 532  * controller and doing that
 533  */
 534 static void native_machine_emergency_restart(void)
 535 {
 536         int i;
 537         int attempt = 0;
 538         int orig_reboot_type = reboot_type;
 539
 540         if (reboot_emergency)
 541                 emergency_vmx_disable_all();
 542
 543         tboot_shutdown(TB_SHUTDOWN_REBOOT);
 544
 545         /* Tell the BIOS if we want cold or warm reboot */
 546         *((unsigned short *)__va(0x472)) = reboot_mode;
 547
 548         for (;;) {
 549                 /* Could also try the reset bit in the Hammer NB */
 550                 switch (reboot_type) {
 551                 case BOOT_KBD:
 552                         mach_reboot_fixups(); /* For board specific fixups */
 553
 554                         for (i = 0; i < 10; i++) {
 555                                 kb_wait();
 556                                 udelay(50);
 557                                 outb(0xfe, 0x64); /* Pulse reset low */
 558                                 udelay(50);
 559                         }
 560                         if (attempt == 0 && orig_reboot_type == BOOT_ACPI) {
 561                                 attempt = 1;
 562                                 reboot_type = BOOT_ACPI;
 563                         } else {
 564                                 reboot_type = BOOT_TRIPLE;
 565                         }
 566                         break;
 567
 568                 case BOOT_TRIPLE:
 569                         load_idt(&no_idt);
 570                         __asm__ __volatile__("int3");
 571
 572                         reboot_type = BOOT_KBD;
 573                         break;
 574
 575                 case BOOT_BIOS:
 576                         machine_real_restart(MRR_BIOS);
 577
 578                         reboot_type = BOOT_KBD;
 579                         break;
 580
 581                 case BOOT_ACPI:
 582                         acpi_reboot();
 583                         reboot_type = BOOT_KBD;
 584                         break;
 585
 586                 case BOOT_EFI:
 587                         if (efi_enabled(EFI_RUNTIME_SERVICES))
 588                                 efi.reset_system(reboot_mode ?
 589                                                  EFI_RESET_WARM :
 590                                                  EFI_RESET_COLD,
 591                                                  EFI_SUCCESS, 0, NULL);
 592                         reboot_type = BOOT_KBD;
 593                         break;
 594
 595                 case BOOT_CF9:
 596                         port_cf9_safe = true;
 597                         /* Fall through */
 598
 599                 case BOOT_CF9_COND:
 600                         if (port_cf9_safe) {
 601                                 u8 cf9 = inb(0xcf9) & ~6;
 602                                 outb(cf9|2, 0xcf9); /* Request hard reset */
 603                                 udelay(50);
 604                                 outb(cf9|6, 0xcf9); /* Actually do the reset */
 605                                 udelay(50);
 606                         }
 607                         reboot_type = BOOT_KBD;
 608                         break;
 609                 }
 610         }
 611 }
 612
 613 void native_machine_shutdown(void)
 614 {
 615         /* Stop the cpus and apics */
 616 #ifdef CONFIG_SMP
 617
 618         /* The boot cpu is always logical cpu 0 */
 619         int reboot_cpu_id = 0;
 620
 621         /* See if there has been given a command line override */
 622         if ((reboot_cpu != -1) && (reboot_cpu < nr_cpu_ids) &&
 623                 cpu_online(reboot_cpu))
 624                 reboot_cpu_id = reboot_cpu;
 625
 626         /* Make certain the cpu I'm about to reboot on is online */
 627         if (!cpu_online(reboot_cpu_id))
 628                 reboot_cpu_id = smp_processor_id();
 629
 630         /* Make certain I only run on the appropriate processor */
 631         set_cpus_allowed_ptr(current, cpumask_of(reboot_cpu_id));
 632
 633         /*
 634          * O.K Now that I'm on the appropriate processor, stop all of the
 635          * others. Also disable the local irq to not receive the per-cpu
 636          * timer interrupt which may trigger scheduler's load balance.
 637          */
 638         local_irq_disable();
 639         stop_other_cpus();
 640 #endif
 641
 642         lapic_shutdown();
 643
 644 #ifdef CONFIG_X86_IO_APIC
 645         disable_IO_APIC();
 646 #endif
 647
 648 #ifdef CONFIG_HPET_TIMER
 649         hpet_disable();
 650 #endif
 651
 652 #ifdef CONFIG_X86_64
 653         x86_platform.iommu_shutdown();
 654 #endif
 655 }
 656
 657 static void __machine_emergency_restart(int emergency)
 658 {
 659         reboot_emergency = emergency;
 660         machine_ops.emergency_restart();
 661 }
 662
 663 static void native_machine_restart(char *__unused)
 664 {
 665         pr_notice("machine restart\n");
 666
 667         if (!reboot_force)
 668                 machine_shutdown();
 669         __machine_emergency_restart(0);
 670 }
 671
 672 static void native_machine_halt(void)
 673 {
 674         /* Stop other cpus and apics */
 675         machine_shutdown();
 676
 677         tboot_shutdown(TB_SHUTDOWN_HALT);
 678
 679         stop_this_cpu(NULL);
 680 }
 681
 682 static void native_machine_power_off(void)
 683 {
 684         if (pm_power_off) {
 685                 if (!reboot_force)
 686                         machine_shutdown();
 687                 pm_power_off();
 688         }
 689         /* A fallback in case there is no PM info available */
 690         tboot_shutdown(TB_SHUTDOWN_HALT);
 691 }
 692
 693 struct machine_ops machine_ops = {
 694         .power_off = native_machine_power_off,
 695         .shutdown = native_machine_shutdown,
 696         .emergency_restart = native_machine_emergency_restart,
 697         .restart = native_machine_restart,
 698         .halt = native_machine_halt,
 699 #ifdef CONFIG_KEXEC
 700         .crash_shutdown = native_machine_crash_shutdown,
 701 #endif
 702 };
 703
 704 void machine_power_off(void)
 705 {
 706         machine_ops.power_off();
 707 }
 708
 709 void machine_shutdown(void)
 710 {
 711         machine_ops.shutdown();
 712 }
 713
 714 void machine_emergency_restart(void)
 715 {
 716         __machine_emergency_restart(1);
 717 }
 718
 719 void machine_restart(char *cmd)
 720 {
 721         machine_ops.restart(cmd);
 722 }
 723
 724 void machine_halt(void)
 725 {
 726         machine_ops.halt();
 727 }
 728
 729 #ifdef CONFIG_KEXEC
 730 void machine_crash_shutdown(struct pt_regs *regs)
 731 {
 732         machine_ops.crash_shutdown(regs);
 733 }
 734 #endif
 735
 736
 737 #if defined(CONFIG_SMP)
 738
 739 /* This keeps a track of which one is crashing cpu. */
 740 static int crashing_cpu;
 741 static nmi_shootdown_cb shootdown_callback;
 742
 743 static atomic_t waiting_for_crash_ipi;
 744
 745 static int crash_nmi_callback(unsigned int val, struct pt_regs *regs)
 746 {
 747         int cpu;
 748
 749         cpu = raw_smp_processor_id();
 750
 751         /*
 752          * Don't do anything if this handler is invoked on crashing cpu.
 753          * Otherwise, system will completely hang. Crashing cpu can get
 754          * an NMI if system was initially booted with nmi_watchdog parameter.
 755          */
 756         if (cpu == crashing_cpu)
 757                 return NMI_HANDLED;
 758         local_irq_disable();
 759
 760         shootdown_callback(cpu, regs);
 761
 762         atomic_dec(&waiting_for_crash_ipi);
 763         /* Assume hlt works */
 764         halt();
 765         for (;;)
 766                 cpu_relax();
 767
 768         return NMI_HANDLED;
 769 }
 770
 771 static void smp_send_nmi_allbutself(void)
 772 {
 773         apic->send_IPI_allbutself(NMI_VECTOR);
 774 }
 775
 776 /*
 777  * Halt all other CPUs, calling the specified function on each of them
 778  *
 779  * This function can be used to halt all other CPUs on crash
 780  * or emergency reboot time. The function passed as parameter
 781  * will be called inside a NMI handler on all CPUs.
 782  */
 783 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
 784 {
 785         unsigned long msecs;
 786         local_irq_disable();
 787
 788         /* Make a note of crashing cpu. Will be used in NMI callback. */
 789         crashing_cpu = safe_smp_processor_id();
 790
 791         shootdown_callback = callback;
 792
 793         atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
 794         /* Would it be better to replace the trap vector here? */
 795         if (register_nmi_handler(NMI_LOCAL, crash_nmi_callback,
 796                                  NMI_FLAG_FIRST, "crash"))
 797                 return;         /* Return what? */
 798         /*
 799          * Ensure the new callback function is set before sending
 800          * out the NMI
 801          */
 802         wmb();
 803
 804         smp_send_nmi_allbutself();
 805
 806         msecs = 1000; /* Wait at most a second for the other cpus to stop */
 807         while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
 808                 mdelay(1);
 809                 msecs--;
 810         }
 811
 812         /* Leave the nmi callback set */
 813 }
 814 #else /* !CONFIG_SMP */
 815 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
 816 {
 817         /* No other CPUs to shoot down */
 818 }
 819 #endif