linux/arch/x86/kernel/reboot.c
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   1// SPDX-License-Identifier: GPL-2.0
   2#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   3
   4#include <linux/export.h>
   5#include <linux/reboot.h>
   6#include <linux/init.h>
   7#include <linux/pm.h>
   8#include <linux/efi.h>
   9#include <linux/dmi.h>
  10#include <linux/sched.h>
  11#include <linux/tboot.h>
  12#include <linux/delay.h>
  13#include <linux/frame.h>
  14#include <acpi/reboot.h>
  15#include <asm/io.h>
  16#include <asm/apic.h>
  17#include <asm/io_apic.h>
  18#include <asm/desc.h>
  19#include <asm/hpet.h>
  20#include <asm/pgtable.h>
  21#include <asm/proto.h>
  22#include <asm/reboot_fixups.h>
  23#include <asm/reboot.h>
  24#include <asm/pci_x86.h>
  25#include <asm/virtext.h>
  26#include <asm/cpu.h>
  27#include <asm/nmi.h>
  28#include <asm/smp.h>
  29
  30#include <linux/ctype.h>
  31#include <linux/mc146818rtc.h>
  32#include <asm/realmode.h>
  33#include <asm/x86_init.h>
  34#include <asm/efi.h>
  35
  36/*
  37 * Power off function, if any
  38 */
  39void (*pm_power_off)(void);
  40EXPORT_SYMBOL(pm_power_off);
  41
  42/*
  43 * This is set if we need to go through the 'emergency' path.
  44 * When machine_emergency_restart() is called, we may be on
  45 * an inconsistent state and won't be able to do a clean cleanup
  46 */
  47static int reboot_emergency;
  48
  49/* This is set by the PCI code if either type 1 or type 2 PCI is detected */
  50bool port_cf9_safe = false;
  51
  52/*
  53 * Reboot options and system auto-detection code provided by
  54 * Dell Inc. so their systems "just work". :-)
  55 */
  56
  57/*
  58 * Some machines require the "reboot=a" commandline options
  59 */
  60static int __init set_acpi_reboot(const struct dmi_system_id *d)
  61{
  62        if (reboot_type != BOOT_ACPI) {
  63                reboot_type = BOOT_ACPI;
  64                pr_info("%s series board detected. Selecting %s-method for reboots.\n",
  65                        d->ident, "ACPI");
  66        }
  67        return 0;
  68}
  69
  70/*
  71 * Some machines require the "reboot=b" or "reboot=k"  commandline options,
  72 * this quirk makes that automatic.
  73 */
  74static int __init set_bios_reboot(const struct dmi_system_id *d)
  75{
  76        if (reboot_type != BOOT_BIOS) {
  77                reboot_type = BOOT_BIOS;
  78                pr_info("%s series board detected. Selecting %s-method for reboots.\n",
  79                        d->ident, "BIOS");
  80        }
  81        return 0;
  82}
  83
  84/*
  85 * Some machines don't handle the default ACPI reboot method and
  86 * require the EFI reboot method:
  87 */
  88static int __init set_efi_reboot(const struct dmi_system_id *d)
  89{
  90        if (reboot_type != BOOT_EFI && !efi_runtime_disabled()) {
  91                reboot_type = BOOT_EFI;
  92                pr_info("%s series board detected. Selecting EFI-method for reboot.\n", d->ident);
  93        }
  94        return 0;
  95}
  96
  97void __noreturn machine_real_restart(unsigned int type)
  98{
  99        local_irq_disable();
 100
 101        /*
 102         * Write zero to CMOS register number 0x0f, which the BIOS POST
 103         * routine will recognize as telling it to do a proper reboot.  (Well
 104         * that's what this book in front of me says -- it may only apply to
 105         * the Phoenix BIOS though, it's not clear).  At the same time,
 106         * disable NMIs by setting the top bit in the CMOS address register,
 107         * as we're about to do peculiar things to the CPU.  I'm not sure if
 108         * `outb_p' is needed instead of just `outb'.  Use it to be on the
 109         * safe side.  (Yes, CMOS_WRITE does outb_p's. -  Paul G.)
 110         */
 111        spin_lock(&rtc_lock);
 112        CMOS_WRITE(0x00, 0x8f);
 113        spin_unlock(&rtc_lock);
 114
 115        /*
 116         * Switch back to the initial page table.
 117         */
 118#ifdef CONFIG_X86_32
 119        load_cr3(initial_page_table);
 120#else
 121        write_cr3(real_mode_header->trampoline_pgd);
 122
 123        /* Exiting long mode will fail if CR4.PCIDE is set. */
 124        if (boot_cpu_has(X86_FEATURE_PCID))
 125                cr4_clear_bits(X86_CR4_PCIDE);
 126#endif
 127
 128        /* Jump to the identity-mapped low memory code */
 129#ifdef CONFIG_X86_32
 130        asm volatile("jmpl *%0" : :
 131                     "rm" (real_mode_header->machine_real_restart_asm),
 132                     "a" (type));
 133#else
 134        asm volatile("ljmpl *%0" : :
 135                     "m" (real_mode_header->machine_real_restart_asm),
 136                     "D" (type));
 137#endif
 138        unreachable();
 139}
 140#ifdef CONFIG_APM_MODULE
 141EXPORT_SYMBOL(machine_real_restart);
 142#endif
 143STACK_FRAME_NON_STANDARD(machine_real_restart);
 144
 145/*
 146 * Some Apple MacBook and MacBookPro's needs reboot=p to be able to reboot
 147 */
 148static int __init set_pci_reboot(const struct dmi_system_id *d)
 149{
 150        if (reboot_type != BOOT_CF9_FORCE) {
 151                reboot_type = BOOT_CF9_FORCE;
 152                pr_info("%s series board detected. Selecting %s-method for reboots.\n",
 153                        d->ident, "PCI");
 154        }
 155        return 0;
 156}
 157
 158static int __init set_kbd_reboot(const struct dmi_system_id *d)
 159{
 160        if (reboot_type != BOOT_KBD) {
 161                reboot_type = BOOT_KBD;
 162                pr_info("%s series board detected. Selecting %s-method for reboot.\n",
 163                        d->ident, "KBD");
 164        }
 165        return 0;
 166}
 167
 168/*
 169 * This is a single dmi_table handling all reboot quirks.
 170 */
 171static const struct dmi_system_id reboot_dmi_table[] __initconst = {
 172
 173        /* Acer */
 174        {       /* Handle reboot issue on Acer Aspire one */
 175                .callback = set_kbd_reboot,
 176                .ident = "Acer Aspire One A110",
 177                .matches = {
 178                        DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
 179                        DMI_MATCH(DMI_PRODUCT_NAME, "AOA110"),
 180                },
 181        },
 182        {       /* Handle reboot issue on Acer TravelMate X514-51T */
 183                .callback = set_efi_reboot,
 184                .ident = "Acer TravelMate X514-51T",
 185                .matches = {
 186                        DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
 187                        DMI_MATCH(DMI_PRODUCT_NAME, "TravelMate X514-51T"),
 188                },
 189        },
 190
 191        /* Apple */
 192        {       /* Handle problems with rebooting on Apple MacBook5 */
 193                .callback = set_pci_reboot,
 194                .ident = "Apple MacBook5",
 195                .matches = {
 196                        DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 197                        DMI_MATCH(DMI_PRODUCT_NAME, "MacBook5"),
 198                },
 199        },
 200        {       /* Handle problems with rebooting on Apple MacBookPro5 */
 201                .callback = set_pci_reboot,
 202                .ident = "Apple MacBookPro5",
 203                .matches = {
 204                        DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 205                        DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro5"),
 206                },
 207        },
 208        {       /* Handle problems with rebooting on Apple Macmini3,1 */
 209                .callback = set_pci_reboot,
 210                .ident = "Apple Macmini3,1",
 211                .matches = {
 212                        DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 213                        DMI_MATCH(DMI_PRODUCT_NAME, "Macmini3,1"),
 214                },
 215        },
 216        {       /* Handle problems with rebooting on the iMac9,1. */
 217                .callback = set_pci_reboot,
 218                .ident = "Apple iMac9,1",
 219                .matches = {
 220                        DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 221                        DMI_MATCH(DMI_PRODUCT_NAME, "iMac9,1"),
 222                },
 223        },
 224        {       /* Handle problems with rebooting on the iMac10,1. */
 225                .callback = set_pci_reboot,
 226                .ident = "Apple iMac10,1",
 227                .matches = {
 228                    DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 229                    DMI_MATCH(DMI_PRODUCT_NAME, "iMac10,1"),
 230                },
 231        },
 232
 233        /* ASRock */
 234        {       /* Handle problems with rebooting on ASRock Q1900DC-ITX */
 235                .callback = set_pci_reboot,
 236                .ident = "ASRock Q1900DC-ITX",
 237                .matches = {
 238                        DMI_MATCH(DMI_BOARD_VENDOR, "ASRock"),
 239                        DMI_MATCH(DMI_BOARD_NAME, "Q1900DC-ITX"),
 240                },
 241        },
 242
 243        /* ASUS */
 244        {       /* Handle problems with rebooting on ASUS P4S800 */
 245                .callback = set_bios_reboot,
 246                .ident = "ASUS P4S800",
 247                .matches = {
 248                        DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
 249                        DMI_MATCH(DMI_BOARD_NAME, "P4S800"),
 250                },
 251        },
 252        {       /* Handle problems with rebooting on ASUS EeeBook X205TA */
 253                .callback = set_acpi_reboot,
 254                .ident = "ASUS EeeBook X205TA",
 255                .matches = {
 256                        DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
 257                        DMI_MATCH(DMI_PRODUCT_NAME, "X205TA"),
 258                },
 259        },
 260        {       /* Handle problems with rebooting on ASUS EeeBook X205TAW */
 261                .callback = set_acpi_reboot,
 262                .ident = "ASUS EeeBook X205TAW",
 263                .matches = {
 264                        DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
 265                        DMI_MATCH(DMI_PRODUCT_NAME, "X205TAW"),
 266                },
 267        },
 268
 269        /* Certec */
 270        {       /* Handle problems with rebooting on Certec BPC600 */
 271                .callback = set_pci_reboot,
 272                .ident = "Certec BPC600",
 273                .matches = {
 274                        DMI_MATCH(DMI_SYS_VENDOR, "Certec"),
 275                        DMI_MATCH(DMI_PRODUCT_NAME, "BPC600"),
 276                },
 277        },
 278
 279        /* Dell */
 280        {       /* Handle problems with rebooting on Dell DXP061 */
 281                .callback = set_bios_reboot,
 282                .ident = "Dell DXP061",
 283                .matches = {
 284                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 285                        DMI_MATCH(DMI_PRODUCT_NAME, "Dell DXP061"),
 286                },
 287        },
 288        {       /* Handle problems with rebooting on Dell E520's */
 289                .callback = set_bios_reboot,
 290                .ident = "Dell E520",
 291                .matches = {
 292                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 293                        DMI_MATCH(DMI_PRODUCT_NAME, "Dell DM061"),
 294                },
 295        },
 296        {       /* Handle problems with rebooting on the Latitude E5410. */
 297                .callback = set_pci_reboot,
 298                .ident = "Dell Latitude E5410",
 299                .matches = {
 300                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 301                        DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E5410"),
 302                },
 303        },
 304        {       /* Handle problems with rebooting on the Latitude E5420. */
 305                .callback = set_pci_reboot,
 306                .ident = "Dell Latitude E5420",
 307                .matches = {
 308                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 309                        DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E5420"),
 310                },
 311        },
 312        {       /* Handle problems with rebooting on the Latitude E6320. */
 313                .callback = set_pci_reboot,
 314                .ident = "Dell Latitude E6320",
 315                .matches = {
 316                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 317                        DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6320"),
 318                },
 319        },
 320        {       /* Handle problems with rebooting on the Latitude E6420. */
 321                .callback = set_pci_reboot,
 322                .ident = "Dell Latitude E6420",
 323                .matches = {
 324                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 325                        DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6420"),
 326                },
 327        },
 328        {       /* Handle problems with rebooting on Dell Optiplex 330 with 0KP561 */
 329                .callback = set_bios_reboot,
 330                .ident = "Dell OptiPlex 330",
 331                .matches = {
 332                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 333                        DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 330"),
 334                        DMI_MATCH(DMI_BOARD_NAME, "0KP561"),
 335                },
 336        },
 337        {       /* Handle problems with rebooting on Dell Optiplex 360 with 0T656F */
 338                .callback = set_bios_reboot,
 339                .ident = "Dell OptiPlex 360",
 340                .matches = {
 341                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 342                        DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 360"),
 343                        DMI_MATCH(DMI_BOARD_NAME, "0T656F"),
 344                },
 345        },
 346        {       /* Handle problems with rebooting on Dell Optiplex 745's SFF */
 347                .callback = set_bios_reboot,
 348                .ident = "Dell OptiPlex 745",
 349                .matches = {
 350                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 351                        DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
 352                },
 353        },
 354        {       /* Handle problems with rebooting on Dell Optiplex 745's DFF */
 355                .callback = set_bios_reboot,
 356                .ident = "Dell OptiPlex 745",
 357                .matches = {
 358                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 359                        DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
 360                        DMI_MATCH(DMI_BOARD_NAME, "0MM599"),
 361                },
 362        },
 363        {       /* Handle problems with rebooting on Dell Optiplex 745 with 0KW626 */
 364                .callback = set_bios_reboot,
 365                .ident = "Dell OptiPlex 745",
 366                .matches = {
 367                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 368                        DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
 369                        DMI_MATCH(DMI_BOARD_NAME, "0KW626"),
 370                },
 371        },
 372        {       /* Handle problems with rebooting on Dell OptiPlex 760 with 0G919G */
 373                .callback = set_bios_reboot,
 374                .ident = "Dell OptiPlex 760",
 375                .matches = {
 376                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 377                        DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 760"),
 378                        DMI_MATCH(DMI_BOARD_NAME, "0G919G"),
 379                },
 380        },
 381        {       /* Handle problems with rebooting on the OptiPlex 990. */
 382                .callback = set_pci_reboot,
 383                .ident = "Dell OptiPlex 990",
 384                .matches = {
 385                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 386                        DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 990"),
 387                },
 388        },
 389        {       /* Handle problems with rebooting on Dell 300's */
 390                .callback = set_bios_reboot,
 391                .ident = "Dell PowerEdge 300",
 392                .matches = {
 393                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 394                        DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"),
 395                },
 396        },
 397        {       /* Handle problems with rebooting on Dell 1300's */
 398                .callback = set_bios_reboot,
 399                .ident = "Dell PowerEdge 1300",
 400                .matches = {
 401                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 402                        DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1300/"),
 403                },
 404        },
 405        {       /* Handle problems with rebooting on Dell 2400's */
 406                .callback = set_bios_reboot,
 407                .ident = "Dell PowerEdge 2400",
 408                .matches = {
 409                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 410                        DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"),
 411                },
 412        },
 413        {       /* Handle problems with rebooting on the Dell PowerEdge C6100. */
 414                .callback = set_pci_reboot,
 415                .ident = "Dell PowerEdge C6100",
 416                .matches = {
 417                        DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
 418                        DMI_MATCH(DMI_PRODUCT_NAME, "C6100"),
 419                },
 420        },
 421        {       /* Handle problems with rebooting on the Precision M6600. */
 422                .callback = set_pci_reboot,
 423                .ident = "Dell Precision M6600",
 424                .matches = {
 425                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 426                        DMI_MATCH(DMI_PRODUCT_NAME, "Precision M6600"),
 427                },
 428        },
 429        {       /* Handle problems with rebooting on Dell T5400's */
 430                .callback = set_bios_reboot,
 431                .ident = "Dell Precision T5400",
 432                .matches = {
 433                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 434                        DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T5400"),
 435                },
 436        },
 437        {       /* Handle problems with rebooting on Dell T7400's */
 438                .callback = set_bios_reboot,
 439                .ident = "Dell Precision T7400",
 440                .matches = {
 441                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 442                        DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T7400"),
 443                },
 444        },
 445        {       /* Handle problems with rebooting on Dell XPS710 */
 446                .callback = set_bios_reboot,
 447                .ident = "Dell XPS710",
 448                .matches = {
 449                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 450                        DMI_MATCH(DMI_PRODUCT_NAME, "Dell XPS710"),
 451                },
 452        },
 453        {       /* Handle problems with rebooting on Dell Optiplex 7450 AIO */
 454                .callback = set_acpi_reboot,
 455                .ident = "Dell OptiPlex 7450 AIO",
 456                .matches = {
 457                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 458                        DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 7450 AIO"),
 459                },
 460        },
 461
 462        /* Hewlett-Packard */
 463        {       /* Handle problems with rebooting on HP laptops */
 464                .callback = set_bios_reboot,
 465                .ident = "HP Compaq Laptop",
 466                .matches = {
 467                        DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 468                        DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"),
 469                },
 470        },
 471
 472        /* Sony */
 473        {       /* Handle problems with rebooting on Sony VGN-Z540N */
 474                .callback = set_bios_reboot,
 475                .ident = "Sony VGN-Z540N",
 476                .matches = {
 477                        DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
 478                        DMI_MATCH(DMI_PRODUCT_NAME, "VGN-Z540N"),
 479                },
 480        },
 481
 482        { }
 483};
 484
 485static int __init reboot_init(void)
 486{
 487        int rv;
 488
 489        /*
 490         * Only do the DMI check if reboot_type hasn't been overridden
 491         * on the command line
 492         */
 493        if (!reboot_default)
 494                return 0;
 495
 496        /*
 497         * The DMI quirks table takes precedence. If no quirks entry
 498         * matches and the ACPI Hardware Reduced bit is set and EFI
 499         * runtime services are enabled, force EFI reboot.
 500         */
 501        rv = dmi_check_system(reboot_dmi_table);
 502
 503        if (!rv && efi_reboot_required() && !efi_runtime_disabled())
 504                reboot_type = BOOT_EFI;
 505
 506        return 0;
 507}
 508core_initcall(reboot_init);
 509
 510static inline void kb_wait(void)
 511{
 512        int i;
 513
 514        for (i = 0; i < 0x10000; i++) {
 515                if ((inb(0x64) & 0x02) == 0)
 516                        break;
 517                udelay(2);
 518        }
 519}
 520
 521static void vmxoff_nmi(int cpu, struct pt_regs *regs)
 522{
 523        cpu_emergency_vmxoff();
 524}
 525
 526/* Use NMIs as IPIs to tell all CPUs to disable virtualization */
 527static void emergency_vmx_disable_all(void)
 528{
 529        /* Just make sure we won't change CPUs while doing this */
 530        local_irq_disable();
 531
 532        /*
 533         * We need to disable VMX on all CPUs before rebooting, otherwise
 534         * we risk hanging up the machine, because the CPU ignores INIT
 535         * signals when VMX is enabled.
 536         *
 537         * We can't take any locks and we may be on an inconsistent
 538         * state, so we use NMIs as IPIs to tell the other CPUs to disable
 539         * VMX and halt.
 540         *
 541         * For safety, we will avoid running the nmi_shootdown_cpus()
 542         * stuff unnecessarily, but we don't have a way to check
 543         * if other CPUs have VMX enabled. So we will call it only if the
 544         * CPU we are running on has VMX enabled.
 545         *
 546         * We will miss cases where VMX is not enabled on all CPUs. This
 547         * shouldn't do much harm because KVM always enable VMX on all
 548         * CPUs anyway. But we can miss it on the small window where KVM
 549         * is still enabling VMX.
 550         */
 551        if (cpu_has_vmx() && cpu_vmx_enabled()) {
 552                /* Disable VMX on this CPU. */
 553                cpu_vmxoff();
 554
 555                /* Halt and disable VMX on the other CPUs */
 556                nmi_shootdown_cpus(vmxoff_nmi);
 557
 558        }
 559}
 560
 561
 562void __attribute__((weak)) mach_reboot_fixups(void)
 563{
 564}
 565
 566/*
 567 * To the best of our knowledge Windows compatible x86 hardware expects
 568 * the following on reboot:
 569 *
 570 * 1) If the FADT has the ACPI reboot register flag set, try it
 571 * 2) If still alive, write to the keyboard controller
 572 * 3) If still alive, write to the ACPI reboot register again
 573 * 4) If still alive, write to the keyboard controller again
 574 * 5) If still alive, call the EFI runtime service to reboot
 575 * 6) If no EFI runtime service, call the BIOS to do a reboot
 576 *
 577 * We default to following the same pattern. We also have
 578 * two other reboot methods: 'triple fault' and 'PCI', which
 579 * can be triggered via the reboot= kernel boot option or
 580 * via quirks.
 581 *
 582 * This means that this function can never return, it can misbehave
 583 * by not rebooting properly and hanging.
 584 */
 585static void native_machine_emergency_restart(void)
 586{
 587        int i;
 588        int attempt = 0;
 589        int orig_reboot_type = reboot_type;
 590        unsigned short mode;
 591
 592        if (reboot_emergency)
 593                emergency_vmx_disable_all();
 594
 595        tboot_shutdown(TB_SHUTDOWN_REBOOT);
 596
 597        /* Tell the BIOS if we want cold or warm reboot */
 598        mode = reboot_mode == REBOOT_WARM ? 0x1234 : 0;
 599        *((unsigned short *)__va(0x472)) = mode;
 600
 601        /*
 602         * If an EFI capsule has been registered with the firmware then
 603         * override the reboot= parameter.
 604         */
 605        if (efi_capsule_pending(NULL)) {
 606                pr_info("EFI capsule is pending, forcing EFI reboot.\n");
 607                reboot_type = BOOT_EFI;
 608        }
 609
 610        for (;;) {
 611                /* Could also try the reset bit in the Hammer NB */
 612                switch (reboot_type) {
 613                case BOOT_ACPI:
 614                        acpi_reboot();
 615                        reboot_type = BOOT_KBD;
 616                        break;
 617
 618                case BOOT_KBD:
 619                        mach_reboot_fixups(); /* For board specific fixups */
 620
 621                        for (i = 0; i < 10; i++) {
 622                                kb_wait();
 623                                udelay(50);
 624                                outb(0xfe, 0x64); /* Pulse reset low */
 625                                udelay(50);
 626                        }
 627                        if (attempt == 0 && orig_reboot_type == BOOT_ACPI) {
 628                                attempt = 1;
 629                                reboot_type = BOOT_ACPI;
 630                        } else {
 631                                reboot_type = BOOT_EFI;
 632                        }
 633                        break;
 634
 635                case BOOT_EFI:
 636                        efi_reboot(reboot_mode, NULL);
 637                        reboot_type = BOOT_BIOS;
 638                        break;
 639
 640                case BOOT_BIOS:
 641                        machine_real_restart(MRR_BIOS);
 642
 643                        /* We're probably dead after this, but... */
 644                        reboot_type = BOOT_CF9_SAFE;
 645                        break;
 646
 647                case BOOT_CF9_FORCE:
 648                        port_cf9_safe = true;
 649                        /* Fall through */
 650
 651                case BOOT_CF9_SAFE:
 652                        if (port_cf9_safe) {
 653                                u8 reboot_code = reboot_mode == REBOOT_WARM ?  0x06 : 0x0E;
 654                                u8 cf9 = inb(0xcf9) & ~reboot_code;
 655                                outb(cf9|2, 0xcf9); /* Request hard reset */
 656                                udelay(50);
 657                                /* Actually do the reset */
 658                                outb(cf9|reboot_code, 0xcf9);
 659                                udelay(50);
 660                        }
 661                        reboot_type = BOOT_TRIPLE;
 662                        break;
 663
 664                case BOOT_TRIPLE:
 665                        idt_invalidate(NULL);
 666                        __asm__ __volatile__("int3");
 667
 668                        /* We're probably dead after this, but... */
 669                        reboot_type = BOOT_KBD;
 670                        break;
 671                }
 672        }
 673}
 674
 675void native_machine_shutdown(void)
 676{
 677        /* Stop the cpus and apics */
 678#ifdef CONFIG_X86_IO_APIC
 679        /*
 680         * Disabling IO APIC before local APIC is a workaround for
 681         * erratum AVR31 in "Intel Atom Processor C2000 Product Family
 682         * Specification Update". In this situation, interrupts that target
 683         * a Logical Processor whose Local APIC is either in the process of
 684         * being hardware disabled or software disabled are neither delivered
 685         * nor discarded. When this erratum occurs, the processor may hang.
 686         *
 687         * Even without the erratum, it still makes sense to quiet IO APIC
 688         * before disabling Local APIC.
 689         */
 690        clear_IO_APIC();
 691#endif
 692
 693#ifdef CONFIG_SMP
 694        /*
 695         * Stop all of the others. Also disable the local irq to
 696         * not receive the per-cpu timer interrupt which may trigger
 697         * scheduler's load balance.
 698         */
 699        local_irq_disable();
 700        stop_other_cpus();
 701#endif
 702
 703        lapic_shutdown();
 704        restore_boot_irq_mode();
 705
 706#ifdef CONFIG_HPET_TIMER
 707        hpet_disable();
 708#endif
 709
 710#ifdef CONFIG_X86_64
 711        x86_platform.iommu_shutdown();
 712#endif
 713}
 714
 715static void __machine_emergency_restart(int emergency)
 716{
 717        reboot_emergency = emergency;
 718        machine_ops.emergency_restart();
 719}
 720
 721static void native_machine_restart(char *__unused)
 722{
 723        pr_notice("machine restart\n");
 724
 725        if (!reboot_force)
 726                machine_shutdown();
 727        __machine_emergency_restart(0);
 728}
 729
 730static void native_machine_halt(void)
 731{
 732        /* Stop other cpus and apics */
 733        machine_shutdown();
 734
 735        tboot_shutdown(TB_SHUTDOWN_HALT);
 736
 737        stop_this_cpu(NULL);
 738}
 739
 740static void native_machine_power_off(void)
 741{
 742        if (pm_power_off) {
 743                if (!reboot_force)
 744                        machine_shutdown();
 745                pm_power_off();
 746        }
 747        /* A fallback in case there is no PM info available */
 748        tboot_shutdown(TB_SHUTDOWN_HALT);
 749}
 750
 751struct machine_ops machine_ops __ro_after_init = {
 752        .power_off = native_machine_power_off,
 753        .shutdown = native_machine_shutdown,
 754        .emergency_restart = native_machine_emergency_restart,
 755        .restart = native_machine_restart,
 756        .halt = native_machine_halt,
 757#ifdef CONFIG_KEXEC_CORE
 758        .crash_shutdown = native_machine_crash_shutdown,
 759#endif
 760};
 761
 762void machine_power_off(void)
 763{
 764        machine_ops.power_off();
 765}
 766
 767void machine_shutdown(void)
 768{
 769        machine_ops.shutdown();
 770}
 771
 772void machine_emergency_restart(void)
 773{
 774        __machine_emergency_restart(1);
 775}
 776
 777void machine_restart(char *cmd)
 778{
 779        machine_ops.restart(cmd);
 780}
 781
 782void machine_halt(void)
 783{
 784        machine_ops.halt();
 785}
 786
 787#ifdef CONFIG_KEXEC_CORE
 788void machine_crash_shutdown(struct pt_regs *regs)
 789{
 790        machine_ops.crash_shutdown(regs);
 791}
 792#endif
 793
 794
 795/* This is the CPU performing the emergency shutdown work. */
 796int crashing_cpu = -1;
 797
 798#if defined(CONFIG_SMP)
 799
 800static nmi_shootdown_cb shootdown_callback;
 801
 802static atomic_t waiting_for_crash_ipi;
 803static int crash_ipi_issued;
 804
 805static int crash_nmi_callback(unsigned int val, struct pt_regs *regs)
 806{
 807        int cpu;
 808
 809        cpu = raw_smp_processor_id();
 810
 811        /*
 812         * Don't do anything if this handler is invoked on crashing cpu.
 813         * Otherwise, system will completely hang. Crashing cpu can get
 814         * an NMI if system was initially booted with nmi_watchdog parameter.
 815         */
 816        if (cpu == crashing_cpu)
 817                return NMI_HANDLED;
 818        local_irq_disable();
 819
 820        shootdown_callback(cpu, regs);
 821
 822        atomic_dec(&waiting_for_crash_ipi);
 823        /* Assume hlt works */
 824        halt();
 825        for (;;)
 826                cpu_relax();
 827
 828        return NMI_HANDLED;
 829}
 830
 831/*
 832 * Halt all other CPUs, calling the specified function on each of them
 833 *
 834 * This function can be used to halt all other CPUs on crash
 835 * or emergency reboot time. The function passed as parameter
 836 * will be called inside a NMI handler on all CPUs.
 837 */
 838void nmi_shootdown_cpus(nmi_shootdown_cb callback)
 839{
 840        unsigned long msecs;
 841        local_irq_disable();
 842
 843        /* Make a note of crashing cpu. Will be used in NMI callback. */
 844        crashing_cpu = safe_smp_processor_id();
 845
 846        shootdown_callback = callback;
 847
 848        atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
 849        /* Would it be better to replace the trap vector here? */
 850        if (register_nmi_handler(NMI_LOCAL, crash_nmi_callback,
 851                                 NMI_FLAG_FIRST, "crash"))
 852                return;         /* Return what? */
 853        /*
 854         * Ensure the new callback function is set before sending
 855         * out the NMI
 856         */
 857        wmb();
 858
 859        apic_send_IPI_allbutself(NMI_VECTOR);
 860
 861        /* Kick CPUs looping in NMI context. */
 862        WRITE_ONCE(crash_ipi_issued, 1);
 863
 864        msecs = 1000; /* Wait at most a second for the other cpus to stop */
 865        while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
 866                mdelay(1);
 867                msecs--;
 868        }
 869
 870        /* Leave the nmi callback set */
 871}
 872
 873/*
 874 * Check if the crash dumping IPI got issued and if so, call its callback
 875 * directly. This function is used when we have already been in NMI handler.
 876 * It doesn't return.
 877 */
 878void run_crash_ipi_callback(struct pt_regs *regs)
 879{
 880        if (crash_ipi_issued)
 881                crash_nmi_callback(0, regs);
 882}
 883
 884/* Override the weak function in kernel/panic.c */
 885void nmi_panic_self_stop(struct pt_regs *regs)
 886{
 887        while (1) {
 888                /* If no CPU is preparing crash dump, we simply loop here. */
 889                run_crash_ipi_callback(regs);
 890                cpu_relax();
 891        }
 892}
 893
 894#else /* !CONFIG_SMP */
 895void nmi_shootdown_cpus(nmi_shootdown_cb callback)
 896{
 897        /* No other CPUs to shoot down */
 898}
 899
 900void run_crash_ipi_callback(struct pt_regs *regs)
 901{
 902}
 903#endif
 904