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/objtool.h>
  14#include <linux/pgtable.h>
  15#include <acpi/reboot.h>
  16#include <asm/io.h>
  17#include <asm/apic.h>
  18#include <asm/io_apic.h>
  19#include <asm/desc.h>
  20#include <asm/hpet.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 MacBook6,1 */
 201                .callback = set_pci_reboot,
 202                .ident = "Apple MacBook6,1",
 203                .matches = {
 204                        DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 205                        DMI_MATCH(DMI_PRODUCT_NAME, "MacBook6,1"),
 206                },
 207        },
 208        {       /* Handle problems with rebooting on Apple MacBookPro5 */
 209                .callback = set_pci_reboot,
 210                .ident = "Apple MacBookPro5",
 211                .matches = {
 212                        DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 213                        DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro5"),
 214                },
 215        },
 216        {       /* Handle problems with rebooting on Apple Macmini3,1 */
 217                .callback = set_pci_reboot,
 218                .ident = "Apple Macmini3,1",
 219                .matches = {
 220                        DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 221                        DMI_MATCH(DMI_PRODUCT_NAME, "Macmini3,1"),
 222                },
 223        },
 224        {       /* Handle problems with rebooting on the iMac9,1. */
 225                .callback = set_pci_reboot,
 226                .ident = "Apple iMac9,1",
 227                .matches = {
 228                        DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 229                        DMI_MATCH(DMI_PRODUCT_NAME, "iMac9,1"),
 230                },
 231        },
 232        {       /* Handle problems with rebooting on the iMac10,1. */
 233                .callback = set_pci_reboot,
 234                .ident = "Apple iMac10,1",
 235                .matches = {
 236                    DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 237                    DMI_MATCH(DMI_PRODUCT_NAME, "iMac10,1"),
 238                },
 239        },
 240
 241        /* ASRock */
 242        {       /* Handle problems with rebooting on ASRock Q1900DC-ITX */
 243                .callback = set_pci_reboot,
 244                .ident = "ASRock Q1900DC-ITX",
 245                .matches = {
 246                        DMI_MATCH(DMI_BOARD_VENDOR, "ASRock"),
 247                        DMI_MATCH(DMI_BOARD_NAME, "Q1900DC-ITX"),
 248                },
 249        },
 250
 251        /* ASUS */
 252        {       /* Handle problems with rebooting on ASUS P4S800 */
 253                .callback = set_bios_reboot,
 254                .ident = "ASUS P4S800",
 255                .matches = {
 256                        DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
 257                        DMI_MATCH(DMI_BOARD_NAME, "P4S800"),
 258                },
 259        },
 260        {       /* Handle problems with rebooting on ASUS EeeBook X205TA */
 261                .callback = set_acpi_reboot,
 262                .ident = "ASUS EeeBook X205TA",
 263                .matches = {
 264                        DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
 265                        DMI_MATCH(DMI_PRODUCT_NAME, "X205TA"),
 266                },
 267        },
 268        {       /* Handle problems with rebooting on ASUS EeeBook X205TAW */
 269                .callback = set_acpi_reboot,
 270                .ident = "ASUS EeeBook X205TAW",
 271                .matches = {
 272                        DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
 273                        DMI_MATCH(DMI_PRODUCT_NAME, "X205TAW"),
 274                },
 275        },
 276
 277        /* Certec */
 278        {       /* Handle problems with rebooting on Certec BPC600 */
 279                .callback = set_pci_reboot,
 280                .ident = "Certec BPC600",
 281                .matches = {
 282                        DMI_MATCH(DMI_SYS_VENDOR, "Certec"),
 283                        DMI_MATCH(DMI_PRODUCT_NAME, "BPC600"),
 284                },
 285        },
 286
 287        /* Dell */
 288        {       /* Handle problems with rebooting on Dell DXP061 */
 289                .callback = set_bios_reboot,
 290                .ident = "Dell DXP061",
 291                .matches = {
 292                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 293                        DMI_MATCH(DMI_PRODUCT_NAME, "Dell DXP061"),
 294                },
 295        },
 296        {       /* Handle problems with rebooting on Dell E520's */
 297                .callback = set_bios_reboot,
 298                .ident = "Dell E520",
 299                .matches = {
 300                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 301                        DMI_MATCH(DMI_PRODUCT_NAME, "Dell DM061"),
 302                },
 303        },
 304        {       /* Handle problems with rebooting on the Latitude E5410. */
 305                .callback = set_pci_reboot,
 306                .ident = "Dell Latitude E5410",
 307                .matches = {
 308                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 309                        DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E5410"),
 310                },
 311        },
 312        {       /* Handle problems with rebooting on the Latitude E5420. */
 313                .callback = set_pci_reboot,
 314                .ident = "Dell Latitude E5420",
 315                .matches = {
 316                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 317                        DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E5420"),
 318                },
 319        },
 320        {       /* Handle problems with rebooting on the Latitude E6320. */
 321                .callback = set_pci_reboot,
 322                .ident = "Dell Latitude E6320",
 323                .matches = {
 324                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 325                        DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6320"),
 326                },
 327        },
 328        {       /* Handle problems with rebooting on the Latitude E6420. */
 329                .callback = set_pci_reboot,
 330                .ident = "Dell Latitude E6420",
 331                .matches = {
 332                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 333                        DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6420"),
 334                },
 335        },
 336        {       /* Handle problems with rebooting on Dell Optiplex 330 with 0KP561 */
 337                .callback = set_bios_reboot,
 338                .ident = "Dell OptiPlex 330",
 339                .matches = {
 340                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 341                        DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 330"),
 342                        DMI_MATCH(DMI_BOARD_NAME, "0KP561"),
 343                },
 344        },
 345        {       /* Handle problems with rebooting on Dell Optiplex 360 with 0T656F */
 346                .callback = set_bios_reboot,
 347                .ident = "Dell OptiPlex 360",
 348                .matches = {
 349                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 350                        DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 360"),
 351                        DMI_MATCH(DMI_BOARD_NAME, "0T656F"),
 352                },
 353        },
 354        {       /* Handle problems with rebooting on Dell Optiplex 745's SFF */
 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                },
 361        },
 362        {       /* Handle problems with rebooting on Dell Optiplex 745's DFF */
 363                .callback = set_bios_reboot,
 364                .ident = "Dell OptiPlex 745",
 365                .matches = {
 366                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 367                        DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
 368                        DMI_MATCH(DMI_BOARD_NAME, "0MM599"),
 369                },
 370        },
 371        {       /* Handle problems with rebooting on Dell Optiplex 745 with 0KW626 */
 372                .callback = set_bios_reboot,
 373                .ident = "Dell OptiPlex 745",
 374                .matches = {
 375                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 376                        DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
 377                        DMI_MATCH(DMI_BOARD_NAME, "0KW626"),
 378                },
 379        },
 380        {       /* Handle problems with rebooting on Dell OptiPlex 760 with 0G919G */
 381                .callback = set_bios_reboot,
 382                .ident = "Dell OptiPlex 760",
 383                .matches = {
 384                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 385                        DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 760"),
 386                        DMI_MATCH(DMI_BOARD_NAME, "0G919G"),
 387                },
 388        },
 389        {       /* Handle problems with rebooting on the OptiPlex 990. */
 390                .callback = set_pci_reboot,
 391                .ident = "Dell OptiPlex 990",
 392                .matches = {
 393                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 394                        DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 990"),
 395                },
 396        },
 397        {       /* Handle problems with rebooting on Dell 300's */
 398                .callback = set_bios_reboot,
 399                .ident = "Dell PowerEdge 300",
 400                .matches = {
 401                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 402                        DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"),
 403                },
 404        },
 405        {       /* Handle problems with rebooting on Dell 1300's */
 406                .callback = set_bios_reboot,
 407                .ident = "Dell PowerEdge 1300",
 408                .matches = {
 409                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 410                        DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1300/"),
 411                },
 412        },
 413        {       /* Handle problems with rebooting on Dell 2400's */
 414                .callback = set_bios_reboot,
 415                .ident = "Dell PowerEdge 2400",
 416                .matches = {
 417                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 418                        DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"),
 419                },
 420        },
 421        {       /* Handle problems with rebooting on the Dell PowerEdge C6100. */
 422                .callback = set_pci_reboot,
 423                .ident = "Dell PowerEdge C6100",
 424                .matches = {
 425                        DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
 426                        DMI_MATCH(DMI_PRODUCT_NAME, "C6100"),
 427                },
 428        },
 429        {       /* Handle problems with rebooting on the Precision M6600. */
 430                .callback = set_pci_reboot,
 431                .ident = "Dell Precision M6600",
 432                .matches = {
 433                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 434                        DMI_MATCH(DMI_PRODUCT_NAME, "Precision M6600"),
 435                },
 436        },
 437        {       /* Handle problems with rebooting on Dell T5400's */
 438                .callback = set_bios_reboot,
 439                .ident = "Dell Precision T5400",
 440                .matches = {
 441                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 442                        DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T5400"),
 443                },
 444        },
 445        {       /* Handle problems with rebooting on Dell T7400's */
 446                .callback = set_bios_reboot,
 447                .ident = "Dell Precision T7400",
 448                .matches = {
 449                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 450                        DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T7400"),
 451                },
 452        },
 453        {       /* Handle problems with rebooting on Dell XPS710 */
 454                .callback = set_bios_reboot,
 455                .ident = "Dell XPS710",
 456                .matches = {
 457                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 458                        DMI_MATCH(DMI_PRODUCT_NAME, "Dell XPS710"),
 459                },
 460        },
 461        {       /* Handle problems with rebooting on Dell Optiplex 7450 AIO */
 462                .callback = set_acpi_reboot,
 463                .ident = "Dell OptiPlex 7450 AIO",
 464                .matches = {
 465                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 466                        DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 7450 AIO"),
 467                },
 468        },
 469
 470        /* Hewlett-Packard */
 471        {       /* Handle problems with rebooting on HP laptops */
 472                .callback = set_bios_reboot,
 473                .ident = "HP Compaq Laptop",
 474                .matches = {
 475                        DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 476                        DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"),
 477                },
 478        },
 479
 480        {       /* PCIe Wifi card isn't detected after reboot otherwise */
 481                .callback = set_pci_reboot,
 482                .ident = "Zotac ZBOX CI327 nano",
 483                .matches = {
 484                        DMI_MATCH(DMI_SYS_VENDOR, "NA"),
 485                        DMI_MATCH(DMI_PRODUCT_NAME, "ZBOX-CI327NANO-GS-01"),
 486                },
 487        },
 488
 489        /* Sony */
 490        {       /* Handle problems with rebooting on Sony VGN-Z540N */
 491                .callback = set_bios_reboot,
 492                .ident = "Sony VGN-Z540N",
 493                .matches = {
 494                        DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
 495                        DMI_MATCH(DMI_PRODUCT_NAME, "VGN-Z540N"),
 496                },
 497        },
 498
 499        { }
 500};
 501
 502static int __init reboot_init(void)
 503{
 504        int rv;
 505
 506        /*
 507         * Only do the DMI check if reboot_type hasn't been overridden
 508         * on the command line
 509         */
 510        if (!reboot_default)
 511                return 0;
 512
 513        /*
 514         * The DMI quirks table takes precedence. If no quirks entry
 515         * matches and the ACPI Hardware Reduced bit is set and EFI
 516         * runtime services are enabled, force EFI reboot.
 517         */
 518        rv = dmi_check_system(reboot_dmi_table);
 519
 520        if (!rv && efi_reboot_required() && !efi_runtime_disabled())
 521                reboot_type = BOOT_EFI;
 522
 523        return 0;
 524}
 525core_initcall(reboot_init);
 526
 527static inline void kb_wait(void)
 528{
 529        int i;
 530
 531        for (i = 0; i < 0x10000; i++) {
 532                if ((inb(0x64) & 0x02) == 0)
 533                        break;
 534                udelay(2);
 535        }
 536}
 537
 538static void vmxoff_nmi(int cpu, struct pt_regs *regs)
 539{
 540        cpu_emergency_vmxoff();
 541}
 542
 543/* Use NMIs as IPIs to tell all CPUs to disable virtualization */
 544static void emergency_vmx_disable_all(void)
 545{
 546        /* Just make sure we won't change CPUs while doing this */
 547        local_irq_disable();
 548
 549        /*
 550         * Disable VMX on all CPUs before rebooting, otherwise we risk hanging
 551         * the machine, because the CPU blocks INIT when it's in VMX root.
 552         *
 553         * We can't take any locks and we may be on an inconsistent state, so
 554         * use NMIs as IPIs to tell the other CPUs to exit VMX root and halt.
 555         *
 556         * Do the NMI shootdown even if VMX if off on _this_ CPU, as that
 557         * doesn't prevent a different CPU from being in VMX root operation.
 558         */
 559        if (cpu_has_vmx()) {
 560                /* Safely force _this_ CPU out of VMX root operation. */
 561                __cpu_emergency_vmxoff();
 562
 563                /* Halt and exit VMX root operation on the other CPUs. */
 564                nmi_shootdown_cpus(vmxoff_nmi);
 565        }
 566}
 567
 568
 569void __attribute__((weak)) mach_reboot_fixups(void)
 570{
 571}
 572
 573/*
 574 * To the best of our knowledge Windows compatible x86 hardware expects
 575 * the following on reboot:
 576 *
 577 * 1) If the FADT has the ACPI reboot register flag set, try it
 578 * 2) If still alive, write to the keyboard controller
 579 * 3) If still alive, write to the ACPI reboot register again
 580 * 4) If still alive, write to the keyboard controller again
 581 * 5) If still alive, call the EFI runtime service to reboot
 582 * 6) If no EFI runtime service, call the BIOS to do a reboot
 583 *
 584 * We default to following the same pattern. We also have
 585 * two other reboot methods: 'triple fault' and 'PCI', which
 586 * can be triggered via the reboot= kernel boot option or
 587 * via quirks.
 588 *
 589 * This means that this function can never return, it can misbehave
 590 * by not rebooting properly and hanging.
 591 */
 592static void native_machine_emergency_restart(void)
 593{
 594        int i;
 595        int attempt = 0;
 596        int orig_reboot_type = reboot_type;
 597        unsigned short mode;
 598
 599        if (reboot_emergency)
 600                emergency_vmx_disable_all();
 601
 602        tboot_shutdown(TB_SHUTDOWN_REBOOT);
 603
 604        /* Tell the BIOS if we want cold or warm reboot */
 605        mode = reboot_mode == REBOOT_WARM ? 0x1234 : 0;
 606        *((unsigned short *)__va(0x472)) = mode;
 607
 608        /*
 609         * If an EFI capsule has been registered with the firmware then
 610         * override the reboot= parameter.
 611         */
 612        if (efi_capsule_pending(NULL)) {
 613                pr_info("EFI capsule is pending, forcing EFI reboot.\n");
 614                reboot_type = BOOT_EFI;
 615        }
 616
 617        for (;;) {
 618                /* Could also try the reset bit in the Hammer NB */
 619                switch (reboot_type) {
 620                case BOOT_ACPI:
 621                        acpi_reboot();
 622                        reboot_type = BOOT_KBD;
 623                        break;
 624
 625                case BOOT_KBD:
 626                        mach_reboot_fixups(); /* For board specific fixups */
 627
 628                        for (i = 0; i < 10; i++) {
 629                                kb_wait();
 630                                udelay(50);
 631                                outb(0xfe, 0x64); /* Pulse reset low */
 632                                udelay(50);
 633                        }
 634                        if (attempt == 0 && orig_reboot_type == BOOT_ACPI) {
 635                                attempt = 1;
 636                                reboot_type = BOOT_ACPI;
 637                        } else {
 638                                reboot_type = BOOT_EFI;
 639                        }
 640                        break;
 641
 642                case BOOT_EFI:
 643                        efi_reboot(reboot_mode, NULL);
 644                        reboot_type = BOOT_BIOS;
 645                        break;
 646
 647                case BOOT_BIOS:
 648                        machine_real_restart(MRR_BIOS);
 649
 650                        /* We're probably dead after this, but... */
 651                        reboot_type = BOOT_CF9_SAFE;
 652                        break;
 653
 654                case BOOT_CF9_FORCE:
 655                        port_cf9_safe = true;
 656                        fallthrough;
 657
 658                case BOOT_CF9_SAFE:
 659                        if (port_cf9_safe) {
 660                                u8 reboot_code = reboot_mode == REBOOT_WARM ?  0x06 : 0x0E;
 661                                u8 cf9 = inb(0xcf9) & ~reboot_code;
 662                                outb(cf9|2, 0xcf9); /* Request hard reset */
 663                                udelay(50);
 664                                /* Actually do the reset */
 665                                outb(cf9|reboot_code, 0xcf9);
 666                                udelay(50);
 667                        }
 668                        reboot_type = BOOT_TRIPLE;
 669                        break;
 670
 671                case BOOT_TRIPLE:
 672                        idt_invalidate();
 673                        __asm__ __volatile__("int3");
 674
 675                        /* We're probably dead after this, but... */
 676                        reboot_type = BOOT_KBD;
 677                        break;
 678                }
 679        }
 680}
 681
 682void native_machine_shutdown(void)
 683{
 684        /* Stop the cpus and apics */
 685#ifdef CONFIG_X86_IO_APIC
 686        /*
 687         * Disabling IO APIC before local APIC is a workaround for
 688         * erratum AVR31 in "Intel Atom Processor C2000 Product Family
 689         * Specification Update". In this situation, interrupts that target
 690         * a Logical Processor whose Local APIC is either in the process of
 691         * being hardware disabled or software disabled are neither delivered
 692         * nor discarded. When this erratum occurs, the processor may hang.
 693         *
 694         * Even without the erratum, it still makes sense to quiet IO APIC
 695         * before disabling Local APIC.
 696         */
 697        clear_IO_APIC();
 698#endif
 699
 700#ifdef CONFIG_SMP
 701        /*
 702         * Stop all of the others. Also disable the local irq to
 703         * not receive the per-cpu timer interrupt which may trigger
 704         * scheduler's load balance.
 705         */
 706        local_irq_disable();
 707        stop_other_cpus();
 708#endif
 709
 710        lapic_shutdown();
 711        restore_boot_irq_mode();
 712
 713#ifdef CONFIG_HPET_TIMER
 714        hpet_disable();
 715#endif
 716
 717#ifdef CONFIG_X86_64
 718        x86_platform.iommu_shutdown();
 719#endif
 720}
 721
 722static void __machine_emergency_restart(int emergency)
 723{
 724        reboot_emergency = emergency;
 725        machine_ops.emergency_restart();
 726}
 727
 728static void native_machine_restart(char *__unused)
 729{
 730        pr_notice("machine restart\n");
 731
 732        if (!reboot_force)
 733                machine_shutdown();
 734        __machine_emergency_restart(0);
 735}
 736
 737static void native_machine_halt(void)
 738{
 739        /* Stop other cpus and apics */
 740        machine_shutdown();
 741
 742        tboot_shutdown(TB_SHUTDOWN_HALT);
 743
 744        stop_this_cpu(NULL);
 745}
 746
 747static void native_machine_power_off(void)
 748{
 749        if (pm_power_off) {
 750                if (!reboot_force)
 751                        machine_shutdown();
 752                pm_power_off();
 753        }
 754        /* A fallback in case there is no PM info available */
 755        tboot_shutdown(TB_SHUTDOWN_HALT);
 756}
 757
 758struct machine_ops machine_ops __ro_after_init = {
 759        .power_off = native_machine_power_off,
 760        .shutdown = native_machine_shutdown,
 761        .emergency_restart = native_machine_emergency_restart,
 762        .restart = native_machine_restart,
 763        .halt = native_machine_halt,
 764#ifdef CONFIG_KEXEC_CORE
 765        .crash_shutdown = native_machine_crash_shutdown,
 766#endif
 767};
 768
 769void machine_power_off(void)
 770{
 771        machine_ops.power_off();
 772}
 773
 774void machine_shutdown(void)
 775{
 776        machine_ops.shutdown();
 777}
 778
 779void machine_emergency_restart(void)
 780{
 781        __machine_emergency_restart(1);
 782}
 783
 784void machine_restart(char *cmd)
 785{
 786        machine_ops.restart(cmd);
 787}
 788
 789void machine_halt(void)
 790{
 791        machine_ops.halt();
 792}
 793
 794#ifdef CONFIG_KEXEC_CORE
 795void machine_crash_shutdown(struct pt_regs *regs)
 796{
 797        machine_ops.crash_shutdown(regs);
 798}
 799#endif
 800
 801
 802/* This is the CPU performing the emergency shutdown work. */
 803int crashing_cpu = -1;
 804
 805#if defined(CONFIG_SMP)
 806
 807static nmi_shootdown_cb shootdown_callback;
 808
 809static atomic_t waiting_for_crash_ipi;
 810static int crash_ipi_issued;
 811
 812static int crash_nmi_callback(unsigned int val, struct pt_regs *regs)
 813{
 814        int cpu;
 815
 816        cpu = raw_smp_processor_id();
 817
 818        /*
 819         * Don't do anything if this handler is invoked on crashing cpu.
 820         * Otherwise, system will completely hang. Crashing cpu can get
 821         * an NMI if system was initially booted with nmi_watchdog parameter.
 822         */
 823        if (cpu == crashing_cpu)
 824                return NMI_HANDLED;
 825        local_irq_disable();
 826
 827        shootdown_callback(cpu, regs);
 828
 829        atomic_dec(&waiting_for_crash_ipi);
 830        /* Assume hlt works */
 831        halt();
 832        for (;;)
 833                cpu_relax();
 834
 835        return NMI_HANDLED;
 836}
 837
 838/*
 839 * Halt all other CPUs, calling the specified function on each of them
 840 *
 841 * This function can be used to halt all other CPUs on crash
 842 * or emergency reboot time. The function passed as parameter
 843 * will be called inside a NMI handler on all CPUs.
 844 */
 845void nmi_shootdown_cpus(nmi_shootdown_cb callback)
 846{
 847        unsigned long msecs;
 848        local_irq_disable();
 849
 850        /* Make a note of crashing cpu. Will be used in NMI callback. */
 851        crashing_cpu = safe_smp_processor_id();
 852
 853        shootdown_callback = callback;
 854
 855        atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
 856        /* Would it be better to replace the trap vector here? */
 857        if (register_nmi_handler(NMI_LOCAL, crash_nmi_callback,
 858                                 NMI_FLAG_FIRST, "crash"))
 859                return;         /* Return what? */
 860        /*
 861         * Ensure the new callback function is set before sending
 862         * out the NMI
 863         */
 864        wmb();
 865
 866        apic_send_IPI_allbutself(NMI_VECTOR);
 867
 868        /* Kick CPUs looping in NMI context. */
 869        WRITE_ONCE(crash_ipi_issued, 1);
 870
 871        msecs = 1000; /* Wait at most a second for the other cpus to stop */
 872        while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
 873                mdelay(1);
 874                msecs--;
 875        }
 876
 877        /* Leave the nmi callback set */
 878}
 879
 880/*
 881 * Check if the crash dumping IPI got issued and if so, call its callback
 882 * directly. This function is used when we have already been in NMI handler.
 883 * It doesn't return.
 884 */
 885void run_crash_ipi_callback(struct pt_regs *regs)
 886{
 887        if (crash_ipi_issued)
 888                crash_nmi_callback(0, regs);
 889}
 890
 891/* Override the weak function in kernel/panic.c */
 892void nmi_panic_self_stop(struct pt_regs *regs)
 893{
 894        while (1) {
 895                /* If no CPU is preparing crash dump, we simply loop here. */
 896                run_crash_ipi_callback(regs);
 897                cpu_relax();
 898        }
 899}
 900
 901#else /* !CONFIG_SMP */
 902void nmi_shootdown_cpus(nmi_shootdown_cb callback)
 903{
 904        /* No other CPUs to shoot down */
 905}
 906
 907void run_crash_ipi_callback(struct pt_regs *regs)
 908{
 909}
 910#endif
 911