arch/x86/kernel/reboot.c

   1 #include <linux/module.h>
   2 #include <linux/reboot.h>
   3 #include <linux/init.h>
   4 #include <linux/pm.h>
   5 #include <linux/efi.h>
   6 #include <acpi/reboot.h>
   7 #include <asm/io.h>
   8 #include <asm/apic.h>
   9 #include <asm/desc.h>
  10 #include <asm/hpet.h>
  11 #include <asm/pgtable.h>
  12 #include <asm/proto.h>
  13 #include <asm/reboot_fixups.h>
  14 #include <asm/reboot.h>
  15
  16 #ifdef CONFIG_X86_32
  17 # include <linux/dmi.h>
  18 # include <linux/ctype.h>
  19 # include <linux/mc146818rtc.h>
  20 #else
  21 # include <asm/iommu.h>
  22 #endif
  23
  24 /*
  25  * Power off function, if any
  26  */
  27 void (*pm_power_off)(void);
  28 EXPORT_SYMBOL(pm_power_off);
  29
  30 static const struct desc_ptr no_idt = {};
  31 static int reboot_mode;
  32 enum reboot_type reboot_type = BOOT_CF9_COND;
  33 int reboot_force;
  34
  35 #if defined(CONFIG_X86_32) && defined(CONFIG_SMP)
  36 static int reboot_cpu = -1;
  37 #endif
  38
  39 /* This is set by the PCI code if either type 1 or type 2 PCI is detected */
  40 bool port_cf9_safe = false;
  41
  42 /* reboot=b[ios] | s[mp] | t[riple] | k[bd] | e[fi] [, [w]arm | [c]old] | p[ci]
  43    warm   Don't set the cold reboot flag
  44    cold   Set the cold reboot flag
  45    bios   Reboot by jumping through the BIOS (only for X86_32)
  46    smp    Reboot by executing reset on BSP or other CPU (only for X86_32)
  47    triple Force a triple fault (init)
  48    kbd    Use the keyboard controller. cold reset (default)
  49    acpi   Use the RESET_REG in the FADT
  50    efi    Use efi reset_system runtime service
  51    pci    Use the so-called "PCI reset register", CF9
  52    force  Avoid anything that could hang.
  53  */
  54 static int __init reboot_setup(char *str)
  55 {
  56         for (;;) {
  57                 switch (*str) {
  58                 case 'w':
  59                         reboot_mode = 0x1234;
  60                         break;
  61
  62                 case 'c':
  63                         reboot_mode = 0;
  64                         break;
  65
  66 #ifdef CONFIG_X86_32
  67 #ifdef CONFIG_SMP
  68                 case 's':
  69                         if (isdigit(*(str+1))) {
  70                                 reboot_cpu = (int) (*(str+1) - '0');
  71                                 if (isdigit(*(str+2)))
  72                                         reboot_cpu = reboot_cpu*10 + (int)(*(str+2) - '0');
  73                         }
  74                                 /* we will leave sorting out the final value
  75                                    when we are ready to reboot, since we might not
  76                                    have set up boot_cpu_id or smp_num_cpu */
  77                         break;
  78 #endif /* CONFIG_SMP */
  79
  80                 case 'b':
  81 #endif
  82                 case 'a':
  83                 case 'k':
  84                 case 't':
  85                 case 'e':
  86                 case 'p':
  87                         reboot_type = *str;
  88                         break;
  89
  90                 case 'f':
  91                         reboot_force = 1;
  92                         break;
  93                 }
  94
  95                 str = strchr(str, ',');
  96                 if (str)
  97                         str++;
  98                 else
  99                         break;
 100         }
 101         return 1;
 102 }
 103
 104 __setup("reboot=", reboot_setup);
 105
 106
 107 #ifdef CONFIG_X86_32
 108 /*
 109  * Reboot options and system auto-detection code provided by
 110  * Dell Inc. so their systems "just work". :-)
 111  */
 112
 113 /*
 114  * Some machines require the "reboot=b"  commandline option,
 115  * this quirk makes that automatic.
 116  */
 117 static int __init set_bios_reboot(const struct dmi_system_id *d)
 118 {
 119         if (reboot_type != BOOT_BIOS) {
 120                 reboot_type = BOOT_BIOS;
 121                 printk(KERN_INFO "%s series board detected. Selecting BIOS-method for reboots.\n", d->ident);
 122         }
 123         return 0;
 124 }
 125
 126 static struct dmi_system_id __initdata reboot_dmi_table[] = {
 127         {       /* Handle problems with rebooting on Dell E520's */
 128                 .callback = set_bios_reboot,
 129                 .ident = "Dell E520",
 130                 .matches = {
 131                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 132                         DMI_MATCH(DMI_PRODUCT_NAME, "Dell DM061"),
 133                 },
 134         },
 135         {       /* Handle problems with rebooting on Dell 1300's */
 136                 .callback = set_bios_reboot,
 137                 .ident = "Dell PowerEdge 1300",
 138                 .matches = {
 139                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 140                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1300/"),
 141                 },
 142         },
 143         {       /* Handle problems with rebooting on Dell 300's */
 144                 .callback = set_bios_reboot,
 145                 .ident = "Dell PowerEdge 300",
 146                 .matches = {
 147                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 148                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"),
 149                 },
 150         },
 151         {       /* Handle problems with rebooting on Dell Optiplex 745's SFF*/
 152                 .callback = set_bios_reboot,
 153                 .ident = "Dell OptiPlex 745",
 154                 .matches = {
 155                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 156                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
 157                 },
 158         },
 159         {       /* Handle problems with rebooting on Dell Optiplex 745's DFF*/
 160                 .callback = set_bios_reboot,
 161                 .ident = "Dell OptiPlex 745",
 162                 .matches = {
 163                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 164                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
 165                         DMI_MATCH(DMI_BOARD_NAME, "0MM599"),
 166                 },
 167         },
 168         {       /* Handle problems with rebooting on Dell Optiplex 745 with 0KW626 */
 169                 .callback = set_bios_reboot,
 170                 .ident = "Dell OptiPlex 745",
 171                 .matches = {
 172                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 173                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
 174                         DMI_MATCH(DMI_BOARD_NAME, "0KW626"),
 175                 },
 176         },
 177         {       /* Handle problems with rebooting on Dell 2400's */
 178                 .callback = set_bios_reboot,
 179                 .ident = "Dell PowerEdge 2400",
 180                 .matches = {
 181                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 182                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"),
 183                 },
 184         },
 185         {       /* Handle problems with rebooting on Dell T5400's */
 186                 .callback = set_bios_reboot,
 187                 .ident = "Dell Precision T5400",
 188                 .matches = {
 189                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 190                         DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T5400"),
 191                 },
 192         },
 193         {       /* Handle problems with rebooting on HP laptops */
 194                 .callback = set_bios_reboot,
 195                 .ident = "HP Compaq Laptop",
 196                 .matches = {
 197                         DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 198                         DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"),
 199                 },
 200         },
 201         { }
 202 };
 203
 204 static int __init reboot_init(void)
 205 {
 206         dmi_check_system(reboot_dmi_table);
 207         return 0;
 208 }
 209 core_initcall(reboot_init);
 210
 211 /* The following code and data reboots the machine by switching to real
 212    mode and jumping to the BIOS reset entry point, as if the CPU has
 213    really been reset.  The previous version asked the keyboard
 214    controller to pulse the CPU reset line, which is more thorough, but
 215    doesn't work with at least one type of 486 motherboard.  It is easy
 216    to stop this code working; hence the copious comments. */
 217 static const unsigned long long
 218 real_mode_gdt_entries [3] =
 219 {
 220         0x0000000000000000ULL,  /* Null descriptor */
 221         0x00009b000000ffffULL,  /* 16-bit real-mode 64k code at 0x00000000 */
 222         0x000093000100ffffULL   /* 16-bit real-mode 64k data at 0x00000100 */
 223 };
 224
 225 static const struct desc_ptr
 226 real_mode_gdt = { sizeof (real_mode_gdt_entries) - 1, (long)real_mode_gdt_entries },
 227 real_mode_idt = { 0x3ff, 0 };
 228
 229 /* This is 16-bit protected mode code to disable paging and the cache,
 230    switch to real mode and jump to the BIOS reset code.
 231
 232    The instruction that switches to real mode by writing to CR0 must be
 233    followed immediately by a far jump instruction, which set CS to a
 234    valid value for real mode, and flushes the prefetch queue to avoid
 235    running instructions that have already been decoded in protected
 236    mode.
 237
 238    Clears all the flags except ET, especially PG (paging), PE
 239    (protected-mode enable) and TS (task switch for coprocessor state
 240    save).  Flushes the TLB after paging has been disabled.  Sets CD and
 241    NW, to disable the cache on a 486, and invalidates the cache.  This
 242    is more like the state of a 486 after reset.  I don't know if
 243    something else should be done for other chips.
 244
 245    More could be done here to set up the registers as if a CPU reset had
 246    occurred; hopefully real BIOSs don't assume much. */
 247 static const unsigned char real_mode_switch [] =
 248 {
 249         0x66, 0x0f, 0x20, 0xc0,                 /*    movl  %cr0,%eax        */
 250         0x66, 0x83, 0xe0, 0x11,                 /*    andl  $0x00000011,%eax */
 251         0x66, 0x0d, 0x00, 0x00, 0x00, 0x60,     /*    orl   $0x60000000,%eax */
 252         0x66, 0x0f, 0x22, 0xc0,                 /*    movl  %eax,%cr0        */
 253         0x66, 0x0f, 0x22, 0xd8,                 /*    movl  %eax,%cr3        */
 254         0x66, 0x0f, 0x20, 0xc3,                 /*    movl  %cr0,%ebx        */
 255         0x66, 0x81, 0xe3, 0x00, 0x00, 0x00, 0x60,       /*    andl  $0x60000000,%ebx */
 256         0x74, 0x02,                             /*    jz    f                */
 257         0x0f, 0x09,                             /*    wbinvd                 */
 258         0x24, 0x10,                             /* f: andb  $0x10,al         */
 259         0x66, 0x0f, 0x22, 0xc0                  /*    movl  %eax,%cr0        */
 260 };
 261 static const unsigned char jump_to_bios [] =
 262 {
 263         0xea, 0x00, 0x00, 0xff, 0xff            /*    ljmp  $0xffff,$0x0000  */
 264 };
 265
 266 /*
 267  * Switch to real mode and then execute the code
 268  * specified by the code and length parameters.
 269  * We assume that length will aways be less that 100!
 270  */
 271 void machine_real_restart(const unsigned char *code, int length)
 272 {
 273         local_irq_disable();
 274
 275         /* Write zero to CMOS register number 0x0f, which the BIOS POST
 276            routine will recognize as telling it to do a proper reboot.  (Well
 277            that's what this book in front of me says -- it may only apply to
 278            the Phoenix BIOS though, it's not clear).  At the same time,
 279            disable NMIs by setting the top bit in the CMOS address register,
 280            as we're about to do peculiar things to the CPU.  I'm not sure if
 281            `outb_p' is needed instead of just `outb'.  Use it to be on the
 282            safe side.  (Yes, CMOS_WRITE does outb_p's. -  Paul G.)
 283          */
 284         spin_lock(&rtc_lock);
 285         CMOS_WRITE(0x00, 0x8f);
 286         spin_unlock(&rtc_lock);
 287
 288         /* Remap the kernel at virtual address zero, as well as offset zero
 289            from the kernel segment.  This assumes the kernel segment starts at
 290            virtual address PAGE_OFFSET. */
 291         memcpy(swapper_pg_dir, swapper_pg_dir + KERNEL_PGD_BOUNDARY,
 292                 sizeof(swapper_pg_dir [0]) * KERNEL_PGD_PTRS);
 293
 294         /*
 295          * Use `swapper_pg_dir' as our page directory.
 296          */
 297         load_cr3(swapper_pg_dir);
 298
 299         /* Write 0x1234 to absolute memory location 0x472.  The BIOS reads
 300            this on booting to tell it to "Bypass memory test (also warm
 301            boot)".  This seems like a fairly standard thing that gets set by
 302            REBOOT.COM programs, and the previous reset routine did this
 303            too. */
 304         *((unsigned short *)0x472) = reboot_mode;
 305
 306         /* For the switch to real mode, copy some code to low memory.  It has
 307            to be in the first 64k because it is running in 16-bit mode, and it
 308            has to have the same physical and virtual address, because it turns
 309            off paging.  Copy it near the end of the first page, out of the way
 310            of BIOS variables. */
 311         memcpy((void *)(0x1000 - sizeof(real_mode_switch) - 100),
 312                 real_mode_switch, sizeof (real_mode_switch));
 313         memcpy((void *)(0x1000 - 100), code, length);
 314
 315         /* Set up the IDT for real mode. */
 316         load_idt(&real_mode_idt);
 317
 318         /* Set up a GDT from which we can load segment descriptors for real
 319            mode.  The GDT is not used in real mode; it is just needed here to
 320            prepare the descriptors. */
 321         load_gdt(&real_mode_gdt);
 322
 323         /* Load the data segment registers, and thus the descriptors ready for
 324            real mode.  The base address of each segment is 0x100, 16 times the
 325            selector value being loaded here.  This is so that the segment
 326            registers don't have to be reloaded after switching to real mode:
 327            the values are consistent for real mode operation already. */
 328         __asm__ __volatile__ ("movl $0x0010,%%eax\n"
 329                                 "\tmovl %%eax,%%ds\n"
 330                                 "\tmovl %%eax,%%es\n"
 331                                 "\tmovl %%eax,%%fs\n"
 332                                 "\tmovl %%eax,%%gs\n"
 333                                 "\tmovl %%eax,%%ss" : : : "eax");
 334
 335         /* Jump to the 16-bit code that we copied earlier.  It disables paging
 336            and the cache, switches to real mode, and jumps to the BIOS reset
 337            entry point. */
 338         __asm__ __volatile__ ("ljmp $0x0008,%0"
 339                                 :
 340                                 : "i" ((void *)(0x1000 - sizeof (real_mode_switch) - 100)));
 341 }
 342 #ifdef CONFIG_APM_MODULE
 343 EXPORT_SYMBOL(machine_real_restart);
 344 #endif
 345
 346 #endif /* CONFIG_X86_32 */
 347
 348 static inline void kb_wait(void)
 349 {
 350         int i;
 351
 352         for (i = 0; i < 0x10000; i++) {
 353                 if ((inb(0x64) & 0x02) == 0)
 354                         break;
 355                 udelay(2);
 356         }
 357 }
 358
 359 void __attribute__((weak)) mach_reboot_fixups(void)
 360 {
 361 }
 362
 363 static void native_machine_emergency_restart(void)
 364 {
 365         int i;
 366
 367         /* Tell the BIOS if we want cold or warm reboot */
 368         *((unsigned short *)__va(0x472)) = reboot_mode;
 369
 370         for (;;) {
 371                 /* Could also try the reset bit in the Hammer NB */
 372                 switch (reboot_type) {
 373                 case BOOT_KBD:
 374                         mach_reboot_fixups(); /* for board specific fixups */
 375
 376                         for (i = 0; i < 10; i++) {
 377                                 kb_wait();
 378                                 udelay(50);
 379                                 outb(0xfe, 0x64); /* pulse reset low */
 380                                 udelay(50);
 381                         }
 382
 383                 case BOOT_TRIPLE:
 384                         load_idt(&no_idt);
 385                         __asm__ __volatile__("int3");
 386
 387                         reboot_type = BOOT_CF9_COND;
 388                         break;
 389
 390 #ifdef CONFIG_X86_32
 391                 case BOOT_BIOS:
 392                         machine_real_restart(jump_to_bios, sizeof(jump_to_bios));
 393
 394                         reboot_type = BOOT_CF9_COND;
 395                         break;
 396 #endif
 397
 398                 case BOOT_ACPI:
 399                         acpi_reboot();
 400                         reboot_type = BOOT_CF9_COND;
 401                         break;
 402
 403                 case BOOT_EFI:
 404                         if (efi_enabled)
 405                                 efi.reset_system(reboot_mode ?
 406                                                  EFI_RESET_WARM :
 407                                                  EFI_RESET_COLD,
 408                                                  EFI_SUCCESS, 0, NULL);
 409                         reboot_type = BOOT_CF9_COND;
 410                         break;
 411
 412                 case BOOT_CF9:
 413                         port_cf9_safe = true;
 414                         /* fall through */
 415
 416                 case BOOT_CF9_COND:
 417                         if (port_cf9_safe) {
 418                                 u8 cf9 = inb(0xcf9) & ~6;
 419                                 outb(cf9|2, 0xcf9); /* Request hard reset */
 420                                 udelay(50);
 421                                 outb(cf9|6, 0xcf9); /* Actually do the reset */
 422                                 udelay(50);
 423                         }
 424                         reboot_type = BOOT_KBD;
 425                         break;
 426                 }
 427         }
 428 }
 429
 430 void native_machine_shutdown(void)
 431 {
 432         /* Stop the cpus and apics */
 433 #ifdef CONFIG_SMP
 434
 435         /* The boot cpu is always logical cpu 0 */
 436         int reboot_cpu_id = 0;
 437
 438 #ifdef CONFIG_X86_32
 439         /* See if there has been given a command line override */
 440         if ((reboot_cpu != -1) && (reboot_cpu < NR_CPUS) &&
 441                 cpu_online(reboot_cpu))
 442                 reboot_cpu_id = reboot_cpu;
 443 #endif
 444
 445         /* Make certain the cpu I'm about to reboot on is online */
 446         if (!cpu_online(reboot_cpu_id))
 447                 reboot_cpu_id = smp_processor_id();
 448
 449         /* Make certain I only run on the appropriate processor */
 450         set_cpus_allowed_ptr(current, &cpumask_of_cpu(reboot_cpu_id));
 451
 452         /* O.K Now that I'm on the appropriate processor,
 453          * stop all of the others.
 454          */
 455         smp_send_stop();
 456 #endif
 457
 458         lapic_shutdown();
 459
 460 #ifdef CONFIG_X86_IO_APIC
 461         disable_IO_APIC();
 462 #endif
 463
 464 #ifdef CONFIG_HPET_TIMER
 465         hpet_disable();
 466 #endif
 467
 468 #ifdef CONFIG_X86_64
 469         pci_iommu_shutdown();
 470 #endif
 471 }
 472
 473 static void native_machine_restart(char *__unused)
 474 {
 475         printk("machine restart\n");
 476
 477         if (!reboot_force)
 478                 machine_shutdown();
 479         machine_emergency_restart();
 480 }
 481
 482 static void native_machine_halt(void)
 483 {
 484         /* stop other cpus and apics */
 485         machine_shutdown();
 486
 487         /* stop this cpu */
 488         stop_this_cpu(NULL);
 489 }
 490
 491 static void native_machine_power_off(void)
 492 {
 493         if (pm_power_off) {
 494                 if (!reboot_force)
 495                         machine_shutdown();
 496                 pm_power_off();
 497         }
 498 }
 499
 500 struct machine_ops machine_ops = {
 501         .power_off = native_machine_power_off,
 502         .shutdown = native_machine_shutdown,
 503         .emergency_restart = native_machine_emergency_restart,
 504         .restart = native_machine_restart,
 505         .halt = native_machine_halt,
 506 #ifdef CONFIG_KEXEC
 507         .crash_shutdown = native_machine_crash_shutdown,
 508 #endif
 509 };
 510
 511 void machine_power_off(void)
 512 {
 513         machine_ops.power_off();
 514 }
 515
 516 void machine_shutdown(void)
 517 {
 518         machine_ops.shutdown();
 519 }
 520
 521 void machine_emergency_restart(void)
 522 {
 523         machine_ops.emergency_restart();
 524 }
 525
 526 void machine_restart(char *cmd)
 527 {
 528         machine_ops.restart(cmd);
 529 }
 530
 531 void machine_halt(void)
 532 {
 533         machine_ops.halt();
 534 }
 535
 536 #ifdef CONFIG_KEXEC
 537 void machine_crash_shutdown(struct pt_regs *regs)
 538 {
 539         machine_ops.crash_shutdown(regs);
 540 }
 541 #endif