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 long no_idt[3];
  31 static int reboot_mode;
  32 enum reboot_type reboot_type = BOOT_KBD;
  33 int reboot_force;
  34
  35 #if defined(CONFIG_X86_32) && defined(CONFIG_SMP)
  36 static int reboot_cpu = -1;
  37 #endif
  38
  39 /* reboot=b[ios] | s[mp] | t[riple] | k[bd] | e[fi] [, [w]arm | [c]old]
  40    warm   Don't set the cold reboot flag
  41    cold   Set the cold reboot flag
  42    bios   Reboot by jumping through the BIOS (only for X86_32)
  43    smp    Reboot by executing reset on BSP or other CPU (only for X86_32)
  44    triple Force a triple fault (init)
  45    kbd    Use the keyboard controller. cold reset (default)
  46    acpi   Use the RESET_REG in the FADT
  47    efi    Use efi reset_system runtime service
  48    force  Avoid anything that could hang.
  49  */
  50 static int __init reboot_setup(char *str)
  51 {
  52         for (;;) {
  53                 switch (*str) {
  54                 case 'w':
  55                         reboot_mode = 0x1234;
  56                         break;
  57
  58                 case 'c':
  59                         reboot_mode = 0;
  60                         break;
  61
  62 #ifdef CONFIG_X86_32
  63 #ifdef CONFIG_SMP
  64                 case 's':
  65                         if (isdigit(*(str+1))) {
  66                                 reboot_cpu = (int) (*(str+1) - '0');
  67                                 if (isdigit(*(str+2)))
  68                                         reboot_cpu = reboot_cpu*10 + (int)(*(str+2) - '0');
  69                         }
  70                                 /* we will leave sorting out the final value
  71                                    when we are ready to reboot, since we might not
  72                                    have set up boot_cpu_id or smp_num_cpu */
  73                         break;
  74 #endif /* CONFIG_SMP */
  75
  76                 case 'b':
  77 #endif
  78                 case 'a':
  79                 case 'k':
  80                 case 't':
  81                 case 'e':
  82                         reboot_type = *str;
  83                         break;
  84
  85                 case 'f':
  86                         reboot_force = 1;
  87                         break;
  88                 }
  89
  90                 str = strchr(str, ',');
  91                 if (str)
  92                         str++;
  93                 else
  94                         break;
  95         }
  96         return 1;
  97 }
  98
  99 __setup("reboot=", reboot_setup);
 100
 101
 102 #ifdef CONFIG_X86_32
 103 /*
 104  * Reboot options and system auto-detection code provided by
 105  * Dell Inc. so their systems "just work". :-)
 106  */
 107
 108 /*
 109  * Some machines require the "reboot=b"  commandline option,
 110  * this quirk makes that automatic.
 111  */
 112 static int __init set_bios_reboot(const struct dmi_system_id *d)
 113 {
 114         if (reboot_type != BOOT_BIOS) {
 115                 reboot_type = BOOT_BIOS;
 116                 printk(KERN_INFO "%s series board detected. Selecting BIOS-method for reboots.\n", d->ident);
 117         }
 118         return 0;
 119 }
 120
 121 static struct dmi_system_id __initdata reboot_dmi_table[] = {
 122         {       /* Handle problems with rebooting on Dell E520's */
 123                 .callback = set_bios_reboot,
 124                 .ident = "Dell E520",
 125                 .matches = {
 126                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 127                         DMI_MATCH(DMI_PRODUCT_NAME, "Dell DM061"),
 128                 },
 129         },
 130         {       /* Handle problems with rebooting on Dell 1300's */
 131                 .callback = set_bios_reboot,
 132                 .ident = "Dell PowerEdge 1300",
 133                 .matches = {
 134                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 135                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1300/"),
 136                 },
 137         },
 138         {       /* Handle problems with rebooting on Dell 300's */
 139                 .callback = set_bios_reboot,
 140                 .ident = "Dell PowerEdge 300",
 141                 .matches = {
 142                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 143                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"),
 144                 },
 145         },
 146         {       /* Handle problems with rebooting on Dell Optiplex 745's SFF*/
 147                 .callback = set_bios_reboot,
 148                 .ident = "Dell OptiPlex 745",
 149                 .matches = {
 150                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 151                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
 152                 },
 153         },
 154         {       /* Handle problems with rebooting on Dell Optiplex 745's DFF*/
 155                 .callback = set_bios_reboot,
 156                 .ident = "Dell OptiPlex 745",
 157                 .matches = {
 158                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 159                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
 160                         DMI_MATCH(DMI_BOARD_NAME, "0MM599"),
 161                 },
 162         },
 163         {       /* Handle problems with rebooting on Dell Optiplex 745 with 0KW626 */
 164                 .callback = set_bios_reboot,
 165                 .ident = "Dell OptiPlex 745",
 166                 .matches = {
 167                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 168                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
 169                         DMI_MATCH(DMI_BOARD_NAME, "0KW626"),
 170                 },
 171         },
 172         {       /* Handle problems with rebooting on Dell 2400's */
 173                 .callback = set_bios_reboot,
 174                 .ident = "Dell PowerEdge 2400",
 175                 .matches = {
 176                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 177                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"),
 178                 },
 179         },
 180         {       /* Handle problems with rebooting on HP laptops */
 181                 .callback = set_bios_reboot,
 182                 .ident = "HP Compaq Laptop",
 183                 .matches = {
 184                         DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 185                         DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"),
 186                 },
 187         },
 188         { }
 189 };
 190
 191 static int __init reboot_init(void)
 192 {
 193         dmi_check_system(reboot_dmi_table);
 194         return 0;
 195 }
 196 core_initcall(reboot_init);
 197
 198 /* The following code and data reboots the machine by switching to real
 199    mode and jumping to the BIOS reset entry point, as if the CPU has
 200    really been reset.  The previous version asked the keyboard
 201    controller to pulse the CPU reset line, which is more thorough, but
 202    doesn't work with at least one type of 486 motherboard.  It is easy
 203    to stop this code working; hence the copious comments. */
 204 static unsigned long long
 205 real_mode_gdt_entries [3] =
 206 {
 207         0x0000000000000000ULL,  /* Null descriptor */
 208         0x00009a000000ffffULL,  /* 16-bit real-mode 64k code at 0x00000000 */
 209         0x000092000100ffffULL   /* 16-bit real-mode 64k data at 0x00000100 */
 210 };
 211
 212 static struct desc_ptr
 213 real_mode_gdt = { sizeof (real_mode_gdt_entries) - 1, (long)real_mode_gdt_entries },
 214 real_mode_idt = { 0x3ff, 0 };
 215
 216 /* This is 16-bit protected mode code to disable paging and the cache,
 217    switch to real mode and jump to the BIOS reset code.
 218
 219    The instruction that switches to real mode by writing to CR0 must be
 220    followed immediately by a far jump instruction, which set CS to a
 221    valid value for real mode, and flushes the prefetch queue to avoid
 222    running instructions that have already been decoded in protected
 223    mode.
 224
 225    Clears all the flags except ET, especially PG (paging), PE
 226    (protected-mode enable) and TS (task switch for coprocessor state
 227    save).  Flushes the TLB after paging has been disabled.  Sets CD and
 228    NW, to disable the cache on a 486, and invalidates the cache.  This
 229    is more like the state of a 486 after reset.  I don't know if
 230    something else should be done for other chips.
 231
 232    More could be done here to set up the registers as if a CPU reset had
 233    occurred; hopefully real BIOSs don't assume much. */
 234 static unsigned char real_mode_switch [] =
 235 {
 236         0x66, 0x0f, 0x20, 0xc0,                 /*    movl  %cr0,%eax        */
 237         0x66, 0x83, 0xe0, 0x11,                 /*    andl  $0x00000011,%eax */
 238         0x66, 0x0d, 0x00, 0x00, 0x00, 0x60,     /*    orl   $0x60000000,%eax */
 239         0x66, 0x0f, 0x22, 0xc0,                 /*    movl  %eax,%cr0        */
 240         0x66, 0x0f, 0x22, 0xd8,                 /*    movl  %eax,%cr3        */
 241         0x66, 0x0f, 0x20, 0xc3,                 /*    movl  %cr0,%ebx        */
 242         0x66, 0x81, 0xe3, 0x00, 0x00, 0x00, 0x60,       /*    andl  $0x60000000,%ebx */
 243         0x74, 0x02,                             /*    jz    f                */
 244         0x0f, 0x09,                             /*    wbinvd                 */
 245         0x24, 0x10,                             /* f: andb  $0x10,al         */
 246         0x66, 0x0f, 0x22, 0xc0                  /*    movl  %eax,%cr0        */
 247 };
 248 static unsigned char jump_to_bios [] =
 249 {
 250         0xea, 0x00, 0x00, 0xff, 0xff            /*    ljmp  $0xffff,$0x0000  */
 251 };
 252
 253 /*
 254  * Switch to real mode and then execute the code
 255  * specified by the code and length parameters.
 256  * We assume that length will aways be less that 100!
 257  */
 258 void machine_real_restart(unsigned char *code, int length)
 259 {
 260         local_irq_disable();
 261
 262         /* Write zero to CMOS register number 0x0f, which the BIOS POST
 263            routine will recognize as telling it to do a proper reboot.  (Well
 264            that's what this book in front of me says -- it may only apply to
 265            the Phoenix BIOS though, it's not clear).  At the same time,
 266            disable NMIs by setting the top bit in the CMOS address register,
 267            as we're about to do peculiar things to the CPU.  I'm not sure if
 268            `outb_p' is needed instead of just `outb'.  Use it to be on the
 269            safe side.  (Yes, CMOS_WRITE does outb_p's. -  Paul G.)
 270          */
 271         spin_lock(&rtc_lock);
 272         CMOS_WRITE(0x00, 0x8f);
 273         spin_unlock(&rtc_lock);
 274
 275         /* Remap the kernel at virtual address zero, as well as offset zero
 276            from the kernel segment.  This assumes the kernel segment starts at
 277            virtual address PAGE_OFFSET. */
 278         memcpy(swapper_pg_dir, swapper_pg_dir + KERNEL_PGD_BOUNDARY,
 279                 sizeof(swapper_pg_dir [0]) * KERNEL_PGD_PTRS);
 280
 281         /*
 282          * Use `swapper_pg_dir' as our page directory.
 283          */
 284         load_cr3(swapper_pg_dir);
 285
 286         /* Write 0x1234 to absolute memory location 0x472.  The BIOS reads
 287            this on booting to tell it to "Bypass memory test (also warm
 288            boot)".  This seems like a fairly standard thing that gets set by
 289            REBOOT.COM programs, and the previous reset routine did this
 290            too. */
 291         *((unsigned short *)0x472) = reboot_mode;
 292
 293         /* For the switch to real mode, copy some code to low memory.  It has
 294            to be in the first 64k because it is running in 16-bit mode, and it
 295            has to have the same physical and virtual address, because it turns
 296            off paging.  Copy it near the end of the first page, out of the way
 297            of BIOS variables. */
 298         memcpy((void *)(0x1000 - sizeof(real_mode_switch) - 100),
 299                 real_mode_switch, sizeof (real_mode_switch));
 300         memcpy((void *)(0x1000 - 100), code, length);
 301
 302         /* Set up the IDT for real mode. */
 303         load_idt(&real_mode_idt);
 304
 305         /* Set up a GDT from which we can load segment descriptors for real
 306            mode.  The GDT is not used in real mode; it is just needed here to
 307            prepare the descriptors. */
 308         load_gdt(&real_mode_gdt);
 309
 310         /* Load the data segment registers, and thus the descriptors ready for
 311            real mode.  The base address of each segment is 0x100, 16 times the
 312            selector value being loaded here.  This is so that the segment
 313            registers don't have to be reloaded after switching to real mode:
 314            the values are consistent for real mode operation already. */
 315         __asm__ __volatile__ ("movl $0x0010,%%eax\n"
 316                                 "\tmovl %%eax,%%ds\n"
 317                                 "\tmovl %%eax,%%es\n"
 318                                 "\tmovl %%eax,%%fs\n"
 319                                 "\tmovl %%eax,%%gs\n"
 320                                 "\tmovl %%eax,%%ss" : : : "eax");
 321
 322         /* Jump to the 16-bit code that we copied earlier.  It disables paging
 323            and the cache, switches to real mode, and jumps to the BIOS reset
 324            entry point. */
 325         __asm__ __volatile__ ("ljmp $0x0008,%0"
 326                                 :
 327                                 : "i" ((void *)(0x1000 - sizeof (real_mode_switch) - 100)));
 328 }
 329 #ifdef CONFIG_APM_MODULE
 330 EXPORT_SYMBOL(machine_real_restart);
 331 #endif
 332
 333 #endif /* CONFIG_X86_32 */
 334
 335 static inline void kb_wait(void)
 336 {
 337         int i;
 338
 339         for (i = 0; i < 0x10000; i++) {
 340                 if ((inb(0x64) & 0x02) == 0)
 341                         break;
 342                 udelay(2);
 343         }
 344 }
 345
 346 void __attribute__((weak)) mach_reboot_fixups(void)
 347 {
 348 }
 349
 350 static void native_machine_emergency_restart(void)
 351 {
 352         int i;
 353
 354         /* Tell the BIOS if we want cold or warm reboot */
 355         *((unsigned short *)__va(0x472)) = reboot_mode;
 356
 357         for (;;) {
 358                 /* Could also try the reset bit in the Hammer NB */
 359                 switch (reboot_type) {
 360                 case BOOT_KBD:
 361                         mach_reboot_fixups(); /* for board specific fixups */
 362
 363                         for (i = 0; i < 10; i++) {
 364                                 kb_wait();
 365                                 udelay(50);
 366                                 outb(0xfe, 0x64); /* pulse reset low */
 367                                 udelay(50);
 368                         }
 369
 370                 case BOOT_TRIPLE:
 371                         load_idt((const struct desc_ptr *)&no_idt);
 372                         __asm__ __volatile__("int3");
 373
 374                         reboot_type = BOOT_KBD;
 375                         break;
 376
 377 #ifdef CONFIG_X86_32
 378                 case BOOT_BIOS:
 379                         machine_real_restart(jump_to_bios, sizeof(jump_to_bios));
 380
 381                         reboot_type = BOOT_KBD;
 382                         break;
 383 #endif
 384
 385                 case BOOT_ACPI:
 386                         acpi_reboot();
 387                         reboot_type = BOOT_KBD;
 388                         break;
 389
 390
 391                 case BOOT_EFI:
 392                         if (efi_enabled)
 393                                 efi.reset_system(reboot_mode ? EFI_RESET_WARM : EFI_RESET_COLD,
 394                                                  EFI_SUCCESS, 0, NULL);
 395
 396                         reboot_type = BOOT_KBD;
 397                         break;
 398                 }
 399         }
 400 }
 401
 402 void native_machine_shutdown(void)
 403 {
 404         /* Stop the cpus and apics */
 405 #ifdef CONFIG_SMP
 406         int reboot_cpu_id;
 407
 408         /* The boot cpu is always logical cpu 0 */
 409         reboot_cpu_id = 0;
 410
 411 #ifdef CONFIG_X86_32
 412         /* See if there has been given a command line override */
 413         if ((reboot_cpu != -1) && (reboot_cpu < NR_CPUS) &&
 414                 cpu_online(reboot_cpu))
 415                 reboot_cpu_id = reboot_cpu;
 416 #endif
 417
 418         /* Make certain the cpu I'm about to reboot on is online */
 419         if (!cpu_online(reboot_cpu_id))
 420                 reboot_cpu_id = smp_processor_id();
 421
 422         /* Make certain I only run on the appropriate processor */
 423         set_cpus_allowed_ptr(current, &cpumask_of_cpu(reboot_cpu_id));
 424
 425         /* O.K Now that I'm on the appropriate processor,
 426          * stop all of the others.
 427          */
 428         smp_send_stop();
 429 #endif
 430
 431         lapic_shutdown();
 432
 433 #ifdef CONFIG_X86_IO_APIC
 434         disable_IO_APIC();
 435 #endif
 436
 437 #ifdef CONFIG_HPET_TIMER
 438         hpet_disable();
 439 #endif
 440
 441 #ifdef CONFIG_X86_64
 442         pci_iommu_shutdown();
 443 #endif
 444 }
 445
 446 static void native_machine_restart(char *__unused)
 447 {
 448         printk("machine restart\n");
 449
 450         if (!reboot_force)
 451                 machine_shutdown();
 452         machine_emergency_restart();
 453 }
 454
 455 static void native_machine_halt(void)
 456 {
 457 }
 458
 459 static void native_machine_power_off(void)
 460 {
 461         if (pm_power_off) {
 462                 if (!reboot_force)
 463                         machine_shutdown();
 464                 pm_power_off();
 465         }
 466 }
 467
 468 struct machine_ops machine_ops = {
 469         .power_off = native_machine_power_off,
 470         .shutdown = native_machine_shutdown,
 471         .emergency_restart = native_machine_emergency_restart,
 472         .restart = native_machine_restart,
 473         .halt = native_machine_halt,
 474 #ifdef CONFIG_KEXEC
 475         .crash_shutdown = native_machine_crash_shutdown,
 476 #endif
 477 };
 478
 479 void machine_power_off(void)
 480 {
 481         machine_ops.power_off();
 482 }
 483
 484 void machine_shutdown(void)
 485 {
 486         machine_ops.shutdown();
 487 }
 488
 489 void machine_emergency_restart(void)
 490 {
 491         machine_ops.emergency_restart();
 492 }
 493
 494 void machine_restart(char *cmd)
 495 {
 496         machine_ops.restart(cmd);
 497 }
 498
 499 void machine_halt(void)
 500 {
 501         machine_ops.halt();
 502 }
 503
 504 #ifdef CONFIG_KEXEC
 505 void machine_crash_shutdown(struct pt_regs *regs)
 506 {
 507         machine_ops.crash_shutdown(regs);
 508 }
 509 #endif