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_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 Dell T5400's */
 181                 .callback = set_bios_reboot,
 182                 .ident = "Dell Precision T5400",
 183                 .matches = {
 184                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 185                         DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T5400"),
 186                 },
 187         },
 188         {       /* Handle problems with rebooting on HP laptops */
 189                 .callback = set_bios_reboot,
 190                 .ident = "HP Compaq Laptop",
 191                 .matches = {
 192                         DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 193                         DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"),
 194                 },
 195         },
 196         { }
 197 };
 198
 199 static int __init reboot_init(void)
 200 {
 201         dmi_check_system(reboot_dmi_table);
 202         return 0;
 203 }
 204 core_initcall(reboot_init);
 205
 206 /* The following code and data reboots the machine by switching to real
 207    mode and jumping to the BIOS reset entry point, as if the CPU has
 208    really been reset.  The previous version asked the keyboard
 209    controller to pulse the CPU reset line, which is more thorough, but
 210    doesn't work with at least one type of 486 motherboard.  It is easy
 211    to stop this code working; hence the copious comments. */
 212 static const unsigned long long
 213 real_mode_gdt_entries [3] =
 214 {
 215         0x0000000000000000ULL,  /* Null descriptor */
 216         0x00009b000000ffffULL,  /* 16-bit real-mode 64k code at 0x00000000 */
 217         0x000093000100ffffULL   /* 16-bit real-mode 64k data at 0x00000100 */
 218 };
 219
 220 static const struct desc_ptr
 221 real_mode_gdt = { sizeof (real_mode_gdt_entries) - 1, (long)real_mode_gdt_entries },
 222 real_mode_idt = { 0x3ff, 0 };
 223
 224 /* This is 16-bit protected mode code to disable paging and the cache,
 225    switch to real mode and jump to the BIOS reset code.
 226
 227    The instruction that switches to real mode by writing to CR0 must be
 228    followed immediately by a far jump instruction, which set CS to a
 229    valid value for real mode, and flushes the prefetch queue to avoid
 230    running instructions that have already been decoded in protected
 231    mode.
 232
 233    Clears all the flags except ET, especially PG (paging), PE
 234    (protected-mode enable) and TS (task switch for coprocessor state
 235    save).  Flushes the TLB after paging has been disabled.  Sets CD and
 236    NW, to disable the cache on a 486, and invalidates the cache.  This
 237    is more like the state of a 486 after reset.  I don't know if
 238    something else should be done for other chips.
 239
 240    More could be done here to set up the registers as if a CPU reset had
 241    occurred; hopefully real BIOSs don't assume much. */
 242 static const unsigned char real_mode_switch [] =
 243 {
 244         0x66, 0x0f, 0x20, 0xc0,                 /*    movl  %cr0,%eax        */
 245         0x66, 0x83, 0xe0, 0x11,                 /*    andl  $0x00000011,%eax */
 246         0x66, 0x0d, 0x00, 0x00, 0x00, 0x60,     /*    orl   $0x60000000,%eax */
 247         0x66, 0x0f, 0x22, 0xc0,                 /*    movl  %eax,%cr0        */
 248         0x66, 0x0f, 0x22, 0xd8,                 /*    movl  %eax,%cr3        */
 249         0x66, 0x0f, 0x20, 0xc3,                 /*    movl  %cr0,%ebx        */
 250         0x66, 0x81, 0xe3, 0x00, 0x00, 0x00, 0x60,       /*    andl  $0x60000000,%ebx */
 251         0x74, 0x02,                             /*    jz    f                */
 252         0x0f, 0x09,                             /*    wbinvd                 */
 253         0x24, 0x10,                             /* f: andb  $0x10,al         */
 254         0x66, 0x0f, 0x22, 0xc0                  /*    movl  %eax,%cr0        */
 255 };
 256 static const unsigned char jump_to_bios [] =
 257 {
 258         0xea, 0x00, 0x00, 0xff, 0xff            /*    ljmp  $0xffff,$0x0000  */
 259 };
 260
 261 /*
 262  * Switch to real mode and then execute the code
 263  * specified by the code and length parameters.
 264  * We assume that length will aways be less that 100!
 265  */
 266 void machine_real_restart(const unsigned char *code, int length)
 267 {
 268         local_irq_disable();
 269
 270         /* Write zero to CMOS register number 0x0f, which the BIOS POST
 271            routine will recognize as telling it to do a proper reboot.  (Well
 272            that's what this book in front of me says -- it may only apply to
 273            the Phoenix BIOS though, it's not clear).  At the same time,
 274            disable NMIs by setting the top bit in the CMOS address register,
 275            as we're about to do peculiar things to the CPU.  I'm not sure if
 276            `outb_p' is needed instead of just `outb'.  Use it to be on the
 277            safe side.  (Yes, CMOS_WRITE does outb_p's. -  Paul G.)
 278          */
 279         spin_lock(&rtc_lock);
 280         CMOS_WRITE(0x00, 0x8f);
 281         spin_unlock(&rtc_lock);
 282
 283         /* Remap the kernel at virtual address zero, as well as offset zero
 284            from the kernel segment.  This assumes the kernel segment starts at
 285            virtual address PAGE_OFFSET. */
 286         memcpy(swapper_pg_dir, swapper_pg_dir + KERNEL_PGD_BOUNDARY,
 287                 sizeof(swapper_pg_dir [0]) * KERNEL_PGD_PTRS);
 288
 289         /*
 290          * Use `swapper_pg_dir' as our page directory.
 291          */
 292         load_cr3(swapper_pg_dir);
 293
 294         /* Write 0x1234 to absolute memory location 0x472.  The BIOS reads
 295            this on booting to tell it to "Bypass memory test (also warm
 296            boot)".  This seems like a fairly standard thing that gets set by
 297            REBOOT.COM programs, and the previous reset routine did this
 298            too. */
 299         *((unsigned short *)0x472) = reboot_mode;
 300
 301         /* For the switch to real mode, copy some code to low memory.  It has
 302            to be in the first 64k because it is running in 16-bit mode, and it
 303            has to have the same physical and virtual address, because it turns
 304            off paging.  Copy it near the end of the first page, out of the way
 305            of BIOS variables. */
 306         memcpy((void *)(0x1000 - sizeof(real_mode_switch) - 100),
 307                 real_mode_switch, sizeof (real_mode_switch));
 308         memcpy((void *)(0x1000 - 100), code, length);
 309
 310         /* Set up the IDT for real mode. */
 311         load_idt(&real_mode_idt);
 312
 313         /* Set up a GDT from which we can load segment descriptors for real
 314            mode.  The GDT is not used in real mode; it is just needed here to
 315            prepare the descriptors. */
 316         load_gdt(&real_mode_gdt);
 317
 318         /* Load the data segment registers, and thus the descriptors ready for
 319            real mode.  The base address of each segment is 0x100, 16 times the
 320            selector value being loaded here.  This is so that the segment
 321            registers don't have to be reloaded after switching to real mode:
 322            the values are consistent for real mode operation already. */
 323         __asm__ __volatile__ ("movl $0x0010,%%eax\n"
 324                                 "\tmovl %%eax,%%ds\n"
 325                                 "\tmovl %%eax,%%es\n"
 326                                 "\tmovl %%eax,%%fs\n"
 327                                 "\tmovl %%eax,%%gs\n"
 328                                 "\tmovl %%eax,%%ss" : : : "eax");
 329
 330         /* Jump to the 16-bit code that we copied earlier.  It disables paging
 331            and the cache, switches to real mode, and jumps to the BIOS reset
 332            entry point. */
 333         __asm__ __volatile__ ("ljmp $0x0008,%0"
 334                                 :
 335                                 : "i" ((void *)(0x1000 - sizeof (real_mode_switch) - 100)));
 336 }
 337 #ifdef CONFIG_APM_MODULE
 338 EXPORT_SYMBOL(machine_real_restart);
 339 #endif
 340
 341 #endif /* CONFIG_X86_32 */
 342
 343 static inline void kb_wait(void)
 344 {
 345         int i;
 346
 347         for (i = 0; i < 0x10000; i++) {
 348                 if ((inb(0x64) & 0x02) == 0)
 349                         break;
 350                 udelay(2);
 351         }
 352 }
 353
 354 void __attribute__((weak)) mach_reboot_fixups(void)
 355 {
 356 }
 357
 358 static void native_machine_emergency_restart(void)
 359 {
 360         int i;
 361
 362         /* Tell the BIOS if we want cold or warm reboot */
 363         *((unsigned short *)__va(0x472)) = reboot_mode;
 364
 365         for (;;) {
 366                 /* Could also try the reset bit in the Hammer NB */
 367                 switch (reboot_type) {
 368                 case BOOT_KBD:
 369                         mach_reboot_fixups(); /* for board specific fixups */
 370
 371                         for (i = 0; i < 10; i++) {
 372                                 kb_wait();
 373                                 udelay(50);
 374                                 outb(0xfe, 0x64); /* pulse reset low */
 375                                 udelay(50);
 376                         }
 377
 378                 case BOOT_TRIPLE:
 379                         load_idt(&no_idt);
 380                         __asm__ __volatile__("int3");
 381
 382                         reboot_type = BOOT_KBD;
 383                         break;
 384
 385 #ifdef CONFIG_X86_32
 386                 case BOOT_BIOS:
 387                         machine_real_restart(jump_to_bios, sizeof(jump_to_bios));
 388
 389                         reboot_type = BOOT_KBD;
 390                         break;
 391 #endif
 392
 393                 case BOOT_ACPI:
 394                         acpi_reboot();
 395                         reboot_type = BOOT_KBD;
 396                         break;
 397
 398
 399                 case BOOT_EFI:
 400                         if (efi_enabled)
 401                                 efi.reset_system(reboot_mode ? EFI_RESET_WARM : EFI_RESET_COLD,
 402                                                  EFI_SUCCESS, 0, NULL);
 403
 404                         reboot_type = BOOT_KBD;
 405                         break;
 406                 }
 407         }
 408 }
 409
 410 void native_machine_shutdown(void)
 411 {
 412         /* Stop the cpus and apics */
 413 #ifdef CONFIG_SMP
 414
 415         /* The boot cpu is always logical cpu 0 */
 416         int reboot_cpu_id = 0;
 417
 418 #ifdef CONFIG_X86_32
 419         /* See if there has been given a command line override */
 420         if ((reboot_cpu != -1) && (reboot_cpu < NR_CPUS) &&
 421                 cpu_online(reboot_cpu))
 422                 reboot_cpu_id = reboot_cpu;
 423 #endif
 424
 425         /* Make certain the cpu I'm about to reboot on is online */
 426         if (!cpu_online(reboot_cpu_id))
 427                 reboot_cpu_id = smp_processor_id();
 428
 429         /* Make certain I only run on the appropriate processor */
 430         set_cpus_allowed_ptr(current, &cpumask_of_cpu(reboot_cpu_id));
 431
 432         /* O.K Now that I'm on the appropriate processor,
 433          * stop all of the others.
 434          */
 435         smp_send_stop();
 436 #endif
 437
 438         lapic_shutdown();
 439
 440 #ifdef CONFIG_X86_IO_APIC
 441         disable_IO_APIC();
 442 #endif
 443
 444 #ifdef CONFIG_HPET_TIMER
 445         hpet_disable();
 446 #endif
 447
 448 #ifdef CONFIG_X86_64
 449         pci_iommu_shutdown();
 450 #endif
 451 }
 452
 453 static void native_machine_restart(char *__unused)
 454 {
 455         printk("machine restart\n");
 456
 457         if (!reboot_force)
 458                 machine_shutdown();
 459         machine_emergency_restart();
 460 }
 461
 462 static void native_machine_halt(void)
 463 {
 464 }
 465
 466 static void native_machine_power_off(void)
 467 {
 468         if (pm_power_off) {
 469                 if (!reboot_force)
 470                         machine_shutdown();
 471                 pm_power_off();
 472         }
 473 }
 474
 475 struct machine_ops machine_ops = {
 476         .power_off = native_machine_power_off,
 477         .shutdown = native_machine_shutdown,
 478         .emergency_restart = native_machine_emergency_restart,
 479         .restart = native_machine_restart,
 480         .halt = native_machine_halt,
 481 #ifdef CONFIG_KEXEC
 482         .crash_shutdown = native_machine_crash_shutdown,
 483 #endif
 484 };
 485
 486 void machine_power_off(void)
 487 {
 488         machine_ops.power_off();
 489 }
 490
 491 void machine_shutdown(void)
 492 {
 493         machine_ops.shutdown();
 494 }
 495
 496 void machine_emergency_restart(void)
 497 {
 498         machine_ops.emergency_restart();
 499 }
 500
 501 void machine_restart(char *cmd)
 502 {
 503         machine_ops.restart(cmd);
 504 }
 505
 506 void machine_halt(void)
 507 {
 508         machine_ops.halt();
 509 }
 510
 511 #ifdef CONFIG_KEXEC
 512 void machine_crash_shutdown(struct pt_regs *regs)
 513 {
 514         machine_ops.crash_shutdown(regs);
 515 }
 516 #endif