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 Optiplex 330 with 0KP561 */
 173                 .callback = set_bios_reboot,
 174                 .ident = "Dell OptiPlex 330",
 175                 .matches = {
 176                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 177                         DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 330"),
 178                         DMI_MATCH(DMI_BOARD_NAME, "0KP561"),
 179                 },
 180         },
 181         {       /* Handle problems with rebooting on Dell 2400's */
 182                 .callback = set_bios_reboot,
 183                 .ident = "Dell PowerEdge 2400",
 184                 .matches = {
 185                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
 186                         DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"),
 187                 },
 188         },
 189         {       /* Handle problems with rebooting on Dell T5400's */
 190                 .callback = set_bios_reboot,
 191                 .ident = "Dell Precision T5400",
 192                 .matches = {
 193                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 194                         DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T5400"),
 195                 },
 196         },
 197         {       /* Handle problems with rebooting on HP laptops */
 198                 .callback = set_bios_reboot,
 199                 .ident = "HP Compaq Laptop",
 200                 .matches = {
 201                         DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 202                         DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"),
 203                 },
 204         },
 205         { }
 206 };
 207
 208 static int __init reboot_init(void)
 209 {
 210         dmi_check_system(reboot_dmi_table);
 211         return 0;
 212 }
 213 core_initcall(reboot_init);
 214
 215 /* The following code and data reboots the machine by switching to real
 216    mode and jumping to the BIOS reset entry point, as if the CPU has
 217    really been reset.  The previous version asked the keyboard
 218    controller to pulse the CPU reset line, which is more thorough, but
 219    doesn't work with at least one type of 486 motherboard.  It is easy
 220    to stop this code working; hence the copious comments. */
 221 static const unsigned long long
 222 real_mode_gdt_entries [3] =
 223 {
 224         0x0000000000000000ULL,  /* Null descriptor */
 225         0x00009b000000ffffULL,  /* 16-bit real-mode 64k code at 0x00000000 */
 226         0x000093000100ffffULL   /* 16-bit real-mode 64k data at 0x00000100 */
 227 };
 228
 229 static const struct desc_ptr
 230 real_mode_gdt = { sizeof (real_mode_gdt_entries) - 1, (long)real_mode_gdt_entries },
 231 real_mode_idt = { 0x3ff, 0 };
 232
 233 /* This is 16-bit protected mode code to disable paging and the cache,
 234    switch to real mode and jump to the BIOS reset code.
 235
 236    The instruction that switches to real mode by writing to CR0 must be
 237    followed immediately by a far jump instruction, which set CS to a
 238    valid value for real mode, and flushes the prefetch queue to avoid
 239    running instructions that have already been decoded in protected
 240    mode.
 241
 242    Clears all the flags except ET, especially PG (paging), PE
 243    (protected-mode enable) and TS (task switch for coprocessor state
 244    save).  Flushes the TLB after paging has been disabled.  Sets CD and
 245    NW, to disable the cache on a 486, and invalidates the cache.  This
 246    is more like the state of a 486 after reset.  I don't know if
 247    something else should be done for other chips.
 248
 249    More could be done here to set up the registers as if a CPU reset had
 250    occurred; hopefully real BIOSs don't assume much. */
 251 static const unsigned char real_mode_switch [] =
 252 {
 253         0x66, 0x0f, 0x20, 0xc0,                 /*    movl  %cr0,%eax        */
 254         0x66, 0x83, 0xe0, 0x11,                 /*    andl  $0x00000011,%eax */
 255         0x66, 0x0d, 0x00, 0x00, 0x00, 0x60,     /*    orl   $0x60000000,%eax */
 256         0x66, 0x0f, 0x22, 0xc0,                 /*    movl  %eax,%cr0        */
 257         0x66, 0x0f, 0x22, 0xd8,                 /*    movl  %eax,%cr3        */
 258         0x66, 0x0f, 0x20, 0xc3,                 /*    movl  %cr0,%ebx        */
 259         0x66, 0x81, 0xe3, 0x00, 0x00, 0x00, 0x60,       /*    andl  $0x60000000,%ebx */
 260         0x74, 0x02,                             /*    jz    f                */
 261         0x0f, 0x09,                             /*    wbinvd                 */
 262         0x24, 0x10,                             /* f: andb  $0x10,al         */
 263         0x66, 0x0f, 0x22, 0xc0                  /*    movl  %eax,%cr0        */
 264 };
 265 static const unsigned char jump_to_bios [] =
 266 {
 267         0xea, 0x00, 0x00, 0xff, 0xff            /*    ljmp  $0xffff,$0x0000  */
 268 };
 269
 270 /*
 271  * Switch to real mode and then execute the code
 272  * specified by the code and length parameters.
 273  * We assume that length will aways be less that 100!
 274  */
 275 void machine_real_restart(const unsigned char *code, int length)
 276 {
 277         local_irq_disable();
 278
 279         /* Write zero to CMOS register number 0x0f, which the BIOS POST
 280            routine will recognize as telling it to do a proper reboot.  (Well
 281            that's what this book in front of me says -- it may only apply to
 282            the Phoenix BIOS though, it's not clear).  At the same time,
 283            disable NMIs by setting the top bit in the CMOS address register,
 284            as we're about to do peculiar things to the CPU.  I'm not sure if
 285            `outb_p' is needed instead of just `outb'.  Use it to be on the
 286            safe side.  (Yes, CMOS_WRITE does outb_p's. -  Paul G.)
 287          */
 288         spin_lock(&rtc_lock);
 289         CMOS_WRITE(0x00, 0x8f);
 290         spin_unlock(&rtc_lock);
 291
 292         /* Remap the kernel at virtual address zero, as well as offset zero
 293            from the kernel segment.  This assumes the kernel segment starts at
 294            virtual address PAGE_OFFSET. */
 295         memcpy(swapper_pg_dir, swapper_pg_dir + KERNEL_PGD_BOUNDARY,
 296                 sizeof(swapper_pg_dir [0]) * KERNEL_PGD_PTRS);
 297
 298         /*
 299          * Use `swapper_pg_dir' as our page directory.
 300          */
 301         load_cr3(swapper_pg_dir);
 302
 303         /* Write 0x1234 to absolute memory location 0x472.  The BIOS reads
 304            this on booting to tell it to "Bypass memory test (also warm
 305            boot)".  This seems like a fairly standard thing that gets set by
 306            REBOOT.COM programs, and the previous reset routine did this
 307            too. */
 308         *((unsigned short *)0x472) = reboot_mode;
 309
 310         /* For the switch to real mode, copy some code to low memory.  It has
 311            to be in the first 64k because it is running in 16-bit mode, and it
 312            has to have the same physical and virtual address, because it turns
 313            off paging.  Copy it near the end of the first page, out of the way
 314            of BIOS variables. */
 315         memcpy((void *)(0x1000 - sizeof(real_mode_switch) - 100),
 316                 real_mode_switch, sizeof (real_mode_switch));
 317         memcpy((void *)(0x1000 - 100), code, length);
 318
 319         /* Set up the IDT for real mode. */
 320         load_idt(&real_mode_idt);
 321
 322         /* Set up a GDT from which we can load segment descriptors for real
 323            mode.  The GDT is not used in real mode; it is just needed here to
 324            prepare the descriptors. */
 325         load_gdt(&real_mode_gdt);
 326
 327         /* Load the data segment registers, and thus the descriptors ready for
 328            real mode.  The base address of each segment is 0x100, 16 times the
 329            selector value being loaded here.  This is so that the segment
 330            registers don't have to be reloaded after switching to real mode:
 331            the values are consistent for real mode operation already. */
 332         __asm__ __volatile__ ("movl $0x0010,%%eax\n"
 333                                 "\tmovl %%eax,%%ds\n"
 334                                 "\tmovl %%eax,%%es\n"
 335                                 "\tmovl %%eax,%%fs\n"
 336                                 "\tmovl %%eax,%%gs\n"
 337                                 "\tmovl %%eax,%%ss" : : : "eax");
 338
 339         /* Jump to the 16-bit code that we copied earlier.  It disables paging
 340            and the cache, switches to real mode, and jumps to the BIOS reset
 341            entry point. */
 342         __asm__ __volatile__ ("ljmp $0x0008,%0"
 343                                 :
 344                                 : "i" ((void *)(0x1000 - sizeof (real_mode_switch) - 100)));
 345 }
 346 #ifdef CONFIG_APM_MODULE
 347 EXPORT_SYMBOL(machine_real_restart);
 348 #endif
 349
 350 #endif /* CONFIG_X86_32 */
 351
 352 static inline void kb_wait(void)
 353 {
 354         int i;
 355
 356         for (i = 0; i < 0x10000; i++) {
 357                 if ((inb(0x64) & 0x02) == 0)
 358                         break;
 359                 udelay(2);
 360         }
 361 }
 362
 363 void __attribute__((weak)) mach_reboot_fixups(void)
 364 {
 365 }
 366
 367 static void native_machine_emergency_restart(void)
 368 {
 369         int i;
 370
 371         /* Tell the BIOS if we want cold or warm reboot */
 372         *((unsigned short *)__va(0x472)) = reboot_mode;
 373
 374         for (;;) {
 375                 /* Could also try the reset bit in the Hammer NB */
 376                 switch (reboot_type) {
 377                 case BOOT_KBD:
 378                         mach_reboot_fixups(); /* for board specific fixups */
 379
 380                         for (i = 0; i < 10; i++) {
 381                                 kb_wait();
 382                                 udelay(50);
 383                                 outb(0xfe, 0x64); /* pulse reset low */
 384                                 udelay(50);
 385                         }
 386
 387                 case BOOT_TRIPLE:
 388                         load_idt(&no_idt);
 389                         __asm__ __volatile__("int3");
 390
 391                         reboot_type = BOOT_KBD;
 392                         break;
 393
 394 #ifdef CONFIG_X86_32
 395                 case BOOT_BIOS:
 396                         machine_real_restart(jump_to_bios, sizeof(jump_to_bios));
 397
 398                         reboot_type = BOOT_KBD;
 399                         break;
 400 #endif
 401
 402                 case BOOT_ACPI:
 403                         acpi_reboot();
 404                         reboot_type = BOOT_KBD;
 405                         break;
 406
 407
 408                 case BOOT_EFI:
 409                         if (efi_enabled)
 410                                 efi.reset_system(reboot_mode ? EFI_RESET_WARM : EFI_RESET_COLD,
 411                                                  EFI_SUCCESS, 0, NULL);
 412
 413                         reboot_type = BOOT_KBD;
 414                         break;
 415                 }
 416         }
 417 }
 418
 419 void native_machine_shutdown(void)
 420 {
 421         /* Stop the cpus and apics */
 422 #ifdef CONFIG_SMP
 423
 424         /* The boot cpu is always logical cpu 0 */
 425         int reboot_cpu_id = 0;
 426
 427 #ifdef CONFIG_X86_32
 428         /* See if there has been given a command line override */
 429         if ((reboot_cpu != -1) && (reboot_cpu < NR_CPUS) &&
 430                 cpu_online(reboot_cpu))
 431                 reboot_cpu_id = reboot_cpu;
 432 #endif
 433
 434         /* Make certain the cpu I'm about to reboot on is online */
 435         if (!cpu_online(reboot_cpu_id))
 436                 reboot_cpu_id = smp_processor_id();
 437
 438         /* Make certain I only run on the appropriate processor */
 439         set_cpus_allowed_ptr(current, &cpumask_of_cpu(reboot_cpu_id));
 440
 441         /* O.K Now that I'm on the appropriate processor,
 442          * stop all of the others.
 443          */
 444         smp_send_stop();
 445 #endif
 446
 447         lapic_shutdown();
 448
 449 #ifdef CONFIG_X86_IO_APIC
 450         disable_IO_APIC();
 451 #endif
 452
 453 #ifdef CONFIG_HPET_TIMER
 454         hpet_disable();
 455 #endif
 456
 457 #ifdef CONFIG_X86_64
 458         pci_iommu_shutdown();
 459 #endif
 460 }
 461
 462 static void native_machine_restart(char *__unused)
 463 {
 464         printk("machine restart\n");
 465
 466         if (!reboot_force)
 467                 machine_shutdown();
 468         machine_emergency_restart();
 469 }
 470
 471 static void native_machine_halt(void)
 472 {
 473 }
 474
 475 static void native_machine_power_off(void)
 476 {
 477         if (pm_power_off) {
 478                 if (!reboot_force)
 479                         machine_shutdown();
 480                 pm_power_off();
 481         }
 482 }
 483
 484 struct machine_ops machine_ops = {
 485         .power_off = native_machine_power_off,
 486         .shutdown = native_machine_shutdown,
 487         .emergency_restart = native_machine_emergency_restart,
 488         .restart = native_machine_restart,
 489         .halt = native_machine_halt,
 490 #ifdef CONFIG_KEXEC
 491         .crash_shutdown = native_machine_crash_shutdown,
 492 #endif
 493 };
 494
 495 void machine_power_off(void)
 496 {
 497         machine_ops.power_off();
 498 }
 499
 500 void machine_shutdown(void)
 501 {
 502         machine_ops.shutdown();
 503 }
 504
 505 void machine_emergency_restart(void)
 506 {
 507         machine_ops.emergency_restart();
 508 }
 509
 510 void machine_restart(char *cmd)
 511 {
 512         machine_ops.restart(cmd);
 513 }
 514
 515 void machine_halt(void)
 516 {
 517         machine_ops.halt();
 518 }
 519
 520 #ifdef CONFIG_KEXEC
 521 void machine_crash_shutdown(struct pt_regs *regs)
 522 {
 523         machine_ops.crash_shutdown(regs);
 524 }
 525 #endif