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 <linux/dmi.h> 7 #include <linux/sched.h> 8 #include <linux/tboot.h> 9 #include <linux/delay.h> 10 #include <acpi/reboot.h> 11 #include <asm/io.h> 12 #include <asm/apic.h> 13 #include <asm/desc.h> 14 #include <asm/hpet.h> 15 #include <asm/pgtable.h> 16 #include <asm/proto.h> 17 #include <asm/reboot_fixups.h> 18 #include <asm/reboot.h> 19 #include <asm/pci_x86.h> 20 #include <asm/virtext.h> 21 #include <asm/cpu.h> 22 #include <asm/nmi.h> 23 24 #ifdef CONFIG_X86_32 25 # include <linux/ctype.h> 26 # include <linux/mc146818rtc.h> 27 #else 28 # include <asm/x86_init.h> 29 #endif 30 31 /* 32 * Power off function, if any 33 */ 34 void (*pm_power_off)(void); 35 EXPORT_SYMBOL(pm_power_off); 36 37 static const struct desc_ptr no_idt = {}; 38 static int reboot_mode; 39 enum reboot_type reboot_type = BOOT_ACPI; 40 int reboot_force; 41 42 #if defined(CONFIG_X86_32) && defined(CONFIG_SMP) 43 static int reboot_cpu = -1; 44 #endif 45 46 /* This is set if we need to go through the 'emergency' path. 47 * When machine_emergency_restart() is called, we may be on 48 * an inconsistent state and won't be able to do a clean cleanup 49 */ 50 static int reboot_emergency; 51 52 /* This is set by the PCI code if either type 1 or type 2 PCI is detected */ 53 bool port_cf9_safe = false; 54 55 /* reboot=b[ios] | s[mp] | t[riple] | k[bd] | e[fi] [, [w]arm | [c]old] | p[ci] 56 warm Don't set the cold reboot flag 57 cold Set the cold reboot flag 58 bios Reboot by jumping through the BIOS (only for X86_32) 59 smp Reboot by executing reset on BSP or other CPU (only for X86_32) 60 triple Force a triple fault (init) 61 kbd Use the keyboard controller. cold reset (default) 62 acpi Use the RESET_REG in the FADT 63 efi Use efi reset_system runtime service 64 pci Use the so-called "PCI reset register", CF9 65 force Avoid anything that could hang. 66 */ 67 static int __init reboot_setup(char *str) 68 { 69 for (;;) { 70 switch (*str) { 71 case 'w': 72 reboot_mode = 0x1234; 73 break; 74 75 case 'c': 76 reboot_mode = 0; 77 break; 78 79 #ifdef CONFIG_X86_32 80 #ifdef CONFIG_SMP 81 case 's': 82 if (isdigit(*(str+1))) { 83 reboot_cpu = (int) (*(str+1) - '0'); 84 if (isdigit(*(str+2))) 85 reboot_cpu = reboot_cpu*10 + (int)(*(str+2) - '0'); 86 } 87 /* we will leave sorting out the final value 88 when we are ready to reboot, since we might not 89 have detected BSP APIC ID or smp_num_cpu */ 90 break; 91 #endif /* CONFIG_SMP */ 92 93 case 'b': 94 #endif 95 case 'a': 96 case 'k': 97 case 't': 98 case 'e': 99 case 'p': 100 reboot_type = *str; 101 break; 102 103 case 'f': 104 reboot_force = 1; 105 break; 106 } 107 108 str = strchr(str, ','); 109 if (str) 110 str++; 111 else 112 break; 113 } 114 return 1; 115 } 116 117 __setup("reboot=", reboot_setup); 118 119 120 #ifdef CONFIG_X86_32 121 /* 122 * Reboot options and system auto-detection code provided by 123 * Dell Inc. so their systems "just work". :-) 124 */ 125 126 /* 127 * Some machines require the "reboot=b" commandline option, 128 * this quirk makes that automatic. 129 */ 130 static int __init set_bios_reboot(const struct dmi_system_id *d) 131 { 132 if (reboot_type != BOOT_BIOS) { 133 reboot_type = BOOT_BIOS; 134 printk(KERN_INFO "%s series board detected. Selecting BIOS-method for reboots.\n", d->ident); 135 } 136 return 0; 137 } 138 139 static struct dmi_system_id __initdata reboot_dmi_table[] = { 140 { /* Handle problems with rebooting on Dell E520's */ 141 .callback = set_bios_reboot, 142 .ident = "Dell E520", 143 .matches = { 144 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 145 DMI_MATCH(DMI_PRODUCT_NAME, "Dell DM061"), 146 }, 147 }, 148 { /* Handle problems with rebooting on Dell 1300's */ 149 .callback = set_bios_reboot, 150 .ident = "Dell PowerEdge 1300", 151 .matches = { 152 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"), 153 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1300/"), 154 }, 155 }, 156 { /* Handle problems with rebooting on Dell 300's */ 157 .callback = set_bios_reboot, 158 .ident = "Dell PowerEdge 300", 159 .matches = { 160 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"), 161 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"), 162 }, 163 }, 164 { /* Handle problems with rebooting on Dell Optiplex 745's SFF*/ 165 .callback = set_bios_reboot, 166 .ident = "Dell OptiPlex 745", 167 .matches = { 168 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 169 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"), 170 }, 171 }, 172 { /* Handle problems with rebooting on Dell Optiplex 745's DFF*/ 173 .callback = set_bios_reboot, 174 .ident = "Dell OptiPlex 745", 175 .matches = { 176 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 177 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"), 178 DMI_MATCH(DMI_BOARD_NAME, "0MM599"), 179 }, 180 }, 181 { /* Handle problems with rebooting on Dell Optiplex 745 with 0KW626 */ 182 .callback = set_bios_reboot, 183 .ident = "Dell OptiPlex 745", 184 .matches = { 185 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 186 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"), 187 DMI_MATCH(DMI_BOARD_NAME, "0KW626"), 188 }, 189 }, 190 { /* Handle problems with rebooting on Dell Optiplex 330 with 0KP561 */ 191 .callback = set_bios_reboot, 192 .ident = "Dell OptiPlex 330", 193 .matches = { 194 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 195 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 330"), 196 DMI_MATCH(DMI_BOARD_NAME, "0KP561"), 197 }, 198 }, 199 { /* Handle problems with rebooting on Dell Optiplex 360 with 0T656F */ 200 .callback = set_bios_reboot, 201 .ident = "Dell OptiPlex 360", 202 .matches = { 203 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 204 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 360"), 205 DMI_MATCH(DMI_BOARD_NAME, "0T656F"), 206 }, 207 }, 208 { /* Handle problems with rebooting on Dell OptiPlex 760 with 0G919G*/ 209 .callback = set_bios_reboot, 210 .ident = "Dell OptiPlex 760", 211 .matches = { 212 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 213 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 760"), 214 DMI_MATCH(DMI_BOARD_NAME, "0G919G"), 215 }, 216 }, 217 { /* Handle problems with rebooting on Dell 2400's */ 218 .callback = set_bios_reboot, 219 .ident = "Dell PowerEdge 2400", 220 .matches = { 221 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"), 222 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"), 223 }, 224 }, 225 { /* Handle problems with rebooting on Dell T5400's */ 226 .callback = set_bios_reboot, 227 .ident = "Dell Precision T5400", 228 .matches = { 229 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 230 DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T5400"), 231 }, 232 }, 233 { /* Handle problems with rebooting on Dell T7400's */ 234 .callback = set_bios_reboot, 235 .ident = "Dell Precision T7400", 236 .matches = { 237 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 238 DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T7400"), 239 }, 240 }, 241 { /* Handle problems with rebooting on HP laptops */ 242 .callback = set_bios_reboot, 243 .ident = "HP Compaq Laptop", 244 .matches = { 245 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"), 246 DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"), 247 }, 248 }, 249 { /* Handle problems with rebooting on Dell XPS710 */ 250 .callback = set_bios_reboot, 251 .ident = "Dell XPS710", 252 .matches = { 253 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 254 DMI_MATCH(DMI_PRODUCT_NAME, "Dell XPS710"), 255 }, 256 }, 257 { /* Handle problems with rebooting on Dell DXP061 */ 258 .callback = set_bios_reboot, 259 .ident = "Dell DXP061", 260 .matches = { 261 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 262 DMI_MATCH(DMI_PRODUCT_NAME, "Dell DXP061"), 263 }, 264 }, 265 { /* Handle problems with rebooting on Sony VGN-Z540N */ 266 .callback = set_bios_reboot, 267 .ident = "Sony VGN-Z540N", 268 .matches = { 269 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"), 270 DMI_MATCH(DMI_PRODUCT_NAME, "VGN-Z540N"), 271 }, 272 }, 273 { /* Handle problems with rebooting on CompuLab SBC-FITPC2 */ 274 .callback = set_bios_reboot, 275 .ident = "CompuLab SBC-FITPC2", 276 .matches = { 277 DMI_MATCH(DMI_SYS_VENDOR, "CompuLab"), 278 DMI_MATCH(DMI_PRODUCT_NAME, "SBC-FITPC2"), 279 }, 280 }, 281 { /* Handle problems with rebooting on ASUS P4S800 */ 282 .callback = set_bios_reboot, 283 .ident = "ASUS P4S800", 284 .matches = { 285 DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."), 286 DMI_MATCH(DMI_BOARD_NAME, "P4S800"), 287 }, 288 }, 289 { /* Handle problems with rebooting on VersaLogic Menlow boards */ 290 .callback = set_bios_reboot, 291 .ident = "VersaLogic Menlow based board", 292 .matches = { 293 DMI_MATCH(DMI_BOARD_VENDOR, "VersaLogic Corporation"), 294 DMI_MATCH(DMI_BOARD_NAME, "VersaLogic Menlow board"), 295 }, 296 }, 297 { /* Handle reboot issue on Acer Aspire one */ 298 .callback = set_bios_reboot, 299 .ident = "Acer Aspire One A110", 300 .matches = { 301 DMI_MATCH(DMI_SYS_VENDOR, "Acer"), 302 DMI_MATCH(DMI_PRODUCT_NAME, "AOA110"), 303 }, 304 }, 305 { } 306 }; 307 308 static int __init reboot_init(void) 309 { 310 dmi_check_system(reboot_dmi_table); 311 return 0; 312 } 313 core_initcall(reboot_init); 314 315 extern const unsigned char machine_real_restart_asm[]; 316 extern const u64 machine_real_restart_gdt[3]; 317 318 void machine_real_restart(unsigned int type) 319 { 320 void *restart_va; 321 unsigned long restart_pa; 322 void (*restart_lowmem)(unsigned int); 323 u64 *lowmem_gdt; 324 325 local_irq_disable(); 326 327 /* Write zero to CMOS register number 0x0f, which the BIOS POST 328 routine will recognize as telling it to do a proper reboot. (Well 329 that's what this book in front of me says -- it may only apply to 330 the Phoenix BIOS though, it's not clear). At the same time, 331 disable NMIs by setting the top bit in the CMOS address register, 332 as we're about to do peculiar things to the CPU. I'm not sure if 333 `outb_p' is needed instead of just `outb'. Use it to be on the 334 safe side. (Yes, CMOS_WRITE does outb_p's. - Paul G.) 335 */ 336 spin_lock(&rtc_lock); 337 CMOS_WRITE(0x00, 0x8f); 338 spin_unlock(&rtc_lock); 339 340 /* 341 * Switch back to the initial page table. 342 */ 343 load_cr3(initial_page_table); 344 345 /* Write 0x1234 to absolute memory location 0x472. The BIOS reads 346 this on booting to tell it to "Bypass memory test (also warm 347 boot)". This seems like a fairly standard thing that gets set by 348 REBOOT.COM programs, and the previous reset routine did this 349 too. */ 350 *((unsigned short *)0x472) = reboot_mode; 351 352 /* Patch the GDT in the low memory trampoline */ 353 lowmem_gdt = TRAMPOLINE_SYM(machine_real_restart_gdt); 354 355 restart_va = TRAMPOLINE_SYM(machine_real_restart_asm); 356 restart_pa = virt_to_phys(restart_va); 357 restart_lowmem = (void (*)(unsigned int))restart_pa; 358 359 /* GDT[0]: GDT self-pointer */ 360 lowmem_gdt[0] = 361 (u64)(sizeof(machine_real_restart_gdt) - 1) + 362 ((u64)virt_to_phys(lowmem_gdt) << 16); 363 /* GDT[1]: 64K real mode code segment */ 364 lowmem_gdt[1] = 365 GDT_ENTRY(0x009b, restart_pa, 0xffff); 366 367 /* Jump to the identity-mapped low memory code */ 368 restart_lowmem(type); 369 } 370 #ifdef CONFIG_APM_MODULE 371 EXPORT_SYMBOL(machine_real_restart); 372 #endif 373 374 #endif /* CONFIG_X86_32 */ 375 376 /* 377 * Some Apple MacBook and MacBookPro's needs reboot=p to be able to reboot 378 */ 379 static int __init set_pci_reboot(const struct dmi_system_id *d) 380 { 381 if (reboot_type != BOOT_CF9) { 382 reboot_type = BOOT_CF9; 383 printk(KERN_INFO "%s series board detected. " 384 "Selecting PCI-method for reboots.\n", d->ident); 385 } 386 return 0; 387 } 388 389 static struct dmi_system_id __initdata pci_reboot_dmi_table[] = { 390 { /* Handle problems with rebooting on Apple MacBook5 */ 391 .callback = set_pci_reboot, 392 .ident = "Apple MacBook5", 393 .matches = { 394 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."), 395 DMI_MATCH(DMI_PRODUCT_NAME, "MacBook5"), 396 }, 397 }, 398 { /* Handle problems with rebooting on Apple MacBookPro5 */ 399 .callback = set_pci_reboot, 400 .ident = "Apple MacBookPro5", 401 .matches = { 402 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."), 403 DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro5"), 404 }, 405 }, 406 { /* Handle problems with rebooting on Apple Macmini3,1 */ 407 .callback = set_pci_reboot, 408 .ident = "Apple Macmini3,1", 409 .matches = { 410 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."), 411 DMI_MATCH(DMI_PRODUCT_NAME, "Macmini3,1"), 412 }, 413 }, 414 { /* Handle problems with rebooting on the iMac9,1. */ 415 .callback = set_pci_reboot, 416 .ident = "Apple iMac9,1", 417 .matches = { 418 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."), 419 DMI_MATCH(DMI_PRODUCT_NAME, "iMac9,1"), 420 }, 421 }, 422 { } 423 }; 424 425 static int __init pci_reboot_init(void) 426 { 427 dmi_check_system(pci_reboot_dmi_table); 428 return 0; 429 } 430 core_initcall(pci_reboot_init); 431 432 static inline void kb_wait(void) 433 { 434 int i; 435 436 for (i = 0; i < 0x10000; i++) { 437 if ((inb(0x64) & 0x02) == 0) 438 break; 439 udelay(2); 440 } 441 } 442 443 static void vmxoff_nmi(int cpu, struct die_args *args) 444 { 445 cpu_emergency_vmxoff(); 446 } 447 448 /* Use NMIs as IPIs to tell all CPUs to disable virtualization 449 */ 450 static void emergency_vmx_disable_all(void) 451 { 452 /* Just make sure we won't change CPUs while doing this */ 453 local_irq_disable(); 454 455 /* We need to disable VMX on all CPUs before rebooting, otherwise 456 * we risk hanging up the machine, because the CPU ignore INIT 457 * signals when VMX is enabled. 458 * 459 * We can't take any locks and we may be on an inconsistent 460 * state, so we use NMIs as IPIs to tell the other CPUs to disable 461 * VMX and halt. 462 * 463 * For safety, we will avoid running the nmi_shootdown_cpus() 464 * stuff unnecessarily, but we don't have a way to check 465 * if other CPUs have VMX enabled. So we will call it only if the 466 * CPU we are running on has VMX enabled. 467 * 468 * We will miss cases where VMX is not enabled on all CPUs. This 469 * shouldn't do much harm because KVM always enable VMX on all 470 * CPUs anyway. But we can miss it on the small window where KVM 471 * is still enabling VMX. 472 */ 473 if (cpu_has_vmx() && cpu_vmx_enabled()) { 474 /* Disable VMX on this CPU. 475 */ 476 cpu_vmxoff(); 477 478 /* Halt and disable VMX on the other CPUs */ 479 nmi_shootdown_cpus(vmxoff_nmi); 480 481 } 482 } 483 484 485 void __attribute__((weak)) mach_reboot_fixups(void) 486 { 487 } 488 489 /* 490 * Windows compatible x86 hardware expects the following on reboot: 491 * 492 * 1) If the FADT has the ACPI reboot register flag set, try it 493 * 2) If still alive, write to the keyboard controller 494 * 3) If still alive, write to the ACPI reboot register again 495 * 4) If still alive, write to the keyboard controller again 496 * 497 * If the machine is still alive at this stage, it gives up. We default to 498 * following the same pattern, except that if we're still alive after (4) we'll 499 * try to force a triple fault and then cycle between hitting the keyboard 500 * controller and doing that 501 */ 502 static void native_machine_emergency_restart(void) 503 { 504 int i; 505 int attempt = 0; 506 int orig_reboot_type = reboot_type; 507 508 if (reboot_emergency) 509 emergency_vmx_disable_all(); 510 511 tboot_shutdown(TB_SHUTDOWN_REBOOT); 512 513 /* Tell the BIOS if we want cold or warm reboot */ 514 *((unsigned short *)__va(0x472)) = reboot_mode; 515 516 for (;;) { 517 /* Could also try the reset bit in the Hammer NB */ 518 switch (reboot_type) { 519 case BOOT_KBD: 520 mach_reboot_fixups(); /* for board specific fixups */ 521 522 for (i = 0; i < 10; i++) { 523 kb_wait(); 524 udelay(50); 525 outb(0xfe, 0x64); /* pulse reset low */ 526 udelay(50); 527 } 528 if (attempt == 0 && orig_reboot_type == BOOT_ACPI) { 529 attempt = 1; 530 reboot_type = BOOT_ACPI; 531 } else { 532 reboot_type = BOOT_TRIPLE; 533 } 534 break; 535 536 case BOOT_TRIPLE: 537 load_idt(&no_idt); 538 __asm__ __volatile__("int3"); 539 540 reboot_type = BOOT_KBD; 541 break; 542 543 #ifdef CONFIG_X86_32 544 case BOOT_BIOS: 545 machine_real_restart(MRR_BIOS); 546 547 reboot_type = BOOT_KBD; 548 break; 549 #endif 550 551 case BOOT_ACPI: 552 acpi_reboot(); 553 reboot_type = BOOT_KBD; 554 break; 555 556 case BOOT_EFI: 557 if (efi_enabled) 558 efi.reset_system(reboot_mode ? 559 EFI_RESET_WARM : 560 EFI_RESET_COLD, 561 EFI_SUCCESS, 0, NULL); 562 reboot_type = BOOT_KBD; 563 break; 564 565 case BOOT_CF9: 566 port_cf9_safe = true; 567 /* fall through */ 568 569 case BOOT_CF9_COND: 570 if (port_cf9_safe) { 571 u8 cf9 = inb(0xcf9) & ~6; 572 outb(cf9|2, 0xcf9); /* Request hard reset */ 573 udelay(50); 574 outb(cf9|6, 0xcf9); /* Actually do the reset */ 575 udelay(50); 576 } 577 reboot_type = BOOT_KBD; 578 break; 579 } 580 } 581 } 582 583 void native_machine_shutdown(void) 584 { 585 /* Stop the cpus and apics */ 586 #ifdef CONFIG_SMP 587 588 /* The boot cpu is always logical cpu 0 */ 589 int reboot_cpu_id = 0; 590 591 #ifdef CONFIG_X86_32 592 /* See if there has been given a command line override */ 593 if ((reboot_cpu != -1) && (reboot_cpu < nr_cpu_ids) && 594 cpu_online(reboot_cpu)) 595 reboot_cpu_id = reboot_cpu; 596 #endif 597 598 /* Make certain the cpu I'm about to reboot on is online */ 599 if (!cpu_online(reboot_cpu_id)) 600 reboot_cpu_id = smp_processor_id(); 601 602 /* Make certain I only run on the appropriate processor */ 603 set_cpus_allowed_ptr(current, cpumask_of(reboot_cpu_id)); 604 605 /* O.K Now that I'm on the appropriate processor, 606 * stop all of the others. 607 */ 608 stop_other_cpus(); 609 #endif 610 611 lapic_shutdown(); 612 613 #ifdef CONFIG_X86_IO_APIC 614 disable_IO_APIC(); 615 #endif 616 617 #ifdef CONFIG_HPET_TIMER 618 hpet_disable(); 619 #endif 620 621 #ifdef CONFIG_X86_64 622 x86_platform.iommu_shutdown(); 623 #endif 624 } 625 626 static void __machine_emergency_restart(int emergency) 627 { 628 reboot_emergency = emergency; 629 machine_ops.emergency_restart(); 630 } 631 632 static void native_machine_restart(char *__unused) 633 { 634 printk("machine restart\n"); 635 636 if (!reboot_force) 637 machine_shutdown(); 638 __machine_emergency_restart(0); 639 } 640 641 static void native_machine_halt(void) 642 { 643 /* stop other cpus and apics */ 644 machine_shutdown(); 645 646 tboot_shutdown(TB_SHUTDOWN_HALT); 647 648 /* stop this cpu */ 649 stop_this_cpu(NULL); 650 } 651 652 static void native_machine_power_off(void) 653 { 654 if (pm_power_off) { 655 if (!reboot_force) 656 machine_shutdown(); 657 pm_power_off(); 658 } 659 /* a fallback in case there is no PM info available */ 660 tboot_shutdown(TB_SHUTDOWN_HALT); 661 } 662 663 struct machine_ops machine_ops = { 664 .power_off = native_machine_power_off, 665 .shutdown = native_machine_shutdown, 666 .emergency_restart = native_machine_emergency_restart, 667 .restart = native_machine_restart, 668 .halt = native_machine_halt, 669 #ifdef CONFIG_KEXEC 670 .crash_shutdown = native_machine_crash_shutdown, 671 #endif 672 }; 673 674 void machine_power_off(void) 675 { 676 machine_ops.power_off(); 677 } 678 679 void machine_shutdown(void) 680 { 681 machine_ops.shutdown(); 682 } 683 684 void machine_emergency_restart(void) 685 { 686 __machine_emergency_restart(1); 687 } 688 689 void machine_restart(char *cmd) 690 { 691 machine_ops.restart(cmd); 692 } 693 694 void machine_halt(void) 695 { 696 machine_ops.halt(); 697 } 698 699 #ifdef CONFIG_KEXEC 700 void machine_crash_shutdown(struct pt_regs *regs) 701 { 702 machine_ops.crash_shutdown(regs); 703 } 704 #endif 705 706 707 #if defined(CONFIG_SMP) 708 709 /* This keeps a track of which one is crashing cpu. */ 710 static int crashing_cpu; 711 static nmi_shootdown_cb shootdown_callback; 712 713 static atomic_t waiting_for_crash_ipi; 714 715 static int crash_nmi_callback(struct notifier_block *self, 716 unsigned long val, void *data) 717 { 718 int cpu; 719 720 if (val != DIE_NMI) 721 return NOTIFY_OK; 722 723 cpu = raw_smp_processor_id(); 724 725 /* Don't do anything if this handler is invoked on crashing cpu. 726 * Otherwise, system will completely hang. Crashing cpu can get 727 * an NMI if system was initially booted with nmi_watchdog parameter. 728 */ 729 if (cpu == crashing_cpu) 730 return NOTIFY_STOP; 731 local_irq_disable(); 732 733 shootdown_callback(cpu, (struct die_args *)data); 734 735 atomic_dec(&waiting_for_crash_ipi); 736 /* Assume hlt works */ 737 halt(); 738 for (;;) 739 cpu_relax(); 740 741 return 1; 742 } 743 744 static void smp_send_nmi_allbutself(void) 745 { 746 apic->send_IPI_allbutself(NMI_VECTOR); 747 } 748 749 static struct notifier_block crash_nmi_nb = { 750 .notifier_call = crash_nmi_callback, 751 /* we want to be the first one called */ 752 .priority = NMI_LOCAL_HIGH_PRIOR+1, 753 }; 754 755 /* Halt all other CPUs, calling the specified function on each of them 756 * 757 * This function can be used to halt all other CPUs on crash 758 * or emergency reboot time. The function passed as parameter 759 * will be called inside a NMI handler on all CPUs. 760 */ 761 void nmi_shootdown_cpus(nmi_shootdown_cb callback) 762 { 763 unsigned long msecs; 764 local_irq_disable(); 765 766 /* Make a note of crashing cpu. Will be used in NMI callback.*/ 767 crashing_cpu = safe_smp_processor_id(); 768 769 shootdown_callback = callback; 770 771 atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1); 772 /* Would it be better to replace the trap vector here? */ 773 if (register_die_notifier(&crash_nmi_nb)) 774 return; /* return what? */ 775 /* Ensure the new callback function is set before sending 776 * out the NMI 777 */ 778 wmb(); 779 780 smp_send_nmi_allbutself(); 781 782 msecs = 1000; /* Wait at most a second for the other cpus to stop */ 783 while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) { 784 mdelay(1); 785 msecs--; 786 } 787 788 /* Leave the nmi callback set */ 789 } 790 #else /* !CONFIG_SMP */ 791 void nmi_shootdown_cpus(nmi_shootdown_cb callback) 792 { 793 /* No other CPUs to shoot down */ 794 } 795 #endif 796