1 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 2 3 #include <linux/module.h> 4 #include <linux/reboot.h> 5 #include <linux/init.h> 6 #include <linux/pm.h> 7 #include <linux/efi.h> 8 #include <linux/dmi.h> 9 #include <linux/sched.h> 10 #include <linux/tboot.h> 11 #include <linux/delay.h> 12 #include <acpi/reboot.h> 13 #include <asm/io.h> 14 #include <asm/apic.h> 15 #include <asm/io_apic.h> 16 #include <asm/desc.h> 17 #include <asm/hpet.h> 18 #include <asm/pgtable.h> 19 #include <asm/proto.h> 20 #include <asm/reboot_fixups.h> 21 #include <asm/reboot.h> 22 #include <asm/pci_x86.h> 23 #include <asm/virtext.h> 24 #include <asm/cpu.h> 25 #include <asm/nmi.h> 26 #include <asm/smp.h> 27 28 #include <linux/ctype.h> 29 #include <linux/mc146818rtc.h> 30 #include <asm/realmode.h> 31 #include <asm/x86_init.h> 32 #include <asm/efi.h> 33 34 /* 35 * Power off function, if any 36 */ 37 void (*pm_power_off)(void); 38 EXPORT_SYMBOL(pm_power_off); 39 40 static const struct desc_ptr no_idt = {}; 41 42 /* 43 * This is set if we need to go through the 'emergency' path. 44 * When machine_emergency_restart() is called, we may be on 45 * an inconsistent state and won't be able to do a clean cleanup 46 */ 47 static int reboot_emergency; 48 49 /* This is set by the PCI code if either type 1 or type 2 PCI is detected */ 50 bool port_cf9_safe = false; 51 52 /* 53 * Reboot options and system auto-detection code provided by 54 * Dell Inc. so their systems "just work". :-) 55 */ 56 57 /* 58 * Some machines require the "reboot=b" or "reboot=k" commandline options, 59 * this quirk makes that automatic. 60 */ 61 static int __init set_bios_reboot(const struct dmi_system_id *d) 62 { 63 if (reboot_type != BOOT_BIOS) { 64 reboot_type = BOOT_BIOS; 65 pr_info("%s series board detected. Selecting %s-method for reboots.\n", 66 d->ident, "BIOS"); 67 } 68 return 0; 69 } 70 71 void __noreturn machine_real_restart(unsigned int type) 72 { 73 local_irq_disable(); 74 75 /* 76 * Write zero to CMOS register number 0x0f, which the BIOS POST 77 * routine will recognize as telling it to do a proper reboot. (Well 78 * that's what this book in front of me says -- it may only apply to 79 * the Phoenix BIOS though, it's not clear). At the same time, 80 * disable NMIs by setting the top bit in the CMOS address register, 81 * as we're about to do peculiar things to the CPU. I'm not sure if 82 * `outb_p' is needed instead of just `outb'. Use it to be on the 83 * safe side. (Yes, CMOS_WRITE does outb_p's. - Paul G.) 84 */ 85 spin_lock(&rtc_lock); 86 CMOS_WRITE(0x00, 0x8f); 87 spin_unlock(&rtc_lock); 88 89 /* 90 * Switch back to the initial page table. 91 */ 92 #ifdef CONFIG_X86_32 93 load_cr3(initial_page_table); 94 #else 95 write_cr3(real_mode_header->trampoline_pgd); 96 #endif 97 98 /* Jump to the identity-mapped low memory code */ 99 #ifdef CONFIG_X86_32 100 asm volatile("jmpl *%0" : : 101 "rm" (real_mode_header->machine_real_restart_asm), 102 "a" (type)); 103 #else 104 asm volatile("ljmpl *%0" : : 105 "m" (real_mode_header->machine_real_restart_asm), 106 "D" (type)); 107 #endif 108 unreachable(); 109 } 110 #ifdef CONFIG_APM_MODULE 111 EXPORT_SYMBOL(machine_real_restart); 112 #endif 113 114 /* 115 * Some Apple MacBook and MacBookPro's needs reboot=p to be able to reboot 116 */ 117 static int __init set_pci_reboot(const struct dmi_system_id *d) 118 { 119 if (reboot_type != BOOT_CF9_FORCE) { 120 reboot_type = BOOT_CF9_FORCE; 121 pr_info("%s series board detected. Selecting %s-method for reboots.\n", 122 d->ident, "PCI"); 123 } 124 return 0; 125 } 126 127 static int __init set_kbd_reboot(const struct dmi_system_id *d) 128 { 129 if (reboot_type != BOOT_KBD) { 130 reboot_type = BOOT_KBD; 131 pr_info("%s series board detected. Selecting %s-method for reboot.\n", 132 d->ident, "KBD"); 133 } 134 return 0; 135 } 136 137 /* 138 * This is a single dmi_table handling all reboot quirks. 139 */ 140 static struct dmi_system_id __initdata reboot_dmi_table[] = { 141 142 /* Acer */ 143 { /* Handle reboot issue on Acer Aspire one */ 144 .callback = set_kbd_reboot, 145 .ident = "Acer Aspire One A110", 146 .matches = { 147 DMI_MATCH(DMI_SYS_VENDOR, "Acer"), 148 DMI_MATCH(DMI_PRODUCT_NAME, "AOA110"), 149 }, 150 }, 151 152 /* Apple */ 153 { /* Handle problems with rebooting on Apple MacBook5 */ 154 .callback = set_pci_reboot, 155 .ident = "Apple MacBook5", 156 .matches = { 157 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."), 158 DMI_MATCH(DMI_PRODUCT_NAME, "MacBook5"), 159 }, 160 }, 161 { /* Handle problems with rebooting on Apple MacBookPro5 */ 162 .callback = set_pci_reboot, 163 .ident = "Apple MacBookPro5", 164 .matches = { 165 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."), 166 DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro5"), 167 }, 168 }, 169 { /* Handle problems with rebooting on Apple Macmini3,1 */ 170 .callback = set_pci_reboot, 171 .ident = "Apple Macmini3,1", 172 .matches = { 173 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."), 174 DMI_MATCH(DMI_PRODUCT_NAME, "Macmini3,1"), 175 }, 176 }, 177 { /* Handle problems with rebooting on the iMac9,1. */ 178 .callback = set_pci_reboot, 179 .ident = "Apple iMac9,1", 180 .matches = { 181 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."), 182 DMI_MATCH(DMI_PRODUCT_NAME, "iMac9,1"), 183 }, 184 }, 185 186 /* ASUS */ 187 { /* Handle problems with rebooting on ASUS P4S800 */ 188 .callback = set_bios_reboot, 189 .ident = "ASUS P4S800", 190 .matches = { 191 DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."), 192 DMI_MATCH(DMI_BOARD_NAME, "P4S800"), 193 }, 194 }, 195 196 /* Certec */ 197 { /* Handle problems with rebooting on Certec BPC600 */ 198 .callback = set_pci_reboot, 199 .ident = "Certec BPC600", 200 .matches = { 201 DMI_MATCH(DMI_SYS_VENDOR, "Certec"), 202 DMI_MATCH(DMI_PRODUCT_NAME, "BPC600"), 203 }, 204 }, 205 206 /* Dell */ 207 { /* Handle problems with rebooting on Dell DXP061 */ 208 .callback = set_bios_reboot, 209 .ident = "Dell DXP061", 210 .matches = { 211 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 212 DMI_MATCH(DMI_PRODUCT_NAME, "Dell DXP061"), 213 }, 214 }, 215 { /* Handle problems with rebooting on Dell E520's */ 216 .callback = set_bios_reboot, 217 .ident = "Dell E520", 218 .matches = { 219 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 220 DMI_MATCH(DMI_PRODUCT_NAME, "Dell DM061"), 221 }, 222 }, 223 { /* Handle problems with rebooting on the Latitude E5410. */ 224 .callback = set_pci_reboot, 225 .ident = "Dell Latitude E5410", 226 .matches = { 227 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 228 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E5410"), 229 }, 230 }, 231 { /* Handle problems with rebooting on the Latitude E5420. */ 232 .callback = set_pci_reboot, 233 .ident = "Dell Latitude E5420", 234 .matches = { 235 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 236 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E5420"), 237 }, 238 }, 239 { /* Handle problems with rebooting on the Latitude E6320. */ 240 .callback = set_pci_reboot, 241 .ident = "Dell Latitude E6320", 242 .matches = { 243 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 244 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6320"), 245 }, 246 }, 247 { /* Handle problems with rebooting on the Latitude E6420. */ 248 .callback = set_pci_reboot, 249 .ident = "Dell Latitude E6420", 250 .matches = { 251 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 252 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6420"), 253 }, 254 }, 255 { /* Handle problems with rebooting on Dell Optiplex 330 with 0KP561 */ 256 .callback = set_bios_reboot, 257 .ident = "Dell OptiPlex 330", 258 .matches = { 259 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 260 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 330"), 261 DMI_MATCH(DMI_BOARD_NAME, "0KP561"), 262 }, 263 }, 264 { /* Handle problems with rebooting on Dell Optiplex 360 with 0T656F */ 265 .callback = set_bios_reboot, 266 .ident = "Dell OptiPlex 360", 267 .matches = { 268 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 269 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 360"), 270 DMI_MATCH(DMI_BOARD_NAME, "0T656F"), 271 }, 272 }, 273 { /* Handle problems with rebooting on Dell Optiplex 745's SFF */ 274 .callback = set_bios_reboot, 275 .ident = "Dell OptiPlex 745", 276 .matches = { 277 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 278 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"), 279 }, 280 }, 281 { /* Handle problems with rebooting on Dell Optiplex 745's DFF */ 282 .callback = set_bios_reboot, 283 .ident = "Dell OptiPlex 745", 284 .matches = { 285 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 286 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"), 287 DMI_MATCH(DMI_BOARD_NAME, "0MM599"), 288 }, 289 }, 290 { /* Handle problems with rebooting on Dell Optiplex 745 with 0KW626 */ 291 .callback = set_bios_reboot, 292 .ident = "Dell OptiPlex 745", 293 .matches = { 294 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 295 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"), 296 DMI_MATCH(DMI_BOARD_NAME, "0KW626"), 297 }, 298 }, 299 { /* Handle problems with rebooting on Dell OptiPlex 760 with 0G919G */ 300 .callback = set_bios_reboot, 301 .ident = "Dell OptiPlex 760", 302 .matches = { 303 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 304 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 760"), 305 DMI_MATCH(DMI_BOARD_NAME, "0G919G"), 306 }, 307 }, 308 { /* Handle problems with rebooting on the OptiPlex 990. */ 309 .callback = set_pci_reboot, 310 .ident = "Dell OptiPlex 990", 311 .matches = { 312 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 313 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 990"), 314 }, 315 }, 316 { /* Handle problems with rebooting on Dell 300's */ 317 .callback = set_bios_reboot, 318 .ident = "Dell PowerEdge 300", 319 .matches = { 320 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"), 321 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"), 322 }, 323 }, 324 { /* Handle problems with rebooting on Dell 1300's */ 325 .callback = set_bios_reboot, 326 .ident = "Dell PowerEdge 1300", 327 .matches = { 328 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"), 329 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1300/"), 330 }, 331 }, 332 { /* Handle problems with rebooting on Dell 2400's */ 333 .callback = set_bios_reboot, 334 .ident = "Dell PowerEdge 2400", 335 .matches = { 336 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"), 337 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"), 338 }, 339 }, 340 { /* Handle problems with rebooting on the Dell PowerEdge C6100. */ 341 .callback = set_pci_reboot, 342 .ident = "Dell PowerEdge C6100", 343 .matches = { 344 DMI_MATCH(DMI_SYS_VENDOR, "Dell"), 345 DMI_MATCH(DMI_PRODUCT_NAME, "C6100"), 346 }, 347 }, 348 { /* Handle problems with rebooting on the Precision M6600. */ 349 .callback = set_pci_reboot, 350 .ident = "Dell Precision M6600", 351 .matches = { 352 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 353 DMI_MATCH(DMI_PRODUCT_NAME, "Precision M6600"), 354 }, 355 }, 356 { /* Handle problems with rebooting on Dell T5400's */ 357 .callback = set_bios_reboot, 358 .ident = "Dell Precision T5400", 359 .matches = { 360 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 361 DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T5400"), 362 }, 363 }, 364 { /* Handle problems with rebooting on Dell T7400's */ 365 .callback = set_bios_reboot, 366 .ident = "Dell Precision T7400", 367 .matches = { 368 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 369 DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T7400"), 370 }, 371 }, 372 { /* Handle problems with rebooting on Dell XPS710 */ 373 .callback = set_bios_reboot, 374 .ident = "Dell XPS710", 375 .matches = { 376 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), 377 DMI_MATCH(DMI_PRODUCT_NAME, "Dell XPS710"), 378 }, 379 }, 380 381 /* Hewlett-Packard */ 382 { /* Handle problems with rebooting on HP laptops */ 383 .callback = set_bios_reboot, 384 .ident = "HP Compaq Laptop", 385 .matches = { 386 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"), 387 DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"), 388 }, 389 }, 390 391 /* Sony */ 392 { /* Handle problems with rebooting on Sony VGN-Z540N */ 393 .callback = set_bios_reboot, 394 .ident = "Sony VGN-Z540N", 395 .matches = { 396 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"), 397 DMI_MATCH(DMI_PRODUCT_NAME, "VGN-Z540N"), 398 }, 399 }, 400 401 { } 402 }; 403 404 static int __init reboot_init(void) 405 { 406 int rv; 407 408 /* 409 * Only do the DMI check if reboot_type hasn't been overridden 410 * on the command line 411 */ 412 if (!reboot_default) 413 return 0; 414 415 /* 416 * The DMI quirks table takes precedence. If no quirks entry 417 * matches and the ACPI Hardware Reduced bit is set, force EFI 418 * reboot. 419 */ 420 rv = dmi_check_system(reboot_dmi_table); 421 422 if (!rv && efi_reboot_required()) 423 reboot_type = BOOT_EFI; 424 425 return 0; 426 } 427 core_initcall(reboot_init); 428 429 static inline void kb_wait(void) 430 { 431 int i; 432 433 for (i = 0; i < 0x10000; i++) { 434 if ((inb(0x64) & 0x02) == 0) 435 break; 436 udelay(2); 437 } 438 } 439 440 static void vmxoff_nmi(int cpu, struct pt_regs *regs) 441 { 442 cpu_emergency_vmxoff(); 443 } 444 445 /* Use NMIs as IPIs to tell all CPUs to disable virtualization */ 446 static void emergency_vmx_disable_all(void) 447 { 448 /* Just make sure we won't change CPUs while doing this */ 449 local_irq_disable(); 450 451 /* 452 * We need to disable VMX on all CPUs before rebooting, otherwise 453 * we risk hanging up the machine, because the CPU ignore INIT 454 * signals when VMX is enabled. 455 * 456 * We can't take any locks and we may be on an inconsistent 457 * state, so we use NMIs as IPIs to tell the other CPUs to disable 458 * VMX and halt. 459 * 460 * For safety, we will avoid running the nmi_shootdown_cpus() 461 * stuff unnecessarily, but we don't have a way to check 462 * if other CPUs have VMX enabled. So we will call it only if the 463 * CPU we are running on has VMX enabled. 464 * 465 * We will miss cases where VMX is not enabled on all CPUs. This 466 * shouldn't do much harm because KVM always enable VMX on all 467 * CPUs anyway. But we can miss it on the small window where KVM 468 * is still enabling VMX. 469 */ 470 if (cpu_has_vmx() && cpu_vmx_enabled()) { 471 /* Disable VMX on this CPU. */ 472 cpu_vmxoff(); 473 474 /* Halt and disable VMX on the other CPUs */ 475 nmi_shootdown_cpus(vmxoff_nmi); 476 477 } 478 } 479 480 481 void __attribute__((weak)) mach_reboot_fixups(void) 482 { 483 } 484 485 /* 486 * To the best of our knowledge Windows compatible x86 hardware expects 487 * the following on reboot: 488 * 489 * 1) If the FADT has the ACPI reboot register flag set, try it 490 * 2) If still alive, write to the keyboard controller 491 * 3) If still alive, write to the ACPI reboot register again 492 * 4) If still alive, write to the keyboard controller again 493 * 5) If still alive, call the EFI runtime service to reboot 494 * 6) If no EFI runtime service, call the BIOS to do a reboot 495 * 496 * We default to following the same pattern. We also have 497 * two other reboot methods: 'triple fault' and 'PCI', which 498 * can be triggered via the reboot= kernel boot option or 499 * via quirks. 500 * 501 * This means that this function can never return, it can misbehave 502 * by not rebooting properly and hanging. 503 */ 504 static void native_machine_emergency_restart(void) 505 { 506 int i; 507 int attempt = 0; 508 int orig_reboot_type = reboot_type; 509 unsigned short mode; 510 511 if (reboot_emergency) 512 emergency_vmx_disable_all(); 513 514 tboot_shutdown(TB_SHUTDOWN_REBOOT); 515 516 /* Tell the BIOS if we want cold or warm reboot */ 517 mode = reboot_mode == REBOOT_WARM ? 0x1234 : 0; 518 *((unsigned short *)__va(0x472)) = mode; 519 520 for (;;) { 521 /* Could also try the reset bit in the Hammer NB */ 522 switch (reboot_type) { 523 case BOOT_ACPI: 524 acpi_reboot(); 525 reboot_type = BOOT_KBD; 526 break; 527 528 case BOOT_KBD: 529 mach_reboot_fixups(); /* For board specific fixups */ 530 531 for (i = 0; i < 10; i++) { 532 kb_wait(); 533 udelay(50); 534 outb(0xfe, 0x64); /* Pulse reset low */ 535 udelay(50); 536 } 537 if (attempt == 0 && orig_reboot_type == BOOT_ACPI) { 538 attempt = 1; 539 reboot_type = BOOT_ACPI; 540 } else { 541 reboot_type = BOOT_EFI; 542 } 543 break; 544 545 case BOOT_EFI: 546 efi_reboot(reboot_mode, NULL); 547 reboot_type = BOOT_BIOS; 548 break; 549 550 case BOOT_BIOS: 551 machine_real_restart(MRR_BIOS); 552 553 /* We're probably dead after this, but... */ 554 reboot_type = BOOT_CF9_SAFE; 555 break; 556 557 case BOOT_CF9_FORCE: 558 port_cf9_safe = true; 559 /* Fall through */ 560 561 case BOOT_CF9_SAFE: 562 if (port_cf9_safe) { 563 u8 reboot_code = reboot_mode == REBOOT_WARM ? 0x06 : 0x0E; 564 u8 cf9 = inb(0xcf9) & ~reboot_code; 565 outb(cf9|2, 0xcf9); /* Request hard reset */ 566 udelay(50); 567 /* Actually do the reset */ 568 outb(cf9|reboot_code, 0xcf9); 569 udelay(50); 570 } 571 reboot_type = BOOT_TRIPLE; 572 break; 573 574 case BOOT_TRIPLE: 575 load_idt(&no_idt); 576 __asm__ __volatile__("int3"); 577 578 /* We're probably dead after this, but... */ 579 reboot_type = BOOT_KBD; 580 break; 581 } 582 } 583 } 584 585 void native_machine_shutdown(void) 586 { 587 /* Stop the cpus and apics */ 588 #ifdef CONFIG_X86_IO_APIC 589 /* 590 * Disabling IO APIC before local APIC is a workaround for 591 * erratum AVR31 in "Intel Atom Processor C2000 Product Family 592 * Specification Update". In this situation, interrupts that target 593 * a Logical Processor whose Local APIC is either in the process of 594 * being hardware disabled or software disabled are neither delivered 595 * nor discarded. When this erratum occurs, the processor may hang. 596 * 597 * Even without the erratum, it still makes sense to quiet IO APIC 598 * before disabling Local APIC. 599 */ 600 disable_IO_APIC(); 601 #endif 602 603 #ifdef CONFIG_SMP 604 /* 605 * Stop all of the others. Also disable the local irq to 606 * not receive the per-cpu timer interrupt which may trigger 607 * scheduler's load balance. 608 */ 609 local_irq_disable(); 610 stop_other_cpus(); 611 #endif 612 613 lapic_shutdown(); 614 615 #ifdef CONFIG_HPET_TIMER 616 hpet_disable(); 617 #endif 618 619 #ifdef CONFIG_X86_64 620 x86_platform.iommu_shutdown(); 621 #endif 622 } 623 624 static void __machine_emergency_restart(int emergency) 625 { 626 reboot_emergency = emergency; 627 machine_ops.emergency_restart(); 628 } 629 630 static void native_machine_restart(char *__unused) 631 { 632 pr_notice("machine restart\n"); 633 634 if (!reboot_force) 635 machine_shutdown(); 636 __machine_emergency_restart(0); 637 } 638 639 static void native_machine_halt(void) 640 { 641 /* Stop other cpus and apics */ 642 machine_shutdown(); 643 644 tboot_shutdown(TB_SHUTDOWN_HALT); 645 646 stop_this_cpu(NULL); 647 } 648 649 static void native_machine_power_off(void) 650 { 651 if (pm_power_off) { 652 if (!reboot_force) 653 machine_shutdown(); 654 pm_power_off(); 655 } 656 /* A fallback in case there is no PM info available */ 657 tboot_shutdown(TB_SHUTDOWN_HALT); 658 } 659 660 struct machine_ops machine_ops = { 661 .power_off = native_machine_power_off, 662 .shutdown = native_machine_shutdown, 663 .emergency_restart = native_machine_emergency_restart, 664 .restart = native_machine_restart, 665 .halt = native_machine_halt, 666 #ifdef CONFIG_KEXEC 667 .crash_shutdown = native_machine_crash_shutdown, 668 #endif 669 }; 670 671 void machine_power_off(void) 672 { 673 machine_ops.power_off(); 674 } 675 676 void machine_shutdown(void) 677 { 678 machine_ops.shutdown(); 679 } 680 681 void machine_emergency_restart(void) 682 { 683 __machine_emergency_restart(1); 684 } 685 686 void machine_restart(char *cmd) 687 { 688 machine_ops.restart(cmd); 689 } 690 691 void machine_halt(void) 692 { 693 machine_ops.halt(); 694 } 695 696 #ifdef CONFIG_KEXEC 697 void machine_crash_shutdown(struct pt_regs *regs) 698 { 699 machine_ops.crash_shutdown(regs); 700 } 701 #endif 702 703 704 #if defined(CONFIG_SMP) 705 706 /* This keeps a track of which one is crashing cpu. */ 707 static int crashing_cpu; 708 static nmi_shootdown_cb shootdown_callback; 709 710 static atomic_t waiting_for_crash_ipi; 711 712 static int crash_nmi_callback(unsigned int val, struct pt_regs *regs) 713 { 714 int cpu; 715 716 cpu = raw_smp_processor_id(); 717 718 /* 719 * Don't do anything if this handler is invoked on crashing cpu. 720 * Otherwise, system will completely hang. Crashing cpu can get 721 * an NMI if system was initially booted with nmi_watchdog parameter. 722 */ 723 if (cpu == crashing_cpu) 724 return NMI_HANDLED; 725 local_irq_disable(); 726 727 shootdown_callback(cpu, regs); 728 729 atomic_dec(&waiting_for_crash_ipi); 730 /* Assume hlt works */ 731 halt(); 732 for (;;) 733 cpu_relax(); 734 735 return NMI_HANDLED; 736 } 737 738 static void smp_send_nmi_allbutself(void) 739 { 740 apic->send_IPI_allbutself(NMI_VECTOR); 741 } 742 743 /* 744 * Halt all other CPUs, calling the specified function on each of them 745 * 746 * This function can be used to halt all other CPUs on crash 747 * or emergency reboot time. The function passed as parameter 748 * will be called inside a NMI handler on all CPUs. 749 */ 750 void nmi_shootdown_cpus(nmi_shootdown_cb callback) 751 { 752 unsigned long msecs; 753 local_irq_disable(); 754 755 /* Make a note of crashing cpu. Will be used in NMI callback. */ 756 crashing_cpu = safe_smp_processor_id(); 757 758 shootdown_callback = callback; 759 760 atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1); 761 /* Would it be better to replace the trap vector here? */ 762 if (register_nmi_handler(NMI_LOCAL, crash_nmi_callback, 763 NMI_FLAG_FIRST, "crash")) 764 return; /* Return what? */ 765 /* 766 * Ensure the new callback function is set before sending 767 * out the NMI 768 */ 769 wmb(); 770 771 smp_send_nmi_allbutself(); 772 773 msecs = 1000; /* Wait at most a second for the other cpus to stop */ 774 while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) { 775 mdelay(1); 776 msecs--; 777 } 778 779 /* Leave the nmi callback set */ 780 } 781 #else /* !CONFIG_SMP */ 782 void nmi_shootdown_cpus(nmi_shootdown_cb callback) 783 { 784 /* No other CPUs to shoot down */ 785 } 786 #endif 787