xref: /linux/arch/x86/kernel/reboot.c (revision d524dac9279b6a41ffdf7ff7958c577f2e387db6)
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 <acpi/reboot.h>
10 #include <asm/io.h>
11 #include <asm/apic.h>
12 #include <asm/desc.h>
13 #include <asm/hpet.h>
14 #include <asm/pgtable.h>
15 #include <asm/proto.h>
16 #include <asm/reboot_fixups.h>
17 #include <asm/reboot.h>
18 #include <asm/pci_x86.h>
19 #include <asm/virtext.h>
20 #include <asm/cpu.h>
21 #include <asm/nmi.h>
22 
23 #ifdef CONFIG_X86_32
24 # include <linux/ctype.h>
25 # include <linux/mc146818rtc.h>
26 #else
27 # include <asm/x86_init.h>
28 #endif
29 
30 /*
31  * Power off function, if any
32  */
33 void (*pm_power_off)(void);
34 EXPORT_SYMBOL(pm_power_off);
35 
36 static const struct desc_ptr no_idt = {};
37 static int reboot_mode;
38 enum reboot_type reboot_type = BOOT_KBD;
39 int reboot_force;
40 
41 #if defined(CONFIG_X86_32) && defined(CONFIG_SMP)
42 static int reboot_cpu = -1;
43 #endif
44 
45 /* This is set if we need to go through the 'emergency' path.
46  * When machine_emergency_restart() is called, we may be on
47  * an inconsistent state and won't be able to do a clean cleanup
48  */
49 static int reboot_emergency;
50 
51 /* This is set by the PCI code if either type 1 or type 2 PCI is detected */
52 bool port_cf9_safe = false;
53 
54 /* reboot=b[ios] | s[mp] | t[riple] | k[bd] | e[fi] [, [w]arm | [c]old] | p[ci]
55    warm   Don't set the cold reboot flag
56    cold   Set the cold reboot flag
57    bios   Reboot by jumping through the BIOS (only for X86_32)
58    smp    Reboot by executing reset on BSP or other CPU (only for X86_32)
59    triple Force a triple fault (init)
60    kbd    Use the keyboard controller. cold reset (default)
61    acpi   Use the RESET_REG in the FADT
62    efi    Use efi reset_system runtime service
63    pci    Use the so-called "PCI reset register", CF9
64    force  Avoid anything that could hang.
65  */
66 static int __init reboot_setup(char *str)
67 {
68 	for (;;) {
69 		switch (*str) {
70 		case 'w':
71 			reboot_mode = 0x1234;
72 			break;
73 
74 		case 'c':
75 			reboot_mode = 0;
76 			break;
77 
78 #ifdef CONFIG_X86_32
79 #ifdef CONFIG_SMP
80 		case 's':
81 			if (isdigit(*(str+1))) {
82 				reboot_cpu = (int) (*(str+1) - '0');
83 				if (isdigit(*(str+2)))
84 					reboot_cpu = reboot_cpu*10 + (int)(*(str+2) - '0');
85 			}
86 				/* we will leave sorting out the final value
87 				   when we are ready to reboot, since we might not
88 				   have detected BSP APIC ID or smp_num_cpu */
89 			break;
90 #endif /* CONFIG_SMP */
91 
92 		case 'b':
93 #endif
94 		case 'a':
95 		case 'k':
96 		case 't':
97 		case 'e':
98 		case 'p':
99 			reboot_type = *str;
100 			break;
101 
102 		case 'f':
103 			reboot_force = 1;
104 			break;
105 		}
106 
107 		str = strchr(str, ',');
108 		if (str)
109 			str++;
110 		else
111 			break;
112 	}
113 	return 1;
114 }
115 
116 __setup("reboot=", reboot_setup);
117 
118 
119 #ifdef CONFIG_X86_32
120 /*
121  * Reboot options and system auto-detection code provided by
122  * Dell Inc. so their systems "just work". :-)
123  */
124 
125 /*
126  * Some machines require the "reboot=b"  commandline option,
127  * this quirk makes that automatic.
128  */
129 static int __init set_bios_reboot(const struct dmi_system_id *d)
130 {
131 	if (reboot_type != BOOT_BIOS) {
132 		reboot_type = BOOT_BIOS;
133 		printk(KERN_INFO "%s series board detected. Selecting BIOS-method for reboots.\n", d->ident);
134 	}
135 	return 0;
136 }
137 
138 static struct dmi_system_id __initdata reboot_dmi_table[] = {
139 	{	/* Handle problems with rebooting on Dell E520's */
140 		.callback = set_bios_reboot,
141 		.ident = "Dell E520",
142 		.matches = {
143 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
144 			DMI_MATCH(DMI_PRODUCT_NAME, "Dell DM061"),
145 		},
146 	},
147 	{	/* Handle problems with rebooting on Dell 1300's */
148 		.callback = set_bios_reboot,
149 		.ident = "Dell PowerEdge 1300",
150 		.matches = {
151 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
152 			DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1300/"),
153 		},
154 	},
155 	{	/* Handle problems with rebooting on Dell 300's */
156 		.callback = set_bios_reboot,
157 		.ident = "Dell PowerEdge 300",
158 		.matches = {
159 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
160 			DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"),
161 		},
162 	},
163 	{       /* Handle problems with rebooting on Dell Optiplex 745's SFF*/
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 		},
170 	},
171 	{       /* Handle problems with rebooting on Dell Optiplex 745's DFF*/
172 		.callback = set_bios_reboot,
173 		.ident = "Dell OptiPlex 745",
174 		.matches = {
175 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
176 			DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
177 			DMI_MATCH(DMI_BOARD_NAME, "0MM599"),
178 		},
179 	},
180 	{       /* Handle problems with rebooting on Dell Optiplex 745 with 0KW626 */
181 		.callback = set_bios_reboot,
182 		.ident = "Dell OptiPlex 745",
183 		.matches = {
184 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
185 			DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
186 			DMI_MATCH(DMI_BOARD_NAME, "0KW626"),
187 		},
188 	},
189 	{   /* Handle problems with rebooting on Dell Optiplex 330 with 0KP561 */
190 		.callback = set_bios_reboot,
191 		.ident = "Dell OptiPlex 330",
192 		.matches = {
193 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
194 			DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 330"),
195 			DMI_MATCH(DMI_BOARD_NAME, "0KP561"),
196 		},
197 	},
198 	{   /* Handle problems with rebooting on Dell Optiplex 360 with 0T656F */
199 		.callback = set_bios_reboot,
200 		.ident = "Dell OptiPlex 360",
201 		.matches = {
202 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
203 			DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 360"),
204 			DMI_MATCH(DMI_BOARD_NAME, "0T656F"),
205 		},
206 	},
207 	{	/* Handle problems with rebooting on Dell OptiPlex 760 with 0G919G*/
208 		.callback = set_bios_reboot,
209 		.ident = "Dell OptiPlex 760",
210 		.matches = {
211 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
212 			DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 760"),
213 			DMI_MATCH(DMI_BOARD_NAME, "0G919G"),
214 		},
215 	},
216 	{	/* Handle problems with rebooting on Dell 2400's */
217 		.callback = set_bios_reboot,
218 		.ident = "Dell PowerEdge 2400",
219 		.matches = {
220 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
221 			DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"),
222 		},
223 	},
224 	{	/* Handle problems with rebooting on Dell T5400's */
225 		.callback = set_bios_reboot,
226 		.ident = "Dell Precision T5400",
227 		.matches = {
228 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
229 			DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T5400"),
230 		},
231 	},
232 	{	/* Handle problems with rebooting on Dell T7400's */
233 		.callback = set_bios_reboot,
234 		.ident = "Dell Precision T7400",
235 		.matches = {
236 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
237 			DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T7400"),
238 		},
239 	},
240 	{	/* Handle problems with rebooting on HP laptops */
241 		.callback = set_bios_reboot,
242 		.ident = "HP Compaq Laptop",
243 		.matches = {
244 			DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
245 			DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"),
246 		},
247 	},
248 	{	/* Handle problems with rebooting on Dell XPS710 */
249 		.callback = set_bios_reboot,
250 		.ident = "Dell XPS710",
251 		.matches = {
252 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
253 			DMI_MATCH(DMI_PRODUCT_NAME, "Dell XPS710"),
254 		},
255 	},
256 	{	/* Handle problems with rebooting on Dell DXP061 */
257 		.callback = set_bios_reboot,
258 		.ident = "Dell DXP061",
259 		.matches = {
260 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
261 			DMI_MATCH(DMI_PRODUCT_NAME, "Dell DXP061"),
262 		},
263 	},
264 	{	/* Handle problems with rebooting on Sony VGN-Z540N */
265 		.callback = set_bios_reboot,
266 		.ident = "Sony VGN-Z540N",
267 		.matches = {
268 			DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
269 			DMI_MATCH(DMI_PRODUCT_NAME, "VGN-Z540N"),
270 		},
271 	},
272 	{	/* Handle problems with rebooting on CompuLab SBC-FITPC2 */
273 		.callback = set_bios_reboot,
274 		.ident = "CompuLab SBC-FITPC2",
275 		.matches = {
276 			DMI_MATCH(DMI_SYS_VENDOR, "CompuLab"),
277 			DMI_MATCH(DMI_PRODUCT_NAME, "SBC-FITPC2"),
278 		},
279 	},
280 	{       /* Handle problems with rebooting on ASUS P4S800 */
281 		.callback = set_bios_reboot,
282 		.ident = "ASUS P4S800",
283 		.matches = {
284 			DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
285 			DMI_MATCH(DMI_BOARD_NAME, "P4S800"),
286 		},
287 	},
288 	{ }
289 };
290 
291 static int __init reboot_init(void)
292 {
293 	dmi_check_system(reboot_dmi_table);
294 	return 0;
295 }
296 core_initcall(reboot_init);
297 
298 /* The following code and data reboots the machine by switching to real
299    mode and jumping to the BIOS reset entry point, as if the CPU has
300    really been reset.  The previous version asked the keyboard
301    controller to pulse the CPU reset line, which is more thorough, but
302    doesn't work with at least one type of 486 motherboard.  It is easy
303    to stop this code working; hence the copious comments. */
304 static const unsigned long long
305 real_mode_gdt_entries [3] =
306 {
307 	0x0000000000000000ULL,	/* Null descriptor */
308 	0x00009b000000ffffULL,	/* 16-bit real-mode 64k code at 0x00000000 */
309 	0x000093000100ffffULL	/* 16-bit real-mode 64k data at 0x00000100 */
310 };
311 
312 static const struct desc_ptr
313 real_mode_gdt = { sizeof (real_mode_gdt_entries) - 1, (long)real_mode_gdt_entries },
314 real_mode_idt = { 0x3ff, 0 };
315 
316 /* This is 16-bit protected mode code to disable paging and the cache,
317    switch to real mode and jump to the BIOS reset code.
318 
319    The instruction that switches to real mode by writing to CR0 must be
320    followed immediately by a far jump instruction, which set CS to a
321    valid value for real mode, and flushes the prefetch queue to avoid
322    running instructions that have already been decoded in protected
323    mode.
324 
325    Clears all the flags except ET, especially PG (paging), PE
326    (protected-mode enable) and TS (task switch for coprocessor state
327    save).  Flushes the TLB after paging has been disabled.  Sets CD and
328    NW, to disable the cache on a 486, and invalidates the cache.  This
329    is more like the state of a 486 after reset.  I don't know if
330    something else should be done for other chips.
331 
332    More could be done here to set up the registers as if a CPU reset had
333    occurred; hopefully real BIOSs don't assume much. */
334 static const unsigned char real_mode_switch [] =
335 {
336 	0x66, 0x0f, 0x20, 0xc0,			/*    movl  %cr0,%eax        */
337 	0x66, 0x83, 0xe0, 0x11,			/*    andl  $0x00000011,%eax */
338 	0x66, 0x0d, 0x00, 0x00, 0x00, 0x60,	/*    orl   $0x60000000,%eax */
339 	0x66, 0x0f, 0x22, 0xc0,			/*    movl  %eax,%cr0        */
340 	0x66, 0x0f, 0x22, 0xd8,			/*    movl  %eax,%cr3        */
341 	0x66, 0x0f, 0x20, 0xc3,			/*    movl  %cr0,%ebx        */
342 	0x66, 0x81, 0xe3, 0x00, 0x00, 0x00, 0x60,	/*    andl  $0x60000000,%ebx */
343 	0x74, 0x02,				/*    jz    f                */
344 	0x0f, 0x09,				/*    wbinvd                 */
345 	0x24, 0x10,				/* f: andb  $0x10,al         */
346 	0x66, 0x0f, 0x22, 0xc0			/*    movl  %eax,%cr0        */
347 };
348 static const unsigned char jump_to_bios [] =
349 {
350 	0xea, 0x00, 0x00, 0xff, 0xff		/*    ljmp  $0xffff,$0x0000  */
351 };
352 
353 /*
354  * Switch to real mode and then execute the code
355  * specified by the code and length parameters.
356  * We assume that length will aways be less that 100!
357  */
358 void machine_real_restart(const unsigned char *code, int length)
359 {
360 	local_irq_disable();
361 
362 	/* Write zero to CMOS register number 0x0f, which the BIOS POST
363 	   routine will recognize as telling it to do a proper reboot.  (Well
364 	   that's what this book in front of me says -- it may only apply to
365 	   the Phoenix BIOS though, it's not clear).  At the same time,
366 	   disable NMIs by setting the top bit in the CMOS address register,
367 	   as we're about to do peculiar things to the CPU.  I'm not sure if
368 	   `outb_p' is needed instead of just `outb'.  Use it to be on the
369 	   safe side.  (Yes, CMOS_WRITE does outb_p's. -  Paul G.)
370 	 */
371 	spin_lock(&rtc_lock);
372 	CMOS_WRITE(0x00, 0x8f);
373 	spin_unlock(&rtc_lock);
374 
375 	/*
376 	 * Switch back to the initial page table.
377 	 */
378 	load_cr3(initial_page_table);
379 
380 	/* Write 0x1234 to absolute memory location 0x472.  The BIOS reads
381 	   this on booting to tell it to "Bypass memory test (also warm
382 	   boot)".  This seems like a fairly standard thing that gets set by
383 	   REBOOT.COM programs, and the previous reset routine did this
384 	   too. */
385 	*((unsigned short *)0x472) = reboot_mode;
386 
387 	/* For the switch to real mode, copy some code to low memory.  It has
388 	   to be in the first 64k because it is running in 16-bit mode, and it
389 	   has to have the same physical and virtual address, because it turns
390 	   off paging.  Copy it near the end of the first page, out of the way
391 	   of BIOS variables. */
392 	memcpy((void *)(0x1000 - sizeof(real_mode_switch) - 100),
393 		real_mode_switch, sizeof (real_mode_switch));
394 	memcpy((void *)(0x1000 - 100), code, length);
395 
396 	/* Set up the IDT for real mode. */
397 	load_idt(&real_mode_idt);
398 
399 	/* Set up a GDT from which we can load segment descriptors for real
400 	   mode.  The GDT is not used in real mode; it is just needed here to
401 	   prepare the descriptors. */
402 	load_gdt(&real_mode_gdt);
403 
404 	/* Load the data segment registers, and thus the descriptors ready for
405 	   real mode.  The base address of each segment is 0x100, 16 times the
406 	   selector value being loaded here.  This is so that the segment
407 	   registers don't have to be reloaded after switching to real mode:
408 	   the values are consistent for real mode operation already. */
409 	__asm__ __volatile__ ("movl $0x0010,%%eax\n"
410 				"\tmovl %%eax,%%ds\n"
411 				"\tmovl %%eax,%%es\n"
412 				"\tmovl %%eax,%%fs\n"
413 				"\tmovl %%eax,%%gs\n"
414 				"\tmovl %%eax,%%ss" : : : "eax");
415 
416 	/* Jump to the 16-bit code that we copied earlier.  It disables paging
417 	   and the cache, switches to real mode, and jumps to the BIOS reset
418 	   entry point. */
419 	__asm__ __volatile__ ("ljmp $0x0008,%0"
420 				:
421 				: "i" ((void *)(0x1000 - sizeof (real_mode_switch) - 100)));
422 }
423 #ifdef CONFIG_APM_MODULE
424 EXPORT_SYMBOL(machine_real_restart);
425 #endif
426 
427 #endif /* CONFIG_X86_32 */
428 
429 /*
430  * Some Apple MacBook and MacBookPro's needs reboot=p to be able to reboot
431  */
432 static int __init set_pci_reboot(const struct dmi_system_id *d)
433 {
434 	if (reboot_type != BOOT_CF9) {
435 		reboot_type = BOOT_CF9;
436 		printk(KERN_INFO "%s series board detected. "
437 		       "Selecting PCI-method for reboots.\n", d->ident);
438 	}
439 	return 0;
440 }
441 
442 static struct dmi_system_id __initdata pci_reboot_dmi_table[] = {
443 	{	/* Handle problems with rebooting on Apple MacBook5 */
444 		.callback = set_pci_reboot,
445 		.ident = "Apple MacBook5",
446 		.matches = {
447 			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
448 			DMI_MATCH(DMI_PRODUCT_NAME, "MacBook5"),
449 		},
450 	},
451 	{	/* Handle problems with rebooting on Apple MacBookPro5 */
452 		.callback = set_pci_reboot,
453 		.ident = "Apple MacBookPro5",
454 		.matches = {
455 			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
456 			DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro5"),
457 		},
458 	},
459 	{	/* Handle problems with rebooting on Apple Macmini3,1 */
460 		.callback = set_pci_reboot,
461 		.ident = "Apple Macmini3,1",
462 		.matches = {
463 			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
464 			DMI_MATCH(DMI_PRODUCT_NAME, "Macmini3,1"),
465 		},
466 	},
467 	{	/* Handle problems with rebooting on the iMac9,1. */
468 		.callback = set_pci_reboot,
469 		.ident = "Apple iMac9,1",
470 		.matches = {
471 			DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
472 			DMI_MATCH(DMI_PRODUCT_NAME, "iMac9,1"),
473 		},
474 	},
475 	{ }
476 };
477 
478 static int __init pci_reboot_init(void)
479 {
480 	dmi_check_system(pci_reboot_dmi_table);
481 	return 0;
482 }
483 core_initcall(pci_reboot_init);
484 
485 static inline void kb_wait(void)
486 {
487 	int i;
488 
489 	for (i = 0; i < 0x10000; i++) {
490 		if ((inb(0x64) & 0x02) == 0)
491 			break;
492 		udelay(2);
493 	}
494 }
495 
496 static void vmxoff_nmi(int cpu, struct die_args *args)
497 {
498 	cpu_emergency_vmxoff();
499 }
500 
501 /* Use NMIs as IPIs to tell all CPUs to disable virtualization
502  */
503 static void emergency_vmx_disable_all(void)
504 {
505 	/* Just make sure we won't change CPUs while doing this */
506 	local_irq_disable();
507 
508 	/* We need to disable VMX on all CPUs before rebooting, otherwise
509 	 * we risk hanging up the machine, because the CPU ignore INIT
510 	 * signals when VMX is enabled.
511 	 *
512 	 * We can't take any locks and we may be on an inconsistent
513 	 * state, so we use NMIs as IPIs to tell the other CPUs to disable
514 	 * VMX and halt.
515 	 *
516 	 * For safety, we will avoid running the nmi_shootdown_cpus()
517 	 * stuff unnecessarily, but we don't have a way to check
518 	 * if other CPUs have VMX enabled. So we will call it only if the
519 	 * CPU we are running on has VMX enabled.
520 	 *
521 	 * We will miss cases where VMX is not enabled on all CPUs. This
522 	 * shouldn't do much harm because KVM always enable VMX on all
523 	 * CPUs anyway. But we can miss it on the small window where KVM
524 	 * is still enabling VMX.
525 	 */
526 	if (cpu_has_vmx() && cpu_vmx_enabled()) {
527 		/* Disable VMX on this CPU.
528 		 */
529 		cpu_vmxoff();
530 
531 		/* Halt and disable VMX on the other CPUs */
532 		nmi_shootdown_cpus(vmxoff_nmi);
533 
534 	}
535 }
536 
537 
538 void __attribute__((weak)) mach_reboot_fixups(void)
539 {
540 }
541 
542 static void native_machine_emergency_restart(void)
543 {
544 	int i;
545 
546 	if (reboot_emergency)
547 		emergency_vmx_disable_all();
548 
549 	tboot_shutdown(TB_SHUTDOWN_REBOOT);
550 
551 	/* Tell the BIOS if we want cold or warm reboot */
552 	*((unsigned short *)__va(0x472)) = reboot_mode;
553 
554 	for (;;) {
555 		/* Could also try the reset bit in the Hammer NB */
556 		switch (reboot_type) {
557 		case BOOT_KBD:
558 			mach_reboot_fixups(); /* for board specific fixups */
559 
560 			for (i = 0; i < 10; i++) {
561 				kb_wait();
562 				udelay(50);
563 				outb(0xfe, 0x64); /* pulse reset low */
564 				udelay(50);
565 			}
566 
567 		case BOOT_TRIPLE:
568 			load_idt(&no_idt);
569 			__asm__ __volatile__("int3");
570 
571 			reboot_type = BOOT_KBD;
572 			break;
573 
574 #ifdef CONFIG_X86_32
575 		case BOOT_BIOS:
576 			machine_real_restart(jump_to_bios, sizeof(jump_to_bios));
577 
578 			reboot_type = BOOT_KBD;
579 			break;
580 #endif
581 
582 		case BOOT_ACPI:
583 			acpi_reboot();
584 			reboot_type = BOOT_KBD;
585 			break;
586 
587 		case BOOT_EFI:
588 			if (efi_enabled)
589 				efi.reset_system(reboot_mode ?
590 						 EFI_RESET_WARM :
591 						 EFI_RESET_COLD,
592 						 EFI_SUCCESS, 0, NULL);
593 			reboot_type = BOOT_KBD;
594 			break;
595 
596 		case BOOT_CF9:
597 			port_cf9_safe = true;
598 			/* fall through */
599 
600 		case BOOT_CF9_COND:
601 			if (port_cf9_safe) {
602 				u8 cf9 = inb(0xcf9) & ~6;
603 				outb(cf9|2, 0xcf9); /* Request hard reset */
604 				udelay(50);
605 				outb(cf9|6, 0xcf9); /* Actually do the reset */
606 				udelay(50);
607 			}
608 			reboot_type = BOOT_KBD;
609 			break;
610 		}
611 	}
612 }
613 
614 void native_machine_shutdown(void)
615 {
616 	/* Stop the cpus and apics */
617 #ifdef CONFIG_SMP
618 
619 	/* The boot cpu is always logical cpu 0 */
620 	int reboot_cpu_id = 0;
621 
622 #ifdef CONFIG_X86_32
623 	/* See if there has been given a command line override */
624 	if ((reboot_cpu != -1) && (reboot_cpu < nr_cpu_ids) &&
625 		cpu_online(reboot_cpu))
626 		reboot_cpu_id = reboot_cpu;
627 #endif
628 
629 	/* Make certain the cpu I'm about to reboot on is online */
630 	if (!cpu_online(reboot_cpu_id))
631 		reboot_cpu_id = smp_processor_id();
632 
633 	/* Make certain I only run on the appropriate processor */
634 	set_cpus_allowed_ptr(current, cpumask_of(reboot_cpu_id));
635 
636 	/* O.K Now that I'm on the appropriate processor,
637 	 * stop all of the others.
638 	 */
639 	stop_other_cpus();
640 #endif
641 
642 	lapic_shutdown();
643 
644 #ifdef CONFIG_X86_IO_APIC
645 	disable_IO_APIC();
646 #endif
647 
648 #ifdef CONFIG_HPET_TIMER
649 	hpet_disable();
650 #endif
651 
652 #ifdef CONFIG_X86_64
653 	x86_platform.iommu_shutdown();
654 #endif
655 }
656 
657 static void __machine_emergency_restart(int emergency)
658 {
659 	reboot_emergency = emergency;
660 	machine_ops.emergency_restart();
661 }
662 
663 static void native_machine_restart(char *__unused)
664 {
665 	printk("machine restart\n");
666 
667 	if (!reboot_force)
668 		machine_shutdown();
669 	__machine_emergency_restart(0);
670 }
671 
672 static void native_machine_halt(void)
673 {
674 	/* stop other cpus and apics */
675 	machine_shutdown();
676 
677 	tboot_shutdown(TB_SHUTDOWN_HALT);
678 
679 	/* stop this cpu */
680 	stop_this_cpu(NULL);
681 }
682 
683 static void native_machine_power_off(void)
684 {
685 	if (pm_power_off) {
686 		if (!reboot_force)
687 			machine_shutdown();
688 		pm_power_off();
689 	}
690 	/* a fallback in case there is no PM info available */
691 	tboot_shutdown(TB_SHUTDOWN_HALT);
692 }
693 
694 struct machine_ops machine_ops = {
695 	.power_off = native_machine_power_off,
696 	.shutdown = native_machine_shutdown,
697 	.emergency_restart = native_machine_emergency_restart,
698 	.restart = native_machine_restart,
699 	.halt = native_machine_halt,
700 #ifdef CONFIG_KEXEC
701 	.crash_shutdown = native_machine_crash_shutdown,
702 #endif
703 };
704 
705 void machine_power_off(void)
706 {
707 	machine_ops.power_off();
708 }
709 
710 void machine_shutdown(void)
711 {
712 	machine_ops.shutdown();
713 }
714 
715 void machine_emergency_restart(void)
716 {
717 	__machine_emergency_restart(1);
718 }
719 
720 void machine_restart(char *cmd)
721 {
722 	machine_ops.restart(cmd);
723 }
724 
725 void machine_halt(void)
726 {
727 	machine_ops.halt();
728 }
729 
730 #ifdef CONFIG_KEXEC
731 void machine_crash_shutdown(struct pt_regs *regs)
732 {
733 	machine_ops.crash_shutdown(regs);
734 }
735 #endif
736 
737 
738 #if defined(CONFIG_SMP)
739 
740 /* This keeps a track of which one is crashing cpu. */
741 static int crashing_cpu;
742 static nmi_shootdown_cb shootdown_callback;
743 
744 static atomic_t waiting_for_crash_ipi;
745 
746 static int crash_nmi_callback(struct notifier_block *self,
747 			unsigned long val, void *data)
748 {
749 	int cpu;
750 
751 	if (val != DIE_NMI)
752 		return NOTIFY_OK;
753 
754 	cpu = raw_smp_processor_id();
755 
756 	/* Don't do anything if this handler is invoked on crashing cpu.
757 	 * Otherwise, system will completely hang. Crashing cpu can get
758 	 * an NMI if system was initially booted with nmi_watchdog parameter.
759 	 */
760 	if (cpu == crashing_cpu)
761 		return NOTIFY_STOP;
762 	local_irq_disable();
763 
764 	shootdown_callback(cpu, (struct die_args *)data);
765 
766 	atomic_dec(&waiting_for_crash_ipi);
767 	/* Assume hlt works */
768 	halt();
769 	for (;;)
770 		cpu_relax();
771 
772 	return 1;
773 }
774 
775 static void smp_send_nmi_allbutself(void)
776 {
777 	apic->send_IPI_allbutself(NMI_VECTOR);
778 }
779 
780 static struct notifier_block crash_nmi_nb = {
781 	.notifier_call = crash_nmi_callback,
782 	/* we want to be the first one called */
783 	.priority = NMI_LOCAL_HIGH_PRIOR+1,
784 };
785 
786 /* Halt all other CPUs, calling the specified function on each of them
787  *
788  * This function can be used to halt all other CPUs on crash
789  * or emergency reboot time. The function passed as parameter
790  * will be called inside a NMI handler on all CPUs.
791  */
792 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
793 {
794 	unsigned long msecs;
795 	local_irq_disable();
796 
797 	/* Make a note of crashing cpu. Will be used in NMI callback.*/
798 	crashing_cpu = safe_smp_processor_id();
799 
800 	shootdown_callback = callback;
801 
802 	atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
803 	/* Would it be better to replace the trap vector here? */
804 	if (register_die_notifier(&crash_nmi_nb))
805 		return;		/* return what? */
806 	/* Ensure the new callback function is set before sending
807 	 * out the NMI
808 	 */
809 	wmb();
810 
811 	smp_send_nmi_allbutself();
812 
813 	msecs = 1000; /* Wait at most a second for the other cpus to stop */
814 	while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
815 		mdelay(1);
816 		msecs--;
817 	}
818 
819 	/* Leave the nmi callback set */
820 }
821 #else /* !CONFIG_SMP */
822 void nmi_shootdown_cpus(nmi_shootdown_cb callback)
823 {
824 	/* No other CPUs to shoot down */
825 }
826 #endif
827