1 #include <linux/module.h>
2 #include <linux/reboot.h>
3 #include <linux/init.h>
6 #include <acpi/reboot.h>
11 #include <asm/pgtable.h>
12 #include <asm/proto.h>
13 #include <asm/reboot_fixups.h>
14 #include <asm/reboot.h>
17 # include <linux/dmi.h>
18 # include <linux/ctype.h>
19 # include <linux/mc146818rtc.h>
21 # include <asm/iommu.h>
25 * Power off function, if any
27 void (*pm_power_off)(void);
28 EXPORT_SYMBOL(pm_power_off);
30 static const struct desc_ptr no_idt = {};
31 static int reboot_mode;
32 enum reboot_type reboot_type = BOOT_KBD;
35 #if defined(CONFIG_X86_32) && defined(CONFIG_SMP)
36 static int reboot_cpu = -1;
39 /* This is set by the PCI code if either type 1 or type 2 PCI is detected */
40 bool port_cf9_safe = false;
42 /* reboot=b[ios] | s[mp] | t[riple] | k[bd] | e[fi] [, [w]arm | [c]old] | p[ci]
43 warm Don't set the cold reboot flag
44 cold Set the cold reboot flag
45 bios Reboot by jumping through the BIOS (only for X86_32)
46 smp Reboot by executing reset on BSP or other CPU (only for X86_32)
47 triple Force a triple fault (init)
48 kbd Use the keyboard controller. cold reset (default)
49 acpi Use the RESET_REG in the FADT
50 efi Use efi reset_system runtime service
51 pci Use the so-called "PCI reset register", CF9
52 force Avoid anything that could hang.
54 static int __init reboot_setup(char *str)
69 if (isdigit(*(str+1))) {
70 reboot_cpu = (int) (*(str+1) - '0');
71 if (isdigit(*(str+2)))
72 reboot_cpu = reboot_cpu*10 + (int)(*(str+2) - '0');
74 /* we will leave sorting out the final value
75 when we are ready to reboot, since we might not
76 have set up boot_cpu_id or smp_num_cpu */
78 #endif /* CONFIG_SMP */
95 str = strchr(str, ',');
104 __setup("reboot=", reboot_setup);
109 * Reboot options and system auto-detection code provided by
110 * Dell Inc. so their systems "just work". :-)
114 * Some machines require the "reboot=b" commandline option,
115 * this quirk makes that automatic.
117 static int __init set_bios_reboot(const struct dmi_system_id *d)
119 if (reboot_type != BOOT_BIOS) {
120 reboot_type = BOOT_BIOS;
121 printk(KERN_INFO "%s series board detected. Selecting BIOS-method for reboots.\n", d->ident);
126 static struct dmi_system_id __initdata reboot_dmi_table[] = {
127 { /* Handle problems with rebooting on Dell E520's */
128 .callback = set_bios_reboot,
129 .ident = "Dell E520",
131 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
132 DMI_MATCH(DMI_PRODUCT_NAME, "Dell DM061"),
135 { /* Handle problems with rebooting on Dell 1300's */
136 .callback = set_bios_reboot,
137 .ident = "Dell PowerEdge 1300",
139 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
140 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1300/"),
143 { /* Handle problems with rebooting on Dell 300's */
144 .callback = set_bios_reboot,
145 .ident = "Dell PowerEdge 300",
147 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
148 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"),
151 { /* Handle problems with rebooting on Dell Optiplex 745's SFF*/
152 .callback = set_bios_reboot,
153 .ident = "Dell OptiPlex 745",
155 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
156 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
159 { /* Handle problems with rebooting on Dell Optiplex 745's DFF*/
160 .callback = set_bios_reboot,
161 .ident = "Dell OptiPlex 745",
163 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
164 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
165 DMI_MATCH(DMI_BOARD_NAME, "0MM599"),
168 { /* Handle problems with rebooting on Dell Optiplex 745 with 0KW626 */
169 .callback = set_bios_reboot,
170 .ident = "Dell OptiPlex 745",
172 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
173 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
174 DMI_MATCH(DMI_BOARD_NAME, "0KW626"),
177 { /* Handle problems with rebooting on Dell 2400's */
178 .callback = set_bios_reboot,
179 .ident = "Dell PowerEdge 2400",
181 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
182 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"),
185 { /* Handle problems with rebooting on Dell T5400's */
186 .callback = set_bios_reboot,
187 .ident = "Dell Precision T5400",
189 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
190 DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T5400"),
193 { /* Handle problems with rebooting on HP laptops */
194 .callback = set_bios_reboot,
195 .ident = "HP Compaq Laptop",
197 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
198 DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"),
204 static int __init reboot_init(void)
206 dmi_check_system(reboot_dmi_table);
209 core_initcall(reboot_init);
211 /* The following code and data reboots the machine by switching to real
212 mode and jumping to the BIOS reset entry point, as if the CPU has
213 really been reset. The previous version asked the keyboard
214 controller to pulse the CPU reset line, which is more thorough, but
215 doesn't work with at least one type of 486 motherboard. It is easy
216 to stop this code working; hence the copious comments. */
217 static const unsigned long long
218 real_mode_gdt_entries [3] =
220 0x0000000000000000ULL, /* Null descriptor */
221 0x00009b000000ffffULL, /* 16-bit real-mode 64k code at 0x00000000 */
222 0x000093000100ffffULL /* 16-bit real-mode 64k data at 0x00000100 */
225 static const struct desc_ptr
226 real_mode_gdt = { sizeof (real_mode_gdt_entries) - 1, (long)real_mode_gdt_entries },
227 real_mode_idt = { 0x3ff, 0 };
229 /* This is 16-bit protected mode code to disable paging and the cache,
230 switch to real mode and jump to the BIOS reset code.
232 The instruction that switches to real mode by writing to CR0 must be
233 followed immediately by a far jump instruction, which set CS to a
234 valid value for real mode, and flushes the prefetch queue to avoid
235 running instructions that have already been decoded in protected
238 Clears all the flags except ET, especially PG (paging), PE
239 (protected-mode enable) and TS (task switch for coprocessor state
240 save). Flushes the TLB after paging has been disabled. Sets CD and
241 NW, to disable the cache on a 486, and invalidates the cache. This
242 is more like the state of a 486 after reset. I don't know if
243 something else should be done for other chips.
245 More could be done here to set up the registers as if a CPU reset had
246 occurred; hopefully real BIOSs don't assume much. */
247 static const unsigned char real_mode_switch [] =
249 0x66, 0x0f, 0x20, 0xc0, /* movl %cr0,%eax */
250 0x66, 0x83, 0xe0, 0x11, /* andl $0x00000011,%eax */
251 0x66, 0x0d, 0x00, 0x00, 0x00, 0x60, /* orl $0x60000000,%eax */
252 0x66, 0x0f, 0x22, 0xc0, /* movl %eax,%cr0 */
253 0x66, 0x0f, 0x22, 0xd8, /* movl %eax,%cr3 */
254 0x66, 0x0f, 0x20, 0xc3, /* movl %cr0,%ebx */
255 0x66, 0x81, 0xe3, 0x00, 0x00, 0x00, 0x60, /* andl $0x60000000,%ebx */
256 0x74, 0x02, /* jz f */
257 0x0f, 0x09, /* wbinvd */
258 0x24, 0x10, /* f: andb $0x10,al */
259 0x66, 0x0f, 0x22, 0xc0 /* movl %eax,%cr0 */
261 static const unsigned char jump_to_bios [] =
263 0xea, 0x00, 0x00, 0xff, 0xff /* ljmp $0xffff,$0x0000 */
267 * Switch to real mode and then execute the code
268 * specified by the code and length parameters.
269 * We assume that length will aways be less that 100!
271 void machine_real_restart(const unsigned char *code, int length)
275 /* Write zero to CMOS register number 0x0f, which the BIOS POST
276 routine will recognize as telling it to do a proper reboot. (Well
277 that's what this book in front of me says -- it may only apply to
278 the Phoenix BIOS though, it's not clear). At the same time,
279 disable NMIs by setting the top bit in the CMOS address register,
280 as we're about to do peculiar things to the CPU. I'm not sure if
281 `outb_p' is needed instead of just `outb'. Use it to be on the
282 safe side. (Yes, CMOS_WRITE does outb_p's. - Paul G.)
284 spin_lock(&rtc_lock);
285 CMOS_WRITE(0x00, 0x8f);
286 spin_unlock(&rtc_lock);
288 /* Remap the kernel at virtual address zero, as well as offset zero
289 from the kernel segment. This assumes the kernel segment starts at
290 virtual address PAGE_OFFSET. */
291 memcpy(swapper_pg_dir, swapper_pg_dir + KERNEL_PGD_BOUNDARY,
292 sizeof(swapper_pg_dir [0]) * KERNEL_PGD_PTRS);
295 * Use `swapper_pg_dir' as our page directory.
297 load_cr3(swapper_pg_dir);
299 /* Write 0x1234 to absolute memory location 0x472. The BIOS reads
300 this on booting to tell it to "Bypass memory test (also warm
301 boot)". This seems like a fairly standard thing that gets set by
302 REBOOT.COM programs, and the previous reset routine did this
304 *((unsigned short *)0x472) = reboot_mode;
306 /* For the switch to real mode, copy some code to low memory. It has
307 to be in the first 64k because it is running in 16-bit mode, and it
308 has to have the same physical and virtual address, because it turns
309 off paging. Copy it near the end of the first page, out of the way
310 of BIOS variables. */
311 memcpy((void *)(0x1000 - sizeof(real_mode_switch) - 100),
312 real_mode_switch, sizeof (real_mode_switch));
313 memcpy((void *)(0x1000 - 100), code, length);
315 /* Set up the IDT for real mode. */
316 load_idt(&real_mode_idt);
318 /* Set up a GDT from which we can load segment descriptors for real
319 mode. The GDT is not used in real mode; it is just needed here to
320 prepare the descriptors. */
321 load_gdt(&real_mode_gdt);
323 /* Load the data segment registers, and thus the descriptors ready for
324 real mode. The base address of each segment is 0x100, 16 times the
325 selector value being loaded here. This is so that the segment
326 registers don't have to be reloaded after switching to real mode:
327 the values are consistent for real mode operation already. */
328 __asm__ __volatile__ ("movl $0x0010,%%eax\n"
329 "\tmovl %%eax,%%ds\n"
330 "\tmovl %%eax,%%es\n"
331 "\tmovl %%eax,%%fs\n"
332 "\tmovl %%eax,%%gs\n"
333 "\tmovl %%eax,%%ss" : : : "eax");
335 /* Jump to the 16-bit code that we copied earlier. It disables paging
336 and the cache, switches to real mode, and jumps to the BIOS reset
338 __asm__ __volatile__ ("ljmp $0x0008,%0"
340 : "i" ((void *)(0x1000 - sizeof (real_mode_switch) - 100)));
342 #ifdef CONFIG_APM_MODULE
343 EXPORT_SYMBOL(machine_real_restart);
346 #endif /* CONFIG_X86_32 */
348 static inline void kb_wait(void)
352 for (i = 0; i < 0x10000; i++) {
353 if ((inb(0x64) & 0x02) == 0)
359 void __attribute__((weak)) mach_reboot_fixups(void)
363 static void native_machine_emergency_restart(void)
367 /* Tell the BIOS if we want cold or warm reboot */
368 *((unsigned short *)__va(0x472)) = reboot_mode;
371 /* Could also try the reset bit in the Hammer NB */
372 switch (reboot_type) {
374 mach_reboot_fixups(); /* for board specific fixups */
376 for (i = 0; i < 10; i++) {
379 outb(0xfe, 0x64); /* pulse reset low */
385 __asm__ __volatile__("int3");
387 reboot_type = BOOT_KBD;
392 machine_real_restart(jump_to_bios, sizeof(jump_to_bios));
394 reboot_type = BOOT_KBD;
400 reboot_type = BOOT_KBD;
405 efi.reset_system(reboot_mode ?
408 EFI_SUCCESS, 0, NULL);
409 reboot_type = BOOT_KBD;
413 port_cf9_safe = true;
418 u8 cf9 = inb(0xcf9) & ~6;
419 outb(cf9|2, 0xcf9); /* Request hard reset */
421 outb(cf9|6, 0xcf9); /* Actually do the reset */
424 reboot_type = BOOT_KBD;
430 void native_machine_shutdown(void)
432 /* Stop the cpus and apics */
435 /* The boot cpu is always logical cpu 0 */
436 int reboot_cpu_id = 0;
439 /* See if there has been given a command line override */
440 if ((reboot_cpu != -1) && (reboot_cpu < NR_CPUS) &&
441 cpu_online(reboot_cpu))
442 reboot_cpu_id = reboot_cpu;
445 /* Make certain the cpu I'm about to reboot on is online */
446 if (!cpu_online(reboot_cpu_id))
447 reboot_cpu_id = smp_processor_id();
449 /* Make certain I only run on the appropriate processor */
450 set_cpus_allowed_ptr(current, &cpumask_of_cpu(reboot_cpu_id));
452 /* O.K Now that I'm on the appropriate processor,
453 * stop all of the others.
460 #ifdef CONFIG_X86_IO_APIC
464 #ifdef CONFIG_HPET_TIMER
469 pci_iommu_shutdown();
473 static void native_machine_restart(char *__unused)
475 printk("machine restart\n");
479 machine_emergency_restart();
482 static void native_machine_halt(void)
484 /* stop other cpus and apics */
491 static void native_machine_power_off(void)
500 struct machine_ops machine_ops = {
501 .power_off = native_machine_power_off,
502 .shutdown = native_machine_shutdown,
503 .emergency_restart = native_machine_emergency_restart,
504 .restart = native_machine_restart,
505 .halt = native_machine_halt,
507 .crash_shutdown = native_machine_crash_shutdown,
511 void machine_power_off(void)
513 machine_ops.power_off();
516 void machine_shutdown(void)
518 machine_ops.shutdown();
521 void machine_emergency_restart(void)
523 machine_ops.emergency_restart();
526 void machine_restart(char *cmd)
528 machine_ops.restart(cmd);
531 void machine_halt(void)
537 void machine_crash_shutdown(struct pt_regs *regs)
539 machine_ops.crash_shutdown(regs);