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/reboot_fixups.h>
13 #include <asm/reboot.h>
16 # include <linux/dmi.h>
17 # include <linux/ctype.h>
18 # include <linux/mc146818rtc.h>
20 # include <asm/iommu.h>
24 * Power off function, if any
26 void (*pm_power_off)(void);
27 EXPORT_SYMBOL(pm_power_off);
29 static long no_idt[3];
30 static int reboot_mode;
31 enum reboot_type reboot_type = BOOT_KBD;
34 #if defined(CONFIG_X86_32) && defined(CONFIG_SMP)
35 static int reboot_cpu = -1;
38 /* reboot=b[ios] | s[mp] | t[riple] | k[bd] | e[fi] [, [w]arm | [c]old]
39 warm Don't set the cold reboot flag
40 cold Set the cold reboot flag
41 bios Reboot by jumping through the BIOS (only for X86_32)
42 smp Reboot by executing reset on BSP or other CPU (only for X86_32)
43 triple Force a triple fault (init)
44 kbd Use the keyboard controller. cold reset (default)
45 acpi Use the RESET_REG in the FADT
46 efi Use efi reset_system runtime service
47 force Avoid anything that could hang.
49 static int __init reboot_setup(char *str)
64 if (isdigit(*(str+1))) {
65 reboot_cpu = (int) (*(str+1) - '0');
66 if (isdigit(*(str+2)))
67 reboot_cpu = reboot_cpu*10 + (int)(*(str+2) - '0');
69 /* we will leave sorting out the final value
70 when we are ready to reboot, since we might not
71 have set up boot_cpu_id or smp_num_cpu */
73 #endif /* CONFIG_SMP */
89 str = strchr(str, ',');
98 __setup("reboot=", reboot_setup);
103 * Reboot options and system auto-detection code provided by
104 * Dell Inc. so their systems "just work". :-)
108 * Some machines require the "reboot=b" commandline option,
109 * this quirk makes that automatic.
111 static int __init set_bios_reboot(const struct dmi_system_id *d)
113 if (reboot_type != BOOT_BIOS) {
114 reboot_type = BOOT_BIOS;
115 printk(KERN_INFO "%s series board detected. Selecting BIOS-method for reboots.\n", d->ident);
120 static struct dmi_system_id __initdata reboot_dmi_table[] = {
121 { /* Handle problems with rebooting on Dell E520's */
122 .callback = set_bios_reboot,
123 .ident = "Dell E520",
125 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
126 DMI_MATCH(DMI_PRODUCT_NAME, "Dell DM061"),
129 { /* Handle problems with rebooting on Dell 1300's */
130 .callback = set_bios_reboot,
131 .ident = "Dell PowerEdge 1300",
133 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
134 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1300/"),
137 { /* Handle problems with rebooting on Dell 300's */
138 .callback = set_bios_reboot,
139 .ident = "Dell PowerEdge 300",
141 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
142 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"),
145 { /* Handle problems with rebooting on Dell Optiplex 745's SFF*/
146 .callback = set_bios_reboot,
147 .ident = "Dell OptiPlex 745",
149 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
150 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
151 DMI_MATCH(DMI_BOARD_NAME, "0WF810"),
154 { /* Handle problems with rebooting on Dell Optiplex 745's DFF*/
155 .callback = set_bios_reboot,
156 .ident = "Dell OptiPlex 745",
158 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
159 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
160 DMI_MATCH(DMI_BOARD_NAME, "0MM599"),
163 { /* Handle problems with rebooting on Dell Optiplex 745 with 0KW626 */
164 .callback = set_bios_reboot,
165 .ident = "Dell OptiPlex 745",
167 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
168 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
169 DMI_MATCH(DMI_BOARD_NAME, "0KW626"),
172 { /* Handle problems with rebooting on Dell 2400's */
173 .callback = set_bios_reboot,
174 .ident = "Dell PowerEdge 2400",
176 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
177 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"),
180 { /* Handle problems with rebooting on HP laptops */
181 .callback = set_bios_reboot,
182 .ident = "HP Compaq Laptop",
184 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
185 DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"),
191 static int __init reboot_init(void)
193 dmi_check_system(reboot_dmi_table);
196 core_initcall(reboot_init);
198 /* The following code and data reboots the machine by switching to real
199 mode and jumping to the BIOS reset entry point, as if the CPU has
200 really been reset. The previous version asked the keyboard
201 controller to pulse the CPU reset line, which is more thorough, but
202 doesn't work with at least one type of 486 motherboard. It is easy
203 to stop this code working; hence the copious comments. */
204 static unsigned long long
205 real_mode_gdt_entries [3] =
207 0x0000000000000000ULL, /* Null descriptor */
208 0x00009a000000ffffULL, /* 16-bit real-mode 64k code at 0x00000000 */
209 0x000092000100ffffULL /* 16-bit real-mode 64k data at 0x00000100 */
212 static struct desc_ptr
213 real_mode_gdt = { sizeof (real_mode_gdt_entries) - 1, (long)real_mode_gdt_entries },
214 real_mode_idt = { 0x3ff, 0 };
216 /* This is 16-bit protected mode code to disable paging and the cache,
217 switch to real mode and jump to the BIOS reset code.
219 The instruction that switches to real mode by writing to CR0 must be
220 followed immediately by a far jump instruction, which set CS to a
221 valid value for real mode, and flushes the prefetch queue to avoid
222 running instructions that have already been decoded in protected
225 Clears all the flags except ET, especially PG (paging), PE
226 (protected-mode enable) and TS (task switch for coprocessor state
227 save). Flushes the TLB after paging has been disabled. Sets CD and
228 NW, to disable the cache on a 486, and invalidates the cache. This
229 is more like the state of a 486 after reset. I don't know if
230 something else should be done for other chips.
232 More could be done here to set up the registers as if a CPU reset had
233 occurred; hopefully real BIOSs don't assume much. */
234 static unsigned char real_mode_switch [] =
236 0x66, 0x0f, 0x20, 0xc0, /* movl %cr0,%eax */
237 0x66, 0x83, 0xe0, 0x11, /* andl $0x00000011,%eax */
238 0x66, 0x0d, 0x00, 0x00, 0x00, 0x60, /* orl $0x60000000,%eax */
239 0x66, 0x0f, 0x22, 0xc0, /* movl %eax,%cr0 */
240 0x66, 0x0f, 0x22, 0xd8, /* movl %eax,%cr3 */
241 0x66, 0x0f, 0x20, 0xc3, /* movl %cr0,%ebx */
242 0x66, 0x81, 0xe3, 0x00, 0x00, 0x00, 0x60, /* andl $0x60000000,%ebx */
243 0x74, 0x02, /* jz f */
244 0x0f, 0x09, /* wbinvd */
245 0x24, 0x10, /* f: andb $0x10,al */
246 0x66, 0x0f, 0x22, 0xc0 /* movl %eax,%cr0 */
248 static unsigned char jump_to_bios [] =
250 0xea, 0x00, 0x00, 0xff, 0xff /* ljmp $0xffff,$0x0000 */
254 * Switch to real mode and then execute the code
255 * specified by the code and length parameters.
256 * We assume that length will aways be less that 100!
258 void machine_real_restart(unsigned char *code, int length)
262 /* Write zero to CMOS register number 0x0f, which the BIOS POST
263 routine will recognize as telling it to do a proper reboot. (Well
264 that's what this book in front of me says -- it may only apply to
265 the Phoenix BIOS though, it's not clear). At the same time,
266 disable NMIs by setting the top bit in the CMOS address register,
267 as we're about to do peculiar things to the CPU. I'm not sure if
268 `outb_p' is needed instead of just `outb'. Use it to be on the
269 safe side. (Yes, CMOS_WRITE does outb_p's. - Paul G.)
271 spin_lock(&rtc_lock);
272 CMOS_WRITE(0x00, 0x8f);
273 spin_unlock(&rtc_lock);
275 /* Remap the kernel at virtual address zero, as well as offset zero
276 from the kernel segment. This assumes the kernel segment starts at
277 virtual address PAGE_OFFSET. */
278 memcpy(swapper_pg_dir, swapper_pg_dir + KERNEL_PGD_BOUNDARY,
279 sizeof(swapper_pg_dir [0]) * KERNEL_PGD_PTRS);
282 * Use `swapper_pg_dir' as our page directory.
284 load_cr3(swapper_pg_dir);
286 /* Write 0x1234 to absolute memory location 0x472. The BIOS reads
287 this on booting to tell it to "Bypass memory test (also warm
288 boot)". This seems like a fairly standard thing that gets set by
289 REBOOT.COM programs, and the previous reset routine did this
291 *((unsigned short *)0x472) = reboot_mode;
293 /* For the switch to real mode, copy some code to low memory. It has
294 to be in the first 64k because it is running in 16-bit mode, and it
295 has to have the same physical and virtual address, because it turns
296 off paging. Copy it near the end of the first page, out of the way
297 of BIOS variables. */
298 memcpy((void *)(0x1000 - sizeof(real_mode_switch) - 100),
299 real_mode_switch, sizeof (real_mode_switch));
300 memcpy((void *)(0x1000 - 100), code, length);
302 /* Set up the IDT for real mode. */
303 load_idt(&real_mode_idt);
305 /* Set up a GDT from which we can load segment descriptors for real
306 mode. The GDT is not used in real mode; it is just needed here to
307 prepare the descriptors. */
308 load_gdt(&real_mode_gdt);
310 /* Load the data segment registers, and thus the descriptors ready for
311 real mode. The base address of each segment is 0x100, 16 times the
312 selector value being loaded here. This is so that the segment
313 registers don't have to be reloaded after switching to real mode:
314 the values are consistent for real mode operation already. */
315 __asm__ __volatile__ ("movl $0x0010,%%eax\n"
316 "\tmovl %%eax,%%ds\n"
317 "\tmovl %%eax,%%es\n"
318 "\tmovl %%eax,%%fs\n"
319 "\tmovl %%eax,%%gs\n"
320 "\tmovl %%eax,%%ss" : : : "eax");
322 /* Jump to the 16-bit code that we copied earlier. It disables paging
323 and the cache, switches to real mode, and jumps to the BIOS reset
325 __asm__ __volatile__ ("ljmp $0x0008,%0"
327 : "i" ((void *)(0x1000 - sizeof (real_mode_switch) - 100)));
329 #ifdef CONFIG_APM_MODULE
330 EXPORT_SYMBOL(machine_real_restart);
333 #endif /* CONFIG_X86_32 */
335 static inline void kb_wait(void)
339 for (i = 0; i < 0x10000; i++) {
340 if ((inb(0x64) & 0x02) == 0)
346 void __attribute__((weak)) mach_reboot_fixups(void)
350 static void native_machine_emergency_restart(void)
354 /* Tell the BIOS if we want cold or warm reboot */
355 *((unsigned short *)__va(0x472)) = reboot_mode;
358 /* Could also try the reset bit in the Hammer NB */
359 switch (reboot_type) {
361 mach_reboot_fixups(); /* for board specific fixups */
363 for (i = 0; i < 10; i++) {
366 outb(0xfe, 0x64); /* pulse reset low */
371 load_idt((const struct desc_ptr *)&no_idt);
372 __asm__ __volatile__("int3");
374 reboot_type = BOOT_KBD;
379 machine_real_restart(jump_to_bios, sizeof(jump_to_bios));
381 reboot_type = BOOT_KBD;
387 reboot_type = BOOT_KBD;
393 efi.reset_system(reboot_mode ? EFI_RESET_WARM : EFI_RESET_COLD,
394 EFI_SUCCESS, 0, NULL);
396 reboot_type = BOOT_KBD;
402 static void native_machine_shutdown(void)
404 /* Stop the cpus and apics */
408 /* The boot cpu is always logical cpu 0 */
412 /* See if there has been given a command line override */
413 if ((reboot_cpu != -1) && (reboot_cpu < NR_CPUS) &&
414 cpu_online(reboot_cpu))
415 reboot_cpu_id = reboot_cpu;
418 /* Make certain the cpu I'm about to reboot on is online */
419 if (!cpu_online(reboot_cpu_id))
420 reboot_cpu_id = smp_processor_id();
422 /* Make certain I only run on the appropriate processor */
423 set_cpus_allowed_ptr(current, &cpumask_of_cpu(reboot_cpu_id));
425 /* O.K Now that I'm on the appropriate processor,
426 * stop all of the others.
433 #ifdef CONFIG_X86_IO_APIC
437 #ifdef CONFIG_HPET_TIMER
442 pci_iommu_shutdown();
446 static void native_machine_restart(char *__unused)
448 printk("machine restart\n");
452 machine_emergency_restart();
455 static void native_machine_halt(void)
459 static void native_machine_power_off(void)
468 struct machine_ops machine_ops = {
469 .power_off = native_machine_power_off,
470 .shutdown = native_machine_shutdown,
471 .emergency_restart = native_machine_emergency_restart,
472 .restart = native_machine_restart,
473 .halt = native_machine_halt
476 void machine_power_off(void)
478 machine_ops.power_off();
481 void machine_shutdown(void)
483 machine_ops.shutdown();
486 void machine_emergency_restart(void)
488 machine_ops.emergency_restart();
491 void machine_restart(char *cmd)
493 machine_ops.restart(cmd);
496 void machine_halt(void)