1 #include <linux/module.h>
2 #include <linux/init.h>
3 #include <linux/reboot.h>
4 #include <linux/init.h>
7 #include <acpi/reboot.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>
19 # include <asm/pgtable.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 long no_idt[3];
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 /* reboot=b[ios] | s[mp] | t[riple] | k[bd] | e[fi] [, [w]arm | [c]old]
40 warm Don't set the cold reboot flag
41 cold Set the cold reboot flag
42 bios Reboot by jumping through the BIOS (only for X86_32)
43 smp Reboot by executing reset on BSP or other CPU (only for X86_32)
44 triple Force a triple fault (init)
45 kbd Use the keyboard controller. cold reset (default)
46 acpi Use the RESET_REG in the FADT
47 efi Use efi reset_system runtime service
48 force Avoid anything that could hang.
50 static int __init reboot_setup(char *str)
65 if (isdigit(*(str+1))) {
66 reboot_cpu = (int) (*(str+1) - '0');
67 if (isdigit(*(str+2)))
68 reboot_cpu = reboot_cpu*10 + (int)(*(str+2) - '0');
70 /* we will leave sorting out the final value
71 when we are ready to reboot, since we might not
72 have set up boot_cpu_id or smp_num_cpu */
74 #endif /* CONFIG_SMP */
90 str = strchr(str, ',');
99 __setup("reboot=", reboot_setup);
104 * Reboot options and system auto-detection code provided by
105 * Dell Inc. so their systems "just work". :-)
109 * Some machines require the "reboot=b" commandline option,
110 * this quirk makes that automatic.
112 static int __init set_bios_reboot(const struct dmi_system_id *d)
114 if (reboot_type != BOOT_BIOS) {
115 reboot_type = BOOT_BIOS;
116 printk(KERN_INFO "%s series board detected. Selecting BIOS-method for reboots.\n", d->ident);
121 static struct dmi_system_id __initdata reboot_dmi_table[] = {
122 { /* Handle problems with rebooting on Dell E520's */
123 .callback = set_bios_reboot,
124 .ident = "Dell E520",
126 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
127 DMI_MATCH(DMI_PRODUCT_NAME, "Dell DM061"),
130 { /* Handle problems with rebooting on Dell 1300's */
131 .callback = set_bios_reboot,
132 .ident = "Dell PowerEdge 1300",
134 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
135 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1300/"),
138 { /* Handle problems with rebooting on Dell 300's */
139 .callback = set_bios_reboot,
140 .ident = "Dell PowerEdge 300",
142 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
143 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"),
146 { /* Handle problems with rebooting on Dell Optiplex 745's SFF*/
147 .callback = set_bios_reboot,
148 .ident = "Dell OptiPlex 745",
150 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
151 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
152 DMI_MATCH(DMI_BOARD_NAME, "0WF810"),
155 { /* Handle problems with rebooting on Dell Optiplex 745's DFF*/
156 .callback = set_bios_reboot,
157 .ident = "Dell OptiPlex 745",
159 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
160 DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
161 DMI_MATCH(DMI_BOARD_NAME, "0MM599"),
164 { /* Handle problems with rebooting on Dell 2400's */
165 .callback = set_bios_reboot,
166 .ident = "Dell PowerEdge 2400",
168 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
169 DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"),
172 { /* Handle problems with rebooting on HP laptops */
173 .callback = set_bios_reboot,
174 .ident = "HP Compaq Laptop",
176 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
177 DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"),
183 static int __init reboot_init(void)
185 dmi_check_system(reboot_dmi_table);
188 core_initcall(reboot_init);
190 /* The following code and data reboots the machine by switching to real
191 mode and jumping to the BIOS reset entry point, as if the CPU has
192 really been reset. The previous version asked the keyboard
193 controller to pulse the CPU reset line, which is more thorough, but
194 doesn't work with at least one type of 486 motherboard. It is easy
195 to stop this code working; hence the copious comments. */
196 static unsigned long long
197 real_mode_gdt_entries [3] =
199 0x0000000000000000ULL, /* Null descriptor */
200 0x00009a000000ffffULL, /* 16-bit real-mode 64k code at 0x00000000 */
201 0x000092000100ffffULL /* 16-bit real-mode 64k data at 0x00000100 */
204 static struct desc_ptr
205 real_mode_gdt = { sizeof (real_mode_gdt_entries) - 1, (long)real_mode_gdt_entries },
206 real_mode_idt = { 0x3ff, 0 };
208 /* This is 16-bit protected mode code to disable paging and the cache,
209 switch to real mode and jump to the BIOS reset code.
211 The instruction that switches to real mode by writing to CR0 must be
212 followed immediately by a far jump instruction, which set CS to a
213 valid value for real mode, and flushes the prefetch queue to avoid
214 running instructions that have already been decoded in protected
217 Clears all the flags except ET, especially PG (paging), PE
218 (protected-mode enable) and TS (task switch for coprocessor state
219 save). Flushes the TLB after paging has been disabled. Sets CD and
220 NW, to disable the cache on a 486, and invalidates the cache. This
221 is more like the state of a 486 after reset. I don't know if
222 something else should be done for other chips.
224 More could be done here to set up the registers as if a CPU reset had
225 occurred; hopefully real BIOSs don't assume much. */
226 static unsigned char real_mode_switch [] =
228 0x66, 0x0f, 0x20, 0xc0, /* movl %cr0,%eax */
229 0x66, 0x83, 0xe0, 0x11, /* andl $0x00000011,%eax */
230 0x66, 0x0d, 0x00, 0x00, 0x00, 0x60, /* orl $0x60000000,%eax */
231 0x66, 0x0f, 0x22, 0xc0, /* movl %eax,%cr0 */
232 0x66, 0x0f, 0x22, 0xd8, /* movl %eax,%cr3 */
233 0x66, 0x0f, 0x20, 0xc3, /* movl %cr0,%ebx */
234 0x66, 0x81, 0xe3, 0x00, 0x00, 0x00, 0x60, /* andl $0x60000000,%ebx */
235 0x74, 0x02, /* jz f */
236 0x0f, 0x09, /* wbinvd */
237 0x24, 0x10, /* f: andb $0x10,al */
238 0x66, 0x0f, 0x22, 0xc0 /* movl %eax,%cr0 */
240 static unsigned char jump_to_bios [] =
242 0xea, 0x00, 0x00, 0xff, 0xff /* ljmp $0xffff,$0x0000 */
246 * Switch to real mode and then execute the code
247 * specified by the code and length parameters.
248 * We assume that length will aways be less that 100!
250 void machine_real_restart(unsigned char *code, int length)
254 /* Write zero to CMOS register number 0x0f, which the BIOS POST
255 routine will recognize as telling it to do a proper reboot. (Well
256 that's what this book in front of me says -- it may only apply to
257 the Phoenix BIOS though, it's not clear). At the same time,
258 disable NMIs by setting the top bit in the CMOS address register,
259 as we're about to do peculiar things to the CPU. I'm not sure if
260 `outb_p' is needed instead of just `outb'. Use it to be on the
261 safe side. (Yes, CMOS_WRITE does outb_p's. - Paul G.)
263 spin_lock(&rtc_lock);
264 CMOS_WRITE(0x00, 0x8f);
265 spin_unlock(&rtc_lock);
267 /* Remap the kernel at virtual address zero, as well as offset zero
268 from the kernel segment. This assumes the kernel segment starts at
269 virtual address PAGE_OFFSET. */
270 memcpy(swapper_pg_dir, swapper_pg_dir + USER_PGD_PTRS,
271 sizeof(swapper_pg_dir [0]) * KERNEL_PGD_PTRS);
274 * Use `swapper_pg_dir' as our page directory.
276 load_cr3(swapper_pg_dir);
278 /* Write 0x1234 to absolute memory location 0x472. The BIOS reads
279 this on booting to tell it to "Bypass memory test (also warm
280 boot)". This seems like a fairly standard thing that gets set by
281 REBOOT.COM programs, and the previous reset routine did this
283 *((unsigned short *)0x472) = reboot_mode;
285 /* For the switch to real mode, copy some code to low memory. It has
286 to be in the first 64k because it is running in 16-bit mode, and it
287 has to have the same physical and virtual address, because it turns
288 off paging. Copy it near the end of the first page, out of the way
289 of BIOS variables. */
290 memcpy((void *)(0x1000 - sizeof(real_mode_switch) - 100),
291 real_mode_switch, sizeof (real_mode_switch));
292 memcpy((void *)(0x1000 - 100), code, length);
294 /* Set up the IDT for real mode. */
295 load_idt(&real_mode_idt);
297 /* Set up a GDT from which we can load segment descriptors for real
298 mode. The GDT is not used in real mode; it is just needed here to
299 prepare the descriptors. */
300 load_gdt(&real_mode_gdt);
302 /* Load the data segment registers, and thus the descriptors ready for
303 real mode. The base address of each segment is 0x100, 16 times the
304 selector value being loaded here. This is so that the segment
305 registers don't have to be reloaded after switching to real mode:
306 the values are consistent for real mode operation already. */
307 __asm__ __volatile__ ("movl $0x0010,%%eax\n"
308 "\tmovl %%eax,%%ds\n"
309 "\tmovl %%eax,%%es\n"
310 "\tmovl %%eax,%%fs\n"
311 "\tmovl %%eax,%%gs\n"
312 "\tmovl %%eax,%%ss" : : : "eax");
314 /* Jump to the 16-bit code that we copied earlier. It disables paging
315 and the cache, switches to real mode, and jumps to the BIOS reset
317 __asm__ __volatile__ ("ljmp $0x0008,%0"
319 : "i" ((void *)(0x1000 - sizeof (real_mode_switch) - 100)));
321 #ifdef CONFIG_APM_MODULE
322 EXPORT_SYMBOL(machine_real_restart);
325 #endif /* CONFIG_X86_32 */
327 static inline void kb_wait(void)
331 for (i = 0; i < 0x10000; i++) {
332 if ((inb(0x64) & 0x02) == 0)
338 void __attribute__((weak)) mach_reboot_fixups(void)
342 static void native_machine_emergency_restart(void)
346 /* Tell the BIOS if we want cold or warm reboot */
347 *((unsigned short *)__va(0x472)) = reboot_mode;
350 /* Could also try the reset bit in the Hammer NB */
351 switch (reboot_type) {
353 mach_reboot_fixups(); /* for board specific fixups */
355 for (i = 0; i < 10; i++) {
358 outb(0xfe, 0x64); /* pulse reset low */
363 load_idt((const struct desc_ptr *)&no_idt);
364 __asm__ __volatile__("int3");
366 reboot_type = BOOT_KBD;
371 machine_real_restart(jump_to_bios, sizeof(jump_to_bios));
373 reboot_type = BOOT_KBD;
379 reboot_type = BOOT_KBD;
385 efi.reset_system(reboot_mode ? EFI_RESET_WARM : EFI_RESET_COLD,
386 EFI_SUCCESS, 0, NULL);
388 reboot_type = BOOT_KBD;
394 static void native_machine_shutdown(void)
396 /* Stop the cpus and apics */
400 /* The boot cpu is always logical cpu 0 */
404 /* See if there has been given a command line override */
405 if ((reboot_cpu != -1) && (reboot_cpu < NR_CPUS) &&
406 cpu_isset(reboot_cpu, cpu_online_map))
407 reboot_cpu_id = reboot_cpu;
410 /* Make certain the cpu I'm about to reboot on is online */
411 if (!cpu_isset(reboot_cpu_id, cpu_online_map))
412 reboot_cpu_id = smp_processor_id();
414 /* Make certain I only run on the appropriate processor */
415 set_cpus_allowed(current, cpumask_of_cpu(reboot_cpu_id));
417 /* O.K Now that I'm on the appropriate processor,
418 * stop all of the others.
425 #ifdef CONFIG_X86_IO_APIC
429 #ifdef CONFIG_HPET_TIMER
434 pci_iommu_shutdown();
438 static void native_machine_restart(char *__unused)
440 printk("machine restart\n");
444 machine_emergency_restart();
447 static void native_machine_halt(void)
451 static void native_machine_power_off(void)
460 struct machine_ops machine_ops = {
461 .power_off = native_machine_power_off,
462 .shutdown = native_machine_shutdown,
463 .emergency_restart = native_machine_emergency_restart,
464 .restart = native_machine_restart,
465 .halt = native_machine_halt
468 void machine_power_off(void)
470 machine_ops.power_off();
473 void machine_shutdown(void)
475 machine_ops.shutdown();
478 void machine_emergency_restart(void)
480 machine_ops.emergency_restart();
483 void machine_restart(char *cmd)
485 machine_ops.restart(cmd);
488 void machine_halt(void)