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1 | /* | |
2 | * linux/arch/i386/kernel/reboot.c | |
3 | */ | |
4 | ||
5 | #include <linux/config.h> | |
6 | #include <linux/mm.h> | |
7 | #include <linux/module.h> | |
8 | #include <linux/delay.h> | |
9 | #include <linux/init.h> | |
10 | #include <linux/interrupt.h> | |
11 | #include <linux/mc146818rtc.h> | |
12 | #include <linux/efi.h> | |
13 | #include <linux/dmi.h> | |
14 | #include <linux/ctype.h> | |
15 | #include <asm/uaccess.h> | |
16 | #include <asm/apic.h> | |
17 | #include <asm/desc.h> | |
18 | #include "mach_reboot.h" | |
19 | #include <linux/reboot_fixups.h> | |
20 | ||
21 | /* | |
22 | * Power off function, if any | |
23 | */ | |
24 | void (*pm_power_off)(void); | |
25 | EXPORT_SYMBOL(pm_power_off); | |
26 | ||
27 | static int reboot_mode; | |
28 | static int reboot_thru_bios; | |
29 | ||
30 | #ifdef CONFIG_SMP | |
31 | static int reboot_cpu = -1; | |
32 | #endif | |
33 | static int __init reboot_setup(char *str) | |
34 | { | |
35 | while(1) { | |
36 | switch (*str) { | |
37 | case 'w': /* "warm" reboot (no memory testing etc) */ | |
38 | reboot_mode = 0x1234; | |
39 | break; | |
40 | case 'c': /* "cold" reboot (with memory testing etc) */ | |
41 | reboot_mode = 0x0; | |
42 | break; | |
43 | case 'b': /* "bios" reboot by jumping through the BIOS */ | |
44 | reboot_thru_bios = 1; | |
45 | break; | |
46 | case 'h': /* "hard" reboot by toggling RESET and/or crashing the CPU */ | |
47 | reboot_thru_bios = 0; | |
48 | break; | |
49 | #ifdef CONFIG_SMP | |
50 | case 's': /* "smp" reboot by executing reset on BSP or other CPU*/ | |
51 | if (isdigit(*(str+1))) { | |
52 | reboot_cpu = (int) (*(str+1) - '0'); | |
53 | if (isdigit(*(str+2))) | |
54 | reboot_cpu = reboot_cpu*10 + (int)(*(str+2) - '0'); | |
55 | } | |
56 | /* we will leave sorting out the final value | |
57 | when we are ready to reboot, since we might not | |
58 | have set up boot_cpu_id or smp_num_cpu */ | |
59 | break; | |
60 | #endif | |
61 | } | |
62 | if((str = strchr(str,',')) != NULL) | |
63 | str++; | |
64 | else | |
65 | break; | |
66 | } | |
67 | return 1; | |
68 | } | |
69 | ||
70 | __setup("reboot=", reboot_setup); | |
71 | ||
72 | /* | |
73 | * Reboot options and system auto-detection code provided by | |
74 | * Dell Inc. so their systems "just work". :-) | |
75 | */ | |
76 | ||
77 | /* | |
78 | * Some machines require the "reboot=b" commandline option, this quirk makes that automatic. | |
79 | */ | |
80 | static int __init set_bios_reboot(struct dmi_system_id *d) | |
81 | { | |
82 | if (!reboot_thru_bios) { | |
83 | reboot_thru_bios = 1; | |
84 | printk(KERN_INFO "%s series board detected. Selecting BIOS-method for reboots.\n", d->ident); | |
85 | } | |
86 | return 0; | |
87 | } | |
88 | ||
89 | static struct dmi_system_id __initdata reboot_dmi_table[] = { | |
90 | { /* Handle problems with rebooting on Dell 1300's */ | |
91 | .callback = set_bios_reboot, | |
92 | .ident = "Dell PowerEdge 1300", | |
93 | .matches = { | |
94 | DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"), | |
95 | DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1300/"), | |
96 | }, | |
97 | }, | |
98 | { /* Handle problems with rebooting on Dell 300's */ | |
99 | .callback = set_bios_reboot, | |
100 | .ident = "Dell PowerEdge 300", | |
101 | .matches = { | |
102 | DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"), | |
103 | DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"), | |
104 | }, | |
105 | }, | |
106 | { /* Handle problems with rebooting on Dell 2400's */ | |
107 | .callback = set_bios_reboot, | |
108 | .ident = "Dell PowerEdge 2400", | |
109 | .matches = { | |
110 | DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"), | |
111 | DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"), | |
112 | }, | |
113 | }, | |
114 | { /* Handle problems with rebooting on HP laptops */ | |
115 | .callback = set_bios_reboot, | |
116 | .ident = "HP Compaq Laptop", | |
117 | .matches = { | |
118 | DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"), | |
119 | DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"), | |
120 | }, | |
121 | }, | |
122 | { } | |
123 | }; | |
124 | ||
125 | static int __init reboot_init(void) | |
126 | { | |
127 | dmi_check_system(reboot_dmi_table); | |
128 | return 0; | |
129 | } | |
130 | ||
131 | core_initcall(reboot_init); | |
132 | ||
133 | /* The following code and data reboots the machine by switching to real | |
134 | mode and jumping to the BIOS reset entry point, as if the CPU has | |
135 | really been reset. The previous version asked the keyboard | |
136 | controller to pulse the CPU reset line, which is more thorough, but | |
137 | doesn't work with at least one type of 486 motherboard. It is easy | |
138 | to stop this code working; hence the copious comments. */ | |
139 | ||
140 | static unsigned long long | |
141 | real_mode_gdt_entries [3] = | |
142 | { | |
143 | 0x0000000000000000ULL, /* Null descriptor */ | |
144 | 0x00009a000000ffffULL, /* 16-bit real-mode 64k code at 0x00000000 */ | |
145 | 0x000092000100ffffULL /* 16-bit real-mode 64k data at 0x00000100 */ | |
146 | }; | |
147 | ||
148 | static struct | |
149 | { | |
150 | unsigned short size __attribute__ ((packed)); | |
151 | unsigned long long * base __attribute__ ((packed)); | |
152 | } | |
153 | real_mode_gdt = { sizeof (real_mode_gdt_entries) - 1, real_mode_gdt_entries }, | |
154 | real_mode_idt = { 0x3ff, NULL }, | |
155 | no_idt = { 0, NULL }; | |
156 | ||
157 | ||
158 | /* This is 16-bit protected mode code to disable paging and the cache, | |
159 | switch to real mode and jump to the BIOS reset code. | |
160 | ||
161 | The instruction that switches to real mode by writing to CR0 must be | |
162 | followed immediately by a far jump instruction, which set CS to a | |
163 | valid value for real mode, and flushes the prefetch queue to avoid | |
164 | running instructions that have already been decoded in protected | |
165 | mode. | |
166 | ||
167 | Clears all the flags except ET, especially PG (paging), PE | |
168 | (protected-mode enable) and TS (task switch for coprocessor state | |
169 | save). Flushes the TLB after paging has been disabled. Sets CD and | |
170 | NW, to disable the cache on a 486, and invalidates the cache. This | |
171 | is more like the state of a 486 after reset. I don't know if | |
172 | something else should be done for other chips. | |
173 | ||
174 | More could be done here to set up the registers as if a CPU reset had | |
175 | occurred; hopefully real BIOSs don't assume much. */ | |
176 | ||
177 | static unsigned char real_mode_switch [] = | |
178 | { | |
179 | 0x66, 0x0f, 0x20, 0xc0, /* movl %cr0,%eax */ | |
180 | 0x66, 0x83, 0xe0, 0x11, /* andl $0x00000011,%eax */ | |
181 | 0x66, 0x0d, 0x00, 0x00, 0x00, 0x60, /* orl $0x60000000,%eax */ | |
182 | 0x66, 0x0f, 0x22, 0xc0, /* movl %eax,%cr0 */ | |
183 | 0x66, 0x0f, 0x22, 0xd8, /* movl %eax,%cr3 */ | |
184 | 0x66, 0x0f, 0x20, 0xc3, /* movl %cr0,%ebx */ | |
185 | 0x66, 0x81, 0xe3, 0x00, 0x00, 0x00, 0x60, /* andl $0x60000000,%ebx */ | |
186 | 0x74, 0x02, /* jz f */ | |
187 | 0x0f, 0x09, /* wbinvd */ | |
188 | 0x24, 0x10, /* f: andb $0x10,al */ | |
189 | 0x66, 0x0f, 0x22, 0xc0 /* movl %eax,%cr0 */ | |
190 | }; | |
191 | static unsigned char jump_to_bios [] = | |
192 | { | |
193 | 0xea, 0x00, 0x00, 0xff, 0xff /* ljmp $0xffff,$0x0000 */ | |
194 | }; | |
195 | ||
196 | /* | |
197 | * Switch to real mode and then execute the code | |
198 | * specified by the code and length parameters. | |
199 | * We assume that length will aways be less that 100! | |
200 | */ | |
201 | void machine_real_restart(unsigned char *code, int length) | |
202 | { | |
203 | unsigned long flags; | |
204 | ||
205 | local_irq_disable(); | |
206 | ||
207 | /* Write zero to CMOS register number 0x0f, which the BIOS POST | |
208 | routine will recognize as telling it to do a proper reboot. (Well | |
209 | that's what this book in front of me says -- it may only apply to | |
210 | the Phoenix BIOS though, it's not clear). At the same time, | |
211 | disable NMIs by setting the top bit in the CMOS address register, | |
212 | as we're about to do peculiar things to the CPU. I'm not sure if | |
213 | `outb_p' is needed instead of just `outb'. Use it to be on the | |
214 | safe side. (Yes, CMOS_WRITE does outb_p's. - Paul G.) | |
215 | */ | |
216 | ||
217 | spin_lock_irqsave(&rtc_lock, flags); | |
218 | CMOS_WRITE(0x00, 0x8f); | |
219 | spin_unlock_irqrestore(&rtc_lock, flags); | |
220 | ||
221 | /* Remap the kernel at virtual address zero, as well as offset zero | |
222 | from the kernel segment. This assumes the kernel segment starts at | |
223 | virtual address PAGE_OFFSET. */ | |
224 | ||
225 | memcpy (swapper_pg_dir, swapper_pg_dir + USER_PGD_PTRS, | |
226 | sizeof (swapper_pg_dir [0]) * KERNEL_PGD_PTRS); | |
227 | ||
228 | /* | |
229 | * Use `swapper_pg_dir' as our page directory. | |
230 | */ | |
231 | load_cr3(swapper_pg_dir); | |
232 | ||
233 | /* Write 0x1234 to absolute memory location 0x472. The BIOS reads | |
234 | this on booting to tell it to "Bypass memory test (also warm | |
235 | boot)". This seems like a fairly standard thing that gets set by | |
236 | REBOOT.COM programs, and the previous reset routine did this | |
237 | too. */ | |
238 | ||
239 | *((unsigned short *)0x472) = reboot_mode; | |
240 | ||
241 | /* For the switch to real mode, copy some code to low memory. It has | |
242 | to be in the first 64k because it is running in 16-bit mode, and it | |
243 | has to have the same physical and virtual address, because it turns | |
244 | off paging. Copy it near the end of the first page, out of the way | |
245 | of BIOS variables. */ | |
246 | ||
247 | memcpy ((void *) (0x1000 - sizeof (real_mode_switch) - 100), | |
248 | real_mode_switch, sizeof (real_mode_switch)); | |
249 | memcpy ((void *) (0x1000 - 100), code, length); | |
250 | ||
251 | /* Set up the IDT for real mode. */ | |
252 | ||
253 | load_idt(&real_mode_idt); | |
254 | ||
255 | /* Set up a GDT from which we can load segment descriptors for real | |
256 | mode. The GDT is not used in real mode; it is just needed here to | |
257 | prepare the descriptors. */ | |
258 | ||
259 | load_gdt(&real_mode_gdt); | |
260 | ||
261 | /* Load the data segment registers, and thus the descriptors ready for | |
262 | real mode. The base address of each segment is 0x100, 16 times the | |
263 | selector value being loaded here. This is so that the segment | |
264 | registers don't have to be reloaded after switching to real mode: | |
265 | the values are consistent for real mode operation already. */ | |
266 | ||
267 | __asm__ __volatile__ ("movl $0x0010,%%eax\n" | |
268 | "\tmovl %%eax,%%ds\n" | |
269 | "\tmovl %%eax,%%es\n" | |
270 | "\tmovl %%eax,%%fs\n" | |
271 | "\tmovl %%eax,%%gs\n" | |
272 | "\tmovl %%eax,%%ss" : : : "eax"); | |
273 | ||
274 | /* Jump to the 16-bit code that we copied earlier. It disables paging | |
275 | and the cache, switches to real mode, and jumps to the BIOS reset | |
276 | entry point. */ | |
277 | ||
278 | __asm__ __volatile__ ("ljmp $0x0008,%0" | |
279 | : | |
280 | : "i" ((void *) (0x1000 - sizeof (real_mode_switch) - 100))); | |
281 | } | |
282 | #ifdef CONFIG_APM_MODULE | |
283 | EXPORT_SYMBOL(machine_real_restart); | |
284 | #endif | |
285 | ||
286 | void machine_shutdown(void) | |
287 | { | |
288 | #ifdef CONFIG_SMP | |
289 | int reboot_cpu_id; | |
290 | ||
291 | /* The boot cpu is always logical cpu 0 */ | |
292 | reboot_cpu_id = 0; | |
293 | ||
294 | /* See if there has been given a command line override */ | |
295 | if ((reboot_cpu != -1) && (reboot_cpu < NR_CPUS) && | |
296 | cpu_isset(reboot_cpu, cpu_online_map)) { | |
297 | reboot_cpu_id = reboot_cpu; | |
298 | } | |
299 | ||
300 | /* Make certain the cpu I'm rebooting on is online */ | |
301 | if (!cpu_isset(reboot_cpu_id, cpu_online_map)) { | |
302 | reboot_cpu_id = smp_processor_id(); | |
303 | } | |
304 | ||
305 | /* Make certain I only run on the appropriate processor */ | |
306 | set_cpus_allowed(current, cpumask_of_cpu(reboot_cpu_id)); | |
307 | ||
308 | /* O.K. Now that I'm on the appropriate processor, stop | |
309 | * all of the others, and disable their local APICs. | |
310 | */ | |
311 | ||
312 | smp_send_stop(); | |
313 | #endif /* CONFIG_SMP */ | |
314 | ||
315 | lapic_shutdown(); | |
316 | ||
317 | #ifdef CONFIG_X86_IO_APIC | |
318 | disable_IO_APIC(); | |
319 | #endif | |
320 | } | |
321 | ||
322 | void machine_emergency_restart(void) | |
323 | { | |
324 | if (!reboot_thru_bios) { | |
325 | if (efi_enabled) { | |
326 | efi.reset_system(EFI_RESET_COLD, EFI_SUCCESS, 0, NULL); | |
327 | load_idt(&no_idt); | |
328 | __asm__ __volatile__("int3"); | |
329 | } | |
330 | /* rebooting needs to touch the page at absolute addr 0 */ | |
331 | *((unsigned short *)__va(0x472)) = reboot_mode; | |
332 | for (;;) { | |
333 | mach_reboot_fixups(); /* for board specific fixups */ | |
334 | mach_reboot(); | |
335 | /* That didn't work - force a triple fault.. */ | |
336 | load_idt(&no_idt); | |
337 | __asm__ __volatile__("int3"); | |
338 | } | |
339 | } | |
340 | if (efi_enabled) | |
341 | efi.reset_system(EFI_RESET_WARM, EFI_SUCCESS, 0, NULL); | |
342 | ||
343 | machine_real_restart(jump_to_bios, sizeof(jump_to_bios)); | |
344 | } | |
345 | ||
346 | void machine_restart(char * __unused) | |
347 | { | |
348 | machine_shutdown(); | |
349 | machine_emergency_restart(); | |
350 | } | |
351 | ||
352 | void machine_halt(void) | |
353 | { | |
354 | } | |
355 | ||
356 | void machine_power_off(void) | |
357 | { | |
358 | machine_shutdown(); | |
359 | ||
360 | if (pm_power_off) | |
361 | pm_power_off(); | |
362 | } | |
363 | ||
364 |