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1da177e4 LT |
1 | /* |
2 | * linux/arch/i386/kernel/reboot.c | |
3 | */ | |
4 | ||
5 | #include <linux/mm.h> | |
6 | #include <linux/module.h> | |
7 | #include <linux/delay.h> | |
8 | #include <linux/init.h> | |
9 | #include <linux/interrupt.h> | |
10 | #include <linux/mc146818rtc.h> | |
11 | #include <linux/efi.h> | |
12 | #include <linux/dmi.h> | |
13 | #include <asm/uaccess.h> | |
14 | #include <asm/apic.h> | |
15 | #include "mach_reboot.h" | |
16 | ||
17 | /* | |
18 | * Power off function, if any | |
19 | */ | |
20 | void (*pm_power_off)(void); | |
21 | ||
22 | static int reboot_mode; | |
23 | static int reboot_thru_bios; | |
24 | ||
25 | #ifdef CONFIG_SMP | |
26 | int reboot_smp = 0; | |
27 | static int reboot_cpu = -1; | |
28 | /* shamelessly grabbed from lib/vsprintf.c for readability */ | |
29 | #define is_digit(c) ((c) >= '0' && (c) <= '9') | |
30 | #endif | |
31 | static int __init reboot_setup(char *str) | |
32 | { | |
33 | while(1) { | |
34 | switch (*str) { | |
35 | case 'w': /* "warm" reboot (no memory testing etc) */ | |
36 | reboot_mode = 0x1234; | |
37 | break; | |
38 | case 'c': /* "cold" reboot (with memory testing etc) */ | |
39 | reboot_mode = 0x0; | |
40 | break; | |
41 | case 'b': /* "bios" reboot by jumping through the BIOS */ | |
42 | reboot_thru_bios = 1; | |
43 | break; | |
44 | case 'h': /* "hard" reboot by toggling RESET and/or crashing the CPU */ | |
45 | reboot_thru_bios = 0; | |
46 | break; | |
47 | #ifdef CONFIG_SMP | |
48 | case 's': /* "smp" reboot by executing reset on BSP or other CPU*/ | |
49 | reboot_smp = 1; | |
50 | if (is_digit(*(str+1))) { | |
51 | reboot_cpu = (int) (*(str+1) - '0'); | |
52 | if (is_digit(*(str+2))) | |
53 | reboot_cpu = reboot_cpu*10 + (int)(*(str+2) - '0'); | |
54 | } | |
55 | /* we will leave sorting out the final value | |
56 | when we are ready to reboot, since we might not | |
57 | have set up boot_cpu_id or smp_num_cpu */ | |
58 | break; | |
59 | #endif | |
60 | } | |
61 | if((str = strchr(str,',')) != NULL) | |
62 | str++; | |
63 | else | |
64 | break; | |
65 | } | |
66 | return 1; | |
67 | } | |
68 | ||
69 | __setup("reboot=", reboot_setup); | |
70 | ||
71 | /* | |
72 | * Reboot options and system auto-detection code provided by | |
73 | * Dell Inc. so their systems "just work". :-) | |
74 | */ | |
75 | ||
76 | /* | |
77 | * Some machines require the "reboot=b" commandline option, this quirk makes that automatic. | |
78 | */ | |
79 | static int __init set_bios_reboot(struct dmi_system_id *d) | |
80 | { | |
81 | if (!reboot_thru_bios) { | |
82 | reboot_thru_bios = 1; | |
83 | printk(KERN_INFO "%s series board detected. Selecting BIOS-method for reboots.\n", d->ident); | |
84 | } | |
85 | return 0; | |
86 | } | |
87 | ||
88 | /* | |
89 | * Some machines require the "reboot=s" commandline option, this quirk makes that automatic. | |
90 | */ | |
91 | static int __init set_smp_reboot(struct dmi_system_id *d) | |
92 | { | |
93 | #ifdef CONFIG_SMP | |
94 | if (!reboot_smp) { | |
95 | reboot_smp = 1; | |
96 | printk(KERN_INFO "%s series board detected. Selecting SMP-method for reboots.\n", d->ident); | |
97 | } | |
98 | #endif | |
99 | return 0; | |
100 | } | |
101 | ||
102 | /* | |
103 | * Some machines require the "reboot=b,s" commandline option, this quirk makes that automatic. | |
104 | */ | |
105 | static int __init set_smp_bios_reboot(struct dmi_system_id *d) | |
106 | { | |
107 | set_smp_reboot(d); | |
108 | set_bios_reboot(d); | |
109 | return 0; | |
110 | } | |
111 | ||
112 | static struct dmi_system_id __initdata reboot_dmi_table[] = { | |
113 | { /* Handle problems with rebooting on Dell 1300's */ | |
114 | .callback = set_smp_bios_reboot, | |
115 | .ident = "Dell PowerEdge 1300", | |
116 | .matches = { | |
117 | DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"), | |
118 | DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1300/"), | |
119 | }, | |
120 | }, | |
121 | { /* Handle problems with rebooting on Dell 300's */ | |
122 | .callback = set_bios_reboot, | |
123 | .ident = "Dell PowerEdge 300", | |
124 | .matches = { | |
125 | DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"), | |
126 | DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"), | |
127 | }, | |
128 | }, | |
129 | { /* Handle problems with rebooting on Dell 2400's */ | |
130 | .callback = set_bios_reboot, | |
131 | .ident = "Dell PowerEdge 2400", | |
132 | .matches = { | |
133 | DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"), | |
134 | DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"), | |
135 | }, | |
136 | }, | |
137 | { } | |
138 | }; | |
139 | ||
140 | static int __init reboot_init(void) | |
141 | { | |
142 | dmi_check_system(reboot_dmi_table); | |
143 | return 0; | |
144 | } | |
145 | ||
146 | core_initcall(reboot_init); | |
147 | ||
148 | /* The following code and data reboots the machine by switching to real | |
149 | mode and jumping to the BIOS reset entry point, as if the CPU has | |
150 | really been reset. The previous version asked the keyboard | |
151 | controller to pulse the CPU reset line, which is more thorough, but | |
152 | doesn't work with at least one type of 486 motherboard. It is easy | |
153 | to stop this code working; hence the copious comments. */ | |
154 | ||
155 | static unsigned long long | |
156 | real_mode_gdt_entries [3] = | |
157 | { | |
158 | 0x0000000000000000ULL, /* Null descriptor */ | |
159 | 0x00009a000000ffffULL, /* 16-bit real-mode 64k code at 0x00000000 */ | |
160 | 0x000092000100ffffULL /* 16-bit real-mode 64k data at 0x00000100 */ | |
161 | }; | |
162 | ||
163 | static struct | |
164 | { | |
165 | unsigned short size __attribute__ ((packed)); | |
166 | unsigned long long * base __attribute__ ((packed)); | |
167 | } | |
168 | real_mode_gdt = { sizeof (real_mode_gdt_entries) - 1, real_mode_gdt_entries }, | |
169 | real_mode_idt = { 0x3ff, NULL }, | |
170 | no_idt = { 0, NULL }; | |
171 | ||
172 | ||
173 | /* This is 16-bit protected mode code to disable paging and the cache, | |
174 | switch to real mode and jump to the BIOS reset code. | |
175 | ||
176 | The instruction that switches to real mode by writing to CR0 must be | |
177 | followed immediately by a far jump instruction, which set CS to a | |
178 | valid value for real mode, and flushes the prefetch queue to avoid | |
179 | running instructions that have already been decoded in protected | |
180 | mode. | |
181 | ||
182 | Clears all the flags except ET, especially PG (paging), PE | |
183 | (protected-mode enable) and TS (task switch for coprocessor state | |
184 | save). Flushes the TLB after paging has been disabled. Sets CD and | |
185 | NW, to disable the cache on a 486, and invalidates the cache. This | |
186 | is more like the state of a 486 after reset. I don't know if | |
187 | something else should be done for other chips. | |
188 | ||
189 | More could be done here to set up the registers as if a CPU reset had | |
190 | occurred; hopefully real BIOSs don't assume much. */ | |
191 | ||
192 | static unsigned char real_mode_switch [] = | |
193 | { | |
194 | 0x66, 0x0f, 0x20, 0xc0, /* movl %cr0,%eax */ | |
195 | 0x66, 0x83, 0xe0, 0x11, /* andl $0x00000011,%eax */ | |
196 | 0x66, 0x0d, 0x00, 0x00, 0x00, 0x60, /* orl $0x60000000,%eax */ | |
197 | 0x66, 0x0f, 0x22, 0xc0, /* movl %eax,%cr0 */ | |
198 | 0x66, 0x0f, 0x22, 0xd8, /* movl %eax,%cr3 */ | |
199 | 0x66, 0x0f, 0x20, 0xc3, /* movl %cr0,%ebx */ | |
200 | 0x66, 0x81, 0xe3, 0x00, 0x00, 0x00, 0x60, /* andl $0x60000000,%ebx */ | |
201 | 0x74, 0x02, /* jz f */ | |
202 | 0x0f, 0x09, /* wbinvd */ | |
203 | 0x24, 0x10, /* f: andb $0x10,al */ | |
204 | 0x66, 0x0f, 0x22, 0xc0 /* movl %eax,%cr0 */ | |
205 | }; | |
206 | static unsigned char jump_to_bios [] = | |
207 | { | |
208 | 0xea, 0x00, 0x00, 0xff, 0xff /* ljmp $0xffff,$0x0000 */ | |
209 | }; | |
210 | ||
211 | /* | |
212 | * Switch to real mode and then execute the code | |
213 | * specified by the code and length parameters. | |
214 | * We assume that length will aways be less that 100! | |
215 | */ | |
216 | void machine_real_restart(unsigned char *code, int length) | |
217 | { | |
218 | unsigned long flags; | |
219 | ||
220 | local_irq_disable(); | |
221 | ||
222 | /* Write zero to CMOS register number 0x0f, which the BIOS POST | |
223 | routine will recognize as telling it to do a proper reboot. (Well | |
224 | that's what this book in front of me says -- it may only apply to | |
225 | the Phoenix BIOS though, it's not clear). At the same time, | |
226 | disable NMIs by setting the top bit in the CMOS address register, | |
227 | as we're about to do peculiar things to the CPU. I'm not sure if | |
228 | `outb_p' is needed instead of just `outb'. Use it to be on the | |
229 | safe side. (Yes, CMOS_WRITE does outb_p's. - Paul G.) | |
230 | */ | |
231 | ||
232 | spin_lock_irqsave(&rtc_lock, flags); | |
233 | CMOS_WRITE(0x00, 0x8f); | |
234 | spin_unlock_irqrestore(&rtc_lock, flags); | |
235 | ||
236 | /* Remap the kernel at virtual address zero, as well as offset zero | |
237 | from the kernel segment. This assumes the kernel segment starts at | |
238 | virtual address PAGE_OFFSET. */ | |
239 | ||
240 | memcpy (swapper_pg_dir, swapper_pg_dir + USER_PGD_PTRS, | |
241 | sizeof (swapper_pg_dir [0]) * KERNEL_PGD_PTRS); | |
242 | ||
243 | /* | |
244 | * Use `swapper_pg_dir' as our page directory. | |
245 | */ | |
246 | load_cr3(swapper_pg_dir); | |
247 | ||
248 | /* Write 0x1234 to absolute memory location 0x472. The BIOS reads | |
249 | this on booting to tell it to "Bypass memory test (also warm | |
250 | boot)". This seems like a fairly standard thing that gets set by | |
251 | REBOOT.COM programs, and the previous reset routine did this | |
252 | too. */ | |
253 | ||
254 | *((unsigned short *)0x472) = reboot_mode; | |
255 | ||
256 | /* For the switch to real mode, copy some code to low memory. It has | |
257 | to be in the first 64k because it is running in 16-bit mode, and it | |
258 | has to have the same physical and virtual address, because it turns | |
259 | off paging. Copy it near the end of the first page, out of the way | |
260 | of BIOS variables. */ | |
261 | ||
262 | memcpy ((void *) (0x1000 - sizeof (real_mode_switch) - 100), | |
263 | real_mode_switch, sizeof (real_mode_switch)); | |
264 | memcpy ((void *) (0x1000 - 100), code, length); | |
265 | ||
266 | /* Set up the IDT for real mode. */ | |
267 | ||
268 | __asm__ __volatile__ ("lidt %0" : : "m" (real_mode_idt)); | |
269 | ||
270 | /* Set up a GDT from which we can load segment descriptors for real | |
271 | mode. The GDT is not used in real mode; it is just needed here to | |
272 | prepare the descriptors. */ | |
273 | ||
274 | __asm__ __volatile__ ("lgdt %0" : : "m" (real_mode_gdt)); | |
275 | ||
276 | /* Load the data segment registers, and thus the descriptors ready for | |
277 | real mode. The base address of each segment is 0x100, 16 times the | |
278 | selector value being loaded here. This is so that the segment | |
279 | registers don't have to be reloaded after switching to real mode: | |
280 | the values are consistent for real mode operation already. */ | |
281 | ||
282 | __asm__ __volatile__ ("movl $0x0010,%%eax\n" | |
283 | "\tmovl %%eax,%%ds\n" | |
284 | "\tmovl %%eax,%%es\n" | |
285 | "\tmovl %%eax,%%fs\n" | |
286 | "\tmovl %%eax,%%gs\n" | |
287 | "\tmovl %%eax,%%ss" : : : "eax"); | |
288 | ||
289 | /* Jump to the 16-bit code that we copied earlier. It disables paging | |
290 | and the cache, switches to real mode, and jumps to the BIOS reset | |
291 | entry point. */ | |
292 | ||
293 | __asm__ __volatile__ ("ljmp $0x0008,%0" | |
294 | : | |
295 | : "i" ((void *) (0x1000 - sizeof (real_mode_switch) - 100))); | |
296 | } | |
297 | ||
298 | void machine_restart(char * __unused) | |
299 | { | |
300 | #ifdef CONFIG_SMP | |
301 | int cpuid; | |
302 | ||
303 | cpuid = GET_APIC_ID(apic_read(APIC_ID)); | |
304 | ||
305 | if (reboot_smp) { | |
306 | ||
307 | /* check to see if reboot_cpu is valid | |
308 | if its not, default to the BSP */ | |
309 | if ((reboot_cpu == -1) || | |
310 | (reboot_cpu > (NR_CPUS -1)) || | |
311 | !physid_isset(cpuid, phys_cpu_present_map)) | |
312 | reboot_cpu = boot_cpu_physical_apicid; | |
313 | ||
314 | reboot_smp = 0; /* use this as a flag to only go through this once*/ | |
315 | /* re-run this function on the other CPUs | |
316 | it will fall though this section since we have | |
317 | cleared reboot_smp, and do the reboot if it is the | |
318 | correct CPU, otherwise it halts. */ | |
319 | if (reboot_cpu != cpuid) | |
320 | smp_call_function((void *)machine_restart , NULL, 1, 0); | |
321 | } | |
322 | ||
323 | /* if reboot_cpu is still -1, then we want a tradional reboot, | |
324 | and if we are not running on the reboot_cpu,, halt */ | |
325 | if ((reboot_cpu != -1) && (cpuid != reboot_cpu)) { | |
326 | for (;;) | |
327 | __asm__ __volatile__ ("hlt"); | |
328 | } | |
329 | /* | |
330 | * Stop all CPUs and turn off local APICs and the IO-APIC, so | |
331 | * other OSs see a clean IRQ state. | |
332 | */ | |
333 | smp_send_stop(); | |
334 | #endif /* CONFIG_SMP */ | |
335 | ||
336 | lapic_shutdown(); | |
337 | ||
338 | #ifdef CONFIG_X86_IO_APIC | |
339 | disable_IO_APIC(); | |
340 | #endif | |
341 | ||
342 | if (!reboot_thru_bios) { | |
343 | if (efi_enabled) { | |
344 | efi.reset_system(EFI_RESET_COLD, EFI_SUCCESS, 0, NULL); | |
345 | __asm__ __volatile__("lidt %0": :"m" (no_idt)); | |
346 | __asm__ __volatile__("int3"); | |
347 | } | |
348 | /* rebooting needs to touch the page at absolute addr 0 */ | |
349 | *((unsigned short *)__va(0x472)) = reboot_mode; | |
350 | for (;;) { | |
351 | mach_reboot(); | |
352 | /* That didn't work - force a triple fault.. */ | |
353 | __asm__ __volatile__("lidt %0": :"m" (no_idt)); | |
354 | __asm__ __volatile__("int3"); | |
355 | } | |
356 | } | |
357 | if (efi_enabled) | |
358 | efi.reset_system(EFI_RESET_WARM, EFI_SUCCESS, 0, NULL); | |
359 | ||
360 | machine_real_restart(jump_to_bios, sizeof(jump_to_bios)); | |
361 | } | |
362 | ||
363 | EXPORT_SYMBOL(machine_restart); | |
364 | ||
365 | void machine_halt(void) | |
366 | { | |
367 | } | |
368 | ||
369 | EXPORT_SYMBOL(machine_halt); | |
370 | ||
371 | void machine_power_off(void) | |
372 | { | |
373 | lapic_shutdown(); | |
374 | ||
375 | if (efi_enabled) | |
376 | efi.reset_system(EFI_RESET_SHUTDOWN, EFI_SUCCESS, 0, NULL); | |
377 | if (pm_power_off) | |
378 | pm_power_off(); | |
379 | } | |
380 | ||
381 | EXPORT_SYMBOL(machine_power_off); | |
382 |