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