diff options
Diffstat (limited to 'arch/x86/kernel/reboot_32.c')
| -rw-r--r-- | arch/x86/kernel/reboot_32.c | 413 |
1 files changed, 413 insertions, 0 deletions
diff --git a/arch/x86/kernel/reboot_32.c b/arch/x86/kernel/reboot_32.c new file mode 100644 index 00000000000..b37ed226830 --- /dev/null +++ b/arch/x86/kernel/reboot_32.c @@ -0,0 +1,413 @@ +/* + * linux/arch/i386/kernel/reboot.c + */ + +#include <linux/mm.h> +#include <linux/module.h> +#include <linux/delay.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/mc146818rtc.h> +#include <linux/efi.h> +#include <linux/dmi.h> +#include <linux/ctype.h> +#include <linux/pm.h> +#include <linux/reboot.h> +#include <asm/uaccess.h> +#include <asm/apic.h> +#include <asm/desc.h> +#include "mach_reboot.h" +#include <asm/reboot_fixups.h> +#include <asm/reboot.h> + +/* + * Power off function, if any + */ +void (*pm_power_off)(void); +EXPORT_SYMBOL(pm_power_off); + +static int reboot_mode; +static int reboot_thru_bios; + +#ifdef CONFIG_SMP +static int reboot_cpu = -1; +#endif +static int __init reboot_setup(char *str) +{ + while(1) { + switch (*str) { + case 'w': /* "warm" reboot (no memory testing etc) */ + reboot_mode = 0x1234; + break; + case 'c': /* "cold" reboot (with memory testing etc) */ + reboot_mode = 0x0; + break; + case 'b': /* "bios" reboot by jumping through the BIOS */ + reboot_thru_bios = 1; + break; + case 'h': /* "hard" reboot by toggling RESET and/or crashing the CPU */ + reboot_thru_bios = 0; + break; +#ifdef CONFIG_SMP + case 's': /* "smp" reboot by executing reset on BSP or other CPU*/ + if (isdigit(*(str+1))) { + reboot_cpu = (int) (*(str+1) - '0'); + if (isdigit(*(str+2))) + reboot_cpu = reboot_cpu*10 + (int)(*(str+2) - '0'); + } + /* we will leave sorting out the final value + when we are ready to reboot, since we might not + have set up boot_cpu_id or smp_num_cpu */ + break; +#endif + } + if((str = strchr(str,',')) != NULL) + str++; + else + break; + } + return 1; +} + +__setup("reboot=", reboot_setup); + +/* + * Reboot options and system auto-detection code provided by + * Dell Inc. so their systems "just work". :-) + */ + +/* + * Some machines require the "reboot=b" commandline option, this quirk makes that automatic. + */ +static int __init set_bios_reboot(const struct dmi_system_id *d) +{ + if (!reboot_thru_bios) { + reboot_thru_bios = 1; + printk(KERN_INFO "%s series board detected. Selecting BIOS-method for reboots.\n", d->ident); + } + return 0; +} + +static struct dmi_system_id __initdata reboot_dmi_table[] = { + { /* Handle problems with rebooting on Dell E520's */ + .callback = set_bios_reboot, + .ident = "Dell E520", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), + DMI_MATCH(DMI_PRODUCT_NAME, "Dell DM061"), + }, + }, + { /* Handle problems with rebooting on Dell 1300's */ + .callback = set_bios_reboot, + .ident = "Dell PowerEdge 1300", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"), + DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1300/"), + }, + }, + { /* Handle problems with rebooting on Dell 300's */ + .callback = set_bios_reboot, + .ident = "Dell PowerEdge 300", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"), + DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"), + }, + }, + { /* Handle problems with rebooting on Dell Optiplex 745's SFF*/ + .callback = set_bios_reboot, + .ident = "Dell OptiPlex 745", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."), + DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"), + DMI_MATCH(DMI_BOARD_NAME, "0WF810"), + }, + }, + { /* Handle problems with rebooting on Dell 2400's */ + .callback = set_bios_reboot, + .ident = "Dell PowerEdge 2400", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"), + DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"), + }, + }, + { /* Handle problems with rebooting on HP laptops */ + .callback = set_bios_reboot, + .ident = "HP Compaq Laptop", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"), + DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"), + }, + }, + { } +}; + +static int __init reboot_init(void) +{ + dmi_check_system(reboot_dmi_table); + return 0; +} + +core_initcall(reboot_init); + +/* The following code and data reboots the machine by switching to real + mode and jumping to the BIOS reset entry point, as if the CPU has + really been reset. The previous version asked the keyboard + controller to pulse the CPU reset line, which is more thorough, but + doesn't work with at least one type of 486 motherboard. It is easy + to stop this code working; hence the copious comments. */ + +static unsigned long long +real_mode_gdt_entries [3] = +{ + 0x0000000000000000ULL, /* Null descriptor */ + 0x00009a000000ffffULL, /* 16-bit real-mode 64k code at 0x00000000 */ + 0x000092000100ffffULL /* 16-bit real-mode 64k data at 0x00000100 */ +}; + +static struct Xgt_desc_struct +real_mode_gdt = { sizeof (real_mode_gdt_entries) - 1, (long)real_mode_gdt_entries }, +real_mode_idt = { 0x3ff, 0 }, +no_idt = { 0, 0 }; + + +/* This is 16-bit protected mode code to disable paging and the cache, + switch to real mode and jump to the BIOS reset code. + + The instruction that switches to real mode by writing to CR0 must be + followed immediately by a far jump instruction, which set CS to a + valid value for real mode, and flushes the prefetch queue to avoid + running instructions that have already been decoded in protected + mode. + + Clears all the flags except ET, especially PG (paging), PE + (protected-mode enable) and TS (task switch for coprocessor state + save). Flushes the TLB after paging has been disabled. Sets CD and + NW, to disable the cache on a 486, and invalidates the cache. This + is more like the state of a 486 after reset. I don't know if + something else should be done for other chips. + + More could be done here to set up the registers as if a CPU reset had + occurred; hopefully real BIOSs don't assume much. */ + +static unsigned char real_mode_switch [] = +{ + 0x66, 0x0f, 0x20, 0xc0, /* movl %cr0,%eax */ + 0x66, 0x83, 0xe0, 0x11, /* andl $0x00000011,%eax */ + 0x66, 0x0d, 0x00, 0x00, 0x00, 0x60, /* orl $0x60000000,%eax */ + 0x66, 0x0f, 0x22, 0xc0, /* movl %eax,%cr0 */ + 0x66, 0x0f, 0x22, 0xd8, /* movl %eax,%cr3 */ + 0x66, 0x0f, 0x20, 0xc3, /* movl %cr0,%ebx */ + 0x66, 0x81, 0xe3, 0x00, 0x00, 0x00, 0x60, /* andl $0x60000000,%ebx */ + 0x74, 0x02, /* jz f */ + 0x0f, 0x09, /* wbinvd */ + 0x24, 0x10, /* f: andb $0x10,al */ + 0x66, 0x0f, 0x22, 0xc0 /* movl %eax,%cr0 */ +}; +static unsigned char jump_to_bios [] = +{ + 0xea, 0x00, 0x00, 0xff, 0xff /* ljmp $0xffff,$0x0000 */ +}; + +/* + * Switch to real mode and then execute the code + * specified by the code and length parameters. + * We assume that length will aways be less that 100! + */ +void machine_real_restart(unsigned char *code, int length) +{ + local_irq_disable(); + + /* Write zero to CMOS register number 0x0f, which the BIOS POST + routine will recognize as telling it to do a proper reboot. (Well + that's what this book in front of me says -- it may only apply to + the Phoenix BIOS though, it's not clear). At the same time, + disable NMIs by setting the top bit in the CMOS address register, + as we're about to do peculiar things to the CPU. I'm not sure if + `outb_p' is needed instead of just `outb'. Use it to be on the + safe side. (Yes, CMOS_WRITE does outb_p's. - Paul G.) + */ + + spin_lock(&rtc_lock); + CMOS_WRITE(0x00, 0x8f); + spin_unlock(&rtc_lock); + + /* Remap the kernel at virtual address zero, as well as offset zero + from the kernel segment. This assumes the kernel segment starts at + virtual address PAGE_OFFSET. */ + + memcpy (swapper_pg_dir, swapper_pg_dir + USER_PGD_PTRS, + sizeof (swapper_pg_dir [0]) * KERNEL_PGD_PTRS); + + /* + * Use `swapper_pg_dir' as our page directory. + */ + load_cr3(swapper_pg_dir); + + /* Write 0x1234 to absolute memory location 0x472. The BIOS reads + this on booting to tell it to "Bypass memory test (also warm + boot)". This seems like a fairly standard thing that gets set by + REBOOT.COM programs, and the previous reset routine did this + too. */ + + *((unsigned short *)0x472) = reboot_mode; + + /* For the switch to real mode, copy some code to low memory. It has + to be in the first 64k because it is running in 16-bit mode, and it + has to have the same physical and virtual address, because it turns + off paging. Copy it near the end of the first page, out of the way + of BIOS variables. */ + + memcpy ((void *) (0x1000 - sizeof (real_mode_switch) - 100), + real_mode_switch, sizeof (real_mode_switch)); + memcpy ((void *) (0x1000 - 100), code, length); + + /* Set up the IDT for real mode. */ + + load_idt(&real_mode_idt); + + /* Set up a GDT from which we can load segment descriptors for real + mode. The GDT is not used in real mode; it is just needed here to + prepare the descriptors. */ + + load_gdt(&real_mode_gdt); + + /* Load the data segment registers, and thus the descriptors ready for + real mode. The base address of each segment is 0x100, 16 times the + selector value being loaded here. This is so that the segment + registers don't have to be reloaded after switching to real mode: + the values are consistent for real mode operation already. */ + + __asm__ __volatile__ ("movl $0x0010,%%eax\n" + "\tmovl %%eax,%%ds\n" + "\tmovl %%eax,%%es\n" + "\tmovl %%eax,%%fs\n" + "\tmovl %%eax,%%gs\n" + "\tmovl %%eax,%%ss" : : : "eax"); + + /* Jump to the 16-bit code that we copied earlier. It disables paging + and the cache, switches to real mode, and jumps to the BIOS reset + entry point. */ + + __asm__ __volatile__ ("ljmp $0x0008,%0" + : + : "i" ((void *) (0x1000 - sizeof (real_mode_switch) - 100))); +} +#ifdef CONFIG_APM_MODULE +EXPORT_SYMBOL(machine_real_restart); +#endif + +static void native_machine_shutdown(void) +{ +#ifdef CONFIG_SMP + int reboot_cpu_id; + + /* The boot cpu is always logical cpu 0 */ + reboot_cpu_id = 0; + + /* See if there has been given a command line override */ + if ((reboot_cpu != -1) && (reboot_cpu < NR_CPUS) && + cpu_isset(reboot_cpu, cpu_online_map)) { + reboot_cpu_id = reboot_cpu; + } + + /* Make certain the cpu I'm rebooting on is online */ + if (!cpu_isset(reboot_cpu_id, cpu_online_map)) { + reboot_cpu_id = smp_processor_id(); + } + + /* Make certain I only run on the appropriate processor */ + set_cpus_allowed(current, cpumask_of_cpu(reboot_cpu_id)); + + /* O.K. Now that I'm on the appropriate processor, stop + * all of the others, and disable their local APICs. + */ + + smp_send_stop(); +#endif /* CONFIG_SMP */ + + lapic_shutdown(); + +#ifdef CONFIG_X86_IO_APIC + disable_IO_APIC(); +#endif +} + +void __attribute__((weak)) mach_reboot_fixups(void) +{ +} + +static void native_machine_emergency_restart(void) +{ + if (!reboot_thru_bios) { + if (efi_enabled) { + efi.reset_system(EFI_RESET_COLD, EFI_SUCCESS, 0, NULL); + load_idt(&no_idt); + __asm__ __volatile__("int3"); + } + /* rebooting needs to touch the page at absolute addr 0 */ + *((unsigned short *)__va(0x472)) = reboot_mode; + for (;;) { + mach_reboot_fixups(); /* for board specific fixups */ + mach_reboot(); + /* That didn't work - force a triple fault.. */ + load_idt(&no_idt); + __asm__ __volatile__("int3"); + } + } + if (efi_enabled) + efi.reset_system(EFI_RESET_WARM, EFI_SUCCESS, 0, NULL); + + machine_real_restart(jump_to_bios, sizeof(jump_to_bios)); +} + +static void native_machine_restart(char * __unused) +{ + machine_shutdown(); + machine_emergency_restart(); +} + +static void native_machine_halt(void) +{ +} + +static void native_machine_power_off(void) +{ + if (pm_power_off) { + machine_shutdown(); + pm_power_off(); + } +} + + +struct machine_ops machine_ops = { + .power_off = native_machine_power_off, + .shutdown = native_machine_shutdown, + .emergency_restart = native_machine_emergency_restart, + .restart = native_machine_restart, + .halt = native_machine_halt, +}; + +void machine_power_off(void) +{ + machine_ops.power_off(); +} + +void machine_shutdown(void) +{ + machine_ops.shutdown(); +} + +void machine_emergency_restart(void) +{ + machine_ops.emergency_restart(); +} + +void machine_restart(char *cmd) +{ + machine_ops.restart(cmd); +} + +void machine_halt(void) +{ + machine_ops.halt(); +} |