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-rw-r--r--arch/i386/kernel/reboot.c382
1 files changed, 382 insertions, 0 deletions
diff --git a/arch/i386/kernel/reboot.c b/arch/i386/kernel/reboot.c
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+++ b/arch/i386/kernel/reboot.c
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+/*
+ * 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 <asm/uaccess.h>
+#include <asm/apic.h>
+#include "mach_reboot.h"
+
+/*
+ * Power off function, if any
+ */
+void (*pm_power_off)(void);
+
+static int reboot_mode;
+static int reboot_thru_bios;
+
+#ifdef CONFIG_SMP
+int reboot_smp = 0;
+static int reboot_cpu = -1;
+/* shamelessly grabbed from lib/vsprintf.c for readability */
+#define is_digit(c) ((c) >= '0' && (c) <= '9')
+#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*/
+ reboot_smp = 1;
+ if (is_digit(*(str+1))) {
+ reboot_cpu = (int) (*(str+1) - '0');
+ if (is_digit(*(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(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;
+}
+
+/*
+ * Some machines require the "reboot=s" commandline option, this quirk makes that automatic.
+ */
+static int __init set_smp_reboot(struct dmi_system_id *d)
+{
+#ifdef CONFIG_SMP
+ if (!reboot_smp) {
+ reboot_smp = 1;
+ printk(KERN_INFO "%s series board detected. Selecting SMP-method for reboots.\n", d->ident);
+ }
+#endif
+ return 0;
+}
+
+/*
+ * Some machines require the "reboot=b,s" commandline option, this quirk makes that automatic.
+ */
+static int __init set_smp_bios_reboot(struct dmi_system_id *d)
+{
+ set_smp_reboot(d);
+ set_bios_reboot(d);
+ return 0;
+}
+
+static struct dmi_system_id __initdata reboot_dmi_table[] = {
+ { /* Handle problems with rebooting on Dell 1300's */
+ .callback = set_smp_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 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"),
+ },
+ },
+ { }
+};
+
+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
+{
+ unsigned short size __attribute__ ((packed));
+ unsigned long long * base __attribute__ ((packed));
+}
+real_mode_gdt = { sizeof (real_mode_gdt_entries) - 1, real_mode_gdt_entries },
+real_mode_idt = { 0x3ff, NULL },
+no_idt = { 0, NULL };
+
+
+/* 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)
+{
+ unsigned long flags;
+
+ 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_irqsave(&rtc_lock, flags);
+ CMOS_WRITE(0x00, 0x8f);
+ spin_unlock_irqrestore(&rtc_lock, flags);
+
+ /* 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. */
+
+ __asm__ __volatile__ ("lidt %0" : : "m" (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. */
+
+ __asm__ __volatile__ ("lgdt %0" : : "m" (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)));
+}
+
+void machine_restart(char * __unused)
+{
+#ifdef CONFIG_SMP
+ int cpuid;
+
+ cpuid = GET_APIC_ID(apic_read(APIC_ID));
+
+ if (reboot_smp) {
+
+ /* check to see if reboot_cpu is valid
+ if its not, default to the BSP */
+ if ((reboot_cpu == -1) ||
+ (reboot_cpu > (NR_CPUS -1)) ||
+ !physid_isset(cpuid, phys_cpu_present_map))
+ reboot_cpu = boot_cpu_physical_apicid;
+
+ reboot_smp = 0; /* use this as a flag to only go through this once*/
+ /* re-run this function on the other CPUs
+ it will fall though this section since we have
+ cleared reboot_smp, and do the reboot if it is the
+ correct CPU, otherwise it halts. */
+ if (reboot_cpu != cpuid)
+ smp_call_function((void *)machine_restart , NULL, 1, 0);
+ }
+
+ /* if reboot_cpu is still -1, then we want a tradional reboot,
+ and if we are not running on the reboot_cpu,, halt */
+ if ((reboot_cpu != -1) && (cpuid != reboot_cpu)) {
+ for (;;)
+ __asm__ __volatile__ ("hlt");
+ }
+ /*
+ * Stop all CPUs and turn off local APICs and the IO-APIC, so
+ * other OSs see a clean IRQ state.
+ */
+ smp_send_stop();
+#endif /* CONFIG_SMP */
+
+ lapic_shutdown();
+
+#ifdef CONFIG_X86_IO_APIC
+ disable_IO_APIC();
+#endif
+
+ if (!reboot_thru_bios) {
+ if (efi_enabled) {
+ efi.reset_system(EFI_RESET_COLD, EFI_SUCCESS, 0, NULL);
+ __asm__ __volatile__("lidt %0": :"m" (no_idt));
+ __asm__ __volatile__("int3");
+ }
+ /* rebooting needs to touch the page at absolute addr 0 */
+ *((unsigned short *)__va(0x472)) = reboot_mode;
+ for (;;) {
+ mach_reboot();
+ /* That didn't work - force a triple fault.. */
+ __asm__ __volatile__("lidt %0": :"m" (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));
+}
+
+EXPORT_SYMBOL(machine_restart);
+
+void machine_halt(void)
+{
+}
+
+EXPORT_SYMBOL(machine_halt);
+
+void machine_power_off(void)
+{
+ lapic_shutdown();
+
+ if (efi_enabled)
+ efi.reset_system(EFI_RESET_SHUTDOWN, EFI_SUCCESS, 0, NULL);
+ if (pm_power_off)
+ pm_power_off();
+}
+
+EXPORT_SYMBOL(machine_power_off);
+