1 files changed, 382 insertions, 0 deletions

diff --git a/arch/i386/kernel/reboot.c b/arch/i386/kernel/reboot.c
new file mode 100644
index 000000000000..3d7e994563df
--- /dev/null
+++ b/arch/i386/kernel/reboot.c
@@ -0,0 +1,382 @@
+/*
+ *  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);
+