x86: reboot_{32|64}.c unification

reboot_{32|64}.c unification patch.

This patch unifies the code from the reboot_32.c and reboot_64.c files.

It has been tested in computers with X86_32 and X86_64 kernels and it
looks like all reboot modes work fine (EFI restart system hasn't been
tested yet).

Probably I made some mistakes (like I usually do) so I hope
we can identify and fix them soon.

Signed-off-by: Miguel Boton <mboton@gmail.com>

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 449 insertions, 0 deletions

diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c
new file mode 100644
index 000000000000..5b32f0b4d133
--- /dev/null
+++ b/arch/x86/kernel/reboot.c
@@ -0,0 +1,449 @@
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/reboot.h>
+#include <linux/init.h>
+#include <linux/pm.h>
+#include <linux/efi.h>
+#include <acpi/reboot.h>
+#include <asm/io.h>
+#include <asm/apic.h>
+#include <asm/desc.h>
+#include <asm/hpet.h>
+#include <asm/reboot_fixups.h>
+#include <asm/reboot.h>
+
+#ifdef CONFIG_X86_32
+# include <linux/dmi.h>
+# include <linux/ctype.h>
+# include <linux/mc146818rtc.h>
+# include <asm/pgtable.h>
+#else
+# include <asm/iommu.h>
+#endif
+
+/*
+ * Power off function, if any
+ */
+void (*pm_power_off)(void);
+EXPORT_SYMBOL(pm_power_off);
+
+static long no_idt[3];
+static int reboot_mode;
+enum reboot_type reboot_type = BOOT_KBD;
+int reboot_force;
+
+#if defined(CONFIG_X86_32) && defined(CONFIG_SMP)
+static int reboot_cpu = -1;
+#endif
+
+/* reboot=b[ios] | s[mp] | t[riple] | k[bd] | e[fi] [, [w]arm | [c]old]
+   warm   Don't set the cold reboot flag
+   cold   Set the cold reboot flag
+   bios   Reboot by jumping through the BIOS (only for X86_32)
+   smp    Reboot by executing reset on BSP or other CPU (only for X86_32)
+   triple Force a triple fault (init)
+   kbd    Use the keyboard controller. cold reset (default)
+   acpi   Use the RESET_REG in the FADT
+   efi    Use efi reset_system runtime service
+   force  Avoid anything that could hang.
+ */
+static int __init reboot_setup(char *str)
+{
+        for (;;) {
+                switch (*str) {
+                case 'w':
+                        reboot_mode = 0x1234;
+                        break;
+
+                case 'c':
+                        reboot_mode = 0;
+                        break;
+
+#ifdef CONFIG_X86_32
+#ifdef CONFIG_SMP
+                case 's':
+                        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 /* CONFIG_SMP */
+
+                case 'b':
+#endif
+                case 'a':
+                case 'k':
+                case 't':
+                case 'e':
+                        reboot_type = *str;
+                        break;
+
+                case 'f':
+                        reboot_force = 1;
+                        break;
+                }
+
+                str = strchr(str, ',');
+                if (str)
+                        str++;
+                else
+                        break;
+        }
+        return 1;
+}
+
+__setup("reboot=", reboot_setup);
+
+
+#ifdef CONFIG_X86_32
+/*
+ * 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_type != BOOT_BIOS) {
+                reboot_type = BOOT_BIOS;
+                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 desc_ptr
+real_mode_gdt = { sizeof (real_mode_gdt_entries) - 1, (long)real_mode_gdt_entries },
+real_mode_idt = { 0x3ff, 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
+
+#endif /* CONFIG_X86_32 */
+
+static inline void kb_wait(void)
+{
+        int i;
+
+        for (i = 0; i < 0x10000; i++)
+                if ((inb_p(0x64) & 0x02) == 0)
+                        break;
+}
+
+void machine_emergency_restart(void)
+{
+        int i;
+
+        /* Tell the BIOS if we want cold or warm reboot */
+        *((unsigned short *)__va(0x472)) = reboot_mode;
+
+        for (;;) {
+                /* Could also try the reset bit in the Hammer NB */
+                switch (reboot_type) {
+                case BOOT_KBD:
+                        for (i = 0; i < 10; i++) {
+                                kb_wait();
+                                udelay(50);
+                                outb(0xfe, 0x64); /* pulse reset low */
+                                udelay(50);
+                        }
+
+                case BOOT_TRIPLE:
+                        load_idt((const struct desc_ptr *)&no_idt);
+                        __asm__ __volatile__("int3");
+
+                        reboot_type = BOOT_KBD;
+                        break;
+
+#ifdef CONFIG_X86_32
+                case BOOT_BIOS:
+                        machine_real_restart(jump_to_bios, sizeof(jump_to_bios));
+
+                        reboot_type = BOOT_KBD;
+                        break;
+#endif
+
+                case BOOT_ACPI:
+                        acpi_reboot();
+                        reboot_type = BOOT_KBD;
+                        break;
+
+
+                case BOOT_EFI:
+                        if (efi_enabled)
+                                efi.reset_system(reboot_mode ? EFI_RESET_WARM : EFI_RESET_COLD,
+                                                 EFI_SUCCESS, 0, NULL);
+
+                        reboot_type = BOOT_KBD;
+                        break;
+                }
+        }
+}
+
+void machine_shutdown(void)
+{
+        /* Stop the cpus and apics */
+#ifdef CONFIG_SMP
+        int reboot_cpu_id;
+
+        /* The boot cpu is always logical cpu 0 */
+        reboot_cpu_id = 0;
+
+#ifdef CONFIG_X86_32
+        /* 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;
+#endif
+
+        /* Make certain the cpu I'm about to reboot 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.
+         */
+        smp_send_stop();
+#endif
+
+        lapic_shutdown();
+
+#ifdef CONFIG_X86_IO_APIC
+        disable_IO_APIC();
+#endif
+
+#ifdef CONFIG_HPET_TIMER
+        hpet_disable();
+#endif
+
+#ifdef CONFIG_X86_64
+        pci_iommu_shutdown();
+#endif
+}
+
+void machine_restart(char *__unused)
+{
+        printk("machine restart\n");
+
+        if (!reboot_force)
+                machine_shutdown();
+        machine_emergency_restart();
+}
+
+void machine_halt(void)
+{
+}
+
+void machine_power_off(void)
+{
+        if (pm_power_off) {
+                if (!reboot_force)
+                        machine_shutdown();
+                pm_power_off();
+        }
+}
+
+struct machine_ops machine_ops = {
+        .power_off = machine_power_off,
+        .shutdown = machine_shutdown,
+        .emergency_restart = machine_emergency_restart,
+        .restart = machine_restart,
+        .halt = machine_halt
+};