- 根目录:
- arch
- x86
- kernel
- reboot.c
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <linux/pm.h>
#include <linux/efi.h>
#include <linux/dmi.h>
#include <linux/sched.h>
#include <linux/tboot.h>
#include <linux/delay.h>
#include <acpi/reboot.h>
#include <asm/io.h>
#include <asm/apic.h>
#include <asm/desc.h>
#include <asm/hpet.h>
#include <asm/pgtable.h>
#include <asm/proto.h>
#include <asm/reboot_fixups.h>
#include <asm/reboot.h>
#include <asm/pci_x86.h>
#include <asm/virtext.h>
#include <asm/cpu.h>
#include <asm/nmi.h>
#include <asm/smp.h>
#include <linux/ctype.h>
#include <linux/mc146818rtc.h>
#include <asm/realmode.h>
#include <asm/x86_init.h>
/*
* Power off function, if any
*/
void (*pm_power_off)(void);
EXPORT_SYMBOL(pm_power_off);
static const struct desc_ptr no_idt = {};
static int reboot_mode;
enum reboot_type reboot_type = BOOT_ACPI;
int reboot_force;
/*
* This variable is used privately to keep track of whether or not
* reboot_type is still set to its default value (i.e., reboot= hasn't
* been set on the command line). This is needed so that we can
* suppress DMI scanning for reboot quirks. Without it, it's
* impossible to override a faulty reboot quirk without recompiling.
*/
static int reboot_default = 1;
#ifdef CONFIG_SMP
static int reboot_cpu = -1;
#endif
/*
* This is set if we need to go through the 'emergency' path.
* When machine_emergency_restart() is called, we may be on
* an inconsistent state and won't be able to do a clean cleanup
*/
static int reboot_emergency;
/* This is set by the PCI code if either type 1 or type 2 PCI is detected */
bool port_cf9_safe = false;
/*
* reboot=b[ios] | s[mp] | t[riple] | k[bd] | e[fi] [, [w]arm | [c]old] | p[ci]
* warm Don't set the cold reboot flag
* cold Set the cold reboot flag
* bios Reboot by jumping through the BIOS
* smp Reboot by executing reset on BSP or other CPU
* 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
* pci Use the so-called "PCI reset register", CF9
* force Avoid anything that could hang.
*/
static int __init reboot_setup(char *str)
{
for (;;) {
/*
* Having anything passed on the command line via
* reboot= will cause us to disable DMI checking
* below.
*/
reboot_default = 0;
switch (*str) {
case 'w':
reboot_mode = 0x1234;
break;
case 'c':
reboot_mode = 0;
break;
#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 detected BSP APIC ID or smp_num_cpu
*/
break;
#endif /* CONFIG_SMP */
case 'b':
case 'a':
case 'k':
case 't':
case 'e':
case 'p':
reboot_type = *str;
break;
case 'f':
reboot_force = 1;
break;
}
str = strchr(str, ',');
if (str)
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" or "reboot=k" commandline options,
* 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;
pr_info("%s series board detected. Selecting %s-method for reboots.\n",
"BIOS", d->ident);
}
return 0;
}
void __noreturn machine_real_restart(unsigned int type)
{
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);
/*
* Switch back to the initial page table.
*/
#ifdef CONFIG_X86_32
load_cr3(initial_page_table);
#else
write_cr3(real_mode_header->trampoline_pgd);
#endif
/* Jump to the identity-mapped low memory code */
#ifdef CONFIG_X86_32
asm volatile("jmpl *%0" : :
"rm" (real_mode_header->machine_real_restart_asm),
"a" (type));
#else
asm volatile("ljmpl *%0" : :
"m" (real_mode_header->machine_real_restart_asm),
"D" (type));
#endif
unreachable();
}
#ifdef CONFIG_APM_MODULE
EXPORT_SYMBOL(machine_real_restart);
#endif
/*
* Some Apple MacBook and MacBookPro's needs reboot=p to be able to reboot
*/
static int __init set_pci_reboot(const struct dmi_system_id *d)
{
if (reboot_type != BOOT_CF9) {
reboot_type = BOOT_CF9;
pr_info("%s series board detected. Selecting %s-method for reboots.\n",
"PCI", d->ident);
}
return 0;
}
static int __init set_kbd_reboot(const struct dmi_system_id *d)
{
if (reboot_type != BOOT_KBD) {
reboot_type = BOOT_KBD;
pr_info("%s series board detected. Selecting %s-method for reboot.\n",
"KBD", d->ident);
}
return 0;
}
/*
* This is a single dmi_table handling all reboot quirks.
*/
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"),
},
},
{ /* Handle problems with rebooting on Dell Optiplex 745's DFF */
.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, "0MM599"),
},
},
{ /* Handle problems with rebooting on Dell Optiplex 745 with 0KW626 */
.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, "0KW626"),
},
},
{ /* Handle problems with rebooting on Dell Optiplex 330 with 0KP561 */
.callback = set_bios_reboot,
.ident = "Dell OptiPlex 330",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 330"),
DMI_MATCH(DMI_BOARD_NAME, "0KP561"),
},
},
{ /* Handle problems with rebooting on Dell Optiplex 360 with 0T656F */
.callback = set_bios_reboot,
.ident = "Dell OptiPlex 360",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 360"),
DMI_MATCH(DMI_BOARD_NAME, "0T656F"),
},
},
{ /* Handle problems with rebooting on Dell OptiPlex 760 with 0G919G */
.callback = set_bios_reboot,
.ident = "Dell OptiPlex 760",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 760"),
DMI_MATCH(DMI_BOARD_NAME, "0G919G"),
},
},
{ /* 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 Dell T5400's */
.callback = set_bios_reboot,
.ident = "Dell Precision T5400",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T5400"),
},
},
{ /* Handle problems with rebooting on Dell T7400's */
.callback = set_bios_reboot,
.ident = "Dell Precision T7400",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
DMI_MATCH(DMI_PRODUCT_NAME, "Precision WorkStation T7400"),
},
},
{ /* 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"),
},
},
{ /* Handle problems with rebooting on Dell XPS710 */
.callback = set_bios_reboot,
.ident = "Dell XPS710",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
DMI_MATCH(DMI_PRODUCT_NAME, "Dell XPS710"),
},
},
{ /* Handle problems with rebooting on Dell DXP061 */
.callback = set_bios_reboot,
.ident = "Dell DXP061",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
DMI_MATCH(DMI_PRODUCT_NAME, "Dell DXP061"),
},
},
{ /* Handle problems with rebooting on Sony VGN-Z540N */
.callback = set_bios_reboot,
.ident = "Sony VGN-Z540N",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
DMI_MATCH(DMI_PRODUCT_NAME, "VGN-Z540N"),
},
},
{ /* Handle problems with rebooting on ASUS P4S800 */
.callback = set_bios_reboot,
.ident = "ASUS P4S800",
.matches = {
DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
DMI_MATCH(DMI_BOARD_NAME, "P4S800"),
},
},
{ /* Handle reboot issue on Acer Aspire one */
.callback = set_kbd_reboot,
.ident = "Acer Aspire One A110",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
DMI_MATCH(DMI_PRODUCT_NAME, "AOA110"),
},
},
{ /* Handle problems with rebooting on Apple MacBook5 */
.callback = set_pci_reboot,
.ident = "Apple MacBook5",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
DMI_MATCH(DMI_PRODUCT_NAME, "MacBook5"),
},
},
{ /* Handle problems with rebooting on Apple MacBookPro5 */
.callback = set_pci_reboot,
.ident = "Apple MacBookPro5",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro5"),
},
},
{ /* Handle problems with rebooting on Apple Macmini3,1 */
.callback = set_pci_reboot,
.ident = "Apple Macmini3,1",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
DMI_MATCH(DMI_PRODUCT_NAME, "Macmini3,1"),
},
},
{ /* Handle problems with rebooting on the iMac9,1. */
.callback = set_pci_reboot,
.ident = "Apple iMac9,1",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
DMI_MATCH(DMI_PRODUCT_NAME, "iMac9,1"),
},
},
{ /* Handle problems with rebooting on the Latitude E6320. */
.callback = set_pci_reboot,
.ident = "Dell Latitude E6320",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6320"),
},
},
{ /* Handle problems with rebooting on the Latitude E5420. */
.callback = set_pci_reboot,
.ident = "Dell Latitude E5420",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E5420"),
},
},
{ /* Handle problems with rebooting on the Latitude E6420. */
.callback = set_pci_reboot,
.ident = "Dell Latitude E6420",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
DMI_MATCH(DMI_PRODUCT_NAME, "Latitude E6420"),
},
},
{ /* Handle problems with rebooting on the OptiPlex 990. */
.callback = set_pci_reboot,
.ident = "Dell OptiPlex 990",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 990"),
},
},
{ /* Handle problems with rebooting on the Precision M6600. */
.callback = set_pci_reboot,
.ident = "Dell OptiPlex 990",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
DMI_MATCH(DMI_PRODUCT_NAME, "Precision M6600"),
},
},
{ }
};
static int __init reboot_init(void)
{
/*
* Only do the DMI check if reboot_type hasn't been overridden
* on the command line
*/
if (reboot_default)
dmi_check_system(reboot_dmi_table);
return 0;
}
core_initcall(reboot_init);
static inline void kb_wait(void)
{
int i;
for (i = 0; i < 0x10000; i++) {
if ((inb(0x64) & 0x02) == 0)
break;
udelay(2);
}
}
static void vmxoff_nmi(int cpu, struct pt_regs *regs)
{
cpu_emergency_vmxoff();
}
/* Use NMIs as IPIs to tell all CPUs to disable virtualization */
static void emergency_vmx_disable_all(void)
{
/* Just make sure we won't change CPUs while doing this */
local_irq_disable();
/*
* We need to disable VMX on all CPUs before rebooting, otherwise
* we risk hanging up the machine, because the CPU ignore INIT
* signals when VMX is enabled.
*
* We can't take any locks and we may be on an inconsistent
* state, so we use NMIs as IPIs to tell the other CPUs to disable
* VMX and halt.
*
* For safety, we will avoid running the nmi_shootdown_cpus()
* stuff unnecessarily, but we don't have a way to check
* if other CPUs have VMX enabled. So we will call it only if the
* CPU we are running on has VMX enabled.
*
* We will miss cases where VMX is not enabled on all CPUs. This
* shouldn't do much harm because KVM always enable VMX on all
* CPUs anyway. But we can miss it on the small window where KVM
* is still enabling VMX.
*/
if (cpu_has_vmx() && cpu_vmx_enabled()) {
/* Disable VMX on this CPU. */
cpu_vmxoff();
/* Halt and disable VMX on the other CPUs */
nmi_shootdown_cpus(vmxoff_nmi);
}
}
void __attribute__((weak)) mach_reboot_fixups(void)
{
}
/*
* Windows compatible x86 hardware expects the following on reboot:
*
* 1) If the FADT has the ACPI reboot register flag set, try it
* 2) If still alive, write to the keyboard controller
* 3) If still alive, write to the ACPI reboot register again
* 4) If still alive, write to the keyboard controller again
*
* If the machine is still alive at this stage, it gives up. We default to
* following the same pattern, except that if we're still alive after (4) we'll
* try to force a triple fault and then cycle between hitting the keyboard
* controller and doing that
*/
static void native_machine_emergency_restart(void)
{
int i;
int attempt = 0;
int orig_reboot_type = reboot_type;
if (reboot_emergency)
emergency_vmx_disable_all();
tboot_shutdown(TB_SHUTDOWN_REBOOT);
/* 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:
mach_reboot_fixups(); /* For board specific fixups */
for (i = 0; i < 10; i++) {
kb_wait();
udelay(50);
outb(0xfe, 0x64); /* Pulse reset low */
udelay(50);
}
if (attempt == 0 && orig_reboot_type == BOOT_ACPI) {
attempt = 1;
reboot_type = BOOT_ACPI;
} else {
reboot_type = BOOT_TRIPLE;
}
break;
case BOOT_TRIPLE:
load_idt(&no_idt);
__asm__ __volatile__("int3");
reboot_type = BOOT_KBD;
break;
case BOOT_BIOS:
machine_real_restart(MRR_BIOS);
reboot_type = BOOT_KBD;
break;
case BOOT_ACPI:
acpi_reboot();
reboot_type = BOOT_KBD;
break;
case BOOT_EFI:
if (efi_enabled(EFI_RUNTIME_SERVICES))
efi.reset_system(reboot_mode ?
EFI_RESET_WARM :
EFI_RESET_COLD,
EFI_SUCCESS, 0, NULL);
reboot_type = BOOT_KBD;
break;
case BOOT_CF9:
port_cf9_safe = true;
/* Fall through */
case BOOT_CF9_COND:
if (port_cf9_safe) {
u8 cf9 = inb(0xcf9) & ~6;
outb(cf9|2, 0xcf9); /* Request hard reset */
udelay(50);
outb(cf9|6, 0xcf9); /* Actually do the reset */
udelay(50);
}
reboot_type = BOOT_KBD;
break;
}
}
}
void native_machine_shutdown(void)
{
/* Stop the cpus and apics */
#ifdef CONFIG_SMP
/* The boot cpu is always logical cpu 0 */
int reboot_cpu_id = 0;
/* See if there has been given a command line override */
if ((reboot_cpu != -1) && (reboot_cpu < nr_cpu_ids) &&
cpu_online(reboot_cpu))
reboot_cpu_id = reboot_cpu;
/* Make certain the cpu I'm about to reboot on is online */
if (!cpu_online(reboot_cpu_id))
reboot_cpu_id = smp_processor_id();
/* Make certain I only run on the appropriate processor */
set_cpus_allowed_ptr(current, cpumask_of(reboot_cpu_id));
/*
* O.K Now that I'm on the appropriate processor, stop all of the
* others. Also disable the local irq to not receive the per-cpu
* timer interrupt which may trigger scheduler's load balance.
*/
local_irq_disable();
stop_other_cpus();
#endif
lapic_shutdown();
#ifdef CONFIG_X86_IO_APIC
disable_IO_APIC();
#endif
#ifdef CONFIG_HPET_TIMER
hpet_disable();
#endif
#ifdef CONFIG_X86_64
x86_platform.iommu_shutdown();
#endif
}
static void __machine_emergency_restart(int emergency)
{
reboot_emergency = emergency;
machine_ops.emergency_restart();
}
static void native_machine_restart(char *__unused)
{
pr_notice("machine restart\n");
if (!reboot_force)
machine_shutdown();
__machine_emergency_restart(0);
}
static void native_machine_halt(void)
{
/* Stop other cpus and apics */
machine_shutdown();
tboot_shutdown(TB_SHUTDOWN_HALT);
stop_this_cpu(NULL);
}
static void native_machine_power_off(void)
{
if (pm_power_off) {
if (!reboot_force)
machine_shutdown();
pm_power_off();
}
/* A fallback in case there is no PM info available */
tboot_shutdown(TB_SHUTDOWN_HALT);
}
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,
#ifdef CONFIG_KEXEC
.crash_shutdown = native_machine_crash_shutdown,
#endif
};
void machine_power_off(void)
{
machine_ops.power_off();
}
void machine_shutdown(void)
{
machine_ops.shutdown();
}
void machine_emergency_restart(void)
{
__machine_emergency_restart(1);
}
void machine_restart(char *cmd)
{
machine_ops.restart(cmd);
}
void machine_halt(void)
{
machine_ops.halt();
}
#ifdef CONFIG_KEXEC
void machine_crash_shutdown(struct pt_regs *regs)
{
machine_ops.crash_shutdown(regs);
}
#endif
#if defined(CONFIG_SMP)
/* This keeps a track of which one is crashing cpu. */
static int crashing_cpu;
static nmi_shootdown_cb shootdown_callback;
static atomic_t waiting_for_crash_ipi;
static int crash_nmi_callback(unsigned int val, struct pt_regs *regs)
{
int cpu;
cpu = raw_smp_processor_id();
/*
* Don't do anything if this handler is invoked on crashing cpu.
* Otherwise, system will completely hang. Crashing cpu can get
* an NMI if system was initially booted with nmi_watchdog parameter.
*/
if (cpu == crashing_cpu)
return NMI_HANDLED;
local_irq_disable();
shootdown_callback(cpu, regs);
atomic_dec(&waiting_for_crash_ipi);
/* Assume hlt works */
halt();
for (;;)
cpu_relax();
return NMI_HANDLED;
}
static void smp_send_nmi_allbutself(void)
{
apic->send_IPI_allbutself(NMI_VECTOR);
}
/*
* Halt all other CPUs, calling the specified function on each of them
*
* This function can be used to halt all other CPUs on crash
* or emergency reboot time. The function passed as parameter
* will be called inside a NMI handler on all CPUs.
*/
void nmi_shootdown_cpus(nmi_shootdown_cb callback)
{
unsigned long msecs;
local_irq_disable();
/* Make a note of crashing cpu. Will be used in NMI callback. */
crashing_cpu = safe_smp_processor_id();
shootdown_callback = callback;
atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1);
/* Would it be better to replace the trap vector here? */
if (register_nmi_handler(NMI_LOCAL, crash_nmi_callback,
NMI_FLAG_FIRST, "crash"))
return; /* Return what? */
/*
* Ensure the new callback function is set before sending
* out the NMI
*/
wmb();
smp_send_nmi_allbutself();
msecs = 1000; /* Wait at most a second for the other cpus to stop */
while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
mdelay(1);
msecs--;
}
/* Leave the nmi callback set */
}
#else /* !CONFIG_SMP */
void nmi_shootdown_cpus(nmi_shootdown_cb callback)
{
/* No other CPUs to shoot down */
}
#endif