aboutsummaryrefslogtreecommitdiff
path: root/arch/x86/kernel/reboot.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/kernel/reboot.c')
-rw-r--r--arch/x86/kernel/reboot.c189
1 files changed, 182 insertions, 7 deletions
diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c
index cc5a2545dd4..2b46eb41643 100644
--- a/arch/x86/kernel/reboot.c
+++ b/arch/x86/kernel/reboot.c
@@ -12,6 +12,8 @@
#include <asm/proto.h>
#include <asm/reboot_fixups.h>
#include <asm/reboot.h>
+#include <asm/pci_x86.h>
+#include <asm/virtext.h>
#ifdef CONFIG_X86_32
# include <linux/dmi.h>
@@ -21,6 +23,8 @@
# include <asm/iommu.h>
#endif
+#include <mach_ipi.h>
+
/*
* Power off function, if any
*/
@@ -36,7 +40,16 @@ int reboot_force;
static int reboot_cpu = -1;
#endif
-/* reboot=b[ios] | s[mp] | t[riple] | k[bd] | e[fi] [, [w]arm | [c]old]
+/* 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 (only for X86_32)
@@ -45,6 +58,7 @@ static int reboot_cpu = -1;
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)
@@ -79,6 +93,7 @@ static int __init reboot_setup(char *str)
case 'k':
case 't':
case 'e':
+ case 'p':
reboot_type = *str;
break;
@@ -360,6 +375,48 @@ static inline void kb_wait(void)
}
}
+static void vmxoff_nmi(int cpu, struct die_args *args)
+{
+ 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)
{
}
@@ -368,6 +425,9 @@ static void native_machine_emergency_restart(void)
{
int i;
+ if (reboot_emergency)
+ emergency_vmx_disable_all();
+
/* Tell the BIOS if we want cold or warm reboot */
*((unsigned short *)__va(0x472)) = reboot_mode;
@@ -404,12 +464,27 @@ static void native_machine_emergency_restart(void)
reboot_type = BOOT_KBD;
break;
-
case BOOT_EFI:
if (efi_enabled)
- efi.reset_system(reboot_mode ? EFI_RESET_WARM : EFI_RESET_COLD,
+ 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;
}
@@ -426,7 +501,7 @@ void native_machine_shutdown(void)
#ifdef CONFIG_X86_32
/* See if there has been given a command line override */
- if ((reboot_cpu != -1) && (reboot_cpu < NR_CPUS) &&
+ if ((reboot_cpu != -1) && (reboot_cpu < nr_cpu_ids) &&
cpu_online(reboot_cpu))
reboot_cpu_id = reboot_cpu;
#endif
@@ -436,7 +511,7 @@ void native_machine_shutdown(void)
reboot_cpu_id = smp_processor_id();
/* Make certain I only run on the appropriate processor */
- set_cpus_allowed_ptr(current, &cpumask_of_cpu(reboot_cpu_id));
+ 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.
@@ -459,17 +534,28 @@ void native_machine_shutdown(void)
#endif
}
+static void __machine_emergency_restart(int emergency)
+{
+ reboot_emergency = emergency;
+ machine_ops.emergency_restart();
+}
+
static void native_machine_restart(char *__unused)
{
printk("machine restart\n");
if (!reboot_force)
machine_shutdown();
- machine_emergency_restart();
+ __machine_emergency_restart(0);
}
static void native_machine_halt(void)
{
+ /* stop other cpus and apics */
+ machine_shutdown();
+
+ /* stop this cpu */
+ stop_this_cpu(NULL);
}
static void native_machine_power_off(void)
@@ -504,7 +590,7 @@ void machine_shutdown(void)
void machine_emergency_restart(void)
{
- machine_ops.emergency_restart();
+ __machine_emergency_restart(1);
}
void machine_restart(char *cmd)
@@ -523,3 +609,92 @@ 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(struct notifier_block *self,
+ unsigned long val, void *data)
+{
+ int cpu;
+
+ if (val != DIE_NMI_IPI)
+ return NOTIFY_OK;
+
+ 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 NOTIFY_STOP;
+ local_irq_disable();
+
+ shootdown_callback(cpu, (struct die_args *)data);
+
+ atomic_dec(&waiting_for_crash_ipi);
+ /* Assume hlt works */
+ halt();
+ for (;;)
+ cpu_relax();
+
+ return 1;
+}
+
+static void smp_send_nmi_allbutself(void)
+{
+ send_IPI_allbutself(NMI_VECTOR);
+}
+
+static struct notifier_block crash_nmi_nb = {
+ .notifier_call = crash_nmi_callback,
+};
+
+/* 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_die_notifier(&crash_nmi_nb))
+ 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