aboutsummaryrefslogtreecommitdiff
path: root/arch/x86/kernel/smp.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/kernel/smp.c')
-rw-r--r--arch/x86/kernel/smp.c72
1 files changed, 70 insertions, 2 deletions
diff --git a/arch/x86/kernel/smp.c b/arch/x86/kernel/smp.c
index 16204dc1548..66c74f481ca 100644
--- a/arch/x86/kernel/smp.c
+++ b/arch/x86/kernel/smp.c
@@ -29,6 +29,7 @@
#include <asm/mmu_context.h>
#include <asm/proto.h>
#include <asm/apic.h>
+#include <asm/nmi.h>
/*
* Some notes on x86 processor bugs affecting SMP operation:
*
@@ -148,6 +149,60 @@ void native_send_call_func_ipi(const struct cpumask *mask)
free_cpumask_var(allbutself);
}
+static atomic_t stopping_cpu = ATOMIC_INIT(-1);
+
+static int smp_stop_nmi_callback(unsigned int val, struct pt_regs *regs)
+{
+ /* We are registered on stopping cpu too, avoid spurious NMI */
+ if (raw_smp_processor_id() == atomic_read(&stopping_cpu))
+ return NMI_HANDLED;
+
+ stop_this_cpu(NULL);
+
+ return NMI_HANDLED;
+}
+
+static void native_nmi_stop_other_cpus(int wait)
+{
+ unsigned long flags;
+ unsigned long timeout;
+
+ if (reboot_force)
+ return;
+
+ /*
+ * Use an own vector here because smp_call_function
+ * does lots of things not suitable in a panic situation.
+ */
+ if (num_online_cpus() > 1) {
+ /* did someone beat us here? */
+ if (atomic_cmpxchg(&stopping_cpu, -1, safe_smp_processor_id()) != -1)
+ return;
+
+ if (register_nmi_handler(NMI_LOCAL, smp_stop_nmi_callback,
+ NMI_FLAG_FIRST, "smp_stop"))
+ /* Note: we ignore failures here */
+ return;
+
+ /* sync above data before sending NMI */
+ wmb();
+
+ apic->send_IPI_allbutself(NMI_VECTOR);
+
+ /*
+ * Don't wait longer than a second if the caller
+ * didn't ask us to wait.
+ */
+ timeout = USEC_PER_SEC;
+ while (num_online_cpus() > 1 && (wait || timeout--))
+ udelay(1);
+ }
+
+ local_irq_save(flags);
+ disable_local_APIC();
+ local_irq_restore(flags);
+}
+
/*
* this function calls the 'stop' function on all other CPUs in the system.
*/
@@ -160,7 +215,7 @@ asmlinkage void smp_reboot_interrupt(void)
irq_exit();
}
-static void native_stop_other_cpus(int wait)
+static void native_irq_stop_other_cpus(int wait)
{
unsigned long flags;
unsigned long timeout;
@@ -194,6 +249,11 @@ static void native_stop_other_cpus(int wait)
local_irq_restore(flags);
}
+static void native_smp_disable_nmi_ipi(void)
+{
+ smp_ops.stop_other_cpus = native_irq_stop_other_cpus;
+}
+
/*
* Reschedule call back.
*/
@@ -225,12 +285,20 @@ void smp_call_function_single_interrupt(struct pt_regs *regs)
irq_exit();
}
+static int __init nonmi_ipi_setup(char *str)
+{
+ native_smp_disable_nmi_ipi();
+ return 1;
+}
+
+__setup("nonmi_ipi", nonmi_ipi_setup);
+
struct smp_ops smp_ops = {
.smp_prepare_boot_cpu = native_smp_prepare_boot_cpu,
.smp_prepare_cpus = native_smp_prepare_cpus,
.smp_cpus_done = native_smp_cpus_done,
- .stop_other_cpus = native_stop_other_cpus,
+ .stop_other_cpus = native_nmi_stop_other_cpus,
.smp_send_reschedule = native_smp_send_reschedule,
.cpu_up = native_cpu_up,