3 files changed, 25 insertions, 18 deletions

diff --git a/arch/x86/kernel/io_apic_32.c b/arch/x86/kernel/io_apic_32.c
index de9aa0e3a9c..09cddb57bec 100644
--- a/arch/x86/kernel/io_apic_32.c
+++ b/arch/x86/kernel/io_apic_32.c
@@ -57,7 +57,7 @@ atomic_t irq_mis_count;
 static struct { int pin, apic; } ioapic_i8259 = { -1, -1 };
 
 static DEFINE_SPINLOCK(ioapic_lock);
-static DEFINE_SPINLOCK(vector_lock);
+DEFINE_SPINLOCK(vector_lock);
 
 int timer_through_8259 __initdata;
 
@@ -1209,10 +1209,6 @@ static int assign_irq_vector(int irq)
 	return vector;
 }
 
-void setup_vector_irq(int cpu)
-{
-}
-
 static struct irq_chip ioapic_chip;
 
 #define IOAPIC_AUTO	-1
diff --git a/arch/x86/kernel/io_apic_64.c b/arch/x86/kernel/io_apic_64.c
index 8269434d170..61a83b70c18 100644
--- a/arch/x86/kernel/io_apic_64.c
+++ b/arch/x86/kernel/io_apic_64.c
@@ -101,7 +101,7 @@ int timer_through_8259 __initdata;
 static struct { int pin, apic; } ioapic_i8259 = { -1, -1 };
 
 static DEFINE_SPINLOCK(ioapic_lock);
-DEFINE_SPINLOCK(vector_lock);
+static DEFINE_SPINLOCK(vector_lock);
 
 /*
  * # of IRQ routing registers
@@ -697,6 +697,19 @@ static int pin_2_irq(int idx, int apic, int pin)
 	return irq;
 }
 
+void lock_vector_lock(void)
+{
+	/* Used to the online set of cpus does not change
+	 * during assign_irq_vector.
+	 */
+	spin_lock(&vector_lock);
+}
+
+void unlock_vector_lock(void)
+{
+	spin_unlock(&vector_lock);
+}
+
 static int __assign_irq_vector(int irq, cpumask_t mask)
 {
 	/*
@@ -802,7 +815,7 @@ static void __clear_irq_vector(int irq)
 	cpus_clear(cfg->domain);
 }
 
-static void __setup_vector_irq(int cpu)
+void __setup_vector_irq(int cpu)
 {
 	/* Initialize vector_irq on a new cpu */
 	/* This function must be called with vector_lock held */
@@ -825,14 +838,6 @@ static void __setup_vector_irq(int cpu)
 	}
 }
 
-void setup_vector_irq(int cpu)
-{
-	spin_lock(&vector_lock);
-	__setup_vector_irq(smp_processor_id());
-	spin_unlock(&vector_lock);
-}
-
-
 static struct irq_chip ioapic_chip;
 
 static void ioapic_register_intr(int irq, unsigned long trigger)
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 332512767f4..da10f07fc59 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -326,12 +326,16 @@ static void __cpuinit start_secondary(void *unused)
 	 * for which cpus receive the IPI. Holding this
 	 * lock helps us to not include this cpu in a currently in progress
 	 * smp_call_function().
+	 *
+	 * We need to hold vector_lock so there the set of online cpus
+	 * does not change while we are assigning vectors to cpus.  Holding
+	 * this lock ensures we don't half assign or remove an irq from a cpu.
 	 */
 	ipi_call_lock_irq();
-#ifdef CONFIG_X86_IO_APIC
-	setup_vector_irq(smp_processor_id());
-#endif
+	lock_vector_lock();
+	__setup_vector_irq(smp_processor_id());
 	cpu_set(smp_processor_id(), cpu_online_map);
+	unlock_vector_lock();
 	ipi_call_unlock_irq();
 	per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
 
@@ -1336,7 +1340,9 @@ int __cpu_disable(void)
 	remove_siblinginfo(cpu);
 
 	/* It's now safe to remove this processor from the online map */
+	lock_vector_lock();
 	remove_cpu_from_maps(cpu);
+	unlock_vector_lock();
 	fixup_irqs(cpu_online_map);
 	return 0;
 }