[PATCH 4.4 334/342] x86/irq: Remove outgoing CPU from vector cleanup mask

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

commit 56d7d2f4bbd00fb198b7907cb3ab657d06115a42 upstream.

We want to synchronize new vector assignments with a pending cleanup. Remove a
dying cpu from a pending cleanup mask.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Tested-by: Borislav Petkov <bp@xxxxxxxxx>
Tested-by: Joe Lawrence <joe.lawrence@xxxxxxxxxxx>
Cc: Jiang Liu <jiang.liu@xxxxxxxxxxxxxxx>
Cc: Jeremiah Mahler <jmmahler@xxxxxxxxx>
Cc: andy.shevchenko@xxxxxxxxx
Cc: Guenter Roeck <linux@xxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/20151231160107.045961667@xxxxxxxxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 arch/x86/kernel/apic/vector.c |   18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

--- a/arch/x86/kernel/apic/vector.c
+++ b/arch/x86/kernel/apic/vector.c
@@ -631,9 +631,23 @@ void irq_complete_move(struct irq_cfg *c
 void irq_force_complete_move(int irq)
 {
 	struct irq_cfg *cfg = irq_cfg(irq);
+	struct apic_chip_data *data;
 
-	if (cfg)
-		__irq_complete_move(cfg, cfg->vector);
+	if (!cfg)
+		return;
+
+	__irq_complete_move(cfg, cfg->vector);
+
+	/*
+	 * Remove this cpu from the cleanup mask. The IPI might have been sent
+	 * just before the cpu was removed from the offline mask, but has not
+	 * been processed because the CPU has interrupts disabled and is on
+	 * the way out.
+	 */
+	raw_spin_lock(&vector_lock);
+	data = container_of(cfg, struct apic_chip_data, cfg);
+	cpumask_clear_cpu(smp_processor_id(), data->old_domain);
+	raw_spin_unlock(&vector_lock);
 }
 #endif