Upgrade to 4.4.50-rt62

[kvmfornfv.git] / kernel / drivers / irqchip / irq-gic.c

diff --git a/kernel/drivers/irqchip/irq-gic.c b/kernel/drivers/irqchip/irq-gic.c
index abf2ffa..cebd8ef 100644 (file)
--- a/kernel/drivers/irqchip/irq-gic.c
+++ b/kernel/drivers/irqchip/irq-gic.c
@@ -347,6 +347,14 @@ static void __exception_irq_entry gic_handle_irq(struct pt_regs *regs)
                        if (static_key_true(&supports_deactivate))
                                writel_relaxed(irqstat, cpu_base + GIC_CPU_DEACTIVATE);
 #ifdef CONFIG_SMP
+                       /*
+                        * Ensure any shared data written by the CPU sending
+                        * the IPI is read after we've read the ACK register
+                        * on the GIC.
+                        *
+                        * Pairs with the write barrier in gic_raise_softirq
+                        */
+                       smp_rmb();
                        handle_IPI(irqnr, regs);
 #endif
                        continue;