Merge tag 'wireless-drivers-next-for-davem-2016-09-15' of git://git.kernel.org/pub...

[cascardo/linux.git] / virt / kvm / arm / vgic / vgic-mmio-v3.c

diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c
index ff668e0..90d8181 100644 (file)
--- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
+++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c
@@ -306,16 +306,19 @@ static void vgic_mmio_write_propbase(struct kvm_vcpu *vcpu,
 {
        struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
        struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
-       u64 propbaser = dist->propbaser;
+       u64 old_propbaser, propbaser;
 
        /* Storing a value with LPIs already enabled is undefined */
        if (vgic_cpu->lpis_enabled)
                return;
 
-       propbaser = update_64bit_reg(propbaser, addr & 4, len, val);
-       propbaser = vgic_sanitise_propbaser(propbaser);
-
-       dist->propbaser = propbaser;
+       do {
+               old_propbaser = dist->propbaser;
+               propbaser = old_propbaser;
+               propbaser = update_64bit_reg(propbaser, addr & 4, len, val);
+               propbaser = vgic_sanitise_propbaser(propbaser);
+       } while (cmpxchg64(&dist->propbaser, old_propbaser,
+                          propbaser) != old_propbaser);
 }
 
 static unsigned long vgic_mmio_read_pendbase(struct kvm_vcpu *vcpu,
@@ -331,16 +334,19 @@ static void vgic_mmio_write_pendbase(struct kvm_vcpu *vcpu,
                                     unsigned long val)
 {
        struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
-       u64 pendbaser = vgic_cpu->pendbaser;
+       u64 old_pendbaser, pendbaser;
 
        /* Storing a value with LPIs already enabled is undefined */
        if (vgic_cpu->lpis_enabled)
                return;
 
-       pendbaser = update_64bit_reg(pendbaser, addr & 4, len, val);
-       pendbaser = vgic_sanitise_pendbaser(pendbaser);
-
-       vgic_cpu->pendbaser = pendbaser;
+       do {
+               old_pendbaser = vgic_cpu->pendbaser;
+               pendbaser = old_pendbaser;
+               pendbaser = update_64bit_reg(pendbaser, addr & 4, len, val);
+               pendbaser = vgic_sanitise_pendbaser(pendbaser);
+       } while (cmpxchg64(&vgic_cpu->pendbaser, old_pendbaser,
+                          pendbaser) != old_pendbaser);
 }
 
 /*