irqchip/gic-v4.1: Wait for completion of redistributor's INVALL operation

In GICv4.1, we emulate a guest-issued INVALL command by a direct write
to GICR_INVALLR.  Before we finish the emulation and go back to guest,
let's make sure the physical invalidate operation is actually completed
and no stale data will be left in redistributor. Per the specification,
this can be achieved by polling the GICR_SYNCR.Busy bit (to zero).

Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/20200302092145.899-1-yuzenghui@huawei.com
Link: https://lore.kernel.org/r/20200304203330.4967-5-maz@kernel.org

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 1af713990123c32561189a0d554396e558c557f3..c84370245bea3ac3a97d2b4a25428ef1bfcea162 100644 (file)
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -3827,6 +3827,8 @@ static void its_vpe_4_1_invall(struct its_vpe *vpe)
        /* Target the redistributor this vPE is currently known on */
        rdbase = per_cpu_ptr(gic_rdists->rdist, vpe->col_idx)->rd_base;
        gic_write_lpir(val, rdbase + GICR_INVALLR);
+
+       wait_for_syncr(rdbase);
 }
 
 static int its_vpe_4_1_set_vcpu_affinity(struct irq_data *d, void *vcpu_info)