From: Marc Zyngier <maz@xxxxxxxxxx>
Since there may be a direct read from the CPU side to the VPT after
unmapping the vPE, we add a cache coherency maintenance at the end
of its_vpe_irq_domain_deactivate() to ensure the validity of the VPT
read later.
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
Signed-off-by: Shenming Lu <lushenming@xxxxxxxxxx>
---
drivers/irqchip/irq-gic-v3-its.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index ed46e6057e33..4eb907f65bd0 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -4554,6 +4554,15 @@ static void its_vpe_irq_domain_deactivate(struct irq_domain *domain,
its_send_vmapp(its, vpe, false);
}
+
+ /*
+ * There may be a direct read to the VPT after unmapping the
+ * vPE, to guarantee the validity of this, we make the VPT
+ * memory coherent with the CPU caches here.
+ */
+ if (find_4_1_its() && !atomic_read(&vpe->vmapp_count))
+ gic_flush_dcache_to_poc(page_address(vpe->vpt_page),
+ LPI_PENDBASE_SZ);
}
static const struct irq_domain_ops its_vpe_domain_ops = {
--
2.19.1
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