The infamous VPE proxy device isn't used with GICv4.1 because: - we can invalidate any LPI from the DirectLPI MMIO interface - the ITS and redistributors understand the life cycle of the doorbell, so we don't need to enable/disable it all the time
So let's escape early from the proxy related functions. Reviewed-by: Zenghui Yu <[email protected]> Signed-off-by: Marc Zyngier <[email protected]> --- drivers/irqchip/irq-gic-v3-its.c | 25 ++++++++++++++++++++++++- 1 file changed, 24 insertions(+), 1 deletion(-) diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c index e3c7d9ae0bdb..86c69b5cc156 100644 --- a/drivers/irqchip/irq-gic-v3-its.c +++ b/drivers/irqchip/irq-gic-v3-its.c @@ -3213,7 +3213,7 @@ static const struct irq_domain_ops its_domain_ops = { /* * This is insane. * - * If a GICv4 doesn't implement Direct LPIs (which is extremely + * If a GICv4.0 doesn't implement Direct LPIs (which is extremely * likely), the only way to perform an invalidate is to use a fake * device to issue an INV command, implying that the LPI has first * been mapped to some event on that device. Since this is not exactly @@ -3221,9 +3221,20 @@ static const struct irq_domain_ops its_domain_ops = { * only issue an UNMAP if we're short on available slots. * * Broken by design(tm). + * + * GICv4.1, on the other hand, mandates that we're able to invalidate + * by writing to a MMIO register. It doesn't implement the whole of + * DirectLPI, but that's good enough. And most of the time, we don't + * even have to invalidate anything, as the redistributor can be told + * whether to generate a doorbell or not (we thus leave it enabled, + * always). */ static void its_vpe_db_proxy_unmap_locked(struct its_vpe *vpe) { + /* GICv4.1 doesn't use a proxy, so nothing to do here */ + if (gic_rdists->has_rvpeid) + return; + /* Already unmapped? */ if (vpe->vpe_proxy_event == -1) return; @@ -3246,6 +3257,10 @@ static void its_vpe_db_proxy_unmap_locked(struct its_vpe *vpe) static void its_vpe_db_proxy_unmap(struct its_vpe *vpe) { + /* GICv4.1 doesn't use a proxy, so nothing to do here */ + if (gic_rdists->has_rvpeid) + return; + if (!gic_rdists->has_direct_lpi) { unsigned long flags; @@ -3257,6 +3272,10 @@ static void its_vpe_db_proxy_unmap(struct its_vpe *vpe) static void its_vpe_db_proxy_map_locked(struct its_vpe *vpe) { + /* GICv4.1 doesn't use a proxy, so nothing to do here */ + if (gic_rdists->has_rvpeid) + return; + /* Already mapped? */ if (vpe->vpe_proxy_event != -1) return; @@ -3279,6 +3298,10 @@ static void its_vpe_db_proxy_move(struct its_vpe *vpe, int from, int to) unsigned long flags; struct its_collection *target_col; + /* GICv4.1 doesn't use a proxy, so nothing to do here */ + if (gic_rdists->has_rvpeid) + return; + if (gic_rdists->has_direct_lpi) { void __iomem *rdbase; -- 2.20.1 _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
