From ce26c371a8ff7b49c98a3b8c7b57199154cbca59 Mon Sep 17 00:00:00 2001 From: Stefano Stabellini Date: Mon, 27 Apr 2020 16:15:26 -0700 Subject: [PATCH] xen: use handle_fasteoi_irq to handle xen events When handling Xen events, we need to make sure the following sequence is followed: - mask event - handle event and clear event (the order does not matter) - unmask event It is not possible to implement this flow with handle_edge_irq, so switch back to handle_fasteoi_irq. Please note that Xen event irqs are ONESHOT. Also note that handle_fasteoi_irq was in-use before the following commit, that is partially reverted by this patch: 7e186bdd0098 xen: do not clear and mask evtchns in __xen_evtchn_do_upcall PIRQ handling is left unchanged. This patch fixes a domU hang observed when using LinuxRT as dom0 kernel. Link: https://lore.kernel.org/lkml/5e256d9a-572c-e01e-7706-407f99245b00@xxxxxxx/ Signed-off-by: Stefano Stabellini --- drivers/xen/events/events_base.c | 13 +++---------- 1 file changed, 3 insertions(+), 10 deletions(-) diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c index 499eff7d3f65..5f9b8104dbcf 100644 --- a/drivers/xen/events/events_base.c +++ b/drivers/xen/events/events_base.c @@ -845,7 +845,7 @@ int bind_evtchn_to_irq(unsigned int evtchn) goto out; irq_set_chip_and_handler_name(irq, &xen_dynamic_chip, - handle_edge_irq, "event"); + handle_fasteoi_irq, "event"); ret = xen_irq_info_evtchn_setup(irq, evtchn); if (ret < 0) { @@ -978,7 +978,7 @@ int bind_virq_to_irq(unsigned int virq, unsigned int cpu, bool percpu) handle_percpu_irq, "virq"); else irq_set_chip_and_handler_name(irq, &xen_dynamic_chip, - handle_edge_irq, "virq"); + handle_fasteoi_irq, "virq"); bind_virq.virq = virq; bind_virq.vcpu = xen_vcpu_nr(cpu); @@ -1377,12 +1377,6 @@ static void ack_dynirq(struct irq_data *data) clear_evtchn(evtchn); } -static void mask_ack_dynirq(struct irq_data *data) -{ - disable_dynirq(data); - ack_dynirq(data); -} - static int retrigger_dynirq(struct irq_data *data) { unsigned int evtchn = evtchn_from_irq(data->irq); @@ -1585,8 +1579,7 @@ static struct irq_chip xen_dynamic_chip __read_mostly = { .irq_mask = disable_dynirq, .irq_unmask = enable_dynirq, - .irq_ack = ack_dynirq, - .irq_mask_ack = mask_ack_dynirq, + .irq_eoi = ack_dynirq, .irq_set_affinity = set_affinity_irq, .irq_retrigger = retrigger_dynirq, -- 2.17.1