From aaca49642b92c8a57d3ca5029a5a94019c7af69f Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Fri, 20 Aug 2010 18:57:53 -0700 Subject: xen: use percpu interrupts for IPIs and VIRQs From: Jeremy Fitzhardinge commit aaca49642b92c8a57d3ca5029a5a94019c7af69f upstream. IPIs and VIRQs are inherently per-cpu event types, so treat them as such: - use a specific percpu irq_chip implementation, and - handle them with handle_percpu_irq This makes the path for delivering these interrupts more efficient (no masking/unmasking, no locks), and it avoid problems with attempts to migrate them. Signed-off-by: Jeremy Fitzhardinge Signed-off-by: Greg Kroah-Hartman --- drivers/xen/events.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) --- a/drivers/xen/events.c +++ b/drivers/xen/events.c @@ -107,6 +107,7 @@ static inline unsigned long *cpu_evtchn_ #define VALID_EVTCHN(chn) ((chn) != 0) static struct irq_chip xen_dynamic_chip; +static struct irq_chip xen_percpu_chip; /* Constructor for packed IRQ information. */ static struct irq_info mk_unbound_info(void) @@ -389,8 +390,8 @@ static int bind_ipi_to_irq(unsigned int if (irq < 0) goto out; - set_irq_chip_and_handler_name(irq, &xen_dynamic_chip, - handle_level_irq, "ipi"); + set_irq_chip_and_handler_name(irq, &xen_percpu_chip, + handle_percpu_irq, "ipi"); bind_ipi.vcpu = cpu; if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi, @@ -430,8 +431,8 @@ static int bind_virq_to_irq(unsigned int irq = find_unbound_irq(); - set_irq_chip_and_handler_name(irq, &xen_dynamic_chip, - handle_level_irq, "virq"); + set_irq_chip_and_handler_name(irq, &xen_percpu_chip, + handle_percpu_irq, "virq"); evtchn_to_irq[evtchn] = irq; irq_info[irq] = mk_virq_info(evtchn, virq); @@ -934,6 +935,16 @@ static struct irq_chip xen_dynamic_chip .retrigger = retrigger_dynirq, }; +static struct irq_chip xen_percpu_chip __read_mostly = { + .name = "xen-percpu", + + .disable = disable_dynirq, + .mask = disable_dynirq, + .unmask = enable_dynirq, + + .ack = ack_dynirq, +}; + void __init xen_init_IRQ(void) { int i;