From eb1e305f4ef201e549ffd475b7dcbcd4ec36d7dc Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Mon, 26 May 2008 23:31:23 +0100 Subject: xen: add rebind_evtchn_irq Add rebind_evtchn_irq(), which will rebind an device driver's existing irq to a new event channel on restore. Since the new event channel will be masked and bound to vcpu0, we update the state accordingly and unmask the irq once everything is set up. Signed-off-by: Jeremy Fitzhardinge Signed-off-by: Thomas Gleixner --- drivers/xen/events.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) (limited to 'drivers/xen') diff --git a/drivers/xen/events.c b/drivers/xen/events.c index 4f0f22b020e..f64e9798129 100644 --- a/drivers/xen/events.c +++ b/drivers/xen/events.c @@ -557,6 +557,33 @@ out: put_cpu(); } +/* Rebind a new event channel to an existing irq. */ +void rebind_evtchn_irq(int evtchn, int irq) +{ + /* Make sure the irq is masked, since the new event channel + will also be masked. */ + disable_irq(irq); + + spin_lock(&irq_mapping_update_lock); + + /* After resume the irq<->evtchn mappings are all cleared out */ + BUG_ON(evtchn_to_irq[evtchn] != -1); + /* Expect irq to have been bound before, + so the bindcount should be non-0 */ + BUG_ON(irq_bindcount[irq] == 0); + + evtchn_to_irq[evtchn] = irq; + irq_info[irq] = mk_irq_info(IRQT_EVTCHN, 0, evtchn); + + spin_unlock(&irq_mapping_update_lock); + + /* new event channels are always bound to cpu 0 */ + irq_set_affinity(irq, cpumask_of_cpu(0)); + + /* Unmask the event channel. */ + enable_irq(irq); +} + /* Rebind an evtchn so that it gets delivered to a specific cpu */ static void rebind_irq_to_cpu(unsigned irq, unsigned tcpu) { -- cgit v1.2.3