e46cdb66c8
Xen implements interrupts in terms of event channels. Each guest domain gets 1024 event channels which can be used for a variety of purposes, such as Xen timer events, inter-domain events, inter-processor events (IPI) or for real hardware IRQs. Within the kernel, we map the event channels to IRQs, and implement the whole interrupt handling using a Xen irq_chip. Rather than setting NR_IRQ to 1024 under PARAVIRT in order to accomodate Xen, we create a dynamic mapping between event channels and IRQs. Ideally, Linux will eventually move towards dynamically allocating per-irq structures, and we can use a 1:1 mapping between event channels and irqs. Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Chris Wright <chrisw@sous-sol.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Eric W. Biederman <ebiederm@xmission.com>
29 lines
913 B
C
29 lines
913 B
C
#ifndef _XEN_EVENTS_H
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#define _XEN_EVENTS_H
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#include <linux/irq.h>
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int bind_evtchn_to_irqhandler(unsigned int evtchn,
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irqreturn_t (*handler)(int, void *),
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unsigned long irqflags, const char *devname,
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void *dev_id);
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int bind_virq_to_irqhandler(unsigned int virq, unsigned int cpu,
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irqreturn_t (*handler)(int, void *),
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unsigned long irqflags, const char *devname, void *dev_id);
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/*
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* Common unbind function for all event sources. Takes IRQ to unbind from.
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* Automatically closes the underlying event channel (even for bindings
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* made with bind_evtchn_to_irqhandler()).
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*/
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void unbind_from_irqhandler(unsigned int irq, void *dev_id);
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static inline void notify_remote_via_evtchn(int port)
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{
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struct evtchn_send send = { .port = port };
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(void)HYPERVISOR_event_channel_op(EVTCHNOP_send, &send);
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}
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extern void notify_remote_via_irq(int irq);
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#endif /* _XEN_EVENTS_H */
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