events.c 35.2 KB
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/*
 * Xen event channels
 *
 * Xen models interrupts with abstract event channels.  Because each
 * domain gets 1024 event channels, but NR_IRQ is not that large, we
 * must dynamically map irqs<->event channels.  The event channels
 * interface with the rest of the kernel by defining a xen interrupt
 * chip.  When an event is recieved, it is mapped to an irq and sent
 * through the normal interrupt processing path.
 *
 * There are four kinds of events which can be mapped to an event
 * channel:
 *
 * 1. Inter-domain notifications.  This includes all the virtual
 *    device events, since they're driven by front-ends in another domain
 *    (typically dom0).
 * 2. VIRQs, typically used for timers.  These are per-cpu events.
 * 3. IPIs.
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 * 4. PIRQs - Hardware interrupts.
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 *
 * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
 */

#include <linux/linkage.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/module.h>
#include <linux/string.h>
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#include <linux/bootmem.h>
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#include <linux/slab.h>
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#include <linux/irqnr.h>
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#include <linux/pci.h>
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#include <asm/desc.h>
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#include <asm/ptrace.h>
#include <asm/irq.h>
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#include <asm/idle.h>
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#include <asm/io_apic.h>
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#include <asm/sync_bitops.h>
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#include <asm/xen/pci.h>
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#include <asm/xen/hypercall.h>
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#include <asm/xen/hypervisor.h>
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#include <xen/xen.h>
#include <xen/hvm.h>
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#include <xen/xen-ops.h>
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#include <xen/events.h>
#include <xen/interface/xen.h>
#include <xen/interface/event_channel.h>
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#include <xen/interface/hvm/hvm_op.h>
#include <xen/interface/hvm/params.h>
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/*
 * This lock protects updates to the following mapping and reference-count
 * arrays. The lock does not need to be acquired to read the mapping tables.
 */
static DEFINE_SPINLOCK(irq_mapping_update_lock);

/* IRQ <-> VIRQ mapping. */
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static DEFINE_PER_CPU(int [NR_VIRQS], virq_to_irq) = {[0 ... NR_VIRQS-1] = -1};
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/* IRQ <-> IPI mapping */
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static DEFINE_PER_CPU(int [XEN_NR_IPIS], ipi_to_irq) = {[0 ... XEN_NR_IPIS-1] = -1};
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/* Interrupt types. */
enum xen_irq_type {
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	IRQT_UNBOUND = 0,
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	IRQT_PIRQ,
	IRQT_VIRQ,
	IRQT_IPI,
	IRQT_EVTCHN
};
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/*
 * Packed IRQ information:
 * type - enum xen_irq_type
 * event channel - irq->event channel mapping
 * cpu - cpu this event channel is bound to
 * index - type-specific information:
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 *    PIRQ - vector, with MSB being "needs EIO", or physical IRQ of the HVM
 *           guest, or GSI (real passthrough IRQ) of the device.
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 *    VIRQ - virq number
 *    IPI - IPI vector
 *    EVTCHN -
 */
struct irq_info
{
	enum xen_irq_type type;	/* type */
	unsigned short evtchn;	/* event channel */
	unsigned short cpu;	/* cpu bound */

	union {
		unsigned short virq;
		enum ipi_vector ipi;
		struct {
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			unsigned short pirq;
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			unsigned short gsi;
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			unsigned char vector;
			unsigned char flags;
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		} pirq;
	} u;
};
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#define PIRQ_NEEDS_EOI	(1 << 0)
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#define PIRQ_SHAREABLE	(1 << 1)
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static struct irq_info *irq_info;
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static int *pirq_to_irq;
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static int nr_pirqs;
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static int *evtchn_to_irq;
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struct cpu_evtchn_s {
	unsigned long bits[NR_EVENT_CHANNELS/BITS_PER_LONG];
};
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static __initdata struct cpu_evtchn_s init_evtchn_mask = {
	.bits[0 ... (NR_EVENT_CHANNELS/BITS_PER_LONG)-1] = ~0ul,
};
static struct cpu_evtchn_s *cpu_evtchn_mask_p = &init_evtchn_mask;

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static inline unsigned long *cpu_evtchn_mask(int cpu)
{
	return cpu_evtchn_mask_p[cpu].bits;
}
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/* Xen will never allocate port zero for any purpose. */
#define VALID_EVTCHN(chn)	((chn) != 0)

static struct irq_chip xen_dynamic_chip;
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static struct irq_chip xen_percpu_chip;
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static struct irq_chip xen_pirq_chip;
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/* Constructor for packed IRQ information. */
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static struct irq_info mk_unbound_info(void)
{
	return (struct irq_info) { .type = IRQT_UNBOUND };
}

static struct irq_info mk_evtchn_info(unsigned short evtchn)
{
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	return (struct irq_info) { .type = IRQT_EVTCHN, .evtchn = evtchn,
			.cpu = 0 };
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}

static struct irq_info mk_ipi_info(unsigned short evtchn, enum ipi_vector ipi)
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{
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	return (struct irq_info) { .type = IRQT_IPI, .evtchn = evtchn,
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			.cpu = 0, .u.ipi = ipi };
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}

static struct irq_info mk_virq_info(unsigned short evtchn, unsigned short virq)
{
	return (struct irq_info) { .type = IRQT_VIRQ, .evtchn = evtchn,
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			.cpu = 0, .u.virq = virq };
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}

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static struct irq_info mk_pirq_info(unsigned short evtchn, unsigned short pirq,
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				    unsigned short gsi, unsigned short vector)
{
	return (struct irq_info) { .type = IRQT_PIRQ, .evtchn = evtchn,
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			.cpu = 0,
			.u.pirq = { .pirq = pirq, .gsi = gsi, .vector = vector } };
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}

/*
 * Accessors for packed IRQ information.
 */
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static struct irq_info *info_for_irq(unsigned irq)
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{
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	return &irq_info[irq];
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}

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static unsigned int evtchn_from_irq(unsigned irq)
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{
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	return info_for_irq(irq)->evtchn;
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}

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unsigned irq_from_evtchn(unsigned int evtchn)
{
	return evtchn_to_irq[evtchn];
}
EXPORT_SYMBOL_GPL(irq_from_evtchn);

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static enum ipi_vector ipi_from_irq(unsigned irq)
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{
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	struct irq_info *info = info_for_irq(irq);

	BUG_ON(info == NULL);
	BUG_ON(info->type != IRQT_IPI);

	return info->u.ipi;
}

static unsigned virq_from_irq(unsigned irq)
{
	struct irq_info *info = info_for_irq(irq);

	BUG_ON(info == NULL);
	BUG_ON(info->type != IRQT_VIRQ);

	return info->u.virq;
}

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static unsigned pirq_from_irq(unsigned irq)
{
	struct irq_info *info = info_for_irq(irq);

	BUG_ON(info == NULL);
	BUG_ON(info->type != IRQT_PIRQ);

	return info->u.pirq.pirq;
}

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static unsigned gsi_from_irq(unsigned irq)
{
	struct irq_info *info = info_for_irq(irq);

	BUG_ON(info == NULL);
	BUG_ON(info->type != IRQT_PIRQ);

	return info->u.pirq.gsi;
}

static unsigned vector_from_irq(unsigned irq)
{
	struct irq_info *info = info_for_irq(irq);

	BUG_ON(info == NULL);
	BUG_ON(info->type != IRQT_PIRQ);

	return info->u.pirq.vector;
}

static enum xen_irq_type type_from_irq(unsigned irq)
{
	return info_for_irq(irq)->type;
}

static unsigned cpu_from_irq(unsigned irq)
{
	return info_for_irq(irq)->cpu;
}

static unsigned int cpu_from_evtchn(unsigned int evtchn)
{
	int irq = evtchn_to_irq[evtchn];
	unsigned ret = 0;

	if (irq != -1)
		ret = cpu_from_irq(irq);

	return ret;
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}

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static bool pirq_needs_eoi(unsigned irq)
{
	struct irq_info *info = info_for_irq(irq);

	BUG_ON(info->type != IRQT_PIRQ);

	return info->u.pirq.flags & PIRQ_NEEDS_EOI;
}

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static inline unsigned long active_evtchns(unsigned int cpu,
					   struct shared_info *sh,
					   unsigned int idx)
{
	return (sh->evtchn_pending[idx] &
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		cpu_evtchn_mask(cpu)[idx] &
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		~sh->evtchn_mask[idx]);
}

static void bind_evtchn_to_cpu(unsigned int chn, unsigned int cpu)
{
	int irq = evtchn_to_irq[chn];

	BUG_ON(irq == -1);
#ifdef CONFIG_SMP
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	cpumask_copy(irq_to_desc(irq)->affinity, cpumask_of(cpu));
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#endif

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	__clear_bit(chn, cpu_evtchn_mask(cpu_from_irq(irq)));
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	__set_bit(chn, cpu_evtchn_mask(cpu));
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	irq_info[irq].cpu = cpu;
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}

static void init_evtchn_cpu_bindings(void)
{
#ifdef CONFIG_SMP
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	struct irq_desc *desc;
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	int i;
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	/* By default all event channels notify CPU#0. */
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	for_each_irq_desc(i, desc) {
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		cpumask_copy(desc->affinity, cpumask_of(0));
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	}
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#endif

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	memset(cpu_evtchn_mask(0), ~0, sizeof(struct cpu_evtchn_s));
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}

static inline void clear_evtchn(int port)
{
	struct shared_info *s = HYPERVISOR_shared_info;
	sync_clear_bit(port, &s->evtchn_pending[0]);
}

static inline void set_evtchn(int port)
{
	struct shared_info *s = HYPERVISOR_shared_info;
	sync_set_bit(port, &s->evtchn_pending[0]);
}

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static inline int test_evtchn(int port)
{
	struct shared_info *s = HYPERVISOR_shared_info;
	return sync_test_bit(port, &s->evtchn_pending[0]);
}

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/**
 * notify_remote_via_irq - send event to remote end of event channel via irq
 * @irq: irq of event channel to send event to
 *
 * Unlike notify_remote_via_evtchn(), this is safe to use across
 * save/restore. Notifications on a broken connection are silently
 * dropped.
 */
void notify_remote_via_irq(int irq)
{
	int evtchn = evtchn_from_irq(irq);

	if (VALID_EVTCHN(evtchn))
		notify_remote_via_evtchn(evtchn);
}
EXPORT_SYMBOL_GPL(notify_remote_via_irq);

static void mask_evtchn(int port)
{
	struct shared_info *s = HYPERVISOR_shared_info;
	sync_set_bit(port, &s->evtchn_mask[0]);
}

static void unmask_evtchn(int port)
{
	struct shared_info *s = HYPERVISOR_shared_info;
	unsigned int cpu = get_cpu();

	BUG_ON(!irqs_disabled());

	/* Slow path (hypercall) if this is a non-local port. */
	if (unlikely(cpu != cpu_from_evtchn(port))) {
		struct evtchn_unmask unmask = { .port = port };
		(void)HYPERVISOR_event_channel_op(EVTCHNOP_unmask, &unmask);
	} else {
		struct vcpu_info *vcpu_info = __get_cpu_var(xen_vcpu);

		sync_clear_bit(port, &s->evtchn_mask[0]);

		/*
		 * The following is basically the equivalent of
		 * 'hw_resend_irq'. Just like a real IO-APIC we 'lose
		 * the interrupt edge' if the channel is masked.
		 */
		if (sync_test_bit(port, &s->evtchn_pending[0]) &&
		    !sync_test_and_set_bit(port / BITS_PER_LONG,
					   &vcpu_info->evtchn_pending_sel))
			vcpu_info->evtchn_upcall_pending = 1;
	}

	put_cpu();
}

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static int get_nr_hw_irqs(void)
{
	int ret = 1;

#ifdef CONFIG_X86_IO_APIC
	ret = get_nr_irqs_gsi();
#endif

	return ret;
}

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/* callers of this function should make sure that PHYSDEVOP_get_nr_pirqs
 * succeeded otherwise nr_pirqs won't hold the right value */
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static int find_unbound_pirq(void)
{
	int i;
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	for (i = nr_pirqs-1; i >= 0; i--) {
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		if (pirq_to_irq[i] < 0)
			return i;
	}
	return -1;
}

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static int find_unbound_irq(void)
{
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	struct irq_data *data;
	int irq, res;
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	int start = get_nr_hw_irqs();
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	if (start == nr_irqs)
		goto no_irqs;

	/* nr_irqs is a magic value. Must not use it.*/
	for (irq = nr_irqs-1; irq > start; irq--) {
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		data = irq_get_irq_data(irq);
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		/* only 0->15 have init'd desc; handle irq > 16 */
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		if (!data)
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			break;
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		if (data->chip == &no_irq_chip)
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			break;
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		if (data->chip != &xen_dynamic_chip)
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			continue;
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		if (irq_info[irq].type == IRQT_UNBOUND)
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			return irq;
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	}
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	if (irq == start)
		goto no_irqs;
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	res = irq_alloc_desc_at(irq, 0);
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	if (WARN_ON(res != irq))
		return -1;
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	return irq;
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no_irqs:
	panic("No available IRQ to bind to: increase nr_irqs!\n");
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}

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static bool identity_mapped_irq(unsigned irq)
{
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	/* identity map all the hardware irqs */
	return irq < get_nr_hw_irqs();
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}

static void pirq_unmask_notify(int irq)
{
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	struct physdev_eoi eoi = { .irq = pirq_from_irq(irq) };
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	if (unlikely(pirq_needs_eoi(irq))) {
		int rc = HYPERVISOR_physdev_op(PHYSDEVOP_eoi, &eoi);
		WARN_ON(rc);
	}
}

static void pirq_query_unmask(int irq)
{
	struct physdev_irq_status_query irq_status;
	struct irq_info *info = info_for_irq(irq);

	BUG_ON(info->type != IRQT_PIRQ);

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	irq_status.irq = pirq_from_irq(irq);
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	if (HYPERVISOR_physdev_op(PHYSDEVOP_irq_status_query, &irq_status))
		irq_status.flags = 0;

	info->u.pirq.flags &= ~PIRQ_NEEDS_EOI;
	if (irq_status.flags & XENIRQSTAT_needs_eoi)
		info->u.pirq.flags |= PIRQ_NEEDS_EOI;
}

static bool probing_irq(int irq)
{
	struct irq_desc *desc = irq_to_desc(irq);

	return desc && desc->action == NULL;
}

static unsigned int startup_pirq(unsigned int irq)
{
	struct evtchn_bind_pirq bind_pirq;
	struct irq_info *info = info_for_irq(irq);
	int evtchn = evtchn_from_irq(irq);
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	int rc;
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	BUG_ON(info->type != IRQT_PIRQ);

	if (VALID_EVTCHN(evtchn))
		goto out;

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	bind_pirq.pirq = pirq_from_irq(irq);
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	/* NB. We are happy to share unless we are probing. */
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	bind_pirq.flags = info->u.pirq.flags & PIRQ_SHAREABLE ?
					BIND_PIRQ__WILL_SHARE : 0;
	rc = HYPERVISOR_event_channel_op(EVTCHNOP_bind_pirq, &bind_pirq);
	if (rc != 0) {
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		if (!probing_irq(irq))
			printk(KERN_INFO "Failed to obtain physical IRQ %d\n",
			       irq);
		return 0;
	}
	evtchn = bind_pirq.port;

	pirq_query_unmask(irq);

	evtchn_to_irq[evtchn] = irq;
	bind_evtchn_to_cpu(evtchn, 0);
	info->evtchn = evtchn;

out:
	unmask_evtchn(evtchn);
	pirq_unmask_notify(irq);

	return 0;
}

static void shutdown_pirq(unsigned int irq)
{
	struct evtchn_close close;
	struct irq_info *info = info_for_irq(irq);
	int evtchn = evtchn_from_irq(irq);

	BUG_ON(info->type != IRQT_PIRQ);

	if (!VALID_EVTCHN(evtchn))
		return;

	mask_evtchn(evtchn);

	close.port = evtchn;
	if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
		BUG();

	bind_evtchn_to_cpu(evtchn, 0);
	evtchn_to_irq[evtchn] = -1;
	info->evtchn = 0;
}

static void enable_pirq(unsigned int irq)
{
	startup_pirq(irq);
}

static void disable_pirq(unsigned int irq)
{
}

static void ack_pirq(unsigned int irq)
{
	int evtchn = evtchn_from_irq(irq);

	move_native_irq(irq);

	if (VALID_EVTCHN(evtchn)) {
		mask_evtchn(evtchn);
		clear_evtchn(evtchn);
	}
}

static void end_pirq(unsigned int irq)
{
	int evtchn = evtchn_from_irq(irq);
	struct irq_desc *desc = irq_to_desc(irq);

	if (WARN_ON(!desc))
		return;

	if ((desc->status & (IRQ_DISABLED|IRQ_PENDING)) ==
	    (IRQ_DISABLED|IRQ_PENDING)) {
		shutdown_pirq(irq);
	} else if (VALID_EVTCHN(evtchn)) {
		unmask_evtchn(evtchn);
		pirq_unmask_notify(irq);
	}
}

static int find_irq_by_gsi(unsigned gsi)
{
	int irq;

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	for (irq = 0; irq < nr_irqs; irq++) {
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		struct irq_info *info = info_for_irq(irq);

		if (info == NULL || info->type != IRQT_PIRQ)
			continue;

		if (gsi_from_irq(irq) == gsi)
			return irq;
	}

	return -1;
}

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int xen_allocate_pirq(unsigned gsi, int shareable, char *name)
{
	return xen_map_pirq_gsi(gsi, gsi, shareable, name);
}

/* xen_map_pirq_gsi might allocate irqs from the top down, as a
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 * consequence don't assume that the irq number returned has a low value
 * or can be used as a pirq number unless you know otherwise.
 *
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 * One notable exception is when xen_map_pirq_gsi is called passing an
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 * hardware gsi as argument, in that case the irq number returned
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 * matches the gsi number passed as second argument.
 *
 * Note: We don't assign an event channel until the irq actually started
 * up.  Return an existing irq if we've already got one for the gsi.
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 */
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int xen_map_pirq_gsi(unsigned pirq, unsigned gsi, int shareable, char *name)
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{
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	int irq = 0;
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	struct physdev_irq irq_op;

	spin_lock(&irq_mapping_update_lock);

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	if ((pirq > nr_pirqs) || (gsi > nr_irqs)) {
		printk(KERN_WARNING "xen_map_pirq_gsi: %s %s is incorrect!\n",
			pirq > nr_pirqs ? "nr_pirqs" :"",
			gsi > nr_irqs ? "nr_irqs" : "");
		goto out;
	}

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	irq = find_irq_by_gsi(gsi);
	if (irq != -1) {
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		printk(KERN_INFO "xen_map_pirq_gsi: returning irq %d for gsi %u\n",
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		       irq, gsi);
		goto out;	/* XXX need refcount? */
	}

625 626
	/* If we are a PV guest, we don't have GSIs (no ACPI passed). Therefore
	 * we are using the !xen_initial_domain() to drop in the function.*/
627 628
	if (identity_mapped_irq(gsi) || (!xen_initial_domain() &&
				xen_pv_domain())) {
629
		irq = gsi;
630
		irq_alloc_desc_at(irq, 0);
631 632 633 634
	} else
		irq = find_unbound_irq();

	set_irq_chip_and_handler_name(irq, &xen_pirq_chip,
635
				      handle_level_irq, name);
636 637

	irq_op.irq = irq;
638 639 640 641 642 643 644
	irq_op.vector = 0;

	/* Only the privileged domain can do this. For non-priv, the pcifront
	 * driver provides a PCI bus that does the call to do exactly
	 * this in the priv domain. */
	if (xen_initial_domain() &&
	    HYPERVISOR_physdev_op(PHYSDEVOP_alloc_irq_vector, &irq_op)) {
645
		irq_free_desc(irq);
646 647 648 649
		irq = -ENOSPC;
		goto out;
	}

S
Stefano Stabellini 已提交
650
	irq_info[irq] = mk_pirq_info(0, pirq, gsi, irq_op.vector);
651
	irq_info[irq].u.pirq.flags |= shareable ? PIRQ_SHAREABLE : 0;
S
Stefano Stabellini 已提交
652
	pirq_to_irq[pirq] = irq;
653 654 655 656 657 658 659

out:
	spin_unlock(&irq_mapping_update_lock);

	return irq;
}

660 661 662 663
#ifdef CONFIG_PCI_MSI
#include <linux/msi.h>
#include "../pci/msi.h"

S
Stefano Stabellini 已提交
664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685
void xen_allocate_pirq_msi(char *name, int *irq, int *pirq)
{
	spin_lock(&irq_mapping_update_lock);

	*irq = find_unbound_irq();
	if (*irq == -1)
		goto out;

	*pirq = find_unbound_pirq();
	if (*pirq == -1)
		goto out;

	set_irq_chip_and_handler_name(*irq, &xen_pirq_chip,
				      handle_level_irq, name);

	irq_info[*irq] = mk_pirq_info(0, *pirq, 0, 0);
	pirq_to_irq[*pirq] = *irq;

out:
	spin_unlock(&irq_mapping_update_lock);
}

686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740
int xen_create_msi_irq(struct pci_dev *dev, struct msi_desc *msidesc, int type)
{
	int irq = -1;
	struct physdev_map_pirq map_irq;
	int rc;
	int pos;
	u32 table_offset, bir;

	memset(&map_irq, 0, sizeof(map_irq));
	map_irq.domid = DOMID_SELF;
	map_irq.type = MAP_PIRQ_TYPE_MSI;
	map_irq.index = -1;
	map_irq.pirq = -1;
	map_irq.bus = dev->bus->number;
	map_irq.devfn = dev->devfn;

	if (type == PCI_CAP_ID_MSIX) {
		pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);

		pci_read_config_dword(dev, msix_table_offset_reg(pos),
					&table_offset);
		bir = (u8)(table_offset & PCI_MSIX_FLAGS_BIRMASK);

		map_irq.table_base = pci_resource_start(dev, bir);
		map_irq.entry_nr = msidesc->msi_attrib.entry_nr;
	}

	spin_lock(&irq_mapping_update_lock);

	irq = find_unbound_irq();

	if (irq == -1)
		goto out;

	rc = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq);
	if (rc) {
		printk(KERN_WARNING "xen map irq failed %d\n", rc);

		irq_free_desc(irq);

		irq = -1;
		goto out;
	}
	irq_info[irq] = mk_pirq_info(0, map_irq.pirq, 0, map_irq.index);

	set_irq_chip_and_handler_name(irq, &xen_pirq_chip,
			handle_level_irq,
			(type == PCI_CAP_ID_MSIX) ? "msi-x":"msi");

out:
	spin_unlock(&irq_mapping_update_lock);
	return irq;
}
#endif

741 742 743
int xen_destroy_irq(int irq)
{
	struct irq_desc *desc;
744 745
	struct physdev_unmap_pirq unmap_irq;
	struct irq_info *info = info_for_irq(irq);
746 747 748 749 750 751 752 753
	int rc = -ENOENT;

	spin_lock(&irq_mapping_update_lock);

	desc = irq_to_desc(irq);
	if (!desc)
		goto out;

754 755 756 757 758 759 760 761 762
	if (xen_initial_domain()) {
		unmap_irq.pirq = info->u.pirq.gsi;
		unmap_irq.domid = DOMID_SELF;
		rc = HYPERVISOR_physdev_op(PHYSDEVOP_unmap_pirq, &unmap_irq);
		if (rc) {
			printk(KERN_WARNING "unmap irq failed %d\n", rc);
			goto out;
		}
	}
763 764
	irq_info[irq] = mk_unbound_info();

765
	irq_free_desc(irq);
766 767 768 769 770 771

out:
	spin_unlock(&irq_mapping_update_lock);
	return rc;
}

772 773 774 775 776 777 778 779
int xen_vector_from_irq(unsigned irq)
{
	return vector_from_irq(irq);
}

int xen_gsi_from_irq(unsigned irq)
{
	return gsi_from_irq(irq);
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Jeremy Fitzhardinge 已提交
780 781
}

782
int bind_evtchn_to_irq(unsigned int evtchn)
J
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783 784 785 786 787 788 789 790 791 792 793
{
	int irq;

	spin_lock(&irq_mapping_update_lock);

	irq = evtchn_to_irq[evtchn];

	if (irq == -1) {
		irq = find_unbound_irq();

		set_irq_chip_and_handler_name(irq, &xen_dynamic_chip,
794
					      handle_fasteoi_irq, "event");
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Jeremy Fitzhardinge 已提交
795 796

		evtchn_to_irq[evtchn] = irq;
797
		irq_info[irq] = mk_evtchn_info(evtchn);
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Jeremy Fitzhardinge 已提交
798 799 800 801 802 803
	}

	spin_unlock(&irq_mapping_update_lock);

	return irq;
}
804
EXPORT_SYMBOL_GPL(bind_evtchn_to_irq);
J
Jeremy Fitzhardinge 已提交
805

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806 807 808 809 810 811 812 813
static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
{
	struct evtchn_bind_ipi bind_ipi;
	int evtchn, irq;

	spin_lock(&irq_mapping_update_lock);

	irq = per_cpu(ipi_to_irq, cpu)[ipi];
814

J
Jeremy Fitzhardinge 已提交
815 816 817 818 819
	if (irq == -1) {
		irq = find_unbound_irq();
		if (irq < 0)
			goto out;

820 821
		set_irq_chip_and_handler_name(irq, &xen_percpu_chip,
					      handle_percpu_irq, "ipi");
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Jeremy Fitzhardinge 已提交
822 823 824 825 826 827 828 829

		bind_ipi.vcpu = cpu;
		if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
						&bind_ipi) != 0)
			BUG();
		evtchn = bind_ipi.port;

		evtchn_to_irq[evtchn] = irq;
830
		irq_info[irq] = mk_ipi_info(evtchn, ipi);
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Jeremy Fitzhardinge 已提交
831 832 833 834 835 836 837 838 839 840 841
		per_cpu(ipi_to_irq, cpu)[ipi] = irq;

		bind_evtchn_to_cpu(evtchn, cpu);
	}

 out:
	spin_unlock(&irq_mapping_update_lock);
	return irq;
}


842
int bind_virq_to_irq(unsigned int virq, unsigned int cpu)
J
Jeremy Fitzhardinge 已提交
843 844 845 846 847 848 849 850 851
{
	struct evtchn_bind_virq bind_virq;
	int evtchn, irq;

	spin_lock(&irq_mapping_update_lock);

	irq = per_cpu(virq_to_irq, cpu)[virq];

	if (irq == -1) {
852 853 854 855 856
		irq = find_unbound_irq();

		set_irq_chip_and_handler_name(irq, &xen_percpu_chip,
					      handle_percpu_irq, "virq");

J
Jeremy Fitzhardinge 已提交
857 858 859 860 861 862 863 864
		bind_virq.virq = virq;
		bind_virq.vcpu = cpu;
		if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
						&bind_virq) != 0)
			BUG();
		evtchn = bind_virq.port;

		evtchn_to_irq[evtchn] = irq;
865
		irq_info[irq] = mk_virq_info(evtchn, virq);
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Jeremy Fitzhardinge 已提交
866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883

		per_cpu(virq_to_irq, cpu)[virq] = irq;

		bind_evtchn_to_cpu(evtchn, cpu);
	}

	spin_unlock(&irq_mapping_update_lock);

	return irq;
}

static void unbind_from_irq(unsigned int irq)
{
	struct evtchn_close close;
	int evtchn = evtchn_from_irq(irq);

	spin_lock(&irq_mapping_update_lock);

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Jeremy Fitzhardinge 已提交
884
	if (VALID_EVTCHN(evtchn)) {
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Jeremy Fitzhardinge 已提交
885 886 887 888 889 890 891
		close.port = evtchn;
		if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
			BUG();

		switch (type_from_irq(irq)) {
		case IRQT_VIRQ:
			per_cpu(virq_to_irq, cpu_from_evtchn(evtchn))
892
				[virq_from_irq(irq)] = -1;
J
Jeremy Fitzhardinge 已提交
893
			break;
A
Alex Nixon 已提交
894 895
		case IRQT_IPI:
			per_cpu(ipi_to_irq, cpu_from_evtchn(evtchn))
896
				[ipi_from_irq(irq)] = -1;
A
Alex Nixon 已提交
897
			break;
J
Jeremy Fitzhardinge 已提交
898 899 900 901 902 903 904 905
		default:
			break;
		}

		/* Closed ports are implicitly re-bound to VCPU0. */
		bind_evtchn_to_cpu(evtchn, 0);

		evtchn_to_irq[evtchn] = -1;
906 907 908
	}

	if (irq_info[irq].type != IRQT_UNBOUND) {
909
		irq_info[irq] = mk_unbound_info();
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Jeremy Fitzhardinge 已提交
910

911
		irq_free_desc(irq);
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912 913 914 915 916 917
	}

	spin_unlock(&irq_mapping_update_lock);
}

int bind_evtchn_to_irqhandler(unsigned int evtchn,
918
			      irq_handler_t handler,
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Jeremy Fitzhardinge 已提交
919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936
			      unsigned long irqflags,
			      const char *devname, void *dev_id)
{
	unsigned int irq;
	int retval;

	irq = bind_evtchn_to_irq(evtchn);
	retval = request_irq(irq, handler, irqflags, devname, dev_id);
	if (retval != 0) {
		unbind_from_irq(irq);
		return retval;
	}

	return irq;
}
EXPORT_SYMBOL_GPL(bind_evtchn_to_irqhandler);

int bind_virq_to_irqhandler(unsigned int virq, unsigned int cpu,
937
			    irq_handler_t handler,
J
Jeremy Fitzhardinge 已提交
938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953
			    unsigned long irqflags, const char *devname, void *dev_id)
{
	unsigned int irq;
	int retval;

	irq = bind_virq_to_irq(virq, cpu);
	retval = request_irq(irq, handler, irqflags, devname, dev_id);
	if (retval != 0) {
		unbind_from_irq(irq);
		return retval;
	}

	return irq;
}
EXPORT_SYMBOL_GPL(bind_virq_to_irqhandler);

J
Jeremy Fitzhardinge 已提交
954 955 956 957 958 959 960 961 962 963 964 965 966
int bind_ipi_to_irqhandler(enum ipi_vector ipi,
			   unsigned int cpu,
			   irq_handler_t handler,
			   unsigned long irqflags,
			   const char *devname,
			   void *dev_id)
{
	int irq, retval;

	irq = bind_ipi_to_irq(ipi, cpu);
	if (irq < 0)
		return irq;

I
Ian Campbell 已提交
967
	irqflags |= IRQF_NO_SUSPEND;
J
Jeremy Fitzhardinge 已提交
968 969 970 971 972 973 974 975 976
	retval = request_irq(irq, handler, irqflags, devname, dev_id);
	if (retval != 0) {
		unbind_from_irq(irq);
		return retval;
	}

	return irq;
}

J
Jeremy Fitzhardinge 已提交
977 978 979 980 981 982 983
void unbind_from_irqhandler(unsigned int irq, void *dev_id)
{
	free_irq(irq, dev_id);
	unbind_from_irq(irq);
}
EXPORT_SYMBOL_GPL(unbind_from_irqhandler);

J
Jeremy Fitzhardinge 已提交
984 985 986 987 988 989 990
void xen_send_IPI_one(unsigned int cpu, enum ipi_vector vector)
{
	int irq = per_cpu(ipi_to_irq, cpu)[vector];
	BUG_ON(irq < 0);
	notify_remote_via_irq(irq);
}

991 992 993 994
irqreturn_t xen_debug_interrupt(int irq, void *dev_id)
{
	struct shared_info *sh = HYPERVISOR_shared_info;
	int cpu = smp_processor_id();
995
	unsigned long *cpu_evtchn = cpu_evtchn_mask(cpu);
996 997 998
	int i;
	unsigned long flags;
	static DEFINE_SPINLOCK(debug_lock);
999
	struct vcpu_info *v;
1000 1001 1002

	spin_lock_irqsave(&debug_lock, flags);

1003
	printk("\nvcpu %d\n  ", cpu);
1004 1005

	for_each_online_cpu(i) {
1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048
		int pending;
		v = per_cpu(xen_vcpu, i);
		pending = (get_irq_regs() && i == cpu)
			? xen_irqs_disabled(get_irq_regs())
			: v->evtchn_upcall_mask;
		printk("%d: masked=%d pending=%d event_sel %0*lx\n  ", i,
		       pending, v->evtchn_upcall_pending,
		       (int)(sizeof(v->evtchn_pending_sel)*2),
		       v->evtchn_pending_sel);
	}
	v = per_cpu(xen_vcpu, cpu);

	printk("\npending:\n   ");
	for (i = ARRAY_SIZE(sh->evtchn_pending)-1; i >= 0; i--)
		printk("%0*lx%s", (int)sizeof(sh->evtchn_pending[0])*2,
		       sh->evtchn_pending[i],
		       i % 8 == 0 ? "\n   " : " ");
	printk("\nglobal mask:\n   ");
	for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--)
		printk("%0*lx%s",
		       (int)(sizeof(sh->evtchn_mask[0])*2),
		       sh->evtchn_mask[i],
		       i % 8 == 0 ? "\n   " : " ");

	printk("\nglobally unmasked:\n   ");
	for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--)
		printk("%0*lx%s", (int)(sizeof(sh->evtchn_mask[0])*2),
		       sh->evtchn_pending[i] & ~sh->evtchn_mask[i],
		       i % 8 == 0 ? "\n   " : " ");

	printk("\nlocal cpu%d mask:\n   ", cpu);
	for (i = (NR_EVENT_CHANNELS/BITS_PER_LONG)-1; i >= 0; i--)
		printk("%0*lx%s", (int)(sizeof(cpu_evtchn[0])*2),
		       cpu_evtchn[i],
		       i % 8 == 0 ? "\n   " : " ");

	printk("\nlocally unmasked:\n   ");
	for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--) {
		unsigned long pending = sh->evtchn_pending[i]
			& ~sh->evtchn_mask[i]
			& cpu_evtchn[i];
		printk("%0*lx%s", (int)(sizeof(sh->evtchn_mask[0])*2),
		       pending, i % 8 == 0 ? "\n   " : " ");
1049 1050 1051
	}

	printk("\npending list:\n");
1052
	for (i = 0; i < NR_EVENT_CHANNELS; i++) {
1053
		if (sync_test_bit(i, sh->evtchn_pending)) {
1054 1055
			int word_idx = i / BITS_PER_LONG;
			printk("  %d: event %d -> irq %d%s%s%s\n",
1056
			       cpu_from_evtchn(i), i,
1057 1058 1059 1060 1061 1062 1063
			       evtchn_to_irq[i],
			       sync_test_bit(word_idx, &v->evtchn_pending_sel)
					     ? "" : " l2-clear",
			       !sync_test_bit(i, sh->evtchn_mask)
					     ? "" : " globally-masked",
			       sync_test_bit(i, cpu_evtchn)
					     ? "" : " locally-masked");
1064 1065 1066 1067 1068 1069 1070 1071
		}
	}

	spin_unlock_irqrestore(&debug_lock, flags);

	return IRQ_HANDLED;
}

1072 1073
static DEFINE_PER_CPU(unsigned, xed_nesting_count);

J
Jeremy Fitzhardinge 已提交
1074 1075 1076 1077 1078 1079 1080 1081 1082
/*
 * Search the CPUs pending events bitmasks.  For each one found, map
 * the event number to an irq, and feed it into do_IRQ() for
 * handling.
 *
 * Xen uses a two-level bitmap to speed searching.  The first level is
 * a bitset of words which contain pending event bits.  The second
 * level is a bitset of pending events themselves.
 */
1083
static void __xen_evtchn_do_upcall(void)
J
Jeremy Fitzhardinge 已提交
1084 1085 1086 1087
{
	int cpu = get_cpu();
	struct shared_info *s = HYPERVISOR_shared_info;
	struct vcpu_info *vcpu_info = __get_cpu_var(xen_vcpu);
1088
 	unsigned count;
J
Jeremy Fitzhardinge 已提交
1089

1090 1091
	do {
		unsigned long pending_words;
J
Jeremy Fitzhardinge 已提交
1092

1093
		vcpu_info->evtchn_upcall_pending = 0;
J
Jeremy Fitzhardinge 已提交
1094

1095
		if (__get_cpu_var(xed_nesting_count)++)
1096
			goto out;
J
Jeremy Fitzhardinge 已提交
1097

1098 1099
#ifndef CONFIG_X86 /* No need for a barrier -- XCHG is a barrier on x86. */
		/* Clear master flag /before/ clearing selector flag. */
1100
		wmb();
1101
#endif
1102 1103 1104 1105 1106 1107 1108 1109 1110 1111
		pending_words = xchg(&vcpu_info->evtchn_pending_sel, 0);
		while (pending_words != 0) {
			unsigned long pending_bits;
			int word_idx = __ffs(pending_words);
			pending_words &= ~(1UL << word_idx);

			while ((pending_bits = active_evtchns(cpu, s, word_idx)) != 0) {
				int bit_idx = __ffs(pending_bits);
				int port = (word_idx * BITS_PER_LONG) + bit_idx;
				int irq = evtchn_to_irq[port];
1112
				struct irq_desc *desc;
1113

1114 1115 1116
				mask_evtchn(port);
				clear_evtchn(port);

1117 1118 1119 1120 1121
				if (irq != -1) {
					desc = irq_to_desc(irq);
					if (desc)
						generic_handle_irq_desc(irq, desc);
				}
J
Jeremy Fitzhardinge 已提交
1122 1123 1124
			}
		}

1125 1126
		BUG_ON(!irqs_disabled());

1127 1128
		count = __get_cpu_var(xed_nesting_count);
		__get_cpu_var(xed_nesting_count) = 0;
1129
	} while (count != 1 || vcpu_info->evtchn_upcall_pending);
1130 1131

out:
1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144

	put_cpu();
}

void xen_evtchn_do_upcall(struct pt_regs *regs)
{
	struct pt_regs *old_regs = set_irq_regs(regs);

	exit_idle();
	irq_enter();

	__xen_evtchn_do_upcall();

1145 1146
	irq_exit();
	set_irq_regs(old_regs);
1147
}
1148

1149 1150 1151
void xen_hvm_evtchn_do_upcall(void)
{
	__xen_evtchn_do_upcall();
J
Jeremy Fitzhardinge 已提交
1152
}
1153
EXPORT_SYMBOL_GPL(xen_hvm_evtchn_do_upcall);
J
Jeremy Fitzhardinge 已提交
1154

J
Jeremy Fitzhardinge 已提交
1155 1156 1157
/* Rebind a new event channel to an existing irq. */
void rebind_evtchn_irq(int evtchn, int irq)
{
J
Jeremy Fitzhardinge 已提交
1158 1159
	struct irq_info *info = info_for_irq(irq);

J
Jeremy Fitzhardinge 已提交
1160 1161 1162 1163 1164 1165 1166 1167 1168
	/* 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,
J
Jeremy Fitzhardinge 已提交
1169 1170
	   so there should be a proper type */
	BUG_ON(info->type == IRQT_UNBOUND);
J
Jeremy Fitzhardinge 已提交
1171 1172

	evtchn_to_irq[evtchn] = irq;
1173
	irq_info[irq] = mk_evtchn_info(evtchn);
J
Jeremy Fitzhardinge 已提交
1174 1175 1176 1177

	spin_unlock(&irq_mapping_update_lock);

	/* new event channels are always bound to cpu 0 */
1178
	irq_set_affinity(irq, cpumask_of(0));
J
Jeremy Fitzhardinge 已提交
1179 1180 1181 1182 1183

	/* Unmask the event channel. */
	enable_irq(irq);
}

J
Jeremy Fitzhardinge 已提交
1184
/* Rebind an evtchn so that it gets delivered to a specific cpu */
1185
static int rebind_irq_to_cpu(unsigned irq, unsigned tcpu)
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{
	struct evtchn_bind_vcpu bind_vcpu;
	int evtchn = evtchn_from_irq(irq);

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	/* events delivered via platform PCI interrupts are always
	 * routed to vcpu 0 */
	if (!VALID_EVTCHN(evtchn) ||
		(xen_hvm_domain() && !xen_have_vector_callback))
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		return -1;
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	/* Send future instances of this interrupt to other vcpu. */
	bind_vcpu.port = evtchn;
	bind_vcpu.vcpu = tcpu;

	/*
	 * If this fails, it usually just indicates that we're dealing with a
	 * virq or IPI channel, which don't actually need to be rebound. Ignore
	 * it, but don't do the xenlinux-level rebind in that case.
	 */
	if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_vcpu, &bind_vcpu) >= 0)
		bind_evtchn_to_cpu(evtchn, tcpu);

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	return 0;
}
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static int set_affinity_irq(unsigned irq, const struct cpumask *dest)
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{
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	unsigned tcpu = cpumask_first(dest);
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	return rebind_irq_to_cpu(irq, tcpu);
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}

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int resend_irq_on_evtchn(unsigned int irq)
{
	int masked, evtchn = evtchn_from_irq(irq);
	struct shared_info *s = HYPERVISOR_shared_info;

	if (!VALID_EVTCHN(evtchn))
		return 1;

	masked = sync_test_and_set_bit(evtchn, s->evtchn_mask);
	sync_set_bit(evtchn, s->evtchn_pending);
	if (!masked)
		unmask_evtchn(evtchn);

	return 1;
}

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static void enable_dynirq(unsigned int irq)
{
	int evtchn = evtchn_from_irq(irq);

	if (VALID_EVTCHN(evtchn))
		unmask_evtchn(evtchn);
}

static void disable_dynirq(unsigned int irq)
{
	int evtchn = evtchn_from_irq(irq);

	if (VALID_EVTCHN(evtchn))
		mask_evtchn(evtchn);
}

static void ack_dynirq(unsigned int irq)
{
	int evtchn = evtchn_from_irq(irq);

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	move_masked_irq(irq);
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	if (VALID_EVTCHN(evtchn))
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		unmask_evtchn(evtchn);
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}

static int retrigger_dynirq(unsigned int irq)
{
	int evtchn = evtchn_from_irq(irq);
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	struct shared_info *sh = HYPERVISOR_shared_info;
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	int ret = 0;

	if (VALID_EVTCHN(evtchn)) {
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		int masked;

		masked = sync_test_and_set_bit(evtchn, sh->evtchn_mask);
		sync_set_bit(evtchn, sh->evtchn_pending);
		if (!masked)
			unmask_evtchn(evtchn);
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		ret = 1;
	}

	return ret;
}

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static void restore_cpu_virqs(unsigned int cpu)
{
	struct evtchn_bind_virq bind_virq;
	int virq, irq, evtchn;

	for (virq = 0; virq < NR_VIRQS; virq++) {
		if ((irq = per_cpu(virq_to_irq, cpu)[virq]) == -1)
			continue;

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		BUG_ON(virq_from_irq(irq) != virq);
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		/* Get a new binding from Xen. */
		bind_virq.virq = virq;
		bind_virq.vcpu = cpu;
		if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
						&bind_virq) != 0)
			BUG();
		evtchn = bind_virq.port;

		/* Record the new mapping. */
		evtchn_to_irq[evtchn] = irq;
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		irq_info[irq] = mk_virq_info(evtchn, virq);
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		bind_evtchn_to_cpu(evtchn, cpu);
	}
}

static void restore_cpu_ipis(unsigned int cpu)
{
	struct evtchn_bind_ipi bind_ipi;
	int ipi, irq, evtchn;

	for (ipi = 0; ipi < XEN_NR_IPIS; ipi++) {
		if ((irq = per_cpu(ipi_to_irq, cpu)[ipi]) == -1)
			continue;

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		BUG_ON(ipi_from_irq(irq) != ipi);
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		/* Get a new binding from Xen. */
		bind_ipi.vcpu = cpu;
		if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
						&bind_ipi) != 0)
			BUG();
		evtchn = bind_ipi.port;

		/* Record the new mapping. */
		evtchn_to_irq[evtchn] = irq;
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		irq_info[irq] = mk_ipi_info(evtchn, ipi);
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		bind_evtchn_to_cpu(evtchn, cpu);
	}
}

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/* Clear an irq's pending state, in preparation for polling on it */
void xen_clear_irq_pending(int irq)
{
	int evtchn = evtchn_from_irq(irq);

	if (VALID_EVTCHN(evtchn))
		clear_evtchn(evtchn);
}
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EXPORT_SYMBOL(xen_clear_irq_pending);
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void xen_set_irq_pending(int irq)
{
	int evtchn = evtchn_from_irq(irq);

	if (VALID_EVTCHN(evtchn))
		set_evtchn(evtchn);
}

bool xen_test_irq_pending(int irq)
{
	int evtchn = evtchn_from_irq(irq);
	bool ret = false;

	if (VALID_EVTCHN(evtchn))
		ret = test_evtchn(evtchn);

	return ret;
}

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/* Poll waiting for an irq to become pending with timeout.  In the usual case,
 * the irq will be disabled so it won't deliver an interrupt. */
void xen_poll_irq_timeout(int irq, u64 timeout)
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{
	evtchn_port_t evtchn = evtchn_from_irq(irq);

	if (VALID_EVTCHN(evtchn)) {
		struct sched_poll poll;

		poll.nr_ports = 1;
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		poll.timeout = timeout;
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		set_xen_guest_handle(poll.ports, &evtchn);
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		if (HYPERVISOR_sched_op(SCHEDOP_poll, &poll) != 0)
			BUG();
	}
}
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EXPORT_SYMBOL(xen_poll_irq_timeout);
/* Poll waiting for an irq to become pending.  In the usual case, the
 * irq will be disabled so it won't deliver an interrupt. */
void xen_poll_irq(int irq)
{
	xen_poll_irq_timeout(irq, 0 /* no timeout */);
}
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void xen_irq_resume(void)
{
	unsigned int cpu, irq, evtchn;
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	struct irq_desc *desc;
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	init_evtchn_cpu_bindings();

	/* New event-channel space is not 'live' yet. */
	for (evtchn = 0; evtchn < NR_EVENT_CHANNELS; evtchn++)
		mask_evtchn(evtchn);

	/* No IRQ <-> event-channel mappings. */
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	for (irq = 0; irq < nr_irqs; irq++)
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		irq_info[irq].evtchn = 0; /* zap event-channel binding */

	for (evtchn = 0; evtchn < NR_EVENT_CHANNELS; evtchn++)
		evtchn_to_irq[evtchn] = -1;

	for_each_possible_cpu(cpu) {
		restore_cpu_virqs(cpu);
		restore_cpu_ipis(cpu);
	}
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	/*
	 * Unmask any IRQF_NO_SUSPEND IRQs which are enabled. These
	 * are not handled by the IRQ core.
	 */
	for_each_irq_desc(irq, desc) {
		if (!desc->action || !(desc->action->flags & IRQF_NO_SUSPEND))
			continue;
		if (desc->status & IRQ_DISABLED)
			continue;

		evtchn = evtchn_from_irq(irq);
		if (evtchn == -1)
			continue;

		unmask_evtchn(evtchn);
	}
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}

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static struct irq_chip xen_dynamic_chip __read_mostly = {
	.name		= "xen-dyn",
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	.disable	= disable_dynirq,
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	.mask		= disable_dynirq,
	.unmask		= enable_dynirq,
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	.eoi		= ack_dynirq,
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	.set_affinity	= set_affinity_irq,
	.retrigger	= retrigger_dynirq,
};

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static struct irq_chip xen_pirq_chip __read_mostly = {
	.name		= "xen-pirq",

	.startup	= startup_pirq,
	.shutdown	= shutdown_pirq,

	.enable		= enable_pirq,
	.unmask		= enable_pirq,

	.disable	= disable_pirq,
	.mask		= disable_pirq,

	.ack		= ack_pirq,
	.end		= end_pirq,

	.set_affinity	= set_affinity_irq,

	.retrigger	= retrigger_dynirq,
};

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static struct irq_chip xen_percpu_chip __read_mostly = {
	.name		= "xen-percpu",

	.disable	= disable_dynirq,
	.mask		= disable_dynirq,
	.unmask		= enable_dynirq,

	.ack		= ack_dynirq,
};

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int xen_set_callback_via(uint64_t via)
{
	struct xen_hvm_param a;
	a.domid = DOMID_SELF;
	a.index = HVM_PARAM_CALLBACK_IRQ;
	a.value = via;
	return HYPERVISOR_hvm_op(HVMOP_set_param, &a);
}
EXPORT_SYMBOL_GPL(xen_set_callback_via);

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#ifdef CONFIG_XEN_PVHVM
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/* Vector callbacks are better than PCI interrupts to receive event
 * channel notifications because we can receive vector callbacks on any
 * vcpu and we don't need PCI support or APIC interactions. */
void xen_callback_vector(void)
{
	int rc;
	uint64_t callback_via;
	if (xen_have_vector_callback) {
		callback_via = HVM_CALLBACK_VECTOR(XEN_HVM_EVTCHN_CALLBACK);
		rc = xen_set_callback_via(callback_via);
		if (rc) {
			printk(KERN_ERR "Request for Xen HVM callback vector"
					" failed.\n");
			xen_have_vector_callback = 0;
			return;
		}
		printk(KERN_INFO "Xen HVM callback vector for event delivery is "
				"enabled\n");
		/* in the restore case the vector has already been allocated */
		if (!test_bit(XEN_HVM_EVTCHN_CALLBACK, used_vectors))
			alloc_intr_gate(XEN_HVM_EVTCHN_CALLBACK, xen_hvm_callback_vector);
	}
}
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#else
void xen_callback_vector(void) {}
#endif
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void __init xen_init_IRQ(void)
{
1506 1507
	int i, rc;
	struct physdev_nr_pirqs op_nr_pirqs;
1508

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	cpu_evtchn_mask_p = kcalloc(nr_cpu_ids, sizeof(struct cpu_evtchn_s),
				    GFP_KERNEL);
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	irq_info = kcalloc(nr_irqs, sizeof(*irq_info), GFP_KERNEL);

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	rc = HYPERVISOR_physdev_op(PHYSDEVOP_get_nr_pirqs, &op_nr_pirqs);
	if (rc < 0) {
		nr_pirqs = nr_irqs;
		if (rc != -ENOSYS)
			printk(KERN_WARNING "PHYSDEVOP_get_nr_pirqs returned rc=%d\n", rc);
	} else {
		if (xen_pv_domain() && !xen_initial_domain())
			nr_pirqs = max((int)op_nr_pirqs.nr_pirqs, nr_irqs);
		else
			nr_pirqs = op_nr_pirqs.nr_pirqs;
	}
	pirq_to_irq = kcalloc(nr_pirqs, sizeof(*pirq_to_irq), GFP_KERNEL);
	for (i = 0; i < nr_pirqs; i++)
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		pirq_to_irq[i] = -1;

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	evtchn_to_irq = kcalloc(NR_EVENT_CHANNELS, sizeof(*evtchn_to_irq),
				    GFP_KERNEL);
	for (i = 0; i < NR_EVENT_CHANNELS; i++)
		evtchn_to_irq[i] = -1;
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	init_evtchn_cpu_bindings();

	/* No event channels are 'live' right now. */
	for (i = 0; i < NR_EVENT_CHANNELS; i++)
		mask_evtchn(i);

1539 1540 1541
	if (xen_hvm_domain()) {
		xen_callback_vector();
		native_init_IRQ();
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		/* pci_xen_hvm_init must be called after native_init_IRQ so that
		 * __acpi_register_gsi can point at the right function */
		pci_xen_hvm_init();
1545 1546
	} else {
		irq_ctx_init(smp_processor_id());
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		if (xen_initial_domain())
			xen_setup_pirqs();
1549
	}
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}