4 * Xen models interrupts with abstract event channels. Because each
5 * domain gets 1024 event channels, but NR_IRQ is not that large, we
6 * must dynamically map irqs<->event channels. The event channels
7 * interface with the rest of the kernel by defining a xen interrupt
8 * chip. When an event is received, it is mapped to an irq and sent
9 * through the normal interrupt processing path.
11 * There are four kinds of events which can be mapped to an event
14 * 1. Inter-domain notifications. This includes all the virtual
15 * device events, since they're driven by front-ends in another domain
17 * 2. VIRQs, typically used for timers. These are per-cpu events.
19 * 4. PIRQs - Hardware interrupts.
21 * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
24 #include <linux/linkage.h>
25 #include <linux/interrupt.h>
26 #include <linux/irq.h>
27 #include <linux/module.h>
28 #include <linux/string.h>
29 #include <linux/bootmem.h>
30 #include <linux/slab.h>
31 #include <linux/irqnr.h>
32 #include <linux/pci.h>
35 #include <asm/ptrace.h>
38 #include <asm/io_apic.h>
39 #include <asm/sync_bitops.h>
40 #include <asm/xen/pci.h>
41 #include <asm/xen/hypercall.h>
42 #include <asm/xen/hypervisor.h>
46 #include <xen/xen-ops.h>
47 #include <xen/events.h>
48 #include <xen/interface/xen.h>
49 #include <xen/interface/event_channel.h>
50 #include <xen/interface/hvm/hvm_op.h>
51 #include <xen/interface/hvm/params.h>
54 * This lock protects updates to the following mapping and reference-count
55 * arrays. The lock does not need to be acquired to read the mapping tables.
57 static DEFINE_MUTEX(irq_mapping_update_lock);
59 static LIST_HEAD(xen_irq_list_head);
61 /* IRQ <-> VIRQ mapping. */
62 static DEFINE_PER_CPU(int [NR_VIRQS], virq_to_irq) = {[0 ... NR_VIRQS-1] = -1};
64 /* IRQ <-> IPI mapping */
65 static DEFINE_PER_CPU(int [XEN_NR_IPIS], ipi_to_irq) = {[0 ... XEN_NR_IPIS-1] = -1};
67 /* Interrupt types. */
77 * Packed IRQ information:
78 * type - enum xen_irq_type
79 * event channel - irq->event channel mapping
80 * cpu - cpu this event channel is bound to
81 * index - type-specific information:
82 * PIRQ - vector, with MSB being "needs EIO", or physical IRQ of the HVM
83 * guest, or GSI (real passthrough IRQ) of the device.
89 struct list_head list;
90 enum xen_irq_type type; /* type */
92 unsigned short evtchn; /* event channel */
93 unsigned short cpu; /* cpu bound */
101 unsigned char vector;
107 #define PIRQ_NEEDS_EOI (1 << 0)
108 #define PIRQ_SHAREABLE (1 << 1)
110 static int *evtchn_to_irq;
112 static DEFINE_PER_CPU(unsigned long [NR_EVENT_CHANNELS/BITS_PER_LONG],
115 /* Xen will never allocate port zero for any purpose. */
116 #define VALID_EVTCHN(chn) ((chn) != 0)
118 static struct irq_chip xen_dynamic_chip;
119 static struct irq_chip xen_percpu_chip;
120 static struct irq_chip xen_pirq_chip;
121 static void enable_dynirq(struct irq_data *data);
122 static void disable_dynirq(struct irq_data *data);
124 /* Get info for IRQ */
125 static struct irq_info *info_for_irq(unsigned irq)
127 return irq_get_handler_data(irq);
130 /* Constructors for packed IRQ information. */
131 static void xen_irq_info_common_init(struct irq_info *info,
133 enum xen_irq_type type,
134 unsigned short evtchn,
138 BUG_ON(info->type != IRQT_UNBOUND && info->type != type);
142 info->evtchn = evtchn;
145 evtchn_to_irq[evtchn] = irq;
148 static void xen_irq_info_evtchn_init(unsigned irq,
149 unsigned short evtchn)
151 struct irq_info *info = info_for_irq(irq);
153 xen_irq_info_common_init(info, irq, IRQT_EVTCHN, evtchn, 0);
156 static void xen_irq_info_ipi_init(unsigned cpu,
158 unsigned short evtchn,
161 struct irq_info *info = info_for_irq(irq);
163 xen_irq_info_common_init(info, irq, IRQT_IPI, evtchn, 0);
167 per_cpu(ipi_to_irq, cpu)[ipi] = irq;
170 static void xen_irq_info_virq_init(unsigned cpu,
172 unsigned short evtchn,
175 struct irq_info *info = info_for_irq(irq);
177 xen_irq_info_common_init(info, irq, IRQT_VIRQ, evtchn, 0);
181 per_cpu(virq_to_irq, cpu)[virq] = irq;
184 static void xen_irq_info_pirq_init(unsigned irq,
185 unsigned short evtchn,
188 unsigned short vector,
192 struct irq_info *info = info_for_irq(irq);
194 xen_irq_info_common_init(info, irq, IRQT_PIRQ, evtchn, 0);
196 info->u.pirq.pirq = pirq;
197 info->u.pirq.gsi = gsi;
198 info->u.pirq.vector = vector;
199 info->u.pirq.domid = domid;
200 info->u.pirq.flags = flags;
204 * Accessors for packed IRQ information.
206 static unsigned int evtchn_from_irq(unsigned irq)
208 if (unlikely(WARN(irq < 0 || irq >= nr_irqs, "Invalid irq %d!\n", irq)))
211 return info_for_irq(irq)->evtchn;
214 unsigned irq_from_evtchn(unsigned int evtchn)
216 return evtchn_to_irq[evtchn];
218 EXPORT_SYMBOL_GPL(irq_from_evtchn);
220 static enum ipi_vector ipi_from_irq(unsigned irq)
222 struct irq_info *info = info_for_irq(irq);
224 BUG_ON(info == NULL);
225 BUG_ON(info->type != IRQT_IPI);
230 static unsigned virq_from_irq(unsigned irq)
232 struct irq_info *info = info_for_irq(irq);
234 BUG_ON(info == NULL);
235 BUG_ON(info->type != IRQT_VIRQ);
240 static unsigned pirq_from_irq(unsigned irq)
242 struct irq_info *info = info_for_irq(irq);
244 BUG_ON(info == NULL);
245 BUG_ON(info->type != IRQT_PIRQ);
247 return info->u.pirq.pirq;
250 static enum xen_irq_type type_from_irq(unsigned irq)
252 return info_for_irq(irq)->type;
255 static unsigned cpu_from_irq(unsigned irq)
257 return info_for_irq(irq)->cpu;
260 static unsigned int cpu_from_evtchn(unsigned int evtchn)
262 int irq = evtchn_to_irq[evtchn];
266 ret = cpu_from_irq(irq);
271 static bool pirq_needs_eoi(unsigned irq)
273 struct irq_info *info = info_for_irq(irq);
275 BUG_ON(info->type != IRQT_PIRQ);
277 return info->u.pirq.flags & PIRQ_NEEDS_EOI;
280 static inline unsigned long active_evtchns(unsigned int cpu,
281 struct shared_info *sh,
284 return sh->evtchn_pending[idx] &
285 per_cpu(cpu_evtchn_mask, cpu)[idx] &
286 ~sh->evtchn_mask[idx];
289 static void bind_evtchn_to_cpu(unsigned int chn, unsigned int cpu)
291 int irq = evtchn_to_irq[chn];
295 cpumask_copy(irq_to_desc(irq)->irq_data.affinity, cpumask_of(cpu));
298 clear_bit(chn, per_cpu(cpu_evtchn_mask, cpu_from_irq(irq)));
299 set_bit(chn, per_cpu(cpu_evtchn_mask, cpu));
301 info_for_irq(irq)->cpu = cpu;
304 static void init_evtchn_cpu_bindings(void)
308 struct irq_info *info;
310 /* By default all event channels notify CPU#0. */
311 list_for_each_entry(info, &xen_irq_list_head, list) {
312 struct irq_desc *desc = irq_to_desc(info->irq);
313 cpumask_copy(desc->irq_data.affinity, cpumask_of(0));
317 for_each_possible_cpu(i)
318 memset(per_cpu(cpu_evtchn_mask, i),
319 (i == 0) ? ~0 : 0, NR_EVENT_CHANNELS/8);
322 static inline void clear_evtchn(int port)
324 struct shared_info *s = HYPERVISOR_shared_info;
325 sync_clear_bit(port, &s->evtchn_pending[0]);
328 static inline void set_evtchn(int port)
330 struct shared_info *s = HYPERVISOR_shared_info;
331 sync_set_bit(port, &s->evtchn_pending[0]);
334 static inline int test_evtchn(int port)
336 struct shared_info *s = HYPERVISOR_shared_info;
337 return sync_test_bit(port, &s->evtchn_pending[0]);
340 static inline int test_and_set_mask(int port)
342 struct shared_info *s = HYPERVISOR_shared_info;
343 return sync_test_and_set_bit(port, &s->evtchn_mask[0]);
348 * notify_remote_via_irq - send event to remote end of event channel via irq
349 * @irq: irq of event channel to send event to
351 * Unlike notify_remote_via_evtchn(), this is safe to use across
352 * save/restore. Notifications on a broken connection are silently
355 void notify_remote_via_irq(int irq)
357 int evtchn = evtchn_from_irq(irq);
359 if (VALID_EVTCHN(evtchn))
360 notify_remote_via_evtchn(evtchn);
362 EXPORT_SYMBOL_GPL(notify_remote_via_irq);
364 static void mask_evtchn(int port)
366 struct shared_info *s = HYPERVISOR_shared_info;
367 sync_set_bit(port, &s->evtchn_mask[0]);
370 static void unmask_evtchn(int port)
372 struct shared_info *s = HYPERVISOR_shared_info;
373 unsigned int cpu = get_cpu();
375 BUG_ON(!irqs_disabled());
377 /* Slow path (hypercall) if this is a non-local port. */
378 if (unlikely(cpu != cpu_from_evtchn(port))) {
379 struct evtchn_unmask unmask = { .port = port };
380 (void)HYPERVISOR_event_channel_op(EVTCHNOP_unmask, &unmask);
382 struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);
384 sync_clear_bit(port, &s->evtchn_mask[0]);
387 * The following is basically the equivalent of
388 * 'hw_resend_irq'. Just like a real IO-APIC we 'lose
389 * the interrupt edge' if the channel is masked.
391 if (sync_test_bit(port, &s->evtchn_pending[0]) &&
392 !sync_test_and_set_bit(port / BITS_PER_LONG,
393 &vcpu_info->evtchn_pending_sel))
394 vcpu_info->evtchn_upcall_pending = 1;
400 static void xen_irq_init(unsigned irq)
402 struct irq_info *info;
404 struct irq_desc *desc = irq_to_desc(irq);
406 /* By default all event channels notify CPU#0. */
407 cpumask_copy(desc->irq_data.affinity, cpumask_of(0));
410 info = kzalloc(sizeof(*info), GFP_KERNEL);
412 panic("Unable to allocate metadata for IRQ%d\n", irq);
414 info->type = IRQT_UNBOUND;
416 irq_set_handler_data(irq, info);
418 list_add_tail(&info->list, &xen_irq_list_head);
421 static int __must_check xen_allocate_irq_dynamic(void)
426 #ifdef CONFIG_X86_IO_APIC
428 * For an HVM guest or domain 0 which see "real" (emulated or
429 * actual respectively) GSIs we allocate dynamic IRQs
430 * e.g. those corresponding to event channels or MSIs
431 * etc. from the range above those "real" GSIs to avoid
434 if (xen_initial_domain() || xen_hvm_domain())
435 first = get_nr_irqs_gsi();
438 irq = irq_alloc_desc_from(first, -1);
446 static int __must_check xen_allocate_irq_gsi(unsigned gsi)
451 * A PV guest has no concept of a GSI (since it has no ACPI
452 * nor access to/knowledge of the physical APICs). Therefore
453 * all IRQs are dynamically allocated from the entire IRQ
456 if (xen_pv_domain() && !xen_initial_domain())
457 return xen_allocate_irq_dynamic();
459 /* Legacy IRQ descriptors are already allocated by the arch. */
460 if (gsi < NR_IRQS_LEGACY)
463 irq = irq_alloc_desc_at(gsi, -1);
470 static void xen_free_irq(unsigned irq)
472 struct irq_info *info = irq_get_handler_data(irq);
474 list_del(&info->list);
476 irq_set_handler_data(irq, NULL);
480 /* Legacy IRQ descriptors are managed by the arch. */
481 if (irq < NR_IRQS_LEGACY)
487 static void pirq_query_unmask(int irq)
489 struct physdev_irq_status_query irq_status;
490 struct irq_info *info = info_for_irq(irq);
492 BUG_ON(info->type != IRQT_PIRQ);
494 irq_status.irq = pirq_from_irq(irq);
495 if (HYPERVISOR_physdev_op(PHYSDEVOP_irq_status_query, &irq_status))
496 irq_status.flags = 0;
498 info->u.pirq.flags &= ~PIRQ_NEEDS_EOI;
499 if (irq_status.flags & XENIRQSTAT_needs_eoi)
500 info->u.pirq.flags |= PIRQ_NEEDS_EOI;
503 static bool probing_irq(int irq)
505 struct irq_desc *desc = irq_to_desc(irq);
507 return desc && desc->action == NULL;
510 static void eoi_pirq(struct irq_data *data)
512 int evtchn = evtchn_from_irq(data->irq);
513 struct physdev_eoi eoi = { .irq = pirq_from_irq(data->irq) };
516 if (!VALID_EVTCHN(evtchn))
519 if (unlikely(irqd_is_setaffinity_pending(data)) &&
520 likely(!irqd_irq_disabled(data))) {
521 int masked = test_and_set_mask(evtchn);
523 clear_evtchn(evtchn);
525 irq_move_masked_irq(data);
528 unmask_evtchn(evtchn);
530 clear_evtchn(evtchn);
532 if (pirq_needs_eoi(data->irq)) {
533 rc = HYPERVISOR_physdev_op(PHYSDEVOP_eoi, &eoi);
538 static void mask_ack_pirq(struct irq_data *data)
540 disable_dynirq(data);
544 static unsigned int __startup_pirq(unsigned int irq)
546 struct evtchn_bind_pirq bind_pirq;
547 struct irq_info *info = info_for_irq(irq);
548 int evtchn = evtchn_from_irq(irq);
551 BUG_ON(info->type != IRQT_PIRQ);
553 if (VALID_EVTCHN(evtchn))
556 bind_pirq.pirq = pirq_from_irq(irq);
557 /* NB. We are happy to share unless we are probing. */
558 bind_pirq.flags = info->u.pirq.flags & PIRQ_SHAREABLE ?
559 BIND_PIRQ__WILL_SHARE : 0;
560 rc = HYPERVISOR_event_channel_op(EVTCHNOP_bind_pirq, &bind_pirq);
562 if (!probing_irq(irq))
563 printk(KERN_INFO "Failed to obtain physical IRQ %d\n",
567 evtchn = bind_pirq.port;
569 pirq_query_unmask(irq);
571 evtchn_to_irq[evtchn] = irq;
572 bind_evtchn_to_cpu(evtchn, 0);
573 info->evtchn = evtchn;
576 unmask_evtchn(evtchn);
577 eoi_pirq(irq_get_irq_data(irq));
582 static unsigned int startup_pirq(struct irq_data *data)
584 return __startup_pirq(data->irq);
587 static void shutdown_pirq(struct irq_data *data)
589 struct evtchn_close close;
590 unsigned int irq = data->irq;
591 struct irq_info *info = info_for_irq(irq);
592 int evtchn = evtchn_from_irq(irq);
594 BUG_ON(info->type != IRQT_PIRQ);
596 if (!VALID_EVTCHN(evtchn))
602 if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
605 bind_evtchn_to_cpu(evtchn, 0);
606 evtchn_to_irq[evtchn] = -1;
610 static void enable_pirq(struct irq_data *data)
615 static void disable_pirq(struct irq_data *data)
617 disable_dynirq(data);
620 int xen_irq_from_gsi(unsigned gsi)
622 struct irq_info *info;
624 list_for_each_entry(info, &xen_irq_list_head, list) {
625 if (info->type != IRQT_PIRQ)
628 if (info->u.pirq.gsi == gsi)
634 EXPORT_SYMBOL_GPL(xen_irq_from_gsi);
637 * Do not make any assumptions regarding the relationship between the
638 * IRQ number returned here and the Xen pirq argument.
640 * Note: We don't assign an event channel until the irq actually started
641 * up. Return an existing irq if we've already got one for the gsi.
643 * Shareable implies level triggered, not shareable implies edge
646 int xen_bind_pirq_gsi_to_irq(unsigned gsi,
647 unsigned pirq, int shareable, char *name)
650 struct physdev_irq irq_op;
652 mutex_lock(&irq_mapping_update_lock);
654 irq = xen_irq_from_gsi(gsi);
656 printk(KERN_INFO "xen_map_pirq_gsi: returning irq %d for gsi %u\n",
658 goto out; /* XXX need refcount? */
661 irq = xen_allocate_irq_gsi(gsi);
668 /* Only the privileged domain can do this. For non-priv, the pcifront
669 * driver provides a PCI bus that does the call to do exactly
670 * this in the priv domain. */
671 if (xen_initial_domain() &&
672 HYPERVISOR_physdev_op(PHYSDEVOP_alloc_irq_vector, &irq_op)) {
678 xen_irq_info_pirq_init(irq, 0, pirq, gsi, irq_op.vector, DOMID_SELF,
679 shareable ? PIRQ_SHAREABLE : 0);
681 pirq_query_unmask(irq);
682 /* We try to use the handler with the appropriate semantic for the
683 * type of interrupt: if the interrupt is an edge triggered
684 * interrupt we use handle_edge_irq.
686 * On the other hand if the interrupt is level triggered we use
687 * handle_fasteoi_irq like the native code does for this kind of
690 * Depending on the Xen version, pirq_needs_eoi might return true
691 * not only for level triggered interrupts but for edge triggered
692 * interrupts too. In any case Xen always honors the eoi mechanism,
693 * not injecting any more pirqs of the same kind if the first one
694 * hasn't received an eoi yet. Therefore using the fasteoi handler
695 * is the right choice either way.
698 irq_set_chip_and_handler_name(irq, &xen_pirq_chip,
699 handle_fasteoi_irq, name);
701 irq_set_chip_and_handler_name(irq, &xen_pirq_chip,
702 handle_edge_irq, name);
705 mutex_unlock(&irq_mapping_update_lock);
710 #ifdef CONFIG_PCI_MSI
711 int xen_allocate_pirq_msi(struct pci_dev *dev, struct msi_desc *msidesc)
714 struct physdev_get_free_pirq op_get_free_pirq;
716 op_get_free_pirq.type = MAP_PIRQ_TYPE_MSI;
717 rc = HYPERVISOR_physdev_op(PHYSDEVOP_get_free_pirq, &op_get_free_pirq);
719 WARN_ONCE(rc == -ENOSYS,
720 "hypervisor does not support the PHYSDEVOP_get_free_pirq interface\n");
722 return rc ? -1 : op_get_free_pirq.pirq;
725 int xen_bind_pirq_msi_to_irq(struct pci_dev *dev, struct msi_desc *msidesc,
726 int pirq, int vector, const char *name,
731 mutex_lock(&irq_mapping_update_lock);
733 irq = xen_allocate_irq_dynamic();
737 irq_set_chip_and_handler_name(irq, &xen_pirq_chip, handle_edge_irq,
740 xen_irq_info_pirq_init(irq, 0, pirq, 0, vector, domid, 0);
741 ret = irq_set_msi_desc(irq, msidesc);
745 mutex_unlock(&irq_mapping_update_lock);
748 mutex_unlock(&irq_mapping_update_lock);
754 int xen_destroy_irq(int irq)
756 struct irq_desc *desc;
757 struct physdev_unmap_pirq unmap_irq;
758 struct irq_info *info = info_for_irq(irq);
761 mutex_lock(&irq_mapping_update_lock);
763 desc = irq_to_desc(irq);
767 if (xen_initial_domain()) {
768 unmap_irq.pirq = info->u.pirq.pirq;
769 unmap_irq.domid = info->u.pirq.domid;
770 rc = HYPERVISOR_physdev_op(PHYSDEVOP_unmap_pirq, &unmap_irq);
771 /* If another domain quits without making the pci_disable_msix
772 * call, the Xen hypervisor takes care of freeing the PIRQs
773 * (free_domain_pirqs).
775 if ((rc == -ESRCH && info->u.pirq.domid != DOMID_SELF))
776 printk(KERN_INFO "domain %d does not have %d anymore\n",
777 info->u.pirq.domid, info->u.pirq.pirq);
779 printk(KERN_WARNING "unmap irq failed %d\n", rc);
787 mutex_unlock(&irq_mapping_update_lock);
791 int xen_irq_from_pirq(unsigned pirq)
795 struct irq_info *info;
797 mutex_lock(&irq_mapping_update_lock);
799 list_for_each_entry(info, &xen_irq_list_head, list) {
800 if (info->type != IRQT_PIRQ)
803 if (info->u.pirq.pirq == pirq)
808 mutex_unlock(&irq_mapping_update_lock);
814 int xen_pirq_from_irq(unsigned irq)
816 return pirq_from_irq(irq);
818 EXPORT_SYMBOL_GPL(xen_pirq_from_irq);
819 int bind_evtchn_to_irq(unsigned int evtchn)
823 mutex_lock(&irq_mapping_update_lock);
825 irq = evtchn_to_irq[evtchn];
828 irq = xen_allocate_irq_dynamic();
832 irq_set_chip_and_handler_name(irq, &xen_dynamic_chip,
833 handle_edge_irq, "event");
835 xen_irq_info_evtchn_init(irq, evtchn);
839 mutex_unlock(&irq_mapping_update_lock);
843 EXPORT_SYMBOL_GPL(bind_evtchn_to_irq);
845 static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
847 struct evtchn_bind_ipi bind_ipi;
850 mutex_lock(&irq_mapping_update_lock);
852 irq = per_cpu(ipi_to_irq, cpu)[ipi];
855 irq = xen_allocate_irq_dynamic();
859 irq_set_chip_and_handler_name(irq, &xen_percpu_chip,
860 handle_percpu_irq, "ipi");
863 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
866 evtchn = bind_ipi.port;
868 xen_irq_info_ipi_init(cpu, irq, evtchn, ipi);
870 bind_evtchn_to_cpu(evtchn, cpu);
874 mutex_unlock(&irq_mapping_update_lock);
878 static int bind_interdomain_evtchn_to_irq(unsigned int remote_domain,
879 unsigned int remote_port)
881 struct evtchn_bind_interdomain bind_interdomain;
884 bind_interdomain.remote_dom = remote_domain;
885 bind_interdomain.remote_port = remote_port;
887 err = HYPERVISOR_event_channel_op(EVTCHNOP_bind_interdomain,
890 return err ? : bind_evtchn_to_irq(bind_interdomain.local_port);
893 static int find_virq(unsigned int virq, unsigned int cpu)
895 struct evtchn_status status;
896 int port, rc = -ENOENT;
898 memset(&status, 0, sizeof(status));
899 for (port = 0; port <= NR_EVENT_CHANNELS; port++) {
900 status.dom = DOMID_SELF;
902 rc = HYPERVISOR_event_channel_op(EVTCHNOP_status, &status);
905 if (status.status != EVTCHNSTAT_virq)
907 if (status.u.virq == virq && status.vcpu == cpu) {
915 int bind_virq_to_irq(unsigned int virq, unsigned int cpu, bool percpu)
917 struct evtchn_bind_virq bind_virq;
918 int evtchn, irq, ret;
920 mutex_lock(&irq_mapping_update_lock);
922 irq = per_cpu(virq_to_irq, cpu)[virq];
925 irq = xen_allocate_irq_dynamic();
930 irq_set_chip_and_handler_name(irq, &xen_percpu_chip,
931 handle_percpu_irq, "virq");
933 irq_set_chip_and_handler_name(irq, &xen_dynamic_chip,
934 handle_edge_irq, "virq");
936 bind_virq.virq = virq;
937 bind_virq.vcpu = cpu;
938 ret = HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
941 evtchn = bind_virq.port;
944 ret = find_virq(virq, cpu);
949 xen_irq_info_virq_init(cpu, irq, evtchn, virq);
951 bind_evtchn_to_cpu(evtchn, cpu);
955 mutex_unlock(&irq_mapping_update_lock);
960 static void unbind_from_irq(unsigned int irq)
962 struct evtchn_close close;
963 int evtchn = evtchn_from_irq(irq);
965 mutex_lock(&irq_mapping_update_lock);
967 if (VALID_EVTCHN(evtchn)) {
969 if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
972 switch (type_from_irq(irq)) {
974 per_cpu(virq_to_irq, cpu_from_evtchn(evtchn))
975 [virq_from_irq(irq)] = -1;
978 per_cpu(ipi_to_irq, cpu_from_evtchn(evtchn))
979 [ipi_from_irq(irq)] = -1;
985 /* Closed ports are implicitly re-bound to VCPU0. */
986 bind_evtchn_to_cpu(evtchn, 0);
988 evtchn_to_irq[evtchn] = -1;
991 BUG_ON(info_for_irq(irq)->type == IRQT_UNBOUND);
995 mutex_unlock(&irq_mapping_update_lock);
998 int bind_evtchn_to_irqhandler(unsigned int evtchn,
999 irq_handler_t handler,
1000 unsigned long irqflags,
1001 const char *devname, void *dev_id)
1005 irq = bind_evtchn_to_irq(evtchn);
1008 retval = request_irq(irq, handler, irqflags, devname, dev_id);
1010 unbind_from_irq(irq);
1016 EXPORT_SYMBOL_GPL(bind_evtchn_to_irqhandler);
1018 int bind_interdomain_evtchn_to_irqhandler(unsigned int remote_domain,
1019 unsigned int remote_port,
1020 irq_handler_t handler,
1021 unsigned long irqflags,
1022 const char *devname,
1027 irq = bind_interdomain_evtchn_to_irq(remote_domain, remote_port);
1031 retval = request_irq(irq, handler, irqflags, devname, dev_id);
1033 unbind_from_irq(irq);
1039 EXPORT_SYMBOL_GPL(bind_interdomain_evtchn_to_irqhandler);
1041 int bind_virq_to_irqhandler(unsigned int virq, unsigned int cpu,
1042 irq_handler_t handler,
1043 unsigned long irqflags, const char *devname, void *dev_id)
1047 irq = bind_virq_to_irq(virq, cpu, irqflags & IRQF_PERCPU);
1050 retval = request_irq(irq, handler, irqflags, devname, dev_id);
1052 unbind_from_irq(irq);
1058 EXPORT_SYMBOL_GPL(bind_virq_to_irqhandler);
1060 int bind_ipi_to_irqhandler(enum ipi_vector ipi,
1062 irq_handler_t handler,
1063 unsigned long irqflags,
1064 const char *devname,
1069 irq = bind_ipi_to_irq(ipi, cpu);
1073 irqflags |= IRQF_NO_SUSPEND | IRQF_FORCE_RESUME | IRQF_EARLY_RESUME;
1074 retval = request_irq(irq, handler, irqflags, devname, dev_id);
1076 unbind_from_irq(irq);
1083 void unbind_from_irqhandler(unsigned int irq, void *dev_id)
1085 free_irq(irq, dev_id);
1086 unbind_from_irq(irq);
1088 EXPORT_SYMBOL_GPL(unbind_from_irqhandler);
1090 void xen_send_IPI_one(unsigned int cpu, enum ipi_vector vector)
1092 int irq = per_cpu(ipi_to_irq, cpu)[vector];
1094 notify_remote_via_irq(irq);
1097 irqreturn_t xen_debug_interrupt(int irq, void *dev_id)
1099 struct shared_info *sh = HYPERVISOR_shared_info;
1100 int cpu = smp_processor_id();
1101 unsigned long *cpu_evtchn = per_cpu(cpu_evtchn_mask, cpu);
1103 unsigned long flags;
1104 static DEFINE_SPINLOCK(debug_lock);
1105 struct vcpu_info *v;
1107 spin_lock_irqsave(&debug_lock, flags);
1109 printk("\nvcpu %d\n ", cpu);
1111 for_each_online_cpu(i) {
1113 v = per_cpu(xen_vcpu, i);
1114 pending = (get_irq_regs() && i == cpu)
1115 ? xen_irqs_disabled(get_irq_regs())
1116 : v->evtchn_upcall_mask;
1117 printk("%d: masked=%d pending=%d event_sel %0*lx\n ", i,
1118 pending, v->evtchn_upcall_pending,
1119 (int)(sizeof(v->evtchn_pending_sel)*2),
1120 v->evtchn_pending_sel);
1122 v = per_cpu(xen_vcpu, cpu);
1124 printk("\npending:\n ");
1125 for (i = ARRAY_SIZE(sh->evtchn_pending)-1; i >= 0; i--)
1126 printk("%0*lx%s", (int)sizeof(sh->evtchn_pending[0])*2,
1127 sh->evtchn_pending[i],
1128 i % 8 == 0 ? "\n " : " ");
1129 printk("\nglobal mask:\n ");
1130 for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--)
1132 (int)(sizeof(sh->evtchn_mask[0])*2),
1134 i % 8 == 0 ? "\n " : " ");
1136 printk("\nglobally unmasked:\n ");
1137 for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--)
1138 printk("%0*lx%s", (int)(sizeof(sh->evtchn_mask[0])*2),
1139 sh->evtchn_pending[i] & ~sh->evtchn_mask[i],
1140 i % 8 == 0 ? "\n " : " ");
1142 printk("\nlocal cpu%d mask:\n ", cpu);
1143 for (i = (NR_EVENT_CHANNELS/BITS_PER_LONG)-1; i >= 0; i--)
1144 printk("%0*lx%s", (int)(sizeof(cpu_evtchn[0])*2),
1146 i % 8 == 0 ? "\n " : " ");
1148 printk("\nlocally unmasked:\n ");
1149 for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--) {
1150 unsigned long pending = sh->evtchn_pending[i]
1151 & ~sh->evtchn_mask[i]
1153 printk("%0*lx%s", (int)(sizeof(sh->evtchn_mask[0])*2),
1154 pending, i % 8 == 0 ? "\n " : " ");
1157 printk("\npending list:\n");
1158 for (i = 0; i < NR_EVENT_CHANNELS; i++) {
1159 if (sync_test_bit(i, sh->evtchn_pending)) {
1160 int word_idx = i / BITS_PER_LONG;
1161 printk(" %d: event %d -> irq %d%s%s%s\n",
1162 cpu_from_evtchn(i), i,
1164 sync_test_bit(word_idx, &v->evtchn_pending_sel)
1166 !sync_test_bit(i, sh->evtchn_mask)
1167 ? "" : " globally-masked",
1168 sync_test_bit(i, cpu_evtchn)
1169 ? "" : " locally-masked");
1173 spin_unlock_irqrestore(&debug_lock, flags);
1178 static DEFINE_PER_CPU(unsigned, xed_nesting_count);
1179 static DEFINE_PER_CPU(unsigned int, current_word_idx);
1180 static DEFINE_PER_CPU(unsigned int, current_bit_idx);
1183 * Mask out the i least significant bits of w
1185 #define MASK_LSBS(w, i) (w & ((~0UL) << i))
1188 * Search the CPUs pending events bitmasks. For each one found, map
1189 * the event number to an irq, and feed it into do_IRQ() for
1192 * Xen uses a two-level bitmap to speed searching. The first level is
1193 * a bitset of words which contain pending event bits. The second
1194 * level is a bitset of pending events themselves.
1196 static void __xen_evtchn_do_upcall(void)
1198 int start_word_idx, start_bit_idx;
1199 int word_idx, bit_idx;
1201 int cpu = get_cpu();
1202 struct shared_info *s = HYPERVISOR_shared_info;
1203 struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);
1207 unsigned long pending_words;
1208 unsigned long pending_bits;
1209 struct irq_desc *desc;
1211 vcpu_info->evtchn_upcall_pending = 0;
1213 if (__this_cpu_inc_return(xed_nesting_count) - 1)
1216 #ifndef CONFIG_X86 /* No need for a barrier -- XCHG is a barrier on x86. */
1217 /* Clear master flag /before/ clearing selector flag. */
1220 if ((irq = per_cpu(virq_to_irq, cpu)[VIRQ_TIMER]) != -1) {
1221 int evtchn = evtchn_from_irq(irq);
1222 word_idx = evtchn / BITS_PER_LONG;
1223 pending_bits = evtchn % BITS_PER_LONG;
1224 if (active_evtchns(cpu, s, word_idx) & (1ULL << pending_bits)) {
1225 desc = irq_to_desc(irq);
1227 generic_handle_irq_desc(irq, desc);
1231 pending_words = xchg(&vcpu_info->evtchn_pending_sel, 0);
1233 start_word_idx = __this_cpu_read(current_word_idx);
1234 start_bit_idx = __this_cpu_read(current_bit_idx);
1236 word_idx = start_word_idx;
1238 for (i = 0; pending_words != 0; i++) {
1239 unsigned long words;
1241 words = MASK_LSBS(pending_words, word_idx);
1244 * If we masked out all events, wrap to beginning.
1251 word_idx = __ffs(words);
1253 pending_bits = active_evtchns(cpu, s, word_idx);
1254 bit_idx = 0; /* usually scan entire word from start */
1255 if (word_idx == start_word_idx) {
1256 /* We scan the starting word in two parts */
1258 /* 1st time: start in the middle */
1259 bit_idx = start_bit_idx;
1261 /* 2nd time: mask bits done already */
1262 bit_idx &= (1UL << start_bit_idx) - 1;
1269 bits = MASK_LSBS(pending_bits, bit_idx);
1271 /* If we masked out all events, move on. */
1275 bit_idx = __ffs(bits);
1278 port = (word_idx * BITS_PER_LONG) + bit_idx;
1279 irq = evtchn_to_irq[port];
1282 desc = irq_to_desc(irq);
1284 generic_handle_irq_desc(irq, desc);
1287 bit_idx = (bit_idx + 1) % BITS_PER_LONG;
1289 /* Next caller starts at last processed + 1 */
1290 __this_cpu_write(current_word_idx,
1291 bit_idx ? word_idx :
1292 (word_idx+1) % BITS_PER_LONG);
1293 __this_cpu_write(current_bit_idx, bit_idx);
1294 } while (bit_idx != 0);
1296 /* Scan start_l1i twice; all others once. */
1297 if ((word_idx != start_word_idx) || (i != 0))
1298 pending_words &= ~(1UL << word_idx);
1300 word_idx = (word_idx + 1) % BITS_PER_LONG;
1303 BUG_ON(!irqs_disabled());
1305 count = __this_cpu_read(xed_nesting_count);
1306 __this_cpu_write(xed_nesting_count, 0);
1307 } while (count != 1 || vcpu_info->evtchn_upcall_pending);
1314 void xen_evtchn_do_upcall(struct pt_regs *regs)
1316 struct pt_regs *old_regs = set_irq_regs(regs);
1321 __xen_evtchn_do_upcall();
1324 set_irq_regs(old_regs);
1327 void xen_hvm_evtchn_do_upcall(void)
1329 __xen_evtchn_do_upcall();
1331 EXPORT_SYMBOL_GPL(xen_hvm_evtchn_do_upcall);
1333 /* Rebind a new event channel to an existing irq. */
1334 void rebind_evtchn_irq(int evtchn, int irq)
1336 struct irq_info *info = info_for_irq(irq);
1338 /* Make sure the irq is masked, since the new event channel
1339 will also be masked. */
1342 mutex_lock(&irq_mapping_update_lock);
1344 /* After resume the irq<->evtchn mappings are all cleared out */
1345 BUG_ON(evtchn_to_irq[evtchn] != -1);
1346 /* Expect irq to have been bound before,
1347 so there should be a proper type */
1348 BUG_ON(info->type == IRQT_UNBOUND);
1350 xen_irq_info_evtchn_init(irq, evtchn);
1352 mutex_unlock(&irq_mapping_update_lock);
1354 /* new event channels are always bound to cpu 0 */
1355 irq_set_affinity(irq, cpumask_of(0));
1357 /* Unmask the event channel. */
1361 /* Rebind an evtchn so that it gets delivered to a specific cpu */
1362 static int rebind_irq_to_cpu(unsigned irq, unsigned tcpu)
1364 struct shared_info *s = HYPERVISOR_shared_info;
1365 struct evtchn_bind_vcpu bind_vcpu;
1366 int evtchn = evtchn_from_irq(irq);
1369 if (!VALID_EVTCHN(evtchn))
1373 * Events delivered via platform PCI interrupts are always
1374 * routed to vcpu 0 and hence cannot be rebound.
1376 if (xen_hvm_domain() && !xen_have_vector_callback)
1379 /* Send future instances of this interrupt to other vcpu. */
1380 bind_vcpu.port = evtchn;
1381 bind_vcpu.vcpu = tcpu;
1384 * Mask the event while changing the VCPU binding to prevent
1385 * it being delivered on an unexpected VCPU.
1387 masked = sync_test_and_set_bit(evtchn, s->evtchn_mask);
1390 * If this fails, it usually just indicates that we're dealing with a
1391 * virq or IPI channel, which don't actually need to be rebound. Ignore
1392 * it, but don't do the xenlinux-level rebind in that case.
1394 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_vcpu, &bind_vcpu) >= 0)
1395 bind_evtchn_to_cpu(evtchn, tcpu);
1398 unmask_evtchn(evtchn);
1403 static int set_affinity_irq(struct irq_data *data, const struct cpumask *dest,
1406 unsigned tcpu = cpumask_first(dest);
1408 return rebind_irq_to_cpu(data->irq, tcpu);
1411 int resend_irq_on_evtchn(unsigned int irq)
1413 int masked, evtchn = evtchn_from_irq(irq);
1414 struct shared_info *s = HYPERVISOR_shared_info;
1416 if (!VALID_EVTCHN(evtchn))
1419 masked = sync_test_and_set_bit(evtchn, s->evtchn_mask);
1420 sync_set_bit(evtchn, s->evtchn_pending);
1422 unmask_evtchn(evtchn);
1427 static void enable_dynirq(struct irq_data *data)
1429 int evtchn = evtchn_from_irq(data->irq);
1431 if (VALID_EVTCHN(evtchn))
1432 unmask_evtchn(evtchn);
1435 static void disable_dynirq(struct irq_data *data)
1437 int evtchn = evtchn_from_irq(data->irq);
1439 if (VALID_EVTCHN(evtchn))
1440 mask_evtchn(evtchn);
1443 static void ack_dynirq(struct irq_data *data)
1445 int evtchn = evtchn_from_irq(data->irq);
1447 if (!VALID_EVTCHN(evtchn))
1450 if (unlikely(irqd_is_setaffinity_pending(data)) &&
1451 likely(!irqd_irq_disabled(data))) {
1452 int masked = test_and_set_mask(evtchn);
1454 clear_evtchn(evtchn);
1456 irq_move_masked_irq(data);
1459 unmask_evtchn(evtchn);
1461 clear_evtchn(evtchn);
1464 static void mask_ack_dynirq(struct irq_data *data)
1466 disable_dynirq(data);
1470 static int retrigger_dynirq(struct irq_data *data)
1472 int evtchn = evtchn_from_irq(data->irq);
1473 struct shared_info *sh = HYPERVISOR_shared_info;
1476 if (VALID_EVTCHN(evtchn)) {
1479 masked = sync_test_and_set_bit(evtchn, sh->evtchn_mask);
1480 sync_set_bit(evtchn, sh->evtchn_pending);
1482 unmask_evtchn(evtchn);
1489 static void restore_pirqs(void)
1491 int pirq, rc, irq, gsi;
1492 struct physdev_map_pirq map_irq;
1493 struct irq_info *info;
1495 list_for_each_entry(info, &xen_irq_list_head, list) {
1496 if (info->type != IRQT_PIRQ)
1499 pirq = info->u.pirq.pirq;
1500 gsi = info->u.pirq.gsi;
1503 /* save/restore of PT devices doesn't work, so at this point the
1504 * only devices present are GSI based emulated devices */
1508 map_irq.domid = DOMID_SELF;
1509 map_irq.type = MAP_PIRQ_TYPE_GSI;
1510 map_irq.index = gsi;
1511 map_irq.pirq = pirq;
1513 rc = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq);
1515 printk(KERN_WARNING "xen map irq failed gsi=%d irq=%d pirq=%d rc=%d\n",
1516 gsi, irq, pirq, rc);
1521 printk(KERN_DEBUG "xen: --> irq=%d, pirq=%d\n", irq, map_irq.pirq);
1523 __startup_pirq(irq);
1527 static void restore_cpu_virqs(unsigned int cpu)
1529 struct evtchn_bind_virq bind_virq;
1530 int virq, irq, evtchn;
1532 for (virq = 0; virq < NR_VIRQS; virq++) {
1533 if ((irq = per_cpu(virq_to_irq, cpu)[virq]) == -1)
1536 BUG_ON(virq_from_irq(irq) != virq);
1538 /* Get a new binding from Xen. */
1539 bind_virq.virq = virq;
1540 bind_virq.vcpu = cpu;
1541 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
1544 evtchn = bind_virq.port;
1546 /* Record the new mapping. */
1547 xen_irq_info_virq_init(cpu, irq, evtchn, virq);
1548 bind_evtchn_to_cpu(evtchn, cpu);
1552 static void restore_cpu_ipis(unsigned int cpu)
1554 struct evtchn_bind_ipi bind_ipi;
1555 int ipi, irq, evtchn;
1557 for (ipi = 0; ipi < XEN_NR_IPIS; ipi++) {
1558 if ((irq = per_cpu(ipi_to_irq, cpu)[ipi]) == -1)
1561 BUG_ON(ipi_from_irq(irq) != ipi);
1563 /* Get a new binding from Xen. */
1564 bind_ipi.vcpu = cpu;
1565 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
1568 evtchn = bind_ipi.port;
1570 /* Record the new mapping. */
1571 xen_irq_info_ipi_init(cpu, irq, evtchn, ipi);
1572 bind_evtchn_to_cpu(evtchn, cpu);
1576 /* Clear an irq's pending state, in preparation for polling on it */
1577 void xen_clear_irq_pending(int irq)
1579 int evtchn = evtchn_from_irq(irq);
1581 if (VALID_EVTCHN(evtchn))
1582 clear_evtchn(evtchn);
1584 EXPORT_SYMBOL(xen_clear_irq_pending);
1585 void xen_set_irq_pending(int irq)
1587 int evtchn = evtchn_from_irq(irq);
1589 if (VALID_EVTCHN(evtchn))
1593 bool xen_test_irq_pending(int irq)
1595 int evtchn = evtchn_from_irq(irq);
1598 if (VALID_EVTCHN(evtchn))
1599 ret = test_evtchn(evtchn);
1604 /* Poll waiting for an irq to become pending with timeout. In the usual case,
1605 * the irq will be disabled so it won't deliver an interrupt. */
1606 void xen_poll_irq_timeout(int irq, u64 timeout)
1608 evtchn_port_t evtchn = evtchn_from_irq(irq);
1610 if (VALID_EVTCHN(evtchn)) {
1611 struct sched_poll poll;
1614 poll.timeout = timeout;
1615 set_xen_guest_handle(poll.ports, &evtchn);
1617 if (HYPERVISOR_sched_op(SCHEDOP_poll, &poll) != 0)
1621 EXPORT_SYMBOL(xen_poll_irq_timeout);
1622 /* Poll waiting for an irq to become pending. In the usual case, the
1623 * irq will be disabled so it won't deliver an interrupt. */
1624 void xen_poll_irq(int irq)
1626 xen_poll_irq_timeout(irq, 0 /* no timeout */);
1629 /* Check whether the IRQ line is shared with other guests. */
1630 int xen_test_irq_shared(int irq)
1632 struct irq_info *info = info_for_irq(irq);
1633 struct physdev_irq_status_query irq_status = { .irq = info->u.pirq.pirq };
1635 if (HYPERVISOR_physdev_op(PHYSDEVOP_irq_status_query, &irq_status))
1637 return !(irq_status.flags & XENIRQSTAT_shared);
1639 EXPORT_SYMBOL_GPL(xen_test_irq_shared);
1641 void xen_irq_resume(void)
1643 unsigned int cpu, evtchn;
1644 struct irq_info *info;
1646 init_evtchn_cpu_bindings();
1648 /* New event-channel space is not 'live' yet. */
1649 for (evtchn = 0; evtchn < NR_EVENT_CHANNELS; evtchn++)
1650 mask_evtchn(evtchn);
1652 /* No IRQ <-> event-channel mappings. */
1653 list_for_each_entry(info, &xen_irq_list_head, list)
1654 info->evtchn = 0; /* zap event-channel binding */
1656 for (evtchn = 0; evtchn < NR_EVENT_CHANNELS; evtchn++)
1657 evtchn_to_irq[evtchn] = -1;
1659 for_each_possible_cpu(cpu) {
1660 restore_cpu_virqs(cpu);
1661 restore_cpu_ipis(cpu);
1667 static struct irq_chip xen_dynamic_chip __read_mostly = {
1670 .irq_disable = disable_dynirq,
1671 .irq_mask = disable_dynirq,
1672 .irq_unmask = enable_dynirq,
1674 .irq_ack = ack_dynirq,
1675 .irq_mask_ack = mask_ack_dynirq,
1677 .irq_set_affinity = set_affinity_irq,
1678 .irq_retrigger = retrigger_dynirq,
1681 static struct irq_chip xen_pirq_chip __read_mostly = {
1684 .irq_startup = startup_pirq,
1685 .irq_shutdown = shutdown_pirq,
1686 .irq_enable = enable_pirq,
1687 .irq_disable = disable_pirq,
1689 .irq_mask = disable_dynirq,
1690 .irq_unmask = enable_dynirq,
1692 .irq_ack = eoi_pirq,
1693 .irq_eoi = eoi_pirq,
1694 .irq_mask_ack = mask_ack_pirq,
1696 .irq_set_affinity = set_affinity_irq,
1698 .irq_retrigger = retrigger_dynirq,
1701 static struct irq_chip xen_percpu_chip __read_mostly = {
1702 .name = "xen-percpu",
1704 .irq_disable = disable_dynirq,
1705 .irq_mask = disable_dynirq,
1706 .irq_unmask = enable_dynirq,
1708 .irq_ack = ack_dynirq,
1711 int xen_set_callback_via(uint64_t via)
1713 struct xen_hvm_param a;
1714 a.domid = DOMID_SELF;
1715 a.index = HVM_PARAM_CALLBACK_IRQ;
1717 return HYPERVISOR_hvm_op(HVMOP_set_param, &a);
1719 EXPORT_SYMBOL_GPL(xen_set_callback_via);
1721 #ifdef CONFIG_XEN_PVHVM
1722 /* Vector callbacks are better than PCI interrupts to receive event
1723 * channel notifications because we can receive vector callbacks on any
1724 * vcpu and we don't need PCI support or APIC interactions. */
1725 void xen_callback_vector(void)
1728 uint64_t callback_via;
1729 if (xen_have_vector_callback) {
1730 callback_via = HVM_CALLBACK_VECTOR(XEN_HVM_EVTCHN_CALLBACK);
1731 rc = xen_set_callback_via(callback_via);
1733 printk(KERN_ERR "Request for Xen HVM callback vector"
1735 xen_have_vector_callback = 0;
1738 printk(KERN_INFO "Xen HVM callback vector for event delivery is "
1740 /* in the restore case the vector has already been allocated */
1741 if (!test_bit(XEN_HVM_EVTCHN_CALLBACK, used_vectors))
1742 alloc_intr_gate(XEN_HVM_EVTCHN_CALLBACK, xen_hvm_callback_vector);
1746 void xen_callback_vector(void) {}
1749 void __init xen_init_IRQ(void)
1753 evtchn_to_irq = kcalloc(NR_EVENT_CHANNELS, sizeof(*evtchn_to_irq),
1755 BUG_ON(!evtchn_to_irq);
1756 for (i = 0; i < NR_EVENT_CHANNELS; i++)
1757 evtchn_to_irq[i] = -1;
1759 init_evtchn_cpu_bindings();
1761 /* No event channels are 'live' right now. */
1762 for (i = 0; i < NR_EVENT_CHANNELS; i++)
1765 if (xen_hvm_domain()) {
1766 xen_callback_vector();
1768 /* pci_xen_hvm_init must be called after native_init_IRQ so that
1769 * __acpi_register_gsi can point at the right function */
1772 irq_ctx_init(smp_processor_id());
1773 if (xen_initial_domain())
1774 pci_xen_initial_domain();