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 recieved, 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_SPINLOCK(irq_mapping_update_lock);
59 /* IRQ <-> VIRQ mapping. */
60 static DEFINE_PER_CPU(int [NR_VIRQS], virq_to_irq) = {[0 ... NR_VIRQS-1] = -1};
62 /* IRQ <-> IPI mapping */
63 static DEFINE_PER_CPU(int [XEN_NR_IPIS], ipi_to_irq) = {[0 ... XEN_NR_IPIS-1] = -1};
65 /* Interrupt types. */
75 * Packed IRQ information:
76 * type - enum xen_irq_type
77 * event channel - irq->event channel mapping
78 * cpu - cpu this event channel is bound to
79 * index - type-specific information:
80 * PIRQ - vector, with MSB being "needs EIO", or physical IRQ of the HVM
81 * guest, or GSI (real passthrough IRQ) of the device.
88 enum xen_irq_type type; /* type */
89 unsigned short evtchn; /* event channel */
90 unsigned short cpu; /* cpu bound */
103 #define PIRQ_NEEDS_EOI (1 << 0)
104 #define PIRQ_SHAREABLE (1 << 1)
106 static struct irq_info *irq_info;
107 static int *pirq_to_irq;
109 static int *evtchn_to_irq;
110 struct cpu_evtchn_s {
111 unsigned long bits[NR_EVENT_CHANNELS/BITS_PER_LONG];
114 static __initdata struct cpu_evtchn_s init_evtchn_mask = {
115 .bits[0 ... (NR_EVENT_CHANNELS/BITS_PER_LONG)-1] = ~0ul,
117 static struct cpu_evtchn_s *cpu_evtchn_mask_p = &init_evtchn_mask;
119 static inline unsigned long *cpu_evtchn_mask(int cpu)
121 return cpu_evtchn_mask_p[cpu].bits;
124 /* Xen will never allocate port zero for any purpose. */
125 #define VALID_EVTCHN(chn) ((chn) != 0)
127 static struct irq_chip xen_dynamic_chip;
128 static struct irq_chip xen_percpu_chip;
129 static struct irq_chip xen_pirq_chip;
131 /* Constructor for packed IRQ information. */
132 static struct irq_info mk_unbound_info(void)
134 return (struct irq_info) { .type = IRQT_UNBOUND };
137 static struct irq_info mk_evtchn_info(unsigned short evtchn)
139 return (struct irq_info) { .type = IRQT_EVTCHN, .evtchn = evtchn,
143 static struct irq_info mk_ipi_info(unsigned short evtchn, enum ipi_vector ipi)
145 return (struct irq_info) { .type = IRQT_IPI, .evtchn = evtchn,
146 .cpu = 0, .u.ipi = ipi };
149 static struct irq_info mk_virq_info(unsigned short evtchn, unsigned short virq)
151 return (struct irq_info) { .type = IRQT_VIRQ, .evtchn = evtchn,
152 .cpu = 0, .u.virq = virq };
155 static struct irq_info mk_pirq_info(unsigned short evtchn, unsigned short pirq,
156 unsigned short gsi, unsigned short vector)
158 return (struct irq_info) { .type = IRQT_PIRQ, .evtchn = evtchn,
160 .u.pirq = { .pirq = pirq, .gsi = gsi, .vector = vector } };
164 * Accessors for packed IRQ information.
166 static struct irq_info *info_for_irq(unsigned irq)
168 return &irq_info[irq];
171 static unsigned int evtchn_from_irq(unsigned irq)
173 if (unlikely(WARN(irq < 0 || irq >= nr_irqs, "Invalid irq %d!\n", irq)))
176 return info_for_irq(irq)->evtchn;
179 unsigned irq_from_evtchn(unsigned int evtchn)
181 return evtchn_to_irq[evtchn];
183 EXPORT_SYMBOL_GPL(irq_from_evtchn);
185 static enum ipi_vector ipi_from_irq(unsigned irq)
187 struct irq_info *info = info_for_irq(irq);
189 BUG_ON(info == NULL);
190 BUG_ON(info->type != IRQT_IPI);
195 static unsigned virq_from_irq(unsigned irq)
197 struct irq_info *info = info_for_irq(irq);
199 BUG_ON(info == NULL);
200 BUG_ON(info->type != IRQT_VIRQ);
205 static unsigned pirq_from_irq(unsigned irq)
207 struct irq_info *info = info_for_irq(irq);
209 BUG_ON(info == NULL);
210 BUG_ON(info->type != IRQT_PIRQ);
212 return info->u.pirq.pirq;
215 static unsigned gsi_from_irq(unsigned irq)
217 struct irq_info *info = info_for_irq(irq);
219 BUG_ON(info == NULL);
220 BUG_ON(info->type != IRQT_PIRQ);
222 return info->u.pirq.gsi;
225 static unsigned vector_from_irq(unsigned irq)
227 struct irq_info *info = info_for_irq(irq);
229 BUG_ON(info == NULL);
230 BUG_ON(info->type != IRQT_PIRQ);
232 return info->u.pirq.vector;
235 static enum xen_irq_type type_from_irq(unsigned irq)
237 return info_for_irq(irq)->type;
240 static unsigned cpu_from_irq(unsigned irq)
242 return info_for_irq(irq)->cpu;
245 static unsigned int cpu_from_evtchn(unsigned int evtchn)
247 int irq = evtchn_to_irq[evtchn];
251 ret = cpu_from_irq(irq);
256 static bool pirq_needs_eoi(unsigned irq)
258 struct irq_info *info = info_for_irq(irq);
260 BUG_ON(info->type != IRQT_PIRQ);
262 return info->u.pirq.flags & PIRQ_NEEDS_EOI;
265 static inline unsigned long active_evtchns(unsigned int cpu,
266 struct shared_info *sh,
269 return (sh->evtchn_pending[idx] &
270 cpu_evtchn_mask(cpu)[idx] &
271 ~sh->evtchn_mask[idx]);
274 static void bind_evtchn_to_cpu(unsigned int chn, unsigned int cpu)
276 int irq = evtchn_to_irq[chn];
280 cpumask_copy(irq_to_desc(irq)->irq_data.affinity, cpumask_of(cpu));
283 clear_bit(chn, cpu_evtchn_mask(cpu_from_irq(irq)));
284 set_bit(chn, cpu_evtchn_mask(cpu));
286 irq_info[irq].cpu = cpu;
289 static void init_evtchn_cpu_bindings(void)
293 struct irq_desc *desc;
295 /* By default all event channels notify CPU#0. */
296 for_each_irq_desc(i, desc) {
297 cpumask_copy(desc->irq_data.affinity, cpumask_of(0));
301 for_each_possible_cpu(i)
302 memset(cpu_evtchn_mask(i),
303 (i == 0) ? ~0 : 0, sizeof(struct cpu_evtchn_s));
307 static inline void clear_evtchn(int port)
309 struct shared_info *s = HYPERVISOR_shared_info;
310 sync_clear_bit(port, &s->evtchn_pending[0]);
313 static inline void set_evtchn(int port)
315 struct shared_info *s = HYPERVISOR_shared_info;
316 sync_set_bit(port, &s->evtchn_pending[0]);
319 static inline int test_evtchn(int port)
321 struct shared_info *s = HYPERVISOR_shared_info;
322 return sync_test_bit(port, &s->evtchn_pending[0]);
327 * notify_remote_via_irq - send event to remote end of event channel via irq
328 * @irq: irq of event channel to send event to
330 * Unlike notify_remote_via_evtchn(), this is safe to use across
331 * save/restore. Notifications on a broken connection are silently
334 void notify_remote_via_irq(int irq)
336 int evtchn = evtchn_from_irq(irq);
338 if (VALID_EVTCHN(evtchn))
339 notify_remote_via_evtchn(evtchn);
341 EXPORT_SYMBOL_GPL(notify_remote_via_irq);
343 static void mask_evtchn(int port)
345 struct shared_info *s = HYPERVISOR_shared_info;
346 sync_set_bit(port, &s->evtchn_mask[0]);
349 static void unmask_evtchn(int port)
351 struct shared_info *s = HYPERVISOR_shared_info;
352 unsigned int cpu = get_cpu();
354 BUG_ON(!irqs_disabled());
356 /* Slow path (hypercall) if this is a non-local port. */
357 if (unlikely(cpu != cpu_from_evtchn(port))) {
358 struct evtchn_unmask unmask = { .port = port };
359 (void)HYPERVISOR_event_channel_op(EVTCHNOP_unmask, &unmask);
361 struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);
363 sync_clear_bit(port, &s->evtchn_mask[0]);
366 * The following is basically the equivalent of
367 * 'hw_resend_irq'. Just like a real IO-APIC we 'lose
368 * the interrupt edge' if the channel is masked.
370 if (sync_test_bit(port, &s->evtchn_pending[0]) &&
371 !sync_test_and_set_bit(port / BITS_PER_LONG,
372 &vcpu_info->evtchn_pending_sel))
373 vcpu_info->evtchn_upcall_pending = 1;
379 static int xen_allocate_irq_dynamic(void)
384 #ifdef CONFIG_X86_IO_APIC
386 * For an HVM guest or domain 0 which see "real" (emulated or
387 * actual repectively) GSIs we allocate dynamic IRQs
388 * e.g. those corresponding to event channels or MSIs
389 * etc. from the range above those "real" GSIs to avoid
392 if (xen_initial_domain() || xen_hvm_domain())
393 first = get_nr_irqs_gsi();
397 irq = irq_alloc_desc_from(first, -1);
399 if (irq == -ENOMEM && first > NR_IRQS_LEGACY) {
400 printk(KERN_ERR "Out of dynamic IRQ space and eating into GSI space. You should increase nr_irqs\n");
401 first = max(NR_IRQS_LEGACY, first - NR_IRQS_LEGACY);
406 panic("No available IRQ to bind to: increase nr_irqs!\n");
411 static int xen_allocate_irq_gsi(unsigned gsi)
416 * A PV guest has no concept of a GSI (since it has no ACPI
417 * nor access to/knowledge of the physical APICs). Therefore
418 * all IRQs are dynamically allocated from the entire IRQ
421 if (xen_pv_domain() && !xen_initial_domain())
422 return xen_allocate_irq_dynamic();
424 /* Legacy IRQ descriptors are already allocated by the arch. */
425 if (gsi < NR_IRQS_LEGACY)
428 irq = irq_alloc_desc_at(gsi, -1);
430 panic("Unable to allocate to IRQ%d (%d)\n", gsi, irq);
435 static void xen_free_irq(unsigned irq)
437 /* Legacy IRQ descriptors are managed by the arch. */
438 if (irq < NR_IRQS_LEGACY)
444 static void pirq_unmask_notify(int irq)
446 struct physdev_eoi eoi = { .irq = pirq_from_irq(irq) };
448 if (unlikely(pirq_needs_eoi(irq))) {
449 int rc = HYPERVISOR_physdev_op(PHYSDEVOP_eoi, &eoi);
454 static void pirq_query_unmask(int irq)
456 struct physdev_irq_status_query irq_status;
457 struct irq_info *info = info_for_irq(irq);
459 BUG_ON(info->type != IRQT_PIRQ);
461 irq_status.irq = pirq_from_irq(irq);
462 if (HYPERVISOR_physdev_op(PHYSDEVOP_irq_status_query, &irq_status))
463 irq_status.flags = 0;
465 info->u.pirq.flags &= ~PIRQ_NEEDS_EOI;
466 if (irq_status.flags & XENIRQSTAT_needs_eoi)
467 info->u.pirq.flags |= PIRQ_NEEDS_EOI;
470 static bool probing_irq(int irq)
472 struct irq_desc *desc = irq_to_desc(irq);
474 return desc && desc->action == NULL;
477 static unsigned int __startup_pirq(unsigned int irq)
479 struct evtchn_bind_pirq bind_pirq;
480 struct irq_info *info = info_for_irq(irq);
481 int evtchn = evtchn_from_irq(irq);
484 BUG_ON(info->type != IRQT_PIRQ);
486 if (VALID_EVTCHN(evtchn))
489 bind_pirq.pirq = pirq_from_irq(irq);
490 /* NB. We are happy to share unless we are probing. */
491 bind_pirq.flags = info->u.pirq.flags & PIRQ_SHAREABLE ?
492 BIND_PIRQ__WILL_SHARE : 0;
493 rc = HYPERVISOR_event_channel_op(EVTCHNOP_bind_pirq, &bind_pirq);
495 if (!probing_irq(irq))
496 printk(KERN_INFO "Failed to obtain physical IRQ %d\n",
500 evtchn = bind_pirq.port;
502 pirq_query_unmask(irq);
504 evtchn_to_irq[evtchn] = irq;
505 bind_evtchn_to_cpu(evtchn, 0);
506 info->evtchn = evtchn;
509 unmask_evtchn(evtchn);
510 pirq_unmask_notify(irq);
515 static unsigned int startup_pirq(struct irq_data *data)
517 return __startup_pirq(data->irq);
520 static void shutdown_pirq(struct irq_data *data)
522 struct evtchn_close close;
523 unsigned int irq = data->irq;
524 struct irq_info *info = info_for_irq(irq);
525 int evtchn = evtchn_from_irq(irq);
527 BUG_ON(info->type != IRQT_PIRQ);
529 if (!VALID_EVTCHN(evtchn))
535 if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
538 bind_evtchn_to_cpu(evtchn, 0);
539 evtchn_to_irq[evtchn] = -1;
543 static void enable_pirq(struct irq_data *data)
548 static void disable_pirq(struct irq_data *data)
552 static void ack_pirq(struct irq_data *data)
554 int evtchn = evtchn_from_irq(data->irq);
556 move_native_irq(data->irq);
558 if (VALID_EVTCHN(evtchn)) {
560 clear_evtchn(evtchn);
564 static int find_irq_by_gsi(unsigned gsi)
568 for (irq = 0; irq < nr_irqs; irq++) {
569 struct irq_info *info = info_for_irq(irq);
571 if (info == NULL || info->type != IRQT_PIRQ)
574 if (gsi_from_irq(irq) == gsi)
581 int xen_allocate_pirq(unsigned gsi, int shareable, char *name)
583 return xen_map_pirq_gsi(gsi, gsi, shareable, name);
587 * Do not make any assumptions regarding the relationship between the
588 * IRQ number returned here and the Xen pirq argument.
590 * Note: We don't assign an event channel until the irq actually started
591 * up. Return an existing irq if we've already got one for the gsi.
593 int xen_map_pirq_gsi(unsigned pirq, unsigned gsi, int shareable, char *name)
596 struct physdev_irq irq_op;
598 spin_lock(&irq_mapping_update_lock);
600 if ((pirq > nr_irqs) || (gsi > nr_irqs)) {
601 printk(KERN_WARNING "xen_map_pirq_gsi: %s %s is incorrect!\n",
602 pirq > nr_irqs ? "pirq" :"",
603 gsi > nr_irqs ? "gsi" : "");
607 irq = find_irq_by_gsi(gsi);
609 printk(KERN_INFO "xen_map_pirq_gsi: returning irq %d for gsi %u\n",
611 goto out; /* XXX need refcount? */
614 irq = xen_allocate_irq_gsi(gsi);
616 set_irq_chip_and_handler_name(irq, &xen_pirq_chip,
617 handle_level_irq, name);
622 /* Only the privileged domain can do this. For non-priv, the pcifront
623 * driver provides a PCI bus that does the call to do exactly
624 * this in the priv domain. */
625 if (xen_initial_domain() &&
626 HYPERVISOR_physdev_op(PHYSDEVOP_alloc_irq_vector, &irq_op)) {
632 irq_info[irq] = mk_pirq_info(0, pirq, gsi, irq_op.vector);
633 irq_info[irq].u.pirq.flags |= shareable ? PIRQ_SHAREABLE : 0;
634 pirq_to_irq[pirq] = irq;
637 spin_unlock(&irq_mapping_update_lock);
642 #ifdef CONFIG_PCI_MSI
643 int xen_allocate_pirq_msi(struct pci_dev *dev, struct msi_desc *msidesc)
646 struct physdev_get_free_pirq op_get_free_pirq;
648 op_get_free_pirq.type = MAP_PIRQ_TYPE_MSI;
649 rc = HYPERVISOR_physdev_op(PHYSDEVOP_get_free_pirq, &op_get_free_pirq);
651 WARN_ONCE(rc == -ENOSYS,
652 "hypervisor does not support the PHYSDEVOP_get_free_pirq interface\n");
654 return rc ? -1 : op_get_free_pirq.pirq;
657 int xen_bind_pirq_msi_to_irq(struct pci_dev *dev, struct msi_desc *msidesc,
658 int pirq, int vector, const char *name)
662 spin_lock(&irq_mapping_update_lock);
664 irq = xen_allocate_irq_dynamic();
668 set_irq_chip_and_handler_name(irq, &xen_pirq_chip,
669 handle_level_irq, name);
671 irq_info[irq] = mk_pirq_info(0, pirq, 0, vector);
672 pirq_to_irq[pirq] = irq;
673 ret = set_irq_msi(irq, msidesc);
677 spin_unlock(&irq_mapping_update_lock);
680 spin_unlock(&irq_mapping_update_lock);
686 int xen_destroy_irq(int irq)
688 struct irq_desc *desc;
689 struct physdev_unmap_pirq unmap_irq;
690 struct irq_info *info = info_for_irq(irq);
693 spin_lock(&irq_mapping_update_lock);
695 desc = irq_to_desc(irq);
699 if (xen_initial_domain()) {
700 unmap_irq.pirq = info->u.pirq.pirq;
701 unmap_irq.domid = DOMID_SELF;
702 rc = HYPERVISOR_physdev_op(PHYSDEVOP_unmap_pirq, &unmap_irq);
704 printk(KERN_WARNING "unmap irq failed %d\n", rc);
708 pirq_to_irq[info->u.pirq.pirq] = -1;
710 irq_info[irq] = mk_unbound_info();
715 spin_unlock(&irq_mapping_update_lock);
719 int xen_vector_from_irq(unsigned irq)
721 return vector_from_irq(irq);
724 int xen_gsi_from_irq(unsigned irq)
726 return gsi_from_irq(irq);
729 int xen_irq_from_pirq(unsigned pirq)
731 return pirq_to_irq[pirq];
734 int bind_evtchn_to_irq(unsigned int evtchn)
738 spin_lock(&irq_mapping_update_lock);
740 irq = evtchn_to_irq[evtchn];
743 irq = xen_allocate_irq_dynamic();
745 set_irq_chip_and_handler_name(irq, &xen_dynamic_chip,
746 handle_fasteoi_irq, "event");
748 evtchn_to_irq[evtchn] = irq;
749 irq_info[irq] = mk_evtchn_info(evtchn);
752 spin_unlock(&irq_mapping_update_lock);
756 EXPORT_SYMBOL_GPL(bind_evtchn_to_irq);
758 static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
760 struct evtchn_bind_ipi bind_ipi;
763 spin_lock(&irq_mapping_update_lock);
765 irq = per_cpu(ipi_to_irq, cpu)[ipi];
768 irq = xen_allocate_irq_dynamic();
772 set_irq_chip_and_handler_name(irq, &xen_percpu_chip,
773 handle_percpu_irq, "ipi");
776 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
779 evtchn = bind_ipi.port;
781 evtchn_to_irq[evtchn] = irq;
782 irq_info[irq] = mk_ipi_info(evtchn, ipi);
783 per_cpu(ipi_to_irq, cpu)[ipi] = irq;
785 bind_evtchn_to_cpu(evtchn, cpu);
789 spin_unlock(&irq_mapping_update_lock);
794 int bind_virq_to_irq(unsigned int virq, unsigned int cpu)
796 struct evtchn_bind_virq bind_virq;
799 spin_lock(&irq_mapping_update_lock);
801 irq = per_cpu(virq_to_irq, cpu)[virq];
804 irq = xen_allocate_irq_dynamic();
806 set_irq_chip_and_handler_name(irq, &xen_percpu_chip,
807 handle_percpu_irq, "virq");
809 bind_virq.virq = virq;
810 bind_virq.vcpu = cpu;
811 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
814 evtchn = bind_virq.port;
816 evtchn_to_irq[evtchn] = irq;
817 irq_info[irq] = mk_virq_info(evtchn, virq);
819 per_cpu(virq_to_irq, cpu)[virq] = irq;
821 bind_evtchn_to_cpu(evtchn, cpu);
824 spin_unlock(&irq_mapping_update_lock);
829 static void unbind_from_irq(unsigned int irq)
831 struct evtchn_close close;
832 int evtchn = evtchn_from_irq(irq);
834 spin_lock(&irq_mapping_update_lock);
836 if (VALID_EVTCHN(evtchn)) {
838 if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
841 switch (type_from_irq(irq)) {
843 per_cpu(virq_to_irq, cpu_from_evtchn(evtchn))
844 [virq_from_irq(irq)] = -1;
847 per_cpu(ipi_to_irq, cpu_from_evtchn(evtchn))
848 [ipi_from_irq(irq)] = -1;
854 /* Closed ports are implicitly re-bound to VCPU0. */
855 bind_evtchn_to_cpu(evtchn, 0);
857 evtchn_to_irq[evtchn] = -1;
860 if (irq_info[irq].type != IRQT_UNBOUND) {
861 irq_info[irq] = mk_unbound_info();
866 spin_unlock(&irq_mapping_update_lock);
869 int bind_evtchn_to_irqhandler(unsigned int evtchn,
870 irq_handler_t handler,
871 unsigned long irqflags,
872 const char *devname, void *dev_id)
877 irq = bind_evtchn_to_irq(evtchn);
878 retval = request_irq(irq, handler, irqflags, devname, dev_id);
880 unbind_from_irq(irq);
886 EXPORT_SYMBOL_GPL(bind_evtchn_to_irqhandler);
888 int bind_virq_to_irqhandler(unsigned int virq, unsigned int cpu,
889 irq_handler_t handler,
890 unsigned long irqflags, const char *devname, void *dev_id)
895 irq = bind_virq_to_irq(virq, cpu);
896 retval = request_irq(irq, handler, irqflags, devname, dev_id);
898 unbind_from_irq(irq);
904 EXPORT_SYMBOL_GPL(bind_virq_to_irqhandler);
906 int bind_ipi_to_irqhandler(enum ipi_vector ipi,
908 irq_handler_t handler,
909 unsigned long irqflags,
915 irq = bind_ipi_to_irq(ipi, cpu);
919 irqflags |= IRQF_NO_SUSPEND | IRQF_FORCE_RESUME;
920 retval = request_irq(irq, handler, irqflags, devname, dev_id);
922 unbind_from_irq(irq);
929 void unbind_from_irqhandler(unsigned int irq, void *dev_id)
931 free_irq(irq, dev_id);
932 unbind_from_irq(irq);
934 EXPORT_SYMBOL_GPL(unbind_from_irqhandler);
936 void xen_send_IPI_one(unsigned int cpu, enum ipi_vector vector)
938 int irq = per_cpu(ipi_to_irq, cpu)[vector];
940 notify_remote_via_irq(irq);
943 irqreturn_t xen_debug_interrupt(int irq, void *dev_id)
945 struct shared_info *sh = HYPERVISOR_shared_info;
946 int cpu = smp_processor_id();
947 unsigned long *cpu_evtchn = cpu_evtchn_mask(cpu);
950 static DEFINE_SPINLOCK(debug_lock);
953 spin_lock_irqsave(&debug_lock, flags);
955 printk("\nvcpu %d\n ", cpu);
957 for_each_online_cpu(i) {
959 v = per_cpu(xen_vcpu, i);
960 pending = (get_irq_regs() && i == cpu)
961 ? xen_irqs_disabled(get_irq_regs())
962 : v->evtchn_upcall_mask;
963 printk("%d: masked=%d pending=%d event_sel %0*lx\n ", i,
964 pending, v->evtchn_upcall_pending,
965 (int)(sizeof(v->evtchn_pending_sel)*2),
966 v->evtchn_pending_sel);
968 v = per_cpu(xen_vcpu, cpu);
970 printk("\npending:\n ");
971 for (i = ARRAY_SIZE(sh->evtchn_pending)-1; i >= 0; i--)
972 printk("%0*lx%s", (int)sizeof(sh->evtchn_pending[0])*2,
973 sh->evtchn_pending[i],
974 i % 8 == 0 ? "\n " : " ");
975 printk("\nglobal mask:\n ");
976 for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--)
978 (int)(sizeof(sh->evtchn_mask[0])*2),
980 i % 8 == 0 ? "\n " : " ");
982 printk("\nglobally unmasked:\n ");
983 for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--)
984 printk("%0*lx%s", (int)(sizeof(sh->evtchn_mask[0])*2),
985 sh->evtchn_pending[i] & ~sh->evtchn_mask[i],
986 i % 8 == 0 ? "\n " : " ");
988 printk("\nlocal cpu%d mask:\n ", cpu);
989 for (i = (NR_EVENT_CHANNELS/BITS_PER_LONG)-1; i >= 0; i--)
990 printk("%0*lx%s", (int)(sizeof(cpu_evtchn[0])*2),
992 i % 8 == 0 ? "\n " : " ");
994 printk("\nlocally unmasked:\n ");
995 for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--) {
996 unsigned long pending = sh->evtchn_pending[i]
997 & ~sh->evtchn_mask[i]
999 printk("%0*lx%s", (int)(sizeof(sh->evtchn_mask[0])*2),
1000 pending, i % 8 == 0 ? "\n " : " ");
1003 printk("\npending list:\n");
1004 for (i = 0; i < NR_EVENT_CHANNELS; i++) {
1005 if (sync_test_bit(i, sh->evtchn_pending)) {
1006 int word_idx = i / BITS_PER_LONG;
1007 printk(" %d: event %d -> irq %d%s%s%s\n",
1008 cpu_from_evtchn(i), i,
1010 sync_test_bit(word_idx, &v->evtchn_pending_sel)
1012 !sync_test_bit(i, sh->evtchn_mask)
1013 ? "" : " globally-masked",
1014 sync_test_bit(i, cpu_evtchn)
1015 ? "" : " locally-masked");
1019 spin_unlock_irqrestore(&debug_lock, flags);
1024 static DEFINE_PER_CPU(unsigned, xed_nesting_count);
1027 * Search the CPUs pending events bitmasks. For each one found, map
1028 * the event number to an irq, and feed it into do_IRQ() for
1031 * Xen uses a two-level bitmap to speed searching. The first level is
1032 * a bitset of words which contain pending event bits. The second
1033 * level is a bitset of pending events themselves.
1035 static void __xen_evtchn_do_upcall(void)
1037 int cpu = get_cpu();
1038 struct shared_info *s = HYPERVISOR_shared_info;
1039 struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);
1043 unsigned long pending_words;
1045 vcpu_info->evtchn_upcall_pending = 0;
1047 if (__this_cpu_inc_return(xed_nesting_count) - 1)
1050 #ifndef CONFIG_X86 /* No need for a barrier -- XCHG is a barrier on x86. */
1051 /* Clear master flag /before/ clearing selector flag. */
1054 pending_words = xchg(&vcpu_info->evtchn_pending_sel, 0);
1055 while (pending_words != 0) {
1056 unsigned long pending_bits;
1057 int word_idx = __ffs(pending_words);
1058 pending_words &= ~(1UL << word_idx);
1060 while ((pending_bits = active_evtchns(cpu, s, word_idx)) != 0) {
1061 int bit_idx = __ffs(pending_bits);
1062 int port = (word_idx * BITS_PER_LONG) + bit_idx;
1063 int irq = evtchn_to_irq[port];
1064 struct irq_desc *desc;
1070 desc = irq_to_desc(irq);
1072 generic_handle_irq_desc(irq, desc);
1077 BUG_ON(!irqs_disabled());
1079 count = __this_cpu_read(xed_nesting_count);
1080 __this_cpu_write(xed_nesting_count, 0);
1081 } while (count != 1 || vcpu_info->evtchn_upcall_pending);
1088 void xen_evtchn_do_upcall(struct pt_regs *regs)
1090 struct pt_regs *old_regs = set_irq_regs(regs);
1095 __xen_evtchn_do_upcall();
1098 set_irq_regs(old_regs);
1101 void xen_hvm_evtchn_do_upcall(void)
1103 __xen_evtchn_do_upcall();
1105 EXPORT_SYMBOL_GPL(xen_hvm_evtchn_do_upcall);
1107 /* Rebind a new event channel to an existing irq. */
1108 void rebind_evtchn_irq(int evtchn, int irq)
1110 struct irq_info *info = info_for_irq(irq);
1112 /* Make sure the irq is masked, since the new event channel
1113 will also be masked. */
1116 spin_lock(&irq_mapping_update_lock);
1118 /* After resume the irq<->evtchn mappings are all cleared out */
1119 BUG_ON(evtchn_to_irq[evtchn] != -1);
1120 /* Expect irq to have been bound before,
1121 so there should be a proper type */
1122 BUG_ON(info->type == IRQT_UNBOUND);
1124 evtchn_to_irq[evtchn] = irq;
1125 irq_info[irq] = mk_evtchn_info(evtchn);
1127 spin_unlock(&irq_mapping_update_lock);
1129 /* new event channels are always bound to cpu 0 */
1130 irq_set_affinity(irq, cpumask_of(0));
1132 /* Unmask the event channel. */
1136 /* Rebind an evtchn so that it gets delivered to a specific cpu */
1137 static int rebind_irq_to_cpu(unsigned irq, unsigned tcpu)
1139 struct evtchn_bind_vcpu bind_vcpu;
1140 int evtchn = evtchn_from_irq(irq);
1142 if (!VALID_EVTCHN(evtchn))
1146 * Events delivered via platform PCI interrupts are always
1147 * routed to vcpu 0 and hence cannot be rebound.
1149 if (xen_hvm_domain() && !xen_have_vector_callback)
1152 /* Send future instances of this interrupt to other vcpu. */
1153 bind_vcpu.port = evtchn;
1154 bind_vcpu.vcpu = tcpu;
1157 * If this fails, it usually just indicates that we're dealing with a
1158 * virq or IPI channel, which don't actually need to be rebound. Ignore
1159 * it, but don't do the xenlinux-level rebind in that case.
1161 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_vcpu, &bind_vcpu) >= 0)
1162 bind_evtchn_to_cpu(evtchn, tcpu);
1167 static int set_affinity_irq(struct irq_data *data, const struct cpumask *dest,
1170 unsigned tcpu = cpumask_first(dest);
1172 return rebind_irq_to_cpu(data->irq, tcpu);
1175 int resend_irq_on_evtchn(unsigned int irq)
1177 int masked, evtchn = evtchn_from_irq(irq);
1178 struct shared_info *s = HYPERVISOR_shared_info;
1180 if (!VALID_EVTCHN(evtchn))
1183 masked = sync_test_and_set_bit(evtchn, s->evtchn_mask);
1184 sync_set_bit(evtchn, s->evtchn_pending);
1186 unmask_evtchn(evtchn);
1191 static void enable_dynirq(struct irq_data *data)
1193 int evtchn = evtchn_from_irq(data->irq);
1195 if (VALID_EVTCHN(evtchn))
1196 unmask_evtchn(evtchn);
1199 static void disable_dynirq(struct irq_data *data)
1201 int evtchn = evtchn_from_irq(data->irq);
1203 if (VALID_EVTCHN(evtchn))
1204 mask_evtchn(evtchn);
1207 static void ack_dynirq(struct irq_data *data)
1209 int evtchn = evtchn_from_irq(data->irq);
1211 move_masked_irq(data->irq);
1213 if (VALID_EVTCHN(evtchn))
1214 unmask_evtchn(evtchn);
1217 static int retrigger_dynirq(struct irq_data *data)
1219 int evtchn = evtchn_from_irq(data->irq);
1220 struct shared_info *sh = HYPERVISOR_shared_info;
1223 if (VALID_EVTCHN(evtchn)) {
1226 masked = sync_test_and_set_bit(evtchn, sh->evtchn_mask);
1227 sync_set_bit(evtchn, sh->evtchn_pending);
1229 unmask_evtchn(evtchn);
1236 static void restore_cpu_pirqs(void)
1238 int pirq, rc, irq, gsi;
1239 struct physdev_map_pirq map_irq;
1241 for (pirq = 0; pirq < nr_irqs; pirq++) {
1242 irq = pirq_to_irq[pirq];
1246 /* save/restore of PT devices doesn't work, so at this point the
1247 * only devices present are GSI based emulated devices */
1248 gsi = gsi_from_irq(irq);
1252 map_irq.domid = DOMID_SELF;
1253 map_irq.type = MAP_PIRQ_TYPE_GSI;
1254 map_irq.index = gsi;
1255 map_irq.pirq = pirq;
1257 rc = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq);
1259 printk(KERN_WARNING "xen map irq failed gsi=%d irq=%d pirq=%d rc=%d\n",
1260 gsi, irq, pirq, rc);
1261 irq_info[irq] = mk_unbound_info();
1262 pirq_to_irq[pirq] = -1;
1266 printk(KERN_DEBUG "xen: --> irq=%d, pirq=%d\n", irq, map_irq.pirq);
1268 __startup_pirq(irq);
1272 static void restore_cpu_virqs(unsigned int cpu)
1274 struct evtchn_bind_virq bind_virq;
1275 int virq, irq, evtchn;
1277 for (virq = 0; virq < NR_VIRQS; virq++) {
1278 if ((irq = per_cpu(virq_to_irq, cpu)[virq]) == -1)
1281 BUG_ON(virq_from_irq(irq) != virq);
1283 /* Get a new binding from Xen. */
1284 bind_virq.virq = virq;
1285 bind_virq.vcpu = cpu;
1286 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
1289 evtchn = bind_virq.port;
1291 /* Record the new mapping. */
1292 evtchn_to_irq[evtchn] = irq;
1293 irq_info[irq] = mk_virq_info(evtchn, virq);
1294 bind_evtchn_to_cpu(evtchn, cpu);
1298 static void restore_cpu_ipis(unsigned int cpu)
1300 struct evtchn_bind_ipi bind_ipi;
1301 int ipi, irq, evtchn;
1303 for (ipi = 0; ipi < XEN_NR_IPIS; ipi++) {
1304 if ((irq = per_cpu(ipi_to_irq, cpu)[ipi]) == -1)
1307 BUG_ON(ipi_from_irq(irq) != ipi);
1309 /* Get a new binding from Xen. */
1310 bind_ipi.vcpu = cpu;
1311 if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
1314 evtchn = bind_ipi.port;
1316 /* Record the new mapping. */
1317 evtchn_to_irq[evtchn] = irq;
1318 irq_info[irq] = mk_ipi_info(evtchn, ipi);
1319 bind_evtchn_to_cpu(evtchn, cpu);
1323 /* Clear an irq's pending state, in preparation for polling on it */
1324 void xen_clear_irq_pending(int irq)
1326 int evtchn = evtchn_from_irq(irq);
1328 if (VALID_EVTCHN(evtchn))
1329 clear_evtchn(evtchn);
1331 EXPORT_SYMBOL(xen_clear_irq_pending);
1332 void xen_set_irq_pending(int irq)
1334 int evtchn = evtchn_from_irq(irq);
1336 if (VALID_EVTCHN(evtchn))
1340 bool xen_test_irq_pending(int irq)
1342 int evtchn = evtchn_from_irq(irq);
1345 if (VALID_EVTCHN(evtchn))
1346 ret = test_evtchn(evtchn);
1351 /* Poll waiting for an irq to become pending with timeout. In the usual case,
1352 * the irq will be disabled so it won't deliver an interrupt. */
1353 void xen_poll_irq_timeout(int irq, u64 timeout)
1355 evtchn_port_t evtchn = evtchn_from_irq(irq);
1357 if (VALID_EVTCHN(evtchn)) {
1358 struct sched_poll poll;
1361 poll.timeout = timeout;
1362 set_xen_guest_handle(poll.ports, &evtchn);
1364 if (HYPERVISOR_sched_op(SCHEDOP_poll, &poll) != 0)
1368 EXPORT_SYMBOL(xen_poll_irq_timeout);
1369 /* Poll waiting for an irq to become pending. In the usual case, the
1370 * irq will be disabled so it won't deliver an interrupt. */
1371 void xen_poll_irq(int irq)
1373 xen_poll_irq_timeout(irq, 0 /* no timeout */);
1376 void xen_irq_resume(void)
1378 unsigned int cpu, irq, evtchn;
1380 init_evtchn_cpu_bindings();
1382 /* New event-channel space is not 'live' yet. */
1383 for (evtchn = 0; evtchn < NR_EVENT_CHANNELS; evtchn++)
1384 mask_evtchn(evtchn);
1386 /* No IRQ <-> event-channel mappings. */
1387 for (irq = 0; irq < nr_irqs; irq++)
1388 irq_info[irq].evtchn = 0; /* zap event-channel binding */
1390 for (evtchn = 0; evtchn < NR_EVENT_CHANNELS; evtchn++)
1391 evtchn_to_irq[evtchn] = -1;
1393 for_each_possible_cpu(cpu) {
1394 restore_cpu_virqs(cpu);
1395 restore_cpu_ipis(cpu);
1398 restore_cpu_pirqs();
1401 static struct irq_chip xen_dynamic_chip __read_mostly = {
1404 .irq_disable = disable_dynirq,
1405 .irq_mask = disable_dynirq,
1406 .irq_unmask = enable_dynirq,
1408 .irq_eoi = ack_dynirq,
1409 .irq_set_affinity = set_affinity_irq,
1410 .irq_retrigger = retrigger_dynirq,
1413 static struct irq_chip xen_pirq_chip __read_mostly = {
1416 .irq_startup = startup_pirq,
1417 .irq_shutdown = shutdown_pirq,
1419 .irq_enable = enable_pirq,
1420 .irq_unmask = enable_pirq,
1422 .irq_disable = disable_pirq,
1423 .irq_mask = disable_pirq,
1425 .irq_ack = ack_pirq,
1427 .irq_set_affinity = set_affinity_irq,
1429 .irq_retrigger = retrigger_dynirq,
1432 static struct irq_chip xen_percpu_chip __read_mostly = {
1433 .name = "xen-percpu",
1435 .irq_disable = disable_dynirq,
1436 .irq_mask = disable_dynirq,
1437 .irq_unmask = enable_dynirq,
1439 .irq_ack = ack_dynirq,
1442 int xen_set_callback_via(uint64_t via)
1444 struct xen_hvm_param a;
1445 a.domid = DOMID_SELF;
1446 a.index = HVM_PARAM_CALLBACK_IRQ;
1448 return HYPERVISOR_hvm_op(HVMOP_set_param, &a);
1450 EXPORT_SYMBOL_GPL(xen_set_callback_via);
1452 #ifdef CONFIG_XEN_PVHVM
1453 /* Vector callbacks are better than PCI interrupts to receive event
1454 * channel notifications because we can receive vector callbacks on any
1455 * vcpu and we don't need PCI support or APIC interactions. */
1456 void xen_callback_vector(void)
1459 uint64_t callback_via;
1460 if (xen_have_vector_callback) {
1461 callback_via = HVM_CALLBACK_VECTOR(XEN_HVM_EVTCHN_CALLBACK);
1462 rc = xen_set_callback_via(callback_via);
1464 printk(KERN_ERR "Request for Xen HVM callback vector"
1466 xen_have_vector_callback = 0;
1469 printk(KERN_INFO "Xen HVM callback vector for event delivery is "
1471 /* in the restore case the vector has already been allocated */
1472 if (!test_bit(XEN_HVM_EVTCHN_CALLBACK, used_vectors))
1473 alloc_intr_gate(XEN_HVM_EVTCHN_CALLBACK, xen_hvm_callback_vector);
1477 void xen_callback_vector(void) {}
1480 void __init xen_init_IRQ(void)
1484 cpu_evtchn_mask_p = kcalloc(nr_cpu_ids, sizeof(struct cpu_evtchn_s),
1486 irq_info = kcalloc(nr_irqs, sizeof(*irq_info), GFP_KERNEL);
1488 /* We are using nr_irqs as the maximum number of pirq available but
1489 * that number is actually chosen by Xen and we don't know exactly
1490 * what it is. Be careful choosing high pirq numbers. */
1491 pirq_to_irq = kcalloc(nr_irqs, sizeof(*pirq_to_irq), GFP_KERNEL);
1492 for (i = 0; i < nr_irqs; i++)
1493 pirq_to_irq[i] = -1;
1495 evtchn_to_irq = kcalloc(NR_EVENT_CHANNELS, sizeof(*evtchn_to_irq),
1497 for (i = 0; i < NR_EVENT_CHANNELS; i++)
1498 evtchn_to_irq[i] = -1;
1500 init_evtchn_cpu_bindings();
1502 /* No event channels are 'live' right now. */
1503 for (i = 0; i < NR_EVENT_CHANNELS; i++)
1506 if (xen_hvm_domain()) {
1507 xen_callback_vector();
1509 /* pci_xen_hvm_init must be called after native_init_IRQ so that
1510 * __acpi_register_gsi can point at the right function */
1513 irq_ctx_init(smp_processor_id());
1514 if (xen_initial_domain())