/* * 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. * 4. PIRQs - Hardware interrupts. * * Jeremy Fitzhardinge , XenSource Inc, 2007 */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * 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. */ static DEFINE_PER_CPU(int [NR_VIRQS], virq_to_irq) = {[0 ... NR_VIRQS-1] = -1}; /* IRQ <-> IPI mapping */ static DEFINE_PER_CPU(int [XEN_NR_IPIS], ipi_to_irq) = {[0 ... XEN_NR_IPIS-1] = -1}; /* Interrupt types. */ enum xen_irq_type { IRQT_UNBOUND = 0, IRQT_PIRQ, IRQT_VIRQ, IRQT_IPI, IRQT_EVTCHN }; /* * 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: * PIRQ - vector, with MSB being "needs EIO" * 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 { unsigned short pirq; unsigned short gsi; unsigned char vector; unsigned char flags; } pirq; } u; }; #define PIRQ_NEEDS_EOI (1 << 0) #define PIRQ_SHAREABLE (1 << 1) static struct irq_info *irq_info; static int *pirq_to_irq; static int nr_pirqs; static int *evtchn_to_irq; struct cpu_evtchn_s { unsigned long bits[NR_EVENT_CHANNELS/BITS_PER_LONG]; }; 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; static inline unsigned long *cpu_evtchn_mask(int cpu) { return cpu_evtchn_mask_p[cpu].bits; } /* Xen will never allocate port zero for any purpose. */ #define VALID_EVTCHN(chn) ((chn) != 0) static struct irq_chip xen_dynamic_chip; static struct irq_chip xen_percpu_chip; static struct irq_chip xen_pirq_chip; /* Constructor for packed IRQ information. */ 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) { return (struct irq_info) { .type = IRQT_EVTCHN, .evtchn = evtchn, .cpu = 0 }; } static struct irq_info mk_ipi_info(unsigned short evtchn, enum ipi_vector ipi) { return (struct irq_info) { .type = IRQT_IPI, .evtchn = evtchn, .cpu = 0, .u.ipi = ipi }; } static struct irq_info mk_virq_info(unsigned short evtchn, unsigned short virq) { return (struct irq_info) { .type = IRQT_VIRQ, .evtchn = evtchn, .cpu = 0, .u.virq = virq }; } static struct irq_info mk_pirq_info(unsigned short evtchn, unsigned short pirq, unsigned short gsi, unsigned short vector) { return (struct irq_info) { .type = IRQT_PIRQ, .evtchn = evtchn, .cpu = 0, .u.pirq = { .pirq = pirq, .gsi = gsi, .vector = vector } }; } /* * Accessors for packed IRQ information. */ static struct irq_info *info_for_irq(unsigned irq) { return &irq_info[irq]; } static unsigned int evtchn_from_irq(unsigned irq) { return info_for_irq(irq)->evtchn; } unsigned irq_from_evtchn(unsigned int evtchn) { return evtchn_to_irq[evtchn]; } EXPORT_SYMBOL_GPL(irq_from_evtchn); static enum ipi_vector ipi_from_irq(unsigned irq) { 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; } 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; } 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; } 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; } static inline unsigned long active_evtchns(unsigned int cpu, struct shared_info *sh, unsigned int idx) { return (sh->evtchn_pending[idx] & cpu_evtchn_mask(cpu)[idx] & ~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 cpumask_copy(irq_to_desc(irq)->affinity, cpumask_of(cpu)); #endif __clear_bit(chn, cpu_evtchn_mask(cpu_from_irq(irq))); __set_bit(chn, cpu_evtchn_mask(cpu)); irq_info[irq].cpu = cpu; } static void init_evtchn_cpu_bindings(void) { #ifdef CONFIG_SMP struct irq_desc *desc; int i; /* By default all event channels notify CPU#0. */ for_each_irq_desc(i, desc) { cpumask_copy(desc->affinity, cpumask_of(0)); } #endif memset(cpu_evtchn_mask(0), ~0, sizeof(cpu_evtchn_mask(0))); } 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]); } static inline int test_evtchn(int port) { struct shared_info *s = HYPERVISOR_shared_info; return sync_test_bit(port, &s->evtchn_pending[0]); } /** * 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(); } static int get_nr_hw_irqs(void) { int ret = 1; #ifdef CONFIG_X86_IO_APIC ret = get_nr_irqs_gsi(); #endif return ret; } /* callers of this function should make sure that PHYSDEVOP_get_nr_pirqs * succeeded otherwise nr_pirqs won't hold the right value */ static int find_unbound_pirq(void) { int i; for (i = nr_pirqs-1; i >= 0; i--) { if (pirq_to_irq[i] < 0) return i; } return -1; } static int find_unbound_irq(void) { struct irq_data *data; int irq, res; int start = get_nr_hw_irqs(); 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--) { data = irq_get_irq_data(irq); /* only 0->15 have init'd desc; handle irq > 16 */ if (!data) break; if (data->chip == &no_irq_chip) break; if (data->chip != &xen_dynamic_chip) continue; if (irq_info[irq].type == IRQT_UNBOUND) return irq; } if (irq == start) goto no_irqs; res = irq_alloc_desc_at(irq, 0); if (WARN_ON(res != irq)) return -1; return irq; no_irqs: panic("No available IRQ to bind to: increase nr_irqs!\n"); } static bool identity_mapped_irq(unsigned irq) { /* identity map all the hardware irqs */ return irq < get_nr_hw_irqs(); } static void pirq_unmask_notify(int irq) { struct physdev_eoi eoi = { .irq = pirq_from_irq(irq) }; 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); irq_status.irq = pirq_from_irq(irq); 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); int rc; BUG_ON(info->type != IRQT_PIRQ); if (VALID_EVTCHN(evtchn)) goto out; bind_pirq.pirq = pirq_from_irq(irq); /* NB. We are happy to share unless we are probing. */ 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) { 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; for (irq = 0; irq < nr_irqs; irq++) { 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; } 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 * 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. * * One notable exception is when xen_map_pirq_gsi is called passing an * hardware gsi as argument, in that case the irq number returned * 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. */ int xen_map_pirq_gsi(unsigned pirq, unsigned gsi, int shareable, char *name) { int irq = 0; struct physdev_irq irq_op; spin_lock(&irq_mapping_update_lock); 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; } irq = find_irq_by_gsi(gsi); if (irq != -1) { printk(KERN_INFO "xen_map_pirq_gsi: returning irq %d for gsi %u\n", irq, gsi); goto out; /* XXX need refcount? */ } /* 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.*/ if (identity_mapped_irq(gsi) || !xen_initial_domain()) { irq = gsi; irq_alloc_desc_at(irq, 0); } else irq = find_unbound_irq(); set_irq_chip_and_handler_name(irq, &xen_pirq_chip, handle_level_irq, name); irq_op.irq = irq; 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)) { irq_free_desc(irq); irq = -ENOSPC; goto out; } irq_info[irq] = mk_pirq_info(0, pirq, gsi, irq_op.vector); irq_info[irq].u.pirq.flags |= shareable ? PIRQ_SHAREABLE : 0; pirq_to_irq[pirq] = irq; out: spin_unlock(&irq_mapping_update_lock); return irq; } int xen_destroy_irq(int irq) { struct irq_desc *desc; int rc = -ENOENT; spin_lock(&irq_mapping_update_lock); desc = irq_to_desc(irq); if (!desc) goto out; irq_info[irq] = mk_unbound_info(); irq_free_desc(irq); out: spin_unlock(&irq_mapping_update_lock); return rc; } int xen_vector_from_irq(unsigned irq) { return vector_from_irq(irq); } int xen_gsi_from_irq(unsigned irq) { return gsi_from_irq(irq); } int bind_evtchn_to_irq(unsigned int evtchn) { 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, handle_edge_irq, "event"); evtchn_to_irq[evtchn] = irq; irq_info[irq] = mk_evtchn_info(evtchn); } spin_unlock(&irq_mapping_update_lock); return irq; } EXPORT_SYMBOL_GPL(bind_evtchn_to_irq); 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]; if (irq == -1) { irq = find_unbound_irq(); if (irq < 0) goto out; set_irq_chip_and_handler_name(irq, &xen_percpu_chip, handle_percpu_irq, "ipi"); 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; irq_info[irq] = mk_ipi_info(evtchn, ipi); per_cpu(ipi_to_irq, cpu)[ipi] = irq; bind_evtchn_to_cpu(evtchn, cpu); } out: spin_unlock(&irq_mapping_update_lock); return irq; } static int bind_virq_to_irq(unsigned int virq, unsigned int cpu) { 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) { bind_virq.virq = virq; bind_virq.vcpu = cpu; if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq, &bind_virq) != 0) BUG(); evtchn = bind_virq.port; irq = find_unbound_irq(); set_irq_chip_and_handler_name(irq, &xen_percpu_chip, handle_percpu_irq, "virq"); evtchn_to_irq[evtchn] = irq; irq_info[irq] = mk_virq_info(evtchn, virq); 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); if (VALID_EVTCHN(evtchn)) { 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)) [virq_from_irq(irq)] = -1; break; case IRQT_IPI: per_cpu(ipi_to_irq, cpu_from_evtchn(evtchn)) [ipi_from_irq(irq)] = -1; break; default: break; } /* Closed ports are implicitly re-bound to VCPU0. */ bind_evtchn_to_cpu(evtchn, 0); evtchn_to_irq[evtchn] = -1; } if (irq_info[irq].type != IRQT_UNBOUND) { irq_info[irq] = mk_unbound_info(); irq_free_desc(irq); } spin_unlock(&irq_mapping_update_lock); } int bind_evtchn_to_irqhandler(unsigned int evtchn, irq_handler_t handler, 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, irq_handler_t handler, 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); 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; irqflags |= IRQF_NO_SUSPEND; retval = request_irq(irq, handler, irqflags, devname, dev_id); if (retval != 0) { unbind_from_irq(irq); return retval; } return irq; } 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); 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); } irqreturn_t xen_debug_interrupt(int irq, void *dev_id) { struct shared_info *sh = HYPERVISOR_shared_info; int cpu = smp_processor_id(); int i; unsigned long flags; static DEFINE_SPINLOCK(debug_lock); spin_lock_irqsave(&debug_lock, flags); printk("vcpu %d\n ", cpu); for_each_online_cpu(i) { struct vcpu_info *v = per_cpu(xen_vcpu, i); printk("%d: masked=%d pending=%d event_sel %08lx\n ", i, (get_irq_regs() && i == cpu) ? xen_irqs_disabled(get_irq_regs()) : v->evtchn_upcall_mask, v->evtchn_upcall_pending, v->evtchn_pending_sel); } printk("pending:\n "); for(i = ARRAY_SIZE(sh->evtchn_pending)-1; i >= 0; i--) printk("%08lx%s", sh->evtchn_pending[i], i % 8 == 0 ? "\n " : " "); printk("\nmasks:\n "); for(i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--) printk("%08lx%s", sh->evtchn_mask[i], i % 8 == 0 ? "\n " : " "); printk("\nunmasked:\n "); for(i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--) printk("%08lx%s", sh->evtchn_pending[i] & ~sh->evtchn_mask[i], i % 8 == 0 ? "\n " : " "); printk("\npending list:\n"); for(i = 0; i < NR_EVENT_CHANNELS; i++) { if (sync_test_bit(i, sh->evtchn_pending)) { printk(" %d: event %d -> irq %d\n", cpu_from_evtchn(i), i, evtchn_to_irq[i]); } } spin_unlock_irqrestore(&debug_lock, flags); return IRQ_HANDLED; } static DEFINE_PER_CPU(unsigned, xed_nesting_count); /* * 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. */ static void __xen_evtchn_do_upcall(void) { int cpu = get_cpu(); struct shared_info *s = HYPERVISOR_shared_info; struct vcpu_info *vcpu_info = __get_cpu_var(xen_vcpu); unsigned count; do { unsigned long pending_words; vcpu_info->evtchn_upcall_pending = 0; if (__get_cpu_var(xed_nesting_count)++) goto out; #ifndef CONFIG_X86 /* No need for a barrier -- XCHG is a barrier on x86. */ /* Clear master flag /before/ clearing selector flag. */ wmb(); #endif 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]; struct irq_desc *desc; if (irq != -1) { desc = irq_to_desc(irq); if (desc) generic_handle_irq_desc(irq, desc); } } } BUG_ON(!irqs_disabled()); count = __get_cpu_var(xed_nesting_count); __get_cpu_var(xed_nesting_count) = 0; } while (count != 1 || vcpu_info->evtchn_upcall_pending); out: 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(); irq_exit(); set_irq_regs(old_regs); } void xen_hvm_evtchn_do_upcall(void) { __xen_evtchn_do_upcall(); } EXPORT_SYMBOL_GPL(xen_hvm_evtchn_do_upcall); /* Rebind a new event channel to an existing irq. */ void rebind_evtchn_irq(int evtchn, int irq) { struct irq_info *info = info_for_irq(irq); /* Make sure the irq is masked, since the new event channel will also be masked. */ disable_irq(irq); spin_lock(&irq_mapping_update_lock); /* After resume the irq<->evtchn mappings are all cleared out */ BUG_ON(evtchn_to_irq[evtchn] != -1); /* Expect irq to have been bound before, so there should be a proper type */ BUG_ON(info->type == IRQT_UNBOUND); evtchn_to_irq[evtchn] = irq; irq_info[irq] = mk_evtchn_info(evtchn); spin_unlock(&irq_mapping_update_lock); /* new event channels are always bound to cpu 0 */ irq_set_affinity(irq, cpumask_of(0)); /* Unmask the event channel. */ enable_irq(irq); } /* Rebind an evtchn so that it gets delivered to a specific cpu */ static int rebind_irq_to_cpu(unsigned irq, unsigned tcpu) { struct evtchn_bind_vcpu bind_vcpu; int evtchn = evtchn_from_irq(irq); /* events delivered via platform PCI interrupts are always * routed to vcpu 0 */ if (!VALID_EVTCHN(evtchn) || (xen_hvm_domain() && !xen_have_vector_callback)) return -1; /* 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); return 0; } static int set_affinity_irq(unsigned irq, const struct cpumask *dest) { unsigned tcpu = cpumask_first(dest); return rebind_irq_to_cpu(irq, tcpu); } 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; } 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); move_native_irq(irq); if (VALID_EVTCHN(evtchn)) clear_evtchn(evtchn); } static int retrigger_dynirq(unsigned int irq) { int evtchn = evtchn_from_irq(irq); struct shared_info *sh = HYPERVISOR_shared_info; int ret = 0; if (VALID_EVTCHN(evtchn)) { int masked; masked = sync_test_and_set_bit(evtchn, sh->evtchn_mask); sync_set_bit(evtchn, sh->evtchn_pending); if (!masked) unmask_evtchn(evtchn); ret = 1; } return ret; } 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; BUG_ON(virq_from_irq(irq) != virq); /* 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; irq_info[irq] = mk_virq_info(evtchn, virq); bind_evtchn_to_cpu(evtchn, cpu); /* Ready for use. */ unmask_evtchn(evtchn); } } 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; BUG_ON(ipi_from_irq(irq) != ipi); /* 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; irq_info[irq] = mk_ipi_info(evtchn, ipi); bind_evtchn_to_cpu(evtchn, cpu); /* Ready for use. */ unmask_evtchn(evtchn); } } /* 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); } EXPORT_SYMBOL(xen_clear_irq_pending); 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; } /* 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) { evtchn_port_t evtchn = evtchn_from_irq(irq); if (VALID_EVTCHN(evtchn)) { struct sched_poll poll; poll.nr_ports = 1; poll.timeout = timeout; set_xen_guest_handle(poll.ports, &evtchn); if (HYPERVISOR_sched_op(SCHEDOP_poll, &poll) != 0) BUG(); } } 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 */); } void xen_irq_resume(void) { unsigned int cpu, irq, evtchn; 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. */ for (irq = 0; irq < nr_irqs; irq++) 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); } } static struct irq_chip xen_dynamic_chip __read_mostly = { .name = "xen-dyn", .disable = disable_dynirq, .mask = disable_dynirq, .unmask = enable_dynirq, .ack = ack_dynirq, .set_affinity = set_affinity_irq, .retrigger = retrigger_dynirq, }; 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, }; static struct irq_chip xen_percpu_chip __read_mostly = { .name = "xen-percpu", .disable = disable_dynirq, .mask = disable_dynirq, .unmask = enable_dynirq, .ack = ack_dynirq, }; 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); #ifdef CONFIG_XEN_PVHVM /* 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); } } #else void xen_callback_vector(void) {} #endif void __init xen_init_IRQ(void) { int i, rc; struct physdev_nr_pirqs op_nr_pirqs; cpu_evtchn_mask_p = kcalloc(nr_cpu_ids, sizeof(struct cpu_evtchn_s), GFP_KERNEL); irq_info = kcalloc(nr_irqs, sizeof(*irq_info), GFP_KERNEL); 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++) pirq_to_irq[i] = -1; 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; init_evtchn_cpu_bindings(); /* No event channels are 'live' right now. */ for (i = 0; i < NR_EVENT_CHANNELS; i++) mask_evtchn(i); if (xen_hvm_domain()) { xen_callback_vector(); native_init_IRQ(); } else { irq_ctx_init(smp_processor_id()); } }