/* * 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 received, 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 <jeremy@xensource.com>, XenSource Inc, 2007 */ #include <linux/linkage.h> #include <linux/interrupt.h> #include <linux/irq.h> #include <linux/module.h> #include <linux/string.h> #include <linux/bootmem.h> #include <linux/slab.h> #include <linux/irqnr.h> #include <linux/pci.h> #include <asm/desc.h> #include <asm/ptrace.h> #include <asm/irq.h> #include <asm/idle.h> #include <asm/io_apic.h> #include <asm/sync_bitops.h> #include <asm/xen/page.h> #include <asm/xen/pci.h> #include <asm/xen/hypercall.h> #include <asm/xen/hypervisor.h> #include <xen/xen.h> #include <xen/hvm.h> #include <xen/xen-ops.h> #include <xen/events.h> #include <xen/interface/xen.h> #include <xen/interface/event_channel.h> #include <xen/interface/hvm/hvm_op.h> #include <xen/interface/hvm/params.h> /* * 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_MUTEX(irq_mapping_update_lock); static LIST_HEAD(xen_irq_list_head); /* 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", or physical IRQ of the HVM * guest, or GSI (real passthrough IRQ) of the device. * VIRQ - virq number * IPI - IPI vector * EVTCHN - */ struct irq_info { struct list_head list; int refcnt; enum xen_irq_type type; /* type */ unsigned irq; 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; uint16_t domid; } pirq; } u; }; #define PIRQ_NEEDS_EOI (1 << 0) #define PIRQ_SHAREABLE (1 << 1) static int *evtchn_to_irq; static unsigned long *pirq_eoi_map; static bool (*pirq_needs_eoi)(unsigned irq); static DEFINE_PER_CPU(unsigned long [NR_EVENT_CHANNELS/BITS_PER_LONG], cpu_evtchn_mask); /* 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; static void enable_dynirq(struct irq_data *data); static void disable_dynirq(struct irq_data *data); /* Get info for IRQ */ static struct irq_info *info_for_irq(unsigned irq) { return irq_get_handler_data(irq); } /* Constructors for packed IRQ information. */ static void xen_irq_info_common_init(struct irq_info *info, unsigned irq, enum xen_irq_type type, unsigned short evtchn, unsigned short cpu) { BUG_ON(info->type != IRQT_UNBOUND && info->type != type); info->type = type; info->irq = irq; info->evtchn = evtchn; info->cpu = cpu; evtchn_to_irq[evtchn] = irq; } static void xen_irq_info_evtchn_init(unsigned irq, unsigned short evtchn) { struct irq_info *info = info_for_irq(irq); xen_irq_info_common_init(info, irq, IRQT_EVTCHN, evtchn, 0); } static void xen_irq_info_ipi_init(unsigned cpu, unsigned irq, unsigned short evtchn, enum ipi_vector ipi) { struct irq_info *info = info_for_irq(irq); xen_irq_info_common_init(info, irq, IRQT_IPI, evtchn, 0); info->u.ipi = ipi; per_cpu(ipi_to_irq, cpu)[ipi] = irq; } static void xen_irq_info_virq_init(unsigned cpu, unsigned irq, unsigned short evtchn, unsigned short virq) { struct irq_info *info = info_for_irq(irq); xen_irq_info_common_init(info, irq, IRQT_VIRQ, evtchn, 0); info->u.virq = virq; per_cpu(virq_to_irq, cpu)[virq] = irq; } static void xen_irq_info_pirq_init(unsigned irq, unsigned short evtchn, unsigned short pirq, unsigned short gsi, unsigned short vector, uint16_t domid, unsigned char flags) { struct irq_info *info = info_for_irq(irq); xen_irq_info_common_init(info, irq, IRQT_PIRQ, evtchn, 0); info->u.pirq.pirq = pirq; info->u.pirq.gsi = gsi; info->u.pirq.vector = vector; info->u.pirq.domid = domid; info->u.pirq.flags = flags; } /* * Accessors for packed IRQ information. */ static unsigned int evtchn_from_irq(unsigned irq) { if (unlikely(WARN(irq < 0 || irq >= nr_irqs, "Invalid irq %d!\n", irq))) return 0; 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 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_check_eoi_map(unsigned irq) { return test_bit(pirq_from_irq(irq), pirq_eoi_map); } static bool pirq_needs_eoi_flag(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] & per_cpu(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)->irq_data.affinity, cpumask_of(cpu)); #endif clear_bit(chn, per_cpu(cpu_evtchn_mask, cpu_from_irq(irq))); set_bit(chn, per_cpu(cpu_evtchn_mask, cpu)); info_for_irq(irq)->cpu = cpu; } static void init_evtchn_cpu_bindings(void) { int i; #ifdef CONFIG_SMP struct irq_info *info; /* By default all event channels notify CPU#0. */ list_for_each_entry(info, &xen_irq_list_head, list) { struct irq_desc *desc = irq_to_desc(info->irq); cpumask_copy(desc->irq_data.affinity, cpumask_of(0)); } #endif for_each_possible_cpu(i) memset(per_cpu(cpu_evtchn_mask, i), (i == 0) ? ~0 : 0, sizeof(*per_cpu(cpu_evtchn_mask, i))); } 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 = __this_cpu_read(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 void xen_irq_init(unsigned irq) { struct irq_info *info; #ifdef CONFIG_SMP struct irq_desc *desc = irq_to_desc(irq); /* By default all event channels notify CPU#0. */ cpumask_copy(desc->irq_data.affinity, cpumask_of(0)); #endif info = kzalloc(sizeof(*info), GFP_KERNEL); if (info == NULL) panic("Unable to allocate metadata for IRQ%d\n", irq); info->type = IRQT_UNBOUND; info->refcnt = -1; irq_set_handler_data(irq, info); list_add_tail(&info->list, &xen_irq_list_head); } static int __must_check xen_allocate_irq_dynamic(void) { int first = 0; int irq; #ifdef CONFIG_X86_IO_APIC /* * For an HVM guest or domain 0 which see "real" (emulated or * actual respectively) GSIs we allocate dynamic IRQs * e.g. those corresponding to event channels or MSIs * etc. from the range above those "real" GSIs to avoid * collisions. */ if (xen_initial_domain() || xen_hvm_domain()) first = get_nr_irqs_gsi(); #endif irq = irq_alloc_desc_from(first, -1); if (irq >= 0) xen_irq_init(irq); return irq; } static int __must_check xen_allocate_irq_gsi(unsigned gsi) { int irq; /* * A PV guest has no concept of a GSI (since it has no ACPI * nor access to/knowledge of the physical APICs). Therefore * all IRQs are dynamically allocated from the entire IRQ * space. */ if (xen_pv_domain() && !xen_initial_domain()) return xen_allocate_irq_dynamic(); /* Legacy IRQ descriptors are already allocated by the arch. */ if (gsi < NR_IRQS_LEGACY) irq = gsi; else irq = irq_alloc_desc_at(gsi, -1); xen_irq_init(irq); return irq; } static void xen_free_irq(unsigned irq) { struct irq_info *info = irq_get_handler_data(irq); list_del(&info->list); irq_set_handler_data(irq, NULL); WARN_ON(info->refcnt > 0); kfree(info); /* Legacy IRQ descriptors are managed by the arch. */ if (irq < NR_IRQS_LEGACY) return; irq_free_desc(irq); } 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 void eoi_pirq(struct irq_data *data) { int evtchn = evtchn_from_irq(data->irq); struct physdev_eoi eoi = { .irq = pirq_from_irq(data->irq) }; int rc = 0; irq_move_irq(data); if (VALID_EVTCHN(evtchn)) clear_evtchn(evtchn); if (pirq_needs_eoi(data->irq)) { rc = HYPERVISOR_physdev_op(PHYSDEVOP_eoi, &eoi); WARN_ON(rc); } } static void mask_ack_pirq(struct irq_data *data) { disable_dynirq(data); eoi_pirq(data); } 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); eoi_pirq(irq_get_irq_data(irq)); return 0; } static unsigned int startup_pirq(struct irq_data *data) { return __startup_pirq(data->irq); } static void shutdown_pirq(struct irq_data *data) { struct evtchn_close close; unsigned int irq = data->irq; 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(struct irq_data *data) { startup_pirq(data); } static void disable_pirq(struct irq_data *data) { disable_dynirq(data); } static int find_irq_by_gsi(unsigned gsi) { struct irq_info *info; list_for_each_entry(info, &xen_irq_list_head, list) { if (info->type != IRQT_PIRQ) continue; if (info->u.pirq.gsi == gsi) return info->irq; } return -1; } /* * Do not make any assumptions regarding the relationship between the * IRQ number returned here and the Xen pirq 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. * * Shareable implies level triggered, not shareable implies edge * triggered here. */ int xen_bind_pirq_gsi_to_irq(unsigned gsi, unsigned pirq, int shareable, char *name) { int irq = -1; struct physdev_irq irq_op; mutex_lock(&irq_mapping_update_lock); 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; } irq = xen_allocate_irq_gsi(gsi); if (irq < 0) goto out; 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)) { xen_free_irq(irq); irq = -ENOSPC; goto out; } xen_irq_info_pirq_init(irq, 0, pirq, gsi, irq_op.vector, DOMID_SELF, shareable ? PIRQ_SHAREABLE : 0); pirq_query_unmask(irq); /* We try to use the handler with the appropriate semantic for the * type of interrupt: if the interrupt is an edge triggered * interrupt we use handle_edge_irq. * * On the other hand if the interrupt is level triggered we use * handle_fasteoi_irq like the native code does for this kind of * interrupts. * * Depending on the Xen version, pirq_needs_eoi might return true * not only for level triggered interrupts but for edge triggered * interrupts too. In any case Xen always honors the eoi mechanism, * not injecting any more pirqs of the same kind if the first one * hasn't received an eoi yet. Therefore using the fasteoi handler * is the right choice either way. */ if (shareable) irq_set_chip_and_handler_name(irq, &xen_pirq_chip, handle_fasteoi_irq, name); else irq_set_chip_and_handler_name(irq, &xen_pirq_chip, handle_edge_irq, name); out: mutex_unlock(&irq_mapping_update_lock); return irq; } #ifdef CONFIG_PCI_MSI int xen_allocate_pirq_msi(struct pci_dev *dev, struct msi_desc *msidesc) { int rc; struct physdev_get_free_pirq op_get_free_pirq; op_get_free_pirq.type = MAP_PIRQ_TYPE_MSI; rc = HYPERVISOR_physdev_op(PHYSDEVOP_get_free_pirq, &op_get_free_pirq); WARN_ONCE(rc == -ENOSYS, "hypervisor does not support the PHYSDEVOP_get_free_pirq interface\n"); return rc ? -1 : op_get_free_pirq.pirq; } int xen_bind_pirq_msi_to_irq(struct pci_dev *dev, struct msi_desc *msidesc, int pirq, int vector, const char *name, domid_t domid) { int irq, ret; mutex_lock(&irq_mapping_update_lock); irq = xen_allocate_irq_dynamic(); if (irq < 0) goto out; irq_set_chip_and_handler_name(irq, &xen_pirq_chip, handle_edge_irq, name); xen_irq_info_pirq_init(irq, 0, pirq, 0, vector, domid, 0); ret = irq_set_msi_desc(irq, msidesc); if (ret < 0) goto error_irq; out: mutex_unlock(&irq_mapping_update_lock); return irq; error_irq: mutex_unlock(&irq_mapping_update_lock); xen_free_irq(irq); return ret; } #endif int xen_destroy_irq(int irq) { struct irq_desc *desc; struct physdev_unmap_pirq unmap_irq; struct irq_info *info = info_for_irq(irq); int rc = -ENOENT; mutex_lock(&irq_mapping_update_lock); desc = irq_to_desc(irq); if (!desc) goto out; if (xen_initial_domain()) { unmap_irq.pirq = info->u.pirq.pirq; unmap_irq.domid = info->u.pirq.domid; rc = HYPERVISOR_physdev_op(PHYSDEVOP_unmap_pirq, &unmap_irq); /* If another domain quits without making the pci_disable_msix * call, the Xen hypervisor takes care of freeing the PIRQs * (free_domain_pirqs). */ if ((rc == -ESRCH && info->u.pirq.domid != DOMID_SELF)) printk(KERN_INFO "domain %d does not have %d anymore\n", info->u.pirq.domid, info->u.pirq.pirq); else if (rc) { printk(KERN_WARNING "unmap irq failed %d\n", rc); goto out; } } xen_free_irq(irq); out: mutex_unlock(&irq_mapping_update_lock); return rc; } int xen_irq_from_pirq(unsigned pirq) { int irq; struct irq_info *info; mutex_lock(&irq_mapping_update_lock); list_for_each_entry(info, &xen_irq_list_head, list) { if (info->type != IRQT_PIRQ) continue; irq = info->irq; if (info->u.pirq.pirq == pirq) goto out; } irq = -1; out: mutex_unlock(&irq_mapping_update_lock); return irq; } int xen_pirq_from_irq(unsigned irq) { return pirq_from_irq(irq); } EXPORT_SYMBOL_GPL(xen_pirq_from_irq); int bind_evtchn_to_irq(unsigned int evtchn) { int irq; mutex_lock(&irq_mapping_update_lock); irq = evtchn_to_irq[evtchn]; if (irq == -1) { irq = xen_allocate_irq_dynamic(); if (irq == -1) goto out; irq_set_chip_and_handler_name(irq, &xen_dynamic_chip, handle_edge_irq, "event"); xen_irq_info_evtchn_init(irq, evtchn); } out: mutex_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; mutex_lock(&irq_mapping_update_lock); irq = per_cpu(ipi_to_irq, cpu)[ipi]; if (irq == -1) { irq = xen_allocate_irq_dynamic(); if (irq < 0) goto out; irq_set_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; xen_irq_info_ipi_init(cpu, irq, evtchn, ipi); bind_evtchn_to_cpu(evtchn, cpu); } out: mutex_unlock(&irq_mapping_update_lock); return irq; } static int bind_interdomain_evtchn_to_irq(unsigned int remote_domain, unsigned int remote_port) { struct evtchn_bind_interdomain bind_interdomain; int err; bind_interdomain.remote_dom = remote_domain; bind_interdomain.remote_port = remote_port; err = HYPERVISOR_event_channel_op(EVTCHNOP_bind_interdomain, &bind_interdomain); return err ? : bind_evtchn_to_irq(bind_interdomain.local_port); } static int find_virq(unsigned int virq, unsigned int cpu) { struct evtchn_status status; int port, rc = -ENOENT; memset(&status, 0, sizeof(status)); for (port = 0; port <= NR_EVENT_CHANNELS; port++) { status.dom = DOMID_SELF; status.port = port; rc = HYPERVISOR_event_channel_op(EVTCHNOP_status, &status); if (rc < 0) continue; if (status.status != EVTCHNSTAT_virq) continue; if (status.u.virq == virq && status.vcpu == cpu) { rc = port; break; } } return rc; } int bind_virq_to_irq(unsigned int virq, unsigned int cpu) { struct evtchn_bind_virq bind_virq; int evtchn, irq, ret; mutex_lock(&irq_mapping_update_lock); irq = per_cpu(virq_to_irq, cpu)[virq]; if (irq == -1) { irq = xen_allocate_irq_dynamic(); if (irq == -1) goto out; irq_set_chip_and_handler_name(irq, &xen_percpu_chip, handle_percpu_irq, "virq"); bind_virq.virq = virq; bind_virq.vcpu = cpu; ret = HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq, &bind_virq); if (ret == 0) evtchn = bind_virq.port; else { if (ret == -EEXIST) ret = find_virq(virq, cpu); BUG_ON(ret < 0); evtchn = ret; } xen_irq_info_virq_init(cpu, irq, evtchn, virq); bind_evtchn_to_cpu(evtchn, cpu); } out: mutex_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); struct irq_info *info = irq_get_handler_data(irq); mutex_lock(&irq_mapping_update_lock); if (info->refcnt > 0) { info->refcnt--; if (info->refcnt != 0) goto done; } 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; } BUG_ON(info_for_irq(irq)->type == IRQT_UNBOUND); xen_free_irq(irq); done: mutex_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) { int irq, retval; irq = bind_evtchn_to_irq(evtchn); if (irq < 0) return irq; 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_interdomain_evtchn_to_irqhandler(unsigned int remote_domain, unsigned int remote_port, irq_handler_t handler, unsigned long irqflags, const char *devname, void *dev_id) { int irq, retval; irq = bind_interdomain_evtchn_to_irq(remote_domain, remote_port); if (irq < 0) return irq; retval = request_irq(irq, handler, irqflags, devname, dev_id); if (retval != 0) { unbind_from_irq(irq); return retval; } return irq; } EXPORT_SYMBOL_GPL(bind_interdomain_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) { int irq, retval; irq = bind_virq_to_irq(virq, cpu); if (irq < 0) return irq; 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 | IRQF_FORCE_RESUME | IRQF_EARLY_RESUME; 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); int evtchn_make_refcounted(unsigned int evtchn) { int irq = evtchn_to_irq[evtchn]; struct irq_info *info; if (irq == -1) return -ENOENT; info = irq_get_handler_data(irq); if (!info) return -ENOENT; WARN_ON(info->refcnt != -1); info->refcnt = 1; return 0; } EXPORT_SYMBOL_GPL(evtchn_make_refcounted); int evtchn_get(unsigned int evtchn) { int irq; struct irq_info *info; int err = -ENOENT; if (evtchn >= NR_EVENT_CHANNELS) return -EINVAL; mutex_lock(&irq_mapping_update_lock); irq = evtchn_to_irq[evtchn]; if (irq == -1) goto done; info = irq_get_handler_data(irq); if (!info) goto done; err = -EINVAL; if (info->refcnt <= 0) goto done; info->refcnt++; err = 0; done: mutex_unlock(&irq_mapping_update_lock); return err; } EXPORT_SYMBOL_GPL(evtchn_get); void evtchn_put(unsigned int evtchn) { int irq = evtchn_to_irq[evtchn]; if (WARN_ON(irq == -1)) return; unbind_from_irq(irq); } EXPORT_SYMBOL_GPL(evtchn_put); 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(); unsigned long *cpu_evtchn = per_cpu(cpu_evtchn_mask, cpu); int i; unsigned long flags; static DEFINE_SPINLOCK(debug_lock); struct vcpu_info *v; spin_lock_irqsave(&debug_lock, flags); printk("\nvcpu %d\n ", cpu); for_each_online_cpu(i) { int pending; v = per_cpu(xen_vcpu, i); pending = (get_irq_regs() && i == cpu) ? xen_irqs_disabled(get_irq_regs()) : v->evtchn_upcall_mask; printk("%d: masked=%d pending=%d event_sel %0*lx\n ", i, pending, v->evtchn_upcall_pending, (int)(sizeof(v->evtchn_pending_sel)*2), v->evtchn_pending_sel); } v = per_cpu(xen_vcpu, cpu); printk("\npending:\n "); for (i = ARRAY_SIZE(sh->evtchn_pending)-1; i >= 0; i--) printk("%0*lx%s", (int)sizeof(sh->evtchn_pending[0])*2, sh->evtchn_pending[i], i % 8 == 0 ? "\n " : " "); printk("\nglobal mask:\n "); for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--) printk("%0*lx%s", (int)(sizeof(sh->evtchn_mask[0])*2), sh->evtchn_mask[i], i % 8 == 0 ? "\n " : " "); printk("\nglobally unmasked:\n "); for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--) printk("%0*lx%s", (int)(sizeof(sh->evtchn_mask[0])*2), sh->evtchn_pending[i] & ~sh->evtchn_mask[i], i % 8 == 0 ? "\n " : " "); printk("\nlocal cpu%d mask:\n ", cpu); for (i = (NR_EVENT_CHANNELS/BITS_PER_LONG)-1; i >= 0; i--) printk("%0*lx%s", (int)(sizeof(cpu_evtchn[0])*2), cpu_evtchn[i], i % 8 == 0 ? "\n " : " "); printk("\nlocally unmasked:\n "); for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--) { unsigned long pending = sh->evtchn_pending[i] & ~sh->evtchn_mask[i] & cpu_evtchn[i]; printk("%0*lx%s", (int)(sizeof(sh->evtchn_mask[0])*2), pending, i % 8 == 0 ? "\n " : " "); } printk("\npending list:\n"); for (i = 0; i < NR_EVENT_CHANNELS; i++) { if (sync_test_bit(i, sh->evtchn_pending)) { int word_idx = i / BITS_PER_LONG; printk(" %d: event %d -> irq %d%s%s%s\n", cpu_from_evtchn(i), i, evtchn_to_irq[i], sync_test_bit(word_idx, &v->evtchn_pending_sel) ? "" : " l2-clear", !sync_test_bit(i, sh->evtchn_mask) ? "" : " globally-masked", sync_test_bit(i, cpu_evtchn) ? "" : " locally-masked"); } } spin_unlock_irqrestore(&debug_lock, flags); return IRQ_HANDLED; } static DEFINE_PER_CPU(unsigned, xed_nesting_count); static DEFINE_PER_CPU(unsigned int, current_word_idx); static DEFINE_PER_CPU(unsigned int, current_bit_idx); /* * Mask out the i least significant bits of w */ #define MASK_LSBS(w, i) (w & ((~0UL) << i)) /* * 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 start_word_idx, start_bit_idx; int word_idx, bit_idx; int i; int cpu = get_cpu(); struct shared_info *s = HYPERVISOR_shared_info; struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu); unsigned count; do { unsigned long pending_words; vcpu_info->evtchn_upcall_pending = 0; if (__this_cpu_inc_return(xed_nesting_count) - 1) 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); start_word_idx = __this_cpu_read(current_word_idx); start_bit_idx = __this_cpu_read(current_bit_idx); word_idx = start_word_idx; for (i = 0; pending_words != 0; i++) { unsigned long pending_bits; unsigned long words; words = MASK_LSBS(pending_words, word_idx); /* * If we masked out all events, wrap to beginning. */ if (words == 0) { word_idx = 0; bit_idx = 0; continue; } word_idx = __ffs(words); pending_bits = active_evtchns(cpu, s, word_idx); bit_idx = 0; /* usually scan entire word from start */ if (word_idx == start_word_idx) { /* We scan the starting word in two parts */ if (i == 0) /* 1st time: start in the middle */ bit_idx = start_bit_idx; else /* 2nd time: mask bits done already */ bit_idx &= (1UL << start_bit_idx) - 1; } do { unsigned long bits; int port, irq; struct irq_desc *desc; bits = MASK_LSBS(pending_bits, bit_idx); /* If we masked out all events, move on. */ if (bits == 0) break; bit_idx = __ffs(bits); /* Process port. */ port = (word_idx * BITS_PER_LONG) + bit_idx; irq = evtchn_to_irq[port]; if (irq != -1) { desc = irq_to_desc(irq); if (desc) generic_handle_irq_desc(irq, desc); } bit_idx = (bit_idx + 1) % BITS_PER_LONG; /* Next caller starts at last processed + 1 */ __this_cpu_write(current_word_idx, bit_idx ? word_idx : (word_idx+1) % BITS_PER_LONG); __this_cpu_write(current_bit_idx, bit_idx); } while (bit_idx != 0); /* Scan start_l1i twice; all others once. */ if ((word_idx != start_word_idx) || (i != 0)) pending_words &= ~(1UL << word_idx); word_idx = (word_idx + 1) % BITS_PER_LONG; } BUG_ON(!irqs_disabled()); count = __this_cpu_read(xed_nesting_count); __this_cpu_write(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); mutex_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); xen_irq_info_evtchn_init(irq, evtchn); mutex_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); if (!VALID_EVTCHN(evtchn)) return -1; /* * Events delivered via platform PCI interrupts are always * routed to vcpu 0 and hence cannot be rebound. */ if (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(struct irq_data *data, const struct cpumask *dest, bool force) { unsigned tcpu = cpumask_first(dest); return rebind_irq_to_cpu(data->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(struct irq_data *data) { int evtchn = evtchn_from_irq(data->irq); if (VALID_EVTCHN(evtchn)) unmask_evtchn(evtchn); } static void disable_dynirq(struct irq_data *data) { int evtchn = evtchn_from_irq(data->irq); if (VALID_EVTCHN(evtchn)) mask_evtchn(evtchn); } static void ack_dynirq(struct irq_data *data) { int evtchn = evtchn_from_irq(data->irq); irq_move_irq(data); if (VALID_EVTCHN(evtchn)) clear_evtchn(evtchn); } static void mask_ack_dynirq(struct irq_data *data) { disable_dynirq(data); ack_dynirq(data); } static int retrigger_dynirq(struct irq_data *data) { int evtchn = evtchn_from_irq(data->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_pirqs(void) { int pirq, rc, irq, gsi; struct physdev_map_pirq map_irq; struct irq_info *info; list_for_each_entry(info, &xen_irq_list_head, list) { if (info->type != IRQT_PIRQ) continue; pirq = info->u.pirq.pirq; gsi = info->u.pirq.gsi; irq = info->irq; /* save/restore of PT devices doesn't work, so at this point the * only devices present are GSI based emulated devices */ if (!gsi) continue; map_irq.domid = DOMID_SELF; map_irq.type = MAP_PIRQ_TYPE_GSI; map_irq.index = gsi; map_irq.pirq = pirq; rc = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq); if (rc) { printk(KERN_WARNING "xen map irq failed gsi=%d irq=%d pirq=%d rc=%d\n", gsi, irq, pirq, rc); xen_free_irq(irq); continue; } printk(KERN_DEBUG "xen: --> irq=%d, pirq=%d\n", irq, map_irq.pirq); __startup_pirq(irq); } } 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. */ xen_irq_info_virq_init(cpu, irq, evtchn, virq); bind_evtchn_to_cpu(evtchn, cpu); } } static void restore_cpu_ipis(unsigned int cpu) { struct evtchn_bind_ipi bind_ipi; int ipi, irq, evtchn; for (ipi = 0; ipi < XEN_NR_IPIS; ipi++) { if ((irq = per_cpu(ipi_to_irq, cpu)[ipi]) == -1) continue; 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. */ xen_irq_info_ipi_init(cpu, irq, evtchn, ipi); bind_evtchn_to_cpu(evtchn, cpu); } } /* 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 */); } /* Check whether the IRQ line is shared with other guests. */ int xen_test_irq_shared(int irq) { struct irq_info *info = info_for_irq(irq); struct physdev_irq_status_query irq_status = { .irq = info->u.pirq.pirq }; if (HYPERVISOR_physdev_op(PHYSDEVOP_irq_status_query, &irq_status)) return 0; return !(irq_status.flags & XENIRQSTAT_shared); } EXPORT_SYMBOL_GPL(xen_test_irq_shared); void xen_irq_resume(void) { unsigned int cpu, evtchn; struct irq_info *info; 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. */ list_for_each_entry(info, &xen_irq_list_head, list) info->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); } restore_pirqs(); } static struct irq_chip xen_dynamic_chip __read_mostly = { .name = "xen-dyn", .irq_disable = disable_dynirq, .irq_mask = disable_dynirq, .irq_unmask = enable_dynirq, .irq_ack = ack_dynirq, .irq_mask_ack = mask_ack_dynirq, .irq_set_affinity = set_affinity_irq, .irq_retrigger = retrigger_dynirq, }; static struct irq_chip xen_pirq_chip __read_mostly = { .name = "xen-pirq", .irq_startup = startup_pirq, .irq_shutdown = shutdown_pirq, .irq_enable = enable_pirq, .irq_disable = disable_pirq, .irq_mask = disable_dynirq, .irq_unmask = enable_dynirq, .irq_ack = eoi_pirq, .irq_eoi = eoi_pirq, .irq_mask_ack = mask_ack_pirq, .irq_set_affinity = set_affinity_irq, .irq_retrigger = retrigger_dynirq, }; static struct irq_chip xen_percpu_chip __read_mostly = { .name = "xen-percpu", .irq_disable = disable_dynirq, .irq_mask = disable_dynirq, .irq_unmask = enable_dynirq, .irq_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; evtchn_to_irq = kcalloc(NR_EVENT_CHANNELS, sizeof(*evtchn_to_irq), GFP_KERNEL); BUG_ON(!evtchn_to_irq); 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); pirq_needs_eoi = pirq_needs_eoi_flag; if (xen_hvm_domain()) { xen_callback_vector(); native_init_IRQ(); /* pci_xen_hvm_init must be called after native_init_IRQ so that * __acpi_register_gsi can point at the right function */ pci_xen_hvm_init(); } else { struct physdev_pirq_eoi_gmfn eoi_gmfn; irq_ctx_init(smp_processor_id()); if (xen_initial_domain()) pci_xen_initial_domain(); pirq_eoi_map = (void *)__get_free_page(GFP_KERNEL|__GFP_ZERO); eoi_gmfn.gmfn = virt_to_mfn(pirq_eoi_map); rc = HYPERVISOR_physdev_op(PHYSDEVOP_pirq_eoi_gmfn_v2, &eoi_gmfn); if (rc != 0) { free_page((unsigned long) pirq_eoi_map); pirq_eoi_map = NULL; } else pirq_needs_eoi = pirq_check_eoi_map; } }