// SPDX-License-Identifier: GPL-2.0-only /* * 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 , XenSource Inc, 2007 */ #define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef CONFIG_X86 #include #include #include #include #include #include #include #include #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "events_internal.h" #undef MODULE_PARAM_PREFIX #define MODULE_PARAM_PREFIX "xen." /* 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; struct list_head eoi_list; struct rcu_work rwork; short refcnt; u8 spurious_cnt; u8 is_accounted; short type; /* type: IRQT_* */ u8 mask_reason; /* Why is event channel masked */ #define EVT_MASK_REASON_EXPLICIT 0x01 #define EVT_MASK_REASON_TEMPORARY 0x02 #define EVT_MASK_REASON_EOI_PENDING 0x04 u8 is_active; /* Is event just being handled? */ unsigned irq; evtchn_port_t evtchn; /* event channel */ unsigned short cpu; /* cpu bound */ unsigned short eoi_cpu; /* EOI must happen on this cpu-1 */ unsigned int irq_epoch; /* If eoi_cpu valid: irq_epoch of event */ u64 eoi_time; /* Time in jiffies when to EOI. */ raw_spinlock_t lock; bool is_static; /* Is event channel static */ 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; struct xenbus_device *interdomain; } u; }; #define PIRQ_NEEDS_EOI (1 << 0) #define PIRQ_SHAREABLE (1 << 1) #define PIRQ_MSI_GROUP (1 << 2) static uint __read_mostly event_loop_timeout = 2; module_param(event_loop_timeout, uint, 0644); static uint __read_mostly event_eoi_delay = 10; module_param(event_eoi_delay, uint, 0644); const struct evtchn_ops *evtchn_ops; /* * 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); /* * Lock hierarchy: * * irq_mapping_update_lock * IRQ-desc lock * percpu eoi_list_lock * irq_info->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}; /* Cache for IPI event channels - needed for hot cpu unplug (avoid RCU usage). */ static DEFINE_PER_CPU(evtchn_port_t [XEN_NR_IPIS], ipi_to_evtchn) = {[0 ... XEN_NR_IPIS-1] = 0}; /* Event channel distribution data */ static atomic_t channels_on_cpu[NR_CPUS]; static int **evtchn_to_irq; #ifdef CONFIG_X86 static unsigned long *pirq_eoi_map; #endif static bool (*pirq_needs_eoi)(struct irq_info *info); #define EVTCHN_ROW(e) (e / (PAGE_SIZE/sizeof(**evtchn_to_irq))) #define EVTCHN_COL(e) (e % (PAGE_SIZE/sizeof(**evtchn_to_irq))) #define EVTCHN_PER_ROW (PAGE_SIZE / sizeof(**evtchn_to_irq)) /* Xen will never allocate port zero for any purpose. */ #define VALID_EVTCHN(chn) ((chn) != 0) static struct irq_info *legacy_info_ptrs[NR_IRQS_LEGACY]; static struct irq_chip xen_dynamic_chip; static struct irq_chip xen_lateeoi_chip; static struct irq_chip xen_percpu_chip; static struct irq_chip xen_pirq_chip; static void enable_dynirq(struct irq_data *data); static DEFINE_PER_CPU(unsigned int, irq_epoch); static void clear_evtchn_to_irq_row(int *evtchn_row) { unsigned col; for (col = 0; col < EVTCHN_PER_ROW; col++) WRITE_ONCE(evtchn_row[col], -1); } static void clear_evtchn_to_irq_all(void) { unsigned row; for (row = 0; row < EVTCHN_ROW(xen_evtchn_max_channels()); row++) { if (evtchn_to_irq[row] == NULL) continue; clear_evtchn_to_irq_row(evtchn_to_irq[row]); } } static int set_evtchn_to_irq(evtchn_port_t evtchn, unsigned int irq) { unsigned row; unsigned col; int *evtchn_row; if (evtchn >= xen_evtchn_max_channels()) return -EINVAL; row = EVTCHN_ROW(evtchn); col = EVTCHN_COL(evtchn); if (evtchn_to_irq[row] == NULL) { /* Unallocated irq entries return -1 anyway */ if (irq == -1) return 0; evtchn_row = (int *) __get_free_pages(GFP_KERNEL, 0); if (evtchn_row == NULL) return -ENOMEM; clear_evtchn_to_irq_row(evtchn_row); /* * We've prepared an empty row for the mapping. If a different * thread was faster inserting it, we can drop ours. */ if (cmpxchg(&evtchn_to_irq[row], NULL, evtchn_row) != NULL) free_page((unsigned long) evtchn_row); } WRITE_ONCE(evtchn_to_irq[row][col], irq); return 0; } /* Get info for IRQ */ static struct irq_info *info_for_irq(unsigned irq) { if (irq < nr_legacy_irqs()) return legacy_info_ptrs[irq]; else return irq_get_chip_data(irq); } static void set_info_for_irq(unsigned int irq, struct irq_info *info) { if (irq < nr_legacy_irqs()) legacy_info_ptrs[irq] = info; else irq_set_chip_data(irq, info); } static struct irq_info *evtchn_to_info(evtchn_port_t evtchn) { int irq; if (evtchn >= xen_evtchn_max_channels()) return NULL; if (evtchn_to_irq[EVTCHN_ROW(evtchn)] == NULL) return NULL; irq = READ_ONCE(evtchn_to_irq[EVTCHN_ROW(evtchn)][EVTCHN_COL(evtchn)]); return (irq < 0) ? NULL : info_for_irq(irq); } /* Per CPU channel accounting */ static void channels_on_cpu_dec(struct irq_info *info) { if (!info->is_accounted) return; info->is_accounted = 0; if (WARN_ON_ONCE(info->cpu >= nr_cpu_ids)) return; WARN_ON_ONCE(!atomic_add_unless(&channels_on_cpu[info->cpu], -1 , 0)); } static void channels_on_cpu_inc(struct irq_info *info) { if (WARN_ON_ONCE(info->cpu >= nr_cpu_ids)) return; if (WARN_ON_ONCE(!atomic_add_unless(&channels_on_cpu[info->cpu], 1, INT_MAX))) return; info->is_accounted = 1; } static void xen_irq_free_desc(unsigned int irq) { /* Legacy IRQ descriptors are managed by the arch. */ if (irq >= nr_legacy_irqs()) irq_free_desc(irq); } static void delayed_free_irq(struct work_struct *work) { struct irq_info *info = container_of(to_rcu_work(work), struct irq_info, rwork); unsigned int irq = info->irq; /* Remove the info pointer only now, with no potential users left. */ set_info_for_irq(irq, NULL); kfree(info); xen_irq_free_desc(irq); } /* Constructors for packed IRQ information. */ static int xen_irq_info_common_setup(struct irq_info *info, enum xen_irq_type type, evtchn_port_t evtchn, unsigned short cpu) { int ret; BUG_ON(info->type != IRQT_UNBOUND && info->type != type); info->type = type; info->evtchn = evtchn; info->cpu = cpu; info->mask_reason = EVT_MASK_REASON_EXPLICIT; raw_spin_lock_init(&info->lock); ret = set_evtchn_to_irq(evtchn, info->irq); if (ret < 0) return ret; irq_clear_status_flags(info->irq, IRQ_NOREQUEST | IRQ_NOAUTOEN); return xen_evtchn_port_setup(evtchn); } static int xen_irq_info_evtchn_setup(struct irq_info *info, evtchn_port_t evtchn, struct xenbus_device *dev) { int ret; ret = xen_irq_info_common_setup(info, IRQT_EVTCHN, evtchn, 0); info->u.interdomain = dev; if (dev) atomic_inc(&dev->event_channels); return ret; } static int xen_irq_info_ipi_setup(struct irq_info *info, unsigned int cpu, evtchn_port_t evtchn, enum ipi_vector ipi) { info->u.ipi = ipi; per_cpu(ipi_to_irq, cpu)[ipi] = info->irq; per_cpu(ipi_to_evtchn, cpu)[ipi] = evtchn; return xen_irq_info_common_setup(info, IRQT_IPI, evtchn, 0); } static int xen_irq_info_virq_setup(struct irq_info *info, unsigned int cpu, evtchn_port_t evtchn, unsigned int virq) { info->u.virq = virq; per_cpu(virq_to_irq, cpu)[virq] = info->irq; return xen_irq_info_common_setup(info, IRQT_VIRQ, evtchn, 0); } static int xen_irq_info_pirq_setup(struct irq_info *info, evtchn_port_t evtchn, unsigned int pirq, unsigned int gsi, uint16_t domid, unsigned char flags) { info->u.pirq.pirq = pirq; info->u.pirq.gsi = gsi; info->u.pirq.domid = domid; info->u.pirq.flags = flags; return xen_irq_info_common_setup(info, IRQT_PIRQ, evtchn, 0); } static void xen_irq_info_cleanup(struct irq_info *info) { set_evtchn_to_irq(info->evtchn, -1); xen_evtchn_port_remove(info->evtchn, info->cpu); info->evtchn = 0; channels_on_cpu_dec(info); } /* * Accessors for packed IRQ information. */ static evtchn_port_t evtchn_from_irq(unsigned int irq) { const struct irq_info *info = NULL; if (likely(irq < irq_get_nr_irqs())) info = info_for_irq(irq); if (!info) return 0; return info->evtchn; } unsigned int irq_from_evtchn(evtchn_port_t evtchn) { struct irq_info *info = evtchn_to_info(evtchn); return info ? info->irq : -1; } EXPORT_SYMBOL_GPL(irq_from_evtchn); int irq_evtchn_from_virq(unsigned int cpu, unsigned int virq, evtchn_port_t *evtchn) { int irq = per_cpu(virq_to_irq, cpu)[virq]; *evtchn = evtchn_from_irq(irq); return irq; } static enum ipi_vector ipi_from_irq(struct irq_info *info) { BUG_ON(info == NULL); BUG_ON(info->type != IRQT_IPI); return info->u.ipi; } static unsigned int virq_from_irq(struct irq_info *info) { BUG_ON(info == NULL); BUG_ON(info->type != IRQT_VIRQ); return info->u.virq; } static unsigned int pirq_from_irq(struct irq_info *info) { BUG_ON(info == NULL); BUG_ON(info->type != IRQT_PIRQ); return info->u.pirq.pirq; } unsigned int cpu_from_evtchn(evtchn_port_t evtchn) { struct irq_info *info = evtchn_to_info(evtchn); return info ? info->cpu : 0; } static void do_mask(struct irq_info *info, u8 reason) { unsigned long flags; raw_spin_lock_irqsave(&info->lock, flags); if (!info->mask_reason) mask_evtchn(info->evtchn); info->mask_reason |= reason; raw_spin_unlock_irqrestore(&info->lock, flags); } static void do_unmask(struct irq_info *info, u8 reason) { unsigned long flags; raw_spin_lock_irqsave(&info->lock, flags); info->mask_reason &= ~reason; if (!info->mask_reason) unmask_evtchn(info->evtchn); raw_spin_unlock_irqrestore(&info->lock, flags); } #ifdef CONFIG_X86 static bool pirq_check_eoi_map(struct irq_info *info) { return test_bit(pirq_from_irq(info), pirq_eoi_map); } #endif static bool pirq_needs_eoi_flag(struct irq_info *info) { BUG_ON(info->type != IRQT_PIRQ); return info->u.pirq.flags & PIRQ_NEEDS_EOI; } static void bind_evtchn_to_cpu(struct irq_info *info, unsigned int cpu, bool force_affinity) { if (IS_ENABLED(CONFIG_SMP) && force_affinity) { struct irq_data *data = irq_get_irq_data(info->irq); irq_data_update_affinity(data, cpumask_of(cpu)); irq_data_update_effective_affinity(data, cpumask_of(cpu)); } xen_evtchn_port_bind_to_cpu(info->evtchn, cpu, info->cpu); channels_on_cpu_dec(info); info->cpu = cpu; channels_on_cpu_inc(info); } /** * 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) { evtchn_port_t evtchn = evtchn_from_irq(irq); if (VALID_EVTCHN(evtchn)) notify_remote_via_evtchn(evtchn); } EXPORT_SYMBOL_GPL(notify_remote_via_irq); struct lateeoi_work { struct delayed_work delayed; spinlock_t eoi_list_lock; struct list_head eoi_list; }; static DEFINE_PER_CPU(struct lateeoi_work, lateeoi); static void lateeoi_list_del(struct irq_info *info) { struct lateeoi_work *eoi = &per_cpu(lateeoi, info->eoi_cpu); unsigned long flags; spin_lock_irqsave(&eoi->eoi_list_lock, flags); list_del_init(&info->eoi_list); spin_unlock_irqrestore(&eoi->eoi_list_lock, flags); } static void lateeoi_list_add(struct irq_info *info) { struct lateeoi_work *eoi = &per_cpu(lateeoi, info->eoi_cpu); struct irq_info *elem; u64 now = get_jiffies_64(); unsigned long delay; unsigned long flags; if (now < info->eoi_time) delay = info->eoi_time - now; else delay = 1; spin_lock_irqsave(&eoi->eoi_list_lock, flags); elem = list_first_entry_or_null(&eoi->eoi_list, struct irq_info, eoi_list); if (!elem || info->eoi_time < elem->eoi_time) { list_add(&info->eoi_list, &eoi->eoi_list); mod_delayed_work_on(info->eoi_cpu, system_wq, &eoi->delayed, delay); } else { list_for_each_entry_reverse(elem, &eoi->eoi_list, eoi_list) { if (elem->eoi_time <= info->eoi_time) break; } list_add(&info->eoi_list, &elem->eoi_list); } spin_unlock_irqrestore(&eoi->eoi_list_lock, flags); } static void xen_irq_lateeoi_locked(struct irq_info *info, bool spurious) { evtchn_port_t evtchn; unsigned int cpu; unsigned int delay = 0; evtchn = info->evtchn; if (!VALID_EVTCHN(evtchn) || !list_empty(&info->eoi_list)) return; if (spurious) { struct xenbus_device *dev = info->u.interdomain; unsigned int threshold = 1; if (dev && dev->spurious_threshold) threshold = dev->spurious_threshold; if ((1 << info->spurious_cnt) < (HZ << 2)) { if (info->spurious_cnt != 0xFF) info->spurious_cnt++; } if (info->spurious_cnt > threshold) { delay = 1 << (info->spurious_cnt - 1 - threshold); if (delay > HZ) delay = HZ; if (!info->eoi_time) info->eoi_cpu = smp_processor_id(); info->eoi_time = get_jiffies_64() + delay; if (dev) atomic_add(delay, &dev->jiffies_eoi_delayed); } if (dev) atomic_inc(&dev->spurious_events); } else { info->spurious_cnt = 0; } cpu = info->eoi_cpu; if (info->eoi_time && (info->irq_epoch == per_cpu(irq_epoch, cpu) || delay)) { lateeoi_list_add(info); return; } info->eoi_time = 0; /* is_active hasn't been reset yet, do it now. */ smp_store_release(&info->is_active, 0); do_unmask(info, EVT_MASK_REASON_EOI_PENDING); } static void xen_irq_lateeoi_worker(struct work_struct *work) { struct lateeoi_work *eoi; struct irq_info *info; u64 now = get_jiffies_64(); unsigned long flags; eoi = container_of(to_delayed_work(work), struct lateeoi_work, delayed); rcu_read_lock(); while (true) { spin_lock_irqsave(&eoi->eoi_list_lock, flags); info = list_first_entry_or_null(&eoi->eoi_list, struct irq_info, eoi_list); if (info == NULL) break; if (now < info->eoi_time) { mod_delayed_work_on(info->eoi_cpu, system_wq, &eoi->delayed, info->eoi_time - now); break; } list_del_init(&info->eoi_list); spin_unlock_irqrestore(&eoi->eoi_list_lock, flags); info->eoi_time = 0; xen_irq_lateeoi_locked(info, false); } spin_unlock_irqrestore(&eoi->eoi_list_lock, flags); rcu_read_unlock(); } static void xen_cpu_init_eoi(unsigned int cpu) { struct lateeoi_work *eoi = &per_cpu(lateeoi, cpu); INIT_DELAYED_WORK(&eoi->delayed, xen_irq_lateeoi_worker); spin_lock_init(&eoi->eoi_list_lock); INIT_LIST_HEAD(&eoi->eoi_list); } void xen_irq_lateeoi(unsigned int irq, unsigned int eoi_flags) { struct irq_info *info; rcu_read_lock(); info = info_for_irq(irq); if (info) xen_irq_lateeoi_locked(info, eoi_flags & XEN_EOI_FLAG_SPURIOUS); rcu_read_unlock(); } EXPORT_SYMBOL_GPL(xen_irq_lateeoi); static struct irq_info *xen_irq_init(unsigned int irq) { struct irq_info *info; info = kzalloc(sizeof(*info), GFP_KERNEL); if (info) { info->irq = irq; info->type = IRQT_UNBOUND; info->refcnt = -1; INIT_RCU_WORK(&info->rwork, delayed_free_irq); set_info_for_irq(irq, info); /* * Interrupt affinity setting can be immediate. No point * in delaying it until an interrupt is handled. */ irq_set_status_flags(irq, IRQ_MOVE_PCNTXT); INIT_LIST_HEAD(&info->eoi_list); list_add_tail(&info->list, &xen_irq_list_head); } return info; } static struct irq_info *xen_allocate_irq_dynamic(void) { int irq = irq_alloc_desc_from(0, -1); struct irq_info *info = NULL; if (irq >= 0) { info = xen_irq_init(irq); if (!info) xen_irq_free_desc(irq); } return info; } static struct irq_info *xen_allocate_irq_gsi(unsigned int gsi) { int irq; struct irq_info *info; /* * 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_legacy_irqs()) irq = gsi; else irq = irq_alloc_desc_at(gsi, -1); info = xen_irq_init(irq); if (!info) xen_irq_free_desc(irq); return info; } static void xen_free_irq(struct irq_info *info) { if (WARN_ON(!info)) return; if (!list_empty(&info->eoi_list)) lateeoi_list_del(info); list_del(&info->list); WARN_ON(info->refcnt > 0); queue_rcu_work(system_wq, &info->rwork); } /* Not called for lateeoi events. */ static void event_handler_exit(struct irq_info *info) { smp_store_release(&info->is_active, 0); clear_evtchn(info->evtchn); } static void pirq_query_unmask(struct irq_info *info) { struct physdev_irq_status_query irq_status; irq_status.irq = pirq_from_irq(info); 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 void do_eoi_pirq(struct irq_info *info) { struct physdev_eoi eoi = { .irq = pirq_from_irq(info) }; int rc = 0; if (!VALID_EVTCHN(info->evtchn)) return; event_handler_exit(info); if (pirq_needs_eoi(info)) { rc = HYPERVISOR_physdev_op(PHYSDEVOP_eoi, &eoi); WARN_ON(rc); } } static void eoi_pirq(struct irq_data *data) { struct irq_info *info = info_for_irq(data->irq); do_eoi_pirq(info); } static void do_disable_dynirq(struct irq_info *info) { if (VALID_EVTCHN(info->evtchn)) do_mask(info, EVT_MASK_REASON_EXPLICIT); } static void disable_dynirq(struct irq_data *data) { struct irq_info *info = info_for_irq(data->irq); if (info) do_disable_dynirq(info); } static void mask_ack_pirq(struct irq_data *data) { struct irq_info *info = info_for_irq(data->irq); if (info) { do_disable_dynirq(info); do_eoi_pirq(info); } } static unsigned int __startup_pirq(struct irq_info *info) { struct evtchn_bind_pirq bind_pirq; evtchn_port_t evtchn = info->evtchn; int rc; if (VALID_EVTCHN(evtchn)) goto out; bind_pirq.pirq = pirq_from_irq(info); /* 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) { pr_warn("Failed to obtain physical IRQ %d\n", info->irq); return 0; } evtchn = bind_pirq.port; pirq_query_unmask(info); rc = set_evtchn_to_irq(evtchn, info->irq); if (rc) goto err; info->evtchn = evtchn; bind_evtchn_to_cpu(info, 0, false); rc = xen_evtchn_port_setup(evtchn); if (rc) goto err; out: do_unmask(info, EVT_MASK_REASON_EXPLICIT); do_eoi_pirq(info); return 0; err: pr_err("irq%d: Failed to set port to irq mapping (%d)\n", info->irq, rc); xen_evtchn_close(evtchn); return 0; } static unsigned int startup_pirq(struct irq_data *data) { struct irq_info *info = info_for_irq(data->irq); return __startup_pirq(info); } static void shutdown_pirq(struct irq_data *data) { struct irq_info *info = info_for_irq(data->irq); evtchn_port_t evtchn = info->evtchn; BUG_ON(info->type != IRQT_PIRQ); if (!VALID_EVTCHN(evtchn)) return; do_mask(info, EVT_MASK_REASON_EXPLICIT); xen_irq_info_cleanup(info); xen_evtchn_close(evtchn); } static void enable_pirq(struct irq_data *data) { enable_dynirq(data); } static void disable_pirq(struct irq_data *data) { disable_dynirq(data); } int xen_irq_from_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; } EXPORT_SYMBOL_GPL(xen_irq_from_gsi); static void __unbind_from_irq(struct irq_info *info, unsigned int irq) { evtchn_port_t evtchn; bool close_evtchn = false; if (!info) { xen_irq_free_desc(irq); return; } if (info->refcnt > 0) { info->refcnt--; if (info->refcnt != 0) return; } evtchn = info->evtchn; if (VALID_EVTCHN(evtchn)) { unsigned int cpu = info->cpu; struct xenbus_device *dev; if (!info->is_static) close_evtchn = true; switch (info->type) { case IRQT_VIRQ: per_cpu(virq_to_irq, cpu)[virq_from_irq(info)] = -1; break; case IRQT_IPI: per_cpu(ipi_to_irq, cpu)[ipi_from_irq(info)] = -1; per_cpu(ipi_to_evtchn, cpu)[ipi_from_irq(info)] = 0; break; case IRQT_EVTCHN: dev = info->u.interdomain; if (dev) atomic_dec(&dev->event_channels); break; default: break; } xen_irq_info_cleanup(info); if (close_evtchn) xen_evtchn_close(evtchn); } xen_free_irq(info); } /* * 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) { struct irq_info *info; struct physdev_irq irq_op; int ret; mutex_lock(&irq_mapping_update_lock); ret = xen_irq_from_gsi(gsi); if (ret != -1) { pr_info("%s: returning irq %d for gsi %u\n", __func__, ret, gsi); goto out; } info = xen_allocate_irq_gsi(gsi); if (!info) goto out; irq_op.irq = info->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(info); ret = -ENOSPC; goto out; } ret = xen_irq_info_pirq_setup(info, 0, pirq, gsi, DOMID_SELF, shareable ? PIRQ_SHAREABLE : 0); if (ret < 0) { __unbind_from_irq(info, info->irq); goto out; } pirq_query_unmask(info); /* 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(info->irq, &xen_pirq_chip, handle_fasteoi_irq, name); else irq_set_chip_and_handler_name(info->irq, &xen_pirq_chip, handle_edge_irq, name); ret = info->irq; out: mutex_unlock(&irq_mapping_update_lock); return ret; } #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 nvec, const char *name, domid_t domid) { int i, irq, ret; struct irq_info *info; mutex_lock(&irq_mapping_update_lock); irq = irq_alloc_descs(-1, 0, nvec, -1); if (irq < 0) goto out; for (i = 0; i < nvec; i++) { info = xen_irq_init(irq + i); if (!info) { ret = -ENOMEM; goto error_irq; } irq_set_chip_and_handler_name(irq + i, &xen_pirq_chip, handle_edge_irq, name); ret = xen_irq_info_pirq_setup(info, 0, pirq + i, 0, domid, i == 0 ? 0 : PIRQ_MSI_GROUP); if (ret < 0) goto error_irq; } ret = irq_set_msi_desc(irq, msidesc); if (ret < 0) goto error_irq; out: mutex_unlock(&irq_mapping_update_lock); return irq; error_irq: while (nvec--) { info = info_for_irq(irq + nvec); __unbind_from_irq(info, irq + nvec); } mutex_unlock(&irq_mapping_update_lock); return ret; } #endif int xen_destroy_irq(int irq) { struct physdev_unmap_pirq unmap_irq; struct irq_info *info = info_for_irq(irq); int rc = -ENOENT; mutex_lock(&irq_mapping_update_lock); /* * If trying to remove a vector in a MSI group different * than the first one skip the PIRQ unmap unless this vector * is the first one in the group. */ if (xen_initial_domain() && !(info->u.pirq.flags & PIRQ_MSI_GROUP)) { 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)) pr_info("domain %d does not have %d anymore\n", info->u.pirq.domid, info->u.pirq.pirq); else if (rc) { pr_warn("unmap irq failed %d\n", rc); goto out; } } xen_free_irq(info); out: mutex_unlock(&irq_mapping_update_lock); return rc; } int xen_pirq_from_irq(unsigned irq) { struct irq_info *info = info_for_irq(irq); return pirq_from_irq(info); } EXPORT_SYMBOL_GPL(xen_pirq_from_irq); static int bind_evtchn_to_irq_chip(evtchn_port_t evtchn, struct irq_chip *chip, struct xenbus_device *dev, bool shared) { int ret = -ENOMEM; struct irq_info *info; if (evtchn >= xen_evtchn_max_channels()) return -ENOMEM; mutex_lock(&irq_mapping_update_lock); info = evtchn_to_info(evtchn); if (!info) { info = xen_allocate_irq_dynamic(); if (!info) goto out; irq_set_chip_and_handler_name(info->irq, chip, handle_edge_irq, "event"); ret = xen_irq_info_evtchn_setup(info, evtchn, dev); if (ret < 0) { __unbind_from_irq(info, info->irq); goto out; } /* * New interdomain events are initially bound to vCPU0 This * is required to setup the event channel in the first * place and also important for UP guests because the * affinity setting is not invoked on them so nothing would * bind the channel. */ bind_evtchn_to_cpu(info, 0, false); } else if (!WARN_ON(info->type != IRQT_EVTCHN)) { if (shared && !WARN_ON(info->refcnt < 0)) info->refcnt++; } ret = info->irq; out: mutex_unlock(&irq_mapping_update_lock); return ret; } int bind_evtchn_to_irq(evtchn_port_t evtchn) { return bind_evtchn_to_irq_chip(evtchn, &xen_dynamic_chip, NULL, false); } EXPORT_SYMBOL_GPL(bind_evtchn_to_irq); int bind_evtchn_to_irq_lateeoi(evtchn_port_t evtchn) { return bind_evtchn_to_irq_chip(evtchn, &xen_lateeoi_chip, NULL, false); } EXPORT_SYMBOL_GPL(bind_evtchn_to_irq_lateeoi); static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu) { struct evtchn_bind_ipi bind_ipi; evtchn_port_t evtchn; struct irq_info *info; int ret; mutex_lock(&irq_mapping_update_lock); ret = per_cpu(ipi_to_irq, cpu)[ipi]; if (ret == -1) { info = xen_allocate_irq_dynamic(); if (!info) goto out; irq_set_chip_and_handler_name(info->irq, &xen_percpu_chip, handle_percpu_irq, "ipi"); bind_ipi.vcpu = xen_vcpu_nr(cpu); if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi, &bind_ipi) != 0) BUG(); evtchn = bind_ipi.port; ret = xen_irq_info_ipi_setup(info, cpu, evtchn, ipi); if (ret < 0) { __unbind_from_irq(info, info->irq); goto out; } /* * Force the affinity mask to the target CPU so proc shows * the correct target. */ bind_evtchn_to_cpu(info, cpu, true); ret = info->irq; } else { info = info_for_irq(ret); WARN_ON(info == NULL || info->type != IRQT_IPI); } out: mutex_unlock(&irq_mapping_update_lock); return ret; } static int bind_interdomain_evtchn_to_irq_chip(struct xenbus_device *dev, evtchn_port_t remote_port, struct irq_chip *chip, bool shared) { struct evtchn_bind_interdomain bind_interdomain; int err; bind_interdomain.remote_dom = dev->otherend_id; bind_interdomain.remote_port = remote_port; err = HYPERVISOR_event_channel_op(EVTCHNOP_bind_interdomain, &bind_interdomain); return err ? : bind_evtchn_to_irq_chip(bind_interdomain.local_port, chip, dev, shared); } int bind_interdomain_evtchn_to_irq_lateeoi(struct xenbus_device *dev, evtchn_port_t remote_port) { return bind_interdomain_evtchn_to_irq_chip(dev, remote_port, &xen_lateeoi_chip, false); } EXPORT_SYMBOL_GPL(bind_interdomain_evtchn_to_irq_lateeoi); static int find_virq(unsigned int virq, unsigned int cpu, evtchn_port_t *evtchn) { struct evtchn_status status; evtchn_port_t port; int rc = -ENOENT; memset(&status, 0, sizeof(status)); for (port = 0; port < xen_evtchn_max_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 == xen_vcpu_nr(cpu)) { *evtchn = port; break; } } return rc; } /** * xen_evtchn_nr_channels - number of usable event channel ports * * This may be less than the maximum supported by the current * hypervisor ABI. Use xen_evtchn_max_channels() for the maximum * supported. */ unsigned xen_evtchn_nr_channels(void) { return evtchn_ops->nr_channels(); } EXPORT_SYMBOL_GPL(xen_evtchn_nr_channels); int bind_virq_to_irq(unsigned int virq, unsigned int cpu, bool percpu) { struct evtchn_bind_virq bind_virq; evtchn_port_t evtchn = 0; struct irq_info *info; int ret; mutex_lock(&irq_mapping_update_lock); ret = per_cpu(virq_to_irq, cpu)[virq]; if (ret == -1) { info = xen_allocate_irq_dynamic(); if (!info) goto out; if (percpu) irq_set_chip_and_handler_name(info->irq, &xen_percpu_chip, handle_percpu_irq, "virq"); else irq_set_chip_and_handler_name(info->irq, &xen_dynamic_chip, handle_edge_irq, "virq"); bind_virq.virq = virq; bind_virq.vcpu = xen_vcpu_nr(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, &evtchn); BUG_ON(ret < 0); } ret = xen_irq_info_virq_setup(info, cpu, evtchn, virq); if (ret < 0) { __unbind_from_irq(info, info->irq); goto out; } /* * Force the affinity mask for percpu interrupts so proc * shows the correct target. */ bind_evtchn_to_cpu(info, cpu, percpu); ret = info->irq; } else { info = info_for_irq(ret); WARN_ON(info == NULL || info->type != IRQT_VIRQ); } out: mutex_unlock(&irq_mapping_update_lock); return ret; } static void unbind_from_irq(unsigned int irq) { struct irq_info *info; mutex_lock(&irq_mapping_update_lock); info = info_for_irq(irq); __unbind_from_irq(info, irq); mutex_unlock(&irq_mapping_update_lock); } static int bind_evtchn_to_irqhandler_chip(evtchn_port_t evtchn, irq_handler_t handler, unsigned long irqflags, const char *devname, void *dev_id, struct irq_chip *chip) { int irq, retval; irq = bind_evtchn_to_irq_chip(evtchn, chip, NULL, irqflags & IRQF_SHARED); 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; } int bind_evtchn_to_irqhandler(evtchn_port_t evtchn, irq_handler_t handler, unsigned long irqflags, const char *devname, void *dev_id) { return bind_evtchn_to_irqhandler_chip(evtchn, handler, irqflags, devname, dev_id, &xen_dynamic_chip); } EXPORT_SYMBOL_GPL(bind_evtchn_to_irqhandler); int bind_evtchn_to_irqhandler_lateeoi(evtchn_port_t evtchn, irq_handler_t handler, unsigned long irqflags, const char *devname, void *dev_id) { return bind_evtchn_to_irqhandler_chip(evtchn, handler, irqflags, devname, dev_id, &xen_lateeoi_chip); } EXPORT_SYMBOL_GPL(bind_evtchn_to_irqhandler_lateeoi); static int bind_interdomain_evtchn_to_irqhandler_chip( struct xenbus_device *dev, evtchn_port_t remote_port, irq_handler_t handler, unsigned long irqflags, const char *devname, void *dev_id, struct irq_chip *chip) { int irq, retval; irq = bind_interdomain_evtchn_to_irq_chip(dev, remote_port, chip, irqflags & IRQF_SHARED); 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; } int bind_interdomain_evtchn_to_irqhandler_lateeoi(struct xenbus_device *dev, evtchn_port_t remote_port, irq_handler_t handler, unsigned long irqflags, const char *devname, void *dev_id) { return bind_interdomain_evtchn_to_irqhandler_chip(dev, remote_port, handler, irqflags, devname, dev_id, &xen_lateeoi_chip); } EXPORT_SYMBOL_GPL(bind_interdomain_evtchn_to_irqhandler_lateeoi); 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, irqflags & IRQF_PERCPU); 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) { struct irq_info *info = info_for_irq(irq); if (WARN_ON(!info)) return; free_irq(irq, dev_id); unbind_from_irq(irq); } EXPORT_SYMBOL_GPL(unbind_from_irqhandler); /** * xen_set_irq_priority() - set an event channel priority. * @irq:irq bound to an event channel. * @priority: priority between XEN_IRQ_PRIORITY_MAX and XEN_IRQ_PRIORITY_MIN. */ int xen_set_irq_priority(unsigned irq, unsigned priority) { struct evtchn_set_priority set_priority; set_priority.port = evtchn_from_irq(irq); set_priority.priority = priority; return HYPERVISOR_event_channel_op(EVTCHNOP_set_priority, &set_priority); } EXPORT_SYMBOL_GPL(xen_set_irq_priority); int evtchn_make_refcounted(evtchn_port_t evtchn, bool is_static) { struct irq_info *info = evtchn_to_info(evtchn); if (!info) return -ENOENT; WARN_ON(info->refcnt != -1); info->refcnt = 1; info->is_static = is_static; return 0; } EXPORT_SYMBOL_GPL(evtchn_make_refcounted); int evtchn_get(evtchn_port_t evtchn) { struct irq_info *info; int err = -ENOENT; if (evtchn >= xen_evtchn_max_channels()) return -EINVAL; mutex_lock(&irq_mapping_update_lock); info = evtchn_to_info(evtchn); if (!info) goto done; err = -EINVAL; if (info->refcnt <= 0 || info->refcnt == SHRT_MAX) goto done; info->refcnt++; err = 0; done: mutex_unlock(&irq_mapping_update_lock); return err; } EXPORT_SYMBOL_GPL(evtchn_get); void evtchn_put(evtchn_port_t evtchn) { struct irq_info *info = evtchn_to_info(evtchn); if (WARN_ON(!info)) return; unbind_from_irq(info->irq); } EXPORT_SYMBOL_GPL(evtchn_put); void xen_send_IPI_one(unsigned int cpu, enum ipi_vector vector) { evtchn_port_t evtchn; #ifdef CONFIG_X86 if (unlikely(vector == XEN_NMI_VECTOR)) { int rc = HYPERVISOR_vcpu_op(VCPUOP_send_nmi, xen_vcpu_nr(cpu), NULL); if (rc < 0) printk(KERN_WARNING "Sending nmi to CPU%d failed (rc:%d)\n", cpu, rc); return; } #endif evtchn = per_cpu(ipi_to_evtchn, cpu)[vector]; BUG_ON(evtchn == 0); notify_remote_via_evtchn(evtchn); } struct evtchn_loop_ctrl { ktime_t timeout; unsigned count; bool defer_eoi; }; void handle_irq_for_port(evtchn_port_t port, struct evtchn_loop_ctrl *ctrl) { struct irq_info *info = evtchn_to_info(port); struct xenbus_device *dev; if (!info) return; /* * Check for timeout every 256 events. * We are setting the timeout value only after the first 256 * events in order to not hurt the common case of few loop * iterations. The 256 is basically an arbitrary value. * * In case we are hitting the timeout we need to defer all further * EOIs in order to ensure to leave the event handling loop rather * sooner than later. */ if (!ctrl->defer_eoi && !(++ctrl->count & 0xff)) { ktime_t kt = ktime_get(); if (!ctrl->timeout) { kt = ktime_add_ms(kt, jiffies_to_msecs(event_loop_timeout)); ctrl->timeout = kt; } else if (kt > ctrl->timeout) { ctrl->defer_eoi = true; } } if (xchg_acquire(&info->is_active, 1)) return; dev = (info->type == IRQT_EVTCHN) ? info->u.interdomain : NULL; if (dev) atomic_inc(&dev->events); if (ctrl->defer_eoi) { info->eoi_cpu = smp_processor_id(); info->irq_epoch = __this_cpu_read(irq_epoch); info->eoi_time = get_jiffies_64() + event_eoi_delay; } generic_handle_irq(info->irq); } int xen_evtchn_do_upcall(void) { struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu); int ret = vcpu_info->evtchn_upcall_pending ? IRQ_HANDLED : IRQ_NONE; int cpu = smp_processor_id(); struct evtchn_loop_ctrl ctrl = { 0 }; /* * When closing an event channel the associated IRQ must not be freed * until all cpus have left the event handling loop. This is ensured * by taking the rcu_read_lock() while handling events, as freeing of * the IRQ is handled via queue_rcu_work() _after_ closing the event * channel. */ rcu_read_lock(); do { vcpu_info->evtchn_upcall_pending = 0; xen_evtchn_handle_events(cpu, &ctrl); BUG_ON(!irqs_disabled()); virt_rmb(); /* Hypervisor can set upcall pending. */ } while (vcpu_info->evtchn_upcall_pending); rcu_read_unlock(); /* * Increment irq_epoch only now to defer EOIs only for * xen_irq_lateeoi() invocations occurring from inside the loop * above. */ __this_cpu_inc(irq_epoch); return ret; } EXPORT_SYMBOL_GPL(xen_evtchn_do_upcall); /* Rebind a new event channel to an existing irq. */ void rebind_evtchn_irq(evtchn_port_t evtchn, int irq) { struct irq_info *info = info_for_irq(irq); if (WARN_ON(!info)) return; /* 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_info(evtchn)); /* Expect irq to have been bound before, so there should be a proper type */ BUG_ON(info->type == IRQT_UNBOUND); info->irq = irq; (void)xen_irq_info_evtchn_setup(info, evtchn, NULL); mutex_unlock(&irq_mapping_update_lock); bind_evtchn_to_cpu(info, info->cpu, false); /* Unmask the event channel. */ enable_irq(irq); } /* Rebind an evtchn so that it gets delivered to a specific cpu */ static int xen_rebind_evtchn_to_cpu(struct irq_info *info, unsigned int tcpu) { struct evtchn_bind_vcpu bind_vcpu; evtchn_port_t evtchn = info ? info->evtchn : 0; if (!VALID_EVTCHN(evtchn)) return -1; if (!xen_support_evtchn_rebind()) return -1; /* Send future instances of this interrupt to other vcpu. */ bind_vcpu.port = evtchn; bind_vcpu.vcpu = xen_vcpu_nr(tcpu); /* * Mask the event while changing the VCPU binding to prevent * it being delivered on an unexpected VCPU. */ do_mask(info, EVT_MASK_REASON_TEMPORARY); /* * 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(info, tcpu, false); do_unmask(info, EVT_MASK_REASON_TEMPORARY); return 0; } /* * Find the CPU within @dest mask which has the least number of channels * assigned. This is not precise as the per cpu counts can be modified * concurrently. */ static unsigned int select_target_cpu(const struct cpumask *dest) { unsigned int cpu, best_cpu = UINT_MAX, minch = UINT_MAX; for_each_cpu_and(cpu, dest, cpu_online_mask) { unsigned int curch = atomic_read(&channels_on_cpu[cpu]); if (curch < minch) { minch = curch; best_cpu = cpu; } } /* * Catch the unlikely case that dest contains no online CPUs. Can't * recurse. */ if (best_cpu == UINT_MAX) return select_target_cpu(cpu_online_mask); return best_cpu; } static int set_affinity_irq(struct irq_data *data, const struct cpumask *dest, bool force) { unsigned int tcpu = select_target_cpu(dest); int ret; ret = xen_rebind_evtchn_to_cpu(info_for_irq(data->irq), tcpu); if (!ret) irq_data_update_effective_affinity(data, cpumask_of(tcpu)); return ret; } static void enable_dynirq(struct irq_data *data) { struct irq_info *info = info_for_irq(data->irq); evtchn_port_t evtchn = info ? info->evtchn : 0; if (VALID_EVTCHN(evtchn)) do_unmask(info, EVT_MASK_REASON_EXPLICIT); } static void do_ack_dynirq(struct irq_info *info) { evtchn_port_t evtchn = info->evtchn; if (VALID_EVTCHN(evtchn)) event_handler_exit(info); } static void ack_dynirq(struct irq_data *data) { struct irq_info *info = info_for_irq(data->irq); if (info) do_ack_dynirq(info); } static void mask_ack_dynirq(struct irq_data *data) { struct irq_info *info = info_for_irq(data->irq); if (info) { do_disable_dynirq(info); do_ack_dynirq(info); } } static void lateeoi_ack_dynirq(struct irq_data *data) { struct irq_info *info = info_for_irq(data->irq); evtchn_port_t evtchn = info ? info->evtchn : 0; if (VALID_EVTCHN(evtchn)) { do_mask(info, EVT_MASK_REASON_EOI_PENDING); /* * Don't call event_handler_exit(). * Need to keep is_active non-zero in order to ignore re-raised * events after cpu affinity changes while a lateeoi is pending. */ clear_evtchn(evtchn); } } static void lateeoi_mask_ack_dynirq(struct irq_data *data) { struct irq_info *info = info_for_irq(data->irq); evtchn_port_t evtchn = info ? info->evtchn : 0; if (VALID_EVTCHN(evtchn)) { do_mask(info, EVT_MASK_REASON_EXPLICIT); event_handler_exit(info); } } static int retrigger_dynirq(struct irq_data *data) { struct irq_info *info = info_for_irq(data->irq); evtchn_port_t evtchn = info ? info->evtchn : 0; if (!VALID_EVTCHN(evtchn)) return 0; do_mask(info, EVT_MASK_REASON_TEMPORARY); set_evtchn(evtchn); do_unmask(info, EVT_MASK_REASON_TEMPORARY); return 1; } 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) { pr_warn("xen map irq failed gsi=%d irq=%d pirq=%d rc=%d\n", gsi, irq, pirq, rc); xen_free_irq(info); continue; } printk(KERN_DEBUG "xen: --> irq=%d, pirq=%d\n", irq, map_irq.pirq); __startup_pirq(info); } } static void restore_cpu_virqs(unsigned int cpu) { struct evtchn_bind_virq bind_virq; evtchn_port_t evtchn; struct irq_info *info; int virq, irq; for (virq = 0; virq < NR_VIRQS; virq++) { if ((irq = per_cpu(virq_to_irq, cpu)[virq]) == -1) continue; info = info_for_irq(irq); BUG_ON(virq_from_irq(info) != virq); /* Get a new binding from Xen. */ bind_virq.virq = virq; bind_virq.vcpu = xen_vcpu_nr(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_setup(info, cpu, evtchn, virq); /* The affinity mask is still valid */ bind_evtchn_to_cpu(info, cpu, false); } } static void restore_cpu_ipis(unsigned int cpu) { struct evtchn_bind_ipi bind_ipi; evtchn_port_t evtchn; struct irq_info *info; int ipi, irq; for (ipi = 0; ipi < XEN_NR_IPIS; ipi++) { if ((irq = per_cpu(ipi_to_irq, cpu)[ipi]) == -1) continue; info = info_for_irq(irq); BUG_ON(ipi_from_irq(info) != ipi); /* Get a new binding from Xen. */ bind_ipi.vcpu = xen_vcpu_nr(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_setup(info, cpu, evtchn, ipi); /* The affinity mask is still valid */ bind_evtchn_to_cpu(info, cpu, false); } } /* Clear an irq's pending state, in preparation for polling on it */ void xen_clear_irq_pending(int irq) { struct irq_info *info = info_for_irq(irq); evtchn_port_t evtchn = info ? info->evtchn : 0; if (VALID_EVTCHN(evtchn)) event_handler_exit(info); } EXPORT_SYMBOL(xen_clear_irq_pending); bool xen_test_irq_pending(int irq) { evtchn_port_t 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; if (WARN_ON(!info)) return -ENOENT; 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; struct irq_info *info; /* New event-channel space is not 'live' yet. */ xen_evtchn_resume(); /* No IRQ <-> event-channel mappings. */ list_for_each_entry(info, &xen_irq_list_head, list) { /* Zap event-channel binding */ info->evtchn = 0; /* Adjust accounting */ channels_on_cpu_dec(info); } clear_evtchn_to_irq_all(); 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_lateeoi_chip __read_mostly = { /* The chip name needs to contain "xen-dyn" for irqbalance to work. */ .name = "xen-dyn-lateeoi", .irq_disable = disable_dynirq, .irq_mask = disable_dynirq, .irq_unmask = enable_dynirq, .irq_ack = lateeoi_ack_dynirq, .irq_mask_ack = lateeoi_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, }; #ifdef CONFIG_X86 #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_setup_callback_vector(void) { uint64_t callback_via; if (xen_have_vector_callback) { callback_via = HVM_CALLBACK_VECTOR(HYPERVISOR_CALLBACK_VECTOR); if (xen_set_callback_via(callback_via)) { pr_err("Request for Xen HVM callback vector failed\n"); xen_have_vector_callback = false; } } } /* * Setup per-vCPU vector-type callbacks. If this setup is unavailable, * fallback to the global vector-type callback. */ static __init void xen_init_setup_upcall_vector(void) { if (!xen_have_vector_callback) return; if ((cpuid_eax(xen_cpuid_base() + 4) & XEN_HVM_CPUID_UPCALL_VECTOR) && !xen_set_upcall_vector(0)) xen_percpu_upcall = true; else if (xen_feature(XENFEAT_hvm_callback_vector)) xen_setup_callback_vector(); else xen_have_vector_callback = false; } int xen_set_upcall_vector(unsigned int cpu) { int rc; xen_hvm_evtchn_upcall_vector_t op = { .vector = HYPERVISOR_CALLBACK_VECTOR, .vcpu = per_cpu(xen_vcpu_id, cpu), }; rc = HYPERVISOR_hvm_op(HVMOP_set_evtchn_upcall_vector, &op); if (rc) return rc; /* Trick toolstack to think we are enlightened. */ if (!cpu) rc = xen_set_callback_via(1); return rc; } static __init void xen_alloc_callback_vector(void) { if (!xen_have_vector_callback) return; pr_info("Xen HVM callback vector for event delivery is enabled\n"); sysvec_install(HYPERVISOR_CALLBACK_VECTOR, sysvec_xen_hvm_callback); } #else void xen_setup_callback_vector(void) {} static inline void xen_init_setup_upcall_vector(void) {} int xen_set_upcall_vector(unsigned int cpu) {} static inline void xen_alloc_callback_vector(void) {} #endif /* CONFIG_XEN_PVHVM */ #endif /* CONFIG_X86 */ bool xen_fifo_events = true; module_param_named(fifo_events, xen_fifo_events, bool, 0); static int xen_evtchn_cpu_prepare(unsigned int cpu) { int ret = 0; xen_cpu_init_eoi(cpu); if (evtchn_ops->percpu_init) ret = evtchn_ops->percpu_init(cpu); return ret; } static int xen_evtchn_cpu_dead(unsigned int cpu) { int ret = 0; if (evtchn_ops->percpu_deinit) ret = evtchn_ops->percpu_deinit(cpu); return ret; } void __init xen_init_IRQ(void) { int ret = -EINVAL; evtchn_port_t evtchn; if (xen_fifo_events) ret = xen_evtchn_fifo_init(); if (ret < 0) { xen_evtchn_2l_init(); xen_fifo_events = false; } xen_cpu_init_eoi(smp_processor_id()); cpuhp_setup_state_nocalls(CPUHP_XEN_EVTCHN_PREPARE, "xen/evtchn:prepare", xen_evtchn_cpu_prepare, xen_evtchn_cpu_dead); evtchn_to_irq = kcalloc(EVTCHN_ROW(xen_evtchn_max_channels()), sizeof(*evtchn_to_irq), GFP_KERNEL); BUG_ON(!evtchn_to_irq); /* No event channels are 'live' right now. */ for (evtchn = 0; evtchn < xen_evtchn_nr_channels(); evtchn++) mask_evtchn(evtchn); pirq_needs_eoi = pirq_needs_eoi_flag; #ifdef CONFIG_X86 if (xen_pv_domain()) { if (xen_initial_domain()) pci_xen_initial_domain(); } xen_init_setup_upcall_vector(); xen_alloc_callback_vector(); if (xen_hvm_domain()) { 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 { int rc; struct physdev_pirq_eoi_gmfn eoi_gmfn; pirq_eoi_map = (void *)__get_free_page(GFP_KERNEL|__GFP_ZERO); eoi_gmfn.gmfn = virt_to_gfn(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; } #endif }