diff options
Diffstat (limited to 'drivers/xen/events.c')
-rw-r--r-- | drivers/xen/events.c | 77 |
1 files changed, 76 insertions, 1 deletions
diff --git a/drivers/xen/events.c b/drivers/xen/events.c index 6e075cdd0c6..e5e5812a101 100644 --- a/drivers/xen/events.c +++ b/drivers/xen/events.c @@ -87,6 +87,7 @@ enum xen_irq_type { */ struct irq_info { struct list_head list; + int refcnt; enum xen_irq_type type; /* type */ unsigned irq; unsigned short evtchn; /* event channel */ @@ -406,6 +407,7 @@ static void xen_irq_init(unsigned irq) panic("Unable to allocate metadata for IRQ%d\n", irq); info->type = IRQT_UNBOUND; + info->refcnt = -1; irq_set_handler_data(irq, info); @@ -469,6 +471,8 @@ static void xen_free_irq(unsigned irq) irq_set_handler_data(irq, NULL); + WARN_ON(info->refcnt > 0); + kfree(info); /* Legacy IRQ descriptors are managed by the arch. */ @@ -637,7 +641,7 @@ int xen_bind_pirq_gsi_to_irq(unsigned 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? */ + goto out; } irq = xen_allocate_irq_gsi(gsi); @@ -939,9 +943,16 @@ 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) @@ -970,6 +981,7 @@ static void unbind_from_irq(unsigned int irq) xen_free_irq(irq); + done: mutex_unlock(&irq_mapping_update_lock); } @@ -1065,6 +1077,69 @@ void unbind_from_irqhandler(unsigned int irq, void *dev_id) } 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]; |