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path: root/drivers/xen/events.c
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Diffstat (limited to 'drivers/xen/events.c')
-rw-r--r--drivers/xen/events.c77
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];