1 files changed, 73 insertions, 0 deletions

diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c
index e37b407a0ee8..6075f2d65335 100644
--- a/arch/x86/pci/xen.c
+++ b/arch/x86/pci/xen.c
@@ -461,3 +461,76 @@ void __init xen_setup_pirqs(void)
         }
 }
 #endif
+
+struct xen_device_domain_owner {
+        domid_t domain;
+        struct pci_dev *dev;
+        struct list_head list;
+};
+
+static DEFINE_SPINLOCK(dev_domain_list_spinlock);
+static struct list_head dev_domain_list = LIST_HEAD_INIT(dev_domain_list);
+
+static struct xen_device_domain_owner *find_device(struct pci_dev *dev)
+{
+        struct xen_device_domain_owner *owner;
+
+        list_for_each_entry(owner, &dev_domain_list, list) {
+                if (owner->dev == dev)
+                        return owner;
+        }
+        return NULL;
+}
+
+int xen_find_device_domain_owner(struct pci_dev *dev)
+{
+        struct xen_device_domain_owner *owner;
+        int domain = -ENODEV;
+
+        spin_lock(&dev_domain_list_spinlock);
+        owner = find_device(dev);
+        if (owner)
+                domain = owner->domain;
+        spin_unlock(&dev_domain_list_spinlock);
+        return domain;
+}
+EXPORT_SYMBOL_GPL(xen_find_device_domain_owner);
+
+int xen_register_device_domain_owner(struct pci_dev *dev, uint16_t domain)
+{
+        struct xen_device_domain_owner *owner;
+
+        owner = kzalloc(sizeof(struct xen_device_domain_owner), GFP_KERNEL);
+        if (!owner)
+                return -ENODEV;
+
+        spin_lock(&dev_domain_list_spinlock);
+        if (find_device(dev)) {
+                spin_unlock(&dev_domain_list_spinlock);
+                kfree(owner);
+                return -EEXIST;
+        }
+        owner->domain = domain;
+        owner->dev = dev;
+        list_add_tail(&owner->list, &dev_domain_list);
+        spin_unlock(&dev_domain_list_spinlock);
+        return 0;
+}
+EXPORT_SYMBOL_GPL(xen_register_device_domain_owner);
+
+int xen_unregister_device_domain_owner(struct pci_dev *dev)
+{
+        struct xen_device_domain_owner *owner;
+
+        spin_lock(&dev_domain_list_spinlock);
+        owner = find_device(dev);
+        if (!owner) {
+                spin_unlock(&dev_domain_list_spinlock);
+                return -ENODEV;
+        }
+        list_del(&owner->list);
+        spin_unlock(&dev_domain_list_spinlock);
+        kfree(owner);
+        return 0;
+}
+EXPORT_SYMBOL_GPL(xen_unregister_device_domain_owner);