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path: root/drivers/xen/pvcalls-back.c
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Diffstat (limited to 'drivers/xen/pvcalls-back.c')
-rw-r--r--drivers/xen/pvcalls-back.c82
1 files changed, 82 insertions, 0 deletions
diff --git a/drivers/xen/pvcalls-back.c b/drivers/xen/pvcalls-back.c
index 72d2fce27a34..48b71236192d 100644
--- a/drivers/xen/pvcalls-back.c
+++ b/drivers/xen/pvcalls-back.c
@@ -33,9 +33,91 @@ struct pvcalls_back_global {
struct semaphore frontends_lock;
} pvcalls_back_global;
+/*
+ * Per-frontend data structure. It contains pointers to the command
+ * ring, its event channel, a list of active sockets and a tree of
+ * passive sockets.
+ */
+struct pvcalls_fedata {
+ struct list_head list;
+ struct xenbus_device *dev;
+ struct xen_pvcalls_sring *sring;
+ struct xen_pvcalls_back_ring ring;
+ int irq;
+ struct list_head socket_mappings;
+ struct radix_tree_root socketpass_mappings;
+ struct semaphore socket_lock;
+};
+
+static irqreturn_t pvcalls_back_event(int irq, void *dev_id)
+{
+ return IRQ_HANDLED;
+}
+
static int backend_connect(struct xenbus_device *dev)
{
+ int err, evtchn;
+ grant_ref_t ring_ref;
+ struct pvcalls_fedata *fedata = NULL;
+
+ fedata = kzalloc(sizeof(struct pvcalls_fedata), GFP_KERNEL);
+ if (!fedata)
+ return -ENOMEM;
+
+ fedata->irq = -1;
+ err = xenbus_scanf(XBT_NIL, dev->otherend, "port", "%u",
+ &evtchn);
+ if (err != 1) {
+ err = -EINVAL;
+ xenbus_dev_fatal(dev, err, "reading %s/event-channel",
+ dev->otherend);
+ goto error;
+ }
+
+ err = xenbus_scanf(XBT_NIL, dev->otherend, "ring-ref", "%u", &ring_ref);
+ if (err != 1) {
+ err = -EINVAL;
+ xenbus_dev_fatal(dev, err, "reading %s/ring-ref",
+ dev->otherend);
+ goto error;
+ }
+
+ err = bind_interdomain_evtchn_to_irq(dev->otherend_id, evtchn);
+ if (err < 0)
+ goto error;
+ fedata->irq = err;
+
+ err = request_threaded_irq(fedata->irq, NULL, pvcalls_back_event,
+ IRQF_ONESHOT, "pvcalls-back", dev);
+ if (err < 0)
+ goto error;
+
+ err = xenbus_map_ring_valloc(dev, &ring_ref, 1,
+ (void **)&fedata->sring);
+ if (err < 0)
+ goto error;
+
+ BACK_RING_INIT(&fedata->ring, fedata->sring, XEN_PAGE_SIZE * 1);
+ fedata->dev = dev;
+
+ INIT_LIST_HEAD(&fedata->socket_mappings);
+ INIT_RADIX_TREE(&fedata->socketpass_mappings, GFP_KERNEL);
+ sema_init(&fedata->socket_lock, 1);
+ dev_set_drvdata(&dev->dev, fedata);
+
+ down(&pvcalls_back_global.frontends_lock);
+ list_add_tail(&fedata->list, &pvcalls_back_global.frontends);
+ up(&pvcalls_back_global.frontends_lock);
+
return 0;
+
+ error:
+ if (fedata->irq >= 0)
+ unbind_from_irqhandler(fedata->irq, dev);
+ if (fedata->sring != NULL)
+ xenbus_unmap_ring_vfree(dev, fedata->sring);
+ kfree(fedata);
+ return err;
}
static int backend_disconnect(struct xenbus_device *dev)