1 files changed, 103 insertions, 0 deletions
diff --git a/drivers/gpu/drm/virtio/virtio_vq.c b/drivers/gpu/drm/virtio/virtio_vq.c
new file mode 100644
index 000000000000..6ed4184c6349
--- /dev/null
+++ b/drivers/gpu/drm/virtio/virtio_vq.c
@@ -0,0 +1,103 @@
+#include <drm/drmP.h>
+#include "virtio_drv.h"
+#include <linux/virtio.h>
+#include <linux/virtio_ring.h>
+
+void virtgpu_ctrl_ack(struct virtqueue *vq)
+{
+	struct drm_device *dev = vq->vdev->priv;
+	struct virtgpu_device *vgdev = dev->dev_private;
+	schedule_work(&vgdev->dequeue_work);
+}
+
+struct virtgpu_vbuffer *virtgpu_allocate_vbuf(struct virtgpu_device *vgdev,
+					      int size)
+{
+	struct virtgpu_vbuffer *vbuf;
+
+	vbuf = kmalloc(sizeof(*vbuf) + size, GFP_KERNEL);
+	if (!vbuf)
+		goto fail;
+
+	vbuf->buf = (void *)vbuf + sizeof(*vbuf);
+	vbuf->size = size;
+
+	return vbuf;
+fail:
+	kfree(vbuf);
+	return ERR_PTR(-ENOMEM);
+}
+
+static void free_vbuf(struct virtgpu_vbuffer *vbuf)
+{
+	kfree(vbuf);
+}
+
+static int reclaim_vbufs(struct virtqueue *vq, struct list_head *reclaim_list)
+{
+	struct virtgpu_vbuffer *vbuf;
+	unsigned int len;
+	int freed = 0;
+	while ((vbuf = virtqueue_get_buf(vq, &len))) {
+		list_add(&vbuf->destroy_list, reclaim_list);
+		freed++;
+	}
+	return freed;
+}
+	
+void virtgpu_dequeue_work_func(struct work_struct *work)
+{
+	struct virtgpu_device *vgdev = container_of(work, struct virtgpu_device,
+					       dequeue_work);
+	int ret;
+	struct list_head reclaim_list;
+	struct virtgpu_vbuffer *entry, *tmp;
+	
+	INIT_LIST_HEAD(&reclaim_list);
+	spin_lock(&vgdev->ctrlq_lock);
+	do {
+		virtqueue_disable_cb(vgdev->ctrlq);
+		ret = reclaim_vbufs(vgdev->ctrlq, &reclaim_list);
+		if (ret == 0)
+			printk("cleaned 0 buffers wierd\n");
+
+	} while (!virtqueue_enable_cb(vgdev->ctrlq));
+	spin_unlock(&vgdev->ctrlq_lock);
+
+	list_for_each_entry_safe(entry, tmp, &reclaim_list, destroy_list) {
+		list_del(&entry->destroy_list);
+		free_vbuf(entry);
+	}
+	wake_up(&vgdev->ctrl_ack_queue);
+}
+			
+int virtgpu_queue_ctrl_buffer(struct virtgpu_device *vgdev,
+			      struct virtgpu_vbuffer *vbuf)
+{
+	struct virtqueue *vq = vgdev->ctrlq;
+	struct scatterlist *sgs[2], vcmd;
+	int outcnt, incnt = 0;
+	int ret;
+
+	sg_init_one(&vcmd, vbuf->buf, vbuf->size);
+	sgs[0] = &vcmd;
+	outcnt = 1;
+       
+	spin_lock(&vgdev->ctrlq_lock);
+retry:
+	ret = virtqueue_add_sgs(vq, sgs, outcnt, incnt, vbuf, GFP_ATOMIC);
+	if (ret == -ENOSPC) {
+		spin_unlock(&vgdev->ctrlq_lock);
+		wait_event(vgdev->ctrl_ack_queue, vq->num_free);
+		spin_lock(&vgdev->ctrlq_lock);
+		goto retry;
+	} else {
+		virtqueue_kick(vq);
+	}
+
+	spin_unlock(&vgdev->ctrlq_lock);
+
+	if (!ret)
+		ret = vq->num_free;
+	return ret;
+}