[RFC PATCH 8/8] drm/virtio: enable per context fencing

[Gurchetan Singh]

If there's a 3D context available, initialize the fence using
the 3D context's fence context.

We can't process just the largest fence id anymore, since it's
not the same as the sequence number now.

Signed-off-by: Gurchetan Singh <gurchetansingh at chromium.org>
---
 drivers/gpu/drm/virtio/virtgpu_fence.c | 15 ++++++++++++---
 drivers/gpu/drm/virtio/virtgpu_vq.c    |  4 +---
 2 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/virtio/virtgpu_fence.c b/drivers/gpu/drm/virtio/virtgpu_fence.c
index a6c6f498e79e..bfcb41bcaa68 100644
--- a/drivers/gpu/drm/virtio/virtgpu_fence.c
+++ b/drivers/gpu/drm/virtio/virtgpu_fence.c
@@ -30,6 +30,8 @@
 #define to_virtio_fence(x) \
 	container_of(x, struct virtio_gpu_fence, f)
 
+static atomic_t fence_seq = ATOMIC_INIT(0);
+
 static const char *virtio_get_driver_name(struct dma_fence *f)
 {
 	return "virtio_gpu";
@@ -52,7 +54,7 @@ static bool virtio_fence_signaled(struct dma_fence *f)
 
 static void virtio_fence_value_str(struct dma_fence *f, char *str, int size)
 {
-	snprintf(str, size, "%llu", f->seqno);
+	snprintf(str, size, "[%llu, %llu]", f->context, f->seqno);
 }
 
 static void virtio_timeline_value_str(struct dma_fence *f, char *str, int size)
@@ -74,9 +76,11 @@ static const struct dma_fence_ops virtio_fence_ops = {
 struct virtio_gpu_fence *virtio_gpu_fence_alloc(struct virtio_gpu_device *vgdev,
 						struct virtio_gpu_fpriv *fpriv)
 {
+	uint64_t context;
 	struct virtio_gpu_fence_driver *drv = &vgdev->fence_drv;
 	struct virtio_gpu_fence *fence = kzalloc(sizeof(struct virtio_gpu_fence),
 							GFP_KERNEL);
+
 	if (!fence)
 		return fence;
 
@@ -86,7 +90,13 @@ struct virtio_gpu_fence *virtio_gpu_fence_alloc(struct virtio_gpu_device *vgdev,
 	 * unknown yet.  The fence must not be used outside of the driver
 	 * until virtio_gpu_fence_emit is called.
 	 */
-	dma_fence_init(&fence->f, &virtio_fence_ops, &drv->lock, drv->context, 0);
+	if (fpriv)
+		context = fpriv->fence_context;
+	else
+		context = drv->context;
+
+	dma_fence_init(&fence->f, &virtio_fence_ops, &drv->lock, context,
+		       atomic_inc_return(&fence_seq));
 
 	return fence;
 }
@@ -100,7 +110,6 @@ void virtio_gpu_fence_emit(struct virtio_gpu_device *vgdev,
 
 	spin_lock_irqsave(&drv->lock, irq_flags);
 	fence->fence_id = ++drv->current_fence_id;
-	fence->f.seqno = fence->fence_id;
 	dma_fence_get(&fence->f);
 	list_add_tail(&fence->node, &drv->fences);
 	spin_unlock_irqrestore(&drv->lock, irq_flags);
diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c
index 73854915ec34..e7d8b2398628 100644
--- a/drivers/gpu/drm/virtio/virtgpu_vq.c
+++ b/drivers/gpu/drm/virtio/virtgpu_vq.c
@@ -239,6 +239,7 @@ void virtio_gpu_dequeue_ctrl_func(struct work_struct *work)
 					  __func__, fence_id, f);
 			} else {
 				fence_id = f;
+				virtio_gpu_fence_event_process(vgdev, fence_id);
 			}
 		}
 		if (entry->resp_cb)
@@ -246,9 +247,6 @@ void virtio_gpu_dequeue_ctrl_func(struct work_struct *work)
 	}
 	wake_up(&vgdev->ctrlq.ack_queue);
 
-	if (fence_id)
-		virtio_gpu_fence_event_process(vgdev, fence_id);
-
 	list_for_each_entry_safe(entry, tmp, &reclaim_list, list) {
 		if (entry->objs)
 			virtio_gpu_array_put_free_delayed(vgdev, entry->objs);
-- 
2.25.1.481.gfbce0eb801-goog