[PATCH v3 2/2] drm/virtio: New fence for every plane update

Dmitry Osipenko dmitry.osipenko at collabora.com
Sun Oct 20 23:08:03 UTC 2024


From: Dongwon Kim <dongwon.kim at intel.com>

Having a fence linked to a virtio_gpu_framebuffer in the plane update
sequence would cause conflict when several planes referencing the same
framebuffer (e.g. Xorg screen covering multi-displays configured for an
extended mode) and those planes are updated concurrently. So it is needed
to allocate a fence for every plane state instead of the framebuffer.

Signed-off-by: Dongwon Kim <dongwon.kim at intel.com>
[dmitry.osipenko at collabora.com: rebase, fix up, edit commit message]
Signed-off-by: Dmitry Osipenko <dmitry.osipenko at collabora.com>
---
 drivers/gpu/drm/virtio/virtgpu_drv.h   |  7 ++++
 drivers/gpu/drm/virtio/virtgpu_plane.c | 58 +++++++++++++++++---------
 2 files changed, 46 insertions(+), 19 deletions(-)

diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.h b/drivers/gpu/drm/virtio/virtgpu_drv.h
index 64c236169db8..5dc8eeaf7123 100644
--- a/drivers/gpu/drm/virtio/virtgpu_drv.h
+++ b/drivers/gpu/drm/virtio/virtgpu_drv.h
@@ -194,6 +194,13 @@ struct virtio_gpu_framebuffer {
 #define to_virtio_gpu_framebuffer(x) \
 	container_of(x, struct virtio_gpu_framebuffer, base)
 
+struct virtio_gpu_plane_state {
+	struct drm_plane_state base;
+	struct virtio_gpu_fence *fence;
+};
+#define to_virtio_gpu_plane_state(x) \
+	container_of(x, struct virtio_gpu_plane_state, base)
+
 struct virtio_gpu_queue {
 	struct virtqueue *vq;
 	spinlock_t qlock;
diff --git a/drivers/gpu/drm/virtio/virtgpu_plane.c b/drivers/gpu/drm/virtio/virtgpu_plane.c
index ab7232921cb7..2add67c6b66d 100644
--- a/drivers/gpu/drm/virtio/virtgpu_plane.c
+++ b/drivers/gpu/drm/virtio/virtgpu_plane.c
@@ -67,11 +67,28 @@ uint32_t virtio_gpu_translate_format(uint32_t drm_fourcc)
 	return format;
 }
 
+static struct
+drm_plane_state *virtio_gpu_plane_duplicate_state(struct drm_plane *plane)
+{
+	struct virtio_gpu_plane_state *new;
+
+	if (WARN_ON(!plane->state))
+		return NULL;
+
+	new = kzalloc(sizeof(*new), GFP_KERNEL);
+	if (!new)
+		return NULL;
+
+	__drm_atomic_helper_plane_duplicate_state(plane, &new->base);
+
+	return &new->base;
+}
+
 static const struct drm_plane_funcs virtio_gpu_plane_funcs = {
 	.update_plane		= drm_atomic_helper_update_plane,
 	.disable_plane		= drm_atomic_helper_disable_plane,
 	.reset			= drm_atomic_helper_plane_reset,
-	.atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state,
+	.atomic_duplicate_state = virtio_gpu_plane_duplicate_state,
 	.atomic_destroy_state	= drm_atomic_helper_plane_destroy_state,
 };
 
@@ -139,11 +156,13 @@ static void virtio_gpu_resource_flush(struct drm_plane *plane,
 	struct drm_device *dev = plane->dev;
 	struct virtio_gpu_device *vgdev = dev->dev_private;
 	struct virtio_gpu_framebuffer *vgfb;
+	struct virtio_gpu_plane_state *vgplane_st;
 	struct virtio_gpu_object *bo;
 
 	vgfb = to_virtio_gpu_framebuffer(plane->state->fb);
+	vgplane_st = to_virtio_gpu_plane_state(plane->state);
 	bo = gem_to_virtio_gpu_obj(vgfb->base.obj[0]);
-	if (vgfb->fence) {
+	if (vgplane_st->fence) {
 		struct virtio_gpu_object_array *objs;
 
 		objs = virtio_gpu_array_alloc(1);
@@ -152,13 +171,11 @@ static void virtio_gpu_resource_flush(struct drm_plane *plane,
 		virtio_gpu_array_add_obj(objs, vgfb->base.obj[0]);
 		virtio_gpu_array_lock_resv(objs);
 		virtio_gpu_cmd_resource_flush(vgdev, bo->hw_res_handle, x, y,
-					      width, height, objs, vgfb->fence);
+					      width, height, objs,
+					      vgplane_st->fence);
 		virtio_gpu_notify(vgdev);
-
-		dma_fence_wait_timeout(&vgfb->fence->f, true,
+		dma_fence_wait_timeout(&vgplane_st->fence->f, true,
 				       msecs_to_jiffies(50));
-		dma_fence_put(&vgfb->fence->f);
-		vgfb->fence = NULL;
 	} else {
 		virtio_gpu_cmd_resource_flush(vgdev, bo->hw_res_handle, x, y,
 					      width, height, NULL, NULL);
@@ -248,12 +265,14 @@ static int virtio_gpu_plane_prepare_fb(struct drm_plane *plane,
 	struct drm_device *dev = plane->dev;
 	struct virtio_gpu_device *vgdev = dev->dev_private;
 	struct virtio_gpu_framebuffer *vgfb;
+	struct virtio_gpu_plane_state *vgplane_st;
 	struct virtio_gpu_object *bo;
 
 	if (!new_state->fb)
 		return 0;
 
 	vgfb = to_virtio_gpu_framebuffer(new_state->fb);
+	vgplane_st = to_virtio_gpu_plane_state(new_state);
 	bo = gem_to_virtio_gpu_obj(vgfb->base.obj[0]);
 
 	drm_gem_plane_helper_prepare_fb(plane, new_state);
@@ -261,10 +280,11 @@ static int virtio_gpu_plane_prepare_fb(struct drm_plane *plane,
 	if (!bo || (plane->type == DRM_PLANE_TYPE_PRIMARY && !bo->guest_blob))
 		return 0;
 
-	if (bo->dumb && (plane->state->fb != new_state->fb)) {
-		vgfb->fence = virtio_gpu_fence_alloc(vgdev, vgdev->fence_drv.context,
+	if (bo->dumb) {
+		vgplane_st->fence = virtio_gpu_fence_alloc(vgdev,
+						     vgdev->fence_drv.context,
 						     0);
-		if (!vgfb->fence)
+		if (!vgplane_st->fence)
 			return -ENOMEM;
 	}
 
@@ -274,15 +294,15 @@ static int virtio_gpu_plane_prepare_fb(struct drm_plane *plane,
 static void virtio_gpu_plane_cleanup_fb(struct drm_plane *plane,
 					struct drm_plane_state *state)
 {
-	struct virtio_gpu_framebuffer *vgfb;
+	struct virtio_gpu_plane_state *vgplane_st;
 
 	if (!state->fb)
 		return;
 
-	vgfb = to_virtio_gpu_framebuffer(state->fb);
-	if (vgfb->fence) {
-		dma_fence_put(&vgfb->fence->f);
-		vgfb->fence = NULL;
+	vgplane_st = to_virtio_gpu_plane_state(state);
+	if (vgplane_st->fence) {
+		dma_fence_put(&vgplane_st->fence->f);
+		vgplane_st->fence = NULL;
 	}
 }
 
@@ -295,6 +315,7 @@ static void virtio_gpu_cursor_plane_update(struct drm_plane *plane,
 	struct virtio_gpu_device *vgdev = dev->dev_private;
 	struct virtio_gpu_output *output = NULL;
 	struct virtio_gpu_framebuffer *vgfb;
+	struct virtio_gpu_plane_state *vgplane_st;
 	struct virtio_gpu_object *bo = NULL;
 	uint32_t handle;
 
@@ -307,6 +328,7 @@ static void virtio_gpu_cursor_plane_update(struct drm_plane *plane,
 
 	if (plane->state->fb) {
 		vgfb = to_virtio_gpu_framebuffer(plane->state->fb);
+		vgplane_st = to_virtio_gpu_plane_state(plane->state);
 		bo = gem_to_virtio_gpu_obj(vgfb->base.obj[0]);
 		handle = bo->hw_res_handle;
 	} else {
@@ -326,11 +348,9 @@ static void virtio_gpu_cursor_plane_update(struct drm_plane *plane,
 			(vgdev, 0,
 			 plane->state->crtc_w,
 			 plane->state->crtc_h,
-			 0, 0, objs, vgfb->fence);
+			 0, 0, objs, vgplane_st->fence);
 		virtio_gpu_notify(vgdev);
-		dma_fence_wait(&vgfb->fence->f, true);
-		dma_fence_put(&vgfb->fence->f);
-		vgfb->fence = NULL;
+		dma_fence_wait(&vgplane_st->fence->f, true);
 	}
 
 	if (plane->state->fb != old_state->fb) {
-- 
2.47.0



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