[PATCH v10 4/6] drm: consider GEM object shared when it is exported

[Yunxiang Li <Yunxiang.Li@xxxxxxx>]

Tracking the state of a GEM object for shared stats is quite difficult
since the handle_count is managed behind driver's back. So instead
considers GEM object shared the moment it is exported with flink ioctl.
This makes it work the same to the dma_buf case. Add a callback for
drivers to get notified when GEM object is being shared.

Signed-off-by: Yunxiang Li <Yunxiang.Li@xxxxxxx>

CC: dri-devel@xxxxxxxxxxxxxxxxxxxxx
---
 drivers/gpu/drm/drm_gem.c   |  3 +++
 drivers/gpu/drm/drm_prime.c |  3 +++
 include/drm/drm_gem.h       | 12 +++++++++++-
 3 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index d4bbc5d109c8b..1ead11de31f6b 100644
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -854,6 +854,9 @@ drm_gem_flink_ioctl(struct drm_device *dev, void *data,
 			goto err;
 
 		obj->name = ret;
+
+		if (obj->funcs->shared)
+			obj->funcs->shared(obj);
 	}
 
 	args->name = (uint64_t) obj->name;
diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
index 0e3f8adf162f6..336d982d69807 100644
--- a/drivers/gpu/drm/drm_prime.c
+++ b/drivers/gpu/drm/drm_prime.c
@@ -406,6 +406,9 @@ static struct dma_buf *export_and_register_object(struct drm_device *dev,
 	obj->dma_buf = dmabuf;
 	get_dma_buf(obj->dma_buf);
 
+	if (obj->funcs->shared)
+		obj->funcs->shared(obj);
+
 	return dmabuf;
 }
 
diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h
index da11c16e212aa..8c5ffcd485752 100644
--- a/include/drm/drm_gem.h
+++ b/include/drm/drm_gem.h
@@ -122,6 +122,16 @@ struct drm_gem_object_funcs {
 	 */
 	struct dma_buf *(*export)(struct drm_gem_object *obj, int flags);
 
+	/**
+	 * @shared:
+	 *
+	 * Callback when GEM object becomes shared, see also
+	 * drm_gem_object_is_shared_for_memory_stats
+	 *
+	 * This callback is optional.
+	 */
+	void (*shared)(struct drm_gem_object *obj);
+
 	/**
 	 * @pin:
 	 *
@@ -568,7 +578,7 @@ int drm_gem_evict(struct drm_gem_object *obj);
  */
 static inline bool drm_gem_object_is_shared_for_memory_stats(struct drm_gem_object *obj)
 {
-	return (obj->handle_count > 1) || obj->dma_buf;
+	return obj->name || obj->dma_buf;
 }
 
 #ifdef CONFIG_LOCKDEP
-- 
2.34.1