[PATCH 2/6] drm: add drm_gem_object_is_shared_for_memory_stats() helper

[Alex Deucher <alexander.deucher@amd.com>]

Add a helper so that drm drivers can consistently report
shared status via the fdinfo shared memory stats interface.

In addition to handle count, show buffers as shared if they
are shared via dma-buf as well (e.g., shared with v4l or some
other subsystem).

Link: https://lore.kernel.org/all/20231207180225.439482-1-alexander.deucher@amd.com/
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---
 drivers/gpu/drm/drm_gem.c | 16 ++++++++++++++++
 include/drm/drm_gem.h     |  1 +
 2 files changed, 17 insertions(+)

diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index 44a948b80ee1..71b5f628d828 100644
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -1506,3 +1506,19 @@ int drm_gem_evict(struct drm_gem_object *obj)
 	return 0;
 }
 EXPORT_SYMBOL(drm_gem_evict);
+
+/**
+ * drm_gem_object_is_shared_for_memory_stats - helper for shared memory stats
+ *
+ * This helper should only be used for fdinfo shared memory stats to determine
+ * if a GEM object is shared.
+ *
+ * @obj: obj in question
+ */
+bool drm_gem_object_is_shared_for_memory_stats(struct drm_gem_object *obj)
+{
+	if ((obj->handle_count > 1) || obj->dma_buf)
+		return true;
+	return false;
+}
+EXPORT_SYMBOL(drm_gem_object_is_shared_for_memory_stats);
diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h
index 369505447acd..86a9c696f038 100644
--- a/include/drm/drm_gem.h
+++ b/include/drm/drm_gem.h
@@ -552,6 +552,7 @@ unsigned long drm_gem_lru_scan(struct drm_gem_lru *lru,
 			       bool (*shrink)(struct drm_gem_object *obj));
 
 int drm_gem_evict(struct drm_gem_object *obj);
+bool drm_gem_object_is_shared_for_memory_stats(struct drm_gem_object *obj);
 
 #ifdef CONFIG_LOCKDEP
 /**
-- 
2.42.0