[PATCH] drm/gpuvm: take refcount on DRM device

[Alice Ryhl <aliceryhl@google.com>]

Currently GPUVM relies on the owner implicitly holding a refcount to the
drm device, and it does not implicitly take a refcount on the drm
device. This design is error-prone, so take a refcount on the device.

Suggested-by: Danilo Krummrich <dakr@kernel.org>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
---
 drivers/gpu/drm/drm_gpuvm.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_gpuvm.c b/drivers/gpu/drm/drm_gpuvm.c
index 44acfe4120d2..000e7910a899 100644
--- a/drivers/gpu/drm/drm_gpuvm.c
+++ b/drivers/gpu/drm/drm_gpuvm.c
@@ -25,6 +25,7 @@
  *
  */
 
+#include <drm/drm_drv.h>
 #include <drm/drm_gpuvm.h>
 #include <drm/drm_print.h>
 
@@ -1117,6 +1118,7 @@ drm_gpuvm_init(struct drm_gpuvm *gpuvm, const char *name,
 	gpuvm->drm = drm;
 	gpuvm->r_obj = r_obj;
 
+	drm_dev_get(drm);
 	drm_gem_object_get(r_obj);
 
 	drm_gpuvm_warn_check_overflow(gpuvm, start_offset, range);
@@ -1160,13 +1162,15 @@ static void
 drm_gpuvm_free(struct kref *kref)
 {
 	struct drm_gpuvm *gpuvm = container_of(kref, struct drm_gpuvm, kref);
+	struct drm_device *drm = gpuvm->drm;
 
 	drm_gpuvm_fini(gpuvm);
 
-	if (drm_WARN_ON(gpuvm->drm, !gpuvm->ops->vm_free))
+	if (drm_WARN_ON(drm, !gpuvm->ops->vm_free))
 		return;
 
 	gpuvm->ops->vm_free(gpuvm);
+	drm_dev_put(drm);
 }
 
 /**

---
base-commit: 126c50bc2fb6ddfe5b7718de67bbd7592a1062bb
change-id: 20260416-gpuvm-drm-dev-get-5ded89c39bb3

Best regards,
-- 
Alice Ryhl <aliceryhl@google.com>