rust: drm: gem: Add set_exportable() method

This allows drivers to control whether a given GEM object is allowed to
be exported via PRIME to other drivers.

Author: hoshinolina

rust/kernel/drm/gem/mod.rs

@@ -51,6 +51,10 @@ pub trait IntoGEMObject: Sized + crate::private::Sealed {
     /// this owning object is valid.
     fn gem_obj(&self) -> &bindings::drm_gem_object;
 
+    /// Returns a reference to the raw `drm_gem_object` structure, which must be valid as long as
+    /// this owning object is valid.
+    fn mut_gem_obj(&mut self) -> &mut bindings::drm_gem_object;
+
     /// Converts a pointer to a `drm_gem_object` into a pointer to this type.
     fn from_gem_obj(obj: *mut bindings::drm_gem_object) -> *mut Self;
 }
@@ -120,6 +124,10 @@ impl<T: DriverObject> IntoGEMObject for Object<T> {
         &self.obj
     }
 
+    fn mut_gem_obj(&mut self) -> &mut bindings::drm_gem_object {
+        &mut self.obj
+    }
+
     fn from_gem_obj(obj: *mut bindings::drm_gem_object) -> *mut Object<T> {
         crate::container_of!(obj, Object<T>, obj) as *mut Object<T>
     }
@@ -132,6 +140,11 @@ pub trait BaseObject: IntoGEMObject {
         self.gem_obj().size
     }
 
+    /// Sets the exportable flag, which controls whether the object can be exported via PRIME.
+    fn set_exportable(&mut self, exportable: bool) {
+        self.mut_gem_obj().exportable = exportable;
+    }
+
     /// Creates a new reference to the object.
     fn reference(&self) -> ObjectRef<Self> {
         // SAFETY: Having a reference to an Object implies holding a GEM reference

rust/kernel/drm/gem/shmem.rs

@@ -241,6 +241,10 @@ impl<T: DriverObject> gem::IntoGEMObject for Object<T> {
         &self.obj.base
     }
 
+    fn mut_gem_obj(&mut self) -> &mut bindings::drm_gem_object {
+        &mut self.obj.base
+    }
+
     fn from_gem_obj(obj: *mut bindings::drm_gem_object) -> *mut Object<T> {
         let shmem = crate::container_of!(obj, bindings::drm_gem_shmem_object, base)
             as *mut bindings::drm_gem_shmem_object;