[RFC,14/18] rust: drm: gem: Add set_exportable() method

Commit Message

Asahi Lina March 7, 2023, 2:25 p.m. UTC

This allows drivers to control whether a given GEM object is allowed to
be exported via PRIME to other drivers.
---
 rust/kernel/drm/gem/mod.rs | 7 +++++++
 1 file changed, 7 insertions(+)

Patch

diff --git a/rust/kernel/drm/gem/mod.rs b/rust/kernel/drm/gem/mod.rs
index e66bdef35c2e..196252a25b5a 100644
--- a/rust/kernel/drm/gem/mod.rs
+++ b/rust/kernel/drm/gem/mod.rs
@@ -135,6 +135,13 @@  pub trait BaseObject: IntoGEMObject {
         self.gem_ref().size
     }
 
+    /// Sets the exportable flag, which controls whether the object can be exported via PRIME.
+    fn set_exportable(&mut self, exportable: bool) {
+        // SAFETY: gem_obj() is valid per the type invariant, and this is safe to write if we
+        // are the only holder (mutable ref).
+        unsafe { (*self.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