Optional trait method for implementing a plane's atomic_check().
Signed-off-by: Lyude Paul <lyude@xxxxxxxxxx>
---
rust/kernel/drm/kms/plane.rs | 41 +++++++++++++++++++++++++++++++++++-
1 file changed, 40 insertions(+), 1 deletion(-)
diff --git a/rust/kernel/drm/kms/plane.rs b/rust/kernel/drm/kms/plane.rs
index 506ed5ced1270..04f1bdfbb1ea2 100644
--- a/rust/kernel/drm/kms/plane.rs
+++ b/rust/kernel/drm/kms/plane.rs
@@ -74,7 +74,7 @@ pub trait DriverPlane: Send + Sync + Sized {
cleanup_fb: None,
begin_fb_access: None, // TODO: someday?
end_fb_access: None, // TODO: someday?
- atomic_check: None,
+ atomic_check: if Self::HAS_ATOMIC_CHECK { Some(atomic_check_callback::<Self>) } else { None },
atomic_update: if Self::HAS_ATOMIC_UPDATE { Some(atomic_update_callback::<Self>) } else { None },
atomic_enable: None, // TODO
atomic_disable: None, // TODO
@@ -118,6 +118,21 @@ fn atomic_update(
) {
build_error::build_error("This should not be reachable")
}
+
+ /// The optional [`drm_plane_helper_funcs.atomic_check`] hook for this plane.
+ ///
+ /// Drivers may use this to customize the atomic check phase of their [`Plane`] objects. The
+ /// result of this function determines whether the atomic check passed or failed.
+ ///
+ /// [`drm_plane_helper_funcs.atomic_check`]: srctree/include/drm/drm_modeset_helper_vtables.h
+ fn atomic_check(
+ plane: &Plane<Self>,
+ new_state: BorrowedPlaneState<'_, PlaneState<Self::State>>,
+ old_state: &PlaneState<Self::State>,
+ state: &AtomicStateComposer<Self::Driver>
+ ) -> Result {
+ build_error::build_error("This should not be reachable")
+ }
}
/// The generated C vtable for a [`DriverPlane`].
@@ -794,3 +809,27 @@ fn deref_mut(&mut self) -> &mut Self::Target {
T::atomic_update(plane, new_state, old_state, &state);
}
+
+unsafe extern "C" fn atomic_check_callback<T: DriverPlane>(
+ plane: *mut bindings::drm_plane,
+ state: *mut bindings::drm_atomic_state,
+) -> i32 {
+ // SAFETY:
+ // * We're guaranteed `plane` is of type `Plane<T>` via type invariants.
+ // * We're guaranteed by DRM that `plane` is pointing to a valid initialized state.
+ let plane = unsafe { Plane::from_raw(plane) };
+
+ // SAFETY: We're guaranteed by DRM that `state` points to a valid instance of `drm_atomic_state`
+ let state = ManuallyDrop::new(unsafe {
+ AtomicStateComposer::<T::Driver>::new(NonNull::new_unchecked(state))
+ });
+
+ // SAFETY: We're guaranteed by DRM that both the old and new atomic state are present within
+ // this `drm_atomic_state`
+ let (old_state, new_state) = unsafe {(
+ state.get_old_plane_state(plane).unwrap_unchecked(),
+ state.get_new_plane_state(plane).unwrap_unchecked(),
+ )};
+
+ from_result(|| T::atomic_check(plane, new_state, old_state, &state).map(|_| 0))
+}
--
2.46.1
