Optional trait methods for implementing the atomic_begin and atomic_flush
callbacks for a CRTC.
Signed-off-by: Lyude Paul <lyude@xxxxxxxxxx>
---
rust/kernel/drm/kms/crtc.rs | 90 ++++++++++++++++++++++++++++++++++++-
1 file changed, 88 insertions(+), 2 deletions(-)
diff --git a/rust/kernel/drm/kms/crtc.rs b/rust/kernel/drm/kms/crtc.rs
index aaa208b35c3c1..131d10505ba07 100644
--- a/rust/kernel/drm/kms/crtc.rs
+++ b/rust/kernel/drm/kms/crtc.rs
@@ -90,8 +90,16 @@ pub trait DriverCrtc: Send + Sync + Sized {
mode_set: None,
mode_valid: None,
mode_fixup: None,
- atomic_begin: None,
- atomic_flush: None,
+ atomic_begin: if Self::HAS_ATOMIC_BEGIN {
+ Some(atomic_begin_callback::<Self>)
+ } else {
+ None
+ },
+ atomic_flush: if Self::HAS_ATOMIC_FLUSH {
+ Some(atomic_flush_callback::<Self>)
+ } else {
+ None
+ },
mode_set_nofb: None,
mode_set_base: None,
mode_set_base_atomic: None,
@@ -132,6 +140,36 @@ fn atomic_check(
) -> Result {
build_error::build_error("This should not be reachable")
}
+
+ /// The optional [`drm_crtc_helper_funcs.atomic_begin`] hook.
+ ///
+ /// This hook will be called before a set of [`Plane`] updates are performed for the given
+ /// [`Crtc`].
+ ///
+ /// [`drm_crtc_helper_funcs.atomic_begin`]: srctree/include/drm/drm_modeset_helper_vtables.h
+ fn atomic_begin(
+ _crtc: &Crtc<Self>,
+ _old_state: &CrtcState<Self::State>,
+ _new_state: CrtcStateMutator<'_, CrtcState<Self::State>>,
+ _state: &AtomicStateMutator<Self::Driver>,
+ ) {
+ build_error::build_error("This should not be reachable")
+ }
+
+ /// The optional [`drm_crtc_helper_funcs.atomic_flush`] hook.
+ ///
+ /// This hook will be called after a set of [`Plane`] updates are performed for the given
+ /// [`Crtc`].
+ ///
+ /// [`drm_crtc_helper_funcs.atomic_flush`]: srctree/include/drm/drm_modeset_helper_vtables.h
+ fn atomic_flush(
+ _crtc: &Crtc<Self>,
+ _old_state: &CrtcState<Self::State>,
+ _new_state: CrtcStateMutator<'_, CrtcState<Self::State>>,
+ _state: &AtomicStateMutator<Self::Driver>,
+ ) {
+ build_error::build_error("This should never be reachable")
+ }
}
/// The generated C vtable for a [`DriverCrtc`].
@@ -918,3 +956,51 @@ fn vtable(&self) -> *const Self::Vtable {
Ok(0)
})
}
+
+unsafe extern "C" fn atomic_begin_callback<T: DriverCrtc>(
+ crtc: *mut bindings::drm_crtc,
+ state: *mut bindings::drm_atomic_state,
+) {
+ // SAFETY:
+ // * We're guaranteed `crtc` is of type `Crtc<T>` via type invariants.
+ // * We're guaranteed by DRM that `crtc` is pointing to a valid initialized state.
+ let crtc = unsafe { Crtc::from_raw(crtc) };
+
+ // SAFETY: We're guaranteed by DRM that `state` points to a valid instance of `drm_atomic_state`
+ let state = unsafe { AtomicStateMutator::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_crtc_state(crtc).unwrap_unchecked(),
+ state.get_new_crtc_state(crtc).unwrap_unchecked(),
+ )
+ };
+
+ T::atomic_begin(crtc, old_state, new_state, &state);
+}
+
+unsafe extern "C" fn atomic_flush_callback<T: DriverCrtc>(
+ crtc: *mut bindings::drm_crtc,
+ state: *mut bindings::drm_atomic_state,
+) {
+ // SAFETY:
+ // - We're guaranteed `crtc` is of type `Crtc<T>` via type invariants.
+ // - We're guaranteed by DRM that `crtc` is pointing to a valid initialized state.
+ let crtc = unsafe { Crtc::from_raw(crtc) };
+
+ // SAFETY: We're guaranteed by DRM that `state` points to a valid instance of `drm_atomic_state`
+ let state = unsafe { AtomicStateMutator::new(NonNull::new_unchecked(state)) };
+
+ // SAFETY: We're in an atomic flush callback, so we know that both the new and old state are
+ // present
+ let (old_state, new_state) = unsafe {
+ (
+ state.get_old_crtc_state(crtc).unwrap_unchecked(),
+ state.get_new_crtc_state(crtc).unwrap_unchecked(),
+ )
+ };
+
+ T::atomic_flush(crtc, old_state, new_state, &state);
+}
--
2.48.1
