1 files changed, 82 insertions, 5 deletions
diff --git a/rust/kernel/drm/device.rs b/rust/kernel/drm/device.rs
index 3ce8f62a0056..adbafe8db54d 100644
--- a/rust/kernel/drm/device.rs
+++ b/rust/kernel/drm/device.rs
@@ -6,15 +6,34 @@
 
 use crate::{
     alloc::allocator::Kmalloc,
-    bindings, device, drm,
-    drm::driver::AllocImpl,
+    bindings, device,
+    drm::{
+        self,
+        driver::AllocImpl, //
+    },
     error::from_err_ptr,
-    error::Result,
     prelude::*,
-    sync::aref::{ARef, AlwaysRefCounted},
+    sync::aref::{
+        ARef,
+        AlwaysRefCounted, //
+    },
     types::Opaque,
+    workqueue::{
+        HasDelayedWork,
+        HasWork,
+        Work,
+        WorkItem, //
+    },
+};
+use core::{
+    alloc::Layout,
+    mem,
+    ops::Deref,
+    ptr::{
+        self,
+        NonNull, //
+    },
 };
-use core::{alloc::Layout, mem, ops::Deref, ptr, ptr::NonNull};
 
 #[cfg(CONFIG_DRM_LEGACY)]
 macro_rules! drm_legacy_fields {
@@ -227,3 +246,61 @@ unsafe impl<T: drm::Driver> Send for Device<T> {}
 // SAFETY: A `drm::Device` can be shared among threads because all immutable methods are protected
 // by the synchronization in `struct drm_device`.
 unsafe impl<T: drm::Driver> Sync for Device<T> {}
+
+impl<T, const ID: u64> WorkItem<ID> for Device<T>
+where
+    T: drm::Driver,
+    T::Data: WorkItem<ID, Pointer = ARef<Device<T>>>,
+    T::Data: HasWork<Device<T>, ID>,
+{
+    type Pointer = ARef<Device<T>>;
+
+    fn run(ptr: ARef<Device<T>>) {
+        T::Data::run(ptr);
+    }
+}
+
+// SAFETY:
+//
+// - `raw_get_work` and `work_container_of` return valid pointers by relying on
+// `T::Data::raw_get_work` and `container_of`. In particular, `T::Data` is
+// stored inline in `drm::Device`, so the `container_of` call is valid.
+//
+// - The two methods are true inverses of each other: given `ptr: *mut
+// Device<T>`, `raw_get_work` will return a `*mut Work<Device<T>, ID>` through
+// `T::Data::raw_get_work` and given a `ptr: *mut Work<Device<T>, ID>`,
+// `work_container_of` will return a `*mut Device<T>` through `container_of`.
+unsafe impl<T, const ID: u64> HasWork<Device<T>, ID> for Device<T>
+where
+    T: drm::Driver,
+    T::Data: HasWork<Device<T>, ID>,
+{
+    unsafe fn raw_get_work(ptr: *mut Self) -> *mut Work<Device<T>, ID> {
+        // SAFETY: The caller promises that `ptr` points to a valid `Device<T>`.
+        let data_ptr = unsafe { &raw mut (*ptr).data };
+
+        // SAFETY: `data_ptr` is a valid pointer to `T::Data`.
+        unsafe { T::Data::raw_get_work(data_ptr) }
+    }
+
+    unsafe fn work_container_of(ptr: *mut Work<Device<T>, ID>) -> *mut Self {
+        // SAFETY: The caller promises that `ptr` points at a `Work` field in
+        // `T::Data`.
+        let data_ptr = unsafe { T::Data::work_container_of(ptr) };
+
+        // SAFETY: `T::Data` is stored as the `data` field in `Device<T>`.
+        unsafe { crate::container_of!(data_ptr, Self, data) }
+    }
+}
+
+// SAFETY: Our `HasWork<T, ID>` implementation returns a `work_struct` that is
+// stored in the `work` field of a `delayed_work` with the same access rules as
+// the `work_struct` owing to the bound on `T::Data: HasDelayedWork<Device<T>,
+// ID>`, which requires that `T::Data::raw_get_work` return a `work_struct` that
+// is inside a `delayed_work`.
+unsafe impl<T, const ID: u64> HasDelayedWork<Device<T>, ID> for Device<T>
+where
+    T: drm::Driver,
+    T::Data: HasDelayedWork<Device<T>, ID>,
+{
+}