rust: pin-init: add pin projections to `#[pin_data]`

Make the `#[pin_data]` macro generate a `*Projection` struct that holds
either `Pin<&mut Field>` or `&mut Field` for every field of the original
struct. Which version is chosen depends on weather there is a `#[pin]`
or not respectively. Access to this projected version is enabled through
generating `fn project(self: Pin<&mut Self>) -> SelfProjection<'_>`.

[ Adapt workqueue to use the new projection instead of its own, custom
  one - Benno ]

Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Benno Lossin <lossin@kernel.org>

1 files changed, 1 insertions, 8 deletions

diff --git a/rust/kernel/workqueue.rs b/rust/kernel/workqueue.rs
index b9343d5bc00f..706e833e9702 100644
--- a/rust/kernel/workqueue.rs
+++ b/rust/kernel/workqueue.rs
@@ -356,18 +356,11 @@ struct ClosureWork<T> {
     func: Option<T>,
 }
 
-impl<T> ClosureWork<T> {
-    fn project(self: Pin<&mut Self>) -> &mut Option<T> {
-        // SAFETY: The `func` field is not structurally pinned.
-        unsafe { &mut self.get_unchecked_mut().func }
-    }
-}
-
 impl<T: FnOnce()> WorkItem for ClosureWork<T> {
     type Pointer = Pin<KBox<Self>>;
 
     fn run(mut this: Pin<KBox<Self>>) {
-        if let Some(func) = this.as_mut().project().take() {
+        if let Some(func) = this.as_mut().project().func.take() {
             (func)()
         }
     }