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diff --git a/rust/kernel/init.rs b/rust/kernel/init.rs
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+++ b/rust/kernel/init.rs
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+// SPDX-License-Identifier: GPL-2.0
+
+//! Extensions to the [`pin-init`] crate.
+//!
+//! Most `struct`s from the [`sync`] module need to be pinned, because they contain self-referential
+//! `struct`s from C. [Pinning][pinning] is Rust's way of ensuring data does not move.
+//!
+//! The [`pin-init`] crate is the way such structs are initialized on the Rust side. Please refer
+//! to its documentation to better understand how to use it. Additionally, there are many examples
+//! throughout the kernel, such as the types from the [`sync`] module. And the ones presented
+//! below.
+//!
+//! [`sync`]: crate::sync
+//! [pinning]: https://doc.rust-lang.org/std/pin/index.html
+//! [`pin-init`]: https://rust.docs.kernel.org/pin_init/
+//!
+//! # [`Opaque<T>`]
+//!
+//! For the special case where initializing a field is a single FFI-function call that cannot fail,
+//! there exist the helper function [`Opaque::ffi_init`]. This function initialize a single
+//! [`Opaque<T>`] field by just delegating to the supplied closure. You can use these in
+//! combination with [`pin_init!`].
+//!
+//! [`Opaque<T>`]: crate::types::Opaque
+//! [`Opaque::ffi_init`]: crate::types::Opaque::ffi_init
+//! [`pin_init!`]: crate::pin_init
+//!
+//! # Examples
+//!
+//! ## General Examples
+//!
+//! ```rust,ignore
+//! # #![allow(clippy::disallowed_names)]
+//! use kernel::types::Opaque;
+//! use pin_init::pin_init_from_closure;
+//!
+//! // assume we have some `raw_foo` type in C:
+//! #[repr(C)]
+//! struct RawFoo([u8; 16]);
+//! extern {
+//!     fn init_foo(_: *mut RawFoo);
+//! }
+//!
+//! #[pin_data]
+//! struct Foo {
+//!     #[pin]
+//!     raw: Opaque<RawFoo>,
+//! }
+//!
+//! impl Foo {
+//!     fn setup(self: Pin<&mut Self>) {
+//!         pr_info!("Setting up foo");
+//!     }
+//! }
+//!
+//! let foo = pin_init!(Foo {
+//!     raw <- unsafe {
+//!         Opaque::ffi_init(|s| {
+//!             // note that this cannot fail.
+//!             init_foo(s);
+//!         })
+//!     },
+//! }).pin_chain(|foo| {
+//!     foo.setup();
+//!     Ok(())
+//! });
+//! ```
+//!
+//! ```rust,ignore
+//! # #![allow(unreachable_pub, clippy::disallowed_names)]
+//! use kernel::{prelude::*, types::Opaque};
+//! use core::{ptr::addr_of_mut, marker::PhantomPinned, pin::Pin};
+//! # mod bindings {
+//! #     #![allow(non_camel_case_types)]
+//! #     pub struct foo;
+//! #     pub unsafe fn init_foo(_ptr: *mut foo) {}
+//! #     pub unsafe fn destroy_foo(_ptr: *mut foo) {}
+//! #     pub unsafe fn enable_foo(_ptr: *mut foo, _flags: u32) -> i32 { 0 }
+//! # }
+//! # // `Error::from_errno` is `pub(crate)` in the `kernel` crate, thus provide a workaround.
+//! # trait FromErrno {
+//! #     fn from_errno(errno: core::ffi::c_int) -> Error {
+//! #         // Dummy error that can be constructed outside the `kernel` crate.
+//! #         Error::from(core::fmt::Error)
+//! #     }
+//! # }
+//! # impl FromErrno for Error {}
+//! /// # Invariants
+//! ///
+//! /// `foo` is always initialized
+//! #[pin_data(PinnedDrop)]
+//! pub struct RawFoo {
+//!     #[pin]
+//!     foo: Opaque<bindings::foo>,
+//!     #[pin]
+//!     _p: PhantomPinned,
+//! }
+//!
+//! impl RawFoo {
+//!     pub fn new(flags: u32) -> impl PinInit<Self, Error> {
+//!         // SAFETY:
+//!         // - when the closure returns `Ok(())`, then it has successfully initialized and
+//!         //   enabled `foo`,
+//!         // - when it returns `Err(e)`, then it has cleaned up before
+//!         unsafe {
+//!             pin_init::pin_init_from_closure(move |slot: *mut Self| {
+//!                 // `slot` contains uninit memory, avoid creating a reference.
+//!                 let foo = addr_of_mut!((*slot).foo);
+//!
+//!                 // Initialize the `foo`
+//!                 bindings::init_foo(Opaque::raw_get(foo));
+//!
+//!                 // Try to enable it.
+//!                 let err = bindings::enable_foo(Opaque::raw_get(foo), flags);
+//!                 if err != 0 {
+//!                     // Enabling has failed, first clean up the foo and then return the error.
+//!                     bindings::destroy_foo(Opaque::raw_get(foo));
+//!                     return Err(Error::from_errno(err));
+//!                 }
+//!
+//!                 // All fields of `RawFoo` have been initialized, since `_p` is a ZST.
+//!                 Ok(())
+//!             })
+//!         }
+//!     }
+//! }
+//!
+//! #[pinned_drop]
+//! impl PinnedDrop for RawFoo {
+//!     fn drop(self: Pin<&mut Self>) {
+//!         // SAFETY: Since `foo` is initialized, destroying is safe.
+//!         unsafe { bindings::destroy_foo(self.foo.get()) };
+//!     }
+//! }
+//! ```