Merge tag 'rust-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux

Pull Rust updates from Miguel Ojeda:
 "Toolchain and infrastructure:

   - Enable a set of Clippy lints: 'ptr_as_ptr', 'ptr_cast_constness',
     'as_ptr_cast_mut', 'as_underscore', 'cast_lossless' and
     'ref_as_ptr'

     These are intended to avoid type casts with the 'as' operator,
     which are quite powerful, into restricted variants that are less
     powerful and thus should help to avoid mistakes

   - Remove the 'author' key now that most instances were moved to the
     plural one in the previous cycle

  'kernel' crate:

   - New 'bug' module: add 'warn_on!' macro which reuses the existing
     'BUG'/'WARN' infrastructure, i.e. it respects the usual sysctls and
     kernel parameters:

         warn_on!(value == 42);

     To avoid duplicating the assembly code, the same strategy is
     followed as for the static branch code in order to share the
     assembly between both C and Rust

     This required a few rearrangements on C arch headers -- the
     existing C macros should still generate the same outputs, thus no
     functional change expected there

   - 'workqueue' module: add delayed work items, including a
     'DelayedWork' struct, a 'impl_has_delayed_work!' macro and an
     'enqueue_delayed' method, e.g.:

         /// Enqueue the struct for execution on the system workqueue,
         /// where its value will be printed 42 jiffies later.
         fn print_later(value: Arc<MyStruct>) {
             let _ = workqueue::system().enqueue_delayed(value, 42);
         }

   - New 'bits' module: add support for 'bit' and 'genmask' functions,
     with runtime- and compile-time variants, e.g.:

         static_assert!(0b00010000 == bit_u8(4));
         static_assert!(0b00011110 == genmask_u8(1..=4));

         assert!(checked_bit_u32(u32::BITS).is_none());

   - 'uaccess' module: add 'UserSliceReader::strcpy_into_buf', which
     reads NUL-terminated strings from userspace into a '&CStr'

     Introduce 'UserPtr' newtype, similar in purpose to '__user' in C,
     to minimize mistakes handling userspace pointers, including mixing
     them up with integers and leaking them via the 'Debug' trait. Add
     it to the prelude, too

   - Start preparations for the replacement of our custom 'CStr' type
     with the analogous type in the 'core' standard library. This will
     take place across several cycles to make it easier. For this one,
     it includes a new 'fmt' module, using upstream method names and
     some other cleanups

     Replace 'fmt!' with a re-export, which helps Clippy lint properly,
     and clean up the found 'uninlined-format-args' instances

   - 'dma' module:

      - Clarify wording and be consistent in 'coherent' nomenclature

      - Convert the 'read!()' and 'write!()' macros to return a 'Result'

      - Add 'as_slice()', 'write()' methods in 'CoherentAllocation'

      - Expose 'count()' and 'size()' in 'CoherentAllocation' and add
        the corresponding type invariants

      - Implement 'CoherentAllocation::dma_handle_with_offset()'

   - 'time' module:

      - Make 'Instant' generic over clock source. This allows the
        compiler to assert that arithmetic expressions involving the
        'Instant' use 'Instants' based on the same clock source

      - Make 'HrTimer' generic over the timer mode. 'HrTimer' timers
        take a 'Duration' or an 'Instant' when setting the expiry time,
        depending on the timer mode. With this change, the compiler can
        check the type matches the timer mode

      - Add an abstraction for 'fsleep'. 'fsleep' is a flexible sleep
        function that will select an appropriate sleep method depending
        on the requested sleep time

      - Avoid 64-bit divisions on 32-bit hardware when calculating
        timestamps

      - Seal the 'HrTimerMode' trait. This prevents users of the
        'HrTimerMode' from implementing the trait on their own types

      - Pass the correct timer mode ID to 'hrtimer_start_range_ns()'

   - 'list' module: remove 'OFFSET' constants, allowing to remove
     pointer arithmetic; now 'impl_list_item!' invokes
     'impl_has_list_links!' or 'impl_has_list_links_self_ptr!'. Other
     simplifications too

   - 'types' module: remove 'ForeignOwnable::PointedTo' in favor of a
     constant, which avoids exposing the type of the opaque pointer, and
     require 'into_foreign' to return non-null

     Remove the 'Either<L, R>' type as well. It is unused, and we want
     to encourage the use of custom enums for concrete use cases

   - 'sync' module: implement 'Borrow' and 'BorrowMut' for 'Arc' types
     to allow them to be used in generic APIs

   - 'alloc' module: implement 'Borrow' and 'BorrowMut' for 'Box<T, A>';
     and 'Borrow', 'BorrowMut' and 'Default' for 'Vec<T, A>'

   - 'Opaque' type: add 'cast_from' method to perform a restricted cast
     that cannot change the inner type and use it in callers of
     'container_of!'. Rename 'raw_get' to 'cast_into' to match it

   - 'rbtree' module: add 'is_empty' method

   - 'sync' module: new 'aref' submodule to hold 'AlwaysRefCounted' and
     'ARef', which are moved from the too general 'types' module which
     we want to reduce or eventually remove. Also fix a safety comment
     in 'static_lock_class'

  'pin-init' crate:

   - Add 'impl<T, E> [Pin]Init<T, E> for Result<T, E>', so results are
     now (pin-)initializers

   - Add 'Zeroable::init_zeroed()' that delegates to 'init_zeroed()'

   - New 'zeroed()', a safe version of 'mem::zeroed()' and also provide
     it via 'Zeroable::zeroed()'

   - Implement 'Zeroable' for 'Option<&T>', 'Option<&mut T>' and for
     'Option<[unsafe] [extern "abi"] fn(...args...) -> ret>' for
     '"Rust"' and '"C"' ABIs and up to 20 arguments

   - Changed blanket impls of 'Init' and 'PinInit' from 'impl<T, E>
     [Pin]Init<T, E> for T' to 'impl<T> [Pin]Init<T> for T'

   - Renamed 'zeroed()' to 'init_zeroed()'

   - Upstream dev news: improve CI more to deny warnings, use
     '--all-targets'. Check the synchronization status of the two
     '-next' branches in upstream and the kernel

  MAINTAINERS:

   - Add Vlastimil Babka, Liam R. Howlett, Uladzislau Rezki and Lorenzo
     Stoakes as reviewers (thanks everyone)

  And a few other cleanups and improvements"

* tag 'rust-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (76 commits)
  rust: Add warn_on macro
  arm64/bug: Add ARCH_WARN_ASM macro for BUG/WARN asm code sharing with Rust
  riscv/bug: Add ARCH_WARN_ASM macro for BUG/WARN asm code sharing with Rust
  x86/bug: Add ARCH_WARN_ASM macro for BUG/WARN asm code sharing with Rust
  rust: kernel: move ARef and AlwaysRefCounted to sync::aref
  rust: sync: fix safety comment for `static_lock_class`
  rust: types: remove `Either<L, R>`
  rust: kernel: use `core::ffi::CStr` method names
  rust: str: add `CStr` methods matching `core::ffi::CStr`
  rust: str: remove unnecessary qualification
  rust: use `kernel::{fmt,prelude::fmt!}`
  rust: kernel: add `fmt` module
  rust: kernel: remove `fmt!`, fix clippy::uninlined-format-args
  scripts: rust: emit path candidates in panic message
  scripts: rust: replace length checks with match
  rust: list: remove nonexistent generic parameter in link
  rust: bits: add support for bits/genmask macros
  rust: list: remove OFFSET constants
  rust: list: add `impl_list_item!` examples
  rust: list: use fully qualified path
  ...

1 files changed, 333 insertions, 9 deletions

diff --git a/rust/kernel/workqueue.rs b/rust/kernel/workqueue.rs
index d092112d843f..b9343d5bc00f 100644
--- a/rust/kernel/workqueue.rs
+++ b/rust/kernel/workqueue.rs
@@ -26,7 +26,7 @@
 //!  * The [`WorkItemPointer`] trait is implemented for the pointer type that points at a something
 //!    that implements [`WorkItem`].
 //!
-//! ## Example
+//! ## Examples
 //!
 //! This example defines a struct that holds an integer and can be scheduled on the workqueue. When
 //! the struct is executed, it will print the integer. Since there is only one `work_struct` field,
@@ -131,10 +131,69 @@
 //! # print_2_later(MyStruct::new(41, 42).unwrap());
 //! ```
 //!
+//! This example shows how you can schedule delayed work items:
+//!
+//! ```
+//! use kernel::sync::Arc;
+//! use kernel::workqueue::{self, impl_has_delayed_work, new_delayed_work, DelayedWork, WorkItem};
+//!
+//! #[pin_data]
+//! struct MyStruct {
+//!     value: i32,
+//!     #[pin]
+//!     work: DelayedWork<MyStruct>,
+//! }
+//!
+//! impl_has_delayed_work! {
+//!     impl HasDelayedWork<Self> for MyStruct { self.work }
+//! }
+//!
+//! impl MyStruct {
+//!     fn new(value: i32) -> Result<Arc<Self>> {
+//!         Arc::pin_init(
+//!             pin_init!(MyStruct {
+//!                 value,
+//!                 work <- new_delayed_work!("MyStruct::work"),
+//!             }),
+//!             GFP_KERNEL,
+//!         )
+//!     }
+//! }
+//!
+//! impl WorkItem for MyStruct {
+//!     type Pointer = Arc<MyStruct>;
+//!
+//!     fn run(this: Arc<MyStruct>) {
+//!         pr_info!("The value is: {}\n", this.value);
+//!     }
+//! }
+//!
+//! /// This method will enqueue the struct for execution on the system workqueue, where its value
+//! /// will be printed 12 jiffies later.
+//! fn print_later(val: Arc<MyStruct>) {
+//!     let _ = workqueue::system().enqueue_delayed(val, 12);
+//! }
+//!
+//! /// It is also possible to use the ordinary `enqueue` method together with `DelayedWork`. This
+//! /// is equivalent to calling `enqueue_delayed` with a delay of zero.
+//! fn print_now(val: Arc<MyStruct>) {
+//!     let _ = workqueue::system().enqueue(val);
+//! }
+//! # print_later(MyStruct::new(42).unwrap());
+//! # print_now(MyStruct::new(42).unwrap());
+//! ```
+//!
 //! C header: [`include/linux/workqueue.h`](srctree/include/linux/workqueue.h)
 
-use crate::alloc::{AllocError, Flags};
-use crate::{prelude::*, sync::Arc, sync::LockClassKey, types::Opaque};
+use crate::{
+    alloc::{AllocError, Flags},
+    container_of,
+    prelude::*,
+    sync::Arc,
+    sync::LockClassKey,
+    time::Jiffies,
+    types::Opaque,
+};
 use core::marker::PhantomData;
 
 /// Creates a [`Work`] initialiser with the given name and a newly-created lock class.
@@ -146,6 +205,33 @@ macro_rules! new_work {
 }
 pub use new_work;
 
+/// Creates a [`DelayedWork`] initialiser with the given name and a newly-created lock class.
+#[macro_export]
+macro_rules! new_delayed_work {
+    () => {
+        $crate::workqueue::DelayedWork::new(
+            $crate::optional_name!(),
+            $crate::static_lock_class!(),
+            $crate::c_str!(::core::concat!(
+                ::core::file!(),
+                ":",
+                ::core::line!(),
+                "_timer"
+            )),
+            $crate::static_lock_class!(),
+        )
+    };
+    ($name:literal) => {
+        $crate::workqueue::DelayedWork::new(
+            $crate::c_str!($name),
+            $crate::static_lock_class!(),
+            $crate::c_str!(::core::concat!($name, "_timer")),
+            $crate::static_lock_class!(),
+        )
+    };
+}
+pub use new_delayed_work;
+
 /// A kernel work queue.
 ///
 /// Wraps the kernel's C `struct workqueue_struct`.
@@ -170,7 +256,7 @@ impl Queue {
     pub unsafe fn from_raw<'a>(ptr: *const bindings::workqueue_struct) -> &'a Queue {
         // SAFETY: The `Queue` type is `#[repr(transparent)]`, so the pointer cast is valid. The
         // caller promises that the pointer is not dangling.
-        unsafe { &*(ptr as *const Queue) }
+        unsafe { &*ptr.cast::<Queue>() }
     }
 
     /// Enqueues a work item.
@@ -198,7 +284,7 @@ impl Queue {
         unsafe {
             w.__enqueue(move |work_ptr| {
                 bindings::queue_work_on(
-                    bindings::wq_misc_consts_WORK_CPU_UNBOUND as _,
+                    bindings::wq_misc_consts_WORK_CPU_UNBOUND as ffi::c_int,
                     queue_ptr,
                     work_ptr,
                 )
@@ -206,6 +292,42 @@ impl Queue {
         }
     }
 
+    /// Enqueues a delayed work item.
+    ///
+    /// This may fail if the work item is already enqueued in a workqueue.
+    ///
+    /// The work item will be submitted using `WORK_CPU_UNBOUND`.
+    pub fn enqueue_delayed<W, const ID: u64>(&self, w: W, delay: Jiffies) -> W::EnqueueOutput
+    where
+        W: RawDelayedWorkItem<ID> + Send + 'static,
+    {
+        let queue_ptr = self.0.get();
+
+        // SAFETY: We only return `false` if the `work_struct` is already in a workqueue. The other
+        // `__enqueue` requirements are not relevant since `W` is `Send` and static.
+        //
+        // The call to `bindings::queue_delayed_work_on` will dereference the provided raw pointer,
+        // which is ok because `__enqueue` guarantees that the pointer is valid for the duration of
+        // this closure, and the safety requirements of `RawDelayedWorkItem` expands this
+        // requirement to apply to the entire `delayed_work`.
+        //
+        // Furthermore, if the C workqueue code accesses the pointer after this call to
+        // `__enqueue`, then the work item was successfully enqueued, and
+        // `bindings::queue_delayed_work_on` will have returned true. In this case, `__enqueue`
+        // promises that the raw pointer will stay valid until we call the function pointer in the
+        // `work_struct`, so the access is ok.
+        unsafe {
+            w.__enqueue(move |work_ptr| {
+                bindings::queue_delayed_work_on(
+                    bindings::wq_misc_consts_WORK_CPU_UNBOUND as ffi::c_int,
+                    queue_ptr,
+                    container_of!(work_ptr, bindings::delayed_work, work),
+                    delay,
+                )
+            })
+        }
+    }
+
     /// Tries to spawn the given function or closure as a work item.
     ///
     /// This method can fail because it allocates memory to store the work item.
@@ -298,6 +420,16 @@ pub unsafe trait RawWorkItem<const ID: u64> {
         F: FnOnce(*mut bindings::work_struct) -> bool;
 }
 
+/// A raw delayed work item.
+///
+/// # Safety
+///
+/// If the `__enqueue` method in the `RawWorkItem` implementation calls the closure, then the
+/// provided pointer must point at the `work` field of a valid `delayed_work`, and the guarantees
+/// that `__enqueue` provides about accessing the `work_struct` must also apply to the rest of the
+/// `delayed_work` struct.
+pub unsafe trait RawDelayedWorkItem<const ID: u64>: RawWorkItem<ID> {}
+
 /// Defines the method that should be called directly when a work item is executed.
 ///
 /// This trait is implemented by `Pin<KBox<T>>` and [`Arc<T>`], and is mainly intended to be
@@ -403,11 +535,11 @@ impl<T: ?Sized, const ID: u64> Work<T, ID> {
         //
         // A pointer cast would also be ok due to `#[repr(transparent)]`. We use `addr_of!` so that
         // the compiler does not complain that the `work` field is unused.
-        unsafe { Opaque::raw_get(core::ptr::addr_of!((*ptr).work)) }
+        unsafe { Opaque::cast_into(core::ptr::addr_of!((*ptr).work)) }
     }
 }
 
-/// Declares that a type has a [`Work<T, ID>`] field.
+/// Declares that a type contains a [`Work<T, ID>`].
 ///
 /// The intended way of using this trait is via the [`impl_has_work!`] macro. You can use the macro
 /// like this:
@@ -506,6 +638,178 @@ impl_has_work! {
     impl{T} HasWork<Self> for ClosureWork<T> { self.work }
 }
 
+/// Links for a delayed work item.
+///
+/// This struct contains a function pointer to the [`run`] function from the [`WorkItemPointer`]
+/// trait, and defines the linked list pointers necessary to enqueue a work item in a workqueue in
+/// a delayed manner.
+///
+/// Wraps the kernel's C `struct delayed_work`.
+///
+/// This is a helper type used to associate a `delayed_work` with the [`WorkItem`] that uses it.
+///
+/// [`run`]: WorkItemPointer::run
+#[pin_data]
+#[repr(transparent)]
+pub struct DelayedWork<T: ?Sized, const ID: u64 = 0> {
+    #[pin]
+    dwork: Opaque<bindings::delayed_work>,
+    _inner: PhantomData<T>,
+}
+
+// SAFETY: Kernel work items are usable from any thread.
+//
+// We do not need to constrain `T` since the work item does not actually contain a `T`.
+unsafe impl<T: ?Sized, const ID: u64> Send for DelayedWork<T, ID> {}
+// SAFETY: Kernel work items are usable from any thread.
+//
+// We do not need to constrain `T` since the work item does not actually contain a `T`.
+unsafe impl<T: ?Sized, const ID: u64> Sync for DelayedWork<T, ID> {}
+
+impl<T: ?Sized, const ID: u64> DelayedWork<T, ID> {
+    /// Creates a new instance of [`DelayedWork`].
+    #[inline]
+    pub fn new(
+        work_name: &'static CStr,
+        work_key: Pin<&'static LockClassKey>,
+        timer_name: &'static CStr,
+        timer_key: Pin<&'static LockClassKey>,
+    ) -> impl PinInit<Self>
+    where
+        T: WorkItem<ID>,
+    {
+        pin_init!(Self {
+            dwork <- Opaque::ffi_init(|slot: *mut bindings::delayed_work| {
+                // SAFETY: The `WorkItemPointer` implementation promises that `run` can be used as
+                // the work item function.
+                unsafe {
+                    bindings::init_work_with_key(
+                        core::ptr::addr_of_mut!((*slot).work),
+                        Some(T::Pointer::run),
+                        false,
+                        work_name.as_char_ptr(),
+                        work_key.as_ptr(),
+                    )
+                }
+
+                // SAFETY: The `delayed_work_timer_fn` function pointer can be used here because
+                // the timer is embedded in a `struct delayed_work`, and only ever scheduled via
+                // the core workqueue code, and configured to run in irqsafe context.
+                unsafe {
+                    bindings::timer_init_key(
+                        core::ptr::addr_of_mut!((*slot).timer),
+                        Some(bindings::delayed_work_timer_fn),
+                        bindings::TIMER_IRQSAFE,
+                        timer_name.as_char_ptr(),
+                        timer_key.as_ptr(),
+                    )
+                }
+            }),
+            _inner: PhantomData,
+        })
+    }
+
+    /// Get a pointer to the inner `delayed_work`.
+    ///
+    /// # Safety
+    ///
+    /// The provided pointer must not be dangling and must be properly aligned. (But the memory
+    /// need not be initialized.)
+    #[inline]
+    pub unsafe fn raw_as_work(ptr: *const Self) -> *mut Work<T, ID> {
+        // SAFETY: The caller promises that the pointer is aligned and not dangling.
+        let dw: *mut bindings::delayed_work =
+            unsafe { Opaque::cast_into(core::ptr::addr_of!((*ptr).dwork)) };
+        // SAFETY: The caller promises that the pointer is aligned and not dangling.
+        let wrk: *mut bindings::work_struct = unsafe { core::ptr::addr_of_mut!((*dw).work) };
+        // CAST: Work and work_struct have compatible layouts.
+        wrk.cast()
+    }
+}
+
+/// Declares that a type contains a [`DelayedWork<T, ID>`].
+///
+/// # Safety
+///
+/// The `HasWork<T, ID>` implementation must return a `work_struct` that is stored in the `work`
+/// field of a `delayed_work` with the same access rules as the `work_struct`.
+pub unsafe trait HasDelayedWork<T, const ID: u64 = 0>: HasWork<T, ID> {}
+
+/// Used to safely implement the [`HasDelayedWork<T, ID>`] trait.
+///
+/// This macro also implements the [`HasWork`] trait, so you do not need to use [`impl_has_work!`]
+/// when using this macro.
+///
+/// # Examples
+///
+/// ```
+/// use kernel::sync::Arc;
+/// use kernel::workqueue::{self, impl_has_delayed_work, DelayedWork};
+///
+/// struct MyStruct<'a, T, const N: usize> {
+///     work_field: DelayedWork<MyStruct<'a, T, N>, 17>,
+///     f: fn(&'a [T; N]),
+/// }
+///
+/// impl_has_delayed_work! {
+///     impl{'a, T, const N: usize} HasDelayedWork<MyStruct<'a, T, N>, 17>
+///     for MyStruct<'a, T, N> { self.work_field }
+/// }
+/// ```
+#[macro_export]
+macro_rules! impl_has_delayed_work {
+    ($(impl$({$($generics:tt)*})?
+       HasDelayedWork<$work_type:ty $(, $id:tt)?>
+       for $self:ty
+       { self.$field:ident }
+    )*) => {$(
+        // SAFETY: The implementation of `raw_get_work` only compiles if the field has the right
+        // type.
+        unsafe impl$(<$($generics)+>)?
+            $crate::workqueue::HasDelayedWork<$work_type $(, $id)?> for $self {}
+
+        // SAFETY: The implementation of `raw_get_work` only compiles if the field has the right
+        // type.
+        unsafe impl$(<$($generics)+>)? $crate::workqueue::HasWork<$work_type $(, $id)?> for $self {
+            #[inline]
+            unsafe fn raw_get_work(
+                ptr: *mut Self
+            ) -> *mut $crate::workqueue::Work<$work_type $(, $id)?> {
+                // SAFETY: The caller promises that the pointer is not dangling.
+                let ptr: *mut $crate::workqueue::DelayedWork<$work_type $(, $id)?> = unsafe {
+                    ::core::ptr::addr_of_mut!((*ptr).$field)
+                };
+
+                // SAFETY: The caller promises that the pointer is not dangling.
+                unsafe { $crate::workqueue::DelayedWork::raw_as_work(ptr) }
+            }
+
+            #[inline]
+            unsafe fn work_container_of(
+                ptr: *mut $crate::workqueue::Work<$work_type $(, $id)?>,
+            ) -> *mut Self {
+                // SAFETY: The caller promises that the pointer points at a field of the right type
+                // in the right kind of struct.
+                let ptr = unsafe { $crate::workqueue::Work::raw_get(ptr) };
+
+                // SAFETY: The caller promises that the pointer points at a field of the right type
+                // in the right kind of struct.
+                let delayed_work = unsafe {
+                    $crate::container_of!(ptr, $crate::bindings::delayed_work, work)
+                };
+
+                let delayed_work: *mut $crate::workqueue::DelayedWork<$work_type $(, $id)?> =
+                    delayed_work.cast();
+
+                // SAFETY: The caller promises that the pointer points at a field of the right type
+                // in the right kind of struct.
+                unsafe { $crate::container_of!(delayed_work, Self, $field) }
+            }
+        }
+    )*};
+}
+pub use impl_has_delayed_work;
+
 // SAFETY: The `__enqueue` implementation in RawWorkItem uses a `work_struct` initialized with the
 // `run` method of this trait as the function pointer because:
 //   - `__enqueue` gets the `work_struct` from the `Work` field, using `T::raw_get_work`.
@@ -522,7 +826,7 @@ where
 {
     unsafe extern "C" fn run(ptr: *mut bindings::work_struct) {
         // The `__enqueue` method always uses a `work_struct` stored in a `Work<T, ID>`.
-        let ptr = ptr as *mut Work<T, ID>;
+        let ptr = ptr.cast::<Work<T, ID>>();
         // SAFETY: This computes the pointer that `__enqueue` got from `Arc::into_raw`.
         let ptr = unsafe { T::work_container_of(ptr) };
         // SAFETY: This pointer comes from `Arc::into_raw` and we've been given back ownership.
@@ -567,6 +871,16 @@ where
     }
 }
 
+// SAFETY: By the safety requirements of `HasDelayedWork`, the `work_struct` returned by methods in
+// `HasWork` provides a `work_struct` that is the `work` field of a `delayed_work`, and the rest of
+// the `delayed_work` has the same access rules as its `work` field.
+unsafe impl<T, const ID: u64> RawDelayedWorkItem<ID> for Arc<T>
+where
+    T: WorkItem<ID, Pointer = Self>,
+    T: HasDelayedWork<T, ID>,
+{
+}
+
 // SAFETY: TODO.
 unsafe impl<T, const ID: u64> WorkItemPointer<ID> for Pin<KBox<T>>
 where
@@ -575,7 +889,7 @@ where
 {
     unsafe extern "C" fn run(ptr: *mut bindings::work_struct) {
         // The `__enqueue` method always uses a `work_struct` stored in a `Work<T, ID>`.
-        let ptr = ptr as *mut Work<T, ID>;
+        let ptr = ptr.cast::<Work<T, ID>>();
         // SAFETY: This computes the pointer that `__enqueue` got from `Arc::into_raw`.
         let ptr = unsafe { T::work_container_of(ptr) };
         // SAFETY: This pointer comes from `Arc::into_raw` and we've been given back ownership.
@@ -617,6 +931,16 @@ where
     }
 }
 
+// SAFETY: By the safety requirements of `HasDelayedWork`, the `work_struct` returned by methods in
+// `HasWork` provides a `work_struct` that is the `work` field of a `delayed_work`, and the rest of
+// the `delayed_work` has the same access rules as its `work` field.
+unsafe impl<T, const ID: u64> RawDelayedWorkItem<ID> for Pin<KBox<T>>
+where
+    T: WorkItem<ID, Pointer = Self>,
+    T: HasDelayedWork<T, ID>,
+{
+}
+
 /// Returns the system work queue (`system_wq`).
 ///
 /// It is the one used by `schedule[_delayed]_work[_on]()`. Multi-CPU multi-threaded. There are