Merge pull request #796 from wedsonaf/workqueue

rust: add support for work queues

Author: wedsonaf

include/linux/workqueue.h

@@ -221,24 +221,31 @@ static inline unsigned int work_static(struct work_struct *work) { return 0; }
  * to generate better code.
  */
 #ifdef CONFIG_LOCKDEP
-#define __INIT_WORK(_work, _func, _onstack)				\
+#define __INIT_WORK_WITH_KEY(_work, _func, _onstack, _key)		\
 	do {								\
-		static struct lock_class_key __key;			\
-									\
 		__init_work((_work), _onstack);				\
 		(_work)->data = (atomic_long_t) WORK_DATA_INIT();	\
-		lockdep_init_map(&(_work)->lockdep_map, "(work_completion)"#_work, &__key, 0); \
+		lockdep_init_map(&(_work)->lockdep_map, "(work_completion)"#_work, _key, 0); \
 		INIT_LIST_HEAD(&(_work)->entry);			\
 		(_work)->func = (_func);				\
 	} while (0)
-#else
+
 #define __INIT_WORK(_work, _func, _onstack)				\
+	do {								\
+		static struct lock_class_key __key;			\
+		__INIT_WORK_WITH_KEY(_work, _func, _onstack, &__key);	\
+	} while (0)
+#else
+#define __INIT_WORK_WITH_KEY(_work, _func, _onstack, _key)		\
 	do {								\
 		__init_work((_work), _onstack);				\
 		(_work)->data = (atomic_long_t) WORK_DATA_INIT();	\
 		INIT_LIST_HEAD(&(_work)->entry);			\
 		(_work)->func = (_func);				\
 	} while (0)
+
+#define __INIT_WORK(_work, _func, _onstack)				\
+	__INIT_WORK_WITH_KEY(_work, _func, _onstack, NULL)
 #endif
 
 #define INIT_WORK(_work, _func)						\

rust/helpers.c

@@ -620,6 +620,13 @@ unsigned int rust_helper_NF_QUEUE_NR(unsigned int n)
 }
 EXPORT_SYMBOL_GPL(rust_helper_NF_QUEUE_NR);
 
+void rust_helper___INIT_WORK_WITH_KEY(struct work_struct *work,
+		work_func_t func, bool on_stack, struct lock_class_key *key)
+{
+	__INIT_WORK_WITH_KEY(work, func, on_stack, key);
+}
+EXPORT_SYMBOL_GPL(rust_helper___INIT_WORK_WITH_KEY);
+
 /*
  * We use `bindgen`'s `--size_t-is-usize` option to bind the C `size_t` type
  * as the Rust `usize` type, so we can use it in contexts where Rust

rust/kernel/lib.rs

@@ -65,6 +65,7 @@ pub mod revocable;
 pub mod security;
 pub mod str;
 pub mod task;
+pub mod workqueue;
 
 pub mod linked_list;
 mod raw_list;
@@ -104,7 +105,8 @@ pub use build_error::build_error;
 
 pub use crate::error::{to_result, Error, Result};
 pub use crate::types::{
-    bit, bits_iter, ARef, AlwaysRefCounted, Bool, False, Mode, Opaque, ScopeGuard, True,
+    bit, bits_iter, ARef, AlwaysRefCounted, Bool, Either, Either::Left, Either::Right, False, Mode,
+    Opaque, ScopeGuard, True,
 };
 
 use core::marker::PhantomData;

rust/kernel/sync.rs

@@ -62,7 +62,7 @@ impl LockClassKey {
         Self(UnsafeCell::new(MaybeUninit::uninit()))
     }
 
-    fn get(&self) -> *mut bindings::lock_class_key {
+    pub(crate) fn get(&self) -> *mut bindings::lock_class_key {
         self.0.get().cast()
     }
 }

rust/kernel/types.rs

@@ -282,6 +282,7 @@ impl<T, F: FnOnce(T)> Drop for ScopeGuard<T, F> {
 /// Stores an opaque value.
 ///
 /// This is meant to be used with FFI objects that are never interpreted by Rust code.
+#[repr(transparent)]
 pub struct Opaque<T>(MaybeUninit<UnsafeCell<T>>);
 
 impl<T> Opaque<T> {
@@ -677,3 +678,12 @@ impl<T: AlwaysRefCounted> Drop for ARef<T> {
         unsafe { T::dec_ref(self.ptr) };
     }
 }
+
+/// A sum type that always holds either a value of type `L` or `R`.
+pub enum Either<L, R> {
+    /// Constructs an instance of [`Either`] containing a value of type `L`.
+    Left(L),
+
+    /// Constructs an instance of [`Either`] containing a value of type `R`.
+    Right(R),
+}