On 20.05.2024 19:25, Danilo Krummrich wrote:
From: Wedson Almeida Filho <wedsonaf@xxxxxxxxx>
This implements the Revocable and AsyncRevocable types.
Revocable allows access to objects to be safely revoked at run time.
This is useful, for example, for resources allocated during device probe;
when the device is removed, the driver should stop accessing the device
resources even if other state is kept in memory due to existing
references (i.e., device context data is ref-counted and has a non-zero
refcount after removal of the device).
AsyncRevocable allows access to objects to be revoked without having to
wait for existing users to complete. This will be used to drop futures
in tasks when executors are being torn down.
Co-developed-by: Andreas Hindborg <a.hindborg@xxxxxxxxxxx>
Signed-off-by: Andreas Hindborg <a.hindborg@xxxxxxxxxxx>
Signed-off-by: Wedson Almeida Filho <wedsonaf@xxxxxxxxx>
Signed-off-by: Danilo Krummrich <dakr@xxxxxxxxxx>
---
rust/kernel/lib.rs | 1 +
rust/kernel/revocable.rs | 441 +++++++++++++++++++++++++++++++++++++++
2 files changed, 442 insertions(+)
create mode 100644 rust/kernel/revocable.rs
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index 698121c925f3..d7d415429517 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -40,6 +40,7 @@
pub mod net;
pub mod prelude;
pub mod print;
+pub mod revocable;
mod static_assert;
#[doc(hidden)]
pub mod std_vendor;
diff --git a/rust/kernel/revocable.rs b/rust/kernel/revocable.rs
new file mode 100644
index 000000000000..71408039a117
--- /dev/null
+++ b/rust/kernel/revocable.rs
@@ -0,0 +1,441 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Revocable objects.
+//!
+//! The [`Revocable`] type wraps other types and allows access to them to be revoked. The existence
+//! of a [`RevocableGuard`] ensures that objects remain valid.
+
+use crate::{
+ bindings,
+ init::{self},
+ prelude::*,
+ sync::rcu,
+};
+use core::{
+ cell::UnsafeCell,
+ marker::PhantomData,
+ mem::MaybeUninit,
+ ops::Deref,
+ ptr::drop_in_place,
+ sync::atomic::{fence, AtomicBool, AtomicU32, Ordering},
+};
+
+/// An object that can become inaccessible at runtime.
+///
+/// Once access is revoked and all concurrent users complete (i.e., all existing instances of
+/// [`RevocableGuard`] are dropped), the wrapped object is also dropped.
+///
+/// # Examples
You might want to enable the doctest and check if the Examples are at
least compiling ;) Here and in devres as well.
Best regards
Dirk
