linux-kernel - [PATCH 2/2] rust: regulator: implement Send and Sync for Regulator<T>

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Message-Id: <20250729-regulator-send-sync-v1-2-8bcbd546b940@collabora.com>
Date: Tue, 29 Jul 2025 14:31:41 -0300
From: Daniel Almeida <daniel.almeida@...labora.com>
To: Liam Girdwood <lgirdwood@...il.com>, Mark Brown <broonie@...nel.org>, 
 Miguel Ojeda <ojeda@...nel.org>, Alex Gaynor <alex.gaynor@...il.com>, 
 Boqun Feng <boqun.feng@...il.com>, Gary Guo <gary@...yguo.net>, 
 Björn Roy Baron <bjorn3_gh@...tonmail.com>, 
 Benno Lossin <lossin@...nel.org>, Andreas Hindborg <a.hindborg@...nel.org>, 
 Alice Ryhl <aliceryhl@...gle.com>, Trevor Gross <tmgross@...ch.edu>, 
 Danilo Krummrich <dakr@...nel.org>
Cc: linux-kernel@...r.kernel.org, rust-for-linux@...r.kernel.org, 
 Daniel Almeida <daniel.almeida@...labora.com>
Subject: [PATCH 2/2] rust: regulator: implement Send and Sync for
 Regulator<T>

Sending a &Regulator<T> to another thread is safe, as the regulator core
will properly handle the locking for us. Additionally, there are no
restrictions that prevents sending a Regulator<T> to another thread.

Given these two facts, implement Send and Sync.

Signed-off-by: Daniel Almeida <daniel.almeida@...labora.com>
---
 rust/kernel/regulator.rs | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/rust/kernel/regulator.rs b/rust/kernel/regulator.rs
index d56aa229e838c45258a27cea742a693dd71e8e40..704147e18bfc9c993a00f7a187105360ad1d4956 100644
--- a/rust/kernel/regulator.rs
+++ b/rust/kernel/regulator.rs
@@ -398,6 +398,14 @@ fn drop(&mut self) {
     }
 }
 
+// SAFETY: It is safe to send a `Regulator<T>` across threads. In particular, a
+// Regulator<T> can be dropped from any thread.
+unsafe impl<T: RegulatorState> Send for Regulator<T> {}
+
+// SAFETY: It is safe to send a &Regulator<T> across threads because the C side
+// handles its own locking.
+unsafe impl<T: RegulatorState> Sync for Regulator<T> {}
+
 /// A voltage.
 ///
 /// This type represents a voltage value in microvolts.

-- 
2.50.0