linux-kernel - [PATCH v3 1/3] rust: clk: implement Send and Sync

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Message-ID: <20251218-clk-send-sync-v3-1-e48b2e2f1eac@google.com>
Date: Thu, 18 Dec 2025 13:27:40 +0000
From: Alice Ryhl <aliceryhl@...gle.com>
To: Michael Turquette <mturquette@...libre.com>, Stephen Boyd <sboyd@...nel.org>, 
	Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>, Maxime Ripard <mripard@...nel.org>, 
	Drew Fustini <fustini@...nel.org>, Guo Ren <guoren@...nel.org>, Fu Wei <wefu@...hat.com>, 
	"Uwe Kleine-König" <ukleinek@...nel.org>, Michal Wilczynski <m.wilczynski@...sung.com>
Cc: Viresh Kumar <viresh.kumar@...aro.org>, Miguel Ojeda <ojeda@...nel.org>, 
	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>, Trevor Gross <tmgross@...ch.edu>, 
	Danilo Krummrich <dakr@...nel.org>, Daniel Almeida <daniel.almeida@...labora.com>, 
	linux-clk@...r.kernel.org, rust-for-linux@...r.kernel.org, 
	linux-kernel@...r.kernel.org, dri-devel@...ts.freedesktop.org, 
	linux-riscv@...ts.infradead.org, linux-pwm@...r.kernel.org, 
	Alice Ryhl <aliceryhl@...gle.com>
Subject: [PATCH v3 1/3] rust: clk: implement Send and Sync

These traits are required for drivers to embed the Clk type in their own
data structures because driver data structures are usually required to
be Send. Since the Clk type is thread-safe, implement the relevant
traits.

Reviewed-by: Daniel Almeida <daniel.almeida@...labora.com>
Reviewed-by: Danilo Krummrich <dakr@...nel.org>
Acked-by: Viresh Kumar <viresh.kumar@...aro.org>
Reviewed-by: Boqun Feng <boqun.feng@...il.com>
Signed-off-by: Alice Ryhl <aliceryhl@...gle.com>
---
 rust/kernel/clk.rs | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/rust/kernel/clk.rs b/rust/kernel/clk.rs
index c1cfaeaa36a22be2e3180b1e9142bb608ab276ea..d192fbd97861212d738d24510eebcd99c9177f2c 100644
--- a/rust/kernel/clk.rs
+++ b/rust/kernel/clk.rs
@@ -129,6 +129,13 @@ mod common_clk {
     #[repr(transparent)]
     pub struct Clk(*mut bindings::clk);
 
+    // SAFETY: It is safe to call `clk_put` on another thread than where `clk_get` was called.
+    unsafe impl Send for Clk {}
+
+    // SAFETY: It is safe to call any combination of the `&self` methods in parallel, as the
+    // methods are synchronized internally.
+    unsafe impl Sync for Clk {}
+
     impl Clk {
         /// Gets [`Clk`] corresponding to a [`Device`] and a connection id.
         ///

-- 
2.52.0.351.gbe84eed79e-goog