From nobody Wed Dec 17 21:26:40 2025 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A4AFD21B1A0; Fri, 6 Dec 2024 19:35:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733513748; cv=none; b=TRol8bp0oLOHgOkK4bkrHihu+a2pxNO8WwQFxuy0AFpMpTHaG8FRoSYHuNjW3u3aRfG84LCiUblPKDHfR+J30ghgp6mJe11izqr/OdzZO0JKApo1NXKNS1P3H1lQ1aL2ovohS5cjiW/IDIYNVYxX9cemoZcykK0kkVvClP+aKkQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733513748; c=relaxed/simple; bh=Gn70I9pN0f4TEQ9qvGFsjodYORtSobyj7JiWCADhVpQ=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=UNimuNwtHoZM0m48pB34A7huFjYuXAn7JIpyDPLKFQ7sAHUO7TJ2Rtp7yb4r8lEAdoLWr5UE72mARWoSom/CQVrtouVATjsQaTpu5mwJXc2M698FoEJgMTb6KpZEMdeLjU5uLgOzfJDpzo4eFzZv4XnSzCqF9nxgqcgwyAm0WP4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Qi7KP1mX; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Qi7KP1mX" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 25E3BC4CEDD; Fri, 6 Dec 2024 19:35:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1733513748; bh=Gn70I9pN0f4TEQ9qvGFsjodYORtSobyj7JiWCADhVpQ=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=Qi7KP1mXsJgXDv6bjK/FjXYDXeJqMuftfSfxZSgNAJLGlKciBnDHR+is3p+YGE2B0 dtxi4ixXZngPyEECp16qWE3d7WVkiu86ALDF2L8e87heOjAq7PT3Zf/wbgcnoN/Ako exPQv/MU0PRuhR9lp7L9I1L4buWWymM2RWQ4tEsDN4FSY4NdpOWcW8JSB4bOGnrVUN XZR63NkUTTYQmuI3OXwKyEwwvBexY6sl3gY/h8wYqnc5mav3b7mt7J0Fb2mTZHC4QY 25V44hlEVF3jfsnA0bPBr6cOvqcD26eXLsjva9KJktNfDpfXRPtTGxKr0JzJ8lig2S TszOn9RygGhZg== From: Andreas Hindborg Date: Fri, 06 Dec 2024 20:32:59 +0100 Subject: [PATCH v4 07/14] rust: hrtimer: implement `UnsafeTimerPointer` for `Pin<&T>` Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20241206-hrtimer-v3-v6-12-rc2-v4-7-6cb8c3673682@kernel.org> References: <20241206-hrtimer-v3-v6-12-rc2-v4-0-6cb8c3673682@kernel.org> In-Reply-To: <20241206-hrtimer-v3-v6-12-rc2-v4-0-6cb8c3673682@kernel.org> To: Miguel Ojeda , Anna-Maria Behnsen , Frederic Weisbecker , Thomas Gleixner , Danilo Krummrich Cc: Alex Gaynor , Boqun Feng , Gary Guo , =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= , Benno Lossin , Alice Ryhl , Trevor Gross , Lyude Paul , rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, Andreas Hindborg X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=openpgp-sha256; l=4022; i=a.hindborg@kernel.org; h=from:subject:message-id; bh=Gn70I9pN0f4TEQ9qvGFsjodYORtSobyj7JiWCADhVpQ=; b=LS0tLS1CRUdJTiBQR1AgTUVTU0FHRS0tLS0tCgpvd0o0bkFGdEFwTDlrQTBEQUFvQjRiZ2FQb mtvWTNjQnl5WmlBR2RUVVc1RjFNa0NZWDlnb2lvU252M3JVUWtFCkZBdDNMeDNtWCtDYVgwdThM UzVFSW9rQ013UUFBUW9BSFJZaEJCTEIrVWRXdjN3cUZkYkFFdUc0R2o1NUtHTjMKQlFKblUxRnV BQW9KRU9HNEdqNTVLR04zS2ZRUC9qT21DcG9aMEFTSFRneHpSQkxWdTNDR09ubTNKYk1BR1N2Uw p5czBublZIbXlyLzZrVVowUEloSVZ3U1V4ajBGb2FMdU9LbitndHNuK3JSN094RzlIS05FUHRVO FhvRHVTVy9kClc1Q3BTTVpEOGJDdHJzTnkwa3BqUXJVSmg1bGdKTWRuSlk4c2hMQm9WWmVENG9p RzNLaXBJNFlmRjJBdWE5WHAKWXRKZ21ZMUF1N2xpaUd1bUV4U0toM2U3U3U1b1dwSDZFRnFsMWV PbE9EdlFWWkpJMHErY1JwK2loQzNYTTFKYwo3aHBMSk1LK3VjNWZSU3ZMM1B5dUVsMVBhL2VIOT d4YkhRTTZvR05kZ0drQ3UrZkYwSWRGWWNDUERoYm9nQ1VhCm5TbUMvZFlQNE5XUnMyNzM5OXk1T GJTcytWMnlzMWxGdUZnVkFOTk1PaTBGZmN0TjZBR2pheUFKcE5FMmFqbXAKcHpBT0lpOEpVNjll VEpMZlNRYUc4ZllZMXRiUUtWb1hUYXlQZ3Q5K3ZOK1hETEFLWXZTN2I4Y3ZzRTA5Z1ZqQwptNnN 0ZVdsNFFNbzErUWFwVHloU2VIcG8xdk5zVUFsZjdJSXhUUG1hK0pUcmpVTmx4Z0xjdDFXYU1EMF Z6cmhaCnBNeWFMMm5nUSt2M1QvY2xrTzhDTHk1YW1ONDdxbFBFSytySGZKL1JMUzRaZmZCODdIM 3N3MHUwM0tLS0x1SkcKMlNmM0xTbWsxZGQzZVBhVU04MmtFUzJxR1IzSFViWWwvbGFxMVA3N3JX WGp3VG5lUUEvUXZLUWJCVG5FVFlmUwpIYzBTbUFueXBKYzJzNGdEYmw5bWZtdkE4MDNMYndQMlE wWHROUzNmbGQ5akhxOUY2QVlKWDRRVDRPMWlvZkhlCmxjbHZTa0RqZnhrbFR3PT0KPUxUUUoKLS 0tLS1FTkQgUEdQIE1FU1NBR0UtLS0tLQo= X-Developer-Key: i=a.hindborg@kernel.org; a=openpgp; fpr=3108C10F46872E248D1FB221376EB100563EF7A7 Allow pinned references to structs that contain a `Timer` node to be scheduled with the `hrtimer` subsystem. Signed-off-by: Andreas Hindborg --- rust/kernel/time/hrtimer.rs | 1 + rust/kernel/time/hrtimer/pin.rs | 95 +++++++++++++++++++++++++++++++++++++= ++++ 2 files changed, 96 insertions(+) diff --git a/rust/kernel/time/hrtimer.rs b/rust/kernel/time/hrtimer.rs index fab9bf2612ceaa1ce936ab9b9bc31b018a1a9aef..ad02e023b78062b368af1849063= d830ffba5f29b 100644 --- a/rust/kernel/time/hrtimer.rs +++ b/rust/kernel/time/hrtimer.rs @@ -363,3 +363,4 @@ unsafe fn raw_get_timer(ptr: *const Self) -> } =20 mod arc; +mod pin; diff --git a/rust/kernel/time/hrtimer/pin.rs b/rust/kernel/time/hrtimer/pin= .rs new file mode 100644 index 0000000000000000000000000000000000000000..7b251f157b2c196a3bde220b126= 19ce0c0ecce6c --- /dev/null +++ b/rust/kernel/time/hrtimer/pin.rs @@ -0,0 +1,95 @@ +// SPDX-License-Identifier: GPL-2.0 + +use super::HasTimer; +use super::RawTimerCallback; +use super::Timer; +use super::TimerCallback; +use super::TimerHandle; +use super::UnsafeTimerPointer; +use crate::time::Ktime; +use core::pin::Pin; + +/// A handle for a `Pin<&HasTimer>`. When the handle exists, the timer mig= ht be +/// running. +pub struct PinTimerHandle<'a, U> +where + U: HasTimer, +{ + pub(crate) inner: Pin<&'a U>, +} + +// SAFETY: We cancel the timer when the handle is dropped. The implementat= ion of +// the `cancel` method will block if the timer handler is running. +unsafe impl<'a, U> TimerHandle for PinTimerHandle<'a, U> +where + U: HasTimer, +{ + fn cancel(&mut self) -> bool { + let self_ptr: *const U =3D self.inner.get_ref(); + + // SAFETY: As we got `self_ptr` from a reference above, it must po= int to + // a valid `U`. + let timer_ptr =3D unsafe { >::raw_get_timer(self_= ptr) }; + + // SAFETY: As `timer_ptr` is derived from a reference, it must poi= nt to + // a valid and initialized `Timer`. + unsafe { Timer::::raw_cancel(timer_ptr) } + } +} + +impl<'a, U> Drop for PinTimerHandle<'a, U> +where + U: HasTimer, +{ + fn drop(&mut self) { + self.cancel(); + } +} + +// SAFETY: We capture the lifetime of `Self` when we create a `PinTimerHan= dle`, +// so `Self` will outlive the handle. +unsafe impl<'a, U> UnsafeTimerPointer for Pin<&'a U> +where + U: Send + Sync, + U: HasTimer, + U: TimerCallback =3D Self>, +{ + type TimerHandle =3D PinTimerHandle<'a, U>; + + unsafe fn start(self, expires: Ktime) -> Self::TimerHandle { + // Cast to pointer + let self_ptr: *const U =3D ::deref(&self= ); + + // SAFETY: As we derive `self_ptr` from a reference above, it must= point + // to a valid `U`. + unsafe { U::start(self_ptr, expires) }; + + PinTimerHandle { inner: self } + } +} + +impl<'a, U> RawTimerCallback for Pin<&'a U> +where + U: HasTimer, + U: TimerCallback =3D Self>, + U: TimerCallback =3D Self>, +{ + unsafe extern "C" fn run(ptr: *mut bindings::hrtimer) -> bindings::hrt= imer_restart { + // `Timer` is `repr(C)` + let timer_ptr =3D ptr as *mut Timer; + + // SAFETY: By the safety requirement of this function, `timer_ptr` + // points to a `Timer` contained in an `U`. + let receiver_ptr =3D unsafe { U::timer_container_of(timer_ptr) }; + + // SAFETY: By the safety requirement of this function, `timer_ptr` + // points to a `Timer` contained in an `U`. + let receiver_ref =3D unsafe { &*receiver_ptr }; + + // SAFETY: `receiver_ref` only exists as pinned, so it is safe to = pin it + // here. + let receiver_pin =3D unsafe { Pin::new_unchecked(receiver_ref) }; + + U::run(receiver_pin).into() + } +} --=20 2.46.0