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 AB6CC1DE2D8; Fri, 6 Dec 2024 19:35:32 +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=1733513732; cv=none; b=BVDsVSehzSVj/M7fuMYRCHE2u4cM5NYVM2NI0RDxW9eD8bILU6ANcp2XfTpp+nBbtfMzqGznuQRZWueOUc5+2yhbtuoUGc3M8HLGoDCgCcNBJXxQ+d5sYm3goLHGRqIOoMxXMPzMP7/oVrTNoEt+HvDKjg9jfszu1AZc4/m0IxQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733513732; c=relaxed/simple; bh=6WgaFtCFG45ZPn9cC//15Oy/uIkYY9hKr/2/l/u9DGU=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=mOUAfQZNgbZYxGww+8+eChcbbLgZ2WuAKyy8GfMdWwxkaeGqbKrr0+uBRdQrXAUC8lGmfg8t+HjPU9K53brIC1fbwxwXYV//0ROZexX5dxOHlvM1tS4FELqP027hHkxIJlARvzTnZD/gWWLwPP/Eb46ozD2fwqSxw0N3Q8e24ZI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=WiOrae7C; 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="WiOrae7C" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 83BAAC4CED1; Fri, 6 Dec 2024 19:35:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1733513732; bh=6WgaFtCFG45ZPn9cC//15Oy/uIkYY9hKr/2/l/u9DGU=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=WiOrae7CZbIPyeN02W+XFTSOotrv5Gx2ifXzaNV2mwLShHRiY8bjUtQwnyv5T8eHm AvzeEntjOrHq2hcaZ7dhO+IEAnCNd5KsQbX/HXhQA0waYQHspE4d4Id+t2L6FE/XrE fh8UeTiM8JcABN7uZZJNYbyC3fFqYmNW0N4JuuyMzkzWbIHjveNXToYOMT9fSGOtoK UmIarGB3DSb8iyz5AUb5A8Qr6vD7+rNIOacJ3gElAM8KjrOMFD/lK1N0zwlldLln5I GAEq8ZpjGx7vAwF2Dcug2yKLF7m0nqhmkfIFT1lZRUhgHgRH3n0A6ufEepqtWXq+BK MzdU/aMWEWaiw== From: Andreas Hindborg Date: Fri, 06 Dec 2024 20:32:56 +0100 Subject: [PATCH v4 04/14] rust: hrtimer: implement `TimerPointer` for `Arc` 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-v4-4-6cb8c3673682@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=4083; i=a.hindborg@kernel.org; h=from:subject:message-id; bh=6WgaFtCFG45ZPn9cC//15Oy/uIkYY9hKr/2/l/u9DGU=; b=LS0tLS1CRUdJTiBQR1AgTUVTU0FHRS0tLS0tCgpvd0o0bkFGdEFwTDlrQTBEQUFvQjRiZ2FQb mtvWTNjQnl5WmlBR2RUVVdzbEVRdG96QUdBTmdwQUNQNHdaOGp5CnB2SDF0QTRNQlBIU2JQSmxp amhxOW9rQ013UUFBUW9BSFJZaEJCTEIrVWRXdjN3cUZkYkFFdUc0R2o1NUtHTjMKQlFKblUxRnJ BQW9KRU9HNEdqNTVLR04zNW9ZUC8xUnR3UWkwTVRxcGp0RVN3WVlqZFVlN09tMEFkTW9KSXB4UQ pObU9wSURvVmNaZVpDUkhUWDRla2FKZ1VpakNFSzNBdHFQM3RFckJhQ2ZCZHBRUzVqVjdxQW1le Eo1RWh3dmVxClpSZFNXdjJQOW9BNXNPa1RJSGxOVG5scEFyTkJMekVWZ2dveXlFQVN1U1p0THla empRbDFiOUYwTmhnbGJIMXAKN2JPditBM3lKeW5MUWJmN1d4RzB4NjVHczg0SVF2eHZubFNsNlQ yRTNtck0zSjZtTm5lYmNkdzF6azB4Y1VVRwpOS0FMZmJSeWVURGY2d2JTUDV4ZHBqVHFLSFEzcS tXai9FNVR4alk2YldJK1NQd3hKY29Qd1RHaGx5WUZuKzNyCk5IejdQdjRpd3M3bXZNQytZZm5BS 29lY0tyYVpBNEhNMU9sY212bHNaNG1Uc0tCdDI3eXdYbFdMSFozL1l6aTcKUXlqTHk5ZEhYeSsx QlBnbkJRdDBraHorY3Bhc0FxcWplSU1HRzIrRVU5a0MyRUFxd3V3aldDWG5xb200VEFicwpSMmV VaHZUR291SmlMNy9CdDgvZWRMcTQ3WHBhT1pBL25mdk1FK0VMNmllUGdQbWJmY1lITzV4OERsVX B5RmtMCjEvMzdpS1hFUVlxWEt3cGZ1RS9tY0txNVBMQnZlcDBiZ09aWEN0QmJxdk1zZit0eXRwe HB2cExNUEs2dUFzQXYKNDhEQ3NVdXJ3TGpiRHBJb2VyMGdIbnVmMlpSTXJaSE1NWWw1WmRCR2dp bm9oMmFOYmpmbWRGN2JKdHFwZUhodQpNTEMwRzlQQUR5L0RockRVRmkwam94eUtCZ2lpWmk1UEZ iS3NlZmZ6NFV3WlpBSDlVQzd3VXpyY3ZvSGlkTHFlCnhkU29iUjRHT0JjaUpBPT0KPXNDUGIKLS 0tLS1FTkQgUEdQIE1FU1NBR0UtLS0tLQo= X-Developer-Key: i=a.hindborg@kernel.org; a=openpgp; fpr=3108C10F46872E248D1FB221376EB100563EF7A7 This patch allows the use of intrusive `hrtimer` fields in structs that are managed by an `Arc`. Signed-off-by: Andreas Hindborg --- rust/kernel/time/hrtimer.rs | 3 +- rust/kernel/time/hrtimer/arc.rs | 89 +++++++++++++++++++++++++++++++++++++= ++++ 2 files changed, 91 insertions(+), 1 deletion(-) diff --git a/rust/kernel/time/hrtimer.rs b/rust/kernel/time/hrtimer.rs index 646cd5bfa6623aec62294f9115fbf6fedc0a426c..e76b864f3435667f56ed607fd3b= f029317eb1332 100644 --- a/rust/kernel/time/hrtimer.rs +++ b/rust/kernel/time/hrtimer.rs @@ -98,7 +98,6 @@ unsafe fn raw_get(ptr: *const Self) -> *mut bindings::hrt= imer { /// # Safety /// /// `self_ptr` must point to a valid `Self`. - #[allow(dead_code)] pub(crate) unsafe fn raw_cancel(self_ptr: *const Self) -> bool { // SAFETY: timer_ptr points to an allocation of at least `Timer` s= ize. let c_timer_ptr =3D unsafe { Timer::raw_get(self_ptr) }; @@ -294,3 +293,5 @@ unsafe fn raw_get_timer(ptr: *const Self) -> } } } + +mod arc; diff --git a/rust/kernel/time/hrtimer/arc.rs b/rust/kernel/time/hrtimer/arc= .rs new file mode 100644 index 0000000000000000000000000000000000000000..3b256292bc86160a495f7b192b3= eda92f2dfcb31 --- /dev/null +++ b/rust/kernel/time/hrtimer/arc.rs @@ -0,0 +1,89 @@ +// SPDX-License-Identifier: GPL-2.0 + +use super::HasTimer; +use super::RawTimerCallback; +use super::Timer; +use super::TimerCallback; +use super::TimerHandle; +use super::TimerPointer; +use crate::sync::Arc; +use crate::sync::ArcBorrow; +use crate::time::Ktime; + +/// A handle for an `Arc>` returned by a call to +/// [`TimerPointer::start`]. +pub struct ArcTimerHandle +where + U: HasTimer, +{ + pub(crate) inner: Arc, +} + +// SAFETY: We implement drop below, and we cancel the timer in the drop +// implementation. +unsafe impl TimerHandle for ArcTimerHandle +where + U: HasTimer, +{ + fn cancel(&mut self) -> bool { + let self_ptr =3D Arc::as_ptr(&self.inner); + + // SAFETY: As we obtained `self_ptr` from a valid reference above,= it + // must point to a valid `U`. + let timer_ptr =3D unsafe { >::raw_get_timer(self_= ptr) }; + + // SAFETY: As `timer_ptr` points into `U` and `U` is valid, `timer= _ptr` + // must point to a valid `Timer` instance. + unsafe { Timer::::raw_cancel(timer_ptr) } + } +} + +impl Drop for ArcTimerHandle +where + U: HasTimer, +{ + fn drop(&mut self) { + self.cancel(); + } +} + +impl TimerPointer for Arc +where + U: Send + Sync, + U: HasTimer, + U: for<'a> TimerCallback =3D Self>, +{ + type TimerHandle =3D ArcTimerHandle; + + fn start(self, expires: Ktime) -> ArcTimerHandle { + // SAFETY: Since we generate the pointer passed to `start` from a + // valid reference, it is a valid pointer. + unsafe { U::start(Arc::as_ptr(&self), expires) }; + + ArcTimerHandle { inner: self } + } +} + +impl RawTimerCallback for Arc +where + U: HasTimer, + U: for<'a> TimerCallback =3D Self>, + U: for<'a> TimerCallback =3D ArcBorrow<'a,= U>>, +{ + unsafe extern "C" fn run(ptr: *mut bindings::hrtimer) -> bindings::hrt= imer_restart { + // `Timer` is `repr(C)` + let timer_ptr =3D ptr.cast::>(); + + // SAFETY: By C API contract `ptr` is the pointer we passed when + // queuing the timer, so it is a `Timer` embedded in a `T`. + let data_ptr =3D unsafe { U::timer_container_of(timer_ptr) }; + + // SAFETY: `data_ptr` points to the `U` that was used to queue the + // timer. This `U` is contained in an `Arc`. + let receiver =3D unsafe { ArcBorrow::from_raw(data_ptr) }; + + U::run(receiver); + + bindings::hrtimer_restart_HRTIMER_NORESTART + } +} --=20 2.46.0