From nobody Fri Dec 19 13:58:07 2025 Received: from mout02.posteo.de (mout02.posteo.de [185.67.36.66]) (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 AB0C528DB52 for ; Sun, 12 Oct 2025 14:52:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.67.36.66 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760280762; cv=none; b=GZj7aQt0gmMLJ601ImGo8t/VdPZTPYwQslCjktqMZdVTgj7DoN0AIJ41r5B3jHlYpbvxm8KtI+9vT3GgcN1umSbJ+jgIm4MOJt4zhVgVsSpPzv23rE8VPIG9rBPeV6fIcE75z6Q37bYy4jb8XJLosrhMMbjj2sY35m/UBPYofGk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760280762; c=relaxed/simple; bh=SRZeeT6WFfS7qF3NEqWnJkw4ui14/yghSMrEf3tuOVI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=eAGSVGQtWOwKDJ6a3E4czjMVIyjM1W1U0Wx851Fzb2VnzBguQgu3MJAeCe/3hf4YeVj5C+q8QvqIAm8yZjypXFNWoJ7pWa520Vp1c07vc6HPX7RpxPYGIe7HNRVVKqBXWS9x+qY3jkia8mBi+X24Qpdb5en8zB63GeCnL178Nnc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=posteo.de; spf=pass smtp.mailfrom=posteo.de; dkim=pass (2048-bit key) header.d=posteo.de header.i=@posteo.de header.b=dYnfNi0N; arc=none smtp.client-ip=185.67.36.66 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=posteo.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=posteo.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=posteo.de header.i=@posteo.de header.b="dYnfNi0N" Received: from submission (posteo.de [185.67.36.169]) by mout02.posteo.de (Postfix) with ESMTPS id E495D240106 for ; Sun, 12 Oct 2025 16:52:38 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=posteo.de; s=2017; t=1760280758; bh=5lmAtN9vcxTOzyOK6mDVeCukdU4Nwkr6xfJNm9/RsLI=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version: Content-Transfer-Encoding:Autocrypt:OpenPGP:From; b=dYnfNi0NU8P31e8g2mgP84fwXmaxlYTwW2OmBeozUHoauqhKF3K97WZXPrR9UqC2y FwBbp4oFhdVDqKCygj7VfptriShO5t3H3MeqJZK62nOCro4TD/JnXl2f1mRB9EWosi h1PLS6Xw8dHf91fWN8fcOlJcm6vRB92Ydq7iJjCmo4QKBjm4QAm7oCwCpwzSHAMlEA yHuXZG9wTRn8w07aneiipcfeihEeprFA1Bx84MsY/PIbCLxwNofZddT4zsABotd31e jD5lI4Nsh50/i44PDpGP62ydE51ro5iBGio9Ivt/5ZmkX0WQj1G3YTkv7lYbCyONsp A77tAhM11SLFg== Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 4cl3P04tLLz6v0X; Sun, 12 Oct 2025 16:52:36 +0200 (CEST) From: Markus Probst To: Danilo Krummrich , Miguel Ojeda , Alex Gaynor , Lee Jones , Pavel Machek Cc: Lorenzo Stoakes , Vlastimil Babka , "Liam R. Howlett" , Uladzislau Rezki , Boqun Feng , Gary Guo , bjorn3_gh@protonmail.com, Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross , Markus Probst , rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, linux-leds@vger.kernel.org Subject: [PATCH v4 1/2] rust: add basic Pin> abstractions Date: Sun, 12 Oct 2025 14:52:38 +0000 Message-ID: <20251012145221.172116-2-markus.probst@posteo.de> In-Reply-To: <20251012145221.172116-1-markus.probst@posteo.de> References: <20251012145221.172116-1-markus.probst@posteo.de> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Autocrypt: addr=markus.probst@posteo.de; prefer-encrypt=mutual; keydata=xsFNBGiDvXgBEADAXUceKafpl46S35UmDh2wRvvx+UfZbcTjeQOlSwKP7YVJ4JOZrVs93qReNLkO WguIqPBxR9blQ4nyYrqSCV+MMw/3ifyXIm6Pw2YRUDg+WTEOjTixRCoWDgUj1nOsvJ9tVAm76Ww+ /pAnepVRafMID0rqEfD9oGv1YrfpeFJhyE2zUw3SyyNLIKWD6QeLRhKQRbSnsXhGLFBXCqt9k5JA RhgQof9zvztcCVlT5KVvuyfC4H+HzeGmu9201BVyihJwKdcKPq+n/aY5FUVxNTgtI9f8wIbmfAja oT1pjXSp+dszakA98fhONM98pOq723o/1ZGMZukyXFfsDGtA3BB79HoopHKujLGWAGskzClwTjRQ xBqxh/U/lL1pc+0xPWikTNCmtziCOvv0KA0arDOMQlyFvImzX6oGVgE4ksKQYbMZ3Ikw6L1Rv1J+ FvN0aNwOKgL2ztBRYscUGcQvA0Zo1fGCAn/BLEJvQYShWKeKqjyncVGoXFsz2AcuFKe1pwETSsN6 OZncjy32e4ktgs07cWBfx0v62b8md36jau+B6RVnnodaA8++oXl3FRwiEW8XfXWIjy4umIv93tb8 8ekYsfOfWkTSewZYXGoqe4RtK80ulMHb/dh2FZQIFyRdN4HOmB4FYO5sEYFr9YjHLmDkrUgNodJC XCeMe4BO4iaxUQARAQABzRdtYXJrdXMucHJvYnN0QHBvc3Rlby5kZcLBkQQTAQgAOxYhBIJ0GMT0 rFjncjDEczR2H/jnrUPSBQJog714AhsDBQsJCAcCAiICBhUKCQgLAgQWAgMBAh4HAheAAAoJEDR2 H/jnrUPSgdkQAISaTk2D345ehXEkn5z2yUEjaVjHIE7ziqRaOgn/QanCgeTUinIv6L6QXUFvvIfH 1OLPwQ1hfvEg9NnNLyFezWSy6jvoVBTIPqicD/r3FkithnQ1IDkdSjrarPMxJkvuh3l7XZHo49GV HQ8i5zh5w4YISrcEtE99lJisvni2Jqx7we5tey9voQFDyM8jxlSWv3pmoUTCtBkX/eKHJXosgsuS B4TGDCVPOjla/emI5c9MhMG7O4WEEmoSdPbmraPw66YZD6uLyhV4DPHbiDWRzXWnClHSyjB9rky9 lausFxogvu4l9H+KDsXIadNDWdLdu1/enS/wDd9zh5S78rY2jeXaG4mnf4seEKamZ7KQ6FIHrcyP ezdDzssPQcTQcGRMQzCn6wP3tlGk7rsfmyHMlFqdRoNNv+ZER/OkmZFPW655zRfbMi0vtrqK2Awm 9ggobb1oktfd9PPNXMUY+DNVlgR2G7jLnenSoQausLUm0pHoNE8TWFv851Y6SOYnvn488sP1Tki5 F3rKwclawQFHUXTCQw+QSh9ay8xgnNZfH+u9NY7w3gPoeKBOAFcBc2BtzcgekeWS8qgEmm2/oNFV G0ivPQbRx8FjRKbuF7g3YhgNZZ0ac8FneuUtJ2PkSIFTZhaAiC0utvxk0ndmWFiW4acEkMZGrLaM L2zWNjrqwsD2zsFNBGiDvXgBEADCXQy1n7wjRxG12DOVADawjghKcG+5LtEf31WftHKLFbp/HArj BhkT6mj+CCI1ClqY+FYU5CK/s0ScMfLxRGLZ0Ktzawb78vOgBVFT3yB1yWBTewsAXdqNqRooaUNo 8cG/NNJLjhccH/7PO/FWX5qftOVUJ/AIsAhKQJ18Tc8Ik73v427EDxuKb9mTAnYQFA3Ev3hAiVbO 6Rv39amVOfJ8sqwiSUGidj2Fctg2aB5JbeMln0KCUbTD1LhEFepeKypfofAXQbGwaCjAhmkWy/q3 IT1mUrPxOngbxdRoOx1tGUC0HCMUW1sFaJgQPMmDcR0JGPOpgsKnitsSnN7ShcCr1buel7vLnUMD +TAZ5opdoF6HjAvAnBQaijtK6minkrM0seNXnCg0KkV8xhMNa6zCs1rq4GgjNLJue2EmuyHooHA4 7JMoLVHcxVeuNTp6K2+XRx0Pk4e2Lj8IVy9yEYyrywEOC5XRW37KJjsiOAsumi1rkvM7QREWgUDe Xs0+RpxI3QrrANh71fLMRo7LKRF3Gvw13NVCCC9ea20P4PwhgWKStkwO2NO+YJsAoS1QycMi/vKu 0EHhknYXamaSV50oZzHKmX56vEeJHTcngrM8R1SwJCYopCx9gkz90bTVYlitJa5hloWTYeMD7FNj Y6jfVSzgM/K4gMgUNDW/PPGeMwARAQABwsF2BBgBCAAgFiEEgnQYxPSsWOdyMMRzNHYf+OetQ9IF AmiDvXgCGwwACgkQNHYf+OetQ9LHDBAAhk+ab8+WrbS/b1/gYW3q1KDiXU719nCtfkUVXKidW5Ec Idlr5HGt8ilLoxSWT2Zi368iHCXS0WenGgPwlv8ifvB7TOZiiTDZROZkXjEBmU4nYjJ7GymawpWv oQwjMsPuq6ysbzWtOZ7eILx7cI0FjQeJ/Q2baRJub0uAZNwBOxCkAS6lpk5Fntd2u8CWmDQo4SYp xeuQ+pwkp0yEP30RhN2BO2DXiBEGSZSYh+ioGbCHQPIV3iVj0h6lcCPOqopZqyeCfigeacBI0nvN jHWz/spzF3+4OS+3RJvoHtAQmProxyGib8iVsTxgZO3UUi4TSODeEt0i0kHSPY4sCciOyXfAyYoD DFqhRjOEwBBxhr+scU4C1T2AflozvDwq3VSONjrKJUkhd8+WsdXxMdPFgBQuiKKwUy11mz6KQfcR wmDehF3UaUoxa+YIhWPbKmycxuX/D8SvnqavzAeAL1OcRbEI/HsoroVlEFbBRNBZLJUlnTPs8ZcU 4+8rq5YX1GUrJL3jf6SAfSgO7UdkEET3PdcKFYtS+ruV1Cp5V0q4kCfI5jk25iiz8grM2wOzVSsc l1mEkhiEPH87HP0whhb544iioSnumd3HJKL7dzhRegsMizatupp8D65A2JziW0WKopa1iw9fti3A aBeNN4ijKZchBXHPgVx+YtWRHfcm4l8= OpenPGP: url=https://posteo.de/keys/markus.probst@posteo.de.asc; preference=encrypt Content-Type: text/plain; charset="utf-8" Implement core Pin> abstractions, including * `Vec::pin` and `Vec::into_pin` for constructing a `Pin>`. If T does not implement `Unpin`, its values will never be moved. * an extension for `Pin>` allowing PinInit to be initialied on a Pin, as well as truncating and popping values from the Vec Signed-off-by: Markus Probst --- rust/kernel/alloc.rs | 1 + rust/kernel/alloc/kvec.rs | 86 +++++++++++++++++++++++++++++++++++++++ rust/kernel/prelude.rs | 2 +- 3 files changed, 88 insertions(+), 1 deletion(-) diff --git a/rust/kernel/alloc.rs b/rust/kernel/alloc.rs index a2c49e5494d3..d1a1200fc1bd 100644 --- a/rust/kernel/alloc.rs +++ b/rust/kernel/alloc.rs @@ -22,6 +22,7 @@ pub use self::kvec::IntoIter; pub use self::kvec::KVVec; pub use self::kvec::KVec; +pub use self::kvec::PinnedVecExt; pub use self::kvec::VVec; pub use self::kvec::Vec; =20 diff --git a/rust/kernel/alloc/kvec.rs b/rust/kernel/alloc/kvec.rs index 3c72e0bdddb8..d5582a7f17e9 100644 --- a/rust/kernel/alloc/kvec.rs +++ b/rust/kernel/alloc/kvec.rs @@ -16,11 +16,13 @@ ops::DerefMut, ops::Index, ops::IndexMut, + pin::Pin, ptr, ptr::NonNull, slice, slice::SliceIndex, }; +use pin_init::PinInit; =20 mod errors; pub use self::errors::{InsertError, PushError, RemoveError}; @@ -109,6 +111,21 @@ pub struct Vec { _p: PhantomData, } =20 +/// Extension for Pin> +pub trait PinnedVecExt { + /// Pin-initializes P and appends it to the back of the [`Vec`] instan= ce without reallocating. + fn push_pin_init>, P: PinInit>(&mut self, i= nit: P) -> Result<(), E>; + + /// Shortens the vector, setting the length to `len` and drops the rem= oved values. + /// If `len` is greater than or equal to the current length, this does= nothing. + /// + /// This has no effect on the capacity and will not allocate. + fn truncate(&mut self, len: usize); + + /// Removes the last element from a vector and drops it returning true= , or false if it is empty. + fn pop(&mut self) -> bool; +} + /// Type alias for [`Vec`] with a [`Kmalloc`] allocator. /// /// # Examples @@ -719,6 +736,18 @@ pub fn retain(&mut self, mut f: impl FnMut(&mut T) -> = bool) { } self.truncate(num_kept); } + + /// Constructs a new `Pin>`. + #[inline] + pub fn pin(capacity: usize, flags: Flags) -> Result, AllocEr= ror> { + Self::with_capacity(capacity, flags).map(Pin::::from) + } + + /// Convert a [`Vec`] to a [`Pin>`]. If `T` does not imp= lement + /// [`Unpin`], then its values will be pinned in memory and can't be m= oved. + pub fn into_pin(this: Self) -> Pin { + this.into() + } } =20 impl Vec { @@ -1294,6 +1323,63 @@ fn drop(&mut self) { } } =20 +impl PinnedVecExt for Pin> { + fn truncate(&mut self, len: usize) { + // SAFETY: truncate will not reallocate the Vec + // CAST: Pin is a transparent wrapper of Ptr + unsafe { &mut *core::ptr::from_mut(self).cast::>() }.tru= ncate(len); + } + + fn push_pin_init>, P: PinInit>(&mut self, i= nit: P) -> Result<(), E> { + // SAFETY: capacity, spare_capacity_mut and inc_len will not + // reallocate the Vec. + // CAST: Pin is a transparent wrapper of Ptr + let this =3D unsafe { &mut *core::ptr::from_mut(self).cast::>() }; + + if this.len() < this.capacity() { + let spare =3D this.spare_capacity_mut(); + // SAFETY: the length is less than the capacity, so `spare` is= non-empty. + unsafe { init.__pinned_init(spare.get_unchecked_mut(0).as_mut_= ptr())? }; + // SAFETY: We just initialised the first spare entry, so it is= safe to + // increase the length by 1. We also know that the new length = is <=3D capacity. + unsafe { this.inc_len(1) }; + Ok(()) + } else { + Err(E::from(PushError(init))) + } + } + + fn pop(&mut self) -> bool { + if self.is_empty() { + return false; + } + + // SAFETY: + // - We just checked that the length is at least one. + // - dec_len will not reallocate the Vec + // CAST: Pin is a transparent wrapper of Ptr + let ptr: *mut [T] =3D unsafe { (*core::ptr::from_mut(self).cast::<= Vec>()).dec_len(1) }; + + // SAFETY: the contract of `dec_len` guarantees that the elements = in `ptr` are + // valid elements whose ownership has been transferred to the call= er. + unsafe { ptr::drop_in_place(ptr) }; + true + } +} + +impl From> for Pin> { + /// Converts a `Vec` into a `Pin>`. If `T` does not im= plement [`Unpin`], then + /// every value in v will be pinned in memory and can't be moved. + /// + /// This moves `v` into `Pin` without moving any of the values of `v` = or allocating and copying + /// any memory. + fn from(v: Vec) -> Self { + // SAFETY: The values wrapped inside a `Pin>` cannot be = moved or replaced as long + // as `T` does not implement `Unpin`. + unsafe { Pin::new_unchecked(v) } + } +} + #[macros::kunit_tests(rust_kvec_kunit)] mod tests { use super::*; diff --git a/rust/kernel/prelude.rs b/rust/kernel/prelude.rs index 25fe97aafd02..7179e2ca2a14 100644 --- a/rust/kernel/prelude.rs +++ b/rust/kernel/prelude.rs @@ -19,7 +19,7 @@ c_ushort, c_void, }; =20 -pub use crate::alloc::{flags::*, Box, KBox, KVBox, KVVec, KVec, VBox, VVec= , Vec}; +pub use crate::alloc::{flags::*, Box, KBox, KVBox, KVVec, KVec, PinnedVecE= xt, VBox, VVec, Vec}; =20 #[doc(no_inline)] pub use macros::{export, kunit_tests, module, vtable}; --=20 2.49.1 From nobody Fri Dec 19 13:58:07 2025 Received: from mout02.posteo.de (mout02.posteo.de [185.67.36.66]) (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 D14D1295DB8 for ; Sun, 12 Oct 2025 14:52:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.67.36.66 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760280765; cv=none; b=QmpiVMg3CxZIdEydApEyzvx0Dl+ptDwdP9NEnDgeeK7J0jesrnFDCdUzRWnuE015LOnVcT3ge+vjqr+qcEMPDFhzJWhb+ztoOebXqBMdwaIPwzNIcqasD9zwvdSa7IdKMjaQVs6sQqTIUf8agYxoU3wiApdQjPI/KRT7YnnrY3E= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760280765; c=relaxed/simple; bh=YdHN5r/+EKTsdn+fJKO0bTn5CVGWrGLALlUo40+bBak=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=TpNUskfPzup/WP4yV3+Z6HjE9+D9HBnpA3QfvQiaaZMnTbGAVmYuzA6+X2O14BNgBOQSGxH8vhXZRhG0Xu9KL8cAVA7RezxiMmFtadCn81h2Wh45WQ3vQbHNqxYQiDRnVT7oyg8rqgsVoM8VyDHBl0sTrsvxVQ1tt/jrl5FdoIU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=posteo.de; spf=pass smtp.mailfrom=posteo.de; dkim=pass (2048-bit key) header.d=posteo.de header.i=@posteo.de header.b=kqS41wrr; arc=none smtp.client-ip=185.67.36.66 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=posteo.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=posteo.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=posteo.de header.i=@posteo.de header.b="kqS41wrr" Received: from submission (posteo.de [185.67.36.169]) by mout02.posteo.de (Postfix) with ESMTPS id 63696240106 for ; Sun, 12 Oct 2025 16:52:40 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=posteo.de; s=2017; t=1760280760; bh=DIBrnIvMai3B5LhGP+fRvFrlZAm7ijtSy83udKoO2fU=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version: Content-Transfer-Encoding:Autocrypt:OpenPGP:From; b=kqS41wrrc4rcC5xQQD+dK0FIw4o+LdnYCoH9aYx9uIjruohamCNys2rTtTmDGPfMX r/vaKj61JFxfLbokzXA4g8Pei2o7QxTztkJxrmL4t77Wkw2jO2JQTzx28I6JynCwJF iL/LJqflv45ceAMPEZdLHeWUy0DypZa3yDFWYugWEwuLE2OAIcxS5s42JXuKVVy0d+ 6urXGDPVnejBQOJ7zvNPOmWpr2sxL/BtUe9TD+NN4KKFMtaIyh25GumDLmJmq/LNT9 qacJzs1MEceyq80knFB8ioBkPvBH0sthkSU7XkBu33yD/HBAb94CaSQ1YyzEIAL2SK BuiUTLaojgYBg== Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 4cl3P20js0z6twb; Sun, 12 Oct 2025 16:52:38 +0200 (CEST) From: Markus Probst To: Danilo Krummrich , Miguel Ojeda , Alex Gaynor , Lee Jones , Pavel Machek Cc: Lorenzo Stoakes , Vlastimil Babka , "Liam R. Howlett" , Uladzislau Rezki , Boqun Feng , Gary Guo , bjorn3_gh@protonmail.com, Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross , Markus Probst , rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, linux-leds@vger.kernel.org Subject: [PATCH v4 2/2] rust: leds: add basic led classdev abstractions Date: Sun, 12 Oct 2025 14:52:39 +0000 Message-ID: <20251012145221.172116-3-markus.probst@posteo.de> In-Reply-To: <20251012145221.172116-1-markus.probst@posteo.de> References: <20251012145221.172116-1-markus.probst@posteo.de> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Autocrypt: addr=markus.probst@posteo.de; prefer-encrypt=mutual; keydata=xsFNBGiDvXgBEADAXUceKafpl46S35UmDh2wRvvx+UfZbcTjeQOlSwKP7YVJ4JOZrVs93qReNLkO WguIqPBxR9blQ4nyYrqSCV+MMw/3ifyXIm6Pw2YRUDg+WTEOjTixRCoWDgUj1nOsvJ9tVAm76Ww+ /pAnepVRafMID0rqEfD9oGv1YrfpeFJhyE2zUw3SyyNLIKWD6QeLRhKQRbSnsXhGLFBXCqt9k5JA RhgQof9zvztcCVlT5KVvuyfC4H+HzeGmu9201BVyihJwKdcKPq+n/aY5FUVxNTgtI9f8wIbmfAja oT1pjXSp+dszakA98fhONM98pOq723o/1ZGMZukyXFfsDGtA3BB79HoopHKujLGWAGskzClwTjRQ xBqxh/U/lL1pc+0xPWikTNCmtziCOvv0KA0arDOMQlyFvImzX6oGVgE4ksKQYbMZ3Ikw6L1Rv1J+ FvN0aNwOKgL2ztBRYscUGcQvA0Zo1fGCAn/BLEJvQYShWKeKqjyncVGoXFsz2AcuFKe1pwETSsN6 OZncjy32e4ktgs07cWBfx0v62b8md36jau+B6RVnnodaA8++oXl3FRwiEW8XfXWIjy4umIv93tb8 8ekYsfOfWkTSewZYXGoqe4RtK80ulMHb/dh2FZQIFyRdN4HOmB4FYO5sEYFr9YjHLmDkrUgNodJC XCeMe4BO4iaxUQARAQABzRdtYXJrdXMucHJvYnN0QHBvc3Rlby5kZcLBkQQTAQgAOxYhBIJ0GMT0 rFjncjDEczR2H/jnrUPSBQJog714AhsDBQsJCAcCAiICBhUKCQgLAgQWAgMBAh4HAheAAAoJEDR2 H/jnrUPSgdkQAISaTk2D345ehXEkn5z2yUEjaVjHIE7ziqRaOgn/QanCgeTUinIv6L6QXUFvvIfH 1OLPwQ1hfvEg9NnNLyFezWSy6jvoVBTIPqicD/r3FkithnQ1IDkdSjrarPMxJkvuh3l7XZHo49GV HQ8i5zh5w4YISrcEtE99lJisvni2Jqx7we5tey9voQFDyM8jxlSWv3pmoUTCtBkX/eKHJXosgsuS B4TGDCVPOjla/emI5c9MhMG7O4WEEmoSdPbmraPw66YZD6uLyhV4DPHbiDWRzXWnClHSyjB9rky9 lausFxogvu4l9H+KDsXIadNDWdLdu1/enS/wDd9zh5S78rY2jeXaG4mnf4seEKamZ7KQ6FIHrcyP ezdDzssPQcTQcGRMQzCn6wP3tlGk7rsfmyHMlFqdRoNNv+ZER/OkmZFPW655zRfbMi0vtrqK2Awm 9ggobb1oktfd9PPNXMUY+DNVlgR2G7jLnenSoQausLUm0pHoNE8TWFv851Y6SOYnvn488sP1Tki5 F3rKwclawQFHUXTCQw+QSh9ay8xgnNZfH+u9NY7w3gPoeKBOAFcBc2BtzcgekeWS8qgEmm2/oNFV G0ivPQbRx8FjRKbuF7g3YhgNZZ0ac8FneuUtJ2PkSIFTZhaAiC0utvxk0ndmWFiW4acEkMZGrLaM L2zWNjrqwsD2zsFNBGiDvXgBEADCXQy1n7wjRxG12DOVADawjghKcG+5LtEf31WftHKLFbp/HArj BhkT6mj+CCI1ClqY+FYU5CK/s0ScMfLxRGLZ0Ktzawb78vOgBVFT3yB1yWBTewsAXdqNqRooaUNo 8cG/NNJLjhccH/7PO/FWX5qftOVUJ/AIsAhKQJ18Tc8Ik73v427EDxuKb9mTAnYQFA3Ev3hAiVbO 6Rv39amVOfJ8sqwiSUGidj2Fctg2aB5JbeMln0KCUbTD1LhEFepeKypfofAXQbGwaCjAhmkWy/q3 IT1mUrPxOngbxdRoOx1tGUC0HCMUW1sFaJgQPMmDcR0JGPOpgsKnitsSnN7ShcCr1buel7vLnUMD +TAZ5opdoF6HjAvAnBQaijtK6minkrM0seNXnCg0KkV8xhMNa6zCs1rq4GgjNLJue2EmuyHooHA4 7JMoLVHcxVeuNTp6K2+XRx0Pk4e2Lj8IVy9yEYyrywEOC5XRW37KJjsiOAsumi1rkvM7QREWgUDe Xs0+RpxI3QrrANh71fLMRo7LKRF3Gvw13NVCCC9ea20P4PwhgWKStkwO2NO+YJsAoS1QycMi/vKu 0EHhknYXamaSV50oZzHKmX56vEeJHTcngrM8R1SwJCYopCx9gkz90bTVYlitJa5hloWTYeMD7FNj Y6jfVSzgM/K4gMgUNDW/PPGeMwARAQABwsF2BBgBCAAgFiEEgnQYxPSsWOdyMMRzNHYf+OetQ9IF AmiDvXgCGwwACgkQNHYf+OetQ9LHDBAAhk+ab8+WrbS/b1/gYW3q1KDiXU719nCtfkUVXKidW5Ec Idlr5HGt8ilLoxSWT2Zi368iHCXS0WenGgPwlv8ifvB7TOZiiTDZROZkXjEBmU4nYjJ7GymawpWv oQwjMsPuq6ysbzWtOZ7eILx7cI0FjQeJ/Q2baRJub0uAZNwBOxCkAS6lpk5Fntd2u8CWmDQo4SYp xeuQ+pwkp0yEP30RhN2BO2DXiBEGSZSYh+ioGbCHQPIV3iVj0h6lcCPOqopZqyeCfigeacBI0nvN jHWz/spzF3+4OS+3RJvoHtAQmProxyGib8iVsTxgZO3UUi4TSODeEt0i0kHSPY4sCciOyXfAyYoD DFqhRjOEwBBxhr+scU4C1T2AflozvDwq3VSONjrKJUkhd8+WsdXxMdPFgBQuiKKwUy11mz6KQfcR wmDehF3UaUoxa+YIhWPbKmycxuX/D8SvnqavzAeAL1OcRbEI/HsoroVlEFbBRNBZLJUlnTPs8ZcU 4+8rq5YX1GUrJL3jf6SAfSgO7UdkEET3PdcKFYtS+ruV1Cp5V0q4kCfI5jk25iiz8grM2wOzVSsc l1mEkhiEPH87HP0whhb544iioSnumd3HJKL7dzhRegsMizatupp8D65A2JziW0WKopa1iw9fti3A aBeNN4ijKZchBXHPgVx+YtWRHfcm4l8= OpenPGP: url=https://posteo.de/keys/markus.probst@posteo.de.asc; preference=encrypt Content-Type: text/plain; charset="utf-8" Implement the core abstractions needed for led class devices, including: * `led::LedOps` - the trait for handling leds, including `brightness_set`, `brightness_get` and `blink_set` * `led::InitData` - data set for the led class device * `led::Device` - a safe wrapper around `led_classdev` Signed-off-by: Markus Probst --- rust/kernel/led.rs | 333 +++++++++++++++++++++++++++++++++++++++++++++ rust/kernel/lib.rs | 1 + 2 files changed, 334 insertions(+) create mode 100644 rust/kernel/led.rs diff --git a/rust/kernel/led.rs b/rust/kernel/led.rs new file mode 100644 index 000000000000..4261c2f5a903 --- /dev/null +++ b/rust/kernel/led.rs @@ -0,0 +1,333 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Abstractions for the leds driver model. +//! +//! C header: [`include/linux/leds.h`](srctree/include/linux/leds.h) + +use core::{marker::PhantomData, pin::Pin, ptr::NonNull}; + +use pin_init::{pin_data, pinned_drop, PinInit}; + +use crate::{ + build_error, container_of, + device::{self, property::FwNode, Bound}, + devres::Devres, + error::{from_result, to_result, Error, Result, VTABLE_DEFAULT_ERROR}, + macros::vtable, + str::CStr, + try_pin_init, + types::{ARef, Opaque}, +}; + +/// The led class device representation. +/// +/// This structure represents the Rust abstraction for a C `struct led_cla= ssdev`. +#[pin_data(PinnedDrop)] +pub struct Device { + ops: T, + #[pin] + classdev: Opaque, +} + +/// The led init data representation. +/// +/// This structure represents the Rust abstraction for a C `struct led_ini= t_data`. +#[derive(Default)] +pub struct InitData<'a> { + fwnode: Option<&'a FwNode>, + default_label: Option<&'a CStr>, + devicename: Option<&'a CStr>, + devname_mandatory: bool, +} + +impl InitData<'static> { + /// Creates a new [`InitData`] + pub fn new() -> Self { + Self::default() + } +} + +impl<'a> InitData<'a> { + /// Sets the firmware node + pub fn fwnode<'b, 'c>(self, fwnode: &'b FwNode) -> InitData<'c> + where + 'a: 'c, + 'b: 'c, + { + InitData { + fwnode: Some(fwnode), + ..self + } + } + + /// Sets a default label + pub fn default_label<'b, 'c>(self, label: &'b CStr) -> InitData<'c> + where + 'a: 'c, + 'b: 'c, + { + InitData { + default_label: Some(label), + ..self + } + } + + /// Sets the device name + pub fn devicename<'b, 'c>(self, devicename: &'b CStr) -> InitData<'c> + where + 'a: 'c, + 'b: 'c, + { + InitData { + devicename: Some(devicename), + ..self + } + } + + /// Sets if a device name is mandatory + pub fn devicename_mandatory(self, mandatory: bool) -> Self { + Self { + devname_mandatory: mandatory, + + ..self + } + } +} + +/// Trait defining the operations for a LED driver. +/// +/// # Examples +/// +///``` +/// # use kernel::{c_str, led, device, devres::Devres, prelude::*, error::= Result, macros::vtable}; +/// # use core::pin::Pin; +/// +/// struct MyLedOps; +/// +/// +/// #[vtable] +/// impl led::LedOps for MyLedOps { +/// const BLOCKING: bool =3D false; +/// const MAX_BRIGHTNESS: u32 =3D 255; +/// +/// fn brightness_set(&self, _brightness: u32) -> Result<()> { +/// // Set the brightness for the led here +/// Ok(()) +/// } +/// } +/// +/// fn register_my_led( +/// parent: &device::Device, +/// ) -> Result>>>> { +/// KBox::pin_init(led::Device::new( +/// parent, +/// led::InitData::new() +/// .default_label(c_str!("my_led")), +/// MyLedOps, +/// ), GFP_KERNEL) +/// } +///``` +/// Led drivers must implement this trait in order to register and handle = a [`Device`]. +#[vtable] +pub trait LedOps: Send + 'static + Sized { + /// If set true, [`LedOps::brightness_set`] and [`LedOps::blink_set`] = must not sleep + /// and perform the operation immediately. + const BLOCKING: bool; + /// The max brightness level + const MAX_BRIGHTNESS: u32; + + /// Sets the brightness level. + /// + /// See also [`LedOps::BLOCKING`] + fn brightness_set(&self, brightness: u32) -> Result<()>; + + /// Gets the current brightness level. + fn brightness_get(&self) -> u32 { + build_error!(VTABLE_DEFAULT_ERROR) + } + + /// Activates hardware accelerated blinking. + /// + /// delays are in milliseconds. If both are zero, a sensible default s= hould be chosen. + /// The caller should adjust the timings in that case and if it can't = match the values + /// specified exactly. Setting the brightness to 0 will disable the ha= rdware accelerated + /// blinking. + /// + /// See also [`LedOps::BLOCKING`] + fn blink_set(&self, _delay_on: &mut usize, _delay_off: &mut usize) -> = Result<()> { + build_error!(VTABLE_DEFAULT_ERROR) + } +} + +// SAFETY: A `led::Device` can be unregistered from any thread. +unsafe impl Send for Device {} + +// SAFETY: `led::Device` can be shared among threads because all methods o= f `led::Device` +// are thread safe. +unsafe impl Sync for Device {} + +impl Device { + /// Registers a new led classdev. + /// + /// The [`Device`] will be unregistered on drop. + pub fn new<'a>( + parent: &'a device::Device, + init_data: InitData<'a>, + ops: T, + ) -> impl PinInit, Error> + 'a { + Devres::new( + parent, + try_pin_init!(Self { + ops, + classdev <- Opaque::try_ffi_init(|ptr: *mut bindings::led_= classdev| { + // SAFETY: `try_ffi_init` guarantees that `ptr` is val= id for write. + // `led_classdev` gets fully initialized in-place by + // `led_classdev_register_ext` including `mutex` and `= list_head`. + unsafe { ptr.write(bindings::led_classdev { + max_brightness: T::MAX_BRIGHTNESS, + brightness_set: T::BLOCKING + .then_some(Adapter::::brightness_set_callba= ck), + brightness_set_blocking: (!T::BLOCKING) + .then_some(Adapter::::brightness_set_blocki= ng_callback), + brightness_get: T::HAS_BRIGHTNESS_GET + .then_some(Adapter::::brightness_get_callba= ck), + blink_set: T::HAS_BLINK_SET + .then_some(Adapter::::blink_set_callback), + .. bindings::led_classdev::default() + }) }; + + let fwnode =3D init_data.fwnode.map(ARef::from); + + let mut init_data =3D bindings::led_init_data { + fwnode: fwnode.as_ref() + .map_or(core::ptr::null_mut(), |fwnode| fwnode= .as_raw()), + default_label: init_data.default_label + .map_or(core::ptr::null(),= CStr::as_char_ptr), + devicename: init_data.devicename + .map_or(core::ptr::null(), CStr::as_char_ptr), + devname_mandatory: init_data.devname_mandatory, + }; + + // SAFETY: + // - `parent.as_raw()` is guaranteed to be a pointer t= o a valid `device` + // or a null pointer. + // - `ptr` is guaranteed to be a pointer to an initial= ized `led_classdev`. + to_result(unsafe { + bindings::led_classdev_register_ext(parent.as_raw(= ), ptr, &mut init_data) + })?; + + core::mem::forget(fwnode); // keep the reference count= incremented + + Ok::<_, Error>(()) + }), + }), + ) + } + + /// # Safety + /// `led_cdev` must be a valid pointer to a `led_classdev` embedded wi= thin a + /// `led::Device`. + unsafe fn from_raw<'a>(led_cdev: *mut bindings::led_classdev) -> &'a S= elf { + // SAFETY: The function's contract guarantees that `led_cdev` poin= ts to a `led_classdev` + // field embedded within a valid `led::Device`. `container_of!` ca= n therefore + // safely calculate the address of the containing struct. + unsafe { &*container_of!(Opaque::cast_from(led_cdev), Self, classd= ev) } + } +} + +struct Adapter { + _p: PhantomData, +} + +impl Adapter { + /// # Safety + /// `led_cdev` must be a valid pointer to a `led_classdev` embedded wi= thin a + /// `led::Device`. + /// This function is called on setting the brightness of a led. + unsafe extern "C" fn brightness_set_callback( + led_cdev: *mut bindings::led_classdev, + brightness: u32, + ) { + // SAFETY: The function's contract guarantees that `led_cdev` is a= valid pointer to a + // `led_classdev` embedded within a `led::Device`. + let _ =3D unsafe { Device::::from_raw(led_cdev) } + .ops + .brightness_set(brightness); + } + + /// # Safety + /// `led_cdev` must be a valid pointer to a `led_classdev` embedded wi= thin a + /// `led::Device`. + /// This function is called on setting the brightness of a led immedia= tely. + unsafe extern "C" fn brightness_set_blocking_callback( + led_cdev: *mut bindings::led_classdev, + brightness: u32, + ) -> i32 { + from_result(|| { + // SAFETY: The function's contract guarantees that `led_cdev` = is a valid pointer to a + // `led_classdev` embedded within a `led::Device`. + unsafe { Device::::from_raw(led_cdev) } + .ops + .brightness_set(brightness)?; + Ok(0) + }) + } + + /// # Safety + /// `led_cdev` must be a valid pointer to a `led_classdev` embedded wi= thin a + /// `led::Device`. + /// This function is called on getting the brightness of a led. + unsafe extern "C" fn brightness_get_callback(led_cdev: *mut bindings::= led_classdev) -> u32 { + // SAFETY: The function's contract guarantees that `led_cdev` is a= valid pointer to a + // `led_classdev` embedded within a `led::Device`. + unsafe { Device::::from_raw(led_cdev) } + .ops + .brightness_get() + } + + /// # Safety + /// `led_cdev` must be a valid pointer to a `led_classdev` embedded wi= thin a + /// `led::Device`. + /// `delay_on` and `delay_off` must be valid pointers to `usize` and h= ave + /// exclusive access for the period of this function. + /// This function is called on enabling hardware accelerated blinking. + unsafe extern "C" fn blink_set_callback( + led_cdev: *mut bindings::led_classdev, + delay_on: *mut usize, + delay_off: *mut usize, + ) -> i32 { + from_result(|| { + // SAFETY: The function's contract guarantees that `led_cdev` = is a valid pointer to a + // `led_classdev` embedded within a `led::Device`. + unsafe { Device::::from_raw(led_cdev) }.ops.blink_set( + // SAFETY: The function's contract guarantees that `delay_= on` points to a `usize` + // and is exclusive for the period of this function. + unsafe { &mut *delay_on }, + // SAFETY: The function's contract guarantees that `delay_= off` points to a `usize` + // and is exclusive for the period of this function. + unsafe { &mut *delay_off }, + )?; + Ok(0) + }) + } +} + +#[pinned_drop] +impl PinnedDrop for Device { + fn drop(self: Pin<&mut Self>) { + let raw =3D self.classdev.get(); + // SAFETY: The existence of `self` guarantees that `self.classdev.= get()` is a pointer to a + // valid `struct led_classdev`. + let dev: &device::Device =3D unsafe { device::Device::from_raw((*r= aw).dev) }; + + let _fwnode =3D dev + .fwnode() + // SAFETY: the reference count of `fwnode` has previously been + // incremented in `led::Device::new`. + .map(|fwnode| unsafe { ARef::from_raw(NonNull::from(fwnode)) }= ); + + // SAFETY: The existence of `self` guarantees that `self.classdev`= has previously been + // successfully registered with `led_classdev_register_ext`. + unsafe { bindings::led_classdev_unregister(self.classdev.get()) }; + } +} diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs index e5247f584ad2..f42c60da21ae 100644 --- a/rust/kernel/lib.rs +++ b/rust/kernel/lib.rs @@ -97,6 +97,7 @@ pub mod jump_label; #[cfg(CONFIG_KUNIT)] pub mod kunit; +pub mod led; pub mod list; pub mod miscdevice; pub mod mm; --=20 2.49.1