From nobody Tue Apr 7 10:41:06 2026 Received: from mout01.posteo.de (mout01.posteo.de [185.67.36.65]) (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 252C83DEAFE for ; Fri, 13 Mar 2026 18:48:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.67.36.65 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773427703; cv=none; b=IjkvEKFG+kidCmlEsOrP+rEYO49UynjFXX6YPcsRc/nUcJyNFHYf76tTijPuOIBfjPVpk/GhWxu2xz0KLqjh5HdQStweXqgtW+FJjH7SJQ8yieyKt+Aq7ETntANWbK7O8dzt1+BbfgHtq/HVxuLxoVVa9KEYuZYHyMsurXHjA1U= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773427703; c=relaxed/simple; bh=HETHM3CRJWMhkQNDAYTp+649XpdPAf3ubTc2qfzj0Cs=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=mp4WWutX4O3YBX5gZ56PInq5uTN1hb8H4HYQeC8Qep7DbMf+ZS7n2mZBIEugAGln/AeP8Ne05TeGnaKLV/QI64ict/khgLKXQmg/N72CoFDYAJ6Z7rSjiKzuGMMczck1pKUhqqtoMJTiKyuDGKuZxSo3IyOQ9lTzDzFHS/LCKxo= 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=e2ZWafo2; arc=none smtp.client-ip=185.67.36.65 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="e2ZWafo2" Received: from submission (posteo.de [185.67.36.169]) by mout01.posteo.de (Postfix) with ESMTPS id AA43E24002A for ; Fri, 13 Mar 2026 19:48:19 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=posteo.de; s=2017; t=1773427699; bh=0HIyLWc8Vasx1rBXj32mNH8IGQOj/mWKDVlVBnQS8vM=; h=From:Date:Subject:MIME-Version:Content-Type: Content-Transfer-Encoding:Message-Id:To:Cc:Autocrypt:OpenPGP:From; b=e2ZWafo2Pvj4CX34JJcgU9mHlpqol3bQbVuu9RByUepWp90ySX16DYt2ZlEvwR/2C Zhn11vRj27e7Wr3L+sbIO3o8I8VVTDooCM3BIq9P2K4ggvsFz1rP+1mLV63Id+ADrR HNJ2JqhmUl2dQXYfcQ8DfeXc0n8OEFyKkOq+fAwvRH8FEXG47WKzMbRYIS/tj0hAFH 68Fl+j9/XYLXGpbkCzvHplZ+BXA9ZUuu5w+xynMFFpRzbpfabMyxj9Jt++82yXuSzv BEmAtMGFWDJ6B1+/qiVA7UavI8w7c9ISd1vKVomTgwushqSMoiNZ3jslfjIKduapYE HtQn6aTmTVX4w== Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 4fXYQl3j6gz9rxL; Fri, 13 Mar 2026 19:48:15 +0100 (CET) From: Markus Probst Date: Fri, 13 Mar 2026 18:48:18 +0000 Subject: [PATCH v3 1/7] rust: Add `parent_unchecked` function to `Device` 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: <20260313-synology_microp_initial-v3-1-16941debd8a0@posteo.de> References: <20260313-synology_microp_initial-v3-0-16941debd8a0@posteo.de> In-Reply-To: <20260313-synology_microp_initial-v3-0-16941debd8a0@posteo.de> To: Lee Jones , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Greg Kroah-Hartman , Miguel Ojeda , Boqun Feng , Gary Guo , =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross , Danilo Krummrich , "Rafael J. Wysocki" , Igor Korotin , Daniel Almeida , Bjorn Helgaas , =?utf-8?q?Krzysztof_Wilczy=C5=84ski?= , Pavel Machek , Len Brown , Robert Moore Cc: devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, rust-for-linux@vger.kernel.org, driver-core@lists.linux.dev, linux-pci@vger.kernel.org, linux-leds@vger.kernel.org, linux-acpi@vger.kernel.org, acpica-devel@lists.linux.dev, Markus Probst X-Developer-Signature: v=1; a=openpgp-sha256; l=2195; i=markus.probst@posteo.de; h=from:subject:message-id; bh=HETHM3CRJWMhkQNDAYTp+649XpdPAf3ubTc2qfzj0Cs=; b=owEBiQJ2/ZANAwAIATR2H/jnrUPSAcsmYgBptFve1jey1DHQR+iLdEcegT4zt+EXofZeyQBar DMTAft8ZZ2JAk8EAAEIADkWIQSCdBjE9KxY53IwxHM0dh/4561D0gUCabRb3hsUgAAAAAAEAA5t YW51MiwyLjUrMS4xMSwyLDIACgkQNHYf+OetQ9JF1RAAmS7t9ZWBEMCQuDDPFA22VFlAmFQIeNS mDLsjWxhvnx2UL77Q+f8EWcFHmOcwwfV2jNxgIoODbBGpIQKovu21jYI7/gc4tAUWUhif2W8rDW /uJ8ImJ0nnUz1ZbfBPv8592dIlCRtPZrWBiPxIaJgKoYdltHsMhJImk7xGi9HSMeQE/WiyBAe7X 8wM1GILbHEmAuzgq74MmG0UzYphrpVVhxyg9DI5RSSivIlZwNnHBHsiUK334OUTioh1F/pVws1V FU7zY6yajh/19I0zD+kEKNeulI/6yrOivM9tXVhLYzhuNgtf4hBdReJ82rPLM8hc5m3BINNCLNA CHfNXMPCLyYyg5Lsu11oM5MQcFnGvOhhInJXBMe+XR3+0jFKlqccCSLVA7PRD/TqbV4BfmIIfdo Sj72KU4b5pEjzaAAbIdOhXBGd7REdCuQYNlFvhkonNSnBRhIyVJ4j7rijSW63+8pacyg+ZeVhSa kt8gt10dO3o85FM0lpjGst+hX/U4ixV+Cu/ypQdiXiSGHyKaNWqH5MQGZ/5kiMv4DQiCDvhMC6E v/S8hqTlMFyfyUktflJ6ZTfNxhkGT8mYAvor31VUBwNS5wFn1HYgd4VN00VBTODZ08iLhcmsVQV gz3LkvEE9bnEYFNgJCMB8koQrSEN6rjZ9I0Qim0mc1DB0md+t5ks= X-Developer-Key: i=markus.probst@posteo.de; a=openpgp; fpr=827418C4F4AC58E77230C47334761FF8E7AD43D2 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 This allows mfd sub-devices to access the bus device of their parent. The existing safe `parent` function has been made public for consistency. Signed-off-by: Markus Probst --- rust/kernel/device.rs | 25 +++++++++++++++++++++++-- 1 file changed, 23 insertions(+), 2 deletions(-) diff --git a/rust/kernel/device.rs b/rust/kernel/device.rs index 94e0548e7687..a53fb8a388e8 100644 --- a/rust/kernel/device.rs +++ b/rust/kernel/device.rs @@ -340,8 +340,7 @@ pub(crate) fn as_raw(&self) -> *mut bindings::device { } =20 /// Returns a reference to the parent device, if any. - #[cfg_attr(not(CONFIG_AUXILIARY_BUS), expect(dead_code))] - pub(crate) fn parent(&self) -> Option<&Device> { + pub fn parent(&self) -> Option<&Device> { // SAFETY: // - By the type invariant `self.as_raw()` is always valid. // - The parent device is only ever set at device creation. @@ -358,6 +357,28 @@ pub(crate) fn parent(&self) -> Option<&Device> { } } =20 + /// Returns a reference to the parent device as bus device. + /// + /// # Safety + /// + /// Callers must ensure that the device has a parent, that is containe= d in `T`. + pub unsafe fn parent_unchecked>(&self) -> &T { + // SAFETY: + // - By the type invariant `self.as_raw()` is always valid. + // - The parent device is only ever set at device creation. + let parent_raw =3D unsafe { (*self.as_raw()).parent }; + + // SAFETY: + // - The safety requirements guarantee that the device has a paren= t, thus `parent_raw` + // must be a pointer to a valid `struct device`. + // - `parent_raw` is valid for the lifetime of `self`, since a `st= ruct device` holds a + // reference count of its parent. + let parent =3D unsafe { Device::from_raw(parent_raw) }; + + // SAFETY: The safety requirements guarantee that the parent devic= e is contained in `T`. + unsafe { T::from_device(parent) } + } + /// Convert a raw C `struct device` pointer to a `&'a Device`. /// /// # Safety --=20 2.52.0