From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from CWXP265CU010.outbound.protection.outlook.com (mail-ukwestazon11022117.outbound.protection.outlook.com [52.101.101.117]) (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 8398B3A9DA4; Mon, 9 Mar 2026 15:30:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=fail smtp.client-ip=52.101.101.117 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773070245; cv=fail; b=ud6xer3yZ1kSpLqJSHO5dWo2xEUoUMiLfQG8zv3A+CK54tq32a6F74V4nrEWScmuE0Hot4Huo0FZZsrIM3Q+7ZYirPzlQtY1Cp4Ag81ugrAv9ovWRizO/JQfRC+6kxgrtnW7i52SZFbhGTyk4JfW3gU51kdC/BPE0OLtAMbScDM= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773070245; c=relaxed/simple; bh=QdZcP/LACdbPOpM+dUSJJwxGovbRw1C+MGKwQSSYK80=; h=Content-Type:Date:Message-Id:Cc:Subject:From:To:References: In-Reply-To:MIME-Version; b=HIN/RWoKDK08gdgyBw4A5RnxEfEOiWW5hLK/EphVWn8xrY9VQN1578HrO6It7hsHnQ6lFcXPa9YZaX1bZ10vaN5i6wq+/sB0TpJJR3IS++nwoe0SIiWoqUUSuXX2j90s0gGIi/bIlXkxBmQcAK9ZONQORQnYMJeaumLZGCmFG1Y= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=garyguo.net; spf=pass smtp.mailfrom=garyguo.net; dkim=pass (1024-bit key) header.d=garyguo.net header.i=@garyguo.net header.b=Bnuw9RH1; arc=fail smtp.client-ip=52.101.101.117 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=garyguo.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=garyguo.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=garyguo.net header.i=@garyguo.net header.b="Bnuw9RH1" ARC-Seal: i=1; a=rsa-sha256; s=arcselector10001; d=microsoft.com; cv=none; b=Y6lQhjQqnwHpGnn1oE6Gb4rVUQNYgJmgPszKKcuVUgHdVvdZABK5czIUPvNg7zY9xFZNows7bBXFxOQvRXMZgCQPz4+hG5xFs0HciuBqfJQVE1EsBozjMXn/gmGnsz8r/43tvn+Y3vamIyDhhK50N1vczbnoUSkaO+W0VE3niR7igmwsmwi6IlZjol+EFAb1M0kgM/zDPZ+CeG8s4vETj234Ic+e2qfJS+tWSWDd/Nk3VzqFNIfgPbakFTjCbo4r9m9Cuc0PLnUFlMOQPbG3uPVlCPVS78c1QIbsk/xwU1xhriWm6U9H6QHddv6Oyz1toYSY5SpTsDgbqFp2sbkJOA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector10001; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=SIy1mXjsj6hAo67QR5V2mtkm7Tgn/z5/+9QzSrn3EMs=; b=AYp/IaweJZs49a5Kip32ELxDVBIROHi8ESt1I7G+k3hMjYmR4h/FlC63d0J3OzuQuCxFSZ3Au1he4tRny4rHIY5TxBYmJidRFnWTrzoYthweeYZXJnsokPy91t1sypRM5MbUisbdkAlar6r2O7Jcp/+G5TIKg3ANVMRE3PoFh/HlphwIfmJKPeWEByyVGWJa4yve76wDPcCdDke4MVcn9mujOnrdNN4H9q99pVbjfDXhrd9QvOIWqT2ylVVoi6bd8IyqB4y6Q3FQFtnToXwOxs2yeuulAwv2Xo4+2HwaxMEO8CTm6XxtFbsnsBPoZLlqOHmBLUHucHwnRgAHDXXZXA== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=garyguo.net; dmarc=pass action=none header.from=garyguo.net; dkim=pass header.d=garyguo.net; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=garyguo.net; s=selector1; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=SIy1mXjsj6hAo67QR5V2mtkm7Tgn/z5/+9QzSrn3EMs=; b=Bnuw9RH1FXc59jc4yN3aMx7QhmKvPPUyjrImTpyx0+/DfRC+UN0IUSf4phEORnlKPh9bF7fv2BFk+uLDs/hYMwO+lMmCYsDagdr4XiranH1c2semiF9UC6PWsj190MS9zZ9++jNP75x5DsVl+j1ei0A7ZceyUl81LNwoA7h4WQU= Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=garyguo.net; Received: from LOVP265MB8871.GBRP265.PROD.OUTLOOK.COM (2603:10a6:600:488::16) by LO4P265MB5931.GBRP265.PROD.OUTLOOK.COM (2603:10a6:600:29a::6) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.9678.25; Mon, 9 Mar 2026 15:30:40 +0000 Received: from LOVP265MB8871.GBRP265.PROD.OUTLOOK.COM ([fe80::1c3:ceba:21b4:9986]) by LOVP265MB8871.GBRP265.PROD.OUTLOOK.COM ([fe80::1c3:ceba:21b4:9986%5]) with mapi id 15.20.9678.024; Mon, 9 Mar 2026 15:30:39 +0000 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=UTF-8 Date: Mon, 09 Mar 2026 15:30:39 +0000 Message-Id: Cc: "Yury Norov" , "John Hubbard" , "Alistair Popple" , "Joel Fernandes" , "Timur Tabi" , "Edwin Peer" , "Eliot Courtney" , "Dirk Behme" , "Steven Price" , , Subject: Re: [PATCH v8 07/10] rust: io: introduce `IntoIoVal` trait and single-argument `write_val` From: "Gary Guo" To: "Alexandre Courbot" , "Danilo Krummrich" , "Alice Ryhl" , "Daniel Almeida" , "Miguel Ojeda" , "Gary Guo" , =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= , "Benno Lossin" , "Andreas Hindborg" , "Trevor Gross" , "Boqun Feng" X-Mailer: aerc 0.21.0 References: <20260310-register-v8-0-424f80dd43bc@nvidia.com> <20260310-register-v8-7-424f80dd43bc@nvidia.com> In-Reply-To: <20260310-register-v8-7-424f80dd43bc@nvidia.com> X-ClientProxiedBy: LO4P123CA0376.GBRP123.PROD.OUTLOOK.COM (2603:10a6:600:18e::21) To LOVP265MB8871.GBRP265.PROD.OUTLOOK.COM (2603:10a6:600:488::16) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: LOVP265MB8871:EE_|LO4P265MB5931:EE_ X-MS-Office365-Filtering-Correlation-Id: c2c0efa8-4ee8-43ce-a206-08de7df0d1c2 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|1800799024|10070799003|366016|376014|7416014|921020|7053199007; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:LOVP265MB8871.GBRP265.PROD.OUTLOOK.COM;PTR:;CAT:NONE;SFS:(13230040)(1800799024)(10070799003)(366016)(376014)(7416014)(921020)(7053199007);DIR:OUT;SFP:1102; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?RzRVRnR6clpSOXE0Um1hb0FOemF3bjV4Sm9LaHlaRVROOG14T2hickZnUUEw?= =?utf-8?B?b0NuL2tQWUFTOFFiYUFZeDlmdTZIeDFMUS8rSy94cXJETGxxZ3o4TWhGKzFT?= =?utf-8?B?bFRvQ2g4Q0QwMFpUZVhXaCtJM2wzNTFyOE8rMXoyN1ZxeXBWVkgyOE81blVz?= =?utf-8?B?Zkx4WGMxOWZEME1WbGZ3MllIQUNnS2ZLQVBTOUprOStKSEZYcGxtR3ZKa2sw?= =?utf-8?B?ZUkxZkFXbUNBV0R6K0VFQTdUamZKK1hzTEVuemF2MjFGc3NsYUJjOHo1U0RG?= =?utf-8?B?eGpNT3I2MEJYV2I5elpvK05KTjh2UExaazRIcnB1Z3Z0S25aWFR4Y2VLQUhp?= =?utf-8?B?SDRCNEN2WVpoSGN0WGpEcU50UW9DajdlbEM3cmw3MTlHRzlTV3J3VDZzYzlw?= =?utf-8?B?aUh3QnUrSTRjWUljcUNmTGR1Yy9aaXd4L3NkYXU5UDBTQktmRnlrNGc4YzZz?= =?utf-8?B?emc5ZGtZK1pITlVvYm9xTDFVZCtZOUlYcndpdUE3ZE05bFJpKzFFOVp4RFFk?= =?utf-8?B?OHlwVkNsUFVqdU5tcjdhM3JSZHlIWDQyZVN6emhBS1FmK2c4Yml1ejg4T0tu?= =?utf-8?B?NUlFY2VkSzJpd2RuR1grWUNuVFpqTG9kZUZkeFF2Q1htYW05aDZSRFgyL1Bx?= =?utf-8?B?MTlqVUJnQ1ljVDF2amdGamZhUFlSdUdGR2JQMDErV1E4NW43YmtQNzRZdUNx?= =?utf-8?B?dFFUbG9ROU01dmxkenFRQlhlMHNGcFdWQng5MlRFOUtKdW85NEppZk9Bd3N6?= =?utf-8?B?NkxWZ1dQK1h1UW1tYUQzVTIzTUtOSGhFb3BhcU90ZzVsODN4V2t6SHpwbytn?= =?utf-8?B?WGhaeUhmcUFQUkZDdjZnaWxOUkIwRjNZblBKOTZmekVSdFk4ZEl2VGllTmtJ?= =?utf-8?B?enhJYXlWZGpuVHlDMm1YVzV0RzZ1eWJCVFdScnRIa3FzVVRXWGgrckxTZzh3?= =?utf-8?B?VURqOFd0elNJbi9RK09OTzVBVXVRdXdTT2xJSi9vRGQwT0tPMkRrYUs3OXRq?= =?utf-8?B?dVNoaGhUcHdGdHFvSThwRnBGWDZBQ0RrNzRBT0NkN2gvUUFTaWplMDBuYlUw?= =?utf-8?B?eEpwL2JhOE9EY0h0a2ZxcjIwYWEyYUdVaEs2Kzl2YlFxTllWZzcyRzRGTTB1?= =?utf-8?B?eUlJYktaZnppYVhGdXh0L09oRFZGTm9xTll6Yyt0Y2tDZ21hamdFTDNJUkpy?= =?utf-8?B?UzV5NzZkSHl1M25mQWZWQzFVYnF0NERmNFNDUWp2bXNWVkhuZ29PclQ1SVZu?= =?utf-8?B?L0lqVmxqUXl5OVhXNGVMNWVCaWY5RzVtVjNBcE5ma1R1eW5WOUVRaEZQaU9o?= =?utf-8?B?emIyT0RaOTZ1NzVKanFtaVJ6TmRkaWFqeGxncmpORnBPYldaWFlaZlZYUFNn?= =?utf-8?B?V1FUQVVpQzBkbnRmOC9pUm1VbnlmV3d3ZXFOS3FQaGRJQWZmTnNNRmFUNjZZ?= =?utf-8?B?VUFOdm1Qb09lUUt3d0Z3SUFWUzZTOW5PQjgwY3RNdjQvUHNvZFZ4ekpvR0VZ?= =?utf-8?B?ZVhuVk9aWmRKQldHaFRLbHNzeFhOb0dUZ2xpcCs0cjdWN3NpS21qQ0krVE1h?= =?utf-8?B?azVINDVoS1dMNG5pNWRSbUF3M1QxSnFKQnVNelQ2T20wTzZ2aUVCTmozbkdJ?= =?utf-8?B?RWtCcXJVMmxmOGsyK2pTdUZhc2htR2NCOWFZQWlzVHc4N1ZSVkhvTFdZS29l?= =?utf-8?B?Z1UxTG1lTWs4elV6b3ZmeG0xcjNZSUtTdUVRQWVpa3pKTmFOZ0pLaTMyelRp?= =?utf-8?B?K09aUThKTmZabDVHSzVzOUE2enlYS2owV29LalBrRlNlbUZmODdWNGh5Y2NH?= =?utf-8?B?Q0RFLy82Wmdqbjh5OEhDMmZrc1hBalZDd1g1L3RPMmhnVG5heituTFBza0Ju?= =?utf-8?B?OEkzREN1WWhCZkpPSlVnK2gydWlpbHZEZ3ZhZXEvRWVXTnlFa1IvWFl3amE5?= =?utf-8?B?anRrZm5ndWpYalprSlhLY1dqWlJxcjBaYUpvWU9TR0s4SVdRRlpOOGVZREdj?= =?utf-8?B?UlExMEVIV0s3TUpmcUEzbVNEY0tvcHNBRVphVTk2MnBFYlJzWCtnUVFqUGNy?= =?utf-8?B?OHNvcldZTWtsUGNOODhYMU1HLytQSmVQWkNRekh6ZkU2WEcrNXhqUkRmMlZ4?= =?utf-8?B?amp5L3Ird0FqbEZrdEIzaEFXSTRuSldjdUltdTM1YXJRNk01ellJL0Z5M2RY?= =?utf-8?B?ZHNPMjVnYkNSbFl0YUY4MkY2cVY4TXBtNy96L2FRZm9sMFRxMjhVazE0Qjlv?= =?utf-8?B?bndQTTYzSmhOMTFJT3VKY0VCalVXL0FCZXlHNWNKT2pHMWZTeWVDQ1pwcFZ0?= =?utf-8?B?NWp4Rmo0amtEUzBRZWw2SHgzeEVGQThrZXVTOG1uRDVxeGpYN2RJQT09?= X-OriginatorOrg: garyguo.net X-MS-Exchange-CrossTenant-Network-Message-Id: c2c0efa8-4ee8-43ce-a206-08de7df0d1c2 X-MS-Exchange-CrossTenant-AuthSource: LOVP265MB8871.GBRP265.PROD.OUTLOOK.COM X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 09 Mar 2026 15:30:39.8901 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: bbc898ad-b10f-4e10-8552-d9377b823d45 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: +7rAskWtoXdEElNV9c4d6lm6op37RwEnq5HTd5dzy6iY5cnH9GUz/lYZwn9t811m2q4IWXXFWKkczLpoS7i1xw== X-MS-Exchange-Transport-CrossTenantHeadersStamped: LO4P265MB5931 On Mon Mar 9, 2026 at 3:14 PM GMT, Alexandre Courbot wrote: > Some I/O types, like fixed address registers, carry their location > alongside their values. For these types, the regular `Io::write` method > can lead into repeating the location information twice: once to provide > the location itself, another time to build the value. > > Add a new `Io::write_val` convenience method that takes a single > argument implementing `IntoIoVal`, a trait that decomposes implementors > into a `(location, value)` tuple. This allows write operations on fixed > offset registers to be done while specifying their name only once. > > Signed-off-by: Alexandre Courbot > --- > rust/kernel/io.rs | 68 +++++++++++++++++++++++++++++++++++++++++++++++++= ++++++ > 1 file changed, 68 insertions(+) > > diff --git a/rust/kernel/io.rs b/rust/kernel/io.rs > index ed6fab001a39..09a0fe06f201 100644 > --- a/rust/kernel/io.rs > +++ b/rust/kernel/io.rs > @@ -216,6 +216,22 @@ fn offset(&self) -> usize { > // Provide the ability to read any primitive type from a [`usize`]. > impl_usize_ioloc!(u8, u16, u32, u64); > =20 > +/// Trait implemented by items that contain both an I/O location and a v= alue to assign to it. > +/// > +/// Implementors can be used with [`Io::write_val`]. > +pub trait IntoIoVal> { Is this generics instead of associative types for some reason? If so, pleas= e mention it in the commit mesasge. > + /// Consumes `self` and returns a `(location, value)` tuple describi= ng a valid I/O write > + /// operation. > + fn into_io_val(self) -> (L, T); > +} > + > +/// `(location, value)` tuples can be used as [`IntoIoVal`]s. > +impl> IntoIoVal for (L, T) { Missing inline annotations. Best, Gary > + fn into_io_val(self) -> (L, T) { > + self > + } > +} > + > /// Types implementing this trait (e.g. MMIO BARs or PCI config regions) > /// can perform I/O operations on regions of memory. > /// > @@ -463,6 +479,32 @@ fn try_write(&self, location: L, value: T) -> = Result > Ok(()) > } > =20 > + /// Generic fallible write of value bearing its location, with runti= me bounds check. > + /// > + /// # Examples > + /// > + /// Tuples carrying a location and a value can be used with this met= hod: > + /// > + /// ```no_run > + /// use kernel::io::{Io, Mmio}; > + /// > + /// fn do_writes(io: &Mmio) -> Result { > + /// // 32-bit write of value `1` at address `0x10`. > + /// io.try_write_val((0x10, 1u32)) > + /// } > + /// ``` > + #[inline(always)] > + fn try_write_val(&self, value: V) -> Result > + where > + L: IoLoc, > + V: IntoIoVal, > + Self: IoCapable, > + { > + let (location, value) =3D value.into_io_val(); > + > + self.try_write(location, value) > + } > + > /// Generic fallible update with runtime bounds check. > /// > /// Caution: this does not perform any synchronization. Race conditi= ons can occur in case of > @@ -559,6 +601,32 @@ fn write(&self, location: L, value: T) > unsafe { self.io_write(io_value, address) } > } > =20 > + /// Generic infallible write of value bearing its location, with com= pile-time bounds check. > + /// > + /// # Examples > + /// > + /// Tuples carrying a location and a value can be used with this met= hod: > + /// > + /// ```no_run > + /// use kernel::io::{Io, Mmio}; > + /// > + /// fn do_writes(io: &Mmio) { > + /// // 32-bit write of value `1` at address `0x10`. > + /// io.write_val((0x10, 1u32)); > + /// } > + /// ``` > + #[inline(always)] > + fn write_val(&self, value: V) > + where > + L: IoLoc, > + V: IntoIoVal, > + Self: IoKnownSize + IoCapable, > + { > + let (location, value) =3D value.into_io_val(); > + > + self.write(location, value) > + } > + > /// Generic infallible update with compile-time bounds check. > /// > /// Caution: this does not perform any synchronization. Race conditi= ons can occur in case of