From mboxrd@z Thu Jan 1 00:00:00 1970 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 58F5E150997; Sun, 17 May 2026 00:03:40 +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=1778976220; cv=none; b=rm9LY0vQKZUTqF1mfGYaLMSVW1t0pzXQ2SlrmPlHgsn5eGuIbXTa7a1N2jIWkx+AJ2thhRdzSvDJdTV2VRDsr8iGsT/N10ZLUmEs8tdnxiGctHg65Pvmb/zRZcjH6fz9iCdWUZA9o1Wre5VLYdI9MkOsX1JuYZZ8h15DF2x/arI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778976220; c=relaxed/simple; bh=Zo6WE+DRYsAkoDwkuP/dDu+ogxcsNbqn59fzAOqKPF4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=tg4aIkPVaY0jsL1FBSa0PYAC6H1Zfu6xBNH7jNu+tpdmpk87fAP+OAKkf9+qdPv/ZLRn6nRxml7sEcPs9HEVHw6ZDb7FnsIJLYCc/9e1Scc9ho2yp5CJ95KmMvdyy6fMbwmMZ/S9PpZXWDVgeVDRvzCUWpe2gnVMzPkp9y5hRFk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=QB+5ABQt; 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="QB+5ABQt" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9697AC2BCC7; Sun, 17 May 2026 00:03:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778976220; bh=Zo6WE+DRYsAkoDwkuP/dDu+ogxcsNbqn59fzAOqKPF4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QB+5ABQtSyihh2Oqc5dx/d10Lxx8hzFyOj8XI5lpgDPCdDGwzZ5r9kkW794hE9WAk Av1ClfGNIOsn1co358RWpVd4/DIwMeDgWVFCZwXrzk0QLDJ+qG9OpnFH0dIwiotqmM AyVWnwZk3HvpSoOREMpkVD+ZfjNT4eiedtNHafuiUH7GHlfhs55JgBSXzcf1VMwaZD 6/HvI5C86HFvNSSayrV1vKqWTcPmorugnHhOPggnpkhGevGjuKbeB3mhD+07rA77yf HTsNPXMbqYpgSaAJNIWvNh1AGzL2om6PYX0hM3VcJUrkHNX1eVt9DE0V/bwWlWTdCJ kWSpZLvmX+iUQ== From: Danilo Krummrich To: gregkh@linuxfoundation.org, rafael@kernel.org, acourbot@nvidia.com, aliceryhl@google.com, david.m.ertman@intel.com, ira.weiny@intel.com, leon@kernel.org, viresh.kumar@linaro.org, m.wilczynski@samsung.com, ukleinek@kernel.org, bhelgaas@google.com, kwilczynski@kernel.org, abdiel.janulgue@gmail.com, robin.murphy@arm.com, markus.probst@posteo.de, ojeda@kernel.org, boqun@kernel.org, gary@garyguo.net, bjorn3_gh@protonmail.com, lossin@kernel.org, a.hindborg@kernel.org, tmgross@umich.edu, igor.korotin@linux.dev, daniel.almeida@collabora.com, pcolberg@redhat.com Cc: driver-core@lists.linux.dev, linux-kernel@vger.kernel.org, nova-gpu@lists.linux.dev, dri-devel@lists.freedesktop.org, linux-pm@vger.kernel.org, linux-pwm@vger.kernel.org, linux-pci@vger.kernel.org, rust-for-linux@vger.kernel.org, Danilo Krummrich Subject: [PATCH v3 14/27] rust: i2c: make Driver trait lifetime-parameterized Date: Sun, 17 May 2026 02:01:02 +0200 Message-ID: <20260517000149.3226762-15-dakr@kernel.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260517000149.3226762-1-dakr@kernel.org> References: <20260517000149.3226762-1-dakr@kernel.org> Precedence: bulk X-Mailing-List: driver-core@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Add a 'bound lifetime to the associated Data, changing type Data to type Data<'bound>. This allows the driver's bus device private data to capture the device / driver bound lifetime; device resources can be stored directly by reference rather than requiring Devres. The probe() and unbind() callbacks thus gain a 'bound lifetime parameter on the methods themselves; avoiding a global lifetime on the trait impl. Existing drivers set type Data<'bound> = Self, preserving the current behavior. Acked-by: Igor Korotin Signed-off-by: Danilo Krummrich --- rust/kernel/i2c.rs | 38 +++++++++++++++++++-------------- samples/rust/rust_driver_i2c.rs | 14 ++++++------ 2 files changed, 29 insertions(+), 23 deletions(-) diff --git a/rust/kernel/i2c.rs b/rust/kernel/i2c.rs index 5a4014f379d5..7b92d42a2b98 100644 --- a/rust/kernel/i2c.rs +++ b/rust/kernel/i2c.rs @@ -98,7 +98,7 @@ macro_rules! i2c_device_table { // - `DEVICE_DRIVER_OFFSET` is the correct byte offset to the embedded `struct device_driver`. unsafe impl driver::DriverLayout for Adapter { type DriverType = bindings::i2c_driver; - type DriverData<'bound> = T::Data; + type DriverData<'bound> = T::Data<'bound>; const DEVICE_DRIVER_OFFSET: usize = core::mem::offset_of!(Self::DriverType, driver); } @@ -177,7 +177,7 @@ extern "C" fn remove_callback(idev: *mut bindings::i2c_client) { // SAFETY: `remove_callback` is only ever called after a successful call to // `probe_callback`, hence it's guaranteed that `I2cClient::set_drvdata()` has been called // and stored a `Pin>`. - let data = unsafe { idev.as_ref().drvdata_borrow::() }; + let data = unsafe { idev.as_ref().drvdata_borrow::>() }; T::unbind(idev, data); } @@ -189,7 +189,7 @@ extern "C" fn shutdown_callback(idev: *mut bindings::i2c_client) { // SAFETY: `shutdown_callback` is only ever called after a successful call to // `probe_callback`, hence it's guaranteed that `Device::set_drvdata()` has been called // and stored a `Pin>`. - let data = unsafe { idev.as_ref().drvdata_borrow::() }; + let data = unsafe { idev.as_ref().drvdata_borrow::>() }; T::shutdown(idev, data); } @@ -294,19 +294,22 @@ macro_rules! module_i2c_driver { /// /// impl i2c::Driver for MyDriver { /// type IdInfo = (); -/// type Data = Self; +/// type Data<'bound> = Self; /// const I2C_ID_TABLE: Option> = Some(&I2C_TABLE); /// const OF_ID_TABLE: Option> = Some(&OF_TABLE); /// const ACPI_ID_TABLE: Option> = Some(&ACPI_TABLE); /// -/// fn probe( -/// _idev: &i2c::I2cClient, -/// _id_info: Option<&Self::IdInfo>, -/// ) -> impl PinInit { +/// fn probe<'bound>( +/// _idev: &'bound i2c::I2cClient, +/// _id_info: Option<&'bound Self::IdInfo>, +/// ) -> impl PinInit, Error> + 'bound { /// Err(ENODEV) /// } /// -/// fn shutdown(_idev: &i2c::I2cClient, this: Pin<&Self::Data>) { +/// fn shutdown<'bound>( +/// _idev: &'bound i2c::I2cClient, +/// this: Pin<&'bound Self::Data<'bound>>, +/// ) { /// } /// } ///``` @@ -320,7 +323,7 @@ pub trait Driver: Send { type IdInfo: 'static; /// The type of the driver's bus device private data. - type Data; + type Data<'bound>: 'bound; /// The table of device ids supported by the driver. const I2C_ID_TABLE: Option> = None; @@ -335,10 +338,10 @@ pub trait Driver: Send { /// /// Called when a new i2c client is added or discovered. /// Implementers should attempt to initialize the client here. - fn probe( - dev: &I2cClient, - id_info: Option<&Self::IdInfo>, - ) -> impl PinInit; + fn probe<'bound>( + dev: &'bound I2cClient, + id_info: Option<&'bound Self::IdInfo>, + ) -> impl PinInit, Error> + 'bound; /// I2C driver shutdown. /// @@ -351,7 +354,10 @@ fn probe( /// This callback is distinct from final resource cleanup, as the driver instance remains valid /// after it returns. Any deallocation or teardown of driver-owned resources should instead be /// handled in `Drop`. - fn shutdown(dev: &I2cClient, this: Pin<&Self::Data>) { + fn shutdown<'bound>( + dev: &'bound I2cClient, + this: Pin<&'bound Self::Data<'bound>>, + ) { let _ = (dev, this); } @@ -365,7 +371,7 @@ fn shutdown(dev: &I2cClient, this: Pin<&Self::Data>) { /// operations to gracefully tear down the device. /// /// Otherwise, release operations for driver resources should be performed in `Drop`. - fn unbind(dev: &I2cClient, this: Pin<&Self::Data>) { + fn unbind<'bound>(dev: &'bound I2cClient, this: Pin<&'bound Self::Data<'bound>>) { let _ = (dev, this); } } diff --git a/samples/rust/rust_driver_i2c.rs b/samples/rust/rust_driver_i2c.rs index 8269f1798611..6fa3b786d652 100644 --- a/samples/rust/rust_driver_i2c.rs +++ b/samples/rust/rust_driver_i2c.rs @@ -35,16 +35,16 @@ impl i2c::Driver for SampleDriver { type IdInfo = u32; - type Data = Self; + type Data<'bound> = Self; const ACPI_ID_TABLE: Option> = Some(&ACPI_TABLE); const I2C_ID_TABLE: Option> = Some(&I2C_TABLE); const OF_ID_TABLE: Option> = Some(&OF_TABLE); - fn probe( - idev: &i2c::I2cClient, - info: Option<&Self::IdInfo>, - ) -> impl PinInit { + fn probe<'bound>( + idev: &'bound i2c::I2cClient, + info: Option<&'bound Self::IdInfo>, + ) -> impl PinInit + 'bound { let dev = idev.as_ref(); dev_info!(dev, "Probe Rust I2C driver sample.\n"); @@ -56,11 +56,11 @@ fn probe( Ok(Self) } - fn shutdown(idev: &i2c::I2cClient, _this: Pin<&Self>) { + fn shutdown<'bound>(idev: &'bound i2c::I2cClient, _this: Pin<&'bound Self>) { dev_info!(idev.as_ref(), "Shutdown Rust I2C driver sample.\n"); } - fn unbind(idev: &i2c::I2cClient, _this: Pin<&Self>) { + fn unbind<'bound>(idev: &'bound i2c::I2cClient, _this: Pin<&'bound Self>) { dev_info!(idev.as_ref(), "Unbind Rust I2C driver sample.\n"); } } -- 2.54.0