From patchwork Tue Oct 22 21:31:38 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Danilo Krummrich X-Patchwork-Id: 13846169 X-Patchwork-Delegate: bhelgaas@google.com 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 12BD61CBEA6; Tue, 22 Oct 2024 21:32:36 +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=1729632757; cv=none; b=ILPtzPpBpeIpviZhZbi3rqeM/AhWxpG3TEa3ZPBKv28zd+N0waLYW0vyC3df9avNNIunOtetJLtJzylqqs09P/yRoOtr+WqkZ0oY8wQDi8YLkayM8JUFEwkXdiXcfTyUnUjqIQjUxNtGvdUCQV2/8Rc39V4Om0z9smVbvQeWcWQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729632757; c=relaxed/simple; bh=L71CeWkKcTgg8yRMExLlk2AGwztXkb1QDYXmPtLBCvQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=MrEfIgCPfRfGg+hwc2+cVQmhtBWSFKkE52POWwTn7aqQNj0y5n29B65bnb3Dd+YDfvLVsrLUdROWPBaGhtLLr0SJpgzzqly8ATxWv7BkAv3r7c5l3VhFKZ3DdUvZj5a9E6S+jbZnG3cOqgNTiLuSkABaTaqi4HolYII6dM1y7RE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=DxW0kewj; 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="DxW0kewj" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5E34DC4CEE3; Tue, 22 Oct 2024 21:32:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1729632756; bh=L71CeWkKcTgg8yRMExLlk2AGwztXkb1QDYXmPtLBCvQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DxW0kewjSPunvZASRyzymLysmqKhXVSiwQMZ/l8zdwRx2ib6ntkP+TYC/G/fcXOty wI7YXG0bzS35faS1Gqcgdiy17oZubE0zAjiQwGPUYuiyXbPV/0TZjQ5fGOQGXgIcsF kM53feURJvfi0/9rRcg9HlgzbyIc+LnsKU7fEBAbrwmER4obZxO9C7QK7bwIXdqWFi qAYXLSzmFdT/SgSQPoj40UZc4z+9k2J1KubnmmZdPtWeD0GY9GcACjnlJaBjfjbLfl cyBkh1TfEk5ZXwYsMCfzYjOyTL26Oo/oHtsyGfWyUfEsq6srKPAx0QOEp47fqyfMk3 H+4bcWr3QlEwg== From: Danilo Krummrich To: gregkh@linuxfoundation.org, rafael@kernel.org, bhelgaas@google.com, ojeda@kernel.org, alex.gaynor@gmail.com, boqun.feng@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com, benno.lossin@proton.me, tmgross@umich.edu, a.hindborg@samsung.com, aliceryhl@google.com, airlied@gmail.com, fujita.tomonori@gmail.com, lina@asahilina.net, pstanner@redhat.com, ajanulgu@redhat.com, lyude@redhat.com, robh@kernel.org, daniel.almeida@collabora.com, saravanak@google.com Cc: rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, devicetree@vger.kernel.org, Wedson Almeida Filho , Danilo Krummrich Subject: [PATCH v3 01/16] rust: init: introduce `Opaque::try_ffi_init` Date: Tue, 22 Oct 2024 23:31:38 +0200 Message-ID: <20241022213221.2383-2-dakr@kernel.org> X-Mailer: git-send-email 2.46.2 In-Reply-To: <20241022213221.2383-1-dakr@kernel.org> References: <20241022213221.2383-1-dakr@kernel.org> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Wedson Almeida Filho This is the same as `Opaque::ffi_init`, but returns a `Result`. This is used by subsequent patches to implement the FFI init of static driver structures on registration. Signed-off-by: Wedson Almeida Filho Signed-off-by: Danilo Krummrich --- rust/kernel/types.rs | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-) diff --git a/rust/kernel/types.rs b/rust/kernel/types.rs index ced143600eb1..236e8de5844b 100644 --- a/rust/kernel/types.rs +++ b/rust/kernel/types.rs @@ -239,14 +239,22 @@ pub const fn uninit() -> Self { /// uninitialized. Additionally, access to the inner `T` requires `unsafe`, so the caller needs /// to verify at that point that the inner value is valid. pub fn ffi_init(init_func: impl FnOnce(*mut T)) -> impl PinInit { + Self::try_ffi_init(move |slot| { + init_func(slot); + Ok(()) + }) + } + + /// Similar to [`Self::ffi_init`], except that the closure can fail. + /// + /// To avoid leaks on failure, the closure must drop any fields it has initialised before the + /// failure. + pub fn try_ffi_init( + init_func: impl FnOnce(*mut T) -> Result<(), E>, + ) -> impl PinInit { // SAFETY: We contain a `MaybeUninit`, so it is OK for the `init_func` to not fully // initialize the `T`. - unsafe { - init::pin_init_from_closure::<_, ::core::convert::Infallible>(move |slot| { - init_func(Self::raw_get(slot)); - Ok(()) - }) - } + unsafe { init::pin_init_from_closure(|slot| init_func(Self::raw_get(slot))) } } /// Returns a raw pointer to the opaque data. From patchwork Tue Oct 22 21:31:39 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Danilo Krummrich X-Patchwork-Id: 13846170 X-Patchwork-Delegate: bhelgaas@google.com 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 B0B0A1CCB31; Tue, 22 Oct 2024 21:32:42 +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=1729632762; cv=none; b=ssCjK1yIvEYzb0sZMIFRV97eWlDjnc1cO47FLqUjIhYwgZAWt5ga6zBdht1a5/PDmWcPBL8TYlR3ZbC0tPjKHpPmqr9/CQBXD2XI6fpE+a2JbLzydULYtcBJM1Boxz+PheW7QP7PkaQMIR3kGn7TfMaTH0lnYKF8tzoKzXv11PE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729632762; c=relaxed/simple; bh=upo39o0TQIUfHpAEP1eM1ZcDVF3KOz3s/hyBNkmOhW0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=VaGVeO2s8qmh918CKgpUvsz95zO9Idx8Kl873KUHZleue3+iFSaqVVE4UUNGKySU5hRFmeaGRcVA+Ul0NnM2VYTZGfjg6oJnRfobjdjxXuv/w7rX8uvSVyoRddS3QiRkWbwF3w4yohGJTaFd6sozQIdw+mI9tL59MLsGX5eY1yY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=t2J/uoJD; 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="t2J/uoJD" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 16DD6C4CEC7; Tue, 22 Oct 2024 21:32:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1729632762; bh=upo39o0TQIUfHpAEP1eM1ZcDVF3KOz3s/hyBNkmOhW0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=t2J/uoJDdDbhKKmHgaNSNYBwDDiFMryaAYLZPPFG4c0iUAaqzBjZzwv1RCld/GZ2H 3m11s68J/yhe4CHrWomGLlx8iEhzE7eUYq5Z5/4f/3F+8f9b/pYSIGLF3HpsAzs9Ia oP8UivU74DvEzGCyPp390Bu1S2Jj+7WYs+3zimby8GEMgVIJhUBRK8wOtpTOVIrWSb kP1AqADavHA20exqfK3hFgRluwzK7dREWt8GVBF7u4bndIRP5LMVSETWoTKdkdcChI Lc691muolL50JBvhjETw3P6fHG3A1N/aqhwDFLieXX/6gBLbyBr5wg6gbFb6RcQC8J 6bve+8WBiRRWg== From: Danilo Krummrich To: gregkh@linuxfoundation.org, rafael@kernel.org, bhelgaas@google.com, ojeda@kernel.org, alex.gaynor@gmail.com, boqun.feng@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com, benno.lossin@proton.me, tmgross@umich.edu, a.hindborg@samsung.com, aliceryhl@google.com, airlied@gmail.com, fujita.tomonori@gmail.com, lina@asahilina.net, pstanner@redhat.com, ajanulgu@redhat.com, lyude@redhat.com, robh@kernel.org, daniel.almeida@collabora.com, saravanak@google.com Cc: rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, devicetree@vger.kernel.org, Wedson Almeida Filho , Danilo Krummrich Subject: [PATCH v3 02/16] rust: introduce `InPlaceModule` Date: Tue, 22 Oct 2024 23:31:39 +0200 Message-ID: <20241022213221.2383-3-dakr@kernel.org> X-Mailer: git-send-email 2.46.2 In-Reply-To: <20241022213221.2383-1-dakr@kernel.org> References: <20241022213221.2383-1-dakr@kernel.org> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Wedson Almeida Filho This allows modules to be initialised in-place in pinned memory, which enables the usage of pinned types (e.g., mutexes, spinlocks, driver registrations, etc.) in modules without any extra allocations. Signed-off-by: Wedson Almeida Filho Signed-off-by: Danilo Krummrich Reviewed-by: Alice Ryhl Acked-by: Miguel Ojeda --- rust/kernel/lib.rs | 23 +++++++++++++++++++++++ rust/macros/module.rs | 28 ++++++++++++---------------- 2 files changed, 35 insertions(+), 16 deletions(-) diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs index b62451f64f6e..4fdb0d91f2ad 100644 --- a/rust/kernel/lib.rs +++ b/rust/kernel/lib.rs @@ -83,6 +83,29 @@ pub trait Module: Sized + Sync + Send { fn init(module: &'static ThisModule) -> error::Result; } +/// A module that is pinned and initialised in-place. +pub trait InPlaceModule: Sync + Send { + /// Creates an initialiser for the module. + /// + /// It is called when the module is loaded. + fn init(module: &'static ThisModule) -> impl init::PinInit; +} + +impl InPlaceModule for T { + fn init(module: &'static ThisModule) -> impl init::PinInit { + let initer = move |slot: *mut Self| { + let m = ::init(module)?; + + // SAFETY: `slot` is valid for write per the contract with `pin_init_from_closure`. + unsafe { slot.write(m) }; + Ok(()) + }; + + // SAFETY: On success, `initer` always fully initialises an instance of `Self`. + unsafe { init::pin_init_from_closure(initer) } + } +} + /// Equivalent to `THIS_MODULE` in the C API. /// /// C header: [`include/linux/init.h`](srctree/include/linux/init.h) diff --git a/rust/macros/module.rs b/rust/macros/module.rs index aef3b132f32b..a03266a78cfb 100644 --- a/rust/macros/module.rs +++ b/rust/macros/module.rs @@ -232,6 +232,7 @@ pub(crate) fn module(ts: TokenStream) -> TokenStream { mod __module_init {{ mod __module_init {{ use super::super::{type_}; + use kernel::init::PinInit; /// The \"Rust loadable module\" mark. // @@ -242,7 +243,8 @@ mod __module_init {{ #[used] static __IS_RUST_MODULE: () = (); - static mut __MOD: Option<{type_}> = None; + static mut __MOD: core::mem::MaybeUninit<{type_}> = + core::mem::MaybeUninit::uninit(); // Loadable modules need to export the `{{init,cleanup}}_module` identifiers. /// # Safety @@ -331,20 +333,14 @@ mod __module_init {{ /// /// This function must only be called once. unsafe fn __init() -> core::ffi::c_int {{ - match <{type_} as kernel::Module>::init(&super::super::THIS_MODULE) {{ - Ok(m) => {{ - // SAFETY: No data race, since `__MOD` can only be accessed by this - // module and there only `__init` and `__exit` access it. These - // functions are only called once and `__exit` cannot be called - // before or during `__init`. - unsafe {{ - __MOD = Some(m); - }} - return 0; - }} - Err(e) => {{ - return e.to_errno(); - }} + let initer = + <{type_} as kernel::InPlaceModule>::init(&super::super::THIS_MODULE); + // SAFETY: No data race, since `__MOD` can only be accessed by this module + // and there only `__init` and `__exit` access it. These functions are only + // called once and `__exit` cannot be called before or during `__init`. + match unsafe {{ initer.__pinned_init(__MOD.as_mut_ptr()) }} {{ + Ok(m) => 0, + Err(e) => e.to_errno(), }} }} @@ -359,7 +355,7 @@ unsafe fn __exit() {{ // called once and `__init` was already called. unsafe {{ // Invokes `drop()` on `__MOD`, which should be used for cleanup. - __MOD = None; + __MOD.assume_init_drop(); }} }} From patchwork Tue Oct 22 21:31:40 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Danilo Krummrich X-Patchwork-Id: 13846171 X-Patchwork-Delegate: bhelgaas@google.com 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 52BA31CDA04; Tue, 22 Oct 2024 21:32:48 +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=1729632768; cv=none; b=noK2osZ86lCUfHZhR+i5hmNNcKyYY1spSh2HM+6i1D8a2wvPy30kVKEY7+X20d8hRTXPRWlmjimsDYxCKan843t965rr+xjrArmd3+APBartw7PmujqRGHTtpXJVLUkYMo92F0fSUAO6u1mWOhrt96DTeVajzZrW7PFLD5gTLCY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729632768; c=relaxed/simple; bh=vBW0av7EC8pdFPFs1anS+QtqcIgaudmaxuc13fjq5aA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=oS/5j5LzO21Gsqr7+TPrvKml1neyR0RJ84HzrhcKl85yR9itmIK+YlbuEnqq73quQ3dRZ82lLdrnYVK4BSgk1zGL4ILEV8F2Xb+oz71EWtvd56Al76BPGE+zkct5xUPMjsPp3MuW3Xvzw7YNCmwpEijkOAwHSktixmc8LQYJieQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Bmvl3wC3; 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="Bmvl3wC3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C21A8C4CEE3; Tue, 22 Oct 2024 21:32:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1729632767; bh=vBW0av7EC8pdFPFs1anS+QtqcIgaudmaxuc13fjq5aA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Bmvl3wC3kXB+AIT+O17CFYh98qBKjfNFrAqXvAAif3sYk0IS1iKIGkIPDRizmHA3T 6FioJrJp0b1rBf+pq5B6/xsNnxLCBL7KuNjLVvEue6wQ0MjhtBc+lQQSus8/HnHBT6 PjsZk1UsjOcL0mlilO1sTP9o/i685DJJcvRaj0Uc7wUG0vKJiOaHVrEkvzPShaVBcq KrslVJvgIJk0H9g6mAinLSScn8UjpicWvwmr8lZIIwDYhYvH0IGwzqoPL/jGvIDV6l v6tCiVemtfxOWkQYlBOFX0weOIKGtY06zfmxRRYO0q0kChqqkXgv6NmvmvGcvgqCPG xtJGhe4UzxwsQ== From: Danilo Krummrich To: gregkh@linuxfoundation.org, rafael@kernel.org, bhelgaas@google.com, ojeda@kernel.org, alex.gaynor@gmail.com, boqun.feng@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com, benno.lossin@proton.me, tmgross@umich.edu, a.hindborg@samsung.com, aliceryhl@google.com, airlied@gmail.com, fujita.tomonori@gmail.com, lina@asahilina.net, pstanner@redhat.com, ajanulgu@redhat.com, lyude@redhat.com, robh@kernel.org, daniel.almeida@collabora.com, saravanak@google.com Cc: rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, devicetree@vger.kernel.org, Danilo Krummrich Subject: [PATCH v3 03/16] rust: pass module name to `Module::init` Date: Tue, 22 Oct 2024 23:31:40 +0200 Message-ID: <20241022213221.2383-4-dakr@kernel.org> X-Mailer: git-send-email 2.46.2 In-Reply-To: <20241022213221.2383-1-dakr@kernel.org> References: <20241022213221.2383-1-dakr@kernel.org> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In a subsequent patch we introduce the `Registration` abstraction used to register driver structures. Some subsystems require the module name on driver registration (e.g. PCI in __pci_register_driver()), hence pass the module name to `Module::init`. Signed-off-by: Danilo Krummrich --- drivers/block/rnull.rs | 2 +- rust/kernel/lib.rs | 14 ++++++++++---- rust/kernel/net/phy.rs | 2 +- rust/macros/module.rs | 6 ++++-- samples/rust/rust_minimal.rs | 2 +- samples/rust/rust_print.rs | 2 +- 6 files changed, 18 insertions(+), 10 deletions(-) diff --git a/drivers/block/rnull.rs b/drivers/block/rnull.rs index 5de7223beb4d..0e0e9ed7851e 100644 --- a/drivers/block/rnull.rs +++ b/drivers/block/rnull.rs @@ -36,7 +36,7 @@ struct NullBlkModule { } impl kernel::Module for NullBlkModule { - fn init(_module: &'static ThisModule) -> Result { + fn init(_name: &'static CStr, _module: &'static ThisModule) -> Result { pr_info!("Rust null_blk loaded\n"); let tagset = Arc::pin_init(TagSet::new(1, 256, 1), flags::GFP_KERNEL)?; diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs index 4fdb0d91f2ad..83f76dc7bad2 100644 --- a/rust/kernel/lib.rs +++ b/rust/kernel/lib.rs @@ -80,7 +80,7 @@ pub trait Module: Sized + Sync + Send { /// should do. /// /// Equivalent to the `module_init` macro in the C API. - fn init(module: &'static ThisModule) -> error::Result; + fn init(name: &'static str::CStr, module: &'static ThisModule) -> error::Result; } /// A module that is pinned and initialised in-place. @@ -88,13 +88,19 @@ pub trait InPlaceModule: Sync + Send { /// Creates an initialiser for the module. /// /// It is called when the module is loaded. - fn init(module: &'static ThisModule) -> impl init::PinInit; + fn init( + name: &'static str::CStr, + module: &'static ThisModule, + ) -> impl init::PinInit; } impl InPlaceModule for T { - fn init(module: &'static ThisModule) -> impl init::PinInit { + fn init( + name: &'static str::CStr, + module: &'static ThisModule, + ) -> impl init::PinInit { let initer = move |slot: *mut Self| { - let m = ::init(module)?; + let m = ::init(name, module)?; // SAFETY: `slot` is valid for write per the contract with `pin_init_from_closure`. unsafe { slot.write(m) }; diff --git a/rust/kernel/net/phy.rs b/rust/kernel/net/phy.rs index 910ce867480a..26631b0e127a 100644 --- a/rust/kernel/net/phy.rs +++ b/rust/kernel/net/phy.rs @@ -899,7 +899,7 @@ struct Module { [$($crate::net::phy::create_phy_driver::<$driver>()),+]; impl $crate::Module for Module { - fn init(module: &'static ThisModule) -> Result { + fn init(_name: &'static CStr, module: &'static ThisModule) -> Result { // SAFETY: The anonymous constant guarantees that nobody else can access // the `DRIVERS` static. The array is used only in the C side. let drivers = unsafe { &mut DRIVERS }; diff --git a/rust/macros/module.rs b/rust/macros/module.rs index a03266a78cfb..3292714ff82e 100644 --- a/rust/macros/module.rs +++ b/rust/macros/module.rs @@ -333,8 +333,10 @@ mod __module_init {{ /// /// This function must only be called once. unsafe fn __init() -> core::ffi::c_int {{ - let initer = - <{type_} as kernel::InPlaceModule>::init(&super::super::THIS_MODULE); + let initer = <{type_} as kernel::InPlaceModule>::init( + kernel::c_str!(\"{name}\"), + &super::super::THIS_MODULE + ); // SAFETY: No data race, since `__MOD` can only be accessed by this module // and there only `__init` and `__exit` access it. These functions are only // called once and `__exit` cannot be called before or during `__init`. diff --git a/samples/rust/rust_minimal.rs b/samples/rust/rust_minimal.rs index 4aaf117bf8e3..1577dc34e563 100644 --- a/samples/rust/rust_minimal.rs +++ b/samples/rust/rust_minimal.rs @@ -17,7 +17,7 @@ struct RustMinimal { } impl kernel::Module for RustMinimal { - fn init(_module: &'static ThisModule) -> Result { + fn init(_name: &'static CStr, _module: &'static ThisModule) -> Result { pr_info!("Rust minimal sample (init)\n"); pr_info!("Am I built-in? {}\n", !cfg!(MODULE)); diff --git a/samples/rust/rust_print.rs b/samples/rust/rust_print.rs index ba1606bdbd75..73763ea2dc09 100644 --- a/samples/rust/rust_print.rs +++ b/samples/rust/rust_print.rs @@ -41,7 +41,7 @@ fn arc_print() -> Result { } impl kernel::Module for RustPrint { - fn init(_module: &'static ThisModule) -> Result { + fn init(_name: &'static CStr, _module: &'static ThisModule) -> Result { pr_info!("Rust printing macros sample (init)\n"); pr_emerg!("Emergency message (level 0) without args\n"); From patchwork Tue Oct 22 21:31:41 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Danilo Krummrich X-Patchwork-Id: 13846172 X-Patchwork-Delegate: bhelgaas@google.com 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 B07F51CDA16; Tue, 22 Oct 2024 21:32:53 +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=1729632773; cv=none; b=HBlcesPox/35YMHefjNJAzyelqs3uN/ayYUn4Y/nlh/H8EMIXuJ9iqXtEhYO+6bKG/ARj+m/DhknKXzA2tUW41QsmCyoE2XzVVBNSeXZ4VrrfuERyrBDbAFiRVzBRJfA8bAHYFqMSO39XAf/9syja7paVFxaa+YDc7L5FM7s27s= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729632773; c=relaxed/simple; bh=Wcg5uOvd6OwKYJm21JYorr4CAYWRph8Sk4X/N1PKSrA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pENcpF+/IWscwNy5g7AJtiarI9OA6WwXbn8YY2MxSLcDiNMjGxtqbn2XnAA5T2z+6mYZmuAlMAPsIncWhYXqjb60nIsT6G1/7jDwi4SJSB/d7p9giQbLsJ5XI60ApUEJRClQJHS9LLyqrOpMThAKZFv4ZGZWzO8wUUTx92aX73U= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Dq6kYKkQ; 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="Dq6kYKkQ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 52FD3C4CECD; Tue, 22 Oct 2024 21:32:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1729632773; bh=Wcg5uOvd6OwKYJm21JYorr4CAYWRph8Sk4X/N1PKSrA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Dq6kYKkQ23T7jUlxRss0fQ7oxfu7MwGqPNEsogggg6KH10lQBo8GqSAKIi0WUijSo GrUb9JXrKioo49BO4r8SdMDOkuiCZJJdBfQqr1PAT+w7S/tOPRxbodFFfR1txTLJfH FpnkTWZosEXuOsfTGxDtymuP6znH+DD8UEj/yoVtmTFn0CoI1gIxa2qxhkmnYNxxIa VTZjfNyqScyeAdos/QYsP6bBaC6LI9RKi5oggg0DKn2OgmbMsbEluaLNNgaYyehPQ1 bI5w/uW/WpCUoasJnwQ2UPKe83DcyREkPba0TkLw+xfe39PaAV4BBUlknoVd2kLYLs e4Gt6ar3KWr2A== From: Danilo Krummrich To: gregkh@linuxfoundation.org, rafael@kernel.org, bhelgaas@google.com, ojeda@kernel.org, alex.gaynor@gmail.com, boqun.feng@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com, benno.lossin@proton.me, tmgross@umich.edu, a.hindborg@samsung.com, aliceryhl@google.com, airlied@gmail.com, fujita.tomonori@gmail.com, lina@asahilina.net, pstanner@redhat.com, ajanulgu@redhat.com, lyude@redhat.com, robh@kernel.org, daniel.almeida@collabora.com, saravanak@google.com Cc: rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, devicetree@vger.kernel.org, Danilo Krummrich , Wedson Almeida Filho Subject: [PATCH v3 04/16] rust: implement generic driver registration Date: Tue, 22 Oct 2024 23:31:41 +0200 Message-ID: <20241022213221.2383-5-dakr@kernel.org> X-Mailer: git-send-email 2.46.2 In-Reply-To: <20241022213221.2383-1-dakr@kernel.org> References: <20241022213221.2383-1-dakr@kernel.org> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Implement the generic `Registration` type and the `DriverOps` trait. The `Registration` structure is the common type that represents a driver registration and is typically bound to the lifetime of a module. However, it doesn't implement actual calls to the kernel's driver core to register drivers itself. Instead the `DriverOps` trait is provided to subsystems, which have to implement `DriverOps::register` and `DrvierOps::unregister`. Subsystems have to provide an implementation for both of those methods where the subsystem specific variants to register / unregister a driver have to implemented. For instance, the PCI subsystem would call __pci_register_driver() from `DriverOps::register` and pci_unregister_driver() from `DrvierOps::unregister`. Co-developed-by: Wedson Almeida Filho Signed-off-by: Wedson Almeida Filho Signed-off-by: Danilo Krummrich --- MAINTAINERS | 1 + rust/kernel/driver.rs | 120 ++++++++++++++++++++++++++++++++++++++++++ rust/kernel/lib.rs | 1 + 3 files changed, 122 insertions(+) create mode 100644 rust/kernel/driver.rs diff --git a/MAINTAINERS b/MAINTAINERS index b77f4495dcf4..29b9ecb63f81 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -6982,6 +6982,7 @@ F: include/linux/kobj* F: include/linux/property.h F: lib/kobj* F: rust/kernel/device.rs +F: rust/kernel/driver.rs DRIVERS FOR OMAP ADAPTIVE VOLTAGE SCALING (AVS) M: Nishanth Menon diff --git a/rust/kernel/driver.rs b/rust/kernel/driver.rs new file mode 100644 index 000000000000..c558f23c33d9 --- /dev/null +++ b/rust/kernel/driver.rs @@ -0,0 +1,120 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Generic support for drivers of different buses (e.g., PCI, Platform, Amba, etc.). +//! +//! Each bus / subsystem is expected to implement [`RegistrationOps`], which allows drivers to +//! register using the [`Registration`] class. + +use crate::error::{Error, Result}; +use crate::{init::PinInit, str::CStr, try_pin_init, types::Opaque, ThisModule}; +use core::pin::Pin; +use macros::{pin_data, pinned_drop}; + +/// The [`RegistrationOps`] trait serves as generic interface for subsystems (e.g., PCI, Platform, +/// Amba, etc.) to privide the corresponding subsystem specific implementation to register / +/// unregister a driver of the particular type (`RegType`). +/// +/// For instance, the PCI subsystem would set `RegType` to `bindings::pci_driver` and call +/// `bindings::__pci_register_driver` from `RegistrationOps::register` and +/// `bindings::pci_unregister_driver` from `RegistrationOps::unregister`. +pub trait RegistrationOps { + /// The type that holds information about the registration. This is typically a struct defined + /// by the C portion of the kernel. + type RegType: Default; + + /// Registers a driver. + /// + /// On success, `reg` must remain pinned and valid until the matching call to + /// [`RegistrationOps::unregister`]. + fn register( + reg: &mut Self::RegType, + name: &'static CStr, + module: &'static ThisModule, + ) -> Result; + + /// Unregisters a driver previously registered with [`RegistrationOps::register`]. + fn unregister(reg: &mut Self::RegType); +} + +/// A [`Registration`] is a generic type that represents the registration of some driver type (e.g. +/// `bindings::pci_driver`). Therefore a [`Registration`] must be initialized with a type that +/// implements the [`RegistrationOps`] trait, such that the generic `T::register` and +/// `T::unregister` calls result in the subsystem specific registration calls. +/// +///Once the `Registration` structure is dropped, the driver is unregistered. +#[pin_data(PinnedDrop)] +pub struct Registration { + #[pin] + reg: Opaque, +} + +// SAFETY: `Registration` has no fields or methods accessible via `&Registration`, so it is safe to +// share references to it with multiple threads as nothing can be done. +unsafe impl Sync for Registration {} + +// SAFETY: Both registration and unregistration are implemented in C and safe to be performed from +// any thread, so `Registration` is `Send`. +unsafe impl Send for Registration {} + +impl Registration { + /// Creates a new instance of the registration object. + pub fn new(name: &'static CStr, module: &'static ThisModule) -> impl PinInit { + try_pin_init!(Self { + reg <- Opaque::try_ffi_init(|ptr: *mut T::RegType| { + // SAFETY: `try_ffi_init` guarantees that `ptr` is valid for write. + unsafe { ptr.write(T::RegType::default()) }; + + // SAFETY: `try_ffi_init` guarantees that `ptr` is valid for write, and it has + // just been initialised above, so it's also valid for read. + let drv = unsafe { &mut *ptr }; + + T::register(drv, name, module) + }), + }) + } +} + +#[pinned_drop] +impl PinnedDrop for Registration { + fn drop(self: Pin<&mut Self>) { + // SAFETY: The existence of the `Registration` guarantees that `self.reg.get()` is properly + // aligned and points to a valid value. + let drv = unsafe { &mut *self.reg.get() }; + + T::unregister(drv); + } +} + +/// A kernel module that only registers the given driver on init. +/// +/// This is a helper struct to make it easier to define single-functionality modules, in this case, +/// modules that offer a single driver. +#[pin_data] +pub struct Module { + #[pin] + _driver: Registration, +} + +impl crate::InPlaceModule for Module { + fn init(name: &'static CStr, module: &'static ThisModule) -> impl PinInit { + try_pin_init!(Self { + _driver <- Registration::::new(name, module), + }) + } +} + +/// Declares a kernel module that exposes a single driver. +/// +/// It is meant to be used as a helper by other subsystems so they can more easily expose their own +/// macros. +#[macro_export] +macro_rules! module_driver { + (<$gen_type:ident>, $driver_ops:ty, { type: $type:ty, $($f:tt)* }) => { + type Ops<$gen_type> = $driver_ops; + type ModuleType = $crate::driver::Module>; + $crate::prelude::module! { + type: ModuleType, + $($f)* + } + } +} diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs index 83f76dc7bad2..f70f258fbcdc 100644 --- a/rust/kernel/lib.rs +++ b/rust/kernel/lib.rs @@ -32,6 +32,7 @@ pub mod block; mod build_assert; pub mod device; +pub mod driver; pub mod error; #[cfg(CONFIG_RUST_FW_LOADER_ABSTRACTIONS)] pub mod firmware; From patchwork Tue Oct 22 21:31:42 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Danilo Krummrich X-Patchwork-Id: 13846173 X-Patchwork-Delegate: bhelgaas@google.com 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 D26BE1CDA3B; Tue, 22 Oct 2024 21:32:59 +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=1729632779; cv=none; b=RVssj5N/Wd4hFbKia6QM4cKsXxrl75NPajHOWVZfdfmMN320QzmKGkeNadGM1hQMQmmv6ZQhpFJJs1Aw6Kqe+sEwUPtY8Q9oZeC9AHH+qf+Fyh02lHghkMlTiqm+SfVAbuLT3cmEuOVchM8eFA248ZYoDbcSYI/7DGT9hBJAuqI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729632779; c=relaxed/simple; bh=hjq/iCB5+fUiAunFy/htFdFhHyEss4Gd+rLypPG7Vo4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=nzTIsWhNBpX9oU7iZC1yD3GTRb20vTgQPw/JUvG9oSHoVgiv5IoDSXzFt+oIYZLJi4UgOF6TLKp5jSPD4kc8wzVt5f24B7HnsXSWS+gTvDHK/qoFHkEhVBtGg5Nl9uxyk0AhZeQsKazsDtUyekbZpWbWfKh0I73zI+uP3NcTMr4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=QoJzs8lC; 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="QoJzs8lC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0A562C4CEE3; Tue, 22 Oct 2024 21:32:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1729632779; bh=hjq/iCB5+fUiAunFy/htFdFhHyEss4Gd+rLypPG7Vo4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QoJzs8lCfqiYMfIsrq5xXPLobWoM8jPHFB4WCJS37GZokUklVTaGrBh6X7I60hUxu NPtj4KzFHKvh9bzBNMN2DYfo64jBVqU4Yz6EPKj56wTQ2AwtLG8PvjVXS8G6m56+Q+ hUIRmG0Ycg0wTI5w5mUCHN7HqXOgukReyu+rmDu2j6tGrqoTBsZaL5pssE0SIG80Tc 2S/OeB3TSyrQ6gpovNu1vkjQecJyJJydDw5dBV3/4pxE9TACHRed6/yX96wqIatEjW 4CTige9nxxGmMIpj2s4HSkaPhwKzhrvfa5AISj6Hd2AHhWjf+BoJO/b0iK8w60e7M1 M1/Srke1pd4jg== From: Danilo Krummrich To: gregkh@linuxfoundation.org, rafael@kernel.org, bhelgaas@google.com, ojeda@kernel.org, alex.gaynor@gmail.com, boqun.feng@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com, benno.lossin@proton.me, tmgross@umich.edu, a.hindborg@samsung.com, aliceryhl@google.com, airlied@gmail.com, fujita.tomonori@gmail.com, lina@asahilina.net, pstanner@redhat.com, ajanulgu@redhat.com, lyude@redhat.com, robh@kernel.org, daniel.almeida@collabora.com, saravanak@google.com Cc: rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, devicetree@vger.kernel.org, Danilo Krummrich , Wedson Almeida Filho , Fabien Parent Subject: [PATCH v3 05/16] rust: implement `IdArray`, `IdTable` and `RawDeviceId` Date: Tue, 22 Oct 2024 23:31:42 +0200 Message-ID: <20241022213221.2383-6-dakr@kernel.org> X-Mailer: git-send-email 2.46.2 In-Reply-To: <20241022213221.2383-1-dakr@kernel.org> References: <20241022213221.2383-1-dakr@kernel.org> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Most subsystems use some kind of ID to match devices and drivers. Hence, we have to provide Rust drivers an abstraction to register an ID table for the driver to match. Generally, those IDs are subsystem specific and hence need to be implemented by the corresponding subsystem. However, the `IdArray`, `IdTable` and `RawDeviceId` types provide a generalized implementation that makes the life of subsystems easier to do so. Co-developed-by: Wedson Almeida Filho Signed-off-by: Wedson Almeida Filho Co-developed-by: Gary Guo Signed-off-by: Gary Guo Co-developed-by: Fabien Parent Signed-off-by: Fabien Parent Signed-off-by: Danilo Krummrich --- MAINTAINERS | 1 + rust/kernel/device_id.rs | 162 +++++++++++++++++++++++++++++++++++++++ rust/kernel/lib.rs | 7 ++ 3 files changed, 170 insertions(+) create mode 100644 rust/kernel/device_id.rs diff --git a/MAINTAINERS b/MAINTAINERS index 29b9ecb63f81..0a8882252257 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -6982,6 +6982,7 @@ F: include/linux/kobj* F: include/linux/property.h F: lib/kobj* F: rust/kernel/device.rs +F: rust/kernel/device_id.rs F: rust/kernel/driver.rs DRIVERS FOR OMAP ADAPTIVE VOLTAGE SCALING (AVS) diff --git a/rust/kernel/device_id.rs b/rust/kernel/device_id.rs new file mode 100644 index 000000000000..5b1329fba528 --- /dev/null +++ b/rust/kernel/device_id.rs @@ -0,0 +1,162 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Generic implementation of device IDs. +//! +//! Each bus / subsystem that matches device and driver through a bus / subsystem specific ID is +//! expected to implement [`RawDeviceId`]. + +use core::mem::MaybeUninit; + +/// Marker trait to indicate a Rust device ID type represents a corresponding C device ID type. +/// +/// This is meant to be implemented by buses/subsystems so that they can use [`IdTable`] to +/// guarantee (at compile-time) zero-termination of device id tables provided by drivers. +/// +/// # Safety +/// +/// Implementers must ensure that: +/// - `Self` is layout-compatible with [`RawDeviceId::RawType`]; i.e. it's safe to transmute to +/// `RawDeviceId`. +/// +/// This requirement is needed so `IdArray::new` can convert `Self` to `RawType` when building +/// the ID table. +/// +/// Ideally, this should be achieved using a const function that does conversion instead of +/// transmute; however, const trait functions relies on `const_trait_impl` unstable feature, +/// which is broken/gone in Rust 1.73. +/// +/// - `DRIVER_DATA_OFFSET` is the offset of context/data field of the device ID (usually named +/// `driver_data`) of the device ID, the field is suitable sized to write a `usize` value. +/// +/// Similar to the previous requirement, the data should ideally be added during `Self` to +/// `RawType` conversion, but there's currently no way to do it when using traits in const. +pub unsafe trait RawDeviceId { + /// The raw type that holds the device id. + /// + /// Id tables created from [`Self`] are going to hold this type in its zero-terminated array. + type RawType: Copy; + + /// The offest to the context/data field. + const DRIVER_DATA_OFFSET: usize; + + /// The index stored at `DRIVER_DATA_OFFSET` of the implementor of the [`RawDeviceId`] trait. + fn index(&self) -> usize; +} + +/// A zero-terminated device id array. +#[repr(C)] +pub struct RawIdArray { + ids: [T::RawType; N], + sentinel: MaybeUninit, +} + +impl RawIdArray { + #[doc(hidden)] + pub const fn size(&self) -> usize { + core::mem::size_of::() + } +} + +/// A zero-terminated device id array, followed by context data. +#[repr(C)] +pub struct IdArray { + raw_ids: RawIdArray, + id_infos: [U; N], +} + +impl IdArray { + /// Creates a new instance of the array. + /// + /// The contents are derived from the given identifiers and context information. + pub const fn new(ids: [(T, U); N]) -> Self { + let mut raw_ids = [const { MaybeUninit::::uninit() }; N]; + let mut infos = [const { MaybeUninit::uninit() }; N]; + + let mut i = 0usize; + while i < N { + // SAFETY: by the safety requirement of `RawDeviceId`, we're guaranteed that `T` is + // layout-wise compatible with `RawType`. + raw_ids[i] = unsafe { core::mem::transmute_copy(&ids[i].0) }; + // SAFETY: by the safety requirement of `RawDeviceId`, this would be effectively + // `raw_ids[i].driver_data = i;`. + unsafe { + raw_ids[i] + .as_mut_ptr() + .byte_offset(T::DRIVER_DATA_OFFSET as _) + .cast::() + .write(i); + } + + // SAFETY: this is effectively a move: `infos[i] = ids[i].1`. We make a copy here but + // later forget `ids`. + infos[i] = MaybeUninit::new(unsafe { core::ptr::read(&ids[i].1) }); + i += 1; + } + + core::mem::forget(ids); + + Self { + raw_ids: RawIdArray { + // SAFETY: this is effectively `array_assume_init`, which is unstable, so we use + // `transmute_copy` instead. We have initialized all elements of `raw_ids` so this + // `array_assume_init` is safe. + ids: unsafe { core::mem::transmute_copy(&raw_ids) }, + sentinel: MaybeUninit::zeroed(), + }, + // SAFETY: We have initialized all elements of `infos` so this `array_assume_init` is + // safe. + id_infos: unsafe { core::mem::transmute_copy(&infos) }, + } + } + + /// Reference to the contained [`RawIdArray`]. + pub const fn raw_ids(&self) -> &RawIdArray { + &self.raw_ids + } +} + +/// A device id table. +/// +/// This trait is only implemented by `IdArray`. +/// +/// The purpose of this trait is to allow `&'static dyn IdArray` to be in context when `N` in +/// `IdArray` doesn't matter. +pub trait IdTable { + /// Obtain the pointer to the ID table. + fn as_ptr(&self) -> *const T::RawType; + + /// Obtain the pointer to the bus specific device ID from an index. + fn id(&self, index: usize) -> &T::RawType; + + /// Obtain the pointer to the driver-specific information from an index. + fn info(&self, index: usize) -> &U; +} + +impl IdTable for IdArray { + fn as_ptr(&self) -> *const T::RawType { + // This cannot be `self.ids.as_ptr()`, as the return pointer must have correct provenance + // to access the sentinel. + (self as *const Self).cast() + } + + fn id(&self, index: usize) -> &T::RawType { + &self.raw_ids.ids[index] + } + + fn info(&self, index: usize) -> &U { + &self.id_infos[index] + } +} + +/// Create device table alias for modpost. +#[macro_export] +macro_rules! module_device_table { + ($table_type: literal, $module_table_name:ident, $table_name:ident) => { + #[rustfmt::skip] + #[export_name = + concat!("__mod_", $table_type, "__", stringify!($table_name), "_device_table") + ] + static $module_table_name: [core::mem::MaybeUninit; $table_name.raw_ids().size()] = + unsafe { core::mem::transmute_copy($table_name.raw_ids()) }; + }; +} diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs index f70f258fbcdc..89f6bd2efcc0 100644 --- a/rust/kernel/lib.rs +++ b/rust/kernel/lib.rs @@ -14,10 +14,16 @@ #![no_std] #![feature(arbitrary_self_types)] #![feature(coerce_unsized)] +#![feature(const_refs_to_cell)] #![feature(dispatch_from_dyn)] #![feature(inline_const)] #![feature(lint_reasons)] #![feature(unsize)] +#![allow(stable_features)] +// Stable in Rust 1.83 +#![feature(const_mut_refs)] +#![feature(const_ptr_write)] +#![feature(const_maybe_uninit_as_mut_ptr)] // Ensure conditional compilation based on the kernel configuration works; // otherwise we may silently break things like initcall handling. @@ -32,6 +38,7 @@ pub mod block; mod build_assert; pub mod device; +pub mod device_id; pub mod driver; pub mod error; #[cfg(CONFIG_RUST_FW_LOADER_ABSTRACTIONS)] From patchwork Tue Oct 22 21:31:43 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Danilo Krummrich X-Patchwork-Id: 13846174 X-Patchwork-Delegate: bhelgaas@google.com 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 9E4CC1CC144; Tue, 22 Oct 2024 21:33:05 +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=1729632785; cv=none; b=RcX7CQ1T9cU/GE3H3Y47U65QPoWWdaONn12muBQkGerZjGo+Dez9U9xkPPyLgFj9As0U2LCdf8YOyX8AZS0vs4DY0Cm0lC7fWoBK5qgccyXzqM/C5Teuov1zoPy7uoV964NrULkfOMX3V/sWipZrEiaYQd9fVkZT6P28xkpVb7g= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729632785; c=relaxed/simple; bh=Noe35AjzbyfXRcjkYKVDR0W06ecTf78zYPGz7+D0E1s=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Pwyt88Ps80x5XlQFfO5IyJ/kA/wGyDnINX8xInHYQ0ATm2hWhLjXhWomZeCAyC0Nm/jLJnQ2smW3qPbnY+Yth3uncbmVKjTUfR0LkuvMXLffsM8/u0+zcqoxmtD/izAMb4R/w/kcgExw2I+tTdHhAPME+gXaeq48HYlK46njJ4A= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=mqr1DSmU; 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="mqr1DSmU" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E28B0C4CEC3; Tue, 22 Oct 2024 21:32:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1729632785; bh=Noe35AjzbyfXRcjkYKVDR0W06ecTf78zYPGz7+D0E1s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mqr1DSmUdTNhts/5YZyeQ9TYBo7V4UHbDjOAzKDQbubGiTEesY0Q5qsnyMQt/aq17 Ne0CR/z/I66/PClKt7DFvDr8bb2xsMI0zyktDzPtolMYo3yGsL4WjGnbhbyIYqMUR8 rOkvM4E+7AHHDZx0JSUSg6ppAn2gu74mJG8XU5ncWGME9ij0PrgCmjCYn+tlaanCnV IRnnvFSw/YIjLvHWepkQHUqoIes9wlQPiFGcsKETDqFjuabLWlY/LFI1G5mZqU0uzR YDNpoT4k1U/FYxPY3n9jkPqgPy52QHwK6IlgroUueefdP/v7he0mzBK+3XWo8rKyYE QSC2KRxF7UWHA== From: Danilo Krummrich To: gregkh@linuxfoundation.org, rafael@kernel.org, bhelgaas@google.com, ojeda@kernel.org, alex.gaynor@gmail.com, boqun.feng@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com, benno.lossin@proton.me, tmgross@umich.edu, a.hindborg@samsung.com, aliceryhl@google.com, airlied@gmail.com, fujita.tomonori@gmail.com, lina@asahilina.net, pstanner@redhat.com, ajanulgu@redhat.com, lyude@redhat.com, robh@kernel.org, daniel.almeida@collabora.com, saravanak@google.com Cc: rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, devicetree@vger.kernel.org, Wedson Almeida Filho , Danilo Krummrich Subject: [PATCH v3 06/16] rust: add rcu abstraction Date: Tue, 22 Oct 2024 23:31:43 +0200 Message-ID: <20241022213221.2383-7-dakr@kernel.org> X-Mailer: git-send-email 2.46.2 In-Reply-To: <20241022213221.2383-1-dakr@kernel.org> References: <20241022213221.2383-1-dakr@kernel.org> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Wedson Almeida Filho Add a simple abstraction to guard critical code sections with an rcu read lock. Signed-off-by: Wedson Almeida Filho Signed-off-by: Danilo Krummrich Reviewed-by: Alice Ryhl --- rust/helpers/helpers.c | 1 + rust/helpers/rcu.c | 13 +++++++++++ rust/kernel/sync.rs | 1 + rust/kernel/sync/rcu.rs | 52 +++++++++++++++++++++++++++++++++++++++++ 4 files changed, 67 insertions(+) create mode 100644 rust/helpers/rcu.c create mode 100644 rust/kernel/sync/rcu.rs diff --git a/rust/helpers/helpers.c b/rust/helpers/helpers.c index 20a0c69d5cc7..0720debccdd4 100644 --- a/rust/helpers/helpers.c +++ b/rust/helpers/helpers.c @@ -16,6 +16,7 @@ #include "mutex.c" #include "page.c" #include "rbtree.c" +#include "rcu.c" #include "refcount.c" #include "signal.c" #include "slab.c" diff --git a/rust/helpers/rcu.c b/rust/helpers/rcu.c new file mode 100644 index 000000000000..f1cec6583513 --- /dev/null +++ b/rust/helpers/rcu.c @@ -0,0 +1,13 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include + +void rust_helper_rcu_read_lock(void) +{ + rcu_read_lock(); +} + +void rust_helper_rcu_read_unlock(void) +{ + rcu_read_unlock(); +} diff --git a/rust/kernel/sync.rs b/rust/kernel/sync.rs index 0ab20975a3b5..1806767359fe 100644 --- a/rust/kernel/sync.rs +++ b/rust/kernel/sync.rs @@ -11,6 +11,7 @@ mod condvar; pub mod lock; mod locked_by; +pub mod rcu; pub use arc::{Arc, ArcBorrow, UniqueArc}; pub use condvar::{new_condvar, CondVar, CondVarTimeoutResult}; diff --git a/rust/kernel/sync/rcu.rs b/rust/kernel/sync/rcu.rs new file mode 100644 index 000000000000..5a35495f69a4 --- /dev/null +++ b/rust/kernel/sync/rcu.rs @@ -0,0 +1,52 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! RCU support. +//! +//! C header: [`include/linux/rcupdate.h`](srctree/include/linux/rcupdate.h) + +use crate::bindings; +use core::marker::PhantomData; + +/// Evidence that the RCU read side lock is held on the current thread/CPU. +/// +/// The type is explicitly not `Send` because this property is per-thread/CPU. +/// +/// # Invariants +/// +/// The RCU read side lock is actually held while instances of this guard exist. +pub struct Guard { + _not_send: PhantomData<*mut ()>, +} + +impl Guard { + /// Acquires the RCU read side lock and returns a guard. + pub fn new() -> Self { + // SAFETY: An FFI call with no additional requirements. + unsafe { bindings::rcu_read_lock() }; + // INVARIANT: The RCU read side lock was just acquired above. + Self { + _not_send: PhantomData, + } + } + + /// Explicitly releases the RCU read side lock. + pub fn unlock(self) {} +} + +impl Default for Guard { + fn default() -> Self { + Self::new() + } +} + +impl Drop for Guard { + fn drop(&mut self) { + // SAFETY: By the type invariants, the rcu read side is locked, so it is ok to unlock it. + unsafe { bindings::rcu_read_unlock() }; + } +} + +/// Acquires the RCU read side lock. +pub fn read_lock() -> Guard { + Guard::new() +} From patchwork Tue Oct 22 21:31:44 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Danilo Krummrich X-Patchwork-Id: 13846175 X-Patchwork-Delegate: bhelgaas@google.com 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 0EEFF1CC144; Tue, 22 Oct 2024 21:33:11 +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=1729632791; cv=none; b=Hyg8/E4ZVUoL+Aw+Xa5xJYOCQgYCPyU5Ou6TIjYiVnWe9MQodC5BRpAy+eIBQ17L1YcNzasGNRhHkelBZBCkP6g1pe3u68xwlmAUJUNiEanaoadQE1a58xUDiIEeRDsOd3BPDCysiQiolRk7+TcvTkpfuxr93FTjvM71tW4nPcQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729632791; c=relaxed/simple; bh=bGH8O0NiH1QvhCfKfneUV89UzatADxWvRdUc0lklgCs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=QtM1JFAqeuQ9YzLn1+s6rybR9+y6TfwmnELojwzYr7JuwxImaNFgcgaZ8NRVQz+kqxY17HCEO98wclg2O/8hs3v71nmUbg1ID5R6jyKwRnwGgriE1cFCQ5eYTn408A78TvY0IqNYqT6xlZKyxvDBSQKHl6T/7NQGC5sFrKuiP7Q= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=uJKCwVMg; 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="uJKCwVMg" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9E41EC4CEC7; Tue, 22 Oct 2024 21:33:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1729632790; bh=bGH8O0NiH1QvhCfKfneUV89UzatADxWvRdUc0lklgCs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uJKCwVMgacQWx8Kq1VbIdfjZgbRcDomK1HOv4rcF0lcP40ws1B1/ybBidmjYbGfya BsYViZ2binhXL34I3nAfDbo8XJstKBlEqadLtaq88p4qrMV0wfxN+9nmm51YGekOpr 4xiVClXPuZi2+7I82rEjYe1Jg+44aXFsP+l83iWuYkS3fI3qanepfWnSV7SLmtfN9Y TlvP2h0EagqueyE66PA0ndobC6taOvmZdueHkgZ5St0F/Prfrd+UhZUOH1IY+FeIKm chOFfUJkbVn7a+PqXj5ar2uQ3ruF4OGfKI7VX+lDAeoNdlbKTYzcnvjs7uboPMYVpr ofyFQaBPiUbcw== From: Danilo Krummrich To: gregkh@linuxfoundation.org, rafael@kernel.org, bhelgaas@google.com, ojeda@kernel.org, alex.gaynor@gmail.com, boqun.feng@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com, benno.lossin@proton.me, tmgross@umich.edu, a.hindborg@samsung.com, aliceryhl@google.com, airlied@gmail.com, fujita.tomonori@gmail.com, lina@asahilina.net, pstanner@redhat.com, ajanulgu@redhat.com, lyude@redhat.com, robh@kernel.org, daniel.almeida@collabora.com, saravanak@google.com Cc: rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, devicetree@vger.kernel.org, Wedson Almeida Filho , Danilo Krummrich Subject: [PATCH v3 07/16] rust: add `Revocable` type Date: Tue, 22 Oct 2024 23:31:44 +0200 Message-ID: <20241022213221.2383-8-dakr@kernel.org> X-Mailer: git-send-email 2.46.2 In-Reply-To: <20241022213221.2383-1-dakr@kernel.org> References: <20241022213221.2383-1-dakr@kernel.org> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Wedson Almeida Filho Revocable allows access to objects to be safely revoked at run time. This is useful, for example, for resources allocated during device probe; when the device is removed, the driver should stop accessing the device resources even if another state is kept in memory due to existing references (i.e., device context data is ref-counted and has a non-zero refcount after removal of the device). Signed-off-by: Wedson Almeida Filho Signed-off-by: Danilo Krummrich --- rust/kernel/lib.rs | 1 + rust/kernel/revocable.rs | 211 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 212 insertions(+) create mode 100644 rust/kernel/revocable.rs diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs index 89f6bd2efcc0..b603b67dcd71 100644 --- a/rust/kernel/lib.rs +++ b/rust/kernel/lib.rs @@ -54,6 +54,7 @@ pub mod prelude; pub mod print; pub mod rbtree; +pub mod revocable; pub mod sizes; mod static_assert; #[doc(hidden)] diff --git a/rust/kernel/revocable.rs b/rust/kernel/revocable.rs new file mode 100644 index 000000000000..83455558d795 --- /dev/null +++ b/rust/kernel/revocable.rs @@ -0,0 +1,211 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Revocable objects. +//! +//! The [`Revocable`] type wraps other types and allows access to them to be revoked. The existence +//! of a [`RevocableGuard`] ensures that objects remain valid. + +use crate::{ + bindings, + init::{self}, + prelude::*, + sync::rcu, +}; +use core::{ + cell::UnsafeCell, + marker::PhantomData, + mem::MaybeUninit, + ops::Deref, + ptr::drop_in_place, + sync::atomic::{AtomicBool, Ordering}, +}; + +/// An object that can become inaccessible at runtime. +/// +/// Once access is revoked and all concurrent users complete (i.e., all existing instances of +/// [`RevocableGuard`] are dropped), the wrapped object is also dropped. +/// +/// # Examples +/// +/// ``` +/// # use kernel::revocable::Revocable; +/// +/// struct Example { +/// a: u32, +/// b: u32, +/// } +/// +/// fn add_two(v: &Revocable) -> Option { +/// let guard = v.try_access()?; +/// Some(guard.a + guard.b) +/// } +/// +/// let v = KBox::pin_init(Revocable::new(Example { a: 10, b: 20 }), GFP_KERNEL).unwrap(); +/// assert_eq!(add_two(&v), Some(30)); +/// v.revoke(); +/// assert_eq!(add_two(&v), None); +/// ``` +/// +/// Sample example as above, but explicitly using the rcu read side lock. +/// +/// ``` +/// # use kernel::revocable::Revocable; +/// use kernel::sync::rcu; +/// +/// struct Example { +/// a: u32, +/// b: u32, +/// } +/// +/// fn add_two(v: &Revocable) -> Option { +/// let guard = rcu::read_lock(); +/// let e = v.try_access_with_guard(&guard)?; +/// Some(e.a + e.b) +/// } +/// +/// let v = KBox::pin_init(Revocable::new(Example { a: 10, b: 20 }), GFP_KERNEL).unwrap(); +/// assert_eq!(add_two(&v), Some(30)); +/// v.revoke(); +/// assert_eq!(add_two(&v), None); +/// ``` +#[pin_data(PinnedDrop)] +pub struct Revocable { + is_available: AtomicBool, + #[pin] + data: MaybeUninit>, +} + +// SAFETY: `Revocable` is `Send` if the wrapped object is also `Send`. This is because while the +// functionality exposed by `Revocable` can be accessed from any thread/CPU, it is possible that +// this isn't supported by the wrapped object. +unsafe impl Send for Revocable {} + +// SAFETY: `Revocable` is `Sync` if the wrapped object is both `Send` and `Sync`. We require `Send` +// from the wrapped object as well because of `Revocable::revoke`, which can trigger the `Drop` +// implementation of the wrapped object from an arbitrary thread. +unsafe impl Sync for Revocable {} + +impl Revocable { + /// Creates a new revocable instance of the given data. + pub fn new(data: impl PinInit) -> impl PinInit { + pin_init!(Self { + is_available: AtomicBool::new(true), + // SAFETY: The closure only returns `Ok(())` if `slot` is fully initialized; on error + // `slot` is not partially initialized and does not need to be dropped. + data <- unsafe { + init::pin_init_from_closure(move |slot: *mut MaybeUninit>| { + init::PinInit::::__pinned_init(data, + slot as *mut T)?; + Ok::<(), core::convert::Infallible>(()) + }) + }, + }) + } + + /// Tries to access the \[revocable\] wrapped object. + /// + /// Returns `None` if the object has been revoked and is therefore no longer accessible. + /// + /// Returns a guard that gives access to the object otherwise; the object is guaranteed to + /// remain accessible while the guard is alive. In such cases, callers are not allowed to sleep + /// because another CPU may be waiting to complete the revocation of this object. + pub fn try_access(&self) -> Option> { + let guard = rcu::read_lock(); + if self.is_available.load(Ordering::Relaxed) { + // SAFETY: Since `self.is_available` is true, data is initialised and has to remain + // valid because the RCU read side lock prevents it from being dropped. + Some(unsafe { RevocableGuard::new(self.data.assume_init_ref().get(), guard) }) + } else { + None + } + } + + /// Tries to access the \[revocable\] wrapped object. + /// + /// Returns `None` if the object has been revoked and is therefore no longer accessible. + /// + /// Returns a shared reference to the object otherwise; the object is guaranteed to + /// remain accessible while the rcu read side guard is alive. In such cases, callers are not + /// allowed to sleep because another CPU may be waiting to complete the revocation of this + /// object. + pub fn try_access_with_guard<'a>(&'a self, _guard: &'a rcu::Guard) -> Option<&'a T> { + if self.is_available.load(Ordering::Relaxed) { + // SAFETY: Since `self.is_available` is true, data is initialised and has to remain + // valid because the RCU read side lock prevents it from being dropped. + Some(unsafe { &*self.data.assume_init_ref().get() }) + } else { + None + } + } + + /// Revokes access to and drops the wrapped object. + /// + /// Access to the object is revoked immediately to new callers of [`Revocable::try_access`]. If + /// there are concurrent users of the object (i.e., ones that called [`Revocable::try_access`] + /// beforehand and still haven't dropped the returned guard), this function waits for the + /// concurrent access to complete before dropping the wrapped object. + pub fn revoke(&self) { + if self + .is_available + .compare_exchange(true, false, Ordering::Relaxed, Ordering::Relaxed) + .is_ok() + { + // SAFETY: Just an FFI call, there are no further requirements. + unsafe { bindings::synchronize_rcu() }; + + // SAFETY: We know `self.data` is valid because only one CPU can succeed the + // `compare_exchange` above that takes `is_available` from `true` to `false`. + unsafe { drop_in_place(self.data.assume_init_ref().get()) }; + } + } +} + +#[pinned_drop] +impl PinnedDrop for Revocable { + fn drop(self: Pin<&mut Self>) { + // Drop only if the data hasn't been revoked yet (in which case it has already been + // dropped). + // SAFETY: We are not moving out of `p`, only dropping in place + let p = unsafe { self.get_unchecked_mut() }; + if *p.is_available.get_mut() { + // SAFETY: We know `self.data` is valid because no other CPU has changed + // `is_available` to `false` yet, and no other CPU can do it anymore because this CPU + // holds the only reference (mutable) to `self` now. + unsafe { drop_in_place(p.data.assume_init_ref().get()) }; + } + } +} + +/// A guard that allows access to a revocable object and keeps it alive. +/// +/// CPUs may not sleep while holding on to [`RevocableGuard`] because it's in atomic context +/// holding the RCU read-side lock. +/// +/// # Invariants +/// +/// The RCU read-side lock is held while the guard is alive. +pub struct RevocableGuard<'a, T> { + data_ref: *const T, + _rcu_guard: rcu::Guard, + _p: PhantomData<&'a ()>, +} + +impl RevocableGuard<'_, T> { + fn new(data_ref: *const T, rcu_guard: rcu::Guard) -> Self { + Self { + data_ref, + _rcu_guard: rcu_guard, + _p: PhantomData, + } + } +} + +impl Deref for RevocableGuard<'_, T> { + type Target = T; + + fn deref(&self) -> &Self::Target { + // SAFETY: By the type invariants, we hold the rcu read-side lock, so the object is + // guaranteed to remain valid. + unsafe { &*self.data_ref } + } +} From patchwork Tue Oct 22 21:31:45 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Danilo Krummrich X-Patchwork-Id: 13846176 X-Patchwork-Delegate: bhelgaas@google.com 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 E79851CCEED; Tue, 22 Oct 2024 21:33:16 +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=1729632797; cv=none; b=XoaMs1me2vMWItvpT7bNtFqKkpb2LUBjKoPG5K+KlZQtfmcrjCTX6Gy9lhaA2olCG7lGRIWcK/ejxn9qhiAvUsDc9sbS8BL6YrKDXyUuRRhKYowWIvhrMEs6sYkVT66cJuadwQNqavUHcR8hiNtjtQDHC9k7jNFCPRskniuO/W8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729632797; c=relaxed/simple; bh=zMwd+PwXLeh2FtxkkTa0m0kTjUL8WGaTf3+bCzOAhaY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Qui0m90y7PBA+Z6wtahUKhGLcWirgukbVwaVDNmd3vi3oIKN+ehmsr92Xd7JgJmnqzoyVpgdb35JxBs+tqagKwfpDZj6131VnOKUi1AizeyzbTwbvFwl7lhpmBYm4LCoZj0AePB48F+n1YEuhRhHH7itiUjor/x0f0CWaCaouX4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=qYM0PmzN; 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="qYM0PmzN" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5DF91C4CEE3; Tue, 22 Oct 2024 21:33:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1729632796; bh=zMwd+PwXLeh2FtxkkTa0m0kTjUL8WGaTf3+bCzOAhaY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qYM0PmzNGtHxSwPG76pIEclci8X6cIJ7yYG4burJUSUgvAW/HrQ+GWDkZLKMYQveQ 11Eao0BZHiNGi3qzyY0Z+82l49iJCO9dY85INwFrqRrtpLYytY3n68r6boP/wDlp1H UFknV/mlULP7SBwvsIPE75xzDxEQikg5rXV5TOzJd9nSkA3Y+pTgm2yPy3bTW2T4xm nfZX1addpdC6TR0Xzgz7d0lhi5YR88jfb2pF82vVN/g6j0svre7eNHN1BOF5VCZa29 3KD85a/RVEW7XJPhpmO8tMnHAqn0P/fgrZMzmMCf6LRVU0LzEionPkJFySaHKCl2rl P6rQv4KdRyl2g== From: Danilo Krummrich To: gregkh@linuxfoundation.org, rafael@kernel.org, bhelgaas@google.com, ojeda@kernel.org, alex.gaynor@gmail.com, boqun.feng@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com, benno.lossin@proton.me, tmgross@umich.edu, a.hindborg@samsung.com, aliceryhl@google.com, airlied@gmail.com, fujita.tomonori@gmail.com, lina@asahilina.net, pstanner@redhat.com, ajanulgu@redhat.com, lyude@redhat.com, robh@kernel.org, daniel.almeida@collabora.com, saravanak@google.com Cc: rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, devicetree@vger.kernel.org, Wedson Almeida Filho , Danilo Krummrich Subject: [PATCH v3 08/16] rust: add `dev_*` print macros. Date: Tue, 22 Oct 2024 23:31:45 +0200 Message-ID: <20241022213221.2383-9-dakr@kernel.org> X-Mailer: git-send-email 2.46.2 In-Reply-To: <20241022213221.2383-1-dakr@kernel.org> References: <20241022213221.2383-1-dakr@kernel.org> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Wedson Almeida Filho Implement `dev_*` print macros for `device::Device`. They behave like the macros with the same names in C, i.e., they print messages to the kernel ring buffer with the given level, prefixing the messages with corresponding device information. Signed-off-by: Wedson Almeida Filho Signed-off-by: Danilo Krummrich --- rust/kernel/device.rs | 319 ++++++++++++++++++++++++++++++++++++++++- rust/kernel/prelude.rs | 2 + 2 files changed, 320 insertions(+), 1 deletion(-) diff --git a/rust/kernel/device.rs b/rust/kernel/device.rs index 851018eef885..0c28b1e6b004 100644 --- a/rust/kernel/device.rs +++ b/rust/kernel/device.rs @@ -8,7 +8,10 @@ bindings, types::{ARef, Opaque}, }; -use core::ptr; +use core::{fmt, ptr}; + +#[cfg(CONFIG_PRINTK)] +use crate::c_str; /// A reference-counted device. /// @@ -82,6 +85,110 @@ pub unsafe fn as_ref<'a>(ptr: *mut bindings::device) -> &'a Self { // SAFETY: Guaranteed by the safety requirements of the function. unsafe { &*ptr.cast() } } + + /// Prints an emergency-level message (level 0) prefixed with device information. + /// + /// More details are available from [`dev_emerg`]. + /// + /// [`dev_emerg`]: crate::dev_emerg + pub fn pr_emerg(&self, args: fmt::Arguments<'_>) { + // SAFETY: `klevel` is null-terminated, uses one of the kernel constants. + unsafe { self.printk(bindings::KERN_EMERG, args) }; + } + + /// Prints an alert-level message (level 1) prefixed with device information. + /// + /// More details are available from [`dev_alert`]. + /// + /// [`dev_alert`]: crate::dev_alert + pub fn pr_alert(&self, args: fmt::Arguments<'_>) { + // SAFETY: `klevel` is null-terminated, uses one of the kernel constants. + unsafe { self.printk(bindings::KERN_ALERT, args) }; + } + + /// Prints a critical-level message (level 2) prefixed with device information. + /// + /// More details are available from [`dev_crit`]. + /// + /// [`dev_crit`]: crate::dev_crit + pub fn pr_crit(&self, args: fmt::Arguments<'_>) { + // SAFETY: `klevel` is null-terminated, uses one of the kernel constants. + unsafe { self.printk(bindings::KERN_CRIT, args) }; + } + + /// Prints an error-level message (level 3) prefixed with device information. + /// + /// More details are available from [`dev_err`]. + /// + /// [`dev_err`]: crate::dev_err + pub fn pr_err(&self, args: fmt::Arguments<'_>) { + // SAFETY: `klevel` is null-terminated, uses one of the kernel constants. + unsafe { self.printk(bindings::KERN_ERR, args) }; + } + + /// Prints a warning-level message (level 4) prefixed with device information. + /// + /// More details are available from [`dev_warn`]. + /// + /// [`dev_warn`]: crate::dev_warn + pub fn pr_warn(&self, args: fmt::Arguments<'_>) { + // SAFETY: `klevel` is null-terminated, uses one of the kernel constants. + unsafe { self.printk(bindings::KERN_WARNING, args) }; + } + + /// Prints a notice-level message (level 5) prefixed with device information. + /// + /// More details are available from [`dev_notice`]. + /// + /// [`dev_notice`]: crate::dev_notice + pub fn pr_notice(&self, args: fmt::Arguments<'_>) { + // SAFETY: `klevel` is null-terminated, uses one of the kernel constants. + unsafe { self.printk(bindings::KERN_NOTICE, args) }; + } + + /// Prints an info-level message (level 6) prefixed with device information. + /// + /// More details are available from [`dev_info`]. + /// + /// [`dev_info`]: crate::dev_info + pub fn pr_info(&self, args: fmt::Arguments<'_>) { + // SAFETY: `klevel` is null-terminated, uses one of the kernel constants. + unsafe { self.printk(bindings::KERN_INFO, args) }; + } + + /// Prints a debug-level message (level 7) prefixed with device information. + /// + /// More details are available from [`dev_dbg`]. + /// + /// [`dev_dbg`]: crate::dev_dbg + pub fn pr_dbg(&self, args: fmt::Arguments<'_>) { + if cfg!(debug_assertions) { + // SAFETY: `klevel` is null-terminated, uses one of the kernel constants. + unsafe { self.printk(bindings::KERN_DEBUG, args) }; + } + } + + /// Prints the provided message to the console. + /// + /// # Safety + /// + /// Callers must ensure that `klevel` is null-terminated; in particular, one of the + /// `KERN_*`constants, for example, `KERN_CRIT`, `KERN_ALERT`, etc. + #[cfg_attr(not(CONFIG_PRINTK), allow(unused_variables))] + unsafe fn printk(&self, klevel: &[u8], msg: fmt::Arguments<'_>) { + // SAFETY: `klevel` is null-terminated and one of the kernel constants. `self.as_raw` + // is valid because `self` is valid. The "%pA" format string expects a pointer to + // `fmt::Arguments`, which is what we're passing as the last argument. + #[cfg(CONFIG_PRINTK)] + unsafe { + bindings::_dev_printk( + klevel as *const _ as *const core::ffi::c_char, + self.as_raw(), + c_str!("%pA").as_char_ptr(), + &msg as *const _ as *const core::ffi::c_void, + ) + }; + } } // SAFETY: Instances of `Device` are always reference-counted. @@ -103,3 +210,213 @@ unsafe impl Send for Device {} // SAFETY: `Device` can be shared among threads because all immutable methods are protected by the // synchronization in `struct device`. unsafe impl Sync for Device {} + +#[doc(hidden)] +#[macro_export] +macro_rules! dev_printk { + ($method:ident, $dev:expr, $($f:tt)*) => { + { + ($dev).$method(core::format_args!($($f)*)); + } + } +} + +/// Prints an emergency-level message (level 0) prefixed with device information. +/// +/// This level should be used if the system is unusable. +/// +/// Equivalent to the kernel's `dev_emerg` macro. +/// +/// Mimics the interface of [`std::print!`]. More information about the syntax is available from +/// [`core::fmt`] and `alloc::format!`. +/// +/// [`std::print!`]: https://doc.rust-lang.org/std/macro.print.html +/// +/// # Examples +/// +/// ``` +/// # use kernel::device::Device; +/// +/// fn example(dev: &Device) { +/// dev_emerg!(dev, "hello {}\n", "there"); +/// } +/// ``` +#[macro_export] +macro_rules! dev_emerg { + ($($f:tt)*) => { $crate::dev_printk!(pr_emerg, $($f)*); } +} + +/// Prints an alert-level message (level 1) prefixed with device information. +/// +/// This level should be used if action must be taken immediately. +/// +/// Equivalent to the kernel's `dev_alert` macro. +/// +/// Mimics the interface of [`std::print!`]. More information about the syntax is available from +/// [`core::fmt`] and `alloc::format!`. +/// +/// [`std::print!`]: https://doc.rust-lang.org/std/macro.print.html +/// +/// # Examples +/// +/// ``` +/// # use kernel::device::Device; +/// +/// fn example(dev: &Device) { +/// dev_alert!(dev, "hello {}\n", "there"); +/// } +/// ``` +#[macro_export] +macro_rules! dev_alert { + ($($f:tt)*) => { $crate::dev_printk!(pr_alert, $($f)*); } +} + +/// Prints a critical-level message (level 2) prefixed with device information. +/// +/// This level should be used in critical conditions. +/// +/// Equivalent to the kernel's `dev_crit` macro. +/// +/// Mimics the interface of [`std::print!`]. More information about the syntax is available from +/// [`core::fmt`] and `alloc::format!`. +/// +/// [`std::print!`]: https://doc.rust-lang.org/std/macro.print.html +/// +/// # Examples +/// +/// ``` +/// # use kernel::device::Device; +/// +/// fn example(dev: &Device) { +/// dev_crit!(dev, "hello {}\n", "there"); +/// } +/// ``` +#[macro_export] +macro_rules! dev_crit { + ($($f:tt)*) => { $crate::dev_printk!(pr_crit, $($f)*); } +} + +/// Prints an error-level message (level 3) prefixed with device information. +/// +/// This level should be used in error conditions. +/// +/// Equivalent to the kernel's `dev_err` macro. +/// +/// Mimics the interface of [`std::print!`]. More information about the syntax is available from +/// [`core::fmt`] and `alloc::format!`. +/// +/// [`std::print!`]: https://doc.rust-lang.org/std/macro.print.html +/// +/// # Examples +/// +/// ``` +/// # use kernel::device::Device; +/// +/// fn example(dev: &Device) { +/// dev_err!(dev, "hello {}\n", "there"); +/// } +/// ``` +#[macro_export] +macro_rules! dev_err { + ($($f:tt)*) => { $crate::dev_printk!(pr_err, $($f)*); } +} + +/// Prints a warning-level message (level 4) prefixed with device information. +/// +/// This level should be used in warning conditions. +/// +/// Equivalent to the kernel's `dev_warn` macro. +/// +/// Mimics the interface of [`std::print!`]. More information about the syntax is available from +/// [`core::fmt`] and `alloc::format!`. +/// +/// [`std::print!`]: https://doc.rust-lang.org/std/macro.print.html +/// +/// # Examples +/// +/// ``` +/// # use kernel::device::Device; +/// +/// fn example(dev: &Device) { +/// dev_warn!(dev, "hello {}\n", "there"); +/// } +/// ``` +#[macro_export] +macro_rules! dev_warn { + ($($f:tt)*) => { $crate::dev_printk!(pr_warn, $($f)*); } +} + +/// Prints a notice-level message (level 5) prefixed with device information. +/// +/// This level should be used in normal but significant conditions. +/// +/// Equivalent to the kernel's `dev_notice` macro. +/// +/// Mimics the interface of [`std::print!`]. More information about the syntax is available from +/// [`core::fmt`] and `alloc::format!`. +/// +/// [`std::print!`]: https://doc.rust-lang.org/std/macro.print.html +/// +/// # Examples +/// +/// ``` +/// # use kernel::device::Device; +/// +/// fn example(dev: &Device) { +/// dev_notice!(dev, "hello {}\n", "there"); +/// } +/// ``` +#[macro_export] +macro_rules! dev_notice { + ($($f:tt)*) => { $crate::dev_printk!(pr_notice, $($f)*); } +} + +/// Prints an info-level message (level 6) prefixed with device information. +/// +/// This level should be used for informational messages. +/// +/// Equivalent to the kernel's `dev_info` macro. +/// +/// Mimics the interface of [`std::print!`]. More information about the syntax is available from +/// [`core::fmt`] and `alloc::format!`. +/// +/// [`std::print!`]: https://doc.rust-lang.org/std/macro.print.html +/// +/// # Examples +/// +/// ``` +/// # use kernel::device::Device; +/// +/// fn example(dev: &Device) { +/// dev_info!(dev, "hello {}\n", "there"); +/// } +/// ``` +#[macro_export] +macro_rules! dev_info { + ($($f:tt)*) => { $crate::dev_printk!(pr_info, $($f)*); } +} + +/// Prints a debug-level message (level 7) prefixed with device information. +/// +/// This level should be used for debug messages. +/// +/// Equivalent to the kernel's `dev_dbg` macro, except that it doesn't support dynamic debug yet. +/// +/// Mimics the interface of [`std::print!`]. More information about the syntax is available from +/// [`core::fmt`] and `alloc::format!`. +/// +/// [`std::print!`]: https://doc.rust-lang.org/std/macro.print.html +/// +/// # Examples +/// +/// ``` +/// # use kernel::device::Device; +/// +/// fn example(dev: &Device) { +/// dev_dbg!(dev, "hello {}\n", "there"); +/// } +/// ``` +#[macro_export] +macro_rules! dev_dbg { + ($($f:tt)*) => { $crate::dev_printk!(pr_dbg, $($f)*); } +} diff --git a/rust/kernel/prelude.rs b/rust/kernel/prelude.rs index 8bdab9aa0d16..9ab4e0b6cbc9 100644 --- a/rust/kernel/prelude.rs +++ b/rust/kernel/prelude.rs @@ -24,6 +24,8 @@ // `super::std_vendor` is hidden, which makes the macro inline for some reason. #[doc(no_inline)] pub use super::dbg; +pub use super::fmt; +pub use super::{dev_alert, dev_crit, dev_dbg, dev_emerg, dev_err, dev_info, dev_notice, dev_warn}; pub use super::{pr_alert, pr_crit, pr_debug, pr_emerg, pr_err, pr_info, pr_notice, pr_warn}; pub use super::{init, pin_init, try_init, try_pin_init}; From patchwork Tue Oct 22 21:31:46 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Danilo Krummrich X-Patchwork-Id: 13846177 X-Patchwork-Delegate: bhelgaas@google.com 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 7941B1CEAA7; Tue, 22 Oct 2024 21:33:22 +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=1729632802; cv=none; b=Zz231xgDLjdqV9/fqxUjOsIGvufarysd6s3mhlrK5BxDpSUIqf8XjYnw1BI0Ffg6MAVH9LQ1O90waAm2eI1pMBSMcx/3yjemF8q/VPL8vf/GDqrNcBwac2cgkEnxX3RxUEEC0lanB86+BCKJpOd6Txn+poWINYHijpe9kRKjnM4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729632802; c=relaxed/simple; bh=6U6WevbcRfqHWqoppQ93TF+01z6ZVOGC3zWvwRloqyM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=q7SCzI2kDdvft3i1ptei6S9e4p97jYIFnd9LL5T/nn1lg+O0eQ5rFY3N8TO0hFfQgyCHnucmX1Z+B1pL/4IuRKilOaYsOb+KOh4BjiDl4N69+csADNTxHWbdRPkXRVgOKu8GTB2/CA2EaVV2C6KK2HqsJFnQstfowbREllTTOn8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=FuAhMZEn; 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="FuAhMZEn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 43A7AC4CECD; Tue, 22 Oct 2024 21:33:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1729632802; bh=6U6WevbcRfqHWqoppQ93TF+01z6ZVOGC3zWvwRloqyM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FuAhMZEnqgYBpmTz9RBe0QrzIrLWfLry+oUjVa7AR/tl/Txjndkvq91qXUDQ4UyeG AYbn8mL/HxXT8Ws/ediC3BPszmNdBudAc94vsC5jxT6tIMv2QigErX3LMgFpY6GSIz XJQKEkVlhx7XwQ7vFLMoydcYt8KVha6fXZ9x3snTl0aKaClCfWIKmL8X7rfuwpE21z UEQf1foJpq+eEppRGj61zL7ZTsVNgGgxSfFKNfsvWMxj/iN+VKlnQbRzuUIkKqPJwe XoXTw+z+h1kEAmW9g5OubZ5HGQ4vNofX3W2FvksTGs8zkWlN5/a/q4uUlDSohBqlXn NnFctwCMQQRfg== From: Danilo Krummrich To: gregkh@linuxfoundation.org, rafael@kernel.org, bhelgaas@google.com, ojeda@kernel.org, alex.gaynor@gmail.com, boqun.feng@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com, benno.lossin@proton.me, tmgross@umich.edu, a.hindborg@samsung.com, aliceryhl@google.com, airlied@gmail.com, fujita.tomonori@gmail.com, lina@asahilina.net, pstanner@redhat.com, ajanulgu@redhat.com, lyude@redhat.com, robh@kernel.org, daniel.almeida@collabora.com, saravanak@google.com Cc: rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, devicetree@vger.kernel.org, Danilo Krummrich Subject: [PATCH v3 09/16] rust: add `io::Io` base type Date: Tue, 22 Oct 2024 23:31:46 +0200 Message-ID: <20241022213221.2383-10-dakr@kernel.org> X-Mailer: git-send-email 2.46.2 In-Reply-To: <20241022213221.2383-1-dakr@kernel.org> References: <20241022213221.2383-1-dakr@kernel.org> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 I/O memory is typically either mapped through direct calls to ioremap() or subsystem / bus specific ones such as pci_iomap(). Even though subsystem / bus specific functions to map I/O memory are based on ioremap() / iounmap() it is not desirable to re-implement them in Rust. Instead, implement a base type for I/O mapped memory, which generically provides the corresponding accessors, such as `Io::readb` or `Io:try_readb`. `Io` supports an optional const generic, such that a driver can indicate the minimal expected and required size of the mapping at compile time. Correspondingly, calls to the 'non-try' accessors, support compile time checks of the I/O memory offset to read / write, while the 'try' accessors, provide boundary checks on runtime. `Io` is meant to be embedded into a structure (e.g. pci::Bar or io::IoMem) which creates the actual I/O memory mapping and initializes `Io` accordingly. To ensure that I/O mapped memory can't out-live the device it may be bound to, subsystems should embedd the corresponding I/O memory type (e.g. pci::Bar) into a `Devres` container, such that it gets revoked once the device is unbound. Co-developed-by: Philipp Stanner Signed-off-by: Philipp Stanner Signed-off-by: Danilo Krummrich --- rust/helpers/helpers.c | 1 + rust/helpers/io.c | 91 ++++++++++++++++ rust/kernel/io.rs | 234 +++++++++++++++++++++++++++++++++++++++++ rust/kernel/lib.rs | 1 + 4 files changed, 327 insertions(+) create mode 100644 rust/helpers/io.c create mode 100644 rust/kernel/io.rs diff --git a/rust/helpers/helpers.c b/rust/helpers/helpers.c index 0720debccdd4..e2f6b2197061 100644 --- a/rust/helpers/helpers.c +++ b/rust/helpers/helpers.c @@ -12,6 +12,7 @@ #include "build_assert.c" #include "build_bug.c" #include "err.c" +#include "io.c" #include "kunit.c" #include "mutex.c" #include "page.c" diff --git a/rust/helpers/io.c b/rust/helpers/io.c new file mode 100644 index 000000000000..f9bb1bbf1fd5 --- /dev/null +++ b/rust/helpers/io.c @@ -0,0 +1,91 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include + +u8 rust_helper_readb(const volatile void __iomem *addr) +{ + return readb(addr); +} + +u16 rust_helper_readw(const volatile void __iomem *addr) +{ + return readw(addr); +} + +u32 rust_helper_readl(const volatile void __iomem *addr) +{ + return readl(addr); +} + +#ifdef CONFIG_64BIT +u64 rust_helper_readq(const volatile void __iomem *addr) +{ + return readq(addr); +} +#endif + +void rust_helper_writeb(u8 value, volatile void __iomem *addr) +{ + writeb(value, addr); +} + +void rust_helper_writew(u16 value, volatile void __iomem *addr) +{ + writew(value, addr); +} + +void rust_helper_writel(u32 value, volatile void __iomem *addr) +{ + writel(value, addr); +} + +#ifdef CONFIG_64BIT +void rust_helper_writeq(u64 value, volatile void __iomem *addr) +{ + writeq(value, addr); +} +#endif + +u8 rust_helper_readb_relaxed(const volatile void __iomem *addr) +{ + return readb_relaxed(addr); +} + +u16 rust_helper_readw_relaxed(const volatile void __iomem *addr) +{ + return readw_relaxed(addr); +} + +u32 rust_helper_readl_relaxed(const volatile void __iomem *addr) +{ + return readl_relaxed(addr); +} + +#ifdef CONFIG_64BIT +u64 rust_helper_readq_relaxed(const volatile void __iomem *addr) +{ + return readq_relaxed(addr); +} +#endif + +void rust_helper_writeb_relaxed(u8 value, volatile void __iomem *addr) +{ + writeb_relaxed(value, addr); +} + +void rust_helper_writew_relaxed(u16 value, volatile void __iomem *addr) +{ + writew_relaxed(value, addr); +} + +void rust_helper_writel_relaxed(u32 value, volatile void __iomem *addr) +{ + writel_relaxed(value, addr); +} + +#ifdef CONFIG_64BIT +void rust_helper_writeq_relaxed(u64 value, volatile void __iomem *addr) +{ + writeq_relaxed(value, addr); +} +#endif diff --git a/rust/kernel/io.rs b/rust/kernel/io.rs new file mode 100644 index 000000000000..750af938f83e --- /dev/null +++ b/rust/kernel/io.rs @@ -0,0 +1,234 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Memory-mapped IO. +//! +//! C header: [`include/asm-generic/io.h`](srctree/include/asm-generic/io.h) + +use crate::error::{code::EINVAL, Result}; +use crate::{bindings, build_assert}; + +/// IO-mapped memory, starting at the base address @addr and spanning @maxlen bytes. +/// +/// The creator (usually a subsystem / bus such as PCI) is responsible for creating the +/// mapping, performing an additional region request etc. +/// +/// # Invariant +/// +/// `addr` is the start and `maxsize` the length of valid I/O mapped memory region of size +/// `maxsize`. +/// +/// # Examples +/// +/// ```no_run +/// # use kernel::{bindings, io::Io}; +/// # use core::ops::Deref; +/// +/// // See also [`pci::Bar`] for a real example. +/// struct IoMem(Io); +/// +/// impl IoMem { +/// /// # Safety +/// /// +/// /// [`paddr`, `paddr` + `SIZE`) must be a valid MMIO region that is mappable into the CPUs +/// /// virtual address space. +/// unsafe fn new(paddr: usize) -> Result{ +/// +/// // SAFETY: By the safety requirements of this function [`paddr`, `paddr` + `SIZE`) is +/// // valid for `ioremap`. +/// let addr = unsafe { bindings::ioremap(paddr as _, SIZE.try_into().unwrap()) }; +/// if addr.is_null() { +/// return Err(ENOMEM); +/// } +/// +/// // SAFETY: `addr` is guaranteed to be the start of a valid I/O mapped memory region of +/// // size `SIZE`. +/// let io = unsafe { Io::new(addr as _, SIZE)? }; +/// +/// Ok(IoMem(io)) +/// } +/// } +/// +/// impl Drop for IoMem { +/// fn drop(&mut self) { +/// // SAFETY: Safe as by the invariant of `Io`. +/// unsafe { bindings::iounmap(self.0.base_addr() as _); }; +/// } +/// } +/// +/// impl Deref for IoMem { +/// type Target = Io; +/// +/// fn deref(&self) -> &Self::Target { +/// &self.0 +/// } +/// } +/// +///# fn no_run() -> Result<(), Error> { +/// // SAFETY: Invalid usage for example purposes. +/// let iomem = unsafe { IoMem::<{ core::mem::size_of::() }>::new(0xBAAAAAAD)? }; +/// iomem.writel(0x42, 0x0); +/// assert!(iomem.try_writel(0x42, 0x0).is_ok()); +/// assert!(iomem.try_writel(0x42, 0x4).is_err()); +/// # Ok(()) +/// # } +/// ``` +pub struct Io { + addr: usize, + maxsize: usize, +} + +macro_rules! define_read { + ($(#[$attr:meta])* $name:ident, $try_name:ident, $type_name:ty) => { + /// Read IO data from a given offset known at compile time. + /// + /// Bound checks are performed on compile time, hence if the offset is not known at compile + /// time, the build will fail. + $(#[$attr])* + #[inline] + pub fn $name(&self, offset: usize) -> $type_name { + let addr = self.io_addr_assert::<$type_name>(offset); + + // SAFETY: By the type invariant `addr` is a valid address for MMIO operations. + unsafe { bindings::$name(addr as _) } + } + + /// Read IO data from a given offset. + /// + /// Bound checks are performed on runtime, it fails if the offset (plus the type size) is + /// out of bounds. + $(#[$attr])* + pub fn $try_name(&self, offset: usize) -> Result<$type_name> { + let addr = self.io_addr::<$type_name>(offset)?; + + // SAFETY: By the type invariant `addr` is a valid address for MMIO operations. + Ok(unsafe { bindings::$name(addr as _) }) + } + }; +} + +macro_rules! define_write { + ($(#[$attr:meta])* $name:ident, $try_name:ident, $type_name:ty) => { + /// Write IO data from a given offset known at compile time. + /// + /// Bound checks are performed on compile time, hence if the offset is not known at compile + /// time, the build will fail. + $(#[$attr])* + #[inline] + pub fn $name(&self, value: $type_name, offset: usize) { + let addr = self.io_addr_assert::<$type_name>(offset); + + // SAFETY: By the type invariant `addr` is a valid address for MMIO operations. + unsafe { bindings::$name(value, addr as _, ) } + } + + /// Write IO data from a given offset. + /// + /// Bound checks are performed on runtime, it fails if the offset (plus the type size) is + /// out of bounds. + $(#[$attr])* + pub fn $try_name(&self, value: $type_name, offset: usize) -> Result { + let addr = self.io_addr::<$type_name>(offset)?; + + // SAFETY: By the type invariant `addr` is a valid address for MMIO operations. + unsafe { bindings::$name(value, addr as _) } + Ok(()) + } + }; +} + +impl Io { + /// + /// + /// # Safety + /// + /// Callers must ensure that `addr` is the start of a valid I/O mapped memory region of size + /// `maxsize`. + pub unsafe fn new(addr: usize, maxsize: usize) -> Result { + if maxsize < SIZE { + return Err(EINVAL); + } + + // INVARIANT: Covered by the safety requirements of this function. + Ok(Self { addr, maxsize }) + } + + /// Returns the base address of this mapping. + #[inline] + pub fn base_addr(&self) -> usize { + self.addr + } + + /// Returns the size of this mapping. + #[inline] + pub fn maxsize(&self) -> usize { + self.maxsize + } + + #[inline] + const fn offset_valid(offset: usize, size: usize) -> bool { + let type_size = core::mem::size_of::(); + if let Some(end) = offset.checked_add(type_size) { + end <= size && offset % type_size == 0 + } else { + false + } + } + + #[inline] + fn io_addr(&self, offset: usize) -> Result { + if !Self::offset_valid::(offset, self.maxsize()) { + return Err(EINVAL); + } + + // Probably no need to check, since the safety requirements of `Self::new` guarantee that + // this can't overflow. + self.base_addr().checked_add(offset).ok_or(EINVAL) + } + + #[inline] + fn io_addr_assert(&self, offset: usize) -> usize { + build_assert!(Self::offset_valid::(offset, SIZE)); + + self.base_addr() + offset + } + + define_read!(readb, try_readb, u8); + define_read!(readw, try_readw, u16); + define_read!(readl, try_readl, u32); + define_read!( + #[cfg(CONFIG_64BIT)] + readq, + try_readq, + u64 + ); + + define_read!(readb_relaxed, try_readb_relaxed, u8); + define_read!(readw_relaxed, try_readw_relaxed, u16); + define_read!(readl_relaxed, try_readl_relaxed, u32); + define_read!( + #[cfg(CONFIG_64BIT)] + readq_relaxed, + try_readq_relaxed, + u64 + ); + + define_write!(writeb, try_writeb, u8); + define_write!(writew, try_writew, u16); + define_write!(writel, try_writel, u32); + define_write!( + #[cfg(CONFIG_64BIT)] + writeq, + try_writeq, + u64 + ); + + define_write!(writeb_relaxed, try_writeb_relaxed, u8); + define_write!(writew_relaxed, try_writew_relaxed, u16); + define_write!(writel_relaxed, try_writel_relaxed, u32); + define_write!( + #[cfg(CONFIG_64BIT)] + writeq_relaxed, + try_writeq_relaxed, + u64 + ); +} diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs index b603b67dcd71..fa3b7514e6ae 100644 --- a/rust/kernel/lib.rs +++ b/rust/kernel/lib.rs @@ -70,6 +70,7 @@ #[doc(hidden)] pub use bindings; +pub mod io; pub use macros; pub use uapi; From patchwork Tue Oct 22 21:31:47 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Danilo Krummrich X-Patchwork-Id: 13846178 X-Patchwork-Delegate: bhelgaas@google.com 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 067261CEAA7; Tue, 22 Oct 2024 21:33:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; 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Tue, 22 Oct 2024 21:33:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1729632807; bh=6D9H3UuKuTE0IPg8G7njtpvFnsNHPt874oP5qIsVUV4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ouhLQVcLbi3+OzRtIXgZ9jQNj5YwA2iqdRfT2SplCFyW3IJ5pjKSIQtwE+VvUgROg GjeT3F+YzyI4JYcIyvTBpgMlu+mIzJxv5XYcSQqQCSWAzxNNPWr3A40bmLdK8khM+Y 5kd4xN+DYqtabtAs6UnUZxXJcDatcm0ujBGLGRWD3xm/ClhT/+9qpxk5KBW/hwhGdh P2ecU8RuySsRVgs1BUrICEo8lbwfkPz7LOpEZCG6qOsOorST7xrKPddnJTsbLvI4q9 WelGQRtH+BPK7zHgOqnMCjWi+2xUx83WOjH/6IDITs0tw2eImUojHFYXm+LcW4yD0F zzY693TFYDedQ== From: Danilo Krummrich To: gregkh@linuxfoundation.org, rafael@kernel.org, bhelgaas@google.com, ojeda@kernel.org, alex.gaynor@gmail.com, boqun.feng@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com, benno.lossin@proton.me, tmgross@umich.edu, a.hindborg@samsung.com, aliceryhl@google.com, airlied@gmail.com, fujita.tomonori@gmail.com, lina@asahilina.net, pstanner@redhat.com, ajanulgu@redhat.com, lyude@redhat.com, robh@kernel.org, daniel.almeida@collabora.com, saravanak@google.com Cc: rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, devicetree@vger.kernel.org, Danilo Krummrich Subject: [PATCH v3 10/16] rust: add devres abstraction Date: Tue, 22 Oct 2024 23:31:47 +0200 Message-ID: <20241022213221.2383-11-dakr@kernel.org> X-Mailer: git-send-email 2.46.2 In-Reply-To: <20241022213221.2383-1-dakr@kernel.org> References: <20241022213221.2383-1-dakr@kernel.org> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Add a Rust abstraction for the kernel's devres (device resource management) implementation. The Devres type acts as a container to manage the lifetime and accessibility of device bound resources. Therefore it registers a devres callback and revokes access to the resource on invocation. Users of the Devres abstraction can simply free the corresponding resources in their Drop implementation, which is invoked when either the Devres instance goes out of scope or the devres callback leads to the resource being revoked, which implies a call to drop_in_place(). Signed-off-by: Danilo Krummrich --- MAINTAINERS | 1 + rust/helpers/device.c | 10 +++ rust/helpers/helpers.c | 1 + rust/kernel/devres.rs | 180 +++++++++++++++++++++++++++++++++++++++++ rust/kernel/lib.rs | 1 + 5 files changed, 193 insertions(+) create mode 100644 rust/helpers/device.c create mode 100644 rust/kernel/devres.rs diff --git a/MAINTAINERS b/MAINTAINERS index 0a8882252257..97914d0752fb 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -6983,6 +6983,7 @@ F: include/linux/property.h F: lib/kobj* F: rust/kernel/device.rs F: rust/kernel/device_id.rs +F: rust/kernel/devres.rs F: rust/kernel/driver.rs DRIVERS FOR OMAP ADAPTIVE VOLTAGE SCALING (AVS) diff --git a/rust/helpers/device.c b/rust/helpers/device.c new file mode 100644 index 000000000000..b2135c6686b0 --- /dev/null +++ b/rust/helpers/device.c @@ -0,0 +1,10 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include + +int rust_helper_devm_add_action(struct device *dev, + void (*action)(void *), + void *data) +{ + return devm_add_action(dev, action, data); +} diff --git a/rust/helpers/helpers.c b/rust/helpers/helpers.c index e2f6b2197061..3acb2b9e52ec 100644 --- a/rust/helpers/helpers.c +++ b/rust/helpers/helpers.c @@ -11,6 +11,7 @@ #include "bug.c" #include "build_assert.c" #include "build_bug.c" +#include "device.c" #include "err.c" #include "io.c" #include "kunit.c" diff --git a/rust/kernel/devres.rs b/rust/kernel/devres.rs new file mode 100644 index 000000000000..b23559f55214 --- /dev/null +++ b/rust/kernel/devres.rs @@ -0,0 +1,180 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Devres abstraction +//! +//! [`Devres`] represents an abstraction for the kernel devres (device resource management) +//! implementation. + +use crate::{ + alloc::Flags, + bindings, + device::Device, + error::{Error, Result}, + prelude::*, + revocable::Revocable, + sync::Arc, +}; + +use core::ffi::c_void; +use core::ops::Deref; + +#[pin_data] +struct DevresInner { + #[pin] + data: Revocable, +} + +/// This abstraction is meant to be used by subsystems to containerize [`Device`] bound resources to +/// manage their lifetime. +/// +/// [`Device`] bound resources should be freed when either the resource goes out of scope or the +/// [`Device`] is unbound respectively, depending on what happens first. +/// +/// To achieve that [`Devres`] registers a devres callback on creation, which is called once the +/// [`Device`] is unbound, revoking access to the encapsulated resource (see also [`Revocable`]). +/// +/// After the [`Devres`] has been unbound it is not possible to access the encapsulated resource +/// anymore. +/// +/// [`Devres`] users should make sure to simply free the corresponding backing resource in `T`'s +/// [`Drop`] implementation. +/// +/// # Example +/// +/// ```no_run +/// # use kernel::{bindings, c_str, device::Device, devres::Devres, io::Io}; +/// # use core::ops::Deref; +/// +/// // See also [`pci::Bar`] for a real example. +/// struct IoMem(Io); +/// +/// impl IoMem { +/// /// # Safety +/// /// +/// /// [`paddr`, `paddr` + `SIZE`) must be a valid MMIO region that is mappable into the CPUs +/// /// virtual address space. +/// unsafe fn new(paddr: usize) -> Result{ +/// +/// // SAFETY: By the safety requirements of this function [`paddr`, `paddr` + `SIZE`) is +/// // valid for `ioremap`. +/// let addr = unsafe { bindings::ioremap(paddr as _, SIZE.try_into().unwrap()) }; +/// if addr.is_null() { +/// return Err(ENOMEM); +/// } +/// +/// // SAFETY: `addr` is guaranteed to be the start of a valid I/O mapped memory region of +/// // size `SIZE`. +/// let io = unsafe { Io::new(addr as _, SIZE)? }; +/// +/// Ok(IoMem(io)) +/// } +/// } +/// +/// impl Drop for IoMem { +/// fn drop(&mut self) { +/// // SAFETY: Safe as by the invariant of `Io`. +/// unsafe { bindings::iounmap(self.0.base_addr() as _); }; +/// } +/// } +/// +/// impl Deref for IoMem { +/// type Target = Io; +/// +/// fn deref(&self) -> &Self::Target { +/// &self.0 +/// } +/// } +/// +/// # fn no_run() -> Result<(), Error> { +/// # // SAFETY: Invalid usage; just for the example to get an `ARef` instance. +/// # let dev = unsafe { Device::from_raw(core::ptr::null_mut()) }; +/// +/// // SAFETY: Invalid usage for example purposes. +/// let iomem = unsafe { IoMem::<{ core::mem::size_of::() }>::new(0xBAAAAAAD)? }; +/// let devres = Devres::new(&dev, iomem, GFP_KERNEL)?; +/// +/// let res = devres.try_access().ok_or(ENXIO)?; +/// res.writel(0x42, 0x0); +/// # Ok(()) +/// # } +/// ``` +pub struct Devres(Arc>); + +impl DevresInner { + fn new(dev: &Device, data: T, flags: Flags) -> Result>> { + let inner = Arc::pin_init( + pin_init!( DevresInner { + data <- Revocable::new(data), + }), + flags, + )?; + + // Convert `Arc` into a raw pointer and make devres own this reference until + // `Self::devres_callback` is called. + let data = inner.clone().into_raw(); + + // SAFETY: `devm_add_action` guarantees to call `Self::devres_callback` once `dev` is + // detached. + let ret = unsafe { + bindings::devm_add_action(dev.as_raw(), Some(Self::devres_callback), data as _) + }; + + if ret != 0 { + // SAFETY: We just created another reference to `inner` in order to pass it to + // `bindings::devm_add_action`. If `bindings::devm_add_action` fails, we have to drop + // this reference accordingly. + let _ = unsafe { Arc::from_raw(data) }; + return Err(Error::from_errno(ret)); + } + + Ok(inner) + } + + #[allow(clippy::missing_safety_doc)] + unsafe extern "C" fn devres_callback(ptr: *mut c_void) { + let ptr = ptr as *mut DevresInner; + // Devres owned this memory; now that we received the callback, drop the `Arc` and hence the + // reference. + // SAFETY: Safe, since we leaked an `Arc` reference to devm_add_action() in + // `DevresInner::new`. + let inner = unsafe { Arc::from_raw(ptr) }; + + inner.data.revoke(); + } +} + +impl Devres { + /// Creates a new [`Devres`] instance of the given `data`. The `data` encapsulated within the + /// returned `Devres` instance' `data` will be revoked once the device is detached. + pub fn new(dev: &Device, data: T, flags: Flags) -> Result { + let inner = DevresInner::new(dev, data, flags)?; + + Ok(Devres(inner)) + } + + /// Same as [`Devres::new`], but does not return a `Devres` instance. Instead the given `data` + /// is owned by devres and will be revoked / dropped, once the device is detached. + pub fn new_foreign_owned(dev: &Device, data: T, flags: Flags) -> Result { + let _ = DevresInner::new(dev, data, flags)?; + + Ok(()) + } +} + +impl Deref for Devres { + type Target = Revocable; + + fn deref(&self) -> &Self::Target { + &self.0.data + } +} + +impl Drop for Devres { + fn drop(&mut self) { + // Revoke the data, such that it gets dropped already and the actual resource is freed. + // `DevresInner` has to stay alive until the devres callback has been called. This is + // necessary since we don't know when `Devres` is dropped and calling + // `devm_remove_action()` instead could race with `devres_release_all()`. + self.revoke(); + } +} diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs index fa3b7514e6ae..5cb892419453 100644 --- a/rust/kernel/lib.rs +++ b/rust/kernel/lib.rs @@ -39,6 +39,7 @@ mod build_assert; pub mod device; pub mod device_id; +pub mod devres; pub mod driver; pub mod error; #[cfg(CONFIG_RUST_FW_LOADER_ABSTRACTIONS)] From patchwork Tue Oct 22 21:31:48 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Danilo Krummrich X-Patchwork-Id: 13846179 X-Patchwork-Delegate: bhelgaas@google.com 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 87C6E1CEAA7; Tue, 22 Oct 2024 21:33:33 +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=1729632813; cv=none; b=KjQvzdzLWDhOjCbMRERswE2qOtTmtq/SSybcqZRzcLPNkQvUgTfKhqSOpaUlaOWlCtgRL/iISxwrtMnHqM12ylvRouTwBtt2m6+f1I0uPZeMG/otrFhh6bZf+p9yVAnuqQSYdtEMuPQb3RXqFXWZcAnVWtVF6xcQg3orIEO0oAk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729632813; c=relaxed/simple; bh=f1g2lGypUnMSWSiEHr5MqHApk0asEuig3kZAXhnIuWM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=bdoAsdGfhVZ1zPWrIe5rRvv0n8WAJNjM/HNVqPv/t9YODvrYxcR1L8zNYRktfqr5c4VciJvL7SOAFg0fer9mIDQb4VRx4IeWG4Le2uQE9TvgY4TYDLcjPsmGf9W3uMuGXDNfZFlIHas3X8VdeEzdQsW2pskmhJaAqj4iRncCgi0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=cVOouSNX; 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="cVOouSNX" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4F7EDC4CEC7; Tue, 22 Oct 2024 21:33:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1729632813; bh=f1g2lGypUnMSWSiEHr5MqHApk0asEuig3kZAXhnIuWM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cVOouSNXzvADmoyI/wvdj2wDtmokqY5U9leZT76/y3i5e24o3NkpM03wnbiQHpoMx KA576ZT7L1OQvom3SGBlgHojy1Ci0lpuTSL/pupWKPskmLOwOtQ7Nhah4YG0+T6kkE zIzIPrXAquwkOHPrGwvg5/bA2SW4V61DBCYyjBrNjMtLORONQwwQrly50yKm73mUUt DjlsRvJBeUBw7rb6RCQNdznmWE/OcUhd3LYlXFnFQpdg0S8SXrKnGdeY02ForiKcqW 1GfAugh3JZU84cp+nA/t8BghiU7VYYQd9fhJ5C08e7Pv+Cy9mL1nPBRBKGNO7Z50yL c6vhOKvIvAjsw== From: Danilo Krummrich To: gregkh@linuxfoundation.org, rafael@kernel.org, bhelgaas@google.com, ojeda@kernel.org, alex.gaynor@gmail.com, boqun.feng@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com, benno.lossin@proton.me, tmgross@umich.edu, a.hindborg@samsung.com, aliceryhl@google.com, airlied@gmail.com, fujita.tomonori@gmail.com, lina@asahilina.net, pstanner@redhat.com, ajanulgu@redhat.com, lyude@redhat.com, robh@kernel.org, daniel.almeida@collabora.com, saravanak@google.com Cc: rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, devicetree@vger.kernel.org, Danilo Krummrich Subject: [PATCH v3 11/16] rust: pci: add basic PCI device / driver abstractions Date: Tue, 22 Oct 2024 23:31:48 +0200 Message-ID: <20241022213221.2383-12-dakr@kernel.org> X-Mailer: git-send-email 2.46.2 In-Reply-To: <20241022213221.2383-1-dakr@kernel.org> References: <20241022213221.2383-1-dakr@kernel.org> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Implement the basic PCI abstractions required to write a basic PCI driver. This includes the following data structures: The `pci::Driver` trait represents the interface to the driver and provides `pci::Driver::probe` for the driver to implement. The `pci::Device` abstraction represents a `struct pci_dev` and provides abstractions for common functions, such as `pci::Device::set_master`. In order to provide the PCI specific parts to a generic `driver::Registration` the `driver::RegistrationOps` trait is implemented by `pci::Adapter`. `pci::DeviceId` implements PCI device IDs based on the generic `device_id::RawDevceId` abstraction. Co-developed-by: FUJITA Tomonori Signed-off-by: FUJITA Tomonori Signed-off-by: Danilo Krummrich --- MAINTAINERS | 1 + rust/bindings/bindings_helper.h | 1 + rust/helpers/helpers.c | 1 + rust/helpers/pci.c | 18 ++ rust/kernel/lib.rs | 2 + rust/kernel/pci.rs | 284 ++++++++++++++++++++++++++++++++ 6 files changed, 307 insertions(+) create mode 100644 rust/helpers/pci.c create mode 100644 rust/kernel/pci.rs diff --git a/MAINTAINERS b/MAINTAINERS index 97914d0752fb..2d00d3845b4a 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -17939,6 +17939,7 @@ F: include/asm-generic/pci* F: include/linux/of_pci.h F: include/linux/pci* F: include/uapi/linux/pci* +F: rust/kernel/pci.rs PCIE DRIVER FOR AMAZON ANNAPURNA LABS M: Jonathan Chocron diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h index a80783fcbe04..cd4edd6496ae 100644 --- a/rust/bindings/bindings_helper.h +++ b/rust/bindings/bindings_helper.h @@ -15,6 +15,7 @@ #include #include #include +#include #include #include #include diff --git a/rust/helpers/helpers.c b/rust/helpers/helpers.c index 3acb2b9e52ec..8bc6e9735589 100644 --- a/rust/helpers/helpers.c +++ b/rust/helpers/helpers.c @@ -17,6 +17,7 @@ #include "kunit.c" #include "mutex.c" #include "page.c" +#include "pci.c" #include "rbtree.c" #include "rcu.c" #include "refcount.c" diff --git a/rust/helpers/pci.c b/rust/helpers/pci.c new file mode 100644 index 000000000000..7c4f3ba49486 --- /dev/null +++ b/rust/helpers/pci.c @@ -0,0 +1,18 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include + +void rust_helper_pci_set_drvdata(struct pci_dev *pdev, void *data) +{ + pci_set_drvdata(pdev, data); +} + +void *rust_helper_pci_get_drvdata(struct pci_dev *pdev) +{ + return pci_get_drvdata(pdev); +} + +u64 rust_helper_pci_resource_len(struct pci_dev *pdev, int bar) +{ + return pci_resource_len(pdev, bar); +} diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs index 5cb892419453..3ec690eb6d43 100644 --- a/rust/kernel/lib.rs +++ b/rust/kernel/lib.rs @@ -73,6 +73,8 @@ pub use bindings; pub mod io; pub use macros; +#[cfg(all(CONFIG_PCI, CONFIG_PCI_MSI))] +pub mod pci; pub use uapi; #[doc(hidden)] diff --git a/rust/kernel/pci.rs b/rust/kernel/pci.rs new file mode 100644 index 000000000000..ccc9a5f322e4 --- /dev/null +++ b/rust/kernel/pci.rs @@ -0,0 +1,284 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Abstractions for the PCI bus. +//! +//! C header: [`include/linux/pci.h`](srctree/include/linux/pci.h) + +use crate::{ + bindings, container_of, device, + device_id::RawDeviceId, + driver, + error::{to_result, Result}, + str::CStr, + types::{ARef, ForeignOwnable}, + ThisModule, +}; +use core::ops::Deref; +use kernel::prelude::*; + +/// An adapter for the registration of PCI drivers. +pub struct Adapter(T); + +impl driver::RegistrationOps for Adapter { + type RegType = bindings::pci_driver; + + fn register( + pdrv: &mut Self::RegType, + name: &'static CStr, + module: &'static ThisModule, + ) -> Result { + pdrv.name = name.as_char_ptr(); + pdrv.probe = Some(Self::probe_callback); + pdrv.remove = Some(Self::remove_callback); + pdrv.id_table = T::ID_TABLE.as_ptr(); + + // SAFETY: `pdrv` is guaranteed to be a valid `RegType`. + to_result(unsafe { + bindings::__pci_register_driver(pdrv as _, module.0, name.as_char_ptr()) + }) + } + + fn unregister(pdrv: &mut Self::RegType) { + // SAFETY: `pdrv` is guaranteed to be a valid `RegType`. + unsafe { bindings::pci_unregister_driver(pdrv) } + } +} + +impl Adapter { + extern "C" fn probe_callback( + pdev: *mut bindings::pci_dev, + id: *const bindings::pci_device_id, + ) -> core::ffi::c_int { + // SAFETY: The PCI bus only ever calls the probe callback with a valid pointer to a + // `struct pci_dev`. + let dev = unsafe { device::Device::from_raw(&mut (*pdev).dev) }; + // SAFETY: `dev` is guaranteed to be embedded in a valid `struct pci_dev` by the call + // above. + let mut pdev = unsafe { Device::from_dev(dev) }; + + // SAFETY: `DeviceId` is a `#[repr(transparent)` wrapper of `struct pci_device_id` and + // does not add additional invariants, so it's safe to transmute. + let id = unsafe { &*id.cast::() }; + let info = T::ID_TABLE.info(id.index()); + + match T::probe(&mut pdev, id, info) { + Ok(data) => { + // Let the `struct pci_dev` own a reference of the driver's private data. + // SAFETY: By the type invariant `pdev.as_raw` returns a valid pointer to a + // `struct pci_dev`. + unsafe { bindings::pci_set_drvdata(pdev.as_raw(), data.into_foreign() as _) }; + } + Err(err) => return Error::to_errno(err), + } + + 0 + } + + extern "C" fn remove_callback(pdev: *mut bindings::pci_dev) { + // SAFETY: The PCI bus only ever calls the remove callback with a valid pointer to a + // `struct pci_dev`. + let ptr = unsafe { bindings::pci_get_drvdata(pdev) }; + + // SAFETY: `remove_callback` is only ever called after a successful call to + // `probe_callback`, hence it's guaranteed that `ptr` points to a valid and initialized + // `KBox` pointer created through `KBox::into_foreign`. + let _ = unsafe { KBox::::from_foreign(ptr) }; + } +} + +/// Declares a kernel module that exposes a single PCI driver. +/// +/// # Example +/// +///```ignore +/// kernel::module_pci_driver! { +/// type: MyDriver, +/// name: "Module name", +/// author: "Author name", +/// description: "Description", +/// license: "GPL v2", +/// } +///``` +#[macro_export] +macro_rules! module_pci_driver { +($($f:tt)*) => { + $crate::module_driver!(, $crate::pci::Adapter, { $($f)* }); +}; +} + +/// Abstraction for bindings::pci_device_id. +#[repr(transparent)] +#[derive(Clone, Copy)] +pub struct DeviceId(bindings::pci_device_id); + +impl DeviceId { + const PCI_ANY_ID: u32 = !0; + + /// PCI_DEVICE macro. + pub const fn new(vendor: u32, device: u32) -> Self { + Self(bindings::pci_device_id { + vendor, + device, + subvendor: DeviceId::PCI_ANY_ID, + subdevice: DeviceId::PCI_ANY_ID, + class: 0, + class_mask: 0, + driver_data: 0, + override_only: 0, + }) + } + + /// PCI_DEVICE_CLASS macro. + pub const fn with_class(class: u32, class_mask: u32) -> Self { + Self(bindings::pci_device_id { + vendor: DeviceId::PCI_ANY_ID, + device: DeviceId::PCI_ANY_ID, + subvendor: DeviceId::PCI_ANY_ID, + subdevice: DeviceId::PCI_ANY_ID, + class, + class_mask, + driver_data: 0, + override_only: 0, + }) + } +} + +// Allow drivers R/O access to the fields of `pci_device_id`; should we prefer accessor functions +// to void exposing C structure fields? +impl Deref for DeviceId { + type Target = bindings::pci_device_id; + + fn deref(&self) -> &Self::Target { + &self.0 + } +} + +// SAFETY: +// * `DeviceId` is a `#[repr(transparent)` wrapper of `pci_device_id` and does not add +// additional invariants, so it's safe to transmute to `RawType`. +// * `DRIVER_DATA_OFFSET` is the offset to the `driver_data` field. +unsafe impl RawDeviceId for DeviceId { + type RawType = bindings::pci_device_id; + + const DRIVER_DATA_OFFSET: usize = core::mem::offset_of!(bindings::pci_device_id, driver_data); + + fn index(&self) -> usize { + self.driver_data as _ + } +} + +/// IdTable type for PCI +pub type IdTable = &'static dyn kernel::device_id::IdTable; + +/// Create a PCI `IdTable` with its alias for modpost. +#[macro_export] +macro_rules! pci_device_table { + ($table_name:ident, $module_table_name:ident, $id_info_type: ty, $table_data: expr) => { + const $table_name: $crate::device_id::IdArray< + $crate::pci::DeviceId, + $id_info_type, + { $table_data.len() }, + > = $crate::device_id::IdArray::new($table_data); + + $crate::module_device_table!("pci", $module_table_name, $table_name); + }; +} + +/// The PCI driver trait. +/// +/// # Example +/// +///``` +/// # use kernel::{bindings, pci}; +/// +/// struct MyDriver; +/// +/// kernel::pci_device_table!( +/// PCI_TABLE, +/// MODULE_PCI_TABLE, +/// ::IdInfo, +/// [ +/// (pci::DeviceId::new(bindings::PCI_VENDOR_ID_REDHAT, bindings::PCI_ANY_ID as u32), ()) +/// ] +/// ); +/// +/// impl pci::Driver for MyDriver { +/// type IdInfo = (); +/// const ID_TABLE: pci::IdTable = &PCI_TABLE; +/// +/// fn probe( +/// _pdev: &mut pci::Device, +/// _id: &pci::DeviceId, +/// _id_info: &Self::IdInfo, +/// ) -> Result>> { +/// Err(ENODEV) +/// } +/// } +///``` +/// Drivers must implement this trait in order to get a PCI driver registered. Please refer to the +/// `Adapter` documentation for an example. +pub trait Driver { + /// The type holding information about each device id supported by the driver. + /// + /// TODO: Use associated_type_defaults once stabilized: + /// + /// type IdInfo: 'static = (); + type IdInfo: 'static; + + /// The table of device ids supported by the driver. + const ID_TABLE: IdTable; + + /// PCI driver probe. + /// + /// Called when a new platform device is added or discovered. + /// Implementers should attempt to initialize the device here. + fn probe(dev: &mut Device, id: &DeviceId, id_info: &Self::IdInfo) -> Result>>; +} + +/// The PCI device representation. +/// +/// A PCI device is based on an always reference counted `device:Device` instance. Cloning a PCI +/// device, hence, also increments the base device' reference count. +#[derive(Clone)] +pub struct Device(ARef); + +impl Device { + /// Create a PCI Device instance from an existing `device::Device`. + /// + /// # Safety + /// + /// `dev` must be an `ARef` whose underlying `bindings::device` is a member of + /// a `bindings::pci_dev`. + pub unsafe fn from_dev(dev: ARef) -> Self { + Self(dev) + } + + fn as_raw(&self) -> *mut bindings::pci_dev { + // SAFETY: By the type invariant `self.0.as_raw` is a pointer to the `struct device` + // embedded in `struct pci_dev`. + unsafe { container_of!(self.0.as_raw(), bindings::pci_dev, dev) as _ } + } + + /// Enable memory resources for this device. + pub fn enable_device_mem(&self) -> Result { + // SAFETY: `self.as_raw` is guaranteed to be a pointer to a valid `struct pci_dev`. + let ret = unsafe { bindings::pci_enable_device_mem(self.as_raw()) }; + if ret != 0 { + Err(Error::from_errno(ret)) + } else { + Ok(()) + } + } + + /// Enable bus-mastering for this device. + pub fn set_master(&self) { + // SAFETY: `self.as_raw` is guaranteed to be a pointer to a valid `struct pci_dev`. + unsafe { bindings::pci_set_master(self.as_raw()) }; + } +} + +impl AsRef for Device { + fn as_ref(&self) -> &device::Device { + &self.0 + } +} From patchwork Tue Oct 22 21:31:49 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Danilo Krummrich X-Patchwork-Id: 13846180 X-Patchwork-Delegate: bhelgaas@google.com 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 07E821CDA01; Tue, 22 Oct 2024 21:33:39 +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=1729632819; cv=none; b=XaNAwoZ3LYSXb/tCkvP/b3lOMZ+HdT1Oi5pBu1Rzq7BSEUJ007d6g2HTfyKjt+hraimaN8dHoT+5xCmmWerFz8dStI4JynQH/vLw35olJLxrZCdtmS2x1mrWiXoYSlgMLH3/3ujgthl/YOzVzX16ZhtyYZI88R5umQhBZoLoMNM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729632819; c=relaxed/simple; bh=z5ECK64GtKy5YT46phRMAyyFvOnRMFYmZAm3K3e4hjY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=bKuGypoDgwonYRYeT8bdI4mJz3AFOX5YTNSn9My9+aLAHS0VD8jxCoFaHTCPWFpv0IuFZgMmnbLTuwINXibTqSh8ac0uetZNwLGoXBSFs57nxj9lv+p8kli/nDPiQW0OLoO3SBWQr4LC9zSf9StK/gnE81adeW7wldE2EEbHv9M= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=K2M+tJxN; 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="K2M+tJxN" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CE35AC4CEE3; Tue, 22 Oct 2024 21:33:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1729632818; bh=z5ECK64GtKy5YT46phRMAyyFvOnRMFYmZAm3K3e4hjY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=K2M+tJxNAO6GiD0xa+EbtI/k2fICfvgCQdG0jJdp/IbDCIQBpwQ4CR0ijmhbypux0 tFb/eZDy57yQvK6DLJDjUk9Se3OgEZDK1FFO/7xuGKW5DnUD83MkttR4z2y2TZXIT0 24Ny9kgFJ1tbK/8TY3KkXeVvuLa7xN/NNDaGBpZNISJ/+ZI7986uB++PAWv/ExJ0+v MFNnVzcHziUi7v4IJn3/t67tPGKa5XT+MvPjeJAqTnxTlOURbTnsqQAQ5kizpeTUSo j2h+y3Wnyzk5D6iB+ks+TjQkTUJloOJyOwv1G63MWncewvQtOW0qgnZHIwo30d3ok8 CBnLIGTg/F2XQ== From: Danilo Krummrich To: gregkh@linuxfoundation.org, rafael@kernel.org, bhelgaas@google.com, ojeda@kernel.org, alex.gaynor@gmail.com, boqun.feng@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com, benno.lossin@proton.me, tmgross@umich.edu, a.hindborg@samsung.com, aliceryhl@google.com, airlied@gmail.com, fujita.tomonori@gmail.com, lina@asahilina.net, pstanner@redhat.com, ajanulgu@redhat.com, lyude@redhat.com, robh@kernel.org, daniel.almeida@collabora.com, saravanak@google.com Cc: rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, devicetree@vger.kernel.org, Danilo Krummrich Subject: [PATCH v3 12/16] rust: pci: implement I/O mappable `pci::Bar` Date: Tue, 22 Oct 2024 23:31:49 +0200 Message-ID: <20241022213221.2383-13-dakr@kernel.org> X-Mailer: git-send-email 2.46.2 In-Reply-To: <20241022213221.2383-1-dakr@kernel.org> References: <20241022213221.2383-1-dakr@kernel.org> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Implement `pci::Bar`, `pci::Device::iomap_region` and `pci::Device::iomap_region_sized` to allow for I/O mappings of PCI BARs. To ensure that a `pci::Bar`, and hence the I/O memory mapping, can't out-live the PCI device, the `pci::Bar` type is always embedded into a `Devres` container, such that the `pci::Bar` is revoked once the device is unbound and hence the I/O mapped memory is unmapped. A `pci::Bar` can be requested with (`pci::Device::iomap_region_sized`) or without (`pci::Device::iomap_region`) a const generic representing the minimal requested size of the I/O mapped memory region. In case of the latter only runtime checked I/O reads / writes are possible. Co-developed-by: Philipp Stanner Signed-off-by: Philipp Stanner Signed-off-by: Danilo Krummrich --- rust/kernel/pci.rs | 145 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 145 insertions(+) diff --git a/rust/kernel/pci.rs b/rust/kernel/pci.rs index ccc9a5f322e4..58f7d9c0045b 100644 --- a/rust/kernel/pci.rs +++ b/rust/kernel/pci.rs @@ -5,10 +5,13 @@ //! C header: [`include/linux/pci.h`](srctree/include/linux/pci.h) use crate::{ + alloc::flags::*, bindings, container_of, device, device_id::RawDeviceId, + devres::Devres, driver, error::{to_result, Result}, + io::Io, str::CStr, types::{ARef, ForeignOwnable}, ThisModule, @@ -239,9 +242,116 @@ pub trait Driver { /// /// A PCI device is based on an always reference counted `device:Device` instance. Cloning a PCI /// device, hence, also increments the base device' reference count. +/// +/// # Invariants +/// +/// `Device` hold a valid reference of `ARef` whose underlying `struct device` is a +/// member of a `struct pci_dev`. #[derive(Clone)] pub struct Device(ARef); +/// A PCI BAR to perform I/O-Operations on. +/// +/// # Invariants +/// +/// `Bar` always holds an `Io` inststance that holds a valid pointer to the start of the I/O memory +/// mapped PCI bar and its size. +pub struct Bar { + pdev: Device, + io: Io, + num: i32, +} + +impl Bar { + fn new(pdev: Device, num: u32, name: &CStr) -> Result { + let len = pdev.resource_len(num)?; + if len == 0 { + return Err(ENOMEM); + } + + // Convert to `i32`, since that's what all the C bindings use. + let num = i32::try_from(num)?; + + // SAFETY: + // `pdev` is valid by the invariants of `Device`. + // `num` is checked for validity by a previous call to `Device::resource_len`. + // `name` is always valid. + let ret = unsafe { bindings::pci_request_region(pdev.as_raw(), num, name.as_char_ptr()) }; + if ret != 0 { + return Err(EBUSY); + } + + // SAFETY: + // `pdev` is valid by the invariants of `Device`. + // `num` is checked for validity by a previous call to `Device::resource_len`. + // `name` is always valid. + let ioptr: usize = unsafe { bindings::pci_iomap(pdev.as_raw(), num, 0) } as usize; + if ioptr == 0 { + // SAFETY: + // `pdev` valid by the invariants of `Device`. + // `num` is checked for validity by a previous call to `Device::resource_len`. + unsafe { bindings::pci_release_region(pdev.as_raw(), num) }; + return Err(ENOMEM); + } + + // SAFETY: `ioptr` is guaranteed to be the start of a valid I/O mapped memory region of size + // `len`. + let io = match unsafe { Io::new(ioptr, len as usize) } { + Ok(io) => io, + Err(err) => { + // SAFETY: + // `pdev` is valid by the invariants of `Device`. + // `ioptr` is guaranteed to be the start of a valid I/O mapped memory region. + // `num` is checked for validity by a previous call to `Device::resource_len`. + unsafe { Self::do_release(&pdev, ioptr, num) }; + return Err(err); + } + }; + + Ok(Bar { pdev, io, num }) + } + + /// # Safety + /// + /// `ioptr` must be a valid pointer to the memory mapped PCI bar number `num`. + unsafe fn do_release(pdev: &Device, ioptr: usize, num: i32) { + // SAFETY: + // `pdev` is valid by the invariants of `Device`. + // `ioptr` is valid by the safety requirements. + // `num` is valid by the safety requirements. + unsafe { + bindings::pci_iounmap(pdev.as_raw(), ioptr as _); + bindings::pci_release_region(pdev.as_raw(), num); + } + } + + fn release(&self) { + // SAFETY: The safety requirements are guaranteed by the type invariant of `self.pdev`. + unsafe { Self::do_release(&self.pdev, self.io.base_addr(), self.num) }; + } +} + +impl Bar { + fn index_is_valid(index: u32) -> bool { + // A `struct pci_dev` owns an array of resources with at most `PCI_NUM_RESOURCES` entries. + index < bindings::PCI_NUM_RESOURCES + } +} + +impl Drop for Bar { + fn drop(&mut self) { + self.release(); + } +} + +impl Deref for Bar { + type Target = Io; + + fn deref(&self) -> &Self::Target { + &self.io + } +} + impl Device { /// Create a PCI Device instance from an existing `device::Device`. /// @@ -275,6 +385,41 @@ pub fn set_master(&self) { // SAFETY: `self.as_raw` is guaranteed to be a pointer to a valid `struct pci_dev`. unsafe { bindings::pci_set_master(self.as_raw()) }; } + + /// Returns the size of the given PCI bar resource. + pub fn resource_len(&self, bar: u32) -> Result { + if !Bar::index_is_valid(bar) { + return Err(EINVAL); + } + + // SAFETY: + // - `bar` is a valid bar number, as guaranteed by the above call to `Bar::index_is_valid`, + // - by its type invariant `self.as_raw` is always a valid pointer to a `struct pci_dev`. + Ok(unsafe { bindings::pci_resource_len(self.as_raw(), bar.try_into()?) }) + } + + /// Mapps an entire PCI-BAR after performing a region-request on it. I/O operation bound checks + /// can be performed on compile time for offsets (plus the requested type size) < SIZE. + pub fn iomap_region_sized( + &self, + bar: u32, + name: &CStr, + ) -> Result>> { + let bar = Bar::::new(self.clone(), bar, name)?; + let devres = Devres::new(self.as_ref(), bar, GFP_KERNEL)?; + + Ok(devres) + } + + /// Mapps an entire PCI-BAR after performing a region-request on it. + pub fn iomap_region(&self, bar: u32, name: &CStr) -> Result> { + self.iomap_region_sized::<0>(bar, name) + } + + /// Returns a new `ARef` of the base `device::Device`. + pub fn as_dev(&self) -> ARef { + self.0.clone() + } } impl AsRef for Device { From patchwork Tue Oct 22 21:31:50 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Danilo Krummrich X-Patchwork-Id: 13846181 X-Patchwork-Delegate: bhelgaas@google.com 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 D40161CDA12; Tue, 22 Oct 2024 21:33:44 +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=1729632825; cv=none; b=P7hcIVr0a4uShNTDrQeE0ZXkUzeASbobHsllhElgW+Qoxs56DDPzG5uYTjtacZJb8JLCwYD5Y+VefnT2Qqhe72nMvBeZ843qvcFMFuNsTMVA0CWoRkb683muLMsawyG5ijv9QE5P14BUVcCG0GqAOMlIneJrtU5ejZd6L+cw4CY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729632825; c=relaxed/simple; bh=6138rNionixW1Bs1ip5f6yRQ69Wk/93MH3AWM5T2VKQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=DzDarVhqE/kthxsQsFby6AtDFjQT5fNx9xBu8AAOEsA6inUut7lOvmwC7CK/CRhu0Ed5rN66K+sZzb0ON2grolohbtclFRb6YXrpmZfLGNXcVAybVoneJclAMv4iv6QDgQ0xM9UsamdZEQlU23I5GKgIpPQPIVHu/Rvl8YuTIQI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=lAOmv1eg; 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="lAOmv1eg" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5819FC4CEC3; Tue, 22 Oct 2024 21:33:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1729632824; bh=6138rNionixW1Bs1ip5f6yRQ69Wk/93MH3AWM5T2VKQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lAOmv1egUC1nf60pQO1WFALvzxr4r5BPVf8FpkOCM/iKR/qMEz5Fo/5nJpt9+xpwQ 5fBMECh+3nNb/f94WZ4dhFtdnaoXgMoqv2HvN2IdJMnH5vNW0SmWJFkwe7KJyAZEKC rtb4DUDccq/EJouKlsyvW8ucN/w/1x2pJmhF5xFkaMKXVhLpTx+UVi5t0YOCCbGjnW HjhAscHr6Gy+IwmxkMyqqjNuproDY73O8TzYBVPueY8re8UJPhp+CfFArpusFLVCJZ DBzjuCINEz98xMl2XigbybLYa69o8efX+Sy1hQ/WY/It69ocxM1R+VWlWSFJQzJEXX 7MacxbvO9i9TA== From: Danilo Krummrich To: gregkh@linuxfoundation.org, rafael@kernel.org, bhelgaas@google.com, ojeda@kernel.org, alex.gaynor@gmail.com, boqun.feng@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com, benno.lossin@proton.me, tmgross@umich.edu, a.hindborg@samsung.com, aliceryhl@google.com, airlied@gmail.com, fujita.tomonori@gmail.com, lina@asahilina.net, pstanner@redhat.com, ajanulgu@redhat.com, lyude@redhat.com, robh@kernel.org, daniel.almeida@collabora.com, saravanak@google.com Cc: rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, devicetree@vger.kernel.org, Danilo Krummrich Subject: [PATCH v3 13/16] samples: rust: add Rust PCI sample driver Date: Tue, 22 Oct 2024 23:31:50 +0200 Message-ID: <20241022213221.2383-14-dakr@kernel.org> X-Mailer: git-send-email 2.46.2 In-Reply-To: <20241022213221.2383-1-dakr@kernel.org> References: <20241022213221.2383-1-dakr@kernel.org> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 This commit adds a sample Rust PCI driver for QEMU's "pci-testdev" device. To enable this device QEMU has to be called with `-device pci-testdev`. The same driver shows how to use the PCI device / driver abstractions, as well as how to request and map PCI BARs, including a short sequence of MMIO operations. Signed-off-by: Danilo Krummrich --- MAINTAINERS | 1 + samples/rust/Kconfig | 11 ++++ samples/rust/Makefile | 1 + samples/rust/rust_driver_pci.rs | 109 ++++++++++++++++++++++++++++++++ 4 files changed, 122 insertions(+) create mode 100644 samples/rust/rust_driver_pci.rs diff --git a/MAINTAINERS b/MAINTAINERS index 2d00d3845b4a..d9c512a3e72b 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -17940,6 +17940,7 @@ F: include/linux/of_pci.h F: include/linux/pci* F: include/uapi/linux/pci* F: rust/kernel/pci.rs +F: samples/rust/rust_driver_pci.rs PCIE DRIVER FOR AMAZON ANNAPURNA LABS M: Jonathan Chocron diff --git a/samples/rust/Kconfig b/samples/rust/Kconfig index b0f74a81c8f9..6d468193cdd8 100644 --- a/samples/rust/Kconfig +++ b/samples/rust/Kconfig @@ -30,6 +30,17 @@ config SAMPLE_RUST_PRINT If unsure, say N. +config SAMPLE_RUST_DRIVER_PCI + tristate "PCI Driver" + depends on PCI + help + This option builds the Rust PCI driver sample. + + To compile this as a module, choose M here: + the module will be called driver_pci. + + If unsure, say N. + config SAMPLE_RUST_HOSTPROGS bool "Host programs" help diff --git a/samples/rust/Makefile b/samples/rust/Makefile index 03086dabbea4..b66767f4a62a 100644 --- a/samples/rust/Makefile +++ b/samples/rust/Makefile @@ -2,5 +2,6 @@ obj-$(CONFIG_SAMPLE_RUST_MINIMAL) += rust_minimal.o obj-$(CONFIG_SAMPLE_RUST_PRINT) += rust_print.o +obj-$(CONFIG_SAMPLE_RUST_DRIVER_PCI) += rust_driver_pci.o subdir-$(CONFIG_SAMPLE_RUST_HOSTPROGS) += hostprogs diff --git a/samples/rust/rust_driver_pci.rs b/samples/rust/rust_driver_pci.rs new file mode 100644 index 000000000000..d24dc1fde9e8 --- /dev/null +++ b/samples/rust/rust_driver_pci.rs @@ -0,0 +1,109 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Rust PCI driver sample (based on QEMU's `pci-testdev`). +//! +//! To make this driver probe, QEMU must be run with `-device pci-testdev`. + +use kernel::{bindings, c_str, devres::Devres, pci, prelude::*}; + +struct Regs; + +impl Regs { + const TEST: usize = 0x0; + const OFFSET: usize = 0x4; + const DATA: usize = 0x8; + const COUNT: usize = 0xC; + const END: usize = 0x10; +} + +type Bar0 = pci::Bar<{ Regs::END }>; + +#[derive(Debug)] +struct TestIndex(u8); + +impl TestIndex { + const NO_EVENTFD: Self = Self(0); +} + +struct SampleDriver { + pdev: pci::Device, + bar: Devres, +} + +kernel::pci_device_table!( + PCI_TABLE, + MODULE_PCI_TABLE, + ::IdInfo, + [( + pci::DeviceId::new(bindings::PCI_VENDOR_ID_REDHAT, 0x5), + TestIndex::NO_EVENTFD + )] +); + +impl SampleDriver { + fn testdev(index: &TestIndex, bar: &Bar0) -> Result { + // Select the test. + bar.writeb(index.0, Regs::TEST); + + let offset = u32::from_le(bar.readl(Regs::OFFSET)) as usize; + let data = bar.readb(Regs::DATA); + + // Write `data` to `offset` to increase `count` by one. + // + // Note that we need `try_writeb`, since `offset` can't be checked at compile-time. + bar.try_writeb(data, offset)?; + + Ok(u32::from_le(bar.readl(Regs::COUNT))) + } +} + +impl pci::Driver for SampleDriver { + type IdInfo = TestIndex; + + const ID_TABLE: pci::IdTable = &PCI_TABLE; + + fn probe( + pdev: &mut pci::Device, + _id: &pci::DeviceId, + info: &Self::IdInfo, + ) -> Result>> { + dev_dbg!(pdev.as_ref(), "Probe Rust PCI driver sample.\n"); + + pdev.enable_device_mem()?; + pdev.set_master(); + + let bar = pdev.iomap_region_sized::<{ Regs::END }>(0, c_str!("rust_driver_pci"))?; + + let drvdata = KBox::new( + Self { + pdev: pdev.clone(), + bar, + }, + GFP_KERNEL, + )?; + + let bar = drvdata.bar.try_access().ok_or(ENXIO)?; + + dev_info!( + pdev.as_ref(), + "pci-testdev data-match count: {}\n", + Self::testdev(info, &bar)? + ); + + Ok(drvdata.into()) + } +} + +impl Drop for SampleDriver { + fn drop(&mut self) { + dev_dbg!(self.pdev.as_ref(), "Remove Rust PCI driver sample.\n"); + } +} + +kernel::module_pci_driver! { + type: SampleDriver, + name: "rust_driver_pci", + author: "Danilo Krummrich", + description: "Rust PCI driver", + license: "GPL v2", +} From patchwork Tue Oct 22 21:31:51 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Danilo Krummrich X-Patchwork-Id: 13846182 X-Patchwork-Delegate: bhelgaas@google.com 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 5FF761CDA12; Tue, 22 Oct 2024 21:33:50 +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=1729632830; cv=none; b=Qkd+MmbVLNiqCeCgKqPlzSJjQ3kXCzWK0ri6jIRdW9aFuhoUpmbzlvoJh0WPfeCd1NurekVgbOOZlQwwXmkqxM0TEwb+lB6QIrTZKk5Emyk3YsW6G+/sb5d9gM4v3Fg+dWXoWgK77VXCvGo1Op0pWuhJ2R6vMFzvvSop3w0jyw8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729632830; c=relaxed/simple; bh=oZxudZpPmp3wO6kvmh14Nmt+ARxxpIUr1MKPymhU6dE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ROrIad3u8/raRgxkn99csH3U5aSg9ZgS567iOn7xNOAwjZqq3g1ygaQmMNAAIWtoe8B8tNbogXzg2J2HTJL/gIBeqQEOdsRSFAFjmnhlWuw1jYyhEPmI+eNmMk3FyOHtDCPmOBU+YG0Vm5d7YiwcZjlxelgxqvbCEMCPvs6l+yk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=dWLlpX82; 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="dWLlpX82" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D3375C4CEE3; Tue, 22 Oct 2024 21:33:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1729632829; bh=oZxudZpPmp3wO6kvmh14Nmt+ARxxpIUr1MKPymhU6dE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=dWLlpX82/K4GKKTMSHc3mx9wavzsZ5VXCkelZAJvziHrudv3FhLTwY3BOaV5uH2gg dTftQvmoH1qr96EpbTM6W/Fn9E9VwuHCVECxljNnY5HxDe00jzynTsX25SHCB4En3C LsEV+zVrnIW/WarTVWGhAUorYRP3iQthVPL01DKnEfIobxr+qd1cpFNdh0KvgVDgQA K65J4roMfmVo+vfsYQVr55k4nKeax9xCpuAjeaioHGM2cjFxXdr+ObDMkotoZFYcKf e3m8Hlunebu/Wq/SbZpg1TKuLhGGPMlaLSZ50V7e/UTTZl+T/m9pcbFUZ9d7ZR2Nkw cKx+4sj56tu+g== From: Danilo Krummrich To: gregkh@linuxfoundation.org, rafael@kernel.org, bhelgaas@google.com, ojeda@kernel.org, alex.gaynor@gmail.com, boqun.feng@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com, benno.lossin@proton.me, tmgross@umich.edu, a.hindborg@samsung.com, aliceryhl@google.com, airlied@gmail.com, fujita.tomonori@gmail.com, lina@asahilina.net, pstanner@redhat.com, ajanulgu@redhat.com, lyude@redhat.com, robh@kernel.org, daniel.almeida@collabora.com, saravanak@google.com Cc: rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, devicetree@vger.kernel.org, Danilo Krummrich Subject: [PATCH v3 14/16] rust: of: add `of::DeviceId` abstraction Date: Tue, 22 Oct 2024 23:31:51 +0200 Message-ID: <20241022213221.2383-15-dakr@kernel.org> X-Mailer: git-send-email 2.46.2 In-Reply-To: <20241022213221.2383-1-dakr@kernel.org> References: <20241022213221.2383-1-dakr@kernel.org> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 `of::DeviceId` is an abstraction around `struct of_device_id`. This is used by subsequent patches, in particular the platform bus abstractions, to create OF device ID tables. Signed-off-by: Danilo Krummrich --- MAINTAINERS | 1 + rust/bindings/bindings_helper.h | 1 + rust/kernel/lib.rs | 1 + rust/kernel/of.rs | 63 +++++++++++++++++++++++++++++++++ 4 files changed, 66 insertions(+) create mode 100644 rust/kernel/of.rs diff --git a/MAINTAINERS b/MAINTAINERS index d9c512a3e72b..87eb9a7869eb 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -17340,6 +17340,7 @@ T: git git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux.git F: Documentation/ABI/testing/sysfs-firmware-ofw F: drivers/of/ F: include/linux/of*.h +F: rust/kernel/of.rs F: scripts/dtc/ F: tools/testing/selftests/dt/ K: of_overlay_notifier_ diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h index cd4edd6496ae..312f03cbdce9 100644 --- a/rust/bindings/bindings_helper.h +++ b/rust/bindings/bindings_helper.h @@ -15,6 +15,7 @@ #include #include #include +#include #include #include #include diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs index 3ec690eb6d43..5946f59f1688 100644 --- a/rust/kernel/lib.rs +++ b/rust/kernel/lib.rs @@ -51,6 +51,7 @@ pub mod list; #[cfg(CONFIG_NET)] pub mod net; +pub mod of; pub mod page; pub mod prelude; pub mod print; diff --git a/rust/kernel/of.rs b/rust/kernel/of.rs new file mode 100644 index 000000000000..a37629997974 --- /dev/null +++ b/rust/kernel/of.rs @@ -0,0 +1,63 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Open Firmware abstractions. +//! +//! C header: [`include/linux/of_*.h`](srctree/include/linux/of_*.h) + +use crate::{bindings, device_id::RawDeviceId, prelude::*}; + +/// An open firmware device id. +#[derive(Clone, Copy)] +pub struct DeviceId(bindings::of_device_id); + +// SAFETY: +// * `DeviceId` is a `#[repr(transparent)` wrapper of `struct of_device_id` and does not add +// additional invariants, so it's safe to transmute to `RawType`. +// * `DRIVER_DATA_OFFSET` is the offset to the `data` field. +unsafe impl RawDeviceId for DeviceId { + type RawType = bindings::of_device_id; + + const DRIVER_DATA_OFFSET: usize = core::mem::offset_of!(bindings::of_device_id, data); + + fn index(&self) -> usize { + self.0.data as _ + } +} + +impl DeviceId { + /// Create a new device id from an OF 'compatible' string. + pub const fn new(compatible: &'static CStr) -> Self { + let src = compatible.as_bytes_with_nul(); + // Replace with `bindings::of_device_id::default()` once stabilized for `const`. + // SAFETY: FFI type is valid to be zero-initialized. + let mut of: bindings::of_device_id = unsafe { core::mem::zeroed() }; + + let mut i = 0; + while i < src.len() { + of.compatible[i] = src[i] as _; + i += 1; + } + + Self(of) + } + + /// The compatible string of the embedded `struct bindings::of_device_id` as `&CStr`. + pub fn compatible<'a>(&self) -> &'a CStr { + // SAFETY: `self.compatible` is a valid `char` pointer. + unsafe { CStr::from_char_ptr(self.0.compatible.as_ptr()) } + } +} + +/// Create an OF `IdTable` with an "alias" for modpost. +#[macro_export] +macro_rules! of_device_table { + ($table_name:ident, $module_table_name:ident, $id_info_type: ty, $table_data: expr) => { + const $table_name: $crate::device_id::IdArray< + $crate::of::DeviceId, + $id_info_type, + { $table_data.len() }, + > = $crate::device_id::IdArray::new($table_data); + + $crate::module_device_table!("of", $module_table_name, $table_name); + }; +} From patchwork Tue Oct 22 21:31:52 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Danilo Krummrich X-Patchwork-Id: 13846183 X-Patchwork-Delegate: bhelgaas@google.com 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 DC1CC1CCECA; Tue, 22 Oct 2024 21:33:55 +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=1729632836; cv=none; b=X3Pj2fvi658B9JrlaEa0MNymQkWZXekAVdxif7nnKLlwFKbbRrAPdcjdNnfXTFE7xjrmIw0FaG23YUFG+0uw3DjLyuW8mlds75HgxvgJ3vhOrYWnEZwxpAzsraXMX1LCdgPdsXMsdKCSHHIZ8hqZ9UNfRy+mIvcRMeG48BnYGBM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729632836; c=relaxed/simple; bh=I99bItPUGGImSDmgGsci4gBQnJK7yi7CqarWLCTyKN4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=XEuVSdsVCHcW7y4gxwtfPXX/XqTo97WtVeGsR6+KmoDXfvFXXmqRh4B7UrFTgBcwDGted8pU5WF82oLGeGdNVpApl27qVeZPytFaWGK1Ha1oWVP1db8Q9RSGGiRI9qvVn4Rq+MAx3/jBJRgk1xUL8LuvM1qIseGLC6LIFvxuKD0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ifJpBmMC; 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="ifJpBmMC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 61774C4CEE6; Tue, 22 Oct 2024 21:33:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1729632835; bh=I99bItPUGGImSDmgGsci4gBQnJK7yi7CqarWLCTyKN4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ifJpBmMC34RJoPDWNMaaGZVmYJaezRiEsY/Ed8u7gjsJRtstuREBufmQRI4LMzxm0 1Eo72sH3Fo53t6qgBbqvAbpJrDh0Ifa7c6CqKo0vCiHiqVfKp5aYSEToEOImPZu/G/ 0DOW+L0L3Ox3uXYANdAPZwHBOwtwlU4ODSQH8fQEXHNXsoNBIJca5MjnJQPBdYIZMT RpvJ3jYLRNnHMrKgja1ip257Ws0g/lnGF/b42uzpyV6MNB8Y3mEtfQMivfwSExBxeW +zk1N6pFFfwVkFe/H50CtUN5+jj/Iz5TXs05YDZz+9jdmWjrvk9RDRLyR4Nuo03dGw zQomzAGFpnXSw== From: Danilo Krummrich To: gregkh@linuxfoundation.org, rafael@kernel.org, bhelgaas@google.com, ojeda@kernel.org, alex.gaynor@gmail.com, boqun.feng@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com, benno.lossin@proton.me, tmgross@umich.edu, a.hindborg@samsung.com, aliceryhl@google.com, airlied@gmail.com, fujita.tomonori@gmail.com, lina@asahilina.net, pstanner@redhat.com, ajanulgu@redhat.com, lyude@redhat.com, robh@kernel.org, daniel.almeida@collabora.com, saravanak@google.com Cc: rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, devicetree@vger.kernel.org, Danilo Krummrich Subject: [PATCH v3 15/16] rust: platform: add basic platform device / driver abstractions Date: Tue, 22 Oct 2024 23:31:52 +0200 Message-ID: <20241022213221.2383-16-dakr@kernel.org> X-Mailer: git-send-email 2.46.2 In-Reply-To: <20241022213221.2383-1-dakr@kernel.org> References: <20241022213221.2383-1-dakr@kernel.org> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Implement the basic platform bus abstractions required to write a basic platform driver. This includes the following data structures: The `platform::Driver` trait represents the interface to the driver and provides `pci::Driver::probe` for the driver to implement. The `platform::Device` abstraction represents a `struct platform_device`. In order to provide the platform bus specific parts to a generic `driver::Registration` the `driver::RegistrationOps` trait is implemented by `platform::Adapter`. Signed-off-by: Danilo Krummrich Signed-off-by: Dirk Behme --- MAINTAINERS | 1 + rust/bindings/bindings_helper.h | 1 + rust/helpers/helpers.c | 1 + rust/helpers/platform.c | 13 ++ rust/kernel/lib.rs | 1 + rust/kernel/platform.rs | 217 ++++++++++++++++++++++++++++++++ 6 files changed, 234 insertions(+) create mode 100644 rust/helpers/platform.c create mode 100644 rust/kernel/platform.rs diff --git a/MAINTAINERS b/MAINTAINERS index 87eb9a7869eb..173540375863 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -6985,6 +6985,7 @@ F: rust/kernel/device.rs F: rust/kernel/device_id.rs F: rust/kernel/devres.rs F: rust/kernel/driver.rs +F: rust/kernel/platform.rs DRIVERS FOR OMAP ADAPTIVE VOLTAGE SCALING (AVS) M: Nishanth Menon diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h index 312f03cbdce9..217c776615b9 100644 --- a/rust/bindings/bindings_helper.h +++ b/rust/bindings/bindings_helper.h @@ -18,6 +18,7 @@ #include #include #include +#include #include #include #include diff --git a/rust/helpers/helpers.c b/rust/helpers/helpers.c index 8bc6e9735589..663cdc2a45e0 100644 --- a/rust/helpers/helpers.c +++ b/rust/helpers/helpers.c @@ -17,6 +17,7 @@ #include "kunit.c" #include "mutex.c" #include "page.c" +#include "platform.c" #include "pci.c" #include "rbtree.c" #include "rcu.c" diff --git a/rust/helpers/platform.c b/rust/helpers/platform.c new file mode 100644 index 000000000000..ab9b9f317301 --- /dev/null +++ b/rust/helpers/platform.c @@ -0,0 +1,13 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include + +void *rust_helper_platform_get_drvdata(const struct platform_device *pdev) +{ + return platform_get_drvdata(pdev); +} + +void rust_helper_platform_set_drvdata(struct platform_device *pdev, void *data) +{ + platform_set_drvdata(pdev, data); +} diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs index 5946f59f1688..9e8dcd6d7c01 100644 --- a/rust/kernel/lib.rs +++ b/rust/kernel/lib.rs @@ -53,6 +53,7 @@ pub mod net; pub mod of; pub mod page; +pub mod platform; pub mod prelude; pub mod print; pub mod rbtree; diff --git a/rust/kernel/platform.rs b/rust/kernel/platform.rs new file mode 100644 index 000000000000..addf5356f44f --- /dev/null +++ b/rust/kernel/platform.rs @@ -0,0 +1,217 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Abstractions for the platform bus. +//! +//! C header: [`include/linux/platform_device.h`](srctree/include/linux/platform_device.h) + +use crate::{ + bindings, container_of, device, + device_id::RawDeviceId, + driver, + error::{to_result, Result}, + of, + prelude::*, + str::CStr, + types::{ARef, ForeignOwnable}, + ThisModule, +}; + +/// An adapter for the registration of platform drivers. +pub struct Adapter(T); + +impl driver::RegistrationOps for Adapter { + type RegType = bindings::platform_driver; + + fn register( + pdrv: &mut Self::RegType, + name: &'static CStr, + module: &'static ThisModule, + ) -> Result { + pdrv.driver.name = name.as_char_ptr(); + pdrv.probe = Some(Self::probe_callback); + + // Both members of this union are identical in data layout and semantics. + pdrv.__bindgen_anon_1.remove = Some(Self::remove_callback); + pdrv.driver.of_match_table = T::ID_TABLE.as_ptr(); + + // SAFETY: `pdrv` is guaranteed to be a valid `RegType`. + to_result(unsafe { bindings::__platform_driver_register(pdrv, module.0) }) + } + + fn unregister(pdrv: &mut Self::RegType) { + // SAFETY: `pdrv` is guaranteed to be a valid `RegType`. + unsafe { bindings::platform_driver_unregister(pdrv) }; + } +} + +impl Adapter { + fn id_info(pdev: &Device) -> Option<&'static T::IdInfo> { + let table = T::ID_TABLE; + let id = T::of_match_device(pdev)?; + + Some(table.info(id.index())) + } + + extern "C" fn probe_callback(pdev: *mut bindings::platform_device) -> core::ffi::c_int { + // SAFETY: The platform bus only ever calls the probe callback with a valid `pdev`. + let dev = unsafe { device::Device::from_raw(&mut (*pdev).dev) }; + // SAFETY: `dev` is guaranteed to be embedded in a valid `struct platform_device` by the + // call above. + let mut pdev = unsafe { Device::from_dev(dev) }; + + let info = Self::id_info(&pdev); + match T::probe(&mut pdev, info) { + Ok(data) => { + // Let the `struct platform_device` own a reference of the driver's private data. + // SAFETY: By the type invariant `pdev.as_raw` returns a valid pointer to a + // `struct platform_device`. + unsafe { bindings::platform_set_drvdata(pdev.as_raw(), data.into_foreign() as _) }; + } + Err(err) => return Error::to_errno(err), + } + + 0 + } + + extern "C" fn remove_callback(pdev: *mut bindings::platform_device) { + // SAFETY: `pdev` is a valid pointer to a `struct platform_device`. + let ptr = unsafe { bindings::platform_get_drvdata(pdev) }; + + // SAFETY: `remove_callback` is only ever called after a successful call to + // `probe_callback`, hence it's guaranteed that `ptr` points to a valid and initialized + // `KBox` pointer created through `KBox::into_foreign`. + let _ = unsafe { KBox::::from_foreign(ptr) }; + } +} + +/// Declares a kernel module that exposes a single platform driver. +/// +/// # Examples +/// +/// ```ignore +/// kernel::module_platform_driver! { +/// type: MyDriver, +/// name: "Module name", +/// author: "Author name", +/// description: "Description", +/// license: "GPL v2", +/// } +/// ``` +#[macro_export] +macro_rules! module_platform_driver { + ($($f:tt)*) => { + $crate::module_driver!(, $crate::platform::Adapter, { $($f)* }); + }; +} + +/// IdTable type for platform drivers. +pub type IdTable = &'static dyn kernel::device_id::IdTable; + +/// The platform driver trait. +/// +/// # Example +/// +///``` +/// # use kernel::{bindings, c_str, of, platform}; +/// +/// struct MyDriver; +/// +/// kernel::of_device_table!( +/// OF_TABLE, +/// MODULE_OF_TABLE, +/// ::IdInfo, +/// [ +/// (of::DeviceId::new(c_str!("redhat,my-device")), ()) +/// ] +/// ); +/// +/// impl platform::Driver for MyDriver { +/// type IdInfo = (); +/// const ID_TABLE: platform::IdTable = &OF_TABLE; +/// +/// fn probe( +/// _pdev: &mut platform::Device, +/// _id_info: Option<&Self::IdInfo>, +/// ) -> Result>> { +/// Err(ENODEV) +/// } +/// } +///``` +/// Drivers must implement this trait in order to get a platform driver registered. Please refer to +/// the `Adapter` documentation for an example. +pub trait Driver { + /// The type holding information about each device id supported by the driver. + /// + /// TODO: Use associated_type_defaults once stabilized: + /// + /// type IdInfo: 'static = (); + type IdInfo: 'static; + + /// The table of device ids supported by the driver. + const ID_TABLE: IdTable; + + /// Platform driver probe. + /// + /// Called when a new platform device is added or discovered. + /// Implementers should attempt to initialize the device here. + fn probe(dev: &mut Device, id_info: Option<&Self::IdInfo>) -> Result>>; + + /// Find the [`of::DeviceId`] within [`Driver::ID_TABLE`] matching the given [`Device`], if any. + fn of_match_device(pdev: &Device) -> Option<&of::DeviceId> { + let table = Self::ID_TABLE; + + // SAFETY: + // - `table` has static lifetime, hence it's valid for read, + // - `dev` is guaranteed to be valid while it's alive, and so is + // `pdev.as_dev().as_raw()`. + let raw_id = unsafe { bindings::of_match_device(table.as_ptr(), pdev.as_dev().as_raw()) }; + + if raw_id.is_null() { + None + } else { + // SAFETY: `DeviceId` is a `#[repr(transparent)` wrapper of `struct of_device_id` and + // does not add additional invariants, so it's safe to transmute. + Some(unsafe { &*raw_id.cast::() }) + } + } +} + +/// The platform device representation. +/// +/// A platform device is based on an always reference counted `device:Device` instance. Cloning a +/// platform device, hence, also increments the base device' reference count. +/// +/// # Invariants +/// +/// `Device` holds a valid reference of `ARef` whose underlying `struct device` is a +/// member of a `struct platform_device`. +#[derive(Clone)] +pub struct Device(ARef); + +impl Device { + /// Convert a raw kernel device into a `Device` + /// + /// # Safety + /// + /// `dev` must be an `Aref` whose underlying `bindings::device` is a member of a + /// `bindings::platform_device`. + unsafe fn from_dev(dev: ARef) -> Self { + Self(dev) + } + + fn as_dev(&self) -> &device::Device { + &self.0 + } + + fn as_raw(&self) -> *mut bindings::platform_device { + // SAFETY: By the type invariant `self.0.as_raw` is a pointer to the `struct device` + // embedded in `struct platform_device`. + unsafe { container_of!(self.0.as_raw(), bindings::platform_device, dev) }.cast_mut() + } +} + +impl AsRef for Device { + fn as_ref(&self) -> &device::Device { + &self.0 + } +} From patchwork Tue Oct 22 21:31:53 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Danilo Krummrich X-Patchwork-Id: 13846184 X-Patchwork-Delegate: bhelgaas@google.com 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 274611E8825; Tue, 22 Oct 2024 21:34:01 +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=1729632841; cv=none; b=Q7/zJk66p/fSPwVDKhkrdh79De549eyl7W32b6mcM4BWyJrGJ6X75MEeb5FTu1U8/wjie+9h6w4W3t5JunEw3lb8Wiw44s2WlQVYSTNCl6yE88N/sHVzcjZLf5Dhin34NHfoXGwmT43n/+Q/Su2FVrHfy8eC/gSouMqouNou+A8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729632841; c=relaxed/simple; bh=Z6xEblxHrjFI+8uux18RRvZlXbj60UUK+yfXOOiMVQA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pjoCli3P5NFF/tD0WMkRP7C8pPcex3GrUlj9Kr4xpsbIQrLVgUZ29GhwzBLIx/gHf/fO9WUwJO18RCSAYpeqfN9rFzjHBao0c7vzT9seiivBO4iE03ZrmNia7rNX80kgq6HKWO8Dxsaq5rWrNpOJh/ZikjX0FpybVfOkxOLJKJc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=gpaIAuxQ; 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="gpaIAuxQ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E3C14C4CEC7; Tue, 22 Oct 2024 21:33:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1729632841; bh=Z6xEblxHrjFI+8uux18RRvZlXbj60UUK+yfXOOiMVQA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gpaIAuxQ7IdPOSXxPbqHTL5sFE/BHMRpR/0dprfssGCmrg1mxjRSxo6zvSL08LYE9 w7A4lJpoX2VF0dDE7TjEtg6txPXHQYjSkPUbghsDh+d3MSv/NNkgPjlDOM69CqLXo0 2NMqa7otl3U7N2PrarXUx4AH7RTyNdpWT8t41VEi164cb1pSFVmpjbMIuDVZJCLvZ8 3oZzYfl0kR4Pxwr/MLMBdcA8DWH8gc/ffNziOAX2xLMzCqhBKDPQWezuWExAyQDdBK 4SMMYZ6tSHbwoUy5DRqG+P7rvSCdVAS5itYom0/JKOOEpqnBpfKu84Ga9yNwM1CMqd 5YAA59SLqapzg== From: Danilo Krummrich To: gregkh@linuxfoundation.org, rafael@kernel.org, bhelgaas@google.com, ojeda@kernel.org, alex.gaynor@gmail.com, boqun.feng@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com, benno.lossin@proton.me, tmgross@umich.edu, a.hindborg@samsung.com, aliceryhl@google.com, airlied@gmail.com, fujita.tomonori@gmail.com, lina@asahilina.net, pstanner@redhat.com, ajanulgu@redhat.com, lyude@redhat.com, robh@kernel.org, daniel.almeida@collabora.com, saravanak@google.com Cc: rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, devicetree@vger.kernel.org, Danilo Krummrich Subject: [PATCH v3 16/16] samples: rust: add Rust platform sample driver Date: Tue, 22 Oct 2024 23:31:53 +0200 Message-ID: <20241022213221.2383-17-dakr@kernel.org> X-Mailer: git-send-email 2.46.2 In-Reply-To: <20241022213221.2383-1-dakr@kernel.org> References: <20241022213221.2383-1-dakr@kernel.org> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Add a sample Rust platform driver illustrating the usage of the platform bus abstractions. This driver probes through either a match of device / driver name or a match within the OF ID table. Signed-off-by: Danilo Krummrich Signed-off-by: Rob Herring (Arm) --- MAINTAINERS | 1 + samples/rust/Kconfig | 10 +++++ samples/rust/Makefile | 1 + samples/rust/rust_driver_platform.rs | 62 ++++++++++++++++++++++++++++ 4 files changed, 74 insertions(+) create mode 100644 samples/rust/rust_driver_platform.rs diff --git a/MAINTAINERS b/MAINTAINERS index 173540375863..583b6588fd1e 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -6986,6 +6986,7 @@ F: rust/kernel/device_id.rs F: rust/kernel/devres.rs F: rust/kernel/driver.rs F: rust/kernel/platform.rs +F: samples/rust/rust_driver_platform.rs DRIVERS FOR OMAP ADAPTIVE VOLTAGE SCALING (AVS) M: Nishanth Menon diff --git a/samples/rust/Kconfig b/samples/rust/Kconfig index 6d468193cdd8..70126b750426 100644 --- a/samples/rust/Kconfig +++ b/samples/rust/Kconfig @@ -41,6 +41,16 @@ config SAMPLE_RUST_DRIVER_PCI If unsure, say N. +config SAMPLE_RUST_DRIVER_PLATFORM + tristate "Platform Driver" + help + This option builds the Rust Platform driver sample. + + To compile this as a module, choose M here: + the module will be called rust_driver_platform. + + If unsure, say N. + config SAMPLE_RUST_HOSTPROGS bool "Host programs" help diff --git a/samples/rust/Makefile b/samples/rust/Makefile index b66767f4a62a..11fcb312ed36 100644 --- a/samples/rust/Makefile +++ b/samples/rust/Makefile @@ -3,5 +3,6 @@ obj-$(CONFIG_SAMPLE_RUST_MINIMAL) += rust_minimal.o obj-$(CONFIG_SAMPLE_RUST_PRINT) += rust_print.o obj-$(CONFIG_SAMPLE_RUST_DRIVER_PCI) += rust_driver_pci.o +obj-$(CONFIG_SAMPLE_RUST_DRIVER_PLATFORM) += rust_driver_platform.o subdir-$(CONFIG_SAMPLE_RUST_HOSTPROGS) += hostprogs diff --git a/samples/rust/rust_driver_platform.rs b/samples/rust/rust_driver_platform.rs new file mode 100644 index 000000000000..55caaaa4f216 --- /dev/null +++ b/samples/rust/rust_driver_platform.rs @@ -0,0 +1,62 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Rust Platform driver sample. + +use kernel::{c_str, of, platform, prelude::*}; + +struct SampleDriver { + pdev: platform::Device, +} + +struct Info(u32); + +kernel::of_device_table!( + OF_TABLE, + MODULE_OF_TABLE, + ::IdInfo, + [( + of::DeviceId::new(c_str!("redhat,rust-sample-platform-driver")), + Info(42) + )] +); + +impl platform::Driver for SampleDriver { + type IdInfo = Info; + const ID_TABLE: platform::IdTable = &OF_TABLE; + + fn probe(pdev: &mut platform::Device, info: Option<&Self::IdInfo>) -> Result>> { + dev_dbg!(pdev.as_ref(), "Probe Rust Platform driver sample.\n"); + + match (Self::of_match_device(pdev), info) { + (Some(id), Some(info)) => { + dev_info!( + pdev.as_ref(), + "Probed by OF compatible match: '{}' with info: '{}'.\n", + id.compatible(), + info.0 + ); + } + _ => { + dev_info!(pdev.as_ref(), "Probed by name.\n"); + } + }; + + let drvdata = KBox::new(Self { pdev: pdev.clone() }, GFP_KERNEL)?; + + Ok(drvdata.into()) + } +} + +impl Drop for SampleDriver { + fn drop(&mut self) { + dev_dbg!(self.pdev.as_ref(), "Remove Rust Platform driver sample.\n"); + } +} + +kernel::module_platform_driver! { + type: SampleDriver, + name: "rust_driver_platform", + author: "Danilo Krummrich", + description: "Rust Platform driver", + license: "GPL v2", +}