From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 984B52F432C; Thu, 12 Jun 2025 12:18:28 +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=1749730708; cv=none; b=jdMTqNLvr2xyw4LgT688kuhlVy5ehGH9jgUGU957Sp2QZOWfQI7WlHQKQ5e2i0RNDdNjQMqEWKjGMoTe96QpwrjL26iRfkMxKrv/NoSYK3ys7mKIUBZqpjx7nHIc2NCpd6uI+zKkWfxXiuK8uclPdX3GK4+X/GFnpkDhTOKQGJU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749730708; c=relaxed/simple; bh=pGIw757m+pB1s3tIiKzy4x/ZyUNFBlz0e0asq3qevaI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=bHrC1Q7kbOW7ZzZ81aLVbplMfkvgv2djP8B6nAKAlsrVkmN+1NaVu1S7GfUYeTfZRktkoKdJJFttreYjGmqdF6UMvWwGEXxzMESpQpgWdVzNQzTx/vJK/vrTIAqOlc8oexPPniJ6T5+iTJnZQ2ZaC8SFzjVYOll4+aDdhk7wxvc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=JZqEX2xU; 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="JZqEX2xU" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8EAECC4CEEA; Thu, 12 Jun 2025 12:18:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1749730708; bh=pGIw757m+pB1s3tIiKzy4x/ZyUNFBlz0e0asq3qevaI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JZqEX2xU5/bHbUwdRSbB+K9KWVq39BA+j2qk+zEmKefZbICDHZrbNqo+2VGBGRO5X sVtWjJPct+rtmKVEsV4co9ognExKllfvimwIubKbA5xiagu3jpHg7v3OTZ/SpMQqKh ALc4/jpGs+zoR/4x/8hjUTkWSpfGuKaURsjpnEIiasmfivFWyaWTGie9h9acMtld4H d328VPHH+rmiBMd7go7hq9IKkqVxEiWYhbViIXxbbCJFfPy3ZazBBVPL4JahNEbwBo qvjrBaaWKCKp/TeFmjCJk/0td9ADkfVNz/B1brao86QfdngotRhjploH9tqVkcaWj6 fVdyipSNaXweA== From: Danilo Krummrich To: gregkh@linuxfoundation.org, rafael@kernel.org, ojeda@kernel.org, alex.gaynor@gmail.com, boqun.feng@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com, benno.lossin@proton.me, a.hindborg@kernel.org, aliceryhl@google.com, tmgross@umich.edu Cc: rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, Danilo Krummrich , Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , Benno Lossin Subject: [PATCH v2 1/3] rust: completion: implement initial abstraction Date: Thu, 12 Jun 2025 14:17:13 +0200 Message-ID: <20250612121817.1621-2-dakr@kernel.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250612121817.1621-1-dakr@kernel.org> References: <20250612121817.1621-1-dakr@kernel.org> Precedence: bulk X-Mailing-List: rust-for-linux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Implement a minimal abstraction for the completion synchronization primitive. This initial abstraction only adds complete_all() and wait_for_completion(), since that is what is required for the subsequent Devres patch. Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Juri Lelli Cc: Vincent Guittot Cc: Dietmar Eggemann Cc: Steven Rostedt Cc: Ben Segall Cc: Mel Gorman Cc: Valentin Schneider Reviewed-by: Alice Ryhl Reviewed-by: Boqun Feng Reviewed-by: Benno Lossin Signed-off-by: Danilo Krummrich --- rust/bindings/bindings_helper.h | 1 + rust/helpers/completion.c | 8 +++ rust/helpers/helpers.c | 1 + rust/kernel/sync.rs | 2 + rust/kernel/sync/completion.rs | 112 ++++++++++++++++++++++++++++++++ 5 files changed, 124 insertions(+) create mode 100644 rust/helpers/completion.c create mode 100644 rust/kernel/sync/completion.rs diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h index bc494745f67b..8cbb660e2ec2 100644 --- a/rust/bindings/bindings_helper.h +++ b/rust/bindings/bindings_helper.h @@ -39,6 +39,7 @@ #include #include #include +#include #include #include #include diff --git a/rust/helpers/completion.c b/rust/helpers/completion.c new file mode 100644 index 000000000000..b2443262a2ae --- /dev/null +++ b/rust/helpers/completion.c @@ -0,0 +1,8 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include + +void rust_helper_init_completion(struct completion *x) +{ + init_completion(x); +} diff --git a/rust/helpers/helpers.c b/rust/helpers/helpers.c index 0f1b5d115985..6451cfd94a8d 100644 --- a/rust/helpers/helpers.c +++ b/rust/helpers/helpers.c @@ -13,6 +13,7 @@ #include "build_assert.c" #include "build_bug.c" #include "clk.c" +#include "completion.c" #include "cpufreq.c" #include "cpumask.c" #include "cred.c" diff --git a/rust/kernel/sync.rs b/rust/kernel/sync.rs index 36a719015583..c23a12639924 100644 --- a/rust/kernel/sync.rs +++ b/rust/kernel/sync.rs @@ -10,6 +10,7 @@ use pin_init; mod arc; +pub mod completion; mod condvar; pub mod lock; mod locked_by; @@ -17,6 +18,7 @@ pub mod rcu; pub use arc::{Arc, ArcBorrow, UniqueArc}; +pub use completion::Completion; pub use condvar::{new_condvar, CondVar, CondVarTimeoutResult}; pub use lock::global::{global_lock, GlobalGuard, GlobalLock, GlobalLockBackend, GlobalLockedBy}; pub use lock::mutex::{new_mutex, Mutex, MutexGuard}; diff --git a/rust/kernel/sync/completion.rs b/rust/kernel/sync/completion.rs new file mode 100644 index 000000000000..595f6be2c4a8 --- /dev/null +++ b/rust/kernel/sync/completion.rs @@ -0,0 +1,112 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Completion support. +//! +//! Reference: +//! +//! C header: [`include/linux/completion.h`](srctree/include/linux/completion.h) + +use crate::{bindings, prelude::*, types::Opaque}; + +/// Synchronization primitive to signal when a certain task has been completed. +/// +/// The [`Completion`] synchronization primitive signales when a certain task has been completed by +/// waking up other tasks that have been queued up to wait for the [`Completion`] to be completed. +/// +/// # Examples +/// +/// ``` +/// use kernel::sync::{Arc, Completion}; +/// use kernel::workqueue::{self, impl_has_work, new_work, Work, WorkItem}; +/// +/// #[pin_data] +/// struct MyTask { +/// #[pin] +/// work: Work, +/// #[pin] +/// done: Completion, +/// } +/// +/// impl_has_work! { +/// impl HasWork for MyTask { self.work } +/// } +/// +/// impl MyTask { +/// fn new() -> Result> { +/// let this = Arc::pin_init(pin_init!(MyTask { +/// work <- new_work!("MyTask::work"), +/// done <- Completion::new(), +/// }), GFP_KERNEL)?; +/// +/// let _ = workqueue::system().enqueue(this.clone()); +/// +/// Ok(this) +/// } +/// +/// fn wait_for_completion(&self) { +/// self.done.wait_for_completion(); +/// +/// pr_info!("Completion: task complete\n"); +/// } +/// } +/// +/// impl WorkItem for MyTask { +/// type Pointer = Arc; +/// +/// fn run(this: Arc) { +/// // process this task +/// this.done.complete_all(); +/// } +/// } +/// +/// let task = MyTask::new()?; +/// task.wait_for_completion(); +/// # Ok::<(), Error>(()) +/// ``` +#[pin_data] +pub struct Completion { + #[pin] + inner: Opaque, +} + +// SAFETY: `Completion` is safe to be send to any task. +unsafe impl Send for Completion {} + +// SAFETY: `Completion` is safe to be accessed concurrently. +unsafe impl Sync for Completion {} + +impl Completion { + /// Create an initializer for a new [`Completion`]. + pub fn new() -> impl PinInit { + pin_init!(Self { + inner <- Opaque::ffi_init(|slot: *mut bindings::completion| { + // SAFETY: `slot` is a valid pointer to an uninitialized `struct completion`. + unsafe { bindings::init_completion(slot) }; + }), + }) + } + + fn as_raw(&self) -> *mut bindings::completion { + self.inner.get() + } + + /// Signal all tasks waiting on this completion. + /// + /// This method wakes up all tasks waiting on this completion; after this operation the + /// completion is permanently done, i.e. signals all current and future waiters. + pub fn complete_all(&self) { + // SAFETY: `self.as_raw()` is a pointer to a valid `struct completion`. + unsafe { bindings::complete_all(self.as_raw()) }; + } + + /// Wait for completion of a task. + /// + /// This method waits for the completion of a task; it is not interruptible and there is no + /// timeout. + /// + /// See also [`Completion::complete_all`]. + pub fn wait_for_completion(&self) { + // SAFETY: `self.as_raw()` is a pointer to a valid `struct completion`. + unsafe { bindings::wait_for_completion(self.as_raw()) }; + } +} -- 2.49.0