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Date:   Thu, 18 May 2023 11:51:17 -0300
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From:   Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Subject: Re: [PATCH v1 1/7] rust: workqueue: add low-level workqueue bindings
To:     Alice Ryhl <aliceryhl@google.com>, rust-for-linux@vger.kernel.org
Cc:     Miguel Ojeda <ojeda@kernel.org>,
        Wedson Almeida Filho <wedsonaf@gmail.com>,
        Tejun Heo <tj@kernel.org>,
        Lai Jiangshan <jiangshanlai@gmail.com>,
        Alex Gaynor <alex.gaynor@gmail.com>,
        Boqun Feng <boqun.feng@gmail.com>, Gary Guo <gary@garyguo.net>,
        =?UTF-8?Q?Bj=c3=b6rn_Roy_Baron?= <bjorn3_gh@protonmail.com>,
        Benno Lossin <benno.lossin@proton.me>,
        linux-kernel@vger.kernel.org, patches@lists.linux.dev
References: <20230517203119.3160435-1-aliceryhl@google.com>
 <20230517203119.3160435-2-aliceryhl@google.com>
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On 5/17/23 17:31, Alice Ryhl wrote:
> Define basic low-level bindings to a kernel workqueue. The API defined
> here can only be used unsafely. Later commits will provide safe
> wrappers.
> 
> Signed-off-by: Alice Ryhl <aliceryhl@google.com>
> ---
> [...]
> +
> +impl Queue {
> +    /// Use the provided `struct workqueue_struct` with Rust.
> +    ///
> +    /// # Safety
> +    ///
> +    /// The caller must ensure that the provided raw pointer is not dangling, that it points at a
> +    /// valid workqueue, and that it remains valid until the end of 'a.
> +    pub unsafe fn from_raw<'a>(ptr: *const bindings::workqueue_struct) -> &'a Queue {
> +        // SAFETY: The `Queue` type is `#[repr(transparent)]`, so the pointer cast is valid. The
> +        // caller promises that the pointer is not dangling.
> +        unsafe { &*(ptr as *const Queue) }
> +    }
> +
> +    /// Enqueues a work item.
> +    ///
> +    /// This may fail if the work item is already enqueued in a workqueue.

Wouldn't be worth to mention that, if not implied, the item it's going
to be worked on an unbound CPU?

> +    pub fn enqueue<T: WorkItem + Send + 'static>(&self, w: T) -> T::EnqueueOutput {
> +        let queue_ptr = self.0.get();
> [...]

Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>