From patchwork Thu Jun 1 13:49:44 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alice Ryhl X-Patchwork-Id: 101951 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:994d:0:b0:3d9:f83d:47d9 with SMTP id k13csp357174vqr; Thu, 1 Jun 2023 07:08:29 -0700 (PDT) X-Google-Smtp-Source: ACHHUZ68i289MXS8XD7uposMFCyEw5a00qSW4RYua0PC5K37CBuQGu7e6sonot8Xd7hQ58b6MB2+ X-Received: by 2002:a05:6a20:12cc:b0:110:7edc:fb50 with SMTP id v12-20020a056a2012cc00b001107edcfb50mr8560872pzg.9.1685628509248; Thu, 01 Jun 2023 07:08:29 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1685628509; cv=none; d=google.com; s=arc-20160816; b=K5ZqbP/qXIETyHuYohPAxY/SY9uu4JMtmd9wrbBeTpKRf91+yDCvyRjEFwUbsxNKIG WJhbJEL8NF3Yevmb7TV0ETjLkyc/vrM5VPnk7VfNsAQhN8x33P1ASCBXgr1kinKcBBXL 4DXAulPiO6n8Cr9RVEEmSAzyDCRrfWZRrhzNu/wM638Tdhe7byf0wQ7qWwTFCc2wFm9/ sGYq9tEGJbTxM17kGvDpcq+viJ7nlLQMW3CYJ8Zi9WDTxTYiSf+3Gaygs09rBS2rtgHf zENBYlAAv/DVx6xOY5TWrXvnUo3qedqb/WUIhsuE3eqKXBrPqHgD2/CEMDYG0JEf/4Bn 5AMA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:cc:to:from:subject:message-id:references :mime-version:in-reply-to:date:dkim-signature; bh=TyRNG5KT1C+kxxh+8DvNZVfySdIBr+c+luuNQvW24B8=; b=SnMCdU1FoW67e7FMkcv4SnsDJ8hd47p/aooFBHJnpFWo3Ww+zvfXy0YsgU4P5TFl/9 57tjVrJ3UJCTF6JCpbISH+5wbXV3E/GXsd990GVuLyTT18VumanTP0lCU6qZsXbgQYr7 JUlj08DOGQmTdu6fSXM/N1/C66RcQalvJqp+E9sDqPeE8/LlPfQXDnTuOMrEN69Jra4Y r3tE9BnSlWyBkkyeCuwtcgBmXTnaM2IwlWUzeLKIa5Fu+kjlxdXunxD4DJPgCBEXruYo Xg/t7GZrl9VWaSFagUnW2O0QPDTo4bGkZ5PSdOlcNyMHll9ZVAqZHj10+vywa2+nDjur wMvA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@google.com header.s=20221208 header.b=rqoKpkOt; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id a63-20020a639042000000b0053b64127cddsi2937454pge.212.2023.06.01.07.07.59; Thu, 01 Jun 2023 07:08:29 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@google.com header.s=20221208 header.b=rqoKpkOt; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233545AbjFAN4R (ORCPT + 99 others); Thu, 1 Jun 2023 09:56:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51950 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232769AbjFAN4P (ORCPT ); Thu, 1 Jun 2023 09:56:15 -0400 Received: from mail-yw1-x114a.google.com (mail-yw1-x114a.google.com [IPv6:2607:f8b0:4864:20::114a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E1E3E129 for ; Thu, 1 Jun 2023 06:56:13 -0700 (PDT) Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-565c380565dso22593137b3.1 for ; Thu, 01 Jun 2023 06:56:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1685627773; x=1688219773; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=TyRNG5KT1C+kxxh+8DvNZVfySdIBr+c+luuNQvW24B8=; b=rqoKpkOtbw5E7aZUP5vKjWc3Rud11Cj869FSLBYeNDUpqqAOXnkZIPl7lj5T2v5p7s DmMa94afp5CNZFk1ywR4ew+ffsOd7nOjrFz827+LCZEp8XI49xI9Wdw9RtCEvPkuo8im TbhBhsVdo138vg3Nl4AMaccmsNOCCPZENyu59Kaii+poHD6Mc9UdWgsN3jNMxvyt2W4I y2/H0+6GzKgtGlccHAiV83rBObv6Oqk4nXU9rcSvjnEk0GniwrycnB1qvh3JpmxgcBKs vNmUwJcJLMtZRaxTJ5rpjwixRZNRXubZmOhOpkg300KRq2lF92feTXVc6m+zgHMAsqIc FyaA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1685627773; x=1688219773; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=TyRNG5KT1C+kxxh+8DvNZVfySdIBr+c+luuNQvW24B8=; b=Av8fzN6acgq9cqPKg8w5NP7W/jPbdPu86oBTUHO74Vf3sOGtJy7tgkixDikDpMuhNS PltCeeHMTszdkiKw8feSgiPyMqffr4+y1/oVAopS5B0vXs1/OV28kc+cFtPfgUqEbNR2 64pDkwjkE9bfo8pyUeVBKYnqSWINJvzYNQPlqVt8+Cv1P5gWes6e3UAcSC3h5cvX0LIJ cGgV+HHOA3qimD6DdeANSIzV2rvNRZjoYSWA2271Nc40aHtNPEYkygV84Ggc8rPtGzl1 ySNXBMhq00xnWpQRWjAc8NHVZPri2vtNKGbxYvhy/9+01hwfwkCl+Srz94lpj9MWinE5 EYdg== X-Gm-Message-State: AC+VfDyOGNxF2hk76dJER4GeGwKikfpjLujBxaRVSYoz0jGPEv/1OVkL A35TSaYNCGXPJH44Tiv+4JXSz8Vwf49Fgd4= X-Received: from aliceryhl.c.googlers.com ([fda3:e722:ac3:cc00:31:98fb:c0a8:6c8]) (user=aliceryhl job=sendgmr) by 2002:a81:7813:0:b0:561:ec3e:62fd with SMTP id t19-20020a817813000000b00561ec3e62fdmr1402978ywc.5.1685627773081; Thu, 01 Jun 2023 06:56:13 -0700 (PDT) Date: Thu, 1 Jun 2023 13:49:44 +0000 In-Reply-To: <20230601134946.3887870-1-aliceryhl@google.com> Mime-Version: 1.0 References: <20230601134946.3887870-1-aliceryhl@google.com> X-Mailer: git-send-email 2.41.0.rc0.172.g3f132b7071-goog Message-ID: <20230601134946.3887870-7-aliceryhl@google.com> Subject: [PATCH v2 6/8] rust: workqueue: implement `WorkItemPointer` for pointer types From: Alice Ryhl To: rust-for-linux@vger.kernel.org Cc: Miguel Ojeda , Wedson Almeida Filho , Tejun Heo , Lai Jiangshan , Alex Gaynor , Boqun Feng , Gary Guo , " =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= " , Benno Lossin , Alice Ryhl , linux-kernel@vger.kernel.org, patches@lists.linux.dev X-Spam-Status: No, score=-9.6 required=5.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE, SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE,USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1767509600066783630?= X-GMAIL-MSGID: =?utf-8?q?1767509600066783630?= This implements the `WorkItemPointer` trait for the pointer types that you are likely to use the workqueue with. The `Arc` type is for reference counted objects, and the `Pin>` type is for objects where the caller has exclusive ownership of the object. Co-developed-by: Gary Guo Signed-off-by: Gary Guo Signed-off-by: Alice Ryhl Reviewed-by: Martin Rodriguez Reboredo Reviewed-by: Andreas Hindborg (Samsung) Reviewed-by: Benno Lossin --- rust/kernel/workqueue.rs | 97 +++++++++++++++++++++++++++++++++++++++- 1 file changed, 96 insertions(+), 1 deletion(-) diff --git a/rust/kernel/workqueue.rs b/rust/kernel/workqueue.rs index dbf0aab29a85..f06a2f036d8b 100644 --- a/rust/kernel/workqueue.rs +++ b/rust/kernel/workqueue.rs @@ -28,8 +28,10 @@ //! //! C header: [`include/linux/workqueue.h`](../../../../include/linux/workqueue.h) -use crate::{bindings, prelude::*, types::Opaque}; +use crate::{bindings, prelude::*, sync::Arc, types::Opaque}; +use alloc::boxed::Box; use core::marker::{PhantomData, PhantomPinned}; +use core::pin::Pin; /// A kernel work queue. /// @@ -323,6 +325,99 @@ unsafe fn raw_get_work(ptr: *mut Self) -> *mut $crate::workqueue::Work<$work_typ )*}; } +unsafe impl WorkItemPointer for Arc +where + T: WorkItem, + T: HasWork, +{ + unsafe extern "C" fn run(ptr: *mut bindings::work_struct) { + // SAFETY: The `__enqueue` method always uses a `work_struct` stored in a `Work`. + let ptr = ptr as *mut Work; + // SAFETY: This computes the pointer that `__enqueue` got from `Arc::into_raw`. + let ptr = unsafe { T::work_container_of(ptr) }; + // SAFETY: This pointer comes from `Arc::into_raw` and we've been given back ownership. + let arc = unsafe { Arc::from_raw(ptr) }; + + T::run(arc) + } +} + +unsafe impl RawWorkItem for Arc +where + T: WorkItem, + T: HasWork, +{ + type EnqueueOutput = Result<(), Self>; + + unsafe fn __enqueue(self, queue_work_on: F) -> Self::EnqueueOutput + where + F: FnOnce(*mut bindings::work_struct) -> bool, + { + // Casting between const and mut is not a problem as long as the pointer is a raw pointer. + let ptr = Arc::into_raw(self) as *mut T; + + // SAFETY: Pointers into an `Arc` point at a valid value. + let work_ptr = unsafe { T::raw_get_work(ptr) }; + // SAFETY: `raw_get_work` returns a pointer to a valid value. + let work_ptr = unsafe { Work::raw_get(work_ptr) }; + + if queue_work_on(work_ptr) { + Ok(()) + } else { + // SAFETY: The work queue has not taken ownership of the pointer. + Err(unsafe { Arc::from_raw(ptr) }) + } + } +} + +unsafe impl WorkItemPointer for Pin> +where + T: WorkItem, + T: HasWork, +{ + unsafe extern "C" fn run(ptr: *mut bindings::work_struct) { + // SAFETY: The `__enqueue` method always uses a `work_struct` stored in a `Work`. + let ptr = ptr as *mut Work; + // SAFETY: This computes the pointer that `__enqueue` got from `Arc::into_raw`. + let ptr = unsafe { T::work_container_of(ptr) }; + // SAFETY: This pointer comes from `Arc::into_raw` and we've been given back ownership. + let boxed = unsafe { Box::from_raw(ptr) }; + // SAFETY: The box was already pinned when it was enqueued. + let pinned = unsafe { Pin::new_unchecked(boxed) }; + + T::run(pinned) + } +} + +unsafe impl RawWorkItem for Pin> +where + T: WorkItem, + T: HasWork, +{ + type EnqueueOutput = (); + + unsafe fn __enqueue(self, queue_work_on: F) -> Self::EnqueueOutput + where + F: FnOnce(*mut bindings::work_struct) -> bool, + { + // SAFETY: We're not going to move `self` or any of its fields, so its okay to temporarily + // remove the `Pin` wrapper. + let boxed = unsafe { Pin::into_inner_unchecked(self) }; + let ptr = Box::into_raw(boxed); + + // SAFETY: Pointers into a `Box` point at a valid value. + let work_ptr = unsafe { T::raw_get_work(ptr) }; + // SAFETY: `raw_get_work` returns a pointer to a valid value. + let work_ptr = unsafe { Work::raw_get(work_ptr) }; + + if !queue_work_on(work_ptr) { + // SAFETY: This method requires exclusive ownership of the box, so it cannot be in a + // workqueue. + unsafe { ::core::hint::unreachable_unchecked() } + } + } +} + /// Returns the system work queue (`system_wq`). /// /// It is the one used by `schedule[_delayed]_work[_on]()`. Multi-CPU multi-threaded. There are