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[2620:137:e000::1:20]) by mx.google.com with ESMTP id d12-20020a056402516c00b0048e82d753a3si35306534ede.227.2023.03.29.22.04.18; Wed, 29 Mar 2023 22:04:42 -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=@gmail.com header.s=20210112 header.b=MLmE4Qc5; 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=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230052AbjC3Els (ORCPT + 99 others); Thu, 30 Mar 2023 00:41:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36962 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229970AbjC3Elc (ORCPT ); Thu, 30 Mar 2023 00:41:32 -0400 Received: from mail-ot1-x336.google.com (mail-ot1-x336.google.com [IPv6:2607:f8b0:4864:20::336]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EF3D255AA; Wed, 29 Mar 2023 21:41:12 -0700 (PDT) Received: by mail-ot1-x336.google.com with SMTP id 6-20020a9d0106000000b006a177038dfeso230217otu.7; Wed, 29 Mar 2023 21:41:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1680151272; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=2cn5PpHPjbVKiTpn7S4FdRJhabCdix+uDXiUAvFeLWQ=; b=MLmE4Qc5UnH4btH/GC2TwCy+UCPp008eyBc8f+wKjsnmwOFtSq6B7qKG9mikCeMp0N 5Ynr1qpJcjIRFvjedJwWLo58Y7ensDgVtTwk+0grH6s1r7EuT+t32S25JhRXMdpSz9Fx 4LaLflnqOYvzjIeSKa5VJ5LdfO+56X3X/gxwRbRDX/251LJQFxjVUKCU2cM4qslOfzHO MH9cGjfjS37ZQdQCOBpUeHDexsgexJJtNUr44DRxNhlIvwO/IxJgW3+d8tkmeZ0A6sDs fXCvPurehpapPUZO1E9Km3uO55GeHhUeH0tdAQltEQuVvhNTMoyXkZzaudaC19cJ0/In svXQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1680151272; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=2cn5PpHPjbVKiTpn7S4FdRJhabCdix+uDXiUAvFeLWQ=; b=Sdjv2PGcj44RO5p+lXIYpcQjV5zyc4zQSTTdKrCN7uFI8LQrYya6e3qsSX3hb+t5Po EiaikeAv51uWG2hbftGV+ffeO5Fm+JAaQqi9FJTyc3o7+xvxIWooMPwgPfPA9shHCwWc +F/Fups4gEXQxYI/iTlGn1KyZKUWsdxR//fN46PDSO7fUj/p7TOQ9wt7/D7J8E5grZkH +WI1QGchTyn1gJ9tAHc5b5pKrpUVowHbKAXA45besn1kP+Tk8GZvGRv5dZXF4xJ9YLqE CMgd/OkAM2jlOHpqGTeduDnTiIyvRiotj+re5T4OuZymOlhzCg2eeSKYkC5npClIxQZA F0XA== X-Gm-Message-State: AO0yUKV87asP5/2UNvaHlqmFXLaKbxByEJofLnLerQOssi5x5RbcJwL2 l32PImcALGMbhh3fkAJVIB7nPjgJr7fOtw== X-Received: by 2002:a05:6830:1602:b0:699:f81a:14bd with SMTP id g2-20020a056830160200b00699f81a14bdmr10935792otr.30.1680151272285; Wed, 29 Mar 2023 21:41:12 -0700 (PDT) Received: from wedsonaf-dev.home.lan ([189.124.190.154]) by smtp.googlemail.com with ESMTPSA id ea43-20020a056870072b00b0017e0c13b29asm7518599oab.36.2023.03.29.21.41.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 29 Mar 2023 21:41:12 -0700 (PDT) From: Wedson Almeida Filho To: rust-for-linux@vger.kernel.org Cc: Miguel Ojeda , Alex Gaynor , Boqun Feng , Gary Guo , =?utf-8?q?B?= =?utf-8?q?j=C3=B6rn_Roy_Baron?= , linux-kernel@vger.kernel.org, Wedson Almeida Filho , Peter Zijlstra , Ingo Molnar , Will Deacon , Waiman Long Subject: [PATCH 07/13] rust: lock: implement `IrqSaveBackend` for `SpinLock` Date: Thu, 30 Mar 2023 01:39:48 -0300 Message-Id: <20230330043954.562237-7-wedsonaf@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230330043954.562237-1-wedsonaf@gmail.com> References: <20230330043954.562237-1-wedsonaf@gmail.com> MIME-Version: 1.0 X-Spam-Status: No, score=-0.2 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM,RCVD_IN_DNSWL_NONE, SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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?1761767779446094635?= X-GMAIL-MSGID: =?utf-8?q?1761767779446094635?= From: Wedson Almeida Filho This allows Rust code to use the `lock_irqsave` variant of spinlocks. Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Will Deacon Cc: Waiman Long Signed-off-by: Wedson Almeida Filho --- rust/helpers.c | 16 +++++++++++++ rust/kernel/sync/lock/spinlock.rs | 38 ++++++++++++++++++++++++++----- 2 files changed, 48 insertions(+), 6 deletions(-) diff --git a/rust/helpers.c b/rust/helpers.c index 05694e3f8f70..e42f5b446f92 100644 --- a/rust/helpers.c +++ b/rust/helpers.c @@ -59,6 +59,22 @@ void rust_helper_spin_unlock(spinlock_t *lock) } EXPORT_SYMBOL_GPL(rust_helper_spin_unlock); +unsigned long rust_helper_spin_lock_irqsave(spinlock_t *lock) +{ + unsigned long flags; + + spin_lock_irqsave(lock, flags); + + return flags; +} +EXPORT_SYMBOL_GPL(rust_helper_spin_lock_irqsave); + +void rust_helper_spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags) +{ + spin_unlock_irqrestore(lock, flags); +} +EXPORT_SYMBOL_GPL(rust_helper_spin_unlock_irqrestore); + refcount_t rust_helper_REFCOUNT_INIT(int n) { return (refcount_t)REFCOUNT_INIT(n); diff --git a/rust/kernel/sync/lock/spinlock.rs b/rust/kernel/sync/lock/spinlock.rs index a52d20fc9755..34dec09a97c0 100644 --- a/rust/kernel/sync/lock/spinlock.rs +++ b/rust/kernel/sync/lock/spinlock.rs @@ -61,6 +61,8 @@ macro_rules! new_spinlock { /// assert_eq!(e.c, 10); /// assert_eq!(e.d.lock().a, 20); /// assert_eq!(e.d.lock().b, 30); +/// assert_eq!(e.d.lock_irqsave().a, 20); +/// assert_eq!(e.d.lock_irqsave().b, 30); /// ``` /// /// The following example shows how to use interior mutability to modify the contents of a struct @@ -79,6 +81,12 @@ macro_rules! new_spinlock { /// guard.a += 10; /// guard.b += 20; /// } +/// +/// fn example2(m: &SpinLock) { +/// let mut guard = m.lock_irqsave(); +/// guard.a += 10; +/// guard.b += 20; +/// } /// ``` /// /// [`spinlock_t`]: ../../../../include/linux/spinlock.h @@ -90,7 +98,7 @@ pub struct SpinLockBackend; // SAFETY: The underlying kernel `spinlock_t` object ensures mutual exclusion. unsafe impl super::Backend for SpinLockBackend { type State = bindings::spinlock_t; - type GuardState = (); + type GuardState = Option; unsafe fn init( ptr: *mut Self::State, @@ -105,12 +113,30 @@ unsafe impl super::Backend for SpinLockBackend { unsafe fn lock(ptr: *mut Self::State) -> Self::GuardState { // SAFETY: The safety requirements of this function ensure that `ptr` points to valid // memory, and that it has been initialised before. - unsafe { bindings::spin_lock(ptr) } + unsafe { bindings::spin_lock(ptr) }; + None } - unsafe fn unlock(ptr: *mut Self::State, _guard_state: &Self::GuardState) { - // SAFETY: The safety requirements of this function ensure that `ptr` is valid and that the - // caller is the owner of the mutex. - unsafe { bindings::spin_unlock(ptr) } + unsafe fn unlock(ptr: *mut Self::State, guard_state: &Self::GuardState) { + match guard_state { + // SAFETY: The safety requirements of this function ensure that `ptr` is valid and that + // the caller is the owner of the mutex. + Some(flags) => unsafe { bindings::spin_unlock_irqrestore(ptr, *flags) }, + // SAFETY: The safety requirements of this function ensure that `ptr` is valid and that + // the caller is the owner of the mutex. + None => unsafe { bindings::spin_unlock(ptr) }, + } + } +} + +// SAFETY: The underlying kernel `spinlock_t` object ensures mutual exclusion. We use the `irqsave` +// variant of the C lock acquisition functions to disable interrupts and retrieve the original +// interrupt state, and the `irqrestore` variant of the lock release functions to restore the state +// in `unlock` -- we use the guard context to determine which method was used to acquire the lock. +unsafe impl super::IrqSaveBackend for SpinLockBackend { + unsafe fn lock_irqsave(ptr: *mut Self::State) -> Self::GuardState { + // SAFETY: The safety requirements of this function ensure that `ptr` points to valid + // memory, and that it has been initialised before. + Some(unsafe { bindings::spin_lock_irqsave(ptr) }) } }