From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6764EC76196 for ; Tue, 11 Apr 2023 05:46:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230070AbjDKFqx (ORCPT ); Tue, 11 Apr 2023 01:46:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57198 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230106AbjDKFqh (ORCPT ); Tue, 11 Apr 2023 01:46:37 -0400 Received: from mail-oi1-x232.google.com (mail-oi1-x232.google.com [IPv6:2607:f8b0:4864:20::232]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 81AD73598; Mon, 10 Apr 2023 22:46:20 -0700 (PDT) Received: by mail-oi1-x232.google.com with SMTP id bf5so4751548oib.8; Mon, 10 Apr 2023 22:46:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1681191979; 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=Pv6qNRZHA9f9WsLjADdwd+ymESG3pRy2ih0fvHz3LhE=; b=ideeZghkQv4t9L4zEwczcldNB4KwoSCk6uFQ9dPWym9BzryvfJwYPw2XLs/OyWaZo2 QUInsoujXxznDtWvKrE0r/T8lbdoNHenhYMy/CR6TEO8jaUjKzI2eBxOaEfOt2bwPWJV R7JTTeNcdb2Mw5WJz5Me/vESsHQJVorJ3lgQUI8gk4xWU+1pBV2xtQdDXUpESzmw2gO7 LvjuE+n7uI2li1sxOt21l80x28UOsCkXhrPF+SZg47OHuObeAnTnsnaDJenmGiM2GGZV iqziTxvPKGMFTZdCetaLj5lI5mbLwRcyLxGzw9BZz0gnxVB5fpsOrsg5TMS6bx+bH4/9 YrKw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1681191979; 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=Pv6qNRZHA9f9WsLjADdwd+ymESG3pRy2ih0fvHz3LhE=; b=eoEkFGqDRSzQd68D66KTrqvCYpxEq5cxvw2kmFlqDpiUKEPu7DwLCrpJqP3Wv/k0F1 QpaxGH4kajdxwCJnM9QXPayd1vmd2wPG+g5fDQdUt+chstqhLWBgVRrZY/PgJxhvK1Qq sX6HHBNvnwantlAEK05MHJC/0JOyhSoBpjhn2JdT6X4Yz6rPiQ63zKBmc/Qvg7vzM5GT fSODy5gl8TdGI24DZJmkoCqjs3HZxXb09oFti2yrSUlrD36R5KbmVMb1DvNSc9O7FQf9 gErcPLiDvOc3LOLn8E2Nl2SnUxzu7uYwRt8KP30//y3XsoeAEZY8OFJJEmv/9x9Rd98j na0Q== X-Gm-Message-State: AAQBX9eKpTZT1g3XMV4A1xtMIkqaiQ1Jh2RTQRU72f56M1T0rItoumRJ ytEI/h5Y8RX0mYsqoql+Er836je7LMY= X-Google-Smtp-Source: AKy350ZlmmcnYNf6PXqv56GbHajDcw4g5tcRTcuH7BamNBiz8Fr0CtLHuwMghHLwvfpMPLo7U8offQ== X-Received: by 2002:a05:6808:3a85:b0:386:a2fd:398e with SMTP id fb5-20020a0568083a8500b00386a2fd398emr9927600oib.18.1681191979391; Mon, 10 Apr 2023 22:46:19 -0700 (PDT) Received: from wedsonaf-dev.home.lan ([189.124.190.154]) by smtp.googlemail.com with ESMTPSA id z186-20020a4a49c3000000b005252d376caesm5440706ooa.22.2023.04.10.22.46.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 10 Apr 2023 22:46:19 -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?Bj=C3=B6rn=20Roy=20Baron?= , linux-kernel@vger.kernel.org, Wedson Almeida Filho , Peter Zijlstra , Ingo Molnar , Will Deacon , Waiman Long , Martin Rodriguez Reboredo Subject: [PATCH v4 07/13] rust: lock: implement `IrqSaveBackend` for `SpinLock` Date: Tue, 11 Apr 2023 02:45:37 -0300 Message-Id: <20230411054543.21278-7-wedsonaf@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230411054543.21278-1-wedsonaf@gmail.com> References: <20230411054543.21278-1-wedsonaf@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: rust-for-linux@vger.kernel.org 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 Reviewed-by: Martin Rodriguez Reboredo Signed-off-by: Wedson Almeida Filho --- v1 -> v2: No changes v2 -> v3: No changes v3 -> v4: No changes 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 141308a78775..efd5b1e86f6e 100644 --- a/rust/helpers.c +++ b/rust/helpers.c @@ -60,6 +60,22 @@ 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) }) } } -- 2.34.1