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[2620:137:e000::1:20]) by mx.google.com with ESMTP id l1-20020a17090a4d4100b0023f064f20c7si1738705pjh.168.2023.04.05.10.59.41; Wed, 05 Apr 2023 10:59:54 -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="qNK/SIs8"; 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 S232442AbjDERwi (ORCPT + 99 others); Wed, 5 Apr 2023 13:52:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39568 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232695AbjDERwd (ORCPT ); Wed, 5 Apr 2023 13:52:33 -0400 Received: from mail-oi1-x22d.google.com (mail-oi1-x22d.google.com [IPv6:2607:f8b0:4864:20::22d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D4F156E80; Wed, 5 Apr 2023 10:52:13 -0700 (PDT) Received: by mail-oi1-x22d.google.com with SMTP id l18so27219028oic.13; Wed, 05 Apr 2023 10:52:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1680717132; 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=thG4ce95lzXfSBdJf4lBPCfVabPBzlVobrhWMpvttHs=; b=qNK/SIs8M2jkyqqxmQ/DCMtwbI3QSDnkF3limYjePtyO/x9fvjArvFmaUqnP8K82al J59iGA8rz000+AE2sTr833F6LQZCsP0AU+WDnCa6bRmIyXxGU+TUqu7B5cktKmX9CLWI +AjdbgvgkVxM8FeffK+8F9+jvCy4h/93U3OXXQT9ZiIIc8DBqaAHWfBS6Dj/c6VELm7z K7GSBgA7PBQiBmpRdHnI2Yy624mTwD3fM/yoTGvOIRhLeX3likGXqsol34v6OmkDik4a 2qOFM/9dzHZZ696M/gszpspo/GZ4oA3yM+17Vzm697Ao3O+YpZtZ33YLeFprLtfhI5sI F92w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1680717132; 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=thG4ce95lzXfSBdJf4lBPCfVabPBzlVobrhWMpvttHs=; b=QU3jkvQruUTq8RLwPpFHEhFpV5iMbK1Lj8VH7foSRehvx4WCqTfq53oKkvhLOWu9ep RO8bqllkRleVtP2rkvLAIW+vxCWyHOA3GZ9JfRMPWhtaFEle9POSyHTzpatLnBIuTevb 5cgbaHVkfpPgFEtVDHCKp9bkno+CiOjRIEfJygsQfgXKPwN8udlMAZ99E5SwT16Wl3+V SQ+jI6Lcghhq75Uvx2Ta2KfQs2XG90Cw6WUrWFuoF2ppzoCfSwiRDbTxYi9oIc3k9S1V 6mUXuYZsEAzH7i9JiC+rouzWQanfpDRwvEMWjRVpJqc2AlgBZNXy15/yNNHl/PSxvULZ PcxQ== X-Gm-Message-State: AAQBX9cr7OiUSP6bM0Q0DMtBY2eMe3tyWbQ5kwvw32BkHeRNOcw/0HsB G0Uz9oMdmYcle8YQ3WCZ1Ei3WNZ7pWYIIQ== X-Received: by 2002:a05:6808:2018:b0:384:8a1:c14b with SMTP id q24-20020a056808201800b0038408a1c14bmr4182868oiw.31.1680717132470; Wed, 05 Apr 2023 10:52:12 -0700 (PDT) Received: from wedsonaf-dev.home.lan ([189.124.190.154]) by smtp.googlemail.com with ESMTPSA id w185-20020aca62c2000000b003896e31867esm6604045oib.49.2023.04.05.10.52.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 05 Apr 2023 10:52:12 -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 v2 07/13] rust: lock: implement `IrqSaveBackend` for `SpinLock` Date: Wed, 5 Apr 2023 14:51:05 -0300 Message-Id: <20230405175111.5974-7-wedsonaf@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230405175111.5974-1-wedsonaf@gmail.com> References: <20230405175111.5974-1-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?1762360132378291296?= X-GMAIL-MSGID: =?utf-8?q?1762360132378291296?= 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 --- v1 -> v2: 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 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) }) } }