From patchwork Fri Nov 1 06:02:31 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Boqun Feng X-Patchwork-Id: 13858739 Received: from mail-qv1-f53.google.com (mail-qv1-f53.google.com [209.85.219.53]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 86E80156654; Fri, 1 Nov 2024 06:04:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.219.53 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730441048; cv=none; b=Po2ncNIEsxdKvbhH9gNh0u3sp/c8oe6lAV7f6tLCrfRZCD7m1i55vtIxg867NjgeLq15+hbrbbEm/BBYAHCQNGJXD9wP+x9sgpf6DhIPNgxf/J8oMuUIGtkY7t/G5aAhoRyWPYjtpnC3P3B7RiM8qyUB64zw3hTbpr6m68T55cg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730441048; c=relaxed/simple; bh=p9btVVa2+xSWu4bOPpbx4eV63bulX64vxQ6AaKLpk8E=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Gjn4hrvVN73HpVn1c3pwPOG1/Ka/B3FFGBEPmRR2Xe3tI1ZKUWurSCnbYMfRZlCuEw/C9qfd9/lsb7cYDBleos8lsgMxqP/oWHjGXoS43lZYBk1tdk/+W5VYMVSn1634fgEu51LniYm2pCKCjQqF5LEIkeHJlmnUjlQisxgs7oA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=k95ZqVoi; arc=none smtp.client-ip=209.85.219.53 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="k95ZqVoi" Received: by mail-qv1-f53.google.com with SMTP id 6a1803df08f44-6cbf0e6414aso9937296d6.1; Thu, 31 Oct 2024 23:04:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1730441044; x=1731045844; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:feedback-id:from:to:cc:subject :date:message-id:reply-to; bh=A6tG39HqwvxlfRrBPWElR6isULD+PRgdHmRoN4FVkag=; b=k95ZqVoicKzRP5E2V6uvQViTJnl3FjAUmoPn7TfSs8CRc475lARdAyxRY//KznktM/ yEYDUg4DygW54K1xSrUsfE/odwgNxqYSs1rA07BMwfQS7tkfKtpOlM0O9HKk7/DkEcJx zH8GyMx9Xha+ZUcGut6lnuSNQMXDPbYUbq0SUQJMm7vBjvkhDs6PG8pPjPuQ4UIAGa1Q Umd7svNwNX0TToIdyj9J3bz/5KpIEjbvRXNigYfH/aAk466/ktqcybPq8jqod0rkRpBG bVy9PsEIqZy5xBM24dRY7jr38j33K3m2WVIGQ0/qzqI5F4RvhKhogj9lHnW28VUi52cz pdMw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1730441044; x=1731045844; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:feedback-id:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=A6tG39HqwvxlfRrBPWElR6isULD+PRgdHmRoN4FVkag=; b=MSsulEAKHKdBRgokWZD1bhWRXvGTeWQG8JE5MIyPurbiwW4pFNRcBeDlxC8kvDQn/2 4qxRtSCJ8la7X+Tldmc9gmOrPsxK6Ni4w083oNnb/UGwZIFbMKyvp99jAj+Tmb0rf/o4 SwET7QmmXgCUcSUs+fNMjwO1ZMGPwAoCdwh7/xHRQnGF/fjyOq+99cmvTOyCpPIjblMp QfARR+1dOdfFpJka6axkxY/y9VHI7ewDfzlcRIeEx6htsQ9gUoNG7htdukNpiDcrzEGL eJyrD2uyRy29X3E8B+beFMbOejxULoCcvDMCF8EVchm4jZAIsFh7aNA5a6UmPIhwHn2+ Ci+A== X-Forwarded-Encrypted: i=1; AJvYcCUfJBbjLznwdjSz6rsFF6dJ3Z5DYVoQ/3qgyhQYNcwdTPHGJdmDIP2cARkf0fWZQWSZbGyiFwU7eoPC@vger.kernel.org, AJvYcCW9fwXpIE/s7iZpATfQxQxq6O2KtvOO8djqeLH7WZykuHWUxeopUeW0FtFOfSC99KIGeIW/d8NV1P4fQZGc@vger.kernel.org, AJvYcCWu3P0+MDhNYSvkCgVH4bw+xK3BS40j1OGfDGckZtPKh4EJjpiQyfDahBRT6teQDDMV+B9x@vger.kernel.org, AJvYcCWve4F6exOuWYcXTegdZcw7TdmTLSIFGX3+qilCxHqyFqgowutvBUdzaCj7AZBcK9Jio0GL1VvsC2cHY39DZA==@vger.kernel.org X-Gm-Message-State: AOJu0YyrsBAI5wPl1dpmyesrEATc5OjWM/P7H1RDplUKsyFI2owBJuSz YkWzI42lIwP9VL521v/L46rz2w+MPe3dRaquI5zaKqUtb5Iur93hSzIncg+7 X-Google-Smtp-Source: AGHT+IHxlQ73l+UhRt/AvbKKPa42h8SqSMj0Mq3h3j32da4pj9FbcxaRnUDspUF1ESyOUj61ypPKLQ== X-Received: by 2002:a05:6214:2f81:b0:6cb:c9bc:1a23 with SMTP id 6a1803df08f44-6d1856ea81dmr253747796d6.24.1730441044400; Thu, 31 Oct 2024 23:04:04 -0700 (PDT) Received: from fauth-a2-smtp.messagingengine.com (fauth-a2-smtp.messagingengine.com. [103.168.172.201]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-6d353fc49fbsm15821596d6.31.2024.10.31.23.04.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 31 Oct 2024 23:04:04 -0700 (PDT) Received: from phl-compute-12.internal (phl-compute-12.phl.internal [10.202.2.52]) by mailfauth.phl.internal (Postfix) with ESMTP id A2B0D1200043; Fri, 1 Nov 2024 02:04:03 -0400 (EDT) Received: from phl-mailfrontend-01 ([10.202.2.162]) by phl-compute-12.internal (MEProxy); Fri, 01 Nov 2024 02:04:03 -0400 X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeeftddrvdekkedgkeekucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdggtfgfnhhsuhgsshgtrhhisggvpdfu rfetoffkrfgpnffqhgenuceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnh htshculddquddttddmnecujfgurhephffvvefufffkofgjfhgggfestdekredtredttden ucfhrhhomhepuehoqhhunhcuhfgvnhhguceosghoqhhunhdrfhgvnhhgsehgmhgrihhlrd gtohhmqeenucggtffrrghtthgvrhhnpeegleejiedthedvheeggfejveefjeejkefgveff ieeujefhueeigfegueehgeeggfenucevlhhushhtvghrufhiiigvpedvnecurfgrrhgrmh epmhgrihhlfhhrohhmpegsohhquhhnodhmvghsmhhtphgruhhthhhpvghrshhonhgrlhhi thihqdeiledvgeehtdeigedqudejjeekheehhedvqdgsohhquhhnrdhfvghngheppehgmh grihhlrdgtohhmsehfihigmhgvrdhnrghmvgdpnhgspghrtghpthhtohepheejpdhmohgu vgepshhmthhpohhuthdprhgtphhtthhopehruhhsthdqfhhorhdqlhhinhhugiesvhhgvg hrrdhkvghrnhgvlhdrohhrghdprhgtphhtthhopehrtghusehvghgvrhdrkhgvrhhnvghl rdhorhhgpdhrtghpthhtoheplhhinhhugidqkhgvrhhnvghlsehvghgvrhdrkhgvrhhnvg hlrdhorhhgpdhrtghpthhtoheplhhinhhugidqrghrtghhsehvghgvrhdrkhgvrhhnvghl rdhorhhgpdhrtghpthhtoheplhhlvhhmsehlihhsthhsrdhlihhnuhigrdguvghvpdhrtg hpthhtoheplhhkmhhmsehlihhsthhsrdhlihhnuhigrdguvghvpdhrtghpthhtohepohhj vggurgeskhgvrhhnvghlrdhorhhgpdhrtghpthhtoheprghlvgigrdhgrgihnhhorhesgh hmrghilhdrtghomhdprhgtphhtthhopeifvggushhonhgrfhesghhmrghilhdrtghomh X-ME-Proxy: Feedback-ID: iad51458e:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Fri, 1 Nov 2024 02:04:03 -0400 (EDT) From: Boqun Feng To: rust-for-linux@vger.kernel.org, rcu@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, llvm@lists.linux.dev, lkmm@lists.linux.dev Cc: Miguel Ojeda , Alex Gaynor , Wedson Almeida Filho , Boqun Feng , Gary Guo , =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= , Benno Lossin , Andreas Hindborg , Alice Ryhl , Alan Stern , Andrea Parri , Will Deacon , Peter Zijlstra , Nicholas Piggin , David Howells , Jade Alglave , Luc Maranget , "Paul E. McKenney" , Akira Yokosawa , Daniel Lustig , Joel Fernandes , Nathan Chancellor , Nick Desaulniers , kent.overstreet@gmail.com, Greg Kroah-Hartman , elver@google.com, Mark Rutland , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Catalin Marinas , torvalds@linux-foundation.org, linux-arm-kernel@lists.infradead.org, linux-fsdevel@vger.kernel.org, Trevor Gross , dakr@redhat.com, Frederic Weisbecker , Neeraj Upadhyay , Josh Triplett , Uladzislau Rezki , Steven Rostedt , Mathieu Desnoyers , Lai Jiangshan , Zqiang , Paul Walmsley , Palmer Dabbelt , Albert Ou , linux-riscv@lists.infradead.org Subject: [RFC v2 08/13] rust: sync: atomic: Add Atomic<{usize,isize}> Date: Thu, 31 Oct 2024 23:02:31 -0700 Message-ID: <20241101060237.1185533-9-boqun.feng@gmail.com> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20241101060237.1185533-1-boqun.feng@gmail.com> References: <20241101060237.1185533-1-boqun.feng@gmail.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Add generic atomic support for `usize` and `isize`. Note that instead of mapping directly to `atomic_long_t`, the represention type (`AllowAtomic::Repr`) is selected based on CONFIG_64BIT. This reduces the necessarity of creating `atomic_long_*` helpers, which could save the binary size of kernel if inline helpers are not available. Signed-off-by: Boqun Feng --- rust/kernel/sync/atomic.rs | 71 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 71 insertions(+) diff --git a/rust/kernel/sync/atomic.rs b/rust/kernel/sync/atomic.rs index b2e81e22c105..4166ad48604f 100644 --- a/rust/kernel/sync/atomic.rs +++ b/rust/kernel/sync/atomic.rs @@ -102,3 +102,74 @@ fn delta_into_repr(d: Self::Delta) -> Self::Repr { d as _ } } + +// SAFETY: `usize` has the same size and the alignment as `i64` for 64bit and the same as `i32` for +// 32bit. +unsafe impl generic::AllowAtomic for usize { + #[cfg(CONFIG_64BIT)] + type Repr = i64; + #[cfg(not(CONFIG_64BIT))] + type Repr = i32; + + fn into_repr(self) -> Self::Repr { + self as _ + } + + fn from_repr(repr: Self::Repr) -> Self { + repr as _ + } +} + +/// ```rust +/// use kernel::sync::atomic::{Atomic, Full, Relaxed}; +/// +/// let x = Atomic::new(42usize); +/// +/// assert_eq!(42, x.fetch_add(12, Full)); +/// assert_eq!(54, x.load(Relaxed)); +/// +/// x.add(13, Relaxed); +/// +/// assert_eq!(67, x.load(Relaxed)); +/// ``` +impl generic::AllowAtomicArithmetic for usize { + type Delta = usize; + + fn delta_into_repr(d: Self::Delta) -> Self::Repr { + d as _ + } +} + +// SAFETY: `isize` has the same size and the alignment as `i64` for 64bit and the same as `i32` for +// 32bit. +unsafe impl generic::AllowAtomic for isize { + type Repr = i64; + + fn into_repr(self) -> Self::Repr { + self as _ + } + + fn from_repr(repr: Self::Repr) -> Self { + repr as _ + } +} + +/// ```rust +/// use kernel::sync::atomic::{Atomic, Full, Relaxed}; +/// +/// let x = Atomic::new(42isize); +/// +/// assert_eq!(42, x.fetch_add(12, Full)); +/// assert_eq!(54, x.load(Relaxed)); +/// +/// x.add(13, Relaxed); +/// +/// assert_eq!(67, x.load(Relaxed)); +/// ``` +impl generic::AllowAtomicArithmetic for isize { + type Delta = isize; + + fn delta_into_repr(d: Self::Delta) -> Self::Repr { + d as _ + } +}