From nobody Tue Dec 16 19:40:38 2025 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 850222080CC; Thu, 20 Feb 2025 16:14:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740068045; cv=none; b=TNV/Hiirx7WqS01Z6t4uXSrPjk/HqiPE05pHtrDQWZb1K5Xhkp7DaSk8BlR5lf+jq0i4W3eUaFTdrYY1xpPyXUEhr/Y7O9/Lrm5q3s7ZM45NGL4n5Y3CYwBvKDuHqlKdLWY17SMN83+N2QBst+gLuqIQ3cXIbve6ntpvrpMc/hA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740068045; c=relaxed/simple; bh=21ND8h3aXwqP4GPXt1SePJHjRlQNFlNVkqExdK3K1F0=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=E6O6kN0RLN8PfcXKep1RyjfJiQDPcueX7zjmxwJHMelFHqPYZq+LfhreWjsktT98DaI7R61Y3N79lKtsUwJJs9cZOU0gfu92g19ozIq2xdEAwJ+E05TFMAMCCScap4RIhjKYu0EClrR9o65Iyr7I9L1mDbFlNAuGfC7jzLb+eyE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=VOi6qfOF; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="VOi6qfOF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 04429C4CEDD; Thu, 20 Feb 2025 16:14:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1740068045; bh=21ND8h3aXwqP4GPXt1SePJHjRlQNFlNVkqExdK3K1F0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VOi6qfOFDxyt4RiKck5m0cbAN4YyCEcXk0Dq99Nvh3HkREbKIZp+vpxFze5Woc0z9 EP0/rZL3ou1HejUF0ew497eLDSEt94cCuao4Ilz9PwL9/cfCjGf1KemBADkIgzurvQ kZdSM3G66az9fKE5vbYbHu9pBuxJMRUlHMomL09XO9y9qA9eYs0lxX9SUUn+5gmK+p 49XMflhLA2ud60wKyXr6PuEqaChE0aE+mIySkStOc6qifUQNiSWxmxdofNmuIOcd5O vIFIMumwRjssuimaHYc80CULKSon8FfszG9k94d5c8GnyehLVW3HRHsvQCmCcGmiY8 9bxtrFvbDDaiA== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id 9E5BACE0B9E; Thu, 20 Feb 2025 08:14:04 -0800 (PST) From: "Paul E. McKenney" To: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, lkmm@lists.linux.dev, kernel-team@meta.com, mingo@kernel.org Cc: stern@rowland.harvard.edu, parri.andrea@gmail.com, will@kernel.org, peterz@infradead.org, boqun.feng@gmail.com, npiggin@gmail.com, dhowells@redhat.com, j.alglave@ucl.ac.uk, luc.maranget@inria.fr, akiyks@gmail.com, Puranjay Mohan , "Paul E . McKenney" , Daniel Lustig , Joel Fernandes Subject: [PATCH memory-model 2/7] tools/memory-model: Add atomic_andnot() with its variants Date: Thu, 20 Feb 2025 08:13:58 -0800 Message-Id: <20250220161403.800831-2-paulmck@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <8cfb51e3-9726-4285-b8ca-0d0abcacb07e@paulmck-laptop> References: <8cfb51e3-9726-4285-b8ca-0d0abcacb07e@paulmck-laptop> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Puranjay Mohan Pull-855[1] added the support of atomic_andnot() to the herd tool. Use this to add the implementation in the LKMM. All of the ordering variants are also added. Here is a small litmus-test that uses this operation: C andnot { atomic_t u =3D ATOMIC_INIT(7); } P0(atomic_t *u) { r0 =3D atomic_fetch_andnot(3, u); r1 =3D READ_ONCE(*u); } exists (0:r0=3D7 /\ 0:r1=3D4) Test andnot Allowed States 1 0:r0=3D7; 0:r1=3D4; Ok Witnesses Positive: 1 Negative: 0 Condition exists (0:r0=3D7 /\ 0:r1=3D4) Observation andnot Always 1 0 Time andnot 0.00 Hash=3D78f011a0b5a0c65fa1cf106fcd62c845 [1] https://github.com/herd/herdtools7/pull/855 Signed-off-by: Puranjay Mohan Acked-by: Andrea Parri Signed-off-by: Paul E. McKenney Cc: Alan Stern Cc: Will Deacon Cc: Peter Zijlstra Cc: Boqun Feng Cc: Nicholas Piggin Cc: David Howells Cc: Jade Alglave Cc: Luc Maranget Cc: Akira Yokosawa Cc: Daniel Lustig Cc: Joel Fernandes Cc: --- tools/memory-model/linux-kernel.def | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/tools/memory-model/linux-kernel.def b/tools/memory-model/linux= -kernel.def index d1f11930ec512..a12b96c547b7a 100644 --- a/tools/memory-model/linux-kernel.def +++ b/tools/memory-model/linux-kernel.def @@ -70,6 +70,7 @@ atomic_or(V,X) { __atomic_op(X,|,V); } atomic_xor(V,X) { __atomic_op(X,^,V); } atomic_inc(X) { __atomic_op(X,+,1); } atomic_dec(X) { __atomic_op(X,-,1); } +atomic_andnot(V,X) { __atomic_op(X,&~,V); } =20 atomic_add_return(V,X) __atomic_op_return{mb}(X,+,V) atomic_add_return_relaxed(V,X) __atomic_op_return{once}(X,+,V) @@ -138,3 +139,8 @@ atomic_add_negative(V,X) __atomic_op_return{mb}(X,+,V) = < 0 atomic_add_negative_relaxed(V,X) __atomic_op_return{once}(X,+,V) < 0 atomic_add_negative_acquire(V,X) __atomic_op_return{acquire}(X,+,V) < 0 atomic_add_negative_release(V,X) __atomic_op_return{release}(X,+,V) < 0 + +atomic_fetch_andnot(V,X) __atomic_fetch_op{mb}(X,&~,V) +atomic_fetch_andnot_acquire(V,X) __atomic_fetch_op{acquire}(X,&~,V) +atomic_fetch_andnot_release(V,X) __atomic_fetch_op{release}(X,&~,V) +atomic_fetch_andnot_relaxed(V,X) __atomic_fetch_op{once}(X,&~,V) --=20 2.40.1