From nobody Mon Feb 9 16:16:48 2026 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 D3242C7EE2A for ; Mon, 5 Jun 2023 07:02:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230447AbjFEHC4 (ORCPT ); Mon, 5 Jun 2023 03:02:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35650 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230377AbjFEHCa (ORCPT ); Mon, 5 Jun 2023 03:02:30 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id E2D1A10CB; Mon, 5 Jun 2023 00:02:03 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 2FFC9152B; Mon, 5 Jun 2023 00:02:49 -0700 (PDT) Received: from lakrids.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id DF8DC3F793; Mon, 5 Jun 2023 00:02:01 -0700 (PDT) From: Mark Rutland To: linux-kernel@vger.kernel.org Cc: akiyks@gmail.com, boqun.feng@gmail.com, corbet@lwn.net, keescook@chromium.org, linux@armlinux.org.uk, linux-doc@vger.kernel.org, mark.rutland@arm.com, mchehab@kernel.org, paulmck@kernel.org, peterz@infradead.org, rdunlap@infradead.org, sstabellini@kernel.org, will@kernel.org Subject: [PATCH v2 12/27] locking/atomic: x86: add preprocessor symbols Date: Mon, 5 Jun 2023 08:01:09 +0100 Message-Id: <20230605070124.3741859-13-mark.rutland@arm.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20230605070124.3741859-1-mark.rutland@arm.com> References: <20230605070124.3741859-1-mark.rutland@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Some atomics can be implemented in several different ways, e.g. FULL/ACQUIRE/RELEASE ordered atomics can be implemented in terms of RELAXED atomics, and ACQUIRE/RELEASE/RELAXED can be implemented in terms of FULL ordered atomics. Other atomics are optional, and don't exist in some configurations (e.g. not all architectures implement the 128-bit cmpxchg ops). Subsequent patches will require that architectures define a preprocessor symbol for any atomic (or ordering variant) which is optional. This will make the fallback ifdeffery more robust, and simplify future changes. Add the required definitions to arch/x86. Signed-off-by: Mark Rutland Reviewed-by: Kees Cook Cc: Boqun Feng Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Will Deacon --- arch/x86/include/asm/cmpxchg_64.h | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/x86/include/asm/cmpxchg_64.h b/arch/x86/include/asm/cmpxc= hg_64.h index 3e6e3eef701b3..44b08b53ab32f 100644 --- a/arch/x86/include/asm/cmpxchg_64.h +++ b/arch/x86/include/asm/cmpxchg_64.h @@ -45,11 +45,13 @@ static __always_inline u128 arch_cmpxchg128(volatile u1= 28 *ptr, u128 old, u128 n { return __arch_cmpxchg128(ptr, old, new, LOCK_PREFIX); } +#define arch_cmpxchg128 arch_cmpxchg128 =20 static __always_inline u128 arch_cmpxchg128_local(volatile u128 *ptr, u128= old, u128 new) { return __arch_cmpxchg128(ptr, old, new,); } +#define arch_cmpxchg128_local arch_cmpxchg128_local =20 #define __arch_try_cmpxchg128(_ptr, _oldp, _new, _lock) \ ({ \ @@ -75,11 +77,13 @@ static __always_inline bool arch_try_cmpxchg128(volatil= e u128 *ptr, u128 *oldp, { return __arch_try_cmpxchg128(ptr, oldp, new, LOCK_PREFIX); } +#define arch_try_cmpxchg128 arch_try_cmpxchg128 =20 static __always_inline bool arch_try_cmpxchg128_local(volatile u128 *ptr, = u128 *oldp, u128 new) { return __arch_try_cmpxchg128(ptr, oldp, new,); } +#define arch_try_cmpxchg128_local arch_try_cmpxchg128_local =20 #define system_has_cmpxchg128() boot_cpu_has(X86_FEATURE_CX16) =20 --=20 2.30.2