From patchwork Tue Dec 15 14:24:14 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Boqun Feng X-Patchwork-Id: 556963 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [103.22.144.68]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 7DD5E1402A9 for ; Wed, 16 Dec 2015 01:28:09 +1100 (AEDT) Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b=t/dik7RR; dkim-atps=neutral Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 561791A15ED for ; Wed, 16 Dec 2015 01:28:09 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b=t/dik7RR; dkim-atps=neutral X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Received: from mail-ob0-x243.google.com (mail-ob0-x243.google.com [IPv6:2607:f8b0:4003:c01::243]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id DCB7F1A0B50 for ; Wed, 16 Dec 2015 01:25:00 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b=t/dik7RR; dkim-atps=neutral Received: by mail-ob0-x243.google.com with SMTP id ny9so722045obb.0 for ; Tue, 15 Dec 2015 06:25:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=DfDqJ/E431pbf95uXFSd35L7c1YtEW/b9fYmpJ6Xl9Q=; b=t/dik7RRcfhupvZKeHvrkv1gVLZ/OqKk/zZsZkLslvo1oR84KW4YGP0KWcT7uq7YeB Nmcm6Ssxyj4HHvfjcZUUwRJ7utg/zzGfSqbqH3mXS1AixP9QDsg8DE3ZBnaXgOvHs7MB l2uDOU4g/B93o6ZAcCYkm6ThsKT4GTczrPEjOXDipn/aXbcybYkNWIlCkVwYr+bvjU+Z fKv3l4gCzqJzffdggHn900G8RIfD6vSO9kQPfaRaF8lwZPgLnHTeLj9f6BP0dcObOnm2 SNGVpE0VmwpyLftV1+upOUYMIUKQ2TLIHIlIKIg84BfE8ZusR5RfhSTFQK3NjJ7PPj8B J+lA== X-Received: by 10.182.227.230 with SMTP id sd6mr30866352obc.6.1450189498272; Tue, 15 Dec 2015 06:24:58 -0800 (PST) Received: from localhost ([45.32.128.109]) by smtp.gmail.com with ESMTPSA id w84sm466415oie.26.2015.12.15.06.24.56 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 15 Dec 2015 06:24:57 -0800 (PST) From: Boqun Feng To: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: [PATCH v6 1/4] atomics: Allow architectures to define their own __atomic_op_* helpers Date: Tue, 15 Dec 2015 22:24:14 +0800 Message-Id: <1450189457-10589-2-git-send-email-boqun.feng@gmail.com> X-Mailer: git-send-email 2.6.4 In-Reply-To: <1450189457-10589-1-git-send-email-boqun.feng@gmail.com> References: <1450189457-10589-1-git-send-email-boqun.feng@gmail.com> X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Waiman Long , Davidlohr Bueso , Peter Zijlstra , Boqun Feng , Will Deacon , Paul Mackerras , Thomas Gleixner , "Paul E. McKenney" , Ingo Molnar MIME-Version: 1.0 Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" Some architectures may have their special barriers for acquire, release and fence semantics, so that general memory barriers(smp_mb__*_atomic()) in the default __atomic_op_*() may be too strong, so allow architectures to define their own helpers which can overwrite the default helpers. Signed-off-by: Boqun Feng --- include/linux/atomic.h | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/include/linux/atomic.h b/include/linux/atomic.h index 301de78..5f3ee5a 100644 --- a/include/linux/atomic.h +++ b/include/linux/atomic.h @@ -34,20 +34,29 @@ * The idea here is to build acquire/release variants by adding explicit * barriers on top of the relaxed variant. In the case where the relaxed * variant is already fully ordered, no additional barriers are needed. + * + * Besides, if an arch has a special barrier for acquire/release, it could + * implement its own __atomic_op_* and use the same framework for building + * variants */ +#ifndef __atomic_op_acquire #define __atomic_op_acquire(op, args...) \ ({ \ typeof(op##_relaxed(args)) __ret = op##_relaxed(args); \ smp_mb__after_atomic(); \ __ret; \ }) +#endif +#ifndef __atomic_op_release #define __atomic_op_release(op, args...) \ ({ \ smp_mb__before_atomic(); \ op##_relaxed(args); \ }) +#endif +#ifndef __atomic_op_fence #define __atomic_op_fence(op, args...) \ ({ \ typeof(op##_relaxed(args)) __ret; \ @@ -56,6 +65,7 @@ smp_mb__after_atomic(); \ __ret; \ }) +#endif /* atomic_add_return_relaxed */ #ifndef atomic_add_return_relaxed