From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 39679C432BE for ; Wed, 4 Aug 2021 19:16:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2528660F58 for ; Wed, 4 Aug 2021 19:16:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240694AbhHDTQm (ORCPT ); Wed, 4 Aug 2021 15:16:42 -0400 Received: from smtprelay-out1.synopsys.com ([149.117.73.133]:58764 "EHLO smtprelay-out1.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240498AbhHDTQV (ORCPT ); Wed, 4 Aug 2021 15:16:21 -0400 Received: from mailhost.synopsys.com (sv1-mailhost1.synopsys.com [10.205.2.131]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (Client CN "mailhost.synopsys.com", Issuer "SNPSica2" (verified OK)) by smtprelay-out1.synopsys.com (Postfix) with ESMTPS id 7D1A540DB7; Wed, 4 Aug 2021 19:16:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=synopsys.com; s=mail; t=1628104567; bh=jS7TMpiuBpexomjIgRV6cQUgUQCWpq/qYioDI73B0rY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=k4Iyy/dTZeIspc8X66Z0Q3020n/LdiZPpj96MU+92Bt1cpPCjC/y5JmvUcawUE+cy DqJyIevzX+wz0suDDiVBl7TMHLeNVojvbVBfkRQ5zpRYKIyIjAoByOgnw7XrCk+u+t sp1DLEJ2DuAbj7mnx0+OtrKQ6g22CtL0LojmA61ceO2D9Usv5K8/HNneWdwlZbqs6m DuG02nCZD52aRSroVtxc8h/e8yIpzhoOIQVJSd3K20LeaeGLHaqchYdkMUhGCNSAlG yo8pWK6GtFO4NGEbftsPrEwRMKCCrHvRG5REWnbUYcIRKZdXdfjDjBnYKIULw9IfeH PUnobod+MNHfg== Received: from vineetg-Latitude-7400.internal.synopsys.com (snps-fugpbdpduq.internal.synopsys.com [10.202.17.37]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (Client did not present a certificate) by mailhost.synopsys.com (Postfix) with ESMTPSA id 40158A0095; Wed, 4 Aug 2021 19:16:06 +0000 (UTC) X-SNPS-Relay: synopsys.com From: Vineet Gupta To: linux-snps-arc@lists.infradead.org Cc: Peter Zijlstra , Will Deacon , Arnd Bergmann , Mark Rutland , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, Vladimir Isaev , Vineet Gupta Subject: [PATCH 08/11] ARC: xchg: !LLSC: remove UP micro-optimization/hack Date: Wed, 4 Aug 2021 12:15:51 -0700 Message-Id: <20210804191554.1252776-9-vgupta@synopsys.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210804191554.1252776-1-vgupta@synopsys.com> References: <20210804191554.1252776-1-vgupta@synopsys.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org It gets in the way of cleaning things up and is a maintenance pain-in-neck ! Signed-off-by: Vineet Gupta --- arch/arc/include/asm/cmpxchg.h | 12 +----------- 1 file changed, 1 insertion(+), 11 deletions(-) diff --git a/arch/arc/include/asm/cmpxchg.h b/arch/arc/include/asm/cmpxchg.h index d42917e803e1..bac9b564a140 100644 --- a/arch/arc/include/asm/cmpxchg.h +++ b/arch/arc/include/asm/cmpxchg.h @@ -113,15 +113,9 @@ static inline unsigned long __xchg(unsigned long val, volatile void *ptr, * - For !LLSC, cmpxchg() needs to use that lock (see above) and there is lot * of kernel code which calls xchg()/cmpxchg() on same data (see llist.h) * Hence xchg() needs to follow same locking rules. - * - * Technically the lock is also needed for UP (boils down to irq save/restore) - * but we can cheat a bit since cmpxchg() atomic_ops_lock() would cause irqs to - * be disabled thus can't possibly be interrupted/preempted/clobbered by xchg() - * Other way around, xchg is one instruction anyways, so can't be interrupted - * as such */ -#if !defined(CONFIG_ARC_HAS_LLSC) && defined(CONFIG_SMP) +#ifndef CONFIG_ARC_HAS_LLSC #define arch_xchg(ptr, with) \ ({ \ @@ -134,10 +128,6 @@ static inline unsigned long __xchg(unsigned long val, volatile void *ptr, old_val; \ }) -#else - -#define arch_xchg(ptr, with) _xchg(ptr, with) - #endif /* -- 2.25.1