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=-16.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,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 F1D19C433B4 for ; Wed, 31 Mar 2021 14:33:44 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7AA9F60FF2 for ; Wed, 31 Mar 2021 14:33:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7AA9F60FF2 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4F9TMW1H13z3c0m for ; Thu, 1 Apr 2021 01:33:43 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=Dy4lrqNV; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kernel.org (client-ip=198.145.29.99; helo=mail.kernel.org; envelope-from=guoren@kernel.org; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=Dy4lrqNV; dkim-atps=neutral Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4F9TKx0GrJz3by1 for ; Thu, 1 Apr 2021 01:32:21 +1100 (AEDT) Received: by mail.kernel.org (Postfix) with ESMTPSA id F176760FF1; Wed, 31 Mar 2021 14:32:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1617201139; bh=ET6mHFYyqB1SBq1ewQ1GZzs5w6YT4Vz0URxeLviz9rs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Dy4lrqNV7m0Yy2r05bp8XCPUAC8z34FNeWbsZGbTVJ+lgmHiGOSKMdqGkne7CRoBG h0aP6WRVV3BKhLHvmSQDrzflE0xWl0GYT7L60PDBgOBiqmYcbTKt2Bu9uZKJRZaUsC JLg3lic8aznTBUZTOQL+OKg8JNXlyE4WjU8cBh3xHk++jJEXBQtzEiQLzHnfiNCq/B g0HKpMzU6FVFUg006DAIrSZXocPI/6dxOd8xDDjfBpSviR9gXQWC7FD1n/kNq2jEoY ZMcJKFPvCAztLJ9A87rOz+Mc+atT+903XzdCNzQmHX5+m1XwlVwCQPi/iackWOsnMS W85nWlUX/+dvg== From: guoren@kernel.org To: guoren@kernel.org Subject: [PATCH v6 4/9] csky: locks: Optimize coding convention Date: Wed, 31 Mar 2021 14:30:35 +0000 Message-Id: <1617201040-83905-5-git-send-email-guoren@kernel.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1617201040-83905-1-git-send-email-guoren@kernel.org> References: <1617201040-83905-1-git-send-email-guoren@kernel.org> X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-arch@vger.kernel.org, linux-xtensa@linux-xtensa.org, Guo Ren , Arnd Bergmann , Peter Zijlstra , linux-kernel@vger.kernel.org, linux-csky@vger.kernel.org, openrisc@lists.librecores.org, sparclinux@vger.kernel.org, linux-riscv@lists.infradead.org, linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" From: Guo Ren - Using smp_cond_load_acquire in arch_spin_lock by Peter's advice. - Using __smp_acquire_fence in arch_spin_trylock - Using smp_store_release in arch_spin_unlock All above are just coding conventions and won't affect the function. TODO in smp_cond_load_acquire for architecture: - current csky only has: lr.w val, sc.w . val2 (Any other stores to p0 will let sc.w failed) - But smp_cond_load_acquire need: lr.w val, wfe (Any stores to p0 will send the event to let wfe retired) Signed-off-by: Guo Ren Link: https://lore.kernel.org/linux-riscv/CAAhSdy1JHLUFwu7RuCaQ+RUWRBks2KsDva7EpRt8--4ZfofSUQ@mail.gmail.com/T/#m13adac285b7f51f4f879a5d6b65753ecb1a7524e Cc: Peter Zijlstra Cc: Arnd Bergmann --- arch/csky/include/asm/spinlock.h | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) diff --git a/arch/csky/include/asm/spinlock.h b/arch/csky/include/asm/spinlock.h index 69f5aa249c5f..69677167977a 100644 --- a/arch/csky/include/asm/spinlock.h +++ b/arch/csky/include/asm/spinlock.h @@ -26,10 +26,8 @@ static inline void arch_spin_lock(arch_spinlock_t *lock) : "r"(p), "r"(ticket_next) : "cc"); - while (lockval.tickets.next != lockval.tickets.owner) - lockval.tickets.owner = READ_ONCE(lock->tickets.owner); - - smp_mb(); + smp_cond_load_acquire(&lock->tickets.owner, + VAL == lockval.tickets.next); } static inline int arch_spin_trylock(arch_spinlock_t *lock) @@ -55,15 +53,14 @@ static inline int arch_spin_trylock(arch_spinlock_t *lock) } while (!res); if (!contended) - smp_mb(); + __smp_acquire_fence(); return !contended; } static inline void arch_spin_unlock(arch_spinlock_t *lock) { - smp_mb(); - WRITE_ONCE(lock->tickets.owner, lock->tickets.owner + 1); + smp_store_release(&lock->tickets.owner, lock->tickets.owner + 1); } static inline int arch_spin_value_unlocked(arch_spinlock_t lock) -- 2.17.1