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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id CF24AC25B78 for ; Tue, 4 Jun 2024 17:04:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=YuBVUA8LYJWdd0rtlJClLDgJMPRw4Zr2D81pmTblG/0=; b=vU5Buo6ZBp9G9P tFqtYsA7ijDNUvvbSLjmcxqWTUlXVeJNhUclOzsD4nak85ESXiv3yXyxW3LP7d4W0KbYUpucojBh6 NOATPDY9w05QKR9xT1mHyAkVi6FzEhtIq+zUEQW9kBbJOkQOL7SXPIo8nMmBbX7/OdF0R4XZLoOH8 VK+snKwNUfyyg8jMFyhNXsI0L0/AFOMQA3nsET2V3cj54DGFBSEAvHI9JCURqqBYlo0c6aiOAZsgg HQym8x7sfactBrJ148w8pe1OxYF2VCKRoSH+0OMu/pVVC/SDgV34i5gYhKJNJWILWwwbsKRXXyt1a mAS0X7hW7lLJCI6tygMg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sEXaX-00000003EX0-1rct; Tue, 04 Jun 2024 17:04:45 +0000 Received: from dfw.source.kernel.org ([2604:1380:4641:c500::1]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sEXaU-00000003EUh-1esM for linux-snps-arc@lists.infradead.org; Tue, 04 Jun 2024 17:04:43 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 9C2A661363; Tue, 4 Jun 2024 17:04:41 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4C318C2BBFC; Tue, 4 Jun 2024 17:04:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1717520681; bh=m6rqAOBQ64nAVbwfoMwra9NFlfK4T5G41qjNyF62BxA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HNF05O/z83KdgySpuamBtdJNQPd+6KMd8DXn+woZXtYeUdCI1eSQfGWa6KtuuXFmR MteA50UrqjFRjOjHRs/udBUOaJWKJe0HyRtAwUJgDy8V6V7k/GVcnEjUbX2MMmS/mK P+lpopMYf4HzqNyqG1TKE6SyW1bm1zrwdUPGYZSPh9/ueugXY2d3O8MQphL6kohvDp Qodja9iSGJwXRX+ySo0tt7Q1/2EOIm8z+DEO7fEMgFbUSH52SBB47s0hmw7B/Gk84Q zzGFnjfhHlwGcq1Pny93N1jAVngBGUrVq4eXMBrbCCMihe9FGaegY6MEzlXhVHxyis prjhj0VWrTClA== Received: by paulmck-ThinkPad-P17-Gen-1.home (Postfix, from userid 1000) id F3F2DCE3F09; Tue, 4 Jun 2024 10:04:40 -0700 (PDT) From: "Paul E. McKenney" To: linux-arch@vger.kernel.org Cc: linux-kernel@vger.kernel.org, kernel-team@meta.com, elver@google.com, akpm@linux-foundation.org, tglx@linutronix.de, peterz@infradead.org, dianders@chromium.org, pmladek@suse.com, torvalds@linux-foundation.org, arnd@arndb.de, "Paul E. McKenney" , Vineet Gupta , Andi Shyti , Andrzej Hajda , Palmer Dabbelt , linux-snps-arc@lists.infradead.org Subject: [PATCH v3 cmpxchg 1/4] ARC: Emulate one-byte cmpxchg Date: Tue, 4 Jun 2024 10:04:34 -0700 Message-Id: <20240604170437.2362545-1-paulmck@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <1dee481f-d584-41d6-a5f1-d84375be5fe8@paulmck-laptop> References: <1dee481f-d584-41d6-a5f1-d84375be5fe8@paulmck-laptop> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240604_100442_554953_8816BF36 X-CRM114-Status: GOOD ( 12.98 ) X-BeenThere: linux-snps-arc@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Linux on Synopsys ARC Processors List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-snps-arc" Errors-To: linux-snps-arc-bounces+linux-snps-arc=archiver.kernel.org@lists.infradead.org Use the new cmpxchg_emu_u8() to emulate one-byte cmpxchg() on arc. [ paulmck: Drop two-byte support per Arnd Bergmann feedback. ] [ paulmck: Apply feedback from Naresh Kamboju. ] [ paulmck: Apply kernel test robot feedback. ] Signed-off-by: Paul E. McKenney Cc: Vineet Gupta Cc: Andi Shyti Cc: Andrzej Hajda Cc: Arnd Bergmann Cc: Palmer Dabbelt Cc: --- arch/arc/Kconfig | 1 + arch/arc/include/asm/cmpxchg.h | 33 ++++++++++++++++++++++++--------- 2 files changed, 25 insertions(+), 9 deletions(-) diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig index fd0b0a0d4686a..163608fd49d18 100644 --- a/arch/arc/Kconfig +++ b/arch/arc/Kconfig @@ -13,6 +13,7 @@ config ARC select ARCH_HAS_SETUP_DMA_OPS select ARCH_HAS_SYNC_DMA_FOR_CPU select ARCH_HAS_SYNC_DMA_FOR_DEVICE + select ARCH_NEED_CMPXCHG_1_EMU select ARCH_SUPPORTS_ATOMIC_RMW if ARC_HAS_LLSC select ARCH_32BIT_OFF_T select BUILDTIME_TABLE_SORT diff --git a/arch/arc/include/asm/cmpxchg.h b/arch/arc/include/asm/cmpxchg.h index e138fde067dea..2102ce076f28b 100644 --- a/arch/arc/include/asm/cmpxchg.h +++ b/arch/arc/include/asm/cmpxchg.h @@ -8,6 +8,7 @@ #include #include +#include #include #include @@ -46,6 +47,9 @@ __typeof__(*(ptr)) _prev_; \ \ switch(sizeof((_p_))) { \ + case 1: \ + _prev_ = (__typeof__(*(ptr)))cmpxchg_emu_u8((volatile u8 *)_p_, (uintptr_t)_o_, (uintptr_t)_n_); \ + break; \ case 4: \ _prev_ = __cmpxchg(_p_, _o_, _n_); \ break; \ @@ -65,16 +69,27 @@ __typeof__(*(ptr)) _prev_; \ unsigned long __flags; \ \ - BUILD_BUG_ON(sizeof(_p_) != 4); \ + switch(sizeof((_p_))) { \ + case 1: \ + __flags = cmpxchg_emu_u8((volatile u8 *)_p_, (uintptr_t)_o_, (uintptr_t)_n_); \ + _prev_ = (__typeof__(*(ptr)))__flags; \ + break; \ + break; \ + case 4: \ + /* \ + * spin lock/unlock provide the needed smp_mb() \ + * before/after \ + */ \ + atomic_ops_lock(__flags); \ + _prev_ = *_p_; \ + if (_prev_ == _o_) \ + *_p_ = _n_; \ + atomic_ops_unlock(__flags); \ + break; \ + default: \ + BUILD_BUG(); \ + } \ \ - /* \ - * spin lock/unlock provide the needed smp_mb() before/after \ - */ \ - atomic_ops_lock(__flags); \ - _prev_ = *_p_; \ - if (_prev_ == _o_) \ - *_p_ = _n_; \ - atomic_ops_unlock(__flags); \ _prev_; \ }) -- 2.40.1 _______________________________________________ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc