From patchwork Tue Dec 13 09:02:20 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vladimir Murzin X-Patchwork-Id: 9471953 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 11558607EE for ; Tue, 13 Dec 2016 09:04:47 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id F090A2845E for ; Tue, 13 Dec 2016 09:04:46 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id DEDAE28495; Tue, 13 Dec 2016 09:04:46 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id E53142845E for ; Tue, 13 Dec 2016 09:04:45 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.85_2 #1 (Red Hat Linux)) id 1cGizL-00039B-52; Tue, 13 Dec 2016 09:03:07 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.85_2 #1 (Red Hat Linux)) id 1cGizE-000313-7F for linux-arm-kernel@lists.infradead.org; Tue, 13 Dec 2016 09:03:00 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 1E3CF154D; Tue, 13 Dec 2016 01:02:42 -0800 (PST) Received: from login2.euhpc.arm.com (login2.euhpc.arm.com [10.6.26.144]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 1DF743F445; Tue, 13 Dec 2016 01:02:40 -0800 (PST) From: Vladimir Murzin To: linux-arm-kernel@lists.infradead.org Subject: [RFC PATCH 2/3] ARM: NOMMU: set ARM_DMA_MEM_BUFFERABLE for M-class cpus Date: Tue, 13 Dec 2016 09:02:20 +0000 Message-Id: <1481619741-35627-3-git-send-email-vladimir.murzin@arm.com> X-Mailer: git-send-email 2.0.0 In-Reply-To: <1481619741-35627-1-git-send-email-vladimir.murzin@arm.com> References: <1481619741-35627-1-git-send-email-vladimir.murzin@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20161213_010300_375177_D4714BE4 X-CRM114-Status: UNSURE ( 7.25 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: sza@esh.hu, robin.murphy@arm.com, linux@armlinux.org.uk, benjamin.gaignard@linaro.org, alexandre.torgue@st.com MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP Now, we have dedicated non-cacheable region for consistent DMA operations. However, that region can still be marked as bufferable by MPU, so it'd be safer to have barriers by default. Signed-off-by: Vladimir Murzin --- arch/arm/mm/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig index 6dffbe4..7f0000d 100644 --- a/arch/arm/mm/Kconfig +++ b/arch/arm/mm/Kconfig @@ -1023,7 +1023,7 @@ config ARM_L1_CACHE_SHIFT config ARM_DMA_MEM_BUFFERABLE bool "Use non-cacheable memory for DMA" if (CPU_V6 || CPU_V6K) && !CPU_V7 - default y if CPU_V6 || CPU_V6K || CPU_V7 + default y if CPU_V6 || CPU_V6K || CPU_V7 || CPU_V7M help Historically, the kernel has used strongly ordered mappings to provide DMA coherent memory. With the advent of ARMv7, mapping