Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1168421AbdDXKSG (ORCPT ); Mon, 24 Apr 2017 06:18:06 -0400 Received: from foss.arm.com ([217.140.101.70]:54710 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1168336AbdDXKRi (ORCPT ); Mon, 24 Apr 2017 06:17:38 -0400 From: Vladimir Murzin To: linux-arm-kernel@lists.infradead.org Cc: sza@esh.hu, robin.murphy@arm.com, alexandre.torgue@st.com, akpm@linux-foundation.org, kbuild-all@01.org, linux-kernel@vger.kernel.org, linux@armlinux.org.uk, gregkh@linuxfoundation.org, arnd@arndb.de Subject: [PATCH v4 6/7] ARM: NOMMU: Set ARM_DMA_MEM_BUFFERABLE for M-class cpus Date: Mon, 24 Apr 2017 11:16:56 +0100 Message-Id: <1493029017-31382-7-git-send-email-vladimir.murzin@arm.com> X-Mailer: git-send-email 2.0.0 In-Reply-To: <1493029017-31382-1-git-send-email-vladimir.murzin@arm.com> References: <1493029017-31382-1-git-send-email-vladimir.murzin@arm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1169 Lines: 30 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. Tested-by: Benjamin Gaignard Tested-by: Andras Szemzo Tested-by: Alexandre TORGUE Reviewed-by: Robin Murphy Signed-off-by: Vladimir Murzin --- arch/arm/mm/Kconfig | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig index d731f28..7e357c6 100644 --- a/arch/arm/mm/Kconfig +++ b/arch/arm/mm/Kconfig @@ -1049,8 +1049,8 @@ config ARM_L1_CACHE_SHIFT default 5 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 + bool "Use non-cacheable memory for DMA" if (CPU_V6 || CPU_V6K || CPU_V7M) && !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 -- 2.0.0