From patchwork Tue May 14 13:04:43 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jonathan Austin X-Patchwork-Id: 2565931 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) by patchwork1.kernel.org (Postfix) with ESMTP id 7C1BA3FD85 for ; Tue, 14 May 2013 13:13:10 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1UcEyt-00030s-Or; Tue, 14 May 2013 13:09:30 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1UcEvh-0005re-VX; Tue, 14 May 2013 13:06:09 +0000 Received: from service87.mimecast.com ([91.220.42.44]) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1UcEuy-0005lP-7u for linux-arm-kernel@lists.infradead.org; Tue, 14 May 2013 13:05:25 +0000 Received: from cam-owa2.Emea.Arm.com (fw-tnat.cambridge.arm.com [217.140.96.21]) by service87.mimecast.com; Tue, 14 May 2013 14:05:02 +0100 Received: from e102895-lin.cambridge.arm.com ([10.1.255.212]) by cam-owa2.Emea.Arm.com with Microsoft SMTPSVC(6.0.3790.3959); Tue, 14 May 2013 14:05:02 +0100 From: Jonathan Austin To: linux-arm-kernel@lists.infradead.org Subject: [PATCH 7/8] ARM: mpu: Allow enabling of the MPU via kconfig Date: Tue, 14 May 2013 14:04:43 +0100 Message-Id: <1368536684-13608-8-git-send-email-jonathan.austin@arm.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1368536684-13608-1-git-send-email-jonathan.austin@arm.com> References: <1368536684-13608-1-git-send-email-jonathan.austin@arm.com> X-OriginalArrivalTime: 14 May 2013 13:05:02.0059 (UTC) FILETIME=[A52093B0:01CE50A3] X-MC-Unique: 113051414050206001 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130514_090524_567778_D0A0E369 X-CRM114-Status: GOOD ( 13.13 ) X-Spam-Score: -2.6 (--) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-2.6 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [91.220.42.44 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: will.deacon@arm.com, Jonathan Austin , hyok.choi@samsung.com, u.kleine-koenig@pengutronix.de X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org Allows the user to select MPU support when compiling for ARM processors that support the PMSAv7. This ensures that CONFIG_SMP depends on the MPU in the case that no MMU is present. CONFIG_SMP_ON_UP is not implemented for nommu, so introduce an MMU dependency there. Signed-off-by: Jonathan Austin Reviewed-by: Will Deacon --- arch/arm/Kconfig | 4 ++-- arch/arm/Kconfig-nommu | 11 +++++++++++ 2 files changed, 13 insertions(+), 2 deletions(-) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index d423d58..e337618 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1413,7 +1413,7 @@ config SMP depends on CPU_V6K || CPU_V7 depends on GENERIC_CLOCKEVENTS depends on HAVE_SMP - depends on MMU + depends on MMU || ARM_MPU select USE_GENERIC_SMP_HELPERS help This enables support for systems with more than one CPU. If you have @@ -1434,7 +1434,7 @@ config SMP config SMP_ON_UP bool "Allow booting SMP kernel on uniprocessor systems (EXPERIMENTAL)" - depends on SMP && !XIP_KERNEL + depends on SMP && !XIP_KERNEL && MMU default y help SMP kernels contain instructions which fail on non-SMP processors. diff --git a/arch/arm/Kconfig-nommu b/arch/arm/Kconfig-nommu index 2cef8e1..8ceed61 100644 --- a/arch/arm/Kconfig-nommu +++ b/arch/arm/Kconfig-nommu @@ -50,3 +50,14 @@ config REMAP_VECTORS_TO_RAM Otherwise, say 'y' here. In this case, the kernel will require external support to redirect the hardware exception vectors to the writable versions located at DRAM_BASE. + +config ARM_MPU + bool 'Use the ARM v7 PMSA Compliant MPU' + default y + help + Some ARM systems without an MMU have instead a Memory Protection + Unit (MPU) that defines the type and permissions for regions of + memory. + + If your CPU has an MPU then you should choose 'y' here unless you + know that you do not want to use the MPU.