Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752753AbbDEQKl (ORCPT ); Sun, 5 Apr 2015 12:10:41 -0400 Received: from pandora.arm.linux.org.uk ([78.32.30.218]:37465 "EHLO pandora.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752041AbbDEQKh (ORCPT ); Sun, 5 Apr 2015 12:10:37 -0400 Date: Sun, 5 Apr 2015 17:10:14 +0100 From: Russell King - ARM Linux To: Stefan Agner Cc: shawn.guo@linaro.org, kernel@pengutronix.de, u.kleine-koenig@pengutronix.de, jason@lakedaemon.net, olof@lixom.net, arnd@arndb.de, daniel.lezcano@linaro.org, tglx@linutronix.de, mark.rutland@arm.com, pawel.moll@arm.com, robh+dt@kernel.org, ijc+devicetree@hellion.org.uk, galak@codeaurora.org, marc.zyngier@arm.com, mcoquelin.stm32@gmail.com, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 07/11] ARM: allow MULTIPLATFORM with !MMU Message-ID: <20150405161014.GG13898@n2100.arm.linux.org.uk> References: <1428090292-21693-1-git-send-email-stefan@agner.ch> <1428090292-21693-8-git-send-email-stefan@agner.ch> <20150403200931.GD13898@n2100.arm.linux.org.uk> <1f84d767d3bb8a8c470a26064cba454e@agner.ch> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1f84d767d3bb8a8c470a26064cba454e@agner.ch> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2183 Lines: 56 On Sat, Apr 04, 2015 at 01:56:20AM +0200, Stefan Agner wrote: > On 2015-04-03 22:09, Russell King - ARM Linux wrote: > > On Fri, Apr 03, 2015 at 09:44:48PM +0200, Stefan Agner wrote: > >> In order to support SoC with heterogenous CPU architectures (such > >> as Freescale Vybrid/i.MXSX) it is preferable to use the same > >> architecture (ARCH_MXC in this case) for the MMU enabled and !MMU > >> CPU. Hence allow to select MULTIPLATFORM even without MMU. > >> > >> Signed-off-by: Stefan Agner > >> --- > >> arch/arm/Kconfig | 21 ++++++++++----------- > >> 1 file changed, 10 insertions(+), 11 deletions(-) > >> > >> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig > >> index 9f1f09a..636cb3f 100644 > >> --- a/arch/arm/Kconfig > >> +++ b/arch/arm/Kconfig > >> @@ -230,7 +230,7 @@ config VECTORS_BASE > >> in size. > >> > >> config ARM_PATCH_PHYS_VIRT > >> - bool "Patch physical to virtual translations at runtime" if EMBEDDED > >> + bool "Patch physical to virtual translations at runtime" if EMBEDDED || (ARCH_MULTIPLATFORM && MMU) > >> default y > > > > This makes no sense. Multiplatform MMU _requires_ this feature, so why > > offer it to the user when multiplatform is enabled _and_ MMU is enabled? > > I see, this is plain wrong. Will replace that with a select ... if MMU > in multiplatform. I think what I'd like to see is, in the top level choice: config ARM_SINGLE_ARMV7M bool "ARM architecture v7M compliant (Cortex-M0/M3/M4) SoC" depends on !MMU select ARM_NVIC ... etc ... which then allows a /multiplatform/ v7M kernel to be built, allowing the selection of EFM32, SOC_VF610, and any other v7M compliant SoC. So, it's very similar to multiplatform in the sense that several SoCs can be built together, but we preserve the need not to build incompatible stuff together. Thoughts? -- FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up according to speedtest.net. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/