From patchwork Thu Aug 11 08:24:13 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Russell King - ARM Linux X-Patchwork-Id: 1056092 Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by demeter2.kernel.org (8.14.4/8.14.4) with ESMTP id p7B8P5FK018965 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Thu, 11 Aug 2011 08:25:26 GMT Received: from canuck.infradead.org ([2001:4978:20e::1]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1QrQZT-0005Y4-DV; Thu, 11 Aug 2011 08:24:55 +0000 Received: from localhost ([127.0.0.1] helo=canuck.infradead.org) by canuck.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1QrQZS-0002N3-U9; Thu, 11 Aug 2011 08:24:54 +0000 Received: from [2002:4e20:1eda::1] (helo=caramon.arm.linux.org.uk) by canuck.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1QrQZO-0002Ml-8K for linux-arm-kernel@lists.infradead.org; Thu, 11 Aug 2011 08:24:52 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=arm.linux.org.uk; s=caramon; h=Sender:In-Reply-To:Content-Type:MIME-Version:References:Message-ID:Subject:Cc:To:From:Date; bh=0ivaadpvI6JvC+dvIuVykh+H36cUdh8K/rF3jXbsQC0=; b=nnW8Rd4mFCVKpyZVwQkYezRlpJpmfe1ro+x5M4UltZrOdmw7HxXmm54UTOQglsjWyuv4prOCJ9EqnDtoviB7oM+5IrUrH8BRzkSYgGt+P4QpCcaJHzQhugBAVmNgza5zUMu96G2V3XJDJlPjQNoctlAQroy79Wd4RI2te5pI4ZU=; Received: from n2100.arm.linux.org.uk ([2002:4e20:1eda:1:214:fdff:fe10:4f86]) by caramon.arm.linux.org.uk with esmtpsa (TLSv1:AES256-SHA:256) (Exim 4.72) (envelope-from ) id 1QrQYp-0003lG-4k; Thu, 11 Aug 2011 09:24:15 +0100 Received: from linux by n2100.arm.linux.org.uk with local (Exim 4.72) (envelope-from ) id 1QrQYn-0003ZG-Js; Thu, 11 Aug 2011 09:24:13 +0100 Date: Thu, 11 Aug 2011 09:24:13 +0100 From: Russell King - ARM Linux To: Will Deacon , Andrew Victor , Nicolas Ferre , Jean-Christophe Plagniol-Villard Subject: Re: Enabling runtime P2V by default (Re: [PATCH 3/5] mach-u300: patch physoffset by default) Message-ID: <20110811082413.GA4775@n2100.arm.linux.org.uk> References: <1312918898-11894-1-git-send-email-linus.walleij@stericsson.com> <20110810091635.GF1831@n2100.arm.linux.org.uk> <20110810092206.GE10121@e102144-lin.cambridge.arm.com> <20110810092955.GG1831@n2100.arm.linux.org.uk> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20110810092955.GG1831@n2100.arm.linux.org.uk> User-Agent: Mutt/1.5.19 (2009-01-05) X-CRM114-Version: 20090807-BlameThorstenAndJenny ( TRE 0.7.6 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20110811_042451_003591_252EDC25 X-CRM114-Status: GOOD ( 34.62 ) X-Spam-Score: 1.2 (+) X-Spam-Report: SpamAssassin version 3.3.1 on canuck.infradead.org summary: Content analysis details: (1.2 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature 1.3 RDNS_NONE Delivered to internal network by a host with no rDNS Cc: Linus Walleij , Lee Jones , Linus Walleij , "linux-arm-kernel@lists.infradead.org" , Nicolas Pitre X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter2.kernel.org [140.211.167.43]); Thu, 11 Aug 2011 08:25:26 +0000 (UTC) On Wed, Aug 10, 2011 at 10:29:55AM +0100, Russell King - ARM Linux wrote: > On Wed, Aug 10, 2011 at 10:22:06AM +0100, Will Deacon wrote: > > On Wed, Aug 10, 2011 at 10:16:35AM +0100, Russell King - ARM Linux wrote: > > > On Tue, Aug 09, 2011 at 09:41:38PM +0200, Linus Walleij wrote: > > > > From: Linus Walleij > > > > > > > > This works like a charm so I'll just default-select it. > > > > > > Well, we can remove the EXPERIMENTAL status of this option now. This > > > raises the question is whether we should now default it to 'y' - I > > > think we should. Anyone have any objections? > > > > I've been running with this option enabled for the collection of ARM boards > > I have and the only problem I have encountered was related to u-boot loading > > at the wrong address. > > > > So I'm all for enabling it by default, especially since it will force out > > any remaining issues for boards where this hasn't been used extensively. > > Maybe also making the option hidden depending on EXPERT, or even EMBEDDED > would be a good idea too. I think it falls into at least the same class > as UID16, sysctl, hotplug, printk, etc. which are all EXPERT options. Right, I'm now committing a patch to hide the option unless EMBEDDED is enabled. I think this means we should get rid of the 'select ARM_PATCH_PHYS_VIRT' statements from the various platforms, so that folk can optimize away that code if they know what they're doing. Note: this patch will conflict with the removal of the 16-bit P2V patching, so we need to sort that out. 8<--------- From: Russell King - ARM Linux ARM: enable ARM_PATCH_PHYS_VIRT by default Enable virtual to physical translation patching by default in all kernels. Hide the option behind EMBEDDED. This can still be turned off if people desire, and they know what they're doing, to shrink the size of the kernel to a minimum. Signed-off-by: Russell King Acked-by: Will Deacon Acked-by: Jean-Christophe PLAGNIOL-VILLARD Acked-by: Nicolas Pitre --- arch/arm/Kconfig | 8 ++++++-- 1 files changed, 6 insertions(+), 2 deletions(-) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 5ebc5d9..6085a6c 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -195,7 +195,8 @@ config VECTORS_BASE The base address of exception vectors. config ARM_PATCH_PHYS_VIRT - bool "Patch physical to virtual translations at runtime" + bool "Patch physical to virtual translations at runtime" if EMBEDDED + default y depends on !XIP_KERNEL && MMU depends on !ARCH_REALVIEW || !SPARSEMEM help @@ -207,6 +208,10 @@ config ARM_PATCH_PHYS_VIRT of physical memory is at a 16MB boundary, or theoretically 64K for the MSM machine class. + Only disable this option if you know what you do not require + this feature (eg, building a kernel for a single machine) and + you need to shrink the kernel to the minimal size. + config ARM_PATCH_PHYS_VIRT_16BIT def_bool y depends on ARM_PATCH_PHYS_VIRT && ARCH_MSM @@ -301,7 +306,6 @@ config ARCH_AT91 select ARCH_REQUIRE_GPIOLIB select HAVE_CLK select CLKDEV_LOOKUP - select ARM_PATCH_PHYS_VIRT if MMU help This enables support for systems based on the Atmel AT91RM9200, AT91SAM9 and AT91CAP9 processors.