From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with ESMTP id 658C96B02A3 for ; Fri, 16 Jul 2010 04:00:25 -0400 (EDT) Date: Fri, 16 Jul 2010 08:58:56 +0100 From: Russell King - ARM Linux Subject: Re: [RFC 1/3 v3] mm: iommu: An API to unify IOMMU, CPU and device memory management Message-ID: <20100716075856.GC16124@n2100.arm.linux.org.uk> References: <4C3C0032.5020702@codeaurora.org> <20100713150311B.fujita.tomonori@lab.ntt.co.jp> <20100713121420.GB4263@codeaurora.org> <20100714104353B.fujita.tomonori@lab.ntt.co.jp> <20100714201149.GA14008@codeaurora.org> <20100714220536.GE18138@n2100.arm.linux.org.uk> <20100715012958.GB2239@codeaurora.org> <20100715085535.GC26212@n2100.arm.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org To: Tim HRM Cc: Zach Pfeffer , FUJITA Tomonori , ebiederm@xmission.com, linux-arch@vger.kernel.org, dwalker@codeaurora.org, mel@csn.ul.ie, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, andi@firstfloor.org, linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org List-ID: On Thu, Jul 15, 2010 at 08:48:36PM -0400, Tim HRM wrote: > Interesting, since I seem to remember the MSM devices mostly conduct > IO through regions of normal RAM, largely accomplished through > ioremap() calls. > > Without more public domain documentation of the MSM chips and AMSS > interfaces I wouldn't know how to avoid this, but I can imagine it > creates a bit of urgency for Qualcomm developers as they attempt to > upstream support for this most interesting SoC. As the patch has been out for RFC since early April on the linux-arm-kernel mailing list (Subject: [RFC] Prohibit ioremap() on kernel managed RAM), and no comments have come back from Qualcomm folk. The restriction on creation of multiple V:P mappings with differing attributes is also fairly hard to miss in the ARM architecture specification when reading the sections about caches. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org