From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail202.messagelabs.com (mail202.messagelabs.com [216.82.254.227]) by kanga.kvack.org (Postfix) with ESMTP id 173EF6B02A3 for ; Fri, 16 Jul 2010 20:01:12 -0400 (EDT) Date: Fri, 16 Jul 2010 17:01:08 -0700 From: Larry Bassel Subject: Re: [RFC 1/3 v3] mm: iommu: An API to unify IOMMU, CPU and device memory management Message-ID: <20100717000108.GB21293@labbmf-linux.quicinc.com> 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> <20100716075856.GC16124@n2100.arm.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100716075856.GC16124@n2100.arm.linux.org.uk> Sender: owner-linux-mm@kvack.org To: Russell King - ARM Linux Cc: Tim HRM , 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 16 Jul 10 08:58, Russell King - ARM Linux wrote: > 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. We are investigating the impact of this change on us, and I will send out more detailed comments next week. > > 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. > Larry Bassel -- Sent by an employee of the Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum. -- 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