From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 26 Jan 2001 10:43:46 +0000 From: "Stephen C. Tweedie" Subject: Re: ioremap_nocache problem? Message-ID: <20010126104346.D11607@redhat.com> References: <3A6D5D28.C132D416@sangate.com> <20010123165117Z131182-221+34@kanga.kvack.org> <20010123165117Z131182-221+34@kanga.kvack.org> <20010125155345Z131181-221+38@kanga.kvack.org> <20010125165001Z132264-460+11@vger.kernel.org> <3A7066A1.5030608@valinux.com> <20010125175027Z131219-222+40@kanga.kvack.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20010125175027Z131219-222+40@kanga.kvack.org>; from ttabi@interactivesi.com on Thu, Jan 25, 2001 at 11:53:01AM -0600 Sender: owner-linux-mm@kvack.org Return-Path: To: Timur Tabi Cc: Jeff Hartmann , linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: Hi, On Thu, Jan 25, 2001 at 11:53:01AM -0600, Timur Tabi wrote: > > > As in an MMIO aperture? If its MMIO on the bus you should be able to > > just call ioremap with the bus address. By nature of it being outside > > of real ram, it should automatically be uncached (unless you've set an > > MTRR over that region saying otherwise). > > It's not outside of real RAM. The device is inside real RAM (it sits on the > DIMM itself), but I need to poke through the entire 4GB range to see how it > responds. kmap() is designed for that, not ioremap(). Is it absolutely essential that your mapping is uncached? If so, extending kmap() to support kmap_nocache() would seem to make a lot more sense than using ioremap(): kmap is there for temporarily poking around in high memory, whereas ioremap is really intended to be used for persistent maps. --Stephen -- 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.eu.org/Linux-MM/