Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261904AbVD0DxK (ORCPT ); Tue, 26 Apr 2005 23:53:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261905AbVD0DxK (ORCPT ); Tue, 26 Apr 2005 23:53:10 -0400 Received: from colo.lackof.org ([198.49.126.79]:17892 "EHLO colo.lackof.org") by vger.kernel.org with ESMTP id S261904AbVD0DxG (ORCPT ); Tue, 26 Apr 2005 23:53:06 -0400 Date: Tue, 26 Apr 2005 21:55:35 -0600 From: Grant Grundler To: Benjamin Herrenschmidt Cc: Grant Grundler , linux-pci@atrey.karlin.mff.cuni.cz, Linux Kernel list , Greg KH , bjorn.helgaas@hp.com Subject: Re: pci-sysfs resource mmap broken Message-ID: <20050427035535.GI2612@colo.lackof.org> References: <1114493609.7183.55.camel@gaston> <20050426163042.GE2612@colo.lackof.org> <1114555655.7183.81.camel@gaston> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1114555655.7183.81.camel@gaston> X-Home-Page: http://www.parisc-linux.org/ User-Agent: Mutt/1.5.6+20040907i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1175 Lines: 29 On Wed, Apr 27, 2005 at 08:47:34AM +1000, Benjamin Herrenschmidt wrote: > No. I don't agree. userspace has no business understanding the kernel > resources content. Sorry - you are right. Userspace doesn't need to understand kernel resources. It just needs some sort of handle so it can talk to the device in whatever way is appropriate. I was thinking the resource content (which happens to be CPU View of a BAR) could be that handle. ... > The only thing I dislike a bit is that forces me to read the BAR on > every access to "un-offset" the kernel resource. We may be able to have > some arch hook do that properly, but for now, that would fix the problem > and make the whole stuff work again. What is wrong with reading the BAR? Is the "IO View" needed in the performance path someplace? It should be trivial since config space is exported via /sys and /proc. libpci probably already has everything that's needed. grant - 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/