From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265255AbUENLTU (ORCPT ); Fri, 14 May 2004 07:19:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264444AbUENLTU (ORCPT ); Fri, 14 May 2004 07:19:20 -0400 Received: from styx.suse.cz ([82.208.2.94]:62855 "EHLO shadow.ucw.cz") by vger.kernel.org with ESMTP id S265253AbUENLSl (ORCPT ); Fri, 14 May 2004 07:18:41 -0400 Date: Fri, 14 May 2004 13:19:26 +0200 From: Vojtech Pavlik To: Jeff Garzik Cc: Andrew Morton , Robert.Picco@hp.com, linux-kernel@vger.kernel.org, venkatesh.pallipadi@intel.com Subject: Re: [PATCH] HPET driver Message-ID: <20040514111926.GA30876@ucw.cz> References: <40A3F805.5090804@hp.com> <40A40204.1060509@pobox.com> <20040513164226.7efb2a83.akpm@osdl.org> <40A40982.60202@pobox.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <40A40982.60202@pobox.com> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, May 13, 2004 at 07:49:22PM -0400, Jeff Garzik wrote: > Andrew Morton wrote: > >Jeff Garzik wrote: > > > >>>+ vma->vm_flags |= (VM_IO | VM_SHM | VM_LOCKED); > >>>+ vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); > >>>+ addr = __pa(addr); > >> > >>where did these flags come from? don't you just want VM_RESERVED? > > > > > >VM_IO is the way to mark mmapped I/O devices. > > > > vma->vm_flags |= VM_IO; > > > >should be sufficient here. > > > >hm, I'm trying to decrypt how the driver accesses the hardware. It's > >taking copies of kernel virtual addresses based off hpet_virt_address, but > >there are no readl's or writel's in there. Is the actual device access > >done over in time_hpet.c? > > > HPET writes into RAM at magic addresses, so it's not really a bus address. Since it lives in the bridge (either north or south), IMO it is a bus address ... at least on AMD machines it's the same space where MMIO comes from. > Thus I think only VM_RESERVED is needed... > > Jeff -- Vojtech Pavlik SuSE Labs, SuSE CR