Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Mon, 9 Sep 2002 13:07:03 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Mon, 9 Sep 2002 13:07:03 -0400 Received: from antigonus.hosting.pacbell.net ([216.100.98.13]:29576 "EHLO antigonus.hosting.pacbell.net") by vger.kernel.org with ESMTP id ; Mon, 9 Sep 2002 13:07:02 -0400 Reply-To: From: "Imran Badr" To: "'David S. Miller'" , Cc: Subject: RE: Calculating kernel logical address .. Date: Mon, 9 Sep 2002 10:06:46 -0700 Message-ID: <019d01c25823$8714c460$9e10a8c0@IMRANPC> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook CWS, Build 9.0.2416 (9.0.2911.0) In-Reply-To: Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4807.1700 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1402 Lines: 43 So, what you gurus suggest me to do? How can I get physical address of a user buffer (which was originally mmap'ed() from a kmalloc() allocation) and which would also be protable across multiple platforms? Thanks. Imran. -----Original Message----- From: David S. Miller [mailto:davem@redhat.com] Sent: Sunday, September 08, 2002 10:28 PM To: phillips@arcor.de Cc: imran.badr@cavium.com; linux-kernel@vger.kernel.org Subject: Re: Calculating kernel logical address .. From: Daniel Phillips Date: Mon, 9 Sep 2002 07:17:30 +0200 On Monday 09 September 2002 07:00, David S. Miller wrote: > Actually, KSEG0 the most Linux friendly design in the world > particularly in 64-bit mode. That's easy to say until you try and work with it (I assume you have, and forgot). Just try to do a 3G/1G split on it, for example. Maybe you missed the "64-bit mode" part of what I said. :-) In 64-bit mode there is no need to do any kind of split. You just use the KSEG mapping with full cache coherency for all of physical memory as the PAGE_OFFSET area. I forget if it was KSEG0 or some other number, but I know it works. - 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/