From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 31 May 2001 06:02:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 31 May 2001 06:02:21 -0400 Received: from ausmtp02.au.ibm.COM ([202.135.136.105]:27402 "EHLO ausmtp02.au.ibm.com") by vger.kernel.org with ESMTP id ; Thu, 31 May 2001 06:02:14 -0400 From: mdaljeet@in.ibm.com X-Lotus-FromDomain: IBMIN@IBMAU To: mingo@elte.hu cc: linux-kernel@vger.kernel.org, Pete Wyckoff Message-ID: Date: Thu, 31 May 2001 15:27:38 +0530 Subject: Re: pte_page Mime-Version: 1.0 Content-type: text/plain; charset=us-ascii Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org I am doing a DMA from a card to system memory. The system memory "physical address" is '0x104000'. I am doing this on x86 with kernel version 2.4.2. Can this address be the address of a user space buffer? Regards, Daljeet. |--------+-----------------------> | | Ingo Molnar | | | | | | | | | 05/30/01 | | | 11:09 PM | | | Please | | | respond to | | | mingo | | | | |--------+-----------------------> >--------------------------------------------------------| | | | To: Pete Wyckoff | | cc: Daljeet Maini/India/IBM@IBMIN, | | linux-kernel@vger.kernel.org | | Subject: Re: pte_page | >--------------------------------------------------------| On Wed, 30 May 2001, Pete Wyckoff wrote: > > __pa(page_address(pte_page(pte))) is the address you want. [or > > pte_val(*pte) & (PAGE_SIZE-1) on x86 but this is platform-dependent.] > > Does this work on x86 non-kmapped highmem user pages too? (i.e. is > page->virtual valid for every potential user page.) you are right, the highmem-compatible solution is to use page-mem_map as the physical page index. Ingo