From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail1.matrix-vision.com (mail1.matrix-vision.com [78.47.19.71]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "localhost", Issuer "localhost" (not verified)) by ozlabs.org (Postfix) with ESMTPS id 685CBB6FB0 for ; Mon, 23 May 2011 19:21:45 +1000 (EST) Message-ID: <4DDA2509.6070702@matrix-vision.de> Date: Mon, 23 May 2011 11:12:41 +0200 From: Andre Schwarz MIME-Version: 1.0 To: "Ira W. Snyder" Subject: PCI DMA to user mem on mpc83xx Content-Type: text/plain; charset=ISO-8859-1; format=flowed Cc: LinuxPPC List List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Ira, we have a pretty old PCI device driver here that needs some basic rework running on 2.6.27 on several MPC83xx. It's a simple char-device with "give me some data" implemented using read() resulting in zero-copy DMA to user mem. There's get_user_pages() working under the hood along with SetPageDirty() and page_cache_release(). Main goal is to prepare a sg-list that gets fed into a DMA controller. I wonder if there's a more up-to-date/efficient and future proof scheme of creating the mapping. Could you provide some pointers or would you stick to the current scheme ? Regards, André MATRIX VISION GmbH, Talstrasse 16, DE-71570 Oppenweiler Registergericht: Amtsgericht Stuttgart, HRB 271090 Geschaeftsfuehrer: Gerhard Thullner, Werner Armingeon, Uwe Furtner