From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756356AbXJTAe2 (ORCPT ); Fri, 19 Oct 2007 20:34:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750878AbXJTAeU (ORCPT ); Fri, 19 Oct 2007 20:34:20 -0400 Received: from web35709.mail.mud.yahoo.com ([66.163.179.163]:22201 "HELO web35709.mail.mud.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1750817AbXJTAeT (ORCPT ); Fri, 19 Oct 2007 20:34:19 -0400 X-Greylist: delayed 400 seconds by postgrey-1.27 at vger.kernel.org; Fri, 19 Oct 2007 20:34:19 EDT DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=X-YMail-OSG:Received:Date:From:Subject:To:MIME-Version:Content-Type:Content-Transfer-Encoding:Message-ID; b=6cluAqBIAe/8vUsDx13E2oAcsWvEeaMPJGjWiEMJ4yDk8HEMEpjURR7+6twQiv+0yPltcCFb9/wThaZaAe8Silct+Jn9q8SoYFPS/u8OelNK8iq1zO+gF+gI7mY5bBihS4MjdcL39O1gnzxY5T7FWawPCQ5a60HqnlhfQxxmZk0=; X-YMail-OSG: AUH02dEVM1lOrwlTDHK0XGPxvNiFq5jyWAhmhTsOu9sH3abje19ZeH7CkrjyN_2xaksJBBmY7vGOAJVr3UpiaVaOv3XUGkt5Myj2EXcHjwxtQ8Tygn0- Date: Fri, 19 Oct 2007 17:27:37 -0700 (PDT) From: Jim Brooks Subject: Re: how to use TLB to prevent Linux accessing a particular memory region To: linux-kernel@vger.kernel.org MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Message-ID: <754003.20445.qm@web35709.mail.mud.yahoo.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > Out of 32MB of DDR 8MB is reserved for use by DSP > processor. But the MIPS processor downloads firmware > into this reserved memory for the DSP. > > Now, is it possible to use the TLB to prevent Linux > from accessing the reserved memory after the firmware > has been downloaded? Well, even if you did remap PTEs (TLBs are N/A), or claimed that special memory, that may be too late. The kernel might've already allocated and stomped over it. A reliable way is to redefine the kernel's "memory map" which takes effect during boot. Look for the memory map as a .h in arch/ (IIRC). -- Jim Brooks __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com