Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758461Ab3GPAAm (ORCPT ); Mon, 15 Jul 2013 20:00:42 -0400 Received: from mail-we0-f174.google.com ([74.125.82.174]:44716 "EHLO mail-we0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755244Ab3GPAAl (ORCPT ); Mon, 15 Jul 2013 20:00:41 -0400 MIME-Version: 1.0 In-Reply-To: References: <20130715230418.GA2649@leaf> Date: Mon, 15 Jul 2013 20:00:39 -0400 Message-ID: Subject: Re: BGRT Pointer in System RAM From: Parag Warudkar To: Josh Triplett Cc: Andy Lutomirski , LKML , linux-acpi@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1037 Lines: 28 On Mon, Jul 15, 2013 at 7:56 PM, Parag Warudkar wrote: > On Mon, Jul 15, 2013 at 7:04 PM, Josh Triplett wrote: > >> We do need to handle the case of a valid pointer into memory that e820 >> calls system RAM, as well as the case of a valid pointer into memory >> reserved for the BIOS or similar, but not the case of an invalid >> pointer. > > Would that be as simple as > > page_is_ram( Damn shortcuts - virt_addr = phys_to_virt(image->base_address); if(page_is_ram(virt_to_page(virt_addr))) { //direct read from virt addr } Would that suffice for the System RAM case or some other MM trickery is involved? Thanks, Parag -- 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/