From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755282AbYJVOkb (ORCPT ); Wed, 22 Oct 2008 10:40:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752198AbYJVOkX (ORCPT ); Wed, 22 Oct 2008 10:40:23 -0400 Received: from relay2.sgi.com ([192.48.171.30]:33794 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752150AbYJVOkX (ORCPT ); Wed, 22 Oct 2008 10:40:23 -0400 Date: Wed, 22 Oct 2008 09:40:22 -0500 From: Russ Anderson To: Ingo Molnar Cc: tglx@linutronix.de, linux-kernel@vger.kernel.org, "H. Peter Anvin" , Andrew Morton Subject: Re: [PATCH 2/3] x86: Add UV memory protection bios call Message-ID: <20081022144021.GB201004@sgi.com> Reply-To: Russ Anderson References: <20081021200112.GD32545@sgi.com> <20081022062235.GD651@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20081022062235.GD651@elte.hu> User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Oct 22, 2008 at 08:22:35AM +0200, Ingo Molnar wrote: > > * Russ Anderson wrote: > > > Add UV bios call to change memory protections. > > > > Signed-off-by: Russ Anderson > > > > --- > > arch/x86/kernel/bios_uv.c | 8 ++++++++ > > include/asm-x86/uv/bios.h | 10 +++++++++- > > 2 files changed, 17 insertions(+), 1 deletion(-) > > > - UV_BIOS_WATCHLIST_FREE > > + UV_BIOS_WATCHLIST_FREE, > > + UV_BIOS_MEMPROTECT > > > +enum uv_memprotect { > > + UV_MEMPROT_RESTRICT_ACCESS, > > + UV_MEMPROT_ALLOW_AMO, > > + UV_MEMPROT_ALLOW_RW > > hm, what does this do? Does it twiddle the southbridge to protect given > physical RAM rages from the CPU altogether? The SGI UV hardware has memory protection to control what types of memory references are allowed to specific physical RAM ranges. This bios call is used to change the protection settings. This is used by the xp driver (drivers/misc/sgi-xp/xp_sn2.c). Dean Nelson submitted a patch yesterday that uses this bios call. http://marc.info/?l=linux-kernel&m=122462425819289&w=2 Thanks, -- Russ Anderson, OS RAS/Partitioning Project Lead SGI - Silicon Graphics Inc rja@sgi.com