From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Subject: Re: [RFC - V2] - Mapping ACPI tables as CACHED Date: Thu, 26 Aug 2010 11:08:02 -0700 Message-ID: <4C76AD82.2030105@zytor.com> References: <20100722152220.GA18290@sgi.com> <20100724001449.GA9618@khazad-dum.debian.net> <4C743C0F.2010101@zytor.com> <20100826171704.GA21584@sgi.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from terminus.zytor.com ([198.137.202.10]:33562 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751681Ab0HZSI1 (ORCPT ); Thu, 26 Aug 2010 14:08:27 -0400 In-Reply-To: <20100826171704.GA21584@sgi.com> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Jack Steiner Cc: hmh@hmh.eng.br, mingo@elte.hu, tglx@linutronix.de, lenb@kernel.org, tony.luck@gmail.com, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org On 08/26/2010 10:17 AM, Jack Steiner wrote: > Map ACPI tables as WB on x86_64. No substantive changes to IA64. > > > Signed-off-by: Jack Steiner > > --- > V2 - Change the patch to unconditionally map ACPI tables as WB on x86_64. > I'm still some paranoid about this because of the potential imapct on > some platforms with weird BIOSs. However, note that on EFI-enabled > systems (like UV), the ACPI tables are already mapped as WB memory. > This is done in the EFI function efi_enter_virtual_mode(). > The ACPI code in acpi_os_map_memory() is not currently aware of the > EFI mapping & currently maps the memory as UC. This seems like a bug. > I really think that it's all a consequence of the fact that ioremap() became implicitly UC when we added PAT support (being the more conservative choice.) Len, want to take this one or should I? -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.