From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753325AbbCYUXl (ORCPT ); Wed, 25 Mar 2015 16:23:41 -0400 Received: from mga11.intel.com ([192.55.52.93]:19396 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752373AbbCYUXk (ORCPT ); Wed, 25 Mar 2015 16:23:40 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.11,466,1422950400"; d="scan'208";a="546316545" Message-ID: <1427315018.14654.2.camel@theros.lm.intel.com> Subject: Re: [PATCH 3/3] x86: add support for the non-standard protected e820 type From: Ross Zwisler To: Christoph Hellwig Cc: linux-nvdimm@ml01.01.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org, boaz@plexistor.com, axboe@kernel.dk Date: Wed, 25 Mar 2015 14:23:38 -0600 In-Reply-To: <1427299449-26722-4-git-send-email-hch@lst.de> References: <1427299449-26722-1-git-send-email-hch@lst.de> <1427299449-26722-4-git-send-email-hch@lst.de> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.10.4 (3.10.4-4.fc20.rez) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2015-03-25 at 17:04 +0100, Christoph Hellwig wrote: > Various recent bioses support NVDIMMs or ADR using a non-standard > e820 memory type, and Intel supplied reference Linux code using this > type to various vendors. > > Wire this e820 table type up to export platform devices for the pmem > driver so that we can use it in Linux, and also provide a memmap= > argument to manually tag memory as protected, which can be used > if the bios doesn't use the standard nonstandard interface, or > we just want to test the pmem driver with regular memory. > > Based on an earlier patch from Dave Jiang > Signed-off-by: Christoph Hellwig > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig > index b7d31ca..93a27e4 100644 > --- a/arch/x86/Kconfig > +++ b/arch/x86/Kconfig > @@ -1430,6 +1430,19 @@ config ILLEGAL_POINTER_VALUE > > source "mm/Kconfig" > > +config X86_PMEM_LEGACY > + bool "Support non-stanard NVDIMMs and ADR protected memory" > + help > + Treat memory marked using the non-stard e820 type of 12 as used > + by the Intel Sandy Bridge-EP reference BIOS as protected memory. > + The kernel will the offer these regions to the pmem driver so > + they can be used for persistent storage. > + > + If you say N the kernel will treat the ADR region like an e820 > + reserved region. > + > + Say Y if unsure Would it make sense to have this default to "y", or is that too strong?