From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matt Fleming Subject: Re: [PATCH V3 4/4] acpi, apei: use EFI memmap to map GHES memory Date: Tue, 23 Jun 2015 10:50:33 +0100 Message-ID: <20150623095033.GC2815@codeblueprint.co.uk> References: <1434047160-23358-1-git-send-email-zjzhang@codeaurora.org> <1434047160-23358-5-git-send-email-zjzhang@codeaurora.org> <20150612162924.GH9084@pd.tnic> <557B6ED9.3020706@codeaurora.org> <20150613082750.GA3470@pd.tnic> <20150615141533.GB17685@codeblueprint.co.uk> <20150615145908.GK4255@pd.tnic> <20150622051131.GA2815@codeblueprint.co.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-wi0-f175.google.com ([209.85.212.175]:36967 "EHLO mail-wi0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752527AbbFWJuh (ORCPT ); Tue, 23 Jun 2015 05:50:37 -0400 Received: by wicgi11 with SMTP id gi11so11123278wic.0 for ; Tue, 23 Jun 2015 02:50:35 -0700 (PDT) Content-Disposition: inline In-Reply-To: <20150622051131.GA2815@codeblueprint.co.uk> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Borislav Petkov Cc: "Zhang, Jonathan Zhixiong" , Matt Fleming , Thomas Gleixner , fu.wei@linaro.org, al.stone@linaro.org, tony.luck@gmail.com, rjw@rjwysocki.net, lenb@kernel.org, ying.huang@intel.com, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org On Mon, 22 Jun, at 06:11:31AM, Matt Fleming wrote: > > Right, but see my previous comment about x86 discarding a bunch of > attributes for memory regions because the kernel "knows better". > > And in most places, yes, the kernel really does know better. But this > APEI case is special because irrespective of what the kernel says we > want to be compatible with the firmware's memory map. > > And we don't have an API for that. Maybe what we want is a new PAGE_* protection that is compatible with any firmware mappings? That'd be nice because we wouldn't have to introduce a whole new API for this GHES case and ioremap_* could do whatever it wanted under the hood. Thougts? -- Matt Fleming, Intel Open Source Technology Center