From patchwork Fri Dec 16 18:35:24 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mike Kravetz X-Patchwork-Id: 706519 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3tgJsw2qbDz9t2N for ; Sat, 17 Dec 2016 05:36:04 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757526AbcLPSgC (ORCPT ); Fri, 16 Dec 2016 13:36:02 -0500 Received: from userp1040.oracle.com ([156.151.31.81]:44535 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757306AbcLPSgB (ORCPT ); Fri, 16 Dec 2016 13:36:01 -0500 Received: from aserv0022.oracle.com (aserv0022.oracle.com [141.146.126.234]) by userp1040.oracle.com (Sentrion-MTA-4.3.2/Sentrion-MTA-4.3.2) with ESMTP id uBGIZqqD029746 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 16 Dec 2016 18:35:53 GMT Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by aserv0022.oracle.com (8.14.4/8.14.4) with ESMTP id uBGIZqx3014271 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 16 Dec 2016 18:35:52 GMT Received: from abhmp0002.oracle.com (abhmp0002.oracle.com [141.146.116.8]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id uBGIZpAF020074; Fri, 16 Dec 2016 18:35:51 GMT Received: from monkey.oracle.com (/50.188.161.229) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Fri, 16 Dec 2016 10:35:51 -0800 From: Mike Kravetz To: sparclinux@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: "David S . Miller" , Bob Picco , Nitin Gupta , Vijay Kumar , Julian Calaby , Adam Buchbinder , "Kirill A . Shutemov" , Michal Hocko , Andrew Morton , Mike Kravetz Subject: [RFC PATCH 01/14] sparc64: placeholder for needed mmu shared context patching Date: Fri, 16 Dec 2016 10:35:24 -0800 Message-Id: <1481913337-9331-2-git-send-email-mike.kravetz@oracle.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1481913337-9331-1-git-send-email-mike.kravetz@oracle.com> References: <1481913337-9331-1-git-send-email-mike.kravetz@oracle.com> X-Source-IP: aserv0022.oracle.com [141.146.126.234] Sender: sparclinux-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: sparclinux@vger.kernel.org MMU shared context patching will be supported on Sun4V platforms with Niagara 2 or later processors. There will be a need for kernel patching based on this criteria. This 'patch' simply adds a comment as a reminder and placeholder to add that support. For now, MMU shared context support will be determined at follows: - sun4v patching will be used for shared context support. This is too general as most but not all sun4v platforms contain the required processors. - A new config option (CONFIG_SHARED_MMU_CTX) is added Signed-off-by: Mike Kravetz --- arch/sparc/kernel/setup_64.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/arch/sparc/kernel/setup_64.c b/arch/sparc/kernel/setup_64.c index 6b7331d..ffda69b 100644 --- a/arch/sparc/kernel/setup_64.c +++ b/arch/sparc/kernel/setup_64.c @@ -276,6 +276,17 @@ void sun_m7_patch_2insn_range(struct sun4v_2insn_patch_entry *start, } } +/* + * FIXME - TODO + * + * Shared MMU context support will only be provided on sun4v platforms + * with Niagara 2 or later processors. A patching mechanism for this + * this type of support will need to be implemented. For now, the code + * is making the too general assumption of supporting shared context on + * all sun4v platforms. This is a placeholder to add correct support + * at a later time. + */ + static void __init sun4v_patch(void) { extern void sun4v_hvapi_init(void);