From patchwork Sun Sep 23 14:55:18 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John David Anglin X-Patchwork-Id: 10611761 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6EA7214BD for ; Sun, 23 Sep 2018 14:55:23 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5B969299C6 for ; Sun, 23 Sep 2018 14:55:23 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4E1A429DD4; Sun, 23 Sep 2018 14:55:23 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI,UNPARSEABLE_RELAY autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D3B7E299C6 for ; Sun, 23 Sep 2018 14:55:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726280AbeIWUxG (ORCPT ); Sun, 23 Sep 2018 16:53:06 -0400 Received: from belmont80srvr.owm.bell.net ([184.150.200.80]:37536 "EHLO mtlfep02.bell.net" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726259AbeIWUxF (ORCPT ); Sun, 23 Sep 2018 16:53:05 -0400 Received: from bell.net mtlfep02 184.150.200.30 by mtlfep02.bell.net with ESMTP id <20180923145520.EFWF11841.mtlfep02.bell.net@mtlspm01.bell.net> for ; Sun, 23 Sep 2018 10:55:20 -0400 Received: from mx3210.localdomain ([70.53.62.196]) by mtlspm01.bell.net with ESMTP id <20180923145520.KFQA28394.mtlspm01.bell.net@mx3210.localdomain>; Sun, 23 Sep 2018 10:55:20 -0400 Received: by mx3210.localdomain (Postfix, from userid 1000) id 6F3AC2200F9; Sun, 23 Sep 2018 10:55:19 -0400 (EDT) Date: Sun, 23 Sep 2018 10:55:18 -0400 From: John David Anglin To: linux-parisc@vger.kernel.org Cc: deller@gmx.de, James.Bottomley@HansenPartnership.com Subject: [PATCH] parisc: Remove PTE load and fault check from L2_ptep macro Message-ID: <20180923145518.GA9595@mx3210.localdomain> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="SLDf9lqlvOQaIe6s" Content-Disposition: inline User-Agent: Mutt/1.10.1 (2018-07-13) X-Cloudmark-Analysis: v=2.2 cv=XaJm9Mx5 c=1 sm=0 tr=0 a=Zvhif4XNTjWcJyJCfFIh1A==:17 a=JBFolyDoGHsA:10 a=FBHGMhGWAAAA:8 a=FssbAEJRoSVUQZ_H9XUA:9 a=CjuIK1q_8ugA:10 a=Njz2nQnGTZkk9KuUsUEA:9 a=ONNS8QRKHyMA:10 a=9gvnlMMaQFpL9xblJ6ne:22 Sender: linux-parisc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-parisc@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This change removes the PTE load and present check from the L2_ptep macro. The load and check for kernel pages is now done in the tlb_lock macro. This avoids a double load and check for user pages. The load and check for user pages is now done inside the lock so the fault handler can't be called while the entry is being updated. Signed-off-by: John David Anglin diff --git a/arch/parisc/kernel/entry.S b/arch/parisc/kernel/entry.S index 1b4732e20137..be1ef02a4799 100644 --- a/arch/parisc/kernel/entry.S +++ b/arch/parisc/kernel/entry.S @@ -430,8 +430,6 @@ extru \va,31-PAGE_SHIFT,ASM_BITS_PER_PTE,\index dep %r0,31,PAGE_SHIFT,\pmd /* clear offset */ shladd \index,BITS_PER_PTE_ENTRY,\pmd,\pmd /* pmd is now pte */ - LDREG %r0(\pmd),\pte - bb,>=,n \pte,_PAGE_PRESENT_BIT,\fault .endm /* Look up PTE in a 3-Level scheme. @@ -462,7 +460,7 @@ L2_ptep \pgd,\pte,\index,\va,\fault .endm - /* Acquire pa_tlb_lock lock and recheck page is still present. */ + /* Acquire pa_tlb_lock lock and check page is present. */ .macro tlb_lock spc,ptp,pte,tmp,tmp1,fault #ifdef CONFIG_SMP cmpib,COND(=),n 0,\spc,2f @@ -471,10 +469,12 @@ cmpib,COND(=) 0,\tmp1,1b nop LDREG 0(\ptp),\pte - bb,<,n \pte,_PAGE_PRESENT_BIT,2f + bb,<,n \pte,_PAGE_PRESENT_BIT,3f b \fault stw \spc,0(\tmp) -2: +2: LDREG 0(\ptp),\pte + bb,>=,n \pte,_PAGE_PRESENT_BIT,\fault +3: #endif .endm