From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4B4E9C433E7 for ; Sat, 10 Oct 2020 15:21:42 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 953F322314 for ; Sat, 10 Oct 2020 15:21:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 953F322314 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=csgroup.eu Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 4C7pZB3x4DzDr22 for ; Sun, 11 Oct 2020 02:21:38 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=csgroup.eu (client-ip=93.17.236.30; helo=pegase1.c-s.fr; envelope-from=christophe.leroy@csgroup.eu; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=csgroup.eu Received: from pegase1.c-s.fr (pegase1.c-s.fr [93.17.236.30]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4C7pQ80MPvzDqsj for ; Sun, 11 Oct 2020 02:14:37 +1100 (AEDT) Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 4C7pQ11p8sz9v1Jd; Sat, 10 Oct 2020 17:14:33 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [192.168.12.234]) (amavisd-new, port 10024) with ESMTP id IX5XROfM-CCd; Sat, 10 Oct 2020 17:14:33 +0200 (CEST) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase1.c-s.fr (Postfix) with ESMTP id 4C7pQ06fYZz9v1JX; Sat, 10 Oct 2020 17:14:32 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id AC42D8B77D; Sat, 10 Oct 2020 17:14:34 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id IWJld82XG3ox; Sat, 10 Oct 2020 17:14:34 +0200 (CEST) Received: from po17688vm.idsi0.si.c-s.fr (unknown [192.168.4.90]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 499FF8B75B; Sat, 10 Oct 2020 17:14:34 +0200 (CEST) Received: by po17688vm.idsi0.si.c-s.fr (Postfix, from userid 0) id 27F01663C3; Sat, 10 Oct 2020 15:14:34 +0000 (UTC) Message-Id: <3213af8764797becb36a4b47730df7bbc6e9b938.1602342819.git.christophe.leroy@csgroup.eu> In-Reply-To: <3f2386f94fada00b541be76d6bc4b6409746a72d.1602342819.git.christophe.leroy@csgroup.eu> References: <3f2386f94fada00b541be76d6bc4b6409746a72d.1602342819.git.christophe.leroy@csgroup.eu> From: Christophe Leroy Subject: [PATCH 3/4] powerpc/8xx: Always fault when _PAGE_ACCESSED is not set To: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman Date: Sat, 10 Oct 2020 15:14:34 +0000 (UTC) X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" The kernel expects pte_young() to work regardless of CONFIG_SWAP. Make sure a minor fault is taken to set _PAGE_ACCESSED when it is not already set, regardless of the selection of CONFIG_SWAP. This adds at least 3 instructions to the TLB miss exception handlers fast path. Following patch will reduce this overhead. Fixes: d069cb4373fe ("powerpc/8xx: Don't touch ACCESSED when no SWAP.") Cc: stable@vger.kernel.org Signed-off-by: Christophe Leroy --- arch/powerpc/kernel/head_8xx.S | 10 ---------- 1 file changed, 10 deletions(-) diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S index 83101c5888e3..6f3799a04121 100644 --- a/arch/powerpc/kernel/head_8xx.S +++ b/arch/powerpc/kernel/head_8xx.S @@ -202,9 +202,7 @@ SystemCall: InstructionTLBMiss: mtspr SPRN_SPRG_SCRATCH0, r10 -#if defined(ITLB_MISS_KERNEL) || defined(CONFIG_SWAP) || defined(CONFIG_HUGETLBFS) mtspr SPRN_SPRG_SCRATCH1, r11 -#endif /* If we are faulting a kernel address, we have to use the * kernel page tables. @@ -238,11 +236,9 @@ InstructionTLBMiss: rlwimi r11, r10, 32 - 9, _PMD_PAGE_512K mtspr SPRN_MI_TWC, r11 #endif -#ifdef CONFIG_SWAP rlwinm r11, r10, 32-7, _PAGE_PRESENT and r11, r11, r10 rlwimi r10, r11, 0, _PAGE_PRESENT -#endif /* The Linux PTE won't go exactly into the MMU TLB. * Software indicator bits 20 and 23 must be clear. * Software indicator bits 22, 24, 25, 26, and 27 must be @@ -256,9 +252,7 @@ InstructionTLBMiss: /* Restore registers */ 0: mfspr r10, SPRN_SPRG_SCRATCH0 -#if defined(ITLB_MISS_KERNEL) || defined(CONFIG_SWAP) || defined(CONFIG_HUGETLBFS) mfspr r11, SPRN_SPRG_SCRATCH1 -#endif rfi patch_site 0b, patch__itlbmiss_exit_1 @@ -268,9 +262,7 @@ InstructionTLBMiss: addi r10, r10, 1 stw r10, (itlb_miss_counter - PAGE_OFFSET)@l(0) mfspr r10, SPRN_SPRG_SCRATCH0 -#if defined(ITLB_MISS_KERNEL) || defined(CONFIG_SWAP) || defined(CONFIG_HUGETLBFS) mfspr r11, SPRN_SPRG_SCRATCH1 -#endif rfi #endif @@ -316,11 +308,9 @@ DataStoreTLBMiss: * r11 = ((r10 & PRESENT) & ((r10 & ACCESSED) >> 5)); * r10 = (r10 & ~PRESENT) | r11; */ -#ifdef CONFIG_SWAP rlwinm r11, r10, 32-7, _PAGE_PRESENT and r11, r11, r10 rlwimi r10, r11, 0, _PAGE_PRESENT -#endif /* The Linux PTE won't go exactly into the MMU TLB. * Software indicator bits 24, 25, 26, and 27 must be * set. All other Linux PTE bits control the behavior -- 2.25.0