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=unavailable 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 AD02CC433DF for ; Mon, 12 Oct 2020 09:00:22 +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 08B7B20773 for ; Mon, 12 Oct 2020 09:00:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 08B7B20773 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 4C8t1J0nt4zDqsC for ; Mon, 12 Oct 2020 20:00:20 +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 4C8stp6p3dzDqcX for ; Mon, 12 Oct 2020 19:54:36 +1100 (AEDT) Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 4C8stX0ccLz9tyQ8; Mon, 12 Oct 2020 10:54:28 +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 Ialckm9zXcR1; Mon, 12 Oct 2020 10:54:28 +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 4C8stW4QBYz9tyQ9; Mon, 12 Oct 2020 10:54:27 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 613FC8B783; Mon, 12 Oct 2020 10:54:32 +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 p8ERK12fs8Fg; Mon, 12 Oct 2020 10:54:32 +0200 (CEST) Received: from po17688vm.idsi0.si.c-s.fr (po15451.idsi0.si.c-s.fr [172.25.230.100]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 0B03B8B788; Mon, 12 Oct 2020 10:54:32 +0200 (CEST) Received: by po17688vm.idsi0.si.c-s.fr (Postfix, from userid 0) id F278166441; Mon, 12 Oct 2020 08:54:31 +0000 (UTC) Message-Id: From: Christophe Leroy Subject: [PATCH v2 1/2] powerpc/8xx: Always fault when _PAGE_ACCESSED is not set To: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman Date: Mon, 12 Oct 2020 08:54:31 +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. Also update the rotation instruction to the correct number of bits to reflect all changes done to _PAGE_ACCESSED over time. Fixes: d069cb4373fe ("powerpc/8xx: Don't touch ACCESSED when no SWAP.") Fixes: 5f356497c384 ("powerpc/8xx: remove unused _PAGE_WRITETHRU") Fixes: e0a8e0d90a9f ("powerpc/8xx: Handle PAGE_USER via APG bits") Fixes: 5b2753fc3e8a ("powerpc/8xx: Implementation of PAGE_EXEC") Fixes: a891c43b97d3 ("powerpc/8xx: Prepare handlers for _PAGE_HUGE for 512k pages.") Cc: stable@vger.kernel.org Signed-off-by: Christophe Leroy --- v2: Backporting to stable will have to be done manually. Squashed the first 3 patches in order to ease that backporting. --- arch/powerpc/kernel/head_8xx.S | 14 ++------------ 1 file changed, 2 insertions(+), 12 deletions(-) diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S index 9f359d3fba74..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, 32-5, _PAGE_PRESENT + 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) 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, 32-5, _PAGE_PRESENT + 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