From patchwork Wed May 10 04:52:31 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hugh Dickins X-Patchwork-Id: 13236361 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CB678C7EE26 for ; Wed, 10 May 2023 04:52:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235696AbjEJEwm (ORCPT ); Wed, 10 May 2023 00:52:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50114 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235465AbjEJEwj (ORCPT ); Wed, 10 May 2023 00:52:39 -0400 Received: from mail-yb1-xb2e.google.com (mail-yb1-xb2e.google.com [IPv6:2607:f8b0:4864:20::b2e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CBA431BD1 for ; Tue, 9 May 2023 21:52:36 -0700 (PDT) Received: by mail-yb1-xb2e.google.com with SMTP id 3f1490d57ef6-b9d881ad689so8684395276.2 for ; Tue, 09 May 2023 21:52:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1683694356; x=1686286356; h=mime-version:references:message-id:in-reply-to:subject:cc:to:from :date:from:to:cc:subject:date:message-id:reply-to; bh=q/pWRyMl+DKjSxR+96RJZ1aR1tS5RvJyhJKXen2hGiQ=; b=xdSNWZzA71Dn4PjSJ/2LhqeF5r1JevaGaRgpoS69f1WOD9bhyOsVwChSsl62EbUoE2 9cnM7TV7zP/+dkaQIS04gEZsgS+3y2H8ZK/Bphg85NyOLG7YB4uljYqtMwzBINkb9uAc Qg8lSbjmhMLr4mA9fzJNs5WYmacpWClDgIdvFtjewDeSGePxRCKcQAns2EMoohHps9+8 S/YpDXqiv4vPhVzyygfg06y+shcq7WCfEpVB4klTCpxP9lMZUivNHG3zXi2wJbvPV+fq bKOy9gNDnov9JiPlPv0RSMj3z9ndQZvcZqYURqj9IDWet3DFKA/Lg6LIl2Rd/fMVxLQn 5Dvw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1683694356; x=1686286356; h=mime-version:references:message-id:in-reply-to:subject:cc:to:from :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=q/pWRyMl+DKjSxR+96RJZ1aR1tS5RvJyhJKXen2hGiQ=; b=eCh3mHWkEcabshuKQyesZy/C9dHi/U/jdaVeMk7YfXLlrIVNEROydLo7qve+k9UdPw DQesEm/H/1I6zVwAJ1yyA0sUFjeTn4UPt7D+6j1KtjxfaGDII9ldFVcG0pMDSR9Px0d3 wJz6tNn7s1pPhU+bfS519CIrRD7geW3/UUMbS2oVUUbRtZ2wYjarOV45/WffJztUS4Q+ 7cis6JC3PzDezgemjwyEL/REQiWanR+DroTKuc8mYamCKzlXTGpKDLxl+8YIZa2YPA1g +h6hSx2FpBR/MBGkG1SGx83ZO7Ya3idR3JFAKYGEDrWvbyLCw16ewIEGmuAaxWY1VT+v /UKA== X-Gm-Message-State: AC+VfDyJwTfDveiDIokbqBsaVxFF/R8xKXPqPKfiXeMbngkiRRN3YwkC MiL0nJxG+iHn6VDBZVkBX9QsdA== X-Google-Smtp-Source: ACHHUZ6J+F8J+T+3sf+ZeNloEZY2mqXZ4z6wckfThiZ54x80vQ+jP1v1hMPi/dn45eihWxG2Dt7Wzw== X-Received: by 2002:a25:344e:0:b0:b9d:b79b:3b89 with SMTP id b75-20020a25344e000000b00b9db79b3b89mr17243065yba.18.1683694355907; Tue, 09 May 2023 21:52:35 -0700 (PDT) Received: from ripple.attlocal.net (172-10-233-147.lightspeed.sntcca.sbcglobal.net. [172.10.233.147]) by smtp.gmail.com with ESMTPSA id h6-20020a258a86000000b00b9a80b9e08esm3435393ybl.12.2023.05.09.21.52.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 09 May 2023 21:52:35 -0700 (PDT) Date: Tue, 9 May 2023 21:52:31 -0700 (PDT) From: Hugh Dickins X-X-Sender: hugh@ripple.attlocal.net To: Andrew Morton cc: Mike Kravetz , Mike Rapoport , "Kirill A. Shutemov" , Matthew Wilcox , David Hildenbrand , Suren Baghdasaryan , Qi Zheng , Russell King , Catalin Marinas , Will Deacon , Geert Uytterhoeven , Greg Ungerer , Michal Simek , Thomas Bogendoerfer , Helge Deller , John David Anglin , "Aneesh Kumar K.V" , Michael Ellerman , Alexandre Ghiti , Palmer Dabbelt , Heiko Carstens , Christian Borntraeger , Claudio Imbrenda , John Paul Adrian Glaubitz , "David S. Miller" , Chris Zankel , Max Filippov , x86@kernel.org, linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 08/23] parisc: add pte_unmap() to balance get_ptep() In-Reply-To: <77a5d8c-406b-7068-4f17-23b7ac53bc83@google.com> Message-ID: <44ebbf90-5fbb-2815-17c7-fcfe3c87d78e@google.com> References: <77a5d8c-406b-7068-4f17-23b7ac53bc83@google.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-parisc@vger.kernel.org To keep balance in future, remember to pte_unmap() after a successful get_ptep(). And (we might as well) pretend that flush_cache_pages() really needed a map there, to read the pfn before "unmapping". Signed-off-by: Hugh Dickins --- arch/parisc/kernel/cache.c | 26 +++++++++++++++++++++----- 1 file changed, 21 insertions(+), 5 deletions(-) diff --git a/arch/parisc/kernel/cache.c b/arch/parisc/kernel/cache.c index 1d3b8bc8a623..b0c969b3a300 100644 --- a/arch/parisc/kernel/cache.c +++ b/arch/parisc/kernel/cache.c @@ -425,10 +425,15 @@ void flush_dcache_page(struct page *page) offset = (pgoff - mpnt->vm_pgoff) << PAGE_SHIFT; addr = mpnt->vm_start + offset; if (parisc_requires_coherency()) { + bool needs_flush = false; pte_t *ptep; ptep = get_ptep(mpnt->vm_mm, addr); - if (ptep && pte_needs_flush(*ptep)) + if (ptep) { + needs_flush = pte_needs_flush(*ptep); + pte_unmap(ptep); + } + if (needs_flush) flush_user_cache_page(mpnt, addr); } else { /* @@ -560,14 +565,20 @@ EXPORT_SYMBOL(flush_kernel_dcache_page_addr); static void flush_cache_page_if_present(struct vm_area_struct *vma, unsigned long vmaddr, unsigned long pfn) { - pte_t *ptep = get_ptep(vma->vm_mm, vmaddr); + bool needs_flush = false; + pte_t *ptep; /* * The pte check is racy and sometimes the flush will trigger * a non-access TLB miss. Hopefully, the page has already been * flushed. */ - if (ptep && pte_needs_flush(*ptep)) + ptep = get_ptep(vma->vm_mm, vmaddr); + if (ptep) { + needs_flush = pte_needs_flush(*ptep)) + pte_unmap(ptep); + } + if (needs_flush) flush_cache_page(vma, vmaddr, pfn); } @@ -634,17 +645,22 @@ static void flush_cache_pages(struct vm_area_struct *vma, unsigned long start, u pte_t *ptep; for (addr = start; addr < end; addr += PAGE_SIZE) { + bool needs_flush = false; /* * The vma can contain pages that aren't present. Although * the pte search is expensive, we need the pte to find the * page pfn and to check whether the page should be flushed. */ ptep = get_ptep(vma->vm_mm, addr); - if (ptep && pte_needs_flush(*ptep)) { + if (ptep) { + needs_flush = pte_needs_flush(*ptep); + pfn = pte_pfn(*ptep); + pte_unmap(ptep); + } + if (needs_flush) { if (parisc_requires_coherency()) { flush_user_cache_page(vma, addr); } else { - pfn = pte_pfn(*ptep); if (WARN_ON(!pfn_valid(pfn))) return; __flush_cache_page(vma, addr, PFN_PHYS(pfn));