From patchwork Thu Nov 7 08:41:11 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Thomas_Hellstr=C3=B6m_=28Intel=29?= X-Patchwork-Id: 11232265 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id C3B16139A for ; Thu, 7 Nov 2019 08:41:38 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 AB75521D7B for ; Thu, 7 Nov 2019 08:41:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AB75521D7B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=shipmail.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 312D16EF15; Thu, 7 Nov 2019 08:41:36 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from pio-pvt-msa1.bahnhof.se (pio-pvt-msa1.bahnhof.se [79.136.2.40]) by gabe.freedesktop.org (Postfix) with ESMTPS id 3217C6EF12 for ; Thu, 7 Nov 2019 08:41:34 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by pio-pvt-msa1.bahnhof.se (Postfix) with ESMTP id 7F9543F560 for ; Thu, 7 Nov 2019 09:41:31 +0100 (CET) X-Virus-Scanned: Debian amavisd-new at bahnhof.se X-Spam-Flag: NO X-Spam-Score: -2.099 X-Spam-Level: X-Spam-Status: No, score=-2.099 tagged_above=-999 required=6.31 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no Received: from pio-pvt-msa1.bahnhof.se ([127.0.0.1]) by localhost (pio-pvt-msa1.bahnhof.se [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id NEEOaxIiVKDZ for ; Thu, 7 Nov 2019 09:41:25 +0100 (CET) Received: from mail1.shipmail.org (h-205-35.A357.priv.bahnhof.se [155.4.205.35]) (Authenticated sender: mb878879) by pio-pvt-msa1.bahnhof.se (Postfix) with ESMTPA id 39C543F4DB for ; Thu, 7 Nov 2019 09:41:24 +0100 (CET) Received: from localhost.localdomain.localdomain (h-205-35.A357.priv.bahnhof.se [155.4.205.35]) by mail1.shipmail.org (Postfix) with ESMTPSA id 5ACB2360191 for ; Thu, 7 Nov 2019 09:41:24 +0100 (CET) From: =?utf-8?q?Thomas_Hellstr=C3=B6m_=28VMware=29?= To: dri-devel@lists.freedesktop.org Subject: [PATCH v7 3/8] mm: Add a walk_page_mapping() function to the pagewalk code Date: Thu, 7 Nov 2019 09:41:11 +0100 Message-Id: <20191107084116.33032-4-thomas_os@shipmail.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191107084116.33032-1-thomas_os@shipmail.org> References: <20191107084116.33032-1-thomas_os@shipmail.org> MIME-Version: 1.0 X-Mailman-Original-DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=shipmail.org; s=mail; t=1573116084; bh=me2VsmIxMG1pjNjIfiklXxPZklwwkkg/Z5RhzKsRayg=; h=From:To:Subject:Date:In-Reply-To:References:From; b=V61BVG8XD1eNxq/We+9Ne5D/P21mSL2seMwV7vuX57Kjxli7Jplk9RMLz4ec2pbOR hAzITL48FdqMAx4Ar4FwrraQF2NtRXe8+A99MUI0LEr3JGEwP6vsnb4V3OxZUvxzBC m2cvupmZg1bQj2iiqDNOo9lPHK6ajEo9i9hrctJ8= X-Mailman-Original-Authentication-Results: pio-pvt-msa1.bahnhof.se; dkim=pass (1024-bit key; unprotected) header.d=shipmail.org header.i=@shipmail.org header.b="V61BVG8X"; dkim-atps=neutral X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" From: Thomas Hellstrom For users that want to travers all page table entries pointing into a region of a struct address_space mapping, introduce a walk_page_mapping() function. The walk_page_mapping() function will be initially be used for dirty- tracking in virtual graphics drivers. Cc: Andrew Morton Cc: Matthew Wilcox Cc: Will Deacon Cc: Peter Zijlstra Cc: Rik van Riel Cc: Minchan Kim Cc: Michal Hocko Cc: Huang Ying Cc: Jérôme Glisse Cc: Kirill A. Shutemov Signed-off-by: Thomas Hellstrom Reviewed-by: Andrew Morton --- include/linux/pagewalk.h | 9 ++++ mm/pagewalk.c | 94 +++++++++++++++++++++++++++++++++++++++- 2 files changed, 102 insertions(+), 1 deletion(-) diff --git a/include/linux/pagewalk.h b/include/linux/pagewalk.h index bddd9759bab9..6ec82e92c87f 100644 --- a/include/linux/pagewalk.h +++ b/include/linux/pagewalk.h @@ -24,6 +24,9 @@ struct mm_walk; * "do page table walk over the current vma", returning * a negative value means "abort current page table walk * right now" and returning 1 means "skip the current vma" + * @pre_vma: if set, called before starting walk on a non-null vma. + * @post_vma: if set, called after a walk on a non-null vma, provided + * that @pre_vma and the vma walk succeeded. */ struct mm_walk_ops { int (*pud_entry)(pud_t *pud, unsigned long addr, @@ -39,6 +42,9 @@ struct mm_walk_ops { struct mm_walk *walk); int (*test_walk)(unsigned long addr, unsigned long next, struct mm_walk *walk); + int (*pre_vma)(unsigned long start, unsigned long end, + struct mm_walk *walk); + void (*post_vma)(struct mm_walk *walk); }; /** @@ -62,5 +68,8 @@ int walk_page_range(struct mm_struct *mm, unsigned long start, void *private); int walk_page_vma(struct vm_area_struct *vma, const struct mm_walk_ops *ops, void *private); +int walk_page_mapping(struct address_space *mapping, pgoff_t first_index, + pgoff_t nr, const struct mm_walk_ops *ops, + void *private); #endif /* _LINUX_PAGEWALK_H */ diff --git a/mm/pagewalk.c b/mm/pagewalk.c index c5fa42cab14f..ea0b9e606ad1 100644 --- a/mm/pagewalk.c +++ b/mm/pagewalk.c @@ -254,13 +254,23 @@ static int __walk_page_range(unsigned long start, unsigned long end, { int err = 0; struct vm_area_struct *vma = walk->vma; + const struct mm_walk_ops *ops = walk->ops; + + if (vma && ops->pre_vma) { + err = ops->pre_vma(start, end, walk); + if (err) + return err; + } if (vma && is_vm_hugetlb_page(vma)) { - if (walk->ops->hugetlb_entry) + if (ops->hugetlb_entry) err = walk_hugetlb_range(start, end, walk); } else err = walk_pgd_range(start, end, walk); + if (vma && ops->post_vma) + ops->post_vma(walk); + return err; } @@ -291,6 +301,11 @@ static int __walk_page_range(unsigned long start, unsigned long end, * its vm_flags. walk_page_test() and @ops->test_walk() are used for this * purpose. * + * If operations need to be staged before and committed after a vma is walked, + * there are two callbacks, pre_vma() and post_vma(). Note that post_vma(), + * since it is intended to handle commit-type operations, can't return any + * errors. + * * struct mm_walk keeps current values of some common data like vma and pmd, * which are useful for the access from callbacks. If you want to pass some * caller-specific data to callbacks, @private should be helpful. @@ -377,3 +392,80 @@ int walk_page_vma(struct vm_area_struct *vma, const struct mm_walk_ops *ops, return err; return __walk_page_range(vma->vm_start, vma->vm_end, &walk); } + +/** + * walk_page_mapping - walk all memory areas mapped into a struct address_space. + * @mapping: Pointer to the struct address_space + * @first_index: First page offset in the address_space + * @nr: Number of incremental page offsets to cover + * @ops: operation to call during the walk + * @private: private data for callbacks' usage + * + * This function walks all memory areas mapped into a struct address_space. + * The walk is limited to only the given page-size index range, but if + * the index boundaries cross a huge page-table entry, that entry will be + * included. + * + * Also see walk_page_range() for additional information. + * + * Locking: + * This function can't require that the struct mm_struct::mmap_sem is held, + * since @mapping may be mapped by multiple processes. Instead + * @mapping->i_mmap_rwsem must be held. This might have implications in the + * callbacks, and it's up tho the caller to ensure that the + * struct mm_struct::mmap_sem is not needed. + * + * Also this means that a caller can't rely on the struct + * vm_area_struct::vm_flags to be constant across a call, + * except for immutable flags. Callers requiring this shouldn't use + * this function. + * + * Return: 0 on success, negative error code on failure, positive number on + * caller defined premature termination. + */ +int walk_page_mapping(struct address_space *mapping, pgoff_t first_index, + pgoff_t nr, const struct mm_walk_ops *ops, + void *private) +{ + struct mm_walk walk = { + .ops = ops, + .private = private, + }; + struct vm_area_struct *vma; + pgoff_t vba, vea, cba, cea; + unsigned long start_addr, end_addr; + int err = 0; + + lockdep_assert_held(&mapping->i_mmap_rwsem); + vma_interval_tree_foreach(vma, &mapping->i_mmap, first_index, + first_index + nr - 1) { + /* Clip to the vma */ + vba = vma->vm_pgoff; + vea = vba + vma_pages(vma); + cba = first_index; + cba = max(cba, vba); + cea = first_index + nr; + cea = min(cea, vea); + + start_addr = ((cba - vba) << PAGE_SHIFT) + vma->vm_start; + end_addr = ((cea - vba) << PAGE_SHIFT) + vma->vm_start; + if (start_addr >= end_addr) + continue; + + walk.vma = vma; + walk.mm = vma->vm_mm; + + err = walk_page_test(vma->vm_start, vma->vm_end, &walk); + if (err > 0) { + err = 0; + break; + } else if (err < 0) + break; + + err = __walk_page_range(start_addr, end_addr, &walk); + if (err) + break; + } + + return err; +}