From patchwork Sat Jan 13 06:52:16 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Kasireddy, Vivek" X-Patchwork-Id: 13518890 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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 7A727C47422 for ; Sat, 13 Jan 2024 07:16:50 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 5D56110E119; Sat, 13 Jan 2024 07:16:43 +0000 (UTC) Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.11]) by gabe.freedesktop.org (Postfix) with ESMTPS id 25E6D10E0F6 for ; Sat, 13 Jan 2024 07:16:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1705130199; x=1736666199; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=Mnov74aVUnZ/JsntlOzaB+N14p4KDWATuD5/BakBI78=; b=fh+Tr7kYW3u08zPlCKIpyndPyps2xEtQgF5Rywoe19g80QehkMuo/cDq c/yKD5935sKx2H1at9/YYO3tn+HsRWSIL4N9sUZqH5SR0gQUj4trdruIL 1KjfvFZomGlT5Wde6tWm7Hw0upzEbpB9WUOJwV6mR4HSfjG7PlHkGAjLT zwV0GCYXm/QAnONxuQ7LMcj4ynO8zC6E2J51O3dwdyCY9Lfh4/vSrZM7h Vt0ckm7knLbNzJbD6B+haCBGEWgO9OiS8djyivAw3u10qyGD9hwK/dsA+ EcZ0CtZp3PO7EYUWy1BTWPnWW/h+2DMn+FPsGatPVYtuhLohqex+Au7td g==; X-IronPort-AV: E=McAfee;i="6600,9927,10951"; a="6078117" X-IronPort-AV: E=Sophos;i="6.04,191,1695711600"; d="scan'208";a="6078117" Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmvoesa105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Jan 2024 23:16:38 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10951"; a="783269487" X-IronPort-AV: E=Sophos;i="6.04,191,1695711600"; d="scan'208";a="783269487" Received: from vkasired-desk2.fm.intel.com ([10.105.128.132]) by orsmga002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Jan 2024 23:16:37 -0800 From: Vivek Kasireddy To: dri-devel@lists.freedesktop.org, linux-mm@kvack.org Subject: [PATCH v11 1/8] mm/gup: Introduce unpin_folio/unpin_folios helpers Date: Fri, 12 Jan 2024 22:52:16 -0800 Message-Id: <20240113065223.1532987-2-vivek.kasireddy@intel.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240113065223.1532987-1-vivek.kasireddy@intel.com> References: <20240113065223.1532987-1-vivek.kasireddy@intel.com> MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: David Hildenbrand , Vivek Kasireddy , Peter Xu , Christoph Hellwig , Matthew Wilcox , Jason Gunthorpe Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" These helpers are the folio versions of unpin_user_page/unpin_user_pages. They are currently only useful for unpinning folios pinned by memfd_pin_folios() or other associated routines. However, they could find new uses in the future, when more and more folio-only helpers are added to GUP. Cc: David Hildenbrand Cc: Matthew Wilcox Cc: Christoph Hellwig Cc: Jason Gunthorpe Cc: Peter Xu Suggested-by: David Hildenbrand Signed-off-by: Vivek Kasireddy --- include/linux/mm.h | 2 ++ mm/gup.c | 81 ++++++++++++++++++++++++++++++++++++++++------ 2 files changed, 74 insertions(+), 9 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index da5219b48d52..a0321adaefad 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1585,11 +1585,13 @@ static inline void put_page(struct page *page) #define GUP_PIN_COUNTING_BIAS (1U << 10) void unpin_user_page(struct page *page); +void unpin_folio(struct folio *folio); void unpin_user_pages_dirty_lock(struct page **pages, unsigned long npages, bool make_dirty); void unpin_user_page_range_dirty_lock(struct page *page, unsigned long npages, bool make_dirty); void unpin_user_pages(struct page **pages, unsigned long npages); +void unpin_folios(struct folio **folios, unsigned long nfolios); static inline bool is_cow_mapping(vm_flags_t flags) { diff --git a/mm/gup.c b/mm/gup.c index 231711efa390..4d7bc4453819 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -30,6 +30,23 @@ struct follow_page_context { unsigned int page_mask; }; +static inline void sanity_check_pinned_folios(struct folio **folios, + unsigned long nfolios) +{ + if (!IS_ENABLED(CONFIG_DEBUG_VM)) + return; + + for (; nfolios; nfolios--, folios++) { + struct folio *folio = *folios; + + if (is_zero_folio(folio) || + !folio_test_anon(folio)) + continue; + + VM_BUG_ON_FOLIO(!PageAnonExclusive(&folio->page), folio); + } +} + static inline void sanity_check_pinned_pages(struct page **pages, unsigned long npages) { @@ -52,15 +69,11 @@ static inline void sanity_check_pinned_pages(struct page **pages, struct page *page = *pages; struct folio *folio = page_folio(page); - if (is_zero_page(page) || - !folio_test_anon(folio)) - continue; - if (!folio_test_large(folio) || folio_test_hugetlb(folio)) - VM_BUG_ON_PAGE(!PageAnonExclusive(&folio->page), page); - else - /* Either a PTE-mapped or a PMD-mapped THP. */ - VM_BUG_ON_PAGE(!PageAnonExclusive(&folio->page) && - !PageAnonExclusive(page), page); + sanity_check_pinned_folios(&folio, 1); + + /* Either a PTE-mapped or a PMD-mapped THP. */ + if (folio_test_large(folio) && !folio_test_hugetlb(folio)) + VM_BUG_ON_PAGE(!PageAnonExclusive(page), page); } } @@ -276,6 +289,21 @@ void unpin_user_page(struct page *page) } EXPORT_SYMBOL(unpin_user_page); +/** + * unpin_folio() - release a dma-pinned folio + * @folio: pointer to folio to be released + * + * Folios that were pinned via memfd_pin_folios() or other similar routines + * must be released either using unpin_folio() or unpin_folios(). This is so + * that such folios can be separately tracked and uniquely handled. + */ +void unpin_folio(struct folio *folio) +{ + sanity_check_pinned_folios(&folio, 1); + gup_put_folio(folio, 1, FOLL_PIN); +} +EXPORT_SYMBOL(unpin_folio); + /** * folio_add_pin - Try to get an additional pin on a pinned folio * @folio: The folio to be pinned @@ -488,6 +516,41 @@ void unpin_user_pages(struct page **pages, unsigned long npages) } EXPORT_SYMBOL(unpin_user_pages); +/** + * unpin_folios() - release an array of gup-pinned folios. + * @folios: array of folios to be marked dirty and released. + * @nfolios: number of folios in the @folios array. + * + * For each folio in the @folios array, release the folio using unpin_folio(). + * + * Please see the unpin_folio() documentation for details. + */ +void unpin_folios(struct folio **folios, unsigned long nfolios) +{ + unsigned long i = 0, j; + + /* + * If this WARN_ON() fires, then the system *might* be leaking folios + * (by leaving them pinned), but probably not. More likely, gup/pup + * returned a hard -ERRNO error to the caller, who erroneously passed + * it here. + */ + if (WARN_ON(IS_ERR_VALUE(nfolios))) + return; + + sanity_check_pinned_folios(folios, nfolios); + while (i < nfolios) { + for (j = i + 1; j < nfolios; j++) + if (folios[i] != folios[j]) + break; + + if (folios[i]) + gup_put_folio(folios[i], j - i, FOLL_PIN); + i = j; + } +} +EXPORT_SYMBOL(unpin_folios); + /* * Set the MMF_HAS_PINNED if not set yet; after set it'll be there for the mm's * lifecycle. Avoid setting the bit unless necessary, or it might cause write