From patchwork Thu Apr 11 06:59:37 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Kasireddy, Vivek" X-Patchwork-Id: 13625522 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 26AD0CD129E for ; Thu, 11 Apr 2024 07:26:36 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id DDF9510EF09; Thu, 11 Apr 2024 07:26:27 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="MNfxsSBj"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.18]) by gabe.freedesktop.org (Postfix) with ESMTPS id C2D4A10EF05 for ; Thu, 11 Apr 2024 07:26:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1712820381; x=1744356381; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=bISZgHGBceajd5sS0GG6xpyZAR2HBITRWLbAKVvkKH4=; b=MNfxsSBjuNtS0U5O587Y4Wvs/yIYtgGuZqVPSMQCRL6KLQ9vn0VUI9Xh XmNwA0xFJ4TQPlxxS6swhVHE0xEgmblrd/dTJ7DBoBXtdAHpvxEdo4zFt vHGAull2oNFNNRJUODm/tMk84Ik/l0M3Pn/DuEegeZg1FEg4H77C3IP85 DCH39I8itetL0lfHm4AC7kHXOdsroyUuBjck7IAqMPjdQ2b5ZblTOgtK9 0GVt+G2t9pk5a/NhwE0T9HzJlD1J2gQOhbxmdOLTSShMh7NTUhuqcfEnt FVmm+Iah/ZzArLrjCP7Jt1HIYLwCKpdTy0eiDOUSTNzNkjuvreUl5KtXR A==; X-CSE-ConnectionGUID: kNJL8bguQki5vAwPabd31g== X-CSE-MsgGUID: mivX28b6Qpmf9e4Lwyq3WA== X-IronPort-AV: E=McAfee;i="6600,9927,11039"; a="8074347" X-IronPort-AV: E=Sophos;i="6.07,192,1708416000"; d="scan'208";a="8074347" Received: from fmviesa009.fm.intel.com ([10.60.135.149]) by fmvoesa112.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Apr 2024 00:26:03 -0700 X-CSE-ConnectionGUID: 2RFC9XLqS6eYHtN2ypTweA== X-CSE-MsgGUID: xUymOPFkT16f2zWGvUfKbA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.07,192,1708416000"; d="scan'208";a="20848535" Received: from vkasired-desk2.fm.intel.com ([10.105.128.132]) by fmviesa009-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Apr 2024 00:26:03 -0700 From: Vivek Kasireddy To: dri-devel@lists.freedesktop.org, linux-mm@kvack.org Cc: Vivek Kasireddy , David Hildenbrand , Matthew Wilcox , Christoph Hellwig , Jason Gunthorpe , Peter Xu Subject: [PATCH v14 1/8] mm/gup: Introduce unpin_folio/unpin_folios helpers Date: Wed, 10 Apr 2024 23:59:37 -0700 Message-ID: <20240411070157.3318425-2-vivek.kasireddy@intel.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240411070157.3318425-1-vivek.kasireddy@intel.com> References: <20240411070157.3318425-1-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: , 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. We should probably sanity check the folio as part of unpin similar to how it is done in unpin_user_page/unpin_user_pages but we cannot cleanly do that at the moment without also checking the subpage. Therefore, sanity checking needs to be added to these routines once we have a way to determine if any given folio is anon-exclusive (via a per folio AnonExclusive flag). Cc: David Hildenbrand Cc: Matthew Wilcox Cc: Christoph Hellwig Cc: Jason Gunthorpe Cc: Peter Xu Suggested-by: David Hildenbrand Reviewed-by: David Hildenbrand Signed-off-by: Vivek Kasireddy --- include/linux/mm.h | 2 ++ mm/gup.c | 47 ++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 49 insertions(+) diff --git a/include/linux/mm.h b/include/linux/mm.h index ef34cf54c14f..d1ebd7a25105 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1612,11 +1612,13 @@ 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 8dcbeae714e2..14e94fdfa827 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -276,6 +276,19 @@ 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(). + */ +void unpin_folio(struct folio *folio) +{ + gup_put_folio(folio, 1, FOLL_PIN); +} +EXPORT_SYMBOL_GPL(unpin_folio); + /** * folio_add_pin - Try to get an additional pin on a pinned folio * @folio: The folio to be pinned @@ -488,6 +501,40 @@ 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 gup_put_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; + + 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_GPL(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