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=-9.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 C7E90C433E0 for ; Sun, 17 May 2020 01:18:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A3606207D3 for ; Sun, 17 May 2020 01:18:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="DgTc3wEM" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726957AbgEQBSk (ORCPT ); Sat, 16 May 2020 21:18:40 -0400 Received: from hqnvemgate24.nvidia.com ([216.228.121.143]:15880 "EHLO hqnvemgate24.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726891AbgEQBSk (ORCPT ); Sat, 16 May 2020 21:18:40 -0400 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate24.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Sat, 16 May 2020 18:16:20 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Sat, 16 May 2020 18:18:39 -0700 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Sat, 16 May 2020 18:18:39 -0700 Received: from HQMAIL111.nvidia.com (172.20.187.18) by HQMAIL111.nvidia.com (172.20.187.18) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Sun, 17 May 2020 01:18:39 +0000 Received: from hqnvemgw03.nvidia.com (10.124.88.68) by HQMAIL111.nvidia.com (172.20.187.18) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Sun, 17 May 2020 01:18:39 +0000 Received: from sandstorm.nvidia.com (Not Verified[10.2.48.175]) by hqnvemgw03.nvidia.com with Trustwave SEG (v7,5,8,10121) id ; Sat, 16 May 2020 18:18:39 -0700 From: John Hubbard To: LKML CC: John Hubbard , Wu Hao , Moritz Fischer , Subject: [PATCH] fpga: dfl: afu: convert get_user_pages() --> pin_user_pages() Date: Sat, 16 May 2020 18:18:37 -0700 Message-ID: <20200517011837.382189-1-jhubbard@nvidia.com> X-Mailer: git-send-email 2.26.2 MIME-Version: 1.0 X-NVConfidentiality: public Content-Transfer-Encoding: quoted-printable Content-Type: text/plain DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1589678180; bh=sy5Ui646d3AglpuvJNOHEZAV8PuLDjy03kGDT/+711M=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: MIME-Version:X-NVConfidentiality:Content-Transfer-Encoding: Content-Type; b=DgTc3wEMsvu2GAVTe6yofPjfTj/tyiextWIZRdMbPXhkzSY/yAA5OoUXktRiPhoRv 0BjkGKWXewSnc4RMorHErEMcKvvNQgDvZQtsgaEE/BovLIivQKFw8gsC7HCnuPkzYO ER8kWAXH14Cz3Zs9HExShG40WMtQvLEnXOHurO6aCcvFSpPo3gvt574Bp4EYm4I0Ag AbnypOmDR8lEtyb5oNrCosXh0MuW//q7GGNn4ZORbCW4iNRjpXotitBIzqibmIjeFY u5yMkyQnjhr10tRkhT7g+1BoJrqeEPw6KUYSF9yiK62Xj5aPW96xhMLgaDASfZdyAd AnEs8xyOkoO1A== Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This code was using get_user_pages_fast(), in a "Case 2" scenario (DMA/RDMA), using the categorization from [1]. That means that it's time to convert the get_user_pages_fast() + put_page() calls to pin_user_pages_fast() + unpin_user_pages() calls. There is some helpful background in [2]: basically, this is a small part of fixing a long-standing disconnect between pinning pages, and file systems' use of those pages. [1] Documentation/core-api/pin_user_pages.rst [2] "Explicit pinning of user-space pages": https://lwn.net/Articles/807108/ Cc: Wu Hao Cc: Moritz Fischer Cc: linux-fpga@vger.kernel.org Signed-off-by: John Hubbard --- drivers/fpga/dfl-afu-dma-region.c | 15 +++------------ 1 file changed, 3 insertions(+), 12 deletions(-) diff --git a/drivers/fpga/dfl-afu-dma-region.c b/drivers/fpga/dfl-afu-dma-r= egion.c index 62f924489db5..84f696d5ba82 100644 --- a/drivers/fpga/dfl-afu-dma-region.c +++ b/drivers/fpga/dfl-afu-dma-region.c @@ -16,15 +16,6 @@ =20 #include "dfl-afu.h" =20 -static void put_all_pages(struct page **pages, int npages) -{ - int i; - - for (i =3D 0; i < npages; i++) - if (pages[i]) - put_page(pages[i]); -} - void afu_dma_region_init(struct dfl_feature_platform_data *pdata) { struct dfl_afu *afu =3D dfl_fpga_pdata_get_private(pdata); @@ -57,7 +48,7 @@ static int afu_dma_pin_pages(struct dfl_feature_platform_= data *pdata, goto unlock_vm; } =20 - pinned =3D get_user_pages_fast(region->user_addr, npages, FOLL_WRITE, + pinned =3D pin_user_pages_fast(region->user_addr, npages, FOLL_WRITE, region->pages); if (pinned < 0) { ret =3D pinned; @@ -72,7 +63,7 @@ static int afu_dma_pin_pages(struct dfl_feature_platform_= data *pdata, return 0; =20 put_pages: - put_all_pages(region->pages, pinned); + unpin_user_pages(region->pages, pinned); free_pages: kfree(region->pages); unlock_vm: @@ -94,7 +85,7 @@ static void afu_dma_unpin_pages(struct dfl_feature_platfo= rm_data *pdata, long npages =3D region->length >> PAGE_SHIFT; struct device *dev =3D &pdata->dev->dev; =20 - put_all_pages(region->pages, npages); + unpin_user_pages(region->pages, npages); kfree(region->pages); account_locked_vm(current->mm, npages, false); =20 base-commit: 3d1c1e5931ce45b3a3f309385bbc00c78e9951c6 --=20 2.26.2