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[23.128.96.18]) by mx.google.com with ESMTP id q26si335837edc.130.2020.05.19.13.16.51; Tue, 19 May 2020 13:17:16 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@nvidia.com header.s=n1 header.b=IxdRdVnS; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=nvidia.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727034AbgESUOw (ORCPT + 99 others); Tue, 19 May 2020 16:14:52 -0400 Received: from hqnvemgate24.nvidia.com ([216.228.121.143]:2923 "EHLO hqnvemgate24.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726333AbgESUOv (ORCPT ); Tue, 19 May 2020 16:14:51 -0400 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate24.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Tue, 19 May 2020 13:12:28 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Tue, 19 May 2020 13:14:51 -0700 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Tue, 19 May 2020 13:14:51 -0700 Received: from HQMAIL111.nvidia.com (172.20.187.18) by HQMAIL105.nvidia.com (172.20.187.12) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Tue, 19 May 2020 20:14:51 +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; Tue, 19 May 2020 20:14:50 +0000 Received: from sandstorm.nvidia.com (Not Verified[10.2.90.179]) by hqnvemgw03.nvidia.com with Trustwave SEG (v7,5,8,10121) id ; Tue, 19 May 2020 13:14:50 -0700 From: John Hubbard To: LKML CC: John Hubbard , Xu Yilun , Wu Hao , Moritz Fischer , Subject: [PATCH v2] fpga: dfl: afu: convert get_user_pages() --> pin_user_pages() Date: Tue, 19 May 2020 13:14:49 -0700 Message-ID: <20200519201449.3136033-1-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=1589919148; bh=pJ6llEOWavFwdUD9sGVI9Hsd6427RYrbByo8iB19GBI=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: MIME-Version:X-NVConfidentiality:Content-Transfer-Encoding: Content-Type; b=IxdRdVnS7o9ITUl3yhAZz8epzgBO7EMfVjjSbeDenYiUzsrUtdWHttFa1OPGyXhda Io72M052YsrgywmA6Dnx9YdG/SL7y4iV4Sov9dRPvIyByheMmGqP/mP0UA9+gged0l RWEKM3oz3qfYOEBhE97EYYqr6hn8sZ6anCgw7eRTotZakp5DHGwAEk2k3ZdegrwOL4 2CEphAVvnb6zi3tz1KBHSsmGCKz9JDF4IbJKO0tfdPRGoEcYsnmLYXZrBmJt0bbpIs KldyrhLnkn81oB3ij/SigpYyK0V80bzsKxvLN1N/9cApcX+EQhvSU4RnD/OAkItVp7 MVWfJPhPBzX0A== 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: Xu Yilun Cc: Wu Hao Cc: Moritz Fischer Cc: linux-fpga@vger.kernel.org Signed-off-by: John Hubbard --- Hi, Changes since v1: Changed the label from "put_pages", to "unpin_pages". thanks, John Hubbard NVIDIA =20 drivers/fpga/dfl-afu-dma-region.c | 19 +++++-------------- 1 file changed, 5 insertions(+), 14 deletions(-) diff --git a/drivers/fpga/dfl-afu-dma-region.c b/drivers/fpga/dfl-afu-dma-r= egion.c index 62f924489db5..a31dd3a7e581 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); @@ -57,11 +48,11 @@ static int afu_dma_pin_pages(struct dfl_feature_platfor= m_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; - goto put_pages; + goto unpin_pages; } else if (pinned !=3D npages) { ret =3D -EFAULT; goto free_pages; @@ -71,8 +62,8 @@ static int afu_dma_pin_pages(struct dfl_feature_platform_= data *pdata, =20 return 0; =20 -put_pages: - put_all_pages(region->pages, pinned); +unpin_pages: + 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 --=20 2.26.2