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,URIBL_BLOCKED, 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 1C6E0C433E0 for ; Wed, 27 May 2020 01:26:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EFAEB2071A for ; Wed, 27 May 2020 01:26:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="IUG2VDZp" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728424AbgE0B0c (ORCPT ); Tue, 26 May 2020 21:26:32 -0400 Received: from hqnvemgate26.nvidia.com ([216.228.121.65]:8781 "EHLO hqnvemgate26.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725320AbgE0B0a (ORCPT ); Tue, 26 May 2020 21:26:30 -0400 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate26.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Tue, 26 May 2020 18:26:18 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Tue, 26 May 2020 18:26:30 -0700 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Tue, 26 May 2020 18:26:30 -0700 Received: from HQMAIL111.nvidia.com (172.20.187.18) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Wed, 27 May 2020 01:26:30 +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; Wed, 27 May 2020 01:26:30 +0000 Received: from sandstorm.nvidia.com (Not Verified[10.2.50.17]) by hqnvemgw03.nvidia.com with Trustwave SEG (v7,5,8,10121) id ; Tue, 26 May 2020 18:26:29 -0700 From: John Hubbard To: LKML CC: Souptick Joarder , John Hubbard , Derek Kiernan , Dragan Cvetic , Arnd Bergmann , Greg Kroah-Hartman , Michal Simek , Subject: [PATCH 3/3] misc: xilinx-sdfec: convert get_user_pages() --> pin_user_pages() Date: Tue, 26 May 2020 18:26:28 -0700 Message-ID: <20200527012628.1100649-4-jhubbard@nvidia.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200527012628.1100649-1-jhubbard@nvidia.com> References: <20200527012628.1100649-1-jhubbard@nvidia.com> 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=1590542778; bh=pIs/SexR7/3J3Zjm6Xj7h9EQRh/1TTydznodYn91aGk=; h=X-PGP-Universal:From:To:CC:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:X-NVConfidentiality: Content-Transfer-Encoding:Content-Type; b=IUG2VDZp6/dk88r0F4O3ym0mwyEuNNu0CeTrd1/j470r4ImZ6HD1mtRg/2AOizQqv 9nWKC3H+q29wkZ25dAd0b0swAgKQ88GWlqaK8RjHwFKND6qe0Bw0k/Uv9HssztrUkw 1T5u3wvw3yKBetOKp+aCtbahP0kv0l5WygMe7r1XfmvIQi709dq9H5CGw/MTi/gjFy EurNZqrtpbtU3YupZp/E2yFAO/TSNPsqdFfCs+axZuRnYq0PWi/8AJVDhahN3F/0is 0YjoEL7EWKgFmcjV4cYAcHNE5GwjmGakNJiwJ8Dyz44GYDzqmXq4sU502j3R4NF/Ic v6+Uuh8oBYr3A== 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*(), in approximately a "Case 1" scenario (Direct IO), using the categorization from [1]. That means that it's time to convert the get_user_pages*() + put_page() calls to pin_user_pages*() + 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: Derek Kiernan Cc: Dragan Cvetic Cc: Arnd Bergmann Cc: Greg Kroah-Hartman Cc: Michal Simek Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: John Hubbard --- drivers/misc/xilinx_sdfec.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/drivers/misc/xilinx_sdfec.c b/drivers/misc/xilinx_sdfec.c index 7e2ee3e547f2..cda3559025d5 100644 --- a/drivers/misc/xilinx_sdfec.c +++ b/drivers/misc/xilinx_sdfec.c @@ -627,12 +627,11 @@ static int xsdfec_table_write(struct xsdfec_dev *xsdf= ec, u32 offset, =20 nr_pages =3D n; =20 - res =3D get_user_pages_fast((unsigned long)src_ptr, nr_pages, 0, pages); + res =3D pin_user_pages_fast((unsigned long)src_ptr, nr_pages, 0, pages); if (res < nr_pages) { - if (res > 0) { - for (i =3D 0; i < res; i++) - put_page(pages[i]); - } + if (res > 0) + unpin_user_pages(pages, res); + return -EINVAL; } =20 @@ -646,7 +645,7 @@ static int xsdfec_table_write(struct xsdfec_dev *xsdfec= , u32 offset, reg++; } while ((reg < len) && ((reg * XSDFEC_REG_WIDTH_JUMP) % PAGE_SIZE)); - put_page(pages[i]); + unpin_user_page(pages[i]); } return 0; } --=20 2.26.2