Received: by 2002:a25:868d:0:0:0:0:0 with SMTP id z13csp3080402ybk; Mon, 18 May 2020 17:25:18 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxVU8euascS3kGiHoIDVdXwp+DGHLc1cqVYS5PBUHvtKnWrMhoczBpOR/U+5c64aig009RS X-Received: by 2002:a05:6402:c8f:: with SMTP id cm15mr15616050edb.117.1589847918224; Mon, 18 May 2020 17:25:18 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1589847918; cv=none; d=google.com; s=arc-20160816; b=FpfkT6KncvZnUPrKf4hlEBnzmGsM/6lQD9cyDlAH6Y5mmsmhGV3CSRVI5aI8pbNW/l KXRssR0PGqzKrvvwG7FA9LYdFSiGfEMP91v649ClFhCOw6ijJbR2Y8oBeN0GEokVD19j JU35/oIE3TDSvtsvW7KSDomco4CVpgpt9h7rpeyrZQ7Ar8BhlyffVVegWzJSGruWPNm2 MxeukSLgW7DT58Udd2zuuye8ByTigxNC3mvKrKI5qYxUA4QPpNLiwOSsw6vnwHmGIPS8 K15helDpuuuxoLujZclxsMQgsFIA2Nmitf0/r/19OpCsUGzTjVP5w1dHiO1rcf/V7+n0 ESzg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:dkim-signature:content-transfer-encoding :mime-version:references:in-reply-to:message-id:date:subject:cc:to :from; bh=7xU/cX1jb0OSvUPxvY/76yHrdB1/qUxN1p1PgUB0arQ=; b=vuNQEkRaxJi78ka8adXoe2AvegBcbqsnVQ1giTvihizJ/5VXiWgGDjxd5dxMMfoK8z p9uXVkmJyesR+Dpzk3sBYQqe+49msB+no/NTWViHaSK6+aMBhr9Pi2zmQj2fNgwvisK2 3FaM70aukZLA+pyITE1Jhop8yqdq/ZwLedwSFDlitew/jw+f7V4qGCZBpKS/6TgWETAo XuzfaPEva/IGn8/ftwk1YHT5jUJaZrFWvOD4IUIXqf6hpa1aR7+oWEAA+7X8nhzT568y jb21AEbH1/OVMF+2Cert2p9+HK4KYnnOSyEZsXSEejtdUSOJANj0nw/+gF4VP5lwoNfG CTHA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@nvidia.com header.s=n1 header.b=r48yEzc8; 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 Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id gu10si6678313ejb.461.2020.05.18.17.24.56; Mon, 18 May 2020 17:25:18 -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=r48yEzc8; 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 S1727835AbgESAVf (ORCPT + 99 others); Mon, 18 May 2020 20:21:35 -0400 Received: from hqnvemgate24.nvidia.com ([216.228.121.143]:9225 "EHLO hqnvemgate24.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727045AbgESAVc (ORCPT ); Mon, 18 May 2020 20:21:32 -0400 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate24.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Mon, 18 May 2020 17:19:10 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Mon, 18 May 2020 17:21:32 -0700 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Mon, 18 May 2020 17:21:32 -0700 Received: from HQMAIL101.nvidia.com (172.20.187.10) by HQMAIL109.nvidia.com (172.20.187.15) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Tue, 19 May 2020 00:21:28 +0000 Received: from rnnvemgw01.nvidia.com (10.128.109.123) by HQMAIL101.nvidia.com (172.20.187.10) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Tue, 19 May 2020 00:21:28 +0000 Received: from sandstorm.nvidia.com (Not Verified[10.2.55.90]) by rnnvemgw01.nvidia.com with Trustwave SEG (v7,5,8,10121) id ; Mon, 18 May 2020 17:21:27 -0700 From: John Hubbard To: Andrew Morton CC: Souptick Joarder , Matthew Wilcox , Jani Nikula , "Joonas Lahtinen" , Rodrigo Vivi , David Airlie , Daniel Vetter , Chris Wilson , Tvrtko Ursulin , Matthew Auld , , , LKML , , John Hubbard Subject: [PATCH 3/4] mm/gup: introduce pin_user_pages_fast_only() Date: Mon, 18 May 2020 17:21:23 -0700 Message-ID: <20200519002124.2025955-4-jhubbard@nvidia.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200519002124.2025955-1-jhubbard@nvidia.com> References: <20200519002124.2025955-1-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=1589847550; bh=7xU/cX1jb0OSvUPxvY/76yHrdB1/qUxN1p1PgUB0arQ=; 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=r48yEzc8/VlzJGlCHnddElsNVrSESzHugDW0m7rVD9ijFFqJcLvxtxA4MMflVytc9 WUwSpWgHBDAil3W+bJZZH1QNCTjgDi0ZfANePqowck2aYza3Z0j+IHP2f9oWunH6If AUhFZRz1Ou2TusLn+TI6/SEFpoyjEjhEhkluta9ETvZORG6F0Ntw9H+GJMukB+UgcS wMg13OjL1On+szpwyont0QlBkO8QXvjKabsh8PrtwE7F70ty+Kz2lgPBck+KJGkZxt JkRSdNGKONbU/YQAAM33skP2BCNtwVpo16KBvgDUNgcfNoa+/GJtUJOJrMALWqhjym tF/Ku8xtpHoig== Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is the FOLL_PIN equivalent of __get_user_pages_fast(), except with a more descriptive name, and gup_flags instead of a boolean "write" in the argument list. Signed-off-by: John Hubbard --- include/linux/mm.h | 2 ++ mm/gup.c | 36 ++++++++++++++++++++++++++++++++++++ 2 files changed, 38 insertions(+) diff --git a/include/linux/mm.h b/include/linux/mm.h index 84b601cab699..98be7289d7e9 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1820,6 +1820,8 @@ extern int mprotect_fixup(struct vm_area_struct *vma, */ int __get_user_pages_fast(unsigned long start, int nr_pages, int write, struct page **pages); +int pin_user_pages_fast_only(unsigned long start, int nr_pages, + unsigned int gup_flags, struct page **pages); /* * per-process(per-mm_struct) statistics. */ diff --git a/mm/gup.c b/mm/gup.c index bb3e2c4288c3..4413f0f94b68 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -2858,6 +2858,42 @@ int pin_user_pages_fast(unsigned long start, int nr_= pages, } EXPORT_SYMBOL_GPL(pin_user_pages_fast); =20 +/* + * This is the FOLL_PIN equivalent of __get_user_pages_fast(). Behavior is= the + * same, except that this one sets FOLL_PIN instead of FOLL_GET. + * + * The API rules are the same, too: no negative values may be returned. + */ +int pin_user_pages_fast_only(unsigned long start, int nr_pages, + unsigned int gup_flags, struct page **pages) +{ + int nr_pinned; + + /* + * FOLL_GET and FOLL_PIN are mutually exclusive. Note that the API + * rules require returning 0, rather than -errno: + */ + if (WARN_ON_ONCE(gup_flags & FOLL_GET)) + return 0; + /* + * FOLL_FAST_ONLY is required in order to match the API description of + * this routine: no fall back to regular ("slow") GUP. + */ + gup_flags |=3D (FOLL_PIN | FOLL_FAST_ONLY); + nr_pinned =3D internal_get_user_pages_fast(start, nr_pages, gup_flags, + pages); + /* + * This routine is not allowed to return negative values. However, + * internal_get_user_pages_fast() *can* return -errno. Therefore, + * correct for that here: + */ + if (nr_pinned < 0) + nr_pinned =3D 0; + + return nr_pinned; +} +EXPORT_SYMBOL_GPL(pin_user_pages_fast_only); + /** * pin_user_pages_remote() - pin pages of a remote process (task !=3D curr= ent) * --=20 2.26.2