From patchwork Tue May 19 00:21:23 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Hubbard X-Patchwork-Id: 11556551 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 8BC99618 for ; Tue, 19 May 2020 00:21:39 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 4EEA320756 for ; Tue, 19 May 2020 00:21:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="r48yEzc8" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4EEA320756 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=nvidia.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 967FC80006; Mon, 18 May 2020 20:21:34 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 8785580005; Mon, 18 May 2020 20:21:34 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6512B80006; Mon, 18 May 2020 20:21:34 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0124.hostedemail.com [216.40.44.124]) by kanga.kvack.org (Postfix) with ESMTP id 3FBB380005 for ; Mon, 18 May 2020 20:21:34 -0400 (EDT) Received: from smtpin29.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 09E1B37F1 for ; Tue, 19 May 2020 00:21:34 +0000 (UTC) X-FDA: 76831564908.29.bear30_64ee12e6a0d3c X-Spam-Summary: 1,0,0,,d41d8cd98f00b204,jhubbard@nvidia.com,,RULES_HIT:30029:30054:30064:30090,0,RBL:216.228.121.143:@nvidia.com:.lbl8.mailshell.net-62.18.0.100 64.10.201.10,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:ft,MSBL:0,DNSBL:neutral,Custom_rules:0:0:0,LFtime:0,LUA_SUMMARY:none X-HE-Tag: bear30_64ee12e6a0d3c X-Filterd-Recvd-Size: 5390 Received: from hqnvemgate24.nvidia.com (hqnvemgate24.nvidia.com [216.228.121.143]) by imf21.hostedemail.com (Postfix) with ESMTP for ; Tue, 19 May 2020 00:21:33 +0000 (UTC) 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 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== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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); +/* + * 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 |= (FOLL_PIN | FOLL_FAST_ONLY); + nr_pinned = 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 = 0; + + return nr_pinned; +} +EXPORT_SYMBOL_GPL(pin_user_pages_fast_only); + /** * pin_user_pages_remote() - pin pages of a remote process (task != current) *