From patchwork Fri May 22 05:19:30 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Hubbard X-Patchwork-Id: 11564691 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 1ED67913 for ; Fri, 22 May 2020 05:19:44 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id E0BA52078D for ; Fri, 22 May 2020 05:19:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="bneeUj0B" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E0BA52078D 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 2E04780007; Fri, 22 May 2020 01:19:36 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id D96188000D; Fri, 22 May 2020 01:19:35 -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 B99378000C; Fri, 22 May 2020 01:19:35 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0251.hostedemail.com [216.40.44.251]) by kanga.kvack.org (Postfix) with ESMTP id 87CAA80007 for ; Fri, 22 May 2020 01:19:35 -0400 (EDT) Received: from smtpin13.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 4709F181AEF31 for ; Fri, 22 May 2020 05:19:35 +0000 (UTC) X-FDA: 76843202310.13.ship36_70be600883356 X-Spam-Summary: 1,0,0,,d41d8cd98f00b204,jhubbard@nvidia.com,,RULES_HIT:30029:30054:30064:30090,0,RBL:216.228.121.65:@nvidia.com:.lbl8.mailshell.net-64.10.201.10 62.18.0.100,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:24,LUA_SUMMARY:none X-HE-Tag: ship36_70be600883356 X-Filterd-Recvd-Size: 5385 Received: from hqnvemgate26.nvidia.com (hqnvemgate26.nvidia.com [216.228.121.65]) by imf19.hostedemail.com (Postfix) with ESMTP for ; Fri, 22 May 2020 05:19:34 +0000 (UTC) Received: from hqpgpgate102.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate26.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Thu, 21 May 2020 22:19:21 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate102.nvidia.com (PGP Universal service); Thu, 21 May 2020 22:19:33 -0700 X-PGP-Universal: processed; by hqpgpgate102.nvidia.com on Thu, 21 May 2020 22:19:33 -0700 Received: from HQMAIL101.nvidia.com (172.20.187.10) by HQMAIL111.nvidia.com (172.20.187.18) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Fri, 22 May 2020 05:19:32 +0000 Received: from hqnvemgw03.nvidia.com (10.124.88.68) by HQMAIL101.nvidia.com (172.20.187.10) with Microsoft SMTP Server (TLS) id 15.0.1473.3 via Frontend Transport; Fri, 22 May 2020 05:19:33 +0000 Received: from sandstorm.nvidia.com (Not Verified[10.2.48.182]) by hqnvemgw03.nvidia.com with Trustwave SEG (v7,5,8,10121) id ; Thu, 21 May 2020 22:19:32 -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 v2 3/4] mm/gup: introduce pin_user_pages_fast_only() Date: Thu, 21 May 2020 22:19:30 -0700 Message-ID: <20200522051931.54191-4-jhubbard@nvidia.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200522051931.54191-1-jhubbard@nvidia.com> References: <20200522051931.54191-1-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=1590124761; bh=P+1HL8fttghTGec3+ulNAcQAsu5wNQW/E5gKuHO8GC4=; 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=bneeUj0Bt2z5PMpIUmj/vwnO5sjU2eO6FydftKzyTt/+yWRh37/8TrU3BzE5bfl/B uSdxa3bQ1gQ4KC22MqJN3KlFA4sb4JqQx15/Jq1ELclVTkxhl0EnXG5KClZE+b3BiX yadkefAkcQo6dA5GIpiklNkKiLHoAD++QKP0ZrShkx5Sz+cLQNcdV+ewxXqkebvquw 5zX7knwFFD5NRVRBRXzJmjJDCIhA+hUfKKNjk6Lyp80+PGm8EvVfOkk2OOprK5q336 StYEhVA+25VoYf5I1Pr4dGcakBPBplqg+qSFcDah/P3HtpwtA/t5+qtnM76vyQHl5j g2esMQrSy6HQA== 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 4564b0dc7d0b..6fa9b2016a53 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -2859,6 +2859,42 @@ 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) *