From patchwork Mon Oct 26 10:58:08 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Daniel Vetter X-Patchwork-Id: 11856551 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=-12.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 426E4C6379D for ; Mon, 26 Oct 2020 10:58:47 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id ECD332225C for ; Mon, 26 Oct 2020 10:58:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=ffwll.ch header.i=@ffwll.ch header.b="E/O7+voK" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ECD332225C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ffwll.ch Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 65D506E96E; Mon, 26 Oct 2020 10:58:45 +0000 (UTC) Received: from mail-wm1-x341.google.com (mail-wm1-x341.google.com [IPv6:2a00:1450:4864:20::341]) by gabe.freedesktop.org (Postfix) with ESMTPS id 671646E0FB for ; Mon, 26 Oct 2020 10:58:34 +0000 (UTC) Received: by mail-wm1-x341.google.com with SMTP id k18so11940278wmj.5 for ; Mon, 26 Oct 2020 03:58:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=cXs1UvblKDwz1YQCIe37x2wwQ5T1EiKP8bli0y6YQUo=; b=E/O7+voKlzMLNr1tMV7GRLom+PNYHCgDQ3OQYV/aWqFBixt9URXmul00B6LbSiurKm FWBH3nEs3LtTvDZrOsKqWR6sU78g5LH1U1/DYzkNraEMVQf7DvkjdRanjf1DSeK2bJTj IABPWNTOBt65UzvJe20ya2kIjM8TNoEQ70DME= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=cXs1UvblKDwz1YQCIe37x2wwQ5T1EiKP8bli0y6YQUo=; b=Kyx0ULC9KunkrQqEExBNJuGyOSwYS8mxSBi+AEsyk/i4nztBeln2KJL014WGyX8XyL Ptw2ZvUHvF/W3r3hTxc7cK/l+6DCKcGhweUGjNKM9rlhp550AEnzugd3PWM6mABEtdGB lTa+4xkxq3aKIcbk0XVnE0BwakSX9Bk8HKZTnUnSSpmIwm89dM3V5vEwQoqKUjq0rWkB ytJ452kpNdOwlklhGCqHQQZzCgQMILOgdZ9k5kH8jqpG8qbu4SIcDPhAXZpMDL9vnQLF ARUtS66X0IwTVpiD0XQN8h6WRENvq1HeFrg7gnO1vteY1es5so14taroLB28mrmP0Jxi 5VGQ== X-Gm-Message-State: AOAM5321LK0tONayZj2xHTw2LfOlWA/A+6paIBU+Q8J7B0ouRycsk4iW PtoqRwN3lN+Ioe7bcs4hylzsqSzexshffJ8E X-Google-Smtp-Source: ABdhPJxmBoKR8n4PO1pSYo1/0YhdisFijwUoQU4+g9izXaJK8ALrEJgk5lU4qb520qBwIoYy7NeuKA== X-Received: by 2002:a1c:2cc2:: with SMTP id s185mr15884686wms.77.1603709912789; Mon, 26 Oct 2020 03:58:32 -0700 (PDT) Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id w83sm21165156wmg.48.2020.10.26.03.58.31 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 26 Oct 2020 03:58:32 -0700 (PDT) From: Daniel Vetter To: DRI Development , LKML Subject: [PATCH v4 05/15] mm/frame-vector: Use FOLL_LONGTERM Date: Mon, 26 Oct 2020 11:58:08 +0100 Message-Id: <20201026105818.2585306-6-daniel.vetter@ffwll.ch> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201026105818.2585306-1-daniel.vetter@ffwll.ch> References: <20201026105818.2585306-1-daniel.vetter@ffwll.ch> MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-s390@vger.kernel.org, linux-samsung-soc@vger.kernel.org, Jan Kara , Pawel Osciak , kvm@vger.kernel.org, Jason Gunthorpe , Daniel Vetter , Mauro Carvalho Chehab , =?utf-8?b?SsOpcsO0bWUgR2xpc3Nl?= , Tomasz Figa , linux-mm@kvack.org, Kyungmin Park , John Hubbard , Daniel Vetter , Andrew Morton , Marek Szyprowski , Dan Williams , linux-arm-kernel@lists.infradead.org, linux-media@vger.kernel.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" This is used by media/videbuf2 for persistent dma mappings, not just for a single dma operation and then freed again, so needs FOLL_LONGTERM. Unfortunately current pup_locked doesn't support FOLL_LONGTERM due to locking issues. Rework the code to pull the pup path out from the mmap_sem critical section as suggested by Jason. By relying entirely on the vma checks in pin_user_pages and follow_pfn (for vm_flags and vma_is_fsdax) we can also streamline the code a lot. Signed-off-by: Daniel Vetter Cc: Jason Gunthorpe Cc: Pawel Osciak Cc: Marek Szyprowski Cc: Kyungmin Park Cc: Tomasz Figa Cc: Mauro Carvalho Chehab Cc: Andrew Morton Cc: John Hubbard Cc: Jérôme Glisse Cc: Jan Kara Cc: Dan Williams Cc: linux-mm@kvack.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-samsung-soc@vger.kernel.org Cc: linux-media@vger.kernel.org Signed-off-by: Daniel Vetter --- v2: Streamline the code and further simplify the loop checks (Jason) --- mm/frame_vector.c | 50 ++++++++++++++--------------------------------- 1 file changed, 15 insertions(+), 35 deletions(-) diff --git a/mm/frame_vector.c b/mm/frame_vector.c index 10f82d5643b6..d44779e56313 100644 --- a/mm/frame_vector.c +++ b/mm/frame_vector.c @@ -38,7 +38,6 @@ int get_vaddr_frames(unsigned long start, unsigned int nr_frames, struct vm_area_struct *vma; int ret = 0; int err; - int locked; if (nr_frames == 0) return 0; @@ -48,40 +47,25 @@ int get_vaddr_frames(unsigned long start, unsigned int nr_frames, start = untagged_addr(start); - mmap_read_lock(mm); - locked = 1; - vma = find_vma_intersection(mm, start, start + 1); - if (!vma) { - ret = -EFAULT; - goto out; - } - - /* - * While get_vaddr_frames() could be used for transient (kernel - * controlled lifetime) pinning of memory pages all current - * users establish long term (userspace controlled lifetime) - * page pinning. Treat get_vaddr_frames() like - * get_user_pages_longterm() and disallow it for filesystem-dax - * mappings. - */ - if (vma_is_fsdax(vma)) { - ret = -EOPNOTSUPP; - goto out; - } - - if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) { + ret = pin_user_pages_fast(start, nr_frames, + FOLL_FORCE | FOLL_WRITE | FOLL_LONGTERM, + (struct page **)(vec->ptrs)); + if (ret > 0) { vec->got_ref = true; vec->is_pfns = false; - ret = pin_user_pages_locked(start, nr_frames, - gup_flags, (struct page **)(vec->ptrs), &locked); - goto out; + goto out_unlocked; } + mmap_read_lock(mm); vec->got_ref = false; vec->is_pfns = true; do { unsigned long *nums = frame_vector_pfns(vec); + vma = find_vma_intersection(mm, start, start + 1); + if (!vma) + break; + while (ret < nr_frames && start + PAGE_SIZE <= vma->vm_end) { err = follow_pfn(vma, start, &nums[ret]); if (err) { @@ -92,17 +76,13 @@ int get_vaddr_frames(unsigned long start, unsigned int nr_frames, start += PAGE_SIZE; ret++; } - /* - * We stop if we have enough pages or if VMA doesn't completely - * cover the tail page. - */ - if (ret >= nr_frames || start < vma->vm_end) + /* Bail out if VMA doesn't completely cover the tail page. */ + if (start < vma->vm_end) break; - vma = find_vma_intersection(mm, start, start + 1); - } while (vma && vma->vm_flags & (VM_IO | VM_PFNMAP)); + } while (ret < nr_frames); out: - if (locked) - mmap_read_unlock(mm); + mmap_read_unlock(mm); +out_unlocked: if (!ret) ret = -EFAULT; if (ret > 0)