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=-12.8 required=3.0 tests=BAYES_00,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=unavailable 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 21579C56201 for ; Mon, 26 Oct 2020 11:00:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BC07E222EA for ; Mon, 26 Oct 2020 11:00:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ffwll.ch header.i=@ffwll.ch header.b="E/O7+voK" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1772750AbgJZLAT (ORCPT ); Mon, 26 Oct 2020 07:00:19 -0400 Received: from mail-wm1-f67.google.com ([209.85.128.67]:39924 "EHLO mail-wm1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1772591AbgJZK6g (ORCPT ); Mon, 26 Oct 2020 06:58:36 -0400 Received: by mail-wm1-f67.google.com with SMTP id d3so11970306wma.4 for ; Mon, 26 Oct 2020 03:58:33 -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=b8I9RrTowkBcyv3YBLG7bbH9Fz1V/gyYBfDdnXC7/8zseN/nbioVCsJ4h7LTiWLQin fjZuE+/U6jV7WDKVUlkO99Rw7D2xEiE4DquYJOT9lMaASoON+k7Yb3gijUNfum8wFz1W GU535i8Gu8NdEvEDsaJ5dw4mL71H/lkhr4M3eBArDMaUmn85ujYi4IAHAVbjhWCMpcUC Gu4VrbT4tvGPdRuXVOYhnWKF/kpY8sHet6JI/vye24IWBbS8BjUrSoYSGm5xGZi29sfl lJZbZBUFbM4U/hkXyuZqWqCL3exUo7e8bQOdUInqaMDZ/MA5966C3Wdvrn2Iqp6PI++6 TFtw== X-Gm-Message-State: AOAM531xHCU2luipIt166Tz1H5RuFWmq7hP4p3KCpSb9Zia3dg/kF+ul acciqVn0reXn5NdHYHZom4NMeA== 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 Cc: kvm@vger.kernel.org, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, linux-media@vger.kernel.org, linux-s390@vger.kernel.org, Daniel Vetter , Daniel Vetter , Jason Gunthorpe , Pawel Osciak , Marek Szyprowski , Kyungmin Park , Tomasz Figa , Mauro Carvalho Chehab , Andrew Morton , John Hubbard , =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= , Jan Kara , Dan Williams 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 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org 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) -- 2.28.0