From patchwork Mon Nov 7 16:17:35 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 13034792 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 791F7C433FE for ; Mon, 7 Nov 2022 16:19:33 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 0484510E474; Mon, 7 Nov 2022 16:19:32 +0000 (UTC) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by gabe.freedesktop.org (Postfix) with ESMTPS id 3196410E47A for ; Mon, 7 Nov 2022 16:19:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1667837966; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=6Fr+6PvBJcVGo49mRUSTVB+G70kkKYpHo7niK5GMhiI=; b=MSmUfjoQAFits01DSJEv5yCGp+GHUzaGtUjMLGAP1e0Ez8gCJH+aO0vKTi2GBVOxzuVDD6 ZKdOC4MfJqymYmaLi6wH86XXRYSmmZDamoFtBP7ba6Obza9Zk6zdgvCLfhOCkRfnvDTbh1 gGocVANJaLIfDfKX7/h7NWMsat5Qm2M= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-75-0nINmOCBNB6j33TN5DvJug-1; Mon, 07 Nov 2022 11:19:21 -0500 X-MC-Unique: 0nINmOCBNB6j33TN5DvJug-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id ED32D185A7AE; Mon, 7 Nov 2022 16:19:19 +0000 (UTC) Received: from t480s.redhat.com (unknown [10.39.195.106]) by smtp.corp.redhat.com (Postfix) with ESMTP id 48FAF4B400F; Mon, 7 Nov 2022 16:19:05 +0000 (UTC) From: David Hildenbrand To: linux-kernel@vger.kernel.org Subject: [PATCH RFC 14/19] drm/etnaviv: remove FOLL_FORCE usage Date: Mon, 7 Nov 2022 17:17:35 +0100 Message-Id: <20221107161740.144456-15-david@redhat.com> In-Reply-To: <20221107161740.144456-1-david@redhat.com> References: <20221107161740.144456-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.9 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: David Hildenbrand , Daniel Vetter , dri-devel@lists.freedesktop.org, linux-mm@kvack.org, Nadav Amit , linux-kselftest@vger.kernel.org, Andrea Arcangeli , linux-samsung-soc@vger.kernel.org, linux-rdma@vger.kernel.org, Hugh Dickins , Matthew Wilcox , Jason Gunthorpe , linux-arm-kernel@lists.infradead.org, Russell King , linux-media@vger.kernel.org, Arnd Bergmann , John Hubbard , etnaviv@lists.freedesktop.org, Peter Xu , Muchun Song , Vlastimil Babka , Greg Kroah-Hartman , Oded Gabbay , Andrew Morton , Linus Torvalds , Mike Kravetz Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" GUP now supports reliable R/O long-term pinning in COW mappings, such that we break COW early. MAP_SHARED VMAs only use the shared zeropage so far in one corner case (DAXFS file with holes), which can be ignored because GUP does not support long-term pinning in fsdax (see check_vma_flags()). commit cd5297b0855f ("drm/etnaviv: Use FOLL_FORCE for userptr") documents that FOLL_FORCE | FOLL_WRITE was really only used for reliable R/O pinning. Consequently, FOLL_FORCE | FOLL_WRITE | FOLL_LONGTERM is no longer required for reliable R/O long-term pinning: FOLL_LONGTERM is sufficient. So stop using FOLL_FORCE, which is really only for debugger access. Cc: Daniel Vetter Cc: Lucas Stach Cc: Russell King Cc: Christian Gmeiner Cc: David Airlie Signed-off-by: David Hildenbrand --- drivers/gpu/drm/etnaviv/etnaviv_gem.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem.c b/drivers/gpu/drm/etnaviv/etnaviv_gem.c index cc386f8a7116..efe2240945d0 100644 --- a/drivers/gpu/drm/etnaviv/etnaviv_gem.c +++ b/drivers/gpu/drm/etnaviv/etnaviv_gem.c @@ -638,6 +638,7 @@ static int etnaviv_gem_userptr_get_pages(struct etnaviv_gem_object *etnaviv_obj) struct page **pvec = NULL; struct etnaviv_gem_userptr *userptr = &etnaviv_obj->userptr; int ret, pinned = 0, npages = etnaviv_obj->base.size >> PAGE_SHIFT; + unsigned int gup_flags = FOLL_LONGTERM; might_lock_read(¤t->mm->mmap_lock); @@ -648,14 +649,15 @@ static int etnaviv_gem_userptr_get_pages(struct etnaviv_gem_object *etnaviv_obj) if (!pvec) return -ENOMEM; + if (!userptr->ro) + gup_flags |= FOLL_WRITE; + do { unsigned num_pages = npages - pinned; uint64_t ptr = userptr->ptr + pinned * PAGE_SIZE; struct page **pages = pvec + pinned; - ret = pin_user_pages_fast(ptr, num_pages, - FOLL_WRITE | FOLL_FORCE | FOLL_LONGTERM, - pages); + ret = pin_user_pages_fast(ptr, num_pages, gup_flags, pages); if (ret < 0) { unpin_user_pages(pvec, pinned); kvfree(pvec);