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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 1BBC8C282C4 for ; Tue, 12 Feb 2019 08:28:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E0EAD2082F for ; Tue, 12 Feb 2019 08:28:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728357AbfBLI2y (ORCPT ); Tue, 12 Feb 2019 03:28:54 -0500 Received: from mx1.redhat.com ([209.132.183.28]:43034 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728170AbfBLI2y (ORCPT ); Tue, 12 Feb 2019 03:28:54 -0500 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 0B230C05001B; Tue, 12 Feb 2019 08:28:54 +0000 (UTC) Received: from carbon (ovpn-200-42.brq.redhat.com [10.40.200.42]) by smtp.corp.redhat.com (Postfix) with ESMTP id 8975A19C7B; Tue, 12 Feb 2019 08:28:47 +0000 (UTC) Date: Tue, 12 Feb 2019 09:28:46 +0100 From: Jesper Dangaard Brouer To: Andrew Morton Cc: netdev@vger.kernel.org, linux-mm@kvack.org, Toke =?UTF-8?B?SMO4aWxh?= =?UTF-8?B?bmQtSsO4cmdlbnNlbg==?= , Ilias Apalodimas , willy@infradead.org, Saeed Mahameed , mgorman@techsingularity.net, "David S. Miller" , Tariq Toukan , brouer@redhat.com Subject: Re: [net-next PATCH 1/2] mm: add dma_addr_t to struct page Message-ID: <20190212092846.109c9bdf@carbon> In-Reply-To: <20190211121624.30c601d0fa4c0f972eeaf1c6@linux-foundation.org> References: <154990116432.24530.10541030990995303432.stgit@firesoul> <154990120685.24530.15350136329514629029.stgit@firesoul> <20190211121624.30c601d0fa4c0f972eeaf1c6@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Tue, 12 Feb 2019 08:28:54 +0000 (UTC) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Mon, 11 Feb 2019 12:16:24 -0800 Andrew Morton wrote: > On Mon, 11 Feb 2019 17:06:46 +0100 Jesper Dangaard Brouer wrote: > > > The page_pool API is using page->private to store DMA addresses. > > As pointed out by David Miller we can't use that on 32-bit architectures > > with 64-bit DMA > > > > This patch adds a new dma_addr_t struct to allow storing DMA addresses > > > > .. > > > > --- a/include/linux/mm_types.h > > +++ b/include/linux/mm_types.h > > @@ -95,6 +95,14 @@ struct page { > > */ > > unsigned long private; > > }; > > + struct { /* page_pool used by netstack */ > > + /** > > + * @dma_addr: Page_pool need to store DMA-addr, and > > + * cannot use @private, as DMA-mappings can be 64-bit > > + * even on 32-bit Architectures. > > + */ > > This comment is a bit awkward. The discussion about why it doesn't use > ->private is uninteresting going forward and is more material for a > changelog. > > How about > > /** > * @dma_addr: page_pool requires a 64-bit value even on > * 32-bit architectures. > */ Much better, I'll use that! > Otherwise, > > Acked-by: Andrew Morton Thanks! -- Best regards, Jesper Dangaard Brouer MSc.CS, Principal Kernel Engineer at Red Hat LinkedIn: http://www.linkedin.com/in/brouer