From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752569AbeCXRDx (ORCPT ); Sat, 24 Mar 2018 13:03:53 -0400 Received: from verein.lst.de ([213.95.11.211]:57066 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752387AbeCXRDw (ORCPT ); Sat, 24 Mar 2018 13:03:52 -0400 Date: Sat, 24 Mar 2018 18:03:51 +0100 From: Christoph Hellwig To: Konrad Rzeszutek Wilk Cc: Christoph Hellwig , tglx@linutronix.de, mingo@elte.hu, linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org Subject: Re: [PATCH] swiotlb: swiotlb_{alloc,free}_buffer should depend on CONFIG_DMA_DIRECT_OPS Message-ID: <20180324170351.GA511@lst.de> References: <20180323174930.17767-1-hch@lst.de> <20180323185707.GD25533@char.us.oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180323185707.GD25533@char.us.oracle.com> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Mar 23, 2018 at 02:57:07PM -0400, Konrad Rzeszutek Wilk wrote: > On Fri, Mar 23, 2018 at 06:49:30PM +0100, Christoph Hellwig wrote: > > Otherwise we might get unused symbol warnings for configs that built > > swiotlb.c only for use by xen-swiotlb.c and that don't otherwise select > > CONFIG_DMA_DIRECT_OPS, which is possible on arm. > > > > Fixes: 16e73adbca76 ("dma/swiotlb: Remove swiotlb_{alloc,free}_coherent()") > > Reported-by: Stephen Rothwell > > Signed-off-by: Christoph Hellwig > > > Alternatively could we set the Kconfig to slect DMA_DIRECT_OPS? IFF we build swiotlb.c only for xen-swiotlb we don't need DMA_DIRECT_OPS. IF you are fine with just requring it as well that would be doable nicely only if we consolidate to a single defintion of CONFIG_SWIOTLB instead of one per architecture. Which is something we should do anyway, so I'll look into it once I get some time.