From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from moutng.kundenserver.de ([212.227.126.187]:53474 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752416Ab1HPNPe (ORCPT ); Tue, 16 Aug 2011 09:15:34 -0400 From: Arnd Bergmann To: Marek Szyprowski Subject: Re: [PATCH 8/9] ARM: integrate CMA with DMA-mapping subsystem Date: Tue, 16 Aug 2011 15:14:52 +0200 Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, linux-mm@kvack.org, linaro-mm-sig@lists.linaro.org, "'Daniel Walker'" , "'Russell King'" , "'Jonathan Corbet'" , "'Mel Gorman'" , "'Chunsang Jeong'" , "'Michal Nazarewicz'" , "'Jesse Barker'" , "'Kyungmin Park'" , "'Ankita Garg'" , "'Shariq Hasnain'" , "'Andrew Morton'" , "'KAMEZAWA Hiroyuki'" References: <1313146711-1767-1-git-send-email-m.szyprowski@samsung.com> <201108121700.30967.arnd@arndb.de> <002b01cc5bf7$0460e350$0d22a9f0$%szyprowski@samsung.com> In-Reply-To: <002b01cc5bf7$0460e350$0d22a9f0$%szyprowski@samsung.com> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201108161514.52953.arnd@arndb.de> Sender: linux-media-owner@vger.kernel.org List-ID: On Tuesday 16 August 2011, Marek Szyprowski wrote: > On Friday, August 12, 2011 5:01 PM Arnd Bergmann wrote: > > How about something like > > > > if (arch_is_coherent() || nommu()) > > ret = alloc_simple_buffer(); > > else if (arch_is_v4_v5()) > > ret = alloc_remap(); > > else if (gfp & GFP_ATOMIC) > > ret = alloc_from_pool(); > > else > > ret = alloc_from_contiguous(); > > > > This also allows a natural conversion to dma_map_ops when we get there. > > Ok. Is it ok to enable CMA permanently for ARMv6+? If CMA is left conditional > the dma pool code will be much more complicated, because it will need to support > both CMA and non-CMA cases. I think that is ok, yes. Arnd