Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751370Ab2E1ITs (ORCPT ); Mon, 28 May 2012 04:19:48 -0400 Received: from mailout1.w1.samsung.com ([210.118.77.11]:11269 "EHLO mailout1.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751076Ab2E1ITp (ORCPT ); Mon, 28 May 2012 04:19:45 -0400 Date: Mon, 28 May 2012 10:19:39 +0200 From: Marek Szyprowski Subject: RE: [PATCHv2 3/4] mm: vmalloc: add VM_DMA flag to indicate areas used by dma-mapping framework In-reply-to: To: "'KOSAKI Motohiro'" , "'Paul Mundt'" Cc: "'Minchan Kim'" , linux-arm-kernel@lists.infradead.org, linaro-mm-sig@lists.linaro.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, "'Kyungmin Park'" , "'Arnd Bergmann'" , "'Russell King - ARM Linux'" , "'Chunsang Jeong'" , "'Krishna Reddy'" , "'Konrad Rzeszutek Wilk'" , "'Hiroshi Doyu'" , "'Subash Patel'" , "'Nick Piggin'" Message-id: <001d01cd3caa$a05d0510$e1170f30$%szyprowski@samsung.com> Organization: SPRC MIME-version: 1.0 X-Mailer: Microsoft Office Outlook 12.0 Content-type: text/plain; charset=us-ascii Content-language: pl Content-transfer-encoding: 7BIT Thread-index: Ac08BT44lU09F0l8TOCrspyaYIvvLwApKrLw References: <1337252085-22039-1-git-send-email-m.szyprowski@samsung.com> <1337252085-22039-4-git-send-email-m.szyprowski@samsung.com> <4FBB3B41.8010102@kernel.org> <01e501cd39a8$67f34ea0$37d9ebe0$%szyprowski@samsung.com> <20120524122854.GD11860@linux-sh.org> X-TM-AS-MML: No Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1494 Lines: 37 Hello, On Sunday, May 27, 2012 2:35 PM KOSAKI Motohiro wrote: > On Thu, May 24, 2012 at 8:28 AM, Paul Mundt wrote: > > On Thu, May 24, 2012 at 02:26:12PM +0200, Marek Szyprowski wrote: > >> On Tuesday, May 22, 2012 9:08 AM Minchan Kim wrote: > >> > Hmm, VM_DMA would become generic flag? > >> > AFAIU, maybe VM_DMA would be used only on ARM arch. > >> > >> Right now yes, it will be used only on ARM architecture, but maybe other architecture will > >> start using it once it is available. > >> > > There's very little about the code in question that is ARM-specific to > > begin with. I plan to adopt similar changes on SH once the work has > > settled one way or the other, so we'll probably use the VMA flag there, > > too. > > I don't think VM_DMA is good idea because x86_64 has two dma zones. x86 unaware > patches make no sense. I see no problems to add VM_DMA64 later if x86_64 starts using vmalloc areas for creating kernel mappings for the dma buffers (I assume that there are 2 dma zones: one 32bit and one 64bit). Right now x86 and x86_64 don't use vmalloc areas for dma buffers, so I hardly see how this patch can be considered as 'x86 unaware'. Best regards -- Marek Szyprowski Samsung Poland R&D Center -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/