From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx187.postini.com [74.125.245.187]) by kanga.kvack.org (Postfix) with SMTP id E17576B0069 for ; Thu, 14 Jun 2012 05:01:30 -0400 (EDT) Received: from epcpsbgm1.samsung.com (mailout3.samsung.com [203.254.224.33]) by mailout3.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0M5L009BHNPZA4V0@mailout3.samsung.com> for linux-mm@kvack.org; Thu, 14 Jun 2012 18:01:28 +0900 (KST) Received: from AMDC159 ([106.116.37.153]) by mmp1.samsung.com (Oracle Communications Messaging Server 7u4-24.01 (7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTPA id <0M5L007VGNQ1R330@mmp1.samsung.com> for linux-mm@kvack.org; Thu, 14 Jun 2012 18:01:27 +0900 (KST) From: Marek Szyprowski References: <1339588218-24398-1-git-send-email-m.szyprowski@samsung.com> <1339588218-24398-2-git-send-email-m.szyprowski@samsung.com> <20120613185202.GM4829@phenom.ffwll.local> In-reply-to: <20120613185202.GM4829@phenom.ffwll.local> Subject: RE: [Linaro-mm-sig] [PATCHv2 1/6] common: DMA-mapping: add DMA_ATTR_NO_KERNEL_MAPPING attribute Date: Thu, 14 Jun 2012 11:01:11 +0200 Message-id: <003601cd4a0c$431d7780$c9586680$%szyprowski@samsung.com> MIME-version: 1.0 Content-type: text/plain; charset=us-ascii Content-transfer-encoding: 7bit Content-language: pl Sender: owner-linux-mm@kvack.org List-ID: To: 'Daniel Vetter' Cc: linux-arm-kernel@lists.infradead.org, linaro-mm-sig@lists.linaro.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, 'Abhinav Kochhar' , 'Russell King - ARM Linux' , 'Arnd Bergmann' , 'Konrad Rzeszutek Wilk' , 'Benjamin Herrenschmidt' , 'Kyungmin Park' , 'Subash Patel' Hello, On Wednesday, June 13, 2012 8:52 PM Daniel Vetter wrote: > On Wed, Jun 13, 2012 at 01:50:13PM +0200, Marek Szyprowski wrote: > > This patch adds DMA_ATTR_NO_KERNEL_MAPPING attribute which lets the > > platform to avoid creating a kernel virtual mapping for the allocated > > buffer. On some architectures creating such mapping is non-trivial task > > and consumes very limited resources (like kernel virtual address space > > or dma consistent address space). Buffers allocated with this attribute > > can be only passed to user space by calling dma_mmap_attrs(). > > > > Signed-off-by: Marek Szyprowski > > Reviewed-by: Kyungmin Park > > Looks like a nice little extension to support dma-buf for the common case, > so: > > Reviewed-by: Daniel Vetter > > One question is whether we should go right ahead and add kmap support for > this, too (with a default implementation that simply returns a pointer to > the coherent&contigous dma mem), but I guess that can wait until a > use-case pops up. I will wait with this until there will be real use cases. Let's get the patch into mainline first. Best regards -- Marek Szyprowski Samsung Poland R&D Center -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org