Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752082AbaAXSHs (ORCPT ); Fri, 24 Jan 2014 13:07:48 -0500 Received: from aserp1040.oracle.com ([141.146.126.69]:40240 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750997AbaAXSHq (ORCPT ); Fri, 24 Jan 2014 13:07:46 -0500 Date: Fri, 24 Jan 2014 13:06:35 -0500 From: Konrad Rzeszutek Wilk To: Akinobu Mita Cc: LKML , Andrew Morton , Marek Szyprowski , David Woodhouse , Don Dutile , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Andi Kleen , x86@kernel.org, iommu@lists.linux-foundation.org Subject: Re: [PATCH v2 2/5] x86: enable DMA CMA with swiotlb Message-ID: <20140124180635.GB15785@phenom.dumpdata.com> References: <1389708830-5841-1-git-send-email-akinobu.mita@gmail.com> <1389708830-5841-3-git-send-email-akinobu.mita@gmail.com> <20140115201224.GD5201@phenom.dumpdata.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) X-Source-IP: ucsinet22.oracle.com [156.151.31.94] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jan 17, 2014 at 08:32:09AM +0900, Akinobu Mita wrote: > 2014/1/16 Konrad Rzeszutek Wilk : > > On Tue, Jan 14, 2014 at 11:13:47PM +0900, Akinobu Mita wrote: > >> The DMA Contiguous Memory Allocator support on x86 is disabled when > >> swiotlb config option is enabled. So DMA CMA is always disabled on > >> x86_64 because swiotlb is always enabled. This attempts to support > >> for DMA CMA with enabling swiotlb config option. > >> > >> The contiguous memory allocator on x86 is integrated in the function > >> dma_generic_alloc_coherent() which is .alloc callback in nommu_dma_ops > >> for dma_alloc_coherent(). > >> > >> x86_swiotlb_alloc_coherent() which is .alloc callback in swiotlb_dma_ops > >> tries to allocate with dma_generic_alloc_coherent() firstly and then > >> swiotlb_alloc_coherent() is called as a fallback. > >> > >> The main part of supporting DMA CMA with swiotlb is that changing > >> x86_swiotlb_free_coherent() which is .free callback in swiotlb_dma_ops > >> for dma_free_coherent() so that it can distinguish memory allocated by > >> dma_generic_alloc_coherent() from one allocated by swiotlb_alloc_coherent() > >> and release it with dma_generic_free_coherent() which can handle contiguous > >> memory. This change requires making is_swiotlb_buffer() global function. > >> > >> This also needs to change .free callback in the dma_map_ops for amd_gart > >> and sta2x11, because these dma_ops are also using > >> dma_generic_alloc_coherent(). > >> > >> Cc: Marek Szyprowski > >> Cc: Konrad Rzeszutek Wilk > >> Cc: David Woodhouse > >> Cc: Don Dutile > >> Cc: Thomas Gleixner > >> Cc: Ingo Molnar > >> Cc: "H. Peter Anvin" > >> Cc: Andi Kleen > >> Cc: x86@kernel.org > >> Cc: iommu@lists.linux-foundation.org > >> Signed-off-by: Akinobu Mita > >> Acked-by: Marek Szyprowski > >> --- > >> No change from the previous version > >> > >> arch/x86/Kconfig | 2 +- > >> arch/x86/include/asm/swiotlb.h | 7 +++++++ > >> arch/x86/kernel/amd_gart_64.c | 2 +- > >> arch/x86/kernel/pci-swiotlb.c | 9 ++++++--- > >> arch/x86/pci/sta2x11-fixup.c | 6 ++---- > >> include/linux/swiotlb.h | 2 ++ > >> lib/swiotlb.c | 2 +- > > > > It looks reasonable from my perspective (as swiotlb maintainer). > > > > Not too thrilled about the 'is_swiotlb_buffer' but that code is > > quite small so it should be fast enough. > > Thanks. Can I get your Acked-by for this patch? Yes. Acked-by: Konrad Rzeszutek Wilk -- 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/