From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx121.postini.com [74.125.245.121]) by kanga.kvack.org (Postfix) with SMTP id 5B4746B00F5 for ; Thu, 12 Apr 2012 07:09:32 -0400 (EDT) From: Arnd Bergmann Subject: Re: [PATCH] ARM: Exynos4: integrate SYSMMU driver with DMA-mapping interface Date: Thu, 12 Apr 2012 11:09:28 +0000 References: <1334155004-5700-1-git-send-email-m.szyprowski@samsung.com> <4F869AF4.3080402@gmail.com> <026301cd188d$32613860$9723a920$%szyprowski@samsung.com> In-Reply-To: <026301cd188d$32613860$9723a920$%szyprowski@samsung.com> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201204121109.28753.arnd@arndb.de> Sender: owner-linux-mm@kvack.org List-ID: To: Marek Szyprowski Cc: 'Subash Patel' , linux-arm-kernel@lists.infradead.org, linaro-mm-sig@lists.linaro.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, iommu@lists.linux-foundation.org, 'Kyungmin Park' , 'Joerg Roedel' , 'Russell King - ARM Linux' , 'Chunsang Jeong' , 'Krishna Reddy' , 'KyongHo Cho' , Andrzej Pietrasiewicz , 'Benjamin Herrenschmidt' , 'Konrad Rzeszutek Wilk' , 'Hiroshi Doyu' On Thursday 12 April 2012, Marek Szyprowski wrote: > + > > > +/* > > > + * s5p_sysmmu_late_init > > > + * Create DMA-mapping IOMMU context for specified devices. This function must > > > + * be called later, once SYSMMU driver gets registered and probed. > > > + */ > > > +static int __init s5p_sysmmu_late_init(void) > > > +{ > > > + platform_set_sysmmu(&SYSMMU_PLATDEV(fimc0).dev,&s5p_device_fimc0.dev); > > > + platform_set_sysmmu(&SYSMMU_PLATDEV(fimc1).dev,&s5p_device_fimc1.dev); > > > + platform_set_sysmmu(&SYSMMU_PLATDEV(fimc2).dev,&s5p_device_fimc2.dev); > > > + platform_set_sysmmu(&SYSMMU_PLATDEV(fimc3).dev,&s5p_device_fimc3.dev); > > > + platform_set_sysmmu(&SYSMMU_PLATDEV(mfc_l).dev,&s5p_device_mfc_l.dev); > > > + platform_set_sysmmu(&SYSMMU_PLATDEV(mfc_r).dev,&s5p_device_mfc_r.dev); > > > + > > > + s5p_create_iommu_mapping(&s5p_device_fimc0.dev, 0x20000000, SZ_128M, 4); > > > + s5p_create_iommu_mapping(&s5p_device_fimc1.dev, 0x20000000, SZ_128M, 4); > > > + s5p_create_iommu_mapping(&s5p_device_fimc2.dev, 0x20000000, SZ_128M, 4); > > > + s5p_create_iommu_mapping(&s5p_device_fimc3.dev, 0x20000000, SZ_128M, 4); > > > + s5p_create_iommu_mapping(&s5p_device_mfc_l.dev, 0x20000000, SZ_128M, 4); > > > + s5p_create_iommu_mapping(&s5p_device_mfc_r.dev, 0x40000000, SZ_128M, 4); > > > + > > > + return 0; > > > +} > > > +device_initcall(s5p_sysmmu_late_init); > > > > Shouldn't these things be specific to a SoC? With this RFC, it happens > > that you will predefine the IOMMU attachment and mapping information for > > devices in common location (dev-sysmmu.c)? This may lead to problems > > because there are some IP's with SYSMMU support in exynos5, but not > > available in exynos4 (eg: GSC, FIMC-LITE, FIMC-ISP) Previously we used > > to do above declaration in individual machine file, which I think was > > more meaningful. > > Right, I simplified the code too much. Keeping these definitions inside machine > files was a better idea. I completely forgot that Exynos sub-platform now covers > both Exynos4 and Exynos5 SoC families. Ideally the information about iommu attachment should come from the device tree. We have the "dma-ranges" properties that define how a dma address space is mapped. I am not entirely sure how that works when you have multiple IOMMUs and if that requires defining addititional properties, but I think we should make it so that we don't have to hardcode specific devices in the source. Arnd -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org