> -----Original Message----- > From: Arnd Bergmann [mailto:arnd@xxxxxxxx] > Sent: Thursday, April 12, 2012 1:09 PM > To: Marek Szyprowski > Cc: 'Subash Patel'; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linaro-mm-sig@xxxxxxxxxxxxxxxx; > linux-mm@xxxxxxxxx; linux-arch@xxxxxxxxxxxxxxx; iommu@xxxxxxxxxxxxxxxxxxxxxxxxxx; 'Kyungmin > Park'; 'Joerg Roedel'; 'Russell King - ARM Linux'; 'Chunsang Jeong'; 'Krishna Reddy'; 'KyongHo > Cho'; Andrzej Pietrasiewicz; 'Benjamin Herrenschmidt'; 'Konrad Rzeszutek Wilk'; 'Hiroshi Doyu' > Subject: Re: [PATCH] ARM: Exynos4: integrate SYSMMU driver with DMA-mapping interface > > 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. Right, until that time machine/board files are imho ok. Best regards -- Marek Szyprowski Samsung Poland R&D Center -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. 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: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>