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