Hi Cho, On Wed, Sep 7, 2011 at 4:30 AM, KyongHo Cho <pullip.cho@xxxxxxxxxxx> wrote: > Please find the following link that I submitted for our IOMMU. > https://lkml.org/lkml/2011/7/3/152 > > s5p_iommu_map/unmap accepts any order of physical address and iova > without support of your suggestion if the order is not less than PAGE_SHIFT That's exactly what I'm trying to prevent; there's no reason to duplicate the exact same logic in every iommu driver. As a result, your map function is quite big (it even duplicates the same logic for every page size it tries). Try to rebase your patch on the "iommu/core: split mapping to page sizes as supported by the hardware" patch I've just sent, and see how significantly simpler your code becomes. Relying on a single implementation, provided by the IOMMU core, means less code to maintain (and debug) and a consistent behavior (across all supported hardware) exposed to users of the IOMMU API. > But I think IOMMU API must not expect that the caller of iommu_map() knows > about the restriction of IOMMU API implementation. Right. But I don't think there's any disagreement here ? If any, then I think that s5p_iommu_map() is more limited than what I propose: if it is given a 64KB region aligned only to a 4KB address, it will BUG_ON() it. While not ideal, I don't think there's any reason not to map it using 4KB pages (which is exactly what the new iommu_map() I propose will do). Thanks, Ohad. -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
