On Tue, Sep 13, 2011 at 1:44 PM, Roedel, Joerg <Joerg.Roedel@xxxxxxx> wrote: > Not necessarily. You could implement this side-by-side with the old code > until all drivers are converted and remove the old code then. This keeps > bisectability. Ok. >> > Intel IOMMU does not support arbitrary page-sizes, afaik. >> >> It does; besides the usual 4K it has "super page sizes" support of >> 2MB, 1GB, 512GB and 1TB. > > But the value ~0xfffUL indicates support for 4k, 8k, 16k .. 2^63, no? Yes, I have done this intentionally, in order to retain the existing behavior for IOMMU drivers which are already capable of handling arbitrary page sizes (intel-iommu handles this in software, see hardware_largepage_caps() and the code that uses it). Long term, it might make more sense to remove hardware_largepage_caps() (and the logic around it) and instead just declare the real page sizes the hardware supports when calling register_iommu(), but I guess it's up to Intel guys. For now it's just safer to declare ~0xfffUL which really means: keep calling me with sizes and alignments that are an order of 4KB, just like you always did. -- 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
