Re: [PATCH] iommu/mediatek: Use totalram_pages to setup enable_4GB

[Christoph Hellwig]

On Thu, Jun 04, 2020 at 01:32:40PM +0200, David Hildenbrand wrote:
> Just a thought: If memory hotplug is applicable as well, you might
> either want to always assume data->enable_4GB, or handle memory hotplug
> events from the memory notifier, when new memory gets onlined (not sure
> how tricky that is).

We probably want a highest_pfn_possible() or similar API instead of
having drivers poking into random VM internals.