[PATCH] iommu/mediatek: Fix share pgtable for iova over 4GB

[Laura Nao]

Hello,

I confirm this fixes decoding on MT8192 and fluster tests are passing again (tested on spherion with next-20230821).

Please note that I was only able to test this patch on MT8192 at the moment.

The regression was originally reported by KernelCI, so:

Reported-by: "kernelci.org bot" <bot at kernelci.org>
Tested-by: Laura Nao <laura.nao at collabora.com>

Thank you!

Laura