cleanup swiotlb initialization v4

Christoph Hellwig
2022-03-01T10:53:33Z

Hi all,

this series tries to clean up the swiotlb initialization, including
that of swiotlb-xen. To get there is also removes the x86 iommu table
infrastructure that massively obsfucates the initialization path.

Git tree:

git://git.infradead.org/users/hch/misc.git swiotlb-init-cleanup

Gitweb:

http://git.infradead.org/users/hch/misc.git/shortlog/refs/heads/swiotlb-init-cleanup

Changes since v3:
- fix a compilation issue on some powerpc configfs
- fix and cleanup how forced bounce buffering is enabled for
guest memory encryption

Changes since v2:
- make ppc_swiotlb_flags actually work again
- also force enable swiotlb for guest encrypted memory to cater
to hyperv which doesn't set the host encrypted memory flag

Changes since v1:
- skip IOMMU initialization on Xen PV kernels
- various small whitespace / typo fixes