iommu/io-pgtable-dart: Add DART PTE support for t6000

The DARTs present in the M1 Pro/Max/Ultra SoC use a diffent PTE format.
They support a 42bit physical address space by shifting the paddr and
extending its mask inside the PTE.
They also come with mandatory sub-page protection now which we just
configure to always allow access to the entire page. This feature is
already present but optional on the previous DARTs which allows to
unconditionally configure it.

Signed-off-by: Sven Peter <sven@svenpeter.dev>
Co-developed-by: Janne Grunau <j@jannau.net>
Signed-off-by: Janne Grunau <j@jannau.net>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Hector Martin <marcan@marcan.st>
Link: https://lore.kernel.org/r/20220916094152.87137-5-j@jannau.net
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/io-pgtable: Add DART subpage protection support

DART allows to only expose a subpage to the device. While this is an
optional feature on the M1 DARTs the new ones present on the Pro/Max
models require this field in every PTE.

Signed-off-by: Sven Peter <sven@svenpeter.dev>
Signed-off-by: Janne Grunau <j@jannau.net>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Hector Martin <marcan@marcan.st>
Link: https://lore.kernel.org/r/20220916094152.87137-4-j@jannau.net
Signed-off-by: Joerg Roedel <jroedel@suse.de>

iommu/io-pgtable: Move Apple DART support to its own file

The pte format used by the DARTs found in the Apple M1 (t8103) is not
fully compatible with io-pgtable-arm. The 24 MSB are used for subpage
protection (mapping only parts of page) and conflict with the address
mask. In addition bit 1 is not available for tagging entries but disables
subpage protection. Subpage protection could be useful to support a CPU
granule of 4k with the fixed IOMMU page size of 16k.

The DARTs found on Apple M1 Pro/Max/Ultra use another different pte
format which is even less compatible. To support an output address size
of 42 bit the address is shifted down by 4. Subpage protection is
mandatory and bit 1 signifies uncached mappings used by the display
controller.

It would be advantageous to share code for all known Apple DART
variants to support common features. The page table allocator for DARTs
is less complex since it uses a two levels of translation table without
support for huge pages.

Signed-off-by: Janne Grunau <j@jannau.net>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Sven Peter <sven@svenpeter.dev>
Acked-by: Hector Martin <marcan@marcan.st>
Link: https://lore.kernel.org/r/20220916094152.87137-3-j@jannau.net
[ joro: Fix compile warning in __dart_alloc_pages()]
Signed-off-by: Joerg Roedel <jroedel@suse.de>