MFC r257995, r258244, r258246,

Rename the "bare" platform "mpc85xx"
Also turn "bare" into a truly bare platform

Move CCSR discovery into the platform module

There is no reason Book-E needs to save XER and CTR on context switches.

MFC r258002, r258024, r258027, r258051, r258052, r258243, r258244, r258002,
r258024, r258027, r258051, r258052, r258243,

Follow up r223485, which made AIM use the ABI thread pointer instead of
PCPU fields for curthread, by doing the same to Book-E.

Use the same implementation of copyinout.c for both AIM and Book-E.

Actually add IOMMU domain to the list of known mappings.

Following the approach with ACPI DMAR on x86, split IOMMU handling into
a variant PCI bus instead of trying to shoehorn it into the PCI host bridge
adapter.

Make sure that TLB1 mappings are aligned correctly.

MFC r257161, r257169, r257178, r257190, r257191

Add pmap_mapdev_attr() and pmap_kenter_attr() interfaces.

Fix concurrency issues with TLB1 updates and make pmap_kextract() search
TLB1 mappings as well

Interrelated improvements to early boot mappings:
- Remove explicit requirement that the SOC registers be found except as an
optimization (although the MPC85XX LAW drivers still require they be found
externally, which should change).
- Remove magic CCSRBAR_VA value.
- Allow bus_machdep.c's early-boot code to handle non 1:1 mappings and
systems not in real-mode or global 1:1 maps in early boot.
- Allow pmap_mapdev() on Book-E to reissue previous addresses if the
area is already mapped. Additionally have it check all mappings, not
just the CCSR area.

Add some extra sanity checking and checks to printf format specifiers.

Bump initial TLB size. The kernel is not necessarily less than 16 MB

Handle (in a slightly ugly way) ePAPR-type loaders that just place a
device tree into r3.

MFC r256814, r256816, r256818, r256846, r256855, r256864 (by nwhitehorn):

- Handle 2GB of ram
- Allow the OFW interrupt mapping code to work with PCI devices not
enumerated by Open Firmware, as in the case of FDT.
- Provide an interface for PCI bus drivers that need some of ofw_pci's
metadata during attach.
- Use standard ofw_bus helpers instead of reinventing the wheel.
- Make hard-wired TLB allocations be at minimum one page.

MFC r257995, r258244, r258246,

Rename the "bare" platform "mpc85xx"
Also turn "bare" into a truly bare platform

Move CCSR discovery into the platform module

There is no reason Book-E needs to save XER and CTR on context switches.

MFC r258002, r258024, r258027, r258051, r258052, r258243, r258244, r258002,
r258024, r258027, r258051, r258052, r258243,

Follow up r223485, which made AIM use the ABI thread pointer instead of
PCPU fields for curthread, by doing the same to Book-E.

Use the same implementation of copyinout.c for both AIM and Book-E.

Actually add IOMMU domain to the list of known mappings.

Following the approach with ACPI DMAR on x86, split IOMMU handling into
a variant PCI bus instead of trying to shoehorn it into the PCI host bridge
adapter.

Make sure that TLB1 mappings are aligned correctly.

MFC r257161, r257169, r257178, r257190, r257191

Add pmap_mapdev_attr() and pmap_kenter_attr() interfaces.

Fix concurrency issues with TLB1 updates and make pmap_kextract() search
TLB1 mappings as well

Interrelated improvements to early boot mappings:
- Remove explicit requirement that the SOC registers be found except as an
optimization (although the MPC85XX LAW drivers still require they be found
externally, which should change).
- Remove magic CCSRBAR_VA value.
- Allow bus_machdep.c's early-boot code to handle non 1:1 mappings and
systems not in real-mode or global 1:1 maps in early boot.
- Allow pmap_mapdev() on Book-E to reissue previous addresses if the
area is already mapped. Additionally have it check all mappings, not
just the CCSR area.

Add some extra sanity checking and checks to printf format specifiers.

Bump initial TLB size. The kernel is not necessarily less than 16 MB

Handle (in a slightly ugly way) ePAPR-type loaders that just place a
device tree into r3.

MFC r256814, r256816, r256818, r256846, r256855, r256864 (by nwhitehorn):

- Handle 2GB of ram
- Allow the OFW interrupt mapping code to work with PCI devices not
enumerated by Open Firmware, as in the case of FDT.
- Provide an interface for PCI bus drivers that need some of ofw_pci's
metadata during attach.
- Use standard ofw_bus helpers instead of reinventing the wheel.
- Make hard-wired TLB allocations be at minimum one page.