since BTLB entries can be scarce and very little of an I/O subsystem normally
needs to be mapped.
Instead, the pmap now allows mappings of I/O space to be entered with
pmap_kenter_pa. bus_space mappings for small amounts of I/O space (as for
virtually all devices) are made this way, with BTLB entries still used for
large mappings for things like framebuffers.
This has led to more and cleaned-up uses of bus_space(9) and has caused
some autoconf cleanup. Also, kgdb is now attached and connected before
autoconfiguration, which is much earlier than before.
they contain. IRQ information for these has been removed from the
kernel configuration file. GSC bus chips now choose an available CPU
IRQ for themselves, and know IRQ information for all of the devices
they may contain. Minor autoconfiguration changes support this.
Renamed the old-style vmstat interrupt counters to say "ipl" and not
"irq", since they've been disconnected from irq numbers. Also provide
a function to allocate an irq bit from an interrupt register, and a
function to report the next ipl bit that will be allocated.
lukem