In the case of platforms where a bios or firmware has not already
assigned all the resources, do so. Requires the platform supply one or
more ranges of physical address space and IO that can be mapped into
BARs.
Handles iterating through bridges, computing the sizes of all the
peripherals downstream and rolling that up as well.
Wire them up on arm and riscv which need them. x86-pc does not, so dont
call it.
Also fix a few miscellaneous bugs, notably PCI not detecting 64bit bars
properly due to an off by one bit error.
Had to rearrange the proble logic somewhat, but now the bus manager will
assign consequtive bus numbers as it finds bridges and recursively
drills down to discover the entire bus structure.
Does not assign resources yet, but need to do this in the first pass
to find all of the devices before can figure out how much space they
occupy.
This fixes an infinite recursion where it was stepped into bridge a
bridge that has the secondary bus set to 0, which caused it to start
over and probe bus 0 until it blew the stack.
Better fix is to actually assign busses.
Probe the size first, and if that turns up anything, mark the bar as
valid, even if the address is set to 0. The address can be configured in
a later pass of the bus manager.
Also print the bars on boot.
Since probing the size of a BAR requires writing and reading back from
the address field, do it at probe time and cache the data instead of at
api time. This should avoid fouling up any mmio transactions in flight.
-Add a bus manager level, which is an object oriented walk of the pci
busses to build a per device object for later manipulation.
-Add features to enable MSI interrupts.
-Extend generic interrupt api to allow the platform to allocate vectors
for MSI interrupts.
-Rearrange a bit of the pc platform for the platform api changes.
-Add PC platform support for using the local apic to EOI MSI vectors.
-Fix up a few existing PCI drivers for small API changes.
-Add a few stubbed out routines for non PC platforms that use PCI.
