Instead of allowing the client to set a caching attribute
in the io_mem() call of the device interface, which was
only used to decide in between of the memory being
write-combined or not, remove it from the API.
Instead use the information delivered by the devices ROM,
whether memory from a PCI BAR is prefetchable or not,
to decide whether it is mapped write-combined or not.
Ref genodelabs/genode#4578
In case of the GPU multiplexer, we need to delegate MMIO memory
to the framebuffer client in form of a managed dataspace. To be
able to attach a given Platform::Device::Mmio object to a region map
we need to access its capability.
Ref genodelabs/genode#4578
Instead of returning an invalid device capability when a device
is (not yet) available, e.g. a PCI device is requested before the
PCI bus got parsed accordingly, we check the device capability
within the Platform::Connection utilities, and register temporarily
an Io_signal_handler to wait for changes of the devices ROM, and
try the device aquisition again. Thereby, simple drivers so not have
to take the burden to do so.
To enable this feature for all drivers, we always have to export a
devices ROM, but limit the information about physical resources
(I/O memory addresses, IRQ numbers, I/O port ranges) to clients with
'info=yes' in their policy description.
Fixgenodelabs/genode#4496
