Re: MI overrides of bus_dma(9), bus_space(9), pci(9)

[Matthias Drochner <M.Drochner%fz-juelich.de@localhost>]

dyoung%pobox.com@localhost said:
>     PCI-* bridges can override bus_space_alloc(9)/bus_space_free(9)
>         in order to (1) allocate space from the upstream bus, (2)
>         widen/narrow its I/O- or memory-space window.  Then we can
>         provide a reliable rbus-like facility to detachable buses
>         through bus_space(9).

This should be a separate set of methods, for two reasons:
-It is unneeded if no device hotplug is intended. NetBSD used to be
 useful for small/embedded systems, so it should be possible to
 leave unneeded code out.
-The bus_space_* functions assume a platform dependent bus_addr_t
 width. This doesn't make sense for buses behind some bridge.
 Examples like 1394 and SCI come to mind which are wider than
 any practical processor bus (sparsely populated of course).
 Use of bus_addr_t et al. should be limited to md code.

best regards
Matthias



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