dyo...@pobox.com said: > (1) If a bus-bridge driver is not configured in the kernel, or if its > module is unloaded, then the code is left out.
I know... but if you add this to the commonly used "ppb" driver there is no way to avoid it. > (2) Do you intend for the new methods to belong to a new API, or to > bus_space(9)? What would the methods' names and contracts be? The new methods should be part of the pci(9) API. That kind of bus space management is inherently bus specific. > I think that you are trying to tell me about some existing limitation to > bus_space(9)? > [...] > > This type is primarily used when mapping and unmap- > > ping bus space. Yes, this is a limitation of the idea of a universal bus_space type. It doesn't consider bridges which map things differently, eg by using split transactions. Generally I find the idea of making the bus methods more MI as you propose a good thing. It just needs to be done in a way which doesn't hurt users with tradiditional/embedded/low memory systems. > on i386, where bus_addr_t was until very recently 32 bits wide, we will > need to extend bus_addr_t to 64 bits. I've seen the mails about this -- if things were designed well, the change for PAE would only affect uvm and the pmap functions dealing with it. A single #define would switch between 32-bit and 64-bit physical addresses, without affecting drivers or userland. (I know that bus_dma_segment_t uses bus_addr_t which is wrong because a DMA address refers to a bus address of the actual device rather than a main bus address of the platform. That's a motivation to refine that interface rather than drawing more design compromises from it.) best regards Matthias ------------------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------------------ Forschungszentrum Juelich GmbH 52425 Juelich Sitz der Gesellschaft: Juelich Eingetragen im Handelsregister des Amtsgerichts Dueren Nr. HR B 3498 Vorsitzende des Aufsichtsrats: MinDir'in Baerbel Brumme-Bothe Geschaeftsfuehrung: Prof. Dr. Achim Bachem (Vorsitzender), Dr. Ulrich Krafft (stellv. Vorsitzender), Prof. Dr.-Ing. Harald Bolt, Prof. Dr. Sebastian M. Schmidt ------------------------------------------------------------------------------------------------ ------------------------------------------------------------------------------------------------
