On Friday, February 4, 2005 2:59 pm, Jon Smirl wrote: > Can you build a no-op version of these that will run on the x86? That > would allow a single user space API for x86, ia64. Maybe the ppc > people will join too.
Shouldn't be too hard I think. > Why does this appear in /sys/class/pci_bus/0000:17/? For example on my > x86 system I have a single legacy space but if I do a dir of > /sys/class/pci_bus I show three buses. You wouldn't want the > legacy_io/mem attributes on each of these three buses since that > implies three independent address spaces. > > [EMAIL PROTECTED] pci_bus]$ ls /sys/class/pci_bus > 0000:00 0000:01 0000:02 In that case they'll all point to the same memory and I/O space. On the machines I coded it on, each bus has its own space. > How would things be sorted out so that legacy_io/mem attributes only > appear on my root bridge chip 0000:00 and not on the child buses. I > guess this also means the user space app has to search through the bus > entries. We might have to add more arch code in that case, but I thought it might be easiest for apps if they could just open the space for the bus they're interested in and it would be routed correctly. I think that'll be ok so long as two apps aren't trying to do stuff on the bus at the same time. > In order to know how many VGA many simultaneous VGA devices you can > have there needs to be some way to count the number of legacy address > spaces. Maybe there should be a /sys/class/legacy to describe the > legacy spaces. Is it possible to have the same legacy space aliased at > two different addresses depending on which root bus is used to get to > it? > > I need to know how to answer these questions: > 1) how many legacy spaces are there Depends on your platform. > 2) how many VGA devices are in each space Ditto since the number of spaces depends on the platform. > 3) how do I do VGA bus routing to access the VGA device This interface just deals with the whole legacy ISA space, not just VGA ports. I guess some chipsets will do VGA only or split them up? > 4) how do I address each of the devices. Jesse - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
