__ioremap_at() in 2.4.0-test9-pre2

Benjamin Herrenschmidt bh40 at calva.net
Fri Sep 29 11:40:53 EST 2000


>Essentially we have two cases with inb/outb - ISA devices and PCI
>devices.  The ISA devices we handle by making sure that inb(0x3f8)
>hits I/O address 0x3f8 on the first PCI host bridge.  The PCI devices
>we handle by setting the pci_dev->resource[].start values to account
>for any mapping we need to do.
>
>My proposal would simplify inb/outb by making _IO_BASE a constant
>rather than a variable.

Well, the ISA space would be on a fixed bus, but not necessarily bus 0
(please  ;)

On uninorth, with the new bus remap code, the PCI slots will be bus 2 or
something like that. Ideally, the arch would tell you which bus to map
first, possibly overriden by a kernel arg.

ben.

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