On Sat, May 06, 2000 at 10:46:29PM +0200, Bernd Harries wrote:
> > On most other machines (ARM, MIPS, PPC), ISA memory
> > space is located somewhere else in PCI memory space.
Or possibly even outside of the PCI bridge since not connected via a
PCI-to-ISA bridge - even in PCI systems.
> - What qualifies a 16 MB region to be called ISA space?
> - Can there only be 1 of these regions? 4 GB could hold 256 spaces a 16
> MB
> > However, there are still some problems left:
> >
> > 1. How to allocate ISA memory space?
> >
> > Some drivers do
> >
> > request_mem_region(0xA0000, 65535, ...)
>
> If start is a long int it it could easyly be 0x7F0A0000 or 0xFE0A0000.
Assume that these addresses are relative to the start of the 16mb ISA mem
space.
> Perhaps an additional (enum) Parameter to select the ISA space?
> Or an additional function to globally select a 16 MB range as THE ISA
> space?
>
> What would it be like to access ISA IO space on archs which have mmapped
> IO?
> Some even have ISA IO inside 64K of _each_ ISA MEM space.
Before even thinking more about this - do we really have things as tastless
as multiple ISA spaces in Linux supported systems? I've seen plenty of
braindead system designs but not yet multiple ISA busses.
Ralf
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Sun May 07 2000 - 21:00:21 EST