Re: amd64 bus_space_*_8() functions

[Andrew Doran <ad%netbsd.org@localhost>]

Hi Dennis,

On Mon, Apr 21, 2008 at 02:48:30PM -0700, Dennis Ferguson wrote:

> I'm porting a driver for a PCI board into NetBSD-current.  The
> device in question has 64-bit registers, so the driver needs
> bus_space_read_8() and bus_space_write_8().  While most of the
> other 64-bit architectures seem to have the _8() versions of these
> functions implemented it looks to me like the amd64 port does not.
> 
> Is there a reason why the amd64 port doesn't have them, or
> is this just because of lack of any previous need for them?
> And if the latter is the case and the functions just need to
> be written, what should the assembler stubs do if they are asked
> to do an 8-byte operation to I/O space?

I think it is simply because there has not been a need for these functions
yet. I think that an 8-byte operation to I/O space should call panic().
Can you see how to implement them (arch/amd64/amd64/busfunc.S) or shall I
do that?

Thanks,
Andrew