PCI rework

[Michael Lorenz]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Hello,

>> there's a good reason not to do it: Many PCI devices put mappable
>> memory addresses in config space outside the standard PCI BARs.  What
>> you really need is an interface to read from PCI config space and an
>> interface to map physicall addresses on the pci bus into memory.  Some
>> standard helper functions to decode the standard BARs is certainly
>> desirable.
>
> Excluding legacy VGA memory, can you name any?

Wacky (embedded) VGAs. The IGS 1682 for instance maps blitter registers 
to a fixed IO address which doesn't show up in any BAR. In fact this 
chip has only one BAR, for the framebuffer.

>> Remapping as in writing different addresses into them?  X might need
>> to do that if the firmware doesn't properly initialize them.  I've
>> seen many, many buggy firmware implementations (ok they're mostly
>> BIOSes) that don't do this properly.
>
> Again, this is a job that the kernel should do.  PERIOD.  On platforms
> where the kernel is that broken (seriously, are there any still?), the
> code that is currently in the X-server could be put it that platform's
> backend in libpciaccess.  Again, this limits the exposure of
> per-platform issues.

Couldn't agree more. X shouldn't try to play operating system and mess 
around with BARs.

have fun
Michael
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.4 (Darwin)

iQEVAwUBRFZouMpnzkX8Yg2nAQKgVQf+NQWvb59dZngNY9UI5M1LT5Ayfv3Yb58E
365FZ5eORCKREH53hacQBeOHSzwBsyfYpyht564RDJ324ub9jhFKJVM81ieVaV55
QM97WIQ2xv+6Kg4QUogn6+Aw8EkgE85j4fug22M9k/+tB5CBFnGscaex8VbGwSdy
I+C4+Si8LBVy4bZG2GDxa0cj1iMAwpIbtqmZn7jUN/zJPL/TYFbTFnKrNNsxv97d
jvwXL+3zA2RWbbRKxcxGW0QN5xBJCL3V3rsmjKqfh7FNOaSYZ0LHXQvy0XbdLM2s
mIdIYHxMu69g1g0ivMlCwRTh/0v6IXxmVqc/SPPbwdJ8LNqELgV7eg==
=kax7
-----END PGP SIGNATURE-----