32 bits X vs. 64 bits PCI

[Benjamin Herrenschmidt]

Hi !

What is the status of fixing X PCI layer nowadays ? Some folks here got
some brand new shinny Power5+ workstations (damn, those things are
faaaaast....). We've tried putting Matrox G400 or old Radeon 7000 PCI in
there, and while the various fbdev's work fine, X doesn't.

What seems to be happening is that basically, X crops the top 32 bits of
all PCI resources :) It then tries to access those bogus addresses
via /dev/mem, which is no good, and instead craps over system memory.

Using a 64 bits X is not simple (most 64 bits POWER users run 32 bits
userland in fact, unlike x86-64, there it's not less sucky to go 64
bits :)

Thus I'm wondering what is the status with reworking X PCI code to,
among others, properly mmap /proc or /sys instead of /dev/mem, stop
assuming PCI resources are 32 bits on 32 bits machines (which is broken
on various other type of chips anyway, for example, some 44x embedded
powerpc's have a 36 bits physical address space and typically devices
sit above 4G), etc...

I know Iain was working on a new library for putting the PCI stuff in,
what is the status of that ?

Cheers,
Ben.