[Linux-fbdev-devel] how to drop access to an ioremapped area ?

[Ghozlane T. <gt...@pr...>]

Hi all ...

I'm looking for  a way to somehow "drop" all access to a specific ioremaped
area ,
for a time , and then "reenable" it .. is there a way to do something like
that ?

mmh .. an explanation of what i'm trying may be more clear :
I'm working on a voodoo1 /voodoo2 fb driver, and i'd like to let it
cooperate with
userland accel programs (namely : glide apps).

Glide initialises completely the board, messing up with the fb driver, but
as glide is using a /dev/3dfx in order to access the board, i guess i can
hack the
/dev/3dfx so it calls an ioctl on the fb driver before letting glide
initialise everything.
The driver can save the state of the board, shutdown the board, and let
glide do
whatever it has to do . at the end of glide, /dev/3dfx would call another
ioctl to restore
the fb driver status . Let's imagine that this is done, and works, now  the
question is
how do i disalow FB applications (namely X_FBDev)  to acces the frame buffer
?

if i unmap the frame buffer when one application is still using it, i'm
quite sure  it'll
die horibly , so i 'd like to somehow redirect all access to uh .. /dev/null
so when glide
is active, the fb app don't mess with the board memory, as the odds are that
glide is using
this memory ...

any advices ? clues,anyone ?

thank you  in advance ,

ghoz