x86/mm/pat, drivers/media/ivtv: Use arch_phys_wc_add() and require PAT disabled

We are burrying direct access to MTRR code support on
x86 in order to take advantage of PAT. In the future, we
also want to make the default behavior of ioremap_nocache()
to use strong UC, at which point the use of mtrr_add() on
those systems would make write-combining void.

In order to help both enable us to later make strong
UC default and in order to phase out direct MTRR access
code, port the driver over to the arch_phys_wc_add() API
and annotate that the device driver requires systems to
boot with PAT disabled, with the 'nopat' kernel parameter.

This is a workable compromise given that the hardware is
really rare these days, and perhaps only some lost souls
stuck with obsolete hardware are expected to be using this
feature of the device driver.

Signed-off-by: Luis R. Rodriguez <[email protected]>
Signed-off-by: Borislav Petkov <[email protected]>
Acked-by: Andy Walls <[email protected]>
Acked-by: Mauro Carvalho Chehab <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Antonino Daplas <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Brian Gerst <[email protected]>
Cc: Daniel Vetter <[email protected]>
Cc: Dave Airlie <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Denys Vlasenko <[email protected]>
Cc: Doug Ledford <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Jean-Christophe Plagniol-Villard <[email protected]>
Cc: Juergen Gross <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Michael S. Tsirkin <[email protected]>
Cc: Oleg Nesterov <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Roger Pau Monné <[email protected]>
Cc: Stefan Bader <[email protected]>
Cc: Suresh Siddha <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Ville Syrjälä <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

0 files changed, 0 insertions, 0 deletions