This adds support for dri2 pageflipping.

v2: precision updates from Mario Kleiner.
v3: Multihead fixes from Mario Kleiner; missing crtc offset
    add note about update pending bit on pre-avivo chips
Signed-off-by: NAlex Deucher <alexdeucher@gmail.com>
Signed-off-by: NMario Kleiner <mario.kleiner@tuebingen.mpg.de>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Needed for scanning out of a tiled buffer.
Signed-off-by: NAlex Deucher <alexdeucher@gmail.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Advanced validation is not implemented yet.
The mesa code that uses this will be released soon.
Signed-off-by: NAlex Deucher <alexdeucher@gmail.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

- disable gui idle interrupt use
  Seems to hang some r5xx chips
- move vbl range check into
  existing vbl check function in
  radeon_pm.c
- disable crtc mc acccess for the
  whole reclocking process
Signed-off-by: NAlex Deucher <alexdeucher@gmail.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

- pm_misc() - handles voltage, pcie lanes, and other non
clock related power mode settings.  Currently disabled.
Needs further debugging

- pm_prepare() - disables crtc mem requests right now.
All memory clients need to be disabled when changing
memory clocks.  This function can be expanded to include
disabling fb access as well.

- pm_finish() - enable active memory clients.
Signed-off-by: NAlex Deucher <alexdeucher@gmail.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

(v2) Add evergreen vbl checks
Signed-off-by: NAlex Deucher <alexdeucher@gmail.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

This adds initial Evergreen KMS support, it doesn't include
any acceleration features or interrupt handling yet.

Major changes are DCE4 handling for PLLs for the > 2 crtcs.
Signed-off-by: NAlex Deucher <alexdeucher@gmail.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>