drm/xe/vf: Don't check has flat ccs in bios on VF

Don't check for flat ccs from VF-level as VF does not have direct
access to the register.

If the BIOS disables FlatCCS support (a use-case that will nearly never
be used) and the has_flat_ccs flag is set, there shouldn't be
any functional impact. The hardware will drop writes to the CCS region,
and reads from the CCS region will always return 0.
For the native case, the flag is disabled if the BIOS disables
it to avoid unnecessary overhead in buffer object (BO) creation
and migration.

Signed-off-by: Jakub Kolakowski <[email protected]>
Suggested-by: Piotr Piórkowski <[email protected]>
Cc: Adam Miszczak <[email protected]>
Cc: Jakub Kolakowski <[email protected]>
Cc: Lukasz Laguna <[email protected]>
Cc: Marcin Bernatowicz <[email protected]>
Cc: Michal Wajdeczko <[email protected]>
Cc: Michal Winiarski <[email protected]>
Cc: Narasimha C V <[email protected]>
Cc: Piotr Piorkowski <[email protected]>
Cc: Satyanarayana K V P <[email protected]>
Cc: Tomasz Lis <[email protected]>
Cc: Matt Roper <[email protected]>
Signed-off-by: Marcin Bernatowicz <[email protected]>
Reviewed-by: Matt Roper <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
Signed-off-by: Matt Roper <[email protected]>

Author: Jakub197

drivers/gpu/drm/xe/xe_device.c

@@ -607,7 +607,7 @@ static int probe_has_flat_ccs(struct xe_device *xe)
 	u32 reg;
 
 	/* Always enabled/disabled, no runtime check to do */
-	if (GRAPHICS_VER(xe) < 20 || !xe->info.has_flat_ccs)
+	if (GRAPHICS_VER(xe) < 20 || !xe->info.has_flat_ccs || IS_SRIOV_VF(xe))
 		return 0;
 
 	gt = xe_root_mmio_gt(xe);