drm/i915: clean up PPGTT checking logic

sanitize_enable_ppgtt is the function that checks all the conditions,
honoring a forced ppgtt status or doing auto-detect as necessary.  Just
make sure it returns the right value in all cases and use that in the
macros instead of the confusing intel_enable_ppgtt() function.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
[danvet: Don't reenable full ppgtt through the backdoor.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_drv.h

@@ -2065,8 +2065,8 @@ struct drm_i915_cmd_table {
 #define HAS_HW_CONTEXTS(dev)	(INTEL_INFO(dev)->gen >= 6)
 #define HAS_ALIASING_PPGTT(dev)	(INTEL_INFO(dev)->gen >= 6)
 #define HAS_PPGTT(dev)		(INTEL_INFO(dev)->gen >= 7 && !IS_GEN8(dev))
-#define USES_PPGTT(dev)		intel_enable_ppgtt(dev, false)
-#define USES_FULL_PPGTT(dev)	intel_enable_ppgtt(dev, true)
+#define USES_PPGTT(dev)		(i915.enable_ppgtt)
+#define USES_FULL_PPGTT(dev)	(i915.enable_ppgtt == 2)
 
 #define HAS_OVERLAY(dev)		(INTEL_INFO(dev)->has_overlay)
 #define OVERLAY_NEEDS_PHYSICAL(dev)	(INTEL_INFO(dev)->overlay_needs_physical)

drivers/gpu/drm/i915/i915_gem_gtt.c

@@ -33,17 +33,6 @@
 static void bdw_setup_private_ppat(struct drm_i915_private *dev_priv);
 static void chv_setup_private_ppat(struct drm_i915_private *dev_priv);
 
-bool intel_enable_ppgtt(struct drm_device *dev, bool full)
-{
-	if (i915.enable_ppgtt == 0)
-		return false;
-
-	if (i915.enable_ppgtt == 1 && full)
-		return false;
-
-	return true;
-}
-
 static int sanitize_enable_ppgtt(struct drm_device *dev, int enable_ppgtt)
 {
 	if (enable_ppgtt == 0 || !HAS_ALIASING_PPGTT(dev))

drivers/gpu/drm/i915/i915_gem_gtt.h

@@ -272,7 +272,6 @@ void i915_gem_init_global_gtt(struct drm_device *dev);
 void i915_gem_setup_global_gtt(struct drm_device *dev, unsigned long start,
 			       unsigned long mappable_end, unsigned long end);
 
-bool intel_enable_ppgtt(struct drm_device *dev, bool full);
 int i915_gem_init_ppgtt(struct drm_device *dev, struct i915_hw_ppgtt *ppgtt);
 
 void i915_check_and_clear_faults(struct drm_device *dev);