[PATCH 13/66] drm/i915: Unify PPGTT codepaths on gen6+

[Ben Widawsky <ben@bwidawsk.net>]

This will allow us to use the same code paths whether or not we have
PPGTT actually turned on. It will do all but actually enable the bits
that tell the HW to use PPGTT.

This patch also will help tie together contexts and PPGTT in the next
patch. That patch wants to disable contexts if there is no PPGTT, and we
disable PPGTT on gen6 with VT-D. Since Mesa depends on gen6+ having HW
contexts, this is a requirement.

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
---
 drivers/gpu/drm/i915/i915_dma.c     | 3 ++-
 drivers/gpu/drm/i915/i915_gem.c     | 6 +++++-
 drivers/gpu/drm/i915/i915_gem_gtt.c | 4 +++-
 3 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index adb319b..cb08907 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -977,7 +977,8 @@ static int i915_getparam(struct drm_device *dev, void *data,
 		value = HAS_LLC(dev);
 		break;
 	case I915_PARAM_HAS_ALIASING_PPGTT:
-		value = dev_priv->mm.aliasing_ppgtt ? 1 : 0;
+		if (intel_enable_ppgtt(dev) && dev_priv->mm.aliasing_ppgtt)
+			value = 1;
 		break;
 	case I915_PARAM_HAS_WAIT_TIMEOUT:
 		value = 1;
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index f3d6059..a337ce1 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -4220,7 +4220,11 @@ int i915_gem_init(struct drm_device *dev)
 			DRM_DEBUG_DRIVER("allow wake ack timed out\n");
 	}
 
-	if (intel_enable_ppgtt(dev) && HAS_ALIASING_PPGTT(dev)) {
+	/* NB: In order to keep the code paths for all platforms with PPGTT the
+	 * same, we run through this next section regardless, but don't actually
+	 * enable the PPGTT via GFX_MODE.
+	 */
+	if (HAS_ALIASING_PPGTT(dev)) {
 		struct i915_hw_ppgtt *ppgtt;
 
 		i915_gem_setup_global_gtt(dev, 0, dev_priv->gtt.mappable_end,
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index 87e5c7a..16a8486 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -154,7 +154,9 @@ static int gen6_ppgtt_enable(struct drm_device *dev)
 		ecochk = I915_READ(GAM_ECOCHK);
 		I915_WRITE(GAM_ECOCHK, ecochk | ECOCHK_SNB_BIT |
 				       ECOCHK_PPGTT_CACHE64B);
-		I915_WRITE(GFX_MODE, _MASKED_BIT_ENABLE(GFX_PPGTT_ENABLE));
+		if (intel_enable_ppgtt(dev))
+			I915_WRITE(GFX_MODE,
+				   _MASKED_BIT_ENABLE(GFX_PPGTT_ENABLE));
 	} else if (INTEL_INFO(dev)->gen >= 7) {
 		uint32_t ecochk, ecobits;
 
-- 
1.8.3.1