drm/i915: Extract PDE writes

It also makes some sense IMO to have these two functions separate
irrespective of the number of callers.

Only the single caller for now, but that will change as we add more
PPGTTs.

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
[danvet: Resolve conflict.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_gem_gtt.c

@@ -100,18 +100,14 @@ static gen6_gtt_pte_t hsw_pte_encode(struct drm_device *dev,
 	return pte;
 }
 
-static int gen6_ppgtt_enable(struct drm_device *dev)
+static void gen6_write_pdes(struct i915_hw_ppgtt *ppgtt)
 {
-	drm_i915_private_t *dev_priv = dev->dev_private;
-	uint32_t pd_offset;
-	struct intel_ring_buffer *ring;
-	struct i915_hw_ppgtt *ppgtt = dev_priv->mm.aliasing_ppgtt;
+	struct drm_i915_private *dev_priv = ppgtt->dev->dev_private;
 	gen6_gtt_pte_t __iomem *pd_addr;
 	uint32_t pd_entry;
 	int i;
 
 	WARN_ON(ppgtt->pd_offset & 0x3f);
-
 	pd_addr = (gen6_gtt_pte_t __iomem*)dev_priv->gtt.gsm +
 		ppgtt->pd_offset / sizeof(gen6_gtt_pte_t);
 	for (i = 0; i < ppgtt->num_pd_entries; i++) {
@@ -124,6 +120,19 @@ static int gen6_ppgtt_enable(struct drm_device *dev)
 		writel(pd_entry, pd_addr + i);
 	}
 	readl(pd_addr);
+}
+
+static int gen6_ppgtt_enable(struct drm_device *dev)
+{
+	drm_i915_private_t *dev_priv = dev->dev_private;
+	uint32_t pd_offset;
+	struct intel_ring_buffer *ring;
+	struct i915_hw_ppgtt *ppgtt = dev_priv->mm.aliasing_ppgtt;
+	int i;
+
+	BUG_ON(ppgtt->pd_offset & 0x3f);
+
+	gen6_write_pdes(ppgtt);
 
 	pd_offset = ppgtt->pd_offset;
 	pd_offset /= 64; /* in cachelines, */