drm/i915: Combine scratch members into a struct

There isn't any special reason to do this other than it makes it obvious
that the two members are connected.
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_drv.h

@@ -465,8 +465,10 @@ struct i915_gtt {
 	void __iomem *gsm;
 
 	bool do_idle_maps;
-	dma_addr_t scratch_page_dma;
-	struct page *scratch_page;
+	struct {
+		dma_addr_t addr;
+		struct page *page;
+	} scratch;
 
 	/* global gtt ops */
 	int (*gtt_probe)(struct drm_device *dev, size_t *gtt_total,

drivers/gpu/drm/i915/i915_gem_gtt.c

@@ -195,7 +195,7 @@ static void gen6_ppgtt_clear_range(struct i915_hw_ppgtt *ppgtt,
 	unsigned last_pte, i;
 
 	scratch_pte = ppgtt->pte_encode(ppgtt->dev,
-					dev_priv->gtt.scratch_page_dma,
+					dev_priv->gtt.scratch.addr,
 					I915_CACHE_LLC);
 
 	while (num_entries) {
@@ -521,8 +521,7 @@ static void gen6_ggtt_clear_range(struct drm_device *dev,
 		 first_entry, num_entries, max_entries))
 		num_entries = max_entries;
 
-	scratch_pte = dev_priv->gtt.pte_encode(dev,
-					       dev_priv->gtt.scratch_page_dma,
+	scratch_pte = dev_priv->gtt.pte_encode(dev, dev_priv->gtt.scratch.addr,
 					       I915_CACHE_LLC);
 	for (i = 0; i < num_entries; i++)
 		iowrite32(scratch_pte, &gtt_base[i]);
@@ -727,8 +726,8 @@ static int setup_scratch_page(struct drm_device *dev)
 #else
 	dma_addr = page_to_phys(page);
 #endif
-	dev_priv->gtt.scratch_page = page;
-	dev_priv->gtt.scratch_page_dma = dma_addr;
+	dev_priv->gtt.scratch.page = page;
+	dev_priv->gtt.scratch.addr = dma_addr;
 
 	return 0;
 }
@@ -736,11 +735,11 @@ static int setup_scratch_page(struct drm_device *dev)
 static void teardown_scratch_page(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
-	set_pages_wb(dev_priv->gtt.scratch_page, 1);
-	pci_unmap_page(dev->pdev, dev_priv->gtt.scratch_page_dma,
+	set_pages_wb(dev_priv->gtt.scratch.page, 1);
+	pci_unmap_page(dev->pdev, dev_priv->gtt.scratch.addr,
 		       PAGE_SIZE, PCI_DMA_BIDIRECTIONAL);
-	put_page(dev_priv->gtt.scratch_page);
-	__free_page(dev_priv->gtt.scratch_page);
+	put_page(dev_priv->gtt.scratch.page);
+	__free_page(dev_priv->gtt.scratch.page);
 }
 
 static inline unsigned int gen6_get_total_gtt_size(u16 snb_gmch_ctl)