drm/i915: simplify swapin/out swizzle checking a bit

Use the helper function already employed by the pwrite/pread
functions.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Keith Packard <keithp@keithp.com>

drivers/gpu/drm/i915/i915_gem.c

@@ -1476,7 +1476,7 @@ i915_gem_object_get_pages_gtt(struct drm_i915_gem_object *obj,
 		obj->pages[i] = page;
 	}
 
-	if (obj->tiling_mode != I915_TILING_NONE)
+	if (i915_gem_object_needs_bit17_swizzle(obj))
 		i915_gem_object_do_bit_17_swizzle(obj);
 
 	return 0;
@@ -1498,7 +1498,7 @@ i915_gem_object_put_pages_gtt(struct drm_i915_gem_object *obj)
 
 	BUG_ON(obj->madv == __I915_MADV_PURGED);
 
-	if (obj->tiling_mode != I915_TILING_NONE)
+	if (i915_gem_object_needs_bit17_swizzle(obj))
 		i915_gem_object_save_bit_17_swizzle(obj);
 
 	if (obj->madv == I915_MADV_DONTNEED)

drivers/gpu/drm/i915/i915_gem_tiling.c

@@ -443,14 +443,9 @@ i915_gem_swizzle_page(struct page *page)
 void
 i915_gem_object_do_bit_17_swizzle(struct drm_i915_gem_object *obj)
 {
-	struct drm_device *dev = obj->base.dev;
-	drm_i915_private_t *dev_priv = dev->dev_private;
 	int page_count = obj->base.size >> PAGE_SHIFT;
 	int i;
 
-	if (dev_priv->mm.bit_6_swizzle_x != I915_BIT_6_SWIZZLE_9_10_17)
-		return;
-
 	if (obj->bit_17 == NULL)
 		return;
 
@@ -467,14 +462,9 @@ i915_gem_object_do_bit_17_swizzle(struct drm_i915_gem_object *obj)
 void
 i915_gem_object_save_bit_17_swizzle(struct drm_i915_gem_object *obj)
 {
-	struct drm_device *dev = obj->base.dev;
-	drm_i915_private_t *dev_priv = dev->dev_private;
 	int page_count = obj->base.size >> PAGE_SHIFT;
 	int i;
 
-	if (dev_priv->mm.bit_6_swizzle_x != I915_BIT_6_SWIZZLE_9_10_17)
-		return;
-
 	if (obj->bit_17 == NULL) {
 		obj->bit_17 = kmalloc(BITS_TO_LONGS(page_count) *
 					   sizeof(long), GFP_KERNEL);