drm/i915: Kill obj->gtt_offset

With the getters in place from the previous patch this members serves no
purpose other than saving one spare pointer chase, which will be killed
in the next patch anyway.

Moving to VMAs, this members adds unnecessary confusion since an object
may exist at different offsets in different VMs.

v2: Properly preserve the stolen offset. This code is a bit hacky but it
all goes away when we embed the drm_mm_node and removes the need for the
incorrect patch I submitted previously: "Use gtt_space->start for stolen
reservation"
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_drv.h

@@ -1201,7 +1201,7 @@ enum hdmi_force_audio {
 	HDMI_AUDIO_ON,			/* force turn on HDMI audio */
 };
 
-#define I915_GTT_RESERVED ((struct drm_mm_node *)0x1)
+#define I915_GTT_RESERVED (1<<0)
 #define I915_GTT_OFFSET_NONE ((u32)-1)
 
 struct drm_i915_gem_object_ops {
@@ -1329,13 +1329,6 @@ struct drm_i915_gem_object {
 	unsigned long exec_handle;
 	struct drm_i915_gem_exec_object2 *exec_entry;
 
-	/**
-	 * Current offset of the object in GTT space.
-	 *
-	 * This is the same as gtt_space->start
-	 */
-	uint32_t gtt_offset;
-
 	struct intel_ring_buffer *ring;
 
 	/** Breadcrumb of last rendering to the buffer. */

drivers/gpu/drm/i915/i915_gem.c

@@ -2634,7 +2634,6 @@ i915_gem_object_unbind(struct drm_i915_gem_object *obj)
 
 	drm_mm_put_block(obj->gtt_space);
 	obj->gtt_space = NULL;
-	obj->gtt_offset = 0;
 
 	return 0;
 }
@@ -3164,7 +3163,6 @@ i915_gem_object_bind_to_gtt(struct drm_i915_gem_object *obj,
 	list_add_tail(&obj->mm_list, &dev_priv->mm.inactive_list);
 
 	obj->gtt_space = node;
-	obj->gtt_offset = node->start;
 
 	fenceable =
 		node->size == fence_size &&

drivers/gpu/drm/i915/i915_gem_gtt.c

@@ -629,18 +629,20 @@ void i915_gem_setup_global_gtt(struct drm_device *dev,
 
 	/* Mark any preallocated objects as occupied */
 	list_for_each_entry(obj, &dev_priv->mm.bound_list, global_list) {
+		uintptr_t offset = (uintptr_t) obj->gtt_space;
 		int ret;
-		DRM_DEBUG_KMS("reserving preallocated space: %x + %zx\n",
-			      obj->gtt_offset, obj->base.size);
+		DRM_DEBUG_KMS("reserving preallocated space: %lx + %zx\n",
+			      offset, obj->base.size);
 
-		BUG_ON(obj->gtt_space != I915_GTT_RESERVED);
+		BUG_ON((offset & I915_GTT_RESERVED) != 0);
+		offset &= ~I915_GTT_RESERVED;
 		obj->gtt_space = kzalloc(sizeof(*obj->gtt_space), GFP_KERNEL);
 		if (!obj->gtt_space) {
-			DRM_ERROR("Failed to preserve object at offset %x\n",
-				  obj->gtt_offset);
+			DRM_ERROR("Failed to preserve object at offset %lx\n",
+				  offset);
 			continue;
 		}
-		obj->gtt_space->start = obj->gtt_offset;
+		obj->gtt_space->start = (unsigned long)offset;
 		obj->gtt_space->size = obj->base.size;
 		ret = drm_mm_reserve_node(&dev_priv->mm.gtt_space,
 					  obj->gtt_space);

drivers/gpu/drm/i915/i915_gem_stolen.c

@@ -389,10 +389,13 @@ i915_gem_object_create_stolen_for_preallocated(struct drm_device *dev,
 			DRM_DEBUG_KMS("failed to allocate stolen GTT space\n");
 			goto free_out;
 		}
-	} else
-		obj->gtt_space = I915_GTT_RESERVED;
+	} else {
+		if (WARN_ON(gtt_offset & ~PAGE_MASK))
+			DRM_DEBUG_KMS("Cannot preserve non page aligned offset\n");
+		obj->gtt_space =
+			(struct drm_mm_node *)((uintptr_t)(I915_GTT_RESERVED | gtt_offset));
+	}
 
-	obj->gtt_offset = gtt_offset;
 	obj->has_global_gtt_mapping = 1;
 
 	list_add_tail(&obj->global_list, &dev_priv->mm.bound_list);