drm/i915: mm_list is per VMA

formerly: "drm/i915: Create VMAs (part 5) - move mm_list"

The mm_list is used for the active/inactive LRUs. Since those LRUs are
per address space, the link should be per VMx .

Because we'll only ever have 1 VMA before this point, it's not incorrect
to defer this change until this point in the patch series, and doing it
here makes the change much easier to understand.

Shamelessly manipulated out of Daniel:
"active/inactive stuff is used by eviction when we run out of address
space, so needs to be per-vma and per-address space. Bound/unbound otoh
is used by the shrinker which only cares about the amount of memory used
and not one bit about in which address space this memory is all used in.
Of course to actual kick out an object we need to unbind it from every
address space, but for that we have the per-object list of vmas."

v2: only bump GGTT LRU in i915_gem_object_set_to_gtt_domain (Chris)

v3: Moved earlier in the series

v4: Add dropped message from v3

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
[danvet: Frob patch to apply and use vma->node.size directly as
discused with Ben. Also drop a needles BUG_ON before move_to_inactive,
the function itself has the same check.]
[danvet 2nd: Rebase on top of the lost "drm/i915: Cleanup more of VMA
in destroy", specifically unlink the vma from the mm_list in
vma_unbind (to keep it symmetric with bind_to_vm) instead of
vma_destroy.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 5eacc49..985a130 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1886,7 +1886,6 @@
 {
 	struct drm_device *dev = obj->base.dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
-	struct i915_address_space *vm = &dev_priv->gtt.base;
 	u32 seqno = intel_ring_get_seqno(ring);
 
 	BUG_ON(ring == NULL);
@@ -1902,8 +1901,6 @@
 		obj->active = 1;
 	}
 
-	/* Move from whatever list we were on to the tail of execution. */
-	list_move_tail(&obj->mm_list, &vm->active_list);
 	list_move_tail(&obj->ring_list, &ring->active_list);
 
 	obj->last_read_seqno = seqno;
@@ -1925,14 +1922,14 @@
 static void
 i915_gem_object_move_to_inactive(struct drm_i915_gem_object *obj)
 {
-	struct drm_device *dev = obj->base.dev;
-	struct drm_i915_private *dev_priv = dev->dev_private;
-	struct i915_address_space *vm = &dev_priv->gtt.base;
+	struct drm_i915_private *dev_priv = obj->base.dev->dev_private;
+	struct i915_address_space *ggtt_vm = &dev_priv->gtt.base;
+	struct i915_vma *vma = i915_gem_obj_to_vma(obj, ggtt_vm);
 
 	BUG_ON(obj->base.write_domain & ~I915_GEM_GPU_DOMAINS);
 	BUG_ON(!obj->active);
 
-	list_move_tail(&obj->mm_list, &vm->inactive_list);
+	list_move_tail(&vma->mm_list, &ggtt_vm->inactive_list);
 
 	list_del_init(&obj->ring_list);
 	obj->ring = NULL;
@@ -2640,7 +2637,7 @@
 	i915_gem_gtt_finish_object(obj);
 	i915_gem_object_unpin_pages(obj);
 
-	list_del(&obj->mm_list);
+	list_del(&vma->mm_list);
 	/* Avoid an unnecessary call to unbind on rebind. */
 	if (i915_is_ggtt(vma->vm))
 		obj->map_and_fenceable = true;
@@ -3187,7 +3184,7 @@
 		goto err_remove_node;
 
 	list_move_tail(&obj->global_list, &dev_priv->mm.bound_list);
-	list_add_tail(&obj->mm_list, &vm->inactive_list);
+	list_add_tail(&vma->mm_list, &vm->inactive_list);
 
 	/* Keep GGTT vmas first to make debug easier */
 	if (i915_is_ggtt(vm))
@@ -3352,9 +3349,14 @@
 					    old_write_domain);
 
 	/* And bump the LRU for this access */
-	if (i915_gem_object_is_inactive(obj))
-		list_move_tail(&obj->mm_list,
-			       &dev_priv->gtt.base.inactive_list);
+	if (i915_gem_object_is_inactive(obj)) {
+		struct i915_vma *vma = i915_gem_obj_to_vma(obj,
+							   &dev_priv->gtt.base);
+		if (vma)
+			list_move_tail(&vma->mm_list,
+				       &dev_priv->gtt.base.inactive_list);
+
+	}
 
 	return 0;
 }
@@ -3927,7 +3929,6 @@
 void i915_gem_object_init(struct drm_i915_gem_object *obj,
 			  const struct drm_i915_gem_object_ops *ops)
 {
-	INIT_LIST_HEAD(&obj->mm_list);
 	INIT_LIST_HEAD(&obj->global_list);
 	INIT_LIST_HEAD(&obj->ring_list);
 	INIT_LIST_HEAD(&obj->exec_list);
@@ -4069,6 +4070,7 @@
 		return ERR_PTR(-ENOMEM);
 
 	INIT_LIST_HEAD(&vma->vma_link);
+	INIT_LIST_HEAD(&vma->mm_list);
 	vma->vm = vm;
 	vma->obj = obj;