drm/i915/gtt: Do not initialize drm_mm twice.

It would be initialized just moments later by i915_init_vm.

Rearrange the code such that i915_init_vm() is next to its callers
inside i915_gem_gtt (and so we can make it static). After removing the
dance around the files, it is clear that we are repeating some work
inside the initializers (such as calling drm_mm_init() multiple times),
so take advantage of the refactor to also remove some redundant code and
clean up the interface.

v2: Commit msg update,
    s/i915_init_vm/i915_address_space_init, move to i915_gem_gtt.c,
    init address_space during i915_gem_setup_global_gtt for ggtt.
v3: Do not init global_link - we are adding it to vm_list moments later,
    make i915_address_space_init static, use OOP style parameter order.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Michel Thierry <michel.thierry@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: Michał Winiarski <michal.winiarski@intel.com>
Reviewed-by Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_drv.h

@@ -2809,8 +2809,6 @@ struct drm_i915_gem_object *i915_gem_alloc_object(struct drm_device *dev,
 						  size_t size);
 struct drm_i915_gem_object *i915_gem_object_create_from_data(
 		struct drm_device *dev, const void *data, size_t size);
-void i915_init_vm(struct drm_i915_private *dev_priv,
-		  struct i915_address_space *vm);
 void i915_gem_free_object(struct drm_gem_object *obj);
 void i915_gem_vma_destroy(struct i915_vma *vma);
 

drivers/gpu/drm/i915/i915_gem.c

@@ -4844,18 +4844,6 @@ init_ring_lists(struct intel_engine_cs *ring)
 	INIT_LIST_HEAD(&ring->request_list);
 }
 
-void i915_init_vm(struct drm_i915_private *dev_priv,
-		  struct i915_address_space *vm)
-{
-	if (!i915_is_ggtt(vm))
-		drm_mm_init(&vm->mm, vm->start, vm->total);
-	vm->dev = dev_priv->dev;
-	INIT_LIST_HEAD(&vm->active_list);
-	INIT_LIST_HEAD(&vm->inactive_list);
-	INIT_LIST_HEAD(&vm->global_link);
-	list_add_tail(&vm->global_link, &dev_priv->vm_list);
-}
-
 void
 i915_gem_load(struct drm_device *dev)
 {
@@ -4879,8 +4867,6 @@ i915_gem_load(struct drm_device *dev)
 				  NULL);
 
 	INIT_LIST_HEAD(&dev_priv->vm_list);
-	i915_init_vm(dev_priv, &dev_priv->gtt.base);
-
 	INIT_LIST_HEAD(&dev_priv->context_list);
 	INIT_LIST_HEAD(&dev_priv->mm.unbound_list);
 	INIT_LIST_HEAD(&dev_priv->mm.bound_list);

drivers/gpu/drm/i915/i915_gem_gtt.c

@@ -2121,6 +2121,16 @@ static int __hw_ppgtt_init(struct drm_device *dev, struct i915_hw_ppgtt *ppgtt)
 		return gen8_ppgtt_init(ppgtt);
 }
 
+static void i915_address_space_init(struct i915_address_space *vm,
+				    struct drm_i915_private *dev_priv)
+{
+	drm_mm_init(&vm->mm, vm->start, vm->total);
+	vm->dev = dev_priv->dev;
+	INIT_LIST_HEAD(&vm->active_list);
+	INIT_LIST_HEAD(&vm->inactive_list);
+	list_add_tail(&vm->global_link, &dev_priv->vm_list);
+}
+
 int i915_ppgtt_init(struct drm_device *dev, struct i915_hw_ppgtt *ppgtt)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
@@ -2129,9 +2139,7 @@ int i915_ppgtt_init(struct drm_device *dev, struct i915_hw_ppgtt *ppgtt)
 	ret = __hw_ppgtt_init(dev, ppgtt);
 	if (ret == 0) {
 		kref_init(&ppgtt->ref);
-		drm_mm_init(&ppgtt->base.mm, ppgtt->base.start,
-			    ppgtt->base.total);
-		i915_init_vm(dev_priv, &ppgtt->base);
+		i915_address_space_init(&ppgtt->base, dev_priv);
 	}
 
 	return ret;
@@ -2618,11 +2626,13 @@ static int i915_gem_setup_global_gtt(struct drm_device *dev,
 
 	BUG_ON(mappable_end > end);
 
-	/* Subtract the guard page ... */
-	drm_mm_init(&ggtt_vm->mm, start, end - start - PAGE_SIZE);
+	ggtt_vm->start = start;
 
-	dev_priv->gtt.base.start = start;
-	dev_priv->gtt.base.total = end - start;
+	/* Subtract the guard page before address space initialization to
+	 * shrink the range used by drm_mm */
+	ggtt_vm->total = end - start - PAGE_SIZE;
+	i915_address_space_init(ggtt_vm, dev_priv);
+	ggtt_vm->total += PAGE_SIZE;
 
 	if (intel_vgpu_active(dev)) {
 		ret = intel_vgt_balloon(dev);
@@ -2631,7 +2641,7 @@ static int i915_gem_setup_global_gtt(struct drm_device *dev,
 	}
 
 	if (!HAS_LLC(dev))
-		dev_priv->gtt.base.mm.color_adjust = i915_gtt_color_adjust;
+		ggtt_vm->mm.color_adjust = i915_gtt_color_adjust;
 
 	/* Mark any preallocated objects as occupied */
 	list_for_each_entry(obj, &dev_priv->mm.bound_list, global_list) {