drm/i915: Add function to clear scanout flag for vmas

Currently frontbuffer tracking code is directly iterating over object vmas
and clearing scanout flags for them. Add function to clear scanout flag for
vmas and use it from frontbuffer tracking code.

v2: describe function parameter.
Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Nirmoy Das <nirmoy.das@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230727064142.751976-5-jouni.hogander@intel.com

drivers/gpu/drm/i915/display/intel_frontbuffer.c

@@ -226,16 +226,10 @@ static void frontbuffer_release(struct kref *ref)
 	struct intel_frontbuffer *front =
 		container_of(ref, typeof(*front), ref);
 	struct drm_i915_gem_object *obj = front->obj;
-	struct i915_vma *vma;
 
 	drm_WARN_ON(&intel_bo_to_i915(obj)->drm, atomic_read(&front->bits));
 
-	spin_lock(&obj->vma.lock);
-	for_each_ggtt_vma(vma, obj) {
-		i915_vma_clear_scanout(vma);
-		vma->display_alignment = I915_GTT_MIN_ALIGNMENT;
-	}
-	spin_unlock(&obj->vma.lock);
+	i915_ggtt_clear_scanout(obj);
 
 	i915_gem_object_set_frontbuffer(obj, NULL);
 	spin_unlock(&intel_bo_to_i915(obj)->display.fb_tracking.lock);

drivers/gpu/drm/i915/i915_vma.c

@@ -1629,6 +1629,26 @@ int i915_ggtt_pin(struct i915_vma *vma, struct i915_gem_ww_ctx *ww,
 	return err;
 }
 
+/**
+ * i915_ggtt_clear_scanout - Clear scanout flag for all objects ggtt vmas
+ * @obj: i915 GEM object
+ * This function clears scanout flags for objects ggtt vmas. These flags are set
+ * when object is pinned for display use and this function to clear them all is
+ * targeted to be called by frontbuffer tracking code when the frontbuffer is
+ * about to be released.
+ */
+void i915_ggtt_clear_scanout(struct drm_i915_gem_object *obj)
+{
+	struct i915_vma *vma;
+
+	spin_lock(&obj->vma.lock);
+	for_each_ggtt_vma(vma, obj) {
+		i915_vma_clear_scanout(vma);
+		vma->display_alignment = I915_GTT_MIN_ALIGNMENT;
+	}
+	spin_unlock(&obj->vma.lock);
+}
+
 static void __vma_close(struct i915_vma *vma, struct intel_gt *gt)
 {
 	/*

drivers/gpu/drm/i915/i915_vma.h

@@ -435,6 +435,8 @@ static inline void i915_vma_clear_scanout(struct i915_vma *vma)
 	clear_bit(I915_VMA_SCANOUT_BIT, __i915_vma_flags(vma));
 }
 
+void i915_ggtt_clear_scanout(struct drm_i915_gem_object *obj);
+
 #define for_each_until(cond) if (cond) break; else
 
 /**