drm/i915: Add intel_atomic_get_bw_*_state helpers

Add correspondent helpers to be able to get old/new bandwidth
global state object.

v2: - Fixed typo in function call
v3: - Changed new functions naming to use convention proposed
      by Jani Nikula, i.e intel_bw_* in intel_bw.c file.
v4: - Change function naming back to intel_atomic* pattern,
      was decided to rename in a separate patch series.
v5: - Fix function naming to match existing practices(Ville)
v6: - Removed spurious whitespace
v7: - Removed bw_state NULL checks(Ville)
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200415143911.10244-3-stanislav.lisovskiy@intel.com

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

@@ -375,7 +375,29 @@ static unsigned int intel_bw_data_rate(struct drm_i915_private *dev_priv,
 	return data_rate;
 }
 
-static struct intel_bw_state *
+struct intel_bw_state *
+intel_atomic_get_old_bw_state(struct intel_atomic_state *state)
+{
+	struct drm_i915_private *dev_priv = to_i915(state->base.dev);
+	struct intel_global_state *bw_state;
+
+	bw_state = intel_atomic_get_old_global_obj_state(state, &dev_priv->bw_obj);
+
+	return to_intel_bw_state(bw_state);
+}
+
+struct intel_bw_state *
+intel_atomic_get_new_bw_state(struct intel_atomic_state *state)
+{
+	struct drm_i915_private *dev_priv = to_i915(state->base.dev);
+	struct intel_global_state *bw_state;
+
+	bw_state = intel_atomic_get_new_global_obj_state(state, &dev_priv->bw_obj);
+
+	return to_intel_bw_state(bw_state);
+}
+
+struct intel_bw_state *
 intel_atomic_get_bw_state(struct intel_atomic_state *state)
 {
 	struct drm_i915_private *dev_priv = to_i915(state->base.dev);

drivers/gpu/drm/i915/display/intel_bw.h

@@ -24,6 +24,15 @@ struct intel_bw_state {
 
 #define to_intel_bw_state(x) container_of((x), struct intel_bw_state, base)
 
+struct intel_bw_state *
+intel_atomic_get_old_bw_state(struct intel_atomic_state *state);
+
+struct intel_bw_state *
+intel_atomic_get_new_bw_state(struct intel_atomic_state *state);
+
+struct intel_bw_state *
+intel_atomic_get_bw_state(struct intel_atomic_state *state);
+
 void intel_bw_init_hw(struct drm_i915_private *dev_priv);
 int intel_bw_init(struct drm_i915_private *dev_priv);
 int intel_bw_atomic_check(struct intel_atomic_state *state);