drm/i915: Add .get_hw_state() method for planes

Add a .get_hw_state() method for planes, returning true or false
depending on whether the plane is enabled. Use it to rewrite the
plane enabled/disabled asserts in platform agnostic fashion.

We do lose the pre-gen4 plane<->pipe mapping checks, but since we're
supposed sanitize that anyway it doesn't really matter.

v2: Reoder patches to not depend on enum old_plane_id
    Just call assert_plane_disabled() from assert_planes_disabled()
v3: Deal with disabled power wells in .get_hw_state()
v4: Rebase due skl primary plane code removal

Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Alex Villacís Lasso <alexvillacislasso@hotmail.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> #v2
Tested-by: Thierry Reding <thierry.reding@gmail.com> #v2
Link: https://patchwork.freedesktop.org/patch/msgid/20171117191917.11506-2-ville.syrjala@linux.intel.comSigned-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

drivers/gpu/drm/i915/intel_drv.h

@@ -866,6 +866,7 @@ struct intel_plane {
 			     const struct intel_plane_state *plane_state);
 	void (*disable_plane)(struct intel_plane *plane,
 			      struct intel_crtc *crtc);
+	bool (*get_hw_state)(struct intel_plane *plane);
 	int (*check_plane)(struct intel_plane *plane,
 			   struct intel_crtc_state *crtc_state,
 			   struct intel_plane_state *state);
@@ -1934,6 +1935,7 @@ void skl_update_plane(struct intel_plane *plane,
 		      const struct intel_crtc_state *crtc_state,
 		      const struct intel_plane_state *plane_state);
 void skl_disable_plane(struct intel_plane *plane, struct intel_crtc *crtc);
+bool skl_plane_get_hw_state(struct intel_plane *plane);
 
 /* intel_tv.c */
 void intel_tv_init(struct drm_i915_private *dev_priv);

drivers/gpu/drm/i915/intel_sprite.c

@@ -325,6 +325,26 @@ skl_disable_plane(struct intel_plane *plane, struct intel_crtc *crtc)
 	spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
 }
 
+bool
+skl_plane_get_hw_state(struct intel_plane *plane)
+{
+	struct drm_i915_private *dev_priv = to_i915(plane->base.dev);
+	enum intel_display_power_domain power_domain;
+	enum plane_id plane_id = plane->id;
+	enum pipe pipe = plane->pipe;
+	bool ret;
+
+	power_domain = POWER_DOMAIN_PIPE(pipe);
+	if (!intel_display_power_get_if_enabled(dev_priv, power_domain))
+		return false;
+
+	ret = I915_READ(PLANE_CTL(pipe, plane_id)) & PLANE_CTL_ENABLE;
+
+	intel_display_power_put(dev_priv, power_domain);
+
+	return ret;
+}
+
 static void
 chv_update_csc(struct intel_plane *plane, uint32_t format)
 {
@@ -502,6 +522,26 @@ vlv_disable_plane(struct intel_plane *plane, struct intel_crtc *crtc)
 	spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
 }
 
+static bool
+vlv_plane_get_hw_state(struct intel_plane *plane)
+{
+	struct drm_i915_private *dev_priv = to_i915(plane->base.dev);
+	enum intel_display_power_domain power_domain;
+	enum plane_id plane_id = plane->id;
+	enum pipe pipe = plane->pipe;
+	bool ret;
+
+	power_domain = POWER_DOMAIN_PIPE(pipe);
+	if (!intel_display_power_get_if_enabled(dev_priv, power_domain))
+		return false;
+
+	ret = I915_READ(SPCNTR(pipe, plane_id)) & SP_ENABLE;
+
+	intel_display_power_put(dev_priv, power_domain);
+
+	return ret;
+}
+
 static u32 ivb_sprite_ctl(const struct intel_crtc_state *crtc_state,
 			  const struct intel_plane_state *plane_state)
 {
@@ -642,6 +682,25 @@ ivb_disable_plane(struct intel_plane *plane, struct intel_crtc *crtc)
 	spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
 }
 
+static bool
+ivb_plane_get_hw_state(struct intel_plane *plane)
+{
+	struct drm_i915_private *dev_priv = to_i915(plane->base.dev);
+	enum intel_display_power_domain power_domain;
+	enum pipe pipe = plane->pipe;
+	bool ret;
+
+	power_domain = POWER_DOMAIN_PIPE(pipe);
+	if (!intel_display_power_get_if_enabled(dev_priv, power_domain))
+		return false;
+
+	ret =  I915_READ(SPRCTL(pipe)) & SPRITE_ENABLE;
+
+	intel_display_power_put(dev_priv, power_domain);
+
+	return ret;
+}
+
 static u32 g4x_sprite_ctl(const struct intel_crtc_state *crtc_state,
 			  const struct intel_plane_state *plane_state)
 {
@@ -773,6 +832,25 @@ g4x_disable_plane(struct intel_plane *plane, struct intel_crtc *crtc)
 	spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
 }
 
+static bool
+g4x_plane_get_hw_state(struct intel_plane *plane)
+{
+	struct drm_i915_private *dev_priv = to_i915(plane->base.dev);
+	enum intel_display_power_domain power_domain;
+	enum pipe pipe = plane->pipe;
+	bool ret;
+
+	power_domain = POWER_DOMAIN_PIPE(pipe);
+	if (!intel_display_power_get_if_enabled(dev_priv, power_domain))
+		return false;
+
+	ret = I915_READ(DVSCNTR(pipe)) & DVS_ENABLE;
+
+	intel_display_power_put(dev_priv, power_domain);
+
+	return ret;
+}
+
 static int
 intel_check_sprite_plane(struct intel_plane *plane,
 			 struct intel_crtc_state *crtc_state,
@@ -1231,6 +1309,7 @@ intel_sprite_plane_create(struct drm_i915_private *dev_priv,
 
 		intel_plane->update_plane = skl_update_plane;
 		intel_plane->disable_plane = skl_disable_plane;
+		intel_plane->get_hw_state = skl_plane_get_hw_state;
 
 		plane_formats = skl_plane_formats;
 		num_plane_formats = ARRAY_SIZE(skl_plane_formats);
@@ -1241,6 +1320,7 @@ intel_sprite_plane_create(struct drm_i915_private *dev_priv,
 
 		intel_plane->update_plane = skl_update_plane;
 		intel_plane->disable_plane = skl_disable_plane;
+		intel_plane->get_hw_state = skl_plane_get_hw_state;
 
 		plane_formats = skl_plane_formats;
 		num_plane_formats = ARRAY_SIZE(skl_plane_formats);
@@ -1251,6 +1331,7 @@ intel_sprite_plane_create(struct drm_i915_private *dev_priv,
 
 		intel_plane->update_plane = vlv_update_plane;
 		intel_plane->disable_plane = vlv_disable_plane;
+		intel_plane->get_hw_state = vlv_plane_get_hw_state;
 
 		plane_formats = vlv_plane_formats;
 		num_plane_formats = ARRAY_SIZE(vlv_plane_formats);
@@ -1266,6 +1347,7 @@ intel_sprite_plane_create(struct drm_i915_private *dev_priv,
 
 		intel_plane->update_plane = ivb_update_plane;
 		intel_plane->disable_plane = ivb_disable_plane;
+		intel_plane->get_hw_state = ivb_plane_get_hw_state;
 
 		plane_formats = snb_plane_formats;
 		num_plane_formats = ARRAY_SIZE(snb_plane_formats);
@@ -1276,6 +1358,7 @@ intel_sprite_plane_create(struct drm_i915_private *dev_priv,
 
 		intel_plane->update_plane = g4x_update_plane;
 		intel_plane->disable_plane = g4x_disable_plane;
+		intel_plane->get_hw_state = g4x_plane_get_hw_state;
 
 		modifiers = i9xx_plane_format_modifiers;
 		if (IS_GEN6(dev_priv)) {