drm/i915/skl: Use correct use counters for force wakes

Write and reads following the block changed use engine specific use counters
and unless that is matched here force wake use counting goes bad. Same
force wake is attempted to be taken twice which leads to at least time outs.

NOTE: Depending on feedback from hardware designers it may not be necessary
to grab force wakes on Gen9 here. But for Gen8 it is needed due to a race
between RC6 and ELSP writes.

v2: Added blitter force wake engine and made more future proof.
    Added commit note.
Reviewed-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NTvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDamien Lespiau <damien.lespiau@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_lrc.c

@@ -276,7 +276,8 @@ static void execlists_elsp_write(struct intel_engine_cs *ring,
 				 struct drm_i915_gem_object *ctx_obj0,
 				 struct drm_i915_gem_object *ctx_obj1)
 {
-	struct drm_i915_private *dev_priv = ring->dev->dev_private;
+	struct drm_device *dev = ring->dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
 	uint64_t temp = 0;
 	uint32_t desc[4];
 	unsigned long flags;
@@ -301,13 +302,18 @@ static void execlists_elsp_write(struct intel_engine_cs *ring,
 	 * Instead, we do the runtime_pm_get/put when creating/destroying requests.
 	 */
 	spin_lock_irqsave(&dev_priv->uncore.lock, flags);
-	if (IS_CHERRYVIEW(dev_priv->dev)) {
+	if (IS_CHERRYVIEW(dev) || INTEL_INFO(dev)->gen >= 9) {
 		if (dev_priv->uncore.fw_rendercount++ == 0)
 			dev_priv->uncore.funcs.force_wake_get(dev_priv,
 							      FORCEWAKE_RENDER);
 		if (dev_priv->uncore.fw_mediacount++ == 0)
 			dev_priv->uncore.funcs.force_wake_get(dev_priv,
 							      FORCEWAKE_MEDIA);
+		if (INTEL_INFO(dev)->gen >= 9) {
+			if (dev_priv->uncore.fw_blittercount++ == 0)
+				dev_priv->uncore.funcs.force_wake_get(dev_priv,
+							FORCEWAKE_BLITTER);
+		}
 	} else {
 		if (dev_priv->uncore.forcewake_count++ == 0)
 			dev_priv->uncore.funcs.force_wake_get(dev_priv,
@@ -326,13 +332,18 @@ static void execlists_elsp_write(struct intel_engine_cs *ring,
 
 	/* Release Force Wakeup (see the big comment above). */
 	spin_lock_irqsave(&dev_priv->uncore.lock, flags);
-	if (IS_CHERRYVIEW(dev_priv->dev)) {
+	if (IS_CHERRYVIEW(dev) || INTEL_INFO(dev)->gen >= 9) {
 		if (--dev_priv->uncore.fw_rendercount == 0)
 			dev_priv->uncore.funcs.force_wake_put(dev_priv,
 							      FORCEWAKE_RENDER);
 		if (--dev_priv->uncore.fw_mediacount == 0)
 			dev_priv->uncore.funcs.force_wake_put(dev_priv,
 							      FORCEWAKE_MEDIA);
+		if (INTEL_INFO(dev)->gen >= 9) {
+			if (--dev_priv->uncore.fw_blittercount == 0)
+				dev_priv->uncore.funcs.force_wake_put(dev_priv,
+							FORCEWAKE_BLITTER);
+		}
 	} else {
 		if (--dev_priv->uncore.forcewake_count == 0)
 			dev_priv->uncore.funcs.force_wake_put(dev_priv,