drm/i915: Consolidate forcewake resetting to a single function

We have two paths that try to reset the forcewake registers back to
known good values, with slightly different semantics and levels of
paranoia. Combine the two by passing a parameter to either restore the
forcewake status or to clear our bookkeeping, and raise the paranoia
level to max.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NMika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_uncore.c

@@ -308,9 +308,17 @@ static void gen6_force_wake_timer(unsigned long arg)
 	intel_runtime_pm_put(dev_priv);
 }
 
-static void intel_uncore_forcewake_reset(struct drm_device *dev)
+static void intel_uncore_forcewake_reset(struct drm_device *dev, bool restore)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
+	unsigned long irqflags;
+
+	del_timer_sync(&dev_priv->uncore.force_wake_timer);
+
+	/* Hold uncore.lock across reset to prevent any register access
+	 * with forcewake not set correctly
+	 */
+	spin_lock_irqsave(&dev_priv->uncore.lock, irqflags);
 
 	if (IS_VALLEYVIEW(dev))
 		vlv_force_wake_reset(dev_priv);
@@ -319,6 +327,35 @@ static void intel_uncore_forcewake_reset(struct drm_device *dev)
 
 	if (IS_IVYBRIDGE(dev) || IS_HASWELL(dev) || IS_GEN8(dev))
 		__gen7_gt_force_wake_mt_reset(dev_priv);
+
+	if (restore) { /* If reset with a user forcewake, try to restore */
+		unsigned fw = 0;
+
+		if (IS_VALLEYVIEW(dev)) {
+			if (dev_priv->uncore.fw_rendercount)
+				fw |= FORCEWAKE_RENDER;
+
+			if (dev_priv->uncore.fw_mediacount)
+				fw |= FORCEWAKE_MEDIA;
+		} else {
+			if (dev_priv->uncore.forcewake_count)
+				fw = FORCEWAKE_ALL;
+		}
+
+		if (fw)
+			dev_priv->uncore.funcs.force_wake_get(dev_priv, fw);
+
+		if (IS_GEN6(dev) || IS_GEN7(dev))
+			dev_priv->uncore.fifo_count =
+				__raw_i915_read32(dev_priv, GTFIFOCTL) &
+				GT_FIFO_FREE_ENTRIES_MASK;
+	} else {
+		dev_priv->uncore.forcewake_count = 0;
+		dev_priv->uncore.fw_rendercount = 0;
+		dev_priv->uncore.fw_mediacount = 0;
+	}
+
+	spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
 }
 
 void intel_uncore_early_sanitize(struct drm_device *dev)
@@ -344,7 +381,7 @@ void intel_uncore_early_sanitize(struct drm_device *dev)
 		__raw_i915_write32(dev_priv, GTFIFODBG,
 				   __raw_i915_read32(dev_priv, GTFIFODBG));
 
-	intel_uncore_forcewake_reset(dev);
+	intel_uncore_forcewake_reset(dev, false);
 }
 
 void intel_uncore_sanitize(struct drm_device *dev)
@@ -798,17 +835,9 @@ void intel_uncore_init(struct drm_device *dev)
 
 void intel_uncore_fini(struct drm_device *dev)
 {
-	struct drm_i915_private *dev_priv = dev->dev_private;
-
-	del_timer_sync(&dev_priv->uncore.force_wake_timer);
-
 	/* Paranoia: make sure we have disabled everything before we exit. */
 	intel_uncore_sanitize(dev);
-	intel_uncore_forcewake_reset(dev);
-
-	dev_priv->uncore.forcewake_count = 0;
-	dev_priv->uncore.fw_rendercount = 0;
-	dev_priv->uncore.fw_mediacount = 0;
+	intel_uncore_forcewake_reset(dev, false);
 }
 
 static const struct register_whitelist {
@@ -957,13 +986,6 @@ static int gen6_do_reset(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	int	ret;
-	unsigned long irqflags;
-	u32 fw_engine = 0;
-
-	/* Hold uncore.lock across reset to prevent any register access
-	 * with forcewake not set correctly
-	 */
-	spin_lock_irqsave(&dev_priv->uncore.lock, irqflags);
 
 	/* Reset the chip */
 
@@ -976,29 +998,8 @@ static int gen6_do_reset(struct drm_device *dev)
 	/* Spin waiting for the device to ack the reset request */
 	ret = wait_for((__raw_i915_read32(dev_priv, GEN6_GDRST) & GEN6_GRDOM_FULL) == 0, 500);
 
-	intel_uncore_forcewake_reset(dev);
-
-	/* If reset with a user forcewake, try to restore */
-	if (IS_VALLEYVIEW(dev)) {
-		if (dev_priv->uncore.fw_rendercount)
-			fw_engine |= FORCEWAKE_RENDER;
-
-		if (dev_priv->uncore.fw_mediacount)
-			fw_engine |= FORCEWAKE_MEDIA;
-	} else {
-		if (dev_priv->uncore.forcewake_count)
-			fw_engine = FORCEWAKE_ALL;
-	}
-
-	if (fw_engine)
-		dev_priv->uncore.funcs.force_wake_get(dev_priv, fw_engine);
+	intel_uncore_forcewake_reset(dev, true);
 
-	if (IS_GEN6(dev) || IS_GEN7(dev))
-		dev_priv->uncore.fifo_count =
-			__raw_i915_read32(dev_priv, GTFIFOCTL) &
-			GT_FIFO_FREE_ENTRIES_MASK;
-
-	spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
 	return ret;
 }