drm/i915: Do uncore early sanitize after domain init

intel_uncore_early_sanitize() will reset the forcewake registers. When
forcewake domains were introduced, the domain init was done after the
sanitization of the forcewake registers. And as the resetting of
registers use the domain accessors, we tried to reset the forcewake
registers with unitialized forcewake domains and failed.

Fix this by sanitizing after all the domains have been initialized. Do
per domain clearing of forcewake register on domain init so that
IVB can do early access to ECOBUS do determine the final configuration.

This regression was introduced in

commit 05a2fb157e44a53c79133805d30eaada43911941
Author: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Date:   Mon Jan 19 16:20:43 2015 +0200

    drm/i915: Consolidate forcewake code

v2: Carve out ellc detect, fw_domain_reset for ivb/ecobus (Chris)

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=88805
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reported-by: Olof Johansson <olof@lixom.net>
Tested-by: Darren Hart <dvhart@linux.intel.com> (v1)
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_uncore.c

@@ -72,6 +72,7 @@ assert_device_not_suspended(struct drm_i915_private *dev_priv)
 static inline void
 fw_domain_reset(const struct intel_uncore_forcewake_domain *d)
 {
+	WARN_ON(d->reg_set == 0);
 	__raw_i915_write32(d->i915, d->reg_set, d->val_reset);
 }
 
@@ -166,6 +167,8 @@ fw_domains_reset(struct drm_i915_private *dev_priv, enum forcewake_domains fw_do
 	struct intel_uncore_forcewake_domain *d;
 	enum forcewake_domain_id id;
 
+	WARN_ON(dev_priv->uncore.fw_domains == 0);
+
 	for_each_fw_domain_mask(d, fw_domains, dev_priv, id)
 		fw_domain_reset(d);
 
@@ -321,14 +324,10 @@ void intel_uncore_forcewake_reset(struct drm_device *dev, bool restore)
 	spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
 }
 
-static void __intel_uncore_early_sanitize(struct drm_device *dev,
-					  bool restore_forcewake)
+static void intel_uncore_ellc_detect(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 
-	if (HAS_FPGA_DBG_UNCLAIMED(dev))
-		__raw_i915_write32(dev_priv, FPGA_DBG, FPGA_DBG_RM_NOCLAIM);
-
 	if ((IS_HASWELL(dev) || IS_BROADWELL(dev)) &&
 	    (__raw_i915_read32(dev_priv, HSW_EDRAM_PRESENT) == 1)) {
 		/* The docs do not explain exactly how the calculation can be
@@ -339,6 +338,15 @@ static void __intel_uncore_early_sanitize(struct drm_device *dev,
 		dev_priv->ellc_size = 128;
 		DRM_INFO("Found %zuMB of eLLC\n", dev_priv->ellc_size);
 	}
+}
+
+static void __intel_uncore_early_sanitize(struct drm_device *dev,
+					  bool restore_forcewake)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+
+	if (HAS_FPGA_DBG_UNCLAIMED(dev))
+		__raw_i915_write32(dev_priv, FPGA_DBG, FPGA_DBG_RM_NOCLAIM);
 
 	/* clear out old GT FIFO errors */
 	if (IS_GEN6(dev) || IS_GEN7(dev))
@@ -982,14 +990,14 @@ static void fw_domain_init(struct drm_i915_private *dev_priv,
 	setup_timer(&d->timer, intel_uncore_fw_release_timer, (unsigned long)d);
 
 	dev_priv->uncore.fw_domains |= (1 << domain_id);
+
+	fw_domain_reset(d);
 }
 
-void intel_uncore_init(struct drm_device *dev)
+static void intel_uncore_fw_domains_init(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 
-	__intel_uncore_early_sanitize(dev, false);
-
 	if (IS_GEN9(dev)) {
 		dev_priv->uncore.funcs.force_wake_get = fw_domains_get;
 		dev_priv->uncore.funcs.force_wake_put = fw_domains_put;
@@ -1035,8 +1043,13 @@ void intel_uncore_init(struct drm_device *dev)
 		dev_priv->uncore.funcs.force_wake_put =
 			fw_domains_put_with_fifo;
 
+		/* We need to init first for ECOBUS access and then
+		 * determine later if we want to reinit, in case of MT access is
+		 * not working
+		 */
 		fw_domain_init(dev_priv, FW_DOMAIN_ID_RENDER,
 			       FORCEWAKE_MT, FORCEWAKE_MT_ACK);
+
 		mutex_lock(&dev->struct_mutex);
 		fw_domains_get_with_thread_status(dev_priv, FORCEWAKE_ALL);
 		ecobus = __raw_i915_read32(dev_priv, ECOBUS);
@@ -1057,6 +1070,15 @@ void intel_uncore_init(struct drm_device *dev)
 		fw_domain_init(dev_priv, FW_DOMAIN_ID_RENDER,
 			       FORCEWAKE, FORCEWAKE_ACK);
 	}
+}
+
+void intel_uncore_init(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+
+	intel_uncore_ellc_detect(dev);
+	intel_uncore_fw_domains_init(dev);
+	__intel_uncore_early_sanitize(dev, false);
 
 	switch (INTEL_INFO(dev)->gen) {
 	default: