drm/i915/gen8+: Add RC6 CTX corruption WA

From Imre Deak
255ed51599dea571ac15afc676b2705cf2f83975 in linux 4.19.y/4.19.84
7e34f4e4aad3fd34c02b294a3cf2321adf5b4438 in mainline linux

6 files changed, 126 insertions, 4 deletions

diff --git a/sys/dev/pci/drm/i915/i915_drv.c b/sys/dev/pci/drm/i915/i915_drv.c
index 3fe63166a9f..5f770610a69 100644
--- a/sys/dev/pci/drm/i915/i915_drv.c
+++ b/sys/dev/pci/drm/i915/i915_drv.c
@@ -1821,6 +1821,7 @@ static int i915_drm_suspend_late(struct drm_device *dev, bool hibernation)
 	i915_gem_suspend_late(dev_priv);
 
 	intel_display_set_init_power(dev_priv, false);
+	i915_rc6_ctx_wa_suspend(dev_priv);
 	intel_uncore_suspend(dev_priv);
 
 	/*
@@ -2049,6 +2050,8 @@ static int i915_drm_resume_early(struct drm_device *dev)
 	else
 		intel_display_set_init_power(dev_priv, true);
 
+	i915_rc6_ctx_wa_resume(dev_priv);
+
 	intel_engines_sanitize(dev_priv);
 
 	enable_rpm_wakeref_asserts(dev_priv);
diff --git a/sys/dev/pci/drm/i915/i915_drv.h b/sys/dev/pci/drm/i915/i915_drv.h
index 230414ee3f7..d690cc87b87 100644
--- a/sys/dev/pci/drm/i915/i915_drv.h
+++ b/sys/dev/pci/drm/i915/i915_drv.h
@@ -902,6 +902,7 @@ struct intel_rps {
 
 struct intel_rc6 {
 	bool enabled;
+	bool ctx_corrupted;
 	u64 prev_hw_residency[4];
 	u64 cur_residency[4];
 };
@@ -2718,10 +2719,12 @@ intel_info(const struct drm_i915_private *dev_priv)
 /* Early gen2 have a totally busted CS tlb and require pinned batches. */
 #define HAS_BROKEN_CS_TLB(dev_priv)	(IS_I830(dev_priv) || IS_I845G(dev_priv))
 
+#define NEEDS_RC6_CTX_CORRUPTION_WA(dev_priv)	\
+	(IS_BROADWELL(dev_priv) || INTEL_GEN(dev_priv) == 9)
+
 /* WaRsDisableCoarsePowerGating:skl,cnl */
 #define NEEDS_WaRsDisableCoarsePowerGating(dev_priv) \
-	(IS_CANNONLAKE(dev_priv) || \
-	 IS_SKL_GT3(dev_priv) || IS_SKL_GT4(dev_priv))
+	(IS_CANNONLAKE(dev_priv) || INTEL_GEN(dev_priv) == 9)
 
 #define HAS_GMBUS_IRQ(dev_priv) (INTEL_GEN(dev_priv) >= 4)
 #define HAS_GMBUS_BURST_READ(dev_priv) (INTEL_GEN(dev_priv) >= 10 || \
diff --git a/sys/dev/pci/drm/i915/i915_gem.c b/sys/dev/pci/drm/i915/i915_gem.c
index baf4b463c4e..7aec91fed54 100644
--- a/sys/dev/pci/drm/i915/i915_gem.c
+++ b/sys/dev/pci/drm/i915/i915_gem.c
@@ -174,6 +174,11 @@ static u32 __i915_gem_park(struct drm_i915_private *i915)
 	if (INTEL_GEN(i915) >= 6)
 		gen6_rps_idle(i915);
 
+	if (NEEDS_RC6_CTX_CORRUPTION_WA(i915)) {
+		i915_rc6_ctx_wa_check(i915);
+		intel_uncore_forcewake_put(i915, FORCEWAKE_ALL);
+	}
+
 	intel_display_power_put(i915, POWER_DOMAIN_GT_IRQ);
 
 	intel_runtime_pm_put(i915);
@@ -220,6 +225,9 @@ void i915_gem_unpark(struct drm_i915_private *i915)
 	 */
 	intel_display_power_get(i915, POWER_DOMAIN_GT_IRQ);
 
+	if (NEEDS_RC6_CTX_CORRUPTION_WA(i915))
+		intel_uncore_forcewake_get(i915, FORCEWAKE_ALL);
+
 	i915->gt.awake = true;
 	if (unlikely(++i915->gt.epoch == 0)) /* keep 0 as invalid */
 		i915->gt.epoch = 1;
diff --git a/sys/dev/pci/drm/i915/i915_reg.h b/sys/dev/pci/drm/i915/i915_reg.h
index ce8396cc16f..a6f4f32dd71 100644
--- a/sys/dev/pci/drm/i915/i915_reg.h
+++ b/sys/dev/pci/drm/i915/i915_reg.h
@@ -387,6 +387,8 @@ static inline bool i915_mmio_reg_valid(i915_reg_t reg)
 #define   ECOCHK_PPGTT_WT_HSW		(0x2 << 3)
 #define   ECOCHK_PPGTT_WB_HSW		(0x3 << 3)
 
+#define GEN8_RC6_CTX_INFO		_MMIO(0x8504)
+
 #define GAC_ECO_BITS			_MMIO(0x14090)
 #define   ECOBITS_SNB_BIT		(1 << 13)
 #define   ECOBITS_PPGTT_CACHE64B	(3 << 8)
diff --git a/sys/dev/pci/drm/i915/intel_drv.h b/sys/dev/pci/drm/i915/intel_drv.h
index d78e8c053c6..2d66298a251 100644
--- a/sys/dev/pci/drm/i915/intel_drv.h
+++ b/sys/dev/pci/drm/i915/intel_drv.h
@@ -2064,6 +2064,9 @@ void intel_sanitize_gt_powersave(struct drm_i915_private *dev_priv);
 void intel_enable_gt_powersave(struct drm_i915_private *dev_priv);
 void intel_disable_gt_powersave(struct drm_i915_private *dev_priv);
 void intel_suspend_gt_powersave(struct drm_i915_private *dev_priv);
+bool i915_rc6_ctx_wa_check(struct drm_i915_private *i915);
+void i915_rc6_ctx_wa_suspend(struct drm_i915_private *i915);
+void i915_rc6_ctx_wa_resume(struct drm_i915_private *i915);
 void gen6_rps_busy(struct drm_i915_private *dev_priv);
 void gen6_rps_reset_ei(struct drm_i915_private *dev_priv);
 void gen6_rps_idle(struct drm_i915_private *dev_priv);
diff --git a/sys/dev/pci/drm/i915/intel_pm.c b/sys/dev/pci/drm/i915/intel_pm.c
index 6544673cfce..a71d6038a3d 100644
--- a/sys/dev/pci/drm/i915/intel_pm.c
+++ b/sys/dev/pci/drm/i915/intel_pm.c
@@ -8209,6 +8209,95 @@ static void intel_init_emon(struct drm_i915_private *dev_priv)
 	dev_priv->ips.corr = (lcfuse & LCFUSE_HIV_MASK);
 }
 
+static bool i915_rc6_ctx_corrupted(struct drm_i915_private *dev_priv)
+{
+	return !I915_READ(GEN8_RC6_CTX_INFO);
+}
+
+static void i915_rc6_ctx_wa_init(struct drm_i915_private *i915)
+{
+	if (!NEEDS_RC6_CTX_CORRUPTION_WA(i915))
+		return;
+
+	if (i915_rc6_ctx_corrupted(i915)) {
+		DRM_INFO("RC6 context corrupted, disabling runtime power management\n");
+		i915->gt_pm.rc6.ctx_corrupted = true;
+		intel_runtime_pm_get(i915);
+	}
+}
+
+static void i915_rc6_ctx_wa_cleanup(struct drm_i915_private *i915)
+{
+	if (i915->gt_pm.rc6.ctx_corrupted) {
+		intel_runtime_pm_put(i915);
+		i915->gt_pm.rc6.ctx_corrupted = false;
+	}
+}
+
+/**
+ * i915_rc6_ctx_wa_suspend - system suspend sequence for the RC6 CTX WA
+ * @i915: i915 device
+ *
+ * Perform any steps needed to clean up the RC6 CTX WA before system suspend.
+ */
+void i915_rc6_ctx_wa_suspend(struct drm_i915_private *i915)
+{
+	if (i915->gt_pm.rc6.ctx_corrupted)
+		intel_runtime_pm_put(i915);
+}
+
+/**
+ * i915_rc6_ctx_wa_resume - system resume sequence for the RC6 CTX WA
+ * @i915: i915 device
+ *
+ * Perform any steps needed to re-init the RC6 CTX WA after system resume.
+ */
+void i915_rc6_ctx_wa_resume(struct drm_i915_private *i915)
+{
+	if (!i915->gt_pm.rc6.ctx_corrupted)
+		return;
+
+	if (i915_rc6_ctx_corrupted(i915)) {
+		intel_runtime_pm_get(i915);
+		return;
+	}
+
+	DRM_INFO("RC6 context restored, re-enabling runtime power management\n");
+	i915->gt_pm.rc6.ctx_corrupted = false;
+}
+
+static void intel_disable_rc6(struct drm_i915_private *dev_priv);
+
+/**
+ * i915_rc6_ctx_wa_check - check for a new RC6 CTX corruption
+ * @i915: i915 device
+ *
+ * Check if an RC6 CTX corruption has happened since the last check and if so
+ * disable RC6 and runtime power management.
+ *
+ * Return false if no context corruption has happened since the last call of
+ * this function, true otherwise.
+*/
+bool i915_rc6_ctx_wa_check(struct drm_i915_private *i915)
+{
+	if (!NEEDS_RC6_CTX_CORRUPTION_WA(i915))
+		return false;
+
+	if (i915->gt_pm.rc6.ctx_corrupted)
+		return false;
+
+	if (!i915_rc6_ctx_corrupted(i915))
+		return false;
+
+	DRM_NOTE("RC6 context corruption, disabling runtime power management\n");
+
+	intel_disable_rc6(i915);
+	i915->gt_pm.rc6.ctx_corrupted = true;
+	intel_runtime_pm_get_noresume(i915);
+
+	return true;
+}
+
 void intel_init_gt_powersave(struct drm_i915_private *dev_priv)
 {
 	struct intel_rps *rps = &dev_priv->gt_pm.rps;
@@ -8224,6 +8313,8 @@ void intel_init_gt_powersave(struct drm_i915_private *dev_priv)
 
 	mutex_lock(&dev_priv->pcu_lock);
 
+	i915_rc6_ctx_wa_init(dev_priv);
+
 	/* Initialize RPS limits (for userspace) */
 	if (IS_CHERRYVIEW(dev_priv))
 		cherryview_init_gt_powersave(dev_priv);
@@ -8270,6 +8361,8 @@ void intel_cleanup_gt_powersave(struct drm_i915_private *dev_priv)
 	if (IS_VALLEYVIEW(dev_priv))
 		valleyview_cleanup_gt_powersave(dev_priv);
 
+	i915_rc6_ctx_wa_cleanup(dev_priv);
+
 	if (!HAS_RC6(dev_priv))
 		intel_runtime_pm_put(dev_priv);
 }
@@ -8314,7 +8407,7 @@ static inline void intel_disable_llc_pstate(struct drm_i915_private *i915)
 	i915->gt_pm.llc_pstate.enabled = false;
 }
 
-static void intel_disable_rc6(struct drm_i915_private *dev_priv)
+static void __intel_disable_rc6(struct drm_i915_private *dev_priv)
 {
 	lockdep_assert_held(&dev_priv->pcu_lock);
 
@@ -8333,6 +8426,13 @@ static void intel_disable_rc6(struct drm_i915_private *dev_priv)
 	dev_priv->gt_pm.rc6.enabled = false;
 }
 
+static void intel_disable_rc6(struct drm_i915_private *dev_priv)
+{
+	mutex_lock(&dev_priv->pcu_lock);
+	__intel_disable_rc6(dev_priv);
+	mutex_unlock(&dev_priv->pcu_lock);
+}
+
 static void intel_disable_rps(struct drm_i915_private *dev_priv)
 {
 	lockdep_assert_held(&dev_priv->pcu_lock);
@@ -8358,7 +8458,7 @@ void intel_disable_gt_powersave(struct drm_i915_private *dev_priv)
 {
 	mutex_lock(&dev_priv->pcu_lock);
 
-	intel_disable_rc6(dev_priv);
+	__intel_disable_rc6(dev_priv);
 	intel_disable_rps(dev_priv);
 	if (HAS_LLC(dev_priv))
 		intel_disable_llc_pstate(dev_priv);
@@ -8385,6 +8485,9 @@ static void intel_enable_rc6(struct drm_i915_private *dev_priv)
 	if (dev_priv->gt_pm.rc6.enabled)
 		return;
 
+	if (dev_priv->gt_pm.rc6.ctx_corrupted)
+		return;
+
 	if (IS_CHERRYVIEW(dev_priv))
 		cherryview_enable_rc6(dev_priv);
 	else if (IS_VALLEYVIEW(dev_priv))