drm/i915: Use Engine1 instance for gen11 pm interrupts

With gen11 the interrupt registers are shared between 2 engines,
with Engine1 instance being upper word and Engine0 instance being
lower. Annoyingly gen11 selected the pm interrupts to be in the
Engine1 instance.

Rectify the situation by shifting the access accordingly,
based on gen.

v2: comments, warn on overzealous rps_events

Bugzilla: https://bugzilla.freedesktop.org/show_bug.cgi?id=108059
Testcase: igt/i915_pm_rps@min-max-config-loaded
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190410105923.18546-6-mika.kuoppala@linux.intel.com

drivers/gpu/drm/i915/i915_irq.c

@@ -369,24 +369,41 @@ static i915_reg_t gen6_pm_iir(struct drm_i915_private *dev_priv)
 	return INTEL_GEN(dev_priv) >= 8 ? GEN8_GT_IIR(2) : GEN6_PMIIR;
 }
 
-static i915_reg_t gen6_pm_imr(struct drm_i915_private *dev_priv)
+static void write_pm_imr(struct drm_i915_private *dev_priv)
 {
-	if (INTEL_GEN(dev_priv) >= 11)
-		return GEN11_GPM_WGBOXPERF_INTR_MASK;
-	else if (INTEL_GEN(dev_priv) >= 8)
-		return GEN8_GT_IMR(2);
-	else
-		return GEN6_PMIMR;
+	i915_reg_t reg;
+	u32 mask = dev_priv->pm_imr;
+
+	if (INTEL_GEN(dev_priv) >= 11) {
+		reg = GEN11_GPM_WGBOXPERF_INTR_MASK;
+		/* pm is in upper half */
+		mask = mask << 16;
+	} else if (INTEL_GEN(dev_priv) >= 8) {
+		reg = GEN8_GT_IMR(2);
+	} else {
+		reg = GEN6_PMIMR;
+	}
+
+	I915_WRITE(reg, mask);
+	POSTING_READ(reg);
 }
 
-static i915_reg_t gen6_pm_ier(struct drm_i915_private *dev_priv)
+static void write_pm_ier(struct drm_i915_private *dev_priv)
 {
-	if (INTEL_GEN(dev_priv) >= 11)
-		return GEN11_GPM_WGBOXPERF_INTR_ENABLE;
-	else if (INTEL_GEN(dev_priv) >= 8)
-		return GEN8_GT_IER(2);
-	else
-		return GEN6_PMIER;
+	i915_reg_t reg;
+	u32 mask = dev_priv->pm_ier;
+
+	if (INTEL_GEN(dev_priv) >= 11) {
+		reg = GEN11_GPM_WGBOXPERF_INTR_ENABLE;
+		/* pm is in upper half */
+		mask = mask << 16;
+	} else if (INTEL_GEN(dev_priv) >= 8) {
+		reg = GEN8_GT_IER(2);
+	} else {
+		reg = GEN6_PMIER;
+	}
+
+	I915_WRITE(reg, mask);
 }
 
 /**
@@ -411,8 +428,7 @@ static void snb_update_pm_irq(struct drm_i915_private *dev_priv,
 
 	if (new_val != dev_priv->pm_imr) {
 		dev_priv->pm_imr = new_val;
-		I915_WRITE(gen6_pm_imr(dev_priv), dev_priv->pm_imr);
-		POSTING_READ(gen6_pm_imr(dev_priv));
+		write_pm_imr(dev_priv);
 	}
 }
 
@@ -453,7 +469,7 @@ static void gen6_enable_pm_irq(struct drm_i915_private *dev_priv, u32 enable_mas
 	lockdep_assert_held(&dev_priv->irq_lock);
 
 	dev_priv->pm_ier |= enable_mask;
-	I915_WRITE(gen6_pm_ier(dev_priv), dev_priv->pm_ier);
+	write_pm_ier(dev_priv);
 	gen6_unmask_pm_irq(dev_priv, enable_mask);
 	/* unmask_pm_irq provides an implicit barrier (POSTING_READ) */
 }
@@ -464,7 +480,7 @@ static void gen6_disable_pm_irq(struct drm_i915_private *dev_priv, u32 disable_m
 
 	dev_priv->pm_ier &= ~disable_mask;
 	__gen6_mask_pm_irq(dev_priv, disable_mask);
-	I915_WRITE(gen6_pm_ier(dev_priv), dev_priv->pm_ier);
+	write_pm_ier(dev_priv);
 	/* though a barrier is missing here, but don't really need a one */
 }
 
@@ -4639,6 +4655,10 @@ void intel_irq_init(struct drm_i915_private *dev_priv)
 					   GEN6_PM_RP_DOWN_THRESHOLD |
 					   GEN6_PM_RP_DOWN_TIMEOUT);
 
+	/* We share the register with other engine */
+	if (INTEL_GEN(dev_priv) > 9)
+		GEM_WARN_ON(dev_priv->pm_rps_events & 0xffff0000);
+
 	rps->pm_intrmsk_mbz = 0;
 
 	/*

drivers/gpu/drm/i915/i915_reg.h

@@ -8704,6 +8704,11 @@ enum {
 #define GEN6_PMIER				_MMIO(0x4402C)
 #define  GEN6_PM_MBOX_EVENT			(1 << 25)
 #define  GEN6_PM_THERMAL_EVENT			(1 << 24)
+
+/*
+ * For Gen11 these are in the upper word of the GPM_WGBOXPERF
+ * registers. Shifting is handled on accessing the imr and ier.
+ */
 #define  GEN6_PM_RP_DOWN_TIMEOUT		(1 << 6)
 #define  GEN6_PM_RP_UP_THRESHOLD		(1 << 5)
 #define  GEN6_PM_RP_DOWN_THRESHOLD		(1 << 4)