drm/i915: Break out common code from gen8_gt_irq_handler

Break out common code from gen8_gt_irq_handler and put it in to
an always inlined function. gcc optimises out the shift at compile
time. (Thomas Daniel/Daniel Vetter/Chris Wilson)

Issue: VIZ-4277
Signed-off-by: Nick Hoath <nicholas.hoath@intel.com>
Cc: Thomas Daniel <thomas.daniel@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1445333036-22164-3-git-send-email-nicholas.hoath@intel.com
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_irq.c

@@ -1290,6 +1290,16 @@ static void snb_gt_irq_handler(struct drm_device *dev,
 		ivybridge_parity_error_irq_handler(dev, gt_iir);
 }
 
+static __always_inline void
+		gen8_cs_irq_handler(struct intel_engine_cs *ring, u32 iir,
+				    int test_shift)
+{
+	if (iir & (GT_RENDER_USER_INTERRUPT << test_shift))
+		notify_ring(ring);
+	if (iir & (GT_CONTEXT_SWITCH_INTERRUPT << test_shift))
+		intel_lrc_irq_handler(ring);
+}
+
 static irqreturn_t gen8_gt_irq_handler(struct drm_i915_private *dev_priv,
 				       u32 master_ctl)
 {
@@ -1301,15 +1311,11 @@ static irqreturn_t gen8_gt_irq_handler(struct drm_i915_private *dev_priv,
 			I915_WRITE_FW(GEN8_GT_IIR(0), iir);
 			ret = IRQ_HANDLED;
 
-			if (iir & (GT_CONTEXT_SWITCH_INTERRUPT << GEN8_RCS_IRQ_SHIFT))
-				intel_lrc_irq_handler(&dev_priv->ring[RCS]);
-			if (iir & (GT_RENDER_USER_INTERRUPT << GEN8_RCS_IRQ_SHIFT))
-				notify_ring(&dev_priv->ring[RCS]);
+			gen8_cs_irq_handler(&dev_priv->ring[RCS],
+					iir, GEN8_RCS_IRQ_SHIFT);
 
-			if (iir & (GT_CONTEXT_SWITCH_INTERRUPT << GEN8_BCS_IRQ_SHIFT))
-				intel_lrc_irq_handler(&dev_priv->ring[BCS]);
-			if (iir & (GT_RENDER_USER_INTERRUPT << GEN8_BCS_IRQ_SHIFT))
-				notify_ring(&dev_priv->ring[BCS]);
+			gen8_cs_irq_handler(&dev_priv->ring[BCS],
+					iir, GEN8_BCS_IRQ_SHIFT);
 		} else
 			DRM_ERROR("The master control interrupt lied (GT0)!\n");
 	}
@@ -1320,15 +1326,11 @@ static irqreturn_t gen8_gt_irq_handler(struct drm_i915_private *dev_priv,
 			I915_WRITE_FW(GEN8_GT_IIR(1), iir);
 			ret = IRQ_HANDLED;
 
-			if (iir & (GT_CONTEXT_SWITCH_INTERRUPT << GEN8_VCS1_IRQ_SHIFT))
-				intel_lrc_irq_handler(&dev_priv->ring[VCS]);
-			if (iir & (GT_RENDER_USER_INTERRUPT << GEN8_VCS1_IRQ_SHIFT))
-				notify_ring(&dev_priv->ring[VCS]);
+			gen8_cs_irq_handler(&dev_priv->ring[VCS],
+					iir, GEN8_VCS1_IRQ_SHIFT);
 
-			if (iir & (GT_CONTEXT_SWITCH_INTERRUPT << GEN8_VCS2_IRQ_SHIFT))
-				intel_lrc_irq_handler(&dev_priv->ring[VCS2]);
-			if (iir & (GT_RENDER_USER_INTERRUPT << GEN8_VCS2_IRQ_SHIFT))
-				notify_ring(&dev_priv->ring[VCS2]);
+			gen8_cs_irq_handler(&dev_priv->ring[VCS2],
+					iir, GEN8_VCS2_IRQ_SHIFT);
 		} else
 			DRM_ERROR("The master control interrupt lied (GT1)!\n");
 	}
@@ -1339,10 +1341,8 @@ static irqreturn_t gen8_gt_irq_handler(struct drm_i915_private *dev_priv,
 			I915_WRITE_FW(GEN8_GT_IIR(3), iir);
 			ret = IRQ_HANDLED;
 
-			if (iir & (GT_CONTEXT_SWITCH_INTERRUPT << GEN8_VECS_IRQ_SHIFT))
-				intel_lrc_irq_handler(&dev_priv->ring[VECS]);
-			if (iir & (GT_RENDER_USER_INTERRUPT << GEN8_VECS_IRQ_SHIFT))
-				notify_ring(&dev_priv->ring[VECS]);
+			gen8_cs_irq_handler(&dev_priv->ring[VECS],
+					iir, GEN8_VECS_IRQ_SHIFT);
 		} else
 			DRM_ERROR("The master control interrupt lied (GT3)!\n");
 	}