drm/i915/gt: Reorganise gen8+ interrupt handler

We always use a deferred bottom-half (either tasklet or irq_work) for
processing the response to an interrupt which means we can recombine the
GT irq ack+handler into one. This simplicity is important in later
patches as we will need to handle and then ack multiple interrupt levels
before acking the GT and master interrupts.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200127231540.3302516-2-chris@chris-wilson.co.uk

3 files changed, 35 insertions, 52 deletions

diff --git a/drivers/gpu/drm/i915/gt/intel_gt_irq.c b/drivers/gpu/drm/i915/gt/intel_gt_irq.c
index f796bdf1ed30..71873a4cafc0 100644
--- a/drivers/gpu/drm/i915/gt/intel_gt_irq.c
+++ b/drivers/gpu/drm/i915/gt/intel_gt_irq.c
@@ -286,59 +286,49 @@ void gen6_gt_irq_handler(struct intel_gt *gt, u32 gt_iir)
 		gen7_parity_error_irq_handler(gt, gt_iir);
 }
 
-void gen8_gt_irq_ack(struct intel_gt *gt, u32 master_ctl, u32 gt_iir[4])
+void gen8_gt_irq_handler(struct intel_gt *gt, u32 master_ctl)
 {
 	void __iomem * const regs = gt->uncore->regs;
+	u32 iir;
 
 	if (master_ctl & (GEN8_GT_RCS_IRQ | GEN8_GT_BCS_IRQ)) {
-		gt_iir[0] = raw_reg_read(regs, GEN8_GT_IIR(0));
-		if (likely(gt_iir[0]))
-			raw_reg_write(regs, GEN8_GT_IIR(0), gt_iir[0]);
-	}
-
-	if (master_ctl & (GEN8_GT_VCS0_IRQ | GEN8_GT_VCS1_IRQ)) {
-		gt_iir[1] = raw_reg_read(regs, GEN8_GT_IIR(1));
-		if (likely(gt_iir[1]))
-			raw_reg_write(regs, GEN8_GT_IIR(1), gt_iir[1]);
-	}
-
-	if (master_ctl & (GEN8_GT_PM_IRQ | GEN8_GT_GUC_IRQ)) {
-		gt_iir[2] = raw_reg_read(regs, GEN8_GT_IIR(2));
-		if (likely(gt_iir[2]))
-			raw_reg_write(regs, GEN8_GT_IIR(2), gt_iir[2]);
-	}
-
-	if (master_ctl & GEN8_GT_VECS_IRQ) {
-		gt_iir[3] = raw_reg_read(regs, GEN8_GT_IIR(3));
-		if (likely(gt_iir[3]))
-			raw_reg_write(regs, GEN8_GT_IIR(3), gt_iir[3]);
-	}
-}
-
-void gen8_gt_irq_handler(struct intel_gt *gt, u32 master_ctl, u32 gt_iir[4])
-{
-	if (master_ctl & (GEN8_GT_RCS_IRQ | GEN8_GT_BCS_IRQ)) {
-		cs_irq_handler(gt->engine_class[RENDER_CLASS][0],
-			       gt_iir[0] >> GEN8_RCS_IRQ_SHIFT);
-		cs_irq_handler(gt->engine_class[COPY_ENGINE_CLASS][0],
-			       gt_iir[0] >> GEN8_BCS_IRQ_SHIFT);
+		iir = raw_reg_read(regs, GEN8_GT_IIR(0));
+		if (likely(iir)) {
+			cs_irq_handler(gt->engine_class[RENDER_CLASS][0],
+				       iir >> GEN8_RCS_IRQ_SHIFT);
+			cs_irq_handler(gt->engine_class[COPY_ENGINE_CLASS][0],
+				       iir >> GEN8_BCS_IRQ_SHIFT);
+			raw_reg_write(regs, GEN8_GT_IIR(0), iir);
+		}
 	}
 
 	if (master_ctl & (GEN8_GT_VCS0_IRQ | GEN8_GT_VCS1_IRQ)) {
-		cs_irq_handler(gt->engine_class[VIDEO_DECODE_CLASS][0],
-			       gt_iir[1] >> GEN8_VCS0_IRQ_SHIFT);
-		cs_irq_handler(gt->engine_class[VIDEO_DECODE_CLASS][1],
-			       gt_iir[1] >> GEN8_VCS1_IRQ_SHIFT);
+		iir = raw_reg_read(regs, GEN8_GT_IIR(1));
+		if (likely(iir)) {
+			cs_irq_handler(gt->engine_class[VIDEO_DECODE_CLASS][0],
+				       iir >> GEN8_VCS0_IRQ_SHIFT);
+			cs_irq_handler(gt->engine_class[VIDEO_DECODE_CLASS][1],
+				       iir >> GEN8_VCS1_IRQ_SHIFT);
+			raw_reg_write(regs, GEN8_GT_IIR(1), iir);
+		}
 	}
 
 	if (master_ctl & GEN8_GT_VECS_IRQ) {
-		cs_irq_handler(gt->engine_class[VIDEO_ENHANCEMENT_CLASS][0],
-			       gt_iir[3] >> GEN8_VECS_IRQ_SHIFT);
+		iir = raw_reg_read(regs, GEN8_GT_IIR(3));
+		if (likely(iir)) {
+			cs_irq_handler(gt->engine_class[VIDEO_ENHANCEMENT_CLASS][0],
+				       iir >> GEN8_VECS_IRQ_SHIFT);
+			raw_reg_write(regs, GEN8_GT_IIR(3), iir);
+		}
 	}
 
 	if (master_ctl & (GEN8_GT_PM_IRQ | GEN8_GT_GUC_IRQ)) {
-		gen6_rps_irq_handler(&gt->rps, gt_iir[2]);
-		guc_irq_handler(&gt->uc.guc, gt_iir[2] >> 16);
+		iir = raw_reg_read(regs, GEN8_GT_IIR(2));
+		if (likely(iir)) {
+			gen6_rps_irq_handler(&gt->rps, iir);
+			guc_irq_handler(&gt->uc.guc, iir >> 16);
+			raw_reg_write(regs, GEN8_GT_IIR(2), iir);
+		}
 	}
 }
 
diff --git a/drivers/gpu/drm/i915/gt/intel_gt_irq.h b/drivers/gpu/drm/i915/gt/intel_gt_irq.h
index 8f37593712c9..886c5cf408a2 100644
--- a/drivers/gpu/drm/i915/gt/intel_gt_irq.h
+++ b/drivers/gpu/drm/i915/gt/intel_gt_irq.h
@@ -36,9 +36,8 @@ void gen5_gt_enable_irq(struct intel_gt *gt, u32 mask);
 
 void gen6_gt_irq_handler(struct intel_gt *gt, u32 gt_iir);
 
-void gen8_gt_irq_ack(struct intel_gt *gt, u32 master_ctl, u32 gt_iir[4]);
+void gen8_gt_irq_handler(struct intel_gt *gt, u32 master_ctl);
 void gen8_gt_irq_reset(struct intel_gt *gt);
-void gen8_gt_irq_handler(struct intel_gt *gt, u32 master_ctl, u32 gt_iir[4]);
 void gen8_gt_irq_postinstall(struct intel_gt *gt);
 
 #endif /* INTEL_GT_IRQ_H */
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 87a6662abc1b..5c2b419c0603 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -1614,7 +1614,6 @@ static irqreturn_t cherryview_irq_handler(int irq, void *arg)
 		u32 master_ctl, iir;
 		u32 pipe_stats[I915_MAX_PIPES] = {};
 		u32 hotplug_status = 0;
-		u32 gt_iir[4];
 		u32 ier = 0;
 
 		master_ctl = I915_READ(GEN8_MASTER_IRQ) & ~GEN8_MASTER_IRQ_CONTROL;
@@ -1642,7 +1641,7 @@ static irqreturn_t cherryview_irq_handler(int irq, void *arg)
 		ier = I915_READ(VLV_IER);
 		I915_WRITE(VLV_IER, 0);
 
-		gen8_gt_irq_ack(&dev_priv->gt, master_ctl, gt_iir);
+		gen8_gt_irq_handler(&dev_priv->gt, master_ctl);
 
 		if (iir & I915_DISPLAY_PORT_INTERRUPT)
 			hotplug_status = i9xx_hpd_irq_ack(dev_priv);
@@ -1666,8 +1665,6 @@ static irqreturn_t cherryview_irq_handler(int irq, void *arg)
 		I915_WRITE(VLV_IER, ier);
 		I915_WRITE(GEN8_MASTER_IRQ, GEN8_MASTER_IRQ_CONTROL);
 
-		gen8_gt_irq_handler(&dev_priv->gt, master_ctl, gt_iir);
-
 		if (hotplug_status)
 			i9xx_hpd_irq_handler(dev_priv, hotplug_status);
 
@@ -2396,7 +2393,6 @@ static irqreturn_t gen8_irq_handler(int irq, void *arg)
 	struct drm_i915_private *dev_priv = arg;
 	void __iomem * const regs = dev_priv->uncore.regs;
 	u32 master_ctl;
-	u32 gt_iir[4];
 
 	if (!intel_irqs_enabled(dev_priv))
 		return IRQ_NONE;
@@ -2407,8 +2403,8 @@ static irqreturn_t gen8_irq_handler(int irq, void *arg)
 		return IRQ_NONE;
 	}
 
-	/* Find, clear, then process each source of interrupt */
-	gen8_gt_irq_ack(&dev_priv->gt, master_ctl, gt_iir);
+	/* Find, queue (onto bottom-halves), then clear each source */
+	gen8_gt_irq_handler(&dev_priv->gt, master_ctl);
 
 	/* IRQs are synced during runtime_suspend, we don't require a wakeref */
 	if (master_ctl & ~GEN8_GT_IRQS) {
@@ -2419,8 +2415,6 @@ static irqreturn_t gen8_irq_handler(int irq, void *arg)
 
 	gen8_master_intr_enable(regs);
 
-	gen8_gt_irq_handler(&dev_priv->gt, master_ctl, gt_iir);
-
 	return IRQ_HANDLED;
 }
 
@@ -2503,7 +2497,7 @@ __gen11_irq_handler(struct drm_i915_private * const i915,
 		return IRQ_NONE;
 	}
 
-	/* Find, clear, then process each source of interrupt. */
+	/* Find, queue (onto bottom-halves), then clear each source */
 	gen11_gt_irq_handler(gt, master_ctl);
 
 	/* IRQs are synced during runtime_suspend, we don't require a wakeref */