drm/i915: Switch over to gen3 irq code on gen2

The only real reason why we have the gen2 vs. gen3+ split
in irq handling is that bspec claims that IIR/IMR/IER/ISR
and EMR are only 16 bits on gen2, as opposed to being 32
bits on gen3+. That doesn't seem to be a meaningful
distinction as 32bit access to these registers works
perfectly fine on gen2

Interestingly the 16 msbs of IMR are in fact hardcoded
to 1 on gen2, which to me indicates that 32bit access
was the plan all along, and perhaps someone just forgot
to update the spec.

Nuke the special 16bit gen2 irq code and switch over to
the gen3 code.

Gen2 doesn't have the ASLE interrupt, which just needs
a small tweak in i915_irq_postinstall().

And so far we've not had a codepath that could enable the
legacy BLC interrupt on gen2. Now we do, but we'll never
actually do it since gen2 machines don't have OpRegion.
(and neither do i915/i945 machines btw). On these older
platforms the legacy BLC interrupt is meant to be used
in conjunction with the LBPC backlight stuff, but we
never actually switch off the legacy/combination mode
and thus don't use the interrupt either.

This was quickly smoke tested on all gen2 variants.

Signed-off-by: Ville Syrjälä <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
Reviewed-by: Jani Nikula <[email protected]>

3 files changed, 9 insertions, 197 deletions

diff --git a/drivers/gpu/drm/i915/display/intel_display_irq.c b/drivers/gpu/drm/i915/display/intel_display_irq.c
index ba82830c464e..8c548ee56c12 100644
--- a/drivers/gpu/drm/i915/display/intel_display_irq.c
+++ b/drivers/gpu/drm/i915/display/intel_display_irq.c
@@ -493,28 +493,10 @@ void i9xx_pipestat_irq_ack(struct drm_i915_private *dev_priv,
 	spin_unlock(&dev_priv->irq_lock);
 }
 
-void i8xx_pipestat_irq_handler(struct drm_i915_private *dev_priv,
-			       u16 iir, u32 pipe_stats[I915_MAX_PIPES])
-{
-	enum pipe pipe;
-
-	for_each_pipe(dev_priv, pipe) {
-		if (pipe_stats[pipe] & PIPE_VBLANK_INTERRUPT_STATUS)
-			intel_handle_vblank(dev_priv, pipe);
-
-		if (pipe_stats[pipe] & PIPE_CRC_DONE_INTERRUPT_STATUS)
-			i9xx_pipe_crc_irq_handler(dev_priv, pipe);
-
-		if (pipe_stats[pipe] & PIPE_FIFO_UNDERRUN_STATUS)
-			intel_cpu_fifo_underrun_irq_handler(dev_priv, pipe);
-	}
-}
-
 void i915_pipestat_irq_handler(struct drm_i915_private *dev_priv,
 			       u32 iir, u32 pipe_stats[I915_MAX_PIPES])
 {
 	struct intel_display *display = &dev_priv->display;
-
 	bool blc_event = false;
 	enum pipe pipe;
 
diff --git a/drivers/gpu/drm/i915/display/intel_display_irq.h b/drivers/gpu/drm/i915/display/intel_display_irq.h
index 093e356a2894..bf9d269d0e3f 100644
--- a/drivers/gpu/drm/i915/display/intel_display_irq.h
+++ b/drivers/gpu/drm/i915/display/intel_display_irq.h
@@ -75,7 +75,6 @@ void i9xx_pipestat_irq_ack(struct drm_i915_private *i915, u32 iir, u32 pipe_stat
 void i915_pipestat_irq_handler(struct drm_i915_private *i915, u32 iir, u32 pipe_stats[I915_MAX_PIPES]);
 void i965_pipestat_irq_handler(struct drm_i915_private *i915, u32 iir, u32 pipe_stats[I915_MAX_PIPES]);
 void valleyview_pipestat_irq_handler(struct drm_i915_private *i915, u32 pipe_stats[I915_MAX_PIPES]);
-void i8xx_pipestat_irq_handler(struct drm_i915_private *i915, u16 iir, u32 pipe_stats[I915_MAX_PIPES]);
 
 void intel_display_irq_init(struct drm_i915_private *i915);
 
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index fb8dbcfd8e87..ef1a60fc26fa 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -92,20 +92,6 @@ void gen3_irq_reset(struct intel_uncore *uncore, i915_reg_t imr,
 	intel_uncore_posting_read(uncore, iir);
 }
 
-static void gen2_irq_reset(struct intel_uncore *uncore)
-{
-	intel_uncore_write16(uncore, GEN2_IMR, 0xffff);
-	intel_uncore_posting_read16(uncore, GEN2_IMR);
-
-	intel_uncore_write16(uncore, GEN2_IER, 0);
-
-	/* IIR can theoretically queue up two events. Be paranoid. */
-	intel_uncore_write16(uncore, GEN2_IIR, 0xffff);
-	intel_uncore_posting_read16(uncore, GEN2_IIR);
-	intel_uncore_write16(uncore, GEN2_IIR, 0xffff);
-	intel_uncore_posting_read16(uncore, GEN2_IIR);
-}
-
 /*
  * We should clear IMR at preinstall/uninstall, and just check at postinstall.
  */
@@ -125,22 +111,6 @@ void gen3_assert_iir_is_zero(struct intel_uncore *uncore, i915_reg_t reg)
 	intel_uncore_posting_read(uncore, reg);
 }
 
-static void gen2_assert_iir_is_zero(struct intel_uncore *uncore)
-{
-	u16 val = intel_uncore_read16(uncore, GEN2_IIR);
-
-	if (val == 0)
-		return;
-
-	drm_WARN(&uncore->i915->drm, 1,
-		 "Interrupt register 0x%x is not zero: 0x%08x\n",
-		 i915_mmio_reg_offset(GEN2_IIR), val);
-	intel_uncore_write16(uncore, GEN2_IIR, 0xffff);
-	intel_uncore_posting_read16(uncore, GEN2_IIR);
-	intel_uncore_write16(uncore, GEN2_IIR, 0xffff);
-	intel_uncore_posting_read16(uncore, GEN2_IIR);
-}
-
 void gen3_irq_init(struct intel_uncore *uncore,
 		   i915_reg_t imr, u32 imr_val,
 		   i915_reg_t ier, u32 ier_val,
@@ -153,16 +123,6 @@ void gen3_irq_init(struct intel_uncore *uncore,
 	intel_uncore_posting_read(uncore, imr);
 }
 
-static void gen2_irq_init(struct intel_uncore *uncore,
-			  u32 imr_val, u32 ier_val)
-{
-	gen2_assert_iir_is_zero(uncore);
-
-	intel_uncore_write16(uncore, GEN2_IER, ier_val);
-	intel_uncore_write16(uncore, GEN2_IMR, imr_val);
-	intel_uncore_posting_read16(uncore, GEN2_IMR);
-}
-
 /**
  * ivb_parity_work - Workqueue called when a parity error interrupt
  * occurred.
@@ -845,16 +805,6 @@ static void cherryview_irq_postinstall(struct drm_i915_private *dev_priv)
 	intel_uncore_posting_read(&dev_priv->uncore, GEN8_MASTER_IRQ);
 }
 
-static void i8xx_irq_reset(struct drm_i915_private *dev_priv)
-{
-	struct intel_uncore *uncore = &dev_priv->uncore;
-
-	i9xx_display_irq_reset(dev_priv);
-
-	gen2_irq_reset(uncore);
-	dev_priv->irq_mask = ~0u;
-}
-
 static u32 i9xx_error_mask(struct drm_i915_private *i915)
 {
 	/*
@@ -876,75 +826,6 @@ static u32 i9xx_error_mask(struct drm_i915_private *i915)
 			 I915_ERROR_MEMORY_REFRESH);
 }
 
-static void i8xx_irq_postinstall(struct drm_i915_private *dev_priv)
-{
-	struct intel_uncore *uncore = &dev_priv->uncore;
-	u16 enable_mask;
-
-	intel_uncore_write16(uncore, EMR, i9xx_error_mask(dev_priv));
-
-	dev_priv->irq_mask =
-		~(I915_DISPLAY_PIPE_A_EVENT_INTERRUPT |
-		  I915_DISPLAY_PIPE_B_EVENT_INTERRUPT |
-		  I915_MASTER_ERROR_INTERRUPT);
-
-	enable_mask =
-		I915_DISPLAY_PIPE_A_EVENT_INTERRUPT |
-		I915_DISPLAY_PIPE_B_EVENT_INTERRUPT |
-		I915_MASTER_ERROR_INTERRUPT |
-		I915_USER_INTERRUPT;
-
-	gen2_irq_init(uncore, dev_priv->irq_mask, enable_mask);
-
-	/* Interrupt setup is already guaranteed to be single-threaded, this is
-	 * just to make the assert_spin_locked check happy. */
-	spin_lock_irq(&dev_priv->irq_lock);
-	i915_enable_pipestat(dev_priv, PIPE_A, PIPE_CRC_DONE_INTERRUPT_STATUS);
-	i915_enable_pipestat(dev_priv, PIPE_B, PIPE_CRC_DONE_INTERRUPT_STATUS);
-	spin_unlock_irq(&dev_priv->irq_lock);
-}
-
-static void i8xx_error_irq_ack(struct drm_i915_private *i915,
-			       u16 *eir, u16 *eir_stuck)
-{
-	struct intel_uncore *uncore = &i915->uncore;
-	u16 emr;
-
-	*eir = intel_uncore_read16(uncore, EIR);
-	intel_uncore_write16(uncore, EIR, *eir);
-
-	*eir_stuck = intel_uncore_read16(uncore, EIR);
-	if (*eir_stuck == 0)
-		return;
-
-	/*
-	 * Toggle all EMR bits to make sure we get an edge
-	 * in the ISR master error bit if we don't clear
-	 * all the EIR bits. Otherwise the edge triggered
-	 * IIR on i965/g4x wouldn't notice that an interrupt
-	 * is still pending. Also some EIR bits can't be
-	 * cleared except by handling the underlying error
-	 * (or by a GPU reset) so we mask any bit that
-	 * remains set.
-	 */
-	emr = intel_uncore_read16(uncore, EMR);
-	intel_uncore_write16(uncore, EMR, 0xffff);
-	intel_uncore_write16(uncore, EMR, emr | *eir_stuck);
-}
-
-static void i8xx_error_irq_handler(struct drm_i915_private *dev_priv,
-				   u16 eir, u16 eir_stuck)
-{
-	drm_dbg(&dev_priv->drm, "Master Error: EIR 0x%04x\n", eir);
-
-	if (eir_stuck)
-		drm_dbg(&dev_priv->drm, "EIR stuck: 0x%04x, masked\n",
-			eir_stuck);
-
-	drm_dbg(&dev_priv->drm, "PGTBL_ER: 0x%08x\n",
-		intel_uncore_read(&dev_priv->uncore, PGTBL_ER));
-}
-
 static void i9xx_error_irq_ack(struct drm_i915_private *dev_priv,
 			       u32 *eir, u32 *eir_stuck)
 {
@@ -985,53 +866,6 @@ static void i9xx_error_irq_handler(struct drm_i915_private *dev_priv,
 		intel_uncore_read(&dev_priv->uncore, PGTBL_ER));
 }
 
-static irqreturn_t i8xx_irq_handler(int irq, void *arg)
-{
-	struct drm_i915_private *dev_priv = arg;
-	irqreturn_t ret = IRQ_NONE;
-
-	if (!intel_irqs_enabled(dev_priv))
-		return IRQ_NONE;
-
-	/* IRQs are synced during runtime_suspend, we don't require a wakeref */
-	disable_rpm_wakeref_asserts(&dev_priv->runtime_pm);
-
-	do {
-		u32 pipe_stats[I915_MAX_PIPES] = {};
-		u16 eir = 0, eir_stuck = 0;
-		u16 iir;
-
-		iir = intel_uncore_read16(&dev_priv->uncore, GEN2_IIR);
-		if (iir == 0)
-			break;
-
-		ret = IRQ_HANDLED;
-
-		/* Call regardless, as some status bits might not be
-		 * signalled in IIR */
-		i9xx_pipestat_irq_ack(dev_priv, iir, pipe_stats);
-
-		if (iir & I915_MASTER_ERROR_INTERRUPT)
-			i8xx_error_irq_ack(dev_priv, &eir, &eir_stuck);
-
-		intel_uncore_write16(&dev_priv->uncore, GEN2_IIR, iir);
-
-		if (iir & I915_USER_INTERRUPT)
-			intel_engine_cs_irq(to_gt(dev_priv)->engine[RCS0], iir);
-
-		if (iir & I915_MASTER_ERROR_INTERRUPT)
-			i8xx_error_irq_handler(dev_priv, eir, eir_stuck);
-
-		i8xx_pipestat_irq_handler(dev_priv, iir, pipe_stats);
-	} while (0);
-
-	pmu_irq_stats(dev_priv, ret);
-
-	enable_rpm_wakeref_asserts(&dev_priv->runtime_pm);
-
-	return ret;
-}
-
 static void i915_irq_reset(struct drm_i915_private *dev_priv)
 {
 	struct intel_uncore *uncore = &dev_priv->uncore;
@@ -1050,18 +884,21 @@ static void i915_irq_postinstall(struct drm_i915_private *dev_priv)
 	intel_uncore_write(uncore, EMR, i9xx_error_mask(dev_priv));
 
 	dev_priv->irq_mask =
-		~(I915_ASLE_INTERRUPT |
-		  I915_DISPLAY_PIPE_A_EVENT_INTERRUPT |
+		~(I915_DISPLAY_PIPE_A_EVENT_INTERRUPT |
 		  I915_DISPLAY_PIPE_B_EVENT_INTERRUPT |
 		  I915_MASTER_ERROR_INTERRUPT);
 
 	enable_mask =
-		I915_ASLE_INTERRUPT |
 		I915_DISPLAY_PIPE_A_EVENT_INTERRUPT |
 		I915_DISPLAY_PIPE_B_EVENT_INTERRUPT |
 		I915_MASTER_ERROR_INTERRUPT |
 		I915_USER_INTERRUPT;
 
+	if (DISPLAY_VER(dev_priv) >= 3) {
+		dev_priv->irq_mask &= ~I915_ASLE_INTERRUPT;
+		enable_mask |= I915_ASLE_INTERRUPT;
+	}
+
 	if (I915_HAS_HOTPLUG(dev_priv)) {
 		dev_priv->irq_mask &= ~I915_DISPLAY_PORT_INTERRUPT;
 		enable_mask |= I915_DISPLAY_PORT_INTERRUPT;
@@ -1303,10 +1140,8 @@ static irq_handler_t intel_irq_handler(struct drm_i915_private *dev_priv)
 			return valleyview_irq_handler;
 		else if (GRAPHICS_VER(dev_priv) == 4)
 			return i965_irq_handler;
-		else if (GRAPHICS_VER(dev_priv) == 3)
-			return i915_irq_handler;
 		else
-			return i8xx_irq_handler;
+			return i915_irq_handler;
 	} else {
 		if (GRAPHICS_VER_FULL(dev_priv) >= IP_VER(12, 10))
 			return dg1_irq_handler;
@@ -1328,10 +1163,8 @@ static void intel_irq_reset(struct drm_i915_private *dev_priv)
 			valleyview_irq_reset(dev_priv);
 		else if (GRAPHICS_VER(dev_priv) == 4)
 			i965_irq_reset(dev_priv);
-		else if (GRAPHICS_VER(dev_priv) == 3)
-			i915_irq_reset(dev_priv);
 		else
-			i8xx_irq_reset(dev_priv);
+			i915_irq_reset(dev_priv);
 	} else {
 		if (GRAPHICS_VER_FULL(dev_priv) >= IP_VER(12, 10))
 			dg1_irq_reset(dev_priv);
@@ -1353,10 +1186,8 @@ static void intel_irq_postinstall(struct drm_i915_private *dev_priv)
 			valleyview_irq_postinstall(dev_priv);
 		else if (GRAPHICS_VER(dev_priv) == 4)
 			i965_irq_postinstall(dev_priv);
-		else if (GRAPHICS_VER(dev_priv) == 3)
-			i915_irq_postinstall(dev_priv);
 		else
-			i8xx_irq_postinstall(dev_priv);
+			i915_irq_postinstall(dev_priv);
 	} else {
 		if (GRAPHICS_VER_FULL(dev_priv) >= IP_VER(12, 10))
 			dg1_irq_postinstall(dev_priv);