drm/i915/bdw: Implement a basic PM interrupt handler

Almost all of it is reusable from the existing code. The primary
difference is we need to do even less in the interrupt handler, since
interrupts are not shared in the same way.

The patch is mostly a copy-paste of the existing snb+ code, with updates
to the relevant parts requiring changes to the interrupt handling. As
such it /should/ be relatively trivial. It's highly likely that I missed
some places where I need a gen8 version of the PM interrupts, but it has
become invisible to me by now.

This patch could probably be split into adding the new functions,
followed by actually handling the interrupts. Since the code is
currently disabled (and broken) I think the patch stands better by
itself.

v2: Move the commit about not touching the ringbuffer interrupt to the
snb_* function where it belongs (Rodrigo)

v3: Rebased on Paulo's runtime PM changes

v4: Not well validated, but rebase on
commit 730488b2eddded4497f63f70867b1256cd9e117c
Author: Paulo Zanoni <paulo.r.zanoni@intel.com>
Date:   Fri Mar 7 20:12:32 2014 -0300

    drm/i915: kill dev_priv->pm.regsave

v5: Rebased on latest code base. (Deepak)

v6: Remove conflict markers, Unnecessary empty line and use right
IIR interrupt (Ville)

v7: mask modified without rmw (Ville Syrjälä)

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Deepak S <deepak.s@linux.intel.com>
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 72 insertions, 2 deletions

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index b10fbde1d5ee..4a88fdefc570 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -248,6 +248,46 @@ static bool ivb_can_enable_err_int(struct drm_device *dev)
 	return true;
 }
 
+/**
+  * bdw_update_pm_irq - update GT interrupt 2
+  * @dev_priv: driver private
+  * @interrupt_mask: mask of interrupt bits to update
+  * @enabled_irq_mask: mask of interrupt bits to enable
+  *
+  * Copied from the snb function, updated with relevant register offsets
+  */
+static void bdw_update_pm_irq(struct drm_i915_private *dev_priv,
+			      uint32_t interrupt_mask,
+			      uint32_t enabled_irq_mask)
+{
+	uint32_t new_val;
+
+	assert_spin_locked(&dev_priv->irq_lock);
+
+	if (WARN_ON(dev_priv->pm.irqs_disabled))
+		return;
+
+	new_val = dev_priv->pm_irq_mask;
+	new_val &= ~interrupt_mask;
+	new_val |= (~enabled_irq_mask & interrupt_mask);
+
+	if (new_val != dev_priv->pm_irq_mask) {
+		dev_priv->pm_irq_mask = new_val;
+		I915_WRITE(GEN8_GT_IMR(2), dev_priv->pm_irq_mask);
+		POSTING_READ(GEN8_GT_IMR(2));
+	}
+}
+
+void bdw_enable_pm_irq(struct drm_i915_private *dev_priv, uint32_t mask)
+{
+	bdw_update_pm_irq(dev_priv, mask, mask);
+}
+
+void bdw_disable_pm_irq(struct drm_i915_private *dev_priv, uint32_t mask)
+{
+	bdw_update_pm_irq(dev_priv, mask, 0);
+}
+
 static bool cpt_can_enable_serr_int(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
@@ -1098,8 +1138,12 @@ static void gen6_pm_rps_work(struct work_struct *work)
 	spin_lock_irq(&dev_priv->irq_lock);
 	pm_iir = dev_priv->rps.pm_iir;
 	dev_priv->rps.pm_iir = 0;
-	/* Make sure not to corrupt PMIMR state used by ringbuffer code */
-	snb_enable_pm_irq(dev_priv, dev_priv->pm_rps_events);
+	if (IS_BROADWELL(dev_priv->dev))
+		bdw_enable_pm_irq(dev_priv, dev_priv->pm_rps_events);
+	else {
+		/* Make sure not to corrupt PMIMR state used by ringbuffer */
+		snb_enable_pm_irq(dev_priv, dev_priv->pm_rps_events);
+	}
 	spin_unlock_irq(&dev_priv->irq_lock);
 
 	/* Make sure we didn't queue anything we're not going to process. */
@@ -1296,6 +1340,19 @@ static void snb_gt_irq_handler(struct drm_device *dev,
 		ivybridge_parity_error_irq_handler(dev, gt_iir);
 }
 
+static void gen8_rps_irq_handler(struct drm_i915_private *dev_priv, u32 pm_iir)
+{
+	if ((pm_iir & dev_priv->pm_rps_events) == 0)
+		return;
+
+	spin_lock(&dev_priv->irq_lock);
+	dev_priv->rps.pm_iir |= pm_iir & dev_priv->pm_rps_events;
+	bdw_disable_pm_irq(dev_priv, pm_iir & dev_priv->pm_rps_events);
+	spin_unlock(&dev_priv->irq_lock);
+
+	queue_work(dev_priv->wq, &dev_priv->rps.work);
+}
+
 static irqreturn_t gen8_gt_irq_handler(struct drm_device *dev,
 				       struct drm_i915_private *dev_priv,
 				       u32 master_ctl)
@@ -1334,6 +1391,17 @@ static irqreturn_t gen8_gt_irq_handler(struct drm_device *dev,
 			DRM_ERROR("The master control interrupt lied (GT1)!\n");
 	}
 
+	if (master_ctl & GEN8_GT_PM_IRQ) {
+		tmp = I915_READ(GEN8_GT_IIR(2));
+		if (tmp & dev_priv->pm_rps_events) {
+			ret = IRQ_HANDLED;
+			gen8_rps_irq_handler(dev_priv, tmp);
+			I915_WRITE(GEN8_GT_IIR(2),
+				   tmp & dev_priv->pm_rps_events);
+		} else
+			DRM_ERROR("The master control interrupt lied (PM)!\n");
+	}
+
 	if (master_ctl & GEN8_GT_VECS_IRQ) {
 		tmp = I915_READ(GEN8_GT_IIR(3));
 		if (tmp) {
@@ -3372,6 +3440,8 @@ static void gen8_gt_irq_postinstall(struct drm_i915_private *dev_priv)
 
 	for (i = 0; i < ARRAY_SIZE(gt_interrupts); i++)
 		GEN8_IRQ_INIT_NDX(GT, i, ~gt_interrupts[i], gt_interrupts[i]);
+
+	dev_priv->pm_irq_mask = 0xffffffff;
 }
 
 static void gen8_de_irq_postinstall(struct drm_i915_private *dev_priv)