disp: msm: sde: add pm QoS vote on CPU receiving display IRQ

Add a QoS vote on CPU receiving display interrupt. QoS vote
will prevent that CPU from going into low power mode avoiding
possible interrupt latency. Using irq notifier, display will
receive notification when display IRQ has switched CPUs and
will adjust the vote accordingly. The vote is also removed and
requested whenever display IRQ is enabled or disabled.

Change-Id: I94b4501896b4b20b37deaca90d6b5ff883d56621
Signed-off-by: Samantha Tran <[email protected]>
Signed-off-by: Lei Chen <[email protected]>

msm/sde/sde_kms.c

@@ -2927,6 +2927,86 @@ static int _sde_kms_active_override(struct sde_kms *sde_kms, bool enable)
 	return 0;
 }
 
+static void sde_kms_update_pm_qos_irq_request(struct sde_kms *sde_kms)
+{
+	struct device *cpu_dev;
+	int cpu = 0;
+
+	if (cpumask_empty(&sde_kms->irq_cpu_mask)) {
+		SDE_DEBUG("%s: irq_cpu_mask is empty\n", __func__);
+		return;
+	}
+
+	for_each_cpu(cpu, &sde_kms->irq_cpu_mask) {
+		cpu_dev = get_cpu_device(cpu);
+		if (!cpu_dev) {
+			SDE_DEBUG("%s: failed to get cpu%d device\n", __func__,
+				cpu);
+			continue;
+		}
+
+		if (dev_pm_qos_request_active(&sde_kms->pm_qos_irq_req[cpu]))
+			dev_pm_qos_update_request(&sde_kms->pm_qos_irq_req[cpu],
+					sde_kms->catalog->perf.cpu_dma_latency);
+		else
+			dev_pm_qos_add_request(cpu_dev,
+				&sde_kms->pm_qos_irq_req[cpu],
+				DEV_PM_QOS_RESUME_LATENCY,
+				sde_kms->catalog->perf.cpu_dma_latency);
+	}
+}
+
+static void sde_kms_remove_pm_qos_irq_request(struct sde_kms *sde_kms)
+{
+	struct device *cpu_dev;
+	int cpu = 0;
+
+	if (cpumask_empty(&sde_kms->irq_cpu_mask)) {
+		SDE_DEBUG("%s: irq_cpu_mask is empty\n", __func__);
+		return;
+	}
+
+	for_each_cpu(cpu, &sde_kms->irq_cpu_mask) {
+		cpu_dev = get_cpu_device(cpu);
+		if (!cpu_dev) {
+			SDE_DEBUG("%s: failed to get cpu%d device\n", __func__,
+				cpu);
+			continue;
+		}
+
+		if (dev_pm_qos_request_active(&sde_kms->pm_qos_irq_req[cpu]))
+			dev_pm_qos_remove_request(
+					&sde_kms->pm_qos_irq_req[cpu]);
+	}
+}
+
+static void sde_kms_irq_affinity_notify(
+		struct irq_affinity_notify *affinity_notify,
+		const cpumask_t *mask)
+{
+	struct msm_drm_private *priv;
+	struct sde_kms *sde_kms = container_of(affinity_notify,
+					struct sde_kms, affinity_notify);
+
+	if (!sde_kms || !sde_kms->dev || !sde_kms->dev->dev_private)
+		return;
+
+	priv = sde_kms->dev->dev_private;
+
+	mutex_lock(&priv->phandle.phandle_lock);
+
+	// save irq cpu mask
+	sde_kms->irq_cpu_mask = *mask;
+
+	// request vote with updated irq cpu mask
+	if (sde_kms->irq_enabled)
+		sde_kms_update_pm_qos_irq_request(sde_kms);
+
+	mutex_unlock(&priv->phandle.phandle_lock);
+}
+
+static void sde_kms_irq_affinity_release(struct kref *ref) {}
+
 static void sde_kms_handle_power_event(u32 event_type, void *usr)
 {
 	struct sde_kms *sde_kms = usr;
@@ -2945,7 +3025,9 @@ static void sde_kms_handle_power_event(u32 event_type, void *usr)
 		sde_kms_init_shared_hw(sde_kms);
 		_sde_kms_set_lutdma_vbif_remap(sde_kms);
 		sde_kms->first_kickoff = true;
+		sde_kms_update_pm_qos_irq_request(sde_kms);
 	} else if (event_type == SDE_POWER_EVENT_PRE_DISABLE) {
+		sde_kms_remove_pm_qos_irq_request(sde_kms);
 		sde_irq_update(msm_kms, false);
 		sde_kms->first_kickoff = false;
 		_sde_kms_active_override(sde_kms, true);
@@ -3360,7 +3442,7 @@ static int sde_kms_hw_init(struct msm_kms *kms)
 	struct drm_device *dev;
 	struct msm_drm_private *priv;
 	struct platform_device *platformdev;
-	int i, rc = -EINVAL;
+	int i, irq_num, rc = -EINVAL;
 
 	if (!kms) {
 		SDE_ERROR("invalid kms\n");
@@ -3432,6 +3514,14 @@ static int sde_kms_hw_init(struct msm_kms *kms)
 
 		pm_runtime_put_sync(sde_kms->dev->dev);
 	}
+
+	sde_kms->affinity_notify.notify = sde_kms_irq_affinity_notify;
+	sde_kms->affinity_notify.release = sde_kms_irq_affinity_release;
+
+	irq_num = platform_get_irq(to_platform_device(sde_kms->dev->dev), 0);
+	SDE_DEBUG("Registering for notification of irq_num: %d\n", irq_num);
+	irq_set_affinity_notifier(irq_num, &sde_kms->affinity_notify);
+
 	return 0;
 
 hw_init_err:

msm/sde/sde_kms.h

@@ -302,6 +302,10 @@ struct sde_kms {
 
 	bool first_kickoff;
 	bool qdss_enabled;
+
+	cpumask_t irq_cpu_mask;
+	struct dev_pm_qos_request pm_qos_irq_req[NR_CPUS];
+	struct irq_affinity_notify affinity_notify;
 };
 
 struct vsync_info {