Merge branch 'irq/tegra-pmc' into irq/irqchip-next

Signed-off-by: Marc Zyngier <maz@kernel.org>

4 files changed, 150 insertions, 58 deletions

diff --git a/drivers/gpio/gpio-tegra186.c b/drivers/gpio/gpio-tegra186.c
index 178e9128ded0b..9500074b1f1b5 100644
--- a/drivers/gpio/gpio-tegra186.c
+++ b/drivers/gpio/gpio-tegra186.c
@@ -430,7 +430,18 @@ static int tegra186_irq_set_type(struct irq_data *data, unsigned int type)
 	else
 		irq_set_handler_locked(data, handle_edge_irq);
 
-	return irq_chip_set_type_parent(data, type);
+	if (data->parent_data)
+		return irq_chip_set_type_parent(data, type);
+
+	return 0;
+}
+
+static int tegra186_irq_set_wake(struct irq_data *data, unsigned int on)
+{
+	if (data->parent_data)
+		return irq_chip_set_wake_parent(data, on);
+
+	return 0;
 }
 
 static void tegra186_gpio_irq(struct irq_desc *desc)
@@ -678,7 +689,7 @@ static int tegra186_gpio_probe(struct platform_device *pdev)
 	gpio->intc.irq_mask = tegra186_irq_mask;
 	gpio->intc.irq_unmask = tegra186_irq_unmask;
 	gpio->intc.irq_set_type = tegra186_irq_set_type;
-	gpio->intc.irq_set_wake = irq_chip_set_wake_parent;
+	gpio->intc.irq_set_wake = tegra186_irq_set_wake;
 
 	irq = &gpio->gpio.irq;
 	irq->chip = &gpio->intc;
diff --git a/drivers/soc/tegra/pmc.c b/drivers/soc/tegra/pmc.c
index d332e5d9abac4..b0bba8ab75bb4 100644
--- a/drivers/soc/tegra/pmc.c
+++ b/drivers/soc/tegra/pmc.c
@@ -1990,44 +1990,17 @@ static int tegra_pmc_irq_alloc(struct irq_domain *domain, unsigned int virq,
 							    event->id,
 							    &pmc->irq, pmc);
 
-			/*
-			 * GPIOs don't have an equivalent interrupt in the
-			 * parent controller (GIC). However some code, such
-			 * as the one in irq_get_irqchip_state(), require a
-			 * valid IRQ chip to be set. Make sure that's the
-			 * case by passing NULL here, which will install a
-			 * dummy IRQ chip for the interrupt in the parent
-			 * domain.
-			 */
-			if (domain->parent)
-				irq_domain_set_hwirq_and_chip(domain->parent,
-							      virq, 0, NULL,
-							      NULL);
-
+			/* GPIO hierarchies stop at the PMC level */
+			if (!err && domain->parent)
+ 				err = irq_domain_disconnect_hierarchy(domain->parent,
+								      virq);
 			break;
 		}
 	}
 
-	/*
-	 * For interrupts that don't have associated wake events, assign a
-	 * dummy hardware IRQ number. This is used in the ->irq_set_type()
-	 * and ->irq_set_wake() callbacks to return early for these IRQs.
-	 */
-	if (i == soc->num_wake_events) {
-		err = irq_domain_set_hwirq_and_chip(domain, virq, ULONG_MAX,
-						    &pmc->irq, pmc);
-
-		/*
-		 * Interrupts without a wake event don't have a corresponding
-		 * interrupt in the parent controller (GIC). Pass NULL for the
-		 * chip here, which causes a dummy IRQ chip to be installed
-		 * for the interrupt in the parent domain, to make this
-		 * explicit.
-		 */
-		if (domain->parent)
-			irq_domain_set_hwirq_and_chip(domain->parent, virq, 0,
-						      NULL, NULL);
-	}
+	/* If there is no wake-up event, there is no PMC mapping */
+	if (i == soc->num_wake_events)
+		err = irq_domain_disconnect_hierarchy(domain, virq);
 
 	return err;
 }
@@ -2043,9 +2016,6 @@ static int tegra210_pmc_irq_set_wake(struct irq_data *data, unsigned int on)
 	unsigned int offset, bit;
 	u32 value;
 
-	if (data->hwirq == ULONG_MAX)
-		return 0;
-
 	offset = data->hwirq / 32;
 	bit = data->hwirq % 32;
 
@@ -2080,9 +2050,6 @@ static int tegra210_pmc_irq_set_type(struct irq_data *data, unsigned int type)
 	unsigned int offset, bit;
 	u32 value;
 
-	if (data->hwirq == ULONG_MAX)
-		return 0;
-
 	offset = data->hwirq / 32;
 	bit = data->hwirq % 32;
 
@@ -2123,10 +2090,6 @@ static int tegra186_pmc_irq_set_wake(struct irq_data *data, unsigned int on)
 	unsigned int offset, bit;
 	u32 value;
 
-	/* nothing to do if there's no associated wake event */
-	if (WARN_ON(data->hwirq == ULONG_MAX))
-		return 0;
-
 	offset = data->hwirq / 32;
 	bit = data->hwirq % 32;
 
@@ -2154,10 +2117,6 @@ static int tegra186_pmc_irq_set_type(struct irq_data *data, unsigned int type)
 	struct tegra_pmc *pmc = irq_data_get_irq_chip_data(data);
 	u32 value;
 
-	/* nothing to do if there's no associated wake event */
-	if (data->hwirq == ULONG_MAX)
-		return 0;
-
 	value = readl(pmc->wake + WAKE_AOWAKE_CNTRL(data->hwirq));
 
 	switch (type) {
@@ -2184,6 +2143,34 @@ static int tegra186_pmc_irq_set_type(struct irq_data *data, unsigned int type)
 	return 0;
 }
 
+static void tegra_irq_mask_parent(struct irq_data *data)
+{
+	if (data->parent_data)
+		irq_chip_mask_parent(data);
+}
+
+static void tegra_irq_unmask_parent(struct irq_data *data)
+{
+	if (data->parent_data)
+		irq_chip_unmask_parent(data);
+}
+
+static void tegra_irq_eoi_parent(struct irq_data *data)
+{
+	if (data->parent_data)
+		irq_chip_eoi_parent(data);
+}
+
+static int tegra_irq_set_affinity_parent(struct irq_data *data,
+					 const struct cpumask *dest,
+					 bool force)
+{
+	if (data->parent_data)
+		return irq_chip_set_affinity_parent(data, dest, force);
+
+	return -EINVAL;
+}
+
 static int tegra_pmc_irq_init(struct tegra_pmc *pmc)
 {
 	struct irq_domain *parent = NULL;
@@ -2199,10 +2186,10 @@ static int tegra_pmc_irq_init(struct tegra_pmc *pmc)
 		return 0;
 
 	pmc->irq.name = dev_name(pmc->dev);
-	pmc->irq.irq_mask = irq_chip_mask_parent;
-	pmc->irq.irq_unmask = irq_chip_unmask_parent;
-	pmc->irq.irq_eoi = irq_chip_eoi_parent;
-	pmc->irq.irq_set_affinity = irq_chip_set_affinity_parent;
+	pmc->irq.irq_mask = tegra_irq_mask_parent;
+	pmc->irq.irq_unmask = tegra_irq_unmask_parent;
+	pmc->irq.irq_eoi = tegra_irq_eoi_parent;
+	pmc->irq.irq_set_affinity = tegra_irq_set_affinity_parent;
 	pmc->irq.irq_set_type = pmc->soc->irq_set_type;
 	pmc->irq.irq_set_wake = pmc->soc->irq_set_wake;
 
diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
index b37350c4fe370..a52b095bd4048 100644
--- a/include/linux/irqdomain.h
+++ b/include/linux/irqdomain.h
@@ -509,6 +509,9 @@ extern void irq_domain_free_irqs_parent(struct irq_domain *domain,
 					unsigned int irq_base,
 					unsigned int nr_irqs);
 
+extern int irq_domain_disconnect_hierarchy(struct irq_domain *domain,
+					   unsigned int virq);
+
 static inline bool irq_domain_is_hierarchy(struct irq_domain *domain)
 {
 	return domain->flags & IRQ_DOMAIN_FLAG_HIERARCHY;
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index 76cd7ebd1178c..cf8b374b892da 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -1136,6 +1136,17 @@ static struct irq_data *irq_domain_insert_irq_data(struct irq_domain *domain,
 	return irq_data;
 }
 
+static void __irq_domain_free_hierarchy(struct irq_data *irq_data)
+{
+	struct irq_data *tmp;
+
+	while (irq_data) {
+		tmp = irq_data;
+		irq_data = irq_data->parent_data;
+		kfree(tmp);
+	}
+}
+
 static void irq_domain_free_irq_data(unsigned int virq, unsigned int nr_irqs)
 {
 	struct irq_data *irq_data, *tmp;
@@ -1147,12 +1158,83 @@ static void irq_domain_free_irq_data(unsigned int virq, unsigned int nr_irqs)
 		irq_data->parent_data = NULL;
 		irq_data->domain = NULL;
 
-		while (tmp) {
-			irq_data = tmp;
-			tmp = tmp->parent_data;
-			kfree(irq_data);
+		__irq_domain_free_hierarchy(tmp);
+	}
+}
+
+/**
+ * irq_domain_disconnect_hierarchy - Mark the first unused level of a hierarchy
+ * @domain:	IRQ domain from which the hierarchy is to be disconnected
+ * @virq:	IRQ number where the hierarchy is to be trimmed
+ *
+ * Marks the @virq level belonging to @domain as disconnected.
+ * Returns -EINVAL if @virq doesn't have a valid irq_data pointing
+ * to @domain.
+ *
+ * Its only use is to be able to trim levels of hierarchy that do not
+ * have any real meaning for this interrupt, and that the driver marks
+ * as such from its .alloc() callback.
+ */
+int irq_domain_disconnect_hierarchy(struct irq_domain *domain,
+				    unsigned int virq)
+{
+	struct irq_data *irqd;
+
+	irqd = irq_domain_get_irq_data(domain, virq);
+	if (!irqd)
+		return -EINVAL;
+
+	irqd->chip = ERR_PTR(-ENOTCONN);
+	return 0;
+}
+
+static int irq_domain_trim_hierarchy(unsigned int virq)
+{
+	struct irq_data *tail, *irqd, *irq_data;
+
+	irq_data = irq_get_irq_data(virq);
+	tail = NULL;
+
+	/* The first entry must have a valid irqchip */
+	if (!irq_data->chip || IS_ERR(irq_data->chip))
+		return -EINVAL;
+
+	/*
+	 * Validate that the irq_data chain is sane in the presence of
+	 * a hierarchy trimming marker.
+	 */
+	for (irqd = irq_data->parent_data; irqd; irq_data = irqd, irqd = irqd->parent_data) {
+		/* Can't have a valid irqchip after a trim marker */
+		if (irqd->chip && tail)
+			return -EINVAL;
+
+		/* Can't have an empty irqchip before a trim marker */
+		if (!irqd->chip && !tail)
+			return -EINVAL;
+
+		if (IS_ERR(irqd->chip)) {
+			/* Only -ENOTCONN is a valid trim marker */
+			if (PTR_ERR(irqd->chip) != -ENOTCONN)
+				return -EINVAL;
+
+			tail = irq_data;
 		}
 	}
+
+	/* No trim marker, nothing to do */
+	if (!tail)
+		return 0;
+
+	pr_info("IRQ%d: trimming hierarchy from %s\n",
+		virq, tail->parent_data->domain->name);
+
+	/* Sever the inner part of the hierarchy...  */
+	irqd = tail;
+	tail = tail->parent_data;
+	irqd->parent_data = NULL;
+	__irq_domain_free_hierarchy(tail);
+
+	return 0;
 }
 
 static int irq_domain_alloc_irq_data(struct irq_domain *domain,
@@ -1362,6 +1444,15 @@ int __irq_domain_alloc_irqs(struct irq_domain *domain, int irq_base,
 		mutex_unlock(&irq_domain_mutex);
 		goto out_free_irq_data;
 	}
+
+	for (i = 0; i < nr_irqs; i++) {
+		ret = irq_domain_trim_hierarchy(virq + i);
+		if (ret) {
+			mutex_unlock(&irq_domain_mutex);
+			goto out_free_irq_data;
+		}
+	}
+	
 	for (i = 0; i < nr_irqs; i++)
 		irq_domain_insert_irq(virq + i);
 	mutex_unlock(&irq_domain_mutex);