Merge branch irq/plic-edge-fixes into irq/irqchip-next

* irq/plic-edge-fixes:
  : .
  : Work around broken PLIC implementations that deal pretty
  : badly with edge-triggered interrupts. Flag two implementations
  : as affected.
  : .
  irqchip/sifive-plic: Fix T-HEAD PLIC edge trigger handling
  dt-bindings: interrupt-controller: Require trigger type for T-HEAD PLIC
  irqchip/sifive-plic: Add support for Renesas RZ/Five SoC
  dt-bindings: interrupt-controller: sifive,plic: Document Renesas RZ/Five SoC

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

Author: Marc Zyngier

Documentation/devicetree/bindings/interrupt-controller/sifive,plic-1.0.0.yaml

@@ -26,9 +26,14 @@ description:
   with priority below this threshold will not cause the PLIC to raise its
   interrupt line leading to the context.
 
-  While the PLIC supports both edge-triggered and level-triggered interrupts,
-  interrupt handlers are oblivious to this distinction and therefore it is not
-  specified in the PLIC device-tree binding.
+  The PLIC supports both edge-triggered and level-triggered interrupts. For
+  edge-triggered interrupts, the RISC-V PLIC spec allows two responses to edges
+  seen while an interrupt handler is active; the PLIC may either queue them or
+  ignore them. In the first case, handlers are oblivious to the trigger type, so
+  it is not included in the interrupt specifier. In the second case, software
+  needs to know the trigger type, so it can reorder the interrupt flow to avoid
+  missing interrupts. This special handling is needed by at least the Renesas
+  RZ/Five SoC (AX45MP AndesCore with a NCEPLIC100) and the T-HEAD C900 PLIC.
 
   While the RISC-V ISA doesn't specify a memory layout for the PLIC, the
   "sifive,plic-1.0.0" device is a concrete implementation of the PLIC that
@@ -47,6 +52,10 @@ maintainers:
 properties:
   compatible:
     oneOf:
+      - items:
+          - enum:
+              - renesas,r9a07g043-plic
+          - const: andestech,nceplic100
       - items:
           - enum:
               - sifive,fu540-c000-plic
@@ -64,8 +73,7 @@ properties:
   '#address-cells':
     const: 0
 
-  '#interrupt-cells':
-    const: 1
+  '#interrupt-cells': true
 
   interrupt-controller: true
 
@@ -82,6 +90,12 @@ properties:
     description:
       Specifies how many external interrupts are supported by this controller.
 
+  clocks: true
+
+  power-domains: true
+
+  resets: true
+
 required:
   - compatible
   - '#address-cells'
@@ -91,6 +105,47 @@ required:
   - interrupts-extended
   - riscv,ndev
 
+allOf:
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - andestech,nceplic100
+              - thead,c900-plic
+
+    then:
+      properties:
+        '#interrupt-cells':
+          const: 2
+
+    else:
+      properties:
+        '#interrupt-cells':
+          const: 1
+
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: renesas,r9a07g043-plic
+
+    then:
+      properties:
+        clocks:
+          maxItems: 1
+
+        power-domains:
+          maxItems: 1
+
+        resets:
+          maxItems: 1
+
+      required:
+        - clocks
+        - power-domains
+        - resets
+
 additionalProperties: false
 
 examples:

drivers/irqchip/irq-sifive-plic.c

@@ -60,10 +60,13 @@
 #define	PLIC_DISABLE_THRESHOLD		0x7
 #define	PLIC_ENABLE_THRESHOLD		0
 
+#define PLIC_QUIRK_EDGE_INTERRUPT	0
+
 struct plic_priv {
 	struct cpumask lmask;
 	struct irq_domain *irqdomain;
 	void __iomem *regs;
+	unsigned long plic_quirks;
 };
 
 struct plic_handler {
@@ -81,6 +84,8 @@ static int plic_parent_irq __ro_after_init;
 static bool plic_cpuhp_setup_done __ro_after_init;
 static DEFINE_PER_CPU(struct plic_handler, plic_handlers);
 
+static int plic_irq_set_type(struct irq_data *d, unsigned int type);
+
 static void __plic_toggle(void __iomem *enable_base, int hwirq, int enable)
 {
 	u32 __iomem *reg = enable_base + (hwirq / 32) * sizeof(u32);
@@ -176,6 +181,17 @@ static void plic_irq_eoi(struct irq_data *d)
 	}
 }
 
+static struct irq_chip plic_edge_chip = {
+	.name		= "SiFive PLIC",
+	.irq_ack	= plic_irq_eoi,
+	.irq_mask	= plic_irq_mask,
+	.irq_unmask	= plic_irq_unmask,
+#ifdef CONFIG_SMP
+	.irq_set_affinity = plic_set_affinity,
+#endif
+	.irq_set_type	= plic_irq_set_type,
+};
+
 static struct irq_chip plic_chip = {
 	.name		= "SiFive PLIC",
 	.irq_mask	= plic_irq_mask,
@@ -184,8 +200,32 @@ static struct irq_chip plic_chip = {
 #ifdef CONFIG_SMP
 	.irq_set_affinity = plic_set_affinity,
 #endif
+	.irq_set_type	= plic_irq_set_type,
 };
 
+static int plic_irq_set_type(struct irq_data *d, unsigned int type)
+{
+	struct plic_priv *priv = irq_data_get_irq_chip_data(d);
+
+	if (!test_bit(PLIC_QUIRK_EDGE_INTERRUPT, &priv->plic_quirks))
+		return IRQ_SET_MASK_OK_NOCOPY;
+
+	switch (type) {
+	case IRQ_TYPE_EDGE_RISING:
+		irq_set_chip_handler_name_locked(d, &plic_edge_chip,
+						 handle_edge_irq, NULL);
+		break;
+	case IRQ_TYPE_LEVEL_HIGH:
+		irq_set_chip_handler_name_locked(d, &plic_chip,
+						 handle_fasteoi_irq, NULL);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return IRQ_SET_MASK_OK;
+}
+
 static int plic_irqdomain_map(struct irq_domain *d, unsigned int irq,
 			      irq_hw_number_t hwirq)
 {
@@ -198,6 +238,19 @@ static int plic_irqdomain_map(struct irq_domain *d, unsigned int irq,
 	return 0;
 }
 
+static int plic_irq_domain_translate(struct irq_domain *d,
+				     struct irq_fwspec *fwspec,
+				     unsigned long *hwirq,
+				     unsigned int *type)
+{
+	struct plic_priv *priv = d->host_data;
+
+	if (test_bit(PLIC_QUIRK_EDGE_INTERRUPT, &priv->plic_quirks))
+		return irq_domain_translate_twocell(d, fwspec, hwirq, type);
+
+	return irq_domain_translate_onecell(d, fwspec, hwirq, type);
+}
+
 static int plic_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
 				 unsigned int nr_irqs, void *arg)
 {
@@ -206,7 +259,7 @@ static int plic_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
 	unsigned int type;
 	struct irq_fwspec *fwspec = arg;
 
-	ret = irq_domain_translate_onecell(domain, fwspec, &hwirq, &type);
+	ret = plic_irq_domain_translate(domain, fwspec, &hwirq, &type);
 	if (ret)
 		return ret;
 
@@ -220,7 +273,7 @@ static int plic_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
 }
 
 static const struct irq_domain_ops plic_irqdomain_ops = {
-	.translate	= irq_domain_translate_onecell,
+	.translate	= plic_irq_domain_translate,
 	.alloc		= plic_irq_domain_alloc,
 	.free		= irq_domain_free_irqs_top,
 };
@@ -281,8 +334,9 @@ static int plic_starting_cpu(unsigned int cpu)
 	return 0;
 }
 
-static int __init plic_init(struct device_node *node,
-		struct device_node *parent)
+static int __init __plic_init(struct device_node *node,
+			      struct device_node *parent,
+			      unsigned long plic_quirks)
 {
 	int error = 0, nr_contexts, nr_handlers = 0, i;
 	u32 nr_irqs;
@@ -293,6 +347,8 @@ static int __init plic_init(struct device_node *node,
 	if (!priv)
 		return -ENOMEM;
 
+	priv->plic_quirks = plic_quirks;
+
 	priv->regs = of_iomap(node, 0);
 	if (WARN_ON(!priv->regs)) {
 		error = -EIO;
@@ -410,6 +466,20 @@ static int __init plic_init(struct device_node *node,
 	return error;
 }
 
+static int __init plic_init(struct device_node *node,
+			    struct device_node *parent)
+{
+	return __plic_init(node, parent, 0);
+}
+
 IRQCHIP_DECLARE(sifive_plic, "sifive,plic-1.0.0", plic_init);
 IRQCHIP_DECLARE(riscv_plic0, "riscv,plic0", plic_init); /* for legacy systems */
-IRQCHIP_DECLARE(thead_c900_plic, "thead,c900-plic", plic_init); /* for firmware driver */
+
+static int __init plic_edge_init(struct device_node *node,
+				 struct device_node *parent)
+{
+	return __plic_init(node, parent, BIT(PLIC_QUIRK_EDGE_INTERRUPT));
+}
+
+IRQCHIP_DECLARE(andestech_nceplic100, "andestech,nceplic100", plic_edge_init);
+IRQCHIP_DECLARE(thead_c900_plic, "thead,c900-plic", plic_edge_init);