1 files changed, 239 insertions, 83 deletions

diff --git a/drivers/irqchip/irq-sifive-plic.c b/drivers/irqchip/irq-sifive-plic.c
index aa4af886e43a..2f4784860df5 100644
--- a/drivers/irqchip/irq-sifive-plic.c
+++ b/drivers/irqchip/irq-sifive-plic.c
@@ -4,10 +4,12 @@
  * Copyright (C) 2018 Christoph Hellwig
  */
 #define pr_fmt(fmt) "plic: " fmt
+#include <linux/cpu.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/irq.h>
 #include <linux/irqchip.h>
+#include <linux/irqchip/chained_irq.h>
 #include <linux/irqdomain.h>
 #include <linux/module.h>
 #include <linux/of.h>
@@ -42,8 +44,8 @@
  * Each hart context has a vector of interrupt enable bits associated with it.
  * There's one bit for each interrupt source.
  */
-#define ENABLE_BASE			0x2000
-#define     ENABLE_PER_HART		0x80
+#define CONTEXT_ENABLE_BASE		0x2000
+#define     CONTEXT_ENABLE_SIZE		0x80
 
 /*
  * Each hart context has a set of control registers associated with it.  Right
@@ -51,11 +53,21 @@
  * take an interrupt, and a register to claim interrupts.
  */
 #define CONTEXT_BASE			0x200000
-#define     CONTEXT_PER_HART		0x1000
+#define     CONTEXT_SIZE		0x1000
 #define     CONTEXT_THRESHOLD		0x00
 #define     CONTEXT_CLAIM		0x04
 
-static void __iomem *plic_regs;
+#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 {
 	bool			present;
@@ -66,49 +78,73 @@ struct plic_handler {
 	 */
 	raw_spinlock_t		enable_lock;
 	void __iomem		*enable_base;
+	struct plic_priv	*priv;
 };
+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 inline void plic_toggle(struct plic_handler *handler,
-				int hwirq, int enable)
+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 = handler->enable_base + (hwirq / 32) * sizeof(u32);
+	u32 __iomem *reg = enable_base + (hwirq / 32) * sizeof(u32);
 	u32 hwirq_mask = 1 << (hwirq % 32);
 
-	raw_spin_lock(&handler->enable_lock);
 	if (enable)
 		writel(readl(reg) | hwirq_mask, reg);
 	else
 		writel(readl(reg) & ~hwirq_mask, reg);
+}
+
+static void plic_toggle(struct plic_handler *handler, int hwirq, int enable)
+{
+	raw_spin_lock(&handler->enable_lock);
+	__plic_toggle(handler->enable_base, hwirq, enable);
 	raw_spin_unlock(&handler->enable_lock);
 }
 
 static inline void plic_irq_toggle(const struct cpumask *mask,
-				   int hwirq, int enable)
+				   struct irq_data *d, int enable)
 {
 	int cpu;
 
-	writel(enable, plic_regs + PRIORITY_BASE + hwirq * PRIORITY_PER_ID);
 	for_each_cpu(cpu, mask) {
 		struct plic_handler *handler = per_cpu_ptr(&plic_handlers, cpu);
 
-		if (handler->present)
-			plic_toggle(handler, hwirq, enable);
+		plic_toggle(handler, d->hwirq, enable);
 	}
 }
 
+static void plic_irq_enable(struct irq_data *d)
+{
+	plic_irq_toggle(irq_data_get_effective_affinity_mask(d), d, 1);
+}
+
+static void plic_irq_disable(struct irq_data *d)
+{
+	plic_irq_toggle(irq_data_get_effective_affinity_mask(d), d, 0);
+}
+
 static void plic_irq_unmask(struct irq_data *d)
 {
-	unsigned int cpu = cpumask_any_and(irq_data_get_affinity_mask(d),
-					   cpu_online_mask);
-	if (WARN_ON_ONCE(cpu >= nr_cpu_ids))
-		return;
-	plic_irq_toggle(cpumask_of(cpu), d->hwirq, 1);
+	struct plic_priv *priv = irq_data_get_irq_chip_data(d);
+
+	writel(1, priv->regs + PRIORITY_BASE + d->hwirq * PRIORITY_PER_ID);
 }
 
 static void plic_irq_mask(struct irq_data *d)
 {
-	plic_irq_toggle(cpu_possible_mask, d->hwirq, 0);
+	struct plic_priv *priv = irq_data_get_irq_chip_data(d);
+
+	writel(0, priv->regs + PRIORITY_BASE + d->hwirq * PRIORITY_PER_ID);
+}
+
+static void plic_irq_eoi(struct irq_data *d)
+{
+	struct plic_handler *handler = this_cpu_ptr(&plic_handlers);
+
+	writel(d->hwirq, handler->hart_base + CONTEXT_CLAIM);
 }
 
 #ifdef CONFIG_SMP
@@ -116,50 +152,106 @@ static int plic_set_affinity(struct irq_data *d,
 			     const struct cpumask *mask_val, bool force)
 {
 	unsigned int cpu;
+	struct cpumask amask;
+	struct plic_priv *priv = irq_data_get_irq_chip_data(d);
+
+	cpumask_and(&amask, &priv->lmask, mask_val);
 
 	if (force)
-		cpu = cpumask_first(mask_val);
+		cpu = cpumask_first(&amask);
 	else
-		cpu = cpumask_any_and(mask_val, cpu_online_mask);
+		cpu = cpumask_any_and(&amask, cpu_online_mask);
 
 	if (cpu >= nr_cpu_ids)
 		return -EINVAL;
 
-	plic_irq_toggle(cpu_possible_mask, d->hwirq, 0);
-	plic_irq_toggle(cpumask_of(cpu), d->hwirq, 1);
+	plic_irq_disable(d);
 
 	irq_data_update_effective_affinity(d, cpumask_of(cpu));
 
+	if (!irqd_irq_disabled(d))
+		plic_irq_enable(d);
+
 	return IRQ_SET_MASK_OK_DONE;
 }
 #endif
 
-static void plic_irq_eoi(struct irq_data *d)
-{
-	struct plic_handler *handler = this_cpu_ptr(&plic_handlers);
-
-	writel(d->hwirq, handler->hart_base + CONTEXT_CLAIM);
-}
+static struct irq_chip plic_edge_chip = {
+	.name		= "SiFive PLIC",
+	.irq_enable	= plic_irq_enable,
+	.irq_disable	= plic_irq_disable,
+	.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,
+	.flags		= IRQCHIP_AFFINITY_PRE_STARTUP,
+};
 
 static struct irq_chip plic_chip = {
 	.name		= "SiFive PLIC",
+	.irq_enable	= plic_irq_enable,
+	.irq_disable	= plic_irq_disable,
 	.irq_mask	= plic_irq_mask,
 	.irq_unmask	= plic_irq_unmask,
 	.irq_eoi	= plic_irq_eoi,
 #ifdef CONFIG_SMP
 	.irq_set_affinity = plic_set_affinity,
 #endif
+	.irq_set_type	= plic_irq_set_type,
+	.flags		= IRQCHIP_AFFINITY_PRE_STARTUP,
 };
 
+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)
 {
+	struct plic_priv *priv = d->host_data;
+
 	irq_domain_set_info(d, irq, hwirq, &plic_chip, d->host_data,
 			    handle_fasteoi_irq, NULL, NULL);
 	irq_set_noprobe(irq);
+	irq_set_affinity(irq, &priv->lmask);
 	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)
 {
@@ -168,7 +260,7 @@ 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;
 
@@ -182,68 +274,87 @@ 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,
 };
 
-static struct irq_domain *plic_irqdomain;
-
 /*
  * Handling an interrupt is a two-step process: first you claim the interrupt
  * by reading the claim register, then you complete the interrupt by writing
  * that source ID back to the same claim register.  This automatically enables
  * and disables the interrupt, so there's nothing else to do.
  */
-static void plic_handle_irq(struct pt_regs *regs)
+static void plic_handle_irq(struct irq_desc *desc)
 {
 	struct plic_handler *handler = this_cpu_ptr(&plic_handlers);
+	struct irq_chip *chip = irq_desc_get_chip(desc);
 	void __iomem *claim = handler->hart_base + CONTEXT_CLAIM;
 	irq_hw_number_t hwirq;
 
 	WARN_ON_ONCE(!handler->present);
 
-	csr_clear(CSR_IE, IE_EIE);
-	while ((hwirq = readl(claim))) {
-		int irq = irq_find_mapping(plic_irqdomain, hwirq);
+	chained_irq_enter(chip, desc);
 
-		if (unlikely(irq <= 0))
+	while ((hwirq = readl(claim))) {
+		int err = generic_handle_domain_irq(handler->priv->irqdomain,
+						    hwirq);
+		if (unlikely(err))
 			pr_warn_ratelimited("can't find mapping for hwirq %lu\n",
 					hwirq);
-		else
-			generic_handle_irq(irq);
 	}
-	csr_set(CSR_IE, IE_EIE);
+
+	chained_irq_exit(chip, desc);
 }
 
-/*
- * Walk up the DT tree until we find an active RISC-V core (HART) node and
- * extract the cpuid from it.
- */
-static int plic_find_hart_id(struct device_node *node)
+static void plic_set_threshold(struct plic_handler *handler, u32 threshold)
 {
-	for (; node; node = node->parent) {
-		if (of_device_is_compatible(node, "riscv"))
-			return riscv_of_processor_hartid(node);
-	}
+	/* priority must be > threshold to trigger an interrupt */
+	writel(threshold, handler->hart_base + CONTEXT_THRESHOLD);
+}
+
+static int plic_dying_cpu(unsigned int cpu)
+{
+	if (plic_parent_irq)
+		disable_percpu_irq(plic_parent_irq);
 
-	return -1;
+	return 0;
 }
 
-static int __init plic_init(struct device_node *node,
-		struct device_node *parent)
+static int plic_starting_cpu(unsigned int cpu)
+{
+	struct plic_handler *handler = this_cpu_ptr(&plic_handlers);
+
+	if (plic_parent_irq)
+		enable_percpu_irq(plic_parent_irq,
+				  irq_get_trigger_type(plic_parent_irq));
+	else
+		pr_warn("cpu%d: parent irq not available\n", cpu);
+	plic_set_threshold(handler, PLIC_ENABLE_THRESHOLD);
+
+	return 0;
+}
+
+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;
+	struct plic_priv *priv;
+	struct plic_handler *handler;
 
-	if (plic_regs) {
-		pr_warn("PLIC already present.\n");
-		return -ENXIO;
-	}
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
 
-	plic_regs = of_iomap(node, 0);
-	if (WARN_ON(!plic_regs))
-		return -EIO;
+	priv->plic_quirks = plic_quirks;
+
+	priv->regs = of_iomap(node, 0);
+	if (WARN_ON(!priv->regs)) {
+		error = -EIO;
+		goto out_free_priv;
+	}
 
 	error = -EINVAL;
 	of_property_read_u32(node, "riscv,ndev", &nr_irqs);
@@ -253,21 +364,18 @@ static int __init plic_init(struct device_node *node,
 	nr_contexts = of_irq_count(node);
 	if (WARN_ON(!nr_contexts))
 		goto out_iounmap;
-	if (WARN_ON(nr_contexts < num_possible_cpus()))
-		goto out_iounmap;
 
 	error = -ENOMEM;
-	plic_irqdomain = irq_domain_add_linear(node, nr_irqs + 1,
-			&plic_irqdomain_ops, NULL);
-	if (WARN_ON(!plic_irqdomain))
+	priv->irqdomain = irq_domain_add_linear(node, nr_irqs + 1,
+			&plic_irqdomain_ops, priv);
+	if (WARN_ON(!priv->irqdomain))
 		goto out_iounmap;
 
 	for (i = 0; i < nr_contexts; i++) {
 		struct of_phandle_args parent;
-		struct plic_handler *handler;
 		irq_hw_number_t hwirq;
-		int cpu, hartid;
-		u32 threshold = 0;
+		int cpu;
+		unsigned long hartid;
 
 		if (of_irq_parse_one(node, i, &parent)) {
 			pr_err("failed to parse parent for context %d.\n", i);
@@ -278,11 +386,21 @@ static int __init plic_init(struct device_node *node,
 		 * Skip contexts other than external interrupts for our
 		 * privilege level.
 		 */
-		if (parent.args[0] != RV_IRQ_EXT)
+		if (parent.args[0] != RV_IRQ_EXT) {
+			/* Disable S-mode enable bits if running in M-mode. */
+			if (IS_ENABLED(CONFIG_RISCV_M_MODE)) {
+				void __iomem *enable_base = priv->regs +
+					CONTEXT_ENABLE_BASE +
+					i * CONTEXT_ENABLE_SIZE;
+
+				for (hwirq = 1; hwirq <= nr_irqs; hwirq++)
+					__plic_toggle(enable_base, hwirq, 0);
+			}
 			continue;
+		}
 
-		hartid = plic_find_hart_id(parent.np);
-		if (hartid < 0) {
+		error = riscv_of_parent_hartid(parent.np, &hartid);
+		if (error < 0) {
 			pr_warn("failed to parse hart ID for context %d.\n", i);
 			continue;
 		}
@@ -293,6 +411,14 @@ static int __init plic_init(struct device_node *node,
 			continue;
 		}
 
+		/* Find parent domain and register chained handler */
+		if (!plic_parent_irq && irq_find_host(parent.np)) {
+			plic_parent_irq = irq_of_parse_and_map(node, i);
+			if (plic_parent_irq)
+				irq_set_chained_handler(plic_parent_irq,
+							plic_handle_irq);
+		}
+
 		/*
 		 * When running in M-mode we need to ignore the S-mode handler.
 		 * Here we assume it always comes later, but that might be a
@@ -301,34 +427,64 @@ static int __init plic_init(struct device_node *node,
 		handler = per_cpu_ptr(&plic_handlers, cpu);
 		if (handler->present) {
 			pr_warn("handler already present for context %d.\n", i);
-			threshold = 0xffffffff;
+			plic_set_threshold(handler, PLIC_DISABLE_THRESHOLD);
 			goto done;
 		}
 
+		cpumask_set_cpu(cpu, &priv->lmask);
 		handler->present = true;
-		handler->hart_base =
-			plic_regs + CONTEXT_BASE + i * CONTEXT_PER_HART;
+		handler->hart_base = priv->regs + CONTEXT_BASE +
+			i * CONTEXT_SIZE;
 		raw_spin_lock_init(&handler->enable_lock);
-		handler->enable_base =
-			plic_regs + ENABLE_BASE + i * ENABLE_PER_HART;
-
+		handler->enable_base = priv->regs + CONTEXT_ENABLE_BASE +
+			i * CONTEXT_ENABLE_SIZE;
+		handler->priv = priv;
 done:
-		/* priority must be > threshold to trigger an interrupt */
-		writel(threshold, handler->hart_base + CONTEXT_THRESHOLD);
-		for (hwirq = 1; hwirq <= nr_irqs; hwirq++)
+		for (hwirq = 1; hwirq <= nr_irqs; hwirq++) {
 			plic_toggle(handler, hwirq, 0);
+			writel(1, priv->regs + PRIORITY_BASE +
+				  hwirq * PRIORITY_PER_ID);
+		}
 		nr_handlers++;
 	}
 
-	pr_info("mapped %d interrupts with %d handlers for %d contexts.\n",
-		nr_irqs, nr_handlers, nr_contexts);
-	set_handle_irq(plic_handle_irq);
+	/*
+	 * We can have multiple PLIC instances so setup cpuhp state only
+	 * when context handler for current/boot CPU is present.
+	 */
+	handler = this_cpu_ptr(&plic_handlers);
+	if (handler->present && !plic_cpuhp_setup_done) {
+		cpuhp_setup_state(CPUHP_AP_IRQ_SIFIVE_PLIC_STARTING,
+				  "irqchip/sifive/plic:starting",
+				  plic_starting_cpu, plic_dying_cpu);
+		plic_cpuhp_setup_done = true;
+	}
+
+	pr_info("%pOFP: mapped %d interrupts with %d handlers for"
+		" %d contexts.\n", node, nr_irqs, nr_handlers, nr_contexts);
 	return 0;
 
 out_iounmap:
-	iounmap(plic_regs);
+	iounmap(priv->regs);
+out_free_priv:
+	kfree(priv);
 	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 */
+
+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);