1 files changed, 408 insertions, 154 deletions

diff --git a/drivers/irqchip/irq-sifive-plic.c b/drivers/irqchip/irq-sifive-plic.c
index e1484905b7bd..210a57959637 100644
--- a/drivers/irqchip/irq-sifive-plic.c
+++ b/drivers/irqchip/irq-sifive-plic.c
@@ -3,7 +3,8 @@
  * Copyright (C) 2017 SiFive
  * Copyright (C) 2018 Christoph Hellwig
  */
-#define pr_fmt(fmt) "plic: " fmt
+#define pr_fmt(fmt) "riscv-plic: " fmt
+#include <linux/acpi.h>
 #include <linux/cpu.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
@@ -48,6 +49,8 @@
 #define CONTEXT_ENABLE_BASE		0x2000
 #define     CONTEXT_ENABLE_SIZE		0x80
 
+#define PENDING_BASE			0x1000
+
 /*
  * Each hart context has a set of control registers associated with it.  Right
  * now there's only two: a source priority threshold over which the hart will
@@ -62,14 +65,18 @@
 #define	PLIC_ENABLE_THRESHOLD		0
 
 #define PLIC_QUIRK_EDGE_INTERRUPT	0
+#define PLIC_QUIRK_CP100_CLAIM_REGISTER_ERRATUM	1
 
 struct plic_priv {
+	struct fwnode_handle *fwnode;
 	struct cpumask lmask;
 	struct irq_domain *irqdomain;
 	void __iomem *regs;
 	unsigned long plic_quirks;
 	unsigned int nr_irqs;
 	unsigned long *prio_save;
+	u32 gsi_base;
+	int acpi_plic_id;
 };
 
 struct plic_handler {
@@ -85,27 +92,36 @@ struct plic_handler {
 	struct plic_priv	*priv;
 };
 static int plic_parent_irq __ro_after_init;
-static bool plic_cpuhp_setup_done __ro_after_init;
+static bool plic_global_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)
+static void __plic_toggle(struct plic_handler *handler, int hwirq, int enable)
 {
-	u32 __iomem *reg = enable_base + (hwirq / 32) * sizeof(u32);
+	u32 __iomem *base = handler->enable_base;
 	u32 hwirq_mask = 1 << (hwirq % 32);
+	int group = hwirq / 32;
+	u32 value;
+
+	value = readl(base + group);
 
 	if (enable)
-		writel(readl(reg) | hwirq_mask, reg);
+		value |= hwirq_mask;
 	else
-		writel(readl(reg) & ~hwirq_mask, reg);
+		value &= ~hwirq_mask;
+
+	handler->enable_save[group] = value;
+	writel(value, base + group);
 }
 
 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);
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&handler->enable_lock, flags);
+	__plic_toggle(handler, hwirq, enable);
+	raw_spin_unlock_irqrestore(&handler->enable_lock, flags);
 }
 
 static inline void plic_irq_toggle(const struct cpumask *mask,
@@ -120,16 +136,6 @@ static inline void plic_irq_toggle(const struct cpumask *mask,
 	}
 }
 
-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)
 {
 	struct plic_priv *priv = irq_data_get_irq_chip_data(d);
@@ -144,11 +150,28 @@ static void plic_irq_mask(struct irq_data *d)
 	writel(0, priv->regs + PRIORITY_BASE + d->hwirq * PRIORITY_PER_ID);
 }
 
+static void plic_irq_enable(struct irq_data *d)
+{
+	plic_irq_toggle(irq_data_get_effective_affinity_mask(d), d, 1);
+	plic_irq_unmask(d);
+}
+
+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_eoi(struct irq_data *d)
 {
 	struct plic_handler *handler = this_cpu_ptr(&plic_handlers);
 
-	writel(d->hwirq, handler->hart_base + CONTEXT_CLAIM);
+	if (unlikely(irqd_irq_disabled(d))) {
+		plic_toggle(handler, d->hwirq, 1);
+		writel(d->hwirq, handler->hart_base + CONTEXT_CLAIM);
+		plic_toggle(handler, d->hwirq, 0);
+	} else {
+		writel(d->hwirq, handler->hart_base + CONTEXT_CLAIM);
+	}
 }
 
 #ifdef CONFIG_SMP
@@ -156,25 +179,24 @@ 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(&amask);
+		cpu = cpumask_first_and(&priv->lmask, mask_val);
 	else
-		cpu = cpumask_any_and(&amask, cpu_online_mask);
+		cpu = cpumask_first_and_and(&priv->lmask, mask_val, cpu_online_mask);
 
 	if (cpu >= nr_cpu_ids)
 		return -EINVAL;
 
-	plic_irq_disable(d);
+	/* Invalidate the original routing entry */
+	plic_irq_toggle(irq_data_get_effective_affinity_mask(d), d, 0);
 
 	irq_data_update_effective_affinity(d, cpumask_of(cpu));
 
+	/* Setting the new routing entry if irq is enabled */
 	if (!irqd_irq_disabled(d))
-		plic_irq_enable(d);
+		plic_irq_toggle(irq_data_get_effective_affinity_mask(d), d, 1);
 
 	return IRQ_SET_MASK_OK_DONE;
 }
@@ -233,71 +255,61 @@ static int plic_irq_set_type(struct irq_data *d, unsigned int type)
 	return IRQ_SET_MASK_OK;
 }
 
-static int plic_irq_suspend(void)
+static int plic_irq_suspend(void *data)
 {
-	unsigned int i, cpu;
-	u32 __iomem *reg;
 	struct plic_priv *priv;
 
 	priv = per_cpu_ptr(&plic_handlers, smp_processor_id())->priv;
 
-	for (i = 0; i < priv->nr_irqs; i++)
-		if (readl(priv->regs + PRIORITY_BASE + i * PRIORITY_PER_ID))
-			__set_bit(i, priv->prio_save);
-		else
-			__clear_bit(i, priv->prio_save);
-
-	for_each_cpu(cpu, cpu_present_mask) {
-		struct plic_handler *handler = per_cpu_ptr(&plic_handlers, cpu);
-
-		if (!handler->present)
-			continue;
-
-		raw_spin_lock(&handler->enable_lock);
-		for (i = 0; i < DIV_ROUND_UP(priv->nr_irqs, 32); i++) {
-			reg = handler->enable_base + i * sizeof(u32);
-			handler->enable_save[i] = readl(reg);
-		}
-		raw_spin_unlock(&handler->enable_lock);
+	/* irq ID 0 is reserved */
+	for (unsigned int i = 1; i < priv->nr_irqs; i++) {
+		__assign_bit(i, priv->prio_save,
+			     readl(priv->regs + PRIORITY_BASE + i * PRIORITY_PER_ID));
 	}
 
 	return 0;
 }
 
-static void plic_irq_resume(void)
+static void plic_irq_resume(void *data)
 {
 	unsigned int i, index, cpu;
+	unsigned long flags;
 	u32 __iomem *reg;
 	struct plic_priv *priv;
 
 	priv = per_cpu_ptr(&plic_handlers, smp_processor_id())->priv;
 
-	for (i = 0; i < priv->nr_irqs; i++) {
+	/* irq ID 0 is reserved */
+	for (i = 1; i < priv->nr_irqs; i++) {
 		index = BIT_WORD(i);
 		writel((priv->prio_save[index] & BIT_MASK(i)) ? 1 : 0,
 		       priv->regs + PRIORITY_BASE + i * PRIORITY_PER_ID);
 	}
 
-	for_each_cpu(cpu, cpu_present_mask) {
+	for_each_present_cpu(cpu) {
 		struct plic_handler *handler = per_cpu_ptr(&plic_handlers, cpu);
 
 		if (!handler->present)
 			continue;
 
-		raw_spin_lock(&handler->enable_lock);
+		raw_spin_lock_irqsave(&handler->enable_lock, flags);
 		for (i = 0; i < DIV_ROUND_UP(priv->nr_irqs, 32); i++) {
 			reg = handler->enable_base + i * sizeof(u32);
 			writel(handler->enable_save[i], reg);
 		}
-		raw_spin_unlock(&handler->enable_lock);
+		raw_spin_unlock_irqrestore(&handler->enable_lock, flags);
 	}
 }
 
-static struct syscore_ops plic_irq_syscore_ops = {
+static const struct syscore_ops plic_irq_syscore_ops = {
 	.suspend	= plic_irq_suspend,
 	.resume		= plic_irq_resume,
 };
 
+static struct syscore plic_irq_syscore = {
+	.ops = &plic_irq_syscore_ops,
+};
+
 static int plic_irqdomain_map(struct irq_domain *d, unsigned int irq,
 			      irq_hw_number_t hwirq)
 {
@@ -317,6 +329,10 @@ static int plic_irq_domain_translate(struct irq_domain *d,
 {
 	struct plic_priv *priv = d->host_data;
 
+	/* For DT, gsi_base is always zero. */
+	if (fwspec->param[0] >= priv->gsi_base)
+		fwspec->param[0] = fwspec->param[0] - priv->gsi_base;
+
 	if (test_bit(PLIC_QUIRK_EDGE_INTERRUPT, &priv->plic_quirks))
 		return irq_domain_translate_twocell(d, fwspec, hwirq, type);
 
@@ -370,9 +386,102 @@ static void plic_handle_irq(struct irq_desc *desc)
 	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);
+		if (unlikely(err)) {
+			pr_warn_ratelimited("%pfwP: can't find mapping for hwirq %lu\n",
+					    handler->priv->fwnode, hwirq);
+		}
+	}
+
+	chained_irq_exit(chip, desc);
+}
+
+static u32 cp100_isolate_pending_irq(int nr_irq_groups, struct plic_handler *handler)
+{
+	u32 __iomem *pending = handler->priv->regs + PENDING_BASE;
+	u32 __iomem *enable = handler->enable_base;
+	u32 pending_irqs = 0;
+	int i, j;
+
+	/* Look for first pending interrupt */
+	for (i = 0; i < nr_irq_groups; i++) {
+		/* Any pending interrupts would be annihilated, so skip checking them */
+		if (!handler->enable_save[i])
+			continue;
+
+		pending_irqs = handler->enable_save[i] & readl_relaxed(pending + i);
+		if (pending_irqs)
+			break;
+	}
+
+	if (!pending_irqs)
+		return 0;
+
+	/* Isolate lowest set bit */
+	pending_irqs &= -pending_irqs;
+
+	/* Disable all interrupts but the first pending one */
+	for (j = 0; j < nr_irq_groups; j++) {
+		u32 new_mask = j == i ? pending_irqs : 0;
+
+		if (new_mask != handler->enable_save[j])
+			writel_relaxed(new_mask, enable + j);
+	}
+	return pending_irqs;
+}
+
+static irq_hw_number_t cp100_get_hwirq(struct plic_handler *handler, void __iomem *claim)
+{
+	int nr_irq_groups = DIV_ROUND_UP(handler->priv->nr_irqs, 32);
+	u32 __iomem *enable = handler->enable_base;
+	irq_hw_number_t hwirq = 0;
+	u32 iso_mask;
+	int i;
+
+	guard(raw_spinlock)(&handler->enable_lock);
+
+	/* Existing enable state is already cached in enable_save */
+	iso_mask = cp100_isolate_pending_irq(nr_irq_groups, handler);
+	if (!iso_mask)
+		return 0;
+
+	/*
+	 * Interrupts delievered to hardware still become pending, but only
+	 * interrupts that are both pending and enabled can be claimed.
+	 * Clearing the enable bit for all interrupts but the first pending
+	 * one avoids a hardware bug that occurs during read from the claim
+	 * register with more than one eligible interrupt.
+	 */
+	hwirq = readl(claim);
+
+	/* Restore previous state */
+	for (i = 0; i < nr_irq_groups; i++) {
+		u32 written = i == hwirq / 32 ? iso_mask : 0;
+		u32 stored = handler->enable_save[i];
+
+		if (stored != written)
+			writel_relaxed(stored, enable + i);
+	}
+	return hwirq;
+}
+
+static void plic_handle_irq_cp100(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);
+
+	chained_irq_enter(chip, desc);
+
+	while ((hwirq = cp100_get_hwirq(handler, claim))) {
+		int err = generic_handle_domain_irq(handler->priv->irqdomain, hwirq);
+
+		if (unlikely(err)) {
+			pr_warn_ratelimited("%pfwP: can't find mapping for hwirq %lu\n",
+					    handler->priv->fwnode, hwirq);
+		}
 	}
 
 	chained_irq_exit(chip, desc);
@@ -400,103 +509,194 @@ static int plic_starting_cpu(unsigned int cpu)
 		enable_percpu_irq(plic_parent_irq,
 				  irq_get_trigger_type(plic_parent_irq));
 	else
-		pr_warn("cpu%d: parent irq not available\n", cpu);
+		pr_warn("%pfwP: cpu%d: parent irq not available\n",
+			handler->priv->fwnode, 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)
+static const struct of_device_id plic_match[] = {
+	{ .compatible = "sifive,plic-1.0.0" },
+	{ .compatible = "riscv,plic0" },
+	{ .compatible = "andestech,nceplic100",
+	  .data = (const void *)BIT(PLIC_QUIRK_EDGE_INTERRUPT) },
+	{ .compatible = "thead,c900-plic",
+	  .data = (const void *)BIT(PLIC_QUIRK_EDGE_INTERRUPT) },
+	{ .compatible = "ultrarisc,cp100-plic",
+	  .data = (const void *)BIT(PLIC_QUIRK_CP100_CLAIM_REGISTER_ERRATUM) },
+	{}
+};
+
+#ifdef CONFIG_ACPI
+
+static const struct acpi_device_id plic_acpi_match[] = {
+	{ "RSCV0001", 0 },
+	{}
+};
+MODULE_DEVICE_TABLE(acpi, plic_acpi_match);
+
+#endif
+static int plic_parse_nr_irqs_and_contexts(struct fwnode_handle *fwnode,
+					   u32 *nr_irqs, u32 *nr_contexts,
+					   u32 *gsi_base, u32 *id)
 {
-	int error = 0, nr_contexts, nr_handlers = 0, i;
-	u32 nr_irqs;
-	struct plic_priv *priv;
-	struct plic_handler *handler;
-	unsigned int cpu;
+	int rc;
 
-	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
-	if (!priv)
-		return -ENOMEM;
+	if (!is_of_node(fwnode)) {
+		rc = riscv_acpi_get_gsi_info(fwnode, gsi_base, id, nr_irqs, NULL);
+		if (rc) {
+			pr_err("%pfwP: failed to find GSI mapping\n", fwnode);
+			return rc;
+		}
 
-	priv->plic_quirks = plic_quirks;
+		*nr_contexts = acpi_rintc_get_plic_nr_contexts(*id);
+		if (WARN_ON(!*nr_contexts)) {
+			pr_err("%pfwP: no PLIC context available\n", fwnode);
+			return -EINVAL;
+		}
 
-	priv->regs = of_iomap(node, 0);
-	if (WARN_ON(!priv->regs)) {
-		error = -EIO;
-		goto out_free_priv;
+		return 0;
 	}
 
-	error = -EINVAL;
-	of_property_read_u32(node, "riscv,ndev", &nr_irqs);
-	if (WARN_ON(!nr_irqs))
-		goto out_iounmap;
+	rc = of_property_read_u32(to_of_node(fwnode), "riscv,ndev", nr_irqs);
+	if (rc) {
+		pr_err("%pfwP: riscv,ndev property not available\n", fwnode);
+		return rc;
+	}
 
-	priv->nr_irqs = nr_irqs;
+	*nr_contexts = of_irq_count(to_of_node(fwnode));
+	if (WARN_ON(!(*nr_contexts))) {
+		pr_err("%pfwP: no PLIC context available\n", fwnode);
+		return -EINVAL;
+	}
 
-	priv->prio_save = bitmap_alloc(nr_irqs, GFP_KERNEL);
-	if (!priv->prio_save)
-		goto out_free_priority_reg;
+	*gsi_base = 0;
+	*id = 0;
 
-	nr_contexts = of_irq_count(node);
-	if (WARN_ON(!nr_contexts))
-		goto out_free_priority_reg;
+	return 0;
+}
 
-	error = -ENOMEM;
-	priv->irqdomain = irq_domain_add_linear(node, nr_irqs + 1,
-			&plic_irqdomain_ops, priv);
-	if (WARN_ON(!priv->irqdomain))
-		goto out_free_priority_reg;
+static int plic_parse_context_parent(struct fwnode_handle *fwnode, u32 context,
+				     u32 *parent_hwirq, int *parent_cpu, u32 id)
+{
+	struct of_phandle_args parent;
+	unsigned long hartid;
+	int rc;
+
+	if (!is_of_node(fwnode)) {
+		hartid = acpi_rintc_ext_parent_to_hartid(id, context);
+		if (hartid == INVALID_HARTID)
+			return -EINVAL;
+
+		*parent_cpu = riscv_hartid_to_cpuid(hartid);
+		*parent_hwirq = RV_IRQ_EXT;
+		return 0;
+	}
 
-	for (i = 0; i < nr_contexts; i++) {
-		struct of_phandle_args parent;
-		irq_hw_number_t hwirq;
-		int cpu;
-		unsigned long hartid;
+	rc = of_irq_parse_one(to_of_node(fwnode), context, &parent);
+	if (rc)
+		return rc;
+
+	rc = riscv_of_parent_hartid(parent.np, &hartid);
+	if (rc)
+		return rc;
+
+	*parent_hwirq = parent.args[0];
+	*parent_cpu = riscv_hartid_to_cpuid(hartid);
+	return 0;
+}
+
+static int plic_probe(struct fwnode_handle *fwnode)
+{
+	int error = 0, nr_contexts, nr_handlers = 0, cpu, i;
+	unsigned long plic_quirks = 0;
+	struct plic_handler *handler;
+	u32 nr_irqs, parent_hwirq;
+	struct plic_priv *priv;
+	irq_hw_number_t hwirq;
+	void __iomem *regs;
+	int id, context_id;
+	u32 gsi_base;
+
+	if (is_of_node(fwnode)) {
+		const struct of_device_id *id;
+
+		id = of_match_node(plic_match, to_of_node(fwnode));
+		if (id)
+			plic_quirks = (unsigned long)id->data;
+
+		regs = of_iomap(to_of_node(fwnode), 0);
+		if (!regs)
+			return -ENOMEM;
+	} else {
+		regs = devm_platform_ioremap_resource(to_platform_device(fwnode->dev), 0);
+		if (IS_ERR(regs))
+			return PTR_ERR(regs);
+	}
+
+	error = plic_parse_nr_irqs_and_contexts(fwnode, &nr_irqs, &nr_contexts, &gsi_base, &id);
+	if (error)
+		goto fail_free_regs;
+
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv) {
+		error = -ENOMEM;
+		goto fail_free_regs;
+	}
 
-		if (of_irq_parse_one(node, i, &parent)) {
-			pr_err("failed to parse parent for context %d.\n", i);
+	priv->fwnode = fwnode;
+	priv->plic_quirks = plic_quirks;
+	priv->nr_irqs = nr_irqs;
+	priv->regs = regs;
+	priv->gsi_base = gsi_base;
+	priv->acpi_plic_id = id;
+
+	priv->prio_save = bitmap_zalloc(nr_irqs, GFP_KERNEL);
+	if (!priv->prio_save) {
+		error = -ENOMEM;
+		goto fail_free_priv;
+	}
+
+	for (i = 0; i < nr_contexts; i++) {
+		error = plic_parse_context_parent(fwnode, i, &parent_hwirq, &cpu,
+						  priv->acpi_plic_id);
+		if (error) {
+			pr_warn("%pfwP: hwirq for context%d not found\n", fwnode, i);
 			continue;
 		}
 
+		if (is_of_node(fwnode)) {
+			context_id = i;
+		} else {
+			context_id = acpi_rintc_get_plic_context(priv->acpi_plic_id, i);
+			if (context_id == INVALID_CONTEXT) {
+				pr_warn("%pfwP: invalid context id for context%d\n", fwnode, i);
+				continue;
+			}
+		}
+
 		/*
 		 * Skip contexts other than external interrupts for our
 		 * privilege level.
 		 */
-		if (parent.args[0] != RV_IRQ_EXT) {
+		if (parent_hwirq != 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;
+				u32 __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);
+				for (int j = 0; j <= nr_irqs / 32; j++)
+					writel(0, enable_base + j);
 			}
 			continue;
 		}
 
-		error = riscv_of_parent_hartid(parent.np, &hartid);
-		if (error < 0) {
-			pr_warn("failed to parse hart ID for context %d.\n", i);
-			continue;
-		}
-
-		cpu = riscv_hartid_to_cpuid(hartid);
 		if (cpu < 0) {
-			pr_warn("Invalid cpuid for context %d\n", i);
+			pr_warn("%pfwP: Invalid cpuid for context %d\n", fwnode, i);
 			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
@@ -504,7 +704,7 @@ 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);
+			pr_warn("%pfwP: handler already present for context %d.\n", fwnode, i);
 			plic_set_threshold(handler, PLIC_DISABLE_THRESHOLD);
 			goto done;
 		}
@@ -512,16 +712,18 @@ static int __init __plic_init(struct device_node *node,
 		cpumask_set_cpu(cpu, &priv->lmask);
 		handler->present = true;
 		handler->hart_base = priv->regs + CONTEXT_BASE +
-			i * CONTEXT_SIZE;
+			context_id * CONTEXT_SIZE;
 		raw_spin_lock_init(&handler->enable_lock);
 		handler->enable_base = priv->regs + CONTEXT_ENABLE_BASE +
-			i * CONTEXT_ENABLE_SIZE;
+			context_id * CONTEXT_ENABLE_SIZE;
 		handler->priv = priv;
 
-		handler->enable_save =  kcalloc(DIV_ROUND_UP(nr_irqs, 32),
-						sizeof(*handler->enable_save), GFP_KERNEL);
-		if (!handler->enable_save)
-			goto out_free_enable_reg;
+		handler->enable_save = kcalloc(DIV_ROUND_UP(nr_irqs, 32),
+					       sizeof(*handler->enable_save), GFP_KERNEL);
+		if (!handler->enable_save) {
+			error = -ENOMEM;
+			goto fail_cleanup_contexts;
+		}
 done:
 		for (hwirq = 1; hwirq <= nr_irqs; hwirq++) {
 			plic_toggle(handler, hwirq, 0);
@@ -531,51 +733,103 @@ done:
 		nr_handlers++;
 	}
 
+	priv->irqdomain = irq_domain_create_linear(fwnode, nr_irqs + 1,
+						   &plic_irqdomain_ops, priv);
+	if (WARN_ON(!priv->irqdomain)) {
+		error = -ENOMEM;
+		goto fail_cleanup_contexts;
+	}
+
 	/*
-	 * We can have multiple PLIC instances so setup cpuhp state only
-	 * when context handler for current/boot CPU is present.
+	 * We can have multiple PLIC instances so setup global state
+	 * and register syscore operations only once after context
+	 * handlers of all online CPUs are initialized.
 	 */
-	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;
+	if (!plic_global_setup_done) {
+		struct irq_domain *domain;
+		bool global_setup = true;
+
+		for_each_online_cpu(cpu) {
+			handler = per_cpu_ptr(&plic_handlers, cpu);
+			if (!handler->present) {
+				global_setup = false;
+				break;
+			}
+		}
+
+		if (global_setup) {
+			void (*handler_fn)(struct irq_desc *) = plic_handle_irq;
+
+			if (test_bit(PLIC_QUIRK_CP100_CLAIM_REGISTER_ERRATUM, &handler->priv->plic_quirks))
+				handler_fn = plic_handle_irq_cp100;
+
+			/* Find parent domain and register chained handler */
+			domain = irq_find_matching_fwnode(riscv_get_intc_hwnode(), DOMAIN_BUS_ANY);
+			if (domain)
+				plic_parent_irq = irq_create_mapping(domain, RV_IRQ_EXT);
+			if (plic_parent_irq)
+				irq_set_chained_handler(plic_parent_irq, handler_fn);
+
+			cpuhp_setup_state(CPUHP_AP_IRQ_SIFIVE_PLIC_STARTING,
+					  "irqchip/sifive/plic:starting",
+					  plic_starting_cpu, plic_dying_cpu);
+			register_syscore(&plic_irq_syscore);
+			plic_global_setup_done = true;
+		}
 	}
-	register_syscore_ops(&plic_irq_syscore_ops);
 
-	pr_info("%pOFP: mapped %d interrupts with %d handlers for"
-		" %d contexts.\n", node, nr_irqs, nr_handlers, nr_contexts);
+#ifdef CONFIG_ACPI
+	if (!acpi_disabled)
+		acpi_dev_clear_dependencies(ACPI_COMPANION(fwnode->dev));
+#endif
+
+	pr_info("%pfwP: mapped %d interrupts with %d handlers for %d contexts.\n",
+		fwnode, nr_irqs, nr_handlers, nr_contexts);
 	return 0;
 
-out_free_enable_reg:
-	for_each_cpu(cpu, cpu_present_mask) {
+fail_cleanup_contexts:
+	for (i = 0; i < nr_contexts; i++) {
+		if (plic_parse_context_parent(fwnode, i, &parent_hwirq, &cpu, priv->acpi_plic_id))
+			continue;
+		if (parent_hwirq != RV_IRQ_EXT || cpu < 0)
+			continue;
+
 		handler = per_cpu_ptr(&plic_handlers, cpu);
+		handler->present = false;
+		handler->hart_base = NULL;
+		handler->enable_base = NULL;
 		kfree(handler->enable_save);
+		handler->enable_save = NULL;
+		handler->priv = NULL;
 	}
-out_free_priority_reg:
-	kfree(priv->prio_save);
-out_iounmap:
-	iounmap(priv->regs);
-out_free_priv:
+	bitmap_free(priv->prio_save);
+fail_free_priv:
 	kfree(priv);
+fail_free_regs:
+	iounmap(regs);
 	return error;
 }
 
-static int __init plic_init(struct device_node *node,
-			    struct device_node *parent)
+static int plic_platform_probe(struct platform_device *pdev)
 {
-	return __plic_init(node, parent, 0);
+	return plic_probe(pdev->dev.fwnode);
 }
 
-IRQCHIP_DECLARE(sifive_plic, "sifive,plic-1.0.0", plic_init);
-IRQCHIP_DECLARE(riscv_plic0, "riscv,plic0", plic_init); /* for legacy systems */
+static struct platform_driver plic_driver = {
+	.driver = {
+		.name		= "riscv-plic",
+		.of_match_table	= plic_match,
+		.suppress_bind_attrs = true,
+		.acpi_match_table = ACPI_PTR(plic_acpi_match),
+	},
+	.probe = plic_platform_probe,
+};
+builtin_platform_driver(plic_driver);
 
-static int __init plic_edge_init(struct device_node *node,
-				 struct device_node *parent)
+static int __init plic_early_probe(struct device_node *node,
+				   struct device_node *parent)
 {
-	return __plic_init(node, parent, BIT(PLIC_QUIRK_EDGE_INTERRUPT));
+	return plic_probe(&node->fwnode);
 }
 
-IRQCHIP_DECLARE(andestech_nceplic100, "andestech,nceplic100", plic_edge_init);
-IRQCHIP_DECLARE(thead_c900_plic, "thead,c900-plic", plic_edge_init);
+IRQCHIP_DECLARE(riscv, "allwinner,sun20i-d1-plic", plic_early_probe);