[linux-block.git] / drivers / irqchip / irq-sifive-plic.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2017 SiFive
 * 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/irqdomain.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/platform_device.h>
#include <linux/spinlock.h>
#include <asm/smp.h>

/*
 * This driver implements a version of the RISC-V PLIC with the actual layout
 * specified in chapter 8 of the SiFive U5 Coreplex Series Manual:
 *
 *     https://static.dev.sifive.com/U54-MC-RVCoreIP.pdf
 *
 * The largest number supported by devices marked as 'sifive,plic-1.0.0', is
 * 1024, of which device 0 is defined as non-existent by the RISC-V Privileged
 * Spec.
 */

#define MAX_DEVICES			1024
#define MAX_CONTEXTS			15872

/*
 * Each interrupt source has a priority register associated with it.
 * We always hardwire it to one in Linux.
 */
#define PRIORITY_BASE			0
#define     PRIORITY_PER_ID		4

/*
 * 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

/*
 * 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
 * take an interrupt, and a register to claim interrupts.
 */
#define CONTEXT_BASE			0x200000
#define     CONTEXT_PER_HART		0x1000
#define     CONTEXT_THRESHOLD		0x00
#define     CONTEXT_CLAIM		0x04

#define	PLIC_DISABLE_THRESHOLD		0x7
#define	PLIC_ENABLE_THRESHOLD		0

struct plic_priv {
	struct cpumask lmask;
	struct irq_domain *irqdomain;
	void __iomem *regs;
};

struct plic_handler {
	bool			present;
	void __iomem		*hart_base;
	/*
	 * Protect mask operations on the registers given that we can't
	 * assume atomic memory operations work on them.
	 */
	raw_spinlock_t		enable_lock;
	void __iomem		*enable_base;
	struct plic_priv	*priv;
};
static bool plic_cpuhp_setup_done;
static DEFINE_PER_CPU(struct plic_handler, plic_handlers);

static inline void plic_toggle(struct plic_handler *handler,
				int hwirq, int enable)
{
	u32 __iomem *reg = handler->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);
	raw_spin_unlock(&handler->enable_lock);
}

static inline void plic_irq_toggle(const struct cpumask *mask,
				   struct irq_data *d, int enable)
{
	int cpu;
	struct plic_priv *priv = irq_get_chip_data(d->irq);

	writel(enable, priv->regs + PRIORITY_BASE + d->hwirq * PRIORITY_PER_ID);
	for_each_cpu(cpu, mask) {
		struct plic_handler *handler = per_cpu_ptr(&plic_handlers, cpu);

		if (handler->present &&
		    cpumask_test_cpu(cpu, &handler->priv->lmask))
			plic_toggle(handler, d->hwirq, enable);
	}
}

static void plic_irq_unmask(struct irq_data *d)
{
	struct cpumask amask;
	unsigned int cpu;
	struct plic_priv *priv = irq_get_chip_data(d->irq);

	cpumask_and(&amask, &priv->lmask, cpu_online_mask);
	cpu = cpumask_any_and(irq_data_get_affinity_mask(d),
					   &amask);
	if (WARN_ON_ONCE(cpu >= nr_cpu_ids))
		return;
	plic_irq_toggle(cpumask_of(cpu), d, 1);
}

static void plic_irq_mask(struct irq_data *d)
{
	struct plic_priv *priv = irq_get_chip_data(d->irq);

	plic_irq_toggle(&priv->lmask, d, 0);
}

#ifdef CONFIG_SMP
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_get_chip_data(d->irq);

	cpumask_and(&amask, &priv->lmask, mask_val);

	if (force)
		cpu = cpumask_first(&amask);
	else
		cpu = cpumask_any_and(&amask, cpu_online_mask);

	if (cpu >= nr_cpu_ids)
		return -EINVAL;

	plic_irq_toggle(&priv->lmask, d, 0);
	plic_irq_toggle(cpumask_of(cpu), d, 1);

	irq_data_update_effective_affinity(d, cpumask_of(cpu));

	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_chip = {
	.name		= "SiFive PLIC",
	.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
};

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_alloc(struct irq_domain *domain, unsigned int virq,
				 unsigned int nr_irqs, void *arg)
{
	int i, ret;
	irq_hw_number_t hwirq;
	unsigned int type;
	struct irq_fwspec *fwspec = arg;

	ret = irq_domain_translate_onecell(domain, fwspec, &hwirq, &type);
	if (ret)
		return ret;

	for (i = 0; i < nr_irqs; i++) {
		ret = plic_irqdomain_map(domain, virq + i, hwirq + i);
		if (ret)
			return ret;
	}

	return 0;
}

static const struct irq_domain_ops plic_irqdomain_ops = {
	.translate	= irq_domain_translate_onecell,
	.alloc		= plic_irq_domain_alloc,
	.free		= irq_domain_free_irqs_top,
};

/*
 * 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)
{
	struct plic_handler *handler = this_cpu_ptr(&plic_handlers);
	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(handler->priv->irqdomain, hwirq);

		if (unlikely(irq <= 0))
			pr_warn_ratelimited("can't find mapping for hwirq %lu\n",
					hwirq);
		else
			generic_handle_irq(irq);
	}
	csr_set(CSR_IE, IE_EIE);
}

/*
 * 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)
{
	for (; node; node = node->parent) {
		if (of_device_is_compatible(node, "riscv"))
			return riscv_of_processor_hartid(node);
	}

	return -1;
}

static void plic_set_threshold(struct plic_handler *handler, u32 threshold)
{
	/* priority must be > threshold to trigger an interrupt */
	writel(threshold, handler->hart_base + CONTEXT_THRESHOLD);
}

static int plic_dying_cpu(unsigned int cpu)
{
	struct plic_handler *handler = this_cpu_ptr(&plic_handlers);

	csr_clear(CSR_IE, IE_EIE);
	plic_set_threshold(handler, PLIC_DISABLE_THRESHOLD);

	return 0;
}

static int plic_starting_cpu(unsigned int cpu)
{
	struct plic_handler *handler = this_cpu_ptr(&plic_handlers);

	csr_set(CSR_IE, IE_EIE);
	plic_set_threshold(handler, PLIC_ENABLE_THRESHOLD);

	return 0;
}

static int __init plic_init(struct device_node *node,
		struct device_node *parent)
{
	int error = 0, nr_contexts, nr_handlers = 0, i;
	u32 nr_irqs;
	struct plic_priv *priv;
	struct plic_handler *handler;

	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;

	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);
	if (WARN_ON(!nr_irqs))
		goto out_iounmap;

	nr_contexts = of_irq_count(node);
	if (WARN_ON(!nr_contexts))
		goto out_iounmap;

	error = -ENOMEM;
	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;
		irq_hw_number_t hwirq;
		int cpu, hartid;

		if (of_irq_parse_one(node, i, &parent)) {
			pr_err("failed to parse parent for context %d.\n", i);
			continue;
		}

		/*
		 * Skip contexts other than external interrupts for our
		 * privilege level.
		 */
		if (parent.args[0] != RV_IRQ_EXT)
			continue;

		hartid = plic_find_hart_id(parent.np);
		if (hartid < 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);
			continue;
		}

		/*
		 * 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
		 * little fragile.
		 */
		handler = per_cpu_ptr(&plic_handlers, cpu);
		if (handler->present) {
			pr_warn("handler already present for context %d.\n", i);
			plic_set_threshold(handler, PLIC_DISABLE_THRESHOLD);
			goto done;
		}

		cpumask_set_cpu(cpu, &priv->lmask);
		handler->present = true;
		handler->hart_base =
			priv->regs + CONTEXT_BASE + i * CONTEXT_PER_HART;
		raw_spin_lock_init(&handler->enable_lock);
		handler->enable_base =
			priv->regs + ENABLE_BASE + i * ENABLE_PER_HART;
		handler->priv = priv;
done:
		for (hwirq = 1; hwirq <= nr_irqs; hwirq++)
			plic_toggle(handler, hwirq, 0);
		nr_handlers++;
	}

	/*
	 * 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);
	set_handle_irq(plic_handle_irq);
	return 0;

out_iounmap:
	iounmap(priv->regs);
out_free_priv:
	kfree(priv);
	return error;
}

IRQCHIP_DECLARE(sifive_plic, "sifive,plic-1.0.0", plic_init);
IRQCHIP_DECLARE(riscv_plic0, "riscv,plic0", plic_init); /* for legacy systems */
Commit	Line	Data
8237f8bc CH	1	// SPDX-License-Identifier: GPL-2.0
	2	/*
	3	* Copyright (C) 2017 SiFive
	4	* Copyright (C) 2018 Christoph Hellwig
	5	*/
	6	#define pr_fmt(fmt) "plic: " fmt
ccbe80ba	7	#include <linux/cpu.h>
8237f8bc CH	8	#include <linux/interrupt.h>
	9	#include <linux/io.h>
	10	#include <linux/irq.h>
	11	#include <linux/irqchip.h>
	12	#include <linux/irqdomain.h>
	13	#include <linux/module.h>
	14	#include <linux/of.h>
	15	#include <linux/of_address.h>
	16	#include <linux/of_irq.h>
	17	#include <linux/platform_device.h>
	18	#include <linux/spinlock.h>
f99fb607	19	#include <asm/smp.h>
8237f8bc CH	20
	21	/*
	22	* This driver implements a version of the RISC-V PLIC with the actual layout
	23	* specified in chapter 8 of the SiFive U5 Coreplex Series Manual:
	24	*
	25	* https://static.dev.sifive.com/U54-MC-RVCoreIP.pdf
	26	*
	27	* The largest number supported by devices marked as 'sifive,plic-1.0.0', is
	28	* 1024, of which device 0 is defined as non-existent by the RISC-V Privileged
	29	* Spec.
	30	*/
	31
	32	#define MAX_DEVICES 1024
	33	#define MAX_CONTEXTS 15872
	34
	35	/*
	36	* Each interrupt source has a priority register associated with it.
	37	* We always hardwire it to one in Linux.
	38	*/
	39	#define PRIORITY_BASE 0
	40	#define PRIORITY_PER_ID 4
	41
	42	/*
	43	* Each hart context has a vector of interrupt enable bits associated with it.
	44	* There's one bit for each interrupt source.
	45	*/
	46	#define ENABLE_BASE 0x2000
	47	#define ENABLE_PER_HART 0x80
	48
	49	/*
	50	* Each hart context has a set of control registers associated with it. Right
	51	* now there's only two: a source priority threshold over which the hart will
	52	* take an interrupt, and a register to claim interrupts.
	53	*/
	54	#define CONTEXT_BASE 0x200000
	55	#define CONTEXT_PER_HART 0x1000
	56	#define CONTEXT_THRESHOLD 0x00
	57	#define CONTEXT_CLAIM 0x04
	58
d727be7b	59	#define PLIC_DISABLE_THRESHOLD 0x7
ccbe80ba AP	60	#define PLIC_ENABLE_THRESHOLD 0
ccbe80ba AP	61
f1ad1133 AP	62	struct plic_priv {
	63	struct cpumask lmask;
	64	struct irq_domain *irqdomain;
	65	void __iomem *regs;
	66	};
8237f8bc CH	67
	68	struct plic_handler {
	69	bool present;
86c7cbf1 AP	70	void __iomem *hart_base;
	71	/*
	72	* Protect mask operations on the registers given that we can't
	73	* assume atomic memory operations work on them.
	74	*/
	75	raw_spinlock_t enable_lock;
	76	void __iomem *enable_base;
f1ad1133	77	struct plic_priv *priv;
8237f8bc	78	};
2234ae84	79	static bool plic_cpuhp_setup_done;
8237f8bc CH	80	static DEFINE_PER_CPU(struct plic_handler, plic_handlers);
8237f8bc CH	81
86c7cbf1 AP	82	static inline void plic_toggle(struct plic_handler *handler,
86c7cbf1 AP	83	int hwirq, int enable)
8237f8bc	84	{
86c7cbf1	85	u32 __iomem reg = handler->enable_base + (hwirq / 32) sizeof(u32);
8237f8bc CH	86	u32 hwirq_mask = 1 << (hwirq % 32);
8237f8bc CH	87
86c7cbf1	88	raw_spin_lock(&handler->enable_lock);
8237f8bc CH	89	if (enable)
	90	writel(readl(reg) \| hwirq_mask, reg);
	91	else
	92	writel(readl(reg) & ~hwirq_mask, reg);
86c7cbf1	93	raw_spin_unlock(&handler->enable_lock);
8237f8bc CH	94	}
8237f8bc CH	95
cc9f04f9	96	static inline void plic_irq_toggle(const struct cpumask *mask,
f1ad1133	97	struct irq_data *d, int enable)
8237f8bc CH	98	{
8237f8bc CH	99	int cpu;
f1ad1133	100	struct plic_priv *priv = irq_get_chip_data(d->irq);
8237f8bc	101
f1ad1133	102	writel(enable, priv->regs + PRIORITY_BASE + d->hwirq * PRIORITY_PER_ID);
cc9f04f9	103	for_each_cpu(cpu, mask) {
8237f8bc CH	104	struct plic_handler *handler = per_cpu_ptr(&plic_handlers, cpu);
8237f8bc CH	105
f1ad1133 AP	106	if (handler->present &&
	107	cpumask_test_cpu(cpu, &handler->priv->lmask))
	108	plic_toggle(handler, d->hwirq, enable);
8237f8bc CH	109	}
	110	}
	111
bb0fed1c	112	static void plic_irq_unmask(struct irq_data *d)
8237f8bc	113	{
f1ad1133 AP	114	struct cpumask amask;
	115	unsigned int cpu;
	116	struct plic_priv *priv = irq_get_chip_data(d->irq);
	117
	118	cpumask_and(&amask, &priv->lmask, cpu_online_mask);
	119	cpu = cpumask_any_and(irq_data_get_affinity_mask(d),
	120	&amask);
cc9f04f9 AP	121	if (WARN_ON_ONCE(cpu >= nr_cpu_ids))
cc9f04f9 AP	122	return;
f1ad1133	123	plic_irq_toggle(cpumask_of(cpu), d, 1);
8237f8bc CH	124	}
8237f8bc CH	125
bb0fed1c	126	static void plic_irq_mask(struct irq_data *d)
8237f8bc	127	{
f1ad1133 AP	128	struct plic_priv *priv = irq_get_chip_data(d->irq);
	129
	130	plic_irq_toggle(&priv->lmask, d, 0);
8237f8bc CH	131	}
8237f8bc CH	132
cc9f04f9 AP	133	#ifdef CONFIG_SMP
	134	static int plic_set_affinity(struct irq_data *d,
	135	const struct cpumask *mask_val, bool force)
	136	{
	137	unsigned int cpu;
f1ad1133 AP	138	struct cpumask amask;
	139	struct plic_priv *priv = irq_get_chip_data(d->irq);
	140
	141	cpumask_and(&amask, &priv->lmask, mask_val);
cc9f04f9 AP	142
cc9f04f9 AP	143	if (force)
f1ad1133	144	cpu = cpumask_first(&amask);
cc9f04f9	145	else
f1ad1133	146	cpu = cpumask_any_and(&amask, cpu_online_mask);
cc9f04f9 AP	147
	148	if (cpu >= nr_cpu_ids)
	149	return -EINVAL;
	150
f1ad1133 AP	151	plic_irq_toggle(&priv->lmask, d, 0);
f1ad1133 AP	152	plic_irq_toggle(cpumask_of(cpu), d, 1);
cc9f04f9 AP	153
	154	irq_data_update_effective_affinity(d, cpumask_of(cpu));
	155
	156	return IRQ_SET_MASK_OK_DONE;
	157	}
	158	#endif
	159
bb0fed1c MZ	160	static void plic_irq_eoi(struct irq_data *d)
	161	{
	162	struct plic_handler *handler = this_cpu_ptr(&plic_handlers);
	163
	164	writel(d->hwirq, handler->hart_base + CONTEXT_CLAIM);
	165	}
	166
8237f8bc CH	167	static struct irq_chip plic_chip = {
8237f8bc CH	168	.name = "SiFive PLIC",
bb0fed1c MZ	169	.irq_mask = plic_irq_mask,
	170	.irq_unmask = plic_irq_unmask,
	171	.irq_eoi = plic_irq_eoi,
cc9f04f9 AP	172	#ifdef CONFIG_SMP
	173	.irq_set_affinity = plic_set_affinity,
	174	#endif
8237f8bc CH	175	};
	176
	177	static int plic_irqdomain_map(struct irq_domain *d, unsigned int irq,
	178	irq_hw_number_t hwirq)
	179	{
2458ed31 AP	180	struct plic_priv *priv = d->host_data;
2458ed31 AP	181
466008f9 YS	182	irq_domain_set_info(d, irq, hwirq, &plic_chip, d->host_data,
466008f9 YS	183	handle_fasteoi_irq, NULL, NULL);
8237f8bc	184	irq_set_noprobe(irq);
2458ed31	185	irq_set_affinity(irq, &priv->lmask);
8237f8bc CH	186	return 0;
	187	}
	188
466008f9 YS	189	static int plic_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
	190	unsigned int nr_irqs, void *arg)
	191	{
	192	int i, ret;
	193	irq_hw_number_t hwirq;
	194	unsigned int type;
	195	struct irq_fwspec *fwspec = arg;
	196
	197	ret = irq_domain_translate_onecell(domain, fwspec, &hwirq, &type);
	198	if (ret)
	199	return ret;
	200
	201	for (i = 0; i < nr_irqs; i++) {
	202	ret = plic_irqdomain_map(domain, virq + i, hwirq + i);
	203	if (ret)
	204	return ret;
	205	}
	206
	207	return 0;
	208	}
	209
8237f8bc	210	static const struct irq_domain_ops plic_irqdomain_ops = {
466008f9 YS	211	.translate = irq_domain_translate_onecell,
	212	.alloc = plic_irq_domain_alloc,
	213	.free = irq_domain_free_irqs_top,
8237f8bc CH	214	};
8237f8bc CH	215
8237f8bc CH	216	/*
	217	* Handling an interrupt is a two-step process: first you claim the interrupt
	218	* by reading the claim register, then you complete the interrupt by writing
	219	* that source ID back to the same claim register. This automatically enables
	220	* and disables the interrupt, so there's nothing else to do.
	221	*/
	222	static void plic_handle_irq(struct pt_regs *regs)
	223	{
	224	struct plic_handler *handler = this_cpu_ptr(&plic_handlers);
86c7cbf1	225	void __iomem *claim = handler->hart_base + CONTEXT_CLAIM;
8237f8bc CH	226	irq_hw_number_t hwirq;
	227
	228	WARN_ON_ONCE(!handler->present);
	229
a4c3733d	230	csr_clear(CSR_IE, IE_EIE);
8237f8bc	231	while ((hwirq = readl(claim))) {
f1ad1133	232	int irq = irq_find_mapping(handler->priv->irqdomain, hwirq);
8237f8bc CH	233
	234	if (unlikely(irq <= 0))
	235	pr_warn_ratelimited("can't find mapping for hwirq %lu\n",
	236	hwirq);
	237	else
	238	generic_handle_irq(irq);
8237f8bc	239	}
a4c3733d	240	csr_set(CSR_IE, IE_EIE);
8237f8bc CH	241	}
	242
	243	/*
	244	* Walk up the DT tree until we find an active RISC-V core (HART) node and
	245	* extract the cpuid from it.
	246	*/
	247	static int plic_find_hart_id(struct device_node *node)
	248	{
	249	for (; node; node = node->parent) {
	250	if (of_device_is_compatible(node, "riscv"))
b2f8cfa7	251	return riscv_of_processor_hartid(node);
8237f8bc CH	252	}
	253
	254	return -1;
	255	}
	256
ccbe80ba AP	257	static void plic_set_threshold(struct plic_handler *handler, u32 threshold)
	258	{
	259	/* priority must be > threshold to trigger an interrupt */
	260	writel(threshold, handler->hart_base + CONTEXT_THRESHOLD);
	261	}
	262
	263	static int plic_dying_cpu(unsigned int cpu)
	264	{
	265	struct plic_handler *handler = this_cpu_ptr(&plic_handlers);
	266
	267	csr_clear(CSR_IE, IE_EIE);
	268	plic_set_threshold(handler, PLIC_DISABLE_THRESHOLD);
	269
	270	return 0;
	271	}
	272
	273	static int plic_starting_cpu(unsigned int cpu)
	274	{
	275	struct plic_handler *handler = this_cpu_ptr(&plic_handlers);
	276
	277	csr_set(CSR_IE, IE_EIE);
	278	plic_set_threshold(handler, PLIC_ENABLE_THRESHOLD);
	279
	280	return 0;
	281	}
	282
8237f8bc CH	283	static int __init plic_init(struct device_node *node,
	284	struct device_node *parent)
	285	{
6adfe8d2	286	int error = 0, nr_contexts, nr_handlers = 0, i;
8237f8bc	287	u32 nr_irqs;
f1ad1133	288	struct plic_priv *priv;
2234ae84	289	struct plic_handler *handler;
8237f8bc	290
f1ad1133 AP	291	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
	292	if (!priv)
	293	return -ENOMEM;
8237f8bc	294
f1ad1133 AP	295	priv->regs = of_iomap(node, 0);
	296	if (WARN_ON(!priv->regs)) {
	297	error = -EIO;
	298	goto out_free_priv;
	299	}
8237f8bc CH	300
	301	error = -EINVAL;
	302	of_property_read_u32(node, "riscv,ndev", &nr_irqs);
	303	if (WARN_ON(!nr_irqs))
	304	goto out_iounmap;
	305
6adfe8d2 AP	306	nr_contexts = of_irq_count(node);
6adfe8d2 AP	307	if (WARN_ON(!nr_contexts))
8237f8bc	308	goto out_iounmap;
8237f8bc CH	309
8237f8bc CH	310	error = -ENOMEM;
f1ad1133 AP	311	priv->irqdomain = irq_domain_add_linear(node, nr_irqs + 1,
	312	&plic_irqdomain_ops, priv);
	313	if (WARN_ON(!priv->irqdomain))
8237f8bc CH	314	goto out_iounmap;
8237f8bc CH	315
6adfe8d2	316	for (i = 0; i < nr_contexts; i++) {
8237f8bc	317	struct of_phandle_args parent;
8237f8bc	318	irq_hw_number_t hwirq;
f99fb607	319	int cpu, hartid;
8237f8bc CH	320
	321	if (of_irq_parse_one(node, i, &parent)) {
	322	pr_err("failed to parse parent for context %d.\n", i);
	323	continue;
	324	}
	325
a4c3733d CH	326	/*
	327	* Skip contexts other than external interrupts for our
	328	* privilege level.
	329	*/
2f3035da	330	if (parent.args[0] != RV_IRQ_EXT)
8237f8bc CH	331	continue;
8237f8bc CH	332
f99fb607 AP	333	hartid = plic_find_hart_id(parent.np);
f99fb607 AP	334	if (hartid < 0) {
8237f8bc CH	335	pr_warn("failed to parse hart ID for context %d.\n", i);
	336	continue;
	337	}
	338
f99fb607	339	cpu = riscv_hartid_to_cpuid(hartid);
fc03acae AP	340	if (cpu < 0) {
	341	pr_warn("Invalid cpuid for context %d\n", i);
	342	continue;
	343	}
	344
9ce06497 CH	345	/*
	346	* When running in M-mode we need to ignore the S-mode handler.
	347	* Here we assume it always comes later, but that might be a
	348	* little fragile.
	349	*/
8237f8bc	350	handler = per_cpu_ptr(&plic_handlers, cpu);
3fecb5aa AP	351	if (handler->present) {
3fecb5aa AP	352	pr_warn("handler already present for context %d.\n", i);
ccbe80ba	353	plic_set_threshold(handler, PLIC_DISABLE_THRESHOLD);
9ce06497	354	goto done;
3fecb5aa AP	355	}
3fecb5aa AP	356
f1ad1133	357	cpumask_set_cpu(cpu, &priv->lmask);
8237f8bc	358	handler->present = true;
86c7cbf1	359	handler->hart_base =
f1ad1133	360	priv->regs + CONTEXT_BASE + i * CONTEXT_PER_HART;
86c7cbf1 AP	361	raw_spin_lock_init(&handler->enable_lock);
86c7cbf1 AP	362	handler->enable_base =
f1ad1133 AP	363	priv->regs + ENABLE_BASE + i * ENABLE_PER_HART;
f1ad1133 AP	364	handler->priv = priv;
9ce06497	365	done:
8237f8bc	366	for (hwirq = 1; hwirq <= nr_irqs; hwirq++)
86c7cbf1	367	plic_toggle(handler, hwirq, 0);
6adfe8d2	368	nr_handlers++;
8237f8bc CH	369	}
8237f8bc CH	370
2234ae84 AP	371	/*
	372	* We can have multiple PLIC instances so setup cpuhp state only
	373	* when context handler for current/boot CPU is present.
	374	*/
	375	handler = this_cpu_ptr(&plic_handlers);
	376	if (handler->present && !plic_cpuhp_setup_done) {
	377	cpuhp_setup_state(CPUHP_AP_IRQ_SIFIVE_PLIC_STARTING,
ccbe80ba AP	378	"irqchip/sifive/plic:starting",
ccbe80ba AP	379	plic_starting_cpu, plic_dying_cpu);
2234ae84 AP	380	plic_cpuhp_setup_done = true;
	381	}
	382
0e375f51 AP	383	pr_info("%pOFP: mapped %d interrupts with %d handlers for"
0e375f51 AP	384	" %d contexts.\n", node, nr_irqs, nr_handlers, nr_contexts);
8237f8bc CH	385	set_handle_irq(plic_handle_irq);
	386	return 0;
	387
	388	out_iounmap:
f1ad1133 AP	389	iounmap(priv->regs);
	390	out_free_priv:
	391	kfree(priv);
8237f8bc CH	392	return error;
	393	}
	394
	395	IRQCHIP_DECLARE(sifive_plic, "sifive,plic-1.0.0", plic_init);
	396	IRQCHIP_DECLARE(riscv_plic0, "riscv,plic0", plic_init); /* for legacy systems */