drivers/irqchip/irq-riscv-aplic-direct.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (C) 2021 Western Digital Corporation or its affiliates.
  * Copyright (C) 2022 Ventana Micro Systems Inc.
  */

 #include <linux/bitfield.h>
 #include <linux/bitops.h>
 #include <linux/cpu.h>
 #include <linux/interrupt.h>
 #include <linux/irqchip.h>
 #include <linux/irqchip/chained_irq.h>
 #include <linux/irqchip/riscv-aplic.h>
 #include <linux/module.h>
 #include <linux/of_address.h>
 #include <linux/printk.h>
 #include <linux/smp.h>

 #include "irq-riscv-aplic-main.h"

 #define APLIC_DISABLE_IDELIVERY		0
 #define APLIC_ENABLE_IDELIVERY		1
 #define APLIC_DISABLE_ITHRESHOLD	1
 #define APLIC_ENABLE_ITHRESHOLD		0

 struct aplic_direct {
 	struct aplic_priv	priv;
 	struct irq_domain	*irqdomain;
 	struct cpumask		lmask;
 };

 struct aplic_idc {
 	unsigned int		hart_index;
 	void __iomem		*regs;
 	struct aplic_direct	*direct;
 };

 static unsigned int aplic_direct_parent_irq;
 static DEFINE_PER_CPU(struct aplic_idc, aplic_idcs);

 static void aplic_direct_irq_eoi(struct irq_data *d)
 {
 	/*
 	 * The fasteoi_handler requires irq_eoi() callback hence
 	 * provide a dummy handler.
 	 */
 }

 #ifdef CONFIG_SMP
 static int aplic_direct_set_affinity(struct irq_data *d, const struct cpumask *mask_val,
 				     bool force)
 {
 	struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
 	struct aplic_direct *direct = container_of(priv, struct aplic_direct, priv);
 	struct aplic_idc *idc;
 	unsigned int cpu, val;
 	void __iomem *target;

 	if (force)
 		cpu = cpumask_first_and(&direct->lmask, mask_val);
 	else
 		cpu = cpumask_first_and_and(&direct->lmask, mask_val, cpu_online_mask);

 	if (cpu >= nr_cpu_ids)
 		return -EINVAL;

 	idc = per_cpu_ptr(&aplic_idcs, cpu);
 	target = priv->regs + APLIC_TARGET_BASE + (d->hwirq - 1) * sizeof(u32);
 	val = FIELD_PREP(APLIC_TARGET_HART_IDX, idc->hart_index);
 	val |= FIELD_PREP(APLIC_TARGET_IPRIO, APLIC_DEFAULT_PRIORITY);
 	writel(val, target);

 	irq_data_update_effective_affinity(d, cpumask_of(cpu));

 	return IRQ_SET_MASK_OK_DONE;
 }
 #endif

 static struct irq_chip aplic_direct_chip = {
 	.name		= "APLIC-DIRECT",
 	.irq_mask	= aplic_irq_mask,
 	.irq_unmask	= aplic_irq_unmask,
 	.irq_set_type	= aplic_irq_set_type,
 	.irq_eoi	= aplic_direct_irq_eoi,
 #ifdef CONFIG_SMP
 	.irq_set_affinity = aplic_direct_set_affinity,
 #endif
 	.flags		= IRQCHIP_SET_TYPE_MASKED |
 			  IRQCHIP_SKIP_SET_WAKE |
 			  IRQCHIP_MASK_ON_SUSPEND,
 };

 static int aplic_direct_irqdomain_translate(struct irq_domain *d, struct irq_fwspec *fwspec,
 					    unsigned long *hwirq, unsigned int *type)
 {
 	struct aplic_priv *priv = d->host_data;

 	return aplic_irqdomain_translate(fwspec, priv->gsi_base, hwirq, type);
 }

 static int aplic_direct_irqdomain_alloc(struct irq_domain *domain, unsigned int virq,
 					unsigned int nr_irqs, void *arg)
 {
 	struct aplic_priv *priv = domain->host_data;
 	struct aplic_direct *direct = container_of(priv, struct aplic_direct, priv);
 	struct irq_fwspec *fwspec = arg;
 	irq_hw_number_t hwirq;
 	unsigned int type;
 	int i, ret;

 	ret = aplic_irqdomain_translate(fwspec, priv->gsi_base, &hwirq, &type);
 	if (ret)
 		return ret;

 	for (i = 0; i < nr_irqs; i++) {
 		irq_domain_set_info(domain, virq + i, hwirq + i, &aplic_direct_chip,
 				    priv, handle_fasteoi_irq, NULL, NULL);
 		irq_set_affinity(virq + i, &direct->lmask);
 	}

 	return 0;
 }

 static const struct irq_domain_ops aplic_direct_irqdomain_ops = {
 	.translate	= aplic_direct_irqdomain_translate,
 	.alloc		= aplic_direct_irqdomain_alloc,
 	.free		= irq_domain_free_irqs_top,
 };

 /*
  * To handle an APLIC direct interrupts, we just read the CLAIMI register
  * which will return highest priority pending interrupt and clear the
  * pending bit of the interrupt. This process is repeated until CLAIMI
  * register return zero value.
  */
 static void aplic_direct_handle_irq(struct irq_desc *desc)
 {
 	struct aplic_idc *idc = this_cpu_ptr(&aplic_idcs);
 	struct irq_domain *irqdomain = idc->direct->irqdomain;
 	struct irq_chip *chip = irq_desc_get_chip(desc);
 	irq_hw_number_t hw_irq;
 	int irq;

 	chained_irq_enter(chip, desc);

 	while ((hw_irq = readl(idc->regs + APLIC_IDC_CLAIMI))) {
 		hw_irq = hw_irq >> APLIC_IDC_TOPI_ID_SHIFT;
 		irq = irq_find_mapping(irqdomain, hw_irq);

 		if (unlikely(irq <= 0)) {
 			dev_warn_ratelimited(idc->direct->priv.dev,
 					     "hw_irq %lu mapping not found\n", hw_irq);
 		} else {
 			generic_handle_irq(irq);
 		}
 	}

 	chained_irq_exit(chip, desc);
 }

 static void aplic_idc_set_delivery(struct aplic_idc *idc, bool en)
 {
 	u32 de = (en) ? APLIC_ENABLE_IDELIVERY : APLIC_DISABLE_IDELIVERY;
 	u32 th = (en) ? APLIC_ENABLE_ITHRESHOLD : APLIC_DISABLE_ITHRESHOLD;

 	/* Priority must be less than threshold for interrupt triggering */
 	writel(th, idc->regs + APLIC_IDC_ITHRESHOLD);

 	/* Delivery must be set to 1 for interrupt triggering */
 	writel(de, idc->regs + APLIC_IDC_IDELIVERY);
 }

 static int aplic_direct_dying_cpu(unsigned int cpu)
 {
 	if (aplic_direct_parent_irq)
 		disable_percpu_irq(aplic_direct_parent_irq);

 	return 0;
 }

 static int aplic_direct_starting_cpu(unsigned int cpu)
 {
 	if (aplic_direct_parent_irq) {
 		enable_percpu_irq(aplic_direct_parent_irq,
 				  irq_get_trigger_type(aplic_direct_parent_irq));
 	}

 	return 0;
 }

 static int aplic_direct_parse_parent_hwirq(struct device *dev, u32 index,
 					   u32 *parent_hwirq, unsigned long *parent_hartid)
 {
 	struct of_phandle_args parent;
 	int rc;

 	/*
 	 * Currently, only OF fwnode is supported so extend this
 	 * function for ACPI support.
 	 */
 	if (!is_of_node(dev->fwnode))
 		return -EINVAL;

 	rc = of_irq_parse_one(to_of_node(dev->fwnode), index, &parent);
 	if (rc)
 		return rc;

 	rc = riscv_of_parent_hartid(parent.np, parent_hartid);
 	if (rc)
 		return rc;

 	*parent_hwirq = parent.args[0];
 	return 0;
 }

 int aplic_direct_setup(struct device *dev, void __iomem *regs)
 {
 	int i, j, rc, cpu, current_cpu, setup_count = 0;
 	struct aplic_direct *direct;
 	struct irq_domain *domain;
 	struct aplic_priv *priv;
 	struct aplic_idc *idc;
 	unsigned long hartid;
 	u32 v, hwirq;

 	direct = devm_kzalloc(dev, sizeof(*direct), GFP_KERNEL);
 	if (!direct)
 		return -ENOMEM;
 	priv = &direct->priv;

 	rc = aplic_setup_priv(priv, dev, regs);
 	if (rc) {
 		dev_err(dev, "failed to create APLIC context\n");
 		return rc;
 	}

 	/* Setup per-CPU IDC and target CPU mask */
 	current_cpu = get_cpu();
 	for (i = 0; i < priv->nr_idcs; i++) {
 		rc = aplic_direct_parse_parent_hwirq(dev, i, &hwirq, &hartid);
 		if (rc) {
 			dev_warn(dev, "parent irq for IDC%d not found\n", i);
 			continue;
 		}

 		/*
 		 * Skip interrupts other than external interrupts for
 		 * current privilege level.
 		 */
 		if (hwirq != RV_IRQ_EXT)
 			continue;

 		cpu = riscv_hartid_to_cpuid(hartid);
 		if (cpu < 0) {
 			dev_warn(dev, "invalid cpuid for IDC%d\n", i);
 			continue;
 		}

 		cpumask_set_cpu(cpu, &direct->lmask);

 		idc = per_cpu_ptr(&aplic_idcs, cpu);
 		idc->hart_index = i;
 		idc->regs = priv->regs + APLIC_IDC_BASE + i * APLIC_IDC_SIZE;
 		idc->direct = direct;

 		aplic_idc_set_delivery(idc, true);

 		/*
 		 * Boot cpu might not have APLIC hart_index = 0 so check
 		 * and update target registers of all interrupts.
 		 */
 		if (cpu == current_cpu && idc->hart_index) {
 			v = FIELD_PREP(APLIC_TARGET_HART_IDX, idc->hart_index);
 			v |= FIELD_PREP(APLIC_TARGET_IPRIO, APLIC_DEFAULT_PRIORITY);
 			for (j = 1; j <= priv->nr_irqs; j++)
 				writel(v, priv->regs + APLIC_TARGET_BASE + (j - 1) * sizeof(u32));
 		}

 		setup_count++;
 	}
 	put_cpu();

 	/* Find parent domain and register chained handler */
 	domain = irq_find_matching_fwnode(riscv_get_intc_hwnode(),
 					  DOMAIN_BUS_ANY);
 	if (!aplic_direct_parent_irq && domain) {
 		aplic_direct_parent_irq = irq_create_mapping(domain, RV_IRQ_EXT);
 		if (aplic_direct_parent_irq) {
 			irq_set_chained_handler(aplic_direct_parent_irq,
 						aplic_direct_handle_irq);

 			/*
 			 * Setup CPUHP notifier to enable parent
 			 * interrupt on all CPUs
 			 */
 			cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
 					  "irqchip/riscv/aplic:starting",
 					  aplic_direct_starting_cpu,
 					  aplic_direct_dying_cpu);
 		}
 	}

 	/* Fail if we were not able to setup IDC for any CPU */
 	if (!setup_count)
 		return -ENODEV;

 	/* Setup global config and interrupt delivery */
 	aplic_init_hw_global(priv, false);

 	/* Create irq domain instance for the APLIC */
 	direct->irqdomain = irq_domain_create_linear(dev->fwnode, priv->nr_irqs + 1,
 						     &aplic_direct_irqdomain_ops, priv);
 	if (!direct->irqdomain) {
 		dev_err(dev, "failed to create direct irq domain\n");
 		return -ENOMEM;
 	}

 	/* Advertise the interrupt controller */
 	dev_info(dev, "%d interrupts directly connected to %d CPUs\n",
 		 priv->nr_irqs, priv->nr_idcs);

 	return 0;
 }
	// SPDX-License-Identifier: GPL-2.0
	/*
	* Copyright (C) 2021 Western Digital Corporation or its affiliates.
	* Copyright (C) 2022 Ventana Micro Systems Inc.
	*/

	#include <linux/bitfield.h>
	#include <linux/bitops.h>
	#include <linux/cpu.h>
	#include <linux/interrupt.h>
	#include <linux/irqchip.h>
	#include <linux/irqchip/chained_irq.h>
	#include <linux/irqchip/riscv-aplic.h>
	#include <linux/module.h>
	#include <linux/of_address.h>
	#include <linux/printk.h>
	#include <linux/smp.h>

	#include "irq-riscv-aplic-main.h"

	#define APLIC_DISABLE_IDELIVERY 0
	#define APLIC_ENABLE_IDELIVERY 1
	#define APLIC_DISABLE_ITHRESHOLD 1
	#define APLIC_ENABLE_ITHRESHOLD 0

	struct aplic_direct {
	struct aplic_priv priv;
	struct irq_domain *irqdomain;
	struct cpumask lmask;
	};

	struct aplic_idc {
	unsigned int hart_index;
	void __iomem *regs;
	struct aplic_direct *direct;
	};

	static unsigned int aplic_direct_parent_irq;
	static DEFINE_PER_CPU(struct aplic_idc, aplic_idcs);

	static void aplic_direct_irq_eoi(struct irq_data *d)
	{
	/*
	* The fasteoi_handler requires irq_eoi() callback hence
	* provide a dummy handler.
	*/
	}

	#ifdef CONFIG_SMP
	static int aplic_direct_set_affinity(struct irq_data d, const struct cpumask mask_val,
	bool force)
	{
	struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
	struct aplic_direct *direct = container_of(priv, struct aplic_direct, priv);
	struct aplic_idc *idc;
	unsigned int cpu, val;
	void __iomem *target;

	if (force)
	cpu = cpumask_first_and(&direct->lmask, mask_val);
	else
	cpu = cpumask_first_and_and(&direct->lmask, mask_val, cpu_online_mask);

	if (cpu >= nr_cpu_ids)
	return -EINVAL;

	idc = per_cpu_ptr(&aplic_idcs, cpu);
	target = priv->regs + APLIC_TARGET_BASE + (d->hwirq - 1) * sizeof(u32);
	val = FIELD_PREP(APLIC_TARGET_HART_IDX, idc->hart_index);
	val \|= FIELD_PREP(APLIC_TARGET_IPRIO, APLIC_DEFAULT_PRIORITY);
	writel(val, target);

	irq_data_update_effective_affinity(d, cpumask_of(cpu));

	return IRQ_SET_MASK_OK_DONE;
	}
	#endif

	static struct irq_chip aplic_direct_chip = {
	.name = "APLIC-DIRECT",
	.irq_mask = aplic_irq_mask,
	.irq_unmask = aplic_irq_unmask,
	.irq_set_type = aplic_irq_set_type,
	.irq_eoi = aplic_direct_irq_eoi,
	#ifdef CONFIG_SMP
	.irq_set_affinity = aplic_direct_set_affinity,
	#endif
	.flags = IRQCHIP_SET_TYPE_MASKED \|
	IRQCHIP_SKIP_SET_WAKE \|
	IRQCHIP_MASK_ON_SUSPEND,
	};

	static int aplic_direct_irqdomain_translate(struct irq_domain d, struct irq_fwspec fwspec,
	unsigned long hwirq, unsigned int type)
	{
	struct aplic_priv *priv = d->host_data;

	return aplic_irqdomain_translate(fwspec, priv->gsi_base, hwirq, type);
	}

	static int aplic_direct_irqdomain_alloc(struct irq_domain *domain, unsigned int virq,
	unsigned int nr_irqs, void *arg)
	{
	struct aplic_priv *priv = domain->host_data;
	struct aplic_direct *direct = container_of(priv, struct aplic_direct, priv);
	struct irq_fwspec *fwspec = arg;
	irq_hw_number_t hwirq;
	unsigned int type;
	int i, ret;

	ret = aplic_irqdomain_translate(fwspec, priv->gsi_base, &hwirq, &type);
	if (ret)
	return ret;

	for (i = 0; i < nr_irqs; i++) {
	irq_domain_set_info(domain, virq + i, hwirq + i, &aplic_direct_chip,
	priv, handle_fasteoi_irq, NULL, NULL);
	irq_set_affinity(virq + i, &direct->lmask);
	}

	return 0;
	}

	static const struct irq_domain_ops aplic_direct_irqdomain_ops = {
	.translate = aplic_direct_irqdomain_translate,
	.alloc = aplic_direct_irqdomain_alloc,
	.free = irq_domain_free_irqs_top,
	};

	/*
	* To handle an APLIC direct interrupts, we just read the CLAIMI register
	* which will return highest priority pending interrupt and clear the
	* pending bit of the interrupt. This process is repeated until CLAIMI
	* register return zero value.
	*/
	static void aplic_direct_handle_irq(struct irq_desc *desc)
	{
	struct aplic_idc *idc = this_cpu_ptr(&aplic_idcs);
	struct irq_domain *irqdomain = idc->direct->irqdomain;
	struct irq_chip *chip = irq_desc_get_chip(desc);
	irq_hw_number_t hw_irq;
	int irq;

	chained_irq_enter(chip, desc);

	while ((hw_irq = readl(idc->regs + APLIC_IDC_CLAIMI))) {
	hw_irq = hw_irq >> APLIC_IDC_TOPI_ID_SHIFT;
	irq = irq_find_mapping(irqdomain, hw_irq);

	if (unlikely(irq <= 0)) {
	dev_warn_ratelimited(idc->direct->priv.dev,
	"hw_irq %lu mapping not found\n", hw_irq);
	} else {
	generic_handle_irq(irq);
	}
	}

	chained_irq_exit(chip, desc);
	}

	static void aplic_idc_set_delivery(struct aplic_idc *idc, bool en)
	{
	u32 de = (en) ? APLIC_ENABLE_IDELIVERY : APLIC_DISABLE_IDELIVERY;
	u32 th = (en) ? APLIC_ENABLE_ITHRESHOLD : APLIC_DISABLE_ITHRESHOLD;

	/* Priority must be less than threshold for interrupt triggering */
	writel(th, idc->regs + APLIC_IDC_ITHRESHOLD);

	/* Delivery must be set to 1 for interrupt triggering */
	writel(de, idc->regs + APLIC_IDC_IDELIVERY);
	}

	static int aplic_direct_dying_cpu(unsigned int cpu)
	{
	if (aplic_direct_parent_irq)
	disable_percpu_irq(aplic_direct_parent_irq);

	return 0;
	}

	static int aplic_direct_starting_cpu(unsigned int cpu)
	{
	if (aplic_direct_parent_irq) {
	enable_percpu_irq(aplic_direct_parent_irq,
	irq_get_trigger_type(aplic_direct_parent_irq));
	}

	return 0;
	}

	static int aplic_direct_parse_parent_hwirq(struct device *dev, u32 index,
	u32 parent_hwirq, unsigned long parent_hartid)
	{
	struct of_phandle_args parent;
	int rc;

	/*
	* Currently, only OF fwnode is supported so extend this
	* function for ACPI support.
	*/
	if (!is_of_node(dev->fwnode))
	return -EINVAL;

	rc = of_irq_parse_one(to_of_node(dev->fwnode), index, &parent);
	if (rc)
	return rc;

	rc = riscv_of_parent_hartid(parent.np, parent_hartid);
	if (rc)
	return rc;

	*parent_hwirq = parent.args[0];
	return 0;
	}

	int aplic_direct_setup(struct device dev, void __iomem regs)
	{
	int i, j, rc, cpu, current_cpu, setup_count = 0;
	struct aplic_direct *direct;
	struct irq_domain *domain;
	struct aplic_priv *priv;
	struct aplic_idc *idc;
	unsigned long hartid;
	u32 v, hwirq;

	direct = devm_kzalloc(dev, sizeof(*direct), GFP_KERNEL);
	if (!direct)
	return -ENOMEM;
	priv = &direct->priv;

	rc = aplic_setup_priv(priv, dev, regs);
	if (rc) {
	dev_err(dev, "failed to create APLIC context\n");
	return rc;
	}

	/* Setup per-CPU IDC and target CPU mask */
	current_cpu = get_cpu();
	for (i = 0; i < priv->nr_idcs; i++) {
	rc = aplic_direct_parse_parent_hwirq(dev, i, &hwirq, &hartid);
	if (rc) {
	dev_warn(dev, "parent irq for IDC%d not found\n", i);
	continue;
	}

	/*
	* Skip interrupts other than external interrupts for
	* current privilege level.
	*/
	if (hwirq != RV_IRQ_EXT)
	continue;

	cpu = riscv_hartid_to_cpuid(hartid);
	if (cpu < 0) {
	dev_warn(dev, "invalid cpuid for IDC%d\n", i);
	continue;
	}

	cpumask_set_cpu(cpu, &direct->lmask);

	idc = per_cpu_ptr(&aplic_idcs, cpu);
	idc->hart_index = i;
	idc->regs = priv->regs + APLIC_IDC_BASE + i * APLIC_IDC_SIZE;
	idc->direct = direct;

	aplic_idc_set_delivery(idc, true);

	/*
	* Boot cpu might not have APLIC hart_index = 0 so check
	* and update target registers of all interrupts.
	*/
	if (cpu == current_cpu && idc->hart_index) {
	v = FIELD_PREP(APLIC_TARGET_HART_IDX, idc->hart_index);
	v \|= FIELD_PREP(APLIC_TARGET_IPRIO, APLIC_DEFAULT_PRIORITY);
	for (j = 1; j <= priv->nr_irqs; j++)
	writel(v, priv->regs + APLIC_TARGET_BASE + (j - 1) * sizeof(u32));
	}

	setup_count++;
	}
	put_cpu();

	/* Find parent domain and register chained handler */
	domain = irq_find_matching_fwnode(riscv_get_intc_hwnode(),
	DOMAIN_BUS_ANY);
	if (!aplic_direct_parent_irq && domain) {
	aplic_direct_parent_irq = irq_create_mapping(domain, RV_IRQ_EXT);
	if (aplic_direct_parent_irq) {
	irq_set_chained_handler(aplic_direct_parent_irq,
	aplic_direct_handle_irq);

	/*
	* Setup CPUHP notifier to enable parent
	* interrupt on all CPUs
	*/
	cpuhp_setup_state(CPUHP_AP_ONLINE_DYN,
	"irqchip/riscv/aplic:starting",
	aplic_direct_starting_cpu,
	aplic_direct_dying_cpu);
	}
	}

	/* Fail if we were not able to setup IDC for any CPU */
	if (!setup_count)
	return -ENODEV;

	/* Setup global config and interrupt delivery */
	aplic_init_hw_global(priv, false);

	/* Create irq domain instance for the APLIC */
	direct->irqdomain = irq_domain_create_linear(dev->fwnode, priv->nr_irqs + 1,
	&aplic_direct_irqdomain_ops, priv);
	if (!direct->irqdomain) {
	dev_err(dev, "failed to create direct irq domain\n");
	return -ENOMEM;
	}

	/* Advertise the interrupt controller */
	dev_info(dev, "%d interrupts directly connected to %d CPUs\n",
	priv->nr_irqs, priv->nr_idcs);

	return 0;
	}