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

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (C) 2012 Regents of the University of California
  * Copyright (C) 2017-2018 SiFive
  * Copyright (C) 2020 Western Digital Corporation or its affiliates.
  */

 #define pr_fmt(fmt) "riscv-intc: " fmt
 #include <linux/acpi.h>
 #include <linux/atomic.h>
 #include <linux/bits.h>
 #include <linux/cpu.h>
 #include <linux/irq.h>
 #include <linux/irqchip.h>
 #include <linux/irqdomain.h>
 #include <linux/interrupt.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/smp.h>
 #include <linux/soc/andes/irq.h>

 #include <asm/hwcap.h>

 static struct irq_domain *intc_domain;
 static unsigned int riscv_intc_nr_irqs __ro_after_init = BITS_PER_LONG;
 static unsigned int riscv_intc_custom_base __ro_after_init = BITS_PER_LONG;
 static unsigned int riscv_intc_custom_nr_irqs __ro_after_init;

 static asmlinkage void riscv_intc_irq(struct pt_regs *regs)
 {
 	unsigned long cause = regs->cause & ~CAUSE_IRQ_FLAG;

 	if (generic_handle_domain_irq(intc_domain, cause))
 		pr_warn_ratelimited("Failed to handle interrupt (cause: %ld)\n", cause);
 }

 static asmlinkage void riscv_intc_aia_irq(struct pt_regs *regs)
 {
 	unsigned long topi;

 	while ((topi = csr_read(CSR_TOPI)))
 		generic_handle_domain_irq(intc_domain, topi >> TOPI_IID_SHIFT);
 }

 /*
  * On RISC-V systems local interrupts are masked or unmasked by writing
  * the SIE (Supervisor Interrupt Enable) CSR.  As CSRs can only be written
  * on the local hart, these functions can only be called on the hart that
  * corresponds to the IRQ chip.
  */

 static void riscv_intc_irq_mask(struct irq_data *d)
 {
 	if (IS_ENABLED(CONFIG_32BIT) && d->hwirq >= BITS_PER_LONG)
 		csr_clear(CSR_IEH, BIT(d->hwirq - BITS_PER_LONG));
 	else
 		csr_clear(CSR_IE, BIT(d->hwirq));
 }

 static void riscv_intc_irq_unmask(struct irq_data *d)
 {
 	if (IS_ENABLED(CONFIG_32BIT) && d->hwirq >= BITS_PER_LONG)
 		csr_set(CSR_IEH, BIT(d->hwirq - BITS_PER_LONG));
 	else
 		csr_set(CSR_IE, BIT(d->hwirq));
 }

 static void andes_intc_irq_mask(struct irq_data *d)
 {
 	/*
 	 * Andes specific S-mode local interrupt causes (hwirq)
 	 * are defined as (256 + n) and controlled by n-th bit
 	 * of SLIE.
 	 */
 	unsigned int mask = BIT(d->hwirq % BITS_PER_LONG);

 	if (d->hwirq < ANDES_SLI_CAUSE_BASE)
 		csr_clear(CSR_IE, mask);
 	else
 		csr_clear(ANDES_CSR_SLIE, mask);
 }

 static void andes_intc_irq_unmask(struct irq_data *d)
 {
 	unsigned int mask = BIT(d->hwirq % BITS_PER_LONG);

 	if (d->hwirq < ANDES_SLI_CAUSE_BASE)
 		csr_set(CSR_IE, mask);
 	else
 		csr_set(ANDES_CSR_SLIE, mask);
 }

 static void riscv_intc_irq_eoi(struct irq_data *d)
 {
 	/*
 	 * The RISC-V INTC driver uses handle_percpu_devid_irq() flow
 	 * for the per-HART local interrupts and child irqchip drivers
 	 * (such as PLIC, SBI IPI, CLINT, APLIC, IMSIC, etc) implement
 	 * chained handlers for the per-HART local interrupts.
 	 *
 	 * In the absence of irq_eoi(), the chained_irq_enter() and
 	 * chained_irq_exit() functions (used by child irqchip drivers)
 	 * will do unnecessary mask/unmask of per-HART local interrupts
 	 * at the time of handling interrupts. To avoid this, we provide
 	 * an empty irq_eoi() callback for RISC-V INTC irqchip.
 	 */
 }

 static struct irq_chip riscv_intc_chip = {
 	.name = "RISC-V INTC",
 	.irq_mask = riscv_intc_irq_mask,
 	.irq_unmask = riscv_intc_irq_unmask,
 	.irq_eoi = riscv_intc_irq_eoi,
 };

 static struct irq_chip andes_intc_chip = {
 	.name		= "RISC-V INTC",
 	.irq_mask	= andes_intc_irq_mask,
 	.irq_unmask	= andes_intc_irq_unmask,
 	.irq_eoi	= riscv_intc_irq_eoi,
 };

 static int riscv_intc_domain_map(struct irq_domain *d, unsigned int irq,
 				 irq_hw_number_t hwirq)
 {
 	struct irq_chip *chip = d->host_data;

 	irq_set_percpu_devid(irq);
 	irq_domain_set_info(d, irq, hwirq, chip, NULL, handle_percpu_devid_irq,
 			    NULL, NULL);

 	return 0;
 }

 static int riscv_intc_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 = IRQ_TYPE_NONE;
 	struct irq_fwspec *fwspec = arg;

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

 	/*
 	 * Only allow hwirq for which we have corresponding standard or
 	 * custom interrupt enable register.
 	 */
 	if ((hwirq >= riscv_intc_nr_irqs && hwirq < riscv_intc_custom_base) ||
 	    (hwirq >= riscv_intc_custom_base + riscv_intc_custom_nr_irqs))
 		return -EINVAL;

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

 	return 0;
 }

 static const struct irq_domain_ops riscv_intc_domain_ops = {
 	.map	= riscv_intc_domain_map,
 	.xlate	= irq_domain_xlate_onecell,
 	.alloc	= riscv_intc_domain_alloc
 };

 static struct fwnode_handle *riscv_intc_hwnode(void)
 {
 	return intc_domain->fwnode;
 }

 static int __init riscv_intc_init_common(struct fwnode_handle *fn, struct irq_chip *chip)
 {
 	int rc;

 	intc_domain = irq_domain_create_tree(fn, &riscv_intc_domain_ops, chip);
 	if (!intc_domain) {
 		pr_err("unable to add IRQ domain\n");
 		return -ENXIO;
 	}

 	if (riscv_isa_extension_available(NULL, SxAIA))
 		rc = set_handle_irq(&riscv_intc_aia_irq);
 	else
 		rc = set_handle_irq(&riscv_intc_irq);
 	if (rc) {
 		pr_err("failed to set irq handler\n");
 		return rc;
 	}

 	riscv_set_intc_hwnode_fn(riscv_intc_hwnode);

 	pr_info("%d local interrupts mapped%s\n",
 		riscv_isa_extension_available(NULL, SxAIA) ? 64 : riscv_intc_nr_irqs,
 		riscv_isa_extension_available(NULL, SxAIA) ? " using AIA" : "");
 	if (riscv_intc_custom_nr_irqs)
 		pr_info("%d custom local interrupts mapped\n", riscv_intc_custom_nr_irqs);

 	return 0;
 }

 static int __init riscv_intc_init(struct device_node *node,
 				  struct device_node *parent)
 {
 	struct irq_chip *chip = &riscv_intc_chip;
 	unsigned long hartid;
 	int rc;

 	rc = riscv_of_parent_hartid(node, &hartid);
 	if (rc < 0) {
 		pr_warn("unable to find hart id for %pOF\n", node);
 		return 0;
 	}

 	/*
 	 * The DT will have one INTC DT node under each CPU (or HART)
 	 * DT node so riscv_intc_init() function will be called once
 	 * for each INTC DT node. We only need to do INTC initialization
 	 * for the INTC DT node belonging to boot CPU (or boot HART).
 	 */
 	if (riscv_hartid_to_cpuid(hartid) != smp_processor_id()) {
 		/*
 		 * The INTC nodes of each CPU are suppliers for downstream
 		 * interrupt controllers (such as PLIC, IMSIC and APLIC
 		 * direct-mode) so we should mark an INTC node as initialized
 		 * if we are not creating IRQ domain for it.
 		 */
 		fwnode_dev_initialized(of_fwnode_handle(node), true);
 		return 0;
 	}

 	if (of_device_is_compatible(node, "andestech,cpu-intc")) {
 		riscv_intc_custom_base = ANDES_SLI_CAUSE_BASE;
 		riscv_intc_custom_nr_irqs = ANDES_RV_IRQ_LAST;
 		chip = &andes_intc_chip;
 	}

 	return riscv_intc_init_common(of_node_to_fwnode(node), chip);
 }

 IRQCHIP_DECLARE(riscv, "riscv,cpu-intc", riscv_intc_init);
 IRQCHIP_DECLARE(andes, "andestech,cpu-intc", riscv_intc_init);

 #ifdef CONFIG_ACPI

 static int __init riscv_intc_acpi_init(union acpi_subtable_headers *header,
 				       const unsigned long end)
 {
 	struct fwnode_handle *fn;
 	struct acpi_madt_rintc *rintc;

 	rintc = (struct acpi_madt_rintc *)header;

 	/*
 	 * The ACPI MADT will have one INTC for each CPU (or HART)
 	 * so riscv_intc_acpi_init() function will be called once
 	 * for each INTC. We only do INTC initialization
 	 * for the INTC belonging to the boot CPU (or boot HART).
 	 */
 	if (riscv_hartid_to_cpuid(rintc->hart_id) != smp_processor_id())
 		return 0;

 	fn = irq_domain_alloc_named_fwnode("RISCV-INTC");
 	if (!fn) {
 		pr_err("unable to allocate INTC FW node\n");
 		return -ENOMEM;
 	}

 	return riscv_intc_init_common(fn, &riscv_intc_chip);
 }

 IRQCHIP_ACPI_DECLARE(riscv_intc, ACPI_MADT_TYPE_RINTC, NULL,
 		     ACPI_MADT_RINTC_VERSION_V1, riscv_intc_acpi_init);
 #endif
	// SPDX-License-Identifier: GPL-2.0
	/*
	* Copyright (C) 2012 Regents of the University of California
	* Copyright (C) 2017-2018 SiFive
	* Copyright (C) 2020 Western Digital Corporation or its affiliates.
	*/

	#define pr_fmt(fmt) "riscv-intc: " fmt
	#include <linux/acpi.h>
	#include <linux/atomic.h>
	#include <linux/bits.h>
	#include <linux/cpu.h>
	#include <linux/irq.h>
	#include <linux/irqchip.h>
	#include <linux/irqdomain.h>
	#include <linux/interrupt.h>
	#include <linux/module.h>
	#include <linux/of.h>
	#include <linux/smp.h>
	#include <linux/soc/andes/irq.h>

	#include <asm/hwcap.h>

	static struct irq_domain *intc_domain;
	static unsigned int riscv_intc_nr_irqs __ro_after_init = BITS_PER_LONG;
	static unsigned int riscv_intc_custom_base __ro_after_init = BITS_PER_LONG;
	static unsigned int riscv_intc_custom_nr_irqs __ro_after_init;

	static asmlinkage void riscv_intc_irq(struct pt_regs *regs)
	{
	unsigned long cause = regs->cause & ~CAUSE_IRQ_FLAG;

	if (generic_handle_domain_irq(intc_domain, cause))
	pr_warn_ratelimited("Failed to handle interrupt (cause: %ld)\n", cause);
	}

	static asmlinkage void riscv_intc_aia_irq(struct pt_regs *regs)
	{
	unsigned long topi;

	while ((topi = csr_read(CSR_TOPI)))
	generic_handle_domain_irq(intc_domain, topi >> TOPI_IID_SHIFT);
	}

	/*
	* On RISC-V systems local interrupts are masked or unmasked by writing
	* the SIE (Supervisor Interrupt Enable) CSR. As CSRs can only be written
	* on the local hart, these functions can only be called on the hart that
	* corresponds to the IRQ chip.
	*/

	static void riscv_intc_irq_mask(struct irq_data *d)
	{
	if (IS_ENABLED(CONFIG_32BIT) && d->hwirq >= BITS_PER_LONG)
	csr_clear(CSR_IEH, BIT(d->hwirq - BITS_PER_LONG));
	else
	csr_clear(CSR_IE, BIT(d->hwirq));
	}

	static void riscv_intc_irq_unmask(struct irq_data *d)
	{
	if (IS_ENABLED(CONFIG_32BIT) && d->hwirq >= BITS_PER_LONG)
	csr_set(CSR_IEH, BIT(d->hwirq - BITS_PER_LONG));
	else
	csr_set(CSR_IE, BIT(d->hwirq));
	}

	static void andes_intc_irq_mask(struct irq_data *d)
	{
	/*
	* Andes specific S-mode local interrupt causes (hwirq)
	* are defined as (256 + n) and controlled by n-th bit
	* of SLIE.
	*/
	unsigned int mask = BIT(d->hwirq % BITS_PER_LONG);

	if (d->hwirq < ANDES_SLI_CAUSE_BASE)
	csr_clear(CSR_IE, mask);
	else
	csr_clear(ANDES_CSR_SLIE, mask);
	}

	static void andes_intc_irq_unmask(struct irq_data *d)
	{
	unsigned int mask = BIT(d->hwirq % BITS_PER_LONG);

	if (d->hwirq < ANDES_SLI_CAUSE_BASE)
	csr_set(CSR_IE, mask);
	else
	csr_set(ANDES_CSR_SLIE, mask);
	}

	static void riscv_intc_irq_eoi(struct irq_data *d)
	{
	/*
	* The RISC-V INTC driver uses handle_percpu_devid_irq() flow
	* for the per-HART local interrupts and child irqchip drivers
	* (such as PLIC, SBI IPI, CLINT, APLIC, IMSIC, etc) implement
	* chained handlers for the per-HART local interrupts.
	*
	* In the absence of irq_eoi(), the chained_irq_enter() and
	* chained_irq_exit() functions (used by child irqchip drivers)
	* will do unnecessary mask/unmask of per-HART local interrupts
	* at the time of handling interrupts. To avoid this, we provide
	* an empty irq_eoi() callback for RISC-V INTC irqchip.
	*/
	}

	static struct irq_chip riscv_intc_chip = {
	.name = "RISC-V INTC",
	.irq_mask = riscv_intc_irq_mask,
	.irq_unmask = riscv_intc_irq_unmask,
	.irq_eoi = riscv_intc_irq_eoi,
	};

	static struct irq_chip andes_intc_chip = {
	.name = "RISC-V INTC",
	.irq_mask = andes_intc_irq_mask,
	.irq_unmask = andes_intc_irq_unmask,
	.irq_eoi = riscv_intc_irq_eoi,
	};

	static int riscv_intc_domain_map(struct irq_domain *d, unsigned int irq,
	irq_hw_number_t hwirq)
	{
	struct irq_chip *chip = d->host_data;

	irq_set_percpu_devid(irq);
	irq_domain_set_info(d, irq, hwirq, chip, NULL, handle_percpu_devid_irq,
	NULL, NULL);

	return 0;
	}

	static int riscv_intc_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 = IRQ_TYPE_NONE;
	struct irq_fwspec *fwspec = arg;

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

	/*
	* Only allow hwirq for which we have corresponding standard or
	* custom interrupt enable register.
	*/
	if ((hwirq >= riscv_intc_nr_irqs && hwirq < riscv_intc_custom_base) \|\|
	(hwirq >= riscv_intc_custom_base + riscv_intc_custom_nr_irqs))
	return -EINVAL;

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

	return 0;
	}

	static const struct irq_domain_ops riscv_intc_domain_ops = {
	.map = riscv_intc_domain_map,
	.xlate = irq_domain_xlate_onecell,
	.alloc = riscv_intc_domain_alloc
	};

	static struct fwnode_handle *riscv_intc_hwnode(void)
	{
	return intc_domain->fwnode;
	}

	static int __init riscv_intc_init_common(struct fwnode_handle fn, struct irq_chip chip)
	{
	int rc;

	intc_domain = irq_domain_create_tree(fn, &riscv_intc_domain_ops, chip);
	if (!intc_domain) {
	pr_err("unable to add IRQ domain\n");
	return -ENXIO;
	}

	if (riscv_isa_extension_available(NULL, SxAIA))
	rc = set_handle_irq(&riscv_intc_aia_irq);
	else
	rc = set_handle_irq(&riscv_intc_irq);
	if (rc) {
	pr_err("failed to set irq handler\n");
	return rc;
	}

	riscv_set_intc_hwnode_fn(riscv_intc_hwnode);

	pr_info("%d local interrupts mapped%s\n",
	riscv_isa_extension_available(NULL, SxAIA) ? 64 : riscv_intc_nr_irqs,
	riscv_isa_extension_available(NULL, SxAIA) ? " using AIA" : "");
	if (riscv_intc_custom_nr_irqs)
	pr_info("%d custom local interrupts mapped\n", riscv_intc_custom_nr_irqs);

	return 0;
	}

	static int __init riscv_intc_init(struct device_node *node,
	struct device_node *parent)
	{
	struct irq_chip *chip = &riscv_intc_chip;
	unsigned long hartid;
	int rc;

	rc = riscv_of_parent_hartid(node, &hartid);
	if (rc < 0) {
	pr_warn("unable to find hart id for %pOF\n", node);
	return 0;
	}

	/*
	* The DT will have one INTC DT node under each CPU (or HART)
	* DT node so riscv_intc_init() function will be called once
	* for each INTC DT node. We only need to do INTC initialization
	* for the INTC DT node belonging to boot CPU (or boot HART).
	*/
	if (riscv_hartid_to_cpuid(hartid) != smp_processor_id()) {
	/*
	* The INTC nodes of each CPU are suppliers for downstream
	* interrupt controllers (such as PLIC, IMSIC and APLIC
	* direct-mode) so we should mark an INTC node as initialized
	* if we are not creating IRQ domain for it.
	*/
	fwnode_dev_initialized(of_fwnode_handle(node), true);
	return 0;
	}

	if (of_device_is_compatible(node, "andestech,cpu-intc")) {
	riscv_intc_custom_base = ANDES_SLI_CAUSE_BASE;
	riscv_intc_custom_nr_irqs = ANDES_RV_IRQ_LAST;
	chip = &andes_intc_chip;
	}

	return riscv_intc_init_common(of_node_to_fwnode(node), chip);
	}

	IRQCHIP_DECLARE(riscv, "riscv,cpu-intc", riscv_intc_init);
	IRQCHIP_DECLARE(andes, "andestech,cpu-intc", riscv_intc_init);

	#ifdef CONFIG_ACPI

	static int __init riscv_intc_acpi_init(union acpi_subtable_headers *header,
	const unsigned long end)
	{
	struct fwnode_handle *fn;
	struct acpi_madt_rintc *rintc;

	rintc = (struct acpi_madt_rintc *)header;

	/*
	* The ACPI MADT will have one INTC for each CPU (or HART)
	* so riscv_intc_acpi_init() function will be called once
	* for each INTC. We only do INTC initialization
	* for the INTC belonging to the boot CPU (or boot HART).
	*/
	if (riscv_hartid_to_cpuid(rintc->hart_id) != smp_processor_id())
	return 0;

	fn = irq_domain_alloc_named_fwnode("RISCV-INTC");
	if (!fn) {
	pr_err("unable to allocate INTC FW node\n");
	return -ENOMEM;
	}

	return riscv_intc_init_common(fn, &riscv_intc_chip);
	}

	IRQCHIP_ACPI_DECLARE(riscv_intc, ACPI_MADT_TYPE_RINTC, NULL,
	ACPI_MADT_RINTC_VERSION_V1, riscv_intc_acpi_init);
	#endif