diff options
Diffstat (limited to 'drivers/irqchip/irq-riscv-aplic-direct.c')
| -rw-r--r-- | drivers/irqchip/irq-riscv-aplic-direct.c | 323 |
1 files changed, 323 insertions, 0 deletions
diff --git a/drivers/irqchip/irq-riscv-aplic-direct.c b/drivers/irqchip/irq-riscv-aplic-direct.c new file mode 100644 index 00000000000000..4a3ffe856d6c30 --- /dev/null +++ b/drivers/irqchip/irq-riscv-aplic-direct.c @@ -0,0 +1,323 @@ +// 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; +} |