| // 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 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 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)) { |
| riscv_intc_nr_irqs = 64; |
| 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_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 |
| |
| struct rintc_data { |
| union { |
| u32 ext_intc_id; |
| struct { |
| u32 context_id : 16, |
| reserved : 8, |
| aplic_plic_id : 8; |
| }; |
| }; |
| unsigned long hart_id; |
| u64 imsic_addr; |
| u32 imsic_size; |
| }; |
| |
| static u32 nr_rintc; |
| static struct rintc_data **rintc_acpi_data; |
| |
| #define for_each_matching_plic(_plic_id) \ |
| unsigned int _plic; \ |
| \ |
| for (_plic = 0; _plic < nr_rintc; _plic++) \ |
| if (rintc_acpi_data[_plic]->aplic_plic_id != _plic_id) \ |
| continue; \ |
| else |
| |
| unsigned int acpi_rintc_get_plic_nr_contexts(unsigned int plic_id) |
| { |
| unsigned int nctx = 0; |
| |
| for_each_matching_plic(plic_id) |
| nctx++; |
| |
| return nctx; |
| } |
| |
| static struct rintc_data *get_plic_context(unsigned int plic_id, unsigned int ctxt_idx) |
| { |
| unsigned int ctxt = 0; |
| |
| for_each_matching_plic(plic_id) { |
| if (ctxt == ctxt_idx) |
| return rintc_acpi_data[_plic]; |
| |
| ctxt++; |
| } |
| |
| return NULL; |
| } |
| |
| unsigned long acpi_rintc_ext_parent_to_hartid(unsigned int plic_id, unsigned int ctxt_idx) |
| { |
| struct rintc_data *data = get_plic_context(plic_id, ctxt_idx); |
| |
| return data ? data->hart_id : INVALID_HARTID; |
| } |
| |
| unsigned int acpi_rintc_get_plic_context(unsigned int plic_id, unsigned int ctxt_idx) |
| { |
| struct rintc_data *data = get_plic_context(plic_id, ctxt_idx); |
| |
| return data ? data->context_id : INVALID_CONTEXT; |
| } |
| |
| unsigned long acpi_rintc_index_to_hartid(u32 index) |
| { |
| return index >= nr_rintc ? INVALID_HARTID : rintc_acpi_data[index]->hart_id; |
| } |
| |
| int acpi_rintc_get_imsic_mmio_info(u32 index, struct resource *res) |
| { |
| if (index >= nr_rintc) |
| return -1; |
| |
| res->start = rintc_acpi_data[index]->imsic_addr; |
| res->end = res->start + rintc_acpi_data[index]->imsic_size - 1; |
| res->flags = IORESOURCE_MEM; |
| return 0; |
| } |
| |
| static int __init riscv_intc_acpi_match(union acpi_subtable_headers *header, |
| const unsigned long end) |
| { |
| return 0; |
| } |
| |
| static int __init riscv_intc_acpi_init(union acpi_subtable_headers *header, |
| const unsigned long end) |
| { |
| struct acpi_madt_rintc *rintc; |
| struct fwnode_handle *fn; |
| int count; |
| int rc; |
| |
| if (!rintc_acpi_data) { |
| count = acpi_table_parse_madt(ACPI_MADT_TYPE_RINTC, riscv_intc_acpi_match, 0); |
| if (count <= 0) |
| return -EINVAL; |
| |
| rintc_acpi_data = kcalloc(count, sizeof(*rintc_acpi_data), GFP_KERNEL); |
| if (!rintc_acpi_data) |
| return -ENOMEM; |
| } |
| |
| rintc = (struct acpi_madt_rintc *)header; |
| rintc_acpi_data[nr_rintc] = kzalloc(sizeof(*rintc_acpi_data[0]), GFP_KERNEL); |
| if (!rintc_acpi_data[nr_rintc]) |
| return -ENOMEM; |
| |
| rintc_acpi_data[nr_rintc]->ext_intc_id = rintc->ext_intc_id; |
| rintc_acpi_data[nr_rintc]->hart_id = rintc->hart_id; |
| rintc_acpi_data[nr_rintc]->imsic_addr = rintc->imsic_addr; |
| rintc_acpi_data[nr_rintc]->imsic_size = rintc->imsic_size; |
| nr_rintc++; |
| |
| /* |
| * 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; |
| } |
| |
| rc = riscv_intc_init_common(fn, &riscv_intc_chip); |
| if (rc) |
| irq_domain_free_fwnode(fn); |
| else |
| acpi_set_irq_model(ACPI_IRQ_MODEL_RINTC, riscv_acpi_get_gsi_domain_id); |
| |
| return rc; |
| } |
| |
| IRQCHIP_ACPI_DECLARE(riscv_intc, ACPI_MADT_TYPE_RINTC, NULL, |
| ACPI_MADT_RINTC_VERSION_V1, riscv_intc_acpi_init); |
| #endif |