/* * Copyright 2001 MontaVista Software Inc. * Author: Jun Sun, jsun@mvista.com or jsun@junsun.net * * Copyright (C) 2001 Ralf Baechle * Copyright (C) 2005 MIPS Technologies, Inc. All rights reserved. * Author: Maciej W. Rozycki <macro@mips.com> * * This file define the irq handler for MIPS CPU interrupts. * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the * Free Software Foundation; either version 2 of the License, or (at your * option) any later version. */ /* * Almost all MIPS CPUs define 8 interrupt sources. They are typically * level triggered (i.e., cannot be cleared from CPU; must be cleared from * device). * * The first two are software interrupts (i.e. not exposed as pins) which * may be used for IPIs in multi-threaded single-core systems. * * The last one is usually the CPU timer interrupt if the counter register * is present, or for old CPUs with an external FPU by convention it's the * FPU exception interrupt. */ #include <linux/init.h> #include <linux/interrupt.h> #include <linux/kernel.h> #include <linux/irq.h> #include <linux/irqchip.h> #include <linux/irqdomain.h> #include <asm/irq_cpu.h> #include <asm/mipsregs.h> #include <asm/mipsmtregs.h> #include <asm/setup.h> static struct irq_domain *irq_domain; static struct irq_domain *ipi_domain; static inline void unmask_mips_irq(struct irq_data *d) { set_c0_status(IE_SW0 << d->hwirq); irq_enable_hazard(); } static inline void mask_mips_irq(struct irq_data *d) { clear_c0_status(IE_SW0 << d->hwirq); irq_disable_hazard(); } static struct irq_chip mips_cpu_irq_controller = { .name = "MIPS", .irq_ack = mask_mips_irq, .irq_mask = mask_mips_irq, .irq_mask_ack = mask_mips_irq, .irq_unmask = unmask_mips_irq, .irq_eoi = unmask_mips_irq, .irq_disable = mask_mips_irq, .irq_enable = unmask_mips_irq, }; /* * Basically the same as above but taking care of all the MT stuff */ static unsigned int mips_mt_cpu_irq_startup(struct irq_data *d) { unsigned int vpflags = dvpe(); clear_c0_cause(C_SW0 << d->hwirq); evpe(vpflags); unmask_mips_irq(d); return 0; } /* * While we ack the interrupt interrupts are disabled and thus we don't need * to deal with concurrency issues. Same for mips_cpu_irq_end. */ static void mips_mt_cpu_irq_ack(struct irq_data *d) { unsigned int vpflags = dvpe(); clear_c0_cause(C_SW0 << d->hwirq); evpe(vpflags); mask_mips_irq(d); } #ifdef CONFIG_GENERIC_IRQ_IPI static void mips_mt_send_ipi(struct irq_data *d, unsigned int cpu) { irq_hw_number_t hwirq = irqd_to_hwirq(d); unsigned long flags; int vpflags; local_irq_save(flags); /* We can only send IPIs to VPEs within the local core */ WARN_ON(!cpus_are_siblings(smp_processor_id(), cpu)); vpflags = dvpe(); settc(cpu_vpe_id(&cpu_data[cpu])); write_vpe_c0_cause(read_vpe_c0_cause() | (C_SW0 << hwirq)); evpe(vpflags); local_irq_restore(flags); } #endif /* CONFIG_GENERIC_IRQ_IPI */ static struct irq_chip mips_mt_cpu_irq_controller = { .name = "MIPS", .irq_startup = mips_mt_cpu_irq_startup, .irq_ack = mips_mt_cpu_irq_ack, .irq_mask = mask_mips_irq, .irq_mask_ack = mips_mt_cpu_irq_ack, .irq_unmask = unmask_mips_irq, .irq_eoi = unmask_mips_irq, .irq_disable = mask_mips_irq, .irq_enable = unmask_mips_irq, #ifdef CONFIG_GENERIC_IRQ_IPI .ipi_send_single = mips_mt_send_ipi, #endif }; asmlinkage void __weak plat_irq_dispatch(void) { unsigned long pending = read_c0_cause() & read_c0_status() & ST0_IM; unsigned int virq; int irq; if (!pending) { spurious_interrupt(); return; } pending >>= CAUSEB_IP; while (pending) { irq = fls(pending) - 1; if (IS_ENABLED(CONFIG_GENERIC_IRQ_IPI) && irq < 2) virq = irq_linear_revmap(ipi_domain, irq); else virq = irq_linear_revmap(irq_domain, irq); do_IRQ(virq); pending &= ~BIT(irq); } } static int mips_cpu_intc_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw) { struct irq_chip *chip; if (hw < 2 && cpu_has_mipsmt) { /* Software interrupts are used for MT/CMT IPI */ chip = &mips_mt_cpu_irq_controller; } else { chip = &mips_cpu_irq_controller; } if (cpu_has_vint) set_vi_handler(hw, plat_irq_dispatch); irq_set_chip_and_handler(irq, chip, handle_percpu_irq); return 0; } static const struct irq_domain_ops mips_cpu_intc_irq_domain_ops = { .map = mips_cpu_intc_map, .xlate = irq_domain_xlate_onecell, }; #ifdef CONFIG_GENERIC_IRQ_IPI struct cpu_ipi_domain_state { DECLARE_BITMAP(allocated, 2); }; static int mips_cpu_ipi_alloc(struct irq_domain *domain, unsigned int virq, unsigned int nr_irqs, void *arg) { struct cpu_ipi_domain_state *state = domain->host_data; unsigned int i, hwirq; int ret; for (i = 0; i < nr_irqs; i++) { hwirq = find_first_zero_bit(state->allocated, 2); if (hwirq == 2) return -EBUSY; bitmap_set(state->allocated, hwirq, 1); ret = irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq, &mips_mt_cpu_irq_controller, NULL); if (ret) return ret; ret = irq_domain_set_hwirq_and_chip(domain->parent, virq + i, hwirq, &mips_mt_cpu_irq_controller, NULL); if (ret) return ret; ret = irq_set_irq_type(virq + i, IRQ_TYPE_LEVEL_HIGH); if (ret) return ret; } return 0; } static int mips_cpu_ipi_match(struct irq_domain *d, struct device_node *node, enum irq_domain_bus_token bus_token) { bool is_ipi; switch (bus_token) { case DOMAIN_BUS_IPI: is_ipi = d->bus_token == bus_token; return (!node || (to_of_node(d->fwnode) == node)) && is_ipi; default: return 0; } } static const struct irq_domain_ops mips_cpu_ipi_chip_ops = { .alloc = mips_cpu_ipi_alloc, .match = mips_cpu_ipi_match, }; static void mips_cpu_register_ipi_domain(struct device_node *of_node) { struct cpu_ipi_domain_state *ipi_domain_state; ipi_domain_state = kzalloc(sizeof(*ipi_domain_state), GFP_KERNEL); ipi_domain = irq_domain_add_hierarchy(irq_domain, IRQ_DOMAIN_FLAG_IPI_SINGLE, 2, of_node, &mips_cpu_ipi_chip_ops, ipi_domain_state); if (!ipi_domain) panic("Failed to add MIPS CPU IPI domain"); irq_domain_update_bus_token(ipi_domain, DOMAIN_BUS_IPI); } #else /* !CONFIG_GENERIC_IRQ_IPI */ static inline void mips_cpu_register_ipi_domain(struct device_node *of_node) {} #endif /* !CONFIG_GENERIC_IRQ_IPI */ static void __init __mips_cpu_irq_init(struct device_node *of_node) { /* Mask interrupts. */ clear_c0_status(ST0_IM); clear_c0_cause(CAUSEF_IP); irq_domain = irq_domain_add_legacy(of_node, 8, MIPS_CPU_IRQ_BASE, 0, &mips_cpu_intc_irq_domain_ops, NULL); if (!irq_domain) panic("Failed to add irqdomain for MIPS CPU"); /* * Only proceed to register the software interrupt IPI implementation * for CPUs which implement the MIPS MT (multi-threading) ASE. */ if (cpu_has_mipsmt) mips_cpu_register_ipi_domain(of_node); } void __init mips_cpu_irq_init(void) { __mips_cpu_irq_init(NULL); } int __init mips_cpu_irq_of_init(struct device_node *of_node, struct device_node *parent) { __mips_cpu_irq_init(of_node); return 0; } IRQCHIP_DECLARE(cpu_intc, "mti,cpu-interrupt-controller", mips_cpu_irq_of_init);