diff options
| -rw-r--r-- | drivers/irqchip/Kconfig | 2 | ||||
| -rw-r--r-- | drivers/irqchip/irq-mips-cpu.c | 125 |
2 files changed, 119 insertions, 8 deletions
diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig index 8162121bb1bc..f03ef434503b 100644 --- a/drivers/irqchip/Kconfig +++ b/drivers/irqchip/Kconfig @@ -128,7 +128,9 @@ config IMGPDC_IRQ config IRQ_MIPS_CPU bool select GENERIC_IRQ_CHIP + select GENERIC_IRQ_IPI if SYS_SUPPORTS_MULTITHREADING select IRQ_DOMAIN + select IRQ_DOMAIN_HIERARCHY if GENERIC_IRQ_IPI config CLPS711X_IRQCHIP bool diff --git a/drivers/irqchip/irq-mips-cpu.c b/drivers/irqchip/irq-mips-cpu.c index 338de924b269..b247f3c743ac 100644 --- a/drivers/irqchip/irq-mips-cpu.c +++ b/drivers/irqchip/irq-mips-cpu.c @@ -17,15 +17,14 @@ /* * 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 which we don't really - * use or support. The last one is usually the CPU timer interrupt if - * counter register is present or, for CPUs with an external FPU, by - * convention it's the FPU exception interrupt. + * device). * - * Don't even think about using this on SMP. You have been warned. + * The first two are software interrupts (i.e. not exposed as pins) which + * may be used for IPIs in multi-threaded single-core systems. * - * This file exports one global function: - * void mips_cpu_irq_init(void); + * 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> @@ -40,6 +39,7 @@ #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) { @@ -90,6 +90,29 @@ static void mips_mt_cpu_irq_ack(struct irq_data *d) 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(cpu_data[cpu].core != current_cpu_data.core); + + 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, @@ -100,6 +123,9 @@ static struct irq_chip mips_mt_cpu_irq_controller = { .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) @@ -116,7 +142,10 @@ asmlinkage void __weak plat_irq_dispatch(void) pending >>= CAUSEB_IP; while (pending) { irq = fls(pending) - 1; - virq = irq_linear_revmap(irq_domain, irq); + 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); } @@ -147,6 +176,79 @@ static const struct irq_domain_ops mips_cpu_intc_irq_domain_ops = { .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_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"); + ipi_domain->bus_token = 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. */ @@ -158,6 +260,13 @@ static void __init __mips_cpu_irq_init(struct device_node *of_node) 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) |