// SPDX-License-Identifier: GPL-2.0+ /* * Root interrupt controller for the BCM2836 (Raspberry Pi 2). * * Copyright 2015 Broadcom */ #include <linux/cpu.h> #include <linux/of_address.h> #include <linux/of_irq.h> #include <linux/irqchip.h> #include <linux/irqdomain.h> #include <linux/irqchip/irq-bcm2836.h> #include <asm/exception.h> struct bcm2836_arm_irqchip_intc { struct irq_domain *domain; void __iomem *base; }; static struct bcm2836_arm_irqchip_intc intc __read_mostly; static void bcm2836_arm_irqchip_mask_per_cpu_irq(unsigned int reg_offset, unsigned int bit, int cpu) { void __iomem *reg = intc.base + reg_offset + 4 * cpu; writel(readl(reg) & ~BIT(bit), reg); } static void bcm2836_arm_irqchip_unmask_per_cpu_irq(unsigned int reg_offset, unsigned int bit, int cpu) { void __iomem *reg = intc.base + reg_offset + 4 * cpu; writel(readl(reg) | BIT(bit), reg); } static void bcm2836_arm_irqchip_mask_timer_irq(struct irq_data *d) { bcm2836_arm_irqchip_mask_per_cpu_irq(LOCAL_TIMER_INT_CONTROL0, d->hwirq - LOCAL_IRQ_CNTPSIRQ, smp_processor_id()); } static void bcm2836_arm_irqchip_unmask_timer_irq(struct irq_data *d) { bcm2836_arm_irqchip_unmask_per_cpu_irq(LOCAL_TIMER_INT_CONTROL0, d->hwirq - LOCAL_IRQ_CNTPSIRQ, smp_processor_id()); } static struct irq_chip bcm2836_arm_irqchip_timer = { .name = "bcm2836-timer", .irq_mask = bcm2836_arm_irqchip_mask_timer_irq, .irq_unmask = bcm2836_arm_irqchip_unmask_timer_irq, }; static void bcm2836_arm_irqchip_mask_pmu_irq(struct irq_data *d) { writel(1 << smp_processor_id(), intc.base + LOCAL_PM_ROUTING_CLR); } static void bcm2836_arm_irqchip_unmask_pmu_irq(struct irq_data *d) { writel(1 << smp_processor_id(), intc.base + LOCAL_PM_ROUTING_SET); } static struct irq_chip bcm2836_arm_irqchip_pmu = { .name = "bcm2836-pmu", .irq_mask = bcm2836_arm_irqchip_mask_pmu_irq, .irq_unmask = bcm2836_arm_irqchip_unmask_pmu_irq, }; static void bcm2836_arm_irqchip_mask_gpu_irq(struct irq_data *d) { } static void bcm2836_arm_irqchip_unmask_gpu_irq(struct irq_data *d) { } static struct irq_chip bcm2836_arm_irqchip_gpu = { .name = "bcm2836-gpu", .irq_mask = bcm2836_arm_irqchip_mask_gpu_irq, .irq_unmask = bcm2836_arm_irqchip_unmask_gpu_irq, }; static int bcm2836_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw) { struct irq_chip *chip; switch (hw) { case LOCAL_IRQ_CNTPSIRQ: case LOCAL_IRQ_CNTPNSIRQ: case LOCAL_IRQ_CNTHPIRQ: case LOCAL_IRQ_CNTVIRQ: chip = &bcm2836_arm_irqchip_timer; break; case LOCAL_IRQ_GPU_FAST: chip = &bcm2836_arm_irqchip_gpu; break; case LOCAL_IRQ_PMU_FAST: chip = &bcm2836_arm_irqchip_pmu; break; default: pr_warn_once("Unexpected hw irq: %lu\n", hw); return -EINVAL; } irq_set_percpu_devid(irq); irq_domain_set_info(d, irq, hw, chip, d->host_data, handle_percpu_devid_irq, NULL, NULL); irq_set_status_flags(irq, IRQ_NOAUTOEN); return 0; } static void __exception_irq_entry bcm2836_arm_irqchip_handle_irq(struct pt_regs *regs) { int cpu = smp_processor_id(); u32 stat; stat = readl_relaxed(intc.base + LOCAL_IRQ_PENDING0 + 4 * cpu); if (stat & BIT(LOCAL_IRQ_MAILBOX0)) { #ifdef CONFIG_SMP void __iomem *mailbox0 = (intc.base + LOCAL_MAILBOX0_CLR0 + 16 * cpu); u32 mbox_val = readl(mailbox0); u32 ipi = ffs(mbox_val) - 1; writel(1 << ipi, mailbox0); handle_IPI(ipi, regs); #endif } else if (stat) { u32 hwirq = ffs(stat) - 1; handle_domain_irq(intc.domain, hwirq, regs); } } #ifdef CONFIG_SMP static void bcm2836_arm_irqchip_send_ipi(const struct cpumask *mask, unsigned int ipi) { int cpu; void __iomem *mailbox0_base = intc.base + LOCAL_MAILBOX0_SET0; /* * Ensure that stores to normal memory are visible to the * other CPUs before issuing the IPI. */ smp_wmb(); for_each_cpu(cpu, mask) { writel(1 << ipi, mailbox0_base + 16 * cpu); } } static int bcm2836_cpu_starting(unsigned int cpu) { bcm2836_arm_irqchip_unmask_per_cpu_irq(LOCAL_MAILBOX_INT_CONTROL0, 0, cpu); return 0; } static int bcm2836_cpu_dying(unsigned int cpu) { bcm2836_arm_irqchip_mask_per_cpu_irq(LOCAL_MAILBOX_INT_CONTROL0, 0, cpu); return 0; } #endif static const struct irq_domain_ops bcm2836_arm_irqchip_intc_ops = { .xlate = irq_domain_xlate_onetwocell, .map = bcm2836_map, }; static void bcm2836_arm_irqchip_smp_init(void) { #ifdef CONFIG_SMP /* Unmask IPIs to the boot CPU. */ cpuhp_setup_state(CPUHP_AP_IRQ_BCM2836_STARTING, "irqchip/bcm2836:starting", bcm2836_cpu_starting, bcm2836_cpu_dying); set_smp_cross_call(bcm2836_arm_irqchip_send_ipi); #endif } /* * The LOCAL_IRQ_CNT* timer firings are based off of the external * oscillator with some scaling. The firmware sets up CNTFRQ to * report 19.2Mhz, but doesn't set up the scaling registers. */ static void bcm2835_init_local_timer_frequency(void) { /* * Set the timer to source from the 19.2Mhz crystal clock (bit * 8 unset), and only increment by 1 instead of 2 (bit 9 * unset). */ writel(0, intc.base + LOCAL_CONTROL); /* * Set the timer prescaler to 1:1 (timer freq = input freq * * 2**31 / prescaler) */ writel(0x80000000, intc.base + LOCAL_PRESCALER); } static int __init bcm2836_arm_irqchip_l1_intc_of_init(struct device_node *node, struct device_node *parent) { intc.base = of_iomap(node, 0); if (!intc.base) { panic("%pOF: unable to map local interrupt registers\n", node); } bcm2835_init_local_timer_frequency(); intc.domain = irq_domain_add_linear(node, LAST_IRQ + 1, &bcm2836_arm_irqchip_intc_ops, NULL); if (!intc.domain) panic("%pOF: unable to create IRQ domain\n", node); bcm2836_arm_irqchip_smp_init(); set_handle_irq(bcm2836_arm_irqchip_handle_irq); return 0; } IRQCHIP_DECLARE(bcm2836_arm_irqchip_l1_intc, "brcm,bcm2836-l1-intc", bcm2836_arm_irqchip_l1_intc_of_init);