// 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/chained_irq.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 void bcm2836_arm_irqchip_dummy_op(struct irq_data *d)
{
}
static struct irq_chip bcm2836_arm_irqchip_dummy = {
.name = "bcm2836-dummy",
.irq_eoi = bcm2836_arm_irqchip_dummy_op,
};
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_MAILBOX0:
chip = &bcm2836_arm_irqchip_dummy;
break;
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) {
u32 hwirq = ffs(stat) - 1;
generic_handle_domain_irq(intc.domain, hwirq);
}
}
#ifdef CONFIG_SMP
static struct irq_domain *ipi_domain;
static void bcm2836_arm_irqchip_handle_ipi(struct irq_desc *desc)
{
struct irq_chip *chip = irq_desc_get_chip(desc);
int cpu = smp_processor_id();
u32 mbox_val;
chained_irq_enter(chip, desc);
mbox_val = readl_relaxed(intc.base + LOCAL_MAILBOX0_CLR0 + 16 * cpu);
if (mbox_val) {
int hwirq = ffs(mbox_val) - 1;
generic_handle_domain_irq(ipi_domain, hwirq);
}
chained_irq_exit(chip, desc);
}
static void bcm2836_arm_irqchip_ipi_ack(struct irq_data *d)
{
int cpu = smp_processor_id();
writel_relaxed(BIT(d->hwirq),
intc.base + LOCAL_MAILBOX0_CLR0 + 16 * cpu);
}
static void bcm2836_arm_irqchip_ipi_send_mask(struct irq_data *d,
const struct cpumask *mask)
{
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_relaxed(BIT(d->hwirq), mailbox0_base + 16 * cpu);
}
static struct irq_chip bcm2836_arm_irqchip_ipi = {
.name = "IPI",
.irq_mask = bcm2836_arm_irqchip_dummy_op,
.irq_unmask = bcm2836_arm_irqchip_dummy_op,
.irq_ack = bcm2836_arm_irqchip_ipi_ack,
.ipi_send_mask = bcm2836_arm_irqchip_ipi_send_mask,
};
static int bcm2836_arm_irqchip_ipi_alloc(struct irq_domain *d,
unsigned int virq,
unsigned int nr_irqs, void *args)
{
int i;
for (i = 0; i < nr_irqs; i++) {
irq_set_percpu_devid(virq + i);
irq_domain_set_info(d, virq + i, i, &bcm2836_arm_irqchip_ipi,
d->host_data,
handle_percpu_devid_irq,
NULL, NULL);
}
return 0;
}
static void bcm2836_arm_irqchip_ipi_free(struct irq_domain *d,
unsigned int virq,
unsigned int nr_irqs)
{
/* Not freeing IPIs */
}
static const struct irq_domain_ops ipi_domain_ops = {
.alloc = bcm2836_arm_irqchip_ipi_alloc,
.free = bcm2836_arm_irqchip_ipi_free,
};
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;
}
#define BITS_PER_MBOX 32
static void __init bcm2836_arm_irqchip_smp_init(void)
{
struct irq_fwspec ipi_fwspec = {
.fwnode = intc.domain->fwnode,
.param_count = 1,
.param = {
[0] = LOCAL_IRQ_MAILBOX0,
},
};
int base_ipi, mux_irq;
mux_irq = irq_create_fwspec_mapping(&ipi_fwspec);
if (WARN_ON(mux_irq <= 0))
return;
ipi_domain = irq_domain_create_linear(intc.domain->fwnode,
BITS_PER_MBOX, &ipi_domain_ops,
NULL);
if (WARN_ON(!ipi_domain))
return;
ipi_domain->flags |= IRQ_DOMAIN_FLAG_IPI_SINGLE;
irq_domain_update_bus_token(ipi_domain, DOMAIN_BUS_IPI);
base_ipi = irq_domain_alloc_irqs(ipi_domain, BITS_PER_MBOX, NUMA_NO_NODE, NULL);
if (WARN_ON(!base_ipi))
return;
set_smp_ipi_range(base_ipi, BITS_PER_MBOX);
irq_set_chained_handler_and_data(mux_irq,
bcm2836_arm_irqchip_handle_ipi, NULL);
/* Unmask IPIs to the boot CPU. */
cpuhp_setup_state(CPUHP_AP_IRQ_BCM2836_STARTING,
"irqchip/bcm2836:starting", bcm2836_cpu_starting,
bcm2836_cpu_dying);
}
#else
#define bcm2836_arm_irqchip_smp_init() do { } while(0)
#endif
static const struct irq_domain_ops bcm2836_arm_irqchip_intc_ops = {
.xlate = irq_domain_xlate_onetwocell,
.map = bcm2836_map,
};
/*
* 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);
irq_domain_update_bus_token(intc.domain, DOMAIN_BUS_WIRED);
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);
