This interrupt controller is the new root interrupt controller with
the timer, PMU events, and IPIs, and the bcm2835's interrupt
controller is chained off of it to handle the peripherals.
I wrote the interrupt chip support, while Andrea Merello wrote the IPI
code.
Signed-off-by: Eric Anholt <eric@xxxxxxxxxx>
Signed-off-by: Andrea Merello <andrea.merello@xxxxxxxxx>
Acked-by: Stephen Warren <swarren@xxxxxxxxxxxxx>
---
v2: Rename functions/globals to bcm2836_arm_local. Treat per-cpu
interrupts as per-cpu in mask/unmask. Add comments about how
registers work.
v3: Drop debug printfs from PMU interrupt masking.
v4: Use cpu notifiers to unmask IPIs only when Linux wants the CPU up.
drivers/irqchip/Makefile | 1 +
drivers/irqchip/irq-bcm2836.c | 275 ++++++++++++++++++++++++++++++++++++++++++
2 files changed, 276 insertions(+)
create mode 100644 drivers/irqchip/irq-bcm2836.c
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index b8d4e96..9727681 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -1,6 +1,7 @@
obj-$(CONFIG_IRQCHIP) += irqchip.o
obj-$(CONFIG_ARCH_BCM2835) += irq-bcm2835.o
+obj-$(CONFIG_ARCH_BCM2835) += irq-bcm2836.o
obj-$(CONFIG_ARCH_EXYNOS) += exynos-combiner.o
obj-$(CONFIG_ARCH_HIP04) += irq-hip04.o
obj-$(CONFIG_ARCH_MMP) += irq-mmp.o
diff --git a/drivers/irqchip/irq-bcm2836.c b/drivers/irqchip/irq-bcm2836.c
new file mode 100644
index 0000000..052bd83
--- /dev/null
+++ b/drivers/irqchip/irq-bcm2836.c
@@ -0,0 +1,275 @@
+/*
+ * Root interrupt controller for the BCM2836 (Raspberry Pi 2).
+ *
+ * Copyright 2015 Broadcom
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/cpu.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/irqchip.h>
+#include <linux/irqdomain.h>
+#include <asm/exception.h>
+
+/*
+ * The low 2 bits identify the CPU that the GPU IRQ goes to, and the
+ * next 2 bits identify the CPU that the GPU FIQ goes to.
+ */
+#define LOCAL_GPU_ROUTING 0x00c
+/* When setting bits 0-3, enables PMU interrupts on that CPU. */
+#define LOCAL_PM_ROUTING_SET 0x010
+/* When setting bits 0-3, disables PMU interrupts on that CPU. */
+#define LOCAL_PM_ROUTING_CLR 0x014
+/*
+ * The low 4 bits of this are the CPU's timer IRQ enables, and the
+ * next 4 bits are the CPU's timer FIQ enables (which override the IRQ
+ * bits).
+ */
+#define LOCAL_TIMER_INT_CONTROL0 0x040
+/*
+ * The low 4 bits of this are the CPU's per-mailbox IRQ enables, and
+ * the next 4 bits are the CPU's per-mailbox FIQ enables (which
+ * override the IRQ bits).
+ */
+#define LOCAL_MAILBOX_INT_CONTROL0 0x050
+/*
+ * The CPU's interrupt status register. Bits are defined by the the
+ * LOCAL_IRQ_* bits below.
+ */
+#define LOCAL_IRQ_PENDING0 0x060
+/* Same status bits as above, but for FIQ. */
+#define LOCAL_FIQ_PENDING0 0x070
+/*
+ * Mailbox0 write-to-set bits. There are 16 mailboxes, 4 per CPU, and
+ * these bits are organized by mailbox number and then CPU number. We
+ * use mailbox 0 for IPIs. The mailbox's interrupt is raised while
+ * any bit is set.
+ */
+#define LOCAL_MAILBOX0_SET0 0x080
+/* Mailbox0 write-to-clear bits. */
+#define LOCAL_MAILBOX0_CLR0 0x0c0
+
+#define LOCAL_IRQ_CNTPSIRQ 0
+#define LOCAL_IRQ_CNTPNSIRQ 1
+#define LOCAL_IRQ_CNTHPIRQ 2
+#define LOCAL_IRQ_CNTVIRQ 3
+#define LOCAL_IRQ_MAILBOX0 4
+#define LOCAL_IRQ_MAILBOX1 5
+#define LOCAL_IRQ_MAILBOX2 6
+#define LOCAL_IRQ_MAILBOX3 7
+#define LOCAL_IRQ_GPU_FAST 8
+#define LOCAL_IRQ_PMU_FAST 9
+#define LAST_IRQ LOCAL_IRQ_PMU_FAST
+
+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_register_irq(int hwirq, struct irq_chip *chip)
+{
+ int irq = irq_create_mapping(intc.domain, hwirq);
+
+ irq_set_percpu_devid(irq);
+ irq_set_chip_and_handler(irq, chip, handle_percpu_devid_irq);
+ irq_set_status_flags(irq, IRQ_NOAUTOEN);
+}
+
+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 & 0x10) {
+#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 {
+ u32 hwirq = ffs(stat) - 1;
+
+ handle_IRQ(irq_linear_revmap(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.
+ */
+ dsb();
+
+ for_each_cpu(cpu, mask) {
+ writel(1 << ipi, mailbox0_base + 16 * cpu);
+ }
+}
+
+/* Unmasks the IPI on the CPU when it's online. */
+static int bcm2836_arm_irqchip_cpu_notify(struct notifier_block *nfb,
+ unsigned long action, void *hcpu)
+{
+ unsigned int cpu = (unsigned long)hcpu;
+ unsigned int int_reg = LOCAL_MAILBOX_INT_CONTROL0;
+ unsigned int mailbox = 0;
+
+ if (action == CPU_STARTING || action == CPU_STARTING_FROZEN)
+ bcm2836_arm_irqchip_unmask_per_cpu_irq(int_reg, mailbox, cpu);
+ else if (action == CPU_DYING)
+ bcm2836_arm_irqchip_mask_per_cpu_irq(int_reg, mailbox, cpu);
+
+ return NOTIFY_OK;
+}
+
+static struct notifier_block bcm2836_arm_irqchip_cpu_notifier = {
+ .notifier_call = bcm2836_arm_irqchip_cpu_notify,
+ .priority = 100,
+};
+#endif
+
+static const struct irq_domain_ops bcm2836_arm_irqchip_intc_ops = {
+ .xlate = irq_domain_xlate_onecell
+};
+
+static void
+bcm2836_arm_irqchip_smp_init(void)
+{
+#ifdef CONFIG_SMP
+ /* Unmask IPIs to the boot CPU. */
+ bcm2836_arm_irqchip_cpu_notify(&bcm2836_arm_irqchip_cpu_notifier,
+ CPU_STARTING,
+ (void *)smp_processor_id());
+ register_cpu_notifier(&bcm2836_arm_irqchip_cpu_notifier);
+
+ set_smp_cross_call(bcm2836_arm_irqchip_send_ipi);
+#endif
+}
+
+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("%s: unable to map local interrupt registers\n",
+ node->full_name);
+ }
+
+ intc.domain = irq_domain_add_linear(node, LAST_IRQ + 1,
+ &bcm2836_arm_irqchip_intc_ops,
+ NULL);
+ if (!intc.domain)
+ panic("%s: unable to create IRQ domain\n", node->full_name);
+
+ bcm2836_arm_irqchip_register_irq(LOCAL_IRQ_CNTPSIRQ,
+ &bcm2836_arm_irqchip_timer);
+ bcm2836_arm_irqchip_register_irq(LOCAL_IRQ_CNTPNSIRQ,
+ &bcm2836_arm_irqchip_timer);
+ bcm2836_arm_irqchip_register_irq(LOCAL_IRQ_CNTHPIRQ,
+ &bcm2836_arm_irqchip_timer);
+ bcm2836_arm_irqchip_register_irq(LOCAL_IRQ_CNTVIRQ,
+ &bcm2836_arm_irqchip_timer);
+ bcm2836_arm_irqchip_register_irq(LOCAL_IRQ_GPU_FAST,
+ &bcm2836_arm_irqchip_gpu);
+ bcm2836_arm_irqchip_register_irq(LOCAL_IRQ_PMU_FAST,
+ &bcm2836_arm_irqchip_pmu);
+
+ 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);
--
2.1.4
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