[PATCH V4 08/10] irqchip: Add LoongArch CPU interrupt controller support

From: Huacai Chen
Date: Tue Aug 31 2021 - 05:31:38 EST


We are preparing to add new Loongson (based on LoongArch, not compatible
with old MIPS-based Loongson) support. This patch add the LoongArch CPU
interrupt controller support.

Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>
---
drivers/irqchip/Kconfig | 10 ++++
drivers/irqchip/Makefile | 1 +
drivers/irqchip/irq-loongarch-cpu.c | 89 +++++++++++++++++++++++++++++
3 files changed, 100 insertions(+)
create mode 100644 drivers/irqchip/irq-loongarch-cpu.c

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 084bc4c2eebd..443c3a7a0cc1 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -528,6 +528,16 @@ config EXYNOS_IRQ_COMBINER
Say yes here to add support for the IRQ combiner devices embedded
in Samsung Exynos chips.

+config IRQ_LOONGARCH_CPU
+ bool
+ select GENERIC_IRQ_CHIP
+ select IRQ_DOMAIN
+ select GENERIC_IRQ_EFFECTIVE_AFF_MASK
+ help
+ Support for the LoongArch CPU Interrupt Controller. For details of
+ irq chip hierarchy on LoongArch platforms please read the document
+ Documentation/loongarch/irq-chip-model.rst.
+
config LOONGSON_LIOINTC
bool "Loongson Local I/O Interrupt Controller"
depends on MACH_LOONGSON64
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index f88cbf36a9d2..4e34eebe180b 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -105,6 +105,7 @@ obj-$(CONFIG_LS1X_IRQ) += irq-ls1x.o
obj-$(CONFIG_TI_SCI_INTR_IRQCHIP) += irq-ti-sci-intr.o
obj-$(CONFIG_TI_SCI_INTA_IRQCHIP) += irq-ti-sci-inta.o
obj-$(CONFIG_TI_PRUSS_INTC) += irq-pruss-intc.o
+obj-$(CONFIG_IRQ_LOONGARCH_CPU) += irq-loongarch-cpu.o
obj-$(CONFIG_LOONGSON_LIOINTC) += irq-loongson-liointc.o
obj-$(CONFIG_LOONGSON_HTPIC) += irq-loongson-htpic.o
obj-$(CONFIG_LOONGSON_HTVEC) += irq-loongson-htvec.o
diff --git a/drivers/irqchip/irq-loongarch-cpu.c b/drivers/irqchip/irq-loongarch-cpu.c
new file mode 100644
index 000000000000..bc15e3cefbd8
--- /dev/null
+++ b/drivers/irqchip/irq-loongarch-cpu.c
@@ -0,0 +1,89 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020-2021 Loongson Technology Corporation Limited
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqchip.h>
+#include <linux/irqdomain.h>
+
+#include <asm/loongarch.h>
+#include <asm/setup.h>
+
+static struct irq_domain *irq_domain;
+
+static void mask_loongarch_irq(struct irq_data *d)
+{
+ clear_csr_ecfg(ECFGF(d->hwirq));
+}
+
+static void unmask_loongarch_irq(struct irq_data *d)
+{
+ set_csr_ecfg(ECFGF(d->hwirq));
+}
+
+static struct irq_chip cpu_irq_controller = {
+ .name = "LoongArch",
+ .irq_mask = mask_loongarch_irq,
+ .irq_unmask = unmask_loongarch_irq,
+};
+
+static void handle_cpu_irq(struct pt_regs *regs)
+{
+ int hwirq;
+ unsigned int estat = read_csr_estat() & CSR_ESTAT_IS;
+
+ while ((hwirq = ffs(estat))) {
+ estat &= ~BIT(hwirq - 1);
+ handle_domain_irq(irq_domain, hwirq - 1, regs);
+ }
+}
+
+int get_ipi_irq(void)
+{
+ return irq_create_mapping(irq_domain, EXCCODE_IPI - EXCCODE_INT_START);
+}
+
+int get_pmc_irq(void)
+{
+ return irq_create_mapping(irq_domain, EXCCODE_PMC - EXCCODE_INT_START);
+}
+
+int get_timer_irq(void)
+{
+ return irq_create_mapping(irq_domain, EXCCODE_TIMER - EXCCODE_INT_START);
+}
+
+static int loongarch_cpu_intc_map(struct irq_domain *d, unsigned int irq,
+ irq_hw_number_t hwirq)
+{
+ irq_set_noprobe(irq);
+ irq_set_chip_and_handler(irq, &cpu_irq_controller, handle_percpu_irq);
+
+ return 0;
+}
+
+static const struct irq_domain_ops loongarch_cpu_intc_irq_domain_ops = {
+ .map = loongarch_cpu_intc_map,
+ .xlate = irq_domain_xlate_onecell,
+};
+
+struct irq_domain * __init loongarch_cpu_irq_init(void)
+{
+ /* Mask interrupts. */
+ clear_csr_ecfg(ECFG0_IM);
+ clear_csr_estat(ESTATF_IP);
+
+ irq_domain = irq_domain_add_simple(NULL, EXCCODE_INT_NUM,
+ 0, &loongarch_cpu_intc_irq_domain_ops, NULL);
+
+ if (!irq_domain)
+ panic("Failed to add irqdomain for LoongArch CPU");
+
+ set_handle_irq(&handle_cpu_irq);
+
+ return irq_domain;
+}
--
2.27.0