irqchip: Add LoongArch CPU interrupt controller support

LoongArch CPUINTC stands for CSR.ECFG/CSR.ESTAT and related interrupt
controller that described in Section 7.4 of "LoongArch Reference Manual,
Vol 1". For more information please refer Documentation/loongarch/irq-
chip-model.rst.

LoongArch CPUINTC has 13 interrupt sources: SWI0~1, HWI0~7, IPI, TI
(Timer) and PCOV (PMC). IRQ mappings of HWI0~7 are configurable (can be
created from DT/ACPI), but IPI, TI (Timer) and PCOV (PMC) are hardcoded
bits, so we expose the fwnode_handle to map them, and get mapped irq
by irq_create_mapping when using them.

Co-developed-by: Jianmin Lv <lvjianmin@loongson.cn>
Signed-off-by: Jianmin Lv <lvjianmin@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/1658314292-35346-13-git-send-email-lvjianmin@loongson.cn

3 files changed, 27 insertions, 10 deletions

diff --git a/arch/loongarch/include/asm/irq.h b/arch/loongarch/include/asm/irq.h
index 67ebcc5495b8..149b2123e7f4 100644
--- a/arch/loongarch/include/asm/irq.h
+++ b/arch/loongarch/include/asm/irq.h
@@ -35,9 +35,6 @@ static inline bool on_irq_stack(int cpu, unsigned long sp)
 	return (low <= sp && sp <= high);
 }
 
-int get_ipi_irq(void);
-int get_pmc_irq(void);
-int get_timer_irq(void);
 void spurious_interrupt(void);
 
 #define NR_IRQS_LEGACY 16
@@ -94,8 +91,6 @@ struct acpi_madt_bio_pic;
 struct acpi_madt_msi_pic;
 struct acpi_madt_lpc_pic;
 
-struct irq_domain *loongarch_cpu_irq_init(void);
-
 int liointc_acpi_init(struct irq_domain *parent,
 					struct acpi_madt_lio_pic *acpi_liointc);
 int eiointc_acpi_init(struct irq_domain *parent,
@@ -128,7 +123,7 @@ extern struct acpi_madt_lpc_pic *acpi_pchlpc;
 extern struct acpi_madt_msi_pic *acpi_pchmsi[MAX_IO_PICS];
 extern struct acpi_madt_bio_pic *acpi_pchpic[MAX_IO_PICS];
 
-extern struct irq_domain *cpu_domain;
+extern struct fwnode_handle *cpuintc_handle;
 extern struct fwnode_handle *liointc_handle;
 extern struct fwnode_handle *pch_lpc_handle;
 extern struct fwnode_handle *pch_pic_handle[MAX_IO_PICS];
diff --git a/arch/loongarch/kernel/irq.c b/arch/loongarch/kernel/irq.c
index da131f51225a..1ba19c76563e 100644
--- a/arch/loongarch/kernel/irq.c
+++ b/arch/loongarch/kernel/irq.c
@@ -25,8 +25,6 @@ DEFINE_PER_CPU(unsigned long, irq_stack);
 DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
 EXPORT_PER_CPU_SYMBOL(irq_stat);
 
-struct irq_domain *cpu_domain;
-
 struct acpi_vector_group pch_group[MAX_IO_PICS];
 struct acpi_vector_group msi_group[MAX_IO_PICS];
 /*
@@ -89,6 +87,16 @@ static void __init init_vec_parent_group(void)
 	acpi_table_parse(ACPI_SIG_MCFG, early_pci_mcfg_parse);
 }
 
+static int __init get_ipi_irq(void)
+{
+	struct irq_domain *d = irq_find_matching_fwnode(cpuintc_handle, DOMAIN_BUS_ANY);
+
+	if (d)
+		return irq_create_mapping(d, EXCCODE_IPI - EXCCODE_INT_START);
+
+	return -EINVAL;
+}
+
 void __init init_IRQ(void)
 {
 	int i;
@@ -105,7 +113,9 @@ void __init init_IRQ(void)
 	init_vec_parent_group();
 	irqchip_init();
 #ifdef CONFIG_SMP
-	ipi_irq = EXCCODE_IPI - EXCCODE_INT_START;
+	ipi_irq = get_ipi_irq();
+	if (ipi_irq < 0)
+		panic("IPI IRQ mapping failed\n");
 	irq_set_percpu_devid(ipi_irq);
 	r = request_percpu_irq(ipi_irq, loongson3_ipi_interrupt, "IPI", &ipi_dummy_dev);
 	if (r < 0)
diff --git a/arch/loongarch/kernel/time.c b/arch/loongarch/kernel/time.c
index fe6823875895..79dc5eddf504 100644
--- a/arch/loongarch/kernel/time.c
+++ b/arch/loongarch/kernel/time.c
@@ -123,6 +123,16 @@ void sync_counter(void)
 	csr_write64(-init_timeval, LOONGARCH_CSR_CNTC);
 }
 
+static int get_timer_irq(void)
+{
+	struct irq_domain *d = irq_find_matching_fwnode(cpuintc_handle, DOMAIN_BUS_ANY);
+
+	if (d)
+		return irq_create_mapping(d, EXCCODE_TIMER - EXCCODE_INT_START);
+
+	return -EINVAL;
+}
+
 int constant_clockevent_init(void)
 {
 	unsigned int irq;
@@ -132,7 +142,9 @@ int constant_clockevent_init(void)
 	struct clock_event_device *cd;
 	static int timer_irq_installed = 0;
 
-	irq = EXCCODE_TIMER - EXCCODE_INT_START;
+	irq = get_timer_irq();
+	if (irq < 0)
+		pr_err("Failed to map irq %d (timer)\n", irq);
 
 	cd = &per_cpu(constant_clockevent_device, cpu);