1 files changed, 137 insertions, 0 deletions
diff --git a/arch/loongarch/kernel/irq.c b/arch/loongarch/kernel/irq.c
new file mode 100644
index 0000000000..883e5066ae
--- /dev/null
+++ b/arch/loongarch/kernel/irq.c
@@ -0,0 +1,137 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#include <linux/kernel.h>
+#include <linux/acpi.h>
+#include <linux/atomic.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irqchip.h>
+#include <linux/kernel_stat.h>
+#include <linux/proc_fs.h>
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <linux/seq_file.h>
+#include <linux/kallsyms.h>
+#include <linux/uaccess.h>
+
+#include <asm/irq.h>
+#include <asm/loongson.h>
+#include <asm/setup.h>
+
+DEFINE_PER_CPU(unsigned long, irq_stack);
+DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
+EXPORT_PER_CPU_SYMBOL(irq_stat);
+
+struct acpi_vector_group pch_group[MAX_IO_PICS];
+struct acpi_vector_group msi_group[MAX_IO_PICS];
+/*
+ * 'what should we do if we get a hw irq event on an illegal vector'.
+ * each architecture has to answer this themselves.
+ */
+void ack_bad_irq(unsigned int irq)
+{
+	pr_warn("Unexpected IRQ # %d\n", irq);
+}
+
+atomic_t irq_err_count;
+
+asmlinkage void spurious_interrupt(void)
+{
+	atomic_inc(&irq_err_count);
+}
+
+int arch_show_interrupts(struct seq_file *p, int prec)
+{
+#ifdef CONFIG_SMP
+	show_ipi_list(p, prec);
+#endif
+	seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count));
+	return 0;
+}
+
+static int __init early_pci_mcfg_parse(struct acpi_table_header *header)
+{
+	struct acpi_table_mcfg *mcfg;
+	struct acpi_mcfg_allocation *mptr;
+	int i, n;
+
+	if (header->length < sizeof(struct acpi_table_mcfg))
+		return -EINVAL;
+
+	n = (header->length - sizeof(struct acpi_table_mcfg)) /
+					sizeof(struct acpi_mcfg_allocation);
+	mcfg = (struct acpi_table_mcfg *)header;
+	mptr = (struct acpi_mcfg_allocation *) &mcfg[1];
+
+	for (i = 0; i < n; i++, mptr++) {
+		msi_group[i].pci_segment = mptr->pci_segment;
+		pch_group[i].node = msi_group[i].node = (mptr->address >> 44) & 0xf;
+	}
+
+	return 0;
+}
+
+static void __init init_vec_parent_group(void)
+{
+	int i;
+
+	for (i = 0; i < MAX_IO_PICS; i++) {
+		msi_group[i].pci_segment = -1;
+		msi_group[i].node = -1;
+		pch_group[i].node = -1;
+	}
+
+	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, INT_IPI);
+
+	return -EINVAL;
+}
+
+void __init init_IRQ(void)
+{
+	int i;
+#ifdef CONFIG_SMP
+	int r, ipi_irq;
+	static int ipi_dummy_dev;
+#endif
+	unsigned int order = get_order(IRQ_STACK_SIZE);
+	struct page *page;
+
+	clear_csr_ecfg(ECFG0_IM);
+	clear_csr_estat(ESTATF_IP);
+
+	init_vec_parent_group();
+	irqchip_init();
+#ifdef CONFIG_SMP
+	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, loongson_ipi_interrupt, "IPI", &ipi_dummy_dev);
+	if (r < 0)
+		panic("IPI IRQ request failed\n");
+#endif
+
+	for (i = 0; i < NR_IRQS; i++)
+		irq_set_noprobe(i);
+
+	for_each_possible_cpu(i) {
+		page = alloc_pages_node(cpu_to_node(i), GFP_KERNEL, order);
+
+		per_cpu(irq_stack, i) = (unsigned long)page_address(page);
+		pr_debug("CPU%d IRQ stack at 0x%lx - 0x%lx\n", i,
+			per_cpu(irq_stack, i), per_cpu(irq_stack, i) + IRQ_STACK_SIZE);
+	}
+
+	set_csr_ecfg(ECFGF_IP0 | ECFGF_IP1 | ECFGF_IP2 | ECFGF_IPI | ECFGF_PMC);
+}