1 files changed, 135 insertions, 0 deletions
diff --git a/arch/arm64/kernel/irq.c b/arch/arm64/kernel/irq.c
new file mode 100644
index 000000000..38dbd3828
--- /dev/null
+++ b/arch/arm64/kernel/irq.c
@@ -0,0 +1,135 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Based on arch/arm/kernel/irq.c
+ *
+ * Copyright (C) 1992 Linus Torvalds
+ * Modifications for ARM processor Copyright (C) 1995-2000 Russell King.
+ * Support for Dynamic Tick Timer Copyright (C) 2004-2005 Nokia Corporation.
+ * Dynamic Tick Timer written by Tony Lindgren <tony@atomide.com> and
+ * Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>.
+ * Copyright (C) 2012 ARM Ltd.
+ */
+
+#include <linux/irq.h>
+#include <linux/memory.h>
+#include <linux/smp.h>
+#include <linux/hardirq.h>
+#include <linux/init.h>
+#include <linux/irqchip.h>
+#include <linux/kprobes.h>
+#include <linux/scs.h>
+#include <linux/seq_file.h>
+#include <linux/vmalloc.h>
+#include <asm/daifflags.h>
+#include <asm/exception.h>
+#include <asm/vmap_stack.h>
+#include <asm/softirq_stack.h>
+
+/* Only access this in an NMI enter/exit */
+DEFINE_PER_CPU(struct nmi_ctx, nmi_contexts);
+
+DEFINE_PER_CPU(unsigned long *, irq_stack_ptr);
+
+
+DECLARE_PER_CPU(unsigned long *, irq_shadow_call_stack_ptr);
+
+#ifdef CONFIG_SHADOW_CALL_STACK
+DEFINE_PER_CPU(unsigned long *, irq_shadow_call_stack_ptr);
+#endif
+
+static void init_irq_scs(void)
+{
+	int cpu;
+
+	if (!IS_ENABLED(CONFIG_SHADOW_CALL_STACK))
+		return;
+
+	for_each_possible_cpu(cpu)
+		per_cpu(irq_shadow_call_stack_ptr, cpu) =
+			scs_alloc(cpu_to_node(cpu));
+}
+
+#ifdef CONFIG_VMAP_STACK
+static void init_irq_stacks(void)
+{
+	int cpu;
+	unsigned long *p;
+
+	for_each_possible_cpu(cpu) {
+		p = arch_alloc_vmap_stack(IRQ_STACK_SIZE, cpu_to_node(cpu));
+		per_cpu(irq_stack_ptr, cpu) = p;
+	}
+}
+#else
+/* irq stack only needs to be 16 byte aligned - not IRQ_STACK_SIZE aligned. */
+DEFINE_PER_CPU_ALIGNED(unsigned long [IRQ_STACK_SIZE/sizeof(long)], irq_stack);
+
+static void init_irq_stacks(void)
+{
+	int cpu;
+
+	for_each_possible_cpu(cpu)
+		per_cpu(irq_stack_ptr, cpu) = per_cpu(irq_stack, cpu);
+}
+#endif
+
+#ifndef CONFIG_PREEMPT_RT
+static void ____do_softirq(struct pt_regs *regs)
+{
+	__do_softirq();
+}
+
+void do_softirq_own_stack(void)
+{
+	call_on_irq_stack(NULL, ____do_softirq);
+}
+#endif
+
+static void default_handle_irq(struct pt_regs *regs)
+{
+	panic("IRQ taken without a root IRQ handler\n");
+}
+
+static void default_handle_fiq(struct pt_regs *regs)
+{
+	panic("FIQ taken without a root FIQ handler\n");
+}
+
+void (*handle_arch_irq)(struct pt_regs *) __ro_after_init = default_handle_irq;
+void (*handle_arch_fiq)(struct pt_regs *) __ro_after_init = default_handle_fiq;
+
+int __init set_handle_irq(void (*handle_irq)(struct pt_regs *))
+{
+	if (handle_arch_irq != default_handle_irq)
+		return -EBUSY;
+
+	handle_arch_irq = handle_irq;
+	pr_info("Root IRQ handler: %ps\n", handle_irq);
+	return 0;
+}
+
+int __init set_handle_fiq(void (*handle_fiq)(struct pt_regs *))
+{
+	if (handle_arch_fiq != default_handle_fiq)
+		return -EBUSY;
+
+	handle_arch_fiq = handle_fiq;
+	pr_info("Root FIQ handler: %ps\n", handle_fiq);
+	return 0;
+}
+
+void __init init_IRQ(void)
+{
+	init_irq_stacks();
+	init_irq_scs();
+	irqchip_init();
+
+	if (system_uses_irq_prio_masking()) {
+		/*
+		 * Now that we have a stack for our IRQ handler, set
+		 * the PMR/PSR pair to a consistent state.
+		 */
+		WARN_ON(read_sysreg(daif) & PSR_A_BIT);
+		local_daif_restore(DAIF_PROCCTX_NOIRQ);
+	}
+}