arch/arm64/kernel/irq.c

Source file repositories/reference/linux-study-clean/arch/arm64/kernel/irq.c

File Facts

System
Linux kernel
Corpus path
arch/arm64/kernel/irq.c
Extension
.c
Size
3083 bytes
Lines
136
Domain
Architecture Layer
Bucket
arch/arm64
Inferred role
Architecture Layer: implementation source
Status
source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

// 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/errno.h>
#include <linux/hardirq.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/irqchip.h>
#include <linux/kprobes.h>
#include <linux/memory.h>
#include <linux/scs.h>
#include <linux/seq_file.h>
#include <linux/smp.h>
#include <linux/vmalloc.h>
#include <asm/daifflags.h>
#include <asm/exception.h>
#include <asm/numa.h>
#include <asm/softirq_stack.h>
#include <asm/stacktrace.h>
#include <asm/vmap_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 int __init init_irq_scs(void)
{
	int cpu;
	void *s;

	if (!scs_is_enabled())
		return 0;

	for_each_possible_cpu(cpu) {
		s = scs_alloc(early_cpu_to_node(cpu));
		if (!s)
			return -ENOMEM;
		per_cpu(irq_shadow_call_stack_ptr, cpu) = s;
	}

	return 0;
}

static int __init init_irq_stacks(void)
{
	int cpu;
	unsigned long *p;

	for_each_possible_cpu(cpu) {
		p = arch_alloc_vmap_stack(IRQ_STACK_SIZE, early_cpu_to_node(cpu));
		if (!p)
			return -ENOMEM;
		per_cpu(irq_stack_ptr, cpu) = p;
	}

	return 0;
}

#ifdef CONFIG_SOFTIRQ_ON_OWN_STACK
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");
}

Annotation

Implementation Notes