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// 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/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 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
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);
}
}
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