1 // SPDX-License-Identifier: GPL-2.0-only
3 * Based on arch/arm/kernel/irq.c
5 * Copyright (C) 1992 Linus Torvalds
6 * Modifications for ARM processor Copyright (C) 1995-2000 Russell King.
7 * Support for Dynamic Tick Timer Copyright (C) 2004-2005 Nokia Corporation.
8 * Dynamic Tick Timer written by Tony Lindgren <tony@atomide.com> and
9 * Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>.
10 * Copyright (C) 2012 ARM Ltd.
13 #include <linux/irq.h>
14 #include <linux/memory.h>
15 #include <linux/smp.h>
16 #include <linux/hardirq.h>
17 #include <linux/init.h>
18 #include <linux/irqchip.h>
19 #include <linux/kprobes.h>
20 #include <linux/scs.h>
21 #include <linux/seq_file.h>
22 #include <linux/vmalloc.h>
23 #include <asm/daifflags.h>
24 #include <asm/vmap_stack.h>
26 /* Only access this in an NMI enter/exit */
27 DEFINE_PER_CPU(struct nmi_ctx, nmi_contexts);
29 DEFINE_PER_CPU(unsigned long *, irq_stack_ptr);
32 DECLARE_PER_CPU(unsigned long *, irq_shadow_call_stack_ptr);
34 #ifdef CONFIG_SHADOW_CALL_STACK
35 DEFINE_PER_CPU(unsigned long *, irq_shadow_call_stack_ptr);
38 static void init_irq_scs(void)
42 if (!IS_ENABLED(CONFIG_SHADOW_CALL_STACK))
45 for_each_possible_cpu(cpu)
46 per_cpu(irq_shadow_call_stack_ptr, cpu) =
47 scs_alloc(cpu_to_node(cpu));
50 #ifdef CONFIG_VMAP_STACK
51 static void init_irq_stacks(void)
56 for_each_possible_cpu(cpu) {
57 p = arch_alloc_vmap_stack(IRQ_STACK_SIZE, cpu_to_node(cpu));
58 per_cpu(irq_stack_ptr, cpu) = p;
62 /* irq stack only needs to be 16 byte aligned - not IRQ_STACK_SIZE aligned. */
63 DEFINE_PER_CPU_ALIGNED(unsigned long [IRQ_STACK_SIZE/sizeof(long)], irq_stack);
65 static void init_irq_stacks(void)
69 for_each_possible_cpu(cpu)
70 per_cpu(irq_stack_ptr, cpu) = per_cpu(irq_stack, cpu);
74 static void default_handle_irq(struct pt_regs *regs)
76 panic("IRQ taken without a root IRQ handler\n");
79 static void default_handle_fiq(struct pt_regs *regs)
81 panic("FIQ taken without a root FIQ handler\n");
84 void (*handle_arch_irq)(struct pt_regs *) __ro_after_init = default_handle_irq;
85 void (*handle_arch_fiq)(struct pt_regs *) __ro_after_init = default_handle_fiq;
87 int __init set_handle_irq(void (*handle_irq)(struct pt_regs *))
89 if (handle_arch_irq != default_handle_irq)
92 handle_arch_irq = handle_irq;
93 pr_info("Root IRQ handler: %ps\n", handle_irq);
97 int __init set_handle_fiq(void (*handle_fiq)(struct pt_regs *))
99 if (handle_arch_fiq != default_handle_fiq)
102 handle_arch_fiq = handle_fiq;
103 pr_info("Root FIQ handler: %ps\n", handle_fiq);
107 void __init init_IRQ(void)
113 if (system_uses_irq_prio_masking()) {
115 * Now that we have a stack for our IRQ handler, set
116 * the PMR/PSR pair to a consistent state.
118 WARN_ON(read_sysreg(daif) & PSR_A_BIT);
119 local_daif_restore(DAIF_PROCCTX_NOIRQ);