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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Based on arch/arm/kernel/irq.c
4 *
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.
11 */
12
13#include <linux/hardirq.h>
14#include <linux/init.h>
15#include <linux/irq.h>
16#include <linux/irqchip.h>
17#include <linux/kprobes.h>
18#include <linux/memory.h>
19#include <linux/scs.h>
20#include <linux/seq_file.h>
21#include <linux/smp.h>
22#include <linux/vmalloc.h>
23#include <asm/daifflags.h>
24#include <asm/exception.h>
25#include <asm/numa.h>
26#include <asm/softirq_stack.h>
27#include <asm/stacktrace.h>
28#include <asm/vmap_stack.h>
29
30/* Only access this in an NMI enter/exit */
31DEFINE_PER_CPU(struct nmi_ctx, nmi_contexts);
32
33DEFINE_PER_CPU(unsigned long *, irq_stack_ptr);
34
35
36DECLARE_PER_CPU(unsigned long *, irq_shadow_call_stack_ptr);
37
38#ifdef CONFIG_SHADOW_CALL_STACK
39DEFINE_PER_CPU(unsigned long *, irq_shadow_call_stack_ptr);
40#endif
41
42static void init_irq_scs(void)
43{
44 int cpu;
45
46 if (!scs_is_enabled())
47 return;
48
49 for_each_possible_cpu(cpu)
50 per_cpu(irq_shadow_call_stack_ptr, cpu) =
51 scs_alloc(node: early_cpu_to_node(cpu));
52}
53
54static void __init init_irq_stacks(void)
55{
56 int cpu;
57 unsigned long *p;
58
59 for_each_possible_cpu(cpu) {
60 p = arch_alloc_vmap_stack(IRQ_STACK_SIZE, early_cpu_to_node(cpu));
61 per_cpu(irq_stack_ptr, cpu) = p;
62 }
63}
64
65#ifdef CONFIG_SOFTIRQ_ON_OWN_STACK
66static void ____do_softirq(struct pt_regs *regs)
67{
68 __do_softirq();
69}
70
71void do_softirq_own_stack(void)
72{
73 call_on_irq_stack(NULL, ____do_softirq);
74}
75#endif
76
77static void default_handle_irq(struct pt_regs *regs)
78{
79 panic(fmt: "IRQ taken without a root IRQ handler\n");
80}
81
82static void default_handle_fiq(struct pt_regs *regs)
83{
84 panic(fmt: "FIQ taken without a root FIQ handler\n");
85}
86
87void (*handle_arch_irq)(struct pt_regs *) __ro_after_init = default_handle_irq;
88void (*handle_arch_fiq)(struct pt_regs *) __ro_after_init = default_handle_fiq;
89
90int __init set_handle_irq(void (*handle_irq)(struct pt_regs *))
91{
92 if (handle_arch_irq != default_handle_irq)
93 return -EBUSY;
94
95 handle_arch_irq = handle_irq;
96 pr_info("Root IRQ handler: %ps\n", handle_irq);
97 return 0;
98}
99
100int __init set_handle_fiq(void (*handle_fiq)(struct pt_regs *))
101{
102 if (handle_arch_fiq != default_handle_fiq)
103 return -EBUSY;
104
105 handle_arch_fiq = handle_fiq;
106 pr_info("Root FIQ handler: %ps\n", handle_fiq);
107 return 0;
108}
109
110void __init init_IRQ(void)
111{
112 init_irq_stacks();
113 init_irq_scs();
114 irqchip_init();
115
116 if (system_uses_irq_prio_masking()) {
117 /*
118 * Now that we have a stack for our IRQ handler, set
119 * the PMR/PSR pair to a consistent state.
120 */
121 WARN_ON(read_sysreg(daif) & PSR_A_BIT);
122 local_daif_restore(DAIF_PROCCTX_NOIRQ);
123 }
124}
125

source code of linux/arch/arm64/kernel/irq.c