1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * linux/arch/arm/kernel/irq.c
4 *
5 * Copyright (C) 1992 Linus Torvalds
6 * Modifications for ARM processor Copyright (C) 1995-2000 Russell King.
7 *
8 * Support for Dynamic Tick Timer Copyright (C) 2004-2005 Nokia Corporation.
9 * Dynamic Tick Timer written by Tony Lindgren <tony@atomide.com> and
10 * Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>.
11 *
12 * This file contains the code used by various IRQ handling routines:
13 * asking for different IRQ's should be done through these routines
14 * instead of just grabbing them. Thus setups with different IRQ numbers
15 * shouldn't result in any weird surprises, and installing new handlers
16 * should be easier.
17 *
18 * IRQ's are in fact implemented a bit like signal handlers for the kernel.
19 * Naturally it's not a 1:1 relation, but there are similarities.
20 */
21 #include <linux/signal.h>
22 #include <linux/ioport.h>
23 #include <linux/interrupt.h>
24 #include <linux/irq.h>
25 #include <linux/irqchip.h>
26 #include <linux/random.h>
27 #include <linux/smp.h>
28 #include <linux/init.h>
29 #include <linux/seq_file.h>
30 #include <linux/errno.h>
31 #include <linux/list.h>
32 #include <linux/kallsyms.h>
33 #include <linux/proc_fs.h>
34 #include <linux/export.h>
35 #include <linux/vmalloc.h>
36
37 #include <asm/hardware/cache-l2x0.h>
38 #include <asm/hardware/cache-uniphier.h>
39 #include <asm/outercache.h>
40 #include <asm/softirq_stack.h>
41 #include <asm/exception.h>
42 #include <asm/mach/arch.h>
43 #include <asm/mach/irq.h>
44 #include <asm/mach/time.h>
45
46 #include "reboot.h"
47
48 unsigned long irq_err_count;
49
50 #ifdef CONFIG_IRQSTACKS
51
52 asmlinkage DEFINE_PER_CPU_READ_MOSTLY(u8 *, irq_stack_ptr);
53
init_irq_stacks(void)54 static void __init init_irq_stacks(void)
55 {
56 u8 *stack;
57 int cpu;
58
59 for_each_possible_cpu(cpu) {
60 if (!IS_ENABLED(CONFIG_VMAP_STACK))
61 stack = (u8 *)__get_free_pages(GFP_KERNEL,
62 THREAD_SIZE_ORDER);
63 else
64 stack = __vmalloc_node(THREAD_SIZE, THREAD_ALIGN,
65 THREADINFO_GFP, NUMA_NO_NODE,
66 __builtin_return_address(0));
67
68 if (WARN_ON(!stack))
69 break;
70 per_cpu(irq_stack_ptr, cpu) = &stack[THREAD_SIZE];
71 }
72 }
73
74 #ifdef CONFIG_SOFTIRQ_ON_OWN_STACK
____do_softirq(void * arg)75 static void ____do_softirq(void *arg)
76 {
77 __do_softirq();
78 }
79
do_softirq_own_stack(void)80 void do_softirq_own_stack(void)
81 {
82 call_with_stack(____do_softirq, NULL,
83 __this_cpu_read(irq_stack_ptr));
84 }
85 #endif
86 #endif
87
arch_show_interrupts(struct seq_file * p,int prec)88 int arch_show_interrupts(struct seq_file *p, int prec)
89 {
90 #ifdef CONFIG_FIQ
91 show_fiq_list(p, prec);
92 #endif
93 #ifdef CONFIG_SMP
94 show_ipi_list(p, prec);
95 #endif
96 seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count);
97 return 0;
98 }
99
100 /*
101 * handle_IRQ handles all hardware IRQ's. Decoded IRQs should
102 * not come via this function. Instead, they should provide their
103 * own 'handler'. Used by platform code implementing C-based 1st
104 * level decoding.
105 */
handle_IRQ(unsigned int irq,struct pt_regs * regs)106 void handle_IRQ(unsigned int irq, struct pt_regs *regs)
107 {
108 struct irq_desc *desc;
109
110 /*
111 * Some hardware gives randomly wrong interrupts. Rather
112 * than crashing, do something sensible.
113 */
114 if (unlikely(!irq || irq >= nr_irqs))
115 desc = NULL;
116 else
117 desc = irq_to_desc(irq);
118
119 if (likely(desc))
120 handle_irq_desc(desc);
121 else
122 ack_bad_irq(irq);
123 }
124
init_IRQ(void)125 void __init init_IRQ(void)
126 {
127 int ret;
128
129 #ifdef CONFIG_IRQSTACKS
130 init_irq_stacks();
131 #endif
132
133 if (IS_ENABLED(CONFIG_OF) && !machine_desc->init_irq)
134 irqchip_init();
135 else
136 machine_desc->init_irq();
137
138 if (IS_ENABLED(CONFIG_OF) && IS_ENABLED(CONFIG_CACHE_L2X0) &&
139 (machine_desc->l2c_aux_mask || machine_desc->l2c_aux_val)) {
140 if (!outer_cache.write_sec)
141 outer_cache.write_sec = machine_desc->l2c_write_sec;
142 ret = l2x0_of_init(machine_desc->l2c_aux_val,
143 machine_desc->l2c_aux_mask);
144 if (ret && ret != -ENODEV)
145 pr_err("L2C: failed to init: %d\n", ret);
146 }
147
148 uniphier_cache_init();
149 }
150
151 #ifdef CONFIG_SPARSE_IRQ
arch_probe_nr_irqs(void)152 int __init arch_probe_nr_irqs(void)
153 {
154 nr_irqs = machine_desc->nr_irqs ? machine_desc->nr_irqs : NR_IRQS;
155 return nr_irqs;
156 }
157 #endif
158