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
36 #include <asm/hardware/cache-l2x0.h>
37 #include <asm/hardware/cache-uniphier.h>
38 #include <asm/outercache.h>
39 #include <asm/softirq_stack.h>
40 #include <asm/exception.h>
41 #include <asm/mach/arch.h>
42 #include <asm/mach/irq.h>
43 #include <asm/mach/time.h>
44
45 #include "reboot.h"
46
47 unsigned long irq_err_count;
48
49 #ifdef CONFIG_IRQSTACKS
50
51 asmlinkage DEFINE_PER_CPU_READ_MOSTLY(u8 *, irq_stack_ptr);
52
init_irq_stacks(void)53 static void __init init_irq_stacks(void)
54 {
55 u8 *stack;
56 int cpu;
57
58 for_each_possible_cpu(cpu) {
59 if (!IS_ENABLED(CONFIG_VMAP_STACK))
60 stack = (u8 *)__get_free_pages(GFP_KERNEL,
61 THREAD_SIZE_ORDER);
62 else
63 stack = __vmalloc_node(THREAD_SIZE, THREAD_ALIGN,
64 THREADINFO_GFP, NUMA_NO_NODE,
65 __builtin_return_address(0));
66
67 if (WARN_ON(!stack))
68 break;
69 per_cpu(irq_stack_ptr, cpu) = &stack[THREAD_SIZE];
70 }
71 }
72
73 #ifdef CONFIG_SOFTIRQ_ON_OWN_STACK
____do_softirq(void * arg)74 static void ____do_softirq(void *arg)
75 {
76 __do_softirq();
77 }
78
do_softirq_own_stack(void)79 void do_softirq_own_stack(void)
80 {
81 call_with_stack(____do_softirq, NULL,
82 __this_cpu_read(irq_stack_ptr));
83 }
84 #endif
85 #endif
86
arch_show_interrupts(struct seq_file * p,int prec)87 int arch_show_interrupts(struct seq_file *p, int prec)
88 {
89 #ifdef CONFIG_FIQ
90 show_fiq_list(p, prec);
91 #endif
92 #ifdef CONFIG_SMP
93 show_ipi_list(p, prec);
94 #endif
95 seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count);
96 return 0;
97 }
98
99 /*
100 * handle_IRQ handles all hardware IRQ's. Decoded IRQs should
101 * not come via this function. Instead, they should provide their
102 * own 'handler'. Used by platform code implementing C-based 1st
103 * level decoding.
104 */
handle_IRQ(unsigned int irq,struct pt_regs * regs)105 void handle_IRQ(unsigned int irq, struct pt_regs *regs)
106 {
107 struct irq_desc *desc;
108
109 /*
110 * Some hardware gives randomly wrong interrupts. Rather
111 * than crashing, do something sensible.
112 */
113 if (unlikely(!irq || irq >= nr_irqs))
114 desc = NULL;
115 else
116 desc = irq_to_desc(irq);
117
118 if (likely(desc))
119 handle_irq_desc(desc);
120 else
121 ack_bad_irq(irq);
122 }
123
init_IRQ(void)124 void __init init_IRQ(void)
125 {
126 int ret;
127
128 #ifdef CONFIG_IRQSTACKS
129 init_irq_stacks();
130 #endif
131
132 if (IS_ENABLED(CONFIG_OF) && !machine_desc->init_irq)
133 irqchip_init();
134 else
135 machine_desc->init_irq();
136
137 if (IS_ENABLED(CONFIG_OF) && IS_ENABLED(CONFIG_CACHE_L2X0) &&
138 (machine_desc->l2c_aux_mask || machine_desc->l2c_aux_val)) {
139 if (!outer_cache.write_sec)
140 outer_cache.write_sec = machine_desc->l2c_write_sec;
141 ret = l2x0_of_init(machine_desc->l2c_aux_val,
142 machine_desc->l2c_aux_mask);
143 if (ret && ret != -ENODEV)
144 pr_err("L2C: failed to init: %d\n", ret);
145 }
146
147 uniphier_cache_init();
148 }
149
150 #ifdef CONFIG_SPARSE_IRQ
arch_probe_nr_irqs(void)151 int __init arch_probe_nr_irqs(void)
152 {
153 nr_irqs = machine_desc->nr_irqs ? machine_desc->nr_irqs : NR_IRQS;
154 return nr_irqs;
155 }
156 #endif
157