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/exception.h>
40 #include <asm/mach/arch.h>
41 #include <asm/mach/irq.h>
42 #include <asm/mach/time.h>
43
44 unsigned long irq_err_count;
45
arch_show_interrupts(struct seq_file * p,int prec)46 int arch_show_interrupts(struct seq_file *p, int prec)
47 {
48 #ifdef CONFIG_FIQ
49 show_fiq_list(p, prec);
50 #endif
51 #ifdef CONFIG_SMP
52 show_ipi_list(p, prec);
53 #endif
54 seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count);
55 return 0;
56 }
57
58 /*
59 * handle_IRQ handles all hardware IRQ's. Decoded IRQs should
60 * not come via this function. Instead, they should provide their
61 * own 'handler'. Used by platform code implementing C-based 1st
62 * level decoding.
63 */
handle_IRQ(unsigned int irq,struct pt_regs * regs)64 void handle_IRQ(unsigned int irq, struct pt_regs *regs)
65 {
66 struct pt_regs *old_regs = set_irq_regs(regs);
67 struct irq_desc *desc;
68
69 irq_enter();
70
71 /*
72 * Some hardware gives randomly wrong interrupts. Rather
73 * than crashing, do something sensible.
74 */
75 if (unlikely(!irq || irq >= nr_irqs))
76 desc = NULL;
77 else
78 desc = irq_to_desc(irq);
79
80 if (likely(desc))
81 handle_irq_desc(desc);
82 else
83 ack_bad_irq(irq);
84
85 irq_exit();
86 set_irq_regs(old_regs);
87 }
88
89 /*
90 * asm_do_IRQ is the interface to be used from assembly code.
91 */
92 asmlinkage void __exception_irq_entry
asm_do_IRQ(unsigned int irq,struct pt_regs * regs)93 asm_do_IRQ(unsigned int irq, struct pt_regs *regs)
94 {
95 handle_IRQ(irq, regs);
96 }
97
init_IRQ(void)98 void __init init_IRQ(void)
99 {
100 int ret;
101
102 if (IS_ENABLED(CONFIG_OF) && !machine_desc->init_irq)
103 irqchip_init();
104 else
105 machine_desc->init_irq();
106
107 if (IS_ENABLED(CONFIG_OF) && IS_ENABLED(CONFIG_CACHE_L2X0) &&
108 (machine_desc->l2c_aux_mask || machine_desc->l2c_aux_val)) {
109 if (!outer_cache.write_sec)
110 outer_cache.write_sec = machine_desc->l2c_write_sec;
111 ret = l2x0_of_init(machine_desc->l2c_aux_val,
112 machine_desc->l2c_aux_mask);
113 if (ret && ret != -ENODEV)
114 pr_err("L2C: failed to init: %d\n", ret);
115 }
116
117 uniphier_cache_init();
118 }
119
120 #ifdef CONFIG_SPARSE_IRQ
arch_probe_nr_irqs(void)121 int __init arch_probe_nr_irqs(void)
122 {
123 nr_irqs = machine_desc->nr_irqs ? machine_desc->nr_irqs : NR_IRQS;
124 return nr_irqs;
125 }
126 #endif
127