1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * linux/arch/alpha/kernel/irq.c
4 *
5 * Copyright (C) 1995 Linus Torvalds
6 *
7 * This file contains the code used by various IRQ handling routines:
8 * asking for different IRQ's should be done through these routines
9 * instead of just grabbing them. Thus setups with different IRQ numbers
10 * shouldn't result in any weird surprises, and installing new handlers
11 * should be easier.
12 */
13
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/errno.h>
17 #include <linux/kernel_stat.h>
18 #include <linux/signal.h>
19 #include <linux/sched.h>
20 #include <linux/ptrace.h>
21 #include <linux/interrupt.h>
22 #include <linux/random.h>
23 #include <linux/irq.h>
24 #include <linux/proc_fs.h>
25 #include <linux/seq_file.h>
26 #include <linux/profile.h>
27 #include <linux/bitops.h>
28
29 #include <asm/io.h>
30 #include <linux/uaccess.h>
31
32 volatile unsigned long irq_err_count;
33 DEFINE_PER_CPU(unsigned long, irq_pmi_count);
34
ack_bad_irq(unsigned int irq)35 void ack_bad_irq(unsigned int irq)
36 {
37 irq_err_count++;
38 printk(KERN_CRIT "Unexpected IRQ trap at vector %u\n", irq);
39 }
40
41 #ifdef CONFIG_SMP
42 static char irq_user_affinity[NR_IRQS];
43
irq_select_affinity(unsigned int irq)44 int irq_select_affinity(unsigned int irq)
45 {
46 struct irq_data *data = irq_get_irq_data(irq);
47 struct irq_chip *chip;
48 static int last_cpu;
49 int cpu = last_cpu + 1;
50
51 if (!data)
52 return 1;
53 chip = irq_data_get_irq_chip(data);
54
55 if (!chip->irq_set_affinity || irq_user_affinity[irq])
56 return 1;
57
58 while (!cpu_possible(cpu) ||
59 !cpumask_test_cpu(cpu, irq_default_affinity))
60 cpu = (cpu < (NR_CPUS-1) ? cpu + 1 : 0);
61 last_cpu = cpu;
62
63 cpumask_copy(irq_data_get_affinity_mask(data), cpumask_of(cpu));
64 chip->irq_set_affinity(data, cpumask_of(cpu), false);
65 return 0;
66 }
67 #endif /* CONFIG_SMP */
68
arch_show_interrupts(struct seq_file * p,int prec)69 int arch_show_interrupts(struct seq_file *p, int prec)
70 {
71 int j;
72
73 #ifdef CONFIG_SMP
74 seq_puts(p, "IPI: ");
75 for_each_online_cpu(j)
76 seq_printf(p, "%10lu ", cpu_data[j].ipi_count);
77 seq_putc(p, '\n');
78 #endif
79 seq_puts(p, "PMI: ");
80 for_each_online_cpu(j)
81 seq_printf(p, "%10lu ", per_cpu(irq_pmi_count, j));
82 seq_puts(p, " Performance Monitoring\n");
83 seq_printf(p, "ERR: %10lu\n", irq_err_count);
84 return 0;
85 }
86
87 /*
88 * handle_irq handles all normal device IRQ's (the special
89 * SMP cross-CPU interrupts have their own specific
90 * handlers).
91 */
92
93 #define MAX_ILLEGAL_IRQS 16
94
95 void
handle_irq(int irq)96 handle_irq(int irq)
97 {
98 /*
99 * We ack quickly, we don't want the irq controller
100 * thinking we're snobs just because some other CPU has
101 * disabled global interrupts (we have already done the
102 * INT_ACK cycles, it's too late to try to pretend to the
103 * controller that we aren't taking the interrupt).
104 *
105 * 0 return value means that this irq is already being
106 * handled by some other CPU. (or is disabled)
107 */
108 static unsigned int illegal_count=0;
109 struct irq_desc *desc = irq_to_desc(irq);
110
111 if (!desc || ((unsigned) irq > ACTUAL_NR_IRQS &&
112 illegal_count < MAX_ILLEGAL_IRQS)) {
113 irq_err_count++;
114 illegal_count++;
115 printk(KERN_CRIT "device_interrupt: invalid interrupt %d\n",
116 irq);
117 return;
118 }
119
120 irq_enter();
121 generic_handle_irq_desc(desc);
122 irq_exit();
123 }
124
