| 1 | |
| 2 | |
| 3 | * linux/arch/alpha/kernel/irq.c
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| 4 | *
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| 5 | * Copyright (C) 1995 Linus Torvalds
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| 6 | *
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| 7 | * This file contains the code used by various IRQ handling routines:
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| 8 | * asking for different IRQ's should be done through these routines
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| 9 | * instead of just grabbing them. Thus setups with different IRQ numbers
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| 10 | * shouldn't result in any weird surprises, and installing new handlers
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| 11 | * should be easier.
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| 12 |
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| 13 |
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| 14 | #include <linux/kernel.h>
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| 15 | #include <linux/module.h>
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| 16 | #include <linux/errno.h>
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| 17 | #include <linux/kernel_stat.h>
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| 18 | #include <linux/signal.h>
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| 19 | #include <linux/sched.h>
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| 20 | #include <linux/ptrace.h>
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| 21 | #include <linux/interrupt.h>
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| 22 | #include <linux/random.h>
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| 23 | #include <linux/irq.h>
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| 24 | #include <linux/proc_fs.h>
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| 25 | #include <linux/seq_file.h>
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| 26 | #include <linux/profile.h>
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| 27 | #include <linux/bitops.h>
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| 28 |
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| 29 | #include <asm/io.h>
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| 30 | #include <linux/uaccess.h>
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| 31 | #include "irq_impl.h"
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| 32 |
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| 33 | volatile unsigned long irq_err_count;
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| 34 | DEFINE_PER_CPU(unsigned long, irq_pmi_count);
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| 35 |
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| 36 | void ack_bad_irq(unsigned int irq)
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| 37 | {
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| 38 | irq_err_count++;
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| 39 | printk(KERN_CRIT "Unexpected IRQ trap at vector %u\n", irq);
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| 40 | }
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| 41 |
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| 42 | #ifdef CONFIG_SMP
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| 43 | static char irq_user_affinity[NR_IRQS];
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| 44 |
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| 45 | int irq_select_affinity(unsigned int irq)
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| 46 | {
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| 47 | struct irq_data *data = irq_get_irq_data(irq);
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| 48 | struct irq_chip *chip;
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| 49 | static int last_cpu;
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| 50 | int cpu = last_cpu + 1;
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| 51 |
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| 52 | if (!data)
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| 53 | return 1;
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| 54 | chip = irq_data_get_irq_chip(data);
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| 55 |
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| 56 | if (!chip->irq_set_affinity || irq_user_affinity[irq])
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| 57 | return 1;
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| 58 |
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| 59 | while (!cpu_possible(cpu) ||
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| 60 | !cpumask_test_cpu(cpu, irq_default_affinity))
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| 61 | cpu = (cpu < (NR_CPUS-1) ? cpu + 1 : 0);
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| 62 | last_cpu = cpu;
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| 63 |
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| 64 | irq_data_update_affinity(data, cpumask_of(cpu));
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| 65 | chip->irq_set_affinity(data, cpumask_of(cpu), false);
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| 66 | return 0;
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| 67 | }
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| 68 | #endif
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| 69 |
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| 70 | int arch_show_interrupts(struct seq_file *p, int prec)
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| 71 | {
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| 72 | int j;
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| 73 |
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| 74 | #ifdef CONFIG_SMP
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| 75 | seq_puts(p, " IPI: ");
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| 76 | for_each_online_cpu(j)
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| 77 | seq_printf(p, "%10lu ", cpu_data[j].ipi_count);
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| 78 | seq_putc(p, '\n');
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| 79 | #endif
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| 80 | seq_puts(p, " PMI: ");
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| 81 | for_each_online_cpu(j)
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| 82 | seq_printf(p, "%10lu ", per_cpu(irq_pmi_count, j));
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| 83 | seq_puts(p, " Performance Monitoring\n");
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| 84 | seq_printf(p, " ERR: %10lu\n", irq_err_count);
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| 85 | return 0;
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| 86 | }
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| 87 |
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| 88 | |
| 89 | * handle_irq handles all normal device IRQ's (the special
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| 90 | * SMP cross-CPU interrupts have their own specific
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| 91 | * handlers).
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| 92 |
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| 93 |
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| 94 | #define MAX_ILLEGAL_IRQS 16
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| 95 |
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| 96 | void
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| 97 | handle_irq(int irq)
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| 98 | {
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| 99 | |
| 100 | * We ack quickly, we don't want the irq controller
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| 101 | * thinking we're snobs just because some other CPU has
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| 102 | * disabled global interrupts (we have already done the
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| 103 | * INT_ACK cycles, it's too late to try to pretend to the
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| 104 | * controller that we aren't taking the interrupt).
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| 105 | *
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| 106 | * 0 return value means that this irq is already being
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| 107 | * handled by some other CPU. (or is disabled)
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| 108 |
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| 109 | static unsigned int illegal_count=0;
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| 110 | struct irq_desc *desc;
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| 111 |
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| 112 | irq_enter();
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| 113 |
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| 114 | desc = irq_to_desc(irq);
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| 115 | if (!desc || ((unsigned) irq > ACTUAL_NR_IRQS &&
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| 116 | illegal_count < MAX_ILLEGAL_IRQS)) {
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| 117 | irq_err_count++;
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| 118 | illegal_count++;
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| 119 | printk(KERN_CRIT "device_interrupt: invalid interrupt %d\n",
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| 120 | irq);
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| 121 | irq_exit();
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| 122 | return;
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| 123 | }
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| 124 |
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| 125 | generic_handle_irq_desc(desc);
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| 126 | irq_exit();
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| 127 | }
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