2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
6 * Code to handle x86 style IRQs plus some generic interrupt stuff.
8 * Copyright (C) 1992 Linus Torvalds
9 * Copyright (C) 1994 - 2000 Ralf Baechle
11 #include <linux/kernel.h>
12 #include <linux/delay.h>
13 #include <linux/init.h>
14 #include <linux/interrupt.h>
15 #include <linux/kernel_stat.h>
16 #include <linux/proc_fs.h>
18 #include <linux/random.h>
19 #include <linux/sched.h>
20 #include <linux/seq_file.h>
21 #include <linux/kallsyms.h>
22 #include <linux/kgdb.h>
23 #include <linux/ftrace.h>
25 #include <linux/atomic.h>
26 #include <asm/uaccess.h>
28 static DECLARE_BITMAP(irq_map, NR_IRQS);
30 int allocate_irqno(void)
35 irq = find_first_zero_bit(irq_map, NR_IRQS);
40 if (test_and_set_bit(irq, irq_map))
47 * Allocate the 16 legacy interrupts for i8259 devices. This happens early
48 * in the kernel initialization so treating allocation failure as BUG() is
51 void __init alloc_legacy_irqno(void)
55 for (i = 0; i <= 16; i++)
56 BUG_ON(test_and_set_bit(i, irq_map));
59 void free_irqno(unsigned int irq)
61 smp_mb__before_atomic();
62 clear_bit(irq, irq_map);
63 smp_mb__after_atomic();
67 * 'what should we do if we get a hw irq event on an illegal vector'.
68 * each architecture has to answer this themselves.
70 void ack_bad_irq(unsigned int irq)
72 printk("unexpected IRQ # %d\n", irq);
75 atomic_t irq_err_count;
77 int arch_show_interrupts(struct seq_file *p, int prec)
79 seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count));
83 asmlinkage void spurious_interrupt(void)
85 atomic_inc(&irq_err_count);
88 void __init init_IRQ(void)
92 for (i = 0; i < NR_IRQS; i++)
98 #ifdef CONFIG_DEBUG_STACKOVERFLOW
99 static inline void check_stack_overflow(void)
103 __asm__ __volatile__("move %0, $sp" : "=r" (sp));
107 * Check for stack overflow: is there less than STACK_WARN free?
108 * STACK_WARN is defined as 1/8 of THREAD_SIZE by default.
110 if (unlikely(sp < (sizeof(struct thread_info) + STACK_WARN))) {
111 printk("do_IRQ: stack overflow: %ld\n",
112 sp - sizeof(struct thread_info));
117 static inline void check_stack_overflow(void) {}
122 * do_IRQ handles all normal device IRQ's (the special
123 * SMP cross-CPU interrupts have their own specific
126 void __irq_entry do_IRQ(unsigned int irq)
129 check_stack_overflow();
130 generic_handle_irq(irq);