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/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Code to handle x86 style IRQs plus some generic interrupt stuff.
*
* Copyright (C) 1992 Linus Torvalds
* Copyright (C) 1994 - 2000 Ralf Baechle
*/
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/kernel_stat.h>
#include <linux/proc_fs.h>
#include <linux/mm.h>
#include <linux/random.h>
#include <linux/sched.h>
#include <linux/seq_file.h>
#include <linux/kallsyms.h>
#include <linux/kgdb.h>
#include <linux/ftrace.h>
#include <linux/atomic.h>
#include <asm/uaccess.h>
#ifdef CONFIG_KGDB
int kgdb_early_setup;
#endif
static DECLARE_BITMAP(irq_map, NR_IRQS);
int allocate_irqno(void)
{
int irq;
again:
irq = find_first_zero_bit(irq_map, NR_IRQS);
if (irq >= NR_IRQS)
return -ENOSPC;
if (test_and_set_bit(irq, irq_map))
goto again;
return irq;
}
/*
* Allocate the 16 legacy interrupts for i8259 devices. This happens early
* in the kernel initialization so treating allocation failure as BUG() is
* ok.
*/
void __init alloc_legacy_irqno(void)
{
int i;
for (i = 0; i <= 16; i++)
BUG_ON(test_and_set_bit(i, irq_map));
}
void free_irqno(unsigned int irq)
{
smp_mb__before_atomic();
clear_bit(irq, irq_map);
smp_mb__after_atomic();
}
/*
* 'what should we do if we get a hw irq event on an illegal vector'.
* each architecture has to answer this themselves.
*/
void ack_bad_irq(unsigned int irq)
{
printk("unexpected IRQ # %d\n", irq);
}
atomic_t irq_err_count;
int arch_show_interrupts(struct seq_file *p, int prec)
{
seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count));
return 0;
}
asmlinkage void spurious_interrupt(void)
{
atomic_inc(&irq_err_count);
}
void __init init_IRQ(void)
{
int i;
#ifdef CONFIG_KGDB
if (kgdb_early_setup)
return;
#endif
for (i = 0; i < NR_IRQS; i++)
irq_set_noprobe(i);
arch_init_irq();
#ifdef CONFIG_KGDB
if (!kgdb_early_setup)
kgdb_early_setup = 1;
#endif
}
#ifdef CONFIG_DEBUG_STACKOVERFLOW
static inline void check_stack_overflow(void)
{
unsigned long sp;
__asm__ __volatile__("move %0, $sp" : "=r" (sp));
sp &= THREAD_MASK;
/*
* Check for stack overflow: is there less than STACK_WARN free?
* STACK_WARN is defined as 1/8 of THREAD_SIZE by default.
*/
if (unlikely(sp < (sizeof(struct thread_info) + STACK_WARN))) {
printk("do_IRQ: stack overflow: %ld\n",
sp - sizeof(struct thread_info));
dump_stack();
}
}
#else
static inline void check_stack_overflow(void) {}
#endif
/*
* do_IRQ handles all normal device IRQ's (the special
* SMP cross-CPU interrupts have their own specific
* handlers).
*/
void __irq_entry do_IRQ(unsigned int irq)
{
irq_enter();
check_stack_overflow();
generic_handle_irq(irq);
irq_exit();
}
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