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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.
*/
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/types.h>
#include <asm/barrier.h>
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();
}
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