forked from luck/tmp_suning_uos_patched
cb2224d7c4
allocate_irqno, free_irqno and alloc_legacy_irqno are a simple allocator for interrupt numbers from the days when the numer of interrupts was still fixed to NR_IRQS. This was necessary for the SGI IP27 architecture which with its flexible architecture and possibly large number of interrupts doesn't easily fit into the old pattern. These days there are better alternatives. Move the allocation code from the arch generic code to the only platform using it, the SGI IP27 aka Origin 200/2000, Onyx 2. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
49 lines
919 B
C
49 lines
919 B
C
/*
|
|
* 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();
|
|
}
|