include/asm-ppc64/irq.h

#ifdef __KERNEL__
#ifndef _ASM_IRQ_H
#define _ASM_IRQ_H

/*
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#include <asm/atomic.h>

extern void disable_irq(unsigned int);
extern void disable_irq_nosync(unsigned int);
extern void enable_irq(unsigned int);

/* Need to keep at 256 (minimum) for iSeries */
#define NR_IRQS  256

#define MAX_IRQS (1<<24)

extern unsigned int _next_irq(unsigned int irq);

/* Define a way to iterate across irqs fairly efficiently. */
#define for_each_irq(i) \
	for ((i) = 0; (i) < MAX_IRQS; (i) = _next_irq(i))


extern void *_irqdesc(unsigned int irq);
extern void *_real_irqdesc(unsigned int irq);
#define irqdesc(irq) ((irq_desc_t *)_irqdesc(irq))
#define real_irqdesc(irq) ((irq_desc_t *)_real_irqdesc(irq))

/*
 * This gets called from serial.c, which is now used on
 * powermacs as well as prep/chrp boxes.
 * Prep and chrp both have cascaded 8259 PICs.
 */
static __inline__ int irq_cannonicalize(int irq)
{
	return irq;
}

/*
 * Because many systems have two overlapping names spaces for
 * interrupts (ISA and XICS for example), and the ISA interrupts
 * have historically not been easy to renumber, we allow ISA
 * interrupts to take values 0 - 15, and shift up the remaining
 * interrupts by 0x10.
 *
 * This would be nice to remove at some point as it adds confusion
 * and adds a nasty end case if any platform native interrupts have
 * values within 0x10 of the end of that namespace.
 */

#define NUM_ISA_INTERRUPTS	0x10

extern inline int irq_offset_up(int irq)
{
	return(irq + NUM_ISA_INTERRUPTS);
}

extern inline int irq_offset_down(int irq)
{
	return(irq - NUM_ISA_INTERRUPTS);
}

extern inline int irq_offset_value(void)
{
	return NUM_ISA_INTERRUPTS;
}

#endif /* _ASM_IRQ_H */
#endif /* __KERNEL__ */