alistair23-linux/arch/powerpc/platforms/86xx/pic.c
Michael Ellerman ef24ba7091 powerpc: Remove all usages of NO_IRQ
NO_IRQ has been == 0 on powerpc for just over ten years (since commit
0ebfff1491 ("[POWERPC] Add new interrupt mapping core and change
platforms to use it")). It's also 0 on most other arches.

Although it's fairly harmless, every now and then it causes confusion
when a driver is built on powerpc and another arch which doesn't define
NO_IRQ. There's at least 6 definitions of NO_IRQ in drivers/, at least
some of which are to work around that problem.

So we'd like to remove it. This is fairly trivial in the arch code, we
just convert:

    if (irq == NO_IRQ)	to	if (!irq)
    if (irq != NO_IRQ)	to	if (irq)
    irq = NO_IRQ;	to	irq = 0;
    return NO_IRQ;	to	return 0;

And a few other odd cases as well.

At least for now we keep the #define NO_IRQ, because there is driver
code that uses NO_IRQ and the fixes to remove those will go via other
trees.

Note we also change some occurrences in PPC sound drivers, drivers/ps3,
and drivers/macintosh.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-09-20 20:57:12 +10:00

72 lines
1.6 KiB
C

/*
* Copyright 2008 Freescale Semiconductor, Inc.
*
* 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 <linux/stddef.h>
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>
#include <asm/mpic.h>
#include <asm/i8259.h>
#ifdef CONFIG_PPC_I8259
static void mpc86xx_8259_cascade(struct irq_desc *desc)
{
struct irq_chip *chip = irq_desc_get_chip(desc);
unsigned int cascade_irq = i8259_irq();
if (cascade_irq)
generic_handle_irq(cascade_irq);
chip->irq_eoi(&desc->irq_data);
}
#endif /* CONFIG_PPC_I8259 */
void __init mpc86xx_init_irq(void)
{
#ifdef CONFIG_PPC_I8259
struct device_node *np;
struct device_node *cascade_node = NULL;
int cascade_irq;
#endif
struct mpic *mpic = mpic_alloc(NULL, 0, MPIC_BIG_ENDIAN |
MPIC_SINGLE_DEST_CPU,
0, 256, " MPIC ");
BUG_ON(mpic == NULL);
mpic_init(mpic);
#ifdef CONFIG_PPC_I8259
/* Initialize i8259 controller */
for_each_node_by_type(np, "interrupt-controller")
if (of_device_is_compatible(np, "chrp,iic")) {
cascade_node = np;
break;
}
if (cascade_node == NULL) {
printk(KERN_DEBUG "Could not find i8259 PIC\n");
return;
}
cascade_irq = irq_of_parse_and_map(cascade_node, 0);
if (!cascade_irq) {
printk(KERN_ERR "Failed to map cascade interrupt\n");
return;
}
i8259_init(cascade_node, 0);
of_node_put(cascade_node);
irq_set_chained_handler(cascade_irq, mpc86xx_8259_cascade);
#endif
}