linux/arch/powerpc/platforms/86xx/pic.c
Kumar Gala 3c10c9c45e powerpc/mpic: Fix regression caused by change of default IRQ affinity
The Freescale implementation of MPIC only allows a single CPU destination
for non-IPI interrupts.  We add a flag to the mpic_init to distinquish
these variants of MPIC.  We pull in the irq_choose_cpu from sparc64 to
select a single CPU as the destination of the interrupt.

This is to deal with the fact that the default smp affinity was
changed by commit 1840475676 ("genirq:
Expose default irq affinity mask (take 3)") to be all CPUs.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-10-31 16:13:50 +11:00

80 lines
1.9 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_platform.h>
#include <asm/system.h>
#include <asm/mpic.h>
#include <asm/i8259.h>
#ifdef CONFIG_PPC_I8259
static void mpc86xx_8259_cascade(unsigned int irq, struct irq_desc *desc)
{
unsigned int cascade_irq = i8259_irq();
if (cascade_irq != NO_IRQ)
generic_handle_irq(cascade_irq);
desc->chip->eoi(irq);
}
#endif /* CONFIG_PPC_I8259 */
void __init mpc86xx_init_irq(void)
{
struct mpic *mpic;
struct device_node *np;
struct resource res;
#ifdef CONFIG_PPC_I8259
struct device_node *cascade_node = NULL;
int cascade_irq;
#endif
/* Determine PIC address. */
np = of_find_node_by_type(NULL, "open-pic");
if (np == NULL)
return;
of_address_to_resource(np, 0, &res);
mpic = mpic_alloc(np, res.start,
MPIC_PRIMARY | MPIC_WANTS_RESET |
MPIC_BIG_ENDIAN | MPIC_BROKEN_FRR_NIRQS |
MPIC_SINGLE_DEST_CPU,
0, 256, " MPIC ");
of_node_put(np);
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 == NO_IRQ) {
printk(KERN_ERR "Failed to map cascade interrupt\n");
return;
}
i8259_init(cascade_node, 0);
of_node_put(cascade_node);
set_irq_chained_handler(cascade_irq, mpc86xx_8259_cascade);
#endif
}