linux_dsm_epyc7002/arch/powerpc/platforms/86xx/pic.c
Kyle Moffett 5019609fce powerpc/mpic: Remove MPIC_BROKEN_FRR_NIRQS and duplicate irq_count
The mpic->irq_count variable is only used as a software error-checking
limit to determine whether or not an IRQ number is valid.  In board code
which does not manually specify an IRQ count to mpic_alloc(), i.e. 0, it
is automatically detected from the number of ISUs and the ISU size.

In practice, all hardware ends up with irq_count == num_sources, so all
of the runtime checks on mpic->irq_count should just check the value of
mpic->num_sources instead.

When platform hardware does not correctly report the number of IRQs,
which only happens on the MPC85xx/MPC86xx, the MPIC_BROKEN_FRR_NIRQS
flag is used to override the detected value of num_sources with the
manual irq_count parameter.  Since there's no need to manually specify
the number of IRQs except in this case, the extra flag can be eliminated
and the test changed to "irq_count != 0".

Signed-off-by: Kyle Moffett <Kyle.D.Moffett@boeing.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-02-23 10:49:59 +11:00

73 lines
1.7 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)
{
struct irq_chip *chip = irq_desc_get_chip(desc);
unsigned int cascade_irq = i8259_irq();
if (cascade_irq != NO_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_WANTS_RESET | 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 == NO_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
}