/*
* Copyright 2001 MontaVista Software Inc.
* Author: Jun Sun, jsun@mvista.com or jsun@junsun.net
*
* Copyright (C) 2001 Ralf Baechle
* Copyright (C) 2005 MIPS Technologies, Inc. All rights reserved.
* Author: Maciej W. Rozycki <macro@mips.com>
*
* This file define the irq handler for MIPS CPU interrupts.
*
* 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.
*/
/*
* Almost all MIPS CPUs define 8 interrupt sources. They are typically
* level triggered (i.e., cannot be cleared from CPU; must be cleared from
* device). The first two are software interrupts which we don't really
* use or support. The last one is usually the CPU timer interrupt if
* counter register is present or, for CPUs with an external FPU, by
* convention it's the FPU exception interrupt.
*
* Don't even think about using this on SMP. You have been warned.
*
* This file exports one global function:
* void mips_cpu_irq_init(void);
*/
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/irq.h>
#include <linux/irqchip.h>
#include <linux/irqdomain.h>
#include <asm/irq_cpu.h>
#include <asm/mipsregs.h>
#include <asm/mipsmtregs.h>
#include <asm/setup.h>
static inline void unmask_mips_irq(struct irq_data *d)
{
set_c0_status(0x100 << (d->irq - MIPS_CPU_IRQ_BASE));
irq_enable_hazard();
}
static inline void mask_mips_irq(struct irq_data *d)
{
clear_c0_status(0x100 << (d->irq - MIPS_CPU_IRQ_BASE));
irq_disable_hazard();
}
static struct irq_chip mips_cpu_irq_controller = {
.name = "MIPS",
.irq_ack = mask_mips_irq,
.irq_mask = mask_mips_irq,
.irq_mask_ack = mask_mips_irq,
.irq_unmask = unmask_mips_irq,
.irq_eoi = unmask_mips_irq,
.irq_disable = mask_mips_irq,
.irq_enable = unmask_mips_irq,
};
/*
* Basically the same as above but taking care of all the MT stuff
*/
static unsigned int mips_mt_cpu_irq_startup(struct irq_data *d)
{
unsigned int vpflags = dvpe();
clear_c0_cause(0x100 << (d->irq - MIPS_CPU_IRQ_BASE));
evpe(vpflags);
unmask_mips_irq(d);
return 0;
}
/*
* While we ack the interrupt interrupts are disabled and thus we don't need
* to deal with concurrency issues. Same for mips_cpu_irq_end.
*/
static void mips_mt_cpu_irq_ack(struct irq_data *d)
{
unsigned int vpflags = dvpe();
clear_c0_cause(0x100 << (d->irq - MIPS_CPU_IRQ_BASE));
evpe(vpflags);
mask_mips_irq(d);
}
static struct irq_chip mips_mt_cpu_irq_controller = {
.name = "MIPS",
.irq_startup = mips_mt_cpu_irq_startup,
.irq_ack = mips_mt_cpu_irq_ack,
.irq_mask = mask_mips_irq,
.irq_mask_ack = mips_mt_cpu_irq_ack,
.irq_unmask = unmask_mips_irq,
.irq_eoi = unmask_mips_irq,
.irq_disable = mask_mips_irq,
.irq_enable = unmask_mips_irq,
};
asmlinkage void __weak plat_irq_dispatch(void)
{
unsigned long pending = read_c0_cause() & read_c0_status() & ST0_IM;
int irq;
if (!pending) {
spurious_interrupt();
return;
}
pending >>= CAUSEB_IP;
while (pending) {
irq = fls(pending) - 1;
do_IRQ(MIPS_CPU_IRQ_BASE + irq);
pending &= ~BIT(irq);
}
}
static int mips_cpu_intc_map(struct irq_domain *d, unsigned int irq,
irq_hw_number_t hw)
{
static struct irq_chip *chip;
if (hw < 2 && cpu_has_mipsmt) {
/* Software interrupts are used for MT/CMT IPI */
chip = &mips_mt_cpu_irq_controller;
} else {
chip = &mips_cpu_irq_controller;
}
if (cpu_has_vint)
set_vi_handler(hw, plat_irq_dispatch);
irq_set_chip_and_handler(irq, chip, handle_percpu_irq);
return 0;
}
static const struct irq_domain_ops mips_cpu_intc_irq_domain_ops = {
.map = mips_cpu_intc_map,
.xlate = irq_domain_xlate_onecell,
};
static void __init __mips_cpu_irq_init(struct device_node *of_node)
{
struct irq_domain *domain;
/* Mask interrupts. */
clear_c0_status(ST0_IM);
clear_c0_cause(CAUSEF_IP);
domain = irq_domain_add_legacy(of_node, 8, MIPS_CPU_IRQ_BASE, 0,
&mips_cpu_intc_irq_domain_ops, NULL);
if (!domain)
panic("Failed to add irqdomain for MIPS CPU");
}
void __init mips_cpu_irq_init(void)
{
__mips_cpu_irq_init(NULL);
}
int __init mips_cpu_irq_of_init(struct device_node *of_node,
struct device_node *parent)
{
__mips_cpu_irq_init(of_node);
return 0;
}
IRQCHIP_DECLARE(cpu_intc, "mti,cpu-interrupt-controller", mips_cpu_irq_of_init);
