linux/drivers/irqchip/irq-mips-cpu.c
Paul Burton fe7a38c625 MIPS: Unify checks for sibling CPUs
Up until now we have open-coded checks for whether CPUs are siblings,
with slight variations on whether we consider the package ID or not.

This will only get more complex when we introduce cluster support, so in
preparation for that this patch introduces a cpus_are_siblings()
function which can be used to check whether or not 2 CPUs are siblings
in a consistent manner.

By checking globalnumber with the VP ID masked out this also has the
neat side effect of being ready for multi-cluster systems already.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Acked-by: Rafael J. Wysocki <rjw@rjwysocki.net>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/17011/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2017-08-30 00:57:27 +02:00

284 lines
6.9 KiB
C

/*
* 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 (i.e. not exposed as pins) which
* may be used for IPIs in multi-threaded single-core systems.
*
* The last one is usually the CPU timer interrupt if the counter register
* is present, or for old CPUs with an external FPU by convention it's the
* FPU exception interrupt.
*/
#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 struct irq_domain *irq_domain;
static struct irq_domain *ipi_domain;
static inline void unmask_mips_irq(struct irq_data *d)
{
set_c0_status(IE_SW0 << d->hwirq);
irq_enable_hazard();
}
static inline void mask_mips_irq(struct irq_data *d)
{
clear_c0_status(IE_SW0 << d->hwirq);
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(C_SW0 << d->hwirq);
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(C_SW0 << d->hwirq);
evpe(vpflags);
mask_mips_irq(d);
}
#ifdef CONFIG_GENERIC_IRQ_IPI
static void mips_mt_send_ipi(struct irq_data *d, unsigned int cpu)
{
irq_hw_number_t hwirq = irqd_to_hwirq(d);
unsigned long flags;
int vpflags;
local_irq_save(flags);
/* We can only send IPIs to VPEs within the local core */
WARN_ON(!cpus_are_siblings(smp_processor_id(), cpu));
vpflags = dvpe();
settc(cpu_vpe_id(&cpu_data[cpu]));
write_vpe_c0_cause(read_vpe_c0_cause() | (C_SW0 << hwirq));
evpe(vpflags);
local_irq_restore(flags);
}
#endif /* CONFIG_GENERIC_IRQ_IPI */
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,
#ifdef CONFIG_GENERIC_IRQ_IPI
.ipi_send_single = mips_mt_send_ipi,
#endif
};
asmlinkage void __weak plat_irq_dispatch(void)
{
unsigned long pending = read_c0_cause() & read_c0_status() & ST0_IM;
unsigned int virq;
int irq;
if (!pending) {
spurious_interrupt();
return;
}
pending >>= CAUSEB_IP;
while (pending) {
irq = fls(pending) - 1;
if (IS_ENABLED(CONFIG_GENERIC_IRQ_IPI) && irq < 2)
virq = irq_linear_revmap(ipi_domain, irq);
else
virq = irq_linear_revmap(irq_domain, irq);
do_IRQ(virq);
pending &= ~BIT(irq);
}
}
static int mips_cpu_intc_map(struct irq_domain *d, unsigned int irq,
irq_hw_number_t hw)
{
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,
};
#ifdef CONFIG_GENERIC_IRQ_IPI
struct cpu_ipi_domain_state {
DECLARE_BITMAP(allocated, 2);
};
static int mips_cpu_ipi_alloc(struct irq_domain *domain, unsigned int virq,
unsigned int nr_irqs, void *arg)
{
struct cpu_ipi_domain_state *state = domain->host_data;
unsigned int i, hwirq;
int ret;
for (i = 0; i < nr_irqs; i++) {
hwirq = find_first_zero_bit(state->allocated, 2);
if (hwirq == 2)
return -EBUSY;
bitmap_set(state->allocated, hwirq, 1);
ret = irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq,
&mips_mt_cpu_irq_controller,
NULL);
if (ret)
return ret;
ret = irq_set_irq_type(virq + i, IRQ_TYPE_LEVEL_HIGH);
if (ret)
return ret;
}
return 0;
}
static int mips_cpu_ipi_match(struct irq_domain *d, struct device_node *node,
enum irq_domain_bus_token bus_token)
{
bool is_ipi;
switch (bus_token) {
case DOMAIN_BUS_IPI:
is_ipi = d->bus_token == bus_token;
return (!node || (to_of_node(d->fwnode) == node)) && is_ipi;
default:
return 0;
}
}
static const struct irq_domain_ops mips_cpu_ipi_chip_ops = {
.alloc = mips_cpu_ipi_alloc,
.match = mips_cpu_ipi_match,
};
static void mips_cpu_register_ipi_domain(struct device_node *of_node)
{
struct cpu_ipi_domain_state *ipi_domain_state;
ipi_domain_state = kzalloc(sizeof(*ipi_domain_state), GFP_KERNEL);
ipi_domain = irq_domain_add_hierarchy(irq_domain,
IRQ_DOMAIN_FLAG_IPI_SINGLE,
2, of_node,
&mips_cpu_ipi_chip_ops,
ipi_domain_state);
if (!ipi_domain)
panic("Failed to add MIPS CPU IPI domain");
irq_domain_update_bus_token(ipi_domain, DOMAIN_BUS_IPI);
}
#else /* !CONFIG_GENERIC_IRQ_IPI */
static inline void mips_cpu_register_ipi_domain(struct device_node *of_node) {}
#endif /* !CONFIG_GENERIC_IRQ_IPI */
static void __init __mips_cpu_irq_init(struct device_node *of_node)
{
/* Mask interrupts. */
clear_c0_status(ST0_IM);
clear_c0_cause(CAUSEF_IP);
irq_domain = irq_domain_add_legacy(of_node, 8, MIPS_CPU_IRQ_BASE, 0,
&mips_cpu_intc_irq_domain_ops,
NULL);
if (!irq_domain)
panic("Failed to add irqdomain for MIPS CPU");
/*
* Only proceed to register the software interrupt IPI implementation
* for CPUs which implement the MIPS MT (multi-threading) ASE.
*/
if (cpu_has_mipsmt)
mips_cpu_register_ipi_domain(of_node);
}
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);