https://github.com/torvalds/linux
Tip revision: 754e0b0e35608ed5206d6a67a791563c631cec07 authored by Linus Torvalds on 13 February 2022, 20:13:30 UTC
Linux 5.17-rc4
Linux 5.17-rc4
Tip revision: 754e0b0
irq.c
// SPDX-License-Identifier: GPL-2.0-only
/*
* linux/arch/arm/kernel/irq.c
*
* Copyright (C) 1992 Linus Torvalds
* Modifications for ARM processor Copyright (C) 1995-2000 Russell King.
*
* Support for Dynamic Tick Timer Copyright (C) 2004-2005 Nokia Corporation.
* Dynamic Tick Timer written by Tony Lindgren <tony@atomide.com> and
* Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>.
*
* This file contains the code used by various IRQ handling routines:
* asking for different IRQ's should be done through these routines
* instead of just grabbing them. Thus setups with different IRQ numbers
* shouldn't result in any weird surprises, and installing new handlers
* should be easier.
*
* IRQ's are in fact implemented a bit like signal handlers for the kernel.
* Naturally it's not a 1:1 relation, but there are similarities.
*/
#include <linux/signal.h>
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/irqchip.h>
#include <linux/random.h>
#include <linux/smp.h>
#include <linux/init.h>
#include <linux/seq_file.h>
#include <linux/errno.h>
#include <linux/list.h>
#include <linux/kallsyms.h>
#include <linux/proc_fs.h>
#include <linux/export.h>
#include <asm/hardware/cache-l2x0.h>
#include <asm/hardware/cache-uniphier.h>
#include <asm/outercache.h>
#include <asm/exception.h>
#include <asm/mach/arch.h>
#include <asm/mach/irq.h>
#include <asm/mach/time.h>
unsigned long irq_err_count;
int arch_show_interrupts(struct seq_file *p, int prec)
{
#ifdef CONFIG_FIQ
show_fiq_list(p, prec);
#endif
#ifdef CONFIG_SMP
show_ipi_list(p, prec);
#endif
seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count);
return 0;
}
/*
* handle_IRQ handles all hardware IRQ's. Decoded IRQs should
* not come via this function. Instead, they should provide their
* own 'handler'. Used by platform code implementing C-based 1st
* level decoding.
*/
void handle_IRQ(unsigned int irq, struct pt_regs *regs)
{
struct irq_desc *desc;
/*
* Some hardware gives randomly wrong interrupts. Rather
* than crashing, do something sensible.
*/
if (unlikely(!irq || irq >= nr_irqs))
desc = NULL;
else
desc = irq_to_desc(irq);
if (likely(desc))
handle_irq_desc(desc);
else
ack_bad_irq(irq);
}
/*
* asm_do_IRQ is the interface to be used from assembly code.
*/
asmlinkage void __exception_irq_entry
asm_do_IRQ(unsigned int irq, struct pt_regs *regs)
{
struct pt_regs *old_regs;
irq_enter();
old_regs = set_irq_regs(regs);
handle_IRQ(irq, regs);
set_irq_regs(old_regs);
irq_exit();
}
void __init init_IRQ(void)
{
int ret;
if (IS_ENABLED(CONFIG_OF) && !machine_desc->init_irq)
irqchip_init();
else
machine_desc->init_irq();
if (IS_ENABLED(CONFIG_OF) && IS_ENABLED(CONFIG_CACHE_L2X0) &&
(machine_desc->l2c_aux_mask || machine_desc->l2c_aux_val)) {
if (!outer_cache.write_sec)
outer_cache.write_sec = machine_desc->l2c_write_sec;
ret = l2x0_of_init(machine_desc->l2c_aux_val,
machine_desc->l2c_aux_mask);
if (ret && ret != -ENODEV)
pr_err("L2C: failed to init: %d\n", ret);
}
uniphier_cache_init();
}
#ifdef CONFIG_SPARSE_IRQ
int __init arch_probe_nr_irqs(void)
{
nr_irqs = machine_desc->nr_irqs ? machine_desc->nr_irqs : NR_IRQS;
return nr_irqs;
}
#endif