irq.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 *  linux/arch/arm/kernel/irq.c
  4 *
  5 *  Copyright (C) 1992 Linus Torvalds
  6 *  Modifications for ARM processor Copyright (C) 1995-2000 Russell King.
  7 *
  8 *  Support for Dynamic Tick Timer Copyright (C) 2004-2005 Nokia Corporation.
  9 *  Dynamic Tick Timer written by Tony Lindgren <tony@atomide.com> and
 10 *  Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>.
 11 *
 12 *  This file contains the code used by various IRQ handling routines:
 13 *  asking for different IRQ's should be done through these routines
 14 *  instead of just grabbing them. Thus setups with different IRQ numbers
 15 *  shouldn't result in any weird surprises, and installing new handlers
 16 *  should be easier.
 17 *
 18 *  IRQ's are in fact implemented a bit like signal handlers for the kernel.
 19 *  Naturally it's not a 1:1 relation, but there are similarities.
 20 */
 21#include <linux/signal.h>
 22#include <linux/ioport.h>
 23#include <linux/interrupt.h>
 24#include <linux/irq.h>
 25#include <linux/irqchip.h>
 26#include <linux/random.h>
 27#include <linux/smp.h>
 28#include <linux/init.h>
 29#include <linux/seq_file.h>
 30#include <linux/errno.h>
 31#include <linux/list.h>
 32#include <linux/kallsyms.h>
 33#include <linux/proc_fs.h>
 34#include <linux/export.h>
 35#include <linux/vmalloc.h>
 36
 37#include <asm/hardware/cache-l2x0.h>
 38#include <asm/hardware/cache-uniphier.h>
 39#include <asm/outercache.h>
 40#include <asm/softirq_stack.h>
 41#include <asm/exception.h>
 42#include <asm/mach/arch.h>
 43#include <asm/mach/irq.h>
 44#include <asm/mach/time.h>
 45
 46#include "reboot.h"
 47
 48unsigned long irq_err_count;
 49
 50#ifdef CONFIG_IRQSTACKS
 51
 52asmlinkage DEFINE_PER_CPU_READ_MOSTLY(u8 *, irq_stack_ptr);
 53
 54static void __init init_irq_stacks(void)
 55{
 56	u8 *stack;
 57	int cpu;
 58
 59	for_each_possible_cpu(cpu) {
 60		if (!IS_ENABLED(CONFIG_VMAP_STACK))
 61			stack = (u8 *)__get_free_pages(GFP_KERNEL,
 62						       THREAD_SIZE_ORDER);
 63		else
 64			stack = __vmalloc_node(THREAD_SIZE, THREAD_ALIGN,
 65					       THREADINFO_GFP, NUMA_NO_NODE,
 66					       __builtin_return_address(0));
 67
 68		if (WARN_ON(!stack))
 69			break;
 70		per_cpu(irq_stack_ptr, cpu) = &stack[THREAD_SIZE];
 71	}
 72}
 73
 74#ifdef CONFIG_SOFTIRQ_ON_OWN_STACK
 75static void ____do_softirq(void *arg)
 76{
 77	__do_softirq();
 78}
 79
 80void do_softirq_own_stack(void)
 81{
 82	call_with_stack(____do_softirq, NULL,
 83			__this_cpu_read(irq_stack_ptr));
 84}
 85#endif
 86#endif
 87
 88int arch_show_interrupts(struct seq_file *p, int prec)
 89{
 90#ifdef CONFIG_FIQ
 91	show_fiq_list(p, prec);
 92#endif
 93#ifdef CONFIG_SMP
 94	show_ipi_list(p, prec);
 95#endif
 96	seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count);
 97	return 0;
 98}
 99
100/*
101 * handle_IRQ handles all hardware IRQ's.  Decoded IRQs should
102 * not come via this function.  Instead, they should provide their
103 * own 'handler'.  Used by platform code implementing C-based 1st
104 * level decoding.
105 */
106void handle_IRQ(unsigned int irq, struct pt_regs *regs)
107{
108	struct irq_desc *desc;
109
110	/*
111	 * Some hardware gives randomly wrong interrupts.  Rather
112	 * than crashing, do something sensible.
113	 */
114	if (unlikely(!irq || irq >= irq_get_nr_irqs()))
115		desc = NULL;
116	else
117		desc = irq_to_desc(irq);
118
119	if (likely(desc))
120		handle_irq_desc(desc);
121	else
122		ack_bad_irq(irq);
123}
124
125void __init init_IRQ(void)
126{
127	int ret;
128
129#ifdef CONFIG_IRQSTACKS
130	init_irq_stacks();
131#endif
132
133	if (IS_ENABLED(CONFIG_OF) && !machine_desc->init_irq)
134		irqchip_init();
135	else
136		machine_desc->init_irq();
137
138	if (IS_ENABLED(CONFIG_OF) && IS_ENABLED(CONFIG_CACHE_L2X0) &&
139	    (machine_desc->l2c_aux_mask || machine_desc->l2c_aux_val)) {
140		if (!outer_cache.write_sec)
141			outer_cache.write_sec = machine_desc->l2c_write_sec;
142		ret = l2x0_of_init(machine_desc->l2c_aux_val,
143				   machine_desc->l2c_aux_mask);
144		if (ret && ret != -ENODEV)
145			pr_err("L2C: failed to init: %d\n", ret);
146	}
147
148	uniphier_cache_init();
149}
150
151#ifdef CONFIG_SPARSE_IRQ
152int __init arch_probe_nr_irqs(void)
153{
154	return irq_set_nr_irqs(machine_desc->nr_irqs ? : NR_IRQS);
155}
156#endif