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 36 #include <asm/hardware/cache-l2x0.h> 37 #include <asm/hardware/cache-uniphier.h> 38 #include <asm/outercache.h> 39 #include <asm/exception.h> 40 #include <asm/mach/arch.h> 41 #include <asm/mach/irq.h> 42 #include <asm/mach/time.h> 43 44 unsigned long irq_err_count; 45 46 int arch_show_interrupts(struct seq_file *p, int prec) 47 { 48 #ifdef CONFIG_FIQ 49 show_fiq_list(p, prec); 50 #endif 51 #ifdef CONFIG_SMP 52 show_ipi_list(p, prec); 53 #endif 54 seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count); 55 return 0; 56 } 57 58 /* 59 * handle_IRQ handles all hardware IRQ's. Decoded IRQs should 60 * not come via this function. Instead, they should provide their 61 * own 'handler'. Used by platform code implementing C-based 1st 62 * level decoding. 63 */ 64 void handle_IRQ(unsigned int irq, struct pt_regs *regs) 65 { 66 struct irq_desc *desc; 67 68 /* 69 * Some hardware gives randomly wrong interrupts. Rather 70 * than crashing, do something sensible. 71 */ 72 if (unlikely(!irq || irq >= nr_irqs)) 73 desc = NULL; 74 else 75 desc = irq_to_desc(irq); 76 77 if (likely(desc)) 78 handle_irq_desc(desc); 79 else 80 ack_bad_irq(irq); 81 } 82 83 /* 84 * asm_do_IRQ is the interface to be used from assembly code. 85 */ 86 asmlinkage void __exception_irq_entry 87 asm_do_IRQ(unsigned int irq, struct pt_regs *regs) 88 { 89 struct pt_regs *old_regs; 90 91 irq_enter(); 92 old_regs = set_irq_regs(regs); 93 94 handle_IRQ(irq, regs); 95 96 set_irq_regs(old_regs); 97 irq_exit(); 98 } 99 100 void __init init_IRQ(void) 101 { 102 int ret; 103 104 if (IS_ENABLED(CONFIG_OF) && !machine_desc->init_irq) 105 irqchip_init(); 106 else 107 machine_desc->init_irq(); 108 109 if (IS_ENABLED(CONFIG_OF) && IS_ENABLED(CONFIG_CACHE_L2X0) && 110 (machine_desc->l2c_aux_mask || machine_desc->l2c_aux_val)) { 111 if (!outer_cache.write_sec) 112 outer_cache.write_sec = machine_desc->l2c_write_sec; 113 ret = l2x0_of_init(machine_desc->l2c_aux_val, 114 machine_desc->l2c_aux_mask); 115 if (ret && ret != -ENODEV) 116 pr_err("L2C: failed to init: %d\n", ret); 117 } 118 119 uniphier_cache_init(); 120 } 121 122 #ifdef CONFIG_SPARSE_IRQ 123 int __init arch_probe_nr_irqs(void) 124 { 125 nr_irqs = machine_desc->nr_irqs ? machine_desc->nr_irqs : NR_IRQS; 126 return nr_irqs; 127 } 128 #endif 129