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/softirq_stack.h> 40 #include <asm/exception.h> 41 #include <asm/mach/arch.h> 42 #include <asm/mach/irq.h> 43 #include <asm/mach/time.h> 44 45 #include "reboot.h" 46 47 unsigned long irq_err_count; 48 49 #ifdef CONFIG_IRQSTACKS 50 51 asmlinkage DEFINE_PER_CPU_READ_MOSTLY(u8 *, irq_stack_ptr); 52 53 static void __init init_irq_stacks(void) 54 { 55 u8 *stack; 56 int cpu; 57 58 for_each_possible_cpu(cpu) { 59 if (!IS_ENABLED(CONFIG_VMAP_STACK)) 60 stack = (u8 *)__get_free_pages(GFP_KERNEL, 61 THREAD_SIZE_ORDER); 62 else 63 stack = __vmalloc_node(THREAD_SIZE, THREAD_ALIGN, 64 THREADINFO_GFP, NUMA_NO_NODE, 65 __builtin_return_address(0)); 66 67 if (WARN_ON(!stack)) 68 break; 69 per_cpu(irq_stack_ptr, cpu) = &stack[THREAD_SIZE]; 70 } 71 } 72 73 #ifndef CONFIG_PREEMPT_RT 74 static void ____do_softirq(void *arg) 75 { 76 __do_softirq(); 77 } 78 79 void do_softirq_own_stack(void) 80 { 81 call_with_stack(____do_softirq, NULL, 82 __this_cpu_read(irq_stack_ptr)); 83 } 84 #endif 85 #endif 86 87 int arch_show_interrupts(struct seq_file *p, int prec) 88 { 89 #ifdef CONFIG_FIQ 90 show_fiq_list(p, prec); 91 #endif 92 #ifdef CONFIG_SMP 93 show_ipi_list(p, prec); 94 #endif 95 seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count); 96 return 0; 97 } 98 99 /* 100 * handle_IRQ handles all hardware IRQ's. Decoded IRQs should 101 * not come via this function. Instead, they should provide their 102 * own 'handler'. Used by platform code implementing C-based 1st 103 * level decoding. 104 */ 105 void handle_IRQ(unsigned int irq, struct pt_regs *regs) 106 { 107 struct irq_desc *desc; 108 109 /* 110 * Some hardware gives randomly wrong interrupts. Rather 111 * than crashing, do something sensible. 112 */ 113 if (unlikely(!irq || irq >= nr_irqs)) 114 desc = NULL; 115 else 116 desc = irq_to_desc(irq); 117 118 if (likely(desc)) 119 handle_irq_desc(desc); 120 else 121 ack_bad_irq(irq); 122 } 123 124 void __init init_IRQ(void) 125 { 126 int ret; 127 128 #ifdef CONFIG_IRQSTACKS 129 init_irq_stacks(); 130 #endif 131 132 if (IS_ENABLED(CONFIG_OF) && !machine_desc->init_irq) 133 irqchip_init(); 134 else 135 machine_desc->init_irq(); 136 137 if (IS_ENABLED(CONFIG_OF) && IS_ENABLED(CONFIG_CACHE_L2X0) && 138 (machine_desc->l2c_aux_mask || machine_desc->l2c_aux_val)) { 139 if (!outer_cache.write_sec) 140 outer_cache.write_sec = machine_desc->l2c_write_sec; 141 ret = l2x0_of_init(machine_desc->l2c_aux_val, 142 machine_desc->l2c_aux_mask); 143 if (ret && ret != -ENODEV) 144 pr_err("L2C: failed to init: %d\n", ret); 145 } 146 147 uniphier_cache_init(); 148 } 149 150 #ifdef CONFIG_SPARSE_IRQ 151 int __init arch_probe_nr_irqs(void) 152 { 153 nr_irqs = machine_desc->nr_irqs ? machine_desc->nr_irqs : NR_IRQS; 154 return nr_irqs; 155 } 156 #endif 157