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 48 unsigned long irq_err_count; 49 50 #ifdef CONFIG_IRQSTACKS 51 52 asmlinkage DEFINE_PER_CPU_READ_MOSTLY(u8 *, irq_stack_ptr); 53 54 static 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 75 static void ____do_softirq(void *arg) 76 { 77 __do_softirq(); 78 } 79 80 void 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 88 int 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 */ 106 void 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 } 124 125 void __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 152 int __init arch_probe_nr_irqs(void) 153 { 154 return irq_set_nr_irqs(machine_desc->nr_irqs ? : NR_IRQS); 155 } 156 #endif 157