arch/arm/kernel/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
  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