arch/arm/kernel/irq.c

   1 /*
   2  *  linux/arch/arm/kernel/irq.c
   3  *
   4  *  Copyright (C) 1992 Linus Torvalds
   5  *  Modifications for ARM processor Copyright (C) 1995-2000 Russell King.
   6  *
   7  *  Support for Dynamic Tick Timer Copyright (C) 2004-2005 Nokia Corporation.
   8  *  Dynamic Tick Timer written by Tony Lindgren <tony@atomide.com> and
   9  *  Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>.
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License version 2 as
  13  * published by the Free Software Foundation.
  14  *
  15  *  This file contains the code used by various IRQ handling routines:
  16  *  asking for different IRQ's should be done through these routines
  17  *  instead of just grabbing them. Thus setups with different IRQ numbers
  18  *  shouldn't result in any weird surprises, and installing new handlers
  19  *  should be easier.
  20  *
  21  *  IRQ's are in fact implemented a bit like signal handlers for the kernel.
  22  *  Naturally it's not a 1:1 relation, but there are similarities.
  23  */
  24 #include <linux/kernel_stat.h>
  25 #include <linux/signal.h>
  26 #include <linux/ioport.h>
  27 #include <linux/interrupt.h>
  28 #include <linux/irq.h>
  29 #include <linux/irqchip.h>
  30 #include <linux/random.h>
  31 #include <linux/smp.h>
  32 #include <linux/init.h>
  33 #include <linux/seq_file.h>
  34 #include <linux/errno.h>
  35 #include <linux/list.h>
  36 #include <linux/kallsyms.h>
  37 #include <linux/proc_fs.h>
  38 #include <linux/export.h>
  39
  40 #include <asm/hardware/cache-l2x0.h>
  41 #include <asm/hardware/cache-uniphier.h>
  42 #include <asm/outercache.h>
  43 #include <asm/exception.h>
  44 #include <asm/mach/arch.h>
  45 #include <asm/mach/irq.h>
  46 #include <asm/mach/time.h>
  47
  48 unsigned long irq_err_count;
  49
  50 int arch_show_interrupts(struct seq_file *p, int prec)
  51 {
  52 #ifdef CONFIG_FIQ
  53         show_fiq_list(p, prec);
  54 #endif
  55 #ifdef CONFIG_SMP
  56         show_ipi_list(p, prec);
  57 #endif
  58         seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count);
  59         return 0;
  60 }
  61
  62 /*
  63  * handle_IRQ handles all hardware IRQ's.  Decoded IRQs should
  64  * not come via this function.  Instead, they should provide their
  65  * own 'handler'.  Used by platform code implementing C-based 1st
  66  * level decoding.
  67  */
  68 void handle_IRQ(unsigned int irq, struct pt_regs *regs)
  69 {
  70         __handle_domain_irq(NULL, irq, false, regs);
  71 }
  72
  73 /*
  74  * asm_do_IRQ is the interface to be used from assembly code.
  75  */
  76 asmlinkage void __exception_irq_entry
  77 asm_do_IRQ(unsigned int irq, struct pt_regs *regs)
  78 {
  79         handle_IRQ(irq, regs);
  80 }
  81
  82 void __init init_IRQ(void)
  83 {
  84         int ret;
  85
  86         if (IS_ENABLED(CONFIG_OF) && !machine_desc->init_irq)
  87                 irqchip_init();
  88         else
  89                 machine_desc->init_irq();
  90
  91         if (IS_ENABLED(CONFIG_OF) && IS_ENABLED(CONFIG_CACHE_L2X0) &&
  92             (machine_desc->l2c_aux_mask || machine_desc->l2c_aux_val)) {
  93                 if (!outer_cache.write_sec)
  94                         outer_cache.write_sec = machine_desc->l2c_write_sec;
  95                 ret = l2x0_of_init(machine_desc->l2c_aux_val,
  96                                    machine_desc->l2c_aux_mask);
  97                 if (ret && ret != -ENODEV)
  98                         pr_err("L2C: failed to init: %d\n", ret);
  99         }
 100
 101         uniphier_cache_init();
 102 }
 103
 104 #ifdef CONFIG_MULTI_IRQ_HANDLER
 105 void __init set_handle_irq(void (*handle_irq)(struct pt_regs *))
 106 {
 107         if (handle_arch_irq)
 108                 return;
 109
 110         handle_arch_irq = handle_irq;
 111 }
 112 #endif
 113
 114 #ifdef CONFIG_SPARSE_IRQ
 115 int __init arch_probe_nr_irqs(void)
 116 {
 117         nr_irqs = machine_desc->nr_irqs ? machine_desc->nr_irqs : NR_IRQS;
 118         return nr_irqs;
 119 }
 120 #endif