arch/arm64/kernel/irq.c

   1 /*
   2  * Based on arch/arm/kernel/irq.c
   3  *
   4  * Copyright (C) 1992 Linus Torvalds
   5  * Modifications for ARM processor Copyright (C) 1995-2000 Russell King.
   6  * Support for Dynamic Tick Timer Copyright (C) 2004-2005 Nokia Corporation.
   7  * Dynamic Tick Timer written by Tony Lindgren <tony@atomide.com> and
   8  * Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com>.
   9  * Copyright (C) 2012 ARM Ltd.
  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 program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  22  */
  23
  24 #include <linux/kernel_stat.h>
  25 #include <linux/irq.h>
  26 #include <linux/smp.h>
  27 #include <linux/init.h>
  28 #include <linux/of_irq.h>
  29 #include <linux/seq_file.h>
  30 #include <linux/ratelimit.h>
  31
  32 unsigned long irq_err_count;
  33
  34 int arch_show_interrupts(struct seq_file *p, int prec)
  35 {
  36 #ifdef CONFIG_SMP
  37         show_ipi_list(p, prec);
  38 #endif
  39         seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count);
  40         return 0;
  41 }
  42
  43 /*
  44  * handle_IRQ handles all hardware IRQ's.  Decoded IRQs should
  45  * not come via this function.  Instead, they should provide their
  46  * own 'handler'.  Used by platform code implementing C-based 1st
  47  * level decoding.
  48  */
  49 void handle_IRQ(unsigned int irq, struct pt_regs *regs)
  50 {
  51         struct pt_regs *old_regs = set_irq_regs(regs);
  52
  53         irq_enter();
  54
  55         /*
  56          * Some hardware gives randomly wrong interrupts.  Rather
  57          * than crashing, do something sensible.
  58          */
  59         if (unlikely(irq >= nr_irqs)) {
  60                 pr_warn_ratelimited("Bad IRQ%u\n", irq);
  61                 ack_bad_irq(irq);
  62         } else {
  63                 generic_handle_irq(irq);
  64         }
  65
  66         irq_exit();
  67         set_irq_regs(old_regs);
  68 }
  69
  70 /*
  71  * Interrupt controllers supported by the kernel.
  72  */
  73 static const struct of_device_id intctrl_of_match[] __initconst = {
  74         /* IRQ controllers { .compatible, .data } info to go here */
  75         {}
  76 };
  77
  78 void __init init_IRQ(void)
  79 {
  80         of_irq_init(intctrl_of_match);
  81
  82         if (!handle_arch_irq)
  83                 panic("No interrupt controller found.");
  84 }