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/memory.h>
  27 #include <linux/smp.h>
  28 #include <linux/init.h>
  29 #include <linux/irqchip.h>
  30 #include <linux/kprobes.h>
  31 #include <linux/seq_file.h>
  32 #include <linux/vmalloc.h>
  33 #include <asm/daifflags.h>
  34 #include <asm/vmap_stack.h>
  35
  36 unsigned long irq_err_count;
  37
  38 /* Only access this in an NMI enter/exit */
  39 DEFINE_PER_CPU(struct nmi_ctx, nmi_contexts);
  40
  41 DEFINE_PER_CPU(unsigned long *, irq_stack_ptr);
  42
  43 int arch_show_interrupts(struct seq_file *p, int prec)
  44 {
  45         show_ipi_list(p, prec);
  46         seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count);
  47         return 0;
  48 }
  49
  50 #ifdef CONFIG_VMAP_STACK
  51 static void init_irq_stacks(void)
  52 {
  53         int cpu;
  54         unsigned long *p;
  55
  56         for_each_possible_cpu(cpu) {
  57                 p = arch_alloc_vmap_stack(IRQ_STACK_SIZE, cpu_to_node(cpu));
  58                 per_cpu(irq_stack_ptr, cpu) = p;
  59         }
  60 }
  61 #else
  62 /* irq stack only needs to be 16 byte aligned - not IRQ_STACK_SIZE aligned. */
  63 DEFINE_PER_CPU_ALIGNED(unsigned long [IRQ_STACK_SIZE/sizeof(long)], irq_stack);
  64
  65 static void init_irq_stacks(void)
  66 {
  67         int cpu;
  68
  69         for_each_possible_cpu(cpu)
  70                 per_cpu(irq_stack_ptr, cpu) = per_cpu(irq_stack, cpu);
  71 }
  72 #endif
  73
  74 void __init init_IRQ(void)
  75 {
  76         init_irq_stacks();
  77         irqchip_init();
  78         if (!handle_arch_irq)
  79                 panic("No interrupt controller found.");
  80 }
  81
  82 /*
  83  * Stubs to make nmi_enter/exit() code callable from ASM
  84  */
  85 asmlinkage void notrace asm_nmi_enter(void)
  86 {
  87         nmi_enter();
  88 }
  89 NOKPROBE_SYMBOL(asm_nmi_enter);
  90
  91 asmlinkage void notrace asm_nmi_exit(void)
  92 {
  93         nmi_exit();
  94 }
  95 NOKPROBE_SYMBOL(asm_nmi_exit);