LXR linux/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
  36unsigned long irq_err_count;
  37
  38/* Only access this in an NMI enter/exit */
  39DEFINE_PER_CPU(struct nmi_ctx, nmi_contexts);
  40
  41DEFINE_PER_CPU(unsigned long *, irq_stack_ptr);
  42
  43int 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
  51static 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. */
  63DEFINE_PER_CPU_ALIGNED(unsigned long [IRQ_STACK_SIZE/sizeof(long)], irq_stack);
  64
  65static 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
  74void __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        if (system_uses_irq_prio_masking()) {
  82                /*
  83                 * Now that we have a stack for our IRQ handler, set
  84                 * the PMR/PSR pair to a consistent state.
  85                 */
  86                WARN_ON(read_sysreg(daif) & PSR_A_BIT);
  87                local_daif_restore(DAIF_PROCCTX_NOIRQ);
  88        }
  89}
  90
  91/*
  92 * Stubs to make nmi_enter/exit() code callable from ASM
  93 */
  94asmlinkage void notrace asm_nmi_enter(void)
  95{
  96        nmi_enter();
  97}
  98NOKPROBE_SYMBOL(asm_nmi_enter);
  99
 100asmlinkage void notrace asm_nmi_exit(void)
 101{
 102        nmi_exit();
 103}
 104NOKPROBE_SYMBOL(asm_nmi_exit);
 105