arch/arm64/kernel/irq.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Based on arch/arm/kernel/irq.c
   4  *
   5  * Copyright (C) 1992 Linus Torvalds
   6  * Modifications for ARM processor Copyright (C) 1995-2000 Russell King.
   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  * Copyright (C) 2012 ARM Ltd.
  11  */
  12
  13 #include <linux/kernel_stat.h>
  14 #include <linux/irq.h>
  15 #include <linux/memory.h>
  16 #include <linux/smp.h>
  17 #include <linux/init.h>
  18 #include <linux/irqchip.h>
  19 #include <linux/kprobes.h>
  20 #include <linux/seq_file.h>
  21 #include <linux/vmalloc.h>
  22 #include <asm/daifflags.h>
  23 #include <asm/vmap_stack.h>
  24
  25 unsigned long irq_err_count;
  26
  27 /* Only access this in an NMI enter/exit */
  28 DEFINE_PER_CPU(struct nmi_ctx, nmi_contexts);
  29
  30 DEFINE_PER_CPU(unsigned long *, irq_stack_ptr);
  31
  32 int arch_show_interrupts(struct seq_file *p, int prec)
  33 {
  34         show_ipi_list(p, prec);
  35         seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count);
  36         return 0;
  37 }
  38
  39 #ifdef CONFIG_VMAP_STACK
  40 static void init_irq_stacks(void)
  41 {
  42         int cpu;
  43         unsigned long *p;
  44
  45         for_each_possible_cpu(cpu) {
  46                 p = arch_alloc_vmap_stack(IRQ_STACK_SIZE, cpu_to_node(cpu));
  47                 per_cpu(irq_stack_ptr, cpu) = p;
  48         }
  49 }
  50 #else
  51 /* irq stack only needs to be 16 byte aligned - not IRQ_STACK_SIZE aligned. */
  52 DEFINE_PER_CPU_ALIGNED(unsigned long [IRQ_STACK_SIZE/sizeof(long)], irq_stack);
  53
  54 static void init_irq_stacks(void)
  55 {
  56         int cpu;
  57
  58         for_each_possible_cpu(cpu)
  59                 per_cpu(irq_stack_ptr, cpu) = per_cpu(irq_stack, cpu);
  60 }
  61 #endif
  62
  63 void __init init_IRQ(void)
  64 {
  65         init_irq_stacks();
  66         irqchip_init();
  67         if (!handle_arch_irq)
  68                 panic("No interrupt controller found.");
  69
  70         if (system_uses_irq_prio_masking()) {
  71                 /*
  72                  * Now that we have a stack for our IRQ handler, set
  73                  * the PMR/PSR pair to a consistent state.
  74                  */
  75                 WARN_ON(read_sysreg(daif) & PSR_A_BIT);
  76                 local_daif_restore(DAIF_PROCCTX_NOIRQ);
  77         }
  78 }
  79
  80 /*
  81  * Stubs to make nmi_enter/exit() code callable from ASM
  82  */
  83 asmlinkage void notrace asm_nmi_enter(void)
  84 {
  85         nmi_enter();
  86 }
  87 NOKPROBE_SYMBOL(asm_nmi_enter);
  88
  89 asmlinkage void notrace asm_nmi_exit(void)
  90 {
  91         nmi_exit();
  92 }
  93 NOKPROBE_SYMBOL(asm_nmi_exit);