xref: /openbmc/linux/arch/arm64/kernel/irq.c (revision 55fd7e02)
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);
94