xref: /openbmc/linux/arch/arm64/kernel/irq.c (revision 17ce302f)
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);
96