xref: /openbmc/linux/arch/arm64/kernel/irq.c (revision ed8b20d4)
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/seq_file.h>
31 #include <linux/vmalloc.h>
32 #include <asm/vmap_stack.h>
33 
34 unsigned long irq_err_count;
35 
36 DEFINE_PER_CPU(unsigned long *, irq_stack_ptr);
37 
38 int arch_show_interrupts(struct seq_file *p, int prec)
39 {
40 	show_ipi_list(p, prec);
41 	seq_printf(p, "%*s: %10lu\n", prec, "Err", irq_err_count);
42 	return 0;
43 }
44 
45 void (*handle_arch_irq)(struct pt_regs *) = NULL;
46 
47 void __init set_handle_irq(void (*handle_irq)(struct pt_regs *))
48 {
49 	if (handle_arch_irq)
50 		return;
51 
52 	handle_arch_irq = handle_irq;
53 }
54 
55 #ifdef CONFIG_VMAP_STACK
56 static void init_irq_stacks(void)
57 {
58 	int cpu;
59 	unsigned long *p;
60 
61 	for_each_possible_cpu(cpu) {
62 		p = arch_alloc_vmap_stack(IRQ_STACK_SIZE, cpu_to_node(cpu));
63 		per_cpu(irq_stack_ptr, cpu) = p;
64 	}
65 }
66 #else
67 /* irq stack only needs to be 16 byte aligned - not IRQ_STACK_SIZE aligned. */
68 DEFINE_PER_CPU_ALIGNED(unsigned long [IRQ_STACK_SIZE/sizeof(long)], irq_stack);
69 
70 static void init_irq_stacks(void)
71 {
72 	int cpu;
73 
74 	for_each_possible_cpu(cpu)
75 		per_cpu(irq_stack_ptr, cpu) = per_cpu(irq_stack, cpu);
76 }
77 #endif
78 
79 void __init init_IRQ(void)
80 {
81 	init_irq_stacks();
82 	irqchip_init();
83 	if (!handle_arch_irq)
84 		panic("No interrupt controller found.");
85 }
86