xref: /linux/arch/riscv/kernel/irq.c (revision b58b13f156c00c2457035b7071eaaac105fe6836)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2012 Regents of the University of California
4  * Copyright (C) 2017 SiFive
5  * Copyright (C) 2018 Christoph Hellwig
6  */
7 
8 #include <linux/interrupt.h>
9 #include <linux/irqchip.h>
10 #include <linux/irqdomain.h>
11 #include <linux/module.h>
12 #include <linux/scs.h>
13 #include <linux/seq_file.h>
14 #include <asm/sbi.h>
15 #include <asm/smp.h>
16 #include <asm/softirq_stack.h>
17 #include <asm/stacktrace.h>
18 
19 static struct fwnode_handle *(*__get_intc_node)(void);
20 
21 void riscv_set_intc_hwnode_fn(struct fwnode_handle *(*fn)(void))
22 {
23 	__get_intc_node = fn;
24 }
25 
26 struct fwnode_handle *riscv_get_intc_hwnode(void)
27 {
28 	if (__get_intc_node)
29 		return __get_intc_node();
30 
31 	return NULL;
32 }
33 EXPORT_SYMBOL_GPL(riscv_get_intc_hwnode);
34 
35 #ifdef CONFIG_IRQ_STACKS
36 #include <asm/irq_stack.h>
37 
38 DECLARE_PER_CPU(ulong *, irq_shadow_call_stack_ptr);
39 
40 #ifdef CONFIG_SHADOW_CALL_STACK
41 DEFINE_PER_CPU(ulong *, irq_shadow_call_stack_ptr);
42 #endif
43 
44 static void init_irq_scs(void)
45 {
46 	int cpu;
47 
48 	if (!scs_is_enabled())
49 		return;
50 
51 	for_each_possible_cpu(cpu)
52 		per_cpu(irq_shadow_call_stack_ptr, cpu) =
53 			scs_alloc(cpu_to_node(cpu));
54 }
55 
56 DEFINE_PER_CPU(ulong *, irq_stack_ptr);
57 
58 #ifdef CONFIG_VMAP_STACK
59 static void init_irq_stacks(void)
60 {
61 	int cpu;
62 	ulong *p;
63 
64 	for_each_possible_cpu(cpu) {
65 		p = arch_alloc_vmap_stack(IRQ_STACK_SIZE, cpu_to_node(cpu));
66 		per_cpu(irq_stack_ptr, cpu) = p;
67 	}
68 }
69 #else
70 /* irq stack only needs to be 16 byte aligned - not IRQ_STACK_SIZE aligned. */
71 DEFINE_PER_CPU_ALIGNED(ulong [IRQ_STACK_SIZE/sizeof(ulong)], irq_stack);
72 
73 static void init_irq_stacks(void)
74 {
75 	int cpu;
76 
77 	for_each_possible_cpu(cpu)
78 		per_cpu(irq_stack_ptr, cpu) = per_cpu(irq_stack, cpu);
79 }
80 #endif /* CONFIG_VMAP_STACK */
81 
82 #ifdef CONFIG_SOFTIRQ_ON_OWN_STACK
83 static void ___do_softirq(struct pt_regs *regs)
84 {
85 	__do_softirq();
86 }
87 
88 void do_softirq_own_stack(void)
89 {
90 	if (on_thread_stack())
91 		call_on_irq_stack(NULL, ___do_softirq);
92 	else
93 		__do_softirq();
94 }
95 #endif /* CONFIG_SOFTIRQ_ON_OWN_STACK */
96 
97 #else
98 static void init_irq_scs(void) {}
99 static void init_irq_stacks(void) {}
100 #endif /* CONFIG_IRQ_STACKS */
101 
102 int arch_show_interrupts(struct seq_file *p, int prec)
103 {
104 	show_ipi_stats(p, prec);
105 	return 0;
106 }
107 
108 void __init init_IRQ(void)
109 {
110 	init_irq_scs();
111 	init_irq_stacks();
112 	irqchip_init();
113 	if (!handle_arch_irq)
114 		panic("No interrupt controller found.");
115 	sbi_ipi_init();
116 }
117