xref: /openbsd/sys/arch/riscv64/dev/riscv_cpu_intc.c (revision 097a140d)
1 /*
2  * Copyright (c) 2020, Mars Li <mengshi.li.mars@gmail.com>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 
17 #include <sys/param.h>
18 #include <sys/systm.h>
19 #include <sys/queue.h>
20 #include <sys/malloc.h>
21 #include <sys/device.h>
22 #include <sys/evcount.h>
23 
24 #include <machine/bus.h>
25 #include <machine/fdt.h>
26 #include <machine/riscvreg.h>
27 
28 #include <dev/ofw/openfirm.h>
29 #include <dev/ofw/fdt.h>
30 
31 #include "riscv64/dev/plic.h"
32 #include "riscv_cpu_intc.h"
33 
34 struct intrhand {
35 	int (*ih_func)(void *);		/* handler */
36 	void *ih_arg;			/* arg for handler */
37 	int ih_irq;			/* IRQ number */
38 	char *ih_name;
39 };
40 
41 struct intrhand* intc_handler[INTC_NIRQS] = {NULL};
42 struct interrupt_controller intc_ic;
43 
44 int	riscv_intc_match(struct device *, void *, void *);
45 void	riscv_intc_attach(struct device *, struct device *, void *);
46 
47 void	riscv_intc_irq_handler(void *);
48 void	*riscv_intc_intr_establish(int, int, int (*)(void *),
49 		void *, char *);
50 void	riscv_intc_intr_disestablish(void *);
51 
52 
53 struct cfattach        intc_ca = {
54        sizeof (struct device), riscv_intc_match, riscv_intc_attach
55 };
56 
57 struct cfdriver intc_cd = {
58        NULL, "rv_cpu_intc", DV_DULL
59 };
60 
61 int
62 riscv_intc_match(struct device *parent, void *match, void *aux)
63 {
64 	struct fdt_attach_args *faa = aux;
65 	int node = faa->fa_node;
66 	return (OF_getproplen(node, "interrupt-controller") >= 0 &&
67 		OF_is_compatible(node, "riscv,cpu-intc"));
68 }
69 
70 void
71 riscv_intc_attach(struct device *parent, struct device *self, void *aux)
72 {
73 	struct fdt_attach_args *faa = aux;/* should only use fa_node field */
74 
75 	riscv_init_smask();
76 
77 	/* hook the intr_handler */
78 	riscv_set_intr_handler(riscv_intc_irq_handler);
79 
80 	intc_ic.ic_node = faa->fa_node;
81 	intc_ic.ic_cookie = &intc_ic;
82 
83 	/*
84 	 * only allow install/uninstall handler to/from global vector
85 	 * by calling riscv_intc_intr_establish/disestablish
86 	 */
87 	intc_ic.ic_establish = NULL;
88 	intc_ic.ic_disestablish = NULL;
89 
90 	riscv_intr_register_fdt(&intc_ic);
91 
92 	/*
93 	 * XXX right time to enable interrupts ??
94 	 * might need to postpone untile autoconf is finished
95 	 */
96 	enable_interrupts();
97 }
98 
99 
100 /* global interrupt handler */
101 void
102 riscv_intc_irq_handler(void *frame)
103 {
104 	int irq;
105 	struct intrhand *ih;
106 	struct trapframe *_frame;
107         _frame = (struct trapframe*) frame;
108 
109 	KASSERTMSG(_frame->tf_scause & EXCP_INTR,
110 		"riscv_cpu_intr: wrong frame passed");
111 
112 	irq = (_frame->tf_scause & EXCP_MASK);
113 #ifdef DEBUG_INTC
114 	printf("irq %d fired\n", irq);
115 #endif
116 
117 	ih = intc_handler[irq];
118 	if (ih->ih_func(frame) == 0)
119 #ifdef DEBUG_INTC
120 		printf("fail in handling irq %d %s\n", irq, ih->ih_name);
121 #else
122 		;
123 #endif /* DEBUG_INTC */
124 }
125 
126 void *
127 riscv_intc_intr_establish(int irqno, int dummy_level, int (*func)(void *),
128     void *arg, char *name)
129 {
130 	int sie;
131 	struct intrhand *ih;
132 
133 	if (irqno < 0 || irqno >= INTC_NIRQS)
134 		panic("intc_intr_establish: bogus irqnumber %d: %s",
135 		     irqno, name);
136 	sie = disable_interrupts();
137 
138 	ih = malloc(sizeof(*ih), M_DEVBUF, M_WAITOK);
139 	ih->ih_func = func;
140 	ih->ih_arg = arg;
141 	ih->ih_irq = irqno;
142 	ih->ih_name = name;
143 
144 	intc_handler[irqno] = ih;
145 #ifdef DEBUG_INTC
146 	printf("\nintc_intr_establish irq %d [%s]\n", irqno, name);
147 #endif
148 	restore_interrupts(sie);
149 	return (ih);
150 }
151 
152 void
153 riscv_intc_intr_disestablish(void *cookie)
154 {
155 	int sie;
156 	struct intrhand *ih = cookie;
157 	int irqno = ih->ih_irq;
158 	sie = disable_interrupts();
159 
160 	intc_handler[irqno] = NULL;
161 	free(ih, M_DEVBUF, 0);
162 
163 	restore_interrupts(sie);
164 }
165