xref: /openbmc/qemu/hw/intc/loongson_liointc.c (revision a8dc82ce)
1 /*
2  * QEMU Loongson Local I/O interrupt controler.
3  *
4  * Copyright (c) 2020 Huacai Chen <chenhc@lemote.com>
5  * Copyright (c) 2020 Jiaxun Yang <jiaxun.yang@flygoat.com>
6  *
7  * This program is free software: you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation, either version 2 of the License, or
10  * (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program. If not, see <https://www.gnu.org/licenses/>.
19  *
20  */
21 
22 #include "qemu/osdep.h"
23 #include "qemu/module.h"
24 #include "qemu/log.h"
25 #include "hw/irq.h"
26 #include "hw/qdev-properties.h"
27 #include "hw/intc/loongson_liointc.h"
28 
29 #define NUM_IRQS                32
30 
31 #define NUM_CORES               4
32 #define NUM_IPS                 4
33 #define NUM_PARENTS             (NUM_CORES * NUM_IPS)
34 #define PARENT_COREx_IPy(x, y)  (NUM_IPS * x + y)
35 
36 #define R_MAPPER_START          0x0
37 #define R_MAPPER_END            0x20
38 #define R_ISR                   R_MAPPER_END
39 #define R_IEN                   0x24
40 #define R_IEN_SET               0x28
41 #define R_IEN_CLR               0x2c
42 #define R_ISR_SIZE              0x8
43 #define R_START                 0x40
44 #define R_END                   0x64
45 
46 struct loongson_liointc {
47     SysBusDevice parent_obj;
48 
49     MemoryRegion mmio;
50     qemu_irq parent_irq[NUM_PARENTS];
51 
52     uint8_t mapper[NUM_IRQS]; /* 0:3 for core, 4:7 for IP */
53     uint32_t isr;
54     uint32_t ien;
55     uint32_t per_core_isr[NUM_CORES];
56 
57     /* state of the interrupt input pins */
58     uint32_t pin_state;
59     bool parent_state[NUM_PARENTS];
60 };
61 
62 static void update_irq(struct loongson_liointc *p)
63 {
64     uint32_t irq, core, ip;
65     uint32_t per_ip_isr[NUM_IPS] = {0};
66 
67     /* level triggered interrupt */
68     p->isr = p->pin_state;
69 
70     /* Clear disabled IRQs */
71     p->isr &= p->ien;
72 
73     /* Clear per_core_isr */
74     for (core = 0; core < NUM_CORES; core++) {
75         p->per_core_isr[core] = 0;
76     }
77 
78     /* Update per_core_isr and per_ip_isr */
79     for (irq = 0; irq < NUM_IRQS; irq++) {
80         if (!(p->isr & (1 << irq))) {
81             continue;
82         }
83 
84         for (core = 0; core < NUM_CORES; core++) {
85             if ((p->mapper[irq] & (1 << core))) {
86                 p->per_core_isr[core] |= (1 << irq);
87             }
88         }
89 
90         for (ip = 0; ip < NUM_IPS; ip++) {
91             if ((p->mapper[irq] & (1 << (ip + 4)))) {
92                 per_ip_isr[ip] |= (1 << irq);
93             }
94         }
95     }
96 
97     /* Emit IRQ to parent! */
98     for (core = 0; core < NUM_CORES; core++) {
99         for (ip = 0; ip < NUM_IPS; ip++) {
100             int parent = PARENT_COREx_IPy(core, ip);
101             if (p->parent_state[parent] !=
102                 (!!p->per_core_isr[core] && !!per_ip_isr[ip])) {
103                 p->parent_state[parent] = !p->parent_state[parent];
104                 qemu_set_irq(p->parent_irq[parent], p->parent_state[parent]);
105             }
106         }
107     }
108 }
109 
110 static uint64_t
111 liointc_read(void *opaque, hwaddr addr, unsigned int size)
112 {
113     struct loongson_liointc *p = opaque;
114     uint32_t r = 0;
115 
116     /* Mapper is 1 byte */
117     if (size == 1 && addr < R_MAPPER_END) {
118         r = p->mapper[addr];
119         goto out;
120     }
121 
122     /* Rest are 4 bytes */
123     if (size != 4 || (addr % 4)) {
124         goto out;
125     }
126 
127     if (addr >= R_START && addr < R_END) {
128         int core = (addr - R_START) / R_ISR_SIZE;
129         r = p->per_core_isr[core];
130         goto out;
131     }
132 
133     switch (addr) {
134     case R_ISR:
135         r = p->isr;
136         break;
137     case R_IEN:
138         r = p->ien;
139         break;
140     default:
141         break;
142     }
143 
144 out:
145     qemu_log_mask(CPU_LOG_INT, "%s: size=%d, addr=%"HWADDR_PRIx", val=%x\n",
146                   __func__, size, addr, r);
147     return r;
148 }
149 
150 static void
151 liointc_write(void *opaque, hwaddr addr,
152           uint64_t val64, unsigned int size)
153 {
154     struct loongson_liointc *p = opaque;
155     uint32_t value = val64;
156 
157     qemu_log_mask(CPU_LOG_INT, "%s: size=%d, addr=%"HWADDR_PRIx", val=%x\n",
158                   __func__, size, addr, value);
159 
160     /* Mapper is 1 byte */
161     if (size == 1 && addr < R_MAPPER_END) {
162         p->mapper[addr] = value;
163         goto out;
164     }
165 
166     /* Rest are 4 bytes */
167     if (size != 4 || (addr % 4)) {
168         goto out;
169     }
170 
171     if (addr >= R_START && addr < R_END) {
172         int core = (addr - R_START) / R_ISR_SIZE;
173         p->per_core_isr[core] = value;
174         goto out;
175     }
176 
177     switch (addr) {
178     case R_IEN_SET:
179         p->ien |= value;
180         break;
181     case R_IEN_CLR:
182         p->ien &= ~value;
183         break;
184     default:
185         break;
186     }
187 
188 out:
189     update_irq(p);
190 }
191 
192 static const MemoryRegionOps pic_ops = {
193     .read = liointc_read,
194     .write = liointc_write,
195     .endianness = DEVICE_NATIVE_ENDIAN,
196     .valid = {
197         .min_access_size = 1,
198         .max_access_size = 4
199     }
200 };
201 
202 static void irq_handler(void *opaque, int irq, int level)
203 {
204     struct loongson_liointc *p = opaque;
205 
206     p->pin_state &= ~(1 << irq);
207     p->pin_state |= level << irq;
208     update_irq(p);
209 }
210 
211 static void loongson_liointc_init(Object *obj)
212 {
213     struct loongson_liointc *p = LOONGSON_LIOINTC(obj);
214     int i;
215 
216     qdev_init_gpio_in(DEVICE(obj), irq_handler, 32);
217 
218     for (i = 0; i < NUM_PARENTS; i++) {
219         sysbus_init_irq(SYS_BUS_DEVICE(obj), &p->parent_irq[i]);
220     }
221 
222     memory_region_init_io(&p->mmio, obj, &pic_ops, p,
223                          TYPE_LOONGSON_LIOINTC, R_END);
224     sysbus_init_mmio(SYS_BUS_DEVICE(obj), &p->mmio);
225 }
226 
227 static const TypeInfo loongson_liointc_info = {
228     .name          = TYPE_LOONGSON_LIOINTC,
229     .parent        = TYPE_SYS_BUS_DEVICE,
230     .instance_size = sizeof(struct loongson_liointc),
231     .instance_init = loongson_liointc_init,
232 };
233 
234 static void loongson_liointc_register_types(void)
235 {
236     type_register_static(&loongson_liointc_info);
237 }
238 
239 type_init(loongson_liointc_register_types)
240