xref: /openbmc/qemu/hw/intc/loongson_liointc.c (revision b91a0fa7)
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                   (R_START + R_ISR_SIZE * NUM_CORES)
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         hwaddr offset = addr - R_START;
129         int core = offset / R_ISR_SIZE;
130 
131         if (offset % R_ISR_SIZE) {
132             goto out;
133         }
134         r = p->per_core_isr[core];
135         goto out;
136     }
137 
138     switch (addr) {
139     case R_ISR:
140         r = p->isr;
141         break;
142     case R_IEN:
143         r = p->ien;
144         break;
145     default:
146         break;
147     }
148 
149 out:
150     qemu_log_mask(CPU_LOG_INT, "%s: size=%d, addr=%"HWADDR_PRIx", val=%x\n",
151                   __func__, size, addr, r);
152     return r;
153 }
154 
155 static void
156 liointc_write(void *opaque, hwaddr addr,
157           uint64_t val64, unsigned int size)
158 {
159     struct loongson_liointc *p = opaque;
160     uint32_t value = val64;
161 
162     qemu_log_mask(CPU_LOG_INT, "%s: size=%d, addr=%"HWADDR_PRIx", val=%x\n",
163                   __func__, size, addr, value);
164 
165     /* Mapper is 1 byte */
166     if (size == 1 && addr < R_MAPPER_END) {
167         p->mapper[addr] = value;
168         goto out;
169     }
170 
171     /* Rest are 4 bytes */
172     if (size != 4 || (addr % 4)) {
173         goto out;
174     }
175 
176     if (addr >= R_START && addr < R_END) {
177         hwaddr offset = addr - R_START;
178         int core = offset / R_ISR_SIZE;
179 
180         if (offset % R_ISR_SIZE) {
181             goto out;
182         }
183         p->per_core_isr[core] = value;
184         goto out;
185     }
186 
187     switch (addr) {
188     case R_IEN_SET:
189         p->ien |= value;
190         break;
191     case R_IEN_CLR:
192         p->ien &= ~value;
193         break;
194     default:
195         break;
196     }
197 
198 out:
199     update_irq(p);
200 }
201 
202 static const MemoryRegionOps pic_ops = {
203     .read = liointc_read,
204     .write = liointc_write,
205     .endianness = DEVICE_NATIVE_ENDIAN,
206     .valid = {
207         .min_access_size = 1,
208         .max_access_size = 4
209     }
210 };
211 
212 static void irq_handler(void *opaque, int irq, int level)
213 {
214     struct loongson_liointc *p = opaque;
215 
216     p->pin_state &= ~(1 << irq);
217     p->pin_state |= level << irq;
218     update_irq(p);
219 }
220 
221 static void loongson_liointc_init(Object *obj)
222 {
223     struct loongson_liointc *p = LOONGSON_LIOINTC(obj);
224     int i;
225 
226     qdev_init_gpio_in(DEVICE(obj), irq_handler, 32);
227 
228     for (i = 0; i < NUM_PARENTS; i++) {
229         sysbus_init_irq(SYS_BUS_DEVICE(obj), &p->parent_irq[i]);
230     }
231 
232     memory_region_init_io(&p->mmio, obj, &pic_ops, p,
233                          TYPE_LOONGSON_LIOINTC, R_END);
234     sysbus_init_mmio(SYS_BUS_DEVICE(obj), &p->mmio);
235 }
236 
237 static const TypeInfo loongson_liointc_info = {
238     .name          = TYPE_LOONGSON_LIOINTC,
239     .parent        = TYPE_SYS_BUS_DEVICE,
240     .instance_size = sizeof(struct loongson_liointc),
241     .instance_init = loongson_liointc_init,
242 };
243 
244 static void loongson_liointc_register_types(void)
245 {
246     type_register_static(&loongson_liointc_info);
247 }
248 
249 type_init(loongson_liointc_register_types)
250