hw/intc/loongson_liointc.c

   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)