hw/intc/grlib_irqmp.c

   1 /*
   2  * QEMU GRLIB IRQMP Emulator
   3  *
   4  * (Extended interrupt not supported)
   5  *
   6  * SPDX-License-Identifier: MIT
   7  *
   8  * Copyright (c) 2010-2024 AdaCore
   9  *
  10  * Permission is hereby granted, free of charge, to any person obtaining a copy
  11  * of this software and associated documentation files (the "Software"), to deal
  12  * in the Software without restriction, including without limitation the rights
  13  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  14  * copies of the Software, and to permit persons to whom the Software is
  15  * furnished to do so, subject to the following conditions:
  16  *
  17  * The above copyright notice and this permission notice shall be included in
  18  * all copies or substantial portions of the Software.
  19  *
  20  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  21  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  23  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  24  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  25  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  26  * THE SOFTWARE.
  27  */
  28
  29 #include "qemu/osdep.h"
  30 #include "hw/irq.h"
  31 #include "hw/sysbus.h"
  32
  33 #include "hw/qdev-properties.h"
  34 #include "hw/intc/grlib_irqmp.h"
  35
  36 #include "trace.h"
  37 #include "qapi/error.h"
  38 #include "qemu/module.h"
  39 #include "qom/object.h"
  40
  41 #define IRQMP_MAX_CPU 16
  42 #define IRQMP_REG_SIZE 256      /* Size of memory mapped registers */
  43
  44 /* Memory mapped register offsets */
  45 #define LEVEL_OFFSET     0x00
  46 #define PENDING_OFFSET   0x04
  47 #define FORCE0_OFFSET    0x08
  48 #define CLEAR_OFFSET     0x0C
  49 #define MP_STATUS_OFFSET 0x10
  50 #define BROADCAST_OFFSET 0x14
  51 #define MASK_OFFSET      0x40
  52 #define FORCE_OFFSET     0x80
  53 #define EXTENDED_OFFSET  0xC0
  54
  55 /* Multiprocessor Status Register  */
  56 #define MP_STATUS_CPU_STATUS_MASK ((1 << IRQMP_MAX_CPU)-2)
  57 #define MP_STATUS_NCPU_SHIFT      28
  58
  59 #define MAX_PILS 16
  60
  61 OBJECT_DECLARE_SIMPLE_TYPE(IRQMP, GRLIB_IRQMP)
  62
  63 typedef struct IRQMPState IRQMPState;
  64
  65 struct IRQMP {
  66     SysBusDevice parent_obj;
  67
  68     MemoryRegion iomem;
  69
  70     unsigned int ncpus;
  71     IRQMPState *state;
  72     qemu_irq start_signal[IRQMP_MAX_CPU];
  73     qemu_irq irq[IRQMP_MAX_CPU];
  74 };
  75
  76 struct IRQMPState {
  77     uint32_t level;
  78     uint32_t pending;
  79     uint32_t clear;
  80     uint32_t mpstatus;
  81     uint32_t broadcast;
  82
  83     uint32_t mask[IRQMP_MAX_CPU];
  84     uint32_t force[IRQMP_MAX_CPU];
  85     uint32_t extended[IRQMP_MAX_CPU];
  86
  87     IRQMP    *parent;
  88 };
  89
  90 static void grlib_irqmp_check_irqs(IRQMPState *state)
  91 {
  92     int i;
  93
  94     assert(state != NULL);
  95     assert(state->parent != NULL);
  96
  97     for (i = 0; i < state->parent->ncpus; i++) {
  98         uint32_t pend = (state->pending | state->force[i]) & state->mask[i];
  99         uint32_t level0 = pend & ~state->level;
 100         uint32_t level1 = pend &  state->level;
 101
 102         trace_grlib_irqmp_check_irqs(state->pending, state->force[i],
 103                                      state->mask[i], level1, level0);
 104
 105         /* Trigger level1 interrupt first and level0 if there is no level1 */
 106         qemu_set_irq(state->parent->irq[i], level1 ?: level0);
 107     }
 108 }
 109
 110 static void grlib_irqmp_ack_mask(IRQMPState *state, unsigned int cpu,
 111                                  uint32_t mask)
 112 {
 113     /* Clear registers */
 114     state->pending  &= ~mask;
 115     state->force[cpu] &= ~mask;
 116
 117     grlib_irqmp_check_irqs(state);
 118 }
 119
 120 void grlib_irqmp_ack(DeviceState *dev, unsigned int cpu, int intno)
 121 {
 122     IRQMP        *irqmp = GRLIB_IRQMP(dev);
 123     IRQMPState   *state;
 124     uint32_t      mask;
 125
 126     state = irqmp->state;
 127     assert(state != NULL);
 128
 129     intno &= 15;
 130     mask = 1 << intno;
 131
 132     trace_grlib_irqmp_ack(intno);
 133
 134     grlib_irqmp_ack_mask(state, cpu, mask);
 135 }
 136
 137 static void grlib_irqmp_set_irq(void *opaque, int irq, int level)
 138 {
 139     IRQMP      *irqmp = GRLIB_IRQMP(opaque);
 140     IRQMPState *s;
 141     int         i = 0;
 142
 143     s = irqmp->state;
 144     assert(s         != NULL);
 145     assert(s->parent != NULL);
 146
 147
 148     if (level) {
 149         trace_grlib_irqmp_set_irq(irq);
 150
 151         if (s->broadcast & 1 << irq) {
 152             /* Broadcasted IRQ */
 153             for (i = 0; i < IRQMP_MAX_CPU; i++) {
 154                 s->force[i] |= 1 << irq;
 155             }
 156         } else {
 157             s->pending |= 1 << irq;
 158         }
 159         grlib_irqmp_check_irqs(s);
 160     }
 161 }
 162
 163 static uint64_t grlib_irqmp_read(void *opaque, hwaddr addr,
 164                                  unsigned size)
 165 {
 166     IRQMP      *irqmp = opaque;
 167     IRQMPState *state;
 168
 169     assert(irqmp != NULL);
 170     state = irqmp->state;
 171     assert(state != NULL);
 172
 173     addr &= 0xff;
 174
 175     /* global registers */
 176     switch (addr) {
 177     case LEVEL_OFFSET:
 178         return state->level;
 179
 180     case PENDING_OFFSET:
 181         return state->pending;
 182
 183     case FORCE0_OFFSET:
 184         /* This register is an "alias" for the force register of CPU 0 */
 185         return state->force[0];
 186
 187     case CLEAR_OFFSET:
 188         /* Always read as 0 */
 189         return 0;
 190
 191     case MP_STATUS_OFFSET:
 192         return state->mpstatus;
 193
 194     case BROADCAST_OFFSET:
 195         return state->broadcast;
 196
 197     default:
 198         break;
 199     }
 200
 201     /* mask registers */
 202     if (addr >= MASK_OFFSET && addr < FORCE_OFFSET) {
 203         int cpu = (addr - MASK_OFFSET) / 4;
 204         assert(cpu >= 0 && cpu < IRQMP_MAX_CPU);
 205
 206         return state->mask[cpu];
 207     }
 208
 209     /* force registers */
 210     if (addr >= FORCE_OFFSET && addr < EXTENDED_OFFSET) {
 211         int cpu = (addr - FORCE_OFFSET) / 4;
 212         assert(cpu >= 0 && cpu < IRQMP_MAX_CPU);
 213
 214         return state->force[cpu];
 215     }
 216
 217     /* extended (not supported) */
 218     if (addr >= EXTENDED_OFFSET && addr < IRQMP_REG_SIZE) {
 219         int cpu = (addr - EXTENDED_OFFSET) / 4;
 220         assert(cpu >= 0 && cpu < IRQMP_MAX_CPU);
 221
 222         return state->extended[cpu];
 223     }
 224
 225     trace_grlib_irqmp_readl_unknown(addr);
 226     return 0;
 227 }
 228
 229 static void grlib_irqmp_write(void *opaque, hwaddr addr,
 230                               uint64_t value, unsigned size)
 231 {
 232     IRQMP *irqmp = opaque;
 233     IRQMPState *state;
 234     int i;
 235
 236     assert(irqmp != NULL);
 237     state = irqmp->state;
 238     assert(state != NULL);
 239
 240     addr &= 0xff;
 241
 242     /* global registers */
 243     switch (addr) {
 244     case LEVEL_OFFSET:
 245         value &= 0xFFFF << 1; /* clean up the value */
 246         state->level = value;
 247         return;
 248
 249     case PENDING_OFFSET:
 250         /* Read Only */
 251         return;
 252
 253     case FORCE0_OFFSET:
 254         /* This register is an "alias" for the force register of CPU 0 */
 255
 256         value &= 0xFFFE; /* clean up the value */
 257         state->force[0] = value;
 258         grlib_irqmp_check_irqs(irqmp->state);
 259         return;
 260
 261     case CLEAR_OFFSET:
 262         value &= ~1; /* clean up the value */
 263         for (i = 0; i < irqmp->ncpus; i++) {
 264             grlib_irqmp_ack_mask(state, i, value);
 265         }
 266         return;
 267
 268     case MP_STATUS_OFFSET:
 269         /*
 270          * Writing and reading operations are reversed for the CPU status.
 271          * Writing "1" will start the CPU, but reading "1" means that the CPU
 272          * is power-down.
 273          */
 274         value &= MP_STATUS_CPU_STATUS_MASK;
 275         for (i = 0; i < irqmp->ncpus; i++) {
 276             if ((value >> i) & 1) {
 277                 qemu_set_irq(irqmp->start_signal[i], 1);
 278                 state->mpstatus &= ~(1 << i);
 279             }
 280         }
 281         return;
 282
 283     case BROADCAST_OFFSET:
 284         value &= 0xFFFE; /* clean up the value */
 285         state->broadcast = value;
 286         return;
 287
 288     default:
 289         break;
 290     }
 291
 292     /* mask registers */
 293     if (addr >= MASK_OFFSET && addr < FORCE_OFFSET) {
 294         int cpu = (addr - MASK_OFFSET) / 4;
 295         assert(cpu >= 0 && cpu < IRQMP_MAX_CPU);
 296
 297         value &= ~1; /* clean up the value */
 298         state->mask[cpu] = value;
 299         grlib_irqmp_check_irqs(irqmp->state);
 300         return;
 301     }
 302
 303     /* force registers */
 304     if (addr >= FORCE_OFFSET && addr < EXTENDED_OFFSET) {
 305         int cpu = (addr - FORCE_OFFSET) / 4;
 306         assert(cpu >= 0 && cpu < IRQMP_MAX_CPU);
 307
 308         uint32_t force = value & 0xFFFE;
 309         uint32_t clear = (value >> 16) & 0xFFFE;
 310         uint32_t old   = state->force[cpu];
 311
 312         state->force[cpu] = (old | force) & ~clear;
 313         grlib_irqmp_check_irqs(irqmp->state);
 314         return;
 315     }
 316
 317     /* extended (not supported) */
 318     if (addr >= EXTENDED_OFFSET && addr < IRQMP_REG_SIZE) {
 319         int cpu = (addr - EXTENDED_OFFSET) / 4;
 320         assert(cpu >= 0 && cpu < IRQMP_MAX_CPU);
 321
 322         value &= 0xF; /* clean up the value */
 323         state->extended[cpu] = value;
 324         return;
 325     }
 326
 327     trace_grlib_irqmp_writel_unknown(addr, value);
 328 }
 329
 330 static const MemoryRegionOps grlib_irqmp_ops = {
 331     .read = grlib_irqmp_read,
 332     .write = grlib_irqmp_write,
 333     .endianness = DEVICE_NATIVE_ENDIAN,
 334     .valid = {
 335         .min_access_size = 4,
 336         .max_access_size = 4,
 337     },
 338 };
 339
 340 static void grlib_irqmp_reset(DeviceState *d)
 341 {
 342     IRQMP *irqmp = GRLIB_IRQMP(d);
 343     assert(irqmp->state != NULL);
 344
 345     memset(irqmp->state, 0, sizeof *irqmp->state);
 346     irqmp->state->parent = irqmp;
 347     irqmp->state->mpstatus = ((irqmp->ncpus - 1) << MP_STATUS_NCPU_SHIFT) |
 348         ((1 << irqmp->ncpus) - 2);
 349 }
 350
 351 static void grlib_irqmp_realize(DeviceState *dev, Error **errp)
 352 {
 353     IRQMP *irqmp = GRLIB_IRQMP(dev);
 354
 355     if ((!irqmp->ncpus) || (irqmp->ncpus > IRQMP_MAX_CPU)) {
 356         error_setg(errp, "Invalid ncpus properties: "
 357                    "%u, must be 0 < ncpus =< %u.", irqmp->ncpus,
 358                    IRQMP_MAX_CPU);
 359         return;
 360     }
 361
 362     qdev_init_gpio_in(dev, grlib_irqmp_set_irq, MAX_PILS);
 363
 364     /*
 365      * Transitionning from 0 to 1 starts the CPUs. The opposite can't
 366      * happen.
 367      */
 368     qdev_init_gpio_out_named(dev, irqmp->start_signal, "grlib-start-cpu",
 369                              IRQMP_MAX_CPU);
 370     qdev_init_gpio_out_named(dev, irqmp->irq, "grlib-irq", irqmp->ncpus);
 371     memory_region_init_io(&irqmp->iomem, OBJECT(dev), &grlib_irqmp_ops, irqmp,
 372                           "irqmp", IRQMP_REG_SIZE);
 373
 374     irqmp->state = g_malloc0(sizeof *irqmp->state);
 375
 376     sysbus_init_mmio(SYS_BUS_DEVICE(dev), &irqmp->iomem);
 377 }
 378
 379 static Property grlib_irqmp_properties[] = {
 380     DEFINE_PROP_UINT32("ncpus", IRQMP, ncpus, 1),
 381     DEFINE_PROP_END_OF_LIST(),
 382 };
 383
 384 static void grlib_irqmp_class_init(ObjectClass *klass, void *data)
 385 {
 386     DeviceClass *dc = DEVICE_CLASS(klass);
 387
 388     dc->realize = grlib_irqmp_realize;
 389     device_class_set_legacy_reset(dc, grlib_irqmp_reset);
 390     device_class_set_props(dc, grlib_irqmp_properties);
 391 }
 392
 393 static const TypeInfo grlib_irqmp_info = {
 394     .name          = TYPE_GRLIB_IRQMP,
 395     .parent        = TYPE_SYS_BUS_DEVICE,
 396     .instance_size = sizeof(IRQMP),
 397     .class_init    = grlib_irqmp_class_init,
 398 };
 399
 400 static void grlib_irqmp_register_types(void)
 401 {
 402     type_register_static(&grlib_irqmp_info);
 403 }
 404
 405 type_init(grlib_irqmp_register_types)