hw/riscv/sifive_plic.c

   1 /*
   2  * SiFive PLIC (Platform Level Interrupt Controller)
   3  *
   4  * Copyright (c) 2017 SiFive, Inc.
   5  *
   6  * This provides a parameterizable interrupt controller based on SiFive's PLIC.
   7  *
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms and conditions of the GNU General Public License,
  10  * version 2 or later, as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope it will be useful, but WITHOUT
  13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  15  * more details.
  16  *
  17  * You should have received a copy of the GNU General Public License along with
  18  * this program.  If not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include "qemu/osdep.h"
  22 #include "qemu/log.h"
  23 #include "qemu/error-report.h"
  24 #include "hw/sysbus.h"
  25 #include "target/riscv/cpu.h"
  26 #include "hw/riscv/sifive_plic.h"
  27
  28 #define RISCV_DEBUG_PLIC 0
  29
  30 static PLICMode char_to_mode(char c)
  31 {
  32     switch (c) {
  33     case 'U': return PLICMode_U;
  34     case 'S': return PLICMode_S;
  35     case 'H': return PLICMode_H;
  36     case 'M': return PLICMode_M;
  37     default:
  38         error_report("plic: invalid mode '%c'", c);
  39         exit(1);
  40     }
  41 }
  42
  43 static char mode_to_char(PLICMode m)
  44 {
  45     switch (m) {
  46     case PLICMode_U: return 'U';
  47     case PLICMode_S: return 'S';
  48     case PLICMode_H: return 'H';
  49     case PLICMode_M: return 'M';
  50     default: return '?';
  51     }
  52 }
  53
  54 static void sifive_plic_print_state(SiFivePLICState *plic)
  55 {
  56     int i;
  57     int addrid;
  58
  59     /* pending */
  60     qemu_log("pending       : ");
  61     for (i = plic->bitfield_words - 1; i >= 0; i--) {
  62         qemu_log("%08x", plic->pending[i]);
  63     }
  64     qemu_log("\n");
  65
  66     /* pending */
  67     qemu_log("claimed       : ");
  68     for (i = plic->bitfield_words - 1; i >= 0; i--) {
  69         qemu_log("%08x", plic->claimed[i]);
  70     }
  71     qemu_log("\n");
  72
  73     for (addrid = 0; addrid < plic->num_addrs; addrid++) {
  74         qemu_log("hart%d-%c enable: ",
  75             plic->addr_config[addrid].hartid,
  76             mode_to_char(plic->addr_config[addrid].mode));
  77         for (i = plic->bitfield_words - 1; i >= 0; i--) {
  78             qemu_log("%08x", plic->enable[addrid * plic->bitfield_words + i]);
  79         }
  80         qemu_log("\n");
  81     }
  82 }
  83
  84 static
  85 void sifive_plic_set_pending(SiFivePLICState *plic, int irq, bool pending)
  86 {
  87     qemu_mutex_lock(&plic->lock);
  88     uint32_t word = irq >> 5;
  89     if (pending) {
  90         plic->pending[word] |= (1 << (irq & 31));
  91     } else {
  92         plic->pending[word] &= ~(1 << (irq & 31));
  93     }
  94     qemu_mutex_unlock(&plic->lock);
  95 }
  96
  97 static
  98 void sifive_plic_set_claimed(SiFivePLICState *plic, int irq, bool claimed)
  99 {
 100     qemu_mutex_lock(&plic->lock);
 101     uint32_t word = irq >> 5;
 102     if (claimed) {
 103         plic->claimed[word] |= (1 << (irq & 31));
 104     } else {
 105         plic->claimed[word] &= ~(1 << (irq & 31));
 106     }
 107     qemu_mutex_unlock(&plic->lock);
 108 }
 109
 110 static
 111 int sifive_plic_num_irqs_pending(SiFivePLICState *plic, uint32_t addrid)
 112 {
 113     int i, j, count = 0;
 114     for (i = 0; i < plic->bitfield_words; i++) {
 115         uint32_t pending_enabled_not_claimed =
 116             (plic->pending[i] & ~plic->claimed[i]) &
 117             plic->enable[addrid * plic->bitfield_words + i];
 118         if (!pending_enabled_not_claimed) {
 119             continue;
 120         }
 121         for (j = 0; j < 32; j++) {
 122             int irq = (i << 5) + j;
 123             uint32_t prio = plic->source_priority[irq];
 124             int enabled = pending_enabled_not_claimed & (1 << j);
 125             if (enabled && prio > plic->target_priority[addrid]) {
 126                 count++;
 127             }
 128         }
 129     }
 130     return count;
 131 }
 132
 133 static void sifive_plic_update(SiFivePLICState *plic)
 134 {
 135     int addrid;
 136
 137     /* raise irq on harts where this irq is enabled */
 138     for (addrid = 0; addrid < plic->num_addrs; addrid++) {
 139         uint32_t hartid = plic->addr_config[addrid].hartid;
 140         PLICMode mode = plic->addr_config[addrid].mode;
 141         CPUState *cpu = qemu_get_cpu(hartid);
 142         CPURISCVState *env = cpu ? cpu->env_ptr : NULL;
 143         if (!env) {
 144             continue;
 145         }
 146         int level = sifive_plic_num_irqs_pending(plic, addrid) > 0;
 147         switch (mode) {
 148         case PLICMode_M:
 149             riscv_set_local_interrupt(RISCV_CPU(cpu), MIP_MEIP, level);
 150             break;
 151         case PLICMode_S:
 152             riscv_set_local_interrupt(RISCV_CPU(cpu), MIP_SEIP, level);
 153             break;
 154         default:
 155             break;
 156         }
 157     }
 158
 159     if (RISCV_DEBUG_PLIC) {
 160         sifive_plic_print_state(plic);
 161     }
 162 }
 163
 164 void sifive_plic_raise_irq(SiFivePLICState *plic, uint32_t irq)
 165 {
 166     sifive_plic_set_pending(plic, irq, true);
 167     sifive_plic_update(plic);
 168 }
 169
 170 void sifive_plic_lower_irq(SiFivePLICState *plic, uint32_t irq)
 171 {
 172     sifive_plic_set_pending(plic, irq, false);
 173     sifive_plic_update(plic);
 174 }
 175
 176 static uint32_t sifive_plic_claim(SiFivePLICState *plic, uint32_t addrid)
 177 {
 178     int i, j;
 179     for (i = 0; i < plic->bitfield_words; i++) {
 180         uint32_t pending_enabled_not_claimed =
 181             (plic->pending[i] & ~plic->claimed[i]) &
 182             plic->enable[addrid * plic->bitfield_words + i];
 183         if (!pending_enabled_not_claimed) {
 184             continue;
 185         }
 186         for (j = 0; j < 32; j++) {
 187             int irq = (i << 5) + j;
 188             uint32_t prio = plic->source_priority[irq];
 189             int enabled = pending_enabled_not_claimed & (1 << j);
 190             if (enabled && prio > plic->target_priority[addrid]) {
 191                 sifive_plic_set_pending(plic, irq, false);
 192                 sifive_plic_set_claimed(plic, irq, true);
 193                 return irq;
 194             }
 195         }
 196     }
 197     return 0;
 198 }
 199
 200 static uint64_t sifive_plic_read(void *opaque, hwaddr addr, unsigned size)
 201 {
 202     SiFivePLICState *plic = opaque;
 203
 204     /* writes must be 4 byte words */
 205     if ((addr & 0x3) != 0) {
 206         goto err;
 207     }
 208
 209     if (addr >= plic->priority_base && /* 4 bytes per source */
 210         addr < plic->priority_base + (plic->num_sources << 2))
 211     {
 212         uint32_t irq = (addr - plic->priority_base) >> 2;
 213         if (RISCV_DEBUG_PLIC) {
 214             qemu_log("plic: read priority: irq=%d priority=%d\n",
 215                 irq, plic->source_priority[irq]);
 216         }
 217         return plic->source_priority[irq];
 218     } else if (addr >= plic->pending_base && /* 1 bit per source */
 219                addr < plic->pending_base + (plic->num_sources >> 3))
 220     {
 221         uint32_t word = (addr - plic->priority_base) >> 2;
 222         if (RISCV_DEBUG_PLIC) {
 223             qemu_log("plic: read pending: word=%d value=%d\n",
 224                 word, plic->pending[word]);
 225         }
 226         return plic->pending[word];
 227     } else if (addr >= plic->enable_base && /* 1 bit per source */
 228              addr < plic->enable_base + plic->num_addrs * plic->enable_stride)
 229     {
 230         uint32_t addrid = (addr - plic->enable_base) / plic->enable_stride;
 231         uint32_t wordid = (addr & (plic->enable_stride - 1)) >> 2;
 232         if (wordid < plic->bitfield_words) {
 233             if (RISCV_DEBUG_PLIC) {
 234                 qemu_log("plic: read enable: hart%d-%c word=%d value=%x\n",
 235                     plic->addr_config[addrid].hartid,
 236                     mode_to_char(plic->addr_config[addrid].mode), wordid,
 237                     plic->enable[addrid * plic->bitfield_words + wordid]);
 238             }
 239             return plic->enable[addrid * plic->bitfield_words + wordid];
 240         }
 241     } else if (addr >= plic->context_base && /* 1 bit per source */
 242              addr < plic->context_base + plic->num_addrs * plic->context_stride)
 243     {
 244         uint32_t addrid = (addr - plic->context_base) / plic->context_stride;
 245         uint32_t contextid = (addr & (plic->context_stride - 1));
 246         if (contextid == 0) {
 247             if (RISCV_DEBUG_PLIC) {
 248                 qemu_log("plic: read priority: hart%d-%c priority=%x\n",
 249                     plic->addr_config[addrid].hartid,
 250                     mode_to_char(plic->addr_config[addrid].mode),
 251                     plic->target_priority[addrid]);
 252             }
 253             return plic->target_priority[addrid];
 254         } else if (contextid == 4) {
 255             uint32_t value = sifive_plic_claim(plic, addrid);
 256             if (RISCV_DEBUG_PLIC) {
 257                 qemu_log("plic: read claim: hart%d-%c irq=%x\n",
 258                     plic->addr_config[addrid].hartid,
 259                     mode_to_char(plic->addr_config[addrid].mode),
 260                     value);
 261                 sifive_plic_print_state(plic);
 262             }
 263             return value;
 264         }
 265     }
 266
 267 err:
 268     error_report("plic: invalid register read: %08x", (uint32_t)addr);
 269     return 0;
 270 }
 271
 272 static void sifive_plic_write(void *opaque, hwaddr addr, uint64_t value,
 273         unsigned size)
 274 {
 275     SiFivePLICState *plic = opaque;
 276
 277     /* writes must be 4 byte words */
 278     if ((addr & 0x3) != 0) {
 279         goto err;
 280     }
 281
 282     if (addr >= plic->priority_base && /* 4 bytes per source */
 283         addr < plic->priority_base + (plic->num_sources << 2))
 284     {
 285         uint32_t irq = (addr - plic->priority_base) >> 2;
 286         plic->source_priority[irq] = value & 7;
 287         if (RISCV_DEBUG_PLIC) {
 288             qemu_log("plic: write priority: irq=%d priority=%d\n",
 289                 irq, plic->source_priority[irq]);
 290         }
 291         return;
 292     } else if (addr >= plic->pending_base && /* 1 bit per source */
 293                addr < plic->pending_base + (plic->num_sources >> 3))
 294     {
 295         error_report("plic: invalid pending write: %08x", (uint32_t)addr);
 296         return;
 297     } else if (addr >= plic->enable_base && /* 1 bit per source */
 298         addr < plic->enable_base + plic->num_addrs * plic->enable_stride)
 299     {
 300         uint32_t addrid = (addr - plic->enable_base) / plic->enable_stride;
 301         uint32_t wordid = (addr & (plic->enable_stride - 1)) >> 2;
 302         if (wordid < plic->bitfield_words) {
 303             plic->enable[addrid * plic->bitfield_words + wordid] = value;
 304             if (RISCV_DEBUG_PLIC) {
 305                 qemu_log("plic: write enable: hart%d-%c word=%d value=%x\n",
 306                     plic->addr_config[addrid].hartid,
 307                     mode_to_char(plic->addr_config[addrid].mode), wordid,
 308                     plic->enable[addrid * plic->bitfield_words + wordid]);
 309             }
 310             return;
 311         }
 312     } else if (addr >= plic->context_base && /* 4 bytes per reg */
 313         addr < plic->context_base + plic->num_addrs * plic->context_stride)
 314     {
 315         uint32_t addrid = (addr - plic->context_base) / plic->context_stride;
 316         uint32_t contextid = (addr & (plic->context_stride - 1));
 317         if (contextid == 0) {
 318             if (RISCV_DEBUG_PLIC) {
 319                 qemu_log("plic: write priority: hart%d-%c priority=%x\n",
 320                     plic->addr_config[addrid].hartid,
 321                     mode_to_char(plic->addr_config[addrid].mode),
 322                     plic->target_priority[addrid]);
 323             }
 324             if (value <= plic->num_priorities) {
 325                 plic->target_priority[addrid] = value;
 326                 sifive_plic_update(plic);
 327             }
 328             return;
 329         } else if (contextid == 4) {
 330             if (RISCV_DEBUG_PLIC) {
 331                 qemu_log("plic: write claim: hart%d-%c irq=%x\n",
 332                     plic->addr_config[addrid].hartid,
 333                     mode_to_char(plic->addr_config[addrid].mode),
 334                     (uint32_t)value);
 335             }
 336             if (value < plic->num_sources) {
 337                 sifive_plic_set_claimed(plic, value, false);
 338                 sifive_plic_update(plic);
 339             }
 340             return;
 341         }
 342     }
 343
 344 err:
 345     error_report("plic: invalid register write: %08x", (uint32_t)addr);
 346 }
 347
 348 static const MemoryRegionOps sifive_plic_ops = {
 349     .read = sifive_plic_read,
 350     .write = sifive_plic_write,
 351     .endianness = DEVICE_LITTLE_ENDIAN,
 352     .valid = {
 353         .min_access_size = 4,
 354         .max_access_size = 4
 355     }
 356 };
 357
 358 static Property sifive_plic_properties[] = {
 359     DEFINE_PROP_STRING("hart-config", SiFivePLICState, hart_config),
 360     DEFINE_PROP_UINT32("num-sources", SiFivePLICState, num_sources, 0),
 361     DEFINE_PROP_UINT32("num-priorities", SiFivePLICState, num_priorities, 0),
 362     DEFINE_PROP_UINT32("priority-base", SiFivePLICState, priority_base, 0),
 363     DEFINE_PROP_UINT32("pending-base", SiFivePLICState, pending_base, 0),
 364     DEFINE_PROP_UINT32("enable-base", SiFivePLICState, enable_base, 0),
 365     DEFINE_PROP_UINT32("enable-stride", SiFivePLICState, enable_stride, 0),
 366     DEFINE_PROP_UINT32("context-base", SiFivePLICState, context_base, 0),
 367     DEFINE_PROP_UINT32("context-stride", SiFivePLICState, context_stride, 0),
 368     DEFINE_PROP_UINT32("aperture-size", SiFivePLICState, aperture_size, 0),
 369     DEFINE_PROP_END_OF_LIST(),
 370 };
 371
 372 /*
 373  * parse PLIC hart/mode address offset config
 374  *
 375  * "M"              1 hart with M mode
 376  * "MS,MS"          2 harts, 0-1 with M and S mode
 377  * "M,MS,MS,MS,MS"  5 harts, 0 with M mode, 1-5 with M and S mode
 378  */
 379 static void parse_hart_config(SiFivePLICState *plic)
 380 {
 381     int addrid, hartid, modes;
 382     const char *p;
 383     char c;
 384
 385     /* count and validate hart/mode combinations */
 386     addrid = 0, hartid = 0, modes = 0;
 387     p = plic->hart_config;
 388     while ((c = *p++)) {
 389         if (c == ',') {
 390             addrid += __builtin_popcount(modes);
 391             modes = 0;
 392             hartid++;
 393         } else {
 394             int m = 1 << char_to_mode(c);
 395             if (modes == (modes | m)) {
 396                 error_report("plic: duplicate mode '%c' in config: %s",
 397                              c, plic->hart_config);
 398                 exit(1);
 399             }
 400             modes |= m;
 401         }
 402     }
 403     if (modes) {
 404         addrid += __builtin_popcount(modes);
 405     }
 406     hartid++;
 407
 408     /* store hart/mode combinations */
 409     plic->num_addrs = addrid;
 410     plic->addr_config = g_new(PLICAddr, plic->num_addrs);
 411     addrid = 0, hartid = 0;
 412     p = plic->hart_config;
 413     while ((c = *p++)) {
 414         if (c == ',') {
 415             hartid++;
 416         } else {
 417             plic->addr_config[addrid].addrid = addrid;
 418             plic->addr_config[addrid].hartid = hartid;
 419             plic->addr_config[addrid].mode = char_to_mode(c);
 420             addrid++;
 421         }
 422     }
 423 }
 424
 425 static void sifive_plic_irq_request(void *opaque, int irq, int level)
 426 {
 427     SiFivePLICState *plic = opaque;
 428     if (RISCV_DEBUG_PLIC) {
 429         qemu_log("sifive_plic_irq_request: irq=%d level=%d\n", irq, level);
 430     }
 431     sifive_plic_set_pending(plic, irq, level > 0);
 432     sifive_plic_update(plic);
 433 }
 434
 435 static void sifive_plic_realize(DeviceState *dev, Error **errp)
 436 {
 437     SiFivePLICState *plic = SIFIVE_PLIC(dev);
 438     int i;
 439
 440     memory_region_init_io(&plic->mmio, OBJECT(dev), &sifive_plic_ops, plic,
 441                           TYPE_SIFIVE_PLIC, plic->aperture_size);
 442     parse_hart_config(plic);
 443     qemu_mutex_init(&plic->lock);
 444     plic->bitfield_words = (plic->num_sources + 31) >> 5;
 445     plic->source_priority = g_new0(uint32_t, plic->num_sources);
 446     plic->target_priority = g_new(uint32_t, plic->num_addrs);
 447     plic->pending = g_new0(uint32_t, plic->bitfield_words);
 448     plic->claimed = g_new0(uint32_t, plic->bitfield_words);
 449     plic->enable = g_new0(uint32_t, plic->bitfield_words * plic->num_addrs);
 450     sysbus_init_mmio(SYS_BUS_DEVICE(dev), &plic->mmio);
 451     plic->irqs = g_new0(qemu_irq, plic->num_sources + 1);
 452     for (i = 0; i <= plic->num_sources; i++) {
 453         plic->irqs[i] = qemu_allocate_irq(sifive_plic_irq_request, plic, i);
 454     }
 455 }
 456
 457 static void sifive_plic_class_init(ObjectClass *klass, void *data)
 458 {
 459     DeviceClass *dc = DEVICE_CLASS(klass);
 460
 461     dc->props = sifive_plic_properties;
 462     dc->realize = sifive_plic_realize;
 463 }
 464
 465 static const TypeInfo sifive_plic_info = {
 466     .name          = TYPE_SIFIVE_PLIC,
 467     .parent        = TYPE_SYS_BUS_DEVICE,
 468     .instance_size = sizeof(SiFivePLICState),
 469     .class_init    = sifive_plic_class_init,
 470 };
 471
 472 static void sifive_plic_register_types(void)
 473 {
 474     type_register_static(&sifive_plic_info);
 475 }
 476
 477 type_init(sifive_plic_register_types)
 478
 479 /*
 480  * Create PLIC device.
 481  */
 482 DeviceState *sifive_plic_create(hwaddr addr, char *hart_config,
 483     uint32_t num_sources, uint32_t num_priorities,
 484     uint32_t priority_base, uint32_t pending_base,
 485     uint32_t enable_base, uint32_t enable_stride,
 486     uint32_t context_base, uint32_t context_stride,
 487     uint32_t aperture_size)
 488 {
 489     DeviceState *dev = qdev_create(NULL, TYPE_SIFIVE_PLIC);
 490     assert(enable_stride == (enable_stride & -enable_stride));
 491     assert(context_stride == (context_stride & -context_stride));
 492     qdev_prop_set_string(dev, "hart-config", hart_config);
 493     qdev_prop_set_uint32(dev, "num-sources", num_sources);
 494     qdev_prop_set_uint32(dev, "num-priorities", num_priorities);
 495     qdev_prop_set_uint32(dev, "priority-base", priority_base);
 496     qdev_prop_set_uint32(dev, "pending-base", pending_base);
 497     qdev_prop_set_uint32(dev, "enable-base", enable_base);
 498     qdev_prop_set_uint32(dev, "enable-stride", enable_stride);
 499     qdev_prop_set_uint32(dev, "context-base", context_base);
 500     qdev_prop_set_uint32(dev, "context-stride", context_stride);
 501     qdev_prop_set_uint32(dev, "aperture-size", aperture_size);
 502     qdev_init_nofail(dev);
 503     sysbus_mmio_map(SYS_BUS_DEVICE(dev), 0, addr);
 504     return dev;
 505 }