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 "qapi/error.h" 23 #include "qemu/log.h" 24 #include "qemu/module.h" 25 #include "qemu/error-report.h" 26 #include "hw/sysbus.h" 27 #include "hw/pci/msi.h" 28 #include "hw/qdev-properties.h" 29 #include "hw/intc/sifive_plic.h" 30 #include "target/riscv/cpu.h" 31 #include "migration/vmstate.h" 32 #include "hw/irq.h" 33 34 #define RISCV_DEBUG_PLIC 0 35 36 static PLICMode char_to_mode(char c) 37 { 38 switch (c) { 39 case 'U': return PLICMode_U; 40 case 'S': return PLICMode_S; 41 case 'H': return PLICMode_H; 42 case 'M': return PLICMode_M; 43 default: 44 error_report("plic: invalid mode '%c'", c); 45 exit(1); 46 } 47 } 48 49 static char mode_to_char(PLICMode m) 50 { 51 switch (m) { 52 case PLICMode_U: return 'U'; 53 case PLICMode_S: return 'S'; 54 case PLICMode_H: return 'H'; 55 case PLICMode_M: return 'M'; 56 default: return '?'; 57 } 58 } 59 60 static void sifive_plic_print_state(SiFivePLICState *plic) 61 { 62 int i; 63 int addrid; 64 65 /* pending */ 66 qemu_log("pending : "); 67 for (i = plic->bitfield_words - 1; i >= 0; i--) { 68 qemu_log("%08x", plic->pending[i]); 69 } 70 qemu_log("\n"); 71 72 /* pending */ 73 qemu_log("claimed : "); 74 for (i = plic->bitfield_words - 1; i >= 0; i--) { 75 qemu_log("%08x", plic->claimed[i]); 76 } 77 qemu_log("\n"); 78 79 for (addrid = 0; addrid < plic->num_addrs; addrid++) { 80 qemu_log("hart%d-%c enable: ", 81 plic->addr_config[addrid].hartid, 82 mode_to_char(plic->addr_config[addrid].mode)); 83 for (i = plic->bitfield_words - 1; i >= 0; i--) { 84 qemu_log("%08x", plic->enable[addrid * plic->bitfield_words + i]); 85 } 86 qemu_log("\n"); 87 } 88 } 89 90 static uint32_t atomic_set_masked(uint32_t *a, uint32_t mask, uint32_t value) 91 { 92 uint32_t old, new, cmp = qatomic_read(a); 93 94 do { 95 old = cmp; 96 new = (old & ~mask) | (value & mask); 97 cmp = qatomic_cmpxchg(a, old, new); 98 } while (old != cmp); 99 100 return old; 101 } 102 103 static void sifive_plic_set_pending(SiFivePLICState *plic, int irq, bool level) 104 { 105 atomic_set_masked(&plic->pending[irq >> 5], 1 << (irq & 31), -!!level); 106 } 107 108 static void sifive_plic_set_claimed(SiFivePLICState *plic, int irq, bool level) 109 { 110 atomic_set_masked(&plic->claimed[irq >> 5], 1 << (irq & 31), -!!level); 111 } 112 113 static int sifive_plic_irqs_pending(SiFivePLICState *plic, uint32_t addrid) 114 { 115 int i, j; 116 for (i = 0; i < plic->bitfield_words; i++) { 117 uint32_t pending_enabled_not_claimed = 118 (plic->pending[i] & ~plic->claimed[i]) & 119 plic->enable[addrid * plic->bitfield_words + i]; 120 if (!pending_enabled_not_claimed) { 121 continue; 122 } 123 for (j = 0; j < 32; j++) { 124 int irq = (i << 5) + j; 125 uint32_t prio = plic->source_priority[irq]; 126 int enabled = pending_enabled_not_claimed & (1 << j); 127 if (enabled && prio > plic->target_priority[addrid]) { 128 return 1; 129 } 130 } 131 } 132 return 0; 133 } 134 135 static void sifive_plic_update(SiFivePLICState *plic) 136 { 137 int addrid; 138 139 /* raise irq on harts where this irq is enabled */ 140 for (addrid = 0; addrid < plic->num_addrs; addrid++) { 141 uint32_t hartid = plic->addr_config[addrid].hartid; 142 PLICMode mode = plic->addr_config[addrid].mode; 143 int level = sifive_plic_irqs_pending(plic, addrid); 144 145 switch (mode) { 146 case PLICMode_M: 147 qemu_set_irq(plic->m_external_irqs[hartid - plic->hartid_base], level); 148 break; 149 case PLICMode_S: 150 qemu_set_irq(plic->s_external_irqs[hartid - plic->hartid_base], level); 151 break; 152 default: 153 break; 154 } 155 } 156 157 if (RISCV_DEBUG_PLIC) { 158 sifive_plic_print_state(plic); 159 } 160 } 161 162 static uint32_t sifive_plic_claim(SiFivePLICState *plic, uint32_t addrid) 163 { 164 int i, j; 165 uint32_t max_irq = 0; 166 uint32_t max_prio = plic->target_priority[addrid]; 167 168 for (i = 0; i < plic->bitfield_words; i++) { 169 uint32_t pending_enabled_not_claimed = 170 (plic->pending[i] & ~plic->claimed[i]) & 171 plic->enable[addrid * plic->bitfield_words + i]; 172 if (!pending_enabled_not_claimed) { 173 continue; 174 } 175 for (j = 0; j < 32; j++) { 176 int irq = (i << 5) + j; 177 uint32_t prio = plic->source_priority[irq]; 178 int enabled = pending_enabled_not_claimed & (1 << j); 179 if (enabled && prio > max_prio) { 180 max_irq = irq; 181 max_prio = prio; 182 } 183 } 184 } 185 186 if (max_irq) { 187 sifive_plic_set_pending(plic, max_irq, false); 188 sifive_plic_set_claimed(plic, max_irq, true); 189 } 190 return max_irq; 191 } 192 193 static uint64_t sifive_plic_read(void *opaque, hwaddr addr, unsigned size) 194 { 195 SiFivePLICState *plic = opaque; 196 197 /* writes must be 4 byte words */ 198 if ((addr & 0x3) != 0) { 199 goto err; 200 } 201 202 if (addr >= plic->priority_base && /* 4 bytes per source */ 203 addr < plic->priority_base + (plic->num_sources << 2)) 204 { 205 uint32_t irq = ((addr - plic->priority_base) >> 2) + 1; 206 if (RISCV_DEBUG_PLIC) { 207 qemu_log("plic: read priority: irq=%d priority=%d\n", 208 irq, plic->source_priority[irq]); 209 } 210 return plic->source_priority[irq]; 211 } else if (addr >= plic->pending_base && /* 1 bit per source */ 212 addr < plic->pending_base + (plic->num_sources >> 3)) 213 { 214 uint32_t word = (addr - plic->pending_base) >> 2; 215 if (RISCV_DEBUG_PLIC) { 216 qemu_log("plic: read pending: word=%d value=%d\n", 217 word, plic->pending[word]); 218 } 219 return plic->pending[word]; 220 } else if (addr >= plic->enable_base && /* 1 bit per source */ 221 addr < plic->enable_base + plic->num_addrs * plic->enable_stride) 222 { 223 uint32_t addrid = (addr - plic->enable_base) / plic->enable_stride; 224 uint32_t wordid = (addr & (plic->enable_stride - 1)) >> 2; 225 if (wordid < plic->bitfield_words) { 226 if (RISCV_DEBUG_PLIC) { 227 qemu_log("plic: read enable: hart%d-%c word=%d value=%x\n", 228 plic->addr_config[addrid].hartid, 229 mode_to_char(plic->addr_config[addrid].mode), wordid, 230 plic->enable[addrid * plic->bitfield_words + wordid]); 231 } 232 return plic->enable[addrid * plic->bitfield_words + wordid]; 233 } 234 } else if (addr >= plic->context_base && /* 1 bit per source */ 235 addr < plic->context_base + plic->num_addrs * plic->context_stride) 236 { 237 uint32_t addrid = (addr - plic->context_base) / plic->context_stride; 238 uint32_t contextid = (addr & (plic->context_stride - 1)); 239 if (contextid == 0) { 240 if (RISCV_DEBUG_PLIC) { 241 qemu_log("plic: read priority: hart%d-%c priority=%x\n", 242 plic->addr_config[addrid].hartid, 243 mode_to_char(plic->addr_config[addrid].mode), 244 plic->target_priority[addrid]); 245 } 246 return plic->target_priority[addrid]; 247 } else if (contextid == 4) { 248 uint32_t value = sifive_plic_claim(plic, addrid); 249 if (RISCV_DEBUG_PLIC) { 250 qemu_log("plic: read claim: hart%d-%c irq=%x\n", 251 plic->addr_config[addrid].hartid, 252 mode_to_char(plic->addr_config[addrid].mode), 253 value); 254 } 255 sifive_plic_update(plic); 256 return value; 257 } 258 } 259 260 err: 261 qemu_log_mask(LOG_GUEST_ERROR, 262 "%s: Invalid register read 0x%" HWADDR_PRIx "\n", 263 __func__, addr); 264 return 0; 265 } 266 267 static void sifive_plic_write(void *opaque, hwaddr addr, uint64_t value, 268 unsigned size) 269 { 270 SiFivePLICState *plic = opaque; 271 272 /* writes must be 4 byte words */ 273 if ((addr & 0x3) != 0) { 274 goto err; 275 } 276 277 if (addr >= plic->priority_base && /* 4 bytes per source */ 278 addr < plic->priority_base + (plic->num_sources << 2)) 279 { 280 uint32_t irq = ((addr - plic->priority_base) >> 2) + 1; 281 plic->source_priority[irq] = value & 7; 282 if (RISCV_DEBUG_PLIC) { 283 qemu_log("plic: write priority: irq=%d priority=%d\n", 284 irq, plic->source_priority[irq]); 285 } 286 sifive_plic_update(plic); 287 return; 288 } else if (addr >= plic->pending_base && /* 1 bit per source */ 289 addr < plic->pending_base + (plic->num_sources >> 3)) 290 { 291 qemu_log_mask(LOG_GUEST_ERROR, 292 "%s: invalid pending write: 0x%" HWADDR_PRIx "", 293 __func__, addr); 294 return; 295 } else if (addr >= plic->enable_base && /* 1 bit per source */ 296 addr < plic->enable_base + plic->num_addrs * plic->enable_stride) 297 { 298 uint32_t addrid = (addr - plic->enable_base) / plic->enable_stride; 299 uint32_t wordid = (addr & (plic->enable_stride - 1)) >> 2; 300 if (wordid < plic->bitfield_words) { 301 plic->enable[addrid * plic->bitfield_words + wordid] = value; 302 if (RISCV_DEBUG_PLIC) { 303 qemu_log("plic: write enable: hart%d-%c word=%d value=%x\n", 304 plic->addr_config[addrid].hartid, 305 mode_to_char(plic->addr_config[addrid].mode), wordid, 306 plic->enable[addrid * plic->bitfield_words + wordid]); 307 } 308 return; 309 } 310 } else if (addr >= plic->context_base && /* 4 bytes per reg */ 311 addr < plic->context_base + plic->num_addrs * plic->context_stride) 312 { 313 uint32_t addrid = (addr - plic->context_base) / plic->context_stride; 314 uint32_t contextid = (addr & (plic->context_stride - 1)); 315 if (contextid == 0) { 316 if (RISCV_DEBUG_PLIC) { 317 qemu_log("plic: write priority: hart%d-%c priority=%x\n", 318 plic->addr_config[addrid].hartid, 319 mode_to_char(plic->addr_config[addrid].mode), 320 plic->target_priority[addrid]); 321 } 322 if (value <= plic->num_priorities) { 323 plic->target_priority[addrid] = value; 324 sifive_plic_update(plic); 325 } 326 return; 327 } else if (contextid == 4) { 328 if (RISCV_DEBUG_PLIC) { 329 qemu_log("plic: write claim: hart%d-%c irq=%x\n", 330 plic->addr_config[addrid].hartid, 331 mode_to_char(plic->addr_config[addrid].mode), 332 (uint32_t)value); 333 } 334 if (value < plic->num_sources) { 335 sifive_plic_set_claimed(plic, value, false); 336 sifive_plic_update(plic); 337 } 338 return; 339 } 340 } 341 342 err: 343 qemu_log_mask(LOG_GUEST_ERROR, 344 "%s: Invalid register write 0x%" HWADDR_PRIx "\n", 345 __func__, 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("hartid-base", SiFivePLICState, hartid_base, 0), 361 DEFINE_PROP_UINT32("num-sources", SiFivePLICState, num_sources, 0), 362 DEFINE_PROP_UINT32("num-priorities", SiFivePLICState, num_priorities, 0), 363 DEFINE_PROP_UINT32("priority-base", SiFivePLICState, priority_base, 0), 364 DEFINE_PROP_UINT32("pending-base", SiFivePLICState, pending_base, 0), 365 DEFINE_PROP_UINT32("enable-base", SiFivePLICState, enable_base, 0), 366 DEFINE_PROP_UINT32("enable-stride", SiFivePLICState, enable_stride, 0), 367 DEFINE_PROP_UINT32("context-base", SiFivePLICState, context_base, 0), 368 DEFINE_PROP_UINT32("context-stride", SiFivePLICState, context_stride, 0), 369 DEFINE_PROP_UINT32("aperture-size", SiFivePLICState, aperture_size, 0), 370 DEFINE_PROP_END_OF_LIST(), 371 }; 372 373 /* 374 * parse PLIC hart/mode address offset config 375 * 376 * "M" 1 hart with M mode 377 * "MS,MS" 2 harts, 0-1 with M and S mode 378 * "M,MS,MS,MS,MS" 5 harts, 0 with M mode, 1-5 with M and S mode 379 */ 380 static void parse_hart_config(SiFivePLICState *plic) 381 { 382 int addrid, hartid, modes; 383 const char *p; 384 char c; 385 386 /* count and validate hart/mode combinations */ 387 addrid = 0, hartid = 0, modes = 0; 388 p = plic->hart_config; 389 while ((c = *p++)) { 390 if (c == ',') { 391 addrid += ctpop8(modes); 392 modes = 0; 393 hartid++; 394 } else { 395 int m = 1 << char_to_mode(c); 396 if (modes == (modes | m)) { 397 error_report("plic: duplicate mode '%c' in config: %s", 398 c, plic->hart_config); 399 exit(1); 400 } 401 modes |= m; 402 } 403 } 404 if (modes) { 405 addrid += ctpop8(modes); 406 } 407 hartid++; 408 409 plic->num_addrs = addrid; 410 plic->num_harts = hartid; 411 412 /* store hart/mode combinations */ 413 plic->addr_config = g_new(PLICAddr, plic->num_addrs); 414 addrid = 0, hartid = plic->hartid_base; 415 p = plic->hart_config; 416 while ((c = *p++)) { 417 if (c == ',') { 418 hartid++; 419 } else { 420 plic->addr_config[addrid].addrid = addrid; 421 plic->addr_config[addrid].hartid = hartid; 422 plic->addr_config[addrid].mode = char_to_mode(c); 423 addrid++; 424 } 425 } 426 } 427 428 static void sifive_plic_irq_request(void *opaque, int irq, int level) 429 { 430 SiFivePLICState *plic = opaque; 431 if (RISCV_DEBUG_PLIC) { 432 qemu_log("sifive_plic_irq_request: irq=%d level=%d\n", irq, level); 433 } 434 sifive_plic_set_pending(plic, irq, level > 0); 435 sifive_plic_update(plic); 436 } 437 438 static void sifive_plic_realize(DeviceState *dev, Error **errp) 439 { 440 SiFivePLICState *plic = SIFIVE_PLIC(dev); 441 int i; 442 443 memory_region_init_io(&plic->mmio, OBJECT(dev), &sifive_plic_ops, plic, 444 TYPE_SIFIVE_PLIC, plic->aperture_size); 445 parse_hart_config(plic); 446 plic->bitfield_words = (plic->num_sources + 31) >> 5; 447 plic->num_enables = plic->bitfield_words * plic->num_addrs; 448 plic->source_priority = g_new0(uint32_t, plic->num_sources); 449 plic->target_priority = g_new(uint32_t, plic->num_addrs); 450 plic->pending = g_new0(uint32_t, plic->bitfield_words); 451 plic->claimed = g_new0(uint32_t, plic->bitfield_words); 452 plic->enable = g_new0(uint32_t, plic->num_enables); 453 sysbus_init_mmio(SYS_BUS_DEVICE(dev), &plic->mmio); 454 qdev_init_gpio_in(dev, sifive_plic_irq_request, plic->num_sources); 455 456 plic->s_external_irqs = g_malloc(sizeof(qemu_irq) * plic->num_harts); 457 qdev_init_gpio_out(dev, plic->s_external_irqs, plic->num_harts); 458 459 plic->m_external_irqs = g_malloc(sizeof(qemu_irq) * plic->num_harts); 460 qdev_init_gpio_out(dev, plic->m_external_irqs, plic->num_harts); 461 462 /* We can't allow the supervisor to control SEIP as this would allow the 463 * supervisor to clear a pending external interrupt which will result in 464 * lost a interrupt in the case a PLIC is attached. The SEIP bit must be 465 * hardware controlled when a PLIC is attached. 466 */ 467 for (i = 0; i < plic->num_harts; i++) { 468 RISCVCPU *cpu = RISCV_CPU(qemu_get_cpu(plic->hartid_base + i)); 469 if (riscv_cpu_claim_interrupts(cpu, MIP_SEIP) < 0) { 470 error_report("SEIP already claimed"); 471 exit(1); 472 } 473 } 474 475 msi_nonbroken = true; 476 } 477 478 static const VMStateDescription vmstate_sifive_plic = { 479 .name = "riscv_sifive_plic", 480 .version_id = 1, 481 .minimum_version_id = 1, 482 .fields = (VMStateField[]) { 483 VMSTATE_VARRAY_UINT32(source_priority, SiFivePLICState, 484 num_sources, 0, 485 vmstate_info_uint32, uint32_t), 486 VMSTATE_VARRAY_UINT32(target_priority, SiFivePLICState, 487 num_addrs, 0, 488 vmstate_info_uint32, uint32_t), 489 VMSTATE_VARRAY_UINT32(pending, SiFivePLICState, bitfield_words, 0, 490 vmstate_info_uint32, uint32_t), 491 VMSTATE_VARRAY_UINT32(claimed, SiFivePLICState, bitfield_words, 0, 492 vmstate_info_uint32, uint32_t), 493 VMSTATE_VARRAY_UINT32(enable, SiFivePLICState, num_enables, 0, 494 vmstate_info_uint32, uint32_t), 495 VMSTATE_END_OF_LIST() 496 } 497 }; 498 499 static void sifive_plic_class_init(ObjectClass *klass, void *data) 500 { 501 DeviceClass *dc = DEVICE_CLASS(klass); 502 503 device_class_set_props(dc, sifive_plic_properties); 504 dc->realize = sifive_plic_realize; 505 dc->vmsd = &vmstate_sifive_plic; 506 } 507 508 static const TypeInfo sifive_plic_info = { 509 .name = TYPE_SIFIVE_PLIC, 510 .parent = TYPE_SYS_BUS_DEVICE, 511 .instance_size = sizeof(SiFivePLICState), 512 .class_init = sifive_plic_class_init, 513 }; 514 515 static void sifive_plic_register_types(void) 516 { 517 type_register_static(&sifive_plic_info); 518 } 519 520 type_init(sifive_plic_register_types) 521 522 /* 523 * Create PLIC device. 524 */ 525 DeviceState *sifive_plic_create(hwaddr addr, char *hart_config, 526 uint32_t num_harts, 527 uint32_t hartid_base, uint32_t num_sources, 528 uint32_t num_priorities, uint32_t priority_base, 529 uint32_t pending_base, uint32_t enable_base, 530 uint32_t enable_stride, uint32_t context_base, 531 uint32_t context_stride, uint32_t aperture_size) 532 { 533 DeviceState *dev = qdev_new(TYPE_SIFIVE_PLIC); 534 int i; 535 536 assert(enable_stride == (enable_stride & -enable_stride)); 537 assert(context_stride == (context_stride & -context_stride)); 538 qdev_prop_set_string(dev, "hart-config", hart_config); 539 qdev_prop_set_uint32(dev, "hartid-base", hartid_base); 540 qdev_prop_set_uint32(dev, "num-sources", num_sources); 541 qdev_prop_set_uint32(dev, "num-priorities", num_priorities); 542 qdev_prop_set_uint32(dev, "priority-base", priority_base); 543 qdev_prop_set_uint32(dev, "pending-base", pending_base); 544 qdev_prop_set_uint32(dev, "enable-base", enable_base); 545 qdev_prop_set_uint32(dev, "enable-stride", enable_stride); 546 qdev_prop_set_uint32(dev, "context-base", context_base); 547 qdev_prop_set_uint32(dev, "context-stride", context_stride); 548 qdev_prop_set_uint32(dev, "aperture-size", aperture_size); 549 sysbus_realize_and_unref(SYS_BUS_DEVICE(dev), &error_fatal); 550 sysbus_mmio_map(SYS_BUS_DEVICE(dev), 0, addr); 551 552 for (i = 0; i < num_harts; i++) { 553 CPUState *cpu = qemu_get_cpu(hartid_base + i); 554 555 qdev_connect_gpio_out(dev, i, 556 qdev_get_gpio_in(DEVICE(cpu), IRQ_S_EXT)); 557 qdev_connect_gpio_out(dev, num_harts + i, 558 qdev_get_gpio_in(DEVICE(cpu), IRQ_M_EXT)); 559 } 560 561 return dev; 562 } 563