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 #include "sysemu/kvm.h" 34 35 static bool addr_between(uint32_t addr, uint32_t base, uint32_t num) 36 { 37 return addr >= base && addr - base < num; 38 } 39 40 static PLICMode char_to_mode(char c) 41 { 42 switch (c) { 43 case 'U': return PLICMode_U; 44 case 'S': return PLICMode_S; 45 case 'H': return PLICMode_H; 46 case 'M': return PLICMode_M; 47 default: 48 error_report("plic: invalid mode '%c'", c); 49 exit(1); 50 } 51 } 52 53 static uint32_t atomic_set_masked(uint32_t *a, uint32_t mask, uint32_t value) 54 { 55 uint32_t old, new, cmp = qatomic_read(a); 56 57 do { 58 old = cmp; 59 new = (old & ~mask) | (value & mask); 60 cmp = qatomic_cmpxchg(a, old, new); 61 } while (old != cmp); 62 63 return old; 64 } 65 66 static void sifive_plic_set_pending(SiFivePLICState *plic, int irq, bool level) 67 { 68 atomic_set_masked(&plic->pending[irq >> 5], 1 << (irq & 31), -!!level); 69 } 70 71 static void sifive_plic_set_claimed(SiFivePLICState *plic, int irq, bool level) 72 { 73 atomic_set_masked(&plic->claimed[irq >> 5], 1 << (irq & 31), -!!level); 74 } 75 76 static uint32_t sifive_plic_claimed(SiFivePLICState *plic, uint32_t addrid) 77 { 78 uint32_t max_irq = 0; 79 uint32_t max_prio = plic->target_priority[addrid]; 80 int i, j; 81 82 for (i = 0; i < plic->bitfield_words; i++) { 83 uint32_t pending_enabled_not_claimed = 84 (plic->pending[i] & ~plic->claimed[i]) & 85 plic->enable[addrid * plic->bitfield_words + i]; 86 87 if (!pending_enabled_not_claimed) { 88 continue; 89 } 90 91 for (j = 0; j < 32; j++) { 92 int irq = (i << 5) + j; 93 uint32_t prio = plic->source_priority[irq]; 94 int enabled = pending_enabled_not_claimed & (1 << j); 95 96 if (enabled && prio > max_prio) { 97 max_irq = irq; 98 max_prio = prio; 99 } 100 } 101 } 102 103 return max_irq; 104 } 105 106 static void sifive_plic_update(SiFivePLICState *plic) 107 { 108 int addrid; 109 110 /* raise irq on harts where this irq is enabled */ 111 for (addrid = 0; addrid < plic->num_addrs; addrid++) { 112 uint32_t hartid = plic->addr_config[addrid].hartid; 113 PLICMode mode = plic->addr_config[addrid].mode; 114 bool level = !!sifive_plic_claimed(plic, addrid); 115 116 switch (mode) { 117 case PLICMode_M: 118 qemu_set_irq(plic->m_external_irqs[hartid - plic->hartid_base], level); 119 break; 120 case PLICMode_S: 121 qemu_set_irq(plic->s_external_irqs[hartid - plic->hartid_base], level); 122 break; 123 default: 124 break; 125 } 126 } 127 } 128 129 static uint64_t sifive_plic_read(void *opaque, hwaddr addr, unsigned size) 130 { 131 SiFivePLICState *plic = opaque; 132 133 if (addr_between(addr, plic->priority_base, plic->num_sources << 2)) { 134 uint32_t irq = ((addr - plic->priority_base) >> 2) + 1; 135 136 return plic->source_priority[irq]; 137 } else if (addr_between(addr, plic->pending_base, plic->num_sources >> 3)) { 138 uint32_t word = (addr - plic->pending_base) >> 2; 139 140 return plic->pending[word]; 141 } else if (addr_between(addr, plic->enable_base, 142 plic->num_addrs * plic->enable_stride)) { 143 uint32_t addrid = (addr - plic->enable_base) / plic->enable_stride; 144 uint32_t wordid = (addr & (plic->enable_stride - 1)) >> 2; 145 146 if (wordid < plic->bitfield_words) { 147 return plic->enable[addrid * plic->bitfield_words + wordid]; 148 } 149 } else if (addr_between(addr, plic->context_base, 150 plic->num_addrs * plic->context_stride)) { 151 uint32_t addrid = (addr - plic->context_base) / plic->context_stride; 152 uint32_t contextid = (addr & (plic->context_stride - 1)); 153 154 if (contextid == 0) { 155 return plic->target_priority[addrid]; 156 } else if (contextid == 4) { 157 uint32_t max_irq = sifive_plic_claimed(plic, addrid); 158 159 if (max_irq) { 160 sifive_plic_set_pending(plic, max_irq, false); 161 sifive_plic_set_claimed(plic, max_irq, true); 162 } 163 164 sifive_plic_update(plic); 165 return max_irq; 166 } 167 } 168 169 qemu_log_mask(LOG_GUEST_ERROR, 170 "%s: Invalid register read 0x%" HWADDR_PRIx "\n", 171 __func__, addr); 172 return 0; 173 } 174 175 static void sifive_plic_write(void *opaque, hwaddr addr, uint64_t value, 176 unsigned size) 177 { 178 SiFivePLICState *plic = opaque; 179 180 if (addr_between(addr, plic->priority_base, plic->num_sources << 2)) { 181 uint32_t irq = ((addr - plic->priority_base) >> 2) + 1; 182 183 if (((plic->num_priorities + 1) & plic->num_priorities) == 0) { 184 /* 185 * if "num_priorities + 1" is power-of-2, make each register bit of 186 * interrupt priority WARL (Write-Any-Read-Legal). Just filter 187 * out the access to unsupported priority bits. 188 */ 189 plic->source_priority[irq] = value % (plic->num_priorities + 1); 190 sifive_plic_update(plic); 191 } else if (value <= plic->num_priorities) { 192 plic->source_priority[irq] = value; 193 sifive_plic_update(plic); 194 } 195 } else if (addr_between(addr, plic->pending_base, 196 plic->num_sources >> 3)) { 197 qemu_log_mask(LOG_GUEST_ERROR, 198 "%s: invalid pending write: 0x%" HWADDR_PRIx "", 199 __func__, addr); 200 } else if (addr_between(addr, plic->enable_base, 201 plic->num_addrs * plic->enable_stride)) { 202 uint32_t addrid = (addr - plic->enable_base) / plic->enable_stride; 203 uint32_t wordid = (addr & (plic->enable_stride - 1)) >> 2; 204 205 if (wordid < plic->bitfield_words) { 206 plic->enable[addrid * plic->bitfield_words + wordid] = value; 207 } else { 208 qemu_log_mask(LOG_GUEST_ERROR, 209 "%s: Invalid enable write 0x%" HWADDR_PRIx "\n", 210 __func__, addr); 211 } 212 } else if (addr_between(addr, plic->context_base, 213 plic->num_addrs * plic->context_stride)) { 214 uint32_t addrid = (addr - plic->context_base) / plic->context_stride; 215 uint32_t contextid = (addr & (plic->context_stride - 1)); 216 217 if (contextid == 0) { 218 if (((plic->num_priorities + 1) & plic->num_priorities) == 0) { 219 /* 220 * if "num_priorities + 1" is power-of-2, each register bit of 221 * interrupt priority is WARL (Write-Any-Read-Legal). Just 222 * filter out the access to unsupported priority bits. 223 */ 224 plic->target_priority[addrid] = value % 225 (plic->num_priorities + 1); 226 sifive_plic_update(plic); 227 } else if (value <= plic->num_priorities) { 228 plic->target_priority[addrid] = value; 229 sifive_plic_update(plic); 230 } 231 } else if (contextid == 4) { 232 if (value < plic->num_sources) { 233 sifive_plic_set_claimed(plic, value, false); 234 sifive_plic_update(plic); 235 } 236 } else { 237 qemu_log_mask(LOG_GUEST_ERROR, 238 "%s: Invalid context write 0x%" HWADDR_PRIx "\n", 239 __func__, addr); 240 } 241 } else { 242 qemu_log_mask(LOG_GUEST_ERROR, 243 "%s: Invalid register write 0x%" HWADDR_PRIx "\n", 244 __func__, addr); 245 } 246 } 247 248 static const MemoryRegionOps sifive_plic_ops = { 249 .read = sifive_plic_read, 250 .write = sifive_plic_write, 251 .endianness = DEVICE_LITTLE_ENDIAN, 252 .valid = { 253 .min_access_size = 4, 254 .max_access_size = 4 255 } 256 }; 257 258 static void sifive_plic_reset(DeviceState *dev) 259 { 260 SiFivePLICState *s = SIFIVE_PLIC(dev); 261 int i; 262 263 memset(s->source_priority, 0, sizeof(uint32_t) * s->num_sources); 264 memset(s->target_priority, 0, sizeof(uint32_t) * s->num_addrs); 265 memset(s->pending, 0, sizeof(uint32_t) * s->bitfield_words); 266 memset(s->claimed, 0, sizeof(uint32_t) * s->bitfield_words); 267 memset(s->enable, 0, sizeof(uint32_t) * s->num_enables); 268 269 for (i = 0; i < s->num_harts; i++) { 270 qemu_set_irq(s->m_external_irqs[i], 0); 271 qemu_set_irq(s->s_external_irqs[i], 0); 272 } 273 } 274 275 /* 276 * parse PLIC hart/mode address offset config 277 * 278 * "M" 1 hart with M mode 279 * "MS,MS" 2 harts, 0-1 with M and S mode 280 * "M,MS,MS,MS,MS" 5 harts, 0 with M mode, 1-5 with M and S mode 281 */ 282 static void parse_hart_config(SiFivePLICState *plic) 283 { 284 int addrid, hartid, modes; 285 const char *p; 286 char c; 287 288 /* count and validate hart/mode combinations */ 289 addrid = 0, hartid = 0, modes = 0; 290 p = plic->hart_config; 291 while ((c = *p++)) { 292 if (c == ',') { 293 addrid += ctpop8(modes); 294 modes = 0; 295 hartid++; 296 } else { 297 int m = 1 << char_to_mode(c); 298 if (modes == (modes | m)) { 299 error_report("plic: duplicate mode '%c' in config: %s", 300 c, plic->hart_config); 301 exit(1); 302 } 303 modes |= m; 304 } 305 } 306 if (modes) { 307 addrid += ctpop8(modes); 308 } 309 hartid++; 310 311 plic->num_addrs = addrid; 312 plic->num_harts = hartid; 313 314 /* store hart/mode combinations */ 315 plic->addr_config = g_new(PLICAddr, plic->num_addrs); 316 addrid = 0, hartid = plic->hartid_base; 317 p = plic->hart_config; 318 while ((c = *p++)) { 319 if (c == ',') { 320 hartid++; 321 } else { 322 plic->addr_config[addrid].addrid = addrid; 323 plic->addr_config[addrid].hartid = hartid; 324 plic->addr_config[addrid].mode = char_to_mode(c); 325 addrid++; 326 } 327 } 328 } 329 330 static void sifive_plic_irq_request(void *opaque, int irq, int level) 331 { 332 SiFivePLICState *s = opaque; 333 334 sifive_plic_set_pending(s, irq, level > 0); 335 sifive_plic_update(s); 336 } 337 338 static void sifive_plic_realize(DeviceState *dev, Error **errp) 339 { 340 SiFivePLICState *s = SIFIVE_PLIC(dev); 341 int i; 342 343 memory_region_init_io(&s->mmio, OBJECT(dev), &sifive_plic_ops, s, 344 TYPE_SIFIVE_PLIC, s->aperture_size); 345 sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->mmio); 346 347 parse_hart_config(s); 348 349 s->bitfield_words = (s->num_sources + 31) >> 5; 350 s->num_enables = s->bitfield_words * s->num_addrs; 351 s->source_priority = g_new0(uint32_t, s->num_sources); 352 s->target_priority = g_new(uint32_t, s->num_addrs); 353 s->pending = g_new0(uint32_t, s->bitfield_words); 354 s->claimed = g_new0(uint32_t, s->bitfield_words); 355 s->enable = g_new0(uint32_t, s->num_enables); 356 357 qdev_init_gpio_in(dev, sifive_plic_irq_request, s->num_sources); 358 359 s->s_external_irqs = g_malloc(sizeof(qemu_irq) * s->num_harts); 360 qdev_init_gpio_out(dev, s->s_external_irqs, s->num_harts); 361 362 s->m_external_irqs = g_malloc(sizeof(qemu_irq) * s->num_harts); 363 qdev_init_gpio_out(dev, s->m_external_irqs, s->num_harts); 364 365 /* We can't allow the supervisor to control SEIP as this would allow the 366 * supervisor to clear a pending external interrupt which will result in 367 * lost a interrupt in the case a PLIC is attached. The SEIP bit must be 368 * hardware controlled when a PLIC is attached. 369 */ 370 for (i = 0; i < s->num_harts; i++) { 371 RISCVCPU *cpu = RISCV_CPU(qemu_get_cpu(s->hartid_base + i)); 372 if (riscv_cpu_claim_interrupts(cpu, MIP_SEIP) < 0) { 373 error_report("SEIP already claimed"); 374 exit(1); 375 } 376 } 377 378 msi_nonbroken = true; 379 } 380 381 static const VMStateDescription vmstate_sifive_plic = { 382 .name = "riscv_sifive_plic", 383 .version_id = 1, 384 .minimum_version_id = 1, 385 .fields = (VMStateField[]) { 386 VMSTATE_VARRAY_UINT32(source_priority, SiFivePLICState, 387 num_sources, 0, 388 vmstate_info_uint32, uint32_t), 389 VMSTATE_VARRAY_UINT32(target_priority, SiFivePLICState, 390 num_addrs, 0, 391 vmstate_info_uint32, uint32_t), 392 VMSTATE_VARRAY_UINT32(pending, SiFivePLICState, bitfield_words, 0, 393 vmstate_info_uint32, uint32_t), 394 VMSTATE_VARRAY_UINT32(claimed, SiFivePLICState, bitfield_words, 0, 395 vmstate_info_uint32, uint32_t), 396 VMSTATE_VARRAY_UINT32(enable, SiFivePLICState, num_enables, 0, 397 vmstate_info_uint32, uint32_t), 398 VMSTATE_END_OF_LIST() 399 } 400 }; 401 402 static Property sifive_plic_properties[] = { 403 DEFINE_PROP_STRING("hart-config", SiFivePLICState, hart_config), 404 DEFINE_PROP_UINT32("hartid-base", SiFivePLICState, hartid_base, 0), 405 DEFINE_PROP_UINT32("num-sources", SiFivePLICState, num_sources, 0), 406 DEFINE_PROP_UINT32("num-priorities", SiFivePLICState, num_priorities, 0), 407 DEFINE_PROP_UINT32("priority-base", SiFivePLICState, priority_base, 0), 408 DEFINE_PROP_UINT32("pending-base", SiFivePLICState, pending_base, 0), 409 DEFINE_PROP_UINT32("enable-base", SiFivePLICState, enable_base, 0), 410 DEFINE_PROP_UINT32("enable-stride", SiFivePLICState, enable_stride, 0), 411 DEFINE_PROP_UINT32("context-base", SiFivePLICState, context_base, 0), 412 DEFINE_PROP_UINT32("context-stride", SiFivePLICState, context_stride, 0), 413 DEFINE_PROP_UINT32("aperture-size", SiFivePLICState, aperture_size, 0), 414 DEFINE_PROP_END_OF_LIST(), 415 }; 416 417 static void sifive_plic_class_init(ObjectClass *klass, void *data) 418 { 419 DeviceClass *dc = DEVICE_CLASS(klass); 420 421 dc->reset = sifive_plic_reset; 422 device_class_set_props(dc, sifive_plic_properties); 423 dc->realize = sifive_plic_realize; 424 dc->vmsd = &vmstate_sifive_plic; 425 } 426 427 static const TypeInfo sifive_plic_info = { 428 .name = TYPE_SIFIVE_PLIC, 429 .parent = TYPE_SYS_BUS_DEVICE, 430 .instance_size = sizeof(SiFivePLICState), 431 .class_init = sifive_plic_class_init, 432 }; 433 434 static void sifive_plic_register_types(void) 435 { 436 type_register_static(&sifive_plic_info); 437 } 438 439 type_init(sifive_plic_register_types) 440 441 /* 442 * Create PLIC device. 443 */ 444 DeviceState *sifive_plic_create(hwaddr addr, char *hart_config, 445 uint32_t num_harts, 446 uint32_t hartid_base, uint32_t num_sources, 447 uint32_t num_priorities, uint32_t priority_base, 448 uint32_t pending_base, uint32_t enable_base, 449 uint32_t enable_stride, uint32_t context_base, 450 uint32_t context_stride, uint32_t aperture_size) 451 { 452 DeviceState *dev = qdev_new(TYPE_SIFIVE_PLIC); 453 int i; 454 SiFivePLICState *plic; 455 456 assert(enable_stride == (enable_stride & -enable_stride)); 457 assert(context_stride == (context_stride & -context_stride)); 458 qdev_prop_set_string(dev, "hart-config", hart_config); 459 qdev_prop_set_uint32(dev, "hartid-base", hartid_base); 460 qdev_prop_set_uint32(dev, "num-sources", num_sources); 461 qdev_prop_set_uint32(dev, "num-priorities", num_priorities); 462 qdev_prop_set_uint32(dev, "priority-base", priority_base); 463 qdev_prop_set_uint32(dev, "pending-base", pending_base); 464 qdev_prop_set_uint32(dev, "enable-base", enable_base); 465 qdev_prop_set_uint32(dev, "enable-stride", enable_stride); 466 qdev_prop_set_uint32(dev, "context-base", context_base); 467 qdev_prop_set_uint32(dev, "context-stride", context_stride); 468 qdev_prop_set_uint32(dev, "aperture-size", aperture_size); 469 sysbus_realize_and_unref(SYS_BUS_DEVICE(dev), &error_fatal); 470 sysbus_mmio_map(SYS_BUS_DEVICE(dev), 0, addr); 471 472 plic = SIFIVE_PLIC(dev); 473 474 for (i = 0; i < plic->num_addrs; i++) { 475 int cpu_num = plic->addr_config[i].hartid; 476 CPUState *cpu = qemu_get_cpu(cpu_num); 477 478 if (plic->addr_config[i].mode == PLICMode_M) { 479 qdev_connect_gpio_out(dev, num_harts - plic->hartid_base + cpu_num, 480 qdev_get_gpio_in(DEVICE(cpu), IRQ_M_EXT)); 481 } 482 if (plic->addr_config[i].mode == PLICMode_S) { 483 qdev_connect_gpio_out(dev, cpu_num, 484 qdev_get_gpio_in(DEVICE(cpu), IRQ_S_EXT)); 485 } 486 } 487 488 return dev; 489 } 490