1 /* 2 * Inter-Thread Communication Unit emulation. 3 * 4 * Copyright (c) 2016 Imagination Technologies 5 * 6 * This library is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU Lesser General Public 8 * License as published by the Free Software Foundation; either 9 * version 2.1 of the License, or (at your option) any later version. 10 * 11 * This library is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 * Lesser General Public License for more details. 15 * 16 * You should have received a copy of the GNU Lesser General Public 17 * License along with this library; if not, see <http://www.gnu.org/licenses/>. 18 */ 19 20 #include "qemu/osdep.h" 21 #include "qemu/units.h" 22 #include "qemu/log.h" 23 #include "qemu/module.h" 24 #include "qapi/error.h" 25 #include "exec/exec-all.h" 26 #include "hw/misc/mips_itu.h" 27 #include "hw/qdev-properties.h" 28 29 #define ITC_TAG_ADDRSPACE_SZ (ITC_ADDRESSMAP_NUM * 8) 30 /* Initialize as 4kB area to fit all 32 cells with default 128B grain. 31 Storage may be resized by the software. */ 32 #define ITC_STORAGE_ADDRSPACE_SZ 0x1000 33 34 #define ITC_FIFO_NUM_MAX 16 35 #define ITC_SEMAPH_NUM_MAX 16 36 #define ITC_AM1_NUMENTRIES_OFS 20 37 38 #define ITC_CELL_PV_MAX_VAL 0xFFFF 39 40 #define ITC_CELL_TAG_FIFO_DEPTH 28 41 #define ITC_CELL_TAG_FIFO_PTR 18 42 #define ITC_CELL_TAG_FIFO 17 43 #define ITC_CELL_TAG_T 16 44 #define ITC_CELL_TAG_F 1 45 #define ITC_CELL_TAG_E 0 46 47 #define ITC_AM0_BASE_ADDRESS_MASK 0xFFFFFC00ULL 48 #define ITC_AM0_EN_MASK 0x1 49 50 #define ITC_AM1_ADDR_MASK_MASK 0x1FC00 51 #define ITC_AM1_ENTRY_GRAIN_MASK 0x7 52 53 typedef enum ITCView { 54 ITCVIEW_BYPASS = 0, 55 ITCVIEW_CONTROL = 1, 56 ITCVIEW_EF_SYNC = 2, 57 ITCVIEW_EF_TRY = 3, 58 ITCVIEW_PV_SYNC = 4, 59 ITCVIEW_PV_TRY = 5, 60 ITCVIEW_PV_ICR0 = 15, 61 } ITCView; 62 63 #define ITC_ICR0_CELL_NUM 16 64 #define ITC_ICR0_BLK_GRAIN 8 65 #define ITC_ICR0_BLK_GRAIN_MASK 0x7 66 #define ITC_ICR0_ERR_AXI 2 67 #define ITC_ICR0_ERR_PARITY 1 68 #define ITC_ICR0_ERR_EXEC 0 69 70 MemoryRegion *mips_itu_get_tag_region(MIPSITUState *itu) 71 { 72 return &itu->tag_io; 73 } 74 75 static uint64_t itc_tag_read(void *opaque, hwaddr addr, unsigned size) 76 { 77 MIPSITUState *tag = (MIPSITUState *)opaque; 78 uint64_t index = addr >> 3; 79 80 if (index >= ITC_ADDRESSMAP_NUM) { 81 qemu_log_mask(LOG_GUEST_ERROR, "Read 0x%" PRIx64 "\n", addr); 82 return 0; 83 } 84 85 return tag->ITCAddressMap[index]; 86 } 87 88 void itc_reconfigure(MIPSITUState *tag) 89 { 90 uint64_t *am = &tag->ITCAddressMap[0]; 91 MemoryRegion *mr = &tag->storage_io; 92 hwaddr address = am[0] & ITC_AM0_BASE_ADDRESS_MASK; 93 uint64_t size = (1 * KiB) + (am[1] & ITC_AM1_ADDR_MASK_MASK); 94 bool is_enabled = (am[0] & ITC_AM0_EN_MASK) != 0; 95 96 if (tag->saar) { 97 address = (tag->saar[0] & 0xFFFFFFFFE000ULL) << 4; 98 size = 1ULL << ((tag->saar[0] >> 1) & 0x1f); 99 is_enabled = tag->saar[0] & 1; 100 } 101 102 memory_region_transaction_begin(); 103 if (!(size & (size - 1))) { 104 memory_region_set_size(mr, size); 105 } 106 memory_region_set_address(mr, address); 107 memory_region_set_enabled(mr, is_enabled); 108 memory_region_transaction_commit(); 109 } 110 111 static void itc_tag_write(void *opaque, hwaddr addr, 112 uint64_t data, unsigned size) 113 { 114 MIPSITUState *tag = (MIPSITUState *)opaque; 115 uint64_t *am = &tag->ITCAddressMap[0]; 116 uint64_t am_old, mask; 117 uint64_t index = addr >> 3; 118 119 switch (index) { 120 case 0: 121 mask = ITC_AM0_BASE_ADDRESS_MASK | ITC_AM0_EN_MASK; 122 break; 123 case 1: 124 mask = ITC_AM1_ADDR_MASK_MASK | ITC_AM1_ENTRY_GRAIN_MASK; 125 break; 126 default: 127 qemu_log_mask(LOG_GUEST_ERROR, "Bad write 0x%" PRIx64 "\n", addr); 128 return; 129 } 130 131 am_old = am[index]; 132 am[index] = (data & mask) | (am_old & ~mask); 133 if (am_old != am[index]) { 134 itc_reconfigure(tag); 135 } 136 } 137 138 static const MemoryRegionOps itc_tag_ops = { 139 .read = itc_tag_read, 140 .write = itc_tag_write, 141 .impl = { 142 .max_access_size = 8, 143 }, 144 .endianness = DEVICE_NATIVE_ENDIAN, 145 }; 146 147 static inline uint32_t get_num_cells(MIPSITUState *s) 148 { 149 return s->num_fifo + s->num_semaphores; 150 } 151 152 static inline ITCView get_itc_view(hwaddr addr) 153 { 154 return (addr >> 3) & 0xf; 155 } 156 157 static inline int get_cell_stride_shift(const MIPSITUState *s) 158 { 159 /* Minimum interval (for EntryGain = 0) is 128 B */ 160 if (s->saar) { 161 return 7 + ((s->icr0 >> ITC_ICR0_BLK_GRAIN) & 162 ITC_ICR0_BLK_GRAIN_MASK); 163 } else { 164 return 7 + (s->ITCAddressMap[1] & ITC_AM1_ENTRY_GRAIN_MASK); 165 } 166 } 167 168 static inline ITCStorageCell *get_cell(MIPSITUState *s, 169 hwaddr addr) 170 { 171 uint32_t cell_idx = addr >> get_cell_stride_shift(s); 172 uint32_t num_cells = get_num_cells(s); 173 174 if (cell_idx >= num_cells) { 175 cell_idx = num_cells - 1; 176 } 177 178 return &s->cell[cell_idx]; 179 } 180 181 static void wake_blocked_threads(ITCStorageCell *c) 182 { 183 CPUState *cs; 184 CPU_FOREACH(cs) { 185 if (cs->halted && (c->blocked_threads & (1ULL << cs->cpu_index))) { 186 cpu_interrupt(cs, CPU_INTERRUPT_WAKE); 187 } 188 } 189 c->blocked_threads = 0; 190 } 191 192 static G_NORETURN 193 void block_thread_and_exit(ITCStorageCell *c) 194 { 195 c->blocked_threads |= 1ULL << current_cpu->cpu_index; 196 current_cpu->halted = 1; 197 current_cpu->exception_index = EXCP_HLT; 198 cpu_loop_exit_restore(current_cpu, current_cpu->mem_io_pc); 199 } 200 201 /* ITC Bypass View */ 202 203 static inline uint64_t view_bypass_read(ITCStorageCell *c) 204 { 205 if (c->tag.FIFO) { 206 return c->data[c->fifo_out]; 207 } else { 208 return c->data[0]; 209 } 210 } 211 212 static inline void view_bypass_write(ITCStorageCell *c, uint64_t val) 213 { 214 if (c->tag.FIFO && (c->tag.FIFOPtr > 0)) { 215 int idx = (c->fifo_out + c->tag.FIFOPtr - 1) % ITC_CELL_DEPTH; 216 c->data[idx] = val; 217 } 218 219 /* ignore a write to the semaphore cell */ 220 } 221 222 /* ITC Control View */ 223 224 static inline uint64_t view_control_read(ITCStorageCell *c) 225 { 226 return ((uint64_t)c->tag.FIFODepth << ITC_CELL_TAG_FIFO_DEPTH) | 227 (c->tag.FIFOPtr << ITC_CELL_TAG_FIFO_PTR) | 228 (c->tag.FIFO << ITC_CELL_TAG_FIFO) | 229 (c->tag.T << ITC_CELL_TAG_T) | 230 (c->tag.E << ITC_CELL_TAG_E) | 231 (c->tag.F << ITC_CELL_TAG_F); 232 } 233 234 static inline void view_control_write(ITCStorageCell *c, uint64_t val) 235 { 236 c->tag.T = (val >> ITC_CELL_TAG_T) & 1; 237 c->tag.E = (val >> ITC_CELL_TAG_E) & 1; 238 c->tag.F = (val >> ITC_CELL_TAG_F) & 1; 239 240 if (c->tag.E) { 241 c->tag.FIFOPtr = 0; 242 } 243 } 244 245 /* ITC Empty/Full View */ 246 247 static uint64_t view_ef_common_read(ITCStorageCell *c, bool blocking) 248 { 249 uint64_t ret = 0; 250 251 if (!c->tag.FIFO) { 252 return 0; 253 } 254 255 c->tag.F = 0; 256 257 if (blocking && c->tag.E) { 258 block_thread_and_exit(c); 259 } 260 261 if (c->blocked_threads) { 262 wake_blocked_threads(c); 263 } 264 265 if (c->tag.FIFOPtr > 0) { 266 ret = c->data[c->fifo_out]; 267 c->fifo_out = (c->fifo_out + 1) % ITC_CELL_DEPTH; 268 c->tag.FIFOPtr--; 269 } 270 271 if (c->tag.FIFOPtr == 0) { 272 c->tag.E = 1; 273 } 274 275 return ret; 276 } 277 278 static uint64_t view_ef_sync_read(ITCStorageCell *c) 279 { 280 return view_ef_common_read(c, true); 281 } 282 283 static uint64_t view_ef_try_read(ITCStorageCell *c) 284 { 285 return view_ef_common_read(c, false); 286 } 287 288 static inline void view_ef_common_write(ITCStorageCell *c, uint64_t val, 289 bool blocking) 290 { 291 if (!c->tag.FIFO) { 292 return; 293 } 294 295 c->tag.E = 0; 296 297 if (blocking && c->tag.F) { 298 block_thread_and_exit(c); 299 } 300 301 if (c->blocked_threads) { 302 wake_blocked_threads(c); 303 } 304 305 if (c->tag.FIFOPtr < ITC_CELL_DEPTH) { 306 int idx = (c->fifo_out + c->tag.FIFOPtr) % ITC_CELL_DEPTH; 307 c->data[idx] = val; 308 c->tag.FIFOPtr++; 309 } 310 311 if (c->tag.FIFOPtr == ITC_CELL_DEPTH) { 312 c->tag.F = 1; 313 } 314 } 315 316 static void view_ef_sync_write(ITCStorageCell *c, uint64_t val) 317 { 318 view_ef_common_write(c, val, true); 319 } 320 321 static void view_ef_try_write(ITCStorageCell *c, uint64_t val) 322 { 323 view_ef_common_write(c, val, false); 324 } 325 326 /* ITC P/V View */ 327 328 static uint64_t view_pv_common_read(ITCStorageCell *c, bool blocking) 329 { 330 uint64_t ret = c->data[0]; 331 332 if (c->tag.FIFO) { 333 return 0; 334 } 335 336 if (c->data[0] > 0) { 337 c->data[0]--; 338 } else if (blocking) { 339 block_thread_and_exit(c); 340 } 341 342 return ret; 343 } 344 345 static uint64_t view_pv_sync_read(ITCStorageCell *c) 346 { 347 return view_pv_common_read(c, true); 348 } 349 350 static uint64_t view_pv_try_read(ITCStorageCell *c) 351 { 352 return view_pv_common_read(c, false); 353 } 354 355 static inline void view_pv_common_write(ITCStorageCell *c) 356 { 357 if (c->tag.FIFO) { 358 return; 359 } 360 361 if (c->data[0] < ITC_CELL_PV_MAX_VAL) { 362 c->data[0]++; 363 } 364 365 if (c->blocked_threads) { 366 wake_blocked_threads(c); 367 } 368 } 369 370 static void view_pv_sync_write(ITCStorageCell *c) 371 { 372 view_pv_common_write(c); 373 } 374 375 static void view_pv_try_write(ITCStorageCell *c) 376 { 377 view_pv_common_write(c); 378 } 379 380 static void raise_exception(int excp) 381 { 382 current_cpu->exception_index = excp; 383 cpu_loop_exit(current_cpu); 384 } 385 386 static uint64_t itc_storage_read(void *opaque, hwaddr addr, unsigned size) 387 { 388 MIPSITUState *s = (MIPSITUState *)opaque; 389 ITCStorageCell *cell = get_cell(s, addr); 390 ITCView view = get_itc_view(addr); 391 uint64_t ret = -1; 392 393 switch (size) { 394 case 1: 395 case 2: 396 s->icr0 |= 1 << ITC_ICR0_ERR_AXI; 397 raise_exception(EXCP_DBE); 398 return 0; 399 } 400 401 switch (view) { 402 case ITCVIEW_BYPASS: 403 ret = view_bypass_read(cell); 404 break; 405 case ITCVIEW_CONTROL: 406 ret = view_control_read(cell); 407 break; 408 case ITCVIEW_EF_SYNC: 409 ret = view_ef_sync_read(cell); 410 break; 411 case ITCVIEW_EF_TRY: 412 ret = view_ef_try_read(cell); 413 break; 414 case ITCVIEW_PV_SYNC: 415 ret = view_pv_sync_read(cell); 416 break; 417 case ITCVIEW_PV_TRY: 418 ret = view_pv_try_read(cell); 419 break; 420 case ITCVIEW_PV_ICR0: 421 ret = s->icr0; 422 break; 423 default: 424 qemu_log_mask(LOG_GUEST_ERROR, 425 "itc_storage_read: Bad ITC View %d\n", (int)view); 426 break; 427 } 428 429 return ret; 430 } 431 432 static void itc_storage_write(void *opaque, hwaddr addr, uint64_t data, 433 unsigned size) 434 { 435 MIPSITUState *s = (MIPSITUState *)opaque; 436 ITCStorageCell *cell = get_cell(s, addr); 437 ITCView view = get_itc_view(addr); 438 439 switch (size) { 440 case 1: 441 case 2: 442 s->icr0 |= 1 << ITC_ICR0_ERR_AXI; 443 raise_exception(EXCP_DBE); 444 return; 445 } 446 447 switch (view) { 448 case ITCVIEW_BYPASS: 449 view_bypass_write(cell, data); 450 break; 451 case ITCVIEW_CONTROL: 452 view_control_write(cell, data); 453 break; 454 case ITCVIEW_EF_SYNC: 455 view_ef_sync_write(cell, data); 456 break; 457 case ITCVIEW_EF_TRY: 458 view_ef_try_write(cell, data); 459 break; 460 case ITCVIEW_PV_SYNC: 461 view_pv_sync_write(cell); 462 break; 463 case ITCVIEW_PV_TRY: 464 view_pv_try_write(cell); 465 break; 466 case ITCVIEW_PV_ICR0: 467 if (data & 0x7) { 468 /* clear ERROR bits */ 469 s->icr0 &= ~(data & 0x7); 470 } 471 /* set BLK_GRAIN */ 472 s->icr0 &= ~0x700; 473 s->icr0 |= data & 0x700; 474 break; 475 default: 476 qemu_log_mask(LOG_GUEST_ERROR, 477 "itc_storage_write: Bad ITC View %d\n", (int)view); 478 break; 479 } 480 481 } 482 483 static const MemoryRegionOps itc_storage_ops = { 484 .read = itc_storage_read, 485 .write = itc_storage_write, 486 .endianness = DEVICE_NATIVE_ENDIAN, 487 }; 488 489 static void itc_reset_cells(MIPSITUState *s) 490 { 491 int i; 492 493 memset(s->cell, 0, get_num_cells(s) * sizeof(s->cell[0])); 494 495 for (i = 0; i < s->num_fifo; i++) { 496 s->cell[i].tag.E = 1; 497 s->cell[i].tag.FIFO = 1; 498 s->cell[i].tag.FIFODepth = ITC_CELL_DEPTH_SHIFT; 499 } 500 } 501 502 static void mips_itu_init(Object *obj) 503 { 504 SysBusDevice *sbd = SYS_BUS_DEVICE(obj); 505 MIPSITUState *s = MIPS_ITU(obj); 506 507 memory_region_init_io(&s->storage_io, OBJECT(s), &itc_storage_ops, s, 508 "mips-itc-storage", ITC_STORAGE_ADDRSPACE_SZ); 509 sysbus_init_mmio(sbd, &s->storage_io); 510 511 memory_region_init_io(&s->tag_io, OBJECT(s), &itc_tag_ops, s, 512 "mips-itc-tag", ITC_TAG_ADDRSPACE_SZ); 513 } 514 515 static void mips_itu_realize(DeviceState *dev, Error **errp) 516 { 517 MIPSITUState *s = MIPS_ITU(dev); 518 CPUMIPSState *env; 519 520 if (s->num_fifo > ITC_FIFO_NUM_MAX) { 521 error_setg(errp, "Exceed maximum number of FIFO cells: %d", 522 s->num_fifo); 523 return; 524 } 525 if (s->num_semaphores > ITC_SEMAPH_NUM_MAX) { 526 error_setg(errp, "Exceed maximum number of Semaphore cells: %d", 527 s->num_semaphores); 528 return; 529 } 530 if (!s->cpu0) { 531 error_setg(errp, "Missing 'cpu[0]' property"); 532 return; 533 } 534 535 env = &MIPS_CPU(s->cpu0)->env; 536 if (env->saarp) { 537 s->saar = env->CP0_SAAR; 538 } 539 540 s->cell = g_new(ITCStorageCell, get_num_cells(s)); 541 } 542 543 static void mips_itu_reset(DeviceState *dev) 544 { 545 MIPSITUState *s = MIPS_ITU(dev); 546 547 if (s->saar) { 548 s->saar[0] = 0x11 << 1; 549 s->icr0 = get_num_cells(s) << ITC_ICR0_CELL_NUM; 550 } else { 551 s->ITCAddressMap[0] = 0; 552 s->ITCAddressMap[1] = 553 ((ITC_STORAGE_ADDRSPACE_SZ - 1) & ITC_AM1_ADDR_MASK_MASK) | 554 (get_num_cells(s) << ITC_AM1_NUMENTRIES_OFS); 555 } 556 itc_reconfigure(s); 557 558 itc_reset_cells(s); 559 } 560 561 static Property mips_itu_properties[] = { 562 DEFINE_PROP_UINT32("num-fifo", MIPSITUState, num_fifo, 563 ITC_FIFO_NUM_MAX), 564 DEFINE_PROP_UINT32("num-semaphores", MIPSITUState, num_semaphores, 565 ITC_SEMAPH_NUM_MAX), 566 DEFINE_PROP_LINK("cpu[0]", MIPSITUState, cpu0, TYPE_MIPS_CPU, ArchCPU *), 567 DEFINE_PROP_END_OF_LIST(), 568 }; 569 570 static void mips_itu_class_init(ObjectClass *klass, void *data) 571 { 572 DeviceClass *dc = DEVICE_CLASS(klass); 573 574 device_class_set_props(dc, mips_itu_properties); 575 dc->realize = mips_itu_realize; 576 dc->reset = mips_itu_reset; 577 } 578 579 static const TypeInfo mips_itu_info = { 580 .name = TYPE_MIPS_ITU, 581 .parent = TYPE_SYS_BUS_DEVICE, 582 .instance_size = sizeof(MIPSITUState), 583 .instance_init = mips_itu_init, 584 .class_init = mips_itu_class_init, 585 }; 586 587 static void mips_itu_register_types(void) 588 { 589 type_register_static(&mips_itu_info); 590 } 591 592 type_init(mips_itu_register_types) 593