1 /* 2 * ARM Nested Vectored Interrupt Controller 3 * 4 * Copyright (c) 2006-2007 CodeSourcery. 5 * Written by Paul Brook 6 * 7 * This code is licensed under the GPL. 8 * 9 * The ARMv7M System controller is fairly tightly tied in with the 10 * NVIC. Much of that is also implemented here. 11 */ 12 13 #include "hw/sysbus.h" 14 #include "qemu/timer.h" 15 #include "hw/arm.h" 16 #include "exec/address-spaces.h" 17 #include "hw/arm_gic_internal.h" 18 19 typedef struct { 20 GICState gic; 21 struct { 22 uint32_t control; 23 uint32_t reload; 24 int64_t tick; 25 QEMUTimer *timer; 26 } systick; 27 MemoryRegion sysregmem; 28 MemoryRegion gic_iomem_alias; 29 MemoryRegion container; 30 uint32_t num_irq; 31 } nvic_state; 32 33 #define TYPE_NVIC "armv7m_nvic" 34 /** 35 * NVICClass: 36 * @parent_reset: the parent class' reset handler. 37 * 38 * A model of the v7M NVIC and System Controller 39 */ 40 typedef struct NVICClass { 41 /*< private >*/ 42 ARMGICClass parent_class; 43 /*< public >*/ 44 DeviceRealize parent_realize; 45 void (*parent_reset)(DeviceState *dev); 46 } NVICClass; 47 48 #define NVIC_CLASS(klass) \ 49 OBJECT_CLASS_CHECK(NVICClass, (klass), TYPE_NVIC) 50 #define NVIC_GET_CLASS(obj) \ 51 OBJECT_GET_CLASS(NVICClass, (obj), TYPE_NVIC) 52 #define NVIC(obj) \ 53 OBJECT_CHECK(nvic_state, (obj), TYPE_NVIC) 54 55 static const uint8_t nvic_id[] = { 56 0x00, 0xb0, 0x1b, 0x00, 0x0d, 0xe0, 0x05, 0xb1 57 }; 58 59 /* qemu timers run at 1GHz. We want something closer to 1MHz. */ 60 #define SYSTICK_SCALE 1000ULL 61 62 #define SYSTICK_ENABLE (1 << 0) 63 #define SYSTICK_TICKINT (1 << 1) 64 #define SYSTICK_CLKSOURCE (1 << 2) 65 #define SYSTICK_COUNTFLAG (1 << 16) 66 67 int system_clock_scale; 68 69 /* Conversion factor from qemu timer to SysTick frequencies. */ 70 static inline int64_t systick_scale(nvic_state *s) 71 { 72 if (s->systick.control & SYSTICK_CLKSOURCE) 73 return system_clock_scale; 74 else 75 return 1000; 76 } 77 78 static void systick_reload(nvic_state *s, int reset) 79 { 80 if (reset) 81 s->systick.tick = qemu_get_clock_ns(vm_clock); 82 s->systick.tick += (s->systick.reload + 1) * systick_scale(s); 83 qemu_mod_timer(s->systick.timer, s->systick.tick); 84 } 85 86 static void systick_timer_tick(void * opaque) 87 { 88 nvic_state *s = (nvic_state *)opaque; 89 s->systick.control |= SYSTICK_COUNTFLAG; 90 if (s->systick.control & SYSTICK_TICKINT) { 91 /* Trigger the interrupt. */ 92 armv7m_nvic_set_pending(s, ARMV7M_EXCP_SYSTICK); 93 } 94 if (s->systick.reload == 0) { 95 s->systick.control &= ~SYSTICK_ENABLE; 96 } else { 97 systick_reload(s, 0); 98 } 99 } 100 101 static void systick_reset(nvic_state *s) 102 { 103 s->systick.control = 0; 104 s->systick.reload = 0; 105 s->systick.tick = 0; 106 qemu_del_timer(s->systick.timer); 107 } 108 109 /* The external routines use the hardware vector numbering, ie. the first 110 IRQ is #16. The internal GIC routines use #32 as the first IRQ. */ 111 void armv7m_nvic_set_pending(void *opaque, int irq) 112 { 113 nvic_state *s = (nvic_state *)opaque; 114 if (irq >= 16) 115 irq += 16; 116 gic_set_pending_private(&s->gic, 0, irq); 117 } 118 119 /* Make pending IRQ active. */ 120 int armv7m_nvic_acknowledge_irq(void *opaque) 121 { 122 nvic_state *s = (nvic_state *)opaque; 123 uint32_t irq; 124 125 irq = gic_acknowledge_irq(&s->gic, 0); 126 if (irq == 1023) 127 hw_error("Interrupt but no vector\n"); 128 if (irq >= 32) 129 irq -= 16; 130 return irq; 131 } 132 133 void armv7m_nvic_complete_irq(void *opaque, int irq) 134 { 135 nvic_state *s = (nvic_state *)opaque; 136 if (irq >= 16) 137 irq += 16; 138 gic_complete_irq(&s->gic, 0, irq); 139 } 140 141 static uint32_t nvic_readl(nvic_state *s, uint32_t offset) 142 { 143 uint32_t val; 144 int irq; 145 146 switch (offset) { 147 case 4: /* Interrupt Control Type. */ 148 return (s->num_irq / 32) - 1; 149 case 0x10: /* SysTick Control and Status. */ 150 val = s->systick.control; 151 s->systick.control &= ~SYSTICK_COUNTFLAG; 152 return val; 153 case 0x14: /* SysTick Reload Value. */ 154 return s->systick.reload; 155 case 0x18: /* SysTick Current Value. */ 156 { 157 int64_t t; 158 if ((s->systick.control & SYSTICK_ENABLE) == 0) 159 return 0; 160 t = qemu_get_clock_ns(vm_clock); 161 if (t >= s->systick.tick) 162 return 0; 163 val = ((s->systick.tick - (t + 1)) / systick_scale(s)) + 1; 164 /* The interrupt in triggered when the timer reaches zero. 165 However the counter is not reloaded until the next clock 166 tick. This is a hack to return zero during the first tick. */ 167 if (val > s->systick.reload) 168 val = 0; 169 return val; 170 } 171 case 0x1c: /* SysTick Calibration Value. */ 172 return 10000; 173 case 0xd00: /* CPUID Base. */ 174 return cpu_single_env->cp15.c0_cpuid; 175 case 0xd04: /* Interrypt Control State. */ 176 /* VECTACTIVE */ 177 val = s->gic.running_irq[0]; 178 if (val == 1023) { 179 val = 0; 180 } else if (val >= 32) { 181 val -= 16; 182 } 183 /* RETTOBASE */ 184 if (s->gic.running_irq[0] == 1023 185 || s->gic.last_active[s->gic.running_irq[0]][0] == 1023) { 186 val |= (1 << 11); 187 } 188 /* VECTPENDING */ 189 if (s->gic.current_pending[0] != 1023) 190 val |= (s->gic.current_pending[0] << 12); 191 /* ISRPENDING */ 192 for (irq = 32; irq < s->num_irq; irq++) { 193 if (s->gic.irq_state[irq].pending) { 194 val |= (1 << 22); 195 break; 196 } 197 } 198 /* PENDSTSET */ 199 if (s->gic.irq_state[ARMV7M_EXCP_SYSTICK].pending) 200 val |= (1 << 26); 201 /* PENDSVSET */ 202 if (s->gic.irq_state[ARMV7M_EXCP_PENDSV].pending) 203 val |= (1 << 28); 204 /* NMIPENDSET */ 205 if (s->gic.irq_state[ARMV7M_EXCP_NMI].pending) 206 val |= (1 << 31); 207 return val; 208 case 0xd08: /* Vector Table Offset. */ 209 return cpu_single_env->v7m.vecbase; 210 case 0xd0c: /* Application Interrupt/Reset Control. */ 211 return 0xfa05000; 212 case 0xd10: /* System Control. */ 213 /* TODO: Implement SLEEPONEXIT. */ 214 return 0; 215 case 0xd14: /* Configuration Control. */ 216 /* TODO: Implement Configuration Control bits. */ 217 return 0; 218 case 0xd24: /* System Handler Status. */ 219 val = 0; 220 if (s->gic.irq_state[ARMV7M_EXCP_MEM].active) val |= (1 << 0); 221 if (s->gic.irq_state[ARMV7M_EXCP_BUS].active) val |= (1 << 1); 222 if (s->gic.irq_state[ARMV7M_EXCP_USAGE].active) val |= (1 << 3); 223 if (s->gic.irq_state[ARMV7M_EXCP_SVC].active) val |= (1 << 7); 224 if (s->gic.irq_state[ARMV7M_EXCP_DEBUG].active) val |= (1 << 8); 225 if (s->gic.irq_state[ARMV7M_EXCP_PENDSV].active) val |= (1 << 10); 226 if (s->gic.irq_state[ARMV7M_EXCP_SYSTICK].active) val |= (1 << 11); 227 if (s->gic.irq_state[ARMV7M_EXCP_USAGE].pending) val |= (1 << 12); 228 if (s->gic.irq_state[ARMV7M_EXCP_MEM].pending) val |= (1 << 13); 229 if (s->gic.irq_state[ARMV7M_EXCP_BUS].pending) val |= (1 << 14); 230 if (s->gic.irq_state[ARMV7M_EXCP_SVC].pending) val |= (1 << 15); 231 if (s->gic.irq_state[ARMV7M_EXCP_MEM].enabled) val |= (1 << 16); 232 if (s->gic.irq_state[ARMV7M_EXCP_BUS].enabled) val |= (1 << 17); 233 if (s->gic.irq_state[ARMV7M_EXCP_USAGE].enabled) val |= (1 << 18); 234 return val; 235 case 0xd28: /* Configurable Fault Status. */ 236 /* TODO: Implement Fault Status. */ 237 qemu_log_mask(LOG_UNIMP, "Configurable Fault Status unimplemented\n"); 238 return 0; 239 case 0xd2c: /* Hard Fault Status. */ 240 case 0xd30: /* Debug Fault Status. */ 241 case 0xd34: /* Mem Manage Address. */ 242 case 0xd38: /* Bus Fault Address. */ 243 case 0xd3c: /* Aux Fault Status. */ 244 /* TODO: Implement fault status registers. */ 245 qemu_log_mask(LOG_UNIMP, "Fault status registers unimplemented\n"); 246 return 0; 247 case 0xd40: /* PFR0. */ 248 return 0x00000030; 249 case 0xd44: /* PRF1. */ 250 return 0x00000200; 251 case 0xd48: /* DFR0. */ 252 return 0x00100000; 253 case 0xd4c: /* AFR0. */ 254 return 0x00000000; 255 case 0xd50: /* MMFR0. */ 256 return 0x00000030; 257 case 0xd54: /* MMFR1. */ 258 return 0x00000000; 259 case 0xd58: /* MMFR2. */ 260 return 0x00000000; 261 case 0xd5c: /* MMFR3. */ 262 return 0x00000000; 263 case 0xd60: /* ISAR0. */ 264 return 0x01141110; 265 case 0xd64: /* ISAR1. */ 266 return 0x02111000; 267 case 0xd68: /* ISAR2. */ 268 return 0x21112231; 269 case 0xd6c: /* ISAR3. */ 270 return 0x01111110; 271 case 0xd70: /* ISAR4. */ 272 return 0x01310102; 273 /* TODO: Implement debug registers. */ 274 default: 275 qemu_log_mask(LOG_GUEST_ERROR, "NVIC: Bad read offset 0x%x\n", offset); 276 return 0; 277 } 278 } 279 280 static void nvic_writel(nvic_state *s, uint32_t offset, uint32_t value) 281 { 282 uint32_t oldval; 283 switch (offset) { 284 case 0x10: /* SysTick Control and Status. */ 285 oldval = s->systick.control; 286 s->systick.control &= 0xfffffff8; 287 s->systick.control |= value & 7; 288 if ((oldval ^ value) & SYSTICK_ENABLE) { 289 int64_t now = qemu_get_clock_ns(vm_clock); 290 if (value & SYSTICK_ENABLE) { 291 if (s->systick.tick) { 292 s->systick.tick += now; 293 qemu_mod_timer(s->systick.timer, s->systick.tick); 294 } else { 295 systick_reload(s, 1); 296 } 297 } else { 298 qemu_del_timer(s->systick.timer); 299 s->systick.tick -= now; 300 if (s->systick.tick < 0) 301 s->systick.tick = 0; 302 } 303 } else if ((oldval ^ value) & SYSTICK_CLKSOURCE) { 304 /* This is a hack. Force the timer to be reloaded 305 when the reference clock is changed. */ 306 systick_reload(s, 1); 307 } 308 break; 309 case 0x14: /* SysTick Reload Value. */ 310 s->systick.reload = value; 311 break; 312 case 0x18: /* SysTick Current Value. Writes reload the timer. */ 313 systick_reload(s, 1); 314 s->systick.control &= ~SYSTICK_COUNTFLAG; 315 break; 316 case 0xd04: /* Interrupt Control State. */ 317 if (value & (1 << 31)) { 318 armv7m_nvic_set_pending(s, ARMV7M_EXCP_NMI); 319 } 320 if (value & (1 << 28)) { 321 armv7m_nvic_set_pending(s, ARMV7M_EXCP_PENDSV); 322 } else if (value & (1 << 27)) { 323 s->gic.irq_state[ARMV7M_EXCP_PENDSV].pending = 0; 324 gic_update(&s->gic); 325 } 326 if (value & (1 << 26)) { 327 armv7m_nvic_set_pending(s, ARMV7M_EXCP_SYSTICK); 328 } else if (value & (1 << 25)) { 329 s->gic.irq_state[ARMV7M_EXCP_SYSTICK].pending = 0; 330 gic_update(&s->gic); 331 } 332 break; 333 case 0xd08: /* Vector Table Offset. */ 334 cpu_single_env->v7m.vecbase = value & 0xffffff80; 335 break; 336 case 0xd0c: /* Application Interrupt/Reset Control. */ 337 if ((value >> 16) == 0x05fa) { 338 if (value & 2) { 339 qemu_log_mask(LOG_UNIMP, "VECTCLRACTIVE unimplemented\n"); 340 } 341 if (value & 5) { 342 qemu_log_mask(LOG_UNIMP, "AIRCR system reset unimplemented\n"); 343 } 344 } 345 break; 346 case 0xd10: /* System Control. */ 347 case 0xd14: /* Configuration Control. */ 348 /* TODO: Implement control registers. */ 349 qemu_log_mask(LOG_UNIMP, "NVIC: SCR and CCR unimplemented\n"); 350 break; 351 case 0xd24: /* System Handler Control. */ 352 /* TODO: Real hardware allows you to set/clear the active bits 353 under some circumstances. We don't implement this. */ 354 s->gic.irq_state[ARMV7M_EXCP_MEM].enabled = (value & (1 << 16)) != 0; 355 s->gic.irq_state[ARMV7M_EXCP_BUS].enabled = (value & (1 << 17)) != 0; 356 s->gic.irq_state[ARMV7M_EXCP_USAGE].enabled = (value & (1 << 18)) != 0; 357 break; 358 case 0xd28: /* Configurable Fault Status. */ 359 case 0xd2c: /* Hard Fault Status. */ 360 case 0xd30: /* Debug Fault Status. */ 361 case 0xd34: /* Mem Manage Address. */ 362 case 0xd38: /* Bus Fault Address. */ 363 case 0xd3c: /* Aux Fault Status. */ 364 qemu_log_mask(LOG_UNIMP, 365 "NVIC: fault status registers unimplemented\n"); 366 break; 367 case 0xf00: /* Software Triggered Interrupt Register */ 368 if ((value & 0x1ff) < s->num_irq) { 369 gic_set_pending_private(&s->gic, 0, value & 0x1ff); 370 } 371 break; 372 default: 373 qemu_log_mask(LOG_GUEST_ERROR, 374 "NVIC: Bad write offset 0x%x\n", offset); 375 } 376 } 377 378 static uint64_t nvic_sysreg_read(void *opaque, hwaddr addr, 379 unsigned size) 380 { 381 nvic_state *s = (nvic_state *)opaque; 382 uint32_t offset = addr; 383 int i; 384 uint32_t val; 385 386 switch (offset) { 387 case 0xd18 ... 0xd23: /* System Handler Priority. */ 388 val = 0; 389 for (i = 0; i < size; i++) { 390 val |= s->gic.priority1[(offset - 0xd14) + i][0] << (i * 8); 391 } 392 return val; 393 case 0xfe0 ... 0xfff: /* ID. */ 394 if (offset & 3) { 395 return 0; 396 } 397 return nvic_id[(offset - 0xfe0) >> 2]; 398 } 399 if (size == 4) { 400 return nvic_readl(s, offset); 401 } 402 qemu_log_mask(LOG_GUEST_ERROR, 403 "NVIC: Bad read of size %d at offset 0x%x\n", size, offset); 404 return 0; 405 } 406 407 static void nvic_sysreg_write(void *opaque, hwaddr addr, 408 uint64_t value, unsigned size) 409 { 410 nvic_state *s = (nvic_state *)opaque; 411 uint32_t offset = addr; 412 int i; 413 414 switch (offset) { 415 case 0xd18 ... 0xd23: /* System Handler Priority. */ 416 for (i = 0; i < size; i++) { 417 s->gic.priority1[(offset - 0xd14) + i][0] = 418 (value >> (i * 8)) & 0xff; 419 } 420 gic_update(&s->gic); 421 return; 422 } 423 if (size == 4) { 424 nvic_writel(s, offset, value); 425 return; 426 } 427 qemu_log_mask(LOG_GUEST_ERROR, 428 "NVIC: Bad write of size %d at offset 0x%x\n", size, offset); 429 } 430 431 static const MemoryRegionOps nvic_sysreg_ops = { 432 .read = nvic_sysreg_read, 433 .write = nvic_sysreg_write, 434 .endianness = DEVICE_NATIVE_ENDIAN, 435 }; 436 437 static const VMStateDescription vmstate_nvic = { 438 .name = "armv7m_nvic", 439 .version_id = 1, 440 .minimum_version_id = 1, 441 .minimum_version_id_old = 1, 442 .fields = (VMStateField[]) { 443 VMSTATE_UINT32(systick.control, nvic_state), 444 VMSTATE_UINT32(systick.reload, nvic_state), 445 VMSTATE_INT64(systick.tick, nvic_state), 446 VMSTATE_TIMER(systick.timer, nvic_state), 447 VMSTATE_END_OF_LIST() 448 } 449 }; 450 451 static void armv7m_nvic_reset(DeviceState *dev) 452 { 453 nvic_state *s = NVIC(dev); 454 NVICClass *nc = NVIC_GET_CLASS(s); 455 nc->parent_reset(dev); 456 /* Common GIC reset resets to disabled; the NVIC doesn't have 457 * per-CPU interfaces so mark our non-existent CPU interface 458 * as enabled by default, and with a priority mask which allows 459 * all interrupts through. 460 */ 461 s->gic.cpu_enabled[0] = true; 462 s->gic.priority_mask[0] = 0x100; 463 /* The NVIC as a whole is always enabled. */ 464 s->gic.enabled = true; 465 systick_reset(s); 466 } 467 468 static void armv7m_nvic_realize(DeviceState *dev, Error **errp) 469 { 470 nvic_state *s = NVIC(dev); 471 NVICClass *nc = NVIC_GET_CLASS(s); 472 473 /* The NVIC always has only one CPU */ 474 s->gic.num_cpu = 1; 475 /* Tell the common code we're an NVIC */ 476 s->gic.revision = 0xffffffff; 477 s->num_irq = s->gic.num_irq; 478 nc->parent_realize(dev, errp); 479 if (error_is_set(errp)) { 480 return; 481 } 482 gic_init_irqs_and_distributor(&s->gic, s->num_irq); 483 /* The NVIC and system controller register area looks like this: 484 * 0..0xff : system control registers, including systick 485 * 0x100..0xcff : GIC-like registers 486 * 0xd00..0xfff : system control registers 487 * We use overlaying to put the GIC like registers 488 * over the top of the system control register region. 489 */ 490 memory_region_init(&s->container, "nvic", 0x1000); 491 /* The system register region goes at the bottom of the priority 492 * stack as it covers the whole page. 493 */ 494 memory_region_init_io(&s->sysregmem, &nvic_sysreg_ops, s, 495 "nvic_sysregs", 0x1000); 496 memory_region_add_subregion(&s->container, 0, &s->sysregmem); 497 /* Alias the GIC region so we can get only the section of it 498 * we need, and layer it on top of the system register region. 499 */ 500 memory_region_init_alias(&s->gic_iomem_alias, "nvic-gic", &s->gic.iomem, 501 0x100, 0xc00); 502 memory_region_add_subregion_overlap(&s->container, 0x100, 503 &s->gic_iomem_alias, 1); 504 /* Map the whole thing into system memory at the location required 505 * by the v7M architecture. 506 */ 507 memory_region_add_subregion(get_system_memory(), 0xe000e000, &s->container); 508 s->systick.timer = qemu_new_timer_ns(vm_clock, systick_timer_tick, s); 509 } 510 511 static void armv7m_nvic_instance_init(Object *obj) 512 { 513 /* We have a different default value for the num-irq property 514 * than our superclass. This function runs after qdev init 515 * has set the defaults from the Property array and before 516 * any user-specified property setting, so just modify the 517 * value in the GICState struct. 518 */ 519 GICState *s = ARM_GIC_COMMON(obj); 520 /* The ARM v7m may have anything from 0 to 496 external interrupt 521 * IRQ lines. We default to 64. Other boards may differ and should 522 * set the num-irq property appropriately. 523 */ 524 s->num_irq = 64; 525 } 526 527 static void armv7m_nvic_class_init(ObjectClass *klass, void *data) 528 { 529 NVICClass *nc = NVIC_CLASS(klass); 530 DeviceClass *dc = DEVICE_CLASS(klass); 531 532 nc->parent_reset = dc->reset; 533 nc->parent_realize = dc->realize; 534 dc->vmsd = &vmstate_nvic; 535 dc->reset = armv7m_nvic_reset; 536 dc->realize = armv7m_nvic_realize; 537 } 538 539 static const TypeInfo armv7m_nvic_info = { 540 .name = TYPE_NVIC, 541 .parent = TYPE_ARM_GIC_COMMON, 542 .instance_init = armv7m_nvic_instance_init, 543 .instance_size = sizeof(nvic_state), 544 .class_init = armv7m_nvic_class_init, 545 .class_size = sizeof(NVICClass), 546 }; 547 548 static void armv7m_nvic_register_types(void) 549 { 550 type_register_static(&armv7m_nvic_info); 551 } 552 553 type_init(armv7m_nvic_register_types) 554