| 1 | /* |
| 2 | * QEMU 8259 interrupt controller emulation |
| 3 | * |
| 4 | * Copyright (c) 2003-2004 Fabrice Bellard |
| 5 | * |
| 6 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
| 7 | * of this software and associated documentation files (the "Software"), to deal |
| 8 | * in the Software without restriction, including without limitation the rights |
| 9 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| 10 | * copies of the Software, and to permit persons to whom the Software is |
| 11 | * furnished to do so, subject to the following conditions: |
| 12 | * |
| 13 | * The above copyright notice and this permission notice shall be included in |
| 14 | * all copies or substantial portions of the Software. |
| 15 | * |
| 16 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 17 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 18 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| 19 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| 20 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| 21 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| 22 | * THE SOFTWARE. |
| 23 | */ |
| 24 | #include "qemu/osdep.h" |
| 25 | #include "hw/hw.h" |
| 26 | #include "hw/i386/pc.h" |
| 27 | #include "hw/isa/isa.h" |
| 28 | #include "qemu/timer.h" |
| 29 | #include "qemu/log.h" |
| 30 | #include "hw/isa/i8259_internal.h" |
| 31 | #include "trace.h" |
| 32 | |
| 33 | /* debug PIC */ |
| 34 | //#define DEBUG_PIC |
| 35 | |
| 36 | //#define DEBUG_IRQ_LATENCY |
| 37 | |
| 38 | #define TYPE_I8259 "isa-i8259" |
| 39 | #define PIC_CLASS(class) OBJECT_CLASS_CHECK(PICClass, (class), TYPE_I8259) |
| 40 | #define PIC_GET_CLASS(obj) OBJECT_GET_CLASS(PICClass, (obj), TYPE_I8259) |
| 41 | |
| 42 | /** |
| 43 | * PICClass: |
| 44 | * @parent_realize: The parent's realizefn. |
| 45 | */ |
| 46 | typedef struct PICClass { |
| 47 | PICCommonClass parent_class; |
| 48 | |
| 49 | DeviceRealize parent_realize; |
| 50 | } PICClass; |
| 51 | |
| 52 | #ifdef DEBUG_IRQ_LATENCY |
| 53 | static int64_t irq_time[16]; |
| 54 | #endif |
| 55 | DeviceState *isa_pic; |
| 56 | static PICCommonState *slave_pic; |
| 57 | |
| 58 | /* return the highest priority found in mask (highest = smallest |
| 59 | number). Return 8 if no irq */ |
| 60 | static int get_priority(PICCommonState *s, int mask) |
| 61 | { |
| 62 | int priority; |
| 63 | |
| 64 | if (mask == 0) { |
| 65 | return 8; |
| 66 | } |
| 67 | priority = 0; |
| 68 | while ((mask & (1 << ((priority + s->priority_add) & 7))) == 0) { |
| 69 | priority++; |
| 70 | } |
| 71 | return priority; |
| 72 | } |
| 73 | |
| 74 | /* return the pic wanted interrupt. return -1 if none */ |
| 75 | static int pic_get_irq(PICCommonState *s) |
| 76 | { |
| 77 | int mask, cur_priority, priority; |
| 78 | |
| 79 | mask = s->irr & ~s->imr; |
| 80 | priority = get_priority(s, mask); |
| 81 | if (priority == 8) { |
| 82 | return -1; |
| 83 | } |
| 84 | /* compute current priority. If special fully nested mode on the |
| 85 | master, the IRQ coming from the slave is not taken into account |
| 86 | for the priority computation. */ |
| 87 | mask = s->isr; |
| 88 | if (s->special_mask) { |
| 89 | mask &= ~s->imr; |
| 90 | } |
| 91 | if (s->special_fully_nested_mode && s->master) { |
| 92 | mask &= ~(1 << 2); |
| 93 | } |
| 94 | cur_priority = get_priority(s, mask); |
| 95 | if (priority < cur_priority) { |
| 96 | /* higher priority found: an irq should be generated */ |
| 97 | return (priority + s->priority_add) & 7; |
| 98 | } else { |
| 99 | return -1; |
| 100 | } |
| 101 | } |
| 102 | |
| 103 | /* Update INT output. Must be called every time the output may have changed. */ |
| 104 | static void pic_update_irq(PICCommonState *s) |
| 105 | { |
| 106 | int irq; |
| 107 | |
| 108 | irq = pic_get_irq(s); |
| 109 | if (irq >= 0) { |
| 110 | trace_pic_update_irq(s->master, s->imr, s->irr, s->priority_add); |
| 111 | qemu_irq_raise(s->int_out[0]); |
| 112 | } else { |
| 113 | qemu_irq_lower(s->int_out[0]); |
| 114 | } |
| 115 | } |
| 116 | |
| 117 | /* set irq level. If an edge is detected, then the IRR is set to 1 */ |
| 118 | static void pic_set_irq(void *opaque, int irq, int level) |
| 119 | { |
| 120 | PICCommonState *s = opaque; |
| 121 | int mask = 1 << irq; |
| 122 | int irq_index = s->master ? irq : irq + 8; |
| 123 | |
| 124 | trace_pic_set_irq(s->master, irq, level); |
| 125 | pic_stat_update_irq(irq_index, level); |
| 126 | |
| 127 | #ifdef DEBUG_IRQ_LATENCY |
| 128 | if (level) { |
| 129 | irq_time[irq_index] = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); |
| 130 | } |
| 131 | #endif |
| 132 | |
| 133 | if (s->elcr & mask) { |
| 134 | /* level triggered */ |
| 135 | if (level) { |
| 136 | s->irr |= mask; |
| 137 | s->last_irr |= mask; |
| 138 | } else { |
| 139 | s->irr &= ~mask; |
| 140 | s->last_irr &= ~mask; |
| 141 | } |
| 142 | } else { |
| 143 | /* edge triggered */ |
| 144 | if (level) { |
| 145 | if ((s->last_irr & mask) == 0) { |
| 146 | s->irr |= mask; |
| 147 | } |
| 148 | s->last_irr |= mask; |
| 149 | } else { |
| 150 | s->last_irr &= ~mask; |
| 151 | } |
| 152 | } |
| 153 | pic_update_irq(s); |
| 154 | } |
| 155 | |
| 156 | /* acknowledge interrupt 'irq' */ |
| 157 | static void pic_intack(PICCommonState *s, int irq) |
| 158 | { |
| 159 | if (s->auto_eoi) { |
| 160 | if (s->rotate_on_auto_eoi) { |
| 161 | s->priority_add = (irq + 1) & 7; |
| 162 | } |
| 163 | } else { |
| 164 | s->isr |= (1 << irq); |
| 165 | } |
| 166 | /* We don't clear a level sensitive interrupt here */ |
| 167 | if (!(s->elcr & (1 << irq))) { |
| 168 | s->irr &= ~(1 << irq); |
| 169 | } |
| 170 | pic_update_irq(s); |
| 171 | } |
| 172 | |
| 173 | int pic_read_irq(DeviceState *d) |
| 174 | { |
| 175 | PICCommonState *s = PIC_COMMON(d); |
| 176 | int irq, irq2, intno; |
| 177 | |
| 178 | irq = pic_get_irq(s); |
| 179 | if (irq >= 0) { |
| 180 | if (irq == 2) { |
| 181 | irq2 = pic_get_irq(slave_pic); |
| 182 | if (irq2 >= 0) { |
| 183 | pic_intack(slave_pic, irq2); |
| 184 | } else { |
| 185 | /* spurious IRQ on slave controller */ |
| 186 | irq2 = 7; |
| 187 | } |
| 188 | intno = slave_pic->irq_base + irq2; |
| 189 | } else { |
| 190 | intno = s->irq_base + irq; |
| 191 | } |
| 192 | pic_intack(s, irq); |
| 193 | } else { |
| 194 | /* spurious IRQ on host controller */ |
| 195 | irq = 7; |
| 196 | intno = s->irq_base + irq; |
| 197 | } |
| 198 | |
| 199 | if (irq == 2) { |
| 200 | irq = irq2 + 8; |
| 201 | } |
| 202 | |
| 203 | #ifdef DEBUG_IRQ_LATENCY |
| 204 | printf("IRQ%d latency=%0.3fus\n", |
| 205 | irq, |
| 206 | (double)(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) - |
| 207 | irq_time[irq]) * 1000000.0 / NANOSECONDS_PER_SECOND); |
| 208 | #endif |
| 209 | |
| 210 | trace_pic_interrupt(irq, intno); |
| 211 | return intno; |
| 212 | } |
| 213 | |
| 214 | static void pic_init_reset(PICCommonState *s) |
| 215 | { |
| 216 | pic_reset_common(s); |
| 217 | pic_update_irq(s); |
| 218 | } |
| 219 | |
| 220 | static void pic_reset(DeviceState *dev) |
| 221 | { |
| 222 | PICCommonState *s = PIC_COMMON(dev); |
| 223 | |
| 224 | s->elcr = 0; |
| 225 | pic_init_reset(s); |
| 226 | } |
| 227 | |
| 228 | static void pic_ioport_write(void *opaque, hwaddr addr64, |
| 229 | uint64_t val64, unsigned size) |
| 230 | { |
| 231 | PICCommonState *s = opaque; |
| 232 | uint32_t addr = addr64; |
| 233 | uint32_t val = val64; |
| 234 | int priority, cmd, irq; |
| 235 | |
| 236 | trace_pic_ioport_write(s->master, addr, val); |
| 237 | |
| 238 | if (addr == 0) { |
| 239 | if (val & 0x10) { |
| 240 | pic_init_reset(s); |
| 241 | s->init_state = 1; |
| 242 | s->init4 = val & 1; |
| 243 | s->single_mode = val & 2; |
| 244 | if (val & 0x08) { |
| 245 | qemu_log_mask(LOG_UNIMP, |
| 246 | "i8259: level sensitive irq not supported\n"); |
| 247 | } |
| 248 | } else if (val & 0x08) { |
| 249 | if (val & 0x04) { |
| 250 | s->poll = 1; |
| 251 | } |
| 252 | if (val & 0x02) { |
| 253 | s->read_reg_select = val & 1; |
| 254 | } |
| 255 | if (val & 0x40) { |
| 256 | s->special_mask = (val >> 5) & 1; |
| 257 | } |
| 258 | } else { |
| 259 | cmd = val >> 5; |
| 260 | switch (cmd) { |
| 261 | case 0: |
| 262 | case 4: |
| 263 | s->rotate_on_auto_eoi = cmd >> 2; |
| 264 | break; |
| 265 | case 1: /* end of interrupt */ |
| 266 | case 5: |
| 267 | priority = get_priority(s, s->isr); |
| 268 | if (priority != 8) { |
| 269 | irq = (priority + s->priority_add) & 7; |
| 270 | s->isr &= ~(1 << irq); |
| 271 | if (cmd == 5) { |
| 272 | s->priority_add = (irq + 1) & 7; |
| 273 | } |
| 274 | pic_update_irq(s); |
| 275 | } |
| 276 | break; |
| 277 | case 3: |
| 278 | irq = val & 7; |
| 279 | s->isr &= ~(1 << irq); |
| 280 | pic_update_irq(s); |
| 281 | break; |
| 282 | case 6: |
| 283 | s->priority_add = (val + 1) & 7; |
| 284 | pic_update_irq(s); |
| 285 | break; |
| 286 | case 7: |
| 287 | irq = val & 7; |
| 288 | s->isr &= ~(1 << irq); |
| 289 | s->priority_add = (irq + 1) & 7; |
| 290 | pic_update_irq(s); |
| 291 | break; |
| 292 | default: |
| 293 | /* no operation */ |
| 294 | break; |
| 295 | } |
| 296 | } |
| 297 | } else { |
| 298 | switch (s->init_state) { |
| 299 | case 0: |
| 300 | /* normal mode */ |
| 301 | s->imr = val; |
| 302 | pic_update_irq(s); |
| 303 | break; |
| 304 | case 1: |
| 305 | s->irq_base = val & 0xf8; |
| 306 | s->init_state = s->single_mode ? (s->init4 ? 3 : 0) : 2; |
| 307 | break; |
| 308 | case 2: |
| 309 | if (s->init4) { |
| 310 | s->init_state = 3; |
| 311 | } else { |
| 312 | s->init_state = 0; |
| 313 | } |
| 314 | break; |
| 315 | case 3: |
| 316 | s->special_fully_nested_mode = (val >> 4) & 1; |
| 317 | s->auto_eoi = (val >> 1) & 1; |
| 318 | s->init_state = 0; |
| 319 | break; |
| 320 | } |
| 321 | } |
| 322 | } |
| 323 | |
| 324 | static uint64_t pic_ioport_read(void *opaque, hwaddr addr, |
| 325 | unsigned size) |
| 326 | { |
| 327 | PICCommonState *s = opaque; |
| 328 | int ret; |
| 329 | |
| 330 | if (s->poll) { |
| 331 | ret = pic_get_irq(s); |
| 332 | if (ret >= 0) { |
| 333 | pic_intack(s, ret); |
| 334 | ret |= 0x80; |
| 335 | } else { |
| 336 | ret = 0; |
| 337 | } |
| 338 | s->poll = 0; |
| 339 | } else { |
| 340 | if (addr == 0) { |
| 341 | if (s->read_reg_select) { |
| 342 | ret = s->isr; |
| 343 | } else { |
| 344 | ret = s->irr; |
| 345 | } |
| 346 | } else { |
| 347 | ret = s->imr; |
| 348 | } |
| 349 | } |
| 350 | trace_pic_ioport_read(s->master, addr, ret); |
| 351 | return ret; |
| 352 | } |
| 353 | |
| 354 | int pic_get_output(DeviceState *d) |
| 355 | { |
| 356 | PICCommonState *s = PIC_COMMON(d); |
| 357 | |
| 358 | return (pic_get_irq(s) >= 0); |
| 359 | } |
| 360 | |
| 361 | static void elcr_ioport_write(void *opaque, hwaddr addr, |
| 362 | uint64_t val, unsigned size) |
| 363 | { |
| 364 | PICCommonState *s = opaque; |
| 365 | s->elcr = val & s->elcr_mask; |
| 366 | } |
| 367 | |
| 368 | static uint64_t elcr_ioport_read(void *opaque, hwaddr addr, |
| 369 | unsigned size) |
| 370 | { |
| 371 | PICCommonState *s = opaque; |
| 372 | return s->elcr; |
| 373 | } |
| 374 | |
| 375 | static const MemoryRegionOps pic_base_ioport_ops = { |
| 376 | .read = pic_ioport_read, |
| 377 | .write = pic_ioport_write, |
| 378 | .impl = { |
| 379 | .min_access_size = 1, |
| 380 | .max_access_size = 1, |
| 381 | }, |
| 382 | }; |
| 383 | |
| 384 | static const MemoryRegionOps pic_elcr_ioport_ops = { |
| 385 | .read = elcr_ioport_read, |
| 386 | .write = elcr_ioport_write, |
| 387 | .impl = { |
| 388 | .min_access_size = 1, |
| 389 | .max_access_size = 1, |
| 390 | }, |
| 391 | }; |
| 392 | |
| 393 | static void pic_realize(DeviceState *dev, Error **errp) |
| 394 | { |
| 395 | PICCommonState *s = PIC_COMMON(dev); |
| 396 | PICClass *pc = PIC_GET_CLASS(dev); |
| 397 | |
| 398 | memory_region_init_io(&s->base_io, OBJECT(s), &pic_base_ioport_ops, s, |
| 399 | "pic", 2); |
| 400 | memory_region_init_io(&s->elcr_io, OBJECT(s), &pic_elcr_ioport_ops, s, |
| 401 | "elcr", 1); |
| 402 | |
| 403 | qdev_init_gpio_out(dev, s->int_out, ARRAY_SIZE(s->int_out)); |
| 404 | qdev_init_gpio_in(dev, pic_set_irq, 8); |
| 405 | |
| 406 | pc->parent_realize(dev, errp); |
| 407 | } |
| 408 | |
| 409 | qemu_irq *i8259_init(ISABus *bus, qemu_irq parent_irq) |
| 410 | { |
| 411 | qemu_irq *irq_set; |
| 412 | DeviceState *dev; |
| 413 | ISADevice *isadev; |
| 414 | int i; |
| 415 | |
| 416 | irq_set = g_new0(qemu_irq, ISA_NUM_IRQS); |
| 417 | |
| 418 | isadev = i8259_init_chip(TYPE_I8259, bus, true); |
| 419 | dev = DEVICE(isadev); |
| 420 | |
| 421 | qdev_connect_gpio_out(dev, 0, parent_irq); |
| 422 | for (i = 0 ; i < 8; i++) { |
| 423 | irq_set[i] = qdev_get_gpio_in(dev, i); |
| 424 | } |
| 425 | |
| 426 | isa_pic = dev; |
| 427 | |
| 428 | isadev = i8259_init_chip(TYPE_I8259, bus, false); |
| 429 | dev = DEVICE(isadev); |
| 430 | |
| 431 | qdev_connect_gpio_out(dev, 0, irq_set[2]); |
| 432 | for (i = 0 ; i < 8; i++) { |
| 433 | irq_set[i + 8] = qdev_get_gpio_in(dev, i); |
| 434 | } |
| 435 | |
| 436 | slave_pic = PIC_COMMON(dev); |
| 437 | |
| 438 | return irq_set; |
| 439 | } |
| 440 | |
| 441 | static void i8259_class_init(ObjectClass *klass, void *data) |
| 442 | { |
| 443 | PICClass *k = PIC_CLASS(klass); |
| 444 | DeviceClass *dc = DEVICE_CLASS(klass); |
| 445 | |
| 446 | device_class_set_parent_realize(dc, pic_realize, &k->parent_realize); |
| 447 | dc->reset = pic_reset; |
| 448 | } |
| 449 | |
| 450 | static const TypeInfo i8259_info = { |
| 451 | .name = TYPE_I8259, |
| 452 | .instance_size = sizeof(PICCommonState), |
| 453 | .parent = TYPE_PIC_COMMON, |
| 454 | .class_init = i8259_class_init, |
| 455 | .class_size = sizeof(PICClass), |
| 456 | }; |
| 457 | |
| 458 | static void pic_register_types(void) |
| 459 | { |
| 460 | type_register_static(&i8259_info); |
| 461 | } |
| 462 | |
| 463 | type_init(pic_register_types) |