hw/hpet.c

   1 /*
   2  *  High Precisition Event Timer emulation
   3  *
   4  *  Copyright (c) 2007 Alexander Graf
   5  *  Copyright (c) 2008 IBM Corporation
   6  *
   7  *  Authors: Beth Kon <bkon@us.ibm.com>
   8  *
   9  * This library is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public
  11  * License as published by the Free Software Foundation; either
  12  * version 2 of the License, or (at your option) any later version.
  13  *
  14  * This library is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with this library; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA  02110-1301 USA
  22  *
  23  * *****************************************************************
  24  *
  25  * This driver attempts to emulate an HPET device in software.
  26  */
  27
  28 #include "hw.h"
  29 #include "pc.h"
  30 #include "console.h"
  31 #include "qemu-timer.h"
  32 #include "hpet_emul.h"
  33
  34 //#define HPET_DEBUG
  35 #ifdef HPET_DEBUG
  36 #define dprintf printf
  37 #else
  38 #define dprintf(...)
  39 #endif
  40
  41 static HPETState *hpet_statep;
  42
  43 uint32_t hpet_in_legacy_mode(void)
  44 {
  45     if (hpet_statep)
  46         return hpet_statep->config & HPET_CFG_LEGACY;
  47     else
  48         return 0;
  49 }
  50
  51 static uint32_t timer_int_route(struct HPETTimer *timer)
  52 {
  53     uint32_t route;
  54     route = (timer->config & HPET_TN_INT_ROUTE_MASK) >> HPET_TN_INT_ROUTE_SHIFT;
  55     return route;
  56 }
  57
  58 static uint32_t hpet_enabled(void)
  59 {
  60     return hpet_statep->config & HPET_CFG_ENABLE;
  61 }
  62
  63 static uint32_t timer_is_periodic(HPETTimer *t)
  64 {
  65     return t->config & HPET_TN_PERIODIC;
  66 }
  67
  68 static uint32_t timer_enabled(HPETTimer *t)
  69 {
  70     return t->config & HPET_TN_ENABLE;
  71 }
  72
  73 static uint32_t hpet_time_after(uint64_t a, uint64_t b)
  74 {
  75     return ((int32_t)(b) - (int32_t)(a) < 0);
  76 }
  77
  78 static uint32_t hpet_time_after64(uint64_t a, uint64_t b)
  79 {
  80     return ((int64_t)(b) - (int64_t)(a) < 0);
  81 }
  82
  83 static uint64_t ticks_to_ns(uint64_t value)
  84 {
  85     return (muldiv64(value, HPET_CLK_PERIOD, FS_PER_NS));
  86 }
  87
  88 static uint64_t ns_to_ticks(uint64_t value)
  89 {
  90     return (muldiv64(value, FS_PER_NS, HPET_CLK_PERIOD));
  91 }
  92
  93 static uint64_t hpet_fixup_reg(uint64_t new, uint64_t old, uint64_t mask)
  94 {
  95     new &= mask;
  96     new |= old & ~mask;
  97     return new;
  98 }
  99
 100 static int activating_bit(uint64_t old, uint64_t new, uint64_t mask)
 101 {
 102     return (!(old & mask) && (new & mask));
 103 }
 104
 105 static int deactivating_bit(uint64_t old, uint64_t new, uint64_t mask)
 106 {
 107     return ((old & mask) && !(new & mask));
 108 }
 109
 110 static uint64_t hpet_get_ticks(void)
 111 {
 112     uint64_t ticks;
 113     ticks = ns_to_ticks(qemu_get_clock(vm_clock) + hpet_statep->hpet_offset);
 114     return ticks;
 115 }
 116
 117 /*
 118  * calculate diff between comparator value and current ticks
 119  */
 120 static inline uint64_t hpet_calculate_diff(HPETTimer *t, uint64_t current)
 121 {
 122
 123     if (t->config & HPET_TN_32BIT) {
 124         uint32_t diff, cmp;
 125         cmp = (uint32_t)t->cmp;
 126         diff = cmp - (uint32_t)current;
 127         diff = (int32_t)diff > 0 ? diff : (uint32_t)0;
 128         return (uint64_t)diff;
 129     } else {
 130         uint64_t diff, cmp;
 131         cmp = t->cmp;
 132         diff = cmp - current;
 133         diff = (int64_t)diff > 0 ? diff : (uint64_t)0;
 134         return diff;
 135     }
 136 }
 137
 138 static void update_irq(struct HPETTimer *timer)
 139 {
 140     qemu_irq irq;
 141     int route;
 142
 143     if (timer->tn <= 1 && hpet_in_legacy_mode()) {
 144         /* if LegacyReplacementRoute bit is set, HPET specification requires
 145          * timer0 be routed to IRQ0 in NON-APIC or IRQ2 in the I/O APIC,
 146          * timer1 be routed to IRQ8 in NON-APIC or IRQ8 in the I/O APIC.
 147          */
 148         if (timer->tn == 0) {
 149             irq=timer->state->irqs[0];
 150         } else
 151             irq=timer->state->irqs[8];
 152     } else {
 153         route=timer_int_route(timer);
 154         irq=timer->state->irqs[route];
 155     }
 156     if (timer_enabled(timer) && hpet_enabled()) {
 157         qemu_irq_pulse(irq);
 158     }
 159 }
 160
 161 static void hpet_save(QEMUFile *f, void *opaque)
 162 {
 163     HPETState *s = opaque;
 164     int i;
 165     qemu_put_be64s(f, &s->config);
 166     qemu_put_be64s(f, &s->isr);
 167     /* save current counter value */
 168     s->hpet_counter = hpet_get_ticks();
 169     qemu_put_be64s(f, &s->hpet_counter);
 170
 171     for (i = 0; i < HPET_NUM_TIMERS; i++) {
 172         qemu_put_8s(f, &s->timer[i].tn);
 173         qemu_put_be64s(f, &s->timer[i].config);
 174         qemu_put_be64s(f, &s->timer[i].cmp);
 175         qemu_put_be64s(f, &s->timer[i].fsb);
 176         qemu_put_be64s(f, &s->timer[i].period);
 177         qemu_put_8s(f, &s->timer[i].wrap_flag);
 178         if (s->timer[i].qemu_timer) {
 179             qemu_put_timer(f, s->timer[i].qemu_timer);
 180         }
 181     }
 182 }
 183
 184 static int hpet_load(QEMUFile *f, void *opaque, int version_id)
 185 {
 186     HPETState *s = opaque;
 187     int i;
 188
 189     if (version_id != 1)
 190         return -EINVAL;
 191
 192     qemu_get_be64s(f, &s->config);
 193     qemu_get_be64s(f, &s->isr);
 194     qemu_get_be64s(f, &s->hpet_counter);
 195     /* Recalculate the offset between the main counter and guest time */
 196     s->hpet_offset = ticks_to_ns(s->hpet_counter) - qemu_get_clock(vm_clock);
 197
 198     for (i = 0; i < HPET_NUM_TIMERS; i++) {
 199         qemu_get_8s(f, &s->timer[i].tn);
 200         qemu_get_be64s(f, &s->timer[i].config);
 201         qemu_get_be64s(f, &s->timer[i].cmp);
 202         qemu_get_be64s(f, &s->timer[i].fsb);
 203         qemu_get_be64s(f, &s->timer[i].period);
 204         qemu_get_8s(f, &s->timer[i].wrap_flag);
 205         if (s->timer[i].qemu_timer) {
 206             qemu_get_timer(f, s->timer[i].qemu_timer);
 207         }
 208     }
 209     return 0;
 210 }
 211
 212 /*
 213  * timer expiration callback
 214  */
 215 static void hpet_timer(void *opaque)
 216 {
 217     HPETTimer *t = (HPETTimer*)opaque;
 218     uint64_t diff;
 219
 220     uint64_t period = t->period;
 221     uint64_t cur_tick = hpet_get_ticks();
 222
 223     if (timer_is_periodic(t) && period != 0) {
 224         if (t->config & HPET_TN_32BIT) {
 225             while (hpet_time_after(cur_tick, t->cmp))
 226                 t->cmp = (uint32_t)(t->cmp + t->period);
 227         } else
 228             while (hpet_time_after64(cur_tick, t->cmp))
 229                 t->cmp += period;
 230
 231         diff = hpet_calculate_diff(t, cur_tick);
 232         qemu_mod_timer(t->qemu_timer, qemu_get_clock(vm_clock)
 233                        + (int64_t)ticks_to_ns(diff));
 234     } else if (t->config & HPET_TN_32BIT && !timer_is_periodic(t)) {
 235         if (t->wrap_flag) {
 236             diff = hpet_calculate_diff(t, cur_tick);
 237             qemu_mod_timer(t->qemu_timer, qemu_get_clock(vm_clock)
 238                            + (int64_t)ticks_to_ns(diff));
 239             t->wrap_flag = 0;
 240         }
 241     }
 242     update_irq(t);
 243 }
 244
 245 static void hpet_set_timer(HPETTimer *t)
 246 {
 247     uint64_t diff;
 248     uint32_t wrap_diff;  /* how many ticks until we wrap? */
 249     uint64_t cur_tick = hpet_get_ticks();
 250
 251     /* whenever new timer is being set up, make sure wrap_flag is 0 */
 252     t->wrap_flag = 0;
 253     diff = hpet_calculate_diff(t, cur_tick);
 254
 255     /* hpet spec says in one-shot 32-bit mode, generate an interrupt when
 256      * counter wraps in addition to an interrupt with comparator match.
 257      */
 258     if (t->config & HPET_TN_32BIT && !timer_is_periodic(t)) {
 259         wrap_diff = 0xffffffff - (uint32_t)cur_tick;
 260         if (wrap_diff < (uint32_t)diff) {
 261             diff = wrap_diff;
 262             t->wrap_flag = 1;
 263         }
 264     }
 265     qemu_mod_timer(t->qemu_timer, qemu_get_clock(vm_clock)
 266                    + (int64_t)ticks_to_ns(diff));
 267 }
 268
 269 static void hpet_del_timer(HPETTimer *t)
 270 {
 271     qemu_del_timer(t->qemu_timer);
 272 }
 273
 274 #ifdef HPET_DEBUG
 275 static uint32_t hpet_ram_readb(void *opaque, target_phys_addr_t addr)
 276 {
 277     printf("qemu: hpet_read b at %" PRIx64 "\n", addr);
 278     return 0;
 279 }
 280
 281 static uint32_t hpet_ram_readw(void *opaque, target_phys_addr_t addr)
 282 {
 283     printf("qemu: hpet_read w at %" PRIx64 "\n", addr);
 284     return 0;
 285 }
 286 #endif
 287
 288 static uint32_t hpet_ram_readl(void *opaque, target_phys_addr_t addr)
 289 {
 290     HPETState *s = (HPETState *)opaque;
 291     uint64_t cur_tick, index;
 292
 293     dprintf("qemu: Enter hpet_ram_readl at %" PRIx64 "\n", addr);
 294     index = addr;
 295     /*address range of all TN regs*/
 296     if (index >= 0x100 && index <= 0x3ff) {
 297         uint8_t timer_id = (addr - 0x100) / 0x20;
 298         if (timer_id > HPET_NUM_TIMERS - 1) {
 299             printf("qemu: timer id out of range\n");
 300             return 0;
 301         }
 302         HPETTimer *timer = &s->timer[timer_id];
 303
 304         switch ((addr - 0x100) % 0x20) {
 305             case HPET_TN_CFG:
 306                 return timer->config;
 307             case HPET_TN_CFG + 4: // Interrupt capabilities
 308                 return timer->config >> 32;
 309             case HPET_TN_CMP: // comparator register
 310                 return timer->cmp;
 311             case HPET_TN_CMP + 4:
 312                 return timer->cmp >> 32;
 313             case HPET_TN_ROUTE:
 314                 return timer->fsb >> 32;
 315             default:
 316                 dprintf("qemu: invalid hpet_ram_readl\n");
 317                 break;
 318         }
 319     } else {
 320         switch (index) {
 321             case HPET_ID:
 322                 return s->capability;
 323             case HPET_PERIOD:
 324                 return s->capability >> 32;
 325             case HPET_CFG:
 326                 return s->config;
 327             case HPET_CFG + 4:
 328                 dprintf("qemu: invalid HPET_CFG + 4 hpet_ram_readl \n");
 329                 return 0;
 330             case HPET_COUNTER:
 331                 if (hpet_enabled())
 332                     cur_tick = hpet_get_ticks();
 333                 else
 334                     cur_tick = s->hpet_counter;
 335                 dprintf("qemu: reading counter  = %" PRIx64 "\n", cur_tick);
 336                 return cur_tick;
 337             case HPET_COUNTER + 4:
 338                 if (hpet_enabled())
 339                     cur_tick = hpet_get_ticks();
 340                 else
 341                     cur_tick = s->hpet_counter;
 342                 dprintf("qemu: reading counter + 4  = %" PRIx64 "\n", cur_tick);
 343                 return cur_tick >> 32;
 344             case HPET_STATUS:
 345                 return s->isr;
 346             default:
 347                 dprintf("qemu: invalid hpet_ram_readl\n");
 348                 break;
 349         }
 350     }
 351     return 0;
 352 }
 353
 354 #ifdef HPET_DEBUG
 355 static void hpet_ram_writeb(void *opaque, target_phys_addr_t addr,
 356                             uint32_t value)
 357 {
 358     printf("qemu: invalid hpet_write b at %" PRIx64 " = %#x\n",
 359            addr, value);
 360 }
 361
 362 static void hpet_ram_writew(void *opaque, target_phys_addr_t addr,
 363                             uint32_t value)
 364 {
 365     printf("qemu: invalid hpet_write w at %" PRIx64 " = %#x\n",
 366            addr, value);
 367 }
 368 #endif
 369
 370 static void hpet_ram_writel(void *opaque, target_phys_addr_t addr,
 371                             uint32_t value)
 372 {
 373     int i;
 374     HPETState *s = (HPETState *)opaque;
 375     uint64_t old_val, new_val, index;
 376
 377     dprintf("qemu: Enter hpet_ram_writel at %" PRIx64 " = %#x\n", addr, value);
 378     index = addr;
 379     old_val = hpet_ram_readl(opaque, addr);
 380     new_val = value;
 381
 382     /*address range of all TN regs*/
 383     if (index >= 0x100 && index <= 0x3ff) {
 384         uint8_t timer_id = (addr - 0x100) / 0x20;
 385         dprintf("qemu: hpet_ram_writel timer_id = %#x \n", timer_id);
 386         HPETTimer *timer = &s->timer[timer_id];
 387
 388         switch ((addr - 0x100) % 0x20) {
 389             case HPET_TN_CFG:
 390                 dprintf("qemu: hpet_ram_writel HPET_TN_CFG\n");
 391                 timer->config = hpet_fixup_reg(new_val, old_val,
 392                                                HPET_TN_CFG_WRITE_MASK);
 393                 if (new_val & HPET_TN_32BIT) {
 394                     timer->cmp = (uint32_t)timer->cmp;
 395                     timer->period = (uint32_t)timer->period;
 396                 }
 397                 if (new_val & HPET_TIMER_TYPE_LEVEL) {
 398                     printf("qemu: level-triggered hpet not supported\n");
 399                     exit (-1);
 400                 }
 401
 402                 break;
 403             case HPET_TN_CFG + 4: // Interrupt capabilities
 404                 dprintf("qemu: invalid HPET_TN_CFG+4 write\n");
 405                 break;
 406             case HPET_TN_CMP: // comparator register
 407                 dprintf("qemu: hpet_ram_writel HPET_TN_CMP \n");
 408                 if (timer->config & HPET_TN_32BIT)
 409                     new_val = (uint32_t)new_val;
 410                 if (!timer_is_periodic(timer) ||
 411                            (timer->config & HPET_TN_SETVAL))
 412                     timer->cmp = (timer->cmp & 0xffffffff00000000ULL)
 413                                   | new_val;
 414                 if (timer_is_periodic(timer)) {
 415                     /*
 416                      * FIXME: Clamp period to reasonable min value?
 417                      * Clamp period to reasonable max value
 418                      */
 419                     new_val &= (timer->config & HPET_TN_32BIT ? ~0u : ~0ull) >> 1;
 420                     timer->period = (timer->period & 0xffffffff00000000ULL)
 421                                      | new_val;
 422                 }
 423                 timer->config &= ~HPET_TN_SETVAL;
 424                 if (hpet_enabled())
 425                     hpet_set_timer(timer);
 426                 break;
 427             case HPET_TN_CMP + 4: // comparator register high order
 428                 dprintf("qemu: hpet_ram_writel HPET_TN_CMP + 4\n");
 429                 if (!timer_is_periodic(timer) ||
 430                            (timer->config & HPET_TN_SETVAL))
 431                     timer->cmp = (timer->cmp & 0xffffffffULL)
 432                                   | new_val << 32;
 433                 else {
 434                     /*
 435                      * FIXME: Clamp period to reasonable min value?
 436                      * Clamp period to reasonable max value
 437                      */
 438                     new_val &= (timer->config
 439                                 & HPET_TN_32BIT ? ~0u : ~0ull) >> 1;
 440                     timer->period = (timer->period & 0xffffffffULL)
 441                                      | new_val << 32;
 442                 }
 443                 timer->config &= ~HPET_TN_SETVAL;
 444                 if (hpet_enabled())
 445                     hpet_set_timer(timer);
 446                 break;
 447             case HPET_TN_ROUTE + 4:
 448                 dprintf("qemu: hpet_ram_writel HPET_TN_ROUTE + 4\n");
 449                 break;
 450             default:
 451                 dprintf("qemu: invalid hpet_ram_writel\n");
 452                 break;
 453         }
 454         return;
 455     } else {
 456         switch (index) {
 457             case HPET_ID:
 458                 return;
 459             case HPET_CFG:
 460                 s->config = hpet_fixup_reg(new_val, old_val,
 461                                            HPET_CFG_WRITE_MASK);
 462                 if (activating_bit(old_val, new_val, HPET_CFG_ENABLE)) {
 463                     /* Enable main counter and interrupt generation. */
 464                     s->hpet_offset = ticks_to_ns(s->hpet_counter)
 465                                      - qemu_get_clock(vm_clock);
 466                     for (i = 0; i < HPET_NUM_TIMERS; i++)
 467                         if ((&s->timer[i])->cmp != ~0ULL)
 468                             hpet_set_timer(&s->timer[i]);
 469                 }
 470                 else if (deactivating_bit(old_val, new_val, HPET_CFG_ENABLE)) {
 471                     /* Halt main counter and disable interrupt generation. */
 472                     s->hpet_counter = hpet_get_ticks();
 473                     for (i = 0; i < HPET_NUM_TIMERS; i++)
 474                         hpet_del_timer(&s->timer[i]);
 475                 }
 476                 /* i8254 and RTC are disabled when HPET is in legacy mode */
 477                 if (activating_bit(old_val, new_val, HPET_CFG_LEGACY)) {
 478                     hpet_pit_disable();
 479                 } else if (deactivating_bit(old_val, new_val, HPET_CFG_LEGACY)) {
 480                     hpet_pit_enable();
 481                 }
 482                 break;
 483             case HPET_CFG + 4:
 484                 dprintf("qemu: invalid HPET_CFG+4 write \n");
 485                 break;
 486             case HPET_STATUS:
 487                 /* FIXME: need to handle level-triggered interrupts */
 488                 break;
 489             case HPET_COUNTER:
 490                if (hpet_enabled())
 491                    printf("qemu: Writing counter while HPET enabled!\n");
 492                s->hpet_counter = (s->hpet_counter & 0xffffffff00000000ULL)
 493                                   | value;
 494                dprintf("qemu: HPET counter written. ctr = %#x -> %" PRIx64 "\n",
 495                         value, s->hpet_counter);
 496                break;
 497             case HPET_COUNTER + 4:
 498                if (hpet_enabled())
 499                    printf("qemu: Writing counter while HPET enabled!\n");
 500                s->hpet_counter = (s->hpet_counter & 0xffffffffULL)
 501                                   | (((uint64_t)value) << 32);
 502                dprintf("qemu: HPET counter + 4 written. ctr = %#x -> %" PRIx64 "\n",
 503                         value, s->hpet_counter);
 504                break;
 505             default:
 506                dprintf("qemu: invalid hpet_ram_writel\n");
 507                break;
 508         }
 509     }
 510 }
 511
 512 static CPUReadMemoryFunc *hpet_ram_read[] = {
 513 #ifdef HPET_DEBUG
 514     hpet_ram_readb,
 515     hpet_ram_readw,
 516 #else
 517     NULL,
 518     NULL,
 519 #endif
 520     hpet_ram_readl,
 521 };
 522
 523 static CPUWriteMemoryFunc *hpet_ram_write[] = {
 524 #ifdef HPET_DEBUG
 525     hpet_ram_writeb,
 526     hpet_ram_writew,
 527 #else
 528     NULL,
 529     NULL,
 530 #endif
 531     hpet_ram_writel,
 532 };
 533
 534 static void hpet_reset(void *opaque) {
 535     HPETState *s = opaque;
 536     int i;
 537     static int count = 0;
 538
 539     for (i=0; i<HPET_NUM_TIMERS; i++) {
 540         HPETTimer *timer = &s->timer[i];
 541         hpet_del_timer(timer);
 542         timer->tn = i;
 543         timer->cmp = ~0ULL;
 544         timer->config =  HPET_TN_PERIODIC_CAP | HPET_TN_SIZE_CAP;
 545         /* advertise availability of irqs 5,10,11 */
 546         timer->config |=  0x00000c20ULL << 32;
 547         timer->state = s;
 548         timer->period = 0ULL;
 549         timer->wrap_flag = 0;
 550     }
 551
 552     s->hpet_counter = 0ULL;
 553     s->hpet_offset = 0ULL;
 554     /* 64-bit main counter; 3 timers supported; LegacyReplacementRoute. */
 555     s->capability = 0x8086a201ULL;
 556     s->capability |= ((HPET_CLK_PERIOD) << 32);
 557     if (count > 0)
 558         /* we don't enable pit when hpet_reset is first called (by hpet_init)
 559          * because hpet is taking over for pit here. On subsequent invocations,
 560          * hpet_reset is called due to system reset. At this point control must
 561          * be returned to pit until SW reenables hpet.
 562          */
 563         hpet_pit_enable();
 564     count = 1;
 565 }
 566
 567
 568 void hpet_init(qemu_irq *irq) {
 569     int i, iomemtype;
 570     HPETState *s;
 571
 572     dprintf ("hpet_init\n");
 573
 574     s = qemu_mallocz(sizeof(HPETState));
 575     hpet_statep = s;
 576     s->irqs = irq;
 577     for (i=0; i<HPET_NUM_TIMERS; i++) {
 578         HPETTimer *timer = &s->timer[i];
 579         timer->qemu_timer = qemu_new_timer(vm_clock, hpet_timer, timer);
 580     }
 581     hpet_reset(s);
 582     register_savevm("hpet", -1, 1, hpet_save, hpet_load, s);
 583     qemu_register_reset(hpet_reset, s);
 584     /* HPET Area */
 585     iomemtype = cpu_register_io_memory(0, hpet_ram_read,
 586                                        hpet_ram_write, s);
 587     cpu_register_physical_memory(HPET_BASE, 0x400, iomemtype);
 588 }