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, see <http://www.gnu.org/licenses/>.
  21  *
  22  * *****************************************************************
  23  *
  24  * This driver attempts to emulate an HPET device in software.
  25  */
  26
  27 #include "hw.h"
  28 #include "pc.h"
  29 #include "console.h"
  30 #include "qemu-timer.h"
  31 #include "hpet_emul.h"
  32 #include "sysbus.h"
  33 #include "mc146818rtc.h"
  34 #include "i8254.h"
  35
  36 //#define HPET_DEBUG
  37 #ifdef HPET_DEBUG
  38 #define DPRINTF printf
  39 #else
  40 #define DPRINTF(...)
  41 #endif
  42
  43 #define HPET_MSI_SUPPORT        0
  44
  45 struct HPETState;
  46 typedef struct HPETTimer {  /* timers */
  47     uint8_t tn;             /*timer number*/
  48     QEMUTimer *qemu_timer;
  49     struct HPETState *state;
  50     /* Memory-mapped, software visible timer registers */
  51     uint64_t config;        /* configuration/cap */
  52     uint64_t cmp;           /* comparator */
  53     uint64_t fsb;           /* FSB route */
  54     /* Hidden register state */
  55     uint64_t period;        /* Last value written to comparator */
  56     uint8_t wrap_flag;      /* timer pop will indicate wrap for one-shot 32-bit
  57                              * mode. Next pop will be actual timer expiration.
  58                              */
  59 } HPETTimer;
  60
  61 typedef struct HPETState {
  62     SysBusDevice busdev;
  63     MemoryRegion iomem;
  64     uint64_t hpet_offset;
  65     qemu_irq irqs[HPET_NUM_IRQ_ROUTES];
  66     uint32_t flags;
  67     uint8_t rtc_irq_level;
  68     qemu_irq pit_enabled;
  69     uint8_t num_timers;
  70     HPETTimer timer[HPET_MAX_TIMERS];
  71
  72     /* Memory-mapped, software visible registers */
  73     uint64_t capability;        /* capabilities */
  74     uint64_t config;            /* configuration */
  75     uint64_t isr;               /* interrupt status reg */
  76     uint64_t hpet_counter;      /* main counter */
  77     uint8_t  hpet_id;           /* instance id */
  78 } HPETState;
  79
  80 static uint32_t hpet_in_legacy_mode(HPETState *s)
  81 {
  82     return s->config & HPET_CFG_LEGACY;
  83 }
  84
  85 static uint32_t timer_int_route(struct HPETTimer *timer)
  86 {
  87     return (timer->config & HPET_TN_INT_ROUTE_MASK) >> HPET_TN_INT_ROUTE_SHIFT;
  88 }
  89
  90 static uint32_t timer_fsb_route(HPETTimer *t)
  91 {
  92     return t->config & HPET_TN_FSB_ENABLE;
  93 }
  94
  95 static uint32_t hpet_enabled(HPETState *s)
  96 {
  97     return s->config & HPET_CFG_ENABLE;
  98 }
  99
 100 static uint32_t timer_is_periodic(HPETTimer *t)
 101 {
 102     return t->config & HPET_TN_PERIODIC;
 103 }
 104
 105 static uint32_t timer_enabled(HPETTimer *t)
 106 {
 107     return t->config & HPET_TN_ENABLE;
 108 }
 109
 110 static uint32_t hpet_time_after(uint64_t a, uint64_t b)
 111 {
 112     return ((int32_t)(b) - (int32_t)(a) < 0);
 113 }
 114
 115 static uint32_t hpet_time_after64(uint64_t a, uint64_t b)
 116 {
 117     return ((int64_t)(b) - (int64_t)(a) < 0);
 118 }
 119
 120 static uint64_t ticks_to_ns(uint64_t value)
 121 {
 122     return (muldiv64(value, HPET_CLK_PERIOD, FS_PER_NS));
 123 }
 124
 125 static uint64_t ns_to_ticks(uint64_t value)
 126 {
 127     return (muldiv64(value, FS_PER_NS, HPET_CLK_PERIOD));
 128 }
 129
 130 static uint64_t hpet_fixup_reg(uint64_t new, uint64_t old, uint64_t mask)
 131 {
 132     new &= mask;
 133     new |= old & ~mask;
 134     return new;
 135 }
 136
 137 static int activating_bit(uint64_t old, uint64_t new, uint64_t mask)
 138 {
 139     return (!(old & mask) && (new & mask));
 140 }
 141
 142 static int deactivating_bit(uint64_t old, uint64_t new, uint64_t mask)
 143 {
 144     return ((old & mask) && !(new & mask));
 145 }
 146
 147 static uint64_t hpet_get_ticks(HPETState *s)
 148 {
 149     return ns_to_ticks(qemu_get_clock_ns(vm_clock) + s->hpet_offset);
 150 }
 151
 152 /*
 153  * calculate diff between comparator value and current ticks
 154  */
 155 static inline uint64_t hpet_calculate_diff(HPETTimer *t, uint64_t current)
 156 {
 157
 158     if (t->config & HPET_TN_32BIT) {
 159         uint32_t diff, cmp;
 160
 161         cmp = (uint32_t)t->cmp;
 162         diff = cmp - (uint32_t)current;
 163         diff = (int32_t)diff > 0 ? diff : (uint32_t)1;
 164         return (uint64_t)diff;
 165     } else {
 166         uint64_t diff, cmp;
 167
 168         cmp = t->cmp;
 169         diff = cmp - current;
 170         diff = (int64_t)diff > 0 ? diff : (uint64_t)1;
 171         return diff;
 172     }
 173 }
 174
 175 static void update_irq(struct HPETTimer *timer, int set)
 176 {
 177     uint64_t mask;
 178     HPETState *s;
 179     int route;
 180
 181     if (timer->tn <= 1 && hpet_in_legacy_mode(timer->state)) {
 182         /* if LegacyReplacementRoute bit is set, HPET specification requires
 183          * timer0 be routed to IRQ0 in NON-APIC or IRQ2 in the I/O APIC,
 184          * timer1 be routed to IRQ8 in NON-APIC or IRQ8 in the I/O APIC.
 185          */
 186         route = (timer->tn == 0) ? 0 : RTC_ISA_IRQ;
 187     } else {
 188         route = timer_int_route(timer);
 189     }
 190     s = timer->state;
 191     mask = 1 << timer->tn;
 192     if (!set || !timer_enabled(timer) || !hpet_enabled(timer->state)) {
 193         s->isr &= ~mask;
 194         if (!timer_fsb_route(timer)) {
 195             qemu_irq_lower(s->irqs[route]);
 196         }
 197     } else if (timer_fsb_route(timer)) {
 198         stl_le_phys(timer->fsb >> 32, timer->fsb & 0xffffffff);
 199     } else if (timer->config & HPET_TN_TYPE_LEVEL) {
 200         s->isr |= mask;
 201         qemu_irq_raise(s->irqs[route]);
 202     } else {
 203         s->isr &= ~mask;
 204         qemu_irq_pulse(s->irqs[route]);
 205     }
 206 }
 207
 208 static void hpet_pre_save(void *opaque)
 209 {
 210     HPETState *s = opaque;
 211
 212     /* save current counter value */
 213     s->hpet_counter = hpet_get_ticks(s);
 214 }
 215
 216 static int hpet_pre_load(void *opaque)
 217 {
 218     HPETState *s = opaque;
 219
 220     /* version 1 only supports 3, later versions will load the actual value */
 221     s->num_timers = HPET_MIN_TIMERS;
 222     return 0;
 223 }
 224
 225 static int hpet_post_load(void *opaque, int version_id)
 226 {
 227     HPETState *s = opaque;
 228
 229     /* Recalculate the offset between the main counter and guest time */
 230     s->hpet_offset = ticks_to_ns(s->hpet_counter) - qemu_get_clock_ns(vm_clock);
 231
 232     /* Push number of timers into capability returned via HPET_ID */
 233     s->capability &= ~HPET_ID_NUM_TIM_MASK;
 234     s->capability |= (s->num_timers - 1) << HPET_ID_NUM_TIM_SHIFT;
 235     hpet_cfg.hpet[s->hpet_id].event_timer_block_id = (uint32_t)s->capability;
 236
 237     /* Derive HPET_MSI_SUPPORT from the capability of the first timer. */
 238     s->flags &= ~(1 << HPET_MSI_SUPPORT);
 239     if (s->timer[0].config & HPET_TN_FSB_CAP) {
 240         s->flags |= 1 << HPET_MSI_SUPPORT;
 241     }
 242     return 0;
 243 }
 244
 245 static bool hpet_rtc_irq_level_needed(void *opaque)
 246 {
 247     HPETState *s = opaque;
 248
 249     return s->rtc_irq_level != 0;
 250 }
 251
 252 static const VMStateDescription vmstate_hpet_rtc_irq_level = {
 253     .name = "hpet/rtc_irq_level",
 254     .version_id = 1,
 255     .minimum_version_id = 1,
 256     .minimum_version_id_old = 1,
 257     .fields      = (VMStateField[]) {
 258         VMSTATE_UINT8(rtc_irq_level, HPETState),
 259         VMSTATE_END_OF_LIST()
 260     }
 261 };
 262
 263 static const VMStateDescription vmstate_hpet_timer = {
 264     .name = "hpet_timer",
 265     .version_id = 1,
 266     .minimum_version_id = 1,
 267     .minimum_version_id_old = 1,
 268     .fields      = (VMStateField []) {
 269         VMSTATE_UINT8(tn, HPETTimer),
 270         VMSTATE_UINT64(config, HPETTimer),
 271         VMSTATE_UINT64(cmp, HPETTimer),
 272         VMSTATE_UINT64(fsb, HPETTimer),
 273         VMSTATE_UINT64(period, HPETTimer),
 274         VMSTATE_UINT8(wrap_flag, HPETTimer),
 275         VMSTATE_TIMER(qemu_timer, HPETTimer),
 276         VMSTATE_END_OF_LIST()
 277     }
 278 };
 279
 280 static const VMStateDescription vmstate_hpet = {
 281     .name = "hpet",
 282     .version_id = 2,
 283     .minimum_version_id = 1,
 284     .minimum_version_id_old = 1,
 285     .pre_save = hpet_pre_save,
 286     .pre_load = hpet_pre_load,
 287     .post_load = hpet_post_load,
 288     .fields      = (VMStateField []) {
 289         VMSTATE_UINT64(config, HPETState),
 290         VMSTATE_UINT64(isr, HPETState),
 291         VMSTATE_UINT64(hpet_counter, HPETState),
 292         VMSTATE_UINT8_V(num_timers, HPETState, 2),
 293         VMSTATE_STRUCT_VARRAY_UINT8(timer, HPETState, num_timers, 0,
 294                                     vmstate_hpet_timer, HPETTimer),
 295         VMSTATE_END_OF_LIST()
 296     },
 297     .subsections = (VMStateSubsection[]) {
 298         {
 299             .vmsd = &vmstate_hpet_rtc_irq_level,
 300             .needed = hpet_rtc_irq_level_needed,
 301         }, {
 302             /* empty */
 303         }
 304     }
 305 };
 306
 307 /*
 308  * timer expiration callback
 309  */
 310 static void hpet_timer(void *opaque)
 311 {
 312     HPETTimer *t = opaque;
 313     uint64_t diff;
 314
 315     uint64_t period = t->period;
 316     uint64_t cur_tick = hpet_get_ticks(t->state);
 317
 318     if (timer_is_periodic(t) && period != 0) {
 319         if (t->config & HPET_TN_32BIT) {
 320             while (hpet_time_after(cur_tick, t->cmp)) {
 321                 t->cmp = (uint32_t)(t->cmp + t->period);
 322             }
 323         } else {
 324             while (hpet_time_after64(cur_tick, t->cmp)) {
 325                 t->cmp += period;
 326             }
 327         }
 328         diff = hpet_calculate_diff(t, cur_tick);
 329         qemu_mod_timer(t->qemu_timer,
 330                        qemu_get_clock_ns(vm_clock) + (int64_t)ticks_to_ns(diff));
 331     } else if (t->config & HPET_TN_32BIT && !timer_is_periodic(t)) {
 332         if (t->wrap_flag) {
 333             diff = hpet_calculate_diff(t, cur_tick);
 334             qemu_mod_timer(t->qemu_timer, qemu_get_clock_ns(vm_clock) +
 335                            (int64_t)ticks_to_ns(diff));
 336             t->wrap_flag = 0;
 337         }
 338     }
 339     update_irq(t, 1);
 340 }
 341
 342 static void hpet_set_timer(HPETTimer *t)
 343 {
 344     uint64_t diff;
 345     uint32_t wrap_diff;  /* how many ticks until we wrap? */
 346     uint64_t cur_tick = hpet_get_ticks(t->state);
 347
 348     /* whenever new timer is being set up, make sure wrap_flag is 0 */
 349     t->wrap_flag = 0;
 350     diff = hpet_calculate_diff(t, cur_tick);
 351
 352     /* hpet spec says in one-shot 32-bit mode, generate an interrupt when
 353      * counter wraps in addition to an interrupt with comparator match.
 354      */
 355     if (t->config & HPET_TN_32BIT && !timer_is_periodic(t)) {
 356         wrap_diff = 0xffffffff - (uint32_t)cur_tick;
 357         if (wrap_diff < (uint32_t)diff) {
 358             diff = wrap_diff;
 359             t->wrap_flag = 1;
 360         }
 361     }
 362     qemu_mod_timer(t->qemu_timer,
 363                    qemu_get_clock_ns(vm_clock) + (int64_t)ticks_to_ns(diff));
 364 }
 365
 366 static void hpet_del_timer(HPETTimer *t)
 367 {
 368     qemu_del_timer(t->qemu_timer);
 369     update_irq(t, 0);
 370 }
 371
 372 #ifdef HPET_DEBUG
 373 static uint32_t hpet_ram_readb(void *opaque, target_phys_addr_t addr)
 374 {
 375     printf("qemu: hpet_read b at %" PRIx64 "\n", addr);
 376     return 0;
 377 }
 378
 379 static uint32_t hpet_ram_readw(void *opaque, target_phys_addr_t addr)
 380 {
 381     printf("qemu: hpet_read w at %" PRIx64 "\n", addr);
 382     return 0;
 383 }
 384 #endif
 385
 386 static uint64_t hpet_ram_read(void *opaque, target_phys_addr_t addr,
 387                               unsigned size)
 388 {
 389     HPETState *s = opaque;
 390     uint64_t cur_tick, index;
 391
 392     DPRINTF("qemu: Enter hpet_ram_readl at %" PRIx64 "\n", addr);
 393     index = addr;
 394     /*address range of all TN regs*/
 395     if (index >= 0x100 && index <= 0x3ff) {
 396         uint8_t timer_id = (addr - 0x100) / 0x20;
 397         HPETTimer *timer = &s->timer[timer_id];
 398
 399         if (timer_id > s->num_timers) {
 400             DPRINTF("qemu: timer id out of range\n");
 401             return 0;
 402         }
 403
 404         switch ((addr - 0x100) % 0x20) {
 405         case HPET_TN_CFG:
 406             return timer->config;
 407         case HPET_TN_CFG + 4: // Interrupt capabilities
 408             return timer->config >> 32;
 409         case HPET_TN_CMP: // comparator register
 410             return timer->cmp;
 411         case HPET_TN_CMP + 4:
 412             return timer->cmp >> 32;
 413         case HPET_TN_ROUTE:
 414             return timer->fsb;
 415         case HPET_TN_ROUTE + 4:
 416             return timer->fsb >> 32;
 417         default:
 418             DPRINTF("qemu: invalid hpet_ram_readl\n");
 419             break;
 420         }
 421     } else {
 422         switch (index) {
 423         case HPET_ID:
 424             return s->capability;
 425         case HPET_PERIOD:
 426             return s->capability >> 32;
 427         case HPET_CFG:
 428             return s->config;
 429         case HPET_CFG + 4:
 430             DPRINTF("qemu: invalid HPET_CFG + 4 hpet_ram_readl\n");
 431             return 0;
 432         case HPET_COUNTER:
 433             if (hpet_enabled(s)) {
 434                 cur_tick = hpet_get_ticks(s);
 435             } else {
 436                 cur_tick = s->hpet_counter;
 437             }
 438             DPRINTF("qemu: reading counter  = %" PRIx64 "\n", cur_tick);
 439             return cur_tick;
 440         case HPET_COUNTER + 4:
 441             if (hpet_enabled(s)) {
 442                 cur_tick = hpet_get_ticks(s);
 443             } else {
 444                 cur_tick = s->hpet_counter;
 445             }
 446             DPRINTF("qemu: reading counter + 4  = %" PRIx64 "\n", cur_tick);
 447             return cur_tick >> 32;
 448         case HPET_STATUS:
 449             return s->isr;
 450         default:
 451             DPRINTF("qemu: invalid hpet_ram_readl\n");
 452             break;
 453         }
 454     }
 455     return 0;
 456 }
 457
 458 static void hpet_ram_write(void *opaque, target_phys_addr_t addr,
 459                            uint64_t value, unsigned size)
 460 {
 461     int i;
 462     HPETState *s = opaque;
 463     uint64_t old_val, new_val, val, index;
 464
 465     DPRINTF("qemu: Enter hpet_ram_writel at %" PRIx64 " = %#x\n", addr, value);
 466     index = addr;
 467     old_val = hpet_ram_read(opaque, addr, 4);
 468     new_val = value;
 469
 470     /*address range of all TN regs*/
 471     if (index >= 0x100 && index <= 0x3ff) {
 472         uint8_t timer_id = (addr - 0x100) / 0x20;
 473         HPETTimer *timer = &s->timer[timer_id];
 474
 475         DPRINTF("qemu: hpet_ram_writel timer_id = %#x\n", timer_id);
 476         if (timer_id > s->num_timers) {
 477             DPRINTF("qemu: timer id out of range\n");
 478             return;
 479         }
 480         switch ((addr - 0x100) % 0x20) {
 481         case HPET_TN_CFG:
 482             DPRINTF("qemu: hpet_ram_writel HPET_TN_CFG\n");
 483             if (activating_bit(old_val, new_val, HPET_TN_FSB_ENABLE)) {
 484                 update_irq(timer, 0);
 485             }
 486             val = hpet_fixup_reg(new_val, old_val, HPET_TN_CFG_WRITE_MASK);
 487             timer->config = (timer->config & 0xffffffff00000000ULL) | val;
 488             if (new_val & HPET_TN_32BIT) {
 489                 timer->cmp = (uint32_t)timer->cmp;
 490                 timer->period = (uint32_t)timer->period;
 491             }
 492             if (activating_bit(old_val, new_val, HPET_TN_ENABLE)) {
 493                 hpet_set_timer(timer);
 494             } else if (deactivating_bit(old_val, new_val, HPET_TN_ENABLE)) {
 495                 hpet_del_timer(timer);
 496             }
 497             break;
 498         case HPET_TN_CFG + 4: // Interrupt capabilities
 499             DPRINTF("qemu: invalid HPET_TN_CFG+4 write\n");
 500             break;
 501         case HPET_TN_CMP: // comparator register
 502             DPRINTF("qemu: hpet_ram_writel HPET_TN_CMP\n");
 503             if (timer->config & HPET_TN_32BIT) {
 504                 new_val = (uint32_t)new_val;
 505             }
 506             if (!timer_is_periodic(timer)
 507                 || (timer->config & HPET_TN_SETVAL)) {
 508                 timer->cmp = (timer->cmp & 0xffffffff00000000ULL) | new_val;
 509             }
 510             if (timer_is_periodic(timer)) {
 511                 /*
 512                  * FIXME: Clamp period to reasonable min value?
 513                  * Clamp period to reasonable max value
 514                  */
 515                 new_val &= (timer->config & HPET_TN_32BIT ? ~0u : ~0ull) >> 1;
 516                 timer->period =
 517                     (timer->period & 0xffffffff00000000ULL) | new_val;
 518             }
 519             timer->config &= ~HPET_TN_SETVAL;
 520             if (hpet_enabled(s)) {
 521                 hpet_set_timer(timer);
 522             }
 523             break;
 524         case HPET_TN_CMP + 4: // comparator register high order
 525             DPRINTF("qemu: hpet_ram_writel HPET_TN_CMP + 4\n");
 526             if (!timer_is_periodic(timer)
 527                 || (timer->config & HPET_TN_SETVAL)) {
 528                 timer->cmp = (timer->cmp & 0xffffffffULL) | new_val << 32;
 529             } else {
 530                 /*
 531                  * FIXME: Clamp period to reasonable min value?
 532                  * Clamp period to reasonable max value
 533                  */
 534                 new_val &= (timer->config & HPET_TN_32BIT ? ~0u : ~0ull) >> 1;
 535                 timer->period =
 536                     (timer->period & 0xffffffffULL) | new_val << 32;
 537                 }
 538                 timer->config &= ~HPET_TN_SETVAL;
 539                 if (hpet_enabled(s)) {
 540                     hpet_set_timer(timer);
 541                 }
 542                 break;
 543         case HPET_TN_ROUTE:
 544             timer->fsb = (timer->fsb & 0xffffffff00000000ULL) | new_val;
 545             break;
 546         case HPET_TN_ROUTE + 4:
 547             timer->fsb = (new_val << 32) | (timer->fsb & 0xffffffff);
 548             break;
 549         default:
 550             DPRINTF("qemu: invalid hpet_ram_writel\n");
 551             break;
 552         }
 553         return;
 554     } else {
 555         switch (index) {
 556         case HPET_ID:
 557             return;
 558         case HPET_CFG:
 559             val = hpet_fixup_reg(new_val, old_val, HPET_CFG_WRITE_MASK);
 560             s->config = (s->config & 0xffffffff00000000ULL) | val;
 561             if (activating_bit(old_val, new_val, HPET_CFG_ENABLE)) {
 562                 /* Enable main counter and interrupt generation. */
 563                 s->hpet_offset =
 564                     ticks_to_ns(s->hpet_counter) - qemu_get_clock_ns(vm_clock);
 565                 for (i = 0; i < s->num_timers; i++) {
 566                     if ((&s->timer[i])->cmp != ~0ULL) {
 567                         hpet_set_timer(&s->timer[i]);
 568                     }
 569                 }
 570             } else if (deactivating_bit(old_val, new_val, HPET_CFG_ENABLE)) {
 571                 /* Halt main counter and disable interrupt generation. */
 572                 s->hpet_counter = hpet_get_ticks(s);
 573                 for (i = 0; i < s->num_timers; i++) {
 574                     hpet_del_timer(&s->timer[i]);
 575                 }
 576             }
 577             /* i8254 and RTC output pins are disabled
 578              * when HPET is in legacy mode */
 579             if (activating_bit(old_val, new_val, HPET_CFG_LEGACY)) {
 580                 qemu_set_irq(s->pit_enabled, 0);
 581                 qemu_irq_lower(s->irqs[0]);
 582                 qemu_irq_lower(s->irqs[RTC_ISA_IRQ]);
 583             } else if (deactivating_bit(old_val, new_val, HPET_CFG_LEGACY)) {
 584                 qemu_irq_lower(s->irqs[0]);
 585                 qemu_set_irq(s->pit_enabled, 1);
 586                 qemu_set_irq(s->irqs[RTC_ISA_IRQ], s->rtc_irq_level);
 587             }
 588             break;
 589         case HPET_CFG + 4:
 590             DPRINTF("qemu: invalid HPET_CFG+4 write\n");
 591             break;
 592         case HPET_STATUS:
 593             val = new_val & s->isr;
 594             for (i = 0; i < s->num_timers; i++) {
 595                 if (val & (1 << i)) {
 596                     update_irq(&s->timer[i], 0);
 597                 }
 598             }
 599             break;
 600         case HPET_COUNTER:
 601             if (hpet_enabled(s)) {
 602                 DPRINTF("qemu: Writing counter while HPET enabled!\n");
 603             }
 604             s->hpet_counter =
 605                 (s->hpet_counter & 0xffffffff00000000ULL) | value;
 606             DPRINTF("qemu: HPET counter written. ctr = %#x -> %" PRIx64 "\n",
 607                     value, s->hpet_counter);
 608             break;
 609         case HPET_COUNTER + 4:
 610             if (hpet_enabled(s)) {
 611                 DPRINTF("qemu: Writing counter while HPET enabled!\n");
 612             }
 613             s->hpet_counter =
 614                 (s->hpet_counter & 0xffffffffULL) | (((uint64_t)value) << 32);
 615             DPRINTF("qemu: HPET counter + 4 written. ctr = %#x -> %" PRIx64 "\n",
 616                     value, s->hpet_counter);
 617             break;
 618         default:
 619             DPRINTF("qemu: invalid hpet_ram_writel\n");
 620             break;
 621         }
 622     }
 623 }
 624
 625 static const MemoryRegionOps hpet_ram_ops = {
 626     .read = hpet_ram_read,
 627     .write = hpet_ram_write,
 628     .valid = {
 629         .min_access_size = 4,
 630         .max_access_size = 4,
 631     },
 632     .endianness = DEVICE_NATIVE_ENDIAN,
 633 };
 634
 635 static void hpet_reset(DeviceState *d)
 636 {
 637     HPETState *s = FROM_SYSBUS(HPETState, sysbus_from_qdev(d));
 638     int i;
 639
 640     for (i = 0; i < s->num_timers; i++) {
 641         HPETTimer *timer = &s->timer[i];
 642
 643         hpet_del_timer(timer);
 644         timer->cmp = ~0ULL;
 645         timer->config = HPET_TN_PERIODIC_CAP | HPET_TN_SIZE_CAP;
 646         if (s->flags & (1 << HPET_MSI_SUPPORT)) {
 647             timer->config |= HPET_TN_FSB_CAP;
 648         }
 649         /* advertise availability of ioapic inti2 */
 650         timer->config |=  0x00000004ULL << 32;
 651         timer->period = 0ULL;
 652         timer->wrap_flag = 0;
 653     }
 654
 655     qemu_set_irq(s->pit_enabled, 1);
 656     s->hpet_counter = 0ULL;
 657     s->hpet_offset = 0ULL;
 658     s->config = 0ULL;
 659     hpet_cfg.hpet[s->hpet_id].event_timer_block_id = (uint32_t)s->capability;
 660     hpet_cfg.hpet[s->hpet_id].address = sysbus_from_qdev(d)->mmio[0].addr;
 661
 662     /* to document that the RTC lowers its output on reset as well */
 663     s->rtc_irq_level = 0;
 664 }
 665
 666 static void hpet_handle_legacy_irq(void *opaque, int n, int level)
 667 {
 668     HPETState *s = FROM_SYSBUS(HPETState, opaque);
 669
 670     if (n == HPET_LEGACY_PIT_INT) {
 671         if (!hpet_in_legacy_mode(s)) {
 672             qemu_set_irq(s->irqs[0], level);
 673         }
 674     } else {
 675         s->rtc_irq_level = level;
 676         if (!hpet_in_legacy_mode(s)) {
 677             qemu_set_irq(s->irqs[RTC_ISA_IRQ], level);
 678         }
 679     }
 680 }
 681
 682 static int hpet_init(SysBusDevice *dev)
 683 {
 684     HPETState *s = FROM_SYSBUS(HPETState, dev);
 685     int i;
 686     HPETTimer *timer;
 687
 688     if (hpet_cfg.count == UINT8_MAX) {
 689         /* first instance */
 690         hpet_cfg.count = 0;
 691     }
 692
 693     if (hpet_cfg.count == 8) {
 694         fprintf(stderr, "Only 8 instances of HPET is allowed\n");
 695         return -1;
 696     }
 697
 698     s->hpet_id = hpet_cfg.count++;
 699
 700     for (i = 0; i < HPET_NUM_IRQ_ROUTES; i++) {
 701         sysbus_init_irq(dev, &s->irqs[i]);
 702     }
 703
 704     if (s->num_timers < HPET_MIN_TIMERS) {
 705         s->num_timers = HPET_MIN_TIMERS;
 706     } else if (s->num_timers > HPET_MAX_TIMERS) {
 707         s->num_timers = HPET_MAX_TIMERS;
 708     }
 709     for (i = 0; i < HPET_MAX_TIMERS; i++) {
 710         timer = &s->timer[i];
 711         timer->qemu_timer = qemu_new_timer_ns(vm_clock, hpet_timer, timer);
 712         timer->tn = i;
 713         timer->state = s;
 714     }
 715
 716     /* 64-bit main counter; LegacyReplacementRoute. */
 717     s->capability = 0x8086a001ULL;
 718     s->capability |= (s->num_timers - 1) << HPET_ID_NUM_TIM_SHIFT;
 719     s->capability |= ((HPET_CLK_PERIOD) << 32);
 720
 721     qdev_init_gpio_in(&dev->qdev, hpet_handle_legacy_irq, 2);
 722     qdev_init_gpio_out(&dev->qdev, &s->pit_enabled, 1);
 723
 724     /* HPET Area */
 725     memory_region_init_io(&s->iomem, &hpet_ram_ops, s, "hpet", 0x400);
 726     sysbus_init_mmio(dev, &s->iomem);
 727     return 0;
 728 }
 729
 730 static Property hpet_device_properties[] = {
 731     DEFINE_PROP_UINT8("timers", HPETState, num_timers, HPET_MIN_TIMERS),
 732     DEFINE_PROP_BIT("msi", HPETState, flags, HPET_MSI_SUPPORT, false),
 733     DEFINE_PROP_END_OF_LIST(),
 734 };
 735
 736 static void hpet_device_class_init(ObjectClass *klass, void *data)
 737 {
 738     DeviceClass *dc = DEVICE_CLASS(klass);
 739     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
 740
 741     k->init = hpet_init;
 742     dc->no_user = 1;
 743     dc->reset = hpet_reset;
 744     dc->vmsd = &vmstate_hpet;
 745     dc->props = hpet_device_properties;
 746 }
 747
 748 static TypeInfo hpet_device_info = {
 749     .name          = "hpet",
 750     .parent        = TYPE_SYS_BUS_DEVICE,
 751     .instance_size = sizeof(HPETState),
 752     .class_init    = hpet_device_class_init,
 753 };
 754
 755 static void hpet_register_types(void)
 756 {
 757     type_register_static(&hpet_device_info);
 758 }
 759
 760 type_init(hpet_register_types)