hw/timer/hpet.c

   1 /*
   2  *  High Precision 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/hw.h"
  28 #include "hw/i386/pc.h"
  29 #include "ui/console.h"
  30 #include "qemu/error-report.h"
  31 #include "qemu/timer.h"
  32 #include "hw/timer/hpet.h"
  33 #include "hw/sysbus.h"
  34 #include "hw/timer/mc146818rtc.h"
  35 #include "hw/timer/i8254.h"
  36
  37 //#define HPET_DEBUG
  38 #ifdef HPET_DEBUG
  39 #define DPRINTF printf
  40 #else
  41 #define DPRINTF(...)
  42 #endif
  43
  44 #define HPET_MSI_SUPPORT        0
  45
  46 #define HPET(obj) OBJECT_CHECK(HPETState, (obj), TYPE_HPET)
  47
  48 struct HPETState;
  49 typedef struct HPETTimer {  /* timers */
  50     uint8_t tn;             /*timer number*/
  51     QEMUTimer *qemu_timer;
  52     struct HPETState *state;
  53     /* Memory-mapped, software visible timer registers */
  54     uint64_t config;        /* configuration/cap */
  55     uint64_t cmp;           /* comparator */
  56     uint64_t fsb;           /* FSB route */
  57     /* Hidden register state */
  58     uint64_t period;        /* Last value written to comparator */
  59     uint8_t wrap_flag;      /* timer pop will indicate wrap for one-shot 32-bit
  60                              * mode. Next pop will be actual timer expiration.
  61                              */
  62 } HPETTimer;
  63
  64 typedef struct HPETState {
  65     /*< private >*/
  66     SysBusDevice parent_obj;
  67     /*< public >*/
  68
  69     MemoryRegion iomem;
  70     uint64_t hpet_offset;
  71     qemu_irq irqs[HPET_NUM_IRQ_ROUTES];
  72     uint32_t flags;
  73     uint8_t rtc_irq_level;
  74     qemu_irq pit_enabled;
  75     uint8_t num_timers;
  76     uint32_t intcap;
  77     HPETTimer timer[HPET_MAX_TIMERS];
  78
  79     /* Memory-mapped, software visible registers */
  80     uint64_t capability;        /* capabilities */
  81     uint64_t config;            /* configuration */
  82     uint64_t isr;               /* interrupt status reg */
  83     uint64_t hpet_counter;      /* main counter */
  84     uint8_t  hpet_id;           /* instance id */
  85 } HPETState;
  86
  87 static uint32_t hpet_in_legacy_mode(HPETState *s)
  88 {
  89     return s->config & HPET_CFG_LEGACY;
  90 }
  91
  92 static uint32_t timer_int_route(struct HPETTimer *timer)
  93 {
  94     return (timer->config & HPET_TN_INT_ROUTE_MASK) >> HPET_TN_INT_ROUTE_SHIFT;
  95 }
  96
  97 static uint32_t timer_fsb_route(HPETTimer *t)
  98 {
  99     return t->config & HPET_TN_FSB_ENABLE;
 100 }
 101
 102 static uint32_t hpet_enabled(HPETState *s)
 103 {
 104     return s->config & HPET_CFG_ENABLE;
 105 }
 106
 107 static uint32_t timer_is_periodic(HPETTimer *t)
 108 {
 109     return t->config & HPET_TN_PERIODIC;
 110 }
 111
 112 static uint32_t timer_enabled(HPETTimer *t)
 113 {
 114     return t->config & HPET_TN_ENABLE;
 115 }
 116
 117 static uint32_t hpet_time_after(uint64_t a, uint64_t b)
 118 {
 119     return ((int32_t)(b) - (int32_t)(a) < 0);
 120 }
 121
 122 static uint32_t hpet_time_after64(uint64_t a, uint64_t b)
 123 {
 124     return ((int64_t)(b) - (int64_t)(a) < 0);
 125 }
 126
 127 static uint64_t ticks_to_ns(uint64_t value)
 128 {
 129     return value * HPET_CLK_PERIOD;
 130 }
 131
 132 static uint64_t ns_to_ticks(uint64_t value)
 133 {
 134     return value / HPET_CLK_PERIOD;
 135 }
 136
 137 static uint64_t hpet_fixup_reg(uint64_t new, uint64_t old, uint64_t mask)
 138 {
 139     new &= mask;
 140     new |= old & ~mask;
 141     return new;
 142 }
 143
 144 static int activating_bit(uint64_t old, uint64_t new, uint64_t mask)
 145 {
 146     return (!(old & mask) && (new & mask));
 147 }
 148
 149 static int deactivating_bit(uint64_t old, uint64_t new, uint64_t mask)
 150 {
 151     return ((old & mask) && !(new & mask));
 152 }
 153
 154 static uint64_t hpet_get_ticks(HPETState *s)
 155 {
 156     return ns_to_ticks(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + s->hpet_offset);
 157 }
 158
 159 /*
 160  * calculate diff between comparator value and current ticks
 161  */
 162 static inline uint64_t hpet_calculate_diff(HPETTimer *t, uint64_t current)
 163 {
 164
 165     if (t->config & HPET_TN_32BIT) {
 166         uint32_t diff, cmp;
 167
 168         cmp = (uint32_t)t->cmp;
 169         diff = cmp - (uint32_t)current;
 170         diff = (int32_t)diff > 0 ? diff : (uint32_t)1;
 171         return (uint64_t)diff;
 172     } else {
 173         uint64_t diff, cmp;
 174
 175         cmp = t->cmp;
 176         diff = cmp - current;
 177         diff = (int64_t)diff > 0 ? diff : (uint64_t)1;
 178         return diff;
 179     }
 180 }
 181
 182 static void update_irq(struct HPETTimer *timer, int set)
 183 {
 184     uint64_t mask;
 185     HPETState *s;
 186     int route;
 187
 188     if (timer->tn <= 1 && hpet_in_legacy_mode(timer->state)) {
 189         /* if LegacyReplacementRoute bit is set, HPET specification requires
 190          * timer0 be routed to IRQ0 in NON-APIC or IRQ2 in the I/O APIC,
 191          * timer1 be routed to IRQ8 in NON-APIC or IRQ8 in the I/O APIC.
 192          */
 193         route = (timer->tn == 0) ? 0 : RTC_ISA_IRQ;
 194     } else {
 195         route = timer_int_route(timer);
 196     }
 197     s = timer->state;
 198     mask = 1 << timer->tn;
 199     if (!set || !timer_enabled(timer) || !hpet_enabled(timer->state)) {
 200         s->isr &= ~mask;
 201         if (!timer_fsb_route(timer)) {
 202             /* fold the ICH PIRQ# pin's internal inversion logic into hpet */
 203             if (route >= ISA_NUM_IRQS) {
 204                 qemu_irq_raise(s->irqs[route]);
 205             } else {
 206                 qemu_irq_lower(s->irqs[route]);
 207             }
 208         }
 209     } else if (timer_fsb_route(timer)) {
 210         address_space_stl_le(&address_space_memory, timer->fsb >> 32,
 211                              timer->fsb & 0xffffffff, MEMTXATTRS_UNSPECIFIED,
 212                              NULL);
 213     } else if (timer->config & HPET_TN_TYPE_LEVEL) {
 214         s->isr |= mask;
 215         /* fold the ICH PIRQ# pin's internal inversion logic into hpet */
 216         if (route >= ISA_NUM_IRQS) {
 217             qemu_irq_lower(s->irqs[route]);
 218         } else {
 219             qemu_irq_raise(s->irqs[route]);
 220         }
 221     } else {
 222         s->isr &= ~mask;
 223         qemu_irq_pulse(s->irqs[route]);
 224     }
 225 }
 226
 227 static void hpet_pre_save(void *opaque)
 228 {
 229     HPETState *s = opaque;
 230
 231     /* save current counter value */
 232     s->hpet_counter = hpet_get_ticks(s);
 233 }
 234
 235 static int hpet_pre_load(void *opaque)
 236 {
 237     HPETState *s = opaque;
 238
 239     /* version 1 only supports 3, later versions will load the actual value */
 240     s->num_timers = HPET_MIN_TIMERS;
 241     return 0;
 242 }
 243
 244 static bool hpet_validate_num_timers(void *opaque, int version_id)
 245 {
 246     HPETState *s = opaque;
 247
 248     if (s->num_timers < HPET_MIN_TIMERS) {
 249         return false;
 250     } else if (s->num_timers > HPET_MAX_TIMERS) {
 251         return false;
 252     }
 253     return true;
 254 }
 255
 256 static int hpet_post_load(void *opaque, int version_id)
 257 {
 258     HPETState *s = opaque;
 259
 260     /* Recalculate the offset between the main counter and guest time */
 261     s->hpet_offset = ticks_to_ns(s->hpet_counter) - qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
 262
 263     /* Push number of timers into capability returned via HPET_ID */
 264     s->capability &= ~HPET_ID_NUM_TIM_MASK;
 265     s->capability |= (s->num_timers - 1) << HPET_ID_NUM_TIM_SHIFT;
 266     hpet_cfg.hpet[s->hpet_id].event_timer_block_id = (uint32_t)s->capability;
 267
 268     /* Derive HPET_MSI_SUPPORT from the capability of the first timer. */
 269     s->flags &= ~(1 << HPET_MSI_SUPPORT);
 270     if (s->timer[0].config & HPET_TN_FSB_CAP) {
 271         s->flags |= 1 << HPET_MSI_SUPPORT;
 272     }
 273     return 0;
 274 }
 275
 276 static bool hpet_rtc_irq_level_needed(void *opaque)
 277 {
 278     HPETState *s = opaque;
 279
 280     return s->rtc_irq_level != 0;
 281 }
 282
 283 static const VMStateDescription vmstate_hpet_rtc_irq_level = {
 284     .name = "hpet/rtc_irq_level",
 285     .version_id = 1,
 286     .minimum_version_id = 1,
 287     .needed = hpet_rtc_irq_level_needed,
 288     .fields = (VMStateField[]) {
 289         VMSTATE_UINT8(rtc_irq_level, HPETState),
 290         VMSTATE_END_OF_LIST()
 291     }
 292 };
 293
 294 static const VMStateDescription vmstate_hpet_timer = {
 295     .name = "hpet_timer",
 296     .version_id = 1,
 297     .minimum_version_id = 1,
 298     .fields = (VMStateField[]) {
 299         VMSTATE_UINT8(tn, HPETTimer),
 300         VMSTATE_UINT64(config, HPETTimer),
 301         VMSTATE_UINT64(cmp, HPETTimer),
 302         VMSTATE_UINT64(fsb, HPETTimer),
 303         VMSTATE_UINT64(period, HPETTimer),
 304         VMSTATE_UINT8(wrap_flag, HPETTimer),
 305         VMSTATE_TIMER_PTR(qemu_timer, HPETTimer),
 306         VMSTATE_END_OF_LIST()
 307     }
 308 };
 309
 310 static const VMStateDescription vmstate_hpet = {
 311     .name = "hpet",
 312     .version_id = 2,
 313     .minimum_version_id = 1,
 314     .pre_save = hpet_pre_save,
 315     .pre_load = hpet_pre_load,
 316     .post_load = hpet_post_load,
 317     .fields = (VMStateField[]) {
 318         VMSTATE_UINT64(config, HPETState),
 319         VMSTATE_UINT64(isr, HPETState),
 320         VMSTATE_UINT64(hpet_counter, HPETState),
 321         VMSTATE_UINT8_V(num_timers, HPETState, 2),
 322         VMSTATE_VALIDATE("num_timers in range", hpet_validate_num_timers),
 323         VMSTATE_STRUCT_VARRAY_UINT8(timer, HPETState, num_timers, 0,
 324                                     vmstate_hpet_timer, HPETTimer),
 325         VMSTATE_END_OF_LIST()
 326     },
 327     .subsections = (const VMStateDescription*[]) {
 328         &vmstate_hpet_rtc_irq_level,
 329         NULL
 330     }
 331 };
 332
 333 /*
 334  * timer expiration callback
 335  */
 336 static void hpet_timer(void *opaque)
 337 {
 338     HPETTimer *t = opaque;
 339     uint64_t diff;
 340
 341     uint64_t period = t->period;
 342     uint64_t cur_tick = hpet_get_ticks(t->state);
 343
 344     if (timer_is_periodic(t) && period != 0) {
 345         if (t->config & HPET_TN_32BIT) {
 346             while (hpet_time_after(cur_tick, t->cmp)) {
 347                 t->cmp = (uint32_t)(t->cmp + t->period);
 348             }
 349         } else {
 350             while (hpet_time_after64(cur_tick, t->cmp)) {
 351                 t->cmp += period;
 352             }
 353         }
 354         diff = hpet_calculate_diff(t, cur_tick);
 355         timer_mod(t->qemu_timer,
 356                        qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + (int64_t)ticks_to_ns(diff));
 357     } else if (t->config & HPET_TN_32BIT && !timer_is_periodic(t)) {
 358         if (t->wrap_flag) {
 359             diff = hpet_calculate_diff(t, cur_tick);
 360             timer_mod(t->qemu_timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) +
 361                            (int64_t)ticks_to_ns(diff));
 362             t->wrap_flag = 0;
 363         }
 364     }
 365     update_irq(t, 1);
 366 }
 367
 368 static void hpet_set_timer(HPETTimer *t)
 369 {
 370     uint64_t diff;
 371     uint32_t wrap_diff;  /* how many ticks until we wrap? */
 372     uint64_t cur_tick = hpet_get_ticks(t->state);
 373
 374     /* whenever new timer is being set up, make sure wrap_flag is 0 */
 375     t->wrap_flag = 0;
 376     diff = hpet_calculate_diff(t, cur_tick);
 377
 378     /* hpet spec says in one-shot 32-bit mode, generate an interrupt when
 379      * counter wraps in addition to an interrupt with comparator match.
 380      */
 381     if (t->config & HPET_TN_32BIT && !timer_is_periodic(t)) {
 382         wrap_diff = 0xffffffff - (uint32_t)cur_tick;
 383         if (wrap_diff < (uint32_t)diff) {
 384             diff = wrap_diff;
 385             t->wrap_flag = 1;
 386         }
 387     }
 388     timer_mod(t->qemu_timer,
 389                    qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + (int64_t)ticks_to_ns(diff));
 390 }
 391
 392 static void hpet_del_timer(HPETTimer *t)
 393 {
 394     timer_del(t->qemu_timer);
 395     update_irq(t, 0);
 396 }
 397
 398 #ifdef HPET_DEBUG
 399 static uint32_t hpet_ram_readb(void *opaque, hwaddr addr)
 400 {
 401     printf("qemu: hpet_read b at %" PRIx64 "\n", addr);
 402     return 0;
 403 }
 404
 405 static uint32_t hpet_ram_readw(void *opaque, hwaddr addr)
 406 {
 407     printf("qemu: hpet_read w at %" PRIx64 "\n", addr);
 408     return 0;
 409 }
 410 #endif
 411
 412 static uint64_t hpet_ram_read(void *opaque, hwaddr addr,
 413                               unsigned size)
 414 {
 415     HPETState *s = opaque;
 416     uint64_t cur_tick, index;
 417
 418     DPRINTF("qemu: Enter hpet_ram_readl at %" PRIx64 "\n", addr);
 419     index = addr;
 420     /*address range of all TN regs*/
 421     if (index >= 0x100 && index <= 0x3ff) {
 422         uint8_t timer_id = (addr - 0x100) / 0x20;
 423         HPETTimer *timer = &s->timer[timer_id];
 424
 425         if (timer_id > s->num_timers) {
 426             DPRINTF("qemu: timer id out of range\n");
 427             return 0;
 428         }
 429
 430         switch ((addr - 0x100) % 0x20) {
 431         case HPET_TN_CFG:
 432             return timer->config;
 433         case HPET_TN_CFG + 4: // Interrupt capabilities
 434             return timer->config >> 32;
 435         case HPET_TN_CMP: // comparator register
 436             return timer->cmp;
 437         case HPET_TN_CMP + 4:
 438             return timer->cmp >> 32;
 439         case HPET_TN_ROUTE:
 440             return timer->fsb;
 441         case HPET_TN_ROUTE + 4:
 442             return timer->fsb >> 32;
 443         default:
 444             DPRINTF("qemu: invalid hpet_ram_readl\n");
 445             break;
 446         }
 447     } else {
 448         switch (index) {
 449         case HPET_ID:
 450             return s->capability;
 451         case HPET_PERIOD:
 452             return s->capability >> 32;
 453         case HPET_CFG:
 454             return s->config;
 455         case HPET_CFG + 4:
 456             DPRINTF("qemu: invalid HPET_CFG + 4 hpet_ram_readl\n");
 457             return 0;
 458         case HPET_COUNTER:
 459             if (hpet_enabled(s)) {
 460                 cur_tick = hpet_get_ticks(s);
 461             } else {
 462                 cur_tick = s->hpet_counter;
 463             }
 464             DPRINTF("qemu: reading counter  = %" PRIx64 "\n", cur_tick);
 465             return cur_tick;
 466         case HPET_COUNTER + 4:
 467             if (hpet_enabled(s)) {
 468                 cur_tick = hpet_get_ticks(s);
 469             } else {
 470                 cur_tick = s->hpet_counter;
 471             }
 472             DPRINTF("qemu: reading counter + 4  = %" PRIx64 "\n", cur_tick);
 473             return cur_tick >> 32;
 474         case HPET_STATUS:
 475             return s->isr;
 476         default:
 477             DPRINTF("qemu: invalid hpet_ram_readl\n");
 478             break;
 479         }
 480     }
 481     return 0;
 482 }
 483
 484 static void hpet_ram_write(void *opaque, hwaddr addr,
 485                            uint64_t value, unsigned size)
 486 {
 487     int i;
 488     HPETState *s = opaque;
 489     uint64_t old_val, new_val, val, index;
 490
 491     DPRINTF("qemu: Enter hpet_ram_writel at %" PRIx64 " = %#x\n", addr, value);
 492     index = addr;
 493     old_val = hpet_ram_read(opaque, addr, 4);
 494     new_val = value;
 495
 496     /*address range of all TN regs*/
 497     if (index >= 0x100 && index <= 0x3ff) {
 498         uint8_t timer_id = (addr - 0x100) / 0x20;
 499         HPETTimer *timer = &s->timer[timer_id];
 500
 501         DPRINTF("qemu: hpet_ram_writel timer_id = %#x\n", timer_id);
 502         if (timer_id > s->num_timers) {
 503             DPRINTF("qemu: timer id out of range\n");
 504             return;
 505         }
 506         switch ((addr - 0x100) % 0x20) {
 507         case HPET_TN_CFG:
 508             DPRINTF("qemu: hpet_ram_writel HPET_TN_CFG\n");
 509             if (activating_bit(old_val, new_val, HPET_TN_FSB_ENABLE)) {
 510                 update_irq(timer, 0);
 511             }
 512             val = hpet_fixup_reg(new_val, old_val, HPET_TN_CFG_WRITE_MASK);
 513             timer->config = (timer->config & 0xffffffff00000000ULL) | val;
 514             if (new_val & HPET_TN_32BIT) {
 515                 timer->cmp = (uint32_t)timer->cmp;
 516                 timer->period = (uint32_t)timer->period;
 517             }
 518             if (activating_bit(old_val, new_val, HPET_TN_ENABLE) &&
 519                 hpet_enabled(s)) {
 520                 hpet_set_timer(timer);
 521             } else if (deactivating_bit(old_val, new_val, HPET_TN_ENABLE)) {
 522                 hpet_del_timer(timer);
 523             }
 524             break;
 525         case HPET_TN_CFG + 4: // Interrupt capabilities
 526             DPRINTF("qemu: invalid HPET_TN_CFG+4 write\n");
 527             break;
 528         case HPET_TN_CMP: // comparator register
 529             DPRINTF("qemu: hpet_ram_writel HPET_TN_CMP\n");
 530             if (timer->config & HPET_TN_32BIT) {
 531                 new_val = (uint32_t)new_val;
 532             }
 533             if (!timer_is_periodic(timer)
 534                 || (timer->config & HPET_TN_SETVAL)) {
 535                 timer->cmp = (timer->cmp & 0xffffffff00000000ULL) | new_val;
 536             }
 537             if (timer_is_periodic(timer)) {
 538                 /*
 539                  * FIXME: Clamp period to reasonable min value?
 540                  * Clamp period to reasonable max value
 541                  */
 542                 new_val &= (timer->config & HPET_TN_32BIT ? ~0u : ~0ull) >> 1;
 543                 timer->period =
 544                     (timer->period & 0xffffffff00000000ULL) | new_val;
 545             }
 546             timer->config &= ~HPET_TN_SETVAL;
 547             if (hpet_enabled(s)) {
 548                 hpet_set_timer(timer);
 549             }
 550             break;
 551         case HPET_TN_CMP + 4: // comparator register high order
 552             DPRINTF("qemu: hpet_ram_writel HPET_TN_CMP + 4\n");
 553             if (!timer_is_periodic(timer)
 554                 || (timer->config & HPET_TN_SETVAL)) {
 555                 timer->cmp = (timer->cmp & 0xffffffffULL) | new_val << 32;
 556             } else {
 557                 /*
 558                  * FIXME: Clamp period to reasonable min value?
 559                  * Clamp period to reasonable max value
 560                  */
 561                 new_val &= (timer->config & HPET_TN_32BIT ? ~0u : ~0ull) >> 1;
 562                 timer->period =
 563                     (timer->period & 0xffffffffULL) | new_val << 32;
 564                 }
 565                 timer->config &= ~HPET_TN_SETVAL;
 566                 if (hpet_enabled(s)) {
 567                     hpet_set_timer(timer);
 568                 }
 569                 break;
 570         case HPET_TN_ROUTE:
 571             timer->fsb = (timer->fsb & 0xffffffff00000000ULL) | new_val;
 572             break;
 573         case HPET_TN_ROUTE + 4:
 574             timer->fsb = (new_val << 32) | (timer->fsb & 0xffffffff);
 575             break;
 576         default:
 577             DPRINTF("qemu: invalid hpet_ram_writel\n");
 578             break;
 579         }
 580         return;
 581     } else {
 582         switch (index) {
 583         case HPET_ID:
 584             return;
 585         case HPET_CFG:
 586             val = hpet_fixup_reg(new_val, old_val, HPET_CFG_WRITE_MASK);
 587             s->config = (s->config & 0xffffffff00000000ULL) | val;
 588             if (activating_bit(old_val, new_val, HPET_CFG_ENABLE)) {
 589                 /* Enable main counter and interrupt generation. */
 590                 s->hpet_offset =
 591                     ticks_to_ns(s->hpet_counter) - qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
 592                 for (i = 0; i < s->num_timers; i++) {
 593                     if ((&s->timer[i])->cmp != ~0ULL) {
 594                         hpet_set_timer(&s->timer[i]);
 595                     }
 596                 }
 597             } else if (deactivating_bit(old_val, new_val, HPET_CFG_ENABLE)) {
 598                 /* Halt main counter and disable interrupt generation. */
 599                 s->hpet_counter = hpet_get_ticks(s);
 600                 for (i = 0; i < s->num_timers; i++) {
 601                     hpet_del_timer(&s->timer[i]);
 602                 }
 603             }
 604             /* i8254 and RTC output pins are disabled
 605              * when HPET is in legacy mode */
 606             if (activating_bit(old_val, new_val, HPET_CFG_LEGACY)) {
 607                 qemu_set_irq(s->pit_enabled, 0);
 608                 qemu_irq_lower(s->irqs[0]);
 609                 qemu_irq_lower(s->irqs[RTC_ISA_IRQ]);
 610             } else if (deactivating_bit(old_val, new_val, HPET_CFG_LEGACY)) {
 611                 qemu_irq_lower(s->irqs[0]);
 612                 qemu_set_irq(s->pit_enabled, 1);
 613                 qemu_set_irq(s->irqs[RTC_ISA_IRQ], s->rtc_irq_level);
 614             }
 615             break;
 616         case HPET_CFG + 4:
 617             DPRINTF("qemu: invalid HPET_CFG+4 write\n");
 618             break;
 619         case HPET_STATUS:
 620             val = new_val & s->isr;
 621             for (i = 0; i < s->num_timers; i++) {
 622                 if (val & (1 << i)) {
 623                     update_irq(&s->timer[i], 0);
 624                 }
 625             }
 626             break;
 627         case HPET_COUNTER:
 628             if (hpet_enabled(s)) {
 629                 DPRINTF("qemu: Writing counter while HPET enabled!\n");
 630             }
 631             s->hpet_counter =
 632                 (s->hpet_counter & 0xffffffff00000000ULL) | value;
 633             DPRINTF("qemu: HPET counter written. ctr = %#x -> %" PRIx64 "\n",
 634                     value, s->hpet_counter);
 635             break;
 636         case HPET_COUNTER + 4:
 637             if (hpet_enabled(s)) {
 638                 DPRINTF("qemu: Writing counter while HPET enabled!\n");
 639             }
 640             s->hpet_counter =
 641                 (s->hpet_counter & 0xffffffffULL) | (((uint64_t)value) << 32);
 642             DPRINTF("qemu: HPET counter + 4 written. ctr = %#x -> %" PRIx64 "\n",
 643                     value, s->hpet_counter);
 644             break;
 645         default:
 646             DPRINTF("qemu: invalid hpet_ram_writel\n");
 647             break;
 648         }
 649     }
 650 }
 651
 652 static const MemoryRegionOps hpet_ram_ops = {
 653     .read = hpet_ram_read,
 654     .write = hpet_ram_write,
 655     .valid = {
 656         .min_access_size = 4,
 657         .max_access_size = 4,
 658     },
 659     .endianness = DEVICE_NATIVE_ENDIAN,
 660 };
 661
 662 static void hpet_reset(DeviceState *d)
 663 {
 664     HPETState *s = HPET(d);
 665     SysBusDevice *sbd = SYS_BUS_DEVICE(d);
 666     int i;
 667
 668     for (i = 0; i < s->num_timers; i++) {
 669         HPETTimer *timer = &s->timer[i];
 670
 671         hpet_del_timer(timer);
 672         timer->cmp = ~0ULL;
 673         timer->config = HPET_TN_PERIODIC_CAP | HPET_TN_SIZE_CAP;
 674         if (s->flags & (1 << HPET_MSI_SUPPORT)) {
 675             timer->config |= HPET_TN_FSB_CAP;
 676         }
 677         /* advertise availability of ioapic int */
 678         timer->config |=  (uint64_t)s->intcap << 32;
 679         timer->period = 0ULL;
 680         timer->wrap_flag = 0;
 681     }
 682
 683     qemu_set_irq(s->pit_enabled, 1);
 684     s->hpet_counter = 0ULL;
 685     s->hpet_offset = 0ULL;
 686     s->config = 0ULL;
 687     hpet_cfg.hpet[s->hpet_id].event_timer_block_id = (uint32_t)s->capability;
 688     hpet_cfg.hpet[s->hpet_id].address = sbd->mmio[0].addr;
 689
 690     /* to document that the RTC lowers its output on reset as well */
 691     s->rtc_irq_level = 0;
 692 }
 693
 694 static void hpet_handle_legacy_irq(void *opaque, int n, int level)
 695 {
 696     HPETState *s = HPET(opaque);
 697
 698     if (n == HPET_LEGACY_PIT_INT) {
 699         if (!hpet_in_legacy_mode(s)) {
 700             qemu_set_irq(s->irqs[0], level);
 701         }
 702     } else {
 703         s->rtc_irq_level = level;
 704         if (!hpet_in_legacy_mode(s)) {
 705             qemu_set_irq(s->irqs[RTC_ISA_IRQ], level);
 706         }
 707     }
 708 }
 709
 710 static void hpet_init(Object *obj)
 711 {
 712     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
 713     HPETState *s = HPET(obj);
 714
 715     /* HPET Area */
 716     memory_region_init_io(&s->iomem, obj, &hpet_ram_ops, s, "hpet", 0x400);
 717     sysbus_init_mmio(sbd, &s->iomem);
 718 }
 719
 720 static void hpet_realize(DeviceState *dev, Error **errp)
 721 {
 722     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
 723     HPETState *s = HPET(dev);
 724     int i;
 725     HPETTimer *timer;
 726
 727     if (!s->intcap) {
 728         error_printf("Hpet's intcap not initialized.\n");
 729     }
 730     if (hpet_cfg.count == UINT8_MAX) {
 731         /* first instance */
 732         hpet_cfg.count = 0;
 733     }
 734
 735     if (hpet_cfg.count == 8) {
 736         error_setg(errp, "Only 8 instances of HPET is allowed");
 737         return;
 738     }
 739
 740     s->hpet_id = hpet_cfg.count++;
 741
 742     for (i = 0; i < HPET_NUM_IRQ_ROUTES; i++) {
 743         sysbus_init_irq(sbd, &s->irqs[i]);
 744     }
 745
 746     if (s->num_timers < HPET_MIN_TIMERS) {
 747         s->num_timers = HPET_MIN_TIMERS;
 748     } else if (s->num_timers > HPET_MAX_TIMERS) {
 749         s->num_timers = HPET_MAX_TIMERS;
 750     }
 751     for (i = 0; i < HPET_MAX_TIMERS; i++) {
 752         timer = &s->timer[i];
 753         timer->qemu_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, hpet_timer, timer);
 754         timer->tn = i;
 755         timer->state = s;
 756     }
 757
 758     /* 64-bit main counter; LegacyReplacementRoute. */
 759     s->capability = 0x8086a001ULL;
 760     s->capability |= (s->num_timers - 1) << HPET_ID_NUM_TIM_SHIFT;
 761     s->capability |= ((uint64_t)(HPET_CLK_PERIOD * FS_PER_NS) << 32);
 762
 763     qdev_init_gpio_in(dev, hpet_handle_legacy_irq, 2);
 764     qdev_init_gpio_out(dev, &s->pit_enabled, 1);
 765 }
 766
 767 static Property hpet_device_properties[] = {
 768     DEFINE_PROP_UINT8("timers", HPETState, num_timers, HPET_MIN_TIMERS),
 769     DEFINE_PROP_BIT("msi", HPETState, flags, HPET_MSI_SUPPORT, false),
 770     DEFINE_PROP_UINT32(HPET_INTCAP, HPETState, intcap, 0),
 771     DEFINE_PROP_END_OF_LIST(),
 772 };
 773
 774 static void hpet_device_class_init(ObjectClass *klass, void *data)
 775 {
 776     DeviceClass *dc = DEVICE_CLASS(klass);
 777
 778     dc->realize = hpet_realize;
 779     dc->reset = hpet_reset;
 780     dc->vmsd = &vmstate_hpet;
 781     dc->props = hpet_device_properties;
 782 }
 783
 784 static const TypeInfo hpet_device_info = {
 785     .name          = TYPE_HPET,
 786     .parent        = TYPE_SYS_BUS_DEVICE,
 787     .instance_size = sizeof(HPETState),
 788     .instance_init = hpet_init,
 789     .class_init    = hpet_device_class_init,
 790 };
 791
 792 static void hpet_register_types(void)
 793 {
 794     type_register_static(&hpet_device_info);
 795 }
 796
 797 type_init(hpet_register_types)