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