xref: /openbmc/qemu/hw/timer/hpet.c (revision 4921d0a7)
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 2.1 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/irq.h"
29 #include "qapi/error.h"
30 #include "qemu/error-report.h"
31 #include "qemu/timer.h"
32 #include "hw/qdev-properties.h"
33 #include "hw/timer/hpet.h"
34 #include "hw/sysbus.h"
35 #include "hw/rtc/mc146818rtc.h"
36 #include "hw/rtc/mc146818rtc_regs.h"
37 #include "migration/vmstate.h"
38 #include "hw/timer/i8254.h"
39 #include "exec/address-spaces.h"
40 #include "qom/object.h"
41 #include "trace.h"
42 
43 #define HPET_MSI_SUPPORT        0
44 
45 OBJECT_DECLARE_SIMPLE_TYPE(HPETState, HPET)
46 
47 struct HPETState;
48 typedef struct HPETTimer {  /* timers */
49     uint8_t tn;             /*timer number*/
50     QEMUTimer *qemu_timer;
51     struct HPETState *state;
52     /* Memory-mapped, software visible timer registers */
53     uint64_t config;        /* configuration/cap */
54     uint64_t cmp;           /* comparator */
55     uint64_t fsb;           /* FSB route */
56     /* Hidden register state */
57     uint64_t period;        /* Last value written to comparator */
58     uint8_t wrap_flag;      /* timer pop will indicate wrap for one-shot 32-bit
59                              * mode. Next pop will be actual timer expiration.
60                              */
61 } HPETTimer;
62 
63 struct HPETState {
64     /*< private >*/
65     SysBusDevice parent_obj;
66     /*< public >*/
67 
68     MemoryRegion iomem;
69     uint64_t hpet_offset;
70     bool hpet_offset_saved;
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 };
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 - a) < 0);
120 }
121 
122 static uint32_t hpet_time_after64(uint64_t a, uint64_t b)
123 {
124     return ((int64_t)(b - 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             qemu_irq_lower(s->irqs[route]);
203         }
204     } else if (timer_fsb_route(timer)) {
205         address_space_stl_le(&address_space_memory, timer->fsb >> 32,
206                              timer->fsb & 0xffffffff, MEMTXATTRS_UNSPECIFIED,
207                              NULL);
208     } else if (timer->config & HPET_TN_TYPE_LEVEL) {
209         s->isr |= mask;
210         qemu_irq_raise(s->irqs[route]);
211     } else {
212         s->isr &= ~mask;
213         qemu_irq_pulse(s->irqs[route]);
214     }
215 }
216 
217 static int hpet_pre_save(void *opaque)
218 {
219     HPETState *s = opaque;
220 
221     /* save current counter value */
222     if (hpet_enabled(s)) {
223         s->hpet_counter = hpet_get_ticks(s);
224     }
225 
226     return 0;
227 }
228 
229 static int hpet_pre_load(void *opaque)
230 {
231     HPETState *s = opaque;
232 
233     /* version 1 only supports 3, later versions will load the actual value */
234     s->num_timers = HPET_MIN_TIMERS;
235     return 0;
236 }
237 
238 static bool hpet_validate_num_timers(void *opaque, int version_id)
239 {
240     HPETState *s = opaque;
241 
242     if (s->num_timers < HPET_MIN_TIMERS) {
243         return false;
244     } else if (s->num_timers > HPET_MAX_TIMERS) {
245         return false;
246     }
247     return true;
248 }
249 
250 static int hpet_post_load(void *opaque, int version_id)
251 {
252     HPETState *s = opaque;
253 
254     /* Recalculate the offset between the main counter and guest time */
255     if (!s->hpet_offset_saved) {
256         s->hpet_offset = ticks_to_ns(s->hpet_counter)
257                         - qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
258     }
259 
260     /* Push number of timers into capability returned via HPET_ID */
261     s->capability &= ~HPET_ID_NUM_TIM_MASK;
262     s->capability |= (s->num_timers - 1) << HPET_ID_NUM_TIM_SHIFT;
263     hpet_cfg.hpet[s->hpet_id].event_timer_block_id = (uint32_t)s->capability;
264 
265     /* Derive HPET_MSI_SUPPORT from the capability of the first timer. */
266     s->flags &= ~(1 << HPET_MSI_SUPPORT);
267     if (s->timer[0].config & HPET_TN_FSB_CAP) {
268         s->flags |= 1 << HPET_MSI_SUPPORT;
269     }
270     return 0;
271 }
272 
273 static bool hpet_offset_needed(void *opaque)
274 {
275     HPETState *s = opaque;
276 
277     return hpet_enabled(s) && s->hpet_offset_saved;
278 }
279 
280 static bool hpet_rtc_irq_level_needed(void *opaque)
281 {
282     HPETState *s = opaque;
283 
284     return s->rtc_irq_level != 0;
285 }
286 
287 static const VMStateDescription vmstate_hpet_rtc_irq_level = {
288     .name = "hpet/rtc_irq_level",
289     .version_id = 1,
290     .minimum_version_id = 1,
291     .needed = hpet_rtc_irq_level_needed,
292     .fields = (const VMStateField[]) {
293         VMSTATE_UINT8(rtc_irq_level, HPETState),
294         VMSTATE_END_OF_LIST()
295     }
296 };
297 
298 static const VMStateDescription vmstate_hpet_offset = {
299     .name = "hpet/offset",
300     .version_id = 1,
301     .minimum_version_id = 1,
302     .needed = hpet_offset_needed,
303     .fields = (const VMStateField[]) {
304         VMSTATE_UINT64(hpet_offset, HPETState),
305         VMSTATE_END_OF_LIST()
306     }
307 };
308 
309 static const VMStateDescription vmstate_hpet_timer = {
310     .name = "hpet_timer",
311     .version_id = 1,
312     .minimum_version_id = 1,
313     .fields = (const VMStateField[]) {
314         VMSTATE_UINT8(tn, HPETTimer),
315         VMSTATE_UINT64(config, HPETTimer),
316         VMSTATE_UINT64(cmp, HPETTimer),
317         VMSTATE_UINT64(fsb, HPETTimer),
318         VMSTATE_UINT64(period, HPETTimer),
319         VMSTATE_UINT8(wrap_flag, HPETTimer),
320         VMSTATE_TIMER_PTR(qemu_timer, HPETTimer),
321         VMSTATE_END_OF_LIST()
322     }
323 };
324 
325 static const VMStateDescription vmstate_hpet = {
326     .name = "hpet",
327     .version_id = 2,
328     .minimum_version_id = 1,
329     .pre_save = hpet_pre_save,
330     .pre_load = hpet_pre_load,
331     .post_load = hpet_post_load,
332     .fields = (const VMStateField[]) {
333         VMSTATE_UINT64(config, HPETState),
334         VMSTATE_UINT64(isr, HPETState),
335         VMSTATE_UINT64(hpet_counter, HPETState),
336         VMSTATE_UINT8_V(num_timers, HPETState, 2),
337         VMSTATE_VALIDATE("num_timers in range", hpet_validate_num_timers),
338         VMSTATE_STRUCT_VARRAY_UINT8(timer, HPETState, num_timers, 0,
339                                     vmstate_hpet_timer, HPETTimer),
340         VMSTATE_END_OF_LIST()
341     },
342     .subsections = (const VMStateDescription * const []) {
343         &vmstate_hpet_rtc_irq_level,
344         &vmstate_hpet_offset,
345         NULL
346     }
347 };
348 
349 static void hpet_arm(HPETTimer *t, uint64_t ticks)
350 {
351     if (ticks < ns_to_ticks(INT64_MAX / 2)) {
352         timer_mod(t->qemu_timer,
353                   qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + ticks_to_ns(ticks));
354     } else {
355         timer_del(t->qemu_timer);
356     }
357 }
358 
359 /*
360  * timer expiration callback
361  */
362 static void hpet_timer(void *opaque)
363 {
364     HPETTimer *t = opaque;
365     uint64_t diff;
366 
367     uint64_t period = t->period;
368     uint64_t cur_tick = hpet_get_ticks(t->state);
369 
370     if (timer_is_periodic(t) && period != 0) {
371         if (t->config & HPET_TN_32BIT) {
372             while (hpet_time_after(cur_tick, t->cmp)) {
373                 t->cmp = (uint32_t)(t->cmp + t->period);
374             }
375         } else {
376             while (hpet_time_after64(cur_tick, t->cmp)) {
377                 t->cmp += period;
378             }
379         }
380         diff = hpet_calculate_diff(t, cur_tick);
381         hpet_arm(t, diff);
382     } else if (t->config & HPET_TN_32BIT && !timer_is_periodic(t)) {
383         if (t->wrap_flag) {
384             diff = hpet_calculate_diff(t, cur_tick);
385             hpet_arm(t, diff);
386             t->wrap_flag = 0;
387         }
388     }
389     update_irq(t, 1);
390 }
391 
392 static void hpet_set_timer(HPETTimer *t)
393 {
394     uint64_t diff;
395     uint32_t wrap_diff;  /* how many ticks until we wrap? */
396     uint64_t cur_tick = hpet_get_ticks(t->state);
397 
398     /* whenever new timer is being set up, make sure wrap_flag is 0 */
399     t->wrap_flag = 0;
400     diff = hpet_calculate_diff(t, cur_tick);
401 
402     /* hpet spec says in one-shot 32-bit mode, generate an interrupt when
403      * counter wraps in addition to an interrupt with comparator match.
404      */
405     if (t->config & HPET_TN_32BIT && !timer_is_periodic(t)) {
406         wrap_diff = 0xffffffff - (uint32_t)cur_tick;
407         if (wrap_diff < (uint32_t)diff) {
408             diff = wrap_diff;
409             t->wrap_flag = 1;
410         }
411     }
412     hpet_arm(t, diff);
413 }
414 
415 static void hpet_del_timer(HPETTimer *t)
416 {
417     timer_del(t->qemu_timer);
418     update_irq(t, 0);
419 }
420 
421 static uint64_t hpet_ram_read(void *opaque, hwaddr addr,
422                               unsigned size)
423 {
424     HPETState *s = opaque;
425     uint64_t cur_tick, index;
426 
427     trace_hpet_ram_read(addr);
428     index = addr;
429     /*address range of all TN regs*/
430     if (index >= 0x100 && index <= 0x3ff) {
431         uint8_t timer_id = (addr - 0x100) / 0x20;
432         HPETTimer *timer = &s->timer[timer_id];
433 
434         if (timer_id > s->num_timers) {
435             trace_hpet_timer_id_out_of_range(timer_id);
436             return 0;
437         }
438 
439         switch ((addr - 0x100) % 0x20) {
440         case HPET_TN_CFG:
441             return timer->config;
442         case HPET_TN_CFG + 4: // Interrupt capabilities
443             return timer->config >> 32;
444         case HPET_TN_CMP: // comparator register
445             return timer->cmp;
446         case HPET_TN_CMP + 4:
447             return timer->cmp >> 32;
448         case HPET_TN_ROUTE:
449             return timer->fsb;
450         case HPET_TN_ROUTE + 4:
451             return timer->fsb >> 32;
452         default:
453             trace_hpet_ram_read_invalid();
454             break;
455         }
456     } else {
457         switch (index) {
458         case HPET_ID:
459             return s->capability;
460         case HPET_PERIOD:
461             return s->capability >> 32;
462         case HPET_CFG:
463             return s->config;
464         case HPET_CFG + 4:
465             trace_hpet_invalid_hpet_cfg(4);
466             return 0;
467         case HPET_COUNTER:
468             if (hpet_enabled(s)) {
469                 cur_tick = hpet_get_ticks(s);
470             } else {
471                 cur_tick = s->hpet_counter;
472             }
473             trace_hpet_ram_read_reading_counter(0, cur_tick);
474             return cur_tick;
475         case HPET_COUNTER + 4:
476             if (hpet_enabled(s)) {
477                 cur_tick = hpet_get_ticks(s);
478             } else {
479                 cur_tick = s->hpet_counter;
480             }
481             trace_hpet_ram_read_reading_counter(4, cur_tick);
482             return cur_tick >> 32;
483         case HPET_STATUS:
484             return s->isr;
485         default:
486             trace_hpet_ram_read_invalid();
487             break;
488         }
489     }
490     return 0;
491 }
492 
493 static void hpet_ram_write(void *opaque, hwaddr addr,
494                            uint64_t value, unsigned size)
495 {
496     int i;
497     HPETState *s = opaque;
498     uint64_t old_val, new_val, val, index;
499 
500     trace_hpet_ram_write(addr, value);
501     index = addr;
502     old_val = hpet_ram_read(opaque, addr, 4);
503     new_val = value;
504 
505     /*address range of all TN regs*/
506     if (index >= 0x100 && index <= 0x3ff) {
507         uint8_t timer_id = (addr - 0x100) / 0x20;
508         HPETTimer *timer = &s->timer[timer_id];
509 
510         trace_hpet_ram_write_timer_id(timer_id);
511         if (timer_id > s->num_timers) {
512             trace_hpet_timer_id_out_of_range(timer_id);
513             return;
514         }
515         switch ((addr - 0x100) % 0x20) {
516         case HPET_TN_CFG:
517             trace_hpet_ram_write_tn_cfg();
518             if (activating_bit(old_val, new_val, HPET_TN_FSB_ENABLE)) {
519                 update_irq(timer, 0);
520             }
521             val = hpet_fixup_reg(new_val, old_val, HPET_TN_CFG_WRITE_MASK);
522             timer->config = (timer->config & 0xffffffff00000000ULL) | val;
523             if (new_val & HPET_TN_32BIT) {
524                 timer->cmp = (uint32_t)timer->cmp;
525                 timer->period = (uint32_t)timer->period;
526             }
527             if (activating_bit(old_val, new_val, HPET_TN_ENABLE) &&
528                 hpet_enabled(s)) {
529                 hpet_set_timer(timer);
530             } else if (deactivating_bit(old_val, new_val, HPET_TN_ENABLE)) {
531                 hpet_del_timer(timer);
532             }
533             break;
534         case HPET_TN_CFG + 4: // Interrupt capabilities
535             trace_hpet_ram_write_invalid_tn_cfg(4);
536             break;
537         case HPET_TN_CMP: // comparator register
538             trace_hpet_ram_write_tn_cmp(0);
539             if (timer->config & HPET_TN_32BIT) {
540                 new_val = (uint32_t)new_val;
541             }
542             if (!timer_is_periodic(timer)
543                 || (timer->config & HPET_TN_SETVAL)) {
544                 timer->cmp = (timer->cmp & 0xffffffff00000000ULL) | new_val;
545             }
546             if (timer_is_periodic(timer)) {
547                 /*
548                  * FIXME: Clamp period to reasonable min value?
549                  * Clamp period to reasonable max value
550                  */
551                 new_val &= (timer->config & HPET_TN_32BIT ? ~0u : ~0ull) >> 1;
552                 timer->period =
553                     (timer->period & 0xffffffff00000000ULL) | new_val;
554             }
555             timer->config &= ~HPET_TN_SETVAL;
556             if (hpet_enabled(s)) {
557                 hpet_set_timer(timer);
558             }
559             break;
560         case HPET_TN_CMP + 4: // comparator register high order
561             trace_hpet_ram_write_tn_cmp(4);
562             if (!timer_is_periodic(timer)
563                 || (timer->config & HPET_TN_SETVAL)) {
564                 timer->cmp = (timer->cmp & 0xffffffffULL) | new_val << 32;
565             } else {
566                 /*
567                  * FIXME: Clamp period to reasonable min value?
568                  * Clamp period to reasonable max value
569                  */
570                 new_val &= (timer->config & HPET_TN_32BIT ? ~0u : ~0ull) >> 1;
571                 timer->period =
572                     (timer->period & 0xffffffffULL) | new_val << 32;
573                 }
574                 timer->config &= ~HPET_TN_SETVAL;
575                 if (hpet_enabled(s)) {
576                     hpet_set_timer(timer);
577                 }
578                 break;
579         case HPET_TN_ROUTE:
580             timer->fsb = (timer->fsb & 0xffffffff00000000ULL) | new_val;
581             break;
582         case HPET_TN_ROUTE + 4:
583             timer->fsb = (new_val << 32) | (timer->fsb & 0xffffffff);
584             break;
585         default:
586             trace_hpet_ram_write_invalid();
587             break;
588         }
589         return;
590     } else {
591         switch (index) {
592         case HPET_ID:
593             return;
594         case HPET_CFG:
595             val = hpet_fixup_reg(new_val, old_val, HPET_CFG_WRITE_MASK);
596             s->config = (s->config & 0xffffffff00000000ULL) | val;
597             if (activating_bit(old_val, new_val, HPET_CFG_ENABLE)) {
598                 /* Enable main counter and interrupt generation. */
599                 s->hpet_offset =
600                     ticks_to_ns(s->hpet_counter) - qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
601                 for (i = 0; i < s->num_timers; i++) {
602                     if ((&s->timer[i])->cmp != ~0ULL) {
603                         hpet_set_timer(&s->timer[i]);
604                     }
605                 }
606             } else if (deactivating_bit(old_val, new_val, HPET_CFG_ENABLE)) {
607                 /* Halt main counter and disable interrupt generation. */
608                 s->hpet_counter = hpet_get_ticks(s);
609                 for (i = 0; i < s->num_timers; i++) {
610                     hpet_del_timer(&s->timer[i]);
611                 }
612             }
613             /* i8254 and RTC output pins are disabled
614              * when HPET is in legacy mode */
615             if (activating_bit(old_val, new_val, HPET_CFG_LEGACY)) {
616                 qemu_set_irq(s->pit_enabled, 0);
617                 qemu_irq_lower(s->irqs[0]);
618                 qemu_irq_lower(s->irqs[RTC_ISA_IRQ]);
619             } else if (deactivating_bit(old_val, new_val, HPET_CFG_LEGACY)) {
620                 qemu_irq_lower(s->irqs[0]);
621                 qemu_set_irq(s->pit_enabled, 1);
622                 qemu_set_irq(s->irqs[RTC_ISA_IRQ], s->rtc_irq_level);
623             }
624             break;
625         case HPET_CFG + 4:
626             trace_hpet_invalid_hpet_cfg(4);
627             break;
628         case HPET_STATUS:
629             val = new_val & s->isr;
630             for (i = 0; i < s->num_timers; i++) {
631                 if (val & (1 << i)) {
632                     update_irq(&s->timer[i], 0);
633                 }
634             }
635             break;
636         case HPET_COUNTER:
637             if (hpet_enabled(s)) {
638                 trace_hpet_ram_write_counter_write_while_enabled();
639             }
640             s->hpet_counter =
641                 (s->hpet_counter & 0xffffffff00000000ULL) | value;
642             trace_hpet_ram_write_counter_written(0, value, s->hpet_counter);
643             break;
644         case HPET_COUNTER + 4:
645             trace_hpet_ram_write_counter_write_while_enabled();
646             s->hpet_counter =
647                 (s->hpet_counter & 0xffffffffULL) | (((uint64_t)value) << 32);
648             trace_hpet_ram_write_counter_written(4, value, s->hpet_counter);
649             break;
650         default:
651             trace_hpet_ram_write_invalid();
652             break;
653         }
654     }
655 }
656 
657 static const MemoryRegionOps hpet_ram_ops = {
658     .read = hpet_ram_read,
659     .write = hpet_ram_write,
660     .valid = {
661         .min_access_size = 4,
662         .max_access_size = 4,
663     },
664     .endianness = DEVICE_NATIVE_ENDIAN,
665 };
666 
667 static void hpet_reset(DeviceState *d)
668 {
669     HPETState *s = HPET(d);
670     SysBusDevice *sbd = SYS_BUS_DEVICE(d);
671     int i;
672 
673     for (i = 0; i < s->num_timers; i++) {
674         HPETTimer *timer = &s->timer[i];
675 
676         hpet_del_timer(timer);
677         timer->cmp = ~0ULL;
678         timer->config = HPET_TN_PERIODIC_CAP | HPET_TN_SIZE_CAP;
679         if (s->flags & (1 << HPET_MSI_SUPPORT)) {
680             timer->config |= HPET_TN_FSB_CAP;
681         }
682         /* advertise availability of ioapic int */
683         timer->config |=  (uint64_t)s->intcap << 32;
684         timer->period = 0ULL;
685         timer->wrap_flag = 0;
686     }
687 
688     qemu_set_irq(s->pit_enabled, 1);
689     s->hpet_counter = 0ULL;
690     s->hpet_offset = 0ULL;
691     s->config = 0ULL;
692     hpet_cfg.hpet[s->hpet_id].event_timer_block_id = (uint32_t)s->capability;
693     hpet_cfg.hpet[s->hpet_id].address = sbd->mmio[0].addr;
694 
695     /* to document that the RTC lowers its output on reset as well */
696     s->rtc_irq_level = 0;
697 }
698 
699 static void hpet_handle_legacy_irq(void *opaque, int n, int level)
700 {
701     HPETState *s = HPET(opaque);
702 
703     if (n == HPET_LEGACY_PIT_INT) {
704         if (!hpet_in_legacy_mode(s)) {
705             qemu_set_irq(s->irqs[0], level);
706         }
707     } else {
708         s->rtc_irq_level = level;
709         if (!hpet_in_legacy_mode(s)) {
710             qemu_set_irq(s->irqs[RTC_ISA_IRQ], level);
711         }
712     }
713 }
714 
715 static void hpet_init(Object *obj)
716 {
717     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
718     HPETState *s = HPET(obj);
719 
720     /* HPET Area */
721     memory_region_init_io(&s->iomem, obj, &hpet_ram_ops, s, "hpet", HPET_LEN);
722     sysbus_init_mmio(sbd, &s->iomem);
723 }
724 
725 static void hpet_realize(DeviceState *dev, Error **errp)
726 {
727     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
728     HPETState *s = HPET(dev);
729     int i;
730     HPETTimer *timer;
731 
732     if (!s->intcap) {
733         warn_report("Hpet's intcap not initialized");
734     }
735     if (hpet_cfg.count == UINT8_MAX) {
736         /* first instance */
737         hpet_cfg.count = 0;
738     }
739 
740     if (hpet_cfg.count == 8) {
741         error_setg(errp, "Only 8 instances of HPET is allowed");
742         return;
743     }
744 
745     s->hpet_id = hpet_cfg.count++;
746 
747     for (i = 0; i < HPET_NUM_IRQ_ROUTES; i++) {
748         sysbus_init_irq(sbd, &s->irqs[i]);
749     }
750 
751     if (s->num_timers < HPET_MIN_TIMERS) {
752         s->num_timers = HPET_MIN_TIMERS;
753     } else if (s->num_timers > HPET_MAX_TIMERS) {
754         s->num_timers = HPET_MAX_TIMERS;
755     }
756     for (i = 0; i < HPET_MAX_TIMERS; i++) {
757         timer = &s->timer[i];
758         timer->qemu_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, hpet_timer, timer);
759         timer->tn = i;
760         timer->state = s;
761     }
762 
763     /* 64-bit main counter; LegacyReplacementRoute. */
764     s->capability = 0x8086a001ULL;
765     s->capability |= (s->num_timers - 1) << HPET_ID_NUM_TIM_SHIFT;
766     s->capability |= ((uint64_t)(HPET_CLK_PERIOD * FS_PER_NS) << 32);
767 
768     qdev_init_gpio_in(dev, hpet_handle_legacy_irq, 2);
769     qdev_init_gpio_out(dev, &s->pit_enabled, 1);
770 }
771 
772 static Property hpet_device_properties[] = {
773     DEFINE_PROP_UINT8("timers", HPETState, num_timers, HPET_MIN_TIMERS),
774     DEFINE_PROP_BIT("msi", HPETState, flags, HPET_MSI_SUPPORT, false),
775     DEFINE_PROP_UINT32(HPET_INTCAP, HPETState, intcap, 0),
776     DEFINE_PROP_BOOL("hpet-offset-saved", HPETState, hpet_offset_saved, true),
777     DEFINE_PROP_END_OF_LIST(),
778 };
779 
780 static void hpet_device_class_init(ObjectClass *klass, void *data)
781 {
782     DeviceClass *dc = DEVICE_CLASS(klass);
783 
784     dc->realize = hpet_realize;
785     dc->reset = hpet_reset;
786     dc->vmsd = &vmstate_hpet;
787     device_class_set_props(dc, hpet_device_properties);
788 }
789 
790 static const TypeInfo hpet_device_info = {
791     .name          = TYPE_HPET,
792     .parent        = TYPE_SYS_BUS_DEVICE,
793     .instance_size = sizeof(HPETState),
794     .instance_init = hpet_init,
795     .class_init    = hpet_device_class_init,
796 };
797 
798 static void hpet_register_types(void)
799 {
800     type_register_static(&hpet_device_info);
801 }
802 
803 type_init(hpet_register_types)
804