xref: /openbmc/qemu/hw/timer/hpet.c (revision fcf5ef2a)
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 "qapi/error.h"
32 #include "qemu/error-report.h"
33 #include "qemu/timer.h"
34 #include "hw/timer/hpet.h"
35 #include "hw/sysbus.h"
36 #include "hw/timer/mc146818rtc.h"
37 #include "hw/timer/i8254.h"
38 
39 //#define HPET_DEBUG
40 #ifdef HPET_DEBUG
41 #define DPRINTF printf
42 #else
43 #define DPRINTF(...)
44 #endif
45 
46 #define HPET_MSI_SUPPORT        0
47 
48 #define HPET(obj) OBJECT_CHECK(HPETState, (obj), TYPE_HPET)
49 
50 struct HPETState;
51 typedef struct HPETTimer {  /* timers */
52     uint8_t tn;             /*timer number*/
53     QEMUTimer *qemu_timer;
54     struct HPETState *state;
55     /* Memory-mapped, software visible timer registers */
56     uint64_t config;        /* configuration/cap */
57     uint64_t cmp;           /* comparator */
58     uint64_t fsb;           /* FSB route */
59     /* Hidden register state */
60     uint64_t period;        /* Last value written to comparator */
61     uint8_t wrap_flag;      /* timer pop will indicate wrap for one-shot 32-bit
62                              * mode. Next pop will be actual timer expiration.
63                              */
64 } HPETTimer;
65 
66 typedef struct HPETState {
67     /*< private >*/
68     SysBusDevice parent_obj;
69     /*< public >*/
70 
71     MemoryRegion iomem;
72     uint64_t hpet_offset;
73     qemu_irq irqs[HPET_NUM_IRQ_ROUTES];
74     uint32_t flags;
75     uint8_t rtc_irq_level;
76     qemu_irq pit_enabled;
77     uint8_t num_timers;
78     uint32_t intcap;
79     HPETTimer timer[HPET_MAX_TIMERS];
80 
81     /* Memory-mapped, software visible registers */
82     uint64_t capability;        /* capabilities */
83     uint64_t config;            /* configuration */
84     uint64_t isr;               /* interrupt status reg */
85     uint64_t hpet_counter;      /* main counter */
86     uint8_t  hpet_id;           /* instance id */
87 } HPETState;
88 
89 static uint32_t hpet_in_legacy_mode(HPETState *s)
90 {
91     return s->config & HPET_CFG_LEGACY;
92 }
93 
94 static uint32_t timer_int_route(struct HPETTimer *timer)
95 {
96     return (timer->config & HPET_TN_INT_ROUTE_MASK) >> HPET_TN_INT_ROUTE_SHIFT;
97 }
98 
99 static uint32_t timer_fsb_route(HPETTimer *t)
100 {
101     return t->config & HPET_TN_FSB_ENABLE;
102 }
103 
104 static uint32_t hpet_enabled(HPETState *s)
105 {
106     return s->config & HPET_CFG_ENABLE;
107 }
108 
109 static uint32_t timer_is_periodic(HPETTimer *t)
110 {
111     return t->config & HPET_TN_PERIODIC;
112 }
113 
114 static uint32_t timer_enabled(HPETTimer *t)
115 {
116     return t->config & HPET_TN_ENABLE;
117 }
118 
119 static uint32_t hpet_time_after(uint64_t a, uint64_t b)
120 {
121     return ((int32_t)(b - a) < 0);
122 }
123 
124 static uint32_t hpet_time_after64(uint64_t a, uint64_t b)
125 {
126     return ((int64_t)(b - a) < 0);
127 }
128 
129 static uint64_t ticks_to_ns(uint64_t value)
130 {
131     return value * HPET_CLK_PERIOD;
132 }
133 
134 static uint64_t ns_to_ticks(uint64_t value)
135 {
136     return value / HPET_CLK_PERIOD;
137 }
138 
139 static uint64_t hpet_fixup_reg(uint64_t new, uint64_t old, uint64_t mask)
140 {
141     new &= mask;
142     new |= old & ~mask;
143     return new;
144 }
145 
146 static int activating_bit(uint64_t old, uint64_t new, uint64_t mask)
147 {
148     return (!(old & mask) && (new & mask));
149 }
150 
151 static int deactivating_bit(uint64_t old, uint64_t new, uint64_t mask)
152 {
153     return ((old & mask) && !(new & mask));
154 }
155 
156 static uint64_t hpet_get_ticks(HPETState *s)
157 {
158     return ns_to_ticks(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + s->hpet_offset);
159 }
160 
161 /*
162  * calculate diff between comparator value and current ticks
163  */
164 static inline uint64_t hpet_calculate_diff(HPETTimer *t, uint64_t current)
165 {
166 
167     if (t->config & HPET_TN_32BIT) {
168         uint32_t diff, cmp;
169 
170         cmp = (uint32_t)t->cmp;
171         diff = cmp - (uint32_t)current;
172         diff = (int32_t)diff > 0 ? diff : (uint32_t)1;
173         return (uint64_t)diff;
174     } else {
175         uint64_t diff, cmp;
176 
177         cmp = t->cmp;
178         diff = cmp - current;
179         diff = (int64_t)diff > 0 ? diff : (uint64_t)1;
180         return diff;
181     }
182 }
183 
184 static void update_irq(struct HPETTimer *timer, int set)
185 {
186     uint64_t mask;
187     HPETState *s;
188     int route;
189 
190     if (timer->tn <= 1 && hpet_in_legacy_mode(timer->state)) {
191         /* if LegacyReplacementRoute bit is set, HPET specification requires
192          * timer0 be routed to IRQ0 in NON-APIC or IRQ2 in the I/O APIC,
193          * timer1 be routed to IRQ8 in NON-APIC or IRQ8 in the I/O APIC.
194          */
195         route = (timer->tn == 0) ? 0 : RTC_ISA_IRQ;
196     } else {
197         route = timer_int_route(timer);
198     }
199     s = timer->state;
200     mask = 1 << timer->tn;
201     if (!set || !timer_enabled(timer) || !hpet_enabled(timer->state)) {
202         s->isr &= ~mask;
203         if (!timer_fsb_route(timer)) {
204             qemu_irq_lower(s->irqs[route]);
205         }
206     } else if (timer_fsb_route(timer)) {
207         address_space_stl_le(&address_space_memory, timer->fsb >> 32,
208                              timer->fsb & 0xffffffff, MEMTXATTRS_UNSPECIFIED,
209                              NULL);
210     } else if (timer->config & HPET_TN_TYPE_LEVEL) {
211         s->isr |= mask;
212         qemu_irq_raise(s->irqs[route]);
213     } else {
214         s->isr &= ~mask;
215         qemu_irq_pulse(s->irqs[route]);
216     }
217 }
218 
219 static void hpet_pre_save(void *opaque)
220 {
221     HPETState *s = opaque;
222 
223     /* save current counter value */
224     s->hpet_counter = hpet_get_ticks(s);
225 }
226 
227 static int hpet_pre_load(void *opaque)
228 {
229     HPETState *s = opaque;
230 
231     /* version 1 only supports 3, later versions will load the actual value */
232     s->num_timers = HPET_MIN_TIMERS;
233     return 0;
234 }
235 
236 static bool hpet_validate_num_timers(void *opaque, int version_id)
237 {
238     HPETState *s = opaque;
239 
240     if (s->num_timers < HPET_MIN_TIMERS) {
241         return false;
242     } else if (s->num_timers > HPET_MAX_TIMERS) {
243         return false;
244     }
245     return true;
246 }
247 
248 static int hpet_post_load(void *opaque, int version_id)
249 {
250     HPETState *s = opaque;
251 
252     /* Recalculate the offset between the main counter and guest time */
253     s->hpet_offset = ticks_to_ns(s->hpet_counter) - qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
254 
255     /* Push number of timers into capability returned via HPET_ID */
256     s->capability &= ~HPET_ID_NUM_TIM_MASK;
257     s->capability |= (s->num_timers - 1) << HPET_ID_NUM_TIM_SHIFT;
258     hpet_cfg.hpet[s->hpet_id].event_timer_block_id = (uint32_t)s->capability;
259 
260     /* Derive HPET_MSI_SUPPORT from the capability of the first timer. */
261     s->flags &= ~(1 << HPET_MSI_SUPPORT);
262     if (s->timer[0].config & HPET_TN_FSB_CAP) {
263         s->flags |= 1 << HPET_MSI_SUPPORT;
264     }
265     return 0;
266 }
267 
268 static bool hpet_rtc_irq_level_needed(void *opaque)
269 {
270     HPETState *s = opaque;
271 
272     return s->rtc_irq_level != 0;
273 }
274 
275 static const VMStateDescription vmstate_hpet_rtc_irq_level = {
276     .name = "hpet/rtc_irq_level",
277     .version_id = 1,
278     .minimum_version_id = 1,
279     .needed = hpet_rtc_irq_level_needed,
280     .fields = (VMStateField[]) {
281         VMSTATE_UINT8(rtc_irq_level, HPETState),
282         VMSTATE_END_OF_LIST()
283     }
284 };
285 
286 static const VMStateDescription vmstate_hpet_timer = {
287     .name = "hpet_timer",
288     .version_id = 1,
289     .minimum_version_id = 1,
290     .fields = (VMStateField[]) {
291         VMSTATE_UINT8(tn, HPETTimer),
292         VMSTATE_UINT64(config, HPETTimer),
293         VMSTATE_UINT64(cmp, HPETTimer),
294         VMSTATE_UINT64(fsb, HPETTimer),
295         VMSTATE_UINT64(period, HPETTimer),
296         VMSTATE_UINT8(wrap_flag, HPETTimer),
297         VMSTATE_TIMER_PTR(qemu_timer, HPETTimer),
298         VMSTATE_END_OF_LIST()
299     }
300 };
301 
302 static const VMStateDescription vmstate_hpet = {
303     .name = "hpet",
304     .version_id = 2,
305     .minimum_version_id = 1,
306     .pre_save = hpet_pre_save,
307     .pre_load = hpet_pre_load,
308     .post_load = hpet_post_load,
309     .fields = (VMStateField[]) {
310         VMSTATE_UINT64(config, HPETState),
311         VMSTATE_UINT64(isr, HPETState),
312         VMSTATE_UINT64(hpet_counter, HPETState),
313         VMSTATE_UINT8_V(num_timers, HPETState, 2),
314         VMSTATE_VALIDATE("num_timers in range", hpet_validate_num_timers),
315         VMSTATE_STRUCT_VARRAY_UINT8(timer, HPETState, num_timers, 0,
316                                     vmstate_hpet_timer, HPETTimer),
317         VMSTATE_END_OF_LIST()
318     },
319     .subsections = (const VMStateDescription*[]) {
320         &vmstate_hpet_rtc_irq_level,
321         NULL
322     }
323 };
324 
325 /*
326  * timer expiration callback
327  */
328 static void hpet_timer(void *opaque)
329 {
330     HPETTimer *t = opaque;
331     uint64_t diff;
332 
333     uint64_t period = t->period;
334     uint64_t cur_tick = hpet_get_ticks(t->state);
335 
336     if (timer_is_periodic(t) && period != 0) {
337         if (t->config & HPET_TN_32BIT) {
338             while (hpet_time_after(cur_tick, t->cmp)) {
339                 t->cmp = (uint32_t)(t->cmp + t->period);
340             }
341         } else {
342             while (hpet_time_after64(cur_tick, t->cmp)) {
343                 t->cmp += period;
344             }
345         }
346         diff = hpet_calculate_diff(t, cur_tick);
347         timer_mod(t->qemu_timer,
348                        qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + (int64_t)ticks_to_ns(diff));
349     } else if (t->config & HPET_TN_32BIT && !timer_is_periodic(t)) {
350         if (t->wrap_flag) {
351             diff = hpet_calculate_diff(t, cur_tick);
352             timer_mod(t->qemu_timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) +
353                            (int64_t)ticks_to_ns(diff));
354             t->wrap_flag = 0;
355         }
356     }
357     update_irq(t, 1);
358 }
359 
360 static void hpet_set_timer(HPETTimer *t)
361 {
362     uint64_t diff;
363     uint32_t wrap_diff;  /* how many ticks until we wrap? */
364     uint64_t cur_tick = hpet_get_ticks(t->state);
365 
366     /* whenever new timer is being set up, make sure wrap_flag is 0 */
367     t->wrap_flag = 0;
368     diff = hpet_calculate_diff(t, cur_tick);
369 
370     /* hpet spec says in one-shot 32-bit mode, generate an interrupt when
371      * counter wraps in addition to an interrupt with comparator match.
372      */
373     if (t->config & HPET_TN_32BIT && !timer_is_periodic(t)) {
374         wrap_diff = 0xffffffff - (uint32_t)cur_tick;
375         if (wrap_diff < (uint32_t)diff) {
376             diff = wrap_diff;
377             t->wrap_flag = 1;
378         }
379     }
380     timer_mod(t->qemu_timer,
381                    qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + (int64_t)ticks_to_ns(diff));
382 }
383 
384 static void hpet_del_timer(HPETTimer *t)
385 {
386     timer_del(t->qemu_timer);
387     update_irq(t, 0);
388 }
389 
390 #ifdef HPET_DEBUG
391 static uint32_t hpet_ram_readb(void *opaque, hwaddr addr)
392 {
393     printf("qemu: hpet_read b at %" PRIx64 "\n", addr);
394     return 0;
395 }
396 
397 static uint32_t hpet_ram_readw(void *opaque, hwaddr addr)
398 {
399     printf("qemu: hpet_read w at %" PRIx64 "\n", addr);
400     return 0;
401 }
402 #endif
403 
404 static uint64_t hpet_ram_read(void *opaque, hwaddr addr,
405                               unsigned size)
406 {
407     HPETState *s = opaque;
408     uint64_t cur_tick, index;
409 
410     DPRINTF("qemu: Enter hpet_ram_readl at %" PRIx64 "\n", addr);
411     index = addr;
412     /*address range of all TN regs*/
413     if (index >= 0x100 && index <= 0x3ff) {
414         uint8_t timer_id = (addr - 0x100) / 0x20;
415         HPETTimer *timer = &s->timer[timer_id];
416 
417         if (timer_id > s->num_timers) {
418             DPRINTF("qemu: timer id out of range\n");
419             return 0;
420         }
421 
422         switch ((addr - 0x100) % 0x20) {
423         case HPET_TN_CFG:
424             return timer->config;
425         case HPET_TN_CFG + 4: // Interrupt capabilities
426             return timer->config >> 32;
427         case HPET_TN_CMP: // comparator register
428             return timer->cmp;
429         case HPET_TN_CMP + 4:
430             return timer->cmp >> 32;
431         case HPET_TN_ROUTE:
432             return timer->fsb;
433         case HPET_TN_ROUTE + 4:
434             return timer->fsb >> 32;
435         default:
436             DPRINTF("qemu: invalid hpet_ram_readl\n");
437             break;
438         }
439     } else {
440         switch (index) {
441         case HPET_ID:
442             return s->capability;
443         case HPET_PERIOD:
444             return s->capability >> 32;
445         case HPET_CFG:
446             return s->config;
447         case HPET_CFG + 4:
448             DPRINTF("qemu: invalid HPET_CFG + 4 hpet_ram_readl\n");
449             return 0;
450         case HPET_COUNTER:
451             if (hpet_enabled(s)) {
452                 cur_tick = hpet_get_ticks(s);
453             } else {
454                 cur_tick = s->hpet_counter;
455             }
456             DPRINTF("qemu: reading counter  = %" PRIx64 "\n", cur_tick);
457             return cur_tick;
458         case HPET_COUNTER + 4:
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 + 4  = %" PRIx64 "\n", cur_tick);
465             return cur_tick >> 32;
466         case HPET_STATUS:
467             return s->isr;
468         default:
469             DPRINTF("qemu: invalid hpet_ram_readl\n");
470             break;
471         }
472     }
473     return 0;
474 }
475 
476 static void hpet_ram_write(void *opaque, hwaddr addr,
477                            uint64_t value, unsigned size)
478 {
479     int i;
480     HPETState *s = opaque;
481     uint64_t old_val, new_val, val, index;
482 
483     DPRINTF("qemu: Enter hpet_ram_writel at %" PRIx64 " = %#x\n", addr, value);
484     index = addr;
485     old_val = hpet_ram_read(opaque, addr, 4);
486     new_val = value;
487 
488     /*address range of all TN regs*/
489     if (index >= 0x100 && index <= 0x3ff) {
490         uint8_t timer_id = (addr - 0x100) / 0x20;
491         HPETTimer *timer = &s->timer[timer_id];
492 
493         DPRINTF("qemu: hpet_ram_writel timer_id = %#x\n", timer_id);
494         if (timer_id > s->num_timers) {
495             DPRINTF("qemu: timer id out of range\n");
496             return;
497         }
498         switch ((addr - 0x100) % 0x20) {
499         case HPET_TN_CFG:
500             DPRINTF("qemu: hpet_ram_writel HPET_TN_CFG\n");
501             if (activating_bit(old_val, new_val, HPET_TN_FSB_ENABLE)) {
502                 update_irq(timer, 0);
503             }
504             val = hpet_fixup_reg(new_val, old_val, HPET_TN_CFG_WRITE_MASK);
505             timer->config = (timer->config & 0xffffffff00000000ULL) | val;
506             if (new_val & HPET_TN_32BIT) {
507                 timer->cmp = (uint32_t)timer->cmp;
508                 timer->period = (uint32_t)timer->period;
509             }
510             if (activating_bit(old_val, new_val, HPET_TN_ENABLE) &&
511                 hpet_enabled(s)) {
512                 hpet_set_timer(timer);
513             } else if (deactivating_bit(old_val, new_val, HPET_TN_ENABLE)) {
514                 hpet_del_timer(timer);
515             }
516             break;
517         case HPET_TN_CFG + 4: // Interrupt capabilities
518             DPRINTF("qemu: invalid HPET_TN_CFG+4 write\n");
519             break;
520         case HPET_TN_CMP: // comparator register
521             DPRINTF("qemu: hpet_ram_writel HPET_TN_CMP\n");
522             if (timer->config & HPET_TN_32BIT) {
523                 new_val = (uint32_t)new_val;
524             }
525             if (!timer_is_periodic(timer)
526                 || (timer->config & HPET_TN_SETVAL)) {
527                 timer->cmp = (timer->cmp & 0xffffffff00000000ULL) | new_val;
528             }
529             if (timer_is_periodic(timer)) {
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 & 0xffffffff00000000ULL) | new_val;
537             }
538             timer->config &= ~HPET_TN_SETVAL;
539             if (hpet_enabled(s)) {
540                 hpet_set_timer(timer);
541             }
542             break;
543         case HPET_TN_CMP + 4: // comparator register high order
544             DPRINTF("qemu: hpet_ram_writel HPET_TN_CMP + 4\n");
545             if (!timer_is_periodic(timer)
546                 || (timer->config & HPET_TN_SETVAL)) {
547                 timer->cmp = (timer->cmp & 0xffffffffULL) | new_val << 32;
548             } else {
549                 /*
550                  * FIXME: Clamp period to reasonable min value?
551                  * Clamp period to reasonable max value
552                  */
553                 new_val &= (timer->config & HPET_TN_32BIT ? ~0u : ~0ull) >> 1;
554                 timer->period =
555                     (timer->period & 0xffffffffULL) | new_val << 32;
556                 }
557                 timer->config &= ~HPET_TN_SETVAL;
558                 if (hpet_enabled(s)) {
559                     hpet_set_timer(timer);
560                 }
561                 break;
562         case HPET_TN_ROUTE:
563             timer->fsb = (timer->fsb & 0xffffffff00000000ULL) | new_val;
564             break;
565         case HPET_TN_ROUTE + 4:
566             timer->fsb = (new_val << 32) | (timer->fsb & 0xffffffff);
567             break;
568         default:
569             DPRINTF("qemu: invalid hpet_ram_writel\n");
570             break;
571         }
572         return;
573     } else {
574         switch (index) {
575         case HPET_ID:
576             return;
577         case HPET_CFG:
578             val = hpet_fixup_reg(new_val, old_val, HPET_CFG_WRITE_MASK);
579             s->config = (s->config & 0xffffffff00000000ULL) | val;
580             if (activating_bit(old_val, new_val, HPET_CFG_ENABLE)) {
581                 /* Enable main counter and interrupt generation. */
582                 s->hpet_offset =
583                     ticks_to_ns(s->hpet_counter) - qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
584                 for (i = 0; i < s->num_timers; i++) {
585                     if ((&s->timer[i])->cmp != ~0ULL) {
586                         hpet_set_timer(&s->timer[i]);
587                     }
588                 }
589             } else if (deactivating_bit(old_val, new_val, HPET_CFG_ENABLE)) {
590                 /* Halt main counter and disable interrupt generation. */
591                 s->hpet_counter = hpet_get_ticks(s);
592                 for (i = 0; i < s->num_timers; i++) {
593                     hpet_del_timer(&s->timer[i]);
594                 }
595             }
596             /* i8254 and RTC output pins are disabled
597              * when HPET is in legacy mode */
598             if (activating_bit(old_val, new_val, HPET_CFG_LEGACY)) {
599                 qemu_set_irq(s->pit_enabled, 0);
600                 qemu_irq_lower(s->irqs[0]);
601                 qemu_irq_lower(s->irqs[RTC_ISA_IRQ]);
602             } else if (deactivating_bit(old_val, new_val, HPET_CFG_LEGACY)) {
603                 qemu_irq_lower(s->irqs[0]);
604                 qemu_set_irq(s->pit_enabled, 1);
605                 qemu_set_irq(s->irqs[RTC_ISA_IRQ], s->rtc_irq_level);
606             }
607             break;
608         case HPET_CFG + 4:
609             DPRINTF("qemu: invalid HPET_CFG+4 write\n");
610             break;
611         case HPET_STATUS:
612             val = new_val & s->isr;
613             for (i = 0; i < s->num_timers; i++) {
614                 if (val & (1 << i)) {
615                     update_irq(&s->timer[i], 0);
616                 }
617             }
618             break;
619         case HPET_COUNTER:
620             if (hpet_enabled(s)) {
621                 DPRINTF("qemu: Writing counter while HPET enabled!\n");
622             }
623             s->hpet_counter =
624                 (s->hpet_counter & 0xffffffff00000000ULL) | value;
625             DPRINTF("qemu: HPET counter written. ctr = %#x -> %" PRIx64 "\n",
626                     value, s->hpet_counter);
627             break;
628         case HPET_COUNTER + 4:
629             if (hpet_enabled(s)) {
630                 DPRINTF("qemu: Writing counter while HPET enabled!\n");
631             }
632             s->hpet_counter =
633                 (s->hpet_counter & 0xffffffffULL) | (((uint64_t)value) << 32);
634             DPRINTF("qemu: HPET counter + 4 written. ctr = %#x -> %" PRIx64 "\n",
635                     value, s->hpet_counter);
636             break;
637         default:
638             DPRINTF("qemu: invalid hpet_ram_writel\n");
639             break;
640         }
641     }
642 }
643 
644 static const MemoryRegionOps hpet_ram_ops = {
645     .read = hpet_ram_read,
646     .write = hpet_ram_write,
647     .valid = {
648         .min_access_size = 4,
649         .max_access_size = 4,
650     },
651     .endianness = DEVICE_NATIVE_ENDIAN,
652 };
653 
654 static void hpet_reset(DeviceState *d)
655 {
656     HPETState *s = HPET(d);
657     SysBusDevice *sbd = SYS_BUS_DEVICE(d);
658     int i;
659 
660     for (i = 0; i < s->num_timers; i++) {
661         HPETTimer *timer = &s->timer[i];
662 
663         hpet_del_timer(timer);
664         timer->cmp = ~0ULL;
665         timer->config = HPET_TN_PERIODIC_CAP | HPET_TN_SIZE_CAP;
666         if (s->flags & (1 << HPET_MSI_SUPPORT)) {
667             timer->config |= HPET_TN_FSB_CAP;
668         }
669         /* advertise availability of ioapic int */
670         timer->config |=  (uint64_t)s->intcap << 32;
671         timer->period = 0ULL;
672         timer->wrap_flag = 0;
673     }
674 
675     qemu_set_irq(s->pit_enabled, 1);
676     s->hpet_counter = 0ULL;
677     s->hpet_offset = 0ULL;
678     s->config = 0ULL;
679     hpet_cfg.hpet[s->hpet_id].event_timer_block_id = (uint32_t)s->capability;
680     hpet_cfg.hpet[s->hpet_id].address = sbd->mmio[0].addr;
681 
682     /* to document that the RTC lowers its output on reset as well */
683     s->rtc_irq_level = 0;
684 }
685 
686 static void hpet_handle_legacy_irq(void *opaque, int n, int level)
687 {
688     HPETState *s = HPET(opaque);
689 
690     if (n == HPET_LEGACY_PIT_INT) {
691         if (!hpet_in_legacy_mode(s)) {
692             qemu_set_irq(s->irqs[0], level);
693         }
694     } else {
695         s->rtc_irq_level = level;
696         if (!hpet_in_legacy_mode(s)) {
697             qemu_set_irq(s->irqs[RTC_ISA_IRQ], level);
698         }
699     }
700 }
701 
702 static void hpet_init(Object *obj)
703 {
704     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
705     HPETState *s = HPET(obj);
706 
707     /* HPET Area */
708     memory_region_init_io(&s->iomem, obj, &hpet_ram_ops, s, "hpet", HPET_LEN);
709     sysbus_init_mmio(sbd, &s->iomem);
710 }
711 
712 static void hpet_realize(DeviceState *dev, Error **errp)
713 {
714     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
715     HPETState *s = HPET(dev);
716     int i;
717     HPETTimer *timer;
718 
719     if (!s->intcap) {
720         error_printf("Hpet's intcap not initialized.\n");
721     }
722     if (hpet_cfg.count == UINT8_MAX) {
723         /* first instance */
724         hpet_cfg.count = 0;
725     }
726 
727     if (hpet_cfg.count == 8) {
728         error_setg(errp, "Only 8 instances of HPET is allowed");
729         return;
730     }
731 
732     s->hpet_id = hpet_cfg.count++;
733 
734     for (i = 0; i < HPET_NUM_IRQ_ROUTES; i++) {
735         sysbus_init_irq(sbd, &s->irqs[i]);
736     }
737 
738     if (s->num_timers < HPET_MIN_TIMERS) {
739         s->num_timers = HPET_MIN_TIMERS;
740     } else if (s->num_timers > HPET_MAX_TIMERS) {
741         s->num_timers = HPET_MAX_TIMERS;
742     }
743     for (i = 0; i < HPET_MAX_TIMERS; i++) {
744         timer = &s->timer[i];
745         timer->qemu_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, hpet_timer, timer);
746         timer->tn = i;
747         timer->state = s;
748     }
749 
750     /* 64-bit main counter; LegacyReplacementRoute. */
751     s->capability = 0x8086a001ULL;
752     s->capability |= (s->num_timers - 1) << HPET_ID_NUM_TIM_SHIFT;
753     s->capability |= ((uint64_t)(HPET_CLK_PERIOD * FS_PER_NS) << 32);
754 
755     qdev_init_gpio_in(dev, hpet_handle_legacy_irq, 2);
756     qdev_init_gpio_out(dev, &s->pit_enabled, 1);
757 }
758 
759 static Property hpet_device_properties[] = {
760     DEFINE_PROP_UINT8("timers", HPETState, num_timers, HPET_MIN_TIMERS),
761     DEFINE_PROP_BIT("msi", HPETState, flags, HPET_MSI_SUPPORT, false),
762     DEFINE_PROP_UINT32(HPET_INTCAP, HPETState, intcap, 0),
763     DEFINE_PROP_END_OF_LIST(),
764 };
765 
766 static void hpet_device_class_init(ObjectClass *klass, void *data)
767 {
768     DeviceClass *dc = DEVICE_CLASS(klass);
769 
770     dc->realize = hpet_realize;
771     dc->reset = hpet_reset;
772     dc->vmsd = &vmstate_hpet;
773     dc->props = hpet_device_properties;
774 }
775 
776 static const TypeInfo hpet_device_info = {
777     .name          = TYPE_HPET,
778     .parent        = TYPE_SYS_BUS_DEVICE,
779     .instance_size = sizeof(HPETState),
780     .instance_init = hpet_init,
781     .class_init    = hpet_device_class_init,
782 };
783 
784 static void hpet_register_types(void)
785 {
786     type_register_static(&hpet_device_info);
787 }
788 
789 type_init(hpet_register_types)
790