2 * High Precisition Event Timer emulation
4 * Copyright (c) 2007 Alexander Graf
5 * Copyright (c) 2008 IBM Corporation
7 * Authors: Beth Kon <bkon@us.ibm.com>
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.
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.
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/>.
22 * *****************************************************************
24 * This driver attempts to emulate an HPET device in software.
30 #include "qemu-timer.h"
31 #include "hpet_emul.h"
33 #include "mc146818rtc.h"
37 #define DPRINTF printf
42 #define HPET_MSI_SUPPORT 0
45 typedef struct HPETTimer
{ /* timers */
46 uint8_t tn
; /*timer number*/
47 QEMUTimer
*qemu_timer
;
48 struct HPETState
*state
;
49 /* Memory-mapped, software visible timer registers */
50 uint64_t config
; /* configuration/cap */
51 uint64_t cmp
; /* comparator */
52 uint64_t fsb
; /* FSB route */
53 /* Hidden register state */
54 uint64_t period
; /* Last value written to comparator */
55 uint8_t wrap_flag
; /* timer pop will indicate wrap for one-shot 32-bit
56 * mode. Next pop will be actual timer expiration.
60 typedef struct HPETState
{
64 qemu_irq irqs
[HPET_NUM_IRQ_ROUTES
];
66 uint8_t rtc_irq_level
;
68 HPETTimer timer
[HPET_MAX_TIMERS
];
70 /* Memory-mapped, software visible registers */
71 uint64_t capability
; /* capabilities */
72 uint64_t config
; /* configuration */
73 uint64_t isr
; /* interrupt status reg */
74 uint64_t hpet_counter
; /* main counter */
75 uint8_t hpet_id
; /* instance id */
78 static uint32_t hpet_in_legacy_mode(HPETState
*s
)
80 return s
->config
& HPET_CFG_LEGACY
;
83 static uint32_t timer_int_route(struct HPETTimer
*timer
)
85 return (timer
->config
& HPET_TN_INT_ROUTE_MASK
) >> HPET_TN_INT_ROUTE_SHIFT
;
88 static uint32_t timer_fsb_route(HPETTimer
*t
)
90 return t
->config
& HPET_TN_FSB_ENABLE
;
93 static uint32_t hpet_enabled(HPETState
*s
)
95 return s
->config
& HPET_CFG_ENABLE
;
98 static uint32_t timer_is_periodic(HPETTimer
*t
)
100 return t
->config
& HPET_TN_PERIODIC
;
103 static uint32_t timer_enabled(HPETTimer
*t
)
105 return t
->config
& HPET_TN_ENABLE
;
108 static uint32_t hpet_time_after(uint64_t a
, uint64_t b
)
110 return ((int32_t)(b
) - (int32_t)(a
) < 0);
113 static uint32_t hpet_time_after64(uint64_t a
, uint64_t b
)
115 return ((int64_t)(b
) - (int64_t)(a
) < 0);
118 static uint64_t ticks_to_ns(uint64_t value
)
120 return (muldiv64(value
, HPET_CLK_PERIOD
, FS_PER_NS
));
123 static uint64_t ns_to_ticks(uint64_t value
)
125 return (muldiv64(value
, FS_PER_NS
, HPET_CLK_PERIOD
));
128 static uint64_t hpet_fixup_reg(uint64_t new, uint64_t old
, uint64_t mask
)
135 static int activating_bit(uint64_t old
, uint64_t new, uint64_t mask
)
137 return (!(old
& mask
) && (new & mask
));
140 static int deactivating_bit(uint64_t old
, uint64_t new, uint64_t mask
)
142 return ((old
& mask
) && !(new & mask
));
145 static uint64_t hpet_get_ticks(HPETState
*s
)
147 return ns_to_ticks(qemu_get_clock_ns(vm_clock
) + s
->hpet_offset
);
151 * calculate diff between comparator value and current ticks
153 static inline uint64_t hpet_calculate_diff(HPETTimer
*t
, uint64_t current
)
156 if (t
->config
& HPET_TN_32BIT
) {
159 cmp
= (uint32_t)t
->cmp
;
160 diff
= cmp
- (uint32_t)current
;
161 diff
= (int32_t)diff
> 0 ? diff
: (uint32_t)1;
162 return (uint64_t)diff
;
167 diff
= cmp
- current
;
168 diff
= (int64_t)diff
> 0 ? diff
: (uint64_t)1;
173 static void update_irq(struct HPETTimer
*timer
, int set
)
179 if (timer
->tn
<= 1 && hpet_in_legacy_mode(timer
->state
)) {
180 /* if LegacyReplacementRoute bit is set, HPET specification requires
181 * timer0 be routed to IRQ0 in NON-APIC or IRQ2 in the I/O APIC,
182 * timer1 be routed to IRQ8 in NON-APIC or IRQ8 in the I/O APIC.
184 route
= (timer
->tn
== 0) ? 0 : RTC_ISA_IRQ
;
186 route
= timer_int_route(timer
);
189 mask
= 1 << timer
->tn
;
190 if (!set
|| !timer_enabled(timer
) || !hpet_enabled(timer
->state
)) {
192 if (!timer_fsb_route(timer
)) {
193 qemu_irq_lower(s
->irqs
[route
]);
195 } else if (timer_fsb_route(timer
)) {
196 stl_le_phys(timer
->fsb
>> 32, timer
->fsb
& 0xffffffff);
197 } else if (timer
->config
& HPET_TN_TYPE_LEVEL
) {
199 qemu_irq_raise(s
->irqs
[route
]);
202 qemu_irq_pulse(s
->irqs
[route
]);
206 static void hpet_pre_save(void *opaque
)
208 HPETState
*s
= opaque
;
210 /* save current counter value */
211 s
->hpet_counter
= hpet_get_ticks(s
);
214 static int hpet_pre_load(void *opaque
)
216 HPETState
*s
= opaque
;
218 /* version 1 only supports 3, later versions will load the actual value */
219 s
->num_timers
= HPET_MIN_TIMERS
;
223 static int hpet_post_load(void *opaque
, int version_id
)
225 HPETState
*s
= opaque
;
227 /* Recalculate the offset between the main counter and guest time */
228 s
->hpet_offset
= ticks_to_ns(s
->hpet_counter
) - qemu_get_clock_ns(vm_clock
);
230 /* Push number of timers into capability returned via HPET_ID */
231 s
->capability
&= ~HPET_ID_NUM_TIM_MASK
;
232 s
->capability
|= (s
->num_timers
- 1) << HPET_ID_NUM_TIM_SHIFT
;
233 hpet_cfg
.hpet
[s
->hpet_id
].event_timer_block_id
= (uint32_t)s
->capability
;
235 /* Derive HPET_MSI_SUPPORT from the capability of the first timer. */
236 s
->flags
&= ~(1 << HPET_MSI_SUPPORT
);
237 if (s
->timer
[0].config
& HPET_TN_FSB_CAP
) {
238 s
->flags
|= 1 << HPET_MSI_SUPPORT
;
243 static const VMStateDescription vmstate_hpet_timer
= {
244 .name
= "hpet_timer",
246 .minimum_version_id
= 1,
247 .minimum_version_id_old
= 1,
248 .fields
= (VMStateField
[]) {
249 VMSTATE_UINT8(tn
, HPETTimer
),
250 VMSTATE_UINT64(config
, HPETTimer
),
251 VMSTATE_UINT64(cmp
, HPETTimer
),
252 VMSTATE_UINT64(fsb
, HPETTimer
),
253 VMSTATE_UINT64(period
, HPETTimer
),
254 VMSTATE_UINT8(wrap_flag
, HPETTimer
),
255 VMSTATE_TIMER(qemu_timer
, HPETTimer
),
256 VMSTATE_END_OF_LIST()
260 static const VMStateDescription vmstate_hpet
= {
263 .minimum_version_id
= 1,
264 .minimum_version_id_old
= 1,
265 .pre_save
= hpet_pre_save
,
266 .pre_load
= hpet_pre_load
,
267 .post_load
= hpet_post_load
,
268 .fields
= (VMStateField
[]) {
269 VMSTATE_UINT64(config
, HPETState
),
270 VMSTATE_UINT64(isr
, HPETState
),
271 VMSTATE_UINT64(hpet_counter
, HPETState
),
272 VMSTATE_UINT8_V(num_timers
, HPETState
, 2),
273 VMSTATE_STRUCT_VARRAY_UINT8(timer
, HPETState
, num_timers
, 0,
274 vmstate_hpet_timer
, HPETTimer
),
275 VMSTATE_END_OF_LIST()
280 * timer expiration callback
282 static void hpet_timer(void *opaque
)
284 HPETTimer
*t
= opaque
;
287 uint64_t period
= t
->period
;
288 uint64_t cur_tick
= hpet_get_ticks(t
->state
);
290 if (timer_is_periodic(t
) && period
!= 0) {
291 if (t
->config
& HPET_TN_32BIT
) {
292 while (hpet_time_after(cur_tick
, t
->cmp
)) {
293 t
->cmp
= (uint32_t)(t
->cmp
+ t
->period
);
296 while (hpet_time_after64(cur_tick
, t
->cmp
)) {
300 diff
= hpet_calculate_diff(t
, cur_tick
);
301 qemu_mod_timer(t
->qemu_timer
,
302 qemu_get_clock_ns(vm_clock
) + (int64_t)ticks_to_ns(diff
));
303 } else if (t
->config
& HPET_TN_32BIT
&& !timer_is_periodic(t
)) {
305 diff
= hpet_calculate_diff(t
, cur_tick
);
306 qemu_mod_timer(t
->qemu_timer
, qemu_get_clock_ns(vm_clock
) +
307 (int64_t)ticks_to_ns(diff
));
314 static void hpet_set_timer(HPETTimer
*t
)
317 uint32_t wrap_diff
; /* how many ticks until we wrap? */
318 uint64_t cur_tick
= hpet_get_ticks(t
->state
);
320 /* whenever new timer is being set up, make sure wrap_flag is 0 */
322 diff
= hpet_calculate_diff(t
, cur_tick
);
324 /* hpet spec says in one-shot 32-bit mode, generate an interrupt when
325 * counter wraps in addition to an interrupt with comparator match.
327 if (t
->config
& HPET_TN_32BIT
&& !timer_is_periodic(t
)) {
328 wrap_diff
= 0xffffffff - (uint32_t)cur_tick
;
329 if (wrap_diff
< (uint32_t)diff
) {
334 qemu_mod_timer(t
->qemu_timer
,
335 qemu_get_clock_ns(vm_clock
) + (int64_t)ticks_to_ns(diff
));
338 static void hpet_del_timer(HPETTimer
*t
)
340 qemu_del_timer(t
->qemu_timer
);
345 static uint32_t hpet_ram_readb(void *opaque
, target_phys_addr_t addr
)
347 printf("qemu: hpet_read b at %" PRIx64
"\n", addr
);
351 static uint32_t hpet_ram_readw(void *opaque
, target_phys_addr_t addr
)
353 printf("qemu: hpet_read w at %" PRIx64
"\n", addr
);
358 static uint64_t hpet_ram_read(void *opaque
, target_phys_addr_t addr
,
361 HPETState
*s
= opaque
;
362 uint64_t cur_tick
, index
;
364 DPRINTF("qemu: Enter hpet_ram_readl at %" PRIx64
"\n", addr
);
366 /*address range of all TN regs*/
367 if (index
>= 0x100 && index
<= 0x3ff) {
368 uint8_t timer_id
= (addr
- 0x100) / 0x20;
369 HPETTimer
*timer
= &s
->timer
[timer_id
];
371 if (timer_id
> s
->num_timers
) {
372 DPRINTF("qemu: timer id out of range\n");
376 switch ((addr
- 0x100) % 0x20) {
378 return timer
->config
;
379 case HPET_TN_CFG
+ 4: // Interrupt capabilities
380 return timer
->config
>> 32;
381 case HPET_TN_CMP
: // comparator register
383 case HPET_TN_CMP
+ 4:
384 return timer
->cmp
>> 32;
387 case HPET_TN_ROUTE
+ 4:
388 return timer
->fsb
>> 32;
390 DPRINTF("qemu: invalid hpet_ram_readl\n");
396 return s
->capability
;
398 return s
->capability
>> 32;
402 DPRINTF("qemu: invalid HPET_CFG + 4 hpet_ram_readl\n");
405 if (hpet_enabled(s
)) {
406 cur_tick
= hpet_get_ticks(s
);
408 cur_tick
= s
->hpet_counter
;
410 DPRINTF("qemu: reading counter = %" PRIx64
"\n", cur_tick
);
412 case HPET_COUNTER
+ 4:
413 if (hpet_enabled(s
)) {
414 cur_tick
= hpet_get_ticks(s
);
416 cur_tick
= s
->hpet_counter
;
418 DPRINTF("qemu: reading counter + 4 = %" PRIx64
"\n", cur_tick
);
419 return cur_tick
>> 32;
423 DPRINTF("qemu: invalid hpet_ram_readl\n");
430 static void hpet_ram_write(void *opaque
, target_phys_addr_t addr
,
431 uint64_t value
, unsigned size
)
434 HPETState
*s
= opaque
;
435 uint64_t old_val
, new_val
, val
, index
;
437 DPRINTF("qemu: Enter hpet_ram_writel at %" PRIx64
" = %#x\n", addr
, value
);
439 old_val
= hpet_ram_read(opaque
, addr
, 4);
442 /*address range of all TN regs*/
443 if (index
>= 0x100 && index
<= 0x3ff) {
444 uint8_t timer_id
= (addr
- 0x100) / 0x20;
445 HPETTimer
*timer
= &s
->timer
[timer_id
];
447 DPRINTF("qemu: hpet_ram_writel timer_id = %#x\n", timer_id
);
448 if (timer_id
> s
->num_timers
) {
449 DPRINTF("qemu: timer id out of range\n");
452 switch ((addr
- 0x100) % 0x20) {
454 DPRINTF("qemu: hpet_ram_writel HPET_TN_CFG\n");
455 if (activating_bit(old_val
, new_val
, HPET_TN_FSB_ENABLE
)) {
456 update_irq(timer
, 0);
458 val
= hpet_fixup_reg(new_val
, old_val
, HPET_TN_CFG_WRITE_MASK
);
459 timer
->config
= (timer
->config
& 0xffffffff00000000ULL
) | val
;
460 if (new_val
& HPET_TN_32BIT
) {
461 timer
->cmp
= (uint32_t)timer
->cmp
;
462 timer
->period
= (uint32_t)timer
->period
;
464 if (activating_bit(old_val
, new_val
, HPET_TN_ENABLE
)) {
465 hpet_set_timer(timer
);
466 } else if (deactivating_bit(old_val
, new_val
, HPET_TN_ENABLE
)) {
467 hpet_del_timer(timer
);
470 case HPET_TN_CFG
+ 4: // Interrupt capabilities
471 DPRINTF("qemu: invalid HPET_TN_CFG+4 write\n");
473 case HPET_TN_CMP
: // comparator register
474 DPRINTF("qemu: hpet_ram_writel HPET_TN_CMP\n");
475 if (timer
->config
& HPET_TN_32BIT
) {
476 new_val
= (uint32_t)new_val
;
478 if (!timer_is_periodic(timer
)
479 || (timer
->config
& HPET_TN_SETVAL
)) {
480 timer
->cmp
= (timer
->cmp
& 0xffffffff00000000ULL
) | new_val
;
482 if (timer_is_periodic(timer
)) {
484 * FIXME: Clamp period to reasonable min value?
485 * Clamp period to reasonable max value
487 new_val
&= (timer
->config
& HPET_TN_32BIT
? ~0u : ~0ull) >> 1;
489 (timer
->period
& 0xffffffff00000000ULL
) | new_val
;
491 timer
->config
&= ~HPET_TN_SETVAL
;
492 if (hpet_enabled(s
)) {
493 hpet_set_timer(timer
);
496 case HPET_TN_CMP
+ 4: // comparator register high order
497 DPRINTF("qemu: hpet_ram_writel HPET_TN_CMP + 4\n");
498 if (!timer_is_periodic(timer
)
499 || (timer
->config
& HPET_TN_SETVAL
)) {
500 timer
->cmp
= (timer
->cmp
& 0xffffffffULL
) | new_val
<< 32;
503 * FIXME: Clamp period to reasonable min value?
504 * Clamp period to reasonable max value
506 new_val
&= (timer
->config
& HPET_TN_32BIT
? ~0u : ~0ull) >> 1;
508 (timer
->period
& 0xffffffffULL
) | new_val
<< 32;
510 timer
->config
&= ~HPET_TN_SETVAL
;
511 if (hpet_enabled(s
)) {
512 hpet_set_timer(timer
);
516 timer
->fsb
= (timer
->fsb
& 0xffffffff00000000ULL
) | new_val
;
518 case HPET_TN_ROUTE
+ 4:
519 timer
->fsb
= (new_val
<< 32) | (timer
->fsb
& 0xffffffff);
522 DPRINTF("qemu: invalid hpet_ram_writel\n");
531 val
= hpet_fixup_reg(new_val
, old_val
, HPET_CFG_WRITE_MASK
);
532 s
->config
= (s
->config
& 0xffffffff00000000ULL
) | val
;
533 if (activating_bit(old_val
, new_val
, HPET_CFG_ENABLE
)) {
534 /* Enable main counter and interrupt generation. */
536 ticks_to_ns(s
->hpet_counter
) - qemu_get_clock_ns(vm_clock
);
537 for (i
= 0; i
< s
->num_timers
; i
++) {
538 if ((&s
->timer
[i
])->cmp
!= ~0ULL) {
539 hpet_set_timer(&s
->timer
[i
]);
542 } else if (deactivating_bit(old_val
, new_val
, HPET_CFG_ENABLE
)) {
543 /* Halt main counter and disable interrupt generation. */
544 s
->hpet_counter
= hpet_get_ticks(s
);
545 for (i
= 0; i
< s
->num_timers
; i
++) {
546 hpet_del_timer(&s
->timer
[i
]);
549 /* i8254 and RTC are disabled when HPET is in legacy mode */
550 if (activating_bit(old_val
, new_val
, HPET_CFG_LEGACY
)) {
552 qemu_irq_lower(s
->irqs
[RTC_ISA_IRQ
]);
553 } else if (deactivating_bit(old_val
, new_val
, HPET_CFG_LEGACY
)) {
555 qemu_set_irq(s
->irqs
[RTC_ISA_IRQ
], s
->rtc_irq_level
);
559 DPRINTF("qemu: invalid HPET_CFG+4 write\n");
562 val
= new_val
& s
->isr
;
563 for (i
= 0; i
< s
->num_timers
; i
++) {
564 if (val
& (1 << i
)) {
565 update_irq(&s
->timer
[i
], 0);
570 if (hpet_enabled(s
)) {
571 DPRINTF("qemu: Writing counter while HPET enabled!\n");
574 (s
->hpet_counter
& 0xffffffff00000000ULL
) | value
;
575 DPRINTF("qemu: HPET counter written. ctr = %#x -> %" PRIx64
"\n",
576 value
, s
->hpet_counter
);
578 case HPET_COUNTER
+ 4:
579 if (hpet_enabled(s
)) {
580 DPRINTF("qemu: Writing counter while HPET enabled!\n");
583 (s
->hpet_counter
& 0xffffffffULL
) | (((uint64_t)value
) << 32);
584 DPRINTF("qemu: HPET counter + 4 written. ctr = %#x -> %" PRIx64
"\n",
585 value
, s
->hpet_counter
);
588 DPRINTF("qemu: invalid hpet_ram_writel\n");
594 static const MemoryRegionOps hpet_ram_ops
= {
595 .read
= hpet_ram_read
,
596 .write
= hpet_ram_write
,
598 .min_access_size
= 4,
599 .max_access_size
= 4,
601 .endianness
= DEVICE_NATIVE_ENDIAN
,
604 static void hpet_reset(DeviceState
*d
)
606 HPETState
*s
= FROM_SYSBUS(HPETState
, sysbus_from_qdev(d
));
608 static int count
= 0;
610 for (i
= 0; i
< s
->num_timers
; i
++) {
611 HPETTimer
*timer
= &s
->timer
[i
];
613 hpet_del_timer(timer
);
615 timer
->config
= HPET_TN_PERIODIC_CAP
| HPET_TN_SIZE_CAP
;
616 if (s
->flags
& (1 << HPET_MSI_SUPPORT
)) {
617 timer
->config
|= HPET_TN_FSB_CAP
;
619 /* advertise availability of ioapic inti2 */
620 timer
->config
|= 0x00000004ULL
<< 32;
621 timer
->period
= 0ULL;
622 timer
->wrap_flag
= 0;
625 s
->hpet_counter
= 0ULL;
626 s
->hpet_offset
= 0ULL;
629 /* we don't enable pit when hpet_reset is first called (by hpet_init)
630 * because hpet is taking over for pit here. On subsequent invocations,
631 * hpet_reset is called due to system reset. At this point control must
632 * be returned to pit until SW reenables hpet.
636 hpet_cfg
.hpet
[s
->hpet_id
].event_timer_block_id
= (uint32_t)s
->capability
;
637 hpet_cfg
.hpet
[s
->hpet_id
].address
= sysbus_from_qdev(d
)->mmio
[0].addr
;
641 static void hpet_handle_rtc_irq(void *opaque
, int n
, int level
)
643 HPETState
*s
= FROM_SYSBUS(HPETState
, opaque
);
645 s
->rtc_irq_level
= level
;
646 if (!hpet_in_legacy_mode(s
)) {
647 qemu_set_irq(s
->irqs
[RTC_ISA_IRQ
], level
);
651 static int hpet_init(SysBusDevice
*dev
)
653 HPETState
*s
= FROM_SYSBUS(HPETState
, dev
);
657 if (hpet_cfg
.count
== UINT8_MAX
) {
662 if (hpet_cfg
.count
== 8) {
663 fprintf(stderr
, "Only 8 instances of HPET is allowed\n");
667 s
->hpet_id
= hpet_cfg
.count
++;
669 for (i
= 0; i
< HPET_NUM_IRQ_ROUTES
; i
++) {
670 sysbus_init_irq(dev
, &s
->irqs
[i
]);
673 if (s
->num_timers
< HPET_MIN_TIMERS
) {
674 s
->num_timers
= HPET_MIN_TIMERS
;
675 } else if (s
->num_timers
> HPET_MAX_TIMERS
) {
676 s
->num_timers
= HPET_MAX_TIMERS
;
678 for (i
= 0; i
< HPET_MAX_TIMERS
; i
++) {
679 timer
= &s
->timer
[i
];
680 timer
->qemu_timer
= qemu_new_timer_ns(vm_clock
, hpet_timer
, timer
);
685 /* 64-bit main counter; LegacyReplacementRoute. */
686 s
->capability
= 0x8086a001ULL
;
687 s
->capability
|= (s
->num_timers
- 1) << HPET_ID_NUM_TIM_SHIFT
;
688 s
->capability
|= ((HPET_CLK_PERIOD
) << 32);
690 qdev_init_gpio_in(&dev
->qdev
, hpet_handle_rtc_irq
, 1);
693 memory_region_init_io(&s
->iomem
, &hpet_ram_ops
, s
, "hpet", 0x400);
694 sysbus_init_mmio(dev
, &s
->iomem
);
698 static Property hpet_device_properties
[] = {
699 DEFINE_PROP_UINT8("timers", HPETState
, num_timers
, HPET_MIN_TIMERS
),
700 DEFINE_PROP_BIT("msi", HPETState
, flags
, HPET_MSI_SUPPORT
, false),
701 DEFINE_PROP_END_OF_LIST(),
704 static void hpet_device_class_init(ObjectClass
*klass
, void *data
)
706 DeviceClass
*dc
= DEVICE_CLASS(klass
);
707 SysBusDeviceClass
*k
= SYS_BUS_DEVICE_CLASS(klass
);
711 dc
->reset
= hpet_reset
;
712 dc
->vmsd
= &vmstate_hpet
;
713 dc
->props
= hpet_device_properties
;
716 static TypeInfo hpet_device_info
= {
718 .parent
= TYPE_SYS_BUS_DEVICE
,
719 .instance_size
= sizeof(HPETState
),
720 .class_init
= hpet_device_class_init
,
723 static void hpet_register_device(void)
725 type_register_static(&hpet_device_info
);
728 device_init(hpet_register_device
)