/*
* High Precisition Event Timer emulation
*
* Copyright (c) 2007 Alexander Graf
* Copyright (c) 2008 IBM Corporation
*
* Authors: Beth Kon <bkon@us.ibm.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*
* *****************************************************************
*
* This driver attempts to emulate an HPET device in software.
*/
#include "hw.h"
#include "pc.h"
#include "console.h"
#include "qemu-timer.h"
#include "hpet_emul.h"
//#define HPET_DEBUG
#ifdef HPET_DEBUG
#define DPRINTF printf
#else
#define DPRINTF(...)
#endif
static HPETState *hpet_statep;
uint32_t hpet_in_legacy_mode(void)
{
if (hpet_statep)
return hpet_statep->config & HPET_CFG_LEGACY;
else
return 0;
}
static uint32_t timer_int_route(struct HPETTimer *timer)
{
uint32_t route;
route = (timer->config & HPET_TN_INT_ROUTE_MASK) >> HPET_TN_INT_ROUTE_SHIFT;
return route;
}
static uint32_t hpet_enabled(void)
{
return hpet_statep->config & HPET_CFG_ENABLE;
}
static uint32_t timer_is_periodic(HPETTimer *t)
{
return t->config & HPET_TN_PERIODIC;
}
static uint32_t timer_enabled(HPETTimer *t)
{
return t->config & HPET_TN_ENABLE;
}
static uint32_t hpet_time_after(uint64_t a, uint64_t b)
{
return ((int32_t)(b) - (int32_t)(a) < 0);
}
static uint32_t hpet_time_after64(uint64_t a, uint64_t b)
{
return ((int64_t)(b) - (int64_t)(a) < 0);
}
static uint64_t ticks_to_ns(uint64_t value)
{
return (muldiv64(value, HPET_CLK_PERIOD, FS_PER_NS));
}
static uint64_t ns_to_ticks(uint64_t value)
{
return (muldiv64(value, FS_PER_NS, HPET_CLK_PERIOD));
}
static uint64_t hpet_fixup_reg(uint64_t new, uint64_t old, uint64_t mask)
{
new &= mask;
new |= old & ~mask;
return new;
}
static int activating_bit(uint64_t old, uint64_t new, uint64_t mask)
{
return (!(old & mask) && (new & mask));
}
static int deactivating_bit(uint64_t old, uint64_t new, uint64_t mask)
{
return ((old & mask) && !(new & mask));
}
static uint64_t hpet_get_ticks(void)
{
uint64_t ticks;
ticks = ns_to_ticks(qemu_get_clock(vm_clock) + hpet_statep->hpet_offset);
return ticks;
}
/*
* calculate diff between comparator value and current ticks
*/
static inline uint64_t hpet_calculate_diff(HPETTimer *t, uint64_t current)
{
if (t->config & HPET_TN_32BIT) {
uint32_t diff, cmp;
cmp = (uint32_t)t->cmp;
diff = cmp - (uint32_t)current;
diff = (int32_t)diff > 0 ? diff : (uint32_t)0;
return (uint64_t)diff;
} else {
uint64_t diff, cmp;
cmp = t->cmp;
diff = cmp - current;
diff = (int64_t)diff > 0 ? diff : (uint64_t)0;
return diff;
}
}
static void update_irq(struct HPETTimer *timer)
{
qemu_irq irq;
int route;
if (timer->tn <= 1 && hpet_in_legacy_mode()) {
/* if LegacyReplacementRoute bit is set, HPET specification requires
* timer0 be routed to IRQ0 in NON-APIC or IRQ2 in the I/O APIC,
* timer1 be routed to IRQ8 in NON-APIC or IRQ8 in the I/O APIC.
*/
if (timer->tn == 0) {
irq=timer->state->irqs[0];
} else
irq=timer->state->irqs[8];
} else {
route=timer_int_route(timer);
irq=timer->state->irqs[route];
}
if (timer_enabled(timer) && hpet_enabled()) {
qemu_irq_pulse(irq);
}
}
static void hpet_pre_save(void *opaque)
{
HPETState *s = opaque;
/* save current counter value */
s->hpet_counter = hpet_get_ticks();
}
static int hpet_post_load(void *opaque, int version_id)
{
HPETState *s = opaque;
/* Recalculate the offset between the main counter and guest time */
s->hpet_offset = ticks_to_ns(s->hpet_counter) - qemu_get_clock(vm_clock);
return 0;
}
static const VMStateDescription vmstate_hpet_timer = {
.name = "hpet_timer",
.version_id = 1,
.minimum_version_id = 1,
.minimum_version_id_old = 1,
.fields = (VMStateField []) {
VMSTATE_UINT8(tn, HPETTimer),
VMSTATE_UINT64(config, HPETTimer),
VMSTATE_UINT64(cmp, HPETTimer),
VMSTATE_UINT64(fsb, HPETTimer),
VMSTATE_UINT64(period, HPETTimer),
VMSTATE_UINT8(wrap_flag, HPETTimer),
VMSTATE_TIMER(qemu_timer, HPETTimer),
VMSTATE_END_OF_LIST()
}
};
static const VMStateDescription vmstate_hpet = {
.name = "hpet",
.version_id = 1,
.minimum_version_id = 1,
.minimum_version_id_old = 1,
.pre_save = hpet_pre_save,
.post_load = hpet_post_load,
.fields = (VMStateField []) {
VMSTATE_UINT64(config, HPETState),
VMSTATE_UINT64(isr, HPETState),
VMSTATE_UINT64(hpet_counter, HPETState),
VMSTATE_STRUCT_ARRAY(timer, HPETState, HPET_NUM_TIMERS, 0,
vmstate_hpet_timer, HPETTimer),
VMSTATE_END_OF_LIST()
}
};
/*
* timer expiration callback
*/
static void hpet_timer(void *opaque)
{
HPETTimer *t = (HPETTimer*)opaque;
uint64_t diff;
uint64_t period = t->period;
uint64_t cur_tick = hpet_get_ticks();
if (timer_is_periodic(t) && period != 0) {
if (t->config & HPET_TN_32BIT) {
while (hpet_time_after(cur_tick, t->cmp))
t->cmp = (uint32_t)(t->cmp + t->period);
} else
while (hpet_time_after64(cur_tick, t->cmp))
t->cmp += period;
diff = hpet_calculate_diff(t, cur_tick);
qemu_mod_timer(t->qemu_timer, qemu_get_clock(vm_clock)
+ (int64_t)ticks_to_ns(diff));
} else if (t->config & HPET_TN_32BIT && !timer_is_periodic(t)) {
if (t->wrap_flag) {
diff = hpet_calculate_diff(t, cur_tick);
qemu_mod_timer(t->qemu_timer, qemu_get_clock(vm_clock)
+ (int64_t)ticks_to_ns(diff));
t->wrap_flag = 0;
}
}
update_irq(t);
}
static void hpet_set_timer(HPETTimer *t)
{
uint64_t diff;
uint32_t wrap_diff; /* how many ticks until we wrap? */
uint64_t cur_tick = hpet_get_ticks();
/* whenever new timer is being set up, make sure wrap_flag is 0 */
t->wrap_flag = 0;
diff = hpet_calculate_diff(t, cur_tick);
/* hpet spec says in one-shot 32-bit mode, generate an interrupt when
* counter wraps in addition to an interrupt with comparator match.
*/
if (t->config & HPET_TN_32BIT && !timer_is_periodic(t)) {
wrap_diff = 0xffffffff - (uint32_t)cur_tick;
if (wrap_diff < (uint32_t)diff) {
diff = wrap_diff;
t->wrap_flag = 1;
}
}
qemu_mod_timer(t->qemu_timer, qemu_get_clock(vm_clock)
+ (int64_t)ticks_to_ns(diff));
}
static void hpet_del_timer(HPETTimer *t)
{
qemu_del_timer(t->qemu_timer);
}
#ifdef HPET_DEBUG
static uint32_t hpet_ram_readb(void *opaque, target_phys_addr_t addr)
{
printf("qemu: hpet_read b at %" PRIx64 "\n", addr);
return 0;
}
static uint32_t hpet_ram_readw(void *opaque, target_phys_addr_t addr)
{
printf("qemu: hpet_read w at %" PRIx64 "\n", addr);
return 0;
}
#endif
static uint32_t hpet_ram_readl(void *opaque, target_phys_addr_t addr)
{
HPETState *s = (HPETState *)opaque;
uint64_t cur_tick, index;
DPRINTF("qemu: Enter hpet_ram_readl at %" PRIx64 "\n", addr);
index = addr;
/*address range of all TN regs*/
if (index >= 0x100 && index <= 0x3ff) {
uint8_t timer_id = (addr - 0x100) / 0x20;
if (timer_id > HPET_NUM_TIMERS - 1) {
printf("qemu: timer id out of range\n");
return 0;
}
HPETTimer *timer = &s->timer[timer_id];
switch ((addr - 0x100) % 0x20) {
case HPET_TN_CFG:
return timer->config;
case HPET_TN_CFG + 4: // Interrupt capabilities
return timer->config >> 32;
case HPET_TN_CMP: // comparator register
return timer->cmp;
case HPET_TN_CMP + 4:
return timer->cmp >> 32;
case HPET_TN_ROUTE:
return timer->fsb >> 32;
default:
DPRINTF("qemu: invalid hpet_ram_readl\n");
break;
}
} else {
switch (index) {
case HPET_ID:
return s->capability;
case HPET_PERIOD:
return s->capability >> 32;
case HPET_CFG:
return s->config;
case HPET_CFG + 4:
DPRINTF("qemu: invalid HPET_CFG + 4 hpet_ram_readl \n");
return 0;
case HPET_COUNTER:
if (hpet_enabled())
cur_tick = hpet_get_ticks();
else
cur_tick = s->hpet_counter;
DPRINTF("qemu: reading counter = %" PRIx64 "\n", cur_tick);
return cur_tick;
case HPET_COUNTER + 4:
if (hpet_enabled())
cur_tick = hpet_get_ticks();
else
cur_tick = s->hpet_counter;
DPRINTF("qemu: reading counter + 4 = %" PRIx64 "\n", cur_tick);
return cur_tick >> 32;
case HPET_STATUS:
return s->isr;
default:
DPRINTF("qemu: invalid hpet_ram_readl\n");
break;
}
}
return 0;
}
#ifdef HPET_DEBUG
static void hpet_ram_writeb(void *opaque, target_phys_addr_t addr,
uint32_t value)
{
printf("qemu: invalid hpet_write b at %" PRIx64 " = %#x\n",
addr, value);
}
static void hpet_ram_writew(void *opaque, target_phys_addr_t addr,
uint32_t value)
{
printf("qemu: invalid hpet_write w at %" PRIx64 " = %#x\n",
addr, value);
}
#endif
static void hpet_ram_writel(void *opaque, target_phys_addr_t addr,
uint32_t value)
{
int i;
HPETState *s = (HPETState *)opaque;
uint64_t old_val, new_val, val, index;
DPRINTF("qemu: Enter hpet_ram_writel at %" PRIx64 " = %#x\n", addr, value);
index = addr;
old_val = hpet_ram_readl(opaque, addr);
new_val = value;
/*address range of all TN regs*/
if (index >= 0x100 && index <= 0x3ff) {
uint8_t timer_id = (addr - 0x100) / 0x20;
DPRINTF("qemu: hpet_ram_writel timer_id = %#x \n", timer_id);
HPETTimer *timer = &s->timer[timer_id];
switch ((addr - 0x100) % 0x20) {
case HPET_TN_CFG:
DPRINTF("qemu: hpet_ram_writel HPET_TN_CFG\n");
val = hpet_fixup_reg(new_val, old_val, HPET_TN_CFG_WRITE_MASK);
timer->config = (timer->config & 0xffffffff00000000ULL) | val;
if (new_val & HPET_TN_32BIT) {
timer->cmp = (uint32_t)timer->cmp;
timer->period = (uint32_t)timer->period;
}
if (new_val & HPET_TIMER_TYPE_LEVEL) {
printf("qemu: level-triggered hpet not supported\n");
exit (-1);
}
break;
case HPET_TN_CFG + 4: // Interrupt capabilities
DPRINTF("qemu: invalid HPET_TN_CFG+4 write\n");
break;
case HPET_TN_CMP: // comparator register
DPRINTF("qemu: hpet_ram_writel HPET_TN_CMP \n");
if (timer->config & HPET_TN_32BIT)
new_val = (uint32_t)new_val;
if (!timer_is_periodic(timer) ||
(timer->config & HPET_TN_SETVAL))
timer->cmp = (timer->cmp & 0xffffffff00000000ULL)
| new_val;
if (timer_is_periodic(timer)) {
/*
* FIXME: Clamp period to reasonable min value?
* Clamp period to reasonable max value
*/
new_val &= (timer->config & HPET_TN_32BIT ? ~0u : ~0ull) >> 1;
timer->period = (timer->period & 0xffffffff00000000ULL)
| new_val;
}
timer->config &= ~HPET_TN_SETVAL;
if (hpet_enabled())
hpet_set_timer(timer);
break;
case HPET_TN_CMP + 4: // comparator register high order
DPRINTF("qemu: hpet_ram_writel HPET_TN_CMP + 4\n");
if (!timer_is_periodic(timer) ||
(timer->config & HPET_TN_SETVAL))
timer->cmp = (timer->cmp & 0xffffffffULL)
| new_val << 32;
else {
/*
* FIXME: Clamp period to reasonable min value?
* Clamp period to reasonable max value
*/
new_val &= (timer->config
& HPET_TN_32BIT ? ~0u : ~0ull) >> 1;
timer->period = (timer->period & 0xffffffffULL)
| new_val << 32;
}
timer->config &= ~HPET_TN_SETVAL;
if (hpet_enabled())
hpet_set_timer(timer);
break;
case HPET_TN_ROUTE + 4:
DPRINTF("qemu: hpet_ram_writel HPET_TN_ROUTE + 4\n");
break;
default:
DPRINTF("qemu: invalid hpet_ram_writel\n");
break;
}
return;
} else {
switch (index) {
case HPET_ID:
return;
case HPET_CFG:
val = hpet_fixup_reg(new_val, old_val, HPET_CFG_WRITE_MASK);
s->config = (s->config & 0xffffffff00000000ULL) | val;
if (activating_bit(old_val, new_val, HPET_CFG_ENABLE)) {
/* Enable main counter and interrupt generation. */
s->hpet_offset = ticks_to_ns(s->hpet_counter)
- qemu_get_clock(vm_clock);
for (i = 0; i < HPET_NUM_TIMERS; i++)
if ((&s->timer[i])->cmp != ~0ULL)
hpet_set_timer(&s->timer[i]);
}
else if (deactivating_bit(old_val, new_val, HPET_CFG_ENABLE)) {
/* Halt main counter and disable interrupt generation. */
s->hpet_counter = hpet_get_ticks();
for (i = 0; i < HPET_NUM_TIMERS; i++)
hpet_del_timer(&s->timer[i]);
}
/* i8254 and RTC are disabled when HPET is in legacy mode */
if (activating_bit(old_val, new_val, HPET_CFG_LEGACY)) {
hpet_pit_disable();
} else if (deactivating_bit(old_val, new_val, HPET_CFG_LEGACY)) {
hpet_pit_enable();
}
break;
case HPET_CFG + 4:
DPRINTF("qemu: invalid HPET_CFG+4 write \n");
break;
case HPET_STATUS:
/* FIXME: need to handle level-triggered interrupts */
break;
case HPET_COUNTER:
if (hpet_enabled())
printf("qemu: Writing counter while HPET enabled!\n");
s->hpet_counter = (s->hpet_counter & 0xffffffff00000000ULL)
| value;
DPRINTF("qemu: HPET counter written. ctr = %#x -> %" PRIx64 "\n",
value, s->hpet_counter);
break;
case HPET_COUNTER + 4:
if (hpet_enabled())
printf("qemu: Writing counter while HPET enabled!\n");
s->hpet_counter = (s->hpet_counter & 0xffffffffULL)
| (((uint64_t)value) << 32);
DPRINTF("qemu: HPET counter + 4 written. ctr = %#x -> %" PRIx64 "\n",
value, s->hpet_counter);
break;
default:
DPRINTF("qemu: invalid hpet_ram_writel\n");
break;
}
}
}
static CPUReadMemoryFunc * const hpet_ram_read[] = {
#ifdef HPET_DEBUG
hpet_ram_readb,
hpet_ram_readw,
#else
NULL,
NULL,
#endif
hpet_ram_readl,
};
static CPUWriteMemoryFunc * const hpet_ram_write[] = {
#ifdef HPET_DEBUG
hpet_ram_writeb,
hpet_ram_writew,
#else
NULL,
NULL,
#endif
hpet_ram_writel,
};
static void hpet_reset(void *opaque) {
HPETState *s = opaque;
int i;
static int count = 0;
for (i=0; i<HPET_NUM_TIMERS; i++) {
HPETTimer *timer = &s->timer[i];
hpet_del_timer(timer);
timer->tn = i;
timer->cmp = ~0ULL;
timer->config = HPET_TN_PERIODIC_CAP | HPET_TN_SIZE_CAP;
/* advertise availability of ioapic inti2 */
timer->config |= 0x00000004ULL << 32;
timer->state = s;
timer->period = 0ULL;
timer->wrap_flag = 0;
}
s->hpet_counter = 0ULL;
s->hpet_offset = 0ULL;
/* 64-bit main counter; 3 timers supported; LegacyReplacementRoute. */
s->capability = 0x8086a201ULL;
s->capability |= ((HPET_CLK_PERIOD) << 32);
s->config = 0ULL;
if (count > 0)
/* we don't enable pit when hpet_reset is first called (by hpet_init)
* because hpet is taking over for pit here. On subsequent invocations,
* hpet_reset is called due to system reset. At this point control must
* be returned to pit until SW reenables hpet.
*/
hpet_pit_enable();
count = 1;
}
void hpet_init(qemu_irq *irq) {
int i, iomemtype;
HPETState *s;
DPRINTF ("hpet_init\n");
s = qemu_mallocz(sizeof(HPETState));
hpet_statep = s;
s->irqs = irq;
for (i=0; i<HPET_NUM_TIMERS; i++) {
HPETTimer *timer = &s->timer[i];
timer->qemu_timer = qemu_new_timer(vm_clock, hpet_timer, timer);
}
vmstate_register(-1, &vmstate_hpet, s);
qemu_register_reset(hpet_reset, s);
/* HPET Area */
iomemtype = cpu_register_io_memory(hpet_ram_read,
hpet_ram_write, s);
cpu_register_physical_memory(HPET_BASE, 0x400, iomemtype);
}
