diff options
| -rw-r--r-- | hw/acpi.c | 84 |
1 files changed, 46 insertions, 38 deletions
@@ -50,12 +50,15 @@ typedef struct PIIX4PMState { uint8_t smb_data[32]; uint8_t smb_index; qemu_irq irq; + int64_t pmtmr; } PIIX4PMState; #define RTC_EN (1 << 10) #define PWRBTN_EN (1 << 8) #define GBL_EN (1 << 5) #define TMROF_EN (1 << 0) +#define TIMER_OVERFLOW_CNT (1 << 23) +#define TIMER_MASK 0xffffffLL #define SCI_EN (1 << 0) @@ -74,47 +77,61 @@ typedef struct PIIX4PMState { PIIX4PMState *pm_state; +static void update_pmtmr(PIIX4PMState *s) +{ + int64_t pmtmr; + + pmtmr = muldiv64(qemu_get_clock(vm_clock), PM_FREQ, ticks_per_sec) + & TIMER_MASK; + + if (!(s->pmsts & TMROF_EN)) { + if ((pmtmr ^ s->pmtmr) & TIMER_OVERFLOW_CNT) { + s->pmsts |= TMROF_EN; + if (s->pmen & TMROF_EN) + qemu_set_irq(s->irq, 1); + } else { + /* Calculate when the timer will neet to set + * the overflow bit again */ + uint64_t delta = TIMER_OVERFLOW_CNT - + (pmtmr & (TIMER_OVERFLOW_CNT - 1)); + + delta = muldiv64(delta, ticks_per_sec, PM_FREQ); + qemu_mod_timer(s->tmr_timer, qemu_get_clock(vm_clock) + delta); + } + } + + s->pmtmr = pmtmr; +} + static uint32_t get_pmtmr(PIIX4PMState *s) { - uint32_t d; - d = muldiv64(qemu_get_clock(vm_clock), PM_FREQ, ticks_per_sec); - return d & 0xffffff; + update_pmtmr(s); + return s->pmtmr & TIMER_MASK; } + static int get_pmsts(PIIX4PMState *s) { - int64_t d; - int pmsts; - pmsts = s->pmsts; - d = muldiv64(qemu_get_clock(vm_clock), PM_FREQ, ticks_per_sec); - if (d >= s->tmr_overflow_time) - s->pmsts |= TMROF_EN; - return pmsts; + /* Just increase the accurancy by double computing the timer value */ + update_pmtmr(s); + + return s->pmsts; } static void pm_update_sci(PIIX4PMState *s) { - int sci_level, pmsts; - int64_t expire_time; - - pmsts = get_pmsts(s); - sci_level = (((pmsts & s->pmen) & - (RTC_EN | PWRBTN_EN | GBL_EN | TMROF_EN)) != 0); - qemu_set_irq(s->irq, sci_level); - /* schedule a timer interruption if needed */ - if ((s->pmen & TMROF_EN) && !(pmsts & TMROF_EN)) { - expire_time = muldiv64(s->tmr_overflow_time, ticks_per_sec, PM_FREQ); - qemu_mod_timer(s->tmr_timer, expire_time); - s->tmr_overflow_time += 0x800000; - } else { - qemu_del_timer(s->tmr_timer); - } + int sci_level; + + sci_level = (((s->pmsts & s->pmen) & + (RTC_EN | PWRBTN_EN | GBL_EN | TMROF_EN)) != 0); + if (!sci_level) + qemu_set_irq(s->irq, sci_level); } static void pm_tmr_timer(void *opaque) { PIIX4PMState *s = opaque; - pm_update_sci(s); + update_pmtmr(s); } static void pm_ioport_writew(void *opaque, uint32_t addr, uint32_t val) @@ -123,18 +140,9 @@ static void pm_ioport_writew(void *opaque, uint32_t addr, uint32_t val) addr &= 0x3f; switch(addr) { case 0x00: - { - int64_t d; - int pmsts; - pmsts = get_pmsts(s); - if (pmsts & val & TMROF_EN) { - /* if TMRSTS is reset, then compute the new overflow time */ - d = muldiv64(qemu_get_clock(vm_clock), PM_FREQ, ticks_per_sec); - s->tmr_overflow_time = (d + 0x800000LL) & ~0x7fffffLL; - } - s->pmsts &= ~val; - pm_update_sci(s); - } + s->pmsts &= ~val; + update_pmtmr(s); + pm_update_sci(s); break; case 0x02: s->pmen = val; |