diff options
| -rw-r--r-- | sys/amd64/isa/clock.c | 41 |
1 files changed, 34 insertions, 7 deletions
diff --git a/sys/amd64/isa/clock.c b/sys/amd64/isa/clock.c index 7e3fd78..914b4b2 100644 --- a/sys/amd64/isa/clock.c +++ b/sys/amd64/isa/clock.c @@ -127,6 +127,7 @@ static u_char rtc_statusb = RTCSB_24HR; static u_char timer2_state; static unsigned i8254_get_timecount(struct timecounter *tc); +static unsigned i8254_simple_get_timecount(struct timecounter *tc); static void set_timer_freq(u_int freq, int intr_freq); static struct timecounter i8254_timecounter = { @@ -518,10 +519,15 @@ set_timer_freq(u_int freq, int intr_freq) { int new_timer0_max_count; + i8254_timecounter.tc_frequency = freq; mtx_lock_spin(&clock_lock); timer_freq = freq; new_timer0_max_count = hardclock_max_count = TIMER_DIV(intr_freq); - if (new_timer0_max_count != timer0_max_count) { + if (using_lapic_timer) { + outb(TIMER_MODE, TIMER_SEL0 | TIMER_RATEGEN | TIMER_16BIT); + outb(TIMER_CNTR0, 0); + outb(TIMER_CNTR0, 0); + } else if (new_timer0_max_count != timer0_max_count) { timer0_max_count = new_timer0_max_count; outb(TIMER_MODE, TIMER_SEL0 | TIMER_RATEGEN | TIMER_16BIT); outb(TIMER_CNTR0, timer0_max_count & 0xff); @@ -575,7 +581,6 @@ startrtclock() } set_timer_freq(timer_freq, hz); - i8254_timecounter.tc_frequency = timer_freq; tc_init(&i8254_timecounter); init_TSC(); @@ -728,15 +733,21 @@ cpu_initclocks() /* * If we aren't using the local APIC timer to drive the kernel * clocks, setup the interrupt handler for the 8254 timer 0 so - * that it can drive hardclock(). + * that it can drive hardclock(). Otherwise, change the 8254 + * timecounter to user a simpler algorithm. */ - if (!using_lapic_timer) { + if (!using_lapic_timer || 1) { intr_add_handler("clk", 0, (driver_intr_t *)clkintr, NULL, INTR_TYPE_CLK | INTR_FAST, NULL); i8254_intsrc = intr_lookup_source(0); if (i8254_intsrc != NULL) i8254_pending = i8254_intsrc->is_pic->pic_source_pending; + } else { + i8254_timecounter.tc_get_timecount = + i8254_simple_get_timecount; + i8254_timecounter.tc_counter_mask = 0xffff; + set_timer_freq(timer_freq, hz); } /* Initialize RTC. */ @@ -804,10 +815,8 @@ sysctl_machdep_i8254_freq(SYSCTL_HANDLER_ARGS) */ freq = timer_freq; error = sysctl_handle_int(oidp, &freq, sizeof(freq), req); - if (error == 0 && req->newptr != NULL) { + if (error == 0 && req->newptr != NULL) set_timer_freq(freq, hz); - i8254_timecounter.tc_frequency = freq; - } return (error); } @@ -815,6 +824,24 @@ SYSCTL_PROC(_machdep, OID_AUTO, i8254_freq, CTLTYPE_INT | CTLFLAG_RW, 0, sizeof(u_int), sysctl_machdep_i8254_freq, "IU", ""); static unsigned +i8254_simple_get_timecount(struct timecounter *tc) +{ + u_int count; + u_int high, low; + + mtx_lock_spin(&clock_lock); + + /* Select timer0 and latch counter value. */ + outb(TIMER_MODE, TIMER_SEL0 | TIMER_LATCH); + + low = inb(TIMER_CNTR0); + high = inb(TIMER_CNTR0); + count = 0xffff - ((high << 8) | low); + mtx_unlock_spin(&clock_lock); + return (count); +} + +static unsigned i8254_get_timecount(struct timecounter *tc) { u_int count; |
