/*
* Test harness for verifying ACPI timer behaviour.
* Boot with debug.acpi.timer_test set to invoke this.
*/
static void
acpi_timer_boot_test(void)
{
uint32_t u1, u2, u3;
u1 = acpi_timer_read();
u2 = acpi_timer_read();
u3 = acpi_timer_read();
device_printf(acpi_timer_dev, "timer test in progress, reboot to quit.\n");
for (;;) {
/*
* The failure case is where u3 > u1, but u2 does not fall between
* the two, ie. it contains garbage.
*/
if (u3 > u1) {
if (u2 < u1 || u2 > u3)
device_printf(acpi_timer_dev,
"timer is not monotonic: 0x%08x,0x%08x,0x%08x\n",
u1, u2, u3);
}
u1 = u2;
u2 = u3;
u3 = acpi_timer_read();
}
}
static void
acpi_timer_suspend_handler(struct timecounter *newtc)
{
struct timecounter *tc;
/* Deregister existing resume event handler. */
if (acpi_timer_eh != NULL) {
EVENTHANDLER_DEREGISTER(power_resume, acpi_timer_eh);
acpi_timer_eh = NULL;
}
if ((timecounter->tc_flags & TC_FLAGS_SUSPEND_SAFE) != 0) {
/*
* If we are using a suspend safe timecounter, don't
* save/restore it across suspend/resume.
*/
return;
}
KASSERT(newtc == &acpi_timer_timecounter,
("acpi_timer_suspend_handler: wrong timecounter"));
tc = timecounter;
if (tc != newtc) {
if (bootverbose)
device_printf(acpi_timer_dev,
"switching timecounter, %s -> %s\n",
tc->tc_name, newtc->tc_name);
(void)acpi_timer_read();
(void)acpi_timer_read();
timecounter = newtc;
acpi_timer_eh = EVENTHANDLER_REGISTER(power_resume,
acpi_timer_resume_handler, tc, EVENTHANDLER_PRI_LAST);
}
}
static int
acpi_timer_test()
{
uint32_t last, this;
int min, max, n, delta;
register_t s;
min = 10000000;
max = 0;
/* Test the timer with interrupts disabled to get accurate results. */
s = intr_disable();
last = acpi_timer_read();
for (n = 0; n < N; n++) {
this = acpi_timer_read();
delta = acpi_TimerDelta(this, last);
if (delta > max)
max = delta;
else if (delta < min)
min = delta;
last = this;
}
intr_restore(s);
if (max - min > 2)
n = 0;
else if (min < 0 || max == 0)
n = 0;
else
n = 1;
if (bootverbose)
printf(" %d/%d", n, max-min);
return (n);
}
static int
acpi_timer_test(void)
{
uint32_t last, this;
int min, max, n, delta;
register_t s;
min = 10000000;
max = 0;
/* Test the timer with interrupts disabled to get accurate results. */
#if defined(__i386__)
s = read_eflags();
#elif defined(__x86_64__)
s = read_rflags();
#else
#error "no read_eflags"
#endif
cpu_disable_intr();
last = acpi_timer_read();
for (n = 0; n < 2000; n++) {
this = acpi_timer_read();
delta = acpi_TimerDelta(this, last);
if (delta > max)
max = delta;
else if (delta < min)
min = delta;
last = this;
}
#if defined(__i386__)
write_eflags(s);
#elif defined(__x86_64__)
write_rflags(s);
#else
#error "no read_eflags"
#endif
if (max - min > 2)
n = 0;
else if (min < 0 || max == 0)
n = 0;
else
n = 1;
if (bootverbose) {
kprintf("ACPI timer looks %s min = %d, max = %d, width = %d\n",
n ? "GOOD" : "BAD ",
min, max, max - min);
}
return (n);
}
/*
* Fetch current time value from hardware that may not correctly
* latch the counter. We need to read until we have three monotonic
* samples and then use the middle one, otherwise we are not protected
* against the fact that the bits can be wrong in two directions. If
* we only cared about monosity, two reads would be enough.
*/
static u_int
acpi_timer_get_timecount_safe(struct timecounter *tc)
{
u_int u1, u2, u3;
u2 = acpi_timer_read();
u3 = acpi_timer_read();
do {
u1 = u2;
u2 = u3;
u3 = acpi_timer_read();
} while (u1 > u2 || u2 > u3);
return (u2);
}
static int
acpi_timer_test()
{
uint32_t last, this;
int delta, max, max2, min, n;
register_t s;
min = INT32_MAX;
max = max2 = 0;
/* Test the timer with interrupts disabled to get accurate results. */
s = intr_disable();
last = acpi_timer_read();
for (n = 0; n < N; n++) {
this = acpi_timer_read();
delta = acpi_TimerDelta(this, last);
if (delta > max) {
max2 = max;
max = delta;
} else if (delta > max2)
max2 = delta;
if (delta < min)
min = delta;
last = this;
}
intr_restore(s);
delta = max2 - min;
if ((max - min > 8 || delta > 3) && vm_guest == VM_GUEST_NO)
n = 0;
else if (min < 0 || max == 0 || max2 == 0)
n = 0;
else
n = 1;
if (bootverbose)
printf(" %d/%d", n, delta);
return (n);
}
/*
* Fetch current time value from reliable hardware.
*
* The cputimer interface requires a 32 bit return value. If the ACPI timer
* is only 24 bits then we have to keep track of the upper 8 bits on our
* own.
*
* XXX we could probably get away with using a per-cpu field for this and
* just use interrupt disablement instead of clock_lock.
*/
static sysclock_t
acpi_timer_get_timecount24(void)
{
sysclock_t counter;
clock_lock();
counter = acpi_timer_read();
if (counter < acpi_last_counter)
acpi_cputimer.base += 0x01000000;
acpi_last_counter = counter;
counter += acpi_cputimer.base;
clock_unlock();
return (counter);
}
/*
* Fetch current time value from hardware that may not correctly
* latch the counter. We need to read until we have three monotonic
* samples and then use the middle one, otherwise we are not protected
* against the fact that the bits can be wrong in two directions. If
* we only cared about monosity, two reads would be enough.
*/
static sysclock_t
acpi_timer_get_timecount_safe(void)
{
u_int u1, u2, u3;
if (acpi_counter_mask != 0xffffffff)
clock_lock();
u2 = acpi_timer_read();
u3 = acpi_timer_read();
do {
u1 = u2;
u2 = u3;
u3 = acpi_timer_read();
} while (u1 > u2 || u2 > u3);
if (acpi_counter_mask != 0xffffffff) {
if (u2 < acpi_last_counter)
acpi_cputimer.base += 0x01000000;
acpi_last_counter = u2;
clock_unlock();
}
return (u2 + acpi_cputimer.base);
}
static sysclock_t
acpi_timer_get_timecount(void)
{
return (acpi_timer_read() + acpi_cputimer.base);
}
/*
* Fetch current time value from reliable hardware.
*/
static u_int
acpi_timer_get_timecount(struct timecounter *tc)
{
return (acpi_timer_read());
}
