void __init time_init(void)
{
time_t sec_o, sec_n = 0;
/* The platform must provide a function to calibrate the processor
* speed for the CALIBRATE.
*/
#ifdef CONFIG_XTENSA_CALIBRATE_CCOUNT
printk("Calibrating CPU frequency ");
platform_calibrate_ccount();
printk("%d.%02d MHz\n", (int)ccount_per_jiffy/(1000000/HZ),
(int)(ccount_per_jiffy/(10000/HZ))%100);
#endif
/* Set time from RTC (if provided) */
if (platform_get_rtc_time(&sec_o) == 0)
while (platform_get_rtc_time(&sec_n))
if (sec_o != sec_n)
break;
xtime.tv_nsec = 0;
last_rtc_update = xtime.tv_sec = sec_n;
last_ccount_stamp = get_ccount();
set_normalized_timespec(&wall_to_monotonic,
-xtime.tv_sec, -xtime.tv_nsec);
/* Initialize the linux timer interrupt. */
setup_irq(LINUX_TIMER_INT, &timer_irqaction);
set_linux_timer(get_ccount() + CCOUNT_PER_JIFFY);
}
irqreturn_t timer_interrupt (int irq, void *dev_id)
{
unsigned long next;
next = get_linux_timer();
again:
while ((signed long)(get_ccount() - next) > 0) {
profile_tick(CPU_PROFILING);
#ifndef CONFIG_SMP
update_process_times(user_mode(get_irq_regs()));
#endif
xtime_update(1); /* Linux handler in kernel/time/timekeeping */
/* Note that writing CCOMPARE clears the interrupt. */
next += CCOUNT_PER_JIFFY;
set_linux_timer(next);
}
/* Allow platform to do something useful (Wdog). */
platform_heartbeat();
/* Make sure we didn't miss any tick... */
if ((signed long)(get_ccount() - next) > 0)
goto again;
return IRQ_HANDLED;
}
irqreturn_t timer_interrupt (int irq, void *dev_id)
{
unsigned long next;
next = get_linux_timer();
again:
while ((signed long)(get_ccount() - next) > 0) {
profile_tick(CPU_PROFILING);
#ifndef CONFIG_SMP
update_process_times(user_mode(get_irq_regs()));
#endif
xtime_update(1); /* */
/* */
next += CCOUNT_PER_JIFFY;
set_linux_timer(next);
}
/* */
platform_heartbeat();
/* */
if ((signed long)(get_ccount() - next) > 0)
goto again;
return IRQ_HANDLED;
}
irqreturn_t timer_interrupt (int irq, void *dev_id)
{
unsigned long next;
next = get_linux_timer();
again:
while ((signed long)(get_ccount() - next) > 0) {
profile_tick(CPU_PROFILING);
#ifndef CONFIG_SMP
update_process_times(user_mode(get_irq_regs()));
#endif
write_seqlock(&xtime_lock);
last_ccount_stamp = next;
next += CCOUNT_PER_JIFFY;
do_timer (1); /* Linux handler in kernel/timer.c */
if (ntp_synced() &&
xtime.tv_sec - last_rtc_update >= 659 &&
abs((xtime.tv_nsec/1000)-(1000000-1000000/HZ))<5000000/HZ) {
if (platform_set_rtc_time(xtime.tv_sec+1) == 0)
last_rtc_update = xtime.tv_sec+1;
else
/* Do it again in 60 s */
last_rtc_update += 60;
}
write_sequnlock(&xtime_lock);
}
/* NOTE: writing CCOMPAREn clears the interrupt. */
set_linux_timer (next);
/* Make sure we didn't miss any tick... */
if ((signed long)(get_ccount() - next) > 0)
goto again;
/* Allow platform to do something useful (Wdog). */
platform_heartbeat();
return IRQ_HANDLED;
}
static int ccount_timer_set_next_event(unsigned long delta,
struct clock_event_device *dev)
{
unsigned long flags, next;
int ret = 0;
local_irq_save(flags);
next = get_ccount() + delta;
set_linux_timer(next);
if (next - get_ccount() > delta)
ret = -ETIME;
local_irq_restore(flags);
return ret;
}
int do_settimeofday(struct timespec *tv)
{
time_t wtm_sec, sec = tv->tv_sec;
long wtm_nsec, nsec = tv->tv_nsec;
unsigned long ccount;
if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
return -EINVAL;
write_seqlock_irq(&xtime_lock);
/* This is revolting. We need to set "xtime" correctly. However, the
* value in this location is the value at the most recent update of
* wall time. Discover what correction gettimeofday() would have
* made, and then undo it!
*/
ccount = get_ccount();
nsec -= (ccount - last_ccount_stamp) * CCOUNT_NSEC;
wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
set_normalized_timespec(&xtime, sec, nsec);
set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
ntp_clear();
write_sequnlock_irq(&xtime_lock);
return 0;
}
static int boot_secondary(unsigned int cpu, struct task_struct *ts)
{
unsigned long timeout = jiffies + msecs_to_jiffies(1000);
unsigned long ccount;
int i;
#ifdef CONFIG_HOTPLUG_CPU
cpu_start_id = cpu;
system_flush_invalidate_dcache_range(
(unsigned long)&cpu_start_id, sizeof(cpu_start_id));
#endif
smp_call_function_single(0, mx_cpu_start, (void *)cpu, 1);
for (i = 0; i < 2; ++i) {
do
ccount = get_ccount();
while (!ccount);
cpu_start_ccount = ccount;
while (time_before(jiffies, timeout)) {
mb();
if (!cpu_start_ccount)
break;
}
if (cpu_start_ccount) {
smp_call_function_single(0, mx_cpu_stop,
(void *)cpu, 1);
cpu_start_ccount = 0;
return -EIO;
}
}
return 0;
}
void __init time_init(void)
{
#ifdef CONFIG_XTENSA_CALIBRATE_CCOUNT
printk("Calibrating CPU frequency ");
platform_calibrate_ccount();
printk("%d.%02d MHz\n", (int)ccount_per_jiffy/(1000000/HZ),
(int)(ccount_per_jiffy/(10000/HZ))%100);
#endif
clocksource_register_hz(&ccount_clocksource, CCOUNT_PER_JIFFY * HZ);
/* Initialize the linux timer interrupt. */
setup_irq(LINUX_TIMER_INT, &timer_irqaction);
set_linux_timer(get_ccount() + CCOUNT_PER_JIFFY);
}
void do_gettimeofday(struct timeval *tv)
{
unsigned long flags;
unsigned long sec, usec, delta, seq;
do {
seq = read_seqbegin_irqsave(&xtime_lock, flags);
delta = get_ccount() - last_ccount_stamp;
sec = xtime.tv_sec;
usec = (xtime.tv_nsec / NSEC_PER_USEC);
} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
usec += (delta * CCOUNT_NSEC) / NSEC_PER_USEC;
for (; usec >= 1000000; sec++, usec -= 1000000)
;
tv->tv_sec = sec;
tv->tv_usec = usec;
}
static int boot_secondary(unsigned int cpu, struct task_struct *ts)
{
unsigned long timeout = jiffies + msecs_to_jiffies(1000);
unsigned long ccount;
int i;
#ifdef CONFIG_HOTPLUG_CPU
WRITE_ONCE(cpu_start_id, cpu);
/* Pairs with the third memw in the cpu_restart */
mb();
system_flush_invalidate_dcache_range((unsigned long)&cpu_start_id,
sizeof(cpu_start_id));
#endif
smp_call_function_single(0, mx_cpu_start, (void *)cpu, 1);
for (i = 0; i < 2; ++i) {
do
ccount = get_ccount();
while (!ccount);
WRITE_ONCE(cpu_start_ccount, ccount);
do {
/*
* Pairs with the first two memws in the
* .Lboot_secondary.
*/
mb();
ccount = READ_ONCE(cpu_start_ccount);
} while (ccount && time_before(jiffies, timeout));
if (ccount) {
smp_call_function_single(0, mx_cpu_stop,
(void *)cpu, 1);
WRITE_ONCE(cpu_start_ccount, 0);
return -EIO;
}
}
return 0;
}
void __init time_init(void)
{
/* FIXME: xtime&wall_to_monotonic are set in timekeeping_init. */
read_persistent_clock(&xtime);
set_normalized_timespec(&wall_to_monotonic,
-xtime.tv_sec, -xtime.tv_nsec);
#ifdef CONFIG_XTENSA_CALIBRATE_CCOUNT
printk("Calibrating CPU frequency ");
platform_calibrate_ccount();
printk("%d.%02d MHz\n", (int)ccount_per_jiffy/(1000000/HZ),
(int)(ccount_per_jiffy/(10000/HZ))%100);
#endif
ccount_clocksource.mult =
clocksource_hz2mult(CCOUNT_PER_JIFFY * HZ,
ccount_clocksource.shift);
clocksource_register(&ccount_clocksource);
/* Initialize the linux timer interrupt. */
setup_irq(LINUX_TIMER_INT, &timer_irqaction);
set_linux_timer(get_ccount() + CCOUNT_PER_JIFFY);
}
void do_gettimeofday(struct timeval *tv)
{
unsigned long flags;
unsigned long volatile sec, usec, delta, seq;
do {
seq = read_seqbegin_irqsave(&xtime_lock, flags);
sec = xtime.tv_sec;
usec = (xtime.tv_nsec / NSEC_PER_USEC);
delta = get_linux_timer() - get_ccount();
} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
usec += (((unsigned long) CCOUNT_PER_JIFFY - delta)
* (unsigned long) NSEC_PER_CCOUNT) / NSEC_PER_USEC;
for (; usec >= 1000000; sec++, usec -= 1000000)
;
tv->tv_sec = sec;
tv->tv_usec = usec;
}
static cycle_t ccount_read(void)
{
return (cycle_t)get_ccount();
}
static u64 notrace ccount_sched_clock_read(void)
{
return get_ccount();
}
static cycle_t ccount_read(struct clocksource *cs)
{
return (cycle_t)get_ccount();
}
