diff options
Diffstat (limited to 'arch/xtensa/kernel/time.c')
| -rw-r--r-- | arch/xtensa/kernel/time.c | 46 |
1 files changed, 29 insertions, 17 deletions
diff --git a/arch/xtensa/kernel/time.c b/arch/xtensa/kernel/time.c index 22949be4a5d..60d29fe0b1b 100644 --- a/arch/xtensa/kernel/time.c +++ b/arch/xtensa/kernel/time.c @@ -32,12 +32,20 @@ EXPORT_SYMBOL(rtc_lock); #ifdef CONFIG_XTENSA_CALIBRATE_CCOUNT unsigned long ccount_per_jiffy; /* per 1/HZ */ -unsigned long ccount_nsec; /* nsec per ccount increment */ +unsigned long nsec_per_ccount; /* nsec per ccount increment */ #endif -unsigned int last_ccount_stamp; static long last_rtc_update = 0; +/* + * Scheduler clock - returns current tim in nanosec units. + */ + +unsigned long long sched_clock(void) +{ + return (unsigned long long)jiffies * (1000000000 / HZ); +} + static irqreturn_t timer_interrupt(int irq, void *dev_id); static struct irqaction timer_irqaction = { .handler = timer_interrupt, @@ -69,7 +77,6 @@ void __init time_init(void) 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); @@ -85,7 +92,7 @@ int do_settimeofday(struct timespec *tv) { time_t wtm_sec, sec = tv->tv_sec; long wtm_nsec, nsec = tv->tv_nsec; - unsigned long ccount; + unsigned long delta; if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC) return -EINVAL; @@ -97,8 +104,10 @@ int do_settimeofday(struct timespec *tv) * wall time. Discover what correction gettimeofday() would have * made, and then undo it! */ - ccount = get_ccount(); - nsec -= (ccount - last_ccount_stamp) * CCOUNT_NSEC; + + delta = CCOUNT_PER_JIFFY; + delta += get_ccount() - get_linux_timer(); + nsec -= delta * NSEC_PER_CCOUNT; wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec); wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec); @@ -117,17 +126,21 @@ EXPORT_SYMBOL(do_settimeofday); void do_gettimeofday(struct timeval *tv) { unsigned long flags; - unsigned long sec, usec, delta, seq; + unsigned long volatile 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); + + delta = get_linux_timer() - get_ccount(); + } while (read_seqretry_irqrestore(&xtime_lock, seq, flags)); - usec += (delta * CCOUNT_NSEC) / NSEC_PER_USEC; + usec += (((unsigned long) CCOUNT_PER_JIFFY - delta) + * (unsigned long) NSEC_PER_CCOUNT) / NSEC_PER_USEC; + for (; usec >= 1000000; sec++, usec -= 1000000) ; @@ -158,9 +171,12 @@ again: write_seqlock(&xtime_lock); - last_ccount_stamp = next; + do_timer(1); /* Linux handler in kernel/timer.c */ + + /* Note that writing CCOMPARE clears the interrupt. */ + next += CCOUNT_PER_JIFFY; - do_timer (1); /* Linux handler in kernel/timer.c */ + set_linux_timer(next); if (ntp_synced() && xtime.tv_sec - last_rtc_update >= 659 && @@ -175,19 +191,15 @@ again: write_sequnlock(&xtime_lock); } - /* NOTE: writing CCOMPAREn clears the interrupt. */ + /* Allow platform to do something useful (Wdog). */ - set_linux_timer (next); + platform_heartbeat(); /* 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; } |