* "A Kernel Model for Precision Timekeeping" by Dave Mills
* Allow time_constant larger than MAXTC(6) for NTP v4 (MAXTC == 10)
* (Even though the technical memorandum forbids it)
+ * 2004-07-14 Christoph Lameter
+ * Added getnstimeofday to allow the posix timer functions to return
+ * with nanosecond accuracy
*/
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/smp_lock.h>
#include <asm/uaccess.h>
+#include <asm/unistd.h>
/*
* The timezone where the local system is located. Used as a default by some
EXPORT_SYMBOL(sys_tz);
-#if !defined(__alpha__) && !defined(__ia64__)
+#ifdef __ARCH_WANT_SYS_TIME
/*
* sys_time() can be implemented in user-level using
*
* XXX This function is NOT 64-bit clean!
*/
-asmlinkage long sys_time(int * tloc)
+asmlinkage long sys_time(int __user * tloc)
{
int i;
struct timeval tv;
* architectures that need it).
*/
-asmlinkage long sys_stime(time_t *tptr)
+asmlinkage long sys_stime(time_t __user *tptr)
{
struct timespec tv;
return 0;
}
-#endif
+#endif /* __ARCH_WANT_SYS_TIME */
asmlinkage long sys_gettimeofday(struct timeval __user *tv, struct timezone __user *tz)
{
write_seqlock_irq(&xtime_lock);
wall_to_monotonic.tv_sec -= sys_tz.tz_minuteswest * 60;
xtime.tv_sec += sys_tz.tz_minuteswest * 60;
- time_interpolator_update(sys_tz.tz_minuteswest * 60 * NSEC_PER_SEC);
+ time_interpolator_reset();
write_sequnlock_irq(&xtime_lock);
clock_was_set();
}
EXPORT_SYMBOL(current_kernel_time);
+#ifdef CONFIG_TIME_INTERPOLATION
+void getnstimeofday (struct timespec *tv)
+{
+ unsigned long seq,sec,nsec;
+
+ do {
+ seq = read_seqbegin(&xtime_lock);
+ sec = xtime.tv_sec;
+ nsec = xtime.tv_nsec+time_interpolator_get_offset();
+ } while (unlikely(read_seqretry(&xtime_lock, seq)));
+
+ while (unlikely(nsec >= NSEC_PER_SEC)) {
+ nsec -= NSEC_PER_SEC;
+ ++sec;
+ }
+ tv->tv_sec = sec;
+ tv->tv_nsec = nsec;
+}
+
+int do_settimeofday (struct timespec *tv)
+{
+ time_t wtm_sec, sec = tv->tv_sec;
+ long wtm_nsec, nsec = tv->tv_nsec;
+
+ 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 done, and then undo
+ * it!
+ */
+ nsec -= time_interpolator_get_offset();
+
+ 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);
+
+ time_adjust = 0; /* stop active adjtime() */
+ time_status |= STA_UNSYNC;
+ time_maxerror = NTP_PHASE_LIMIT;
+ time_esterror = NTP_PHASE_LIMIT;
+ time_interpolator_reset();
+ }
+ write_sequnlock_irq(&xtime_lock);
+ clock_was_set();
+ return 0;
+}
+
+EXPORT_SYMBOL(do_settimeofday);
+
+void do_gettimeofday (struct timeval *tv)
+{
+ unsigned long seq, nsec, usec, sec, offset;
+ do {
+ seq = read_seqbegin(&xtime_lock);
+ offset = time_interpolator_get_offset();
+ sec = xtime.tv_sec;
+ nsec = xtime.tv_nsec;
+ } while (unlikely(read_seqretry(&xtime_lock, seq)));
+
+ usec = (nsec + offset) / 1000;
+
+ while (unlikely(usec >= USEC_PER_SEC)) {
+ usec -= USEC_PER_SEC;
+ ++sec;
+ }
+
+ tv->tv_sec = sec;
+ tv->tv_usec = usec;
+}
+
+EXPORT_SYMBOL(do_gettimeofday);
+
+
+#else
+/*
+ * Simulate gettimeofday using do_gettimeofday which only allows a timeval
+ * and therefore only yields usec accuracy
+ */
+void getnstimeofday(struct timespec *tv)
+{
+ struct timeval x;
+
+ do_gettimeofday(&x);
+ tv->tv_sec = x.tv_sec;
+ tv->tv_nsec = x.tv_usec * NSEC_PER_USEC;
+}
+#endif
+
+EXPORT_SYMBOL(getnstimeofday);
+
#if (BITS_PER_LONG < 64)
u64 get_jiffies_64(void)
{