diff options
Diffstat (limited to 'kernel/time/time.c')
| -rw-r--r-- | kernel/time/time.c | 53 |
1 files changed, 28 insertions, 25 deletions
diff --git a/kernel/time/time.c b/kernel/time/time.c index 85d5bb1d67eb..86751c68e08d 100644 --- a/kernel/time/time.c +++ b/kernel/time/time.c @@ -268,10 +268,14 @@ EXPORT_SYMBOL(jiffies_to_msecs); unsigned int jiffies_to_usecs(const unsigned long j) { -#if HZ <= USEC_PER_SEC && !(USEC_PER_SEC % HZ) + /* + * Hz usually doesn't go much further MSEC_PER_SEC. + * jiffies_to_usecs() and usecs_to_jiffies() depend on that. + */ + BUILD_BUG_ON(HZ > USEC_PER_SEC); + +#if !(USEC_PER_SEC % HZ) return (USEC_PER_SEC / HZ) * j; -#elif HZ > USEC_PER_SEC && !(HZ % USEC_PER_SEC) - return (j + (HZ / USEC_PER_SEC) - 1)/(HZ / USEC_PER_SEC); #else # if BITS_PER_LONG == 32 return (HZ_TO_USEC_MUL32 * j) >> HZ_TO_USEC_SHR32; @@ -287,26 +291,20 @@ EXPORT_SYMBOL(jiffies_to_usecs); * @t: Timespec * @gran: Granularity in ns. * - * Truncate a timespec to a granularity. gran must be smaller than a second. - * Always rounds down. - * - * This function should be only used for timestamps returned by - * current_kernel_time() or CURRENT_TIME, not with do_gettimeofday() because - * it doesn't handle the better resolution of the latter. + * Truncate a timespec to a granularity. Always rounds down. gran must + * not be 0 nor greater than a second (NSEC_PER_SEC, or 10^9 ns). */ struct timespec timespec_trunc(struct timespec t, unsigned gran) { - /* - * Division is pretty slow so avoid it for common cases. - * Currently current_kernel_time() never returns better than - * jiffies resolution. Exploit that. - */ - if (gran <= jiffies_to_usecs(1) * 1000) { + /* Avoid division in the common cases 1 ns and 1 s. */ + if (gran == 1) { /* nothing */ - } else if (gran == 1000000000) { + } else if (gran == NSEC_PER_SEC) { t.tv_nsec = 0; - } else { + } else if (gran > 1 && gran < NSEC_PER_SEC) { t.tv_nsec -= t.tv_nsec % gran; + } else { + WARN(1, "illegal file time granularity: %u", gran); } return t; } @@ -546,7 +544,7 @@ EXPORT_SYMBOL(__usecs_to_jiffies); * value to a scaled second value. */ static unsigned long -__timespec_to_jiffies(unsigned long sec, long nsec) +__timespec64_to_jiffies(u64 sec, long nsec) { nsec = nsec + TICK_NSEC - 1; @@ -554,22 +552,27 @@ __timespec_to_jiffies(unsigned long sec, long nsec) sec = MAX_SEC_IN_JIFFIES; nsec = 0; } - return (((u64)sec * SEC_CONVERSION) + + return ((sec * SEC_CONVERSION) + (((u64)nsec * NSEC_CONVERSION) >> (NSEC_JIFFIE_SC - SEC_JIFFIE_SC))) >> SEC_JIFFIE_SC; } -unsigned long -timespec_to_jiffies(const struct timespec *value) +static unsigned long +__timespec_to_jiffies(unsigned long sec, long nsec) { - return __timespec_to_jiffies(value->tv_sec, value->tv_nsec); + return __timespec64_to_jiffies((u64)sec, nsec); } -EXPORT_SYMBOL(timespec_to_jiffies); +unsigned long +timespec64_to_jiffies(const struct timespec64 *value) +{ + return __timespec64_to_jiffies(value->tv_sec, value->tv_nsec); +} +EXPORT_SYMBOL(timespec64_to_jiffies); void -jiffies_to_timespec(const unsigned long jiffies, struct timespec *value) +jiffies_to_timespec64(const unsigned long jiffies, struct timespec64 *value) { /* * Convert jiffies to nanoseconds and separate with @@ -580,7 +583,7 @@ jiffies_to_timespec(const unsigned long jiffies, struct timespec *value) NSEC_PER_SEC, &rem); value->tv_nsec = rem; } -EXPORT_SYMBOL(jiffies_to_timespec); +EXPORT_SYMBOL(jiffies_to_timespec64); /* * We could use a similar algorithm to timespec_to_jiffies (with a |