diff options
| -rw-r--r-- | include/linux/ktime.h | 21 | ||||
| -rw-r--r-- | kernel/hrtimer.c | 24 |
2 files changed, 45 insertions, 0 deletions
diff --git a/include/linux/ktime.h b/include/linux/ktime.h index dae7143644f..a6ddec141f9 100644 --- a/include/linux/ktime.h +++ b/include/linux/ktime.h @@ -102,6 +102,13 @@ static inline ktime_t ktime_set(const long secs, const unsigned long nsecs) #define ktime_add_ns(kt, nsval) \ ({ (ktime_t){ .tv64 = (kt).tv64 + (nsval) }; }) +/* + * Subtract a scalar nanosecod from a ktime_t variable + * res = kt - nsval: + */ +#define ktime_sub_ns(kt, nsval) \ + ({ (ktime_t){ .tv64 = (kt).tv64 - (nsval) }; }) + /* convert a timespec to ktime_t format: */ static inline ktime_t timespec_to_ktime(struct timespec ts) { @@ -200,6 +207,15 @@ static inline ktime_t ktime_add(const ktime_t add1, const ktime_t add2) extern ktime_t ktime_add_ns(const ktime_t kt, u64 nsec); /** + * ktime_sub_ns - Subtract a scalar nanoseconds value from a ktime_t variable + * @kt: minuend + * @nsec: the scalar nsec value to subtract + * + * Returns the subtraction of @nsec from @kt in ktime_t format + */ +extern ktime_t ktime_sub_ns(const ktime_t kt, u64 nsec); + +/** * timespec_to_ktime - convert a timespec to ktime_t format * @ts: the timespec variable to convert * @@ -289,6 +305,11 @@ static inline ktime_t ktime_add_us(const ktime_t kt, const u64 usec) return ktime_add_ns(kt, usec * 1000); } +static inline ktime_t ktime_sub_us(const ktime_t kt, const u64 usec) +{ + return ktime_sub_ns(kt, usec * 1000); +} + /* * The resolution of the clocks. The resolution value is returned in * the clock_getres() system call to give application programmers an diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c index c21ca6bfaa6..dc8a4451d79 100644 --- a/kernel/hrtimer.c +++ b/kernel/hrtimer.c @@ -277,6 +277,30 @@ ktime_t ktime_add_ns(const ktime_t kt, u64 nsec) } EXPORT_SYMBOL_GPL(ktime_add_ns); + +/** + * ktime_sub_ns - Subtract a scalar nanoseconds value from a ktime_t variable + * @kt: minuend + * @nsec: the scalar nsec value to subtract + * + * Returns the subtraction of @nsec from @kt in ktime_t format + */ +ktime_t ktime_sub_ns(const ktime_t kt, u64 nsec) +{ + ktime_t tmp; + + if (likely(nsec < NSEC_PER_SEC)) { + tmp.tv64 = nsec; + } else { + unsigned long rem = do_div(nsec, NSEC_PER_SEC); + + tmp = ktime_set((long)nsec, rem); + } + + return ktime_sub(kt, tmp); +} + +EXPORT_SYMBOL_GPL(ktime_sub_ns); # endif /* !CONFIG_KTIME_SCALAR */ /* |