[PATCH] hrtimer: introduce nsec_t type and conversion functions
- introduce the nsec_t type
- basic nsec conversion routines: timespec_to_ns(), timeval_to_ns(),
ns_to_timespec(), ns_to_timeval().
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/time.h b/include/linux/time.h
index 64e7974..f639fde 100644
--- a/include/linux/time.h
+++ b/include/linux/time.h
@@ -50,6 +50,12 @@
#define timespec_valid(ts) \
(((ts)->tv_sec >= 0) && (((unsigned) (ts)->tv_nsec) < NSEC_PER_SEC))
+/*
+ * 64-bit nanosec type. Large enough to span 292+ years in nanosecond
+ * resolution. Ought to be enough for a while.
+ */
+typedef s64 nsec_t;
+
extern struct timespec xtime;
extern struct timespec wall_to_monotonic;
extern seqlock_t xtime_lock;
@@ -79,6 +85,47 @@
extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
+/**
+ * timespec_to_ns - Convert timespec to nanoseconds
+ * @ts: pointer to the timespec variable to be converted
+ *
+ * Returns the scalar nanosecond representation of the timespec
+ * parameter.
+ */
+static inline nsec_t timespec_to_ns(const struct timespec *ts)
+{
+ return ((nsec_t) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
+}
+
+/**
+ * timeval_to_ns - Convert timeval to nanoseconds
+ * @ts: pointer to the timeval variable to be converted
+ *
+ * Returns the scalar nanosecond representation of the timeval
+ * parameter.
+ */
+static inline nsec_t timeval_to_ns(const struct timeval *tv)
+{
+ return ((nsec_t) tv->tv_sec * NSEC_PER_SEC) +
+ tv->tv_usec * NSEC_PER_USEC;
+}
+
+/**
+ * ns_to_timespec - Convert nanoseconds to timespec
+ * @nsec: the nanoseconds value to be converted
+ *
+ * Returns the timespec representation of the nsec parameter.
+ */
+extern struct timespec ns_to_timespec(const nsec_t nsec);
+
+/**
+ * ns_to_timeval - Convert nanoseconds to timeval
+ * @nsec: the nanoseconds value to be converted
+ *
+ * Returns the timeval representation of the nsec parameter.
+ */
+extern struct timeval ns_to_timeval(const nsec_t nsec);
+
#endif /* __KERNEL__ */
#define NFDBITS __NFDBITS
diff --git a/kernel/time.c b/kernel/time.c
index c689b53..cf5a458 100644
--- a/kernel/time.c
+++ b/kernel/time.c
@@ -652,6 +652,42 @@
ts->tv_nsec = nsec;
}
+/**
+ * ns_to_timespec - Convert nanoseconds to timespec
+ * @nsec: the nanoseconds value to be converted
+ *
+ * Returns the timespec representation of the nsec parameter.
+ */
+inline struct timespec ns_to_timespec(const nsec_t nsec)
+{
+ struct timespec ts;
+
+ if (nsec)
+ ts.tv_sec = div_long_long_rem_signed(nsec, NSEC_PER_SEC,
+ &ts.tv_nsec);
+ else
+ ts.tv_sec = ts.tv_nsec = 0;
+
+ return ts;
+}
+
+/**
+ * ns_to_timeval - Convert nanoseconds to timeval
+ * @nsec: the nanoseconds value to be converted
+ *
+ * Returns the timeval representation of the nsec parameter.
+ */
+struct timeval ns_to_timeval(const nsec_t nsec)
+{
+ struct timespec ts = ns_to_timespec(nsec);
+ struct timeval tv;
+
+ tv.tv_sec = ts.tv_sec;
+ tv.tv_usec = (suseconds_t) ts.tv_nsec / 1000;
+
+ return tv;
+}
+
#if (BITS_PER_LONG < 64)
u64 get_jiffies_64(void)
{
