X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=include%2Flinux%2Fktime.h;h=ce5983225be4e6430cadbff9cc5cbf448a66e647;hb=30ca60c15a725f655e5d3f14e0238a066bc5aeb7;hp=dae7143644fe8b87c18aa1fb57e175d6f61865c2;hpb=dcb76f88683618ed6ef0df66643dba1285881ee5;p=linux-2.6

diff --git a/include/linux/ktime.h b/include/linux/ktime.h
index dae7143644..ce5983225b 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)
 {
@@ -199,6 +206,15 @@ 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
@@ -289,13 +305,21 @@ 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);
+}
+
+extern ktime_t ktime_add_safe(const ktime_t lhs, const ktime_t rhs);
+
 /*
  * The resolution of the clocks. The resolution value is returned in
  * the clock_getres() system call to give application programmers an
  * idea of the (in)accuracy of timers. Timer values are rounded up to
  * this resolution values.
  */
-#define KTIME_LOW_RES		(ktime_t){ .tv64 = TICK_NSEC }
+#define LOW_RES_NSEC		TICK_NSEC
+#define KTIME_LOW_RES		(ktime_t){ .tv64 = LOW_RES_NSEC }
 
 /* Get the monotonic time in timespec format: */
 extern void ktime_get_ts(struct timespec *ts);
@@ -303,4 +327,10 @@ extern void ktime_get_ts(struct timespec *ts);
 /* Get the real (wall-) time in timespec format: */
 #define ktime_get_real_ts(ts)	getnstimeofday(ts)
 
+static inline ktime_t ns_to_ktime(u64 ns)
+{
+	static const ktime_t ktime_zero = { .tv64 = 0 };
+	return ktime_add_ns(ktime_zero, ns);
+}
+
 #endif