1 files changed, 299 insertions, 0 deletions
diff --git a/kernel/include/linux/ktime.h b/kernel/include/linux/ktime.h
new file mode 100644
index 000000000..2b6a204bd
--- /dev/null
+++ b/kernel/include/linux/ktime.h
@@ -0,0 +1,299 @@
+/*
+ *  include/linux/ktime.h
+ *
+ *  ktime_t - nanosecond-resolution time format.
+ *
+ *   Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de>
+ *   Copyright(C) 2005, Red Hat, Inc., Ingo Molnar
+ *
+ *  data type definitions, declarations, prototypes and macros.
+ *
+ *  Started by: Thomas Gleixner and Ingo Molnar
+ *
+ *  Credits:
+ *
+ *  	Roman Zippel provided the ideas and primary code snippets of
+ *  	the ktime_t union and further simplifications of the original
+ *  	code.
+ *
+ *  For licencing details see kernel-base/COPYING
+ */
+#ifndef _LINUX_KTIME_H
+#define _LINUX_KTIME_H
+
+#include <linux/time.h>
+#include <linux/jiffies.h>
+
+/*
+ * ktime_t:
+ *
+ * A single 64-bit variable is used to store the hrtimers
+ * internal representation of time values in scalar nanoseconds. The
+ * design plays out best on 64-bit CPUs, where most conversions are
+ * NOPs and most arithmetic ktime_t operations are plain arithmetic
+ * operations.
+ *
+ */
+union ktime {
+	s64	tv64;
+};
+
+typedef union ktime ktime_t;		/* Kill this */
+
+/**
+ * ktime_set - Set a ktime_t variable from a seconds/nanoseconds value
+ * @secs:	seconds to set
+ * @nsecs:	nanoseconds to set
+ *
+ * Return: The ktime_t representation of the value.
+ */
+static inline ktime_t ktime_set(const s64 secs, const unsigned long nsecs)
+{
+	if (unlikely(secs >= KTIME_SEC_MAX))
+		return (ktime_t){ .tv64 = KTIME_MAX };
+
+	return (ktime_t) { .tv64 = secs * NSEC_PER_SEC + (s64)nsecs };
+}
+
+/* Subtract two ktime_t variables. rem = lhs -rhs: */
+#define ktime_sub(lhs, rhs) \
+		({ (ktime_t){ .tv64 = (lhs).tv64 - (rhs).tv64 }; })
+
+/* Add two ktime_t variables. res = lhs + rhs: */
+#define ktime_add(lhs, rhs) \
+		({ (ktime_t){ .tv64 = (lhs).tv64 + (rhs).tv64 }; })
+
+/*
+ * Add a ktime_t variable and a scalar nanosecond value.
+ * res = kt + nsval:
+ */
+#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)
+{
+	return ktime_set(ts.tv_sec, ts.tv_nsec);
+}
+
+/* convert a timespec64 to ktime_t format: */
+static inline ktime_t timespec64_to_ktime(struct timespec64 ts)
+{
+	return ktime_set(ts.tv_sec, ts.tv_nsec);
+}
+
+/* convert a timeval to ktime_t format: */
+static inline ktime_t timeval_to_ktime(struct timeval tv)
+{
+	return ktime_set(tv.tv_sec, tv.tv_usec * NSEC_PER_USEC);
+}
+
+/* Map the ktime_t to timespec conversion to ns_to_timespec function */
+#define ktime_to_timespec(kt)		ns_to_timespec((kt).tv64)
+
+/* Map the ktime_t to timespec conversion to ns_to_timespec function */
+#define ktime_to_timespec64(kt)		ns_to_timespec64((kt).tv64)
+
+/* Map the ktime_t to timeval conversion to ns_to_timeval function */
+#define ktime_to_timeval(kt)		ns_to_timeval((kt).tv64)
+
+/* Convert ktime_t to nanoseconds - NOP in the scalar storage format: */
+#define ktime_to_ns(kt)			((kt).tv64)
+
+
+/**
+ * ktime_equal - Compares two ktime_t variables to see if they are equal
+ * @cmp1:	comparable1
+ * @cmp2:	comparable2
+ *
+ * Compare two ktime_t variables.
+ *
+ * Return: 1 if equal.
+ */
+static inline int ktime_equal(const ktime_t cmp1, const ktime_t cmp2)
+{
+	return cmp1.tv64 == cmp2.tv64;
+}
+
+/**
+ * ktime_compare - Compares two ktime_t variables for less, greater or equal
+ * @cmp1:	comparable1
+ * @cmp2:	comparable2
+ *
+ * Return: ...
+ *   cmp1  < cmp2: return <0
+ *   cmp1 == cmp2: return 0
+ *   cmp1  > cmp2: return >0
+ */
+static inline int ktime_compare(const ktime_t cmp1, const ktime_t cmp2)
+{
+	if (cmp1.tv64 < cmp2.tv64)
+		return -1;
+	if (cmp1.tv64 > cmp2.tv64)
+		return 1;
+	return 0;
+}
+
+/**
+ * ktime_after - Compare if a ktime_t value is bigger than another one.
+ * @cmp1:	comparable1
+ * @cmp2:	comparable2
+ *
+ * Return: true if cmp1 happened after cmp2.
+ */
+static inline bool ktime_after(const ktime_t cmp1, const ktime_t cmp2)
+{
+	return ktime_compare(cmp1, cmp2) > 0;
+}
+
+/**
+ * ktime_before - Compare if a ktime_t value is smaller than another one.
+ * @cmp1:	comparable1
+ * @cmp2:	comparable2
+ *
+ * Return: true if cmp1 happened before cmp2.
+ */
+static inline bool ktime_before(const ktime_t cmp1, const ktime_t cmp2)
+{
+	return ktime_compare(cmp1, cmp2) < 0;
+}
+
+#if BITS_PER_LONG < 64
+extern s64 __ktime_divns(const ktime_t kt, s64 div);
+static inline s64 ktime_divns(const ktime_t kt, s64 div)
+{
+	/*
+	 * Negative divisors could cause an inf loop,
+	 * so bug out here.
+	 */
+	BUG_ON(div < 0);
+	if (__builtin_constant_p(div) && !(div >> 32)) {
+		s64 ns = kt.tv64;
+		u64 tmp = ns < 0 ? -ns : ns;
+
+		do_div(tmp, div);
+		return ns < 0 ? -tmp : tmp;
+	} else {
+		return __ktime_divns(kt, div);
+	}
+}
+#else /* BITS_PER_LONG < 64 */
+static inline s64 ktime_divns(const ktime_t kt, s64 div)
+{
+	/*
+	 * 32-bit implementation cannot handle negative divisors,
+	 * so catch them on 64bit as well.
+	 */
+	WARN_ON(div < 0);
+	return kt.tv64 / div;
+}
+#endif
+
+static inline s64 ktime_to_us(const ktime_t kt)
+{
+	return ktime_divns(kt, NSEC_PER_USEC);
+}
+
+static inline s64 ktime_to_ms(const ktime_t kt)
+{
+	return ktime_divns(kt, NSEC_PER_MSEC);
+}
+
+static inline s64 ktime_us_delta(const ktime_t later, const ktime_t earlier)
+{
+       return ktime_to_us(ktime_sub(later, earlier));
+}
+
+static inline s64 ktime_ms_delta(const ktime_t later, const ktime_t earlier)
+{
+	return ktime_to_ms(ktime_sub(later, earlier));
+}
+
+static inline ktime_t ktime_add_us(const ktime_t kt, const u64 usec)
+{
+	return ktime_add_ns(kt, usec * NSEC_PER_USEC);
+}
+
+static inline ktime_t ktime_add_ms(const ktime_t kt, const u64 msec)
+{
+	return ktime_add_ns(kt, msec * NSEC_PER_MSEC);
+}
+
+static inline ktime_t ktime_sub_us(const ktime_t kt, const u64 usec)
+{
+	return ktime_sub_ns(kt, usec * NSEC_PER_USEC);
+}
+
+extern ktime_t ktime_add_safe(const ktime_t lhs, const ktime_t rhs);
+
+/**
+ * ktime_to_timespec_cond - convert a ktime_t variable to timespec
+ *			    format only if the variable contains data
+ * @kt:		the ktime_t variable to convert
+ * @ts:		the timespec variable to store the result in
+ *
+ * Return: %true if there was a successful conversion, %false if kt was 0.
+ */
+static inline __must_check bool ktime_to_timespec_cond(const ktime_t kt,
+						       struct timespec *ts)
+{
+	if (kt.tv64) {
+		*ts = ktime_to_timespec(kt);
+		return true;
+	} else {
+		return false;
+	}
+}
+
+/**
+ * ktime_to_timespec64_cond - convert a ktime_t variable to timespec64
+ *			    format only if the variable contains data
+ * @kt:		the ktime_t variable to convert
+ * @ts:		the timespec variable to store the result in
+ *
+ * Return: %true if there was a successful conversion, %false if kt was 0.
+ */
+static inline __must_check bool ktime_to_timespec64_cond(const ktime_t kt,
+						       struct timespec64 *ts)
+{
+	if (kt.tv64) {
+		*ts = ktime_to_timespec64(kt);
+		return true;
+	} else {
+		return false;
+	}
+}
+
+/*
+ * 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 LOW_RES_NSEC		TICK_NSEC
+#define KTIME_LOW_RES		(ktime_t){ .tv64 = LOW_RES_NSEC }
+
+static inline ktime_t ns_to_ktime(u64 ns)
+{
+	static const ktime_t ktime_zero = { .tv64 = 0 };
+
+	return ktime_add_ns(ktime_zero, ns);
+}
+
+static inline ktime_t ms_to_ktime(u64 ms)
+{
+	static const ktime_t ktime_zero = { .tv64 = 0 };
+
+	return ktime_add_ms(ktime_zero, ms);
+}
+
+# include <linux/timekeeping.h>
+
+#endif