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diff --git a/include/linux/ktime.h b/include/linux/ktime.h
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+/*
+ *  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:
+ *
+ * On 64-bit CPUs 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.
+ *
+ * On 32-bit CPUs an optimized representation of the timespec structure
+ * is used to avoid expensive conversions from and to timespecs. The
+ * endian-aware order of the tv struct members is chosen to allow
+ * mathematical operations on the tv64 member of the union too, which
+ * for certain operations produces better code.
+ *
+ * For architectures with efficient support for 64/32-bit conversions the
+ * plain scalar nanosecond based representation can be selected by the
+ * config switch CONFIG_KTIME_SCALAR.
+ */
+union ktime {
+	s64	tv64;
+#if BITS_PER_LONG != 64 && !defined(CONFIG_KTIME_SCALAR)
+	struct {
+# ifdef __BIG_ENDIAN
+	s32	sec, nsec;
+# else
+	s32	nsec, sec;
+# endif
+	} tv;
+#endif
+};
+
+typedef union ktime ktime_t;		/* Kill this */
+
+#define KTIME_MAX			((s64)~((u64)1 << 63))
+#if (BITS_PER_LONG == 64)
+# define KTIME_SEC_MAX			(KTIME_MAX / NSEC_PER_SEC)
+#else
+# define KTIME_SEC_MAX			LONG_MAX
+#endif
+
+/*
+ * ktime_t definitions when using the 64-bit scalar representation:
+ */
+
+#if (BITS_PER_LONG == 64) || defined(CONFIG_KTIME_SCALAR)
+
+/**
+ * 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 long secs, const unsigned long nsecs)
+{
+#if (BITS_PER_LONG == 64)
+	if (unlikely(secs >= KTIME_SEC_MAX))
+		return (ktime_t){ .tv64 = KTIME_MAX };
+#endif
+	return (ktime_t) { .tv64 = (s64)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 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 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)
+
+#else	/* !((BITS_PER_LONG == 64) || defined(CONFIG_KTIME_SCALAR)) */
+
+/*
+ * Helper macros/inlines to get the ktime_t math right in the timespec
+ * representation. The macros are sometimes ugly - their actual use is
+ * pretty okay-ish, given the circumstances. We do all this for
+ * performance reasons. The pure scalar nsec_t based code was nice and
+ * simple, but created too many 64-bit / 32-bit conversions and divisions.
+ *
+ * Be especially aware that negative values are represented in a way
+ * that the tv.sec field is negative and the tv.nsec field is greater
+ * or equal to zero but less than nanoseconds per second. This is the
+ * same representation which is used by timespecs.
+ *
+ *   tv.sec < 0 and 0 >= tv.nsec < NSEC_PER_SEC
+ */
+
+/* Set a ktime_t variable to a value in sec/nsec representation: */
+static inline ktime_t ktime_set(const long secs, const unsigned long nsecs)
+{
+	return (ktime_t) { .tv = { .sec = secs, .nsec = nsecs } };
+}
+
+/**
+ * ktime_sub - subtract two ktime_t variables
+ * @lhs:	minuend
+ * @rhs:	subtrahend
+ *
+ * Returns the remainder of the subtraction
+ */
+static inline ktime_t ktime_sub(const ktime_t lhs, const ktime_t rhs)
+{
+	ktime_t res;
+
+	res.tv64 = lhs.tv64 - rhs.tv64;
+	if (res.tv.nsec < 0)
+		res.tv.nsec += NSEC_PER_SEC;
+
+	return res;
+}
+
+/**
+ * ktime_add - add two ktime_t variables
+ * @add1:	addend1
+ * @add2:	addend2
+ *
+ * Returns the sum of @add1 and @add2.
+ */
+static inline ktime_t ktime_add(const ktime_t add1, const ktime_t add2)
+{
+	ktime_t res;
+
+	res.tv64 = add1.tv64 + add2.tv64;
+	/*
+	 * performance trick: the (u32) -NSEC gives 0x00000000Fxxxxxxx
+	 * so we subtract NSEC_PER_SEC and add 1 to the upper 32 bit.
+	 *
+	 * it's equivalent to:
+	 *   tv.nsec -= NSEC_PER_SEC
+	 *   tv.sec ++;
+	 */
+	if (res.tv.nsec >= NSEC_PER_SEC)
+		res.tv64 += (u32)-NSEC_PER_SEC;
+
+	return res;
+}
+
+/**
+ * ktime_add_ns - Add a scalar nanoseconds value to a ktime_t variable
+ * @kt:		addend
+ * @nsec:	the scalar nsec value to add
+ *
+ * Returns the sum of @kt and @nsec in ktime_t format
+ */
+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
+ *
+ * Returns a ktime_t variable with the converted timespec value
+ */
+static inline ktime_t timespec_to_ktime(const struct timespec ts)
+{
+	return (ktime_t) { .tv = { .sec = (s32)ts.tv_sec,
+			   	   .nsec = (s32)ts.tv_nsec } };
+}
+
+/**
+ * timeval_to_ktime - convert a timeval to ktime_t format
+ * @tv:		the timeval variable to convert
+ *
+ * Returns a ktime_t variable with the converted timeval value
+ */
+static inline ktime_t timeval_to_ktime(const struct timeval tv)
+{
+	return (ktime_t) { .tv = { .sec = (s32)tv.tv_sec,
+				   .nsec = (s32)tv.tv_usec * 1000 } };
+}
+
+/**
+ * ktime_to_timespec - convert a ktime_t variable to timespec format
+ * @kt:		the ktime_t variable to convert
+ *
+ * Returns the timespec representation of the ktime value
+ */
+static inline struct timespec ktime_to_timespec(const ktime_t kt)
+{
+	return (struct timespec) { .tv_sec = (time_t) kt.tv.sec,
+				   .tv_nsec = (long) kt.tv.nsec };
+}
+
+/**
+ * ktime_to_timeval - convert a ktime_t variable to timeval format
+ * @kt:		the ktime_t variable to convert
+ *
+ * Returns the timeval representation of the ktime value
+ */
+static inline struct timeval ktime_to_timeval(const ktime_t kt)
+{
+	return (struct timeval) {
+		.tv_sec = (time_t) kt.tv.sec,
+		.tv_usec = (suseconds_t) (kt.tv.nsec / NSEC_PER_USEC) };
+}
+
+/**
+ * ktime_to_ns - convert a ktime_t variable to scalar nanoseconds
+ * @kt:		the ktime_t variable to convert
+ *
+ * Returns the scalar nanoseconds representation of @kt
+ */
+static inline s64 ktime_to_ns(const ktime_t kt)
+{
+	return (s64) kt.tv.sec * NSEC_PER_SEC + kt.tv.nsec;
+}
+
+#endif	/* !((BITS_PER_LONG == 64) || defined(CONFIG_KTIME_SCALAR)) */
+
+/**
+ * ktime_equal - Compares two ktime_t variables to see if they are equal
+ * @cmp1:	comparable1
+ * @cmp2:	comparable2
+ *
+ * Compare two ktime_t variables, returns 1 if equal
+ */
+static inline int ktime_equal(const ktime_t cmp1, const ktime_t cmp2)
+{
+	return cmp1.tv64 == cmp2.tv64;
+}
+
+static inline s64 ktime_to_us(const ktime_t kt)
+{
+	struct timeval tv = ktime_to_timeval(kt);
+	return (s64) tv.tv_sec * USEC_PER_SEC + tv.tv_usec;
+}
+
+static inline s64 ktime_to_ms(const ktime_t kt)
+{
+	struct timeval tv = ktime_to_timeval(kt);
+	return (s64) tv.tv_sec * MSEC_PER_SEC + tv.tv_usec / USEC_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 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 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);
+
+/* 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