v4.19.13 snapshot.
diff --git a/include/linux/time64.h b/include/linux/time64.h
new file mode 100644
index 0000000..05634af
--- /dev/null
+++ b/include/linux/time64.h
@@ -0,0 +1,152 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_TIME64_H
+#define _LINUX_TIME64_H
+
+#include <linux/math64.h>
+
+typedef __s64 time64_t;
+typedef __u64 timeu64_t;
+
+/* CONFIG_64BIT_TIME enables new 64 bit time_t syscalls in the compat path
+ * and 32-bit emulation.
+ */
+#ifndef CONFIG_64BIT_TIME
+#define __kernel_timespec timespec
+#define __kernel_itimerspec itimerspec
+#endif
+
+#include <uapi/linux/time.h>
+
+struct timespec64 {
+ time64_t tv_sec; /* seconds */
+ long tv_nsec; /* nanoseconds */
+};
+
+struct itimerspec64 {
+ struct timespec64 it_interval;
+ struct timespec64 it_value;
+};
+
+/* Parameters used to convert the timespec values: */
+#define MSEC_PER_SEC 1000L
+#define USEC_PER_MSEC 1000L
+#define NSEC_PER_USEC 1000L
+#define NSEC_PER_MSEC 1000000L
+#define USEC_PER_SEC 1000000L
+#define NSEC_PER_SEC 1000000000L
+#define FSEC_PER_SEC 1000000000000000LL
+
+/* Located here for timespec[64]_valid_strict */
+#define TIME64_MAX ((s64)~((u64)1 << 63))
+#define KTIME_MAX ((s64)~((u64)1 << 63))
+#define KTIME_SEC_MAX (KTIME_MAX / NSEC_PER_SEC)
+
+static inline int timespec64_equal(const struct timespec64 *a,
+ const struct timespec64 *b)
+{
+ return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec);
+}
+
+/*
+ * lhs < rhs: return <0
+ * lhs == rhs: return 0
+ * lhs > rhs: return >0
+ */
+static inline int timespec64_compare(const struct timespec64 *lhs, const struct timespec64 *rhs)
+{
+ if (lhs->tv_sec < rhs->tv_sec)
+ return -1;
+ if (lhs->tv_sec > rhs->tv_sec)
+ return 1;
+ return lhs->tv_nsec - rhs->tv_nsec;
+}
+
+extern void set_normalized_timespec64(struct timespec64 *ts, time64_t sec, s64 nsec);
+
+static inline struct timespec64 timespec64_add(struct timespec64 lhs,
+ struct timespec64 rhs)
+{
+ struct timespec64 ts_delta;
+ set_normalized_timespec64(&ts_delta, lhs.tv_sec + rhs.tv_sec,
+ lhs.tv_nsec + rhs.tv_nsec);
+ return ts_delta;
+}
+
+/*
+ * sub = lhs - rhs, in normalized form
+ */
+static inline struct timespec64 timespec64_sub(struct timespec64 lhs,
+ struct timespec64 rhs)
+{
+ struct timespec64 ts_delta;
+ set_normalized_timespec64(&ts_delta, lhs.tv_sec - rhs.tv_sec,
+ lhs.tv_nsec - rhs.tv_nsec);
+ return ts_delta;
+}
+
+/*
+ * Returns true if the timespec64 is norm, false if denorm:
+ */
+static inline bool timespec64_valid(const struct timespec64 *ts)
+{
+ /* Dates before 1970 are bogus */
+ if (ts->tv_sec < 0)
+ return false;
+ /* Can't have more nanoseconds then a second */
+ if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
+ return false;
+ return true;
+}
+
+static inline bool timespec64_valid_strict(const struct timespec64 *ts)
+{
+ if (!timespec64_valid(ts))
+ return false;
+ /* Disallow values that could overflow ktime_t */
+ if ((unsigned long long)ts->tv_sec >= KTIME_SEC_MAX)
+ return false;
+ return true;
+}
+
+/**
+ * timespec64_to_ns - Convert timespec64 to nanoseconds
+ * @ts: pointer to the timespec64 variable to be converted
+ *
+ * Returns the scalar nanosecond representation of the timespec64
+ * parameter.
+ */
+static inline s64 timespec64_to_ns(const struct timespec64 *ts)
+{
+ return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
+}
+
+/**
+ * ns_to_timespec64 - Convert nanoseconds to timespec64
+ * @nsec: the nanoseconds value to be converted
+ *
+ * Returns the timespec64 representation of the nsec parameter.
+ */
+extern struct timespec64 ns_to_timespec64(const s64 nsec);
+
+/**
+ * timespec64_add_ns - Adds nanoseconds to a timespec64
+ * @a: pointer to timespec64 to be incremented
+ * @ns: unsigned nanoseconds value to be added
+ *
+ * This must always be inlined because its used from the x86-64 vdso,
+ * which cannot call other kernel functions.
+ */
+static __always_inline void timespec64_add_ns(struct timespec64 *a, u64 ns)
+{
+ a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns);
+ a->tv_nsec = ns;
+}
+
+/*
+ * timespec64_add_safe assumes both values are positive and checks for
+ * overflow. It will return TIME64_MAX in case of overflow.
+ */
+extern struct timespec64 timespec64_add_safe(const struct timespec64 lhs,
+ const struct timespec64 rhs);
+
+#endif /* _LINUX_TIME64_H */