time: Move time_t conversion helpers to time32.h

On 64-bit architectures, the timespec64 based helpers in linux/time.h
are defined as macros pointing to their timespec based counterparts.
This made sense when they were first introduced, but as we are migrating
away from timespec in general, it's much less intuitive now.

This changes the macros to work in the exact opposite way: we always
provide the timespec64 based helpers and define the old interfaces as
macros for them. Now we can move those macros into linux/time32.h, which
already contains the respective helpers for 32-bit architectures.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Miroslav Lichvar <mlichvar@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Stephen Boyd <stephen.boyd@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: John Stultz <john.stultz@linaro.org>

1 files changed, 45 insertions, 0 deletions

diff --git a/include/linux/time32.h b/include/linux/time32.h
index 9b9c43f0d39b..65b1de25198d 100644
--- a/include/linux/time32.h
+++ b/include/linux/time32.h
@@ -13,6 +13,49 @@
 
 #define TIME_T_MAX	(time_t)((1UL << ((sizeof(time_t) << 3) - 1)) - 1)
 
+#if __BITS_PER_LONG == 64
+
+/* timespec64 is defined as timespec here */
+static inline struct timespec timespec64_to_timespec(const struct timespec64 ts64)
+{
+	return ts64;
+}
+
+static inline struct timespec64 timespec_to_timespec64(const struct timespec ts)
+{
+	return ts;
+}
+
+# define timespec_equal			timespec64_equal
+# define timespec_compare		timespec64_compare
+# define set_normalized_timespec	set_normalized_timespec64
+# define timespec_add			timespec64_add
+# define timespec_sub			timespec64_sub
+# define timespec_valid			timespec64_valid
+# define timespec_valid_strict		timespec64_valid_strict
+# define timespec_to_ns			timespec64_to_ns
+# define ns_to_timespec			ns_to_timespec64
+# define timespec_add_ns		timespec64_add_ns
+
+#else
+static inline struct timespec timespec64_to_timespec(const struct timespec64 ts64)
+{
+	struct timespec ret;
+
+	ret.tv_sec = (time_t)ts64.tv_sec;
+	ret.tv_nsec = ts64.tv_nsec;
+	return ret;
+}
+
+static inline struct timespec64 timespec_to_timespec64(const struct timespec ts)
+{
+	struct timespec64 ret;
+
+	ret.tv_sec = ts.tv_sec;
+	ret.tv_nsec = ts.tv_nsec;
+	return ret;
+}
+
 static inline int timespec_equal(const struct timespec *a,
 				 const struct timespec *b)
 {
@@ -116,6 +159,8 @@ static __always_inline void timespec_add_ns(struct timespec *a, u64 ns)
 	a->tv_nsec = ns;
 }
 
+#endif
+
 /**
  * time_to_tm - converts the calendar time to local broken-down time
  *