linux/time32.h: Extract common header for vDSO

The vDSO library should only include the necessary headers required for
a userspace library (UAPI and a minimal set of kernel headers). To make
this possible it is necessary to isolate from the kernel headers the
common parts that are strictly necessary to build the library.

Split time32.h into linux and common headers to make the latter suitable
for inclusion in the vDSO library.
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200320145351.32292-12-vincenzo.frascino@arm.com

include/linux/time32.h

@@ -12,19 +12,9 @@
 #include <linux/time64.h>
 #include <linux/timex.h>
 
-#define TIME_T_MAX	(__kernel_old_time_t)((1UL << ((sizeof(__kernel_old_time_t) << 3) - 1)) - 1)
-
-typedef s32		old_time32_t;
-
-struct old_timespec32 {
-	old_time32_t	tv_sec;
-	s32		tv_nsec;
-};
+#include <vdso/time32.h>
 
-struct old_timeval32 {
-	old_time32_t	tv_sec;
-	s32		tv_usec;
-};
+#define TIME_T_MAX	(__kernel_old_time_t)((1UL << ((sizeof(__kernel_old_time_t) << 3) - 1)) - 1)
 
 struct old_itimerspec32 {
 	struct old_timespec32 it_interval;

include/vdso/time32.h

+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __VDSO_TIME32_H
+#define __VDSO_TIME32_H
+
+typedef s32		old_time32_t;
+
+struct old_timespec32 {
+	old_time32_t	tv_sec;
+	s32		tv_nsec;
+};
+
+struct old_timeval32 {
+	old_time32_t	tv_sec;
+	s32		tv_usec;
+};
+
+#endif /* __VDSO_TIME32_H */