include: linux: Reorganize timekeeping and ktime headers

The timekeeping subsystem could use some reorganization. Reorganize and
separate the headers by making ktime.h take care of the ktime_get()
family of functions, and reserve timekeeping.h for the actual timekeeping.

This also helps to avoid implicit function errors and strengthens the
header dependencies, since timekeeping.h was using ktime_to_ns(), a static
function defined in a header it does no include, ktime.h.

Include the header timekeeping.h wherever it is necessary for a successful
compilation after the header code reorganization for all archs.

Signed-off-by: Carlos Bilbao <carlos.bilbao@amd.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Reported-by: kernel test robot <lkp@intel.com>

arch/arm64/kvm/hypercalls.c

@@ -3,6 +3,7 @@
 
 #include <linux/arm-smccc.h>
 #include <linux/kvm_host.h>
+#include <linux/timekeeping.h>
 
 #include <asm/kvm_emulate.h>
 

arch/ia64/kernel/time.c

@@ -22,6 +22,7 @@
 #include <linux/efi.h>
 #include <linux/timex.h>
 #include <linux/timekeeper_internal.h>
+#include <linux/timekeeping.h>
 #include <linux/platform_device.h>
 #include <linux/sched/cputime.h>
 

arch/m68k/atari/time.c

@@ -19,6 +19,7 @@
 #include <linux/clocksource.h>
 #include <linux/delay.h>
 #include <linux/export.h>
+#include <linux/timekeeping.h>
 
 #include <asm/atariints.h>
 #include <asm/machdep.h>

arch/m68k/hp300/time.c

@@ -14,6 +14,8 @@
 #include <linux/sched.h>
 #include <linux/kernel_stat.h>
 #include <linux/interrupt.h>
+#include <linux/timekeeping.h>
+
 #include <asm/machdep.h>
 #include <asm/irq.h>
 #include <asm/io.h>

arch/m68k/kernel/time.c

@@ -28,6 +28,7 @@
 #include <asm/irq_regs.h>
 
 #include <linux/time.h>
+#include <linux/timekeeping.h>
 #include <linux/timex.h>
 #include <linux/profile.h>
 

arch/m68k/mac/via.c

@@ -31,6 +31,7 @@
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/irq.h>
+#include <linux/timekeeping.h>
 
 #include <asm/macintosh.h>
 #include <asm/macints.h>

arch/m68k/mvme16x/config.c

@@ -28,6 +28,7 @@
 #include <linux/rtc.h>
 #include <linux/interrupt.h>
 #include <linux/module.h>
+#include <linux/timekeeping.h>
 
 #include <asm/bootinfo.h>
 #include <asm/bootinfo-vme.h>

arch/m68k/sun3/sun3ints.c

@@ -11,6 +11,7 @@
 #include <linux/sched.h>
 #include <linux/kernel_stat.h>
 #include <linux/interrupt.h>
+#include <linux/timekeeping.h>
 #include <asm/intersil.h>
 #include <asm/oplib.h>
 #include <asm/sun3ints.h>

arch/powerpc/kernel/time.c

@@ -54,6 +54,7 @@
 #include <linux/of_clk.h>
 #include <linux/suspend.h>
 #include <linux/processor.h>
+#include <linux/timekeeping.h>
 #include <asm/trace.h>
 
 #include <asm/interrupt.h>

arch/um/kernel/time.c

@@ -20,6 +20,7 @@
 #include <kern_util.h>
 #include <os.h>
 #include <linux/time-internal.h>
+#include <linux/timekeeping.h>
 #include <linux/um_timetravel.h>
 #include <shared/init.h>
 

arch/x86/kernel/rtc.c

@@ -9,6 +9,7 @@
 #include <linux/export.h>
 #include <linux/pnp.h>
 #include <linux/of.h>
+#include <linux/timekeeping.h>
 
 #include <asm/vsyscall.h>
 #include <asm/x86_init.h>

arch/x86/kernel/tsc.c

@@ -15,6 +15,7 @@
 #include <linux/timex.h>
 #include <linux/static_key.h>
 #include <linux/static_call.h>
+#include <linux/timekeeping.h>
 
 #include <asm/hpet.h>
 #include <asm/timer.h>

drivers/rtc/class.c

@@ -16,6 +16,7 @@
 #include <linux/kdev_t.h>
 #include <linux/idr.h>
 #include <linux/slab.h>
+#include <linux/timekeeping.h>
 #include <linux/workqueue.h>
 
 #include "rtc-core.h"

include/linux/ktime.h

@@ -229,6 +229,198 @@ static inline ktime_t ms_to_ktime(u64 ms)
 	return ms * NSEC_PER_MSEC;
 }
 
-# include <linux/timekeeping.h>
+/*
+ * ktime_get() family: read the current time in a multitude of ways,
+ *
+ * The default time reference is CLOCK_MONOTONIC, starting at
+ * boot time but not counting the time spent in suspend.
+ * For other references, use the functions with "real", "clocktai",
+ * "boottime" and "raw" suffixes.
+ *
+ * To get the time in a different format, use the ones wit
+ * "ns", "ts64" and "seconds" suffix.
+ *
+ * See Documentation/core-api/timekeeping.rst for more details.
+ */
 
-#endif
+
+/*
+ * timespec64 based interfaces
+ */
+extern void ktime_get_raw_ts64(struct timespec64 *ts);
+extern void ktime_get_ts64(struct timespec64 *ts);
+extern void ktime_get_real_ts64(struct timespec64 *tv);
+extern void ktime_get_coarse_ts64(struct timespec64 *ts);
+extern void ktime_get_coarse_real_ts64(struct timespec64 *ts);
+
+void getboottime64(struct timespec64 *ts);
+
+/*
+ * time64_t base interfaces
+ */
+extern time64_t ktime_get_seconds(void);
+extern time64_t __ktime_get_real_seconds(void);
+extern time64_t ktime_get_real_seconds(void);
+
+/*
+ * ktime_t based interfaces
+ */
+
+enum tk_offsets {
+	TK_OFFS_REAL,
+	TK_OFFS_BOOT,
+	TK_OFFS_TAI,
+	TK_OFFS_MAX,
+};
+
+extern ktime_t ktime_get(void);
+extern ktime_t ktime_get_with_offset(enum tk_offsets offs);
+extern ktime_t ktime_get_coarse_with_offset(enum tk_offsets offs);
+extern ktime_t ktime_mono_to_any(ktime_t tmono, enum tk_offsets offs);
+extern ktime_t ktime_get_raw(void);
+extern u32 ktime_get_resolution_ns(void);
+
+/**
+ * ktime_get_real - get the real (wall-) time in ktime_t format
+ */
+static inline ktime_t ktime_get_real(void)
+{
+	return ktime_get_with_offset(TK_OFFS_REAL);
+}
+
+static inline ktime_t ktime_get_coarse_real(void)
+{
+	return ktime_get_coarse_with_offset(TK_OFFS_REAL);
+}
+
+/**
+ * ktime_get_boottime - Returns monotonic time since boot in ktime_t format
+ *
+ * This is similar to CLOCK_MONTONIC/ktime_get, but also includes the
+ * time spent in suspend.
+ */
+static inline ktime_t ktime_get_boottime(void)
+{
+	return ktime_get_with_offset(TK_OFFS_BOOT);
+}
+
+static inline ktime_t ktime_get_coarse_boottime(void)
+{
+	return ktime_get_coarse_with_offset(TK_OFFS_BOOT);
+}
+
+/**
+ * ktime_get_clocktai - Returns the TAI time of day in ktime_t format
+ */
+static inline ktime_t ktime_get_clocktai(void)
+{
+	return ktime_get_with_offset(TK_OFFS_TAI);
+}
+
+static inline ktime_t ktime_get_coarse_clocktai(void)
+{
+	return ktime_get_coarse_with_offset(TK_OFFS_TAI);
+}
+
+static inline ktime_t ktime_get_coarse(void)
+{
+	struct timespec64 ts;
+
+	ktime_get_coarse_ts64(&ts);
+	return timespec64_to_ktime(ts);
+}
+
+static inline u64 ktime_get_coarse_ns(void)
+{
+	return ktime_to_ns(ktime_get_coarse());
+}
+
+static inline u64 ktime_get_coarse_real_ns(void)
+{
+	return ktime_to_ns(ktime_get_coarse_real());
+}
+
+static inline u64 ktime_get_coarse_boottime_ns(void)
+{
+	return ktime_to_ns(ktime_get_coarse_boottime());
+}
+
+static inline u64 ktime_get_coarse_clocktai_ns(void)
+{
+	return ktime_to_ns(ktime_get_coarse_clocktai());
+}
+
+/**
+ * ktime_mono_to_real - Convert monotonic time to clock realtime
+ */
+static inline ktime_t ktime_mono_to_real(ktime_t mono)
+{
+	return ktime_mono_to_any(mono, TK_OFFS_REAL);
+}
+
+static inline u64 ktime_get_ns(void)
+{
+	return ktime_to_ns(ktime_get());
+}
+
+static inline u64 ktime_get_real_ns(void)
+{
+	return ktime_to_ns(ktime_get_real());
+}
+
+static inline u64 ktime_get_boottime_ns(void)
+{
+	return ktime_to_ns(ktime_get_boottime());
+}
+
+static inline u64 ktime_get_clocktai_ns(void)
+{
+	return ktime_to_ns(ktime_get_clocktai());
+}
+
+static inline u64 ktime_get_raw_ns(void)
+{
+	return ktime_to_ns(ktime_get_raw());
+}
+
+extern u64 ktime_get_mono_fast_ns(void);
+extern u64 ktime_get_raw_fast_ns(void);
+extern u64 ktime_get_boot_fast_ns(void);
+extern u64 ktime_get_real_fast_ns(void);
+
+/*
+ * timespec64/time64_t interfaces utilizing the ktime based ones
+ * for API completeness, these could be implemented more efficiently
+ * if needed.
+ */
+static inline void ktime_get_boottime_ts64(struct timespec64 *ts)
+{
+	*ts = ktime_to_timespec64(ktime_get_boottime());
+}
+
+static inline void ktime_get_coarse_boottime_ts64(struct timespec64 *ts)
+{
+	*ts = ktime_to_timespec64(ktime_get_coarse_boottime());
+}
+
+static inline time64_t ktime_get_boottime_seconds(void)
+{
+	return ktime_divns(ktime_get_coarse_boottime(), NSEC_PER_SEC);
+}
+
+static inline void ktime_get_clocktai_ts64(struct timespec64 *ts)
+{
+	*ts = ktime_to_timespec64(ktime_get_clocktai());
+}
+
+static inline void ktime_get_coarse_clocktai_ts64(struct timespec64 *ts)
+{
+	*ts = ktime_to_timespec64(ktime_get_coarse_clocktai());
+}
+
+static inline time64_t ktime_get_clocktai_seconds(void)
+{
+	return ktime_divns(ktime_get_coarse_clocktai(), NSEC_PER_SEC);
+}
+
+#endif /* _LINUX_KTIME_H */

include/linux/pps_kernel.h

@@ -12,6 +12,7 @@
 #include <linux/cdev.h>
 #include <linux/device.h>
 #include <linux/time.h>
+#include <linux/timekeeping.h>
 
 /*
  * Global defines

include/linux/sched_clock.h

@@ -5,6 +5,8 @@
 #ifndef LINUX_SCHED_CLOCK
 #define LINUX_SCHED_CLOCK
 
+#include <linux/timekeeping.h>
+
 #ifdef CONFIG_GENERIC_SCHED_CLOCK
 /**
  * struct clock_read_data - data required to read from sched_clock()

include/linux/stmmac.h

@@ -14,6 +14,7 @@
 
 #include <linux/platform_device.h>
 #include <linux/phy.h>
+#include <linux/timekeeping.h>
 
 #define MTL_MAX_RX_QUEUES	8
 #define MTL_MAX_TX_QUEUES	8