[PATCH 0/5] timekeeping: API cleanup and extensions

[PATCH 0/5] timekeeping: API cleanup and extensions

[Arnd Bergmann]

Hi Thomas,

I've had these patches for a while but never got around to submitting
them. I recently rebased them after the boot time removal and now again
after the revert.

I'd like to see these go into v4.18 as a preparation for a last set of
driver conversions to y2038-safe interfaces that I've held off for now
since the interfaces were suboptimal.

The problems solved by this series are:
- aliasing timespec to timespec64 is a little erorr-prone,
  and in particular requires ugly casts to print a tv_sec field
  using the same format string across architectures

- naming is inconsistent, and while converting from the
  deprecated time_t to something else, I'd like to also
  convert to a ktime_get_*() API for consistency

- drivers that use current_kernel_time() today often care
  about the call being fast but don't care about it being
  CLOCK_REALTIME based, so they are better off being changed
  to a CLOCK_MONOTONIC or CLOCK_BOOTTIME based accessor
  to avoid issues with time going backwards.

	Arnd

Arnd Bergmann (5):
  timekeeping: Remove timespec64 hack
  timekeeping: Clean up ktime_get_real_ts64
  timekeeping: Standardize on ktime_get_*() naming
  timekeeping: Add ktime_get_coarse_with_offset
  timekeeping: Add more coarse clocktai/boottime interfaces

 include/linux/time32.h        | 18 ++-------
 include/linux/time64.h        |  7 ----
 include/linux/timekeeping.h   | 91 ++++++++++++++++++++++++++++++++++++-------
 include/linux/timekeeping32.h | 70 ++++++---------------------------
 kernel/time/time.c            |  2 -
 kernel/time/timekeeping.c     | 73 ++++++++++++++++------------------
 6 files changed, 124 insertions(+), 137 deletions(-)

-- 
2.9.0

[PATCH 1/5] timekeeping: Remove timespec64 hack

[Arnd Bergmann]

At this point, we have converted most of the kernel to use timespec64
consistently in place of timespec, so it seems it's time to make
timespec64 the native structure and define timespec in terms of that
one on 64-bit architectures.

Starting with gcc-5, the compiler can completely optimize away the
timespec_to_timespec64 and timespec64_to_timespec functions on 64-bit
architectures. With older compilers, we introduce a couple of extra
copies of local variables, but those are easily avoided by using
the timespec64 based interfaces consistently, as we do in most of the
important code paths already.

The main upside of removing the hack is that printing the tv_sec
field of a timespec64 structure can now use the %lld format
string on all architectures without a cast to time64_t. Without
this patch, the field is a 'long' type and would have to be printed
using %ld on 64-bit architectures.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 include/linux/time32.h        | 18 +++--------------
 include/linux/time64.h        |  7 -------
 include/linux/timekeeping32.h | 45 -------------------------------------------
 kernel/time/time.c            |  2 --
 4 files changed, 3 insertions(+), 69 deletions(-)

diff --git a/include/linux/time32.h b/include/linux/time32.h
index d2bcd4377b56..0b14f936100a 100644
--- a/include/linux/time32.h
+++ b/include/linux/time32.h
@@ -18,25 +18,14 @@
 /* timespec64 is defined as timespec here */
 static inline struct timespec timespec64_to_timespec(const struct timespec64 ts64)
 {
-	return ts64;
+	return *(const struct timespec *)&ts64;
 }
 
 static inline struct timespec64 timespec_to_timespec64(const struct timespec ts)
 {
-	return ts;
+	return *(const struct timespec64 *)&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)
 {
@@ -55,6 +44,7 @@ static inline struct timespec64 timespec_to_timespec64(const struct timespec ts)
 	ret.tv_nsec = ts.tv_nsec;
 	return ret;
 }
+#endif
 
 static inline int timespec_equal(const struct timespec *a,
 				 const struct timespec *b)
@@ -159,8 +149,6 @@ 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
  *
diff --git a/include/linux/time64.h b/include/linux/time64.h
index 0d96887ba4e0..0a7b2f79cec7 100644
--- a/include/linux/time64.h
+++ b/include/linux/time64.h
@@ -16,11 +16,6 @@ typedef __u64 timeu64_t;
 
 #include <uapi/linux/time.h>
 
-#if __BITS_PER_LONG == 64
-/* this trick allows us to optimize out timespec64_to_timespec */
-# define timespec64 timespec
-#define itimerspec64 itimerspec
-#else
 struct timespec64 {
 	time64_t	tv_sec;			/* seconds */
 	long		tv_nsec;		/* nanoseconds */
@@ -31,8 +26,6 @@ struct itimerspec64 {
 	struct timespec64 it_value;
 };
 
-#endif
-
 /* Parameters used to convert the timespec values: */
 #define MSEC_PER_SEC	1000L
 #define USEC_PER_MSEC	1000L
diff --git a/include/linux/timekeeping32.h b/include/linux/timekeeping32.h
index 3616b4becb59..4ea45d0df1d4 100644
--- a/include/linux/timekeeping32.h
+++ b/include/linux/timekeeping32.h
@@ -16,50 +16,6 @@ static inline struct timespec current_kernel_time(void)
 	return timespec64_to_timespec(now);
 }
 
-#if BITS_PER_LONG == 64
-/**
- * Deprecated. Use do_settimeofday64().
- */
-static inline int do_settimeofday(const struct timespec *ts)
-{
-	return do_settimeofday64(ts);
-}
-
-static inline int __getnstimeofday(struct timespec *ts)
-{
-	return __getnstimeofday64(ts);
-}
-
-static inline void getnstimeofday(struct timespec *ts)
-{
-	getnstimeofday64(ts);
-}
-
-static inline void ktime_get_ts(struct timespec *ts)
-{
-	ktime_get_ts64(ts);
-}
-
-static inline void ktime_get_real_ts(struct timespec *ts)
-{
-	getnstimeofday64(ts);
-}
-
-static inline void getrawmonotonic(struct timespec *ts)
-{
-	getrawmonotonic64(ts);
-}
-
-static inline struct timespec get_monotonic_coarse(void)
-{
-	return get_monotonic_coarse64();
-}
-
-static inline void getboottime(struct timespec *ts)
-{
-	return getboottime64(ts);
-}
-#else
 /**
  * Deprecated. Use do_settimeofday64().
  */
@@ -124,7 +80,6 @@ static inline void getboottime(struct timespec *ts)
 	getboottime64(&ts64);
 	*ts = timespec64_to_timespec(ts64);
 }
-#endif
 
 /*
  * Timespec interfaces utilizing the ktime based ones
diff --git a/kernel/time/time.c b/kernel/time/time.c
index 3ddf10b6523c..8e4f3fd2f84b 100644
--- a/kernel/time/time.c
+++ b/kernel/time/time.c
@@ -407,7 +407,6 @@ time64_t mktime64(const unsigned int year0, const unsigned int mon0,
 }
 EXPORT_SYMBOL(mktime64);
 
-#if __BITS_PER_LONG == 32
 /**
  * set_normalized_timespec - set timespec sec and nsec parts and normalize
  *
@@ -468,7 +467,6 @@ struct timespec ns_to_timespec(const s64 nsec)
 	return ts;
 }
 EXPORT_SYMBOL(ns_to_timespec);
-#endif
 
 /**
  * ns_to_timeval - Convert nanoseconds to timeval
-- 
2.9.0

[PATCH 2/5] timekeeping: Clean up ktime_get_real_ts64

[Arnd Bergmann]

In a move to make ktime_get_*() the preferred driver interface into the
timekeeping code, sanitizes ktime_get_real_ts64() to be a proper exported
symbol rather than an alias for getnstimeofday64().

The internal __getnstimeofday64() is no longer used, so remove that
and merge it into ktime_get_real_ts64().

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 include/linux/timekeeping.h   |  8 +++++---
 include/linux/timekeeping32.h | 13 ++-----------
 kernel/time/timekeeping.c     | 31 ++++++-------------------------
 3 files changed, 13 insertions(+), 39 deletions(-)

diff --git a/include/linux/timekeeping.h b/include/linux/timekeeping.h
index 588a0e4b1ab9..415dae6bf1f5 100644
--- a/include/linux/timekeeping.h
+++ b/include/linux/timekeeping.h
@@ -30,15 +30,13 @@ struct timespec64 current_kernel_time64(void);
 struct timespec64 get_monotonic_coarse64(void);
 extern void getrawmonotonic64(struct timespec64 *ts);
 extern void ktime_get_ts64(struct timespec64 *ts);
+extern void ktime_get_real_ts64(struct timespec64 *tv);
 extern time64_t ktime_get_seconds(void);
 extern time64_t __ktime_get_real_seconds(void);
 extern time64_t ktime_get_real_seconds(void);
 
-extern int __getnstimeofday64(struct timespec64 *tv);
-extern void getnstimeofday64(struct timespec64 *tv);
 extern void getboottime64(struct timespec64 *ts);
 
-#define ktime_get_real_ts64(ts)	getnstimeofday64(ts)
 
 /*
  * ktime_t based interfaces
@@ -210,5 +208,9 @@ extern void read_persistent_clock64(struct timespec64 *ts);
 extern void read_boot_clock64(struct timespec64 *ts);
 extern int update_persistent_clock64(struct timespec64 now);
 
+/*
+ * deprecated aliases, don't use in new code
+ */
+#define getnstimeofday64(ts)		ktime_get_real_ts64(ts)
 
 #endif
diff --git a/include/linux/timekeeping32.h b/include/linux/timekeeping32.h
index 4ea45d0df1d4..5abff52d07fd 100644
--- a/include/linux/timekeeping32.h
+++ b/include/linux/timekeeping32.h
@@ -27,20 +27,11 @@ static inline int do_settimeofday(const struct timespec *ts)
 	return do_settimeofday64(&ts64);
 }
 
-static inline int __getnstimeofday(struct timespec *ts)
-{
-	struct timespec64 ts64;
-	int ret = __getnstimeofday64(&ts64);
-
-	*ts = timespec64_to_timespec(ts64);
-	return ret;
-}
-
 static inline void getnstimeofday(struct timespec *ts)
 {
 	struct timespec64 ts64;
 
-	getnstimeofday64(&ts64);
+	ktime_get_real_ts64(&ts64);
 	*ts = timespec64_to_timespec(ts64);
 }
 
@@ -56,7 +47,7 @@ static inline void ktime_get_real_ts(struct timespec *ts)
 {
 	struct timespec64 ts64;
 
-	getnstimeofday64(&ts64);
+	ktime_get_real_ts64(&ts64);
 	*ts = timespec64_to_timespec(ts64);
 }
 
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 49cbceef5deb..7bbc7a6e6095 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -705,18 +705,19 @@ static void timekeeping_forward_now(struct timekeeper *tk)
 }
 
 /**
- * __getnstimeofday64 - Returns the time of day in a timespec64.
+ * ktime_get_real_ts64 - Returns the time of day in a timespec64.
  * @ts:		pointer to the timespec to be set
  *
- * Updates the time of day in the timespec.
- * Returns 0 on success, or -ve when suspended (timespec will be undefined).
+ * Returns the time of day in a timespec64 (WARN if suspended).
  */
-int __getnstimeofday64(struct timespec64 *ts)
+void ktime_get_real_ts64(struct timespec64 *ts)
 {
 	struct timekeeper *tk = &tk_core.timekeeper;
 	unsigned long seq;
 	u64 nsecs;
 
+	WARN_ON(timekeeping_suspended);
+
 	do {
 		seq = read_seqcount_begin(&tk_core.seq);
 
@@ -727,28 +728,8 @@ int __getnstimeofday64(struct timespec64 *ts)
 
 	ts->tv_nsec = 0;
 	timespec64_add_ns(ts, nsecs);
-
-	/*
-	 * Do not bail out early, in case there were callers still using
-	 * the value, even in the face of the WARN_ON.
-	 */
-	if (unlikely(timekeeping_suspended))
-		return -EAGAIN;
-	return 0;
-}
-EXPORT_SYMBOL(__getnstimeofday64);
-
-/**
- * getnstimeofday64 - Returns the time of day in a timespec64.
- * @ts:		pointer to the timespec64 to be set
- *
- * Returns the time of day in a timespec64 (WARN if suspended).
- */
-void getnstimeofday64(struct timespec64 *ts)
-{
-	WARN_ON(__getnstimeofday64(ts));
 }
-EXPORT_SYMBOL(getnstimeofday64);
+EXPORT_SYMBOL(ktime_get_real_ts64);
 
 ktime_t ktime_get(void)
 {
-- 
2.9.0

[PATCH 3/5] timekeeping: Standardize on ktime_get_*() naming

[Arnd Bergmann]

The current_kernel_time64, get_monotonic_coarse64, getrawmonotonic64,
get_monotonic_boottime64 and timekeeping_clocktai64 interfaces have
rather inconsistent naming, and they differ in the calling conventions
by passing the output either by reference or as a return value.

Rename them to ktime_get_coarse_real_ts64, ktime_get_coarse_ts64,
ktime_get_raw_ts64, ktime_get_boottime_ts64 and ktime_get_clocktai_ts64
respectively, and provide the interfaces with macros or inline
functions as needed.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 include/linux/timekeeping.h   | 43 ++++++++++++++++++++++++++++++++-----------
 include/linux/timekeeping32.h | 14 ++++++++++----
 kernel/time/timekeeping.c     | 23 +++++++++--------------
 3 files changed, 51 insertions(+), 29 deletions(-)

diff --git a/include/linux/timekeeping.h b/include/linux/timekeeping.h
index 415dae6bf1f5..3ef9791d7d75 100644
--- a/include/linux/timekeeping.h
+++ b/include/linux/timekeeping.h
@@ -19,25 +19,25 @@ extern void xtime_update(unsigned long ticks);
 extern int do_settimeofday64(const struct timespec64 *ts);
 extern int do_sys_settimeofday64(const struct timespec64 *tv,
 				 const struct timezone *tz);
-/*
- * Kernel time accessors
- */
-struct timespec64 current_kernel_time64(void);
 
 /*
  * timespec64 based interfaces
  */
-struct timespec64 get_monotonic_coarse64(void);
-extern void getrawmonotonic64(struct timespec64 *ts);
+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);
 
-extern void getboottime64(struct timespec64 *ts);
-
-
 /*
  * ktime_t based interfaces
  */
@@ -123,12 +123,12 @@ extern u64 ktime_get_real_fast_ns(void);
 /*
  * timespec64 interfaces utilizing the ktime based ones
  */
-static inline void get_monotonic_boottime64(struct timespec64 *ts)
+static inline void ktime_get_boottime_ts64(struct timespec64 *ts)
 {
 	*ts = ktime_to_timespec64(ktime_get_boottime());
 }
 
-static inline void timekeeping_clocktai64(struct timespec64 *ts)
+static inline void ktime_get_clocktai_ts64(struct timespec64 *ts)
 {
 	*ts = ktime_to_timespec64(ktime_get_clocktai());
 }
@@ -212,5 +212,26 @@ extern int update_persistent_clock64(struct timespec64 now);
  * deprecated aliases, don't use in new code
  */
 #define getnstimeofday64(ts)		ktime_get_real_ts64(ts)
+#define get_monotonic_boottime64(ts)	ktime_get_boottime_ts64(ts)
+#define getrawmonotonic64(ts)		ktime_get_raw_ts64(ts)
+#define timekeeping_clocktai64(ts)	ktime_get_clocktai_ts64(ts)
+
+static inline struct timespec64 current_kernel_time64(void)
+{
+	struct timespec64 ts;
+
+	ktime_get_coarse_real_ts64(&ts);
+
+	return ts;
+}
+
+static inline struct timespec64 get_monotonic_coarse64(void)
+{
+	struct timespec64 ts;
+
+	ktime_get_coarse_ts64(&ts);
+
+	return ts;
+}
 
 #endif
diff --git a/include/linux/timekeeping32.h b/include/linux/timekeeping32.h
index 5abff52d07fd..8762c2f45f8b 100644
--- a/include/linux/timekeeping32.h
+++ b/include/linux/timekeeping32.h
@@ -11,9 +11,11 @@ unsigned long get_seconds(void);
 
 static inline struct timespec current_kernel_time(void)
 {
-	struct timespec64 now = current_kernel_time64();
+	struct timespec64 ts64;
+
+	ktime_get_coarse_real_ts64(&ts64);
 
-	return timespec64_to_timespec(now);
+	return timespec64_to_timespec(ts64);
 }
 
 /**
@@ -55,13 +57,17 @@ static inline void getrawmonotonic(struct timespec *ts)
 {
 	struct timespec64 ts64;
 
-	getrawmonotonic64(&ts64);
+	ktime_get_raw_ts64(&ts64);
 	*ts = timespec64_to_timespec(ts64);
 }
 
 static inline struct timespec get_monotonic_coarse(void)
 {
-	return timespec64_to_timespec(get_monotonic_coarse64());
+	struct timespec64 ts64;
+
+	ktime_get_coarse_ts64(&ts64);
+
+	return timespec64_to_timespec(ts64);
 }
 
 static inline void getboottime(struct timespec *ts)
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 7bbc7a6e6095..ed9b74ec9c0b 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -1391,12 +1391,12 @@ int timekeeping_notify(struct clocksource *clock)
 }
 
 /**
- * getrawmonotonic64 - Returns the raw monotonic time in a timespec
+ * ktime_get_raw_ts64 - Returns the raw monotonic time in a timespec
  * @ts:		pointer to the timespec64 to be set
  *
  * Returns the raw monotonic time (completely un-modified by ntp)
  */
-void getrawmonotonic64(struct timespec64 *ts)
+void ktime_get_raw_ts64(struct timespec64 *ts)
 {
 	struct timekeeper *tk = &tk_core.timekeeper;
 	unsigned long seq;
@@ -1412,7 +1412,7 @@ void getrawmonotonic64(struct timespec64 *ts)
 	ts->tv_nsec = 0;
 	timespec64_add_ns(ts, nsecs);
 }
-EXPORT_SYMBOL(getrawmonotonic64);
+EXPORT_SYMBOL(ktime_get_raw_ts64);
 
 
 /**
@@ -2114,23 +2114,20 @@ unsigned long get_seconds(void)
 }
 EXPORT_SYMBOL(get_seconds);
 
-struct timespec64 current_kernel_time64(void)
+void ktime_get_coarse_real_ts64(struct timespec64 *ts)
 {
 	struct timekeeper *tk = &tk_core.timekeeper;
-	struct timespec64 now;
 	unsigned long seq;
 
 	do {
 		seq = read_seqcount_begin(&tk_core.seq);
 
-		now = tk_xtime(tk);
+		*ts = tk_xtime(tk);
 	} while (read_seqcount_retry(&tk_core.seq, seq));
-
-	return now;
 }
-EXPORT_SYMBOL(current_kernel_time64);
+EXPORT_SYMBOL(ktime_get_coarse_real_ts64);
 
-struct timespec64 get_monotonic_coarse64(void)
+void ktime_get_coarse_ts64(struct timespec64 *ts)
 {
 	struct timekeeper *tk = &tk_core.timekeeper;
 	struct timespec64 now, mono;
@@ -2143,12 +2140,10 @@ struct timespec64 get_monotonic_coarse64(void)
 		mono = tk->wall_to_monotonic;
 	} while (read_seqcount_retry(&tk_core.seq, seq));
 
-	set_normalized_timespec64(&now, now.tv_sec + mono.tv_sec,
+	set_normalized_timespec64(ts, now.tv_sec + mono.tv_sec,
 				now.tv_nsec + mono.tv_nsec);
-
-	return now;
 }
-EXPORT_SYMBOL(get_monotonic_coarse64);
+EXPORT_SYMBOL(ktime_get_coarse_ts64);
 
 /*
  * Must hold jiffies_lock
-- 
2.9.0

[PATCH 4/5] timekeeping: Add ktime_get_coarse_with_offset

[Arnd Bergmann]

I have run into a couple of drivers using current_kernel_time()
suffering from the y2038 problem, and they could be converted
to using ktime_t, but don't have interfaces that skip the nanosecond
calculation at the moment.

This introduces ktime_get_coarse_with_offset() as a simpler
variant of ktime_get_with_offset(), and adds wrappers for the
three time domains we support with the existing function.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 include/linux/timekeeping.h | 16 ++++++++++++++++
 kernel/time/timekeeping.c   | 19 +++++++++++++++++++
 2 files changed, 35 insertions(+)

diff --git a/include/linux/timekeeping.h b/include/linux/timekeeping.h
index 3ef9791d7d75..42f71f4b658a 100644
--- a/include/linux/timekeeping.h
+++ b/include/linux/timekeeping.h
@@ -51,6 +51,7 @@ enum tk_offsets {
 
 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);
@@ -63,6 +64,11 @@ 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
  *
@@ -74,6 +80,11 @@ 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
  */
@@ -82,6 +93,11 @@ 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);
+}
+
 /**
  * ktime_mono_to_real - Convert monotonic time to clock realtime
  */
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index ed9b74ec9c0b..4786df904c22 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -795,6 +795,25 @@ ktime_t ktime_get_with_offset(enum tk_offsets offs)
 }
 EXPORT_SYMBOL_GPL(ktime_get_with_offset);
 
+ktime_t ktime_get_coarse_with_offset(enum tk_offsets offs)
+{
+	struct timekeeper *tk = &tk_core.timekeeper;
+	unsigned int seq;
+	ktime_t base, *offset = offsets[offs];
+
+	WARN_ON(timekeeping_suspended);
+
+	do {
+		seq = read_seqcount_begin(&tk_core.seq);
+		base = ktime_add(tk->tkr_mono.base, *offset);
+
+	} while (read_seqcount_retry(&tk_core.seq, seq));
+
+	return base;
+
+}
+EXPORT_SYMBOL_GPL(ktime_get_coarse_with_offset);
+
 /**
  * ktime_mono_to_any() - convert mononotic time to any other time
  * @tmono:	time to convert.
-- 
2.9.0

[PATCH 5/5] timekeeping: Add more coarse clocktai/boottime interfaces

[Arnd Bergmann]

The set of APIs we provide has a few holes for coarse times, e.g. we
provide ktime_get_coarse_boottime() and ktime_get_boottime_ts64(),
but not the combination of the two.

This adds four new functions:

ktime_get_coarse_boottime_ts64()
ktime_get_boottime_seconds()
ktime_get_coarse_clocktai_ts64()
ktime_get_clocktai_seconds()

to fill in some of the missing pieces. I have missed only the
ktime_get_boottime_seconds() accessor in a few occasions in
the past, but it seems better to just provide all four together,
as there is very little cost to having them.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 include/linux/timekeeping.h | 24 +++++++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/include/linux/timekeeping.h b/include/linux/timekeeping.h
index 42f71f4b658a..86bc2026efce 100644
--- a/include/linux/timekeeping.h
+++ b/include/linux/timekeeping.h
@@ -137,18 +137,40 @@ extern u64 ktime_get_boot_fast_ns(void);
 extern u64 ktime_get_real_fast_ns(void);
 
 /*
- * timespec64 interfaces utilizing the ktime based ones
+ * 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);
+}
+
 /*
  * RTC specific
  */
-- 
2.9.0

Re: [PATCH 1/5] timekeeping: Remove timespec64 hack

[Arnd Bergmann]

On Fri, Apr 27, 2018 at 3:40 PM, Arnd Bergmann <arnd@arndb.de> wrote:

> The main upside of removing the hack is that printing the tv_sec
> field of a timespec64 structure can now use the %lld format
> string on all architectures without a cast to time64_t. Without
> this patch, the field is a 'long' type and would have to be printed
> using %ld on 64-bit architectures.

As mentioned in another thread, this patch is now also a
prerequisite for the cleaned up patch "[v3] x86: Convert
x86_platform_ops to timespec64", which used to rely
on an ugly hack to avoid a forward-declaration of
'struct timespec64', which is now allowed on 64-bit
architectures after timespec64 is a structure rather than
a macro now.

      Arnd

[tip:timers/2038] timekeeping: Remove timespec64 hack

[tip-bot for Arnd Bergmann]

Commit-ID:  4f0fad9a603aee91a374e8411c23953894a77479
Gitweb:     https://git.kernel.org/tip/4f0fad9a603aee91a374e8411c23953894a77479
Author:     Arnd Bergmann <arnd@arndb.de>
AuthorDate: Fri, 27 Apr 2018 15:40:12 +0200
Committer:  Thomas Gleixner <tglx@linutronix.de>
CommitDate: Sat, 19 May 2018 13:57:31 +0200

timekeeping: Remove timespec64 hack

At this point, we have converted most of the kernel to use timespec64
consistently in place of timespec, so it seems it's time to make
timespec64 the native structure and define timespec in terms of that
one on 64-bit architectures.

Starting with gcc-5, the compiler can completely optimize away the
timespec_to_timespec64 and timespec64_to_timespec functions on 64-bit
architectures. With older compilers, we introduce a couple of extra
copies of local variables, but those are easily avoided by using
the timespec64 based interfaces consistently, as we do in most of the
important code paths already.

The main upside of removing the hack is that printing the tv_sec
field of a timespec64 structure can now use the %lld format
string on all architectures without a cast to time64_t. Without
this patch, the field is a 'long' type and would have to be printed
using %ld on 64-bit architectures.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: y2038@lists.linaro.org
Cc: John Stultz <john.stultz@linaro.org>
Link: https://lkml.kernel.org/r/20180427134016.2525989-2-arnd@arndb.de

---
 include/linux/time32.h        | 18 +++--------------
 include/linux/time64.h        |  7 -------
 include/linux/timekeeping32.h | 45 -------------------------------------------
 kernel/time/time.c            |  2 --
 4 files changed, 3 insertions(+), 69 deletions(-)

diff --git a/include/linux/time32.h b/include/linux/time32.h
index d2bcd4377b56..0b14f936100a 100644
--- a/include/linux/time32.h
+++ b/include/linux/time32.h
@@ -18,25 +18,14 @@
 /* timespec64 is defined as timespec here */
 static inline struct timespec timespec64_to_timespec(const struct timespec64 ts64)
 {
-	return ts64;
+	return *(const struct timespec *)&ts64;
 }
 
 static inline struct timespec64 timespec_to_timespec64(const struct timespec ts)
 {
-	return ts;
+	return *(const struct timespec64 *)&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)
 {
@@ -55,6 +44,7 @@ static inline struct timespec64 timespec_to_timespec64(const struct timespec ts)
 	ret.tv_nsec = ts.tv_nsec;
 	return ret;
 }
+#endif
 
 static inline int timespec_equal(const struct timespec *a,
 				 const struct timespec *b)
@@ -159,8 +149,6 @@ 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
  *
diff --git a/include/linux/time64.h b/include/linux/time64.h
index 0d96887ba4e0..0a7b2f79cec7 100644
--- a/include/linux/time64.h
+++ b/include/linux/time64.h
@@ -16,11 +16,6 @@ typedef __u64 timeu64_t;
 
 #include <uapi/linux/time.h>
 
-#if __BITS_PER_LONG == 64
-/* this trick allows us to optimize out timespec64_to_timespec */
-# define timespec64 timespec
-#define itimerspec64 itimerspec
-#else
 struct timespec64 {
 	time64_t	tv_sec;			/* seconds */
 	long		tv_nsec;		/* nanoseconds */
@@ -31,8 +26,6 @@ struct itimerspec64 {
 	struct timespec64 it_value;
 };
 
-#endif
-
 /* Parameters used to convert the timespec values: */
 #define MSEC_PER_SEC	1000L
 #define USEC_PER_MSEC	1000L
diff --git a/include/linux/timekeeping32.h b/include/linux/timekeeping32.h
index 3616b4becb59..4ea45d0df1d4 100644
--- a/include/linux/timekeeping32.h
+++ b/include/linux/timekeeping32.h
@@ -16,50 +16,6 @@ static inline struct timespec current_kernel_time(void)
 	return timespec64_to_timespec(now);
 }
 
-#if BITS_PER_LONG == 64
-/**
- * Deprecated. Use do_settimeofday64().
- */
-static inline int do_settimeofday(const struct timespec *ts)
-{
-	return do_settimeofday64(ts);
-}
-
-static inline int __getnstimeofday(struct timespec *ts)
-{
-	return __getnstimeofday64(ts);
-}
-
-static inline void getnstimeofday(struct timespec *ts)
-{
-	getnstimeofday64(ts);
-}
-
-static inline void ktime_get_ts(struct timespec *ts)
-{
-	ktime_get_ts64(ts);
-}
-
-static inline void ktime_get_real_ts(struct timespec *ts)
-{
-	getnstimeofday64(ts);
-}
-
-static inline void getrawmonotonic(struct timespec *ts)
-{
-	getrawmonotonic64(ts);
-}
-
-static inline struct timespec get_monotonic_coarse(void)
-{
-	return get_monotonic_coarse64();
-}
-
-static inline void getboottime(struct timespec *ts)
-{
-	return getboottime64(ts);
-}
-#else
 /**
  * Deprecated. Use do_settimeofday64().
  */
@@ -124,7 +80,6 @@ static inline void getboottime(struct timespec *ts)
 	getboottime64(&ts64);
 	*ts = timespec64_to_timespec(ts64);
 }
-#endif
 
 /*
  * Timespec interfaces utilizing the ktime based ones
diff --git a/kernel/time/time.c b/kernel/time/time.c
index ccd751e95fcb..6fa99213fc72 100644
--- a/kernel/time/time.c
+++ b/kernel/time/time.c
@@ -407,7 +407,6 @@ time64_t mktime64(const unsigned int year0, const unsigned int mon0,
 }
 EXPORT_SYMBOL(mktime64);
 
-#if __BITS_PER_LONG == 32
 /**
  * set_normalized_timespec - set timespec sec and nsec parts and normalize
  *
@@ -468,7 +467,6 @@ struct timespec ns_to_timespec(const s64 nsec)
 	return ts;
 }
 EXPORT_SYMBOL(ns_to_timespec);
-#endif
 
 /**
  * ns_to_timeval - Convert nanoseconds to timeval

[tip:timers/2038] timekeeping: Clean up ktime_get_real_ts64

[tip-bot for Arnd Bergmann]

Commit-ID:  edca71fecb77e2697337d192cbfe96f513407761
Gitweb:     https://git.kernel.org/tip/edca71fecb77e2697337d192cbfe96f513407761
Author:     Arnd Bergmann <arnd@arndb.de>
AuthorDate: Fri, 27 Apr 2018 15:40:13 +0200
Committer:  Thomas Gleixner <tglx@linutronix.de>
CommitDate: Sat, 19 May 2018 13:57:32 +0200

timekeeping: Clean up ktime_get_real_ts64

In a move to make ktime_get_*() the preferred driver interface into the
timekeeping code, sanitizes ktime_get_real_ts64() to be a proper exported
symbol rather than an alias for getnstimeofday64().

The internal __getnstimeofday64() is no longer used, so remove that
and merge it into ktime_get_real_ts64().

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: y2038@lists.linaro.org
Cc: John Stultz <john.stultz@linaro.org>
Link: https://lkml.kernel.org/r/20180427134016.2525989-3-arnd@arndb.de

---
 include/linux/timekeeping.h   |  8 +++++---
 include/linux/timekeeping32.h | 13 ++-----------
 kernel/time/timekeeping.c     | 31 ++++++-------------------------
 3 files changed, 13 insertions(+), 39 deletions(-)

diff --git a/include/linux/timekeeping.h b/include/linux/timekeeping.h
index 588a0e4b1ab9..415dae6bf1f5 100644
--- a/include/linux/timekeeping.h
+++ b/include/linux/timekeeping.h
@@ -30,15 +30,13 @@ struct timespec64 current_kernel_time64(void);
 struct timespec64 get_monotonic_coarse64(void);
 extern void getrawmonotonic64(struct timespec64 *ts);
 extern void ktime_get_ts64(struct timespec64 *ts);
+extern void ktime_get_real_ts64(struct timespec64 *tv);
 extern time64_t ktime_get_seconds(void);
 extern time64_t __ktime_get_real_seconds(void);
 extern time64_t ktime_get_real_seconds(void);
 
-extern int __getnstimeofday64(struct timespec64 *tv);
-extern void getnstimeofday64(struct timespec64 *tv);
 extern void getboottime64(struct timespec64 *ts);
 
-#define ktime_get_real_ts64(ts)	getnstimeofday64(ts)
 
 /*
  * ktime_t based interfaces
@@ -210,5 +208,9 @@ extern void read_persistent_clock64(struct timespec64 *ts);
 extern void read_boot_clock64(struct timespec64 *ts);
 extern int update_persistent_clock64(struct timespec64 now);
 
+/*
+ * deprecated aliases, don't use in new code
+ */
+#define getnstimeofday64(ts)		ktime_get_real_ts64(ts)
 
 #endif
diff --git a/include/linux/timekeeping32.h b/include/linux/timekeeping32.h
index 4ea45d0df1d4..5abff52d07fd 100644
--- a/include/linux/timekeeping32.h
+++ b/include/linux/timekeeping32.h
@@ -27,20 +27,11 @@ static inline int do_settimeofday(const struct timespec *ts)
 	return do_settimeofday64(&ts64);
 }
 
-static inline int __getnstimeofday(struct timespec *ts)
-{
-	struct timespec64 ts64;
-	int ret = __getnstimeofday64(&ts64);
-
-	*ts = timespec64_to_timespec(ts64);
-	return ret;
-}
-
 static inline void getnstimeofday(struct timespec *ts)
 {
 	struct timespec64 ts64;
 
-	getnstimeofday64(&ts64);
+	ktime_get_real_ts64(&ts64);
 	*ts = timespec64_to_timespec(ts64);
 }
 
@@ -56,7 +47,7 @@ static inline void ktime_get_real_ts(struct timespec *ts)
 {
 	struct timespec64 ts64;
 
-	getnstimeofday64(&ts64);
+	ktime_get_real_ts64(&ts64);
 	*ts = timespec64_to_timespec(ts64);
 }
 
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 49cbceef5deb..7bbc7a6e6095 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -705,18 +705,19 @@ static void timekeeping_forward_now(struct timekeeper *tk)
 }
 
 /**
- * __getnstimeofday64 - Returns the time of day in a timespec64.
+ * ktime_get_real_ts64 - Returns the time of day in a timespec64.
  * @ts:		pointer to the timespec to be set
  *
- * Updates the time of day in the timespec.
- * Returns 0 on success, or -ve when suspended (timespec will be undefined).
+ * Returns the time of day in a timespec64 (WARN if suspended).
  */
-int __getnstimeofday64(struct timespec64 *ts)
+void ktime_get_real_ts64(struct timespec64 *ts)
 {
 	struct timekeeper *tk = &tk_core.timekeeper;
 	unsigned long seq;
 	u64 nsecs;
 
+	WARN_ON(timekeeping_suspended);
+
 	do {
 		seq = read_seqcount_begin(&tk_core.seq);
 
@@ -727,28 +728,8 @@ int __getnstimeofday64(struct timespec64 *ts)
 
 	ts->tv_nsec = 0;
 	timespec64_add_ns(ts, nsecs);
-
-	/*
-	 * Do not bail out early, in case there were callers still using
-	 * the value, even in the face of the WARN_ON.
-	 */
-	if (unlikely(timekeeping_suspended))
-		return -EAGAIN;
-	return 0;
-}
-EXPORT_SYMBOL(__getnstimeofday64);
-
-/**
- * getnstimeofday64 - Returns the time of day in a timespec64.
- * @ts:		pointer to the timespec64 to be set
- *
- * Returns the time of day in a timespec64 (WARN if suspended).
- */
-void getnstimeofday64(struct timespec64 *ts)
-{
-	WARN_ON(__getnstimeofday64(ts));
 }
-EXPORT_SYMBOL(getnstimeofday64);
+EXPORT_SYMBOL(ktime_get_real_ts64);
 
 ktime_t ktime_get(void)
 {

[tip:timers/2038] timekeeping: Standardize on ktime_get_*() naming

[tip-bot for Arnd Bergmann]

Commit-ID:  fb7fcc96a86cfaef0f6dcc0665516aa68611e736
Gitweb:     https://git.kernel.org/tip/fb7fcc96a86cfaef0f6dcc0665516aa68611e736
Author:     Arnd Bergmann <arnd@arndb.de>
AuthorDate: Fri, 27 Apr 2018 15:40:14 +0200
Committer:  Thomas Gleixner <tglx@linutronix.de>
CommitDate: Sat, 19 May 2018 13:57:32 +0200

timekeeping: Standardize on ktime_get_*() naming

The current_kernel_time64, get_monotonic_coarse64, getrawmonotonic64,
get_monotonic_boottime64 and timekeeping_clocktai64 interfaces have
rather inconsistent naming, and they differ in the calling conventions
by passing the output either by reference or as a return value.

Rename them to ktime_get_coarse_real_ts64, ktime_get_coarse_ts64,
ktime_get_raw_ts64, ktime_get_boottime_ts64 and ktime_get_clocktai_ts64
respectively, and provide the interfaces with macros or inline
functions as needed.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: y2038@lists.linaro.org
Cc: John Stultz <john.stultz@linaro.org>
Link: https://lkml.kernel.org/r/20180427134016.2525989-4-arnd@arndb.de

---
 include/linux/timekeeping.h   | 43 ++++++++++++++++++++++++++++++++-----------
 include/linux/timekeeping32.h | 14 ++++++++++----
 kernel/time/timekeeping.c     | 23 +++++++++--------------
 3 files changed, 51 insertions(+), 29 deletions(-)

diff --git a/include/linux/timekeeping.h b/include/linux/timekeeping.h
index 415dae6bf1f5..3ef9791d7d75 100644
--- a/include/linux/timekeeping.h
+++ b/include/linux/timekeeping.h
@@ -19,25 +19,25 @@ extern void xtime_update(unsigned long ticks);
 extern int do_settimeofday64(const struct timespec64 *ts);
 extern int do_sys_settimeofday64(const struct timespec64 *tv,
 				 const struct timezone *tz);
-/*
- * Kernel time accessors
- */
-struct timespec64 current_kernel_time64(void);
 
 /*
  * timespec64 based interfaces
  */
-struct timespec64 get_monotonic_coarse64(void);
-extern void getrawmonotonic64(struct timespec64 *ts);
+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);
 
-extern void getboottime64(struct timespec64 *ts);
-
-
 /*
  * ktime_t based interfaces
  */
@@ -123,12 +123,12 @@ extern u64 ktime_get_real_fast_ns(void);
 /*
  * timespec64 interfaces utilizing the ktime based ones
  */
-static inline void get_monotonic_boottime64(struct timespec64 *ts)
+static inline void ktime_get_boottime_ts64(struct timespec64 *ts)
 {
 	*ts = ktime_to_timespec64(ktime_get_boottime());
 }
 
-static inline void timekeeping_clocktai64(struct timespec64 *ts)
+static inline void ktime_get_clocktai_ts64(struct timespec64 *ts)
 {
 	*ts = ktime_to_timespec64(ktime_get_clocktai());
 }
@@ -212,5 +212,26 @@ extern int update_persistent_clock64(struct timespec64 now);
  * deprecated aliases, don't use in new code
  */
 #define getnstimeofday64(ts)		ktime_get_real_ts64(ts)
+#define get_monotonic_boottime64(ts)	ktime_get_boottime_ts64(ts)
+#define getrawmonotonic64(ts)		ktime_get_raw_ts64(ts)
+#define timekeeping_clocktai64(ts)	ktime_get_clocktai_ts64(ts)
+
+static inline struct timespec64 current_kernel_time64(void)
+{
+	struct timespec64 ts;
+
+	ktime_get_coarse_real_ts64(&ts);
+
+	return ts;
+}
+
+static inline struct timespec64 get_monotonic_coarse64(void)
+{
+	struct timespec64 ts;
+
+	ktime_get_coarse_ts64(&ts);
+
+	return ts;
+}
 
 #endif
diff --git a/include/linux/timekeeping32.h b/include/linux/timekeeping32.h
index 5abff52d07fd..8762c2f45f8b 100644
--- a/include/linux/timekeeping32.h
+++ b/include/linux/timekeeping32.h
@@ -11,9 +11,11 @@ unsigned long get_seconds(void);
 
 static inline struct timespec current_kernel_time(void)
 {
-	struct timespec64 now = current_kernel_time64();
+	struct timespec64 ts64;
+
+	ktime_get_coarse_real_ts64(&ts64);
 
-	return timespec64_to_timespec(now);
+	return timespec64_to_timespec(ts64);
 }
 
 /**
@@ -55,13 +57,17 @@ static inline void getrawmonotonic(struct timespec *ts)
 {
 	struct timespec64 ts64;
 
-	getrawmonotonic64(&ts64);
+	ktime_get_raw_ts64(&ts64);
 	*ts = timespec64_to_timespec(ts64);
 }
 
 static inline struct timespec get_monotonic_coarse(void)
 {
-	return timespec64_to_timespec(get_monotonic_coarse64());
+	struct timespec64 ts64;
+
+	ktime_get_coarse_ts64(&ts64);
+
+	return timespec64_to_timespec(ts64);
 }
 
 static inline void getboottime(struct timespec *ts)
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 7bbc7a6e6095..ed9b74ec9c0b 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -1391,12 +1391,12 @@ int timekeeping_notify(struct clocksource *clock)
 }
 
 /**
- * getrawmonotonic64 - Returns the raw monotonic time in a timespec
+ * ktime_get_raw_ts64 - Returns the raw monotonic time in a timespec
  * @ts:		pointer to the timespec64 to be set
  *
  * Returns the raw monotonic time (completely un-modified by ntp)
  */
-void getrawmonotonic64(struct timespec64 *ts)
+void ktime_get_raw_ts64(struct timespec64 *ts)
 {
 	struct timekeeper *tk = &tk_core.timekeeper;
 	unsigned long seq;
@@ -1412,7 +1412,7 @@ void getrawmonotonic64(struct timespec64 *ts)
 	ts->tv_nsec = 0;
 	timespec64_add_ns(ts, nsecs);
 }
-EXPORT_SYMBOL(getrawmonotonic64);
+EXPORT_SYMBOL(ktime_get_raw_ts64);
 
 
 /**
@@ -2114,23 +2114,20 @@ unsigned long get_seconds(void)
 }
 EXPORT_SYMBOL(get_seconds);
 
-struct timespec64 current_kernel_time64(void)
+void ktime_get_coarse_real_ts64(struct timespec64 *ts)
 {
 	struct timekeeper *tk = &tk_core.timekeeper;
-	struct timespec64 now;
 	unsigned long seq;
 
 	do {
 		seq = read_seqcount_begin(&tk_core.seq);
 
-		now = tk_xtime(tk);
+		*ts = tk_xtime(tk);
 	} while (read_seqcount_retry(&tk_core.seq, seq));
-
-	return now;
 }
-EXPORT_SYMBOL(current_kernel_time64);
+EXPORT_SYMBOL(ktime_get_coarse_real_ts64);
 
-struct timespec64 get_monotonic_coarse64(void)
+void ktime_get_coarse_ts64(struct timespec64 *ts)
 {
 	struct timekeeper *tk = &tk_core.timekeeper;
 	struct timespec64 now, mono;
@@ -2143,12 +2140,10 @@ struct timespec64 get_monotonic_coarse64(void)
 		mono = tk->wall_to_monotonic;
 	} while (read_seqcount_retry(&tk_core.seq, seq));
 
-	set_normalized_timespec64(&now, now.tv_sec + mono.tv_sec,
+	set_normalized_timespec64(ts, now.tv_sec + mono.tv_sec,
 				now.tv_nsec + mono.tv_nsec);
-
-	return now;
 }
-EXPORT_SYMBOL(get_monotonic_coarse64);
+EXPORT_SYMBOL(ktime_get_coarse_ts64);
 
 /*
  * Must hold jiffies_lock

[tip:timers/2038] timekeeping: Add ktime_get_coarse_with_offset

[tip-bot for Arnd Bergmann]

Commit-ID:  b9ff604cff1135cc576cf952d394ed9401aa234b
Gitweb:     https://git.kernel.org/tip/b9ff604cff1135cc576cf952d394ed9401aa234b
Author:     Arnd Bergmann <arnd@arndb.de>
AuthorDate: Fri, 27 Apr 2018 15:40:15 +0200
Committer:  Thomas Gleixner <tglx@linutronix.de>
CommitDate: Sat, 19 May 2018 13:57:32 +0200

timekeeping: Add ktime_get_coarse_with_offset

I have run into a couple of drivers using current_kernel_time()
suffering from the y2038 problem, and they could be converted
to using ktime_t, but don't have interfaces that skip the nanosecond
calculation at the moment.

This introduces ktime_get_coarse_with_offset() as a simpler
variant of ktime_get_with_offset(), and adds wrappers for the
three time domains we support with the existing function.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: y2038@lists.linaro.org
Cc: John Stultz <john.stultz@linaro.org>
Link: https://lkml.kernel.org/r/20180427134016.2525989-5-arnd@arndb.de

---
 include/linux/timekeeping.h | 16 ++++++++++++++++
 kernel/time/timekeeping.c   | 19 +++++++++++++++++++
 2 files changed, 35 insertions(+)

diff --git a/include/linux/timekeeping.h b/include/linux/timekeeping.h
index 3ef9791d7d75..42f71f4b658a 100644
--- a/include/linux/timekeeping.h
+++ b/include/linux/timekeeping.h
@@ -51,6 +51,7 @@ enum tk_offsets {
 
 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);
@@ -63,6 +64,11 @@ 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
  *
@@ -74,6 +80,11 @@ 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
  */
@@ -82,6 +93,11 @@ 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);
+}
+
 /**
  * ktime_mono_to_real - Convert monotonic time to clock realtime
  */
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index ed9b74ec9c0b..4786df904c22 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -795,6 +795,25 @@ ktime_t ktime_get_with_offset(enum tk_offsets offs)
 }
 EXPORT_SYMBOL_GPL(ktime_get_with_offset);
 
+ktime_t ktime_get_coarse_with_offset(enum tk_offsets offs)
+{
+	struct timekeeper *tk = &tk_core.timekeeper;
+	unsigned int seq;
+	ktime_t base, *offset = offsets[offs];
+
+	WARN_ON(timekeeping_suspended);
+
+	do {
+		seq = read_seqcount_begin(&tk_core.seq);
+		base = ktime_add(tk->tkr_mono.base, *offset);
+
+	} while (read_seqcount_retry(&tk_core.seq, seq));
+
+	return base;
+
+}
+EXPORT_SYMBOL_GPL(ktime_get_coarse_with_offset);
+
 /**
  * ktime_mono_to_any() - convert mononotic time to any other time
  * @tmono:	time to convert.

[tip:timers/2038] timekeeping: Add more coarse clocktai/boottime interfaces

[tip-bot for Arnd Bergmann]

Commit-ID:  06aa376903b6e8c8741395a4702d78d47c7c27c6
Gitweb:     https://git.kernel.org/tip/06aa376903b6e8c8741395a4702d78d47c7c27c6
Author:     Arnd Bergmann <arnd@arndb.de>
AuthorDate: Fri, 27 Apr 2018 15:40:16 +0200
Committer:  Thomas Gleixner <tglx@linutronix.de>
CommitDate: Sat, 19 May 2018 13:57:33 +0200

timekeeping: Add more coarse clocktai/boottime interfaces

The set of APIs we provide has a few holes for coarse times, e.g. we
provide ktime_get_coarse_boottime() and ktime_get_boottime_ts64(),
but not the combination of the two.

This adds four new functions:

ktime_get_coarse_boottime_ts64()
ktime_get_boottime_seconds()
ktime_get_coarse_clocktai_ts64()
ktime_get_clocktai_seconds()

to fill in some of the missing pieces. I have missed only the
ktime_get_boottime_seconds() accessor in a few occasions in
the past, but it seems better to just provide all four together,
as there is very little cost to having them.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: y2038@lists.linaro.org
Cc: John Stultz <john.stultz@linaro.org>
Link: https://lkml.kernel.org/r/20180427134016.2525989-6-arnd@arndb.de

---
 include/linux/timekeeping.h | 24 +++++++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/include/linux/timekeeping.h b/include/linux/timekeeping.h
index 42f71f4b658a..86bc2026efce 100644
--- a/include/linux/timekeeping.h
+++ b/include/linux/timekeeping.h
@@ -137,18 +137,40 @@ extern u64 ktime_get_boot_fast_ns(void);
 extern u64 ktime_get_real_fast_ns(void);
 
 /*
- * timespec64 interfaces utilizing the ktime based ones
+ * 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);
+}
+
 /*
  * RTC specific
  */