Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer and time updates from Thomas Gleixner:
 "A rather large update of timers, timekeeping & co

   - Core timekeeping code is year-2038 safe now for 32bit machines.
     Now we just need to fix all in kernel users and the gazillion of
     user space interfaces which rely on timespec/timeval :)

   - Better cache layout for the timekeeping internal data structures.

   - Proper nanosecond based interfaces for in kernel users.

   - Tree wide cleanup of code which wants nanoseconds but does hoops
     and loops to convert back and forth from timespecs.  Some of it
     definitely belongs into the ugly code museum.

   - Consolidation of the timekeeping interface zoo.

   - A fast NMI safe accessor to clock monotonic for tracing.  This is a
     long standing request to support correlated user/kernel space
     traces.  With proper NTP frequency correction it's also suitable
     for correlation of traces accross separate machines.

   - Checkpoint/restart support for timerfd.

   - A few NOHZ[_FULL] improvements in the [hr]timer code.

   - Code move from kernel to kernel/time of all time* related code.

   - New clocksource/event drivers from the ARM universe.  I'm really
     impressed that despite an architected timer in the newer chips SoC
     manufacturers insist on inventing new and differently broken SoC
     specific timers.

[ Ed. "Impressed"? I don't think that word means what you think it means ]

   - Another round of code move from arch to drivers.  Looks like most
     of the legacy mess in ARM regarding timers is sorted out except for
     a few obnoxious strongholds.

   - The usual updates and fixlets all over the place"

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (114 commits)
  timekeeping: Fixup typo in update_vsyscall_old definition
  clocksource: document some basic timekeeping concepts
  timekeeping: Use cached ntp_tick_length when accumulating error
  timekeeping: Rework frequency adjustments to work better w/ nohz
  timekeeping: Minor fixup for timespec64->timespec assignment
  ftrace: Provide trace clocks monotonic
  timekeeping: Provide fast and NMI safe access to CLOCK_MONOTONIC
  seqcount: Add raw_write_seqcount_latch()
  seqcount: Provide raw_read_seqcount()
  timekeeping: Use tk_read_base as argument for timekeeping_get_ns()
  timekeeping: Create struct tk_read_base and use it in struct timekeeper
  timekeeping: Restructure the timekeeper some more
  clocksource: Get rid of cycle_last
  clocksource: Move cycle_last validation to core code
  clocksource: Make delta calculation a function
  wireless: ath9k: Get rid of timespec conversions
  drm: vmwgfx: Use nsec based interfaces
  drm: i915: Use nsec based interfaces
  timekeeping: Provide ktime_get_raw()
  hangcheck-timer: Use ktime_get_ns()
  ...

15 files changed, 583 insertions, 348 deletions

diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
index a16b497d5159..653f0e2b6ca9 100644
--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -162,7 +162,6 @@ extern u64 timecounter_cyc2time(struct timecounter *tc,
  * @archdata:		arch-specific data
  * @suspend:		suspend function for the clocksource, if necessary
  * @resume:		resume function for the clocksource, if necessary
- * @cycle_last:		most recent cycle counter value seen by ::read()
  * @owner:		module reference, must be set by clocksource in modules
  */
 struct clocksource {
@@ -171,7 +170,6 @@ struct clocksource {
 	 * clocksource itself is cacheline aligned.
 	 */
 	cycle_t (*read)(struct clocksource *cs);
-	cycle_t cycle_last;
 	cycle_t mask;
 	u32 mult;
 	u32 shift;
diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
index e7a8d3fa91d5..a036d058a249 100644
--- a/include/linux/hrtimer.h
+++ b/include/linux/hrtimer.h
@@ -165,6 +165,7 @@ enum  hrtimer_base_type {
  * struct hrtimer_cpu_base - the per cpu clock bases
  * @lock:		lock protecting the base and associated clock bases
  *			and timers
+ * @cpu:		cpu number
  * @active_bases:	Bitfield to mark bases with active timers
  * @clock_was_set:	Indicates that clock was set from irq context.
  * @expires_next:	absolute time of the next event which was scheduled
@@ -179,6 +180,7 @@ enum  hrtimer_base_type {
  */
 struct hrtimer_cpu_base {
 	raw_spinlock_t			lock;
+	unsigned int			cpu;
 	unsigned int			active_bases;
 	unsigned int			clock_was_set;
 #ifdef CONFIG_HIGH_RES_TIMERS
@@ -324,14 +326,6 @@ static inline void timerfd_clock_was_set(void) { }
 #endif
 extern void hrtimers_resume(void);
 
-extern ktime_t ktime_get(void);
-extern ktime_t ktime_get_real(void);
-extern ktime_t ktime_get_boottime(void);
-extern ktime_t ktime_get_monotonic_offset(void);
-extern ktime_t ktime_get_clocktai(void);
-extern ktime_t ktime_get_update_offsets(ktime_t *offs_real, ktime_t *offs_boot,
-					 ktime_t *offs_tai);
-
 DECLARE_PER_CPU(struct tick_device, tick_cpu_device);
 
 
@@ -452,12 +446,6 @@ extern void hrtimer_run_pending(void);
 /* Bootup initialization: */
 extern void __init hrtimers_init(void);
 
-#if BITS_PER_LONG < 64
-extern u64 ktime_divns(const ktime_t kt, s64 div);
-#else /* BITS_PER_LONG < 64 */
-# define ktime_divns(kt, div)		(u64)((kt).tv64 / (div))
-#endif
-
 /* Show pending timers: */
 extern void sysrq_timer_list_show(void);
 
diff --git a/include/linux/iio/iio.h b/include/linux/iio/iio.h
index ccde91725f98..15dc6bc2bdd2 100644
--- a/include/linux/iio/iio.h
+++ b/include/linux/iio/iio.h
@@ -277,14 +277,7 @@ static inline bool iio_channel_has_info(const struct iio_chan_spec *chan,
  **/
 static inline s64 iio_get_time_ns(void)
 {
-	struct timespec ts;
-	/*
-	 * calls getnstimeofday.
-	 * If hrtimers then up to ns accurate, if not microsecond.
-	 */
-	ktime_get_real_ts(&ts);
-
-	return timespec_to_ns(&ts);
+	return ktime_get_real_ns();
 }
 
 /* Device operating modes */
diff --git a/include/linux/io.h b/include/linux/io.h
index b76e6e545806..d5fc9b8d8b03 100644
--- a/include/linux/io.h
+++ b/include/linux/io.h
@@ -58,6 +58,8 @@ static inline void devm_ioport_unmap(struct device *dev, void __iomem *addr)
 }
 #endif
 
+#define IOMEM_ERR_PTR(err) (__force void __iomem *)ERR_PTR(err)
+
 void __iomem *devm_ioremap(struct device *dev, resource_size_t offset,
 			    unsigned long size);
 void __iomem *devm_ioremap_nocache(struct device *dev, resource_size_t offset,
diff --git a/include/linux/ktime.h b/include/linux/ktime.h
index de9e46e6bcc9..c9d645ad98ff 100644
--- a/include/linux/ktime.h
+++ b/include/linux/ktime.h
@@ -27,43 +27,19 @@
 /*
  * ktime_t:
  *
- * On 64-bit CPUs a single 64-bit variable is used to store the hrtimers
+ * A single 64-bit variable is used to store the hrtimers
  * internal representation of time values in scalar nanoseconds. The
  * design plays out best on 64-bit CPUs, where most conversions are
  * NOPs and most arithmetic ktime_t operations are plain arithmetic
  * operations.
  *
- * On 32-bit CPUs an optimized representation of the timespec structure
- * is used to avoid expensive conversions from and to timespecs. The
- * endian-aware order of the tv struct members is chosen to allow
- * mathematical operations on the tv64 member of the union too, which
- * for certain operations produces better code.
- *
- * For architectures with efficient support for 64/32-bit conversions the
- * plain scalar nanosecond based representation can be selected by the
- * config switch CONFIG_KTIME_SCALAR.
  */
 union ktime {
 	s64	tv64;
-#if BITS_PER_LONG != 64 && !defined(CONFIG_KTIME_SCALAR)
-	struct {
-# ifdef __BIG_ENDIAN
-	s32	sec, nsec;
-# else
-	s32	nsec, sec;
-# endif
-	} tv;
-#endif
 };
 
 typedef union ktime ktime_t;		/* Kill this */
 
-/*
- * ktime_t definitions when using the 64-bit scalar representation:
- */
-
-#if (BITS_PER_LONG == 64) || defined(CONFIG_KTIME_SCALAR)
-
 /**
  * ktime_set - Set a ktime_t variable from a seconds/nanoseconds value
  * @secs:	seconds to set
@@ -71,13 +47,12 @@ typedef union ktime ktime_t;		/* Kill this */
  *
  * Return: The ktime_t representation of the value.
  */
-static inline ktime_t ktime_set(const long secs, const unsigned long nsecs)
+static inline ktime_t ktime_set(const s64 secs, const unsigned long nsecs)
 {
-#if (BITS_PER_LONG == 64)
 	if (unlikely(secs >= KTIME_SEC_MAX))
 		return (ktime_t){ .tv64 = KTIME_MAX };
-#endif
-	return (ktime_t) { .tv64 = (s64)secs * NSEC_PER_SEC + (s64)nsecs };
+
+	return (ktime_t) { .tv64 = secs * NSEC_PER_SEC + (s64)nsecs };
 }
 
 /* Subtract two ktime_t variables. rem = lhs -rhs: */
@@ -108,6 +83,12 @@ static inline ktime_t timespec_to_ktime(struct timespec ts)
 	return ktime_set(ts.tv_sec, ts.tv_nsec);
 }
 
+/* convert a timespec64 to ktime_t format: */
+static inline ktime_t timespec64_to_ktime(struct timespec64 ts)
+{
+	return ktime_set(ts.tv_sec, ts.tv_nsec);
+}
+
 /* convert a timeval to ktime_t format: */
 static inline ktime_t timeval_to_ktime(struct timeval tv)
 {
@@ -117,159 +98,15 @@ static inline ktime_t timeval_to_ktime(struct timeval tv)
 /* Map the ktime_t to timespec conversion to ns_to_timespec function */
 #define ktime_to_timespec(kt)		ns_to_timespec((kt).tv64)
 
+/* Map the ktime_t to timespec conversion to ns_to_timespec function */
+#define ktime_to_timespec64(kt)		ns_to_timespec64((kt).tv64)
+
 /* Map the ktime_t to timeval conversion to ns_to_timeval function */
 #define ktime_to_timeval(kt)		ns_to_timeval((kt).tv64)
 
 /* Convert ktime_t to nanoseconds - NOP in the scalar storage format: */
 #define ktime_to_ns(kt)			((kt).tv64)
 
-#else	/* !((BITS_PER_LONG == 64) || defined(CONFIG_KTIME_SCALAR)) */
-
-/*
- * Helper macros/inlines to get the ktime_t math right in the timespec
- * representation. The macros are sometimes ugly - their actual use is
- * pretty okay-ish, given the circumstances. We do all this for
- * performance reasons. The pure scalar nsec_t based code was nice and
- * simple, but created too many 64-bit / 32-bit conversions and divisions.
- *
- * Be especially aware that negative values are represented in a way
- * that the tv.sec field is negative and the tv.nsec field is greater
- * or equal to zero but less than nanoseconds per second. This is the
- * same representation which is used by timespecs.
- *
- *   tv.sec < 0 and 0 >= tv.nsec < NSEC_PER_SEC
- */
-
-/* Set a ktime_t variable to a value in sec/nsec representation: */
-static inline ktime_t ktime_set(const long secs, const unsigned long nsecs)
-{
-	return (ktime_t) { .tv = { .sec = secs, .nsec = nsecs } };
-}
-
-/**
- * ktime_sub - subtract two ktime_t variables
- * @lhs:	minuend
- * @rhs:	subtrahend
- *
- * Return: The remainder of the subtraction.
- */
-static inline ktime_t ktime_sub(const ktime_t lhs, const ktime_t rhs)
-{
-	ktime_t res;
-
-	res.tv64 = lhs.tv64 - rhs.tv64;
-	if (res.tv.nsec < 0)
-		res.tv.nsec += NSEC_PER_SEC;
-
-	return res;
-}
-
-/**
- * ktime_add - add two ktime_t variables
- * @add1:	addend1
- * @add2:	addend2
- *
- * Return: The sum of @add1 and @add2.
- */
-static inline ktime_t ktime_add(const ktime_t add1, const ktime_t add2)
-{
-	ktime_t res;
-
-	res.tv64 = add1.tv64 + add2.tv64;
-	/*
-	 * performance trick: the (u32) -NSEC gives 0x00000000Fxxxxxxx
-	 * so we subtract NSEC_PER_SEC and add 1 to the upper 32 bit.
-	 *
-	 * it's equivalent to:
-	 *   tv.nsec -= NSEC_PER_SEC
-	 *   tv.sec ++;
-	 */
-	if (res.tv.nsec >= NSEC_PER_SEC)
-		res.tv64 += (u32)-NSEC_PER_SEC;
-
-	return res;
-}
-
-/**
- * ktime_add_ns - Add a scalar nanoseconds value to a ktime_t variable
- * @kt:		addend
- * @nsec:	the scalar nsec value to add
- *
- * Return: The sum of @kt and @nsec in ktime_t format.
- */
-extern ktime_t ktime_add_ns(const ktime_t kt, u64 nsec);
-
-/**
- * ktime_sub_ns - Subtract a scalar nanoseconds value from a ktime_t variable
- * @kt:		minuend
- * @nsec:	the scalar nsec value to subtract
- *
- * Return: The subtraction of @nsec from @kt in ktime_t format.
- */
-extern ktime_t ktime_sub_ns(const ktime_t kt, u64 nsec);
-
-/**
- * timespec_to_ktime - convert a timespec to ktime_t format
- * @ts:		the timespec variable to convert
- *
- * Return: A ktime_t variable with the converted timespec value.
- */
-static inline ktime_t timespec_to_ktime(const struct timespec ts)
-{
-	return (ktime_t) { .tv = { .sec = (s32)ts.tv_sec,
-			   	   .nsec = (s32)ts.tv_nsec } };
-}
-
-/**
- * timeval_to_ktime - convert a timeval to ktime_t format
- * @tv:		the timeval variable to convert
- *
- * Return: A ktime_t variable with the converted timeval value.
- */
-static inline ktime_t timeval_to_ktime(const struct timeval tv)
-{
-	return (ktime_t) { .tv = { .sec = (s32)tv.tv_sec,
-				   .nsec = (s32)(tv.tv_usec *
-						 NSEC_PER_USEC) } };
-}
-
-/**
- * ktime_to_timespec - convert a ktime_t variable to timespec format
- * @kt:		the ktime_t variable to convert
- *
- * Return: The timespec representation of the ktime value.
- */
-static inline struct timespec ktime_to_timespec(const ktime_t kt)
-{
-	return (struct timespec) { .tv_sec = (time_t) kt.tv.sec,
-				   .tv_nsec = (long) kt.tv.nsec };
-}
-
-/**
- * ktime_to_timeval - convert a ktime_t variable to timeval format
- * @kt:		the ktime_t variable to convert
- *
- * Return: The timeval representation of the ktime value.
- */
-static inline struct timeval ktime_to_timeval(const ktime_t kt)
-{
-	return (struct timeval) {
-		.tv_sec = (time_t) kt.tv.sec,
-		.tv_usec = (suseconds_t) (kt.tv.nsec / NSEC_PER_USEC) };
-}
-
-/**
- * ktime_to_ns - convert a ktime_t variable to scalar nanoseconds
- * @kt:		the ktime_t variable to convert
- *
- * Return: The scalar nanoseconds representation of @kt.
- */
-static inline s64 ktime_to_ns(const ktime_t kt)
-{
-	return (s64) kt.tv.sec * NSEC_PER_SEC + kt.tv.nsec;
-}
-
-#endif	/* !((BITS_PER_LONG == 64) || defined(CONFIG_KTIME_SCALAR)) */
 
 /**
  * ktime_equal - Compares two ktime_t variables to see if they are equal
@@ -328,16 +165,20 @@ static inline bool ktime_before(const ktime_t cmp1, const ktime_t cmp2)
 	return ktime_compare(cmp1, cmp2) < 0;
 }
 
+#if BITS_PER_LONG < 64
+extern u64 ktime_divns(const ktime_t kt, s64 div);
+#else /* BITS_PER_LONG < 64 */
+# define ktime_divns(kt, div)		(u64)((kt).tv64 / (div))
+#endif
+
 static inline s64 ktime_to_us(const ktime_t kt)
 {
-	struct timeval tv = ktime_to_timeval(kt);
-	return (s64) tv.tv_sec * USEC_PER_SEC + tv.tv_usec;
+	return ktime_divns(kt, NSEC_PER_USEC);
 }
 
 static inline s64 ktime_to_ms(const ktime_t kt)
 {
-	struct timeval tv = ktime_to_timeval(kt);
-	return (s64) tv.tv_sec * MSEC_PER_SEC + tv.tv_usec / USEC_PER_MSEC;
+	return ktime_divns(kt, NSEC_PER_MSEC);
 }
 
 static inline s64 ktime_us_delta(const ktime_t later, const ktime_t earlier)
@@ -381,6 +222,25 @@ static inline __must_check bool ktime_to_timespec_cond(const ktime_t kt,
 	}
 }
 
+/**
+ * ktime_to_timespec64_cond - convert a ktime_t variable to timespec64
+ *			    format only if the variable contains data
+ * @kt:		the ktime_t variable to convert
+ * @ts:		the timespec variable to store the result in
+ *
+ * Return: %true if there was a successful conversion, %false if kt was 0.
+ */
+static inline __must_check bool ktime_to_timespec64_cond(const ktime_t kt,
+						       struct timespec64 *ts)
+{
+	if (kt.tv64) {
+		*ts = ktime_to_timespec64(kt);
+		return true;
+	} else {
+		return false;
+	}
+}
+
 /*
  * The resolution of the clocks. The resolution value is returned in
  * the clock_getres() system call to give application programmers an
@@ -390,12 +250,6 @@ static inline __must_check bool ktime_to_timespec_cond(const ktime_t kt,
 #define LOW_RES_NSEC		TICK_NSEC
 #define KTIME_LOW_RES		(ktime_t){ .tv64 = LOW_RES_NSEC }
 
-/* Get the monotonic time in timespec format: */
-extern void ktime_get_ts(struct timespec *ts);
-
-/* Get the real (wall-) time in timespec format: */
-#define ktime_get_real_ts(ts)	getnstimeofday(ts)
-
 static inline ktime_t ns_to_ktime(u64 ns)
 {
 	static const ktime_t ktime_zero = { .tv64 = 0 };
@@ -410,4 +264,6 @@ static inline ktime_t ms_to_ktime(u64 ms)
 	return ktime_add_ms(ktime_zero, ms);
 }
 
+# include <linux/timekeeping.h>
+
 #endif
diff --git a/include/linux/mlx5/driver.h b/include/linux/mlx5/driver.h
index 2bce4aad2570..52d631ca32cf 100644
--- a/include/linux/mlx5/driver.h
+++ b/include/linux/mlx5/driver.h
@@ -604,8 +604,8 @@ struct mlx5_cmd_work_ent {
 	int			page_queue;
 	u8			status;
 	u8			token;
-	struct timespec		ts1;
-	struct timespec		ts2;
+	u64			ts1;
+	u64			ts2;
 	u16			op;
 };
 
diff --git a/include/linux/of_address.h b/include/linux/of_address.h
index c13b8782a4eb..fb7b7221e063 100644
--- a/include/linux/of_address.h
+++ b/include/linux/of_address.h
@@ -109,7 +109,12 @@ static inline bool of_dma_is_coherent(struct device_node *np)
 extern int of_address_to_resource(struct device_node *dev, int index,
 				  struct resource *r);
 void __iomem *of_iomap(struct device_node *node, int index);
+void __iomem *of_io_request_and_map(struct device_node *device,
+					int index, char *name);
 #else
+
+#include <linux/io.h>
+
 static inline int of_address_to_resource(struct device_node *dev, int index,
 					 struct resource *r)
 {
@@ -120,6 +125,12 @@ static inline void __iomem *of_iomap(struct device_node *device, int index)
 {
 	return NULL;
 }
+
+static inline void __iomem *of_io_request_and_map(struct device_node *device,
+					int index, char *name)
+{
+	return IOMEM_ERR_PTR(-EINVAL);
+}
 #endif
 
 #if defined(CONFIG_OF_ADDRESS) && defined(CONFIG_PCI)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 42cac4dc2157..66124d63371a 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -813,7 +813,7 @@ struct task_delay_info {
 	 * associated with the operation is added to XXX_delay.
 	 * XXX_delay contains the accumulated delay time in nanoseconds.
 	 */
-	struct timespec blkio_start, blkio_end;	/* Shared by blkio, swapin */
+	u64 blkio_start;	/* Shared by blkio, swapin */
 	u64 blkio_delay;	/* wait for sync block io completion */
 	u64 swapin_delay;	/* wait for swapin block io completion */
 	u32 blkio_count;	/* total count of the number of sync block */
@@ -821,7 +821,7 @@ struct task_delay_info {
 	u32 swapin_count;	/* total count of the number of swapin block */
 				/* io operations performed */
 
-	struct timespec freepages_start, freepages_end;
+	u64 freepages_start;
 	u64 freepages_delay;	/* wait for memory reclaim */
 	u32 freepages_count;	/* total count of memory reclaim */
 };
@@ -1364,8 +1364,8 @@ struct task_struct {
 	} vtime_snap_whence;
 #endif
 	unsigned long nvcsw, nivcsw; /* context switch counts */
-	struct timespec start_time; 		/* monotonic time */
-	struct timespec real_start_time;	/* boot based time */
+	u64 start_time;		/* monotonic time in nsec */
+	u64 real_start_time;	/* boot based time in nsec */
 /* mm fault and swap info: this can arguably be seen as either mm-specific or thread-specific */
 	unsigned long min_flt, maj_flt;
 
diff --git a/include/linux/seqlock.h b/include/linux/seqlock.h
index 8cf350325dc6..cc359636cfa3 100644
--- a/include/linux/seqlock.h
+++ b/include/linux/seqlock.h
@@ -117,6 +117,22 @@ repeat:
 }
 
 /**
+ * raw_read_seqcount - Read the raw seqcount
+ * @s: pointer to seqcount_t
+ * Returns: count to be passed to read_seqcount_retry
+ *
+ * raw_read_seqcount opens a read critical section of the given
+ * seqcount without any lockdep checking and without checking or
+ * masking the LSB. Calling code is responsible for handling that.
+ */
+static inline unsigned raw_read_seqcount(const seqcount_t *s)
+{
+	unsigned ret = ACCESS_ONCE(s->sequence);
+	smp_rmb();
+	return ret;
+}
+
+/**
  * raw_read_seqcount_begin - start seq-read critical section w/o lockdep
  * @s: pointer to seqcount_t
  * Returns: count to be passed to read_seqcount_retry
@@ -218,6 +234,17 @@ static inline void raw_write_seqcount_end(seqcount_t *s)
 }
 
 /*
+ * raw_write_seqcount_latch - redirect readers to even/odd copy
+ * @s: pointer to seqcount_t
+ */
+static inline void raw_write_seqcount_latch(seqcount_t *s)
+{
+       smp_wmb();      /* prior stores before incrementing "sequence" */
+       s->sequence++;
+       smp_wmb();      /* increment "sequence" before following stores */
+}
+
+/*
  * Sequence counter only version assumes that callers are using their
  * own mutexing.
  */
diff --git a/include/linux/sh_timer.h b/include/linux/sh_timer.h
index 8e1e036d6d45..64638b058076 100644
--- a/include/linux/sh_timer.h
+++ b/include/linux/sh_timer.h
@@ -2,11 +2,6 @@
 #define __SH_TIMER_H__
 
 struct sh_timer_config {
-	char *name;
-	long channel_offset;
-	int timer_bit;
-	unsigned long clockevent_rating;
-	unsigned long clocksource_rating;
 	unsigned int channels_mask;
 };
 
diff --git a/include/linux/time.h b/include/linux/time.h
index d5d229b2e5af..8c42cf8d2444 100644
--- a/include/linux/time.h
+++ b/include/linux/time.h
@@ -4,19 +4,10 @@
 # include <linux/cache.h>
 # include <linux/seqlock.h>
 # include <linux/math64.h>
-#include <uapi/linux/time.h>
+# include <linux/time64.h>
 
 extern struct timezone sys_tz;
 
-/* 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
-
 #define TIME_T_MAX	(time_t)((1UL << ((sizeof(time_t) << 3) - 1)) - 1)
 
 static inline int timespec_equal(const struct timespec *a,
@@ -84,13 +75,6 @@ static inline struct timespec timespec_sub(struct timespec lhs,
 	return ts_delta;
 }
 
-#define KTIME_MAX			((s64)~((u64)1 << 63))
-#if (BITS_PER_LONG == 64)
-# define KTIME_SEC_MAX			(KTIME_MAX / NSEC_PER_SEC)
-#else
-# define KTIME_SEC_MAX			LONG_MAX
-#endif
-
 /*
  * Returns true if the timespec is norm, false if denorm:
  */
@@ -115,27 +99,7 @@ static inline bool timespec_valid_strict(const struct timespec *ts)
 	return true;
 }
 
-extern bool persistent_clock_exist;
-
-static inline bool has_persistent_clock(void)
-{
-	return persistent_clock_exist;
-}
-
-extern void read_persistent_clock(struct timespec *ts);
-extern void read_boot_clock(struct timespec *ts);
-extern int persistent_clock_is_local;
-extern int update_persistent_clock(struct timespec now);
-void timekeeping_init(void);
-extern int timekeeping_suspended;
-
-unsigned long get_seconds(void);
-struct timespec current_kernel_time(void);
-struct timespec __current_kernel_time(void); /* does not take xtime_lock */
-struct timespec get_monotonic_coarse(void);
-void get_xtime_and_monotonic_and_sleep_offset(struct timespec *xtim,
-				struct timespec *wtom, struct timespec *sleep);
-void timekeeping_inject_sleeptime(struct timespec *delta);
+extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
 
 #define CURRENT_TIME		(current_kernel_time())
 #define CURRENT_TIME_SEC	((struct timespec) { get_seconds(), 0 })
@@ -153,33 +117,14 @@ void timekeeping_inject_sleeptime(struct timespec *delta);
 extern u32 (*arch_gettimeoffset)(void);
 #endif
 
-extern void do_gettimeofday(struct timeval *tv);
-extern int do_settimeofday(const struct timespec *tv);
-extern int do_sys_settimeofday(const struct timespec *tv,
-			       const struct timezone *tz);
-#define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts)
-extern long do_utimes(int dfd, const char __user *filename, struct timespec *times, int flags);
 struct itimerval;
 extern int do_setitimer(int which, struct itimerval *value,
 			struct itimerval *ovalue);
-extern unsigned int alarm_setitimer(unsigned int seconds);
 extern int do_getitimer(int which, struct itimerval *value);
-extern int __getnstimeofday(struct timespec *tv);
-extern void getnstimeofday(struct timespec *tv);
-extern void getrawmonotonic(struct timespec *ts);
-extern void getnstime_raw_and_real(struct timespec *ts_raw,
-		struct timespec *ts_real);
-extern void getboottime(struct timespec *ts);
-extern void monotonic_to_bootbased(struct timespec *ts);
-extern void get_monotonic_boottime(struct timespec *ts);
 
-extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
-extern int timekeeping_valid_for_hres(void);
-extern u64 timekeeping_max_deferment(void);
-extern int timekeeping_inject_offset(struct timespec *ts);
-extern s32 timekeeping_get_tai_offset(void);
-extern void timekeeping_set_tai_offset(s32 tai_offset);
-extern void timekeeping_clocktai(struct timespec *ts);
+extern unsigned int alarm_setitimer(unsigned int seconds);
+
+extern long do_utimes(int dfd, const char __user *filename, struct timespec *times, int flags);
 
 struct tms;
 extern void do_sys_times(struct tms *);
diff --git a/include/linux/time64.h b/include/linux/time64.h
new file mode 100644
index 000000000000..a3831478d9cf
--- /dev/null
+++ b/include/linux/time64.h
@@ -0,0 +1,190 @@
+#ifndef _LINUX_TIME64_H
+#define _LINUX_TIME64_H
+
+#include <uapi/linux/time.h>
+
+typedef __s64 time64_t;
+
+/*
+ * This wants to go into uapi/linux/time.h once we agreed about the
+ * userspace interfaces.
+ */
+#if __BITS_PER_LONG == 64
+# define timespec64 timespec
+#else
+struct timespec64 {
+	time64_t	tv_sec;			/* seconds */
+	long		tv_nsec;		/* nanoseconds */
+};
+#endif
+
+/* 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 KTIME_MAX			((s64)~((u64)1 << 63))
+#define KTIME_SEC_MAX			(KTIME_MAX / NSEC_PER_SEC)
+
+#if __BITS_PER_LONG == 64
+
+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 timespec64_equal		timespec_equal
+# define timespec64_compare		timespec_compare
+# define set_normalized_timespec64	set_normalized_timespec
+# define timespec64_add_safe		timespec_add_safe
+# define timespec64_add			timespec_add
+# define timespec64_sub			timespec_sub
+# define timespec64_valid		timespec_valid
+# define timespec64_valid_strict	timespec_valid_strict
+# define timespec64_to_ns		timespec_to_ns
+# define ns_to_timespec64		ns_to_timespec
+# define timespec64_add_ns		timespec_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 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);
+
+/*
+ * timespec64_add_safe assumes both values are positive and checks for
+ * overflow. It will return TIME_T_MAX if the returned value would be
+ * smaller then either of the arguments.
+ */
+extern struct timespec64 timespec64_add_safe(const struct timespec64 lhs,
+					 const struct timespec64 rhs);
+
+
+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;
+}
+
+#endif
+
+#endif /* _LINUX_TIME64_H */
diff --git a/include/linux/timekeeper_internal.h b/include/linux/timekeeper_internal.h
index c1825eb436ed..95640dcd1899 100644
--- a/include/linux/timekeeper_internal.h
+++ b/include/linux/timekeeper_internal.h
@@ -10,77 +10,100 @@
 #include <linux/jiffies.h>
 #include <linux/time.h>
 
-/* Structure holding internal timekeeping values. */
-struct timekeeper {
-	/* Current clocksource used for timekeeping. */
+/**
+ * struct tk_read_base - base structure for timekeeping readout
+ * @clock:	Current clocksource used for timekeeping.
+ * @read:	Read function of @clock
+ * @mask:	Bitmask for two's complement subtraction of non 64bit clocks
+ * @cycle_last: @clock cycle value at last update
+ * @mult:	NTP adjusted multiplier for scaled math conversion
+ * @shift:	Shift value for scaled math conversion
+ * @xtime_nsec: Shifted (fractional) nano seconds offset for readout
+ * @base_mono:  ktime_t (nanoseconds) base time for readout
+ *
+ * This struct has size 56 byte on 64 bit. Together with a seqcount it
+ * occupies a single 64byte cache line.
+ *
+ * The struct is separate from struct timekeeper as it is also used
+ * for a fast NMI safe accessor to clock monotonic.
+ */
+struct tk_read_base {
 	struct clocksource	*clock;
-	/* NTP adjusted clock multiplier */
+	cycle_t			(*read)(struct clocksource *cs);
+	cycle_t			mask;
+	cycle_t			cycle_last;
 	u32			mult;
-	/* The shift value of the current clocksource. */
 	u32			shift;
-	/* Number of clock cycles in one NTP interval. */
+	u64			xtime_nsec;
+	ktime_t			base_mono;
+};
+
+/**
+ * struct timekeeper - Structure holding internal timekeeping values.
+ * @tkr:		The readout base structure
+ * @xtime_sec:		Current CLOCK_REALTIME time in seconds
+ * @wall_to_monotonic:	CLOCK_REALTIME to CLOCK_MONOTONIC offset
+ * @offs_real:		Offset clock monotonic -> clock realtime
+ * @offs_boot:		Offset clock monotonic -> clock boottime
+ * @offs_tai:		Offset clock monotonic -> clock tai
+ * @tai_offset:		The current UTC to TAI offset in seconds
+ * @base_raw:		Monotonic raw base time in ktime_t format
+ * @raw_time:		Monotonic raw base time in timespec64 format
+ * @cycle_interval:	Number of clock cycles in one NTP interval
+ * @xtime_interval:	Number of clock shifted nano seconds in one NTP
+ *			interval.
+ * @xtime_remainder:	Shifted nano seconds left over when rounding
+ *			@cycle_interval
+ * @raw_interval:	Raw nano seconds accumulated per NTP interval.
+ * @ntp_error:		Difference between accumulated time and NTP time in ntp
+ *			shifted nano seconds.
+ * @ntp_error_shift:	Shift conversion between clock shifted nano seconds and
+ *			ntp shifted nano seconds.
+ *
+ * Note: For timespec(64) based interfaces wall_to_monotonic is what
+ * we need to add to xtime (or xtime corrected for sub jiffie times)
+ * to get to monotonic time.  Monotonic is pegged at zero at system
+ * boot time, so wall_to_monotonic will be negative, however, we will
+ * ALWAYS keep the tv_nsec part positive so we can use the usual
+ * normalization.
+ *
+ * wall_to_monotonic is moved after resume from suspend for the
+ * monotonic time not to jump. We need to add total_sleep_time to
+ * wall_to_monotonic to get the real boot based time offset.
+ *
+ * wall_to_monotonic is no longer the boot time, getboottime must be
+ * used instead.
+ */
+struct timekeeper {
+	struct tk_read_base	tkr;
+	u64			xtime_sec;
+	struct timespec64	wall_to_monotonic;
+	ktime_t			offs_real;
+	ktime_t			offs_boot;
+	ktime_t			offs_tai;
+	s32			tai_offset;
+	ktime_t			base_raw;
+	struct timespec64	raw_time;
+
+	/* The following members are for timekeeping internal use */
 	cycle_t			cycle_interval;
-	/* Last cycle value (also stored in clock->cycle_last) */
-	cycle_t			cycle_last;
-	/* Number of clock shifted nano seconds in one NTP interval. */
 	u64			xtime_interval;
-	/* shifted nano seconds left over when rounding cycle_interval */
 	s64			xtime_remainder;
-	/* Raw nano seconds accumulated per NTP interval. */
 	u32			raw_interval;
-
-	/* Current CLOCK_REALTIME time in seconds */
-	u64			xtime_sec;
-	/* Clock shifted nano seconds */
-	u64			xtime_nsec;
-
+	/* The ntp_tick_length() value currently being used.
+	 * This cached copy ensures we consistently apply the tick
+	 * length for an entire tick, as ntp_tick_length may change
+	 * mid-tick, and we don't want to apply that new value to
+	 * the tick in progress.
+	 */
+	u64			ntp_tick;
 	/* Difference between accumulated time and NTP time in ntp
 	 * shifted nano seconds. */
 	s64			ntp_error;
-	/* Shift conversion between clock shifted nano seconds and
-	 * ntp shifted nano seconds. */
 	u32			ntp_error_shift;
-
-	/*
-	 * wall_to_monotonic is what we need to add to xtime (or xtime corrected
-	 * for sub jiffie times) to get to monotonic time.  Monotonic is pegged
-	 * at zero at system boot time, so wall_to_monotonic will be negative,
-	 * however, we will ALWAYS keep the tv_nsec part positive so we can use
-	 * the usual normalization.
-	 *
-	 * wall_to_monotonic is moved after resume from suspend for the
-	 * monotonic time not to jump. We need to add total_sleep_time to
-	 * wall_to_monotonic to get the real boot based time offset.
-	 *
-	 * - wall_to_monotonic is no longer the boot time, getboottime must be
-	 * used instead.
-	 */
-	struct timespec		wall_to_monotonic;
-	/* Offset clock monotonic -> clock realtime */
-	ktime_t			offs_real;
-	/* time spent in suspend */
-	struct timespec		total_sleep_time;
-	/* Offset clock monotonic -> clock boottime */
-	ktime_t			offs_boot;
-	/* The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock. */
-	struct timespec		raw_time;
-	/* The current UTC to TAI offset in seconds */
-	s32			tai_offset;
-	/* Offset clock monotonic -> clock tai */
-	ktime_t			offs_tai;
-
+	u32			ntp_err_mult;
 };
 
-static inline struct timespec tk_xtime(struct timekeeper *tk)
-{
-	struct timespec ts;
-
-	ts.tv_sec = tk->xtime_sec;
-	ts.tv_nsec = (long)(tk->xtime_nsec >> tk->shift);
-	return ts;
-}
-
-
 #ifdef CONFIG_GENERIC_TIME_VSYSCALL
 
 extern void update_vsyscall(struct timekeeper *tk);
@@ -89,17 +112,10 @@ extern void update_vsyscall_tz(void);
 #elif defined(CONFIG_GENERIC_TIME_VSYSCALL_OLD)
 
 extern void update_vsyscall_old(struct timespec *ts, struct timespec *wtm,
-				struct clocksource *c, u32 mult);
+				struct clocksource *c, u32 mult,
+				cycle_t cycle_last);
 extern void update_vsyscall_tz(void);
 
-static inline void update_vsyscall(struct timekeeper *tk)
-{
-	struct timespec xt;
-
-	xt = tk_xtime(tk);
-	update_vsyscall_old(&xt, &tk->wall_to_monotonic, tk->clock, tk->mult);
-}
-
 #else
 
 static inline void update_vsyscall(struct timekeeper *tk)
diff --git a/include/linux/timekeeping.h b/include/linux/timekeeping.h
new file mode 100644
index 000000000000..1caa6b04fdc5
--- /dev/null
+++ b/include/linux/timekeeping.h
@@ -0,0 +1,209 @@
+#ifndef _LINUX_TIMEKEEPING_H
+#define _LINUX_TIMEKEEPING_H
+
+/* Included from linux/ktime.h */
+
+void timekeeping_init(void);
+extern int timekeeping_suspended;
+
+/*
+ * Get and set timeofday
+ */
+extern void do_gettimeofday(struct timeval *tv);
+extern int do_settimeofday(const struct timespec *tv);
+extern int do_sys_settimeofday(const struct timespec *tv,
+			       const struct timezone *tz);
+
+/*
+ * Kernel time accessors
+ */
+unsigned long get_seconds(void);
+struct timespec current_kernel_time(void);
+/* does not take xtime_lock */
+struct timespec __current_kernel_time(void);
+
+/*
+ * timespec based interfaces
+ */
+struct timespec get_monotonic_coarse(void);
+extern void getrawmonotonic(struct timespec *ts);
+extern void ktime_get_ts64(struct timespec64 *ts);
+
+extern int __getnstimeofday64(struct timespec64 *tv);
+extern void getnstimeofday64(struct timespec64 *tv);
+
+#if BITS_PER_LONG == 64
+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);
+}
+
+#else
+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);
+	*ts = timespec64_to_timespec(ts64);
+}
+
+static inline void ktime_get_ts(struct timespec *ts)
+{
+	struct timespec64 ts64;
+
+	ktime_get_ts64(&ts64);
+	*ts = timespec64_to_timespec(ts64);
+}
+
+static inline void ktime_get_real_ts(struct timespec *ts)
+{
+	struct timespec64 ts64;
+
+	getnstimeofday64(&ts64);
+	*ts = timespec64_to_timespec(ts64);
+}
+#endif
+
+extern void getboottime(struct timespec *ts);
+
+#define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts)
+#define ktime_get_real_ts64(ts)	getnstimeofday64(ts)
+
+/*
+ * 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_mono_to_any(ktime_t tmono, enum tk_offsets offs);
+extern ktime_t ktime_get_raw(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);
+}
+
+/**
+ * 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);
+}
+
+/**
+ * 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);
+}
+
+/**
+ * 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_boot_ns(void)
+{
+	return ktime_to_ns(ktime_get_boottime());
+}
+
+static inline u64 ktime_get_raw_ns(void)
+{
+	return ktime_to_ns(ktime_get_raw());
+}
+
+extern u64 ktime_get_mono_fast_ns(void);
+
+/*
+ * Timespec interfaces utilizing the ktime based ones
+ */
+static inline void get_monotonic_boottime(struct timespec *ts)
+{
+	*ts = ktime_to_timespec(ktime_get_boottime());
+}
+
+static inline void timekeeping_clocktai(struct timespec *ts)
+{
+	*ts = ktime_to_timespec(ktime_get_clocktai());
+}
+
+/*
+ * RTC specific
+ */
+extern void timekeeping_inject_sleeptime(struct timespec *delta);
+
+/*
+ * PPS accessor
+ */
+extern void getnstime_raw_and_real(struct timespec *ts_raw,
+				   struct timespec *ts_real);
+
+/*
+ * Persistent clock related interfaces
+ */
+extern bool persistent_clock_exist;
+extern int persistent_clock_is_local;
+
+static inline bool has_persistent_clock(void)
+{
+	return persistent_clock_exist;
+}
+
+extern void read_persistent_clock(struct timespec *ts);
+extern void read_boot_clock(struct timespec *ts);
+extern int update_persistent_clock(struct timespec now);
+
+
+#endif
diff --git a/include/linux/timerfd.h b/include/linux/timerfd.h
index d3b57fa12225..bd36ce431e32 100644
--- a/include/linux/timerfd.h
+++ b/include/linux/timerfd.h
@@ -11,6 +11,9 @@
 /* For O_CLOEXEC and O_NONBLOCK */
 #include <linux/fcntl.h>
 
+/* For _IO helpers */
+#include <linux/ioctl.h>
+
 /*
  * CAREFUL: Check include/asm-generic/fcntl.h when defining
  * new flags, since they might collide with O_* ones. We want
@@ -29,4 +32,6 @@
 /* Flags for timerfd_settime.  */
 #define TFD_SETTIME_FLAGS (TFD_TIMER_ABSTIME | TFD_TIMER_CANCEL_ON_SET)
 
+#define TFD_IOC_SET_TICKS	_IOW('T', 0, u64)
+
 #endif /* _LINUX_TIMERFD_H */