The only user of the cycle_last validation is the x86 TSC. In order to
provide NMI safe accessor functions for clock monotonic and
monotonic_raw we need to do that in the core.

We can't do the TSC specific

    if (now < cycle_last)
       	    now = cycle_last;

for the other wrapping around clocksources, but TSC has
CLOCKSOURCE_MASK(64) which actually does not mask out anything so if
now is less than cycle_last the subtraction will give a negative
result. So we can check for that in clocksource_delta() and return 0
for that case.

Implement and enable it for x86
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

We want to move the TSC sanity check into core code to make NMI safe
accessors to clock monotonic[_raw] possible. For this we need to
sanity check the delta calculation. Create a helper function and
convert all sites to use it.

[ Build fix from jstultz ]
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

We have interfaces. Remove the open coded cruft. Reduces text size
along with the code.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: QCA ath9k Development <ath9k-devel@qca.qualcomm.com>
Cc: John W. Linville <linville@tuxdriver.com>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

No point in converting timespecs back and forth.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

Use ktime_get_raw_ns() and get rid of the back and forth timespec
conversions.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

Provide a ktime_t based interface for raw monotonic time.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

There is no point in having a S390 private implementation and there is
no point in using the raw monotonic time. The NTP freqeuency
adjustment of CLOCK_MONOTONIC is really not doing any harm for the
hang check timer.

Use ktime_get_ns() for everything and get rid of the timespec
conversions.

V2: Drop the raw monotonic and the S390 special case
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

timekeeping_clocktai() is not used in fast pathes, so the extra
timespec conversion is not problematic.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

No more users. Remove it
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

Subtracting plain nsec values and converting to timespec is simpler
than the whole timespec math. Not really fastpath code, so the
division is not an issue.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

get_monotonic_boottime() is not used in fast pathes, so the extra
timespec conversion is not problematic.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

No more users.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

Convert the relevant base data right away to nanoseconds instead of
doing the conversion on every readout. Reduces text size by 160 bytes.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Acked-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

Use the new nanoseconds based interface and get rid of the timespec
conversion dance.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Acked-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

Use the nanoseconds based interface instead of converting from a
timespec.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

No idea why iio needs wall clock based time stamps, but we can avoid
the timespec conversion dance by using the new interfaces.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NJonathan Cameron <jic23@kernel.org>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

Using the wall clock time for delta time calculations is wrong to
begin with because wall clock time can be set from userspace and NTP.
Such data wants to be based on clock monotonic.

The calculations also are done on a nanosecond basis. Use the
nanoseconds based interface right away.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Jean Delvare <jdelvare@suse.de>
Acked-by: NJean Delvare <jdelvare@suse.de>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

Replace the ever recurring:
        ts = ktime_get_ts();
        ns = timespec_to_ns(&ts);
with
        ns = ktime_get_ns();
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NTrond Myklebust <trond.myklebust@primarydata.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

This code is beyond silly:

     struct timespec ts = ktime_get_ts();
     ktime_t ktime = timespec_to_ktime(ts);

Further down the code builds the delta of two ktime_t values and
converts the result to nanoseconds.

Use ktime_get_ns() and replace all the nonsense.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Eli Cohen <eli@mellanox.com>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

Replace the ever recurring:
        ts = ktime_get_ts();
        ns = timespec_to_ns(&ts);
with
        ns = ktime_get_ns();
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

Replace the ever recurring:
	ts = ktime_get_ts();
	ns = timespec_to_ns(&ts);
with
	ns = ktime_get_ns();
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NLee Jones <lee.jones@linaro.org>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

Replace the ever recurring:
        ts = ktime_get_ts();
        ns = timespec_to_ns(&ts);
with
        ns = ktime_get_ns();
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

Replace the ever recurring:
	ts = ktime_get_ts();
	ns = timespec_to_ns(&ts);
with
	ns = ktime_get_ns();
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

Converting cputime to timespec and timespec to nanoseconds makes no
sense. Use cputime_to_ns() and be done with it.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

Kill the timespec juggling and calculate with plain nanoseconds.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

Simplify the timespec to nsec/usec conversions.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

Simplify the only user of this data by removing the timespec
conversion.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

Required for moving drivers to the nanosecond based interfaces.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

A lot of code converts either timespecs or ktime_t to
nanoseconds. Provide helper functions.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

No more users.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

Convert the monotonic timestamp with ktime_mono_to_real() in
drm_calc_vbltimestamp_from_scanoutpos().

In get_drm_timestamp we can call either ktime_get() or
ktime_get_real() depending on drm_timestamp_monotonic. No point in
having two calls into the core for CLOCK_REALTIME.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

Convert the monotonic timestamp with ktime_mono_to_real() in
evdev_events().

In evdev_queue_syn_dropped() we can call either ktime_get() or
ktime_get_real() depending on the clkid. No point in having two calls
for CLOCK_REALTIME.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

We have a few other use cases of ktime_get_monotonic_offset() which
can be optimized with ktime_mono_to_real(). The timerfd code uses the
offset only for comparison, so we can use ktime_mono_to_real(0) for
this as well.

Funny enough text size shrinks with that on ARM and x8664 !?
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

ktime based conversion function to map a monotonic time stamp to a
different CLOCK.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

No need to juggle with timespecs.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

No need to juggle with timespecs.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

Speed up the readout.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

Provide a helper function which lets us implement ktime_t based
interfaces for real, boot and tai clocks.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>