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>

Speed up ktime_get() by using ktime_t based data. Text size shrinks by
64 bytes on x8664.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

The ktime_t based interfaces are used a lot in performance critical
code pathes. Add ktime_t based data so the interfaces don't have to
convert from the xtime/timespec based data.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

We already have a function which does the right thing, that also makes
sure that the coming ktime_t based cached values are getting updated.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

struct timekeeper is quite badly sorted for the hot readout path. Most
time access functions need to load two cache lines.

Rearrange it so ktime_get() and getnstimeofday() are happy with a
single cache line.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

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

To convert callers of the core code to timespec64 we need to provide
the proper interfaces.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

Right now we have time related prototypes in 3 different header
files. Move it to a single timekeeping header file and move the core
internal stuff into a core private header.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

Convert the core timekeeping logic to use timespec64s. This moves the
2038 issues out of the core logic and into all of the accessor
functions.

Future changes will need to push the timespec64s out to all
timekeeping users, but that can be done interface by interface.
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>

Helper and conversion functions for timespec64.
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>

Define the timespec64 structure and standard helper functions.

[ tglx: Make it 32bit only. 64bit really can map timespec to timespec64 ]
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>

In order to support dates past 2038 on 32bit systems, ktime_set()
needs to handle 64bit second values.

[ tglx: Removed the BITS_PER_LONG check ]
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>

With the plain nanoseconds based ktime_t we can simply use
ktime_divns() instead of going through loops and hoops of
timespec/timeval conversion.
Reported-by: NJohn Stultz <john.stultz@linaro.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

The non-scalar ktime_t implementation is basically a timespec
which has to be changed to support dates past 2038 on 32bit
systems.

This patch removes the non-scalar ktime_t implementation, forcing
the scalar s64 nanosecond version on all architectures.

This may have additional performance overhead on some 32bit
systems when converting between ktime_t and timespec structures,
however the majority of 32bit systems (arm and i386) were already
using scalar ktime_t, so no performance regressions will be seen
on those platforms.

On affected platforms, I'm open to finding optimizations, including
avoiding converting to timespecs where possible.

[ tglx: We can now cleanup the ktime_t.tv64 mess, but thats a
  different issue and we can throw a coccinelle script at it ]
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>

Rather then having two similar but totally different implementations
that provide timekeeping state to the hrtimer code, try to unify the
two implementations to be more simliar.

Thus this clarifies ktime_get_update_offsets to
ktime_get_update_offsets_now and changes get_xtime...  to
ktime_get_update_offsets_tick.
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>

Provide a default stub function instead of having the extra
conditional. Cuts binary size on a m68k build by ~100 bytes.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

The code was only halfarsed converted to the new VSDO update mechanism
and still uses the inaccurate base value which lacks the fractional
part of xtime_nsec. Fix it up.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

This script makes use of the udelay_test module to exercise udelay()
and ensure that it is delaying long enough (as compared to ktime).
Signed-off-by: NDavid Riley <davidriley@chromium.org>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

Create a module that allows udelay() to be executed to ensure that
it is delaying at least as long as requested (with a little bit of
error allowed).

There are some configurations which don't have reliably udelay
due to using a loop delay with cpufreq changes which should use
a counter time based delay instead.  This test aims to identify
those configurations where timing is unreliable.
Signed-off-by: NDavid Riley <davidriley@chromium.org>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

Merge branch 'clockevents/3.17' of git://git.linaro.org/people/daniel.lezcano/linux into timers/core

Pull clockevents from Danel Lezcano:
 * New timer driver for the Cirrus Logic CLPS711X SoC
 * New driver for the Mediatek SoC which includes:
 * A new function for of, acked by Rob Herring
 * Move the PXA driver to drivers/clocksource, add DT support
 * Optimization of the exynos_mct driver
 * DT support for the renesas timers family.
 * Some Kconfig and driver fixlets

The MCT has a nice 64-bit counter.  That means that we _can_ register
as a 64-bit clocksource and sched_clock.  ...but that doesn't mean we
should.

The 64-bit counter is read by reading two 32-bit registers.  That
means reading needs to be something like:
- Read upper half
- Read lower half
- Read upper half and confirm that it hasn't changed.

That wouldn't be terrible, but:
- THe MCT isn't very fast to access (hundreds of nanoseconds).
- The clocksource is queried _all the time_.

In total system profiles of real workloads on ChromeOS, we've seen
exynos_frc_read() taking 2% or more of CPU time even after optimizing
the 3 reads above to 2 (see below).

The MCT is clocked at ~24MHz on all known systems.  That means that
the 32-bit half of the counter rolls over every ~178 seconds.  This
inspired an optimization in ChromeOS to cache the upper half between
calls, moving 3 reads to 2.  ...but we can do better!  Having a 32-bit
timer that flips every 178 seconds is more than sufficient for Linux.
Let's just use the lower half of the MCT.

Times on 5420 to do 1000000 gettimeofday() calls from userspace:
* Original code:                      1323852 us
* ChromeOS cache upper half:          1173084 us
* ChromeOS + ldmia to optimize:       1045674 us
* Use lower 32-bit only (this code):  1014429 us

As you can see, the time used doesn't increase linearly with the
number of reads and we can make 64-bit work almost as fast as 32-bit
with a bit of assembly code.  But since there's no real gain for
64-bit, let's go with the simplest and fastest implementation.

Note: with this change roughly half the time for gettimeofday() is
spent in exynos_frc_read().  The rest is timer / system call overhead.

Also note: this patch disables the use of the MCT on ARM64 systems
until we've sorted out how to make "cycles_t" always 32-bit.  Really
ARM64 systems should be using arch timers anyway.
Signed-off-by: NDoug Anderson <dianders@chromium.org>
Acked-by Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

Using the __raw functions is discouraged.  Update the file to
consistently use the proper functions.
Signed-off-by: NDoug Anderson <dianders@chromium.org>
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

As clocksource pxa_timer was moved to clocksource framework, the
pxa_timer initialization needs to be a bit amended, to pass the
necessary informations to clocksource, ie :
 - the timer interrupt (mach specific)
 - the timer registers base (ditto)
 - the timer clockrate
Signed-off-by: NRobert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

Select CLKSRC_OF for PXA architectures.
Signed-off-by: NRobert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

Add device-tree support to PXA platforms.
The driver still needs to maintain backward non device-tree
compatibility as well, which implies :
 - a non device-tree init function
 - a static registers base address in the driver
Signed-off-by: NRobert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

Move time.c from arch/arm/mach-pxa/time.c to
drivers/clocksource/pxa_timer.c.
Signed-off-by: NRobert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

This patch adds DT binding documentation for the Cirrus Logic
CLPS711X-based CPUs clocksource subsystem.
Signed-off-by: NAlexander Shiyan <shc_work@mail.ru>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

This adds the clocksource driver for Cirrus Logic CLPS711X series SoCs.
Designed primarily for migration CLPS711X subarch for multiplatform & DT,
for this as the "OF" and "non-OF" calls implemented.
Signed-off-by: NAlexander Shiyan <shc_work@mail.ru>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

In the clocksource driver, we didn't explicitly enable the clock. it makes the
clk reference counter wrong. We didn't encounter any hang issue because the
tick's clock input has been open and is shared by some other hardware
components, but if we don't enable those components in kernel, in the stage of
disabling unused clk in kernel boot, Linux tick hangs.

This patch fixes it. it does an explicit prepare and enable to the clock input,
and increases the usage counter of the clk.
Signed-off-by: NZhiwu Song <Zhiwu.Song@csr.com>
Signed-off-by: NBarry Song <Baohua.Song@csr.com>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

In 'em_sti.c', it will call devm_ioremap_resource() which need
HAS_IOMEM. So need let EM_TIMER_STI depend on HAS_IOMEM, too.

The related error (with allmodconfig under score):

  LD      init/built-in.o
em_sti.c:(.text.em_sti_probe+0x84): undefined reference to `devm_ioremap_resource'
make: *** [vmlinux] Error 1
Signed-off-by: NChen Gang <gang.chen.5i5j@gmail.com>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

Signed-off-by: NMatthias Brugger <matthias.bgg@gmail.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

Add binding documentation for the General Purpose Timer driver of
the Mediatek SoCs.
Signed-off-by: NMatthias Brugger <matthias.bgg@gmail.com>
Acked-by: NSören Brinkmann <soren.brinkmann@xilinx.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

This patch adds a clock source and clock event for the timer found
on the Mediatek SoCs.

The Mediatek General Purpose Timer block provides five 32 bit timers and
one 64 bit timer.

Two 32 bit timers are used by this driver:
TIMER1: clock events supporting periodic and oneshot events
TIMER2: clock source configured as a free running counter

The General Purpose Timer block can be run with two clocks. A 13 MHz system
clock and the RTC clock running at 32 KHz. This implementation uses the system
clock with no clock source divider.

The interrupts are shared between the different timers and have to be read back
from a register. We just enable one interrupt for the clock event. The clock
event timer is used by all cores.
Signed-off-by: NMatthias Brugger <matthias.bgg@gmail.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

A call to of_iomap does not request the memory region. This patch adds the
function of_io_request_and_map which requests the memory region before
mapping it.
Signed-off-by: NMatthias Brugger <matthias.bgg@gmail.com>
Suggested-by: NThomas Gleixner <tglx@linutronix.de>
Suggested-by: NRob Herring <robh@kernel.org>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

It should be "MTU2" instead of "TMU2"
Signed-off-by: NKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: NWolfram Sang <wsa@sang-engineering.com>
Acked-by: NSimon Horman <horms+renesas@verge.net.au>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

The read() of timerfd files allows to fetch the number of timer ticks
while there is no way to set it back from userspace.

To restore the timer's state as it was at checkpoint moment we need
a path to bring @ticks back. Initially I thought about writing ticks
back via write() interface but it seems such API is somehow obscure.

Instead implement timerfd_ioctl() method with TFD_IOC_SET_TICKS
command which allows to adjust @ticks into non-zero value waking
up the waiters.

I wrapped code with CONFIG_CHECKPOINT_RESTORE which can be
dropped off if there users except c/r camp appear.

v2 (by akpm@):
 - Use define timerfd_ioctl NULL for non c/r config

v3:
 - Use copy_from_user for @ticks fetching since
   not all arch support get_user for 8 byte argument
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Andrey Vagin <avagin@openvz.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christopher Covington <cov@codeaurora.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Link: http://lkml.kernel.org/r/20140715215703.285617923@openvz.orgSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Andrey Vagin <avagin@openvz.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Link: http://lkml.kernel.org/r/20140715215703.199905126@openvz.orgSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

For checkpoint/restore of timerfd files we need to know how exactly
the timer were armed, to be able to recreate it on restore stage.
Thus implement show_fdinfo method which provides enough information
for that.

One of significant changes I think is the addition of @settime_flags
member. Currently there are two flags TFD_TIMER_ABSTIME and
TFD_TIMER_CANCEL_ON_SET, and the second can be found from
@might_cancel variable but in case if the flags will be extended
in future we most probably will have to somehow remember them
explicitly anyway so I guss doing that right now won't hurt.

To not bloat the timerfd_ctx structure I've converted @expired
to short integer and defined @settime_flags as short too.

v2 (by avagin@, vdavydov@ and tglx@):

 - Add it_value/it_interval fields
 - Save flags being used in timerfd_setup in context

v3 (by tglx@):
 - don't forget to use CONFIG_PROC_FS

v4 (by akpm@):
 -Use define timerfd_show NULL for non c/r config
Signed-off-by: NCyrill Gorcunov <gorcunov@openvz.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Andrey Vagin <avagin@openvz.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Link: http://lkml.kernel.org/r/20140715215703.114365649@openvz.orgSigned-off-by: NThomas Gleixner <tglx@linutronix.de>