Implement an ARM delay timer to be used for udelay(). This allows us to
skip the delay loop calibration at boot on Marvell BG2, BG2Q, BG2CD
platforms. And after this patch, udelay() will be unaffected by CPU
frequency changes.

Note: Although in case there are several possible delay timers, we may
not select the "best" delay timer. Take one Marvell Berlin platform for
example: we have arch timer and dw-apb timer. The arch timer freq is
25MHZ while the dw-apb timer freq is 100MHZ, current selection would
choose the dw-apb timer. But the dw apb timer is on the APB bus while
arch timer sits in CPU, the cost of accessing the apb timer is higher
than the arch timer. We could introduce "rating" concept to delay
timer, but this approach "brings a lot of complexity and workarounds
in the code for a small benefit" as pointed out by Daniel.

Later, Arnd pointed out "However, we could argue that this actually
doesn't matter at all, because the entire point of the ndelay()/
udelay()/mdelay() functions is to waste CPU cycles doing not much at
all, so we can just as well waste them reading the timer register
than spinning on the CPU reading the arch timer more often.", so we
just simply register the dw apb base delay timer.
Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

In order to compile on all arch without error with 'allyesconfig' make
sure the platform selected the GENERIC_CLOCKEVENTS. Without this patch
the new added drivers will prevent the kernel to compile on PARISC.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Increase the compilation test coverage by adding the COMPILE_TEST option.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Increase the compilation test coverage by adding the COMPILE_TEST option.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Let the platform's Kconfig to select the clock instead of having a reverse
dependency from the driver to the platform options.

Add the COMPILE_TEST option for the compilation test coverage. Due to the
non portable 'delay' code, this driver is only compilable on ARM.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Tested-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>

Let the platform's Kconfig to select the clock instead of having a reverse
dependency from the driver to the platform options.

Add the COMPILE_TEST option for the compilation test coverage.

This change is debatable as the option itself in the Kconfig allows to
select the driver for the platform or not. This change will make the prcmu
timer always selected.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>

Increase the compilation test coverage by adding the COMPILE_TEST option.

Due to the non portable code for the delay timer, this option is only
available for the ARM architecture.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Increase the compilation test coverage by adding the COMPILE_TEST option.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Increase the compilation test coverage by adding the COMPILE_TEST option.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Increase the compilation test coverage by adding the COMPILE_TEST option.

The driver depends on the common clock framework, thus the dependency added
on COMMON_CLK.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Increase the compilation test coverage by adding the COMPILE_TEST option.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Remove the <asm/time.h> header inclusion which is pointless.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Increase the compilation test coverage by adding the COMPILE_TEST option.

Due to the non portable code for the delay timer, this option is only
available for the ARM architecture.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Increase the compilation test coverage by adding the COMPILE_TEST option.

The driver depends on the common clock framework, thus the dependency added
on COMMON_CLK.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Increase the compilation test coverage by adding the COMPILE_TEST option.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Increase the compilation test coverage by adding the COMPILE_TEST option.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Increase the compilation test coverage by adding the COMPILE_TEST option.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Increase the compilation test coverage by adding the COMPILE_TEST option.

The driver is using the atomic_io API which is not portable, so the
compilation is restricted to ARM only.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Increase the compilation test coverage by adding the COMPILE_TEST option.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Increase the compilation test coverage by adding the COMPILE_TEST option.

Due to the non portable 'delay' code, the compilation is restricted to the
ARM architecture only.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Increase the compilation test coverage by adding the COMPILE_TEST option.

Due to the dsb() usage in the driver, this driver is only compilable on
ARM and ARM64.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Increase the compilation test coverage by adding the COMPILE_TEST option.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Increase the compilation test coverage by adding the COMPILE_TEST option.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Increase the compilation test coverage by adding the COMPILE_TEST option.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Increase the compilation test coverage by adding the COMPILE_TEST option.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Instead of having the clocksource's Kconfig depending on the arch, let the
arch to select the timer it needs.

The CLKSRC_OF dependency is removed because already selected by the
ARCH_PXA, and it is added for SA1100.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Increase the compilation test coverage by adding the COMPILE_TEST option.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Change the Kconfig selection rule by letting the STI arch to select
the timer.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Maxime Coquelin <maxime.coquelin@st.com>

In order to be consistent with the rest of the drivers compilation, let's
introduce the COMPILE_TEST option. Unfortunately, the delay.h code is not
portable, so the compilation test coverage will be restricted to the ARM
architecture.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

The dsb() instruction is pointless in this code.

Remove it.

That also fixes the ARM64 compilation issue.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Tested-by: Caesar Wang <wxt@rock-chips.com>

When we try to compile a clocksource driver with the COMPILE_TEST option,
we can't select the GENERIC_SCHED_CLOCK because the sched_clock() symbol
will be duplicated with the one defined for the x86.

In order to fix that, we don't select the GENERIC_SCHED_CLOCK in the
driver Kconfig's file but we define some empty functions for the different
symbols in order to prevent the unresolved ones.

This patch fixes the COMPILE_TEST option for the compile test coverage for
the clocksource drivers. Without this patch, we can't add the COMPILE_TEST
option for the clocksource drivers using the GENERIC_SCHED_CLOCK.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Let's checkstyle to clean up the macros with such trivial details.
Signed-off-by: Caesar Wang <wxt@rock-chips.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Allow the timer core to change the smp affinity of the broadcast timer
irq by setting CLOCK_EVT_FEAT_DYNIRQ flag.

This reduces interrupt pressure and wakeups on CPU0 as well as vastly
reducing the number of timer broadcast IPIs.
Signed-off-by: Lucas Stach <dev@lynxeye.de>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Add error path to clear evt struct allocated by kzalloc() in the beginning of
function mtk_timer_init().
Acked-by: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: Alexey Klimov <alexey.klimov@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

1) Change pr_warn()s to pr_err()s. These messages are actually errors and not
   warnings.
2) Add missing \n.
3) Error message for kzalloc() failure is removed per suggestion by Joe Perches.
   There is generic stack_dump() for allocation issues.
Signed-off-by: Alexey Klimov <alexey.klimov@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

It's a bit unclear what subsystem/driver emits some messages to dmesg in
the function mtk_init_timer(). Use pr_fmt to auto-prefix the messages
appropriately.
Acked-by: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: Alexey Klimov <alexey.klimov@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

While going through the nohz code I got stumped by some of it.

This patch adds a few comments clarifying the code; based on discussion
with Thomas.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20151119162106.GO3816@twins.programming.kicks-ass.netSigned-off-by: Thomas Gleixner <tglx@linutronix.de>

We cache all hotpath members of a clocksource in the time keeper
core. So there is no requirement in general to cache line align struct
clocksource. Remove the enforces alignment.

That allows users which need to wrap struct clocksource into their own
struct to align the struct without getting extra padding.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Russell King - ARM Linux <linux@arm.linux.org.uk>
Cc: Marc Gonzalez <marc_gonzalez@sigmadesigns.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Mans Rullgard <mans@mansr.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Nicolas Pitre <nico@linaro.org>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Sebastian Frias <sebastian_frias@sigmadesigns.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1511191209000.3898@nanos

Merge slub bulk allocator updates from Andrew Morton:
 "This missed the merge window because I was waiting for some repairs to
  come in.  Nothing actually uses the bulk allocator yet and the changes
  to other code paths are pretty small.  And the net guys are waiting
  for this so they can start merging the client code"

More comments from Jesper Dangaard Brouer:
 "The kmem_cache_alloc_bulk() call, in mm/slub.c, were included in
  previous kernel.  The present version contains a bug.  Vladimir
  Davydov noticed it contained a bug, when kernel is compiled with
  CONFIG_MEMCG_KMEM (see commit 03ec0ed5: "slub: fix kmem cgroup
  bug in kmem_cache_alloc_bulk").  Plus the mem cgroup counterpart in
  kmem_cache_free_bulk() were missing (see commit 03374518 "slub:
  add missing kmem cgroup support to kmem_cache_free_bulk").

  I don't consider the fix stable-material because there are no in-tree
  users of the API.

  But with known bugs (for memcg) I cannot start using the API in the
  net-tree"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  slab/slub: adjust kmem_cache_alloc_bulk API
  slub: add missing kmem cgroup support to kmem_cache_free_bulk
  slub: fix kmem cgroup bug in kmem_cache_alloc_bulk
  slub: optimize bulk slowpath free by detached freelist
  slub: support for bulk free with SLUB freelists