The ARM architected timer produces level-triggered interrupts (this
is mandated by the architecture). Unfortunately, a number of
device-trees get this wrong, and expose an edge-triggered interrupt.

Until now, this wasn't too much an issue, as the programming of the
trigger would fail (the corresponding PPI cannot be reconfigured),
and the kernel would be happy with this. But we're about to change
this, and trust DT a lot if the driver doesn't provide its own
trigger information. In that context, the timer breaks badly.

While we do need to fix the DTs, there is also some userspace out
there (kvmtool) that generates the same kind of broken DT on the
fly, and that will completely break with newer kernels.

As a safety measure, and to keep buggy software alive as well as
buying us some time to fix DTs all over the place, let's check
what trigger configuration has been given us by the firmware.
If this is not a level configuration, then we know that the
DT/ACPI configuration is bust, and we pick some defaults which
won't be worse than the existing setup.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Liu Gang <Gang.Liu@nxp.com>
Cc: Mark Rutland <marc.rutland@arm.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Wenbin Song <Wenbin.Song@freescale.com>
Cc: Mingkai Hu <Mingkai.Hu@freescale.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: Jon Hunter <jonathanh@nvidia.com>
Cc: arm@kernel.org
Cc: bcm-kernel-feedback-list@broadcom.com
Cc: linux-arm-kernel@lists.infradead.org
Cc: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Ray Jui <rjui@broadcom.com>
Cc: "Hou Zhiqiang" <B48286@freescale.com>
Cc: Tirumalesh Chalamarla <tchalamarla@cavium.com>
Cc: linux-samsung-soc@vger.kernel.org
Cc: Yuan Yao <yao.yuan@nxp.com>
Cc: Jan Glauber <jglauber@cavium.com>
Cc: Gregory Clement <gregory.clement@free-electrons.com>
Cc: linux-amlogic@lists.infradead.org
Cc: soren.brinkmann@xilinx.com
Cc: Rajesh Bhagat <rajesh.bhagat@freescale.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: Duc Dang <dhdang@apm.com>
Cc: Kukjin Kim <kgene@kernel.org>
Cc: Carlo Caione <carlo@caione.org>
Cc: Dinh Nguyen <dinguyen@opensource.altera.com>
Link: http://lkml.kernel.org/r/1470045256-9032-2-git-send-email-marc.zyngier@arm.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Install the callbacks via the state machine and let the core invoke
the callbacks on the already online CPUs.
Signed-off-by: NRichard Cochran <rcochran@linutronix.de>
Signed-off-by: NAnna-Maria Gleixner <anna-maria@linutronix.de>
Reviewed-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160713153336.048259040@linutronix.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

Disabling the eventstream can be useful for both remotely debugging a
deployed production system and development of code using WFE-based
polling loops. Whilst this can currently be controlled via a Kconfig
option (CONFIG_ARM_ARCH_TIMER_EVTSTREAM), it's often desirable to toggle
the feature on the command line, so this patch adds a new command-line
option ("clocksource.arm_arch_timer.evtstrm") to do just that. The
default behaviour is determined based on CONFIG_ARM_ARCH_TIMER_EVTSTREAM.

Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

All the clocksource drivers's init function are now converted to return
an error code. CLOCKSOURCE_OF_DECLARE is no longer used as well as the
clksrc-of table.

Let's convert back the names:
 - CLOCKSOURCE_OF_DECLARE_RET => CLOCKSOURCE_OF_DECLARE
 - clksrc-of-ret              => clksrc-of
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

For exynos_mct and samsung_pwm_timer:
Acked-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>

For arch/arc:
Acked-by: NVineet Gupta <vgupta@synopsys.com>

For mediatek driver:
Acked-by: NMatthias Brugger <matthias.bgg@gmail.com>

For the Rockchip-part
Acked-by: NHeiko Stuebner <heiko@sntech.de>

For STi :
Acked-by: NPatrice Chotard <patrice.chotard@st.com>

For the mps2-timer.c and versatile.c changes:
Acked-by: NLiviu Dudau <Liviu.Dudau@arm.com>

For the OXNAS part :
Acked-by: NNeil Armstrong <narmstrong@baylibre.com>

For LPC32xx driver:
Acked-by: NSylvain Lemieux <slemieux.tyco@gmail.com>

For Broadcom Kona timer change:
Acked-by: NRay Jui <ray.jui@broadcom.com>

For Sun4i and Sun5i:
Acked-by: NChen-Yu Tsai <wens@csie.org>

For Meson6:
Acked-by: NCarlo Caione <carlo@caione.org>

For Keystone:
Acked-by: NSantosh Shilimkar <ssantosh@kernel.org>

For NPS:
Acked-by: NNoam Camus <noamca@mellanox.com>

For bcm2835:
Acked-by: NEric Anholt <eric@anholt.net>

The init functions do not return any error. They behave as the following:

  - panic, thus leading to a kernel crash while another timer may work and
       make the system boot up correctly

  or

  - print an error and let the caller unaware if the state of the system

Change that by converting the init functions to return an error conforming
to the CLOCKSOURCE_OF_RET prototype.

Proper error handling (rollback, errno value) will be changed later case
by case, thus this change just return back an error or success in the init
function.
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

The only call of arch_timer_get_timecounter (in KVM) has been removed.
Signed-off-by: NJulien Grall <julien.grall@arm.com>
Acked-by: NChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>

Currently, the firmware table is parsed by the virtual timer code in
order to retrieve the virtual timer interrupt. However, this is already
done by the arch timer driver.

To avoid code duplication, extend arch_timer_kvm_info to get the virtual
IRQ.

Note that the KVM code will be modified in a subsequent patch.
Signed-off-by: NJulien Grall <julien.grall@arm.com>
Acked-by: NChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>

Introduce a structure which are filled up by the arch timer driver and
used by the virtual timer in KVM.

The first member of this structure will be the timecounter. More members
will be added later.

A stub for the new helper isn't introduced because KVM requires the arch
timer for both ARM64 and ARM32.

The function arch_timer_get_timecounter is kept for the time being and
will be dropped in a subsequent patch.
Signed-off-by: NJulien Grall <julien.grall@arm.com>
Acked-by: NChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>

With the ARMv8.1 VHE, the kernel can run in HYP mode, and thus
use the HYP timer instead of the normal guest timer in a mostly
transparent way, except for the interrupt line.

This patch reworks the arch timer code to allow the selection of
the HYP PPI, possibly falling back to the guest timer if not
available.
Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

set_state_oneshot_stopped() is called by the clkevt core, when the next
event is required at an expiry time of 'KTIME_MAX'. This normally
happens with NO_HZ_{IDLE|FULL} in both LOWRES/HIGHRES modes.

This patch makes the clockevent device to stop on such an event, to
avoid spurious interrupts, as explained by: commit 8fff52fd
("clockevents: Introduce CLOCK_EVT_STATE_ONESHOT_STOPPED state").
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

So far, we have been blindly assuming that having access to a
memory-mapped timer frame implies that the individual elements of that
frame frame are already enabled. Whilst it's the firmware's job to give
us non-secure access to frames in the first place, we should not rely
on implementations always being generous enough to also configure CNTACR
for those non-secure frames (e.g. [1]).

Explicitly enable feature-level access per-frame, and verify that the
access we want is really implemented before trying to make use of it.

[1]:https://github.com/ARM-software/tf-issues/issues/170Acked-by: NMark Rutland <mark.rutland@arm.com>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Tested-by: NStephen Boyd <sboyd@codeaurora.org>
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

It is now absolutely trivial to convert the arch timer driver to
use ACPI probing, just like its DT counterpart.

Let's enjoy another crapectomy.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Tested-by: NHanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Migrate arm_arch_timer driver to the new 'set-state' interface provided
by the clockevents core, the earlier 'set-mode' interface is marked
obsolete now.

This also enables us to implement callbacks for new states of clockevent
devices, for example: ONESHOT_STOPPED.

Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

clocksource/drivers/arm_arch_timer: Rename 'arch_timer_probed()' to 'arch_timer_needs_probing()' to reflect behaviour

The arch_timer_probed() function returns whether the given time
doesn't need to be probed. This can be the case when the timer
has been probed already, but also when it has no corresponding
enabled node in DT.

Rename the function to arch_timer_needs_probing() and invert its
return value to better reflect the function's purpose and
behaviour.
Signed-off-by: NLaurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: NSudeep Holla <sudeep.holla@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1427796746-373-1-git-send-email-daniel.lezcano@linaro.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>

Using the information presented by GTDT (Generic Timer Description Table)
to initialize the arch timer (not memory-mapped).

CC: Daniel Lezcano <daniel.lezcano@linaro.org>
CC: Thomas Gleixner <tglx@linutronix.de>
Originally-by: NAmit Daniel Kachhap <amit.daniel@samsung.com>
Tested-by: NSuravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Tested-by: NYijing Wang <wangyijing@huawei.com>
Tested-by: NMark Langsdorf <mlangsdo@redhat.com>
Tested-by: NJon Masters <jcm@redhat.com>
Tested-by: NTimur Tabi <timur@codeaurora.org>
Tested-by: NRobert Richter <rrichter@cavium.com>
Acked-by: NRobert Richter <rrichter@cavium.com>
Acked-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: NGrant Likely <grant.likely@linaro.org>
Signed-off-by: NHanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

This driver makes use of the clocksource code. Previously it had only
included the proper header indirectly, but that chain was inadvertently
broken by 74d23cc7 "time: move the timecounter/cyclecounter code into its
own file."

This patch fixes the issue by including clocksource.h directly.
Signed-off-by: NRichard Cochran <richardcochran@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 0b46b8a7 (clocksource: arch_timer: Fix code to use physical
timers when requested) introduces the use of physical counters in the
ARM architected timer driver. However, he arm64 kernel uses CNTVCT in
VDSO. When booting in EL2, the kernel switches to the physical timers to
make things easier for KVM but it continues to use the virtual counter
both in user and kernel. While in such scenario CNTVCT == CNTPCT (since
CNTVOFF is initialised by the kernel to 0), we want to spot firmware
bugs corrupting CNTVOFF early (which would affect CNTVCT).
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Tested-by: NYingjoe Chen <yingjoe.chen@mediatek.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>

Some 32-bit (ARMv7) systems are architected like this:

* The firmware doesn't know and doesn't care about hypervisor mode and
  we don't want to add the complexity of hypervisor there.

* The firmware isn't involved in SMP bringup or resume.

* The ARCH timer come up with an uninitialized offset (CNTVOFF)
  between the virtual and physical counters.  Each core gets a
  different random offset.

* The device boots in "Secure SVC" mode.

* Nothing has touched the reset value of CNTHCTL.PL1PCEN or
  CNTHCTL.PL1PCTEN (both default to 1 at reset)

On systems like the above, it doesn't make sense to use the virtual
counter.  There's nobody managing the offset and each time a core goes
down and comes back up it will get reinitialized to some other random
value.

This adds an optional property which can inform the kernel of this
situation, and firmware is free to remove the property if it is going
to initialize the CNTVOFF registers when each CPU comes out of reset.

Currently, the best course of action in this case is to use the
physical timer, which is why it is important that CNTHCTL hasn't been
changed from its reset value and it's a reasonable assumption given
that the firmware has never entered HYP mode.

Note that it's been said that on ARMv8 systems the firmware and
kernel really can't be architected as described above.  That means
using the physical timer like this really only makes sense for ARMv7
systems.
Signed-off-by: NDoug Anderson <dianders@chromium.org>
Signed-off-by: NSonny Rao <sonnyrao@chromium.org>
Reviewed-by: NMark Rutland <mark.rutland@arm.com>
Acked-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NOlof Johansson <olof@lixom.net>

This is a bug fix for using physical arch timers when
the arch_timer_use_virtual boolean is false.  It restores the
arch_counter_get_cntpct() function after removal in

0d651e4e "clocksource: arch_timer: use virtual counters"

We need this on certain ARMv7 systems which are architected like this:

* The firmware doesn't know and doesn't care about hypervisor mode and
  we don't want to add the complexity of hypervisor there.

* The firmware isn't involved in SMP bringup or resume.

* The ARCH timer come up with an uninitialized offset between the
  virtual and physical counters.  Each core gets a different random
  offset.

* The device boots in "Secure SVC" mode.

* Nothing has touched the reset value of CNTHCTL.PL1PCEN or
  CNTHCTL.PL1PCTEN (both default to 1 at reset)

One example of such as system is RK3288 where it is much simpler to
use the physical counter since there's nobody managing the offset and
each time a core goes down and comes back up it will get reinitialized
to some other random value.

Fixes: 0d651e4e ("clocksource: arch_timer: use virtual counters")
Cc: stable@vger.kernel.org
Signed-off-by: NSonny Rao <sonnyrao@chromium.org>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Acked-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: NOlof Johansson <olof@lixom.net>

Commit c387f07e (clocksource: arm_arch_timer: Discard unavailable
timers correctly) changed the way the driver makes sure both the memory
and system-register timers have been probed before finalizing the probing.

There is a interesting flaw in this logic that leads to this final step
never to be executed. Things seems to work pretty well until something
actually needs the data that is produced during this final stage.

For example, KVM explodes on the first run of a guest when executed on
a platform that has both memory and sysreg nodes (Juno, for example).

Just fix the damned logic, and enjoy booting VMs again.

Tested on a Juno system.

Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Christoffer Dall <christoffer.dall@linaro.org>
Reported-by: NRiku Voipio <riku.voipio@linaro.org>
Acked-by: NMark Rutland <mark.rutland@arm.com>
Acked-by: NSudeep Holla <sudeep.holla@arm.com>
Tested-by: NSudeep Holla <sudeep.holla@arm.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

The arch_timer_evtstrm_enable hooks in arm and arm64 are substantially
similar, the only difference being a CONFIG_COMPAT-conditional section
which is relevant only for arm64.  Copy the arm64 version to the
driver, removing the arch-specific hooks.
Signed-off-by: NNathan Lynch <nathan_lynch@mentor.com>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: NWill Deacon <will.deacon@arm.com>

The only difference between arm and arm64's implementations of
arch_counter_set_user_access is that 32-bit ARM does not enable user
access to the virtual counter.  We want to enable this access for the
32-bit ARM VDSO, so copy the arm64 version to the driver itself, and
remove the arch-specific implementations.
Signed-off-by: NNathan Lynch <nathan_lynch@mentor.com>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: NWill Deacon <will.deacon@arm.com>

The arm and arm64 VDSOs need CP15 access to the architected counter.
If this is unavailable (which is allowed by ARM v7), indicate this by
changing the clocksource name to "arch_mem_counter" before registering
the clocksource.

Suggested by Stephen Boyd.
Signed-off-by: NNathan Lynch <nathan_lynch@mentor.com>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: NWill Deacon <will.deacon@arm.com>

Currently we wait until both cp15 and mem timers are probed if we
have both timer device nodes present in the device tree without
checking if the device is actually available. If one of the timer
device node present is disabled, the system locks up on the boot
as no timer gets registered.

This patch adds the check for the availability of the timer device
so that unavailable timers are discarded correctly. It also adds
the missing of_node_put.
Signed-off-by: NSudeep Holla <sudeep.holla@arm.com>
Reviewed-by: NStephen Boyd <sboyd@codeaurora.org>
Acked-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

ARM arch timers are tightly coupled with the CPU logic and lose context
on platform implementing HW power management when cores are powered
down at run-time. Marking the arch timers as C3STOP regardless of power
management capabilities causes issues on platforms with no power management,
since in that case the arch timers cannot possibly enter states where the
timer loses context at runtime and therefore can always be used as a high
resolution clockevent device.

In order to fix the C3STOP issue in a way compliant with how real HW
works, this patch adds a boolean property to the arch timer bindings
to define if the arch timer is managed by an always-on power domain.

This power domain is present on all ARM platforms to date, and manages
HW that must not be turned off, whatever the state of other HW
components (eg power controller). On platforms with no power management
capabilities, it is the only power domain present, which encompasses
and manages power supply for all HW components in the system.

If the timer is powered by the always-on power domain, the always-on
property must be present in the bindings which means that the timer cannot
be shutdown at runtime, so it is not a C3STOP clockevent device.
If the timer binding does not contain the always-on property, the timer is
assumed to be power-gateable, hence it must be defined as a C3STOP
clockevent device.

Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Magnus Damm <damm@opensource.se>
Cc: Marc Carino <marc.ceeeee@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

Set the CLOCK_EVT_FEAT_DYNIRQ flag on the memory mapped
clockevent so that we save power by waking up the CPU with the
next event when this timer is used in broadcast mode.
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

Commit:

   65cd4f6c ("arch_timer: Move to generic sched_clock framework")

added code to register the arch_sys_counter in arch_timer_register(),
but it is already registered in arch_counter_register().

This results in the timer being added to the clocksource list twice,
therefore causing an infinite loop in the list.

Remove the duplicate registration and register the scheduler
clock after the original registration instead.

This fixes a hang during boot on Tegra114 (Cortex-A15).

[ While I've only tested this on Tegra114, I suspect the same hang
  during boot happens for all processors that use this clock source. ]
Signed-off-by: NThierry Reding <treding@nvidia.com>
Acked-by: NJohn Stultz <john.stultz@linaro.org>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: http://lkml.kernel.org/r/1381843911-31962-1-git-send-email-treding@nvidia.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Register with the generic sched_clock framework now that it
supports 64 bits. This fixes two problems with the current
sched_clock support for machines using the architected timers.
First off, we don't subtract the start value from subsequent
sched_clock calls so we can potentially start off with
sched_clock returning gigantic numbers. Second, there is no
support for suspend/resume handling so problems such as discussed
in 6a4dae5e (ARM: 7565/1: sched: stop sched_clock() during
suspend, 2012-10-23) can happen without this patch. Finally, it
allows us to move the sched_clock setup into drivers clocksource
out of the arch ports.

Cc: Christopher Covington <cov@codeaurora.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

The ARM architected timers keep counting during suspend so we can
mark this clocksource with the CLOCK_SOURCE_SUSPEND_NONSTOP flag.
This flag will indicate that this clocksource can be used for
calculating suspend time and injecting sleep time into the
timekeeping core. This should be more accurate than using an
external RTC or architecture specific persistent clock.

Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

Few control settings done in architected timer as part of initialisation
can be lost when CPU enters deeper power states. They need to be
restored when the CPU is (warm)reset again.

This patch adds CPU PM notifiers to save the counter control register
when entering low power modes and restore it when CPU exits low power.
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Reviewed-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: NWill Deacon <will.deacon@arm.com>
Acked-by: NOlof Johansson <olof@lixom.net>
Signed-off-by: NSudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>

The ARM architected timer can generate events (used for waking up
CPUs executing the wfe instruction) at a frequency represented as a
power-of-2 divisor of the clock rate.

An event stream might be used:
- To implement wfe-based timeouts for userspace locking implementations.
- To impose a timeout on a wfe for safeguarding against any programming
  error in case an expected event is not generated.

This patch computes the event stream frequency aiming for a period
of 100us between events. It uses ARM/ARM64 specific backends to configure
and enable the event stream.

Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Acked-by: NOlof Johansson <olof@lixom.net>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
[sudeep: moving ARM/ARM64 changes into separate patches
         and adding Kconfig option]
Signed-off-by: NSudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>

Add support for the memory mapped timers by filling in the
read/write functions and adding some parsing code. Note that we
only register one clocksource, preferring the cp15 based
clocksource over the mmio one.

To keep things simple we register one global clockevent. This
covers the case of UP and SMP systems with only mmio hardware and
systems where the memory mapped timers are used as the broadcast
timer in low power modes.

The DT binding allows for per-CPU memory mapped timers in case we
want to support that in the future, but the code isn't added
here. We also don't do much for hypervisor support, although it
should be possible to support it by searching for at least two
frames where one frame has the virtual capability and then
updating KVM timers to support it.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <Marc.Zyngier@arm.com>
Cc: Rob Herring <robherring2@gmail.com>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: NMark Rutland <mark.rutland@arm.com>

We're going to introduce support to read and write the memory
mapped timer registers in the next patch, so push the cp15
read/write functions one level deeper. This simplifies the next
patch and makes it clearer what's going on.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <Marc.Zyngier@arm.com>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: NMark Rutland <mark.rutland@arm.com>

There isn't any reason why we don't pass the event here and we'll
need it in the near future for memory mapped arch timers anyway.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <Marc.Zyngier@arm.com>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: NMark Rutland <mark.rutland@arm.com>

Using an enum for the register we wish to access allows newer
compilers to determine if we've forgotten a case in our switch
statement. This allows us to remove the BUILD_BUG() instances in
the arm64 port, avoiding problems where optimizations may not
happen.

To try and force better code generation we're currently marking
the accessor functions as inline, but newer compilers can ignore
the inline keyword unless it's marked __always_inline. Luckily on
arm and arm64 inline is __always_inline, but let's make
everything __always_inline to be explicit.
Suggested-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <Marc.Zyngier@arm.com>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: NMark Rutland <mark.rutland@arm.com>

The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications.  For example, the fix in
commit 5e427ec2 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.

After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out.  Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.

This removes all the drivers/clocksource and drivers/irqchip uses of
the __cpuinit macros from all C files.

[1] https://lkml.org/lkml/2013/5/20/589

Cc: John Stultz <john.stultz@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Switching between reading the virtual or physical counters is
problematic, as some core code wants a view of time before we're fully
set up. Using a function pointer and switching the source after the
first read can make time appear to go backwards, and having a check in
the read function is an unfortunate block on what we want to be a fast
path.

Instead, this patch makes us always use the virtual counters. If we're a
guest, or don't have hyp mode, we'll use the virtual timers, and as such
don't care about CNTVOFF as long as it doesn't change in such a way as
to make time appear to travel backwards. As the guest will use the
virtual timers, a (potential) KVM host must use the physical timers
(which can wake up the host even if they fire while a guest is
executing), and hence a host must have CNTVOFF set to zero so as to have
a consistent view of time between the physical timers and virtual
counters.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Rob Herring <rob.herring@calxeda.com>

Hot-plugging with CONFIG_DEBUG_PREEMPT=y on a device with arm
architected timers causes a slew of "using smp_processor_id() in
preemptible" warnings:

  BUG: using smp_processor_id() in preemptible [00000000] code: sh/111
  caller is arch_timer_cpu_notify+0x14/0xc8

This happens because sometimes the cpu notifier,
arch_timer_cpu_notify(), is called in preemptible context and
other times in non-preemptible context but we use this_cpu_ptr()
to retrieve the clockevent in all cases. We're only going to
actually use the pointer in non-preemptible context though, so
push the this_cpu_ptr() access down into the cases to force the
checks to occur only in non-preemptible contexts.

Cc: John Stultz <john.stultz@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Acked-by: NMarc Zyngier <Marc.Zyngier@arm.com>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NOlof Johansson <olof@lixom.net>

This converts arm and arm64 to use CLKSRC_OF DT based initialization for
the arch timer. A new function arch_timer_arch_init is added to allow for
arch specific setup.

This has a side effect of enabling sched_clock on omap5 and exynos5. There
should not be any reason not to use the arch timers for sched_clock.
Signed-off-by: NRob Herring <rob.herring@calxeda.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Simon Horman <horms@verge.net.au>
Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-samsung-soc@vger.kernel.org
Cc: linux-omap@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>

If we're booted in HYP mode, it is possible that we'll run some
kind of virtualized environment. In this case, it is a better to
switch to the physical timers, and leave the virtual timers to
guests.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>