treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

Based on 2 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ARM: 8822/1: smp_twd: Remove legacy TWD registration

As of commit 7484c727b636a838 ("ARM: realview: delete the RealView board
files"), the ARM Timer and Watchdog Unit is instantiated from DT only.
Moreover, the driver is selected from ARCH_MULTIPLATFORM platforms only,
which implies OF, TIMER_OF, and COMMON_CLK.

Hence remove all unused legacy infrastructure from the driver.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

clocksource/drivers: Rename CLOCKSOURCE_OF_DECLARE to TIMER_OF_DECLARE

The CLOCKSOURCE_OF_DECLARE macro is used widely for the timers to declare the
clocksource at early stage. However, this macro is also used to initialize
the clockevent if any, or the clockevent only.

It was originally suggested to declare another macro to initialize a
clockevent, so in order to separate the two entities even they belong to the
same IP. This was not accepted because of the impact on the DT where splitting
a clocksource/clockevent definition does not make sense as it is a Linux
concept not a hardware description.

On the other side, the clocksource has not interrupt declared while the
clockevent has, so it is easy from the driver to know if the description is
for a clockevent or a clocksource, IOW it could be implemented at the driver
level.

So instead of dealing with a named clocksource macro, let's use a more generic
one: TIMER_OF_DECLARE.

The patch has not functional changes.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Matthias Brugger <matthias.bgg@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

cpu/hotplug: Cleanup state names

When the state names got added a script was used to add the extra argument
to the calls. The script basically converted the state constant to a
string, but the cleanup to convert these strings into meaningful ones did
not happen.

Replace all the useless strings with 'subsys/xxx/yyy:state' strings which
are used in all the other places already.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Link: http://lkml.kernel.org/r/20161221192112.085444152@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

arm/twd: Convert to hotplug state machine

Install the callbacks via the state machine. The callbacks won't be invoked on
already online CPUs.

Signed-off-by: Richard Cochran <rcochran@linutronix.de>
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Eric Anholt <eric@anholt.net>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Marc Gonzalez <marc_gonzalez@sigmadesigns.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160713153336.881124821@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

clocksources: Switch back to the clksrc table

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: Daniel Lezcano <daniel.lezcano@linaro.org>

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

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

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

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

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

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

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

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

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

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

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

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

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

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

clocksource/drivers/smp_twd: Convert init function to return error

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: Daniel Lezcano <daniel.lezcano@linaro.org>

ARM: clean up TWD after previous patch

Rename feat_c3stop to twd_features to match the other variables in this
file. Initialise it with the standard features that we always support,
and arrange to set the CLOCK_EVT_FEAT_C3STOP when appropriate.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: 8441/2: twd: Don't set CLOCK_EVT_FEAT_C3STOP unconditionally

In 5388a6b266 ("ARM: SMP: Always enable clock event broadcast support")
Russell noted that "the TWD local timers are unable to wake up the CPU
when it is placed into a low power mode".

However, some platforms do not stop the TWD block in low-power mode,
and can thus use the TWD timer in one-shot mode, without setting up
a broadcast device.

Make the driver check for the "always-on" boolean property, and set
the CLOCK_EVT_FEAT_C3STOP flag accordingly.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Gonzalez <marc_gonzalez@sigmadesigns.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: 8434/2: Revert "7655/1: smp_twd: make twd_local_timer_of_register() no-op for nosmp"

This reverts commit 904464b91eca8c665acea033489225af02eeb75a.

The problem pointed out by commit 904464b91eca ("ARM: 7655/1:
smp_twd: make twd_local_timer_of_register() no-op for nosmp")
doesn't exist anymore.

We can safely boot with nosmp and the warning won't show up.

The other side benefit of this patch is that TWD has a chance
to probe on single-core A9 systems such as AM437x which sport
TWD.

While at that, also drop SMP dependency from TWD's Kconfig entry.

Cc: Shawn Guo <shawn.guo@linaro.org>
Cc: Dirk Behme <dirk.behme@de.bosch.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM/smp_twd: Migrate to new 'set-state' interface

Migrate smp_twd driver to the new 'set-state' interface provided by
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: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

ARM: convert printk(KERN_* to pr_*

Convert many (but not all) printk(KERN_* to pr_* to simplify the code.
We take the opportunity to join some printk lines together so we don't
split the message across several lines, and we also add a few levels
to some messages which were previously missing them.

Tested-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arm: Replace __this_cpu_ptr with raw_cpu_ptr

__this_cpu_ptr is being phased out. So replace with raw_cpu_ptr.

Cc: Russell King <linux@arm.linux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

cpufreq: remove unused notifier: CPUFREQ_{SUSPENDCHANGE|RESUMECHANGE}

Two cpufreq notifiers CPUFREQ_RESUMECHANGE and CPUFREQ_SUSPENDCHANGE have
not been used for some time, so remove them to clean up code a bit.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
[rjw: Changelog]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ARM: twd: data endian fix

Ensure the twd driver uses the correct calls to access the hardware
to ensure that we do not end up with data in the wrong endian format.

Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>

arm: delete __cpuinit/__CPUINIT usage from all ARM users

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 5e427ec2d0 ("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.

Note that some harmless section mismatch warnings may result, since
notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c)
and are flagged as __cpuinit -- so if we remove the __cpuinit from
the arch specific callers, we will also get section mismatch warnings.
As an intermediate step, we intend to turn the linux/init.h cpuinit
related content into no-ops as early as possible, since that will get
rid of these warnings. In any case, they are temporary and harmless.

This removes all the ARM uses of the __cpuinit macros from C code,
and all __CPUINIT from assembly code. It also had two ".previous"
section statements that were paired off against __CPUINIT
(aka .section ".cpuinit.text") that also get removed here.

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

Cc: Russell King <linux@arm.linux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

ARM: 7778/1: smp_twd: twd_update_frequency need be run on all online CPUs

When the local timer freq changed, the twd_update_frequency function
should be run all the CPUs include itself, otherwise, the twd freq will
not get updated and the local timer will not run correcttly.

smp_call_function will run functions on all other CPUs, but not include
himself, this is not correct,use on_each_cpu instead to fix this issue.

Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: stable@vger.kernel.org
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Jason Liu <r64343@freescale.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: smp_twd: Divorce smp_twd from local timer API

Separate the smp_twd timers from the local timer API. This will
allow us to remove ARM local timer support in the near future and
gets us closer to moving this driver to drivers/clocksource.

Tested-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Tony Lindgren <tony@atomide.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

ARM: smp_twd: convert to use CLKSRC_OF init

Now that we have OF based init with CLKSRC_OF, convert smp_twd init
function to use it and covert all callers of
twd_local_timer_of_register.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Viresh Kumar <viresh.linux@gmail.com>
Cc: Shiraz Hashim <shiraz.hashim@st.com>
Cc: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Cc: John Stultz <johnstul@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-omap@vger.kernel.org
Cc: spear-devel@list.st.com
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>

ARM: 7655/1: smp_twd: make twd_local_timer_of_register() no-op for nosmp

When booting a SMP build kernel with nosmp on kernel cmdline, the
following fat warning will be hit.

------------[ cut here ]------------
WARNING: at arch/arm/kernel/smp_twd.c:345
twd_local_timer_of_register+0x7c/0x90()
twd_local_timer_of_register failed (-6)
Modules linked in:
Backtrace:
[<80011f14>] (dump_backtrace+0x0/0x10c) from [<8044dd30>]
(dump_stack+0x18/0x1c)
r7:805e9f58 r6:805ba84c r5:80539331 r4:00000159
[<8044dd18>] (dump_stack+0x0/0x1c) from [<80020fbc>]
(warn_slowpath_common+0x54/0x6c)
[<80020f68>] (warn_slowpath_common+0x0/0x6c) from [<80021078>]
(warn_slowpath_fmt+0x38/0x40)
r9:412fc09a r8:8fffffff r7:ffffffff r6:00000001 r5:80633b8c
r4:80b32da8
[<80021040>] (warn_slowpath_fmt+0x0/0x40) from [<805ba84]
(twd_local_timer_of_register+0x7c/0x90)
r3:fffffffa r2:8053934b
[<805ba7d0>] (twd_local_timer_of_register+0x0/0x90) from [<805c0bec>]
(imx6q_timer_init+0x18/0x4c)
r5:80633800 r4:8053b701
[<805c0bd4>] (imx6q_timer_init+0x0/0x4c) from [<805ba4e8>]
(time_init+0x28/0x38)
r5:80633800 r4:805dc0f4
[<805ba4c0>] (time_init+0x0/0x38) from [<805b6854>]
(start_kernel+0x1a0/0x310)
[<805b66b4>] (start_kernel+0x0/0x310) from [<10008044>] (0x10008044)
r8:1000406a r7:805f3f8c r6:805dc0c4 r5:805f0518 r4:10c5387d
---[ end trace 1b75b31a2719ed1c ]---

Check (!is_smp() || !setup_max_cpus) in twd_local_timer_of_register()
to make it be a no-op for the conditions, thus avoid above warning.

Reported-by: Dirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: use device tree to get smp_twd clock

Move clk setup to twd_local_timer_common_register and rely on
twd_timer_rate being 0 to force calibration if there is no clock.
Remove common_setup_called as it is no longer needed.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Mark Langsdorf <mark.langsdorf@calxeda.com>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ARM: remove mach .handle_irq for GIC users

Now that the GIC initialization sets up the handle_arch_irq pointer, we
can remove it for all machines and make it static.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Anton Vorontsov <avorontsov@mvista.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: David Brown <davidb@codeaurora.org>
Cc: Daniel Walker <dwalker@fifo99.com>
Cc: Bryan Huntsman <bryanh@codeaurora.org>
Acked-by: Tony Lindgren <tony@atomide.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: Dinh Nguyen <dinguyen@altera.com>
Cc: Shiraz Hashim <shiraz.hashim@st.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Cc: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Olof Johansson <olof@lixom.net>
Acked-by: Arnd Bergmann <arnd@arndb.de>

ARM: smp_twd: fix build warning

0336517b38c "ARM: smp_twd: don't warn on no DT node" introduced
a silly build warning by returning an error from a void function.
This keeps the intention of that patch but fixes the warning by
removing the error code

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

ARM: 7563/1: SMP_TWD: make setup()/stop() reentrant

It has been brought to my knowledge that the .setup()/.stop()
function pair in the SMP TWD is going to be called from atomic
contexts for CPUs coming and going, and then the
clk_prepare()/clk_unprepare() calls cannot be called
on subsequent .setup()/.stop() iterations. This is however
just the tip of an iceberg as the function pair is not
designed to be reentrant at all.

This change makes the SMP_TWD clock .setup()/.stop() pair reentrant
by splitting the .setup() function in three parts:

- One COMMON part that is executed the first time the first CPU
in the TWD cluster is initialized. This will fetch the TWD
clk for the cluster and prepare+enable it. If no clk is
available it will calibrate the rate instead.

- One part that is executed the FIRST TIME a certain CPU is
brought on-line. This initializes and sets up the clock event
for a certain CPU.

- One part that is executed on every subsequent .setup() call.
This will re-initialize the clock event. This is augmented
to call the clk_enable()/clk_disable() pair properly.

Cc: Shawn Guo <shawn.guo@linaro.org>
Reported-by: Peter Chen <peter.chen@freescale.com>
Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: 7561/1: SMP_TWD: use clk_prepare_enable()

A minor code refactoring saving a few lines by merging prepare()
and enable() calls.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: smp_twd: don't warn on no DT node

Not having a TWD is valid if we have multiple platforms with different
cores, so remove the warning message.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>

ARM: 7560/1: SMP_TWD: use DIV_ROUND_CLOSEST() for periodic mode

The periodic mode is currently calculated by a simple division
but we should pay more attention to our integer arithmetics.
Also delete a comment that does not make any sense.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: 7535/1: Reprogram smp_twd based on new common clk framework notifiers

Running cpufreq driver on imx6q, the following warning is seen.

$ BUG: sleeping function called from invalid context at kernel/mutex.c:269

<snip>

stack backtrace:
Backtrace:
[<80011d64>] (dump_backtrace+0x0/0x10c) from [<803fc164>] (dump_stack+0x18/0x1c)
r6:bf8142e0 r5:bf814000 r4:806ac794 r3:bf814000
[<803fc14c>] (dump_stack+0x0/0x1c) from [<803fd444>] (print_usage_bug+0x250/0x2b
8)
[<803fd1f4>] (print_usage_bug+0x0/0x2b8) from [<80060f90>] (mark_lock+0x56c/0x67
0)
[<80060a24>] (mark_lock+0x0/0x670) from [<80061a20>] (__lock_acquire+0x98c/0x19b
4)
[<80061094>] (__lock_acquire+0x0/0x19b4) from [<80062f14>] (lock_acquire+0x68/0x
7c)
[<80062eac>] (lock_acquire+0x0/0x7c) from [<80400f28>] (mutex_lock_nested+0x78/0
x344)
r7:00000000 r6:bf872000 r5:805cc858 r4:805c2a04
[<80400eb0>] (mutex_lock_nested+0x0/0x344) from [<803089ac>] (clk_get_rate+0x1c/
0x58)
[<80308990>] (clk_get_rate+0x0/0x58) from [<80013c48>] (twd_update_frequency+0x1
8/0x50)
r5:bf253d04 r4:805cadf4
[<80013c30>] (twd_update_frequency+0x0/0x50) from [<80068e20>] (generic_smp_call
_function_single_interrupt+0xd4/0x13c)
r4:bf873ee0 r3:80013c30
[<80068d4c>] (generic_smp_call_function_single_interrupt+0x0/0x13c) from [<80013
34c>] (handle_IPI+0xc0/0x194)
r8:00000001 r7:00000000 r6:80574e48 r5:bf872000 r4:80593958
[<8001328c>] (handle_IPI+0x0/0x194) from [<800084e8>] (gic_handle_irq+0x58/0x60)
r8:00000000 r7:bf873f8c r6:bf873f58 r5:80593070 r4:f4000100
r3:00000005
[<80008490>] (gic_handle_irq+0x0/0x60) from [<8000e124>] (__irq_svc+0x44/0x60)
Exception stack(0xbf873f58 to 0xbf873fa0)
3f40: 00000001 00000001
3f60: 00000000 bf814000 bf872000 805cab48 80405aa4 80597648 00000000 412fc09a
3f80: bf872000 bf873fac bf873f70 bf873fa0 80063844 8000f1f8 20000013 ffffffff
r6:ffffffff r5:20000013 r4:8000f1f8 r3:bf814000
[<8000f1b8>] (default_idle+0x0/0x4c) from [<8000f428>] (cpu_idle+0x98/0x114)
[<8000f390>] (cpu_idle+0x0/0x114) from [<803f9834>] (secondary_start_kernel+0x11
c/0x140)
[<803f9718>] (secondary_start_kernel+0x0/0x140) from [<103f9234>] (0x103f9234)
r6:10c03c7d r5:0000001f r4:4f86806a r3:803f921c

It looks that the warning is caused by that twd_update_frequency() gets
called from an atomic context while it calls clk_get_rate() where a
mutex gets held.

To fix the warning, let's convert common clk users over to clk notifiers
in place of CPUfreq notifiers. This works out nicely for Cortex-A9
MPcore designs that scale all CPUs at the same frequency.

Platforms that have not been converted to the common clk framework and
support CPUfreq will rely on the old mechanism. Once these platforms
are converted over fully then we can remove the CPUfreq-specific bits
for good.

Signed-off-by: Mike Turquette <mturquette@linaro.org>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Revert "ARM: 7359/2: smp_twd: Only wait for reprogramming on active cpus"

This reverts commit 9f85550347f51c79a917b2aec04c90691c11e20a.

Peter Zijlstra says:
| Argh, how did that ever make it upstream, please drop.
|
| Russell, please make that go away upstream.
|
| Like I said, this is both completely the wrong way to solve, and you're
| so not paying attention, see:
|
| 5fbd036b552f633abb394a319f7c62a5c86a9cd7
| 2baab4e90495ebc9826c93f79d74d6e60a828d24
| e3831edd59edf57ca11fc289f08961b20baf5146
|
| What's even worse:
|
| git describe --contains 9f85550347f51c79a917b2aec04c90691c11e20a --match "v*"
| v3.4-rc3~1^2~3
|
| that nonsense got merged long after those other commits.

Linus Walleij says:
| My bad, was because the initial patch was submitted march 9th before
| these fixes were merged:
| http://marc.info/?l=linux-arm-kernel&m=133159655513844&w=2
|
| It was pending for a while in Russell's patch tracker and I
| rebased it to -rc2 without paying enough attention to recent
| related scheduler fixes ... lesson learned.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: 7359/2: smp_twd: Only wait for reprogramming on active cpus

During booting of cpu1, there is a short window where cpu1
is online, but not active where cpu1 is occupied by waiting
to become active. If cpu0 then decides to schedule something
on cpu1 and wait for it to complete, before cpu0 has set
cpu1 active, we have a deadlock.

Typically it's this CPU frequency transition that happens at
this time, so let's just not wait for it to happen, it will
happen whenever the CPU eventually comes online instead.

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@kernel.org
Signed-off-by: Jonas Aaberg <jonas.aberg@stericsson.com>
Reviewed-by: Rickard Andersson <rickard.andersson@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: smp_twd: remove old local timer interface

Now that all users of the previous local timer interface
have been converted to the runtime registration API, make
this interface the only one supported for this driver.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

ARM: smp_twd: add device tree support

Add bindings to support DT discovery of the ARM Timer Watchdog
(aka TWD). Only the timer side is converted by this patch.

Acked-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

ARM: smp_twd: add runtime registration support

Add support for the new registration interface to smp_twd.
Platforms can populate a struct twd_local_timer with MMIO
and IRQ resources, and then call twd_local_timer_register()
to have the timer registered with the core.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

ARM: smp_twd: make local_timer_stop a symbol instead of a #define

When CONFIG_HAVE_ARM_TWD is selected, local_timer_stop is a #define,
while all other local timers are using a real function.

Convert it to an alias of twd_timer_stop, as it helps converting
all local timers to another internal API in a sane way.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

ARM: 7336/1: smp_twd: Don't register CPUFREQ notifiers if local timers are not initialised

Current ARM local timer code registers CPUFREQ notifiers even in case
the twd_timer_setup() isn't called. That seems to be wrong and
would eventually lead to kernel crash on the CPU frequency transitions
on the SOCs where the local timer doesn't exist or broken because of
hardware BUG. Fix it by testing twd_evt and *__this_cpu_ptr(twd_evt).

The issue was observed with v3.3-rc3 and building an OMAP2+ kernel
on OMAP3 SOC which doesn't have TWD.

Below is the dump for reference :

Unable to handle kernel paging request at virtual address 007e900
pgd = cdc20000
[007e9000] *pgd=00000000
Internal error: Oops: 5 [#1] SMP
Modules linked in:
CPU: 0 Not tainted (3.3.0-rc3-pm+debug+initramfs #9)
PC is at twd_update_frequency+0x34/0x48
LR is at twd_update_frequency+0x10/0x48
pc : [<c001382c>] lr : [<c0013808>] psr: 60000093
sp : ce311dd8 ip : 00000000 fp : 00000000
r10: 00000000 r9 : 00000001 r8 : ce310000
r7 : c0440458 r6 : c00137f8 r5 : 00000000 r4 : c0947a74
r3 : 00000000 r2 : 007e9000 r1 : 00000000 r0 : 00000000
Flags: nZCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment usr
Control: 10c5387d Table: 8dc20019 DAC: 00000015
Process sh (pid: 599, stack limit = 0xce3102f8)
Stack: (0xce311dd8 to 0xce312000)
1dc0: 6000c
1de0: 00000001 00000002 00000000 00000000 00000000 00000000 00000
1e00: ffffffff c093d8f0 00000000 ce311ebc 00000001 00000001 ce310
1e20: c001386c c0437c4c c0e95b60 c0e95ba8 00000001 c0e95bf8 ffff4
1e40: 00000000 00000000 c005ef74 ce310000 c0435cf0 ce311ebc 00000
1e60: ce352b40 0007a120 c08d5108 c08ba040 c08ba040 c005f030 00000
1e80: c08bc554 c032fe2c 0007a120 c08d4b64 ce352b40 c08d8618 ffff8
1ea0: c08ba040 c033364c ce311ecc c0433b50 00000002 ffffffea c0330
1ec0: 0007a120 0007a120 22222201 00000000 22222222 00000000 ce357
1ee0: ce3d6000 cdc2aed8 ce352ba0 c0470164 00000002 c032f47c 00034
1f00: c0331cac ce352b40 00000007 c032f6d0 ce352bbc 0003d090 c0930
1f20: c093d8bc c03306a4 00000007 ce311f80 00000007 cdc2aec0 ce358
1f40: ce8d20c0 00000007 b6fe5000 ce311f80 00000007 ce310000 0000c
1f60: c000de74 ce987400 ce8d20c0 b6fe5000 00000000 00000000 0000c
1f80: 00000000 00000000 001fbac8 00000000 00000007 001fbac8 00004
1fa0: c000df04 c000dd60 00000007 001fbac8 00000001 b6fe5000 00000
1fc0: 00000007 001fbac8 00000007 00000004 b6fe5000 00000000 00202
1fe0: 00000000 beb565f8 00101ffc 00008e8c 60000010 00000001 00000
[<c001382c>] (twd_update_frequency+0x34/0x48) from [<c008ac4c>] )
[<c008ac4c>] (smp_call_function_single+0x17c/0x1c8) from [<c0013)
[<c0013890>] (twd_cpufreq_transition+0x24/0x30) from [<c0437c4c>)
[<c0437c4c>] (notifier_call_chain+0x44/0x84) from [<c005efe4>] ()
[<c005efe4>] (__srcu_notifier_call_chain+0x70/0xa4) from [<c005f)
[<c005f030>] (srcu_notifier_call_chain+0x18/0x20) from [<c032fe2)
[<c032fe2c>] (cpufreq_notify_transition+0xc8/0x1b0) from [<c0333)
[<c033364c>] (omap_target+0x1b4/0x28c) from [<c032f47c>] (__cpuf)
[<c032f47c>] (__cpufreq_driver_target+0x50/0x64) from [<c0331d24)
[<c0331d24>] (cpufreq_set+0x78/0x98) from [<c032f6d0>] (store_sc)
[<c032f6d0>] (store_scaling_setspeed+0x5c/0x74) from [<c03306a4>)
[<c03306a4>] (store+0x58/0x74) from [<c014d868>] (sysfs_write_fi)
[<c014d868>] (sysfs_write_file+0x80/0xb4) from [<c00f2c2c>] (vfs)
[<c00f2c2c>] (vfs_write+0xa8/0x138) from [<c00f2e9c>] (sys_write)
[<c00f2e9c>] (sys_write+0x40/0x6c) from [<c000dd60>] (ret_fast_s)
Code: e594300c e792210c e1a01000 e5840004 (e7930002)
---[ end trace 5da3b5167c1ecdda ]---

Reported-by: Kevin Hilman <khilman@ti.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: 7297/1: smp_twd: make sure timer is stopped before registering it

On secondary CPUs, the Timer Control Register is not reset
to a sane value before the timer is registered, and the TRM
doesn't seem to indicate any reset value either. In some cases,
the kernel will take an interrupt too early, depending on what
junk was present in the registers at reset time.

The fix is to set the Timer Control Register to 0 before
registering the clock_event_device and enabling the interrupt.

Problem seen on VE (Cortex A5) and Tegra.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: 7212/1: smp_twd: reconfigure clockevents after cpufreq change

This break-out from Colin Cross' cpufreq-aware TWD patch
will handle the case when our localtimer's clock changes with
the cpu clock. A cpufreq transtion notifier will be registered
only if the platform has supplied a specified clock to the TWD.

After a cpufreq transition, update the clockevent's frequency
by fetching the new clock rate from the clock framework and
reprogram the next clock event.

The necessary changes in the clockevents framework was done by
Thomas Gleixner in kernel v3.0.

ChangeLog v1->v2:
- Replace IS_ERR_OR_NULL() with IS_ERR() in twd_clk check.
- Update code to use the already existing per-cpu array of TWD
clockevents instead of adding cruft.

[Broke out, ifdef:ed CPUfreq stuff for non-cpufreq configs]
[Rebased to newer TWD base with per-CPU clock array]

Signed-off-by: Colin Cross <ccross@android.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: 7211/1: smp_twd: get the rate from a clock

This break-out from Colin Cross' cpufreq-aware TWD patch will
optionally retrieve the clock rate of the TWD from an external
clock. A variant of this patch has been proposed by Rob Herring
as well.

The basic idea is to avoid recalibrating the rate of the clock
at boot if the platform already know what rate the clock to the
TWD block has.

ChangeLog v1->v2: added clk_[prepare|unprepare] calls.

[Broke out of larger SMP TWD patch]

Signed-off-by: Colin Cross <ccross@android.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: 7210/1: smp_twd: modernize clock event registration

This break-out from Colin Cross' cpufreq-aware TWD patch will
just modernize the clock event registration code to use
clockevents_config_and_register().

[Broke out of larger SMP TWD patch]

Signed-off-by: Colin Cross <ccross@android.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: gic, local timers: use the request_percpu_irq() interface

This patch remove the hardcoded link between local timers and PPIs,
and convert the PPI users (TWD, MCT and MSM timers) to the new
*_percpu_irq interface. Also some collateral cleanup
(local_timer_ack() is gone, and the interrupt handler is strictly
private to each driver).

PPIs are now useable for more than just the local timers.

Additional testing by David Brown (msm8250 and msm8660) and
Shawn Guo (imx6q).

Cc: David Brown <davidb@codeaurora.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Acked-by: David Brown <davidb@codeaurora.org>
Tested-by: David Brown <davidb@codeaurora.org>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

ARM: twd: register clockevents device before enabling PPI

The smp_twd clockevents driver currently enables the local timer PPI
before the clockevents device is registered. This can lead to a kernel
panic if a spurious timer interrupt is generated before registration
has completed since the kernel will treat it as an IPI timer.

This patch moves the clockevents device registration before the IRQ
unmasking so that we can always handle timer interrupts once they can
occur.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

ARM: 6994/1: smp_twd: Fix typo in 'twd_timer_rate' printing

To get hundredths of MHz the rate needs to be divided by 10'000.
Here is an example:
twd_timer_rate = 123456789
Before the patch:
twd_timer_rate / 1000000 = 123
(twd_timer_rate / 1000000) % 100 = 23
Result: 123.23MHz.
After being fixed:
twd_timer_rate / 1000000 = 123
(twd_timer_rate / 10000) % 100 = 45
Result: 123.45MHz.

Signed-off-by: Vitaly Kuzmichev <vkuzmichev@mvista.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: twd: ensure timer reload is reprogrammed on entry to periodic mode

Ensure that the twd timer reload value is reprogrammed each time we
enter periodic mode. This ensures that the reload value is always
reset correctly.

Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Colin Cross <ccross@android.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: twd: fix display of twd frequency

The fraction of MHz was not being displayed correctly as the calculation
was a factor of 10 out. Fix this.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: localtimer: clean up local timer on hot unplug

When a CPU is hot unplugged, the generic tick code cleans up the
clock event device, but fails to call down to the device's set_mode
function to actually shut the device down.

To work around this, we've historically had a local_timer_stop()
callback out of the hotplug code. However, this adds needless
complexity when we have the clock event device itself available.

Explicitly call the clock event device's set_mode function with
CLOCK_EVT_MODE_UNUSED, so that the hardware can be cleanly shutdown
without any special external callbacks. When/if the generic code
is fixed, percpu_timer_stop() can be killed off.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: GIC: move enablement of PPI interrupts to gic.c

Avoid adding nasty genirq-specific code to local timers to enable PPI
interrupts. Instead, provide a gic function to do this.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: SMP: Always enable clock event broadcast support

The TWD local timers are unable to wake up the CPU when it is placed
into a low power mode, eg. C3. Therefore, we need to adapt things
such that the TWD code can cope with this.

We do this by always providing a broadcast tick function, and marking
the fact that the TWD local timer will stop in low power modes. This
means that when the CPU is placed into a low power mode, the core
timer code marks this fact, and allows an IPI to be given to the core.

Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>

ARM: 6125/1: ARM TWD: move TWD registers to common header

This moves the TWD register set of MPcore to a common
existing file so that watchdog driver can access it

Signed-off-by: srinidhi kasagar <srinidhi.kasagar@stericsson.com>
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

ARM: Do not allow the probing of the local timer

Since this IRQ descriptor doesn't have an action registered, it is
allowed for probing via probe_irq_on/off() and it will be disabled by
the latter function. This patch sets the IRQ_NOPROBE status bit for the
local timer descriptor.

Signed-off-by: Varun Swara <Varun.Swara@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

ARM: Fix __cpuexit section mismatch warnings

Fix:

WARNING: vmlinux.o(.text+0x247c): Section mismatch in reference from the function cpu_idle() to the function .cpuexit.text:cpu_die()
The function cpu_idle() references a function in an exit section.
Often the function cpu_die() has valid usage outside the exit section
and the fix is to remove the __cpuexit annotation of cpu_die.

WARNING: vmlinux.o(.cpuexit.text+0x3c): Section mismatch in reference from the function cpu_die() to the function .cpuinit.text:secondary_start_kernel()
The function __cpuexit cpu_die() references
a function __cpuinit secondary_start_kernel().
This is often seen when error handling in the exit function
uses functionality in the init path.
The fix is often to remove the __cpuinit annotation of
secondary_start_kernel() so it may be used outside an init section.

Sam says:
> The annotation of cpu_die() is wrong.
> To be annotated __cpuexit the function shall:
> - be used in exit context and only in exit context with HOTPLUG_CPU=n
> - be used outside exit context with HOTPLUG_CPU=y

So, this also means __cpu_disable(), __cpu_die() and twd_timer_stop() are
also wrong. However, removing __cpuexit from cpu_die() creates:

WARNING: vmlinux.o(.text+0x6834): Section mismatch in reference from the function cpu_die() to the function .cpuinit.text:secondary_start_kernel()
The function cpu_die() references
the function __cpuinit secondary_start_kernel().
This is often because cpu_die lacks a __cpuinit
annotation or the annotation of secondary_start_kernel is wrong.

so fix this using __ref.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Sam Ravnborg <sam@ravnborg.org>

[ARM] smp: fix style issues in smp_twd.c

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

[ARM] smp: allow re-use of realview localtimer TWD support

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>