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>

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>

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>

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>

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>

Conflicts:
	arch/arm/Kconfig
	arch/arm/common/Makefile
	arch/arm/kernel/Makefile
	arch/arm/kernel/smp.c

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>

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>

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>

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>