linux-toradex.git/drivers/clocksource/arm_arch_timer.c, branch v4.10

Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2016-12-25T22:30:04+00:00

Pull timer type cleanups from Thomas Gleixner:
 "This series does a tree wide cleanup of types related to
  timers/timekeeping.

   - Get rid of cycles_t and use a plain u64. The type is not really
     helpful and caused more confusion than clarity

   - Get rid of the ktime union. The union has become useless as we use
     the scalar nanoseconds storage unconditionally now. The 32bit
     timespec alike storage got removed due to the Y2038 limitations
     some time ago.

     That leaves the odd union access around for no reason. Clean it up.

  Both changes have been done with coccinelle and a small amount of
  manual mopping up"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  ktime: Get rid of ktime_equal()
  ktime: Cleanup ktime_set() usage
  ktime: Get rid of the union
  clocksource: Use a plain u64 instead of cycle_t

clocksource: Use a plain u64 instead of cycle_t

2016-12-25T10:04:12+00:00

There is no point in having an extra type for extra confusion. u64 is
unambiguous.

Conversion was done with the following coccinelle script:

@rem@
@@
-typedef u64 cycle_t;

@fix@
typedef cycle_t;
@@
-cycle_t
+u64

Signed-off-by: Thomas Gleixner 
Cc: Peter Zijlstra 
Cc: John Stultz

cpu/hotplug: Cleanup state names

2016-12-25T09:47:44+00:00

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

clocksource/drivers/arm_arch_timer: Map frame with of_io_request_and_map()

2016-11-21T10:15:29+00:00

Let's use the of_io_request_and_map() API so that the frame
region is protected and shows up in /proc/iomem.

Signed-off-by: Stephen Boyd 
Signed-off-by: Daniel Lezcano 
Acked-by: Marc Zyngier

clocksource/drivers/arm_arch_timer: Don't assume clock runs in suspend

2016-11-21T10:05:36+00:00

The ARM specifies that the system counter "must be implemented in an
always-on power domain," and so we try to use the counter as a source of
timekeeping across suspend/resume. Unfortunately, some SoCs (e.g.,
Rockchip's RK3399) do not keep the counter ticking properly when
switched from their high-power clock to the lower-power clock used in
system suspend. Support this quirk by adding a new device tree property.

Signed-off-by: Brian Norris 
Reviewed-by: Douglas Anderson 
Acked-by: Marc Zyngier 
Signed-off-by: Daniel Lezcano

arm/arm64: arch_timer: Use archdata to indicate vdso suitability

2016-09-23T16:19:25+00:00

Instead of comparing the name to a magic string, use archdata to
explicitly communicate whether the arch timer is suitable for
direct vdso access.

Acked-by: Will Deacon 
Acked-by: Russell King 
Acked-by: Marc Zyngier 
Signed-off-by: Scott Wood 
Signed-off-by: Will Deacon

arm64: arch_timer: Work around QorIQ Erratum A-008585

2016-09-23T16:19:25+00:00

Erratum A-008585 says that the ARM generic timer counter "has the
potential to contain an erroneous value for a small number of core
clock cycles every time the timer value changes".  Accesses to TVAL
(both read and write) are also affected due to the implicit counter
read.  Accesses to CVAL are not affected.

The workaround is to reread TVAL and count registers until successive
reads return the same value.  Writes to TVAL are replaced with an
equivalent write to CVAL.

The workaround is to reread TVAL and count registers until successive reads
return the same value, and when writing TVAL to retry until counter
reads before and after the write return the same value.

The workaround is enabled if the fsl,erratum-a008585 property is found in
the timer node in the device tree.  This can be overridden with the
clocksource.arm_arch_timer.fsl-a008585 boot parameter, which allows KVM
users to enable the workaround until a mechanism is implemented to
automatically communicate this information.

This erratum can be found on LS1043A and LS2080A.

Acked-by: Marc Zyngier 
Signed-off-by: Scott Wood 
[will: renamed read macro to reflect that it's not usually unstable]
Signed-off-by: Will Deacon

clocksource/arm_arch_timer: Force per-CPU interrupt to be level-triggered

2016-08-01T14:15:53+00:00

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: Marc Zyngier 
Cc: Andrew Lunn 
Cc: Liu Gang 
Cc: Mark Rutland 
Cc: Masahiro Yamada 
Cc: Wenbin Song 
Cc: Mingkai Hu 
Cc: Florian Fainelli 
Cc: Kevin Hilman 
Cc: Daniel Lezcano 
Cc: Michal Simek 
Cc: Jon Hunter 
Cc: arm@kernel.org
Cc: bcm-kernel-feedback-list@broadcom.com
Cc: linux-arm-kernel@lists.infradead.org
Cc: Sebastian Hesselbarth 
Cc: Jason Cooper 
Cc: Ray Jui 
Cc: "Hou Zhiqiang" 
Cc: Tirumalesh Chalamarla 
Cc: linux-samsung-soc@vger.kernel.org
Cc: Yuan Yao 
Cc: Jan Glauber 
Cc: Gregory Clement 
Cc: linux-amlogic@lists.infradead.org
Cc: soren.brinkmann@xilinx.com
Cc: Rajesh Bhagat 
Cc: Scott Branden 
Cc: Duc Dang 
Cc: Kukjin Kim 
Cc: Carlo Caione 
Cc: Dinh Nguyen 
Link: http://lkml.kernel.org/r/1470045256-9032-2-git-send-email-marc.zyngier@arm.com
Signed-off-by: Thomas Gleixner

clocksource/arm_arch_timer: Convert to hotplug state machine

2016-07-15T08:40:24+00:00

Install the callbacks via the state machine and let the core invoke
the callbacks on the already online CPUs.

Signed-off-by: Richard Cochran 
Signed-off-by: Anna-Maria Gleixner 
Reviewed-by: Sebastian Andrzej Siewior 
Cc: Daniel Lezcano 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160713153336.048259040@linutronix.de
Signed-off-by: Ingo Molnar

clocksource/drivers/arm_arch_timer: Control the evtstrm via the cmdline

2016-06-28T09:35:50+00:00

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 
Cc: Mark Rutland 
Signed-off-by: Will Deacon 
Signed-off-by: Daniel Lezcano