Pull timer updates from Thomas Gleixner:
"Rather large, but nothing exiting:
- new range check for settimeofday() to prevent that boot time
becomes negative.
- fix for file time rounding
- a few simplifications of the hrtimer code
- fix for the proc/timerlist code so the output of clock realtime
timers is accurate
- more y2038 work
- tree wide conversion of clockevent drivers to the new callbacks"
* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (88 commits)
hrtimer: Handle failure of tick_init_highres() gracefully
hrtimer: Unconfuse switch_hrtimer_base() a bit
hrtimer: Simplify get_target_base() by returning current base
hrtimer: Drop return code of hrtimer_switch_to_hres()
time: Introduce timespec64_to_jiffies()/jiffies_to_timespec64()
time: Introduce current_kernel_time64()
time: Introduce struct itimerspec64
time: Add the common weak version of update_persistent_clock()
time: Always make sure wall_to_monotonic isn't positive
time: Fix nanosecond file time rounding in timespec_trunc()
timer_list: Add the base offset so remaining nsecs are accurate for non monotonic timers
cris/time: Migrate to new 'set-state' interface
kernel: broadcast-hrtimer: Migrate to new 'set-state' interface
xtensa/time: Migrate to new 'set-state' interface
unicore/time: Migrate to new 'set-state' interface
um/time: Migrate to new 'set-state' interface
sparc/time: Migrate to new 'set-state' interface
sh/localtimer: Migrate to new 'set-state' interface
score/time: Migrate to new 'set-state' interface
s390/time: Migrate to new 'set-state' interface
...
Since the removal of the r8a7740 legacy SoC code in commit
44d88c754e ("ARM: shmobile: Remove legacy SoC code for R-Mobile
A1"), all former users of the "sh-cmt-48-gen2" platform device name are
only supported in generic DT-only ARM multi-platform builds. The driver
doesn't need to match platform devices by name anymore, hence remove the
corresponding platform_device_id entry.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Since commit 914d7d1484 ("ARM: shmobile: r8a73a4: Remove legacy
code"), all former users of the "sh-cmt-48-gen2" platform device name
are only supported in generic DT-only ARM multi-platform builds. The
driver doesn't need to match platform devices by name anymore, hence
remove the corresponding platform_device_id entry.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Since commit 59b89af1d5 ("ARM: shmobile: sh7372: Remove Legacy C
SoC code"), there are no more users left of the "sh-cmt-32-fast"
platform device name. Hence remove the corresponding platform_device_id
entry from the driver.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Currently the sh_cmt clocksource timer is disabled or enabled
unconditionally on clocksource suspend resp. resume, even if a
better clocksource is present (e.g. arch_sys_counter) and the
sh_cmt clocksource is not enabled.
As sh_cmt is a syscore device when its timer is enabled, this
may lead to a genpd.prepared_count imbalance in the presence of
PM Domains, which may cause a lock-up during reboot after s2ram.
During suspend:
- pm_genpd_prepare() is called for all non-syscore devices (incl.
sh_cmt), increasing genpd.prepared_count for each device,
- clocksource.suspend() is called for all clocksource devices,
- sh_cmt_clocksource_suspend() calls sh_cmt_stop(), which is a no-op
as the clocksource was not enabled.
During resume:
- clocksource.resume() is called for all clocksource devices,
- sh_cmt_clocksource_resume() calls sh_cmt_start(), which enables the
clocksource timer, and turns sh_cmt into a syscore device,
- pm_genpd_complete() is called for all non-syscore devices (excl.
sh_cmt now!), decreasing genpd.prepared_count for each device but
sh_cmt.
Now genpd.prepared_count of the PM Domain containing sh_cmt is
still 1 instead of zero. On subsequent suspend/resume cycles,
sh_cmt is still a syscore device, hence it's skipped for
pm_genpd_{prepare,complete}(), keeping the imbalance of
genpd.prepared_count at 1.
During reboot:
- platform_drv_shutdown() is called for any platform device that has
a driver with a .shutdown() method (only rcar-dmac on R-Car Gen2),
- platform_drv_shutdown() calls dev_pm_domain_detach(), which
calls genpd_dev_pm_detach(),
- genpd_dev_pm_detach() keeps calling pm_genpd_remove_device() until
it doesn't return -EAGAIN[*],
- If the device is part of the same PM Domain as sh_cmt,
pm_genpd_remove_device() always fails with -EAGAIN due to
genpd.prepared_count > 0.
- Infinite loop in genpd_dev_pm_detach()[*].
[*] Commit 93af5e9354 ("PM / Domains: Avoid infinite loops in
attach/detach code") already limited the number of loop iterations,
avoiding the lock-up.
To fix this, only disable or enable the clocksource timer on
clocksource suspend resp. resume if the clocksource was enabled.
This was tested on r8a7791/koelsch with the CPG Clock Domain:
- using arch_sys_counter as the clocksource, which is the default, and
which showed the problem,
- using sh_cmt as a clocksource ("echo ffca0000.timer > \
/sys/devices/system/clocksource/clocksource0/current_clocksource"),
which behaves the same as before.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1438875126-12596-2-git-send-email-daniel.lezcano@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The global spinlock is used to protect the shared start/stop register.
Now that all CMT channels are handled by a single device instance, use a
per-device spinlock.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Tested-by: Simon Horman <horms+renesas@verge.net.au>
The site-specific OOM messages are unnecessary, because they
duplicate the MM subsystem generic OOM message.
[dlezcano] : refreshed against latest modifications: kmalloc -> kzalloc
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Clock sources don't need an IRQ, request the IRQ only for channels used
as clock event devices.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Do not include the paragraph about writing to the Free Software
Foundation's mailing address from the sample GPL notice. The FSF has
changed addresses in the past, and may do so again. Linux already
includes a copy of the GPL.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
The sh_cmt driver gets the CMT functional clock using a connection ID of
"cmt_fck". While all SH SoCs create clock lookup entries with a NULL
device ID and a "cmt_fck" connection ID, the ARM SoCs use the device ID
only with a NULL connection ID. This works on legacy platforms but will
break on ARM with DT boot.
Fix the situation by using a connection ID of "fck" in the non-legacy
platform data case. Clock lookup entries will be renamed to use the
device ID as well as the connection ID as platforms get moved to new
platform data. The legacy code will eventually be dropped, leaving us
with device ID based clock lookup, compatible with DT boot.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
CMT hardware devices can support multiple channels, with global
registers and per-channel registers. The sh_cmt driver currently models
the hardware with one Linux device per channel. This model makes it
difficult to handle global registers in a clean way.
Add support for a new model that uses one Linux device per timer with
multiple channels per device. This requires changes to platform data,
add new channel configuration fields.
Support for the legacy model is kept and will be removed after all
platforms switch to the new model.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
All boards use or should use a clock source rating of 125 for the CMT,
hardcode it in the driver.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
All boards use or should use a clock event rating of 125 for the CMT,
hardcode it in the driver.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
The CMT is a global timer not restricted to a single CPU. It has a lower
rating than the TMU or ARM architected timer, but is still useful on
systems where the other timers are stopped during CPU sleep.
When multiple timers are available the timers core selects which timer
to use based on timer ratings.
On SMP systems where timer broadcasting is required, one dummy timer is
instantiated per CPU with a rating of 100. On those systems the CMT
timer has a rating of 80, which makes the dummy timer selected by
default on all CPUs. The CMT is then available, and will be used as a
broadcast timer.
On UP systems no dummy timer is instantiated. The CMT timer has a rating
of 125 on those systems and is used directly as a clock event device for
CPU0 without broadcasting.
The CMT rating shouldn't depend on whether we boot a UP or SMP system.
We can't raise the CMT rating to 125 on SMP systems. This would select
CMT as the clock event device for CPU0 as its rating is higher than the
dummy timer rating, and would leave the system without a broadcast
timer. We could instead lower the rating to 80 on all systems, but that
wouldn't reflect reality as ratings between 1 and 99 are documented as
"unfit for real use".
We should raise the rating above 99 and still have the CMT selected as a
broadcast timer. This can be done by changing the cpumask from
cpumask_of(0) to cpu_possible_mask. In that case the timer selection
logic will prefer the previously probed and already selected dummy timer
for all CPUs based on the fact that already selected per-cpu timers are
preferred over new global timers, regardless of their respective
ratings. This also better reflects reality, as the CMT is not tied to
the boot CPU.
Ideally the timer selection logic should realize that the CMT needs to
be used as a broadcast timer on SMP systems as no other broadcast timer
is available, regardless of the cpumask and rating.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Create a new sh_cmt_info structure to hold static information about the
device model and reference that structure from the sh_cmt_device
structure.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Alexey Klimov
Linus Torvalds
Geert Uytterhoeven
Viresh Kumar
John Stultz
Laurent Pinchart
Jingoo Han