The new omap4 cpuidle implementation currently requires
ARCH_NEEDS_CPU_IDLE_COUPLED, which only works on SMP.
This patch makes it possible to build a non-SMP kernel
for that platform. This is not normally desired for
end-users but can be useful for testing.
Without this patch, building rand-0y2jSKT results in:
drivers/cpuidle/coupled.c: In function 'cpuidle_coupled_poke':
drivers/cpuidle/coupled.c:317:3: error: implicit declaration of function '__smp_call_function_single' [-Werror=implicit-function-declaration]
It's not clear if this patch is the best solution for
the problem at hand. I have made sure that we can now
build the kernel in all configurations, but that does
not mean it will actually work on an OMAP44xx.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Kevin Hilman <khilman@ti.com>
Cc: Tony Lindgren <tony@atomide.com>
Coupled cpuidle was meant to merge for 3.5 through Len Brown's tree, but
didn't go in because the pull request ended up rejected. So it just got
merged, and we got this staged branch that enables the coupled cpuidle
code on OMAP.
With a stable git workflow from the other maintainer we could have staged
this earlier, but that wasn't the case so we have had to merge it late.
The alternative is to hold it off until 3.7 but given that the code is
well-isolated to OMAP and they are eager to see it go in, I didn't push
back hard in that direction.
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Merge tag 'pm2' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull arm-soc cpuidle enablement for OMAP from Olof Johansson:
"Coupled cpuidle was meant to merge for 3.5 through Len Brown's tree,
but didn't go in because the pull request ended up rejected. So it
just got merged, and we got this staged branch that enables the
coupled cpuidle code on OMAP.
With a stable git workflow from the other maintainer we could have
staged this earlier, but that wasn't the case so we have had to merge
it late.
The alternative is to hold it off until 3.7 but given that the code is
well-isolated to OMAP and they are eager to see it go in, I didn't
push back hard in that direction."
* tag 'pm2' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
ARM: OMAP4: CPUidle: Open broadcast clock-event device.
ARM: OMAP4: CPUidle: add synchronization for coupled idle states
ARM: OMAP4: CPUidle: Use coupled cpuidle states to implement SMP cpuidle.
ARM: OMAP: timer: allow gp timer clock-event to be used on both cpus
OMAP4 idle driver uses CLOCK_EVT_NOTIFY_BROADCAST_[ENTER/EXIT]
for broadcast clock events. But _ENTER/_EXIT doesn't really open
broadcast clock events and to explicitly setup the broadcast device,
CLOCK_EVT_NOTIFY_BROADCAST_ON should be used.
Add the missing CLOCK_EVT_NOTIFY_BROADCAST_ON clockevent notifications.
This will setup the broadcast timer in either periodic/oneshot modes
correctly. Recent clockevent infrastructure change 77b0d60 {leave the
broadcast device in shutdown mode when not needed} exposed this bug
leading to boot hangs in oneshot mode. Prior to this, periodic broadcast
mode was also broken. This change fixes both the periodic/oneshot broadcast
modes.
Discussion thread :
https://lkml.org/lkml/2012/4/9/13
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>
With coupled idle states, a failure for any CPU to hit a low power
state must be coordinated such that all CPUs abort.
On OMAP4, when entering a coupled state, CPU0 has to wait for CPU1 to
enter its low power state before it can enter its low power state.
This is implemented by letting CPU0 wait for the CPU1 powerdomain to
hit off. However, there are conditions where CPU1 might abort/fail
and not hit off while CPU0 is waiting for it. For example, a CPU1
wakeup or a failed attempt to hit off due to hardware conditions.
To avoid the deadlock where CPU0 would continually wait for CPU1 to
hit off-mode, this patch adds a flag to signal when each CPU has come
out of its low-power state. CPU0 then checks whether CPU1 has hit off
*or* has already completed its attempt to hit off. If the latter,
CPU0 must abort its attempt to hit a low-power state so the coupled
state enter method can return.
In addition, cpuidle_coupled_parallel_barrier() is used to ensure the
clearing of the 'done' flag is synchronized on all CPUs.
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>
OMAP4 CPUDILE driver is converted mainly based on notes from the
coupled cpuidle patch series.
The changes include :
- Register both CPUs and C-states to cpuidle driver.
- Set struct cpuidle_device.coupled_cpus
- Set struct cpuidle_device.safe_state to non coupled state.
- Set CPUIDLE_FLAG_COUPLED in struct cpuidle_state.flags for each
state that affects multiple cpus.
- Separate ->enter hooks for coupled & simple idle.
- CPU0 wait loop for CPU1 power transition.
- CPU1 wakeup mechanism for the idle exit.
- Enabling ARCH_NEEDS_CPU_IDLE_COUPLED for OMAP4.
Thanks to Kevin Hilman and Colin Cross on the suggestions/fixes
on the intermediate version of this patch.
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>
The current Makefile compiles the cpuidle34xx.c and cpuidle44xx.c files
even if the cpuidle option is not set in the kernel.
This patch fixes this by creating a section in the Makefile where these
files are compiled only if the CONFIG_CPU_IDLE option is set.
This modification breaks an implicit dependency between CPU_IDLE and PM as
they belong to the same block in the Makefile. This is fixed in the Kconfig
by selecting explicitely PM is CPU_IDLE is set.
The linux coding style recommend to use no-op functions in the headers
when the subsystem is disabled instead of adding big section in C files.
This patch fix this also.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Jean Pihet <j-pihet@ti.com>
Reviewed-by: Rajendra Nayak <rnayak@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>
We initialized it at compile time, no need to do that at boot
time.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Jean Pihet <j-pihet@ti.com>
Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>
We are storing the 'omap4_idle_data' in the private data field
of the cpuidle device. As we are using this variable only in this file,
that does not really make sense. Let's use the global variable directly.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Jean Pihet <j-pihet@ti.com>
Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>
We initialize the omap4_idle_data variable at compile time allowing us
to remove in the next patch the initialization done at boot time.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Jean Pihet <j-pihet@ti.com>
Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>
Add the static declaration for the omap4_idle_data variable because its scope
is in the file only.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Jean Pihet <j-pihet@ti.com>
Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>
We do not longer need this table as we defined the values
in the driver states.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Jean Pihet <j-pihet@ti.com>
Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>
The cpuidle API allows to declare statically the states in the driver
structure. Let's use it.
We do no longer need the fill_cstate function called at runtime and
by the way adding more instructions at boot time.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Jean Pihet <j-pihet@ti.com>
Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>
The 'valid' field is never used in the code, let's remove it.
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Jean Pihet <j-pihet@ti.com>
Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>
Enable core cpuidle timekeeping and irq enabling and remove that
handling from this code.
Signed-off-by: Robert Lee <rob.lee@linaro.org>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Jean Pihet <j-pihet@ti.com>
Signed-off-by: Len Brown <len.brown@intel.com>
OMAP4 cpuidle driver is reporting the state requested by governor
rather than the actually attempted one.
This is obviously misleading sysfs and powertop cpuidle statistics.
Fix it so that stats are reported correctly.
Reported-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
[khilman@ti.com: minor changelog edits]
Signed-off-by: Kevin Hilman <khilman@ti.com>
CPU local timer(TWD) stops when the CPU is transitioning into
deeper C-States. Since these timers are not wakeup capable, we
need the wakeup capable global timer to program the wakeup time
depending on the next timer expiry.
It can be handled by registering a global wakeup capable timer along
with local timers marked with (mis)feature flag CLOCK_EVT_FEAT_C3STOP.
Then notify the clock events layer from idle code using
CLOCK_EVT_NOTIFY_BROADCAST_ENTER/EXIT).
ARM local timers are already marked with C3STOP feature. Add the
notifiers to OMAP4 CPU idle code for the broadcast entry and exit.
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Jean Pihet <j-pihet@ti.com>
Acked-by: Kevin Hilman <khilman@ti.com>
Tested-by: Vishwanath BS <vishwanath.bs@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>
Add OMAP4 CPUIDLE support. CPU1 is left with defualt idle and
the low power state for it is managed via cpu-hotplug.
This patch adds MPUSS low power states in cpuidle.
C1 - CPU0 ON + CPU1 ON + MPU ON
C2 - CPU0 OFF + CPU1 OFF + MPU CSWR
C3 - CPU0 OFF + CPU1 OFF + MPU OSWR
OMAP4460 onwards, MPUSS power domain doesn't support OFF state any more
anymore just like CORE power domain. The deepest state supported is OSWr.
Ofcourse when MPUSS and CORE PD transitions to OSWR along with device
off mode, even the memory contemts are lost which is as good as
the PD off state.
On OMAP4 because of hardware constraints, no low power states are
targeted when both CPUs are online and in SMP mode. The low power
states are attempted only when secondary CPU gets offline to OFF
through hotplug infrastructure.
Thanks to Nicole Chalhoub <n-chalhoub@ti.com> for doing exhaustive
C-state latency profiling.
Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Jean Pihet <j-pihet@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Tested-by: Vishwanath BS <vishwanath.bs@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>
