To select domain idlestates for cpuidle-psci when OSI mode has been
enabled, the PM domains via genpd are being managed through runtime PM.
This works fine for the regular idlepath, but it doesn't during system wide
suspend. More precisely, the domain idlestates becomes temporarily
disabled, which is because the PM core disables runtime PM for devices
during system wide suspend.
Later in the system suspend phase, genpd intends to deal with this from its
->suspend_noirq() callback, but this doesn't work as expected for a device
corresponding to a CPU, because the domain idlestates needs to be selected
on a per CPU basis (the PM core doesn't invoke the callbacks like that).
To address this problem, let's enable the syscore flag for the
corresponding CPU device that becomes successfully attached to its PM
domain (applicable only in OSI mode). This informs the PM core to skip
invoke the system wide suspend/resume callbacks for the device, thus also
prevents genpd from screwing up its internal state of it.
Moreover, to properly select a domain idlestate for the CPUs during
suspend-to-idle, let's assign a specific ->enter_s2idle() callback for the
corresponding domain idlestate (applicable only in OSI mode). From that
callback, let's invoke dev_pm_genpd_suspend|resume(), as this allows a
domain idlestate to be selected for the current CPU by genpd.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
If the PSCI OSI mode isn't supported or fails to be enabled, the PM domain
topology with the genpd providers isn't initialized. This is perfectly fine
from cpuidle-psci point of view.
However, since the PM domain topology in the DTS files is a description of
the HW, no matter of whether the PSCI OSI mode is supported or not, other
consumers besides the CPUs may rely on it.
Therefore, let's always allow the initialization of the PM domain topology
to succeed, independently of whether the PSCI OSI mode is supported.
Consequentially we need to track if we succeed to enable the OSI mode, as
to know when a domain idlestate can be selected.
Note that, CPU devices are still not being attached to the PM domain
topology, unless the PSCI OSI mode is supported.
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The current user (cpuidle-psci) of psci_set_osi_mode() only needs to enable
the PSCI OSI mode. Although, as subsequent changes shows, there is a need
to be able to reset back into the PSCI PC mode.
Therefore, let's extend psci_set_osi_mode() to take a bool as in-parameter,
to let the user indicate whether to enable OSI or to switch back to PC
mode.
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Depending on the SoC/platform, additional devices may be part of the PSCI
PM domain topology. This is the case with 'qcom,rpmh-rsc' device, for
example, even if this is not yet visible in the corresponding DTS-files.
Without going into too much details, a device like the 'qcom,rpmh-rsc' may
have HW constraints that needs to be obeyed to, before a domain idlestate
can be picked.
Therefore, let's implement the ->sync_state() callback to receive a
notification when all consumers of the PSCI PM domain providers have been
attached/probed to it. In this way, we can make sure all constraints from
all relevant devices, are taken into account before allowing a domain
idlestate to be picked.
Acked-by: Saravana Kannan <saravanak@google.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
To enable support for deferred probing and to allow implementation of the
->sync_state() callback from subsequent changes, let's convert into a
platform driver.
Reviewed-by: Lina Iyer <ilina@codeaurora.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The current error paths for the cpuidle-psci driver, may leak memory or
possibly leave CPU devices attached to their PM domains. These are quite
harmless issues, but still deserves to be taken care of.
Although, rather than fixing them by keeping track of allocations that
needs to be freed, which tends to become a bit messy, let's convert into a
platform driver. In this way, it gets easier to fix the memory leaks as we
can rely on the devm_* functions.
Moreover, converting to a platform driver also enables support for deferred
probe, which subsequent changes takes benefit from.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Currently we allow the cpuidle driver registration to succeed, even if we
failed to enable the OSI mode when the hierarchical DT layout is used. This
means running in a degraded mode, by using the available idle states per
CPU, while also preventing the domain idle states.
Moving forward, this behaviour looks quite questionable to maintain, as
complexity seems to grow around it, especially when trying to add support
for deferred probe, for example.
Therefore, let's make the cpuidle driver registration to fail in this
situation, thus relying on the default architectural cpuidle backend for
WFI to be used.
Reviewed-by: Lina Iyer <ilina@codeaurora.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
When the hierarchical CPU topology layout is used in DT and the PSCI OSI
mode is supported by the PSCI FW, let's initialize a corresponding PM
domain topology by using genpd. This enables a CPU and a group of CPUs,
when attached to the topology, to be power-managed accordingly.
To trigger the attempt to initialize the genpd data structures let's use a
subsys_initcall, which should be early enough to allow CPUs, but also other
devices to be attached.
The initialization consists of parsing the PSCI OF node for the topology
and the "domain idle states" DT bindings. In case the idle states are
compatible with "domain-idle-state", the initialized genpd becomes
responsible of selecting an idle state for the PM domain, via assigning it
a genpd governor.
Note that, a successful initialization of the genpd data structures, is
followed by a call to psci_set_osi_mode(), as to try to enable the OSI mode
in the PSCI FW. In case this fails, we fall back into a degraded mode
rather than bailing out and returning error codes.
Co-developed-by: Lina Iyer <lina.iyer@linaro.org>
Signed-off-by: Lina Iyer <lina.iyer@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Introduce a PSCI DT helper function, psci_dt_attach_cpu(), which takes a
CPU number as an in-parameter and tries to attach the CPU's struct device
to its corresponding PM domain.
Let's makes use of dev_pm_domain_attach_by_name(), as it allows us to
specify "psci" as the "name" of the PM domain to attach to. Additionally,
let's also prepare the attached device to be power managed via runtime PM.
Note that, the implementation of the new helper function is in a new
separate c-file, which may seems a bit too much at this point. However,
subsequent changes that implements the remaining part of the PM domain
support for cpuidle-psci, helps to justify this split.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Ulf Hansson