Commit Graph

40 Commits

Author SHA1 Message Date
Beata Michalska
606a5d4227 opp: Don't drop extra references to OPPs accidentally
We are required to call dev_pm_opp_put() from outside of the
opp_table->lock as debugfs removal needs to happen lock-less to avoid
circular dependency issues.

commit cf1fac943c ("opp: Reduce the size of critical section in
_opp_kref_release()") tried to fix that introducing a new routine
_opp_get_next() which keeps returning OPPs that can be freed by the
callers and this routine shall be called without holding the
opp_table->lock.

Though the commit overlooked the fact that the OPPs can be referenced by
other users as well and this routine will end up dropping references
which were taken by other users and hence freeing the OPPs prematurely.

In effect, other users of the OPPs will end up having invalid pointers
at hand. We didn't see any crash reports earlier as the exact situation
never happened, though it is certainly possible.

We need a way to mark which OPPs are no longer referenced by the OPP
core, so we don't drop extra references to them accidentally.

This commit adds another OPP flag, "removed", which is used to track
this. And now we should never end up dropping extra references to the
OPPs.

Cc: v5.11+ <stable@vger.kernel.org> # v5.11+
Fixes: cf1fac943c ("opp: Reduce the size of critical section in _opp_kref_release()")
Signed-off-by: Beata Michalska <beata.michalska@arm.com>
[ Viresh: Almost rewrote entire patch, added new "removed" field,
	  rewrote commit log and added the correct Fixes tag. ]
Co-developed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2021-03-12 09:26:52 +05:30
Jonathan Marek
de04241ab8 opp: Don't skip freq update for different frequency
We skip the OPP update if the current and target OPPs are same. This is
fine for the devices that don't support frequency but may cause issues
for the ones that need to program frequency.

An OPP entry doesn't really signify a single operating frequency but
rather the highest frequency at which the other properties of the OPP
entry apply. And we may reach here with different frequency values,
while all of them would point to the same OPP entry in the OPP table.

We just need to update the clock frequency in that case, though in order
to not add special exit points we reuse the code flow from a normal
path.

While at it, rearrange the conditionals in the 'if' statement to check
'enabled' flag at the end.

Fixes: 81c4d8a3c4 ("opp: Keep track of currently programmed OPP")
Signed-off-by: Jonathan Marek <jonathan@marek.ca>
[ Viresh: Improved commit log and subject, rename current_freq as
	  current_rate, document it, remove local variable and rearrange
	  code. ]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2021-02-18 12:31:08 +05:30
Viresh Kumar
7eba0c7641 opp: Allow lazy-linking of required-opps
The OPP core currently requires the required opp tables to be available
before the dependent OPP table is added, as it needs to create links
from the dependent OPP table to the required ones. This may not be
convenient for all the platforms though, as this requires strict
ordering for probing the drivers.

This patch allows lazy-linking of the required-opps. The OPP tables for
which the required-opp-tables aren't available at the time of their
initialization, are added to a special list of OPP tables:
lazy_opp_tables. Later on, whenever a new OPP table is registered with
the OPP core, we check if it is required by an OPP table in the pending
list; if yes, then we complete the linking then and there.

An OPP table is marked unusable until the time all its required-opp
tables are available. And if lazy-linking fails for an OPP table, the
OPP core disables all of its OPPs to make sure no one can use them.

Tested-by: Hsin-Yi Wang <hsinyi@chromium.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2021-02-02 10:30:53 +05:30
Viresh Kumar
81c4d8a3c4 opp: Keep track of currently programmed OPP
The dev_pm_opp_set_rate() helper needs to know the currently programmed
OPP to make few decisions and currently we try to find it on every
invocation of this routine.

Lets start keeping track of the current_opp programmed for the devices
of the opp table, that will be quite useful going forward.

If we fail to find the current OPP, we pick the first one available in
the list, as the list is in ascending order of frequencies, level, or
bandwidth and that's the best guess we can make anyway.

Note that we used to do the frequency comparison a bit early in
dev_pm_opp_set_rate() previously, and now instead we check the target
opp, which shall be more accurate anyway.

We need to make sure that current_opp's memory doesn't get freed while
it is being used and so we keep a reference of it until the time it is
used.

Now that current_opp will always be set, we can drop some unnecessary
checks as well.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Tested-by: Dmitry Osipenko <digetx@gmail.com>
2021-02-02 10:27:52 +05:30
Viresh Kumar
38bb343938 opp: Prepare for ->set_opp() helper to work without regulators
Until now the ->set_opp() helper (i.e. special implementation for
setting the OPPs for platforms) was implemented only to take care of
multiple regulators case, but going forward we would need that for other
use cases as well.

This patch prepares for that by allocating the regulator specific part
from dev_pm_opp_set_regulators() and the opp helper part from
dev_pm_opp_register_set_opp_helper().

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Tested-by: Dmitry Osipenko <digetx@gmail.com>
2021-02-02 10:27:39 +05:30
Viresh Kumar
32439ac753 opp: Defer acquiring the clk until OPPs are added
We acquire the clk at the time the OPP table is allocated, though it
works fine, it is not the best place to do so. One of the main reason
being we may need to acquire it again from dev_pm_opp_set_clkname() if
the platform wants another clock to be acquired instead.

There is also requirement from some of the platforms where they do not
want the OPP core to manage the clock at all.

This patch hence defers acquiring the clk until the time we are certain
about which clk we need to acquire and if we really need to acquire one.
With this commit, the clk will get acquired either from
dev_pm_opp_set_clkname() or while we initialize the OPPs within the
table.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Tested-by: Dmitry Osipenko <digetx@gmail.com>
2021-02-02 10:27:20 +05:30
Viresh Kumar
d758eaf5f8 opp: Staticize _add_opp_table()
_add_opp_table() isn't used outside of core.c, mark it static.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2021-02-02 10:26:58 +05:30
Viresh Kumar
e77dcb0b73 opp: Don't create an OPP table from dev_pm_opp_get_opp_table()
It has been found that some users (like cpufreq-dt and others on LKML)
have abused the helper dev_pm_opp_get_opp_table() to create the OPP
table instead of just finding it, which is the wrong thing to do. This
routine was meant for OPP core's internal working and exposed the whole
functionality by mistake.

Change the scope of dev_pm_opp_get_opp_table() to only finding the
table. The internal helpers _opp_get_opp_table*() are thus renamed to
_add_opp_table*(), dev_pm_opp_get_opp_table_indexed() is removed (as we
don't need the index field for finding the OPP table) and so the only
user, genpd, is updated.

Note that the prototype of _add_opp_table() was already left in opp.h by
mistake when it was removed earlier and so we weren't required to add it
now.

Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-12-09 11:21:11 +05:30
Rafael J. Wysocki
757e282188 Merge branch 'opp/linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/pm
Pull opertaing performance points (OPP) framework fixes for 5.10-rc1
from Viresh Kumar:

"- Return -EPROBE_DEFER properly from dev_pm_opp_get_opp_table()
   (Stephan Gerhold).

 - Minor cleanups around required-opps (Stephan Gerhold).

 - Extends opp-supported-hw property to contain multiple versions
   (Viresh Kumar).

 - Multiple cleanups around dev_pm_opp_attach_genpd() (Viresh Kumar).

 - Multiple fixes, cleanups in the OPP core for overall better design
   (Viresh Kumar)."

* 'opp/linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/pm:
  opp: Allow opp-level to be set to 0
  opp: Prevent memory leak in dev_pm_opp_attach_genpd()
  ARM: tegra: Pass multiple versions in opp-supported-hw property
  opp: Allow opp-supported-hw to contain multiple versions
  dt-bindings: opp: Allow opp-supported-hw to contain multiple versions
  opp: Set required OPPs in reverse order when scaling down
  opp: Reduce code duplication in _set_required_opps()
  opp: Drop unnecessary check from dev_pm_opp_attach_genpd()
  opp: Handle multiple calls for same OPP table in _of_add_opp_table_v1()
  opp: Allow dev_pm_opp_get_opp_table() to return -EPROBE_DEFER
  opp: Remove _dev_pm_opp_find_and_remove_table() wrapper
  opp: Split out _opp_set_rate_zero()
  opp: Reuse the enabled flag in !target_freq path
  opp: Rename regulator_enabled and use it as status of all resources
2020-10-05 13:31:32 +02:00
Viresh Kumar
922ff0759a opp: Don't drop reference for an OPP table that was never parsed
dev_pm_opp_remove_table() should drop a reference to the OPP table only
if the DT OPP table was parsed earlier with a call to
dev_pm_opp_of_add_table() earlier. Else it may end up dropping the
reference to the OPP table, which was added as a result of other calls
like dev_pm_opp_set_clkname(). And would hence result in undesirable
behavior later on when caller would try to free the resource again.

Fixes: 03758d6026 ("opp: Replace list_kref with a local counter")
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Reported-by: Anders Roxell <anders.roxell@linaro.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-08-31 14:49:47 +05:30
Viresh Kumar
8aaf6264fc opp: Remove _dev_pm_opp_find_and_remove_table() wrapper
Remove the unnecessary wrapper and merge
_dev_pm_opp_find_and_remove_table() with dev_pm_opp_remove_table().

Tested-by: Rajendra Nayak <rnayak@codeaurora.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-08-24 17:04:37 +05:30
Viresh Kumar
72f80ce4ef opp: Rename regulator_enabled and use it as status of all resources
Expand the scope of the regulator_enabled flag and use it to track
status of all the resources. This will be used for other stuff in the
next patch.

Tested-by: Rajendra Nayak <rnayak@codeaurora.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-08-24 17:04:17 +05:30
Kamil Konieczny
8d45719caa opp: core: add regulators enable and disable
Add enable regulators to dev_pm_opp_set_regulators() and disable
regulators to dev_pm_opp_put_regulators(). Even if bootloader
leaves regulators enabled, they should be enabled in kernel in
order to increase the reference count.

Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Clément Péron <peron.clem@gmail.com>
Tested-by: Clément Péron <peron.clem@gmail.com>
Signed-off-by: Kamil Konieczny <k.konieczny@samsung.com>
[ Viresh: Enable the regulator only after it is programmed and add a
	  flag to track its status. ]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-05-29 10:15:12 +05:30
Georgi Djakov
6d3f922c46 opp: Add support for parsing interconnect bandwidth
The OPP bindings now support bandwidth values, so add support to parse it
from device tree and store it into the new dev_pm_opp_icc_bw struct, which
is part of the dev_pm_opp.

Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
[ Viresh: Create _read_bw() and use it, renamed _of_find_icc_paths() to
	  dev_pm_opp_of_find_icc_paths(), exported it and made opp_table
	  argument optional. Also drop the depends on from Kconfig. ]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-05-29 10:15:08 +05:30
Saravana Kannan
6c591eec67 OPP: Add helpers for reading the binding properties
The opp-hz DT property is not mandatory and we may use another property
as a key in the OPP table. Add helper functions to simplify the reading
and comparing the keys.

Signed-off-by: Saravana Kannan <saravanak@google.com>
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Sibi Sankar <sibis@codeaurora.org>
[ Viresh: Removed an unnecessary comment ]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2020-05-13 11:48:13 +05:30
Viresh Kumar
03758d6026 opp: Replace list_kref with a local counter
A kref or refcount isn't the right tool to be used here for counting
number of devices that are sharing the static OPPs created for the OPP
table. For example, we are reinitializing the kref again, after it
reaches a value of 0 and frees the resources, if the static OPPs get
added for the same OPP table structure (as the OPP table structure was
never freed). That is messy and very unclear.

This patch makes parsed_static_opps an unsigned integer and uses it to
count the number of users of the static OPPs. The increment and
decrement to parsed_static_opps is done under opp_table->lock now to
make sure no races are possible if the OPP table is getting added and
removed in parallel (which doesn't happen in practice, but can in
theory).

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2019-12-10 15:57:00 +05:30
Thomas Gleixner
d2912cb15b treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500
Based on 2 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 17:09:55 +02:00
Linus Torvalds
ef8006846a Power management updates for 5.1-rc1
- Update the PM-runtime framework to use ktime instead of
    jiffies for accounting (Thara Gopinath, Vincent Guittot).
 
  - Optimize the autosuspend code in the PM-runtime framework
    somewhat (Ladislav Michl).
 
  - Add a PM core flag to mark devices that don't need any form of
    power management (Sudeep Holla).
 
  - Introduce driver API documentation for cpuidle and add a new
    cpuidle governor for tickless systems (Rafael Wysocki).
 
  - Add Jacobsville support to the intel_idle driver (Zhang Rui).
 
  - Clean up a cpuidle core header file and the cpuidle-dt and ACPI
    processor-idle drivers (Yangtao Li, Joseph Lo, Yazen Ghannam).
 
  - Add new cpufreq driver for Armada 8K (Gregory Clement).
 
  - Fix and clean up cpufreq core (Rafael Wysocki, Viresh Kumar,
    Amit Kucheria).
 
  - Add support for light-weight tear-down and bring-up of CPUs to the
    cpufreq core and use it in the cpufreq-dt driver (Viresh Kumar).
 
  - Fix cpu_cooling Kconfig dependencies, add support for CPU cooling
    auto-registration to the cpufreq core and use it in multiple
    cpufreq drivers (Amit Kucheria).
 
  - Fix some minor issues and do some cleanups in the davinci,
    e_powersaver, ap806, s5pv210, qcom and kryo cpufreq drivers
    (Bartosz Golaszewski, Gustavo Silva, Julia Lawall, Paweł Chmiel,
    Taniya Das, Viresh Kumar).
 
  - Add a Hisilicon CPPC quirk to the cppc_cpufreq driver (Xiongfeng
    Wang).
 
  - Clean up the intel_pstate and acpi-cpufreq drivers (Erwan Velu,
    Rafael Wysocki).
 
  - Clean up multiple cpufreq drivers (Yangtao Li).
 
  - Update cpufreq-related MAINTAINERS entries (Baruch Siach, Lukas
    Bulwahn).
 
  - Add support for exposing the Energy Model via debugfs and make
    multiple cpufreq drivers register an Energy Model to support
    energy-aware scheduling (Quentin Perret, Dietmar Eggemann,
    Matthias Kaehlcke).
 
  - Add Ice Lake mobile and Jacobsville support to the Intel RAPL
    power-capping driver (Gayatri Kammela, Zhang Rui).
 
  - Add a power estimation helper to the operating performance points
    (OPP) framework and clean up a core function in it (Quentin Perret,
    Viresh Kumar).
 
  - Make minor improvements in the generic power domains (genpd), OPP
    and system suspend frameworks and in the PM core (Aditya Pakki,
    Douglas Anderson, Greg Kroah-Hartman, Rafael Wysocki, Yangtao Li).
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Merge tag 'pm-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management updates from Rafael Wysocki:
 "These are PM-runtime framework changes to use ktime instead of jiffies
  for accounting, new PM core flag to mark devices that don't need any
  form of power management, cpuidle updates including driver API
  documentation and a new governor, cpufreq updates including a new
  driver for Armada 8K, thermal cleanups and more, some energy-aware
  scheduling (EAS) enabling changes, new chips support in the intel_idle
  and RAPL drivers and assorted cleanups in some other places.

  Specifics:

   - Update the PM-runtime framework to use ktime instead of jiffies for
     accounting (Thara Gopinath, Vincent Guittot)

   - Optimize the autosuspend code in the PM-runtime framework somewhat
     (Ladislav Michl)

   - Add a PM core flag to mark devices that don't need any form of
     power management (Sudeep Holla)

   - Introduce driver API documentation for cpuidle and add a new
     cpuidle governor for tickless systems (Rafael Wysocki)

   - Add Jacobsville support to the intel_idle driver (Zhang Rui)

   - Clean up a cpuidle core header file and the cpuidle-dt and ACPI
     processor-idle drivers (Yangtao Li, Joseph Lo, Yazen Ghannam)

   - Add new cpufreq driver for Armada 8K (Gregory Clement)

   - Fix and clean up cpufreq core (Rafael Wysocki, Viresh Kumar, Amit
     Kucheria)

   - Add support for light-weight tear-down and bring-up of CPUs to the
     cpufreq core and use it in the cpufreq-dt driver (Viresh Kumar)

   - Fix cpu_cooling Kconfig dependencies, add support for CPU cooling
     auto-registration to the cpufreq core and use it in multiple
     cpufreq drivers (Amit Kucheria)

   - Fix some minor issues and do some cleanups in the davinci,
     e_powersaver, ap806, s5pv210, qcom and kryo cpufreq drivers
     (Bartosz Golaszewski, Gustavo Silva, Julia Lawall, Paweł Chmiel,
     Taniya Das, Viresh Kumar)

   - Add a Hisilicon CPPC quirk to the cppc_cpufreq driver (Xiongfeng
     Wang)

   - Clean up the intel_pstate and acpi-cpufreq drivers (Erwan Velu,
     Rafael Wysocki)

   - Clean up multiple cpufreq drivers (Yangtao Li)

   - Update cpufreq-related MAINTAINERS entries (Baruch Siach, Lukas
     Bulwahn)

   - Add support for exposing the Energy Model via debugfs and make
     multiple cpufreq drivers register an Energy Model to support
     energy-aware scheduling (Quentin Perret, Dietmar Eggemann, Matthias
     Kaehlcke)

   - Add Ice Lake mobile and Jacobsville support to the Intel RAPL
     power-capping driver (Gayatri Kammela, Zhang Rui)

   - Add a power estimation helper to the operating performance points
     (OPP) framework and clean up a core function in it (Quentin Perret,
     Viresh Kumar)

   - Make minor improvements in the generic power domains (genpd), OPP
     and system suspend frameworks and in the PM core (Aditya Pakki,
     Douglas Anderson, Greg Kroah-Hartman, Rafael Wysocki, Yangtao Li)"

* tag 'pm-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (80 commits)
  cpufreq: kryo: Release OPP tables on module removal
  cpufreq: ap806: add missing of_node_put after of_device_is_available
  cpufreq: acpi-cpufreq: Report if CPU doesn't support boost technologies
  cpufreq: Pass updated policy to driver ->setpolicy() callback
  cpufreq: Fix two debug messages in cpufreq_set_policy()
  cpufreq: Reorder and simplify cpufreq_update_policy()
  cpufreq: Add kerneldoc comments for two core functions
  PM / core: Add support to skip power management in device/driver model
  cpufreq: intel_pstate: Rework iowait boosting to be less aggressive
  cpufreq: intel_pstate: Eliminate intel_pstate_get_base_pstate()
  cpufreq: intel_pstate: Avoid redundant initialization of local vars
  powercap/intel_rapl: add Ice Lake mobile
  ACPI / processor: Set P_LVL{2,3} idle state descriptions
  cpufreq / cppc: Work around for Hisilicon CPPC cpufreq
  ACPI / CPPC: Add a helper to get desired performance
  cpufreq: davinci: move configuration to include/linux/platform_data
  cpufreq: speedstep: convert BUG() to BUG_ON()
  cpufreq: powernv: fix missing check of return value in init_powernv_pstates()
  cpufreq: longhaul: remove unneeded semicolon
  cpufreq: pcc-cpufreq: remove unneeded semicolon
  ..
2019-03-06 12:59:46 -08:00
Greg Kroah-Hartman
a2dea4cb90 opp: no need to check return value of debugfs_create functions
When calling debugfs functions, there is no need to ever check the
return value.  The function can work or not, but the code logic should
never do something different based on this.

Cc: Viresh Kumar <vireshk@kernel.org>
Cc: Nishanth Menon <nm@ti.com>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: linux-pm@vger.kernel.org
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2019-02-07 09:58:32 +05:30
Rajendra Nayak
5b93ac5423 OPP: Add support for parsing the 'opp-level' property
Now that the OPP bindings are updated to include an optional
'opp-level' property, add support to parse it from device tree
and store it as part of dev_pm_opp structure.
Also add and export an helper 'dev_pm_opp_get_level()' that can be
used to get the level value read from device tree when present.

Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>
2019-01-22 15:06:11 -06:00
Viresh Kumar
ade0c9493e Merge branch 'opp/genpd/propagation' into opp/linux-next 2018-12-14 16:28:52 +05:30
Viresh Kumar
46f48aca2e OPP: Fix missing debugfs supply directory for OPPs
There is one case where we may end up with no "supply" directory for the
OPPs in debugfs. That happens when the OPP core isn't managing the
regulators for the device and the device's OPP do have microvolt
property. It happens because the opp_table->regulator_count remains set
to 0 and the debugfs routines don't add any supply directory in such a
case.

This commit fixes that by setting opp_table->regulator_count to 1 in
that particular case. But to make everything work nicely and not break
other parts of the core, regulator_count is defined as "int" now instead
of "unsigned int" and it can have different special values now. It is
set to -1 initially to mark it "uninitialized" and later only we set it
to 0 or positive values after checking how many supplies are there.

This also helps in finding the bugs where only few of the OPPs have the
"opp-microvolt" property set and not all.

Fixes: 1fae788ed6 ("PM / OPP: Don't create debugfs "supply-0" directory unnecessarily")
Reported-by: Quentin Perret <quentin.perret@arm.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2018-12-11 16:51:56 +05:30
Viresh Kumar
4f018bc0e1 OPP: Add dev_pm_opp_{set|put}_genpd_virt_dev() helper
Multiple generic power domains for a consumer device are supported with
the help of virtual devices, which are created for each consumer device
- genpd pair. These are the device structures which are attached to the
power domain and are required by the OPP core to set the performance
state of the genpd.

The helpers added by this commit are required to be called once for each
of these virtual devices. These are required only if multiple domains
are available for a device, otherwise the actual device structure will
be used instead by the OPP core.

The new helpers also support the complex cases where the consumer device
wouldn't always require all the domains. For example, a camera may
require only one power domain during normal operations but two during
high resolution operations. The consumer driver can call
dev_pm_opp_put_genpd_virt_dev(high_resolution_genpd_virt_dev) if it is
currently operating in the normal mode and doesn't have any performance
requirements from the genpd which manages high resolution power
requirements. The consumer driver can later call
dev_pm_opp_set_genpd_virt_dev(high_resolution_genpd_virt_dev) once it
switches back to the high resolution mode.

The new helpers differ from other OPP set/put helpers as the new ones
can be called with OPPs initialized for the table as we may need to call
them on the fly because of the complex case explained above. For this
reason it is possible that the genpd virt_dev structure may be used in
parallel while the new helpers are running and a new mutex is added to
protect against that. We didn't use the existing opp_table->lock mutex
as that is widely used in the OPP core and we will need this lock in the
dev_pm_opp_set_rate() helper while changing OPP and we need to make sure
there is not much contention while doing that as that's the hotpath.

Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2018-11-05 07:40:43 +05:30
Viresh Kumar
da544b61eb OPP: Populate OPPs from "required-opps" property
An earlier commit populated the OPP tables from the "required-opps"
property, this commit populates the individual OPPs. This is repeated
for each OPP in the OPP table and these populated OPPs will be used by
later commits.

Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2018-11-05 07:40:42 +05:30
Viresh Kumar
5d6d106fa4 OPP: Populate required opp tables from "required-opps" property
The current implementation works only for the case where a single
phandle is present in the "required-opps" property, while DT allows
multiple phandles to be present there.

This patch adds new infrastructure to parse all the phandles present in
"required-opps" property and save pointers of the required OPP's OPP
tables. These will be used by later commits.

Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2018-11-05 07:40:42 +05:30
Viresh Kumar
61d8e7c73b OPP: Identify and mark genpd OPP tables
We need to handle genpd OPP tables differently, this is already the case
at one location and will be extended going forward. Add another field to
the OPP table to check if the table belongs to a genpd or not.

Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2018-11-05 07:40:42 +05:30
Viresh Kumar
283d55e68d OPP: Prevent creating multiple OPP tables for devices sharing OPP nodes
When two or more devices are sharing their clock and voltage rails, they
share the same OPP table. But there are some corner cases where the OPP
core incorrectly creates separate OPP tables for them.

For example, CPU 0 and 1 share clock/voltage rails. The platform
specific code calls dev_pm_opp_set_regulators() for CPU0 and the OPP
core creates an OPP table for it (the individual OPPs aren't initialized
as of now). The same is repeated for CPU1 then. Because
_opp_get_opp_table() doesn't compare DT node pointers currently, it
fails to find the link between CPU0 and CPU1 and so creates a new OPP
table.

Fix this by calling _managed_opp() from _opp_get_opp_table().
_managed_opp() gain an additional argument (index) to get the right node
pointer. This resulted in simplifying code in _of_add_opp_table_v2() as
well.

Tested-by: Niklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2018-10-01 15:00:31 +05:30
Viresh Kumar
cdd6ed90cd OPP: Use a single mechanism to free the OPP table
Currently there are two separate ways to free the OPP table based on how
it is created in the first place.

We call _dev_pm_opp_remove_table() to free the static and/or dynamic
OPP, OPP list devices, etc. This is done for the case where the OPP
table is added while initializing the OPPs, like via the path
dev_pm_opp_of_add_table().

We also call dev_pm_opp_put_opp_table() in some cases which eventually
frees the OPP table structure once the reference count reaches 0. This
is used by the first case as well as other cases like
dev_pm_opp_set_regulators() where the OPPs aren't necessarily
initialized at this point.

This whole thing is a bit unclear and messy and obstruct any further
cleanup/fixup of OPP core.

This patch tries to streamline this by keeping a single path for OPP
table destruction, i.e. dev_pm_opp_put_opp_table().

All the cleanup happens in _opp_table_kref_release() now after the
reference count reaches 0. _dev_pm_opp_remove_table() is removed as it
isn't required anymore.

We don't drop the reference to the OPP table after creating it from
_of_add_opp_table_v{1|2}() anymore and the same is dropped only when we
try to remove them.

Tested-by: Niklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2018-09-19 14:56:46 -07:00
Viresh Kumar
2a4eb7358a OPP: Don't remove dynamic OPPs from _dev_pm_opp_remove_table()
Only one platform was depending on this feature and it is already
updated now. Stop removing dynamic OPPs from _dev_pm_opp_remove_table().
This simplifies lot of paths and removes unnecessary parameters.

Tested-by: Niklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2018-09-19 14:56:45 -07:00
Viresh Kumar
d0e8ae6c26 OPP: Create separate kref for static OPPs list
The static OPPs don't always get freed with the OPP table, it can happen
before that as well. For example, if the OPP table is first created
using helpers like dev_pm_opp_set_supported_hw() and the OPPs are
created at a later point. Now when the OPPs are removed, the OPP table
stays until the time dev_pm_opp_put_supported_hw() is called.

Later patches will streamline the freeing of OPP table and that requires
the static OPPs to get freed with help of a separate kernel reference.
This patch prepares for that by creating a separate kref for static OPPs
list.

Tested-by: Niklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2018-09-19 14:56:43 -07:00
Viresh Kumar
f06ed90e70 OPP: Parse OPP table's DT properties from _of_init_opp_table()
Parse the DT properties present in the OPP table from
_of_init_opp_table(), which is a dedicated routine for DT parsing.

Minor relocation of helpers is required for this.

It is possible now for _managed_opp() to return a partially initialized
OPP table if the OPP table is created via the helpers like
dev_pm_opp_set_supported_hw() and we need another flag to indicate if
the static OPP are already parsed or not to make sure we don't
incorrectly skip initializing the static OPPs.

Tested-by: Niklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2018-09-19 14:56:42 -07:00
Viresh Kumar
eb7c8743d6 OPP: Pass index to _of_init_opp_table()
This is a preparatory patch required for the next commit which will
start using OPP table's node pointer in _of_init_opp_table(), which
requires the index in order to read the OPP table's phandle.

This commit adds the index argument in the call chains in order to get
it delivered to _of_init_opp_table().

Tested-by: Niklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2018-09-19 14:56:41 -07:00
Viresh Kumar
3d2556992a OPP: Protect dev_list with opp_table lock
The dev_list needs to be protected with a lock, else we may have
simultaneous access (addition/removal) to it and that would be racy.
Extend scope of the opp_table lock to protect dev_list as well.

Tested-by: Niklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2018-09-19 14:56:40 -07:00
Viresh Kumar
404b1369ea OPP: Don't try to remove all OPP tables on failure
dev_pm_opp_of_cpumask_add_table() creates the OPP table for all CPUs
present in the cpumask and on errors it should revert all changes it has
done.

It actually is doing a bit more than that. On errors, it tries to free
all the OPP tables, even the one it hasn't created yet. This may also
end up freeing the OPP tables which were created from separate path,
like dev_pm_opp_set_supported_hw().

Reported-and-tested-by: Niklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2018-09-19 14:56:40 -07:00
Viresh Kumar
28fa4aca26 PM / OPP: Remove dev_pm_opp_{un}register_get_pstate_helper()
These helpers aren't used anymore, remove them.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
2018-05-09 10:15:21 +05:30
Viresh Kumar
a88bd2a51e PM / OPP: Implement of_dev_pm_opp_find_required_opp()
A device's DT node or its OPP nodes can contain a phandle to other
device's OPP node, in the "required-opps" property.

This patch implements a routine to find that required OPP from the node
that contains the "required-opps" property.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
2018-05-09 10:15:19 +05:30
Viresh Kumar
a1e8c13600 PM / OPP: "opp-hz" is optional for power domains
"opp-hz" property is optional for power domains now and we shouldn't
error out if it is missing for power domains.

This patch creates two new routines, _get_opp_count() and
_opp_is_duplicate(), by separating existing code from their parent
functions. Also skip duplicate OPP check for power domain OPPs as they
may not have any the "opp-hz" field, but a platform specific performance
state binding to uniquely identify OPP nodes.

By default the debugfs OPP nodes are named using the "rate" value, but
that isn't possible for the power domain OPP nodes and hence they use
the index of the OPP node in the OPP node list instead.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
2018-05-09 10:15:18 +05:30
Viresh Kumar
b6aa98364f PM / OPP: Add dev_pm_opp_{un}register_get_pstate_helper()
This adds the dev_pm_opp_{un}register_get_pstate_helper() helper
routines which will be used to set the get_pstate() callback for a
device. This callback will be later called internally by the OPP core to
get performance state corresponding to an OPP.

This is required temporarily until the time we have proper DT bindings
to include the performance state information.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-10-14 00:54:41 +02:00
Viresh Kumar
009acd196f PM / OPP: Support updating performance state of device's power domain
The genpd framework now provides an API to request device's power
domain to update its performance state.  Use that interface from the
OPP core for devices whose power domains support performance states.

Note that this commit doesn't add any mechanism by which performance
states are made available to the OPP core. That would be done by a
later commit.

Note that the current implementation is restricted to the case where
the device doesn't have separate regulators for itself. We shouldn't
over engineer the code before we have real use case for them. We can
always come back and add more code to support such cases later on.

Tested-by: Rajendra Nayak <rnayak@codeaurora.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-10-14 00:54:40 +02:00
Viresh Kumar
7813dd6fc7 PM / OPP: Move the OPP directory out of power/
The drivers/base/power/ directory is special and contains code related
to power management core like system suspend/resume, hibernation, etc.
It was fine to keep the OPP code inside it when we had just one file for
it, but it is growing now and already has a directory for itself.

Lets move it directly under drivers/ directory, just like cpufreq and
cpuidle.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-10-03 02:45:12 +02:00