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>

The static OPPs aren't getting freed properly, if errors occur while
adding them. Fix that by calling _put_opp_list_kref() and putting their
reference on failures.

Fixes: 11e1a1648298 ("opp: Don't decrement uninitialized list_kref")
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

The list_kref reaches a count of 0 when all the static OPPs are removed,
for example when dev_pm_opp_of_cpumask_remove_table() is called, though
the actual OPP table may not get freed as it may still be referenced by
other parts of the kernel, like from a call to
dev_pm_opp_set_supported_hw(). And if we call
dev_pm_opp_of_cpumask_add_table() again at this point, we must
reinitialize the list_kref otherwise the kernel will hit a WARN() in
kref infrastructure for incrementing a kref with value 0.

Fixes: 11e1a1648298 ("opp: Don't decrement uninitialized list_kref")
Reported-by: Dmitry Osipenko <digetx@gmail.com>
Tested-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

_find_opp_of_np() doesn't traverse the list of OPP tables but instead
just the entries within an OPP table and so only requires to lock the
OPP table itself.

The lockdep_assert_held() was added there by mistake and isn't really
required.

Fixes: 5d6d106fa455 ("OPP: Populate required opp tables from "required-opps" property")
Cc: v5.0+ <stable@vger.kernel.org> # v5.0+
Reported-by: Niklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

With property "opp-supported-hw" introduced, the OPP table
in DT could be a large OPP table and ONLY a subset of OPPs
are available, based on the version of the hardware running
on. That introduces restriction of using "opp-suspend"
property to define the suspend OPP, as we are NOT sure if the
OPP containing "opp-suspend" property is available for the
hardware running on, and the of opp core does NOT allow multiple
suspend OPPs defined in DT OPP table.

To eliminate this restrition, make of opp core allow multiple
suspend OPPs defined in DT, and pick the OPP with highest rate
and with "opp-suspend" property present to be suspend OPP, it
can speed up the suspend/resume process.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

The list_kref was added for static OPPs and to track their users. The
kref is initialized while the static OPPs are added, but removed
unconditionally even if the static OPPs were never added. This causes
refcount mismatch warnings currently.

Fix that by always initializing the kref when the OPP table is first
initialized. The refcount is later incremented only for the second user
onwards.

Fixes: d0e8ae6c26da ("OPP: Create separate kref for static OPPs list")
Reported-by: Rajendra Nayak <rnayak@codeaurora.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

Pull operating performance points (OPP) framework changes for v5.3
from Viresh Kumar:

"This pull request contains:

 - OPP core changes to support a wider range of devices, like IO
   devices (Rajendra Nayak and Stehpen Boyd).
 - Fixes around genpd_virt_devs (Viresh Kumar).
 - Fix for platform with set_opp() callback (Dmitry Osipenko)."

* 'opp/linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/pm:
  opp: Don't use IS_ERR on invalid supplies
  opp: Make dev_pm_opp_set_rate() handle freq = 0 to drop performance votes
  opp: Don't overwrite rounded clk rate
  opp: Allocate genpd_virt_devs from dev_pm_opp_attach_genpd()
  opp: Attach genpds to devices from within OPP core

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>

Currently the space for the array of virtual devices is allocated along
with the OPP table, but that isn't going to work well from now onwards.
For single power domain case, a driver can either use the original
device structure for setting the performance state (if genpd attached
with dev_pm_domain_attach()) or use the virtual device structure (if
genpd attached with dev_pm_domain_attach_by_name(), which returns the
virtual device) and so we can't know in advance if we are going to need
genpd_virt_devs array or not.

Lets delay the allocation a bit and do it along with
dev_pm_opp_attach_genpd() rather. The deallocation is done from
dev_pm_opp_detach_genpd().

Tested-by: Niklas Cassel <niklas.cassel@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

We seem to rely on the number of phandles specified in the
'required-opps' property to identify cases where a device is
associated with multiple power domains and hence would have
multiple virtual devices that have to be dealt with.

In cases where we do have devices with multiple power domains
but with only one of them being scalable, this logic seems to
fail.

Instead read the number of power domains from DT to identify
such cases.

Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>