thermal: core: remove unnecessary check in trip_point_hyst_store()

This code was shuffled around a bit recently. We no longer need to
check the value of "ret" because we know it's zero.

Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

thermal: core: Drop the .set_trip_hyst() thermal zone operation

None of the users of the thermal core provides a .set_trip_hyst()
thermal zone operation, so drop that callback from struct
thermal_zone_device_ops and update trip_point_hyst_store()
accordingly.

No functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>

thermal: core: Add flags to struct thermal_trip

In order to allow thermal zone creators to specify the writability of
trip point temperature and hysteresis on a per-trip basis, add a flags
field to struct thermal_trip and define flags to represent the desired
trip properties.

Also make thermal_zone_device_register_with_trips() set the
THERMAL_TRIP_FLAG_RW_TEMP flag for all trips covered by the writable
trips mask passed to it and modify the thermal sysfs code to look at
the trip flags instead of using the writable trips mask directly or
checking the presence of the .set_trip_hyst() zone callback.

Additionally, make trip_point_temp_store() and trip_point_hyst_store()
fail with an error code if the trip passed to one of them has
THERMAL_TRIP_FLAG_RW_TEMP or THERMAL_TRIP_FLAG_RW_HYST,
respectively, clear in its flags.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

thermal: Get rid of CONFIG_THERMAL_WRITABLE_TRIPS

The only difference made by CONFIG_THERMAL_WRITABLE_TRIPS is whether or
not the writable trips mask passed during thermal zone registration
will take any effect, but whoever passes a non-zero writable trips mask
to thermal_zone_device_register_with_trips() can be forgiven thinking
that it will always work.

Moreover, some thermal drivers expect user space to set trip temperature
values, so they select CONFIG_THERMAL_WRITABLE_TRIPS, possibly overriding
a manual choice to unset it and going against the design purportedly
allowing system integrators to decide on the writability of trip points
for the given kernel build. It is also set in one platform's defconfig.

Forthermore, CONFIG_THERMAL_WRITABLE_TRIPS only affects trip temperature,
because trip hysteresis is writable as long as the thermal zone provides
a callback to update it, regardless of the CONFIG_THERMAL_WRITABLE_TRIPS
value.

The above means that the symbol in question is used inconsistently and
its purpose is at least moot, so remove it and always take the writable
trip mask passed to thermal_zone_device_register_with_trips() into
account.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>

thermal: core: Store zone ops in struct thermal_zone_device

The current code requires thermal zone creators to pass pointers to
writable ops structures to thermal_zone_device_register_with_trips()
which needs to modify the target struct thermal_zone_device_ops object
if the "critical" operation in it is NULL.

Moreover, the callers of thermal_zone_device_register_with_trips() are
required to hold on to the struct thermal_zone_device_ops object passed
to it until the given thermal zone is unregistered.

Both of these requirements are quite inconvenient, so modify struct
thermal_zone_device to contain struct thermal_zone_device_ops as field and
make thermal_zone_device_register_with_trips() copy the contents of the
struct thermal_zone_device_ops passed to it via a pointer (which can be
const now) to that field.

Also adjust the code using thermal zone ops accordingly and modify
thermal_of_zone_register() to use a local ops variable during
thermal zone registration so ops do not need to be freed in
thermal_of_zone_unregister() any more.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>
Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>

thermal: sysfs: Fix up white space in trip_point_temp_store()

Remove an excess tab character from an otherwise empty code line.

No functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>

thermal/sysfs: Update governors when the 'weight' has changed

Support governors update when the thermal instance's weight has changed.
This allows to adjust internal state for the governor.

Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
[ rjw: Add two empty code lines aroung the locking ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

thermal/sysfs: Update instance->weight under tz lock

User space can change the weight of a thermal instance via sysfs while the
.throttle() callback is running for a governor, because weight_store()
does not use the zone lock.

The IPA governor uses instance weight values for power calculations and
caches the sum of them as total_weight, so it gets confused when one of
them changes while its .throttle() callback is running.

To prevent that from happening, use thermal zone locking in
weight_store().

Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

thermal: trip: Send trip change notifications on all trip updates

The _store callbacks of the trip point temperature and hysteresis sysfs
attributes invoke thermal_notify_tz_trip_change() to send a notification
regarding the trip point change, but when trip points are updated by the
platform firmware, trip point change notifications are not sent.

To make the behavior after a trip point change more consistent,
modify all of the 3 places where trip point temperature is updated
to use a new function called thermal_zone_set_trip_temp() for this
purpose and make that function call thermal_notify_tz_trip_change().

Note that trip point hysteresis can only be updated via sysfs and
trip_point_hyst_store() calls thermal_notify_tz_trip_change() already,
so this code path need not be changed.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>

thermal: Drop redundant and confusing device_is_registered() checks

Multiple places in the thermal subsystem (most importantly, sysfs
attribute callback functions) check if the given thermal zone device is
still registered in order to return early in case the device_del() in
thermal_zone_device_unregister() has run already.

However, after thermal_zone_device_unregister() has been made wait for
all of the zone-related activity to complete before returning, it is
not necessary to do that any more, because all of the code holding a
reference to the thermal zone device object will be waited for even if
it does not do anything special to enforce this.

Accordingly, drop all of the device_is_registered() checks that are now
redundant and get rid of the zone locking that is not necessary any more
after dropping them.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-and-tested-by: Lukasz Luba <lukasz.luba@arm.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>

thermal: sysfs: Rework the reading of trip point attributes

Rework the _show() callback functions for the trip point temperature,
hysteresis and type attributes to avoid copying the values of struct
thermal_trip fields that they do not use and make them carry out the
same validation checks as the corresponding _store() callback functions.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>

thermal: sysfs: Rework the handling of trip point updates

Both trip_point_temp_store() and trip_point_hyst_store() use
thermal_zone_set_trip() to update a given trip point, but none of them
actually needs to change more than one field in struct thermal_trip
representing it. However, each of them effectively calls
__thermal_zone_get_trip() twice in a row for the same trip index value,
once directly and once via thermal_zone_set_trip(), which is not
particularly efficient, and the way in which thermal_zone_set_trip()
carries out the update is not particularly straightforward.

Moreover, input processing need not be done under the thermal zone lock
in any of these functions.

Rework trip_point_temp_store() and trip_point_hyst_store() to address
the above, move the part of thermal_zone_set_trip() that is still
useful to a new function called thermal_zone_trip_updated() and drop
the rest of it.

While at it, make trip_point_hyst_store() reject negative hysteresis
values.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>

thermal: core: Store trip pointer in struct thermal_instance

Replace the integer trip number stored in struct thermal_instance with
a pointer to the relevant trip and adjust the code using the structure
in question accordingly.

The main reason for making this change is to allow the trip point to
cooling device binding code more straightforward, as illustrated by
subsequent modifications of the ACPI thermal driver, but it also helps
to clarify the overall design and allows the governor code overhead to
be reduced (through subsequent modifications).

The only case in which it adds complexity is trip_point_show() that
needs to walk the trips[] table to find the index of the given trip
point, but this is not a critical path and the interface that
trip_point_show() belongs to is problematic anyway (for instance, it
doesn't cover the case when the same cooling devices is associated
with multiple trip points).

This is a preliminary change and the affected code will be refined by
a series of subsequent modifications of thermal governors, the core and
the ACPI thermal driver.

The general functionality is not expected to be affected by this change.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>

thermal: sysfs: Fix trip_point_hyst_store()

After commit 2e38a2a981b2 ("thermal/core: Add a generic thermal_zone_set_trip()
function") updating a trip point temperature doesn't actually work,
because the value supplied by user space is subsequently overwritten
with the current trip point hysteresis value.

Fix this by changing the code to parse the number string supplied by
user space after retrieving the current trip point data from the
thermal zone.

Also drop a redundant tab character from the code in question.

Fixes: 2e38a2a981b2 ("thermal/core: Add a generic thermal_zone_set_trip() function")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: 6.3+ <stable@vger.kernel.org> # 6.3+

thermal: core: Drop excessive lockdep_assert_held() calls

The lockdep_assert_held() calls added to cooling_device_stats_setup()
and cooling_device_stats_destroy() by commit 790930f44289 ("thermal:
core: Introduce thermal_cooling_device_update()") trigger false-positive
lockdep reports in code paths that are not subject to race conditions
(before cooling device registration and after cooling device removal).

For this reason, remove the lockdep_assert_held() calls from both
cooling_device_stats_setup() and cooling_device_stats_destroy() and
add one to thermal_cooling_device_stats_reinit() that has to be called
under the cdev lock.

Fixes: 790930f44289 ("thermal: core: Introduce thermal_cooling_device_update()")
Link: https://lore.kernel.org/linux-acpi/ZCIDTLFt27Ei7+V6@ideak-desk.fi.intel.com
Reported-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

thermal: core: Introduce thermal_cooling_device_update()

Introduce a core thermal API function, thermal_cooling_device_update(),
for updating the max_state value for a cooling device and rearranging
its statistics in sysfs after a possible change of its ->get_max_state()
callback return value.

That callback is now invoked only once, during cooling device
registration, to populate the max_state field in the cooling device
object, so if its return value changes, it needs to be invoked again
and the new return value needs to be stored as max_state. Moreover,
the statistics presented in sysfs need to be rearranged in general,
because there may not be enough room in them to store data for all
of the possible states (in the case when max_state grows).

The new function takes care of that (and some other minor things
related to it), but some extra locking and lockdep annotations are
added in several places too to protect against crashes in the cases
when the statistics are not present or when a stale max_state value
might be used by sysfs attributes.

Note that the actual user of the new function will be added separately.

Link: https://lore.kernel.org/linux-pm/53ec1f06f61c984100868926f282647e57ecfb2d.camel@intel.com/
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Zhang Rui <rui.zhang@intel.com>
Reviewed-by: Zhang Rui <rui.zhang@intel.com>

thermal/core: Add a generic thermal_zone_set_trip() function

The thermal zone ops defines a set_trip callback where we can invoke
the backend driver to set an interrupt for the next trip point
temperature being crossed the way up or down, or setting the low level
with the hysteresis.

The ops is only called from the thermal sysfs code where the userspace
has the ability to modify a trip point characteristic.

With the effort of encapsulating the thermal framework core code,
let's create a thermal_zone_set_trip() which is the writable side of
the thermal_zone_get_trip() and put there all the ops encapsulation.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20221003092602.1323944-4-daniel.lezcano@linaro.org

thermal/sysfs: Always expose hysteresis attributes

Instead of avoiding to expose the hysteresis attributes of a thermal
zone when its get_trip_hyst() operation is not defined, which is
confusing, expose them always and use the default
thermal_zone_get_trip() function returning 0 hysteresis when that
operation is not present.

The hysteresis of 0 is perfectly valid, so this change should not
introduce any backwards compatibility issues.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20221003092602.1323944-3-daniel.lezcano@linaro.org

thermal/core: Add a generic thermal_zone_get_trip() function

The thermal_zone_device_ops structure defines a set of ops family,
get_trip_temp(), get_trip_hyst(), get_trip_type(). Each of them is
returning a property of a trip point.

The result is the code is calling the ops everywhere to get a trip
point which is supposed to be defined in the backend driver. It is a
non-sense as a thermal trip can be generic and used by the backend
driver to declare its trip points.

Part of the thermal framework has been changed and all the OF thermal
drivers are using the same definition for the trip point and use a
thermal zone registration variant to pass those trip points which are
part of the thermal zone device structure.

Consequently, we can use a generic function to get the trip points
when they are stored in the thermal zone device structure.

This approach can be generalized to all the drivers and we can get rid
of the ops->get_trip_*. That will result to a much more simpler code
and make possible to rework how the thermal trip are handled in the
thermal core framework as discussed previously.

This change adds a function thermal_zone_get_trip() where we get the
thermal trip point structure which contains all the properties (type,
temp, hyst) instead of doing multiple calls to ops->get_trip_*.

That opens the door for trip point extension with more attributes. For
instance, replacing the trip points disabled bitmask with a 'disabled'
field in the structure.

Here we replace all the calls to ops->get_trip_* in the thermal core
code with a call to the thermal_zone_get_trip() function.

The thermal zone ops defines a callback to retrieve the critical
temperature. As the trip handling is being reworked, all the trip
points will be the same whatever the driver and consequently finding
the critical trip temperature will be just a loop to search for a
critical trip point type.

Provide such a generic function, so we encapsulate the ops
get_crit_temp() which can be removed when all the backend drivers are
using the generic trip points handling.

While at it, add the thermal_zone_get_num_trips() to encapsulate the
code more and reduce the grip with the thermal framework internals.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Zhang Rui <rui.zhang@intel.com>
Link: https://lore.kernel.org/r/20221003092602.1323944-2-daniel.lezcano@linaro.org

thermal/core: Protect sysfs accesses to thermal operations with thermal zone mutex

Protect access to thermal operations against thermal zone removal by
acquiring the thermal zone device mutex. After acquiring the mutex, check
if the thermal zone device is registered and abort the operation if not.

With this change, we can call __thermal_zone_device_update() instead of
thermal_zone_device_update() from trip_point_temp_store() and from
emul_temp_store(). Similar, we can call __thermal_zone_set_trips() instead
of thermal_zone_set_trips() from trip_point_hyst_store().

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

thermal: sysfs: Reuse cdev->max_state

Now that the cooling device structure stores the max_state value, reuse
it and drop max_states from struct cooling_dev_stats.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

thermal: Validate new state in cur_state_store()

In cur_state_store(), the new state of the cooling device is received
from user-space and is not validated by the thermal core but the same is
left for the individual drivers to take care of. Apart from duplicating
the code it leaves possibility for introducing bugs where a driver may
not do it right.

Lets make the thermal core check the new state itself and store the max
value in the cooling device structure.

Link: https://lore.kernel.org/all/Y0ltRJRjO7AkawvE@kili/
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

thermal/core: Add a check before calling set_trip_temp()

The thermal driver [0] for Renesas RZ/G2L SoC does not implement
set_trip_temp() callback but has trips commit 9326167058e8
("thermal/core: Move set_trip_temp ops to the sysfs code") changed
the behaviour which causes the below panic when trying to set the
trip temperature:

root@smarc-rzg2l:~# echo 51000 > /sys/class/thermal/thermal_zone0/trip_point_0_temp
[ 92.461521] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
[ 92.470958] Mem abort info:
[ 92.474311] ESR = 0x0000000086000004
[ 92.478546] EC = 0x21: IABT (current EL), IL = 32 bits
[ 92.484290] SET = 0, FnV = 0
[ 92.487693] EA = 0, S1PTW = 0
[ 92.491153] FSC = 0x04: level 0 translation fault
[ 92.496461] user pgtable: 4k pages, 48-bit VAs, pgdp=000000004e885000
[ 92.503736] [0000000000000000] pgd=0000000000000000, p4d=0000000000000000
[ 92.510869] Internal error: Oops: 86000004 [#3] PREEMPT SMP
[ 92.516556] CPU: 0 PID: 290 Comm: sh Tainted: G D 6.0.0-rc4-next-20220906-arm64-renesas-00124-g84633c87c5f6-dirty #509
[ 92.528814] Hardware name: Renesas SMARC EVK based on r9a07g044l2 (DT)
[ 92.535441] pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[ 92.542516] pc : 0x0
[ 92.544764] lr : trip_point_temp_store+0x84/0x140
[ 92.549582] sp : ffff80000a92bc10
[ 92.552961] x29: ffff80000a92bc10 x28: ffff00000d8a45c0 x27: 0000000000000000
[ 92.560249] x26: 0000000000000000 x25: ffff8000082b53e8 x24: ffff00000eaffc20
[ 92.567532] x23: ffff80000a92bd68 x22: ffff00000d3e0f80 x21: 0000000000000006
[ 92.574814] x20: ffff800009149000 x19: ffff00000b8ab000 x18: 0000000000000000
[ 92.582097] x17: 0000000000000000 x16: 0000000000000000 x15: 0000aaab028cdee0
[ 92.589378] x14: 0000000000000000 x13: 0000000000000000 x12: ffff80000a92bbd0
[ 92.596659] x11: ffff00000d3e0f80 x10: ffff800009149eb8 x9 : 000000000000000a
[ 92.603940] x8 : 00000000ffffffc9 x7 : 0000000000000005 x6 : 000000000000002a
[ 92.611220] x5 : 000000000000c738 x4 : 00000000ffffffd3 x3 : 0000000000000000
[ 92.618500] x2 : 000000000000c738 x1 : 0000000000000000 x0 : ffff00000b8ab000
[ 92.625781] Call trace:
[ 92.628282] 0x0
[ 92.630176] dev_attr_store+0x14/0x28
[ 92.633935] sysfs_kf_write+0x4c/0x70
[ 92.637681] kernfs_fop_write_iter+0x160/0x1e0
[ 92.642213] vfs_write+0x474/0x540
[ 92.645703] ksys_write+0x68/0xf8
[ 92.649100] __arm64_sys_write+0x18/0x20
[ 92.653111] invoke_syscall+0x40/0xf8
[ 92.656866] el0_svc_common.constprop.3+0x88/0x110
[ 92.661758] do_el0_svc+0x20/0x78
[ 92.665158] el0_svc+0x3c/0x90
[ 92.668291] el0t_64_sync_handler+0x90/0xb8
[ 92.672563] el0t_64_sync+0x148/0x14c
[ 92.676322] Code: bad PC value
[ 92.679453] ---[ end trace 0000000000000000 ]---
/bin/start_getty: line 40: 290 Segmentation fault ${setsid:-} ${getty} -L $1 $2 $3

Poky (Yocto Project Reference Distro) 3.2.1 smarc-rzg2l ttySC0

smarc-rzg2l login:

This patch fixes the above issue by adding a check to see if
set_trip_temp() callback is implemented before calling it.

[0] drivers/thermal/rzg2l_thermal.c

Fixes: 9326167058e8 ("thermal/core: Move set_trip_temp ops to the sysfs code")
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20220908174610.7837-1-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

thermal/core: Move the mutex inside the thermal_zone_device_update() function

All the different calls inside the thermal_zone_device_update()
function take the mutex.

The previous changes move the mutex out of the different functions,
like the throttling ops. Now that the mutexes are all at the same
level in the call stack for the thermal_zone_device_update() function,
they can be moved inside this one.

That has the benefit of:

1. Simplify the code by not having a plethora of places where the lock is taken

2. Probably closes more race windows because releasing the lock from
one line to another can give the opportunity to the thermal zone to change
its state in the meantime. For example, the thermal zone can be
enabled right after checking it is disabled.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20220805153834.2510142-5-daniel.lezcano@linaro.org

thermal/core: Move set_trip_temp ops to the sysfs code

Given the trip points can be set in the thermal zone structure, there
is no need of a specific OF function to do that. Move the code in the
place where it is generic, in the sysfs set_trip_temp storing
function.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linexp.org>
Link: https://lore.kernel.org/r/20220804224349.1926752-33-daniel.lezcano@linexp.org
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

thermal: sysfs: Fix cooling_device_stats_setup() error code path

If cooling_device_stats_setup() fails to create the stats object, it
must clear the last slot in cooling_device_attr_groups that was
initially empty (so as to make it possible to add stats attributes to
the cooling device attribute groups).

Failing to do so may cause the stats attributes to be created by
mistake for a device that doesn't have a stats object, because the
slot in question might be populated previously during the registration
of another cooling device.

Fixes: 8ea229511e06 ("thermal: Add cooling device's statistics in sysfs")
Reported-by: Di Shen <di.shen@unisoc.com>
Tested-by: Di Shen <di.shen@unisoc.com>
Cc: 4.17+ <stable@vger.kernel.org> # 4.17+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

thermal/core: Rename 'trips' to 'num_trips'

In order to use thermal trips defined in the thermal structure, rename
the 'trips' field to 'num_trips' to have the 'trips' field containing the
thermal trip points.

Cc: Alexandre Bailon <abailon@baylibre.com>
Cc: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linexp.org>
Link: https://lore.kernel.org/r/20220722200007.1839356-8-daniel.lezcano@linexp.org
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Revert "thermal/core: Deprecate changing cooling device state from userspace"

This reverts commit a67a46af4ad6342378e332b7420c1d1a2818c53f.

It has been reported the warning is annoying as the cooling device
state is still needed on some production system.

Meanwhile we provide a way to consolidate the thermal framework to
prevent multiple actors acting on the cooling devices with conflicting
decisions, let's revert this warning.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

thermal/core: Deprecate changing cooling device state from userspace

The cooling devices have their cooling device set_cur_state
read-writable all the time in the sysfs directory, thus allowing the
userspace to act on it.

The thermal framework is wrongly used by userspace as a power capping
framework by acting on the cooling device opaque state. This one then
competes with the in-kernel governor decision.

We have seen in out-of-tree kernels, a big number of devices which are
abusely declaring themselves as cooling device just to act on their
power.

The role of the thermal framework is to protect the junction
temperature of the silicon. Letting the userspace to play with a
cooling device is invalid and potentially dangerous.

The powercap framework is the right framework to do power capping and
moreover it deals with the aggregation via the dev pm qos.

As the userspace governor is marked deprecated and about to be
removed, there is no point to keep this file writable also in the
future.

Emit a warning and deprecate the interface.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Link: https://lore.kernel.org/r/20211019163506.2831454-2-daniel.lezcano@linaro.org

thermal/core: Add NULL pointer check before using cooling device stats

There is a possible chance that some cooling device stats buffer
allocation fails due to very high cooling device max state value.
Later cooling device update sysfs can try to access stats data
for the same cooling device. It will lead to NULL pointer
dereference issue.

Add a NULL pointer check before accessing thermal cooling device
stats data. It fixes the following bug

[ 26.812833] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000004
[ 27.122960] Call trace:
[ 27.122963] do_raw_spin_lock+0x18/0xe8
[ 27.122966] _raw_spin_lock+0x24/0x30
[ 27.128157] thermal_cooling_device_stats_update+0x24/0x98
[ 27.128162] cur_state_store+0x88/0xb8
[ 27.128166] dev_attr_store+0x40/0x58
[ 27.128169] sysfs_kf_write+0x50/0x68
[ 27.133358] kernfs_fop_write+0x12c/0x1c8
[ 27.133362] __vfs_write+0x54/0x160
[ 27.152297] vfs_write+0xcc/0x188
[ 27.157132] ksys_write+0x78/0x108
[ 27.162050] ksys_write+0xf8/0x108
[ 27.166968] __arm_smccc_hvc+0x158/0x4b0
[ 27.166973] __arm_smccc_hvc+0x9c/0x4b0
[ 27.186005] el0_svc+0x8/0xc

Signed-off-by: Manaf Meethalavalappu Pallikunhi <manafm@codeaurora.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/1607367181-24589-1-git-send-email-manafm@codeaurora.org

thermal/core: Remove pointless test with the THERMAL_TRIPS_NONE macro

The THERMAL_TRIPS_NONE is equal to -1, it is pointless to do a
conversion in this function.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Thara Gopinath <thara.gopinath@linaro.org>
Link: https://lore.kernel.org/r/20201214233811.485669-3-daniel.lezcano@linaro.org

thermal/core: Remove the 'forced_passive' option

The code was reorganized in 2012 with the commit 0c01ebbfd3caf1.

The main change is a loop on the trip points array and a unconditional
call to the throttle() ops of the governors for each of them even if
the trip temperature is not reached yet.

With this change, the 'forced_passive' is no longer checked in the
thermal_zone_device_update() function but in the step wise governor's
throttle() callback.

As the force_passive does no belong to the trip point array, the
thermal_zone_device_update() can not compare with the specified
passive temperature, thus does not detect the passive limit has been
crossed. Consequently, throttle() is never called and the
'forced_passive' branch is unreached.

In addition, the default processor cooling device is not automatically
bound to the thermal zone if there is not passive trip point, thus the
'forced_passive' can not operate.

If there is an active trip point, then the throttle function will be
called to mitigate at this temperature and the 'forced_passive' will
override the mitigation of the active trip point in this case but with
the default cooling device bound to the thermal zone, so usually a
fan, and that is not a passive cooling effect.

Given the regression exists since more than 8 years, nobody complained
and at the best of my knowledge there is no bug open in
https://bugzilla.kernel.org, it is reasonable to say it is unused.

Remove the 'forced_passive' related code.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Thara Gopinath <thara.gopinath@linaro.org>
Link: https://lore.kernel.org/r/20201214233811.485669-1-daniel.lezcano@linaro.org

thermal: core: Constify static attribute_group structs

The only usage of these structs is to assign their address to the
thermal_zone_attribute_groups array, which consists of pointers to
const, so make them const to allow the compiler to put them in read-only
memory.

Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20201128234342.36684-1-rikard.falkeborn@gmail.com

thermal: Use kobj_to_dev() instead of container_of()

Use kobj_to_dev() instead of container_of()

Signed-off-by: Tian Tao <tiantao6@hisilicon.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/1597799671-11530-1-git-send-email-tiantao6@hisilicon.com

thermal: core: Add notifications call in the framework

The generic netlink protocol is implemented but the different
notification functions are not yet connected to the core code.

These changes add the notification calls in the different
corresponding places.

Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Zhang Rui <rui.zhang@intel.com>
Link: https://lore.kernel.org/r/20200706105538.2159-4-daniel.lezcano@linaro.org

thermal: Use mode helpers in drivers

Use thermal_zone_device_{en|dis}able() and thermal_zone_device_is_enabled().

Consequently, all set_mode() implementations in drivers:

- can stop modifying tzd's "mode" member,
- shall stop taking tzd's lock, as it is taken in the helpers
- shall stop calling thermal_zone_device_update() as it is called in the
helpers
- can assume they are called when the mode truly changes, so checks to
verify that can be dropped

Not providing set_mode() by a driver no longer prevents the core from
being able to set tzd's mode, so the relevant check in mode_store() is
removed.

Other comments:

- acpi/thermal.c: tz->thermal_zone->mode will be updated only after we
return from set_mode(), so use function parameter in thermal_set_mode()
instead, no need to call acpi_thermal_check() in set_mode()
- thermal/imx_thermal.c: regmap writes and mode assignment are done in
thermal_zone_device_{en|dis}able() and set_mode() callback
- thermal/intel/intel_quark_dts_thermal.c: soc_dts_{en|dis}able() are a
part of set_mode() callback, so they don't need to modify tzd->mode, and
don't need to fall back to the opposite mode if unsuccessful, as the return
value will be propagated to thermal_zone_device_{en|dis}able() and
ultimately tzd's member will not be changed in thermal_zone_device_set_mode().
- thermal/of-thermal.c: no need to set zone->mode to DISABLED in
of_parse_thermal_zones() as a tzd is kzalloc'ed so mode is DISABLED anyway

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@collabora.com>
[for acerhdf]
Acked-by: Peter Kaestle <peter@piie.net>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200629122925.21729-8-andrzej.p@collabora.com

thermal: remove get_mode() operation of drivers

get_mode() is now redundant, as the state is stored in struct
thermal_zone_device.

Consequently the "mode" attribute in sysfs can always be visible, because
it is always possible to get the mode from struct tzd.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@collabora.com>
[for acerhdf]
Acked-by: Peter Kaestle <peter@piie.net>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200629122925.21729-6-andrzej.p@collabora.com

thermal: Fix locking in cooling device sysfs update cur_state

Sysfs interface to update cooling device cur_state does not
currently holding cooling device lock sometimes leading to
stale values in cur_state if getting updated simultanelously
from user space and thermal framework. Adding the proper locking
code fixes this issue.

Signed-off-by: Thara Gopinath <thara.gopinath@linaro.org>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

drivers: thermal: Update license to SPDX format

Update licences format for core thermal files.

Signed-off-by: Lina Iyer <ilina@codeaurora.org>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

thermal: Use DEVICE_ATTR_{RO|RW|WO}() variants

Use the DEVICE_ATTR_{RO|RW|WO}() variants instead of DEVICE_ATTR().

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

thermal: Shorten name of sysfs callbacks

The naming isn't consistent across all sysfs callbacks in the thermal
core, some have a short name like type_show() and others have long names
like thermal_cooling_device_weight_show(). This patch tries to make it
consistent by shortening the name of sysfs callbacks.

Some of the sysfs files are named similarly for both thermal zone and
cooling device (like: type) and to avoid name clash between their
show/store routines, the cooling device specific sysfs callbacks are
prefixed with "cdev_".

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

thermal: Add cooling device's statistics in sysfs

This extends the sysfs interface for thermal cooling devices and exposes
some pretty useful statistics. These statistics have proven to be quite
useful specially while doing benchmarks related to the task scheduler,
where we want to make sure that nothing has disrupted the test,
specially the cooling device which may have put constraints on the CPUs.
The information exposed here tells us to what extent the CPUs were
constrained by the thermal framework.

The write-only "reset" file is used to reset the statistics.

The read-only "time_in_state_ms" file shows the time (in msec) spent by the
device in the respective cooling states, and it prints one line per
cooling state.

The read-only "total_trans" file shows single positive integer value
showing the total number of cooling state transitions the device has
gone through since the time the cooling device is registered or the time
when statistics were reset last.

The read-only "trans_table" file shows a two dimensional matrix, where
an entry <i,j> (row i, column j) represents the number of transitions
from State_i to State_j.

This is how the directory structure looks like for a single cooling
device:

$ ls -R /sys/class/thermal/cooling_device0/
/sys/class/thermal/cooling_device0/:
cur_state max_state power stats subsystem type uevent

/sys/class/thermal/cooling_device0/power:
autosuspend_delay_ms runtime_active_time runtime_suspended_time
control runtime_status

/sys/class/thermal/cooling_device0/stats:
reset time_in_state_ms total_trans trans_table

This is tested on ARM 64-bit Hisilicon hikey620 board running Ubuntu and
ARM 64-bit Hisilicon hikey960 board running Android.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

treewide: Use DEVICE_ATTR_WO

Convert DEVICE_ATTR uses to DEVICE_ATTR_WO where possible.

Done with perl script:

$ git grep -w --name-only DEVICE_ATTR | \
xargs perl -i -e 'local $/; while (<>) { s/\bDEVICE_ATTR\s*\(\s*(\w+)\s*,\s*\(?(?:\s*S_IWUSR\s*|\s*0200\s*)\)?\s*,\s*NULL\s*,\s*\s_store\s*\)/DEVICE_ATTR_WO(\1)/g; print;}'

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

treewide: Use DEVICE_ATTR_RO

Convert DEVICE_ATTR uses to DEVICE_ATTR_RO where possible.

Done with perl script:

$ git grep -w --name-only DEVICE_ATTR | \
xargs perl -i -e 'local $/; while (<>) { s/\bDEVICE_ATTR\s*\(\s*(\w+)\s*,\s*\(?(?:\s*S_IRUGO\s*|\s*0444\s*)\)?\s*,\s*\1_show\s*,\s*NULL\s*\)/DEVICE_ATTR_RO(\1)/g; print;}'

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Acked-by: Sagi Grimberg <sagi@grimberg.me>
Acked-by: Zhang Rui <rui.zhang@intel.com>
Acked-by: Harald Freudenberger <freude@linux.vnet.ibm.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

treewide: Use DEVICE_ATTR_RW

Convert DEVICE_ATTR uses to DEVICE_ATTR_RW where possible.

Done with perl script:

$ git grep -w --name-only DEVICE_ATTR | \
xargs perl -i -e 'local $/; while (<>) { s/\bDEVICE_ATTR\s*\(\s*(\w+)\s*,\s*\(?(\s*S_IRUGO\s*\|\s*S_IWUSR|\s*S_IWUSR\s*\|\s*S_IRUGO\s*|\s*0644\s*)\)?\s*,\s*\1_show\s*,\s*\1_store\s*\)/DEVICE_ATTR_RW(\1)/g; print;}'

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Acked-by: Zhang Rui <rui.zhang@intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@bitmer.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

thermal: core: Add some new helper functions to free resources

In order to easily free resources allocated by
'thermal_zone_create_device_groups()' we need 2 new helper functions.

The first one undoes 'thermal_zone_create_device_groups()'.
The 2nd one undoes 'create_trip_attrs()', which is a function called by
'thermal_zone_create_device_groups()'.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

thermal: sysfs: use kcalloc() instead of kzalloc()

Simplify size computation by using kcalloc() for
allocating memory for arrays.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

thermal: sysfs: remove symbols of emul_temp when config is disabled

Remove the following warning:
In file included from drivers/thermal/thermal_sysfs.c:19:0:
include/linux/device.h:575:26: warning: ‘dev_attr_emul_temp’ defined but not used [-Wunused-variable]
struct device_attribute dev_attr_##_name = __ATTR(_name, _mode, _show, _store)
^
drivers/thermal/thermal_sysfs.c:395:8: note: in expansion of macro ‘DEVICE_ATTR’

when emul temp is disabled at Kconfig.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

thermal: core: move cooling device sysfs to thermal_sysfs.c

This is a code reorganization, simply to concentrate
the sysfs handling functions in thermal_sysfs.c.

This patch moves the cooling device handling functions.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

thermal: core: move thermal_zone sysfs to thermal_sysfs.c

This is a code reorganization, simply to concentrate
the code handling sysfs in a specific file: thermal_sysfs.c.

Right now, moving only the sysfs entries of thermal_zone_device.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>