304 Commits

Author SHA1 Message Date
Rafael J. Wysocki
8dff6e8438 thermal/debugfs: Rename thermal_debug_update_temp() to thermal_debug_update_trip_stats()
Rename thermal_debug_update_temp() to thermal_debug_update_trip_stats()
which is a better match for the purpose of the function.

No functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-04-24 20:43:09 +02:00
Rafael J. Wysocki
0a293c7758 thermal/debugfs: Avoid excessive updates of trip point statistics
Since thermal_debug_update_temp() is called before invoking
thermal_debug_tz_trip_down() for the trips that were crossed by the
zone temperature on the way up, it updates the statistics for them
as though the current zone temperature was above the low temperature
of each of them.  However, if a given trip has just been crossed on the
way down, the zone temperature is in fact below its low temperature,
but this is handled by thermal_debug_tz_trip_down() running after the
update of the trip statistics.

The remedy is to call thermal_debug_update_temp() after
thermal_debug_tz_trip_down() has been invoked for all of the
trips in question, but then thermal_debug_tz_trip_up() needs to
be adjusted, so it does not update the statistics for the trips
that has just been crossed on the way up, as that will be taken
care of by thermal_debug_update_temp() down the road.

Modify the code accordingly.

Fixes: 7ef01f228c9f ("thermal/debugfs: Add thermal debugfs information for mitigation episodes")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-04-24 20:43:02 +02:00
Rafael J. Wysocki
2ae0998c67 thermal: core: Relocate critical and hot trip handling
Modify handle_thermal_trip() to call handle_critical_trips() only after
finding that the trip temperature has been crossed on the way up and
remove the redundant temperature check from the latter.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-04-24 20:42:39 +02:00
Rafael J. Wysocki
ad2f8bccd0 thermal: core: Drop the .throttle() governor callback
Since all of the governors in the tree have been switched over to using
the new callbacks, either .trip_crossed() or .manage(), the .throttle()
governor callback is not used any more, so drop it.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-04-24 20:42:31 +02:00
Rafael J. Wysocki
976f44133f thermal: core: Introduce .manage() callback for thermal governors
Introduce a new thermal governor callback called .manage() that will be
invoked once per thermal zone update after processing all of the trip
points in the core.

This will allow governors that look at multiple trip points together
to check all of them in a consistent configuration, so they don't need
to play tricks with skipping .throttle() invocations that they are not
interested in and they can avoid carrying out the same computations for
multiple times in one cycle.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-04-23 20:38:41 +02:00
Rafael J. Wysocki
80f5fd45c7 thermal: core: Introduce .trip_crossed() callback for thermal governors
Introduce a new thermal governor callback called .trip_crossed()
that will be invoked whenever a trip point is crossed by the zone
temperature, either on the way up or on the way down.

The trip crossing direction information will be passed to it and if
multiple trips are crossed in the same direction during one thermal zone
update, the new callback will be invoked for them in temperature order,
either ascending or descending, depending on the trip crossing
direction.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
2024-04-19 22:11:06 +02:00
Rafael J. Wysocki
7454f2c42c thermal: core: Sort trip point crossing notifications by temperature
If multiple trip points are crossed in one go and the trips table in
the thermal zone device object is not sorted, the corresponding trip
point crossing notifications sent to user space will not be ordered
either.

Moreover, if the trips table is sorted by trip temperature in ascending
order, the trip crossing notifications on the way up will be sent in that
order too, but the trip crossing notifications on the way down will be
sent in the reverse order.

This is generally confusing and it is better to make the kernel send the
notifications in the order of growing (on the way up) or falling (on the
way down) trip temperature.

To achieve that, instead of sending a trip crossing notification and
recording a trip crossing event in the statistics right away from
handle_thermal_trip(), put the trip in question on a list that will be
sorted by __thermal_zone_device_update() after processing all of the trips
and before sending the notifications and recording trip crossing events.

Link: https://lore.kernel.org/linux-pm/20240306085428.88011-1-daniel.lezcano@linaro.org/
Reported-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
2024-04-08 16:01:20 +02:00
Rafael J. Wysocki
9ad18043fb thermal: core: Send trip crossing notifications at init time if needed
If a trip point is already exceeded by the zone temperature at the
initialization time, no trip crossing notification is send regarding
this even though mitigation should be started then.

Address this by rearranging the code in handle_thermal_trip() to
send a trip crossing notification for trip points already exceeded
by the zone temperature initially which also allows to reduce its
size by using the observation that the initialization and regular
trip crossing on the way up become the same case then.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
2024-04-08 16:01:20 +02:00
Rafael J. Wysocki
f99c1b87a9 thermal: core: Rewrite comments in handle_thermal_trip()
Make the comments regarding trip crossing and threshold updates in
handle_thermal_trip() slightly more clear.

No functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-04-08 16:01:20 +02:00
Rafael J. Wysocki
daeeb032f4 thermal: core: Move threshold out of struct thermal_trip
The threshold field in struct thermal_trip is only used internally by
the thermal core and it is better to prevent drivers from misusing it.
It also takes some space unnecessarily in the trip tables passed by
drivers to the core during thermal zone registration.

For this reason, introduce struct thermal_trip_desc as a wrapper around
struct thermal_trip, move the threshold field directly into it and make
the thermal core store struct thermal_trip_desc objects in the internal
thermal zone trip tables.  Adjust all of the code using trip tables in
the thermal core accordingly.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
2024-04-08 16:01:20 +02:00
Flavio Suligoi
32abd25087 thermal: core: Remove excess empty line from a comment
The first and the third lines of the kerneldoc comment for:

thermal_zone_device_set_polling()

belong to the same sentences, so join them together.

Signed-off-by: Flavio Suligoi <f.suligoi@asem.it>
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2024-03-05 13:17:33 +01:00
Rafael J. Wysocki
4a62d588a8 thermal: core: Eliminate writable trip points masks
All of the thermal_zone_device_register_with_trips() callers pass zero
writable trip points masks to it, so drop the mask argument from that
function and update all of its callers accordingly.

This also removes the artificial trip points per zone limit of 32,
related to using writable trip points masks.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-02-27 12:04:38 +01:00
Rafael J. Wysocki
5340f76472 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>
2024-02-27 12:02:50 +01:00
Nathan Chancellor
da1983355c thermal: core: Move initial num_trips assignment before memcpy()
When booting a CONFIG_FORTIFY_SOURCE=y kernel compiled with a toolchain
that supports __counted_by() (such as clang-18 and newer), there is a
panic on boot:

  [    2.913770] memcpy: detected buffer overflow: 72 byte write of buffer size 0
  [    2.920834] WARNING: CPU: 2 PID: 1 at lib/string_helpers.c:1027 __fortify_report+0x5c/0x74
  ...
  [    3.039208] Call trace:
  [    3.041643]  __fortify_report+0x5c/0x74
  [    3.045469]  __fortify_panic+0x18/0x20
  [    3.049209]  thermal_zone_device_register_with_trips+0x4c8/0x4f8

This panic occurs because trips is counted by num_trips but num_trips is
assigned after the call to memcpy(), so the fortify checks think the
buffer size is zero because tz was allocated with kzalloc().

Move the num_trips assignment before the memcpy() to resolve the panic
and ensure that the fortify checks work properly.

Fixes: 9b0a62758665 ("thermal: core: Store zone trips table in struct thermal_zone_device")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2024-02-27 11:58:47 +01:00
Rafael J. Wysocki
698a1eb1f7 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>
2024-02-23 18:24:48 +01:00
Rafael J. Wysocki
9b0a627586 thermal: core: Store zone trips table in struct thermal_zone_device
The current code expects thermal zone creators to pass a pointer to a
writable trips table to thermal_zone_device_register_with_trips() and
that trips table is then used by the thermal core going forward.

Consequently, the callers of thermal_zone_device_register_with_trips()
are required to hold on to the trips table passed to it until the given
thermal zone is unregistered, at which point the trips table can be
freed, but at the same time they are not expected to access that table
directly.  This is both error prone and confusing.

To address it, turn the trips table pointer in struct thermal_zone_device
into a flex array (counted by its num_trips field), allocate it during
thermal zone device allocation and copy the contents of the trips table
supplied by the zone creator (which can be const now) into it, which
will allow the callers of thermal_zone_device_register_with_trips() to
drop their trip tables right after the zone registration.

This requires the imx thermal driver to be adjusted to store the new
temperature in its internal trips table in imx_set_trip_temp(), because
it will be separate from the core's trips table now and it has to be
explicitly kept in sync with the latter.

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>
2024-02-23 18:24:47 +01:00
Christophe JAILLET
57a427c81c thermal: core: Use kstrdup_const() during cooling device registration
Some *thermal_cooling_device_register() calls pass a string literal as
the 'type' parameter, so kstrdup_const() can be used instead of
kstrdup() to avoid a memory allocation in such cases.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2024-01-12 15:38:23 +01:00
Daniel Lezcano
7ef01f228c thermal/debugfs: Add thermal debugfs information for mitigation episodes
The mitigation episodes are recorded. A mitigation episode happens
when the first trip point is crossed the way up and then the way
down. During this episode other trip points can be crossed also and
are accounted for this mitigation episode. The interesting information
is the average temperature at the trip point, the undershot and the
overshot. The standard deviation of the mitigated temperature will be
added later.

The thermal debugfs directory structure tries to stay consistent with
the sysfs one but in a very simplified way:

thermal/
 `-- thermal_zones
     |-- 0
     |   `-- mitigations
     `-- 1
         `-- mitigations

The content of the mitigations file has the following format:

,-Mitigation at 349988258us, duration=130136ms
| trip |     type | temp(°mC) | hyst(°mC) |  duration  |  avg(°mC) |  min(°mC) |  max(°mC) |
|    0 |  passive |     65000 |      2000 |     130136 |     68227 |     62500 |     75625 |
|    1 |  passive |     75000 |      2000 |     104209 |     74857 |     71666 |     77500 |
,-Mitigation at 272451637us, duration=75000ms
| trip |     type | temp(°mC) | hyst(°mC) |  duration  |  avg(°mC) |  min(°mC) |  max(°mC) |
|    0 |  passive |     65000 |      2000 |      75000 |     68561 |     62500 |     75000 |
|    1 |  passive |     75000 |      2000 |      60714 |     74820 |     70555 |     77500 |
,-Mitigation at 238184119us, duration=27316ms
| trip |     type | temp(°mC) | hyst(°mC) |  duration  |  avg(°mC) |  min(°mC) |  max(°mC) |
|    0 |  passive |     65000 |      2000 |      27316 |     73377 |     62500 |     75000 |
|    1 |  passive |     75000 |      2000 |      19468 |     75284 |     69444 |     77500 |
,-Mitigation at 39863713us, duration=136196ms
| trip |     type | temp(°mC) | hyst(°mC) |  duration  |  avg(°mC) |  min(°mC) |  max(°mC) |
|    0 |  passive |     65000 |      2000 |     136196 |     73922 |     62500 |     75000 |
|    1 |  passive |     75000 |      2000 |      91721 |     74386 |     69444 |     78125 |

More information for a better understanding of the thermal behavior
will be added after. The idea is to give detailed statistics
information about the undershots and overshots, the temperature speed,
etc... As all the information in a single file is too much, the idea
would be to create a directory named with the mitigation timestamp
where all data could be added.

Please note this code is immune against trip ordering but not against
a trip temperature change while a mitigation is happening. However,
this situation should be extremely rare, perhaps not happening and we
might question ourselves if something should be done in the core
framework for other components first.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
[ rjw: White space fixups, rebase ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2024-01-12 15:37:49 +01:00
Daniel Lezcano
755113d767 thermal/debugfs: Add thermal cooling device debugfs information
The thermal framework does not have any debug information except a
sysfs stat which is a bit controversial. This one allocates big chunks
of memory for every cooling devices with a high number of states and
could represent on some systems in production several megabytes of
memory for just a portion of it. As the sysfs is limited to a page
size, the output is not exploitable with large data array and gets
truncated.

The patch provides the same information than sysfs except the
transitions are dynamically allocated, thus they won't show more
events than the ones which actually occurred. There is no longer a
size limitation and it opens the field for more debugging information
where the debugfs is designed for, not sysfs.

The thermal debugfs directory structure tries to stay consistent with
the sysfs one but in a very simplified way:

thermal/
 -- cooling_devices
    |-- 0
    |   |-- clear
    |   |-- time_in_state_ms
    |   |-- total_trans
    |   `-- trans_table
    |-- 1
    |   |-- clear
    |   |-- time_in_state_ms
    |   |-- total_trans
    |   `-- trans_table
    |-- 2
    |   |-- clear
    |   |-- time_in_state_ms
    |   |-- total_trans
    |   `-- trans_table
    |-- 3
    |   |-- clear
    |   |-- time_in_state_ms
    |   |-- total_trans
    |   `-- trans_table
    `-- 4
        |-- clear
        |-- time_in_state_ms
        |-- total_trans
        `-- trans_table

The content of the files in the cooling devices directory is the same
as the sysfs one except for the trans_table which has the following
format:

Transition	Hits
1->0      	246
0->1      	246
2->1      	632
1->2      	632
3->2      	98
2->3      	98

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
[ rjw: White space fixups, rebase ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2024-01-12 15:34:56 +01:00
Rafael J. Wysocki
2f521890aa thermal: netlink: Pass thermal zone pointer to notify routines
There are several rountines in the thermal netlink API that take a
thermal zone ID or a thermal zone type as their arguments, but from
their callers perspective it would be more convenient to pass a thermal
zone pointer to them and let them extract the necessary data from the
given thermal zone object by themselves.

Modify the code accordingly.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-01-09 13:32:23 +01:00
Rafael J. Wysocki
f52557edf0 thermal: netlink: Pass pointers to thermal_notify_tz_trip_up/down()
Instead of requiring the callers of thermal_notify_tz_trip_up/down() to
provide specific values needed to populate struct param in them, make
them extract those values from objects passed by the callers via const
pointers.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-01-09 13:31:37 +01:00
Rafael J. Wysocki
d654362d53 - Converted Mediatek Thermal to the json-schema (Rafał Miłecki)
- Fixed DT bindings issue on Loongson (Binbin Zhou)
 
 - Fixed returning NULL instead of -ENODEV on Loogsoo (Binbin Zhou)
 
 - Added the DT binding for the tsens on SM8650 platform (Neil Armstrong)
 
 - Added a reboot on critical option feature (Fabio Estevam)
 
 - Made usage of DEFINE_SIMPLE_DEV_PM_OPS on AmLogic (Uwe Kleine-König)
 
 - Added the D1/T113s THS controller support on Sun8i (Maxim Kiselev)
 
 - Fixed example in the DT binding for QCom SPMI (Johan Hovold)
 
 - Fixed compilation warning for the tmon utility (Florian Eckert)
 
 - Added interrupt based configuration on Exynos along with a set of
   related cleanups (Mateusz Majewski)
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Merge tag 'thermal-v6.8-rc1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/thermal/linux into thermal

Merge thermal control material for 6.8-rc1 from Daniel Lezcano:

"- Converted Mediatek Thermal to the json-schema (Rafał Miłecki)

 - Fixed DT bindings issue on Loongson (Binbin Zhou)

 - Fixed returning NULL instead of -ENODEV on Loogsoo (Binbin Zhou)

 - Added the DT binding for the tsens on SM8650 platform (Neil Armstrong)

 - Added a reboot on critical option feature (Fabio Estevam)

 - Made usage of DEFINE_SIMPLE_DEV_PM_OPS on AmLogic (Uwe Kleine-König)

 - Added the D1/T113s THS controller support on Sun8i (Maxim Kiselev)

 - Fixed example in the DT binding for QCom SPMI (Johan Hovold)

 - Fixed compilation warning for the tmon utility (Florian Eckert)

 - Added interrupt based configuration on Exynos along with a set of
   related cleanups (Mateusz Majewski)"

* tag 'thermal-v6.8-rc1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/thermal/linux: (24 commits)
  thermal/drivers/exynos: Use set_trips ops
  thermal/drivers/exynos: Use BIT wherever possible
  thermal/drivers/exynos: Split initialization of TMU and the thermal zone
  thermal/drivers/exynos: Stop using the threshold mechanism on Exynos 4210
  thermal/drivers/exynos: Simplify regulator (de)initialization
  thermal/drivers/exynos: Handle devm_regulator_get_optional return value correctly
  thermal/drivers/exynos: Wwitch from workqueue-driven interrupt handling to threaded interrupts
  thermal/drivers/exynos: Drop id field
  thermal/drivers/exynos: Remove an unnecessary field description
  tools/thermal/tmon: Fix compilation warning for wrong format
  dt-bindings: thermal: qcom-spmi-adc-tm5/hc: Clean up examples
  dt-bindings: thermal: qcom-spmi-adc-tm5/hc: Fix example node names
  thermal/drivers/sun8i: Add D1/T113s THS controller support
  dt-bindings: thermal: sun8i: Add binding for D1/T113s THS controller
  thermal: amlogic: Use DEFINE_SIMPLE_DEV_PM_OPS for PM functions
  thermal: amlogic: Make amlogic_thermal_disable() return void
  thermal/thermal_of: Allow rebooting after critical temp
  reboot: Introduce thermal_zone_device_critical_reboot()
  thermal/core: Prepare for introduction of thermal reboot
  dt-bindings: thermal-zones: Document critical-action
  ...
2024-01-02 13:45:36 +01:00
Fabio Estevam
79fa723ba8 reboot: Introduce thermal_zone_device_critical_reboot()
Introduce thermal_zone_device_critical_reboot() to trigger an
emergency reboot.

It is a counterpart of thermal_zone_device_critical() with the
difference that it will force a reboot instead of shutdown.

The motivation for doing this is to allow the thermal subystem
to trigger a reboot when the temperature reaches the critical
temperature.

Signed-off-by: Fabio Estevam <festevam@denx.de>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20231129124330.519423-3-festevam@gmail.com
2024-01-02 09:33:18 +01:00
Fabio Estevam
5a0e241003 thermal/core: Prepare for introduction of thermal reboot
Add some helper functions to make it easier introducing the support
for thermal reboot.

No functional change.

Signed-off-by: Fabio Estevam <festevam@denx.de>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20231129124330.519423-2-festevam@gmail.com
2024-01-02 09:33:18 +01:00
Lukasz Luba
a8c959402d thermal: core: Add governor callback for thermal zone change
Add a new callback to the struct thermal_governor. It can be used for
updating governors when there is a change in the thermal zone internals,
e.g. thermal cooling device is bind to the thermal zone.

That makes possible to move some heavy operations like memory allocations
related to the number of cooling instances out of the throttle() callback.

Both callback code paths (throttle() and update_tz()) are protected with
the same thermal zone lock, which guaranties the consistency.

Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2023-12-29 18:01:00 +01:00
Rafael J. Wysocki
5a5efdaffd thermal: core: Resume thermal zones asynchronously
The resume of thermal zones in thermal_pm_notify() is carried out
sequentially, which may be a problem if __thermal_zone_device_update()
takes a significant time to run for some thermal zones, because some
other thermal zones may need to wait for them to resume then and if
any other PM notifiers are going to be invoked after the thermal one,
they will need to wait for it either.

To address this, make thermal_pm_notify() switch the poll_queue delayed
work over to a one-shot thermal_zone_device_resume() work function that
will restore the original one during the thermal zone resume and queue
up poll_queue without a delay for each thermal zone.

Link: https://lore.kernel.org/linux-pm/20231120234015.3273143-1-radusolea@google.com/
Reported-by: Radu Solea <radusolea@google.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2023-12-28 14:20:16 +01:00
Rafael J. Wysocki
33fcb595dc thermal: core: Initialize poll_queue in thermal_zone_device_init()
In preparation for a subsequent change, move the initialization of the
poll_queue delayed work from thermal_zone_device_register_with_trips()
to thermal_zone_device_init() which is called by the former.

However, because thermal_zone_device_init() is also called by
thermal_pm_notify(), make the latter call cancel_delayed_work() on
poll_queue before invoking the former, so as to allow the work
item to be re-initialized safely.

Also move thermal_zone_device_check() which needs to be defined
before thermal_zone_device_init(), so the latter can pass it to the
INIT_DELAYED_WORK() macro.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2023-12-28 14:20:16 +01:00
Rafael J. Wysocki
4e814173a8 thermal: core: Fix thermal zone suspend-resume synchronization
There are 3 synchronization issues with thermal zone suspend-resume
during system-wide transitions:

 1. The resume code runs in a PM notifier which is invoked after user
    space has been thawed, so it can run concurrently with user space
    which can trigger a thermal zone device removal.  If that happens,
    the thermal zone resume code may use a stale pointer to the next
    list element and crash, because it does not hold thermal_list_lock
    while walking thermal_tz_list.

 2. The thermal zone resume code calls thermal_zone_device_init()
    outside the zone lock, so user space or an update triggered by
    the platform firmware may see an inconsistent state of a
    thermal zone leading to unexpected behavior.

 3. Clearing the in_suspend global variable in thermal_pm_notify()
    allows __thermal_zone_device_update() to continue for all thermal
    zones and it may as well run before the thermal_tz_list walk (or
    at any point during the list walk for that matter) and attempt to
    operate on a thermal zone that has not been resumed yet.  It may
    also race destructively with thermal_zone_device_init().

To address these issues, add thermal_list_lock locking to
thermal_pm_notify(), especially arount the thermal_tz_list,
make it call thermal_zone_device_init() back-to-back with
__thermal_zone_device_update() under the zone lock and replace
in_suspend with per-zone bool "suspend" indicators set and unset
under the given zone's lock.

Link: https://lore.kernel.org/linux-pm/20231218162348.69101-1-bo.ye@mediatek.com/
Reported-by: Bo Ye <bo.ye@mediatek.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2023-12-28 14:20:15 +01:00
Rafael J. Wysocki
04e6ccfc93 thermal: core: Fix NULL pointer dereference in zone registration error path
If device_register() in thermal_zone_device_register_with_trips()
returns an error, the tz variable is set to NULL and subsequently
dereferenced in kfree(tz->tzp).

Commit adc8749b150c ("thermal/drivers/core: Use put_device() if
device_register() fails") added the tz = NULL assignment in question to
avoid a possible double-free after dropping the reference to the zone
device.  However, after commit 4649620d9404 ("thermal: core: Make
thermal_zone_device_unregister() return after freeing the zone"), that
assignment has become redundant, because dropping the reference to the
zone device does not cause the zone object to be freed any more.

Drop it to address the NULL pointer dereference.

Fixes: 3d439b1a2ad3 ("thermal/core: Alloc-copy-free the thermal zone parameters structure")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
2023-12-15 18:24:24 +01:00
Daniel Lezcano
404f62cd64 thermal/core: Check get_temp ops is present when registering a tz
Initially the check against the get_temp ops in the
thermal_zone_device_update() was put in there in order to catch
drivers not providing this method.

Instead of checking again and again the function if the ops exists in
the update function, let's do the check at registration time, so it is
checked one time and for all.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2023-12-13 14:35:32 +01:00
Rafael J. Wysocki
b38aa87f67 thermal: core: Rework thermal zone availability check
In order to avoid running __thermal_zone_device_update() for thermal
zones going away, the thermal zone lock is held around device_del()
in thermal_zone_device_unregister() and thermal_zone_device_update()
passes the given thermal zone device to device_is_registered().
This allows thermal_zone_device_update() to skip the
__thermal_zone_device_update() if device_del() has already run for
the thermal zone at hand.

However, instead of looking at driver core internals, the thermal
subsystem may as well rely on its own data structures for this
purpose.  Namely, if the thermal zone is not present in
thermal_tz_list, it can be regarded as unavailable, which in fact is
already the case in thermal_zone_device_unregister().  Accordingly,
the device_is_registered() check in thermal_zone_device_update() can
be replaced with checking whether or not the node list_head in struct
thermal_zone_device is empty, in which case it is not there in
thermal_tz_list.

To make this work, though, it is necessary to initialize tz->node
in thermal_zone_device_register_with_trips() before registering the
thermal zone device and it needs to be added to thermal_tz_list and
deleted from it under its zone lock.

After the above modifications, the zone lock does not need to be
held around device_del() in thermal_zone_device_unregister() any more.

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>
2023-12-12 13:01:03 +01:00
Rafael J. Wysocki
c3ffdfff97 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>
2023-12-12 13:00:28 +01:00
Rafael J. Wysocki
4649620d94 thermal: core: Make thermal_zone_device_unregister() return after freeing the zone
Make thermal_zone_device_unregister() wait until all of the references
to the given thermal zone object have been dropped and free it before
returning.

This guarantees that when thermal_zone_device_unregister() returns,
there is no leftover activity regarding the thermal zone in question
which is required by some of its callers (for instance, modular driver
code that wants to know when it is safe to let the module go away).

Subsequently, this will allow some confusing device_is_registered()
checks to be dropped from the thermal sysfs and core code.

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>
2023-12-11 20:49:53 +01:00
Rafael J. Wysocki
44844db913 thermal: core: Add trip thresholds for trip crossing detection
The trip crossing detection in handle_thermal_trip() does not work
correctly in the cases when a trip point is crossed on the way up and
then the zone temperature stays above its low temperature (that is, its
temperature decreased by its hysteresis).  The trip temperature may
be passed by the zone temperature subsequently in that case, even
multiple times, but that does not count as the trip crossing as long as
the zone temperature does not fall below the trip's low temperature or,
in other words, until the trip is crossed on the way down.

|-----------low--------high------------|
             |<--------->|
             |    hyst   |
             |           |
             |          -|--> crossed on the way up
             |
         <---|-- crossed on the way down

However, handle_thermal_trip() will invoke thermal_notify_tz_trip_up()
every time the trip temperature is passed by the zone temperature on
the way up regardless of whether or not the trip has been crossed on
the way down yet.  Moreover, it will not call thermal_notify_tz_trip_down()
if the last zone temperature was between the trip's temperature and its
low temperature, so some "trip crossed on the way down" events may not
be reported.

To address this issue, introduce trip thresholds equal to either the
temperature of the given trip, or its low temperature, such that if
the trip's threshold is passed by the zone temperature on the way up,
its value will be set to the trip's low temperature and
thermal_notify_tz_trip_up() will be called, and if the trip's threshold
is passed by the zone temperature on the way down, its value will be set
to the trip's temperature (high) and thermal_notify_tz_trip_down() will
be called.  Accordingly, if the threshold is passed on the way up, it
cannot be passed on the way up again until its passed on the way down
and if it is passed on the way down, it cannot be passed on the way down
again until it is passed on the way up which guarantees correct
triggering of trip crossing notifications.

If the last temperature of the zone is invalid, the trip's threshold
will be set depending of the zone's current temperature: If that
temperature is above the trip's temperature, its threshold will be
set to its low temperature or otherwise its threshold will be set to
its (high) temperature.  Because the zone temperature is initially
set to invalid and tz->last_temperature is only updated by
update_temperature(), this is sufficient to set the correct initial
threshold values for all trips.

Link: https://lore.kernel.org/all/20220718145038.1114379-4-daniel.lezcano@linaro.org
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2023-11-20 16:59:55 +01:00
Rafael J. Wysocki
8c35b1f472 thermal: core: Pass trip pointer to governor throttle callback
Modify the governor .throttle() callback definition so that it takes a
trip pointer instead of a trip index as its second argument, adjust the
governors accordingly and update the core code invoking .throttle().

This causes the governors to become independent of the representation
of the list of trips in the thermal zone structure.

This change is not expected to alter the general functionality.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2023-10-20 19:26:37 +02:00
Rafael J. Wysocki
a26b452e83 Merge branch 'acpi-thermal'
The ACPI thermal driver changes include some thermal core modifications
that are depended on by subsequent thermal core changes, so merge them.

* acpi-thermal: (26 commits)
  thermal: trip: Drop lockdep assertion from thermal_zone_trip_id()
  thermal: trip: Remove lockdep assertion from for_each_thermal_trip()
  thermal: core: Drop thermal_zone_device_exec()
  ACPI: thermal: Use thermal_zone_for_each_trip() for updating trips
  ACPI: thermal: Combine passive and active trip update functions
  ACPI: thermal: Move get_active_temp()
  ACPI: thermal: Fix up function header formatting in two places
  ACPI: thermal: Drop list of device ACPI handles from struct acpi_thermal
  ACPI: thermal: Rename structure fields holding temperature in deci-Kelvin
  ACPI: thermal: Drop critical_valid and hot_valid trip flags
  ACPI: thermal: Do not use trip indices for cooling device binding
  ACPI: thermal: Mark uninitialized active trips as invalid
  ACPI: thermal: Merge trip initialization functions
  ACPI: thermal: Collapse trip devices update function wrappers
  ACPI: thermal: Collapse trip devices update functions
  ACPI: thermal: Add device list to struct acpi_thermal_trip
  ACPI: thermal: Fix a small leak in acpi_thermal_add()
  ACPI: thermal: Drop valid flag from struct acpi_thermal_trip
  ACPI: thermal: Drop redundant trip point flags
  ACPI: thermal: Untangle initialization and updates of active trips
  ...
2023-10-11 17:56:51 +02:00
Dan Carpenter
c99626092e thermal: core: prevent potential string overflow
The dev->id value comes from ida_alloc() so it's a number between zero
and INT_MAX.  If it's too high then these sprintf()s will overflow.

Fixes: 203d3d4aa482 ("the generic thermal sysfs driver")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2023-10-11 16:15:09 +02:00
Rafael J. Wysocki
4963e34ce7 thermal: core: Drop thermal_zone_device_exec()
Because thermal_zone_device_exec() has no users any more and there are
no plans to use it anywhere, revert commit 9a99a996d1ec ("thermal: core:
Introduce thermal_zone_device_exec()") that introduced it.

No functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2023-10-05 13:32:55 +02:00
Rafael J. Wysocki
d069ed6b75 thermal: core: Allow trip pointers to be used for cooling device binding
Add new helper functions, thermal_bind_cdev_to_trip() and
thermal_unbind_cdev_from_trip(), to allow a trip pointer to be used for
binding a cooling device to a trip point and unbinding it, respectively,
and redefine the existing helpers, thermal_zone_bind_cooling_device()
and thermal_zone_unbind_cooling_device(), as wrappers around the new
ones, respectively.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2023-09-28 12:57:10 +02:00
Rafael J. Wysocki
2c7b4bfade 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>
2023-09-28 12:55:29 +02:00
Rafael J. Wysocki
9502108876 thermal: core: Drop trips_disabled bitmask
After recent changes, thermal_zone_get_trip() cannot fail, as invoked
from thermal_zone_device_register_with_trips(), so the only role of
the trips_disabled bitmask is struct thermal_zone_device is to make
handle_thermal_trip() skip trip points whose temperature was initially
zero.  However, since the unit of temperature in the thermal core is
millicelsius, zero may very well be a valid temperature value at least
in some usage scenarios and the trip temperature may as well change
later.  Thus there is no reason to permanently disable trip points
with initial temperature equal to zero.

Accordingly, drop the trips_disabled bitmask along with the code
related to it.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2023-09-25 11:46:19 +02:00
Rafael J. Wysocki
fb2c10245f thermal: core: Fix disabled trip point check in handle_thermal_trip()
Commit bc840ea5f9a9 ("thermal: core: Do not handle trip points with
invalid temperature") added a check for invalid temperature to the
disabled trip point check in handle_thermal_trip(), but that check was
added at a point when the trip structure has not been initialized yet.

This may cause handle_thermal_trip() to skip a valid trip point in some
cases, so fix it by moving the check to a suitable place, after
__thermal_zone_get_trip() has been called to populate the trip
structure.

Fixes: bc840ea5f9a9 ("thermal: core: Do not handle trip points with invalid temperature")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2023-09-14 21:51:49 +02:00
Rafael J. Wysocki
edd220b33f thermal: core: Drop thermal_zone_device_register()
There are no more users of thermal_zone_device_register(), so drop it
from the core.

Note that thermal_zone_device_register_with_trips() may be renamed to
thermal_zone_device_register() in the future, but only after a grace
period allowing all of the possible work in progress that may be using
the latter to adjust.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2023-09-05 21:42:18 +02:00
Rafael J. Wysocki
d332db8fc1 thermal: core: Add function for registering tripless thermal zones
Multiple callers of thermal_zone_device_register() don't pass any trips
to it and they might use a shortened argument list for that, so add
a special function with fewer arguments for this purpose.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2023-09-05 21:42:18 +02:00
Rafael J. Wysocki
35d8dbbb25 thermal: core: Drop unused .get_trip_*() callbacks
After recent changes in the ACPI thermal driver and in the Intel DTS
IOSF thermal driver, all thermal zone drivers are expected to use trip
tables for initialization and none of them should implement
.get_trip_type(), .get_trip_temp() or .get_trip_hyst() callbacks, so
drop these callbacks entirely from the core.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2023-08-29 20:46:31 +02:00
Rafael J. Wysocki
0c2ec0f165 Merge branch 'acpi-thermal'
Merge ACPI thermal driver changes for 6.6-rc1:

 - Drop non-functional nocrt parameter from ACPI thermal (Mario
   Limonciello).

 - Clean up the ACPI thermal driver, rework the handling of firmware
   notifications in it and make it provide a table of generic trip point
   structures to the core during initialization (Rafael Wysocki).

* acpi-thermal:
  ACPI: thermal: Eliminate code duplication from acpi_thermal_notify()
  ACPI: thermal: Drop unnecessary thermal zone callbacks
  ACPI: thermal: Rework thermal_get_trend()
  ACPI: thermal: Use trip point table to register thermal zones
  thermal: core: Rework and rename __for_each_thermal_trip()
  ACPI: thermal: Introduce struct acpi_thermal_trip
  ACPI: thermal: Carry out trip point updates under zone lock
  ACPI: thermal: Clean up acpi_thermal_register_thermal_zone()
  thermal: core: Add priv pointer to struct thermal_trip
  thermal: core: Introduce thermal_zone_device_exec()
  thermal: core: Do not handle trip points with invalid temperature
  ACPI: thermal: Drop redundant local variable from acpi_thermal_resume()
  ACPI: thermal: Do not attach private data to ACPI handles
  ACPI: thermal: Drop enabled flag from struct acpi_thermal_active
  ACPI: thermal: Drop nocrt parameter
2023-08-25 20:44:26 +02:00
Rafael J. Wysocki
9a99a996d1 thermal: core: Introduce thermal_zone_device_exec()
Introduce a new helper function, thermal_zone_device_exec(), that can
be used by drivers to run a given callback routine under the zone lock.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2023-08-17 11:23:32 +02:00
Rafael J. Wysocki
bc840ea5f9 thermal: core: Do not handle trip points with invalid temperature
Trip points with temperature set to THERMAL_TEMP_INVALID are as good as
disabled, so make handle_thermal_trip() ignore them.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2023-08-10 20:57:35 +02:00
Ahmad Fatoum
80ddce5f2d thermal: core: constify params in thermal_zone_device_register
Since commit 3d439b1a2ad3 ("thermal/core: Alloc-copy-free the thermal zone
parameters structure"), thermal_zone_device_register() allocates a copy
of the tzp argument and callers need not explicitly manage its lifetime.

This means the function no longer cares about the parameter being
mutable, so constify it.

No functional change.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2023-07-24 09:51:31 +02:00
Daniel Lezcano
7cefbaf081 thermal: core: Encapsulate tz->device field
There are still some drivers needing to play with the thermal zone
device internals. That is not the best but until we can figure out if
the information is really needed, let's encapsulate the field used in
the thermal zone device structure, so we can move forward relocating
the thermal zone device structure definition in the thermal framework
private headers.

Some drivers are accessing tz->device, that implies they need to have
the knowledge of the thermal_zone_device structure but we want to
self-encapsulate this structure and reduce the scope of the structure
to the thermal core only.

By adding this wrapper, these drivers won't need the thermal zone
device structure definition and are no longer an obstacle to its
relocation to the private thermal core headers.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2023-04-27 19:20:12 +02:00