27 Commits

Author SHA1 Message Date
Rafael J. Wysocki
f41f23b0ca thermal: trip: Use common set of trip type names
Use the same set of trip type names in sysfs and in the thermal debug
code output.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-06-11 21:04:40 +02:00
Rafael J. Wysocki
8f9025baf6 thermal/debugfs: Move some statements from under thermal_dbg->lock
The tz_dbg local variable assignments in thermal_debug_tz_trip_up(),
thermal_debug_tz_trip_down(), and thermal_debug_update_trip_stats()
need not be carried out under thermal_dbg->lock, so move them from
under that lock (to avoid possible future confusion).

While at it, reorder local variable definitions in
thermal_debug_tz_trip_up() for more clarity.

No functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-06-11 21:04:34 +02:00
Rafael J. Wysocki
881c084fc9 thermal/debugfs: Compute maximum temperature for mitigation episode as a whole
Notice that the maximum temperature above the trip point must be the
same for all of the trip points involved in a given mitigation episode,
so it need not be computerd for each of them separately.

It is sufficient to compute the maximum temperature for the mitigation
episode as a whole and print it accordingly, so do that.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-06-11 21:04:28 +02:00
Rafael J. Wysocki
993c87047d thermal/debugfs: Adjust check for trips without statistics in tze_seq_show()
Initialize the trip_temp field in struct trip_stats to
THERMAL_TEMP_INVALID and adjust the check for trips without
statistics in tze_seq_show() to look at that field instead of
comparing min and max.

This will mostly be useful to simplify subsequent changes.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-06-11 21:04:21 +02:00
Rafael J. Wysocki
ea6a3c5202 thermal/debugfs: Fix up units in "mitigations" files
Print temperature units as m°C rather than °mC (the meaning of which is
unclear) and add time unit to the duration column.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-06-11 21:04:13 +02:00
Rafael J. Wysocki
cc86c139ae thermal/debugfs: Print mitigation timestamp value in milliseconds
Because mitigation episode duration is printed in milliseconds, there
is no reason to print timestamp information for mitigation episodes in
smaller units which also makes it somewhat harder to interpret the
numbers.

Print it in milliseconds for consistency.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-06-11 21:04:06 +02:00
Rafael J. Wysocki
9b73b5052a thermal/debugfs: Do not extend mitigation episodes beyond system resume
Because thermal zone handling by the thermal core is started from
scratch during resume from system-wide suspend, prevent the debug
code from extending mitigation episodes beyond that point by ending
the mitigation episode currently in progress, if any, for each thermal
zone.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-06-11 21:04:00 +02:00
Rafael J. Wysocki
8b95bed0ce thermal/debugfs: Use helper to update trip point overstepping duration
Add a helper for updating trip point overstepping duration to be called
from thermal_debug_tz_trip_down().

Subsequently, it will also be used during resume from system-wide
suspend.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-06-11 21:01:21 +02:00
Rafael J. Wysocki
5a599e10e5 thermal/debugfs: Allow tze_seq_show() to print statistics for invalid trips
Commit a6258fde8de3 ("thermal/debugfs: Make tze_seq_show() skip invalid
trips and trips with no stats") modified tze_seq_show() to skip invalid
trips, but it overlooked the fact that a trip may become invalid during
a mitigation eposide involving it, in which case its statistics should
still be reported.

For this reason, remove the invalid trip temperature check from the
main loop in tze_seq_show().

The trips that have never been valid will still be skipped after this
change because there are no statistics to report for them.

Fixes: a6258fde8de3 ("thermal/debugfs: Make tze_seq_show() skip invalid trips and trips with no stats")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2024-05-27 13:00:00 +02:00
Rafael J. Wysocki
9e69acc1de thermal/debugfs: Print initial trip temperature and hysteresis in tze_seq_show()
The temperature and hysteresis of a trip point may change during a
mitigation episode it is involved in (it may even become invalid
altogether), so in order to avoid possible confusion related to that,
store the temperature and hysteresis of trip points at the time they
are crossed on the way up and print those values instead of their
current temperature and hysteresis.

Fixes: 7ef01f228c9f ("thermal/debugfs: Add thermal debugfs information for mitigation episodes")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2024-05-27 13:00:00 +02:00
Rafael J. Wysocki
bd700ba9ad thermal/debugfs: Avoid printing zero duration for mitigation events in progress
If a thermal mitigation event is in progress, its duration value has
not been updated yet, so 0 will be printed as the event duration by
tze_seq_show() which is confusing.

Avoid doing that by marking the beginning of the event with the
KTIME_MIN duration value and making tze_seq_show() compute the current
event duration on the fly, in which case '>' will be printed instead of
'=' in the event duration value field.

Similarly, for trip points that have been crossed on the down, mark
the end of mitigation with the KTIME_MAX timestamp value and make
tze_seq_show() compute the current duration on the fly for the trip
points still involved in the mitigation, in which cases the duration
value printed by it will be prepended with a '>' character.

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>
Tested-by: Lukasz Luba <lukasz.luba@arm.com>
2024-04-26 15:01:56 +02:00
Rafael J. Wysocki
31a0fa0019 thermal/debugfs: Pass cooling device state to thermal_debug_cdev_add()
If cdev_dt_seq_show() runs before the first state transition of a cooling
device, it will not print any state residency information for it, even
though it might be reasonably expected to print residency information for
the initial state of the cooling device.

For this reason, rearrange the code to get the initial state of a cooling
device at the registration time and pass it to thermal_debug_cdev_add(),
so that the latter can create a duration record for that state which will
allow cdev_dt_seq_show() to print its residency information.

Fixes: 755113d76786 ("thermal/debugfs: Add thermal cooling device debugfs information")
Reported-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Tested-by: Lukasz Luba <lukasz.luba@arm.com>
2024-04-26 15:01:56 +02:00
Rafael J. Wysocki
f4ae18fcb6 thermal/debugfs: Create records for cdev states as they get used
Because thermal_debug_cdev_state_update() only creates a duration record
for the old state of a cooling device, if its new state is used for the
first time, there will be no record for it and cdev_dt_seq_show() will
not print the duration information for it even though it contains code
to compute the duration value in that case.

Address this by making thermal_debug_cdev_state_update() create a
duration record for the new state if there is none.

Fixes: 755113d76786 ("thermal/debugfs: Add thermal cooling device debugfs information")
Reported-by: Lukasz Luba <lukasz.luba@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Tested-by: Lukasz Luba <lukasz.luba@arm.com>
2024-04-26 15:01:56 +02:00
Rafael J. Wysocki
8c882f172f Merge back earlier thermal core changes for v6.10. 2024-04-26 15:00:56 +02:00
Rafael J. Wysocki
d351eb0ab0 thermal/debugfs: Prevent use-after-free from occurring after cdev removal
Since thermal_debug_cdev_remove() does not run under cdev->lock, it can
run in parallel with thermal_debug_cdev_state_update() and it may free
the struct thermal_debugfs object used by the latter after it has been
checked against NULL.

If that happens, thermal_debug_cdev_state_update() will access memory
that has been freed already causing the kernel to crash.

Address this by using cdev->lock in thermal_debug_cdev_remove() around
the cdev->debugfs value check (in case the same cdev is removed at the
same time in two different threads) and its reset to NULL.

Fixes: 755113d76786 ("thermal/debugfs: Add thermal cooling device debugfs information")
Cc :6.8+ <stable@vger.kernel.org> # 6.8+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
2024-04-26 14:57:50 +02:00
Rafael J. Wysocki
c7f7c37271 thermal/debugfs: Fix two locking issues with thermal zone debug
With the current thermal zone locking arrangement in the debugfs code,
user space can open the "mitigations" file for a thermal zone before
the zone's debugfs pointer is set which will result in a NULL pointer
dereference in tze_seq_start().

Moreover, thermal_debug_tz_remove() is not called under the thermal
zone lock, so it can run in parallel with the other functions accessing
the thermal zone's struct thermal_debugfs object.  Then, it may clear
tz->debugfs after one of those functions has checked it and the
struct thermal_debugfs object may be freed prematurely.

To address the first problem, pass a pointer to the thermal zone's
struct thermal_debugfs object to debugfs_create_file() in
thermal_debug_tz_add() and make tze_seq_start(), tze_seq_next(),
tze_seq_stop(), and tze_seq_show() retrieve it from s->private
instead of a pointer to the thermal zone object.  This will ensure
that tz_debugfs will be valid across the "mitigations" file accesses
until thermal_debugfs_remove_id() called by thermal_debug_tz_remove()
removes that file.

To address the second problem, use tz->lock in thermal_debug_tz_remove()
around the tz->debugfs value check (in case the same thermal zone is
removed at the same time in two different threads) and its reset to NULL.

Fixes: 7ef01f228c9f ("thermal/debugfs: Add thermal debugfs information for mitigation episodes")
Cc :6.8+ <stable@vger.kernel.org> # 6.8+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
2024-04-26 11:11:30 +02:00
Rafael J. Wysocki
72c1afffa4 thermal/debugfs: Free all thermal zone debug memory on zone removal
Because thermal_debug_tz_remove() does not free all memory allocated for
thermal zone diagnostics, some of that memory becomes unreachable after
freeing the thermal zone's struct thermal_debugfs object.

Address this by making thermal_debug_tz_remove() free all of the memory
in question.

Fixes: 7ef01f228c9f ("thermal/debugfs: Add thermal debugfs information for mitigation episodes")
Cc :6.8+ <stable@vger.kernel.org> # 6.8+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
2024-04-26 11:11:00 +02:00
Rafael J. Wysocki
a6258fde8d thermal/debugfs: Make tze_seq_show() skip invalid trips and trips with no stats
Currently, tze_seq_show() output includes all of the trips in the zone
except for critical ones, including invalid trips and trips with no stats
which is confusing.

Make it skip the trips for which there is not mitigation information.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2024-04-24 20:43:11 +02:00
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
e271f9974d thermal/debugfs: Clean up thermal_debug_update_temp()
Notice that it is not necessary to compute tze in every iteration of the
for () loop in thermal_debug_update_temp() because it is the same for all
trips, so compute it once before the loop starts.

Also use a trip_stats local variable to make the code in that loop easier
to follow and move the trip_id variable definition into that loop because
it is not used elsewhere in the function.

While at it, change to order of local variable definitions in the function
to follow the reverse-xmas-tree pattern.

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 20:43:06 +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
5c897a9a12 Merge back earlier thermal control material for v6.10. 2024-04-19 15:17:21 +02:00
Rafael J. Wysocki
b552f63cd4 thermal/debugfs: Add missing count increment to thermal_debug_tz_trip_up()
The count field in struct trip_stats, representing the number of times
the zone temperature was above the trip point, needs to be incremented
in thermal_debug_tz_trip_up(), for two reasons.

First, if a trip point is crossed on the way up for the first time,
thermal_debug_update_temp() called from update_temperature() does
not see it because it has not been added to trips_crossed[] array
in the thermal zone's struct tz_debugfs object yet.  Therefore, when
thermal_debug_tz_trip_up() is called after that, the trip point's
count value is 0, and the attempt to divide by it during the average
temperature computation leads to a divide error which causes the kernel
to crash.  Setting the count to 1 before the division by incrementing it
fixes this problem.

Second, if a trip point is crossed on the way up, but it has been
crossed on the way up already before, its count value needs to be
incremented to make a record of the fact that the zone temperature is
above the trip now.  Without doing that, if the mitigations applied
after crossing the trip cause the zone temperature to drop below its
threshold, the count will not be updated for this episode at all and
the average temperature in the trip statistics record will be somewhat
higher than it should be.

Fixes: 7ef01f228c9f ("thermal/debugfs: Add thermal debugfs information for mitigation episodes")
Cc :6.8+ <stable@vger.kernel.org> # 6.8+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2024-04-19 15:08:19 +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
Dan Carpenter
6dcb35088e thermal/debugfs: Unlock on error path in thermal_debug_tz_trip_up()
Add a missing mutex_unlock(&thermal_dbg->lock) to this error path.

Fixes: 7ef01f228c9f ("thermal/debugfs: Add thermal debugfs information for mitigation episodes")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2024-01-12 15:53:54 +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