thermal: netlink: Rework notify API for cooling devices

In analogy with some previous thermal netlink API changes, redefine
thermal_notify_cdev_state_update(), thermal_notify_cdev_add() and
thermal_notify_cdev_delete() to take a const cdev pointer as their
first argument and let them extract the requisite information from
there by themselves.

No intentional functional impact.

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

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>

thermal: netlink: Drop thermal_notify_tz_trip_add/delete()

Because thermal_notify_tz_trip_add/delete() are never used, drop them
entirely along with the related code.

The addition or removal of trip points is not supported by the thermal
core and is unlikely to be supported in the future, so it is also
unlikely that these functions will ever be needed.

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>

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>

thermal: netlink: Pass pointers to thermal_notify_tz_trip_change()

Instead of requiring the caller of thermal_notify_tz_trip_change() to
provide specific values needed to populate struct param in it, make it
extract those values from objects passed to it by the caller 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>

thermal: netlink: Add thermal_group_has_listeners() helper

Add a helper function to check if there are listeners for
thermal_gnl_family multicast groups.

For now use it to avoid unnecessary allocations and sending
thermal genl messages when there are no recipients.

In the future, in conjunction with (not yet implemented) notification
of change in the netlink socket group membership, this helper can be
used to open/close hardware interfaces based on the presence of
user space subscribers.

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

thermal: netlink: Add enum for mutlicast groups indexes

Use enum instead of hard-coded numbers for indexing multicast groups.

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

thermal: netlink: Use for_each_trip() in thermal_genl_cmd_tz_get_trip()

Make thermal_genl_cmd_tz_get_trip() use for_each_trip() instead of an open-
coded loop over trip indices.

No intentional functional impact.

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

thermal/core: Fix unregistering netlink at thermal init time

The thermal subsystem initialization miss an netlink unregistering
function in the error. Add it.

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

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

genetlink: start to validate reserved header bytes

We had historically not checked that genlmsghdr.reserved
is 0 on input which prevents us from using those precious
bytes in the future.

One use case would be to extend the cmd field, which is
currently just 8 bits wide and 256 is not a lot of commands
for some core families.

To make sure that new families do the right thing by default
put the onus of opting out of validation on existing families.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Paul Moore <paul@paul-moore.com> (NetLabel)
Signed-off-by: David S. Miller <davem@davemloft.net>

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>

thermal: netlink: Add a new event to notify CPU capabilities change

Add a new netlink event to notify change in CPU capabilities in terms of
performance and efficiency.

Firmware may change CPU capabilities as a result of thermal events in the
system or to account for changes in the TDP (thermal design power) level.

This notification type will allow user space to avoid running workloads
on certain CPUs or proactively adjust power limits to avoid future events.

The netlink message consists of a nested attribute
(THERMAL_GENL_ATTR_CPU_CAPABILITY) with three attributes:

* THERMAL_GENL_ATTR_CPU_CAPABILITY_ID (type u32):
-- logical CPU number
* THERMAL_GENL_ATTR_CPU_CAPABILITY_PERFORMANCE (type u32):
-- Scaled performance from 0-1023
* THERMAL_GENL_ATTR_CPU_CAPABILITY_EFFICIENCY (type u32):
-- Scaled efficiency from 0-1023

Reviewed-by: Len Brown <len.brown@intel.com>
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

thermal: core: Fix TZ_GET_TRIP NULL pointer dereference

Do not call get_trip_hyst() from thermal_genl_cmd_tz_get_trip() if
the thermal zone does not define one.

Fixes: 1ce50e7d408e ("thermal: core: genetlink support for events/cmd/sampling")
Signed-off-by: Nicolas Cavallari <nicolas.cavallari@green-communications.fr>
Cc: 5.10+ <stable@vger.kernel.org> # 5.10+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

thermal/drivers/netlink: Add the temperature when crossing a trip point

The slope of the temperature increase or decrease can be high and when
the temperature crosses the trip point, there could be a significant
difference between the trip temperature and the measured temperatures.

That forces the userspace to read the temperature back right after
receiving a trip violation notification.

In order to be efficient, give the temperature which resulted in the
trip violation.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20211001223323.1836640-1-daniel.lezcano@linaro.org

thermal: core: Adding missing nlmsg_free() in thermal_genl_sampling_temp()

thermal_genl_sampling_temp() misses to call nlmsg_free() in an error path.

Jump to out_free to fix it.

Fixes: 1ce50e7d408ef2 ("thermal: core: genetlink support for events/cmd/sampling")
Signed-off-by: Jing Xiangfeng <jingxiangfeng@huawei.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200929082652.59876-1-jingxiangfeng@huawei.com

genetlink: move to smaller ops wherever possible

Bulk of the genetlink users can use smaller ops, move them.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

genetlink: add small version of ops

We want to add maxattr and policy back to genl_ops, to enable
dumping per command policy to user space. This, however, would
cause bloat for all the families with global policies. Introduce
smaller version of ops (half the size of genl_ops). Translate
these smaller ops into a full blown struct before use in the
core.

v1:
- use struct assignment
- put a full copy of the op in struct genl_dumpit_info
- s/light/small/

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

thermal: netlink: Improve the initcall ordering

The initcalls like to play joke. In our case, the thermal-netlink
initcall is called after the thermal-core initcall but this one sends
a notification before the former is initialized. No issue was spotted,
but it could lead to a memory corruption, so instead of relying on the
core_initcall for the thermal-netlink, let's initialize directly from
the thermal-core init routine, so we have full control of the init
ordering.

Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Link: https://lore.kernel.org/r/20200717164217.18819-1-daniel.lezcano@linaro.org

thermal: core: remove redundant initialization of variable ret

The variable ret is being initialized with a value that is never read
and it is being updated later with a new value. The initialization is
redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200706140747.489075-1-colin.king@canonical.com

thermal: core: genetlink support for events/cmd/sampling

Initially the thermal framework had a very simple notification
mechanism to send generic netlink messages to the userspace.

The notification function was never called from anywhere and the
corresponding dead code was removed. It was probably a first attempt
to introduce the netlink notification.

At LPC2018, the presentation "Linux thermal: User kernel interface",
proposed to create the notifications to the userspace via a kfifo.

The advantage of the kfifo is the performance. It is usually used from
a 1:1 communication channel where a driver captures data and sends it
as fast as possible to a userspace process.

The drawback is that only one process uses the notification channel
exclusively, thus no other process is allowed to use the channel to
get temperature or notifications.

This patch defines a generic netlink API to discover the current
thermal setup and adds event notifications as well as temperature
sampling. As any genetlink protocol, it can evolve and the versioning
allows to keep the backward compatibility.

In order to prevent the user from getting flooded with data on a
single channel, there are two multicast channels, one for the
temperature sampling when the thermal zone is updated and another one
for the events, so the user can get the events only without the
thermal zone temperature sampling.

Also, a list of commands to discover the thermal setup is added and
can be extended when needed.

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/20200706105538.2159-3-daniel.lezcano@linaro.org