Add a tool PMU for hwmon events but don't enable.
The hwmon sysfs ABI is defined in
Documentation/hwmon/sysfs-interface.rst. Create a PMU that reads the
hwmon input and can be used in `perf stat` and metrics much as an
uncore PMU can.
For example, when enabled by a later patch, the following shows
reading the CPU temperature and 2 fan speeds alongside the uncore
frequency:
```
$ perf stat -e temp_cpu,fan1,hwmon_thinkpad/fan2/,tool/num_cpus_online/ -M UNCORE_FREQ -I 1000
1.001153138 52.00 'C temp_cpu
1.001153138 2,588 rpm fan1
1.001153138 2,482 rpm hwmon_thinkpad/fan2/
1.001153138 8 tool/num_cpus_online/
1.001153138 1,077,101,397 UNC_CLOCK.SOCKET # 1.08 UNCORE_FREQ
1.001153138 1,012,773,595 duration_time
...
```
The PMUs are named from /sys/class/hwmon/hwmon<num>/name and have an
alias of hwmon<num>.
Hwmon data is presented in multiple <type><number>_<item> files. The
<type><number> is used to identify the event as is the <type> followed
by the contents of the <type>_label file if it exists. The
<type><number>_input file gives the data read by perf.
When enabled by a later patch, in `perf list` the other hwmon <item>
files are used to give a richer description, for example:
```
hwmon:
temp1
[Temperature in unit acpitz named temp1. Unit: hwmon_acpitz]
in0
[Voltage in unit bat0 named in0. Unit: hwmon_bat0]
temp_core_0 OR temp2
[Temperature in unit coretemp named Core 0. crit=100'C,max=100'C crit_alarm=0'C. Unit:
hwmon_coretemp]
temp_core_1 OR temp3
[Temperature in unit coretemp named Core 1. crit=100'C,max=100'C crit_alarm=0'C. Unit:
hwmon_coretemp]
...
temp_package_id_0 OR temp1
[Temperature in unit coretemp named Package id 0. crit=100'C,max=100'C crit_alarm=0'C.
Unit: hwmon_coretemp]
temp1
[Temperature in unit iwlwifi_1 named temp1. Unit: hwmon_iwlwifi_1]
temp_composite OR temp1
[Temperature in unit nvme named Composite. alarm=0'C,crit=86.85'C,max=75.85'C,
min=-273.15'C. Unit: hwmon_nvme]
temp_sensor_1 OR temp2
[Temperature in unit nvme named Sensor 1. max=65261.8'C,min=-273.15'C. Unit: hwmon_nvme]
temp_sensor_2 OR temp3
[Temperature in unit nvme named Sensor 2. max=65261.8'C,min=-273.15'C. Unit: hwmon_nvme]
fan1
[Fan in unit thinkpad named fan1. Unit: hwmon_thinkpad]
fan2
[Fan in unit thinkpad named fan2. Unit: hwmon_thinkpad]
...
temp_cpu OR temp1
[Temperature in unit thinkpad named CPU. Unit: hwmon_thinkpad]
temp_gpu OR temp2
[Temperature in unit thinkpad named GPU. Unit: hwmon_thinkpad]
curr1
[Current in unit ucsi_source_psy_usbc000_0 named curr1. max=1.5A. Unit:
hwmon_ucsi_source_psy_usbc000_0]
in0
[Voltage in unit ucsi_source_psy_usbc000_0 named in0. max=5V,min=5V. Unit:
hwmon_ucsi_source_psy_usbc000_0]
```
As there may be multiple hwmon devices a range of PMU types are
reserved for their use and to identify the PMU as belonging to the
hwmon types.
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Yoshihiro Furudera <fj5100bi@fujitsu.com>
Cc: Howard Chu <howardchu95@gmail.com>
Cc: Ze Gao <zegao2021@gmail.com>
Cc: Changbin Du <changbin.du@huawei.com>
Cc: Junhao He <hejunhao3@huawei.com>
Cc: Weilin Wang <weilin.wang@intel.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: Athira Jajeev <atrajeev@linux.vnet.ibm.com>
Link: https://lore.kernel.org/r/20241109003759.473460-5-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
53cc0b351e