Re: [PATCH v3 9/9] Documentation: hisi-pmu: Add introduction to HiSilicon V3 PMU

[Yicong Yang]

On 2025/8/29 18:14, Yushan Wang wrote:
> Some of HiSilicon V3 PMU hardware is divided into parts to fulfill the
> job of monitoring specific parts of a device.  Add description on that
> as well as the newly added ext option for L3C PMU.
> 
> Acked-by: Jonathan Cameron <jonathan.cameron@xxxxxxxxxx>
> Signed-off-by: Yushan Wang <wangyushan12@xxxxxxxxxx>

Reviewed-by: Yicong Yang <yangyicong@xxxxxxxxxxxxx>

> ---
>  Documentation/admin-guide/perf/hisi-pmu.rst | 33 +++++++++++++++++++++
>  1 file changed, 33 insertions(+)
> 
> diff --git a/Documentation/admin-guide/perf/hisi-pmu.rst b/Documentation/admin-guide/perf/hisi-pmu.rst
> index a307bce2f5c5..b78381a1e5e9 100644
> --- a/Documentation/admin-guide/perf/hisi-pmu.rst
> +++ b/Documentation/admin-guide/perf/hisi-pmu.rst
> @@ -113,6 +113,39 @@ uring channel. It is 2 bits. Some important codes are as follows:
>  - 2'b00: default value, count the events which sent to the both uring and
>    uring_ext channel;
>  
> +For HiSilicon uncore PMU v3 whose identifier is 0x40, some uncore PMUs are
> +further divided into parts for finer granularity of tracing, each part has its
> +own dedicated PMU, and all such PMUs together cover the monitoring job of events
> +on particular uncore device. Such PMUs are described in sysfs with name format
> +slightly changed::
> +
> +/sys/bus/event_source/devices/hisi_sccl{X}_<l3c{Y}_{Z}/ddrc{Y}_{Z}/noc{Y}_{Z}>
> +
> +Z is the sub-id, indicating different PMUs for part of hardware device.
> +
> +Usage of most PMUs with different sub-ids are identical. Specially, L3C PMU
> +provides ``ext`` option to allow exploration of even finer granual statistics
> +of L3C PMU.  L3C PMU driver uses that as hint of termination when delivering
> +perf command to hardware:
> +
> +- ext=0: Default, could be used with event names.
> +- ext=1 and ext=2: Must be used with event codes, event names are not supported.
> +
> +An example of perf command could be::
> +
> +  $# perf stat -a -e hisi_sccl0_l3c1_0/rd_spipe/ sleep 5
> +
> +or::
> +
> +  $# perf stat -a -e hisi_sccl0_l3c1_0/event=0x1,ext=1/ sleep 5
> +
> +As above, ``hisi_sccl0_l3c1_0`` locates PMU of Super CPU CLuster 0, L3 cache 1
> +pipe0.
> +
> +First command locates the first part of L3C since ``ext=0`` is implied by
> +default. Second command issues the counting on another part of L3C with the
> +event ``0x1``.
> +
>  Users could configure IDs to count data come from specific CCL/ICL, by setting
>  srcid_cmd & srcid_msk, and data desitined for specific CCL/ICL by setting
>  tgtid_cmd & tgtid_msk. A set bit in srcid_msk/tgtid_msk means the PMU will not
>