drivers/perf: hisi: Add TLP filter support

The PMU support to filter the TLP when counting the bandwidth with below
options:

- only count the TLP headers
- only count the TLP payloads
- count both TLP headers and payloads

In the current driver it's default to count the TLP payloads only, which
will have an implicity side effects that on the traffic only have header
only TLPs, we'll get no data.

Make this user configuration through "len_mode" parameter and make it
default to count both TLP headers and payloads when user not specified.
Also update the documentation for it.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Link: https://lore.kernel.org/r/20221117084136.53572-5-yangyicong@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>

1 files changed, 18 insertions, 0 deletions

diff --git a/Documentation/admin-guide/perf/hisi-pcie-pmu.rst b/Documentation/admin-guide/perf/hisi-pcie-pmu.rst
index 645f08f65429..7e863662e2d4 100644
--- a/Documentation/admin-guide/perf/hisi-pcie-pmu.rst
+++ b/Documentation/admin-guide/perf/hisi-pcie-pmu.rst
@@ -110,3 +110,21 @@ Filter options
    Example usage of perf::
 
      $# perf stat -e hisi_pcie0_core0/rx_mrd_flux,thr_len=0x4,thr_mode=1/ sleep 5
+
+4. TLP Length filter
+
+   When counting bandwidth, the data can be composed of certain parts of TLP
+   packets. You can specify it through "len_mode":
+
+   - 2'b00: Reserved (Do not use this since the behaviour is undefined)
+   - 2'b01: Bandwidth of TLP payloads
+   - 2'b10: Bandwidth of TLP headers
+   - 2'b11: Bandwidth of both TLP payloads and headers
+
+   For example, "len_mode=2" means only counting the bandwidth of TLP headers
+   and "len_mode=3" means the final bandwidth data is composed of both TLP
+   headers and payloads. Default value if not specified is 2'b11.
+
+   Example usage of perf::
+
+     $# perf stat -e hisi_pcie0_core0/rx_mrd_flux,len_mode=0x1/ sleep 5