perf/marvell: Marvell PEM performance monitor support

perf/marvell: Marvell PEM performance monitor support

PCI Express Interface PMU includes various performance counters
to monitor the data that is transmitted over the PCIe link. The
counters track various inbound and outbound transactions which
includes separate counters for posted/non-posted/completion TLPs.
Also, inbound and outbound memory read requests along with their
latencies can also be monitored. Address Translation Services(ATS)events
such as ATS Translation, ATS Page Request, ATS Invalidation along with
their corresponding latencies are also supported.

The performance counters are 64 bits wide.

For instance,
perf stat -e ib_tlp_pr <workload>
tracks the inbound posted TLPs for the workload.

Co-developed-by: Linu Cherian <lcherian@marvell.com>
Signed-off-by: Linu Cherian <lcherian@marvell.com>
Signed-off-by: Gowthami Thiagarajan <gthiagarajan@marvell.com>
Link: https://lore.kernel.org/r/20241028055309.17893-1-gthiagarajan@marvell.com
Signed-off-by: Will Deacon <will@kernel.org>