The lan969x switch device supports manual frame injection and extraction
to and from the switch core, using a number of injection and extraction
queues. This technique is currently supported, but delivers poor
performance compared to Frame DMA (FDMA).
This lan969x implementation of FDMA, hooks into the existing FDMA for
Sparx5, but requires its own RX and TX handling, as lan969x does not
support the same native cache coherency that Sparx5 does. Effectively,
this means that we are going to use the DMA mapping API for mapping and
unmapping TX buffers. The RX loop will utilize the page pool API for
efficient RX handling. Other than that, the implementation is largely
the same, and utilizes the FDMA library for DCB and DB handling.
Some numbers:
Manual injection/extraction (before this series):
// iperf3 -c 1.0.1.1
[ ID] Interval Transfer Bitrate
[ 5] 0.00-10.02 sec 345 MBytes 289 Mbits/sec sender
[ 5] 0.00-10.06 sec 345 MBytes 288 Mbits/sec receiver
FDMA (after this series):
// iperf3 -c 1.0.1.1
[ ID] Interval Transfer Bitrate
[ 5] 0.00-10.03 sec 1.10 GBytes 940 Mbits/sec sender
[ 5] 0.00-10.07 sec 1.10 GBytes 936 Mbits/sec receiver
Reviewed-by: Steen Hegelund <Steen.Hegelund@microchip.com>
Signed-off-by: Daniel Machon <daniel.machon@microchip.com>
Link: https://patch.msgid.link/20250113-sparx5-lan969x-switch-driver-5-v2-5-c468f02fd623@microchip.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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