[PATCH net-next v4 0/4] net: lan966x: Add support for FDMA

[Horatiu Vultur]

Currently when injecting or extracting a frame from CPU, the frame
is given to the HW each word at a time. There is another way to
inject/extract frames from CPU using FDMA(Frame Direct Memory Access).
In this way the entire frame is given to the HW. This improves both
RX and TX bitrate.

Tested-by: Michael Walle <michael@xxxxxxxx> # on kontron-kswitch-d10

v3->v4:
- fix race conditions when changing the MTU
- build skbs once frames are received and not before
- use NAPI_POLL_WEIGHT instead of FDMA_WEIGHT

v2->v3:
- move skb_tx_timestamp before the IFH is inserted, because in case of PHY
  timestamping, the PHY should not see the IFH.
- use lower/upper_32_bits()
- reimplement the RX path in case of memory pressure.
- use devm_request_irq instead of devm_request_threaded_irq
- add various checks for return values.

v1->v2:
- fix typo in commit message in last patch
- remove first patch as the changes are already there
- make sure that there is space in skb to put the FCS
- move skb_tx_timestamp closer to the handover of the frame to the HW

Horatiu Vultur (4):
  net: lan966x: Add registers that are used for FDMA.
  net: lan966x: Expose functions that are needed by FDMA
  net: lan966x: Add FDMA functionality
  net: lan966x: Update FDMA to change MTU.

 .../net/ethernet/microchip/lan966x/Makefile   |   2 +-
 .../ethernet/microchip/lan966x/lan966x_fdma.c | 842 ++++++++++++++++++
 .../ethernet/microchip/lan966x/lan966x_main.c |  59 +-
 .../ethernet/microchip/lan966x/lan966x_main.h | 117 +++
 .../ethernet/microchip/lan966x/lan966x_port.c |   3 +
 .../ethernet/microchip/lan966x/lan966x_regs.h | 106 +++
 6 files changed, 1117 insertions(+), 12 deletions(-)
 create mode 100644 drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c

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2.33.0