[PATCH net-next v3 0/4] net: lan966x: Add support for FDMA

From: Horatiu Vultur
Date: Mon Apr 04 2022 - 09:04:06 EST


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.

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 | 783 ++++++++++++++++++
.../ethernet/microchip/lan966x/lan966x_main.c | 49 +-
.../ethernet/microchip/lan966x/lan966x_main.h | 121 +++
.../ethernet/microchip/lan966x/lan966x_port.c | 3 +
.../ethernet/microchip/lan966x/lan966x_regs.h | 106 +++
6 files changed, 1052 insertions(+), 12 deletions(-)
create mode 100644 drivers/net/ethernet/microchip/lan966x/lan966x_fdma.c

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2.33.0